Дисертації з теми "Wine sensor"
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Moffat, Tessa. "Sensor technology to assess grape bunch temperature variability in Vitis vinifera L. cv. Shiraz." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80102.
Повний текст джерелаENGLISH ABSTRACT: The microclimate environment around the bunch is complex. The spatial distribution of leaves as well as bunch position and morphology impact on the path of direct radiation received by the berries. Canopy microclimate is largely determined by the meteorological conditions (air temperature, solar radiation, wind speed and direction, relative humidity, and precipitation) as well as management practices (trellis/training system, canopy height, vine spacing, row orientation, canopy management practices, irrigation and soil variability and management). The fact that the grapevine continuously responds to its environment, adds to the complexity and dynamic nature of the microclimate that the bunches experience. Field studies involving the effect of the natural bunch environment (i.e. light and temperature conditions) on berry composition, are therefore a challenge, due to the difficulties in quantifying meteorological elements such as temperature and light, which can be hugely variable. There are different sensors available to assess bunch and berry temperature and it can be deployed in different ways within the grapevine canopy, but the difficulty remains in studying the variability that exists within a bunch. This study investigated the value of available sensor technology to measure bunch/berry temperature as well as the spatial and temporal variability on a bunch. Differences in temperature on an intra-berry level were assessed whereas the impact of canopy configuration and bunch orientation on the different sensor levels was also investigated. The contribution of macro- and mesoclimate on bunch and berry temperature was addressed by measuring at two locations (Robertson and Stellenbosch). The potential long term differences in temperature within a bunch with regard to thermal accumulation are discussed. Issues around sensor placement and some technical difficulties related to the sensors are discussed. The results indicated how the effects of mesoclimate were transferred through to the different sensors. A dominating effect of the sea breeze in Stellenbosch was found. Canopy configuration/architecture affected the light regime in the canopy, consequently impacting on bunch temperature variability, specifically in Stellenbosch where a "Ballerina" trellising system was used. Bunch orientation resulted in differences in the temporal variability of bunch/berry temperature and little variability was observed in temperature within the berry. Temperatures of berries situated at the back of the bunch were judged more optimal compared to exposed berries. Direct radiation caused extreme temperatures in exposed berries, which may be detrimental to berry composition and wine quality. This emphasized the importance of the canopy (trellis/training system and management practices) in protecting the bunch from extreme conditions. The large on-bunch spatial variability, observed from measurements with the thermal imager, demonstrated the importance of sensor placement in quantifying the bunch temperature regime; this is also relevant for the future development of berry temperature modelling. Thermal accumulation through the season also illustrated the variability that existed within a bunch, suggesting a potential long term effect on the berry composition. This study proved, in conditions similar to those that may prevail in the South African wine industry, that sensor type and positioning need to be carefully considered in any viticultural/oenological study where bunch microclimate and grape temperatures are assessed.
AFRIKAANSE OPSOMMING: Die mikroklimaat omgewing rondom die tros is kompleks. Die ruimtelike verspreiding van blare sowel as trosposisie en -morfologie het 'n impak op die pad waarlangs direkte straling ontvang word deur die korrels. Lowermikroklimaat word grootliks bepaal deur die meteorologiese kondisies (lugtemperatuur, sonstraling, windspoed en -rigting, relatiewe humiditeit en reënval) sowel as bestuurspraktyke (prieel/opleistelsel, lowerhoogte, wingerdstokspasiëring, ry-oriëntasie, lowerbestuurspraktyke, besproeiing asook grondvariasie en bestuur). Die feit dat die wingerdstok voortdurend reageer op sy omgewing dra by tot die kompleksiteit en dinamiese aard van die mikroklimaat wat die trosse ervaar. Veldstudies gemoeid met die effek van die natuurlike trosomgewing (d.w.s. lig- en temperatuurkondisies) op korrelsamestelling is daarom 'n uitdaging. Die rede hiervoor is dat dit problematies is om meteorologiese elemente soos temperatuur en lig, wat baie veranderlik kan wees, te kwantifiseer. Verskillende sensors is beskikbaar waarmee tros- en korreltemperatuur bepaal kan word en dit kan op verskillende wyses binne die wingerdstoklower aangewend word. Die bestudering van die variasie wat bestaan binne 'n tros is egter steeds problematies. Hierdie studie het die waarde ondersoek van die beskikbare sensortegnologie vir die meting van tros/korreltemperatuur en die ruimtelike en tydsvariasie op 'n tros. Verskille in temperatuur op 'n intra-korrelvlak is bepaal terwyl die impak van lowerkonfigurasie en trosoriëntasie op die verskillende sensorvlakke ook ondersoek is. Die bydrae van makro- en mesoklimaat tot tros- en korreltemperatuur is ondersoek deur te meet by twee verskillende liggings (Robertson en Stellenbosch). Die potensiële langtermyn verskille in temperatuur binne-in 'n tros met betrekking tot temperatuur akkumulasie word bespreek. Kwessies rakende sensorplasing en sommige tegniese probleme wat verband hou met sensors word bespreek. Die resultate het aangedui hoedat die effekte van mesoklimaat oorgedra is na die verskillende sensors. 'n Dominerende effek van die seebries is waargeneem in Stellenbosch. Lowerkonfigurasie/argitektuur het die ligregime in die lower beïnvloed en gevolglik 'n invloed gehad op die trostemperatuur veranderlikheid. Dit was veral die geval in Stellenbosch waar 'n "Ballerina" opleistelsel gebruik is. Trosoriëntasie het gelei tot verskille in tydsvariasie van tros/ korreltemperatuur en min variasie is waargeneem in temperatuur binne die korrel. Temperature van korrels wat voorkom aan die agterkant van die tros is beoordeel as meer optimaal vergeleke met blootgestelde korrels. Direkte straling het uiterste temperature in blootgestelde korrels veroorsaak wat nadelig kan wees vir korrelsamestelling en wynkwaliteit. Hierdeur is die belang van die lower (prieel/opleistelsel en bestuurspraktyke) om die tros te beskerm teen uiterste kondisies beklemtoon. Die groot ruimtelike variasie op 'n tros, soos waargeneem in metings met die termiese kamera, het die belangrikheid van sensorplasing in die kwantifisering van die trostemperatuur regime beklemtoon. Dit is ook relevant vir die toekomstige ontwikkeling van korreltemperatuur modellering. Termiese akkumulasie gedurende die seisoen is ook geïllustreer deur die veranderlikheid wat voorkom binne 'n tros, wat dui op 'n potensiële langtermyn effek op die korrelsamestelling. Hierdie studie het bewys, in kondisies wat algemeen voorkom in die Suid-Afrikaanse wynbedryf, dat sensortipe en -plasing sorgvuldig in ag geneem moet word in enige wingerd/wynkundige studie waar trosmikroklimaat en druiftemperature bepaal word.
Winetech and the National Research Foundation for their financial support of the project
Artigas, Pursals Judit. "Desenvolupament de sensors potenciomètrics d'estat sòlid per a usos mediambientals i agroalimentaris." Doctoral thesis, Universitat Autònoma de Barcelona, 2003. http://hdl.handle.net/10803/3162.
Повний текст джерелаLa present tesi té com a objectiu global el disseny, la construcció i l'avaluació de nous sensors potenciomètrics d'estat sòlid així com la instrumentació i el material necessari per tal d'utilitzar-los en aplicacions de l'àmbit mediambiental i agroalimentari. Per tal de construir els sensors s'empraren transductors tant diferents com els electrodes selectius d'ions (ESIs), els sensors planars de capa gruixuda i els transistors d'efecte de camp sensible a ions (ISFETs). Es van optimitzar diferents membranes per tal d'analitzar diferents analits d'interès mediambiental i agrònom, com són el nitrat, el calci, el potassi, la urea i el pH. En funció del transductor emprat es van emprar membranes amb matriu de PVC i membranes basades en polímers fotocurables, concretament un polímer diacrilat-poliuretà (l'Ebecryl 270). Els treballs presentats en aquesta tesi es detallen breument.
Per tal de realitzar l'anàlisi de sòls i/o substrats inerts, es va dissenyar una cel·la per facilitar la inserció dels sensors en el medi. Es va observar la viabilitat d'emprar sensors tipus ISFETs així com un fil de coure com a elèctrode de referència per tal de realitzar satisfactòriament les mesures in situ per períodes superiors a tres mesos, en el cas de pH, calci i potassi, i d'un mes en el cas de nitrats. La construcció i avaluació de sondes de nitrats emprant ESI i elèctrodes de capa gruixuda amb membranes de PVC va permetre millorar el temps de vida dels dispositius, essent en aquest cas el temps superior a instal·lables directament en el sòl emprant elèctrodes selctius d'ions va permetre realitzar mesures a llarg plaç observant-se que les membranes responien correctament tot i estar més de 5 mesos inserides en sòls. Es va avaluar la resposta dels sensors en el medi i es va estudiar la possibilitat de calibrar els sensors directament en el sòl.
Es va observar també la viabilitat dels sensors per tal de controlar el procés d'estabilització tartàrica emprant resines d'intercanvi així com l'anàlisi de paràmetres com calci, potassi i pH en vins. S'observa com el medi hidroalcohòlic no afectava al temps de vida ni a les característiques de resposta de les membranes fotocurables desenvolupades.
Va ser possible identificar i analitzar diferents varietats de fruita emprant ISFETs de calci, potassi i nitrats. S'avaluarà la viabilitat d'emprar els sensors, a peu de camp, per tal d'obtenir una mesura que pugui ser un indicador més de maduresa de les fruites.
The use of chemical sensors for environmental and agricultural applications has been described. ISEs and ISFETs based on all-solid-state internal reference are fabricated in our research group. These sensors have been applied lately in several fields such as industrial processes monitoring, biomedicine and environment. The use of photopolymers as matrix for ion selective membranes have a high number of advantages in front of PVC: Improvement of the adhesion to the semiconductor surface (previous silanisation), simple and faster preparation methods (there is not solvent evaporation) and compatibility with photolithographic techniques used in semiconductor technology, allowing its deposition and patterning on-wafer level. Among the most widely used UV-curable compounds are the acrylated based polymers. The fabrication of ion-sensitive electrochemical sensors for calcium is described in the present work. The membrane uses a photocurable polymer based on aliphatic diacrylated polyurethane. Membranes sensitive to calcium ions were optimised according the type of plasticizer and the polymer/plasticizer ratio. Ion-selective electrodes (ISEs) with a solid internal reference and ISFETs were used to evaluate the membrane. The resulting sensors were functional for periods of more than 8 months and the resulting sensitivities were quasi-Nernstian (26-27mV/dec) in a range of 5·10-6 - 8·10-2 M.
The present work describe the construction and the evaluation of new potentiometric all-solid sensors and the all necessary instrumentation to obtain results in a completely automated fashion. The work is divided with three different applications:
Standard methods to measure nutrient levels in soil are complex and time consuming due to the extraction and pre-treatment processes involved. Besides, the instrumentation used for these measurements is also expensive. Therefore, the use of chemical sensors would we interesting since they can be applied directly in the soil and results can be provided in real or quasi real time at a moderate cost. The control of these nutrients with sensors will permit an optimisation of the overall production process of the crop. Besides, this approach will be useful for reducing the environmental impact caused by the excess of nutrients in crop soils. In this work, the use of chemical sensors based on Ion Sensitive Field Effect Transistors (ISFETs) for soil analysis is proposed. Fabrication of pH, Ca2+, K+ and NO3- ISFETs and the cell to be applied in soil and their evaluation is reported. From the preliminary results of their application in soils it is possible to confirm their feasibility as sensors for in-soil monitoring and the promising future applications they have.
The continuous monitoring of processes in the food.
Jacquet, Antoine. "Capsules hélicoïdales d’oligoamides aromatiques : détecteurs moléculaires pour le dosage d’acides organiques du vin." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0921/document.
Повний текст джерелаSome relevant wine small molecular components can be selectively recognized by foldamer capsules – artificial oligomeric compounds able to fold into well-defined objects possessing an inner cavity. In recent years, selective and high affinity receptors for fructose, tartaric acid and malic acid have been reported. Here, a new methodology, using solid phase synthetic techniques, for the preparation of a gluconic acid receptor will be discussed. To transform these receptors into sensors, a fluorescent moiety has been incorporated in the binding site. A proof of concept has been achieved using a fluorescence titration of tartaric acid. Indeed, when the guest is encapsulated, a modification of the fluorescence emission is observed. Finally, these fluorescent receptors have been anchored to silica surfaces and pave the way to the development of mobile detection devices. Such sensors could be useful to the wine industry to ensure proper control of biological processes for example during fermentation
Yeo, Chin Liong. "Command Wire Sensor Measurements." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/17483.
Повний текст джерелаAfter the recent success in jamming wireless improvised explosive devices (IEDs), the threat nowadays has shifted towards the use of buried command wires. A capability to immediately detect the presence of a command wire would be of great value to the troops on the ground. The major challenge of a command wire sensor is to detect the wire in clutter and achieve a high probability of detection without large number of false alarms. The objective of this thesis is to investigate the wire scattering behavior and clutter characteristics through measurements performed in the NPS anechoic chamber. The research has successfully resolved the various multipath components within the anechoic chamber. The transmit-receive coupling between the antennas was reduced through the appropriate use of absorbers. Various wire scattering and clutter characteristics were established through the measurement results. In addition, the measurement results have also demonstrated close-in clutter rejection by utilizing time gating. Recommendations for future work were proposed to gather more data to support the ongoing NPS research on the Command Wire Sensor design.
Basson, Shantelle. "Consumer acceptance of a selection of South African red wines : intrinsic, extrinsic and socio-demographic influences." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20380.
