Dissertations / Theses on the topic 'Cold storage'

Diss. (sammanfattning) Stockholm : Stockholms universitet, 2010.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Härtill 4 uppsatser.

This thesis concerns cold energy storage (CES) technology. Such a technology produces cold energy by consuming electricity in a refrigerator and stores cold energy in an eutectic phase change material (PCM) in a temperature range of (TPCM is the PCM storage temperature and Ta is the environmental temperature), resulting in a cold exergy efficiency less than 100%. The stored cold energy can be either directly extracted by a cold discharge process or utilized through a Rankine cycle at peak hours for electricity generation. The aim of the research is to study fundamental aspects and address the scientific and technological challenges associated with the CES technology. Methods for storing high grade, high energy density and temperature-adaptive cold energy are to be developed. Another objective is to develop innovative solutions for enhancing charge/ discharge processes. Particular attention is paid to the use of a prototype CO2 based CES system to investigate the feasibility of CES technology for small scale systems. In this work, a criteria for PCM selection for high grade and high energy density cold storage is established. For enhancing charging/ discharging rate of a PCM device, metal foams are embedded in PCM to form a PCM composite. Parametric study on the CES system is done based on a CO2 Rankine cycle for achieving an optimal cold storage efficiency. Investigations have been carried out on the performance of a small scale CES system. These include CES with an open and a close Rankine cycle and a piston based engine for cold to power conversion in the cycle. A method for improving grade of stored cold energy is using eutectic salt-water solutions for forming a binary/ ternary cold storage system, by which the eutectic temperature is lowered. PCMs with lower freezing temperature and smaller molecular weight are selected as components in the binary/ ternary system. However, due to the potential issue of compatibility of PCM molecular structures, it is critical to select PCMs which have comparable melting temperatures and compatible molecular structures. PCM composite is formed by embedding metal foams in PCM solutions. Cold discharging rate, defined as the power transfer of cold energy per unit time during the discharge process, is greatly affected by thermal diffusivity and thermal conductivity of the PCM composite. Combined effect of cold radiation and convection is to be considered for assessing the value of cold discharging rate, which becomes more significant for large PCM capsules under low PCM temperatures and low Reynolds number (Re). Cold utilisation in a CES system using Rankine cycles is theoretically studied. Storage efficiency of the CES system is a round trip efficiency of electricity, which is defined as ratio of output electricity to the input electricity. A storage efficiency as high as 43.9% has been shown to be possible for the CES system. However, the storage efficiency is generally between 30%~40% in consideration of the actual efficiencies of cryogen pump, regenerator, engine and refrigerator. Piston based engines with a new valve scheme is experimentally investigated. Compared with small engine, large engine system has apparently larger capacity for power generation, but the engine efficiency is reduced due to the block of the exhaust gas in the chamber. In the presented case study, the efficiency of the large engine is 38.5% while the storage efficiency of the CES system is approximately 22.0%. In the point view of net electricity output for peak-shifting, CES is a feasible technology that need to be further developed. In brief, the work of the CES research are summarized as follows: • Improvement of cold charging/ discharging rate by embedding open-cell metal foams in PCM; • Assessment of cold discharging rate by considering the combined effect of cold radiation and convection; • Optimization of cold storage efficiency by developing computer program based on sub-critical CO2 properties; • Cold to power conversion by using a piston based engine coupled with a new valve scheme.

Thesis (MScAgric)--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: Quality of certain Leucospermum and Leucadendron cultivars after approximately 21 days shipping has been reported to be substandard due to ‘drying out’ of leaves and, in the case of Leucadendrons, involucral leaves. The nature of the symptoms of this ‘drying out’ and the conditions under which they form, viz. long exposures to low temperatures, has led us to hypothesize that these are symptoms of chilling injury (CI). Chilling injury, as far as we are aware, has not been documented on Leucospermums or Leucadendrons. Typical CI symptomology is discussed and shown for Leucospermum ‘Gold Dust’, ‘High Gold’ and ‘Succession’ and for Leucadendron ‘Chameleon’, ‘Laurel Yellow’ and ‘Safari Sunset’. The nature of CI symptoms for Leucospermums and Leucadendrons was generally membranous breakdown that manifested in some cases as a ‘water soaked’ appearance which, at a more advanced stage, was generally visible as ‘dried out’ patches on the leaves. In the case of the Leucadendrons CI was also visible on the immature involucral leaves which are more sensitive to chilling conditions than mature leaves. Dark discoloration of especially immature involucral leaves is also a symptom of CI. As water uptake of shoots with chilling injury is hindered the styles of the Leucospermums wilt. As can be expected, the lower the temperature below the threshold temperature and the longer the exposure the more severe the symptoms. CI was recorded on cut flower shoots of Leucospermum ‘Gold Dust’, ‘High Gold’, ‘Rigoletto’, ‘Succession’ and ‘Vlam’ after 21 and 24 days storage at 1ºC. After 24 days storage the chilling injury was more severe than after 21 days storage in most cases. Each cultivar was pulsed with 5 ml per stem of a 2% (w/v) sugar solution of either lactulose, sucrose, glucose, fructose or mannose before storage. After storage, CI was recorded on day 0, 3, 7 and 10 of the vase phase. Of the cultivars tested ‘Vlam’ and especially ‘Rigoletto’ were more prone to chilling injury development. ‘High Gold’ and ‘Vlam’ shoots were pulsed with 0 (control), 1.5, 3 or 4% (w/v) solutions of either mannose or fructose. The best control of CI for both cultivars was achieved with 1.5% (w/v) solution. Lower concentrations of mannose and fructose were tested on ‘High Gold’ shoots, with a 1% (w/v) solution giving the best control for both. At high concentrations signs of toxicity became evident directly after pulsing. ‘High Gold’ shoots were pulsed with 1% (w/v) solutions of mannose and fructose and sugar analyses were performed on shoots at different stages of storage and after 10 days in the vase. A slight increase in mannose and fructose was detectable in the stems of the shoots directly after pulsing but not in the leaves or the inflorescences. This is due to the low concentrations being used. The levels of all the carbohydrates decreased during the 21 days storage and more so during the vase phase of the flowering shoots. The fact that such low concentrations were effective in controlling chilling injury suggests that the sugars may have an effect other than on the osmotic potential. Cut ‘flower’ shoots of Leucadendron ‘Chameleon’, ‘Laurel Yellow’ and ‘Safari Sunset’ were stored for 14, 21 and 28 days, at 1º, 3º and 5ºC and CI development recorded during the subsequent 10 day vase phase. ‘Laurel Yellow’ and ‘Safari Sunset’ showed signs of chilling injury on the leaves after 28 days storage at 3ºC or lower and ‘Safari Sunset’ stored for 21 days developed chilling injury during the vase phase. Immature involucral leaves were more sensitive to chilling injury than leaves. CI increased with longer exposure times and lower storage temperatures for all three cultivars evaluated. ‘Chameleon’ was the most chilling tolerant of the cultivars up to 21 days. At 5ºC chilling injury was low irrespective of cold storage duration but longer exposures to 1º and 3ºC resulted in increased chilling injury development during the vase phase. All three cultivars were pulsed with 5 ml per stem of a 1% (w/v) solution of lactulose, sucrose, glucose, fructose or mannose and stored for 14, 21 and 28 days at 1ºC. The sugars reduced chilling injury on the leaves for ‘Safari Sunset’ when stored for 28 days and, to a lesser extent, in ‘Chameleon’. The sugars failed to reduce chilling injury of the involucral leaves of ‘Chameleon’ and ‘Laurel Yellow’ whereas there was some control especially after 28 days for ‘Safari Sunset’. In some cases the sugar pulse exacerbated chilling injury. Chilling injury generally increased rapidly after storage during the first three days in the vase and then at a lower rate for the next seven days. Leucadendron ‘Chameleon’, ‘Laurel Yellow’ and ‘Safari Sunset’ ‘cut flower’ shoots were pulsed with a 1% (w/v) glucose solution. Expressed on a dry weight basis, an increase in glucose concentration was not detected. The reduction in chilling injury of leaves by a sugar pulse is speculated, as for the Leucospermums, to be as a result of their presence in the apoplast and not the symplast and that their presence there protects the membranes against chilling conditions in some way.
AFRIKAANSE OPSOMMING: Die kwaliteit van sekere Leucospermum en Leucadendron kultivars na ongeveer 21 dae verskeping is waargeneem as substandaard as gevolg van die uitdroog van blare en, in die geval van Leucadendrons, die ‘involucral’ blare. Die aard van die simptome van hierdie uitdroging en die toestande waaronder dit plaasvind nl. lang periodes van blootstelling aan lae temperature, het ons tot die hipotese gebring dat hierdie simptome van koueskade is. Sover as wat ons bewus is, is koueskade nog nie gedokumenteer op Leucospermums of Leucadendrons nie. Tipiese koueskade simptomologie word bespreek en gewys vir Leucospermum ‘Gold Dust’, ‘High Gold’ en ‘Succession’ en vir Leucadendron ‘Chameleon’, ‘Laurel Yellow’ en ‘Safari Sunset’. Die koueskade simptome vir Leucospermums en Leucadendrons was oor die algemeen membraan afbraak wat ‘n water deurdrenkte voorkoms tot gevolg gehad het wat in ‘n meer gevorderde stadium sigbaar was as uitgedroogde kolle op die blare. In die geval van Leucadendrons was koueskade ook sigbaar op die onvolwasse ‘involucral’ blare wat meer sensitief is vir koue toestande as volwasse blare. Donker verkleuring van veral onvolwasse ‘involucral’ blare is ook ‘n simptoom van koueskade. Aangesien wateropname van stele met koueskade verhinder word, verwelk die ‘styles’ van die Leucospermums. Soos verwag kan word hoe laer die temperature onder die drempel temperatuur en hoe langer die blootstelling, hoe meer ernstig die simptome. Koueskade is aangeteken op gesnyde blomstele van Leucospermum ‘Gold Dust’, ‘High Gold’, ‘Rigoletto’, ‘Succession’ en ‘Vlam’ na 21 en 24 dae opberging by 1°C. Na 24 dae opberging was die koueskade meer ernstig as na 21 dae opberging in meeste gevalle. Elke kultivar het 5ml per steel van ‘n 2% (g/v) suiker oplossing van laktolose, sucrose, glucose, fruktose of mannose voor opberging opgeneem. Na opberging is koueskade aangeteken op dag 0, 3, 7 en 10. Van die kultivars wat getoets is, was ‘Vlam’ en veral ‘Rigoletto’ meer geneig tot koueskade ontwikkeling. ‘High Gold’ en ‘Vlam’ stele is geplaas in oplossings van 0 (kontrole), 1.5, 3 of 4 % (g/v) oplossings van mannose of fruktose. Die beste beheer van koueskade vir beide kultivars is deur die 1.5 (g/v) oplossing behaal. Laer konsentrasies van mannose en fruktose is getoets op ‘High Gold’ stele met ‘n 1% (g/v) mannose oplossing wat die beste beheer gegee het. Met hoë konsentrasies het tekens van toksisiteit sigbaar geword direk na opneem van die oplossing. ‘High Gold’ stele is geplaas in 1% (g/v) oplossings van mannose of fruktose en suiker analises is uitgevoer op stele by verskillende stadiums van opberging en na 10 dae in die vaas. ‘n Effense toename in mannose en fruktose is waargeneem in die stele van die blomme direk na opname van die oplossing, maar nie in die blare of die blomme nie. Dit is as gevolg van die lae konsentrasies wat gebruik is. Die vlakke van al die koolhidrate het afgeneem gedurende die 21 dae opberging en nog meer so gedurende die vaas periode van die blommende stele. Die feit dat sulke lae konsentrasies effektief is in die beheer van koueskade dui daarop dat die suikers ‘n effek het anders as op die osmotiese potensiaal. Snyblomme van Leucadendron ‘Chameleon’, ‘Laurel Yellow’ en ‘Safari Sunset’ is opgeberg vir 14, 21 en 28 dae, by 1º, 3º en 5°C en koueskade ontwikkeling is aangeteken gedurende die opvolgende 10 dae vaas periode. ‘Laurel Yellow’ en ‘Safari Sunset’ het tekens gewys van koueskade op die blare na 28 dae opberging by 3°C of laer en ‘Safari Sunset’ opgeberg vir 21 dae het koueskade ontwikkel gedurende die vaas periode. Onvolwasse ‘involucral’ blare was meer sensitief vir koueskade as die blare. Koueskade het toegeneem met langer blootstellingstye en laer opbergins temperature vir al drie kultivars geëvalueer. ‘Chameleon’ was die mees koueverdraagsaam van die drie kultivars tot op 21 dae. By 5°C was laag ongeag van die koue opberging tydperk, maar langer blootstellings aan 1º en 3°C het gelei tot toename in koueskade ontwikkeling gedurende die vaas periode. Al drie kultivars is voorsien met 5ml per steel van ‘n 1% (g/v) oplossing van lactulose, sucrose, glucose, fruktose of mannose en opgeberg vir 14, 21 en 28 dae by 1°C. Die suikers het koueskade verminder op die blare van ‘Safari Sunset’ wanneer opgeberg vir 28 dae en, tot ‘n mindere mate, in ‘Chameleon’. Die suikers het egter nie koueskade verminder van die ‘involucral’ blare van ‘Chameleon’ en ‘Laurel Yellow’ nie, waar daar egter wel in ‘n mate beheer was veral na 28 dae vir ‘Safari Sunset’. In sommige gevalle het die voorsiening van suiker die koueskade vererger. Koueskade het oor die algemeen vinnig toegeneem na opberging gedurende die eerste drie dae in die vaas en dan teen ‘n laer tempo vir die volgende sewe dae. Leucadendron ‘Chameleon’, ‘Laurel Yellow’ en ‘Safari Sunset’ snyblom stele is voorsien van ‘n 1% (g/v) glukose oplossing. Uitgedruk op ‘n droëmassa basis is ‘n toename in glukose konsentrasie nie waargeneem nie. Die afname in koueskade van blare deur die voorsiening van ‘n suiker oplossing is gespekuleer vir die Leucospermums, om ‘n resultaat te wees van hulle teenwoordigheid in die apoplas en nie die simplas nie, en dat die teenwoordigheid daar die membrane op ‘n manier beskerm teen koue toestande.