Повний текст джерелаENGLISH ABSTRACT: In this study an industry-selected and diverse range of South African red wines were analysed for sensory and chemical attributes, as well as degree of liking using a target group of black South African consumers. Segments of consumers that differed in degree of liking were then tested for their response to intrinsic (sensory) and extrinsic (non-sensory) cues. The selection of wines included eighteen dry and natural sweet red wines, representing low-end inexpensive wines together with high-end, top quality wines. Sensory profiles for all samples were established using Quantitative descriptive analysis (QDA). The results revealed that cultivar specific dry red wines associated with a wide range of sensory descriptors such as woody, vegetative and fruity, while the sweet red wines associated with the fruity and sweet-associated attributes. Chemically there was a significant variation between wines regarding the alcohol and sugar content. Gas chromatography with flame ionisation detection (GC-FID) indicated the major volatile constituents present in the wine, i.e. esters, alcohols and fatty acids. When investigating the association between the chemical and sensory data, it was revealed that the red blends were driven by the presence of alcohols and esters, and sensory descriptors such as high roast oak, coffee and mixed spice, whereas the red cultivar wines were mostly driven by fatty acids and esters and the sensory descriptors, green bean and asparagus. The sweet red blends were closely associated with acids and the sensory descriptors sweet-associated and floral. Degree of liking of a subset of 18 wines was investigated based on the preferences of black consumers from the Western Cape area, South Africa. These consumers predominantly preferred the sweet red wines with high sugar content, in a blind tasting session. Purchase intent was also evaluated by viewing actual photographs of packaging formats of the respective wines and the results indicated that the consumers preferred the well-known cultivar wines with a perception of value and style. Cluster analysis was furthermore performed to ascertain whether these consumers differed in their degree of liking of the intrinsic character of the respective wines. Four different clusters of consumers were identified: 1) Consumers preferring both dry and sweet red wines equally, 2) Consumers who strongly favoured sweet red wines and moderately liked dry red wines, 3) Consumers who strongly favoured sweet red wines with little preference for dry red wines; and 4) Consumers preferring dry red wines. Consumers were also probed on their general opinions or perceptions on the extrinsic character of the wines, and thus factors that influence the purchasing process. It was found that black consumers who don‟t consume wine often, preferred wines that they are familiar with, while consumers that drink wine more frequently enjoy to broaden their horizons by experimenting with more expensive wine brands. Extrinsic or non-sensory cues such as alcohol content, label, vintage, price and cultivar were found to be the most important considered factors when purchasing red wines, while awards and type of closure were regarded as the least important. It was also found that the discerning consumers, who purchase high-end wines, took more of the latter aspects into consideration, whereas consumers who purchase low-end wines considered a limited number of the non-sensory cues.
AFRIKAANSE OPSOMMING: In hierdie studie is 'n diverse reeks industrie-geselekteerde, Suid-Afrikaanse rooiwyne geanaliseer vir hul sensoriese en chemiese eienskappe. Verbruikersvoorkeur van die wyne is getoets, asook tot watter mate verbruikersvoorkeure beïnvloed word deur intrinsieke (sensoriese) en ekstrinsieke (nie-sensoriese) faktore. Die reeks van agtien wyne het bestaan uit droë en soet rooi wyne, wat op hul beurt verder verdeel kan word in goedkoper, kwaliteit wyne en duurder, ultra-premium wyne. Die sensoriese profiel van al die wyne is bepaal deur beskrywende sensoriese analise. Resultate het getoon dat die kultivar-spesifieke droë rooiwyne geassosieer word met 'n wye reeks sensoriese eienskappe soos houtagtig, kruidagtig en vrugtig, terwyl die soet rooiwyne beskryf is as vrugtige en soet-geassosieerd. In terme van die chemiese analises was daar betekenisvolle verskille betreffende die alkohol- en suikerinhoud van die wyne. Gas chromatografie gekoppel met vlam-ioniserende deteksie (GC-FID) het die mees vlugtige verbindings teenwoordig in die wyn aangedui, naamlik esters, alkohole en vetsure. Met die korrelasie van die chemiese en sensoriese data is gevind dat die droë versnitwyne gedryf word deur die teenwoordigheid van alkohole en esters, asook sensoriese eienskappe soos gehout, koffie, en gemengde spesery, terwyl die kultivar-spesieke wyne weer meestal gedryf word deur vetsure en esters en sensoriese eienskappe soos groenboontjie en aspersie. Die soet rooiwyne het chemies geassosieer met sure en sensoriese terme soos soet-geassosieerd en blomagtig. Die aanvaarbaarheid van 'n kleiner groepering wyne is bepaal deur gebruik te maak van swart verbruikers in die Wes-Kaap area, Suid-Afrika. Die verbruikers het in 'n blinde proesessie onderskeie wyne se wynverpakking besigtig en aangedui of hulle die wyne sou koop. Hierdie resultate het getoon dat die verbruikers bekende kultivarwyne verkies wat 'n persepsie van waarde en styl geïllustreer het. Segmentasie tegnieke is op die data uitgevoer ten einde te bepaal of verbruikers in groepe verdeel kan word, wat betref hul voorkeur van die sensoriese of intrinsieke eienskappe van die wyne. Vier verskillende groepe is geïdentifiseer, nl. verbruikers wat 1) droë en soet rooiwyne ewe veel verkies; 2) soet rooiwyne en tot 'n mate ook droë rooiwyne verkies; 3) soet rooiwyne en tot 'n mindere mate droë rooiwyne verkies; en laastens 4) slegs droë rooiwyne verkies. Verbruikers se algemene opinies en persepsies betreffende die ekstrinsieke eienskappe van die wyne is ook ondersoek, met ander woorde faktore wat die aankoop van wyne beïnvloed. Daar is gevind dat swart verbruikers wat nie gereeld wyn drink, bekende handelsmerke verkies, terwyl verbruikers wat gereeld wyn drink, daarvan hou om hul horisonne te verbreed en te eksperimenteer met 'n verskeidenheid handelsmerke. Ekstrinsieke of nie-sensoriese aspekte soos, alkohol-inhoud, etiket, oesjaar, prys en kultivar is die belangrikste faktore wat in ag geneem word wanneer rooiwyne gekoop word, terwyl wyntoekennings en die feit dat die wyn met kurke gebotteleer word, nie as belangrik beskou word nie. Daar is ook gevind dat die meer ingeligte verbruiker, wat hoë kwaliteit wyne koop, meer van die bogenoemde aspekte in ag neem tydens die aankoopproses, terwyl die verbruiker wat meer geneig is om goedkoper wyne te koop, slegs 'n paar ekstrinsieke faktore in ag neem.
Van, Antwerpen Lindi. "Chemical and sensory profiling of dry and semi-dry South African Chenin blanc wines." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71853.
Повний текст джерелаENGLISH ABSTRACT: Chenin blanc wine is of economic importance to South Africa and a range of diverse dry and semi-dry wines are locally produced in this genre. Currently, the use of three distinctly different style names, each aimed at providing consumers with information about the flavour of the wines, is encouraged by the South African (SA) wine industry. The styles are fresh and fruity (FF), rich and ripe unwooded (RRUW) and rich and ripe wooded (RRW). Feedback from retail sectors over the past few years, however, repeatedly suggested that the style names are perceived as confusing by SA consumers. This master study was undertaken to re-evaluate the FF, RRUW and RRW style classification, based on both the volatile fermentation-derived aroma composition and the sensory attributes of a set of wines containing all the styles under investigation. For the purposes of chemical profiling, a set of 105 commercial Chenin blanc wines, selected to be representative of these three styles and originating from the major SA wine producing areas, were analysed by Gas Chromatography (GC) to quantify fermentation-derived volatile aroma compounds in the wines. ANOVA performed on the chemical data showed that 29 compounds represent significant differences between at least two of the 3 styles (FF, RRUW and RRW). Principal component analysis (PCA) of the volatile compounds showed a large degree differentiation between FF and RRW wine styles, however, RRUW wine styles overlapped with the other two styles. Considering vintage effects, ANOVA indicated no significant differences within FF (vintages 2009 and 2010) and RRW (vintages 2008 and 2009) styles, whereas only 2 esters and 4 terpenes showed significant differences between the three wine producing regions investigated for this purpose, Paarl/Wellington, Breede River and Stellenbosch. Volatile aroma compounds generated for Chenin blanc were included in the Winetech database consisting of the most important cultivars of South Africa. Combining the data for the volatiles for Chardonnay and Sauvignon blanc from this database and the data for Chenin blanc obtained in this study, a PCA indicated a clear separation between Chenin blanc and the other two white cultivars. Sensory evaluation of the style classification was done by two separate sensory tests. Firstly, a sorting task was performed by wine industry experts to categorise 21 Chenin blanc wines (FF, RRUW and RRW) based on their similarity. The results showed a differentiation between FF and RRW styles, however, RRUW was mostly classified together with FF wines. This indicated a possible continuum between the three styles, as opposed to three distinct different categories, currently suggested by the style names. The second sensory analysis test, Descriptive Sensory Analysis (DSA), was performed by a trained panel to generate sensory profiles for 42 wines. ANOVA of the flavour attribute intensities between different styles once again showed significant differences between FF and RRW, with RRUW wines forming a continuum between the FF and RRW styles. These results provide valuable information that could be used by the wine industry for labelling purposes.
AFRIKAANSE OPSOMMING: Chenin blanc is van ekonomiese belang vir Suid Afrika en ‘n wye reeks droë en semi-droë wyne word plaaslik geproduseer in hierdie kategorie. Tans word die gebruik van drie duidelike verskillende stylbenamings, elkeen daarop gemik om aan die verbruiker inligting te verskaf oor die geur van die wyn, deur die Suid Afrikaanse (SA) wynindustrie aangemoedig. Die style is vars en vrugtig, ryk en ryp ongehout en ryk en ryp gehout. Terugvoer van die handelssektor oor die afgelope aantal jare, het daarop gedui dat die stylbenamings tot verwarring onder SA verbruikers lei. Hierdie meestersstudie is onderneem om die stylklassifikasie, vars en vrugtig, ryk en ryp ongehout en ryk en ryp gehout, te her-evalueer op grond van die vlugtige aroma komponente wat tydens die fermentasie proses gevorm word, asook die sensoriese eienskappe van ‘n verteenwoordigende stel wyne van elk van die style wat ondersoek is. Vir die doel van die chemiese profilering, is ‘n stel van 105 kommersiële wyne, wat geselekteer is om verteenwoordigend te wees van die drie style ondersoek en ook afkomstig is van die vernaamste SA wynproduserende streke, gebruik. Die wyne is met behulp van gas chromatografie ontleed om die vlugtige komponente wat van die fermentasie proses afkomstig is, te kwantifiseer. Die analise van variansie, het getoon dat 29 komponente statisties beduidend verskil het tussen die drie style. Hoofkomponent analise van die vlugtige komponente, het getoon dat die vars en vrugtige wyne en ryk en ryp gehoute wyne, duidelik onderskeibaar was van mekaar op grond van die vlugtige data, maar die ryk en ryp ongehoute wyne het met die ander twee style oorvleuel. In terme van oesjaar effekte, was daar geen beduidende verskille in die aroma profiele van die vars en vrugtige styl (oesjare 2009 en 2010) en ryk en ryp ongehoute styl (oesjare 2008 en 2009) nie, terwyl die konsentrasie van slegs twee esters en 4 terpene statisties beduidend verskil het tussen die wynproduserende streke Paarl/Wellington, Breederivier en Stellenbosch. Resultate van die gekwantifiseerde vlugtige komponente is in die databasis van Winetech gevoeg, waar die konsentrasies van soortgelyke komponente van die vernaamste SA wynkultivars reeds vervat is. Hoofkomponent analises van die gekombineerde resultate vir Chenin blanc, Chardonnay en Sauvignon blanc wyne, het getoon dat daar ‘n duidelike verkil tussen Chenin blanc en die ander twee wit wynkultivars was. Die sensoriese evaluerings is uitgevoer deur van twee verskillende metodes gebruik te maak. Eerstens is 21 wyne (met al drie style verteenwoordig) deur wynindustrie eksperts gesorteer op grond van die waargenome eendersheid van die onderskeie wyne en die resultate is grafies geprojekteer. Die resultate het getoon dat daar ‘n duidelike verskil waargeneem is deur die assessors tussen die vars en vrugtige styl en ryk en ryp gehoute styl. Die ryk en ryp ongehoute wyne het in die analises meer met die vars en vrugtige style geassosieer, as die ryk en ryp gehoute wyne. Die tweede sensoriese metode is uitgevoer deur sensoriese paneel wat vir die doel van hierdie studie opgelei is om die geur eienskappe van 42 wyne (al drie style verteenwoordig) te profileer. Analise van statistiese beduidende verskille tussen die voorkoms van die geurkomponente en hul intensiteite vir elke styl, het weereens aangedui dat daar ‘n kontinuum bestaan tussen die style. Hierdie resultate kan van waarde vir die wynindustrie wees in besluite rakende etikettering.
Eccles, Lee H. "PRESSURE BELT FOR WING LOADS MEASUREMENT." International Foundation for Telemetering, 2001. http://hdl.handle.net/10150/606396.
Повний текст джерелаBoeing Commercial Airplanes has used many methods in the past to measure the structural loads on the wings of its airplanes. The most recent approach is to use arrays of MEMS pressure sensors on the top and bottom surfaces of the wings. By knowing the difference in pressure between the top and bottom of the wings the structural loads on the wings can be calculated. It was decided that in order to build an array of 1100 sensors it would be necessary to condition the sensors and convert the analog output to a digital form at the site of the pressure measurement. This process was taken one step further by converting the output of the A/D converter into engineering units within the sensor module as well. The array is built using a flex circuit card in one foot sections that can be interconnected to form an array of up to 125 sensors. There is a sensor location every two inches on the flex circuit but not all locations are populated. This paper will describe not only the pressure belt but the lessons learned during the development and the implications that these lessons have for smart transducers in general.
Nell, Marissa. "Sensory characterisation of several red cultivar (Vitis vinifera L.) wines, using berry sugar accumulation as a physiological indicator and sequential harvest." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96887.
Повний текст джерелаENGLISH ABSTRACT: The global wine industry has shifted to a more adopted ‘consumer-preference’ production. Modern wine consumers are more knowledgeable and cultivated in their understanding of wine quality, value and style. The quality of red wines mainly depends on grape composition, the wine making process and the ability of tasters to recognise sensory attributes. The harvest date/stage has an influence on the grape composition, thus making the decision on when to harvest an important factor in the production of quality wines or different wine styles. The traditional indicators used in the wine industry to determine time of harvest are more related to the perception of taste and mouthfeel and give little indication of the style of wine in terms of aromatic profile. A new physiological indicator using berry sugar accumulation for the purpose of sequential harvest is proposed to assist the winemaker in producing wines with possible different sensory profiles. This indicator can be used in association with the classical indicators of ripening to affect the diversity of wine styles from a single vineyard or a group of vineyards. The wines could thus have different potential aroma profiles, depending on when the grapes were harvested. The main aim of this study was to assess the effect of performing sequential harvest using a physiological indicator on red wine’s sensory composition. This was done to study the possible relation between harvest time (e.g. fruit composition evolution) and the wine styles/sensory attributes across the different harvest times, thereby possibly increasing the diversity of wine styles. A theoretical berry sugar loading concept was compiled and displays a phase of rapid sugar loading starting at véraison followed by a plateau phase. Depending on whether grapes were harvested in the beginning, mid or end of the plateau phase of fruit sugar accumulation the wines could have different potential aroma profiles. Three main stages: fresh fruit (FF), neutral (N) or pre ripe and mature fruit (MF) has been previously proposed using the sugar loading concept and in terms of harvesting dates. Cabernet Sauvignon and Merlot grapes form Eikendal Vineyards, Stellenbosch were used to make wines according to sequential harvest. Four harvest stages were considered, pre fresh fruit (Pre FF), fresh fruit (FF), mature fruit (MF) and over ripe (OR). The wines were tasted and analysed using two different sensory techniques. In both Merlot and Cabernet Sauvignon wines, the PreFF and OR stages could be more easily discriminated than the two harvest stages in-between, FF and MF. The results suggested that the wines made from the FF and MF stages could not be distinguished from each other in general when the attribute citation frequency method or sorting tasks were performed. However, a trend could be observed for both Cabernet Sauvignon and Merlot wines in terms of aroma attributes with attributes changing from green to ripe fruit during ripening using expert tasters. Relevant research should be engaged to refine sequential harvest in order to obtain more diverse wine styles from a single site or a group of vineyards.
AFRIKAANSE OPSOMMING: Die wêreldwye wynbedryf het ’n verskuiwing ondergaan na ’n verbruikersvoorkeurbenadering in produksie. Wynverbruikers is deesdae beter ingelig en meer ontwikkeld ten opsigte van hulle kennis van wyngehalte, wynstyl, asook die waarde van wyn. Die gehalte van rooiwyn hang hoofsaaklik af van die druifsamestelling, die wynmaakproses en die vermoë van proewers om sensoriese eienskappe te herken. Aangesien die oesdatum/-fase ’n invloed het op druifsamestelling, is die besluit oor wanneer daar geoes moet word ’n belangrike faktor in die vervaardiging van gehaltewyne of verskillende wynstyle. Die tradisionele aanwysers wat in die wynbedryf gebruik word om oestyd te bepaal, hou verband met die waarneming van smaak en mondgevoel en gee weinig aanduiding van die wynstyl op grond van die aromatiese profiel. ’n Nuwe fisiologiese aanwyser wat gebruik maak van suikerakkumulasie in die druiwekorrel in opeenvolgende oeste, het ten doel om die wynmaker te help om wyne met verskeie moontlike sensoriese profiele te vervaardig. Hierdie aanwyser kan saam met die klassieke aanwysers van rypwording gebruik word om ’n verskeidenheid wynstyle uit een wingerd of wingerdgroep te vervaardig. Die wyne kan dus potensieel oor verskillende aromatiese profiele beskik, afhangend van wanneer die druiwe geoes is. Die hoofdoel van die studie was om die invloed van opeenvolgende oes te toets deur ’n fisiologiese aanwyser op rooiwyn se sensoriese samestelling toe te pas. Dit word gedoen deur die moontlike verhouding tussen die oestyd (bv. ontwikkeling van vrugsamestelling) en die wynstyle of wyn se sensoriese kenmerke op verskillende oestye te bestudeer ten einde die verskeidenheid wynstyle potensieel te vermeerder. ’n Teoretiese konsep van druifsuikeropname is saamgestel wat dui op ’n fase van vinnige suikeropname wat by véraison begin, gevolg deur ’n plato-fase. Wyn kan oor verskillende moontlike aromatiese profiele beskik, afhangend daarvan of die druiwe aan die begin, middel of einde van die plato-fase van suikeropname geoes is. Drie hooffases is al voorheen voorgestel deur gebruik te maak van die konsep van suikeropname volgens oesdatum, te wete vars vrugte (VV) (“fresh fruit”, FF), neutraal (N) (“neutral”, N) of voor ryp (“pre ripe”), en ryp vrugte (RF) (“mature fruit”, MF). Cabernet Sauvignon- en Merlot-druiwe van Eikendal, Stellenbosch, se wingerde is gebruik om wyn volgens opeenvolgende oes te maak. Vier oesfases is oorweeg, te wete voor vars vrugte (VVV) (“pre fresh fruit”, Pre FF), vars vrugte (VV) (“fresh fruit”, FF), ryp vrugte (RV) (“mature fruit”, MF), en oorryp (OR) (“over ripe”, OR). Die wyn is geproe en geanaliseer deur gebruik te maak van twee verskille sensoriese tegnieke. In die geval van beide die Merlot- en Cabernet Sauvignon-wyn kon die VVV- en OR-fases makliker onderskei word as die twee tussenin-fases, VV en RV. Resultate dui daarop dat wyn wat van die VV- en RV-fases gemaak is, oor die algemeen nie van mekaar onderskei kan word wanneer die frekwensie van kenmerkaanhaling-metode en sorteringstaak uitgevoer word nie. ’n Tendens kon egter waargeneem word vir Cabernet Sauvignon- én Merlot-wyn ten opsigte van aromatiese kenmerke, deurdat kenmerke gedurende rypwording van groen na ryp vrugte verander het indien ekspertproewers gebruik is. Verdere navorsing moet gedoen word om opeenvolgende oes te verfyn ten einde ’n wyer verskeidenheid wynstyle van ’n enkele area of wingerdgroep te verkry.
Kallithraka, Stamatina. "Sensory and instrumental astringency determination in wine." Thesis, University of Surrey, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336989.
Повний текст джерелаSanborn, Melissa. "The impact of fining on the chemical and sensory properties of Washington State Chardonnay and Gewürztraminer wines." Online access for everyone, 2008. http://www.dissertations.wsu.edu/Thesis/Summer2008/M_Sanborn_081308.pdf.
Повний текст джерелаBester, Inneke. "Classifying South African Chenin blanc wine styles." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/18048.
Повний текст джерелаENGLISH ABSTRACT: South African Chenin blanc wine is characterised by its style diversity and has been receiving more industry limelight over the past few years. Three dry Chenin blanc wine styles are currently described by the wine industry as Fresh and Fruity (FF), Rich and Ripe unwooded (RR-unwooded) and, Rich and Ripe wooded (RR-wooded). According to the South African wine industry, however, consumers seem to be somewhat confused by these various Chenin blanc wine styles, which have not yet been clearly defined and classified. During this study we investigated the following perspectives of this wine style classification confusion: Currently, no specified sensory method is being used to differentiate between wine styles of a single wine cultivar, such as Chenin blanc. The sorting method can be used as a more cost and time effective classification and profiling method than general quantitative descriptive analysis (QDA). It was therefore investigated whether both uninstructed and instructed sorting, with consumers and wine experts, can be used to classify and describe the Chenin blanc wine styles similarly to QDA. The increase in young wine consumers, Generation Y, introduces new wine marketing opportunities for the wine industry which need to be investigated. Young consumers are not aware of the various Chenin blanc wine styles, which may influence their wine preferences. The influence of wine style knowledge on these consumers’ wine style preferences were investigated during blind and wine style informed preference test. Any segmentation within this Generation Y group was also investigated with regards to their Chenin blanc wine style preferences and/or exploratory data. The following scientific and industrial findings were made: QDA was successfully substituted by instructed and uninstructed sorting tasks. Although the sorting tasks easily differentiated between wooded and unwooded wines, QDA differentiated more successfully between the unwooded wines. Wine tasting experience did not significantly influence the sorting results of the consumers versus the wine experts, but more experienced panellists consistently used fewer descriptors than untrained consumers. All panellists sorted products slightly better when they were provided with wine style sorting instructions. However, there were no significant differences between the instructed and uninstructed sorting task results, i.e. a wine style descriptor list did not improve panellists’ abilities to describe their sorted wine groups. South African Chenin blanc wines can definitely be divided into wooded and unwooded wine styles, i.e. two wine style groups, but the unwooded Chenin blanc wine spectrum formed a wine-style-continuum. This finding is apparent from both the sorting and QDA methods. The unwooded continuum wines can further be differentiated from one another with the use of a fresh-to-mature scale and/or a light-to-full body scale during QDA. Generation Y wine consumers preferred all the Chenin blanc wine styles equally and moderately during the blind tasting, but their knowledge of the wine style concepts significantly increased their preferences for the wines during the informed wine style tasting. The cognitive influence of wine style knowledge is therefore powerful in terms of influencing a consumer’s wine preferences. Other interesting correlations were also made between Generation Y consumers’ wine style preferences and their exploratory data.
AFRIKAANSE OPSOMMING: Suid-Afrikaanse Chenin blanc wyn word gekarakteriseer deur styl diversiteit en is die afgelope paar jaar meer in die kollig. Drie droë Chenin blanc wynstyle word tans deur die wynbedryf beskryf as: Vars en Vrugtig, Ryk en Ryp ongehout en, Ryk en Ryp gehout. Volgens die Suid- Afrikaanse wynbedryf is daar heelwat verwarring is tussen hierdie Chenin blanc wynstyle weens die feit dat hierdie wynstyle nog nie duidelik gedefinieer en geklassifiseer is nie. Tydens die huidige studie het ons die volgende perspektiewe van hierdie wynstyl-verwarring ondersoek: Huidiglik word daar geen gespesifiseerde sensoriese metode gebruik om te onderskei tussen verskillende wynstyle van ’n enkele wyn kultivar, soos Chenin blanc, nie. Die sorteringsmetode kan gebruik word, instede van kwantitatiewe beskrywende analise, as ’n meer koste- en tyd-effektiewe produk klassifikasie en profileringsmetode. DIt was dus ondersoek of beide geïnstrukteerde en ongeïnstrukteerde sorteringstake, met verbruikers en wynkundiges, gebruik kan word om die verskeie Chenin blanc wynstyle kan profileer en klassifiseer soortgelyk soos kwantitatiewe beskrywende analise. Die toename in jong verbruikers, Generasie Y, skep nuwe wynbemarkingsgeleenthede wat ondersoek moet word. Jong verbruikers se onbewustheid van die verskeidenheid Chenin blanc wynstyle mag hulle voorkeure vir hierdie wyne beïnvloed. Die invloed van wynstyl kennis op hierdie jong verbruikers se wynstyl voorkeure was ook ondersoek gedurende ’n blinde en ’n wynstyl-ingeligte voorkeur toets. Enige segmentasie binne hierdie Generasie Y verbruikersgroep was ook ondersoek in verband met hul Chenin blanc wynstyl voorkeure en/of verkennende data. Die volgende wetenskaplike en industriële bevindings is gemaak: Kwantitatiewe beskrywende analise kan suksesvol vervang word deur beide geïnstrukteerde en ongeïnstrukteerde sorteringsmetodes. Alhoewel die sorteringsmetodes maklik gebruik kon word om te onderskei tussen gehoute en ongehoute wyne, kan kwantitatiewe beskrywende analise fyner onderskeid tref tussen die individuele ongehoute wyne. Die wynproe-ervaringsvlak het geen invloed op die sorteringsresultate gehad nie, maar meer ervare paneellede het konsekwent gebruik gemaak van minder beskrywende terme as onopgeleide verbruikers wat baie meer en verskillende soorte terme gebruik het. Beide panele het effens beter gesorteer wanneer hulle spesifieke wynstyl sorteringsinstruksies ontvang het. Daar was egter geen beduidende verskille tussen die geïnstrukteerde en ongeïnstrukteerde sorteringsresultate nie, wat daarop dui dat sorteringsinstruksies en ’n lys van wynstyl beskrywings nie die paneellede se wyse van sortering verander het nie. Suid-Afrikaanse Chenin blanc wyne kan definitief verdeel word in gehoute en ongehoute wynstyle, d.w.s twee wynstyl groepe, maar die ongehoute Chenin blanc wyn spektrum vorm ’n wynstyl-kontinuum. Laasgenoemde is bevind tydens beide die sorteringstake asook kwantitatiewe beskrywende analise. Die ongehoute kontinuum wyne kan verder van mekaar onderskei word met behulp van ‘n vars-tot-volryp en/of ‘n ligte-tot-volmond skaal tydens kwantitatiewe beskrywende analise. Alle jong wyn verbruikers het ewe veel van al die wynstyle gehou tydens die blinde wynstyl voorkeur toets, maar tydens die wynstyl-ingeligte voorkeur toets het hulle voorkeure vir al die wynstyle drasties verbeter. Die kognitiewe invloed van Chenin blanc wynstyl kennis kan dus lei tot hoër voorkeure vir die wynstyle. Ander interessante korrelasies is ook bevind tussen hierdie Generasie Y wyn verbruikersgroep se wynstyl voorkeure en hul verkennende data.