This master thesis contributes to the design of a stratified cold-water storage. The objective is to provide a second opinion on the design of the water distributors and charging/ discharging parameters, by means of numerical simulations. The first chapter is an introduction to district cooling, it provides some concepts essentials to the understanding of this project and details the challenges associated with the particular case of a stratified cold-water storage. The second chapter focuses on fluid dynamics considerations. The third chapter reminds the fundamentals of perforated distributors theory, derives formula for pressure evolutions in the distributor and a design criterion. The fourth and fifth chapters give the results of the numerical simulations. For the distributor’s design, the theory has been tested by numerical methods which gave coherent results. A design has been determined. Regarding thermocline formation, we observed that injection water at 14C led to a thermocline of 2.5 m. All other things remaining equal, using the district heating network to inject water at 25C leads to a thermocline of 1 m. When it comes to thermocline evolution, the results brought out the limited influence of either the number of pipes or the flow rates characteristics on the thickness evolution.
Den här masteruppsatsen bidrar till designen av ett stratifierat kyllager. Syftet är att, med hjälp av numeriska simulationer, tillhandahålla en annan åsikt om designen av vattenfördelningen och laddning/urladdningsparametrar. Det första kapitlet är en introduktion till fjärrkyla, där några koncept som är essentiella för förståelsen av det här projektet redovisas och på ett detaljerat tillvägagöngssätt studerar utmaningarna associerade med det särskilda fallet av ett stratifierat kyllager. Det andra kapitlet fokuserar på fluiddynamiska teorier. Det tredje kapitlet erinrar om grundprinciperna av perforerad rörteori som erhåller formler för tryckevolution i fördelaren samt ett designkriterium. Det fjärde kapitlet visar resultaten av de numeriska simulationerna. För designen på fördelaren har teorin blivit testad av numeriska metoder som givit sammanhängande resultat. En design har blivit fastställd. Angående termoklinbildningen observerades att vatten som injicerats vid 14C ledde till en termoklin på 2.5 m. Utan att ändra de andra parametrarna blir resultatet en termoklin på 1 m när vatten injicerats vid 25C med hjälp av ett fjärrvärmenät. När det gäller termoklinevolutionen har resultaten konstaterat den limiterade influensen av antalet rör eller flödeshastighetens karaktär på tjockleksevolutionen.

Jojoba stem tip cuttings were stored under refrigerated conditions of 34° and 42°F for up to 2 months with no loss in rooting potential. Rooting percent for cuttings of two clones which were rooted with no prior storage was 64.8%. Rooting after 7, 14, 28 and 56 days of storage was 81.7, 72.9, 71.7 and 81.2 %, respectively.

An evaluation of the use of short-term cold storage of tomatoes to tide over the cyclical market glut of horticultural products was conducted in Coimbatore, Tamil Nadu, India. Farmers stored their harvest at a rental commercial cold-storage facility in the city and at an experimental cold store at the Tamil Nadu Agricultural University in Coimbatore. The goal was to study the storage characteristics of the produce as well as to assess the economic benefits of adopting such an intervention. The temperature and relative humidity conditions at both locations and the fate of the produce were monitored. The proportion of marketable produce diminished significantly as the storage period increased, with major losses occurring due to microbial damage. Differences in the air conditions at the locations did not have a significant effect on the storage-related losses of produce. Economic analysis showed that short-term cold storage would not aid farmers unless measures were taken to reduce the microbiological losses during postharvest handling.
Une évaluation d'entreposage de tomates à court terme a été effectuée à Coimbatore, dans l'état du Tamil Nadu en Inde, dans le but d'aider les fermiers à pallier la saturation cyclique du marché des fruits et légumes frais. Des fermiers ont entreposé leur récolte de tomates dans un entrepôt frigorifique commercial situé dans la ville, ainsi que dans un entrepôt frigorifique expérimental situé dans le Tamil Nadu Agricultural University dans la même ville indienne. Le but de l'expérience était d'étudier les caractéristiques d'entreposage du produit, ainsi que d'évaluer les bénéfices économiques liés à l'adoption d'une telle intervention. La température, l'humidité relative et le sort des produits horticoles ont été surveillés. Avec l'augmentation des temps d'entreposage, la proportion des fruits frais ayant une valeur marchande a baissé considérablement; la plupart des pertes était due à des infections microbiennes. Les différences dans les conditions ambiantes des deux entrepôts n'ont pas eu d'effet considérable sur les pertes de fruits frais dues à l'entreposage. Une analyse économique a démontré que l'entreposage à court terme n'aidera pas les fermiers à moins que des mesures supplémentaires soient adoptées afin de réduire les pertes microbiennes durant les manipulations post-récoltes.