Cheng, Hsiu-Yu. "Wide dynamic range CMOS image sensor." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.547452.
Повний текст джерелаDas, Dipayan. "Wide dynamic range CMOS image sensor." Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572608.
Повний текст джерелаBotha, Janita J. "Sensory, chemical and consumer analysis of Brettanomyces spoilage in South African wines." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4141.
Повний текст джерелаENGLISH ABSTRACT: This study focussed on the sensory effects of the main volatile compounds produced by Brettanomyces yeast causing spoilage in wine. This research firstly aimed to determine the detection thresholds of eight Brett-related spoilage compounds in wine. The second aim was to determine the sensory effect of the four most important Brett-related compounds when present individually in wine. The third aim was to determine the sensory effects of these four compounds when present in wine in a range of combinations, and to further investigate their effect on consumer liking. Finally, this project aimed to investigate the incidence of these compounds in a small range of South African wines. The sensory detection thresholds of 4-ethylphenol, 4-ethylguaiacol, 4-ethylcatechol, 4- vinylphenol, 4-vinylguaiacol, isovaleric acid, isobutyric acid and acetic acid were determined. Apart from 4-ethylcatechol, these values generally agreed well with recent literature where values determined in wine are available. However, the discrepancies highlighted the importance of the effect of the medium (wine) when determining sensory detection thresholds. The use of the median as alternative calculation method was also investigated, and it was found that this method gives more insightful results than the standard American Society of Testing Materials (ASTM E679-04) method. Four compounds, namely 4-ethylphenol, 4-ethylguaiacol, 4-ethylcatechol and isovaleric acid were profiled individually in wine using a trained sensory panel. It was found that all four compounds caused a suppression of the natural berry-like character in the wine, which induced a sick-sweet character. 4-ethylphenol contributed Elastoplast™ and leather aromas in the wine, both of which are commonly associated with Brettanomyces taint. 4-ethylguaiacol added a medicinal aroma to the wine, and 4-ethylcatechol and isovaleric acid were responsible for savoury and pungent aromas, respectively. 4-ethylphenol, 4-ethylguaiacol, 4-ethylcatechol and isovaleric acid were also profiled in combination according to the central composite design. Several univariate and multivariate methods were applied to the dataset obtained. PARAFAC, a multiway method not widely utilized regarding sensory data, was applied to the data, the results of which were complementary to those obtained during univariate and multivariate analyses. It was found that there is a great deal of interaction between the four compounds profiled in terms of sensory effects. The most notable was the Elastoplast™ attribute, the intensity of which was affected by all four compounds. The pungent attribute was also affected by the 4-ethylphenol concentration. Consumer analysis revealed that some of the samples spiked with Brettanomyces-spoilage compounds were preferred to the unspiked (control sample). However, no further relationship could be found between consumer liking and either chemical composition or sensory profile. It is therefore speculated that consumer liking of Brettanomyces infected wine is driven by more complex sensory or socio-demographic factors. Finally, the concentration of 4-ethylphenol, 4-ethylguaiacol, 4-ethylcatechol, 4-vinylphenol, 4- vinylguaiacol, isovaleric acid, isobutyric acid and acetic acid was determined in a small set of South African wines, selected to contain a high proportion of wines spoiled by Brettanomyces. Significant correlations were found between 4-ethylphenol and 4-ethylguaiacol, as well as 4- ethylphenol and isovaleric acid. However, no correlation could be found between 4-ethylphenol and 4-ethylcatechol. It is speculated that this lack of relationship is due to the different precursor profiles present in the analysed wines. This study paved the way for future investigations on the sensory effects of Brettanomyces spoilage in Pinotage red wine.
AFRIKAANSE OPSOMMING: Hierdie studie het gefokus op die sensoriese invloed van die belangrikste vlugtige komponente wat deur die Brettanomyces gis geproduseer word en bederf veroorsaak in wyn. Eerstens is gefokus op die bepaling van die deteksiedrempelwaardes van agt Brett-verwante bederwende komponente. Die tweede doelwit was om die sensoriese invloed van vier van die mees belangrike Brett-komponente te bepaal wanneer hulle individueel in wyn voorkom. Die derde doelwit was om die sensoriese invloed van hierdie vier komponente te bepaal wanneer hulle in verskillende kombinasies in wyn voorkom, asook die effek daarvan op verbruikervoorkeur. Laastens is gepoog om die voorkoms van hierdie komponente in ‘n klein seleksie van Suid- Afrikaanse wyne te bepaal. Die sensoriese deteksiedrempelwaardes vir 4-etielfenol, 4-etielguaiacol, 4-etielcatechol, 4- vinielfenol, 4-vinielguaiacol, isovaleraatsuur, isobuteraatsuur en asynsuur is bepaal. Met die uitsondering van 4-etielcatechol het die waardes oor die algemeen goed ooreengestem met waardes wat onlangs in die wetenskaplike literatuur gepubliseer is. Die uitsonderings het egter die belangrikheid van die medium (wyn) gedurende die bepaling van sensoriese deteksiedrempelwaardes uitgelig. Die gebruik van die mediaan as ‘n alternatiewe berekeningsmetode is ook ondersoek en daar is gevind dat hierdie metode meer insiggewende resultate lewer as die standaard American Society of Testing Materials (ASTM E679-04) metode. Vier komponente naamlik 4-etielfenol, 4-etielguaiacol, 4-etielcatechol en isovaleraatsuur is individueel in wyn geprofileer met behulp van ‘n opgeleide sensoriese paneel. Daar is gevind dat al vier die komponente die natuurlike bessiekarakter in die wyn onderdruk terwyl dit aanleiding gee tot ‘n onnatuurlike soet karakter. 4-etielfenol is gekenmerk aan Elastoplast™ en leeragtige aromas in die wyn en beide van hulle word algemeen geassosieer met Brettanomyces bederf. 4-etielguaiacol het ‘n medisinale aroma tot die wyn toegevoeg en 4- etielcatechol en isovaleraatsuur het respektiewelik souterige (“savoury”) en sterk (“pungent”) aromas tot gevolg gehad. 4-etielfenol, 4-etielguaiacol, 4-etielcatechol en isovaleraatsuur is ook in verskeie kombinasies geprofileer volgens die sentrale saamgestelde ontwerp (“central composite design”). Verskeie enkelveranderlike en meerveranderlike statistiese analisemetodes is ook op die datastel uitgevoer. PARAFAC, ‘n meerrigtingsmetode wat nie normaalweg vir sensoriese analise data gebruik word nie, is ook uitgevoer op die data en die resultate was komplimentêr tot die van die enkelveranderlike en meerveranderlike analisemetodes. Daar is gevind dat, met betrekking tot sensoriese effekte, daar noemenswaardige interaksie tussen die vier komponente plaasvind. Die mees opmerklike hiervan was die Elastoplast™ aroma, waarvan die intensiteit deur al vier die ander komponente geaffekteer is. Verder is die sterk (“pungent”) aroma beïnvloed deur die 4-etielfenol konsentrasie. Verbruikersvoorkeur-analise het aangedui dat sommige van die monsters waarby Brettanomyces bederwende komponente gevoeg is, verkies word bó die kontrole-wyn. Daar kon egter geen verdere verband gevind word tussen die verbruiker se voorkeur en, nog die chemise komposisie of sensoriese profiele, van die wyn nie. Daar kan dus gespekuleer word dat verbruiker voorkeur van Brettanomyces bederfde wyn gedryf word deur meer komplekse en sosio-demografiese faktore. Laastens is die konsentrasies van 4-etielfenol, 4-etielguaiacol, 4-etielcatechol, 4-vinielfenol, 4- vinielguaiacol, isovaleraatsuur, isobuteraatsuur en asynsuur in ‘n seleksie van Suid-Afrikaanse wyne bepaal. Dié wyne is spesifiek so gekies sodat ‘n aansienlike aantal van hulle met Brettanomyces bederf was. Betekenisvolle korrelasies is gevind tussen 4-etielfenol and 4- etielguaiacol, sowel as 4-etielfenol en isovaleraatsuur. Daar is egter geen korrelasie tussen 4- etielfenol and 4-etielcatechol gevind nie. Daar word vermoed dat hierdie gebrek aan korrelasie te wyte is aan die voorloperkomponent profiele teenwoordig in die wyne. Hierdie studie het die weg gebaan vir verdere ondersoeke na die sensoriese effekte van Brettanomyces bederf in Pinotage rooi wyn.
Coetzee, Carien. "Oxidation treatments affecting Sauvignon blanc wine sensory and chemical composition." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86321.
Повний текст джерелаENGLISH ABSTRACT: This study focussed on the effect of oxygen on the chemical and sensory evolution of Sauvignon blanc wine under controlled oxidation conditions. The sensorial interactive effects between Sauvignon blanc varietal aroma compounds and compounds that typically arise during oxidation of white wines were also investigated. In the first research chapter the sensorial interactive effects of Sauvignon blanc impact compounds with aldehydes typically originating from oxidation of white wines were investigated. Four compounds, 3‐ mercaptohexan‐1‐ol (3MH), 3‐isobutyl‐2‐methoxypyrazine (IBMP), 3‐(methylthio)‐propionaldehyde (methional) and phenylacetaldehyde were added together in a model wine medium at varying concentrations. The concentrations chosen were according to those reported in literature to occur in Sauvignon blanc wines. The sensory effects of these compounds were profiled using a trained sensory panel. Compounds were first profiled individually and results showed that the change in comcpound concentration not only led to a change in intensity ratings but also in some cases a change in the descriptor. All four compounds in the same sample showed complicated interactive effects. Data were statistically analysed using relatively novel techniques such as statistical networks that allowed deeper insights into the interactions involved. Various observations were made such as the contribution of 3MH to the ‘green’ character of the wine, the potent suppressing abilities of methional on 3MH and IBMP and the additive effect of methional and IBMP contributing to the ‘cooked’ character of the sample. In the second research chapter the effect of repetitive oxidation on a fresh and fruity style Sauvignon blanc wine was investigated. Results showed the progress and evolution of aromatic and non‐aromatic compounds during an oxidative aging period. A large range of chemical analyses were conducted together with extensive sensory profiling. Results showed a decrease in volatile thiols responsible for the fruity nuances and an increase in oxidation‐related compounds, such as acetaldehyde, during the course of the oxidation. Sensory profiling showed the evolution of the wine aroma during oxidation. The wine evolved from a fresh and fruity wine to slight oxidation and then developed extreme oxidative characteristics. The Control samples (no oxygen added) developed a ‘cooked’ character which could indicate the formation of reductive compounds in these wines. Conversely, the wines that received a single dose of oxygen did not develop this flavour and were perceived to be more fresh and fruity than the Control samples. The evolution of the wine colour was also monitored using a spectrophotometer as well as a sensory panel and results suggest that the colour of the wine evolved before the disappearance of the pleasant aroma. The advantages and disadvantages of oxygen exposure to this type of wine style are discussed as well as the complexity of the wine matrix and sensory interactions occurring in the specific wine. The aim of the third research chapter was again to investigate further sensory interactions between Sauvignon blanc varietal aroma compounds and an oxidation‐related compound. After the observations reported in the second research chapter, the inclusion of acetaldehyde in an interaction study seemed to be of critical importance. Acetaldehyde can reach significant concentrations during oxidation and can have a detrimental effect on wine aroma. This interaction study included three compounds, 3MH, IBMP and acetaldehyde. Acetaldehyde was able to effectively mask the ‘green’ character of the sample, while it also enhanced certain fruity nuances when present at specific concentrations. 3MH was able to suppress the oxidising character of acetaldehyde when present at sufficient concentrations. The results from this study clearly showed the complexity of the wine medium and the interactions involved. It also highlighted the importance of performing these types of sensory studies in a simple medium opposed to a complex matrix such as wine. The effect of oxygen on various aspects of the wine was investigated and the combination of chemical and sensory data delivered some interesting conclusions also involving interactions that occurred. This study paved the way for future investigations on the sensory relationships of Sauvignon blanc aroma compounds and the role of proper oxygen management in the production of quality wines.
AFRIKAANSE OPSOMMING: Die doelwit van die studie was om die effek van gekontroleerde oksidasie op die ontwikkeling en verloop van verskeie chemiese komponente asook die ontwikkeling van die sensoriese profiel van ‘n Sauvignon blanc wyn te ondersoek. Bykomende studies ondersoek die interaksie/wisselwerking tussen aromakomponente in ‘n eenvoudige matriks. Interaksies tussen spesifieke Sauvignon blanc kultivargeassosieerde aromakomponente en komponente wat normaalweg tydens die oksidasie van witwyne ontwikkel, word ondersoek. Die eerste navorsingshoofstuk het ten doel om die interaksie tussen tipiese Sauvignon blanc aromakomponente (of impakkomponente) met aldehiede wat normaalweg tydens oksidasie van witwyne ontwikkel, na te vors. Vier komponente is in ‘n modelwyn gevoeg teen verskeie konsentrasies, wat oor die algemeen in die literatuur gerapporteer is om voor the kom in Sauvignon blanc wyne. Die komponente wat ondersoek is, is: 3‐merkaptoheksanol (3MH), 3‐isobutiel‐2‐metoksiepirasien (IBMP), 3‐ (metieltio)‐propionaldehied (methional) en fenielasetaldehied. Die sensoriese effekte van die komponente is deur ‘n opgeleide sensoriese paneel geëvalueer. Komponente is eers individueel geanaliseer en die resultate het getoon dat dat die intensiteit van die spesifieke aroma verander namate die konsentrasie verander. In sommige gevalle het die beskrywende woord vir die aroma ook verander. Deur al vier komponente in dieselfde monster te voeg word die ondersoek gekompliseer. Die data is statisties geanaliseer deur gebruik te maak van relatiewe nuwe tegnieke soos statistiese netwerke wat dieper insig in die betrokke interaksies bewerkstellig. Verskeie waarnemings word gerapporteer onder andere die bydrae van 3MH tot die ‘groen’ karakter van die wyn, die kragtige onderdrukkingsvermoë van methional op 3MH en IBMP asook die opbouende effek van methional en IBMP wat bydra tot die ‘gekookte’ karakter van die monster. Die tweede navorsingshoofstuk is daarop gemik om die effek van herhalende oksidasie op 'n vars en vrugtige styl Sauvignon blanc wyn te ondersoek en om die vordering en ontwikkeling van aromatiese en nie‐aromatiese komponente gedurende hierdie tydperk te analiseer. ‘n Wye reeks chemiese komponente is geanaliseer tesame met omvangryke sensoriese analise. ‘n Afname in die vlugtige tiole, wat verantwoordelik is vir die vrugtige geure, is gevind tesame met ‘n toename in oksidasie‐verwante komponente (soos asetaldehied). Sensoriese ondersoeke toon ook die evolusie van die wynaroma tydens oksidasie. Die wyn het ontwikkel van ‘n vars en vrugtige styl na effense oksidasiegeure waarna ekstreme oksidasiekarakters waargeneem is. Die Kontrole monsters het ‘n ‘gekookte’ karakter ontwikkel wat ‘n aanduiding van die ontwikkeling van ‘reduktiewe’ komponente in hierdie wyn kan wees. Aan die ander kant het wyne wat een suurstofdosering ontvang het, geen van hierdie geure ontwikkel nie en die wyn is as varser en vrugtiger beskryf in vergelyking met die Kontrole monsters. Die ontwikkeling van die wynkleur is ook gemonitor deur gebruik te maak van ‘n spektrofotometer asook 'n sensoriese paneel. Resultate stel voor dat die kleur van die wyn ontwikkel voor die aangename geure begin verdwyn. Die voor‐ en nadele van suurstofblootstelling aan hierdie tipe wynstyl word bespreek asook die kompleksiteit van die wynmatriks en sensoriese interaksies wat in hierdie spesifieke wyn voorkom. Die derde navorsingshoofstuk is weereens daarop gemik om die sensoriese interaksie tussen tipiese Sauvignon blanc kultivar‐geassosieerde aromakomponente en nog ‘n oksidasie‐geassosierde aromakomponent te ondersoek. Die resultate vanuit die tweede navorsingshoofstuk het die insluiting van asetaldehied in die interaksiestudie genoodsaak. Asetaldehied kan betekenisvolle konsentrasies tydens oksidasie behaal en kan ook nadelige effekte op wynaroma hê. Hierdie interaksiestudie het die volgende drie komponente ingesluit: 3MH, IBMP en asetaldehied. Asetaldehied het die ‘groen’ karakter van IBMP effektief gemaskeer terwyl dit die waarneming van die vrugtige aroma ondersteun en selfs verhoog het wanneer dit teen sekere konsentrasies teenwoordig was. 3‐Merkaptoheksanol het die oksidasiekarakter van asetaldehied onderdruk wanneer dit teen genoegsame konsentrasies teenwoordig was. Die kompleksiteit van wyn as ‘n navorsingsmedium is duidelik vanuit die studie veral in die ondersoeking van interaksie‐effekte tussen komponente. Die belangrikheid van die gebruik van 'n eenvoudige medium teenoor ‘n komplekse medium vir soortgelyke studies is dus duidelik. Die effek van suurstof op verskeie aspekte van witwyn is ondersoek en die kombinasie van chemiese en sensoriese data het interessante gevolgtrekkings gelewer. Die studie het die pad vir toekomstige studies gebaan in terme van sensoriese interaksies met betrekking tot Sauvignon blanc aroma. Die belangrikheid van oordeelkundige suurstofbestuur tydens die produksie van kwaliteit wyne is ook uitgelig.
Brown, Rachel Christine, and rcbrown@adam com au. "gamma-Lactones in wine: Synthesis, quantification and sensory studies." Flinders University. School of Chemistry, Physics and Earth Sciences, 2007. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20080226.234630.
Повний текст джерелаWeightman, Jayne. "Characterization of Chenin Blanc wines produced by natural fermentation and skin contact : focus on application of rapid sensory profiling methods." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/96008.
Повний текст джерелаENGLISH ABSTRACT: Producers of South African (SA) dry and semi-dry Chenin blanc table wines are currently experimenting with winemaking techniques to modulate the flavours of the predominantly fruity styles of this genre. An important stage during wine style development is sensory profiling paired with consumer acceptance testing, before wine is produced on industrial scale. With those aforementioned goals in mind, this study was conducted in partnership with two commercial SA wine cellars. The main focus of the study was an investigation into the treatment effects of two winemaking techniques, respectively grape skin contact and natural fermentation, on the sensory profiles of experimentally produced Chenin blanc wines. Results obtained with descriptive sensory analysis (DA) of the wines were compared to those obtained by two rapid sensory profiling methods, namely projective mapping (PM) and frequency of attribute citation (FC). A consumer preference study was also done on the wines. In order to understand the treatment effects better, the dominant non-Saccharomyces yeasts that were present during the natural fermentations were identified using polymerase chain reaction (PCR), while the major volatile chemical compounds were identified with chromatography and mass spectrometry. The sensory and chemical profiles of the naturally fermented wines were significantly different from those of the inoculated wines. PCR analysis identified some of the yeasts present during alcoholic fermentation. In comparison to the inoculated fermented wines, the naturally fermented wines were generally perceived to have more intense and riper tropical fruity aromas, with enhanced sweetness and reduced intensities of sourness, bitterness and astringency. The wines fermented on the skins (FoS) had lower ester and volatile thiol concentrations than the control wines (with no skin contact) and limited skin contact wines. Sensory attributes linked to the FoS wines included aromas of dried fruit, dried grass and a vegetative character, with an increased sour and bitter taste and astringent mouthfeel. In contrast, the wines that were produced with limited skin contact (12 hours) retained their tropical fruity aromas better than the FoS wines. Limited skin contact seemed to have had a less harsh effect on the taste and mouthfeel than the FoS wines. A consumer study was done to establish a Generation Y consumer group’s (18-35 years) preference for the different treated wines. Overall, the naturally fermented wines, which were described as having a strong tropical fruit character, were preferred. The FoS wines were generally disliked by the consumers. Results obtained from the three sensory analysis methods, respectively DA, PM and FC, were similar, thereby confirming the suitability of the rapid methods PM and FC, to extract qualitative information from the sensory profiling of white wine. The results of this study made a significant contribution towards validation of rapid sensory methods for wine evaluation, which are particularly valuable in the context of sustainability and technology transfer to research and industry alike. The knowledge gained on the chemical profiles of SA Chenin blanc is novel and this is one of the first reports on the volatile thiol content of SA Chenin blanc wine.
AFRIKAANSE OPSOMMING: Produsente van Suid-Afrikaanse (SA) droë en semi-droë Chenin blanc tafelwyne eksperimenteer tans met wynmaaktegnieke om die oorwegend vrugtige style van hierdie genre te varieer. ‘n Belangrike fase van wynstylontwikkeling is sensoriese profilering van die produkte met gepaardgaande verbruikersaanvaardingstoetse, voordat die wyne op industriële skaal geproduseer word. Met dié bogenoemde doelwitte in gedagte, was hierdie studie in vennootskap met twee kommersiële SA wynkelders gedoen. Die hooffokus van die studie was om die invloed van twee wynmaaktegnieke, onderskeidelik druifdopkontak en natuurlike fermentasie, op die sensoriese profiele van eksperimenteel geproduseerde Chenin blanc wyne te ondersoek. Resultate wat met beskrywende sensoriese analise (DA) van die wyne verkry is, is vergelyk met dié wat deur twee vinniger sensoriese profileringsmetodes metodes, naamlik projektiewe kartering (PM) en frekwensie van kenmerkaanhaling (FC) verkry is. 'n Verbruikervoorkeurstudie is ook op die wyne gedoen. Ten einde die behandelingseffekte beter te verstaan, is die dominante nie-Saccharomyces giste wat teenwoordig was tydens die natuurlike fermentasie geïdentifiseer met behulp van die polimerasekettingreaksie (PCR), terwyl die vernaamste vlugtige chemiese verbindings geïdentifiseer is met chromatografie en massaspektrometrie. Die sensoriese en chemiese profiele van die natuurlike gefermenteerde wyne was beduidend anders as dié van die geiinokuleerde wyne. PCR analise het sommige giste wat teenwoordig was tydens alkoholies fermentasie geïdentifiseer. In vergelyking met die geiinokuleerde wyne, het die natuurlik gefermenteerde wyne intenser en ryper tropiese vrugtige aromas getoon, met ‘n verhoogde perspesie van soetheid en laer intensiteite van suurheid, bitterheid en vrankheid. Die wyne wat berei is deur fermentasie op die druifdoppe (FoS) het laer konsentrasies van esters en vlugtige swawelverbinding gehad, as die kontrole wyne (geen dopkontak) en beperkte dopkontak wyne. Sensoriese eienskappe gekoppel aan die FoS wyne was geasssosieer met gedroogde vrugte, gedroogde gras en 'n vegetatiewe aroma, met gepaardgaande verhoogde suur en bitter smaakpersepsies en ‘n frank mondgevoel. In teenstelling, het die wyne wat geproduseer is met 'n beperkte dopkontak (12 uur) hul tropiese vrugtige aroma beter behou as die FoS wyne. Beperkte dopkontak het ook ‘n minder negatiewe uitwerking op die smaakpersepies van bitterheid en vrankheid gehad. ‘n Verbruikerstudie is gedoen om 'n groep jong Generasie Y verbruikers (18-35 jaar) se voorkeure vir die verskillende behandelings te bepaal. Oor die algemeen is die natuurlike gefermenteerde wyne, wat beskryf is met 'n sterk tropiese vrugtekarakter verkies, terwyl die groep nie van die FoS wyne gehou het nie. Resultate wat verkry is met drie sensoriese analise metodes, onderskeidelik DA, PM en FC, was soortgelyk en die geskiktheid van die vinniger metodes, PM en FC, om kwalitatiewe inligting van witwyn se sensoriese eienskappe te verkry, is bevestig. Die resultate verkry met hierdie studie maak ‘n beduidende bydrae tot die validering van vinniger sensoriese metodes vir wynevaluering, wat veral waardevol is in die konteks van volhoubaarheid en tegnologieoordrag na navorsing en die industrie. Die nuwe kennis wat in hierdie studie gegenereer is met die chemiese profilering van SA Chenin blanc wyn is baie waardevol en hierdie is een van die eerste narvorsingsprojekte oor die inhoud van vlugtige swawelverbings in SA Chenin blanc wyn.
Almeida, Susana Cristina Aleixo de. "Emotional responses elicited by wine when pairing with high fat food." Master's thesis, ISA, 2017. http://hdl.handle.net/10400.5/14827.
Повний текст джерелаThis work was aimed at the evaluation of emotional responses elicited by wine before and after food consumption. The tastings were performed by one trained panel and by consumers, segmented by gender, Vinotype, 6-n-propylthiouracil (PROP) sensitivity and Saliva flow rate. Three commercial red wines with different sensory features were used: i) Grand Gold awarded wine from Alentejo (2013); ii) wine from altitude vineyards in Douro (2011), iii) classical European old wine (1999) from Bairrada. Wines were evaluated using a tasting sheet with emotional and conventional tasting descriptors before and after eating a typical Portuguese dish, whose distinctive feature was its high fat content. Overall, food did not change the global evaluation scores given to the wines but some of their characteristics were scored significantly different through the emotional tasting. The results of both panels demonstrated that the emotional responses were more correlated with the global evaluation of the wines than the classical sensory descriptors. Within the trained individuals, the main correlations with global evaluation were obtained with “Initial Impression”, “Expectation for the mouth” and “Impression in relation to odor”. In particular, the global evaluation for the Bairrada wine, could be predicted by a model including these three variables with a R2=0.73. With the untrained tasters, the correlation with global evaluation was only significant for the “Impression in relation to odor”. The average scores given to the three wines by both panels did not diverge, despite their different sensory attributes. Therefore, our work only reflected trends in wine preferences. The untrained panel preferred the Alentejo wine while the trained panel preferred the Douro wine, before the food ingestion. The correlations between the global evaluation and the other sensory descriptors for the Alentejo wine could not explain this preference. We speculate that the untrained panel scored the wines based on what they are used to drink, giving lower scores to the unfamiliar one. The trained panel demonstrated a higher correlation between emotional and sensory descriptors. In fact, the trained panel seemed to understand better the different range of qualities of the wines. After ingesting food, the preference changed only for the trained panel, showing preference to the Bairrada wine. Both panels agreed that the old Bairrada was the most complex and difficult wine to understand In conclusion, the emotional tasting sheet was easy to interpret by all segments of consumers, leading to open and fair answers because it appeals to individual personal feelings. This tasting approach appears to be promising in the rapid learning of the different wine styles. In the future, it would be interesting to evaluate the evolution of scores given to unfamiliar wines that would require time to be appreciated using appropriate foods. This way, the classical European wines, that are difficult to understand by consumers, would have a better chance to be correctly appreciated
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Malherbe, Sulette. "Investigation of the impact of commercial malolactic fermentation starter cultures on red wine aroma compounds, sensory properties and consumer preference." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6587.