Thesis (Ph.D.) -- University of Western Sydney, Hawkesbury, 1998.
Thesis submitted for the degree of doctor of philosophy. Reprints of related publications by N. Abdi, P. Holford and W.B. McGlasson included in back. Includes bibliographical references (leaves 129-152).

Devices that exploit the properties of quantum mechanics for their operation can offer unique advantages over their classical counterparts. Interference of matter waves can be used to dramatically increase the rotational sensitivity of gyroscopes. Complete control of the quantum evolution of a system could produce a new powerful computational device known as a quantum computer. Research into these technologies offers a deeper understanding of quantum mechanics as well as exciting new insights into many other areas of science. Currently, a limiting factor in many quantum devices using neutral atoms is accurate motional control over the atoms. This thesis describes two recent advancements in neutral atom motional control using both magnetic and electromagnetic confining fields. Part I reports on the demonstration of the first storage ring for neutral atoms. This storage ring may one day provide the basis for the world's most sensitive gyroscope. Part II describes the optical delivery of neutral atoms into the mode of a high-finesse cavity for applications in quantum computing and communication.

L’objectiu d’aquesta tesis doctoral és el desenvolupament d’un sistema d’emmagatzematge d’energia tèrmica (TES) mitjançant la utilització de materials de canvi de fase (PCM) per aplicacions a baixa temperatura, en particular, per a congeladors comercials. Es provarà tant experimental com numèricament la millora de les condicions de l’emmagatzematge i també la millora de la qualitat dels aliments emmagatzemats/transportats. També inclou la investigació de nous PCMs, estudiant la modificació de la temperatura de canvi de fase i analitzant velocitats de degradació i corrosió amb els materials recipients. Els resultats obtinguts a les diferents aplicacions estudiades demostren el clarament el benefici de la utilització de PCM, reduint les fluctuacions i les caigudes de temperatura tant al interior dels sistemes com del producte, i per tant millorant la qualitat d’aquests.
El objetivo de esta tesis doctoral es el desarrollo de un sistema de almacenamiento de energía térmica (TES) mediante la utilización de materiales de cambio de fase (PCM) para aplicaciones a baja temperatura, en particular, para los congeladores comerciales. Se probará experimental y numéricamente la mejora de las condiciones de almacenamiento, y también la mejora de la calidad de los alimentos almacenados/transportados. También incluye la investigación de nuevos PCM, estudiando la modificación de la temperatura de cambio de fase y analizando velocidades de degradación y corrosión con los materiales contenedores. Los resultados obtenidos en las diferentes aplicaciones demuestran el beneficio de usar PCM, reduciendo las fluctuaciones y las caídas de temperatura tanto del interior de los sistemas como del producto almacenado y por tanto la mejoría de la calidad de éstos.
The aim of this PhD thesis is to develop a thermal energy storage (TES) system using phase change materials (PCM) for cold temperature applications in particular for commercial freezers testing experimentally and numerically the improvement of its thermal performance and the food quality stored. This thesis also includes the research on PCM with attractive properties for low temperature applications such as controllable phase change temperature and low corrosion and degradation rate. The results obtained in the proposed applications have proved the benefit of using PCM in the proposed cold applications based on reduction of the interior/product temperature fluctuations and

Dissertação de Mestrado Integrado em Medicina Veterinária
Semen refrigeration is usually recommended as a cheap and simple procedure that facilitates artificial reproduction techniques. The main objective of this experiment was to develop a semen refrigeration protocol for meagre that is considered a potential candidate for aquaculture diversification in Southern Europe. This thesis also contributes for the understanding of the causes of the fish sperm quality degradation during refrigeration. Three extenders (non-activating medium (Fauvel et al., 1998); NaCl 0.9% and; NaCl 0.9% with glycine and glucose) and three different dilutions (1:4, 1:9 and 1:19, sperm:extender) were tested in a full factorial design. The following quality parameters were assessed along the storage time: sperm motility parameters; percentage of viable sperm; adenosine triphosphate (ATP); lipid peroxidation in the form of malondialdehyde (MDA); and bacteriology. The 0.9% NaCl and the 0.9% NaCl with glycine and glucose extenders and the dilutions 1:4 and 1:9 kept a higher percentage of motile cells for longer, as well as higher sperm velocity. Sperm viability and ATP had better results with 0.9% NaCl and the 0.9% NaCl with glycine and glucose extenders. The MDA values were lower in treatments with dilution 1:4 when compared to those with dilution 1:9. In the CFU/ml values, no differences were found between extenders and dilutions. Motility parameters were strongly correlated with viability, whereas no or weak correlations existed with the remaining parameters. Thus, motility and viability seem to have the most impact in the loss of semen quality. According to the results, meagre semen could be kept refrigerated using 0.9% NaCl, in dilution 1:4, for up to 10 days.
RESUMO - AVALIAÇÃO DE DIFERENTES DILUIDORES PARA A REFRIGERAÇÃO DE SÉMEN DE CORVINA (ARGYROSOMUS REGIUS) - A refrigeração de sémen é tipicamente recomendada como um procedimento barato e simples que facilita as técnicas de reprodução artificial. O principal objectivo desta experiência foi desenvolver um protocolo de refrigeração de sémen para a corvina, que é considerada uma potencial candidata para a diversificação de aquacultura no sul da Europa. Esta tese contribui também para a compreensão das causas da degradação da qualidade de sémen de peixe durante a refrigeração. Três diluidores (non-activating medium (Fauvel et al., 1998); NaCl 0,9%; e NaCl 0,9% com glicina e glucose) em três diferentes diluições (1:4, 1:9 e 1:19, sémen:diluidor) foram testados num plano factorial completo. Os seguintes parâmetros de qualidade espermática foram avaliados ao longo do tempo de armazenamento: parâmetros de mobilidade do sémen; percentagem de espermatozoides viáveis; adenosina trifosfato (ATP); peroxidação lipídica na forma de malondialdeído (MDA); e bacteriologia. Os diluidores NaCl 0,9% e NaCl 0,9% com glicina e glucose e as diluições 1:4 e 1:9 mantiveram uma percentagem de células móveis mais elevada por mais tempo, bem como maior velocidade dos espermatozóides. A viabilidade e o ATP tiveram melhores resultados com NaCl 0,9% e NaCl 0,9% com glicina e glucose. Os valores de MDA foram mais baixos em tratamentos com as diluições 1:4, quando comparados com aqueles com as diluições 1:9. Nos valores de bacteriologia não foram encontradas diferenças entre diluidores e diluições testadas. Os parâmetros de mobilidade correlacionaram-se fortemente com a viabilidade, enquanto inexistentes ou fracas correlações foram encontradas entre os restantes parâmetros. Por conseguinte, mobilidade e viabilidade parecem ter o maior impacto na perda de qualidade do sémen. De acordo com os resultados, o sémen de corvina pode ser mantido refrigerado usando o diluidor NaCl 0,9% na diluição 1:4 até 10 dias.
N/A

Plants inherently produce polyphenols (i.e., antioxidants) as a response to reduce oxidative stress caused by abusive environmental pre- and postharvest conditions. These antioxidants, as well as vitamin C, are present in considerable levels in strawberries; however, excessive oxidative stress brought on by improper postharvest handling conditions can reduce the levels of antioxidants in the fruit and shorten the shelf-life of strawberries. Nevertheless, it may be possible to utilize strawberry’s naturally occurring polyphenols to reduce postharvest stress and extend their shelf life. The polyphenolic profile has been previously investigated in several strawberry cultivars, however no studies have determined the unique polyphenolic profiles of three important Florida strawberry cultivars (‘Florida Radiance’, Sweet Sensation® ‘Florida 127’and ‘Florida Beauty’) at harvest and during cold storage. Therefore, in order to better understand the distribution of individual polyphenols within these cultivars and their impact on postharvest shelf-life, this study examined the polyphenolic profiles throughout 7 days of cold storage (1 °C) using an HPLC-DAD. The activity of phenylalanine ammonia lyase (PAL), a key enzyme in the biosynthesis of polyphenols, and polyphenol oxidase (PPO), the enzyme responsible for polyphenol degradation, were also examined during cold storage to understand their possible influences on postharvest synthesis or degradation of polyphenols. This study revealed that the polyphenolic profile of strawberry fruit was genotype dependent; however, pelargonidin 3-glucoside was consistently the anthocyanin found in higher concentrations in the fruit regardless of the cultivar. Apart from the anthocyanins, the flavonols showed the most variation among the three cultivars. PAL was slightly induced during strawberry postharvest storage suggesting that a stress response occurred during cold storage while PPO showed variable induction patterns across all three cultivars most likely due to their different polyphenol profiles. Analysis of the distribution of polyphenols in the cortex and pith of strawberries showed that polyphenols were mostly concentrated in the cortex of the fruit and that the concentration of individual polyphenol in each fruit tissue varied by cultivar. These results indicate that the oxidative stress response varies in each of the strawberry cultivars studied contributing to their unique polyphenolic profile. Results from this study can ultimately help to identify the polyphenols and enzymes related to superior postharvest quality in future studies.