Повний текст джерелаENGLISH ABSTRACT: Wine is the result of a variety of biochemical reactions and microbial interactions which contribute to the organoleptic properties of wine. Wine aroma and flavour encapsulate the sensory experience of wine and could ultimately determine wine quality and consequently influence consumer acceptance and preference of a product. A thorough understanding of potential factors influencing wine aroma and flavour is therefore needed in order to exploit such factors. The aim of this study was to evaluate the influence of commercial malolactic fermentation (MLF) starter cultures on wine composition, aroma and flavour and the potential impact on consumer preference of experimentally produced red wines. An analytical platform was established to capture the compositional changes induced by different MLF bacteria in experimentally produced red wines. A fast gas chromatography flame ionisation detection (GC-FID) method was developed to determine 39 wine volatile compounds in less than 15 minutes per sample. A 3-fold reduction in analysis time was achieved in comparison to a conventional GC-FID method (40 minutes). Analytes quantified comprise a large boiling point and polarity range which illustrates the robustness of the method. A method was also developed for the direct quantification of carbonyl compounds including diacetyl, acetoin, 2,3-pentanedione and certain aldehydes using headspace solid phase microextraction coupled to gas chromatography mass spectrometry (HS-SPME GC-MS). Both analytical methods showed satisfactory linearity, repeatability and limits of quantification. The contribution of four commercial Oenococcus oeni malolactic fermentation (MLF) starter cultures to the volatile composition, organic acid content and infrared spectral properties of experimentally produced South African red wines, showed significant strain-specific variations in the organic acid profiles, especially for the production of citric acid and lactic acid during MLF. Subsequently, concentrations of compounds related to citric acid metabolism, namely ethyl lactate, acetic acid, diacetyl and acetoin, were influenced accordingly. Bacterial metabolic activity increased the concentration of higher alcohols, fatty acids and esters, with a larger increase observed in ethyl esters compared to acetate esters. A strain-specific tendency to reduce total aldehyde concentrations was found at the completion of MLF, however, further investigation is needed to clarify this observation. Infrared spectral fingerprints were used to characterise the different bacteria and in addition, the prediction of MLF related compounds, diacetyl, acetoin and 2,3-pentanedione, from mid-infrared spectra was explored by partial least squares (PLS) models. Quantitative descriptive analysis (QDA) results depicted significant differences between wines fermented with different starter cultures, in terms of sensory attributes including buttery, fruity, nutty and yoghurt/buttermilk aroma as well as smoothness and mouth-feel attributes. Consumer preference testing results indicate that sensory differences imparted by different MLF bacteria could influence consumer-liking. Preference mapping revealed interesting relationships between sensory attributes and consumer-liking, that can be used for preliminary interpretative purposes. In conclusion, this study illustrated the potential impact of bacterial strains on wine aroma and flavour, resulting sensory properties and consumer preference through an integrative approach combining compositional, spectral, sensory and consumer data. The results presented in this study are of significance to the wine industry since they illustrate and reiterate the potential of different MLF starter cultures as an additional tool to contribute to wine aroma and flavour, and potentially influencing consumer preference and product liking.
AFRIKAANSE OPSOMMING: Wyn is die resultaat van ‘n verskeidenheid biochemiese reaksies en mikrobiologiese interaksies wat tot die organoleptiese eienskappe van die finale produk bydra. Wynaroma en geur vang die sensoriese ervaring van wyn vas en dit kan dus wynkwaliteit bepaal en gevolglik verbruikersaanvaarding asook voorkeur van ‘n produk beïnvloed. Die potensiële faktore wat wynaroma en geur kan beïnvloed moet dus vir hierdie rede deeglik bestudeer word ten einde sulke faktore ten volle te benut. Die doel van hierdie studie was om die invloed van kommersiële applemelksuurgisting (AMG) aanvangskulture op wynsamestelling, die gevolglike aroma en geur eienskappe en die potensiële impak op verbruikersvoorkeure te ondersoek. ‘n Analitiese platform is gevestig om die veranderings in samestelling veroorsaak deur verskillende AMG bakterieë in eksperimenteel bereide rooi wyne vas te vang. ‘n Vinnige gas chromatografiese vlam geïoniseerde deteksie (GC-FID) metode is ontwikkel vir die meting van 39 vlugtige komponente in minder as 15 minute per wynmonster. In vergelyking met ‘n konvensionele GC-FID metode (40 minute) is ’n 3-voudige vermindering in analise tyd behaal. Gekwantifiseerde komponente bestaan uit ‘n wye kookpunt- en polariteitsreeks wat die robustheid van die metode illustreer. ‘n Metode vir die direkte kwantifisering van karboniel komponente, insluitende diasetiel, asetoïen, 2,3-pentanedioon en verskeie aldehiede is ontwikkel met die gebruik van dampfase soliede fase mikroekstraksie gekoppel aan gas chromatografie massa spektrometrie (HS-SPME GC-MS). Albei analitiese metodes besit voldoende lineariteit, herhaalbaarheid en lae deteksie limiete. Die bydrae van vier kommersiële Oenococcus oeni AMG aanvangskulture tot die vlugtige samestelling, organiese suurinhoud en infrarooi spektrale eienskappe van Suid-Afrikaanse rooiwyn het beduidende ras spesifieke variasies in die organiese suur profiele, spesifiek vir die produksie van sitroensuur en melksuur gedurende AMG, vertoon. Gevolglik is die konsentrasies van komponente verwant aan sitroensuur metabolisme, naamlik etiellaktaat, asynsuur, diasetiel en asetoïen, dien ooreenkomstig beïnvloed. Bakteriese metaboliese aktiwiteit het ‘n toename tot gevolg gehad in die hoër alkohole, vetsure en algemene ester konsentrasies met ‘n groter toename in etiel-esters in vergelyking met asetaat-esters. ‘n Ras-spesifieke tendens om die totale aldehiedkonsentrasie te verminder na afloop van AMG, is waargeneem alhoewel verdere ondersoek in hierdie area nodig is. Infrarooi spektrale patrone is gebruik om verskillende bakterieë te karakteriseer asook om die voorspelling van spesifieke AMG verwante komponente soos diasetiel, asetoïen en 2,3-pentanedioon met die gebruik van mid-infrarooi spektrala parsiële kleinste kwadraat verskille (PLS) modelle te ondersoek. Kwantitiewe beskrywende sensoriese analise illustreer beduidende verskille tussen wyne wat gefermenteer is met verskillende aanvangskulture in terme van geure soos botteragtigheid, vrugtigheid, neutagtigheid, joghurt/karringmelkgeur, asook gladheid en mondgevoel eienskappe. Verbruikersvoorkeur resultate illustreer die groot invloed wat sensoriese verskille veroorsaak deur verskillende AMG bakterieë op verbruikersvoorkeure kan hê. Voorkeur kartering het interessante verhoudings tussen sensoriese eienskappe en verbruikersvoorkeure uitgelig. Hierdie studie illustreer die impak van bakteriese rasse op wynaroma en geur en verbruikersvoorkeure deur ‘n geïntegreerde benadering waarin samestellende, spektrale, sensoriese en verbruikersdata gekombineer is. Die resultate van hierdie studie is van belang vir die wynindustrie deurdat dit die potensiële bydrae van verskillende AMG kulture tot wynaroma en geur asook die potensiaal om verbruikersvoorkeure te beïnvloed, illustreer en beklemtoon.
Wilker, Karl Lawrence. "Effect of oak aging treatments on the phenolic composition and sensory quality of Seyval blanc wines /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu148726802174669.
Повний текст джерелаSharareh, Shiva. "Critical evaluation of the coated wire glucose sensor." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/31512.
Повний текст джерелаApplied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
Williams, Jon A. "Enabling Validation of a CubeSat Compatible Wind Sensor." Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/78711.
Повний текст джерелаMaster of Science
Sitter, Nicholas James. "Two-wire, low component count soil temperature sensor." Thesis, University of Iowa, 2011. https://ir.uiowa.edu/etd/1081.
Повний текст джерелаLouw, Leanie. "Sensory analysis of brandy: the application of rapid profiling methodologies." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86483.
Повний текст джерелаENGLISH ABSTRACT: Brandy has a high alcohol content of at least 36% alcohol by volume and a complex volatile chemical structure. Due to this, the sensory evaluation of brandy is challenging to execute and must be carefully managed to avoid panellists’ sensory and mental fatigue. Although rapid sensory profiling methods, such as projective mapping (PM), are commonly used for fast moving consumer goods, it was unclear whether these methods could accommodate the difficulties associated with brandy evaluation. The primary objective of this study was to validate PM, also called Napping®, as a reliable tool for brandy evaluation. Two variations of PM were tested: global napping (GN) where products are evaluated based on overall sensory perception, and partial napping (PN) where the product perception is broken down in to separate sensory modalities, in this case appearance, aroma and in-mouth sensations. Several practical aspects of PM were investigated in order to optimise the method for brandy evaluation and to gain understanding into practical methodological aspects that have not been fully understood at the onset of this study. The results showed that both GN and PN delivered reliable results, but that PN was more reproducible and better suited to larger sample sets (10 products). The concept of in-mouth sensations was found to be ineffective in extracting useful information on mouthfeel differences in the product set and that retronasal flavour should be separated from basic tastes and mouthfeel. A verbal instruction to the panellists was sufficient to obtain reliable information on mouthfeel differences; it was not necessary to use black glasses or nose-clips to eliminate the influence of appearance and flavour perception. In response to the insufficient reproducibility of GN, the sorting method was tested and validated as a suitable screening method that delivered reliable product maps of larger sample sets (10 products) in one replication, compared to GN which has to be replicated several times. A recent hypothesis states that the elongated horizontal dimension of a rectangular PM tasting sheet could be used to elicit more prominent product differences, while tasting sheets without an elongated axis, such as circles or squares, could be used to bring forth more subtle differences. This hypothesis was challenged by testing rectangular, square and round tasting sheet shapes. Although differences were observed between the shapes in terms of product configuration and panellist performance, the practical value of using different tasting sheet shapes to obtain specific information could not be established. The impact of high alcohol content and product complexity on panellist performance in PM was tested and it was concluded that product complexity did influence the panellists’ performance, particularly for high alcohol products. It was also found that prior knowledge of a products’ high alcohol content influenced the panellists’ descriptive language to include more alcohol-related terms. A new panellist performance measure was developed, namely the Relative Performance Index (RPI). This measure can be used to monitor trained panellists’ performance in the PM task more effectively to thereby ensure reliable results. The outcomes of this study extended the brandy sensory evaluation toolbox. Practical measures were identified that can be used to overcome the challenges associated with the sensory evaluation of complex high alcohol products.
AFRIKAANSE OPSOMMING: Met ‘n alkohol inhoud van mintens 36% alkohol per volume en ‘n komplekse vlugtige chemise samestelling is brandewyn ‘n uitdagende produk om sensories te evalueer. Maatreëls moet in plek gestel word om te verhoed dat sensoriese paneellede nie uitgeput raak nie om sodoende betroubare resultate te verseker. Hoewel vinnige sensoriese toetsmetodes, soos projeksiekartering (PM) en sortering, gereeld gebruik word vir die evaluasie van vining bewegende verbruikersgoedere was dit weens die voorafgenoemde redes onduidelik of die metodes geskik sou wees vir brandewynevaluasie. Die oorhoofse doelwit van hierdie projek was om PM, ook genoem Napping®, te valideer as ‘n geskikte metode vir die sensoriese evaluering van brandewyn. Twee variasies van PM is ondersoek: oorhoofse kartering (GN) waar die produkte op grond van ‘n algehele sensoriese waarneming evalueer word, en gedeeltelike kartering (PN), waar die verskillende sensoriese waarnemingsmodaliteite afsonderlik gemeet word. In hierdie geval is voorkoms, aroma en algehele binne-mondse ervaring gemeet. Verskeie aspekte van GN en PN is ondersoek ten einde die metodes vir brandewynevaluasie te optimiseer asook lig te werp op praktiese metodologiese aspekte waaroor daar nog onsekerheid was by die aanvang van hierdie studie. Die resultate het getoon dat beide GN en PN betroubare inligting oor brandewyn kan oplewer, maar dat PN meer herhaalbaar en beter geskik is vir groter produkstelle (10 produkte). Dit is egter bevind dat die konsep van algehele binne-mondse waarneming nie doeltreffend was om mondgevoelverskille tussen produkte uit te lig nie. Smaak- en mondgevoelwaarnemings moet liefs onderskei word van binne-mondse geurwaarneming. Dis bevind dat dit voldoende is om hierdie onderskeid deur skriftelike instruksies tot die paneel te bewerkstelling en dat die gebruik van swart glase en neusknippies nie nodig was om betekenisvolle inligting oor mondgevoel te bekom nie. Na aanleiding van die swak herhaalbaarheid van GN, is sortering getoets en gevalideer as ‘n geskikte siftingsmetode wat betroubare produkkaarte van groot produkstelle (10 produkte) kan oplewer met slegs een evaluasie, teenoor GN waarvoor meer as een sessie benodig word. ‘n Onlangse hipotese stel dat die langer horisontale dimensie van reghoekige PM proekaarte gebruik kan word om meer prominente verskille tussen produkte uit te wys, terwyl proekaarte sonder verlengde asse, soos sirkels en vierkante, gebruik kan word om meer subtiele verskille uit te wys. Hierdie hipotese is bevraagteken deur reghoekige, vierkantige en ronde PM proekaarte teenoor mekaar te toets. Hoewel die resultate vanaf die verskillende proekaarte effens verskil het in terme van produk konfigurasie en die paneel se taakverrigting, kon die praktiese waarde van die gebruik van produkkaarte met verskillende vorms om spesifieke inligting te bekom nie bevestig word nie. Die impak van hoë alkohol en produkkompleksiteit op paneellede se PM taakverrigting is ondersoek. Dit is bevind dat produkkompleksiteit wel hul taakuitvoering beinvloed, en dat hierdie invloed groter is vir hoë alkohol produkte. Dit is ook gevind dat paneellede se beskrywende taalgebruik beïnvloed om meer alkoholverwante woorde in te sluit word indien hul kennis dra van ‘n produk se hoë alkohol inhoud. ‘n Nuwe vaardigheidsberaming vir die meet van paneellede se taakverrigting is ontwikkel, naamlik die Relatiewe Taakverrigtingsindeks (RTW). Dit kan gebruik word om paneellede se vaardigheid in PM meer doeltreffend te monitor en sodoende betroubare resultate te verseker. Die uitkomste van die studie het die poel beskikbare metodes vir die sensoriese evaluering van brandewyn suksesvol verbreed en praktiese maatreëls is geidentifiseer om die uitdagings van ‘n komplekse hoë alkohol produkte te oorkom.
Hanekom, Evette. "Chemical, sensory and consumer profiling of a selection of South African Chenin blanc wines produced from bush vines." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71812.
Повний текст джерелаENGLISH ABSTRACT: Twenty five commercial Chenin blanc wines produced solely from bush vine vineyards and including three vintages, three styles and five production areas, were sourced for this study. Descriptive sensory analysis (DSA) and chemical analyses including GC-FID (gas chromatography fitted with a flame ionisation detector) and FTMIR (Fourier transform mid-infrared) spectroscopy were employed to establish the sensory and chemical characteristics, whereas consumer tests were conducted to determine consumer perception and liking of bush vine Chenin blanc wines. DSA (a profiling technique) was also compared to the sorting task (a classification technique) with a description assignment to evaluate the sorting task’s ability to profile wines. According to the results of DSA, the wines separated into two groups. One group associated with sensory attributes which can be considered indicative of the Fresh and Fruity Chenin blanc style. The other group associated with sensory attributes which can be considered indicative of the Rich and Ripe style of Chenin blanc. No separation between the wooded and unwooded Rich and Ripe styles was apparent. According to the results of the chemical analyses, the wines also separated into two groups. This separation seemed to be caused by vintage and the chemical changes associated with ageing as the wines from the youngest vintage (2010) was strongly associated with high levels of esters and malic acid. The older wines were situated farthest away from these attributes indicating low concentrations. When comparing the results from the sorting task and DSA, it could be seen that similar wine style groupings formed, indicating that DSA can also be regarded as an effective tool when categorising wines. The differences in the positioning of some of the wines and attributes on the DSA multivariate plots and the sorting task plots could be attributed to the difference in panels used. The sorting task was conducted using an expert panel with persons illustrating significant technical knowledge of Chenin blanc wines. Experience, exposure and technical knowledge tend to establish a common language amongst wine experts which could have caused the expert panel to perceive some wines differently when comparing the results of the latter panel to that of the trained panel. DSA was found to remain the most effective method for establishing a comprehensive sensory profile. Consumer analyses showed that regular white wine drinkers prefer the unwooded styles (Fresh and Fruity and Rich and Ripe unwooded) of Chenin blanc more than the wooded style. It was also found that consumers with a higher level of objective wine knowledge tend to associate the terms ‘bush vine’ and ‘old bush vine’ with the Rich and Ripe style of Chenin blanc, whereas consumers with a lower level of objective wine knowledge associated ‘old bush vine’ with the Fresh and Fruity style. Since all the wines used in the consumer analysis were produced from old bush vines, it is evident that consumer education on the impact of bush vine training system and vine age on wine quality is needed. Better understanding of these principles could lead to elevated product appraisals and consumer satisfaction.
AFRIKAANSE OPSOMMING: Vyf en twintig kommersiële Chenin blanc wyne, uitsluitlik van bosstok wingerde geproduseer, is bekom vir hierdie studie. Die wyne het drie style, drie oesjare en vyf produksiestreke ingesluit. Beskrywende sensoriese analise (BSA) en chemiese analises, wat GC-FID (gas chromatografie gekoppel met vlam-ioniserende deteksie) en FTMIR (Fourier-transformering mid-infrarooi) spektroskopie insluit, is uitgevoer om onderskeidelik die sensoriese en chemiese eienskappe van die wyne te bepaal. Verbruikerstoetse is ook uitgevoer om verbruikerspersepsie en -voorkeure vir bosstok Chenin blanc wyne te bepaal. BSA (‘n profilerings tegniek) was ook vergelyk met ‘n sorterings taak (‘n klassifikasie tegniek) met ‘n beskrywings opdrag, primêr om die sorterings taak se vermoë om wyne te profileer te ondersoek. Volgens die resultate van BSA, het die wyne in twee groepe verdeel. Een groep het met die sensoriese eienskappe wat op ‘n Vars-en-Vrugtige-styl dui, geassosieër. Die ander groep het met sensoriese eienskappe geassosieër wat met die Volrond-styl verband hou. Geen verdeling tussen die gehoute en ongehoute wyne binne die Volrond-styl was sigbaar nie. Volgens die resultate van die chemiese analises, het die wyne ook in twee groepe verdeel. Die verdeling blyk asof dit veroorsaak is deur oesjaar en die chemiese veranderinge wat met wynveroudering gepaard gaan. Wyne van die jongste oesjaar (2010) het ‘n sterk verband met hoë vlakke van esters en appelsuur getoon. Die ouer wyne was verder weg van hierdie eienskappe geleë, wat op laer ester en appelsuur konsentrasies dui. Wanneer die meerveranderlike resultate van die sorterings taak (met en sonder die aanduiding van sensoriese eienskappe) en dit van BSA vergelyk word, kon soortgelyke groeperings gesien word. Dit is ‘n aanduiding dat BSA ook wyne effektief kan kategoriseer. Die verskil in posisionering van sommige wyne tussen die BSA en sorterings taak resultate, kan toegeskryf word aan die verskillende panele wat gebruik is om die tegnieke uit te voer. ‘n Deskundige paneel (wynkenners) is gebruik om die sortingstaak uit te voer. Ervaring, blootstelling en tegniese kennis is geneig om te lei tot die vestiging van ‘n gemeenskaplike taal onder wynkenners. Hierdie gemeenskaplike taal kan as rede aangevoer word vir die uiteenlopende analise van sommige wyne wanneer die resultate van die deskundige paneel met dié van die opgeleide paneel (in BSA gebruik) vergelyk word. Dit is gevind dat BSA, wanneer ‘n omvattende sensoriese profiel bepaal moet word, die mees effektiefste metode bly. Verbruikerstoetse het getoon dat gereelde witwyn-verbruikers die ongehoute Chenin blanc style (Vars-en-Vrugtig en ongehoute Volrond) bo die gehoute styl verkies. Dit is ook bepaal dat verbruikers met ‘n hoër vlak van objektiewe wynkennis neig om die terme ‘bosstok’ en ‘ou bosstok’ met die Volrond-styl van Chenin blanc te assosieer, terwyl verbruikers met ‘n laer vlak van objektiewe wynkennis die term ‘ou bosstok’ met die Vars-en-Vrugtige Chenin blanc styl assosieër. Aangesien al die wyne wat in die verbruikerstoetse ingesluit is van ou bosstok wingerde geproduseer is, is dit duidelik dat verbruikeropvoeding insake die effek van die gebruik van bosstokke en ou wingerdstokke op wynkwaliteit noodsaaklik is. ‘n Beter begrip van hierdie beginsels sal lei tot verhoogde produkwaardasie, asook ‘n toename in verbruikertevredenheid.
Robbins, Lisa R. "The Effects of Hyperoxidation and Storage Temperatures on the Flavor Profile and Sensory Quality of Riesling Wine." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1511893070533362.
Повний текст джерелаWilson, Colin Frank. "Measurement of wind on the surface of Mars." Thesis, University of Oxford, 2003. http://ora.ox.ac.uk/objects/uuid:08343673-77de-4e46-a2fd-5c7c6e3be0e8.
Повний текст джерелаCheung, Chun Kau. "Small Wind Turbine Blade Sensor for Condition Based Maintenance." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/628.
Повний текст джерелаCorreia, Carlos André Silva Henriques Martins. "Efeitos da poda manual e mecânica e da aplicação de diferentes correctivos orgânicos ao solo na composição química e análise sensorial de uvas e vinhos da casta Syrah nas regiões do Tejo e de Lisboa." Master's thesis, ISA, 2014. http://hdl.handle.net/10400.5/6874.
Повний текст джерелаWith the aim of studying the mechanization of vine pruning while still maintaining plant vigor and fertility of the soil, this study has tested the use of different types of fertilization in mechanical and manual pruning, in two different estates. The vinification of the grapes took place in the cellar of the Instituto Superior de Agronomia where, after natural clarification and stabilization the wines were bottled and subsequently analyzed. The analyzes were made on each of the different samples and consisted in the following parameters: Alcohol, Total Dry Extract, Total Acidity, Total Polyphenols, Total Anthocyanins, Color Intensity, Color tone, as well as the levels of Iron, Potassium, Calcium and Copper. In terms of results, the wines showed very similar parameters with small changes in values, but when subjected to a statistical analysis the results revealed not statistically significant, with the exception of Color tone and Potassium, although with very close values as well. With regard to sensory analysis it was observed a consistency in terms of results with the chemical analyzes, and it was also not evident a standard differentiator between the samples, confirmed by the variance analysis performed.
Lund, Cynthia M. "Investigation of New Zealand Sauvignon Blanc Wine Using Trained Sensory Panels." Thesis, University of Auckland, 2009. http://hdl.handle.net/2292/5168.
Повний текст джерелаPrangova, Mimi. "Visualization of Sensory Perception Descriptions." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-9130.
Повний текст джерелаGalvez, Carrillo Manuel Ricardo. "Sensor fault diagnosis for wind-driven doubly-fed induction generators." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209982.
Повний текст джерелаThe present thesis deals with fault diagnosis in sensors of a doubly-fed induction generator (DFIG) for wind turbine (WT) applications. In particular we are interested in performing fault detection and isolation (FDI) of incipient faults affecting the measurements of the three-phase signals (currents and voltages) in a controlled DFIG. Although different authors have dealt with FDI for sensors in induction machines and in DFIGs, most of them rely on the machine model with
constant parameters. However, the parameter uncertainties due to changes in the operating conditions will produce degradation in the performance of such FDI systems.
In this work we propose a systematic methodology for the design of sensor FDI systems with the following characteristics: i) capable of detecting and isolating incipient additive (bias, drifts) and multiplicative (changes in the sensor
gain) faults, ii) robust against changes in the references/disturbances affecting the controlled DFIG as well as modelling/parametric uncertainties, iii) residual generation system based on a multi-observer strategy to enhance the isolation process, iv) decision system based on statistical-change detection algorithms to treat the entire residual and perform fault detection and isolation at once.
Three novel sensor FDI approaches are proposed. The first is a signal-based approach, that uses the model of the balanced three-phase signals (currents or voltages) for residual generation purposes. The second is a model-based approach
that accounts for variation in the parameters. Finally, a third approach that combines the benefits of both the signal- and the model-based approaches is proposed. The designed sensor FDI systems have been validated using measured voltages, as well as simulated data from a controlled DFIG and a speed-controlled induction
motor.
In addition, in this work we propose a discrete-time multiple input multiple output (MIMO) regulator for each power converter, namely for the rotor side converter (RSC) and for the grid side converter (GSC). In particular, for RSC
control, we propose a modified feedback linearization technique to obtain a linear time invariant (LTI) model dynamics for the compensated DFIG. The novelty of this approach is that the compensation does not depend on highly uncertain parameters such as the rotor resistance. For GSC control, a LTI model dynamics
is derived using the ideas behind feedback linearization. The obtained LTI model dynamics are used to design Linear Quadratic Gaussian (LQG) regulators. A single design is needed for all the possible operating conditions.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Cao, Siyang. "Flexible bond wire capacitive strain sensor for a vehicle tyre." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6619/.
Повний текст джерелаVendruscolo, Tiago Piovesan. "Sensor wire-mesh de impedância para investigação de escoamentos multifásicos." Universidade Tecnológica Federal do Paraná, 2012. http://repositorio.utfpr.edu.br/jspui/handle/1/329.