The primary objective of the research was to study the physiological and biochemical changes in Hass avocado fruit stored in different combination of oxygen and carbon dioxide concentrations at both 0 degrees and 5 degrees Centigrade (C), and to determine whether storage in controlled atmosphere (CA) can decrease the incidence of chilling injury (CI). A secondary objective was to identify possible correlations between CA, the incidence of CI, the activity of some ripening related enzymes and changes in proteins during ripening at 20 degrees C following storage at low temperatures. Fruit suffered no CI and ripened normally following CA storage for 3 weeks at both 0 degrees and 5 degrees C, then transferred to air for 6 days at 20 degrees C. CI symptoms did develop after CA storage for 6 and 9 weeks at 0 degrees C. Changes in proteins during ripening were analysed by 2D-PAGE. Some polypeptides were detected in unripe fruit but decreased with ripening. Polypeptides of 16.5, 25, 36 and 56 kD (kilo Dalton) were present early in ripening and their levels further increased during ripening. The appearance of three ripening related polypeptides with estimated molecular weights 80 kD (pI 3.6), 36 kD (pI 5.8) and 16.5 kD (pI 5.7) was observed in fruit at the climacteric stage. Three polypeptides with estimated molecular weights of 41 kD (pI7.8), 36 kD (pI 5.8) and 33 kD (pI 5.1) were found in air stored fruit but were not detected in fruit stored in CA. This research showed that CA did not ameliorate CI at 0 degrees C, instead storage at 0 degrees C caused a premature increase in ethylene production when the fruit were returned to air at 20 degrees C. In contrast, CA storage at 5 degrees C retarded ethylene production and ripening in fruit after it was returned to air at 20 degrees C.

L’incremento del consumo energetico legato ad un forte aumento della domanda energetica mondiale, rappresenta la principale causa delle attuali problematiche ambientali legate al riscaldamento globale, come l’effetto serra e il cambiamento climatico. Le nuove politiche del settore energetico mirano ad una radicale decarbonizzazione della rete che ha notevolmente ridotto la produzione energia prodotta da fonti fossili, incrementando la penetrazione delle fonti rinnovabili. Il maggiore svantaggio di queste ultime è legato alla loro intermittenza e alla loro imprevedibilità. I nuovi obiettivi del settore energetico, sono quindi focalizzati nel risolvere le problematiche legate alle fonti rinnovabili e l’ottimizzazione del bilancio tra potenza prodotta e la domanda energetica. L’integrazione di sistemi di accumulo (energy storage) risulta quindi fondamentale per garantire la flessibilità del sistema energetico. Infatti questi ultimi hanno la capacità di accumulare la potenza elettrica per essere utilizzata in un tempo successivo. Le grandi quantità di energia termica a temperatura criogenica dissipate nell’ambiente durante la rigassificazione del GNL (gas naturale liquefatto) e i grandi volumi di azoto liquido prodotto non utilizzato, hanno suggerito lo studio dei liquidi criogenici come vettori energetici alternativi che possono utilizzati sia essere mezzi di stoccaggio, ma anche applicati nel settore dei trasporti definendo una "liquid air economy". In questo contesto i sistemi LAES (Liquid Air Energy Storage) rappresentano un sistema di accumulo basato sul concetto che l’aria ambiente può essere liquefatta a -196°C riducendo il suo volume specifico di circa 700 volte, ed essere stoccata in serbatoi a bassa pressione. L’aria liquida può essere quindi utilizzata nuovamente, per produrre potenza elettrica mediante un espansore. Alcune idee per utilizzare l’aria liquida come mezzo di stoccaggio sono state proposte nel 1977 e nei primi anni 2000, ma senza ulteriori sviluppi. Nel 2005 University of Leeds e Highview Power hanno brevettato un sistema LAES con un ciclo di liquefazione basato su un ciclo Linde-Hampson. Il progetto di ricerca ha portato allo sviluppo e alla realizzazione di un impianto pilota LAES con una potenza di 300 kW e una capacità di stoccaggio di 2.5 MWh. L’impianto, commissionato ad Aprile 2010, è stato inizialmente integrato con un impianto a biomasse di 80MW locato allo Slough Heat and Power di Greater London e successivamente rilocato a University of Birmingham. Negli ultimi anni, grazie alla realizzazione del primo impianto pilota e alla dimostrazione potenziale dei liquidi criogenici come vettori energetici, il LAES è diventato oggetto di interesse di molti ricercatori grazie ai diversi vantaggi che la tecnologia offre, come la durata dell’impianto e l’assenza di vincoli ambientali. Inoltre il LAES può essere facilmente scalabile, grazie alla consolidata tecnologia basata su componenti già utilizzati in ambito criogenico. Il maggiore svantaggio, che compromette la fattibilità dei sistemi LAES, è la bassa efficienza che può essere stimata del 50-60 % per sistemi di larga scala. La maggior parte dell’interesse in letteratura è dedicato a sistemi di scala industriale con un ciclo di liquefazione basato su una produzione giornaliera di aria liquida maggiore di 300 tonnellate. Questi sistemi sono studiati per competere con i sistemi di accumulo energetico di larga scala di medio o lungo periodo come gli storage ad aria compressa (CAES) o i sistemi di accumulo con pompaggio di acqua (PHE). Sebbene ancora una grande porzione di potenza elettrica viene prodotta da grandi sistemi centralizzati, negli ultimi anni il sistema energetico mondiale si sta muovendo verso sistemi decentralizzati con le sorgenti di generazione distribuita (DER) e le microgrids. Il potenziale della tecnologia LAES e i suoi vantaggi, rendono interessante lo studio di un LAES di piccola scala (microgrid scale LAES) che può essere dedicato come sistema di accumulo di medio o lungo periodo per applicazioni di generazione distribuita e microgrid. In questa tesi il microgrid scale LAES è stato proposto definendo un impianto che integra un ciclo di liquefazione con una produzione giornaliera di aria liquida da poche tonnellate a poche decine di tonnellate al giorno. L’obiettivo di questo lavoro è quello di intraprendere la sfida nel ridurre la scala di un sistema LAES contribuendo alla comunità scientifica a definirne le potenzialità e ispirare la ricerca a possibili lavori futuri. La prima parte di questa tesi analizza diversi cicli di liquefazione, adatti per essere applicati ad un LAES di piccola scala, con l’obiettivo di trovare una configurazione ottimale che minimizza il consumo specifico. Il confronto dei diversi cicli di liquefazione è stato basato su una analisi parametrica eseguita tramite il software di simulazione Aspen HYSYS. Un ciclo Kapitza supercritico (oltre 40 bar) con un doppio stadio di compressione, risulta la migliore configurazione e, se integrato ad un serbatoio di aria liquida pressurizzato, il consumo specifico stimato può essere inferiore ai 500 kWh/t. Inoltre, l’analisi exergetica, evidenzia una grande porzione di exergia persa durante l’interrefrigerazione tra i due stadi di compressione che suggerisce l’integrazione di un sistema di recupero dell’energia termica ad alta temperatura. Combinando il ciclo di liquefazione con un ciclo ad assorbimento a singolo effetto basato su un ciclo con acqua e bromuro di litio (LiBr), il consumo specifico del microgrid scale LAES può essere ridotto del 10%. Nella seconda parte del lavoro, il ciclo di liquefazione Kapitza è stato integrato in una configurazione completa del microgrid scale LAES che include sia la sezione di scarica, che i sistemi di recupero dell’energia termica ad alta e bassa temperatura. Una analisi parametrica del sistema è stata eseguita assumendo un’ampia variazione delle condizioni operative del sistema valutandone l’effetto nelle prestazioni e nell’efficienza finale. I risultati, sono stati usati per elaborare quattro mappe di performance. Queste possono essere usate come un semplice strumento che può essere usato per stimare l’efficienza del sistema LAES e trovare le configurazioni ottimali che migliorano il consumo specifico, la potenza prodotta e l’efficienza globale dell’impianto. Lo storage termico a bassa temperatura o "High Grade Cold Storage" (HGCS) è il componente principale del sistema di recupero di energia termica a bassa temperatura che risulta fondamentale per migliorare le prestazioni del microgrid LAES e diminuire il consumo specifico del ciclo di liquefazione. Per ridurre le dimensioni del sistema di accumulo termico incrementando la densità energetica, una soluzione di HGCS ibrida è stata proposta in questo lavoro. Lo storage ibrido è parte di un progetto basato al TESLAB@NTU nella Nanyang Technological Uuniversity di Singapore, e prevede l’integrazione di una o più parti di materiali a cambiamento di fase (PCM) nelle attuali soluzioni di HGCS basate su sistemi di accumulo termico a calore sensibile. Il design dei sistemi di accumulo termico che utilizzano PCM, richiedono la conoscenza del comportamento termico del mezzo di stoccaggio durante le fasi di carica e scarica. Questa tesi si focalizza nella caratterizzazione termica dei materiali a cambiamento di fase a bassa temperatura, proponendo una metodologia che può essere utilizzata per misurare e prevedere il comportamento termico dei PCM. In particolare un apparato sperimentale è stato progettato per misurare la temperatura in differenti punti di un PCM contenuto in un contenitore cilindrico. I risultati sono stati quindi usati per validare un semplice modello 1-D che può essere utilizzato per prevedere il comportamento termico di PCM a bassa temperatura. Per questo obiettivo, il container è stato progettato per ottenere dal PCM un comportamento simile ad un processo di trasferimento di calore monodimensionale. Il modello 1-D è stato calibrato e validato con i risultati sperimentali ottenuti con la carica e la scarica di acqua deionizzata. L’attendibilità dei risultati è stata verificata con due test differenti, valutando la solidificazione e lo scioglimento in differenti punti del container. La metodologia è stata quindi testata con diverso PCM basato una soluzione di glicole etilenico (EG) dissolta con una concentrazione del 30% in acqua pura. Le soluzioni alcoliche acquose risultano difficili da testare a causa del basso valore di calore latente (o entalpia di fusione) e la bassa velocità di nucleazione. I risultati ottenuti con il modello 1-D, mostrano una buona corrispondenza con i dati sperimentali. Il metodo proposto risulta quindi essere un valido e semplice strumento per approssimare e prevedere il tempo di carica e scarica di diversi PCM e confrontare i differenti comportamenti. Inoltre, la semplicità del codice numerico, permette a quest’ultimo di essere facilmente integrato in modelli numerici più complessi ed essere utilizzato per un modello completo dello storage termico a bassa temperatura.
The increasing of the energy consumption related to the global energy demand is the main cause of environmental issues, such as greenhouse effect and climate change. The new policies related to the energy sector are aiming to a deep decarbonization of the grid that has led to reducing the energy produced from fossil fuels increasing the penetration of renewable energy sources in the actual energy system. The main drawback of clean energy sources is related to their unpredictable nature. The new challenge of the energy sector is then to overcome the problem related to the intermittency of renewable sources optimizing the balance between energy supply and energy demand. The use of energy storages has a fundamental role to guarantee the flexibility of the energy system capturing the wrong-time power from the renewables giving the possibility to be used in a later time or in a different place. The large amounts of cold thermal energy wasted (from spare liquid nitrogen and LNG regasification) and the research of a new and sustainable energy vector have led to study the potential of cryogens on grid, transport and cooling applications defining a possible "liquid air economy". In the grid context, Liquid Air Energy Storage (LAES) is based on the concept that air at ambient pressure can be liquefied at -196°C, reducing the specific volume of around 700 times, to be stored in low-pressure vessels. The liquid air then can be expanded in a later time in a power producing device (e.g. turboexpander, reciprocating engine) to produce electric power. The first concept son using the liquid air as storage medium was proposed in 1977 and again in the early 2000 but with no further developments. In 2005 University of Leeds and Highview Power patented a LAES system with a liquefaction system based on a Linde-Hampson cycle. The research starting from lab scale components has led to develop a 300kW/2.5MWh LAES pilot plant. The plant initially commissioned in April 2010 was located at Scottish and Southern Energy 80MW biomass plant at Slough Heat and Power in Greater London and now relocated at the University of Birmingham. In the recent years, the realization of the first pilot plant and the demonstration of the potential of cryogens as an energy vector, have led the LAES to attract the attention of many researchers due to their several advantages, such as long lifetime and no geological constraints. Furthermore, LAES can be easily scalable to large size due to the system made with existing mature components and sustainable materials. Although those benefits, the main disadvantage that compromises the LAES feasibility, is the low round-trip efficiency that is estimated around 50-60 % for large-scale systems. The most of the interest in the literature available is dedicated to industrial scale systems (up to 300 tons per day) to compete with large-scale technologies used for medium or long-term storage such as compressed air energy storage (CAES) and pumped hydroelectric (PHE). However, although a large portion of electric power produced still realize on large centralized systems, the energy system is moving towards to a decentralized energy production system with distributed energy resources (DER) and microgrids. The potential of the LAES technology and the related advantages make it interesting to investigate a small-scale (microgrid scale) that can be suitable for DER and microgrid applications as a medium or long-term energy storage. In this work, a microgrid scale LAES is proposed defining a system that integrates a liquefaction plant with a daily production ranging between few tons and few tens of tons of liquid air. The aim of this work is to start the challenge of scaling down and reduce the size of the LAES contributing to the scientific community to understand the potential of this technology and inspire future research. The first part of this thesis analyses different liquefaction cycles, suitable for small-scale LAES with the aim to find an optimal configuration that minimizes the specific consumption of the plant. Indeed, the liquefaction cycle mainly affects the roundtrip efficiency of the system. The analysis, done by software simulation Aspen HYSYS, is based on parametric analysis and a comparison between the liquefaction cycles. A Kapitza cycle configuration with a two-stage compression working at supercritical pressures (over 40 bar), is the best cycle configuration that, if integrated to a pressurized phase separator, can achieve a specific consumption below 500 kWh/t. Furthermore, the high exergy loss at the compressor aftercoolers suggests that the integration of a waste heat recycle can increase the exergy efficiency of the system. Combining the system with a 105.5 kW single-effect water-Lithium Bromide absorption chiller the specific consumption of the microgrid scale LAES liquefier can be reduced of around 10%. In the second part of the work, the Kapitza cycle has been integrated into a complete configuration of a microgrid LAES system that includes both the discharge section and the waste heat and cold thermal energy recovery system. A wide range of operating conditions has been assumed to evaluate the effect on the system performance. The results have been used to elaborated four performance maps to be used as a simple and immediate method that can be applied by engineers and researcher to estimate the LAES performance and optimize the design in terms of term of specific consumption, specific electric power output, and round-trip efficiency. The performance maps highlight that the reuse of the cold energy released by the liquid air before the expansion in the discharge cycle allows to improve the performance of the charge side of the LAES decreasing the specific consumption of the liquefaction cycle and increase the overall roundtrip efficiency of the system. Therefore, the last part of the thesis focuses on the High Grade Cold Storage (HGCS) that represents the main component of the waste cold recovery system. HGCS is fundamental to improve the performance the microgrid LAES and decrease the specific consumption of the liquefaction plant. To reduce the dimension of the storage increasing the energy density, a hybrid HGCS solution that integrates one or more part of phase change materials (PCM) has been proposed to improve the actual bulky solutions based on a sensible heat storage. The hybrid HGCS is part of a project based at TESLAB@NTU in the Nanyang Technological University of Singapore. The design of the storage using PCM requires a good understanding of the thermal behaviour of the storage medium during the charging and the discharging. Therefore, this work focuses on the thermal response and thermal characterization of PCM proposing a methodology to measure and predict the thermal behaviour of low temperature PCM. In particular, an experimental rig has been designed to measure the temperature in different points of a PCM placed inside a cylindrical shape container. The results are then used to validate a simple 1-D model that can be used to predict the thermal behaviour of different low temperature PCM. For this purpose, the container has been designed to obtain a similar thermal behaviour of the PCM involving a one-dimensional heat transfer process. The 1-D model has been calibrated and validated with the experimental results obtained with the melting and the solidification of pure deionized water. The reliability of the results has been verified with two different tests evaluating the solidification and the melting in different positions of the container. The methodology has been tested with a solution with a concentration of 30% of ethylene glycol (EG30) by weight in deionized water. Although aqueous alcohols are difficult to test due to their low latent heat and slow nucleation rate, the results of the 1-D model show a good agreement with the experimental data representing a valid and simple method to approximate and predict the time of charge and discharge of the PCM and to compare the thermal profiles of different materials. Furthermore, the simplicity of the code allows the numerical model to be integrated into a more complex numerical model, particularly suitable for the complete modelling of HGCS.

This thesis studies the thermophysical properties and the phase change behaviour of EG-water and Salt-water based PCMs for cold storage applications, and investigates the role of adding MCNT on the thermophysical properties and the phase change processes. First, the structure of MCNT clusters is linked to the rheological behaviour of the nanofluids by fitting the experimental viscosity data to the modified K-D model. Second, the MCNT cluster information is used to predict thermal conductivity. The effective thermal conductivity of nanofluids not only relies on the particle concentration, but also depends on the particle cluster structure. The specific heat of MCNT nanofluids is decreasing proportionally with the concentration of MCNT. The supercooling degree of EG-water and salt-water based samples can be reduced by adding MCNT particles. The crystallization process of salt-water basefluid and nanofluid was observed and recorded under an optical microscope with cooling stage. Adding MCNT can promote the crystal growth rate.

The effect of strong interatomic interactions on an optical field stored in Rydberg states of a cold atomic gas is investigated. Due to their large dipole moments Rydberg atoms interact very strongly with each other. The strength of these interactions can be significant over length scales of several microns. An effect known as dipole blockade leads to a suppression in the number of Rydberg excitations supported in a medium of finite size. The experiments described in this thesis aim to exploit this effect to create a medium with a non-linear response which occurs at the level of single-photons. A cold atomic cloud is tightly confined such that only a few Rydberg excitations are supported. It is shown that the dipole blockade phenomenon leads to strong photon-photon interactions, resulting in the generation of quantum states of light. A microwave field is used to control the strength and range over which the interactions between the stored optical photons occur. In addition, it is shown that the propagation of the optical field through the medium is non-trivial. Preliminary evidence is presented suggesting that the slow-light group delay in the medium is dependent on the number of propagating photons.

Bulbs of three varieties of oriental hybrid lilies were stored at 4 °C for 6 to 12 weeks prior to greenhouse forcing at 18 °C night temperature. Increasing duration of storage reduced the number of days to shoot emergence, visible flower buck and anthesis for each variety. The number of days from planting to anthesis ranged from 70 to 102 and varied with cultivar and storage duration. Increasing durations of storage had no commercially significant effect on the number of flowers reaching anthesis, number of leaves or aborted flower buds. The varieties used in this study flower earlier than commercially established cultivars and may be successfully forced in Arizona for early spring holidays.

The steel production is a highly capital and energy intensive industry that due to recent raw materials’ price increase and lowered demand, it has been squeezed and forced to look more deeply on how to add value to the customer at lower operative costs. The project was carried out on site at the ArcelorMittal’s millin Esch-Belval, Luxembourg which comprises an integrated melt shop, continuous casting plant and the rolling mill with the objectives of proposing optimization rules for the cold sector of the rolling mill and to analyze the impact of the future truckbay shipment area. The course of action followed was to draw a Value Stream Map (VSM) in order to understand the plants’ current status and serve as a roadmap to build a discrete event simulation model that after its validation, served as a support tool to analyze what-if scenarios. Similarly, a current status analysis of the  shipment/stock area was conducted collecting statistics about potential truckshipments and finally proposing a series of recommendations for its operation. The main proposed solutions to optimize the rolling mill’s cold sector were:(a) Integer programming model to globally optimize the scrap level when cutting the mother beams to customer size beams. (b) Updating pacemaker parameters and (c) Local process time improvements. Concerning the future truck loading, the simulation model was used as a support tool to dimension the transition area between the cranes’ and forklift operations resulting in a 6-9 bundles buffer capacity. Additionally, the current length-based storage policy was found to have competitive objectives so a turnover class-based storage policy is proposed with A, B, C classes which should provide an improved organization of the stock and travel distance of the cranes. The evaluation of the cranes’ performance remains an issue since there are currently no objective measures like, for instance, travelled distance. Optical measuring devices are suggested as one option to have a performance indicator that would help further investigate root cause problems in the shipping/stock area.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 81-82).
Air cooled power plants experience significant performance fluctuations as plant cooling capacity reduces due to higher daytime temperature than nighttime temperature. The purpose of this thesis is to simulate the detailed operation of a cold side thermal energy storage system in order to evaluate its potential. An organic Rankine cycle geothermal power station is used as an example application. Detailed sizing and operation considerations are discussed. Several representative case studies compare the performance of candidate configurations. Operation of the selected configuration is then simulated for a full year and a proposed integration of the system with existing plant hardware is laid out. A correlation between weather trends and production is outlined. Finally an economic cost/benefit analysis performed to determine the payback period for implementing the proposed system. The cold side TES system is shown to shift substantial power generation capability from nighttime to daytime when electrical demand is highest, especially during hot summer months. For example, daily energy production is shown to increase by up to 18% under particularly favorable conditions. This redistribution of the power generation curve is accomplished with less than a 5% reduction in overall annual energy production in Mega-Watt hours. The system is shown to be more effective at shifting power generation capacity during warmer months than cooler months. The reduced day to night temperature fluctuation during cooler months results in a reduced thermal storage benefit under similar parasitic loads. The economic benefits of this system are dependent upon the on-peak vs off-peak electricity prices. Economic analysis using 2011 transient price data from the U.S. Midwest Region results in a small increase in annual income. The increased income from the proposed cold side TES system is found to be insufficient to outweigh the required capital investment at current electricity prices.
by Daniel David Williams.
S.M.

The influences of loading cholesterol into stallion spermatozoa membranes prior to cold storage or cryopreservation were determined using cholesterol loaded cyclodextrin (CLC) before preservation, followed by the unloading of cholesterol after preservation using methyl beta cyclodextrin (MBCD). Experiment I: dose response trials determining optimal amounts of CLC and MBCD based on percentages of progressively motile spermatozoa (PMS) following preservation. Experiment II: influences of CLC and MBCD on PMS, the percentages of live intact (LI) and live non-intact (LNI) spermatozoa following cold storage. Experiment III: influences of CLC before cryopreservation and MBCD on PMS, LI, and LNI post-thaw. Addition of CLC improved (P<0.05) PMS and LI following preservation when compared to the control. Unloading cholesterol using MBCD does not alter PMS, LI nor LNI. Addition of CLC is beneficial to survival of spermatozoa following preservation and addition of MBCD in small amounts does not negatively influence PMS, LI or LNI.

This report investigates the down-aisle buckling load capacity of steel storage rack uprights. The effects of discrete torsional restraints provided by the frame bracing in the cross-aisle direction is considered in this report. Since current theoretical methods used to predict the buckling capacity of rack uprights appear to be over-conservative and complex, this research may provide engineers an alternative method of design using detailed finite element analysis. In this study, the results from experimental testing of upright frames with K-bracing are compared to finite element predictions of displacements and maximum axial loads. The finite element analysis is then used to determine the buckling loads on braced and un-braced uprights of various lengths. The upright capacities can then be compared with standard design methods which generally do not accurately take into account the torsional resistance that the cross-aisle frame bracing provides to the upright. The information contained in this report would be beneficial to engineers or manufacturers who are involved in the design of rack uprights or other discretely braced complex light gauge steel members subject to axial loads.

Master of Engineering (Research)
This report investigates the down-aisle buckling load capacity of steel storage rack uprights. The effects of discrete torsional restraints provided by the frame bracing in the cross-aisle direction is considered in this report. Since current theoretical methods used to predict the buckling capacity of rack uprights appear to be over-conservative and complex, this research may provide engineers an alternative method of design using detailed finite element analysis. In this study, the results from experimental testing of upright frames with K-bracing are compared to finite element predictions of displacements and maximum axial loads. The finite element analysis is then used to determine the buckling loads on braced and un-braced uprights of various lengths. The upright capacities can then be compared with standard design methods which generally do not accurately take into account the torsional resistance that the cross-aisle frame bracing provides to the upright. The information contained in this report would be beneficial to engineers or manufacturers who are involved in the design of rack uprights or other discretely braced complex light gauge steel members subject to axial loads.

Abstract Flaxseed oil cake from a South African factory was screened for proximate composition, mineral content, fatty acid profile and storage stability. The oil cake was included at 10 and 15% levels (w/w) in brown bread and evaluated using a 96-member consumer panel. The oil cake contained between 38.0 and 47.3% protein, 12.8 and 26.1% crude fat and 3.7 and 5.1% ash. The total carbohydrates were mostly dietary fiber. Calcium, magnesium, phosphorus and potassium were in the range of 3.3 to 3.8, 4.8 to 5.9, 6.4 to 8.2 and 9.0 to 10.1 (mg/g), respectively. The oil from the flaxseed oil cake contained 58.5 to 59.7% of C18 omega-3 fatty acids. Peroxide levels of the flaxseed oil cake were below the threshold limits after 6 months storage. Thiobarbituric acid threshold values were exceeded after 5 months aerobic storage at 20C. Bread samples with inclusion levels of 10 and 15% flaxseed oil cake were acceptable to the consumer sensory panel.

Ingestion of cold (<10°C) compared to warm (>37°C) fluid has been suggested to attenuate heat storage levels during exercise. However, modulations in sweat output may yield differences in evaporative heat loss that are greater than differences in heat transfer with the ingested fluid. The purpose of the thesis was to evaluate thermoregulatory control and human heat balance, and compare thermometrically derived values of heat storage with those derived from partitional calorimetry following water ingestion of varying temperature during exercise. We found that water ingestion of 50°C compared to 1.5°C decreases heat storage in thermoneutral environments, and further exacerbates the error of thermometric heat storage estimations. Differences in heat storage were attributed exclusively to disproportionate reductions in whole-body and local sweat output and thus evaporative heat loss potential. Ingested fluid temperature only minimally altered skin blood flow and did not influence dry heat exchange with the ambient environment.

Published Article
A study involving two incubation experiments and a germination experiment in sandy soil was conducted to determine the influence of Multiplied Effective Micro-organisms (M-EM) that were exposed to different levels of irradiation and temperature fluctuation as well as prolonged storage, on the germination and seedling vigour of maize, sorghum and sunflower. Irrespective of poor handling and/or prolonged storage of M-EM, seed treatment with M-EM improved germination under optimal conditions for all crops compared to the control. Increased planting depths and cold stress were used to create conditions where seed treatment with M-EM may improve germination and seedling growth. Seed treatment with M-EM significantly improved germination and seedling vigour of the stress-tolerant maize cultivar following cold stress. Similar improved seedling vigour results were observed for the stress-tolerant sunflower cultivar at increased planting depth. It was concluded that the beneficial influence of M-EM as a seed treatment was remarkable, even after exposure of M-EM to unfavourable environmental conditions and prolonged storage before application. Further research under field conditions and in different cultivation systems are required before the large scale application of M-EM as seed treatment can be recommended.

In response to concern over the failure and poor growth of many interior and white spruce plantations in British Columbia the effect of storage duration and soil temperature on the photosynthetic ability of white spruce seedlings was explored. Seedlings of Picea glauca were dark freezer stored (-5°C) from 9.6 to 30.6 weeks, thawed and grown for 28 days in a growth chamber at three different soil temperatures (3,7,11°C). During this period gas exchange variables and chlorophyll fluorescence kinetics were followed. Seedlings stored for periods of 22 weeks or longer had significantly lower rates of photosynthesis dependent on the outplanting soil temperature. Stomatal conductance was initially low upon outplanting and showed a recovery period of 4-7 days duration. The level of stomatal conductance increased in seedlings after they were stored for 26.1 weeks or longer. Chlorophyll fluorescence measurements of seedlings stored from 22 to 30.6 weeks showed a recovery period in photosynthetic efficiency (Fy/Fp) related to changes in photosynthesis. A decrease in seedling Fy/Fp with increasing periods of storage was noted at day 5 after outplanting. A disproportionate increase in new root growth with the increasing soil temperatures, measured after the 28 day growth period, suggested a soil temperature threshold for root growth exists between the 7°C and ll°C. In contrast, the stomatal conductance and photosynthesis results suggest the seedling shoots were not directly affected by the cold soil temperatures. In general, the results suggest Picea glauca seedlings stored longer than 22 weeks in freezer conditions have reduced photosynthetic ability, root growth and overall vigor. Fluorescence and bud break data suggest the reduction was possibly due to freezing damage sustained in storage affecting photosynthetic electron transport through photoinhibition upon returning seedlings to the light.
Forestry, Faculty of
Graduate

AN ABSTRACT OF THE THESIS OF Travis Killion, for the Master of Science degree in Plant, Soil, and Agricultural Systems, presented on April 4, 2014, at Southern Illinois University Carbondale. TITLE: LYCOPENE AND ASCORBIC ACID CONTENT OF FRESH TOMATOES BASED ON GENOTYPE, MATURITY STAGE AND COLD STORAGE INTERVAL MAJOR PROFESSOR: Dr. S. Alan Walters Tomatoes are one of the most widely consumed vegetables and provide a major source of antioxidants to human diets around the world. Since this vegetable is consumed in such high quantities, the nutritional qualities of the tomato fruit were determined based on the tomato's genetic makeup, the stage at which it was harvested, and length of time in cold storage. Therefore, field and storage studies were conducted during the 2012 and 2013 growing seasons at the SIUC Horticulture Research Center in Carbondale. Three field experiments were conducted to determine ascorbic acid (AA, also commonly known as vitamin C) and lycopene content of fresh tomato fruit based on cultivar, harvest stage and time in cold storage. The first experiment evaluated 20 tomato cultivars, while `Rocky Top' tomato was grown using standard production practices and harvested at different stages (mature-green, breaker, turning, pink, light red, and red) to determine the effect of harvest stage on the resulting lycopene and AA content of a red-ripe fruit. Harvested fruit were stored at room temperature (21º C) until they had developed to the red ripe stage and were then immediately evaluated. The effects of short-term cold storage on the lycopene and AA content of red-ripe harvested `Rocky Top' tomato fruit were also determined; tomatoes were placed in cooler at 4º C, with samples retrieved at 0, 1, 2, 3 and 4 weeks. Results indicated that cultivars differed (P ≤ 0.05), with smaller-sized tomatoes having ii higher AA content than larger-sized cultivars. The AA content ranged from 13.4 to 29.8 mg per 100 g of tomato fruit, with higher amounts being observed in the smaller tomato varieties (`Red Currant' and `Sugar Plum'). Lycopene analysis indicated that there were also significant differences amongst cultivars, and the analyses indicated differences between the 2012 and 2013 growing seasons. Higher lycopene content was found in the red varieties, with lower amounts found in lighter colored tomatoes, especially those that were orange colored. In 2012, lycopene content ranged from 4.80 to 100.39 μg/g in tomato fruit, while in 2013, values ranged from 41.4 to 83.7 μg/g. The short-term cold storage evaluation determined that both AA and lycopene concentration decreased over time. For AA and lycopene, a 43% and 24% loss occurred in `Rocky Top' tomato fruit, respectively, after 4 weeks in cold storage. For the tomato stage of maturity experiment, tomatoes harvested at the red-ripe stage had the greatest AA concentrations (0.187 mg/g), with a gradual decline occurring based on the ripeness of the fruit when it was harvested. Fruit that were harvested at a more ripe stage had greater AA concentrations compared to those harvested at lesser ripened stages, with red ripe tomatoes that developed from fruit harvested at the green maturity stage having the least AA content (0.116 mg/g). Similar to AA, lycopene concentrations were higher in tomatoes harvested closer to the red-ripe stage and steadily declined in tomatoes harvested at earlier stages of development, with lowest values observed in red-ripe fruit that developed from mature green tomatoes. Based on the results from this study, tomatoes vary significantly among cultivars, harvest stage, and time in cold storage for both AA and lycopene content. Marketing tomatoes based on antioxidant content has not been widely utilized, but may help local growers explore a different approach to selling tomatoes and to increase profits and customer bases.

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2017.
Agriculture has emerged as a major economic activity in the African continent. Therefore, fruits and vegetables are considered as essential source of vitamins, minerals and proteins. However, fruits and vegetables are perishing rapidly. Thus, the adequate handling starts from the field, by applying appropriate method of storage and preservation in order to reduce post-harvest losses and extend its shelf life. Preservation by removing heat from the products is the most common method of preservation. In rural areas, the access to the grid is expensive or in some cases impossible. Therefore, researchers have been paying more attention to find alternative sources of power to run the cooling units. This study provides proof of a concept for the use of solar energy to cool down harvested fruits and vegetables at the farm level to an adequate farm storage temperature. The target storage temperature range is between 5 and 15 oC. A model refrigerator was designed and constructed in the mechanical engineering workshop of Cape Peninsula University of Technology. It was installed and tested in outdoor conditions to get the effect of different weather conditions. The model consists of a typical vapour compression system powered by a 12 V solar PV system. A DC compressor was used, and therefore, there is no inverter. The model was first tested without a product and then with 20 kg batches of different fruits for a period of two weeks in April 2016. Wind speed, ambient temperature and solar radiation intensity data were monitored and collected from a Campbell Scientific weather station mounted on the roof adjacent to the model. By monitoring the temperatures and compressor current hourly, the refrigeration effect, power consumption and coefficient of performance were determined. The overall COP based on input solar energy was 2.8. It was thus proved that a suitably sized PV system could be designed and implemented at farm level to cool harvested fruits from ambient to storage temperature without the use of an inverter. This could go some way to helping retard deterioration of fruits and vegetables before delivery to a marketplace or to storage.

Thesis (MSc Food Sc)--Stellenbosch University, 2003.
ENGLISH ABSTRACT: Post-storage quality of the stone fruit, apricots and peaches, is the major factor determining their suitability for canning after cold storage in South Africa. Short harvesting periods and the limited capacity of the factory to process the large quantities of fruit within two days after delivery, necessitates cold storage until canning. Apricots develop internal breakdown, whereas peaches develop internal breakdown accompanied by loosening of the skin and adhesion of the flesh to the stone. The deterioration takes place within the fruit during a cold storage period of one to two weeks. The tendency of the fruit to develop internal defects can, to date, not be identified prior to storage and are only discovered after destoning during canning. Near infrared spectroscopy (NIRS) combined with chemometrics were investigated as a non-destructive method to predict post-storage quality in Bulida apricots and clingstone peach cultivars. Near infrared (NIR) spectra (645-1201 nm), measured on the intact fruit just after harvesting, were correlated with subjective quality evaluations performed on the cut and destoned fruit after cold storage. The cold storage periods for apricots were four weeks (2002 season) and three and two weeks for peach cultivars for the 2002 and 2003 seasons, respectively. Soft independent modelling by class analogy (SIMCA) and multivariate adaptive regression splines (MARS) were applied to the spectral and reference data to develop models for good and poor post-storage quality. The ability of these models to predict post-storage quality was evaluated in terms of recognition (sensitivity) and rejection (specificity) of the samples in independent validation sets. Total correct classification rates of 50.00% and 69.00% were obtained with Bulida apricots, using SIMCA and MARS, respectively. Classification results with apricots showed that MARS performed better than SIMCA and is thus recommended for this application. Total correct classification rates of 53.00% to 60.00% (SIMCA) and 57.65% to 65.12% (MARS) were obtained for data sets of combined peach cultivars within seasons and over both seasons. Additional aspects of fruit quality were investigated to identify possible indices of post-storage quality. Classification trees were used to find correlations between the post-storage quality and the fruit mass, diameter, firmness and soluble solids content (SSC). Among these, fruit diameter and firmness were the major indices of post-storage quality. Accurate predictions of firmness could not be achieved by near infrared spectroscopy (NlRS), making the combination of NIRS and classification trees not yet suitable for predicting post-storage quality. NIRS was further used to predict poststorage SSC within seasons in Bulida apricots and intact peach cultivars. This confirmed sufficient NIR light penetration into the intact fruit and also provided a further application of NIRS for ripeness evaluation in the canning industry. Validations on peach samples obtained correlation coefficients (r) of 0.77-0.85 and SEP-values of 1.35-1.60 °Brix using partial least squares (PLS) regression. MARS obtained r = 0.77-0.82 and SEP = 1.42-1.55 °Brix. Predictions of sse in apricots were less accurate, with r = 0.39-0.88, SEP = 1.24-2.21 °Brix (PLS) and r = 0.51-0.82, SEP = 1.54-2.19 °Brix (MARS). It is suggested that the accuracy of sse measurements, and the subsequent predictions, were affected by the cold storage periods as well as internal variation within the fruit. This study showed that a combination of NIRS and chemometrics can be used to predict post-storage quality in intact peaches and apricots. A small scale feasibility study showed that 4% (R117 720) (apricot industry) and 3% (R610 740) (peach industry) of production losses can be saved if this method is implemented in the South African canning industry. Although it was difficult to assign specific chemical components or quality attributes to the formulation of the storage potential models, important hidden information in the spectra could be revealed by chemometric classification methods. NIRS promises to be a useful and unique quality evaluation tool for the South African fruit canning industry. Several recommendations are made for the canning practices to reduce losses and for future research to improve the current prediction models.
AFRIKAANSE OPSOMMING: Die kwaliteit van die steenvrugte, appelkose en perskes, is die hoof bepalende faktor vir hul geskiktheid vir inmaakdoeleindes na koelopberging in Suid-Afrika. Die vrugte moet opgeberg word by lae temperature vir een tot twee weke, aangesien die oestydperk kort is en die kapasiteit van die fabriek te beperk is om die groot hoeveeheid vrugte dadelik in te maak. Tydens hierdie opbergingstydperk vind agteruitgang in die vrugte plaas. Dit word in appelkose gekenmerk deur interne verval en in perskes gekenmerk aan interne verval, tesame met enlos skil en die vaskleef van die vrugvlees aan die pit. Tot dusver, bestaan daar geen metode om hierdie tipe agteruitgang in vrugte voor opberging te identifiseer nie. Dit word eers na opberging opgemerk wanneer die vrugte ontpit word. Naby-infrarooi spektroskopie (NIRS), gekombineerd met chemometriese metodes is gebruik om opbergingspotensiaal in Bulida appelkose en taaipitperske kultivars te bepaal. enKorrelasie is gemaak tussen naby-infrarooi (NIR) spektra, gemeet op die heel vrugte voor opberging en subjektiewe evaluering van kwaliteit, geïdentifiseer op die gesnyde vrugte na opberging. Die opbergingstydperke vir perskes was vir drie en twee weke vir die 2002 en die 2003 seisoene, onderskeldeflk, terwyl die appelkose vir vier weke opgeberg is. Twee chemometriese metodes, "soft independent modelling by class analogy" (SIMCA) en "multivariate adaptive regression splines" (MARS) is gebruik om die spektra en ooreenstemmende subjektiewe data te kombineer en modelle is ontwikkel vir goeie en swak opbergingspotensiaal. Die vermoë van die modelle om die vrugkwaliteit na die opbergingstydperk te voorspel, is geêvalueer in terme van herkenning en verwerping van vrugtemonsters in onafhanklike toetsstelle. Totale korrekte klassifikasies van 50.00% and 69.00% is verkry vir Bulida appelkose, met SIMCA en MARS, onderskeidelik. Die klassifikasie resultate het gewys dat MARS beter gevaar het as SIMCA en word dus sterk aanbeveel vir hierdie toepassing. Totale korrekte klassifikasies van 53.00% tot 60.00% (SIMCA) and 57.65% tot 65.12% (MARS) is verkry vir gekombineerde perskekultivars tussen seisoene en oor seisoene. Verdere aspekte van vrugkwaliteit is geêvalueer om enmoontlike indeks van opbergingspotensiaal te verkry. Klassifikasiebome is gebruik om en korrelasie te vind tussen kwaliteit na opberging en vrugmassa, deursnee, fermheid en totale oplosbare vastestowwe (TOV). Diameter en fermheid het die meeste gekorreleer met die kwaliteit na opberging. Voorspellings van fermheid deur die gebruik van naby infrarooi spektroskopie (NIRS) was ~gter nie akkuraat nie. Dus word die kombinasie van klassifikasiebome en NIRS om opbergingspotensiaal te voorspel nie tans aanbeveel nie. NIRS is verder gebruik om TOV te voorspel binne seisoene in heel Bulida appelkose en perskekultivars. Dit is uitgevoer om voldoende NIR ligpenitrasie in die vrugte te bevestig en ook om 'n verdere toepassing van kwaliteitsbepaling (as indeks van soetheid en rypheid) vir die inmaakindustrie te verskaf. Validasies is op perskemonsters uitgevoer en korrelasiekoêffisiente (r) van 0.77-0.85 en voorspellingsfoute van 1.35-1.60 °Brix is verkry met "partial least squares" (PLS) regressie. MARS het r = 0.77-0.82 and voorspellingsfoute = 1.42-1.55 °Brix verkry. Die akkuraatheid van die TOV meetings en gevolglike voorspellings is waarskynlik beïnvloed deur interne variasie binne die vrugte sowel as die opbergings tydperke wat verloop het tussen metings. Hierdie studie wys dat NIRS en chemometriese metodes wel gebruik kan word om opbergingspotensiaal in heel perskes in appelkose te voorspel. 'n Kosteberekening het gewys dat besparings van 4% (R117 720) (appelkoos industrie) en 3% (R610 740) (perske industrie) moontlik is indien NIRS en MARS geïmplementeer word. Alhoewel dit moeilik was om spesifieke chemiese komponente en .sekere kwaliteitsaspekte aan die ontwikkeling van die modelle te koppel, is belangrike verborge informasie in die spectra uitgebring deur chemornetriese metodes. NIRS beloof om 'n bruikbare en unieke kwaliteitskontrole maatstaf te wees vir die Suid-Afrikaanse inmaakindustrie. Verskeie aanbevelings is gemaak vir die inmaakpraktyke om verliese te voorkom en ook vir toekomstige navorsing om die huidige klassifikasiemodelle te verbeter.

Made available in DSpace on 2014-06-11T19:30:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-01-20Bitstream added on 2014-06-13T19:00:13Z : No. of bitstreams: 1 silva_gs_me_botfca.pdf: 632349 bytes, checksum: 498e1b397bf6abc7096a3228b6ca7ca0 (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O processo limitante na produção de mudas de algumas palmeiras é a germinação, pois, suas sementes perdem a viabilidade rapidamente depois de colhidas. Essa pesquisa teve como objetivo avaliar o armazenamento de plântulas de Euterpe edulis em câmara fria a 100C (0, 3, 6 e 9 meses), em diferentes estádios de desenvolvimento (de zero a dez semanas do início do processo germinativo), visando a obtenção de plântulas ao longo do ano. Foram coletadas amostras de cada tratamento para a determinação da atividade da peroxidase, envolvida no germinação de sementes, desenvolvimento de plântulas e também, ligadas ao estresse e senescência, possibilitando avaliar os efeitos na fisiologia das sementes provocados pelos tratamentos. Foi observado o desenvolvimento vegetativo das sementes e/ou plântulas após os tratamentos em condições de casa de vegetação, por período de 6 meses, para determinar a taxa de sucesso (plântulas com desenvolvimento normal). A taxa de sucesso de plântulas foi afetada negativamente pela permanência das sementes/plântulas em câmara de germinação e armazenamento em câmara fria. Dos parâmetros morfológicos de desenvolvimento analisados no final do experimento (comprimento de parte aérea, comprimento de parte aérea total, comprimento de raiz, diâmetro do coleto, massa de matéria fresca e massa de matéria seca), somente ocorreu diminuição do comprimento da raiz, sob estas condições. A atividade da peroxidase aumentou em decorrência do aumento do período de armazenamento em câmara fria, relacionada com a senescência das plântulas. Apesar da redução da taxa de sucesso das plântulas, não ocorreu redução dos parâmetros de desenvolvimento vegetativo (exceto comprimento de raiz) analisados das sementes/plântulas, portanto, o armazenamento em câmara fria é um instrumento viável para prolongar o período de uso das sementes de Euterpe...
Germination is the limiting process in the seedling production of some palm trees, since their seeds lose viability rapidly after collection. This study aimed to evaluate the storage of Euterpe edulis seedlings in a cold chamber at 10ºC (0, 3, 6 and 9 months) at different developmental stages (from zero to ten weeks after the initiation of the germinative process) in order to obtain seedlings throughout the year. Samples from each treatment were collected for assay of peroxidase activity, involved in seed germination, seedling development and also related to stress and senescence, which allows evaluating the treatment effect on seed physiology. The vegetative development of seeds and/or seedlings was observed under greenhouse conditions for six months to determine the success rate (seedlings presenting normal development). The success rate of seedlings was negatively affected by the maintenance of seeds/seedlings in germination chamber and storage in cold chamber. Among the morphological traits of development analyzed at the end of the experiment (shoot length, total shoot length, root length, stem diameter