Повний текст джерелаEscoamentos multifásicos estão presentes em diversas atividades industriais como na exploração, produção e transporte de petróleo e gás, onde é comum encontrar escoando por dutos uma mistura de óleo, gás e água. Em muitos casos, o tipo de escoamento determina a eficiência e segurança dos processos e equipamentos onde ocorrem. Com isso, investigações experimentais de escoamento multifásicos são de grande importância no auxilio do desenvolvimento de modelos teóricos e na validação de predições realizadas por simulações, ampliando o entendimento do fenômeno. No passado algumas técnicas para investigação de escoamentos multifásicos foram propostas e aplicadas. Contudo, estas técnicas, na sua maioria, estão limitadas a investigação de escoamentos envolvendo apenas duas fases. Neste trabalho, foi proposta uma nova eletrônica para operar um sensor de malha de eletrodos (Wire-Mesh Sensor) que é capaz de investigar escoamentos contendo até três fases. Inicialmente proposto para visualização de escoamentos bifásicos, o sensor wire-mesh realiza o imageamento da distribuição de fases de uma seção transversal. Com a passagem do escoamento através do sensor, o mapeamento das fases é realizado de forma intrusiva com alta resolução temporal e espacial. Para possibilitar seu uso em escoamentos trifásicos, neste trabalho foi desenvolvida uma nova eletrônica capaz de medir simultaneamente a permissividade elétrica e a condutividade elétrica do fluido presente entre os eletrodos do sensor. O princípio básico do funcionamento é baseado na excitação com duas frequências distintas. Além do hardware foi também desenvolvido um software, onde é possível salvar os dados adquiridos em uma base de dados para futuros estudos. O desempenho da nova eletrônica foi verificado através de medições em componentes (rede RC) com valores de referência. O sistema completo foi utilizado para gerar imagens de uma mistura trifásica ar-óleo-água em condições estáticas e dinâmicas, apresentando bons resultados. Desta forma, a principal contribuição deste trabalho é a disponibilização de uma nova ferramenta para análise de escoamentos multifásicos.
Multiphase flows are present in many industrial activities such as in exploration, production and transportation of oil and gas, in which is common to find a mixture of oil, gas and water flowing inside pipes. In many cases this type of flow determines the efficiency and safety of the processes and equipment where they occur. In this way, experimental investigations of multiphase flow are of great value to develop new theoretical models and to validate predictions made by computer simulations, hence increasing the understanding of the flow phenomena. In this work, a new measuring electronics to operate a wire-mesh sensor (WMS) is introduced. Initially proposed for visualization of two-phase flow, the WMS performs the imaging of the phase distribution of a cross section based on the multiplexed measurement of an electrical property of the fluid in contact with the mesh grid of the sensor. With the passage of flow through the sensor, the phase mapping is realized by intrusive electrodes at high temporal and spatial resolution. To allow its use in multiphase flows, the new electronics developed in this work simultaneously measures the electrical permittivity and electrical conductivity of the media in the mesh grid. The basic idea is to activate the electrodes with a signal composed of two distinct frequencies. Besides the development of the electronics' hardware, a software was also implemented, by which data can be acquired and for future investigation. The performance of the new instrument has been verified by use of components (RC network) with reference values. The developed system was used to generate images of a multiphase mixture of air-oil-water in static and dynamic conditions, showing good results. Thus, the main contribution of this work is to make available a new tool for the investigation of multiphase flows.
Choubey, Bhaskar. "On wide dynamic range logarithmic CMOS image sensors." Thesis, University of Oxford, 2006. http://ora.ox.ac.uk/objects/uuid:f2d8ea6d-6b71-45bf-80dc-7dadb1421e3b.
Повний текст джерелаNajar, salwan. "Simulering av 1-Wire sensorer." Thesis, KTH, Skolan för teknik och hälsa (STH), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104086.
Повний текст джерелаMelvås, Patrik. "UltraminiaturizedPressure Sensor for Catheter Based Applications." Doctoral thesis, KTH, Signals, Sensors and Systems, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3373.
Повний текст джерелаCeciliani, Francesco. "Taster responses to acidity in white wines." Master's thesis, ISA-UL, 2017. http://hdl.handle.net/10400.5/13344.
Повний текст джерелаThe aim of this study was to evaluate the responses of a panel of tasters trained to acidity in white wines. The training of tastes and sensations of the mouth was performed in relation to the acidity, sweetness, bitterness and astringency. Next, the tasters were segmented according to vinotype, sensitivity to PROP (6-n-propylthiouracil) and saliva flow. This panel was used to determine the detection and recognition thresholds of tartaric, malic and lactic acids in white wine with 4.2 g / L of total acidity. The detection and recognition thresholds were 1.05 g/L and 1.32 g/L for tartaric acid, 0.85 g/L and 1.06 g/L for malic acid and 1.12 g/L and 1.30 g/L for lactic acid, respectively. These acids were added to an Arinto wine at concentrations 1.5 times higher than the recognition threshold, obtaining responses regarding the flavor effect considering intensity, persistence, salinity and appreciation. There were no differences (p<0.05) in relation to the first 3 parameters, while the appreciation was higher in relation to lactic and malic acids. The statistical treatment of the responses according to the segmentation revealed relationships (p<0.05) between saliva flow and sensitivity to PROP, and between saliva flow and the tartaric acid recognition threshold. The acidity appreciation was higher in men than in women. The results obtained can be used by the wine industry in the sense of adapting the white wines to the preference of the consumers, taking into account the recent trend towards the consumption of cold climate wines.
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Mayberry, Curtis Lee. "Interface circuits for readout and control of a micro-hemispherical resonating gyroscope." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53116.
Повний текст джерелаRomano, Mylena. "The influence of the organic label on the sensory profile and liking of wines. Is our perception and appreciation biased?" Master's thesis, ISA, 2019. http://hdl.handle.net/10400.5/19583.
Повний текст джерелаAiming to assess the influence of the organic mode of production on the acceptance and sensory profile of wines, consumers responded to a preliminary online survey to obtain information on willingness to pay and acceptance of unfamiliar flavours in organic wines. A knowledgeable and trained panel characterized several organic and conventional wines by free descriptive sensory analysis and provided their degree of liking, familiarity and willingness to pay (WTP). A total of 8 wines were tasted during 3 tasting sessions accompanied by 4 wines used as distractors. The information given to tasters was different in each session: (i) all wines were told to be conventional; (ii) all wines were told to be organic, and (iii) tasters were asked to guess the mode of production. The online survey showed the positive consumer opinion regarding organic wines for their environmental aspects reflected in higher WTP. Respondents were willing to accept flavour differences from conventional wines but leniency regarding any flaw was not supported. Tasters showed increasing liking scores and WTP in the organic labeled session. The liking scores grew 76.5% and the WTP, 98.7% when the tasters thought the wines were organic. The sensory profile of the wines varied according to the information, revealing an increased utilization of positive fruity and floral flavours. However, these observations were contradicted when tasters had to guess the production’s mode. Then, organic wines were linked to the eventual presence of negative flavours like animal and earthy while flawless wines were considered more likely to be conventional. Moreover, the emotional response “Unpleasant” was mostly used in the “guess” session and worked as a cue to define the mode of production. Finally, the organic label exerted a clear halo effect on wine appreciation, even when wines were evidently tainted and recognized as unpleasant by a knowledgeable tasting panel
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Schatz, Lauren H., R. Phillip Scott, Ryan S. Bronson, Lucas R. W. Sanchez, and Michael Hart. "Design of wide-field imaging shack Hartmann testbed." SPIE-INT SOC OPTICAL ENGINEERING, 2016. http://hdl.handle.net/10150/622718.
Повний текст джерелаHughson, Angus. "Cork and talk the cognitive and perceptual bases of wine expertise /." Connect to full text, 2003. http://hdl.handle.net/2123/490.
Повний текст джерелаTitle from title screen (viewed Apr. 24, 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Psychology, Faculty of Science. Includes bibliography. Also available in print form.
Pardal, Rafaela Alexandra Cerqueira. "Physicochemical and sensory analysis of Syrah wines from vineyards mechanically pruned treated with different organic amendments." Master's thesis, ISA/UL, 2015. http://hdl.handle.net/10400.5/10922.
Повний текст джерелаIn order to study the effect of mechanical pruning and the addition of organic amendments to the vineyard in Syrah wine quality, three vineyards from different viticultural areas were tested – Quinta do Côro (Tejo), Quinta do Gradil (Lisboa) and Herdade de Rio Frio (Setúbal). In order to evaluate the influence of the treatments applied the wines were subjected to a physicochemical analysis as well as chromatic characteristics determination, total nitrogen content, mineral and heavy metals and other elements analysis and the tasting panel performed sensory analysis to determine if the differences were perceived. The results show that mechanical pruning led to wines with lower alcohol content, color intensity, total anthocyanin content as well as less tannin power and inferior tannin content. This type of pruning technique also led to lesser accumulation of minerals and lower levels of some heavy metals. In the sensory analysis, the wines from mechanically pruned vines were less appreciated by the tasters receiving worse scores, including lower global appreciation marks. The organic amendment that led to lower overall results in the studied parameters was sewage sludge, it reduced alcoholic content and color intensity as well as total anthocyanin content while grime and the control plots led to better results
Wittmann, Philipp. "Measurement of the convective heat transfer with wind : Developing and testing an Earth Scaled Atmospheric Temperature Sensor." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-59864.
Повний текст джерелаMelvås, Patrik. "Ultraminiaturized Pressure Sensor for Catheter Based Applications." Doctoral thesis, KTH, Signaler, sensorer och system, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3373.
Повний текст джерелаDahal, Nischal. "STANDARDS-BASED SENSOR WEB FOR WIDE AREA MONITORING OF POWER SYSTEMS." MSSTATE, 2009. http://sun.library.msstate.edu/ETD-db/theses/available/etd-06292009-125550/.
Повний текст джерелаDias, Felipe de Assis. "Increasing image resolution for wire-mesh sensor based on statistical reconstruction." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2880.
Повний текст джерелаSensores wire-mesh (WMS) são capazes de gerar imagens da seção transversal de escoamentos multifásicos e tem sido amplamente utilizados para investigar fenômenos de escoamentos em plantas piloto. Tais dispositivos são capazes de medir parâmetros de escoamento tais como distribuição da fração de fase (por exemplo fração de gás ou líquido) e visualizar escoamentos multifásicos com alta resolução temporal e espacial. Sendo portanto, uma ferramenta importante para investigações de escoamentos mais detalhadas. No entanto, seu princípio de medição é baseado em eletrodos intrusivos posicionados dentro do tubo onde o escoamento flui. A resolução da imagem gerada pelo sensor é dada pelo número de cruzamentos entre os fios transmissores e receptores. Em muitos processos, no entanto, efeitos de intrusividade de tal sensor pode ser uma limitação no seu uso. Por isso, um número reduzido de fios poderia permitir uma expansão do campo de aplicações do sensor wire-mesh. Por essa razão, o presente trabalho sugere um método de reconstrução de imagem para aumentar a resolução dos dados de um sensor wire-mesh com um número de eletrodos menor que o ótimo. Desta forma, os efeitos de intrusividade no processo investigado poderiam ser reduzidos. O método de reconstrução é baseado em uma abordagem estatística de regularização e é conhecido como Maximum a Posteriori (MAP). Dados de escoamento de um WMS 16x16 são usados para determinar um modelo gaussiano multivariável do escoamento, o qual são empregados como regularização na reconstrução. Uma matriz de sensitividade é estimada pelo método de elementos finitos (FEM) para incorporar o algoritmo MAP. Dados experimentais são usados para validar o método proposto, sendo comparado com interpolação do tipo spline. Resultados experimentais mostram que a reconstrução por MAP possui um desempenho melhor do que interpolação do tipo spline, alcançando desvios de fração de vazio dentro de uma faixa de ± 10% na grande maioria dos pontos de operação. A validação foi executada em um loop de escoamento horizontal água/gás em regime intermitente (golfada).
Wire-mesh sensors (WMS) are able to generate cross-sectional images of multiphase flow and have been widely used to investigate flow phenomena in pilot plant studies. Such devices are able to measure flow parameters such as phase fraction (e.g. gas/liquid fraction) distribution and visualize multiphase flows with high temporal and spatial resolution. Hence, being important tool for detailed flow investigation. However, its sensing principle is based on intrusive electrodes placed inside the pipe where a multiphase flow streams. The image resolution generated by the sensor is given by the number of crossing points formed by the transmitter and receptor wires. In many processes, however, the intrusive effect of such sensor might be a limitation on its use. Therefore, a reduced number of wires could possibly increase the application field of wire-mesh sensors. For this reason, the present work presents an image reconstruction method to increase resolution of WMS data with less than optimal number of electrode wires. In this way, a reduction of intrusive effects on the process under investigation may be achieved. The reconstruction method is based on statistical view of regularization and is known as Maximum a Posterior (MAP). 16x16 WMS flow data are used to determine a Multivariate Gaussian flow model, which in turn is used as regularization in the reconstruction. A sensitive matrix is estimated by finite element method (FEM) to incorporate MAP algorithm. Experimental data are used to validate the proposed method, which is compared with spline interpolation. Experimental results show that the MAP reconstruction performs better than interpolation and achieves deviation in gas void fraction estimation in the range of ±10% in the vast majority of operating points. The tests were performed in a horizontal water-gas flow loop operating at intermittent (slug) flow regime.
Feng, Chao. "GREY-MODEL BASED ICE PREDICTION SENSOR SYSTEM ON WIND TURBINE SYSTEM." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1323893527.
Повний текст джерелаKrämer, Sebastian Gerhard Maxim. "Ferrimagnetic fiber optic sensor system for lightning detection on wind turbines." Aachen Shaker, 2008. http://d-nb.info/991820983/04.
Повний текст джерелаSuzuki, Takeharu, and n/a. "Integrated, Intelligent Sensor Fabrication Strategies for Environmental Monitoring." Griffith University. School of Microelectronic Engineering, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040813.131206.
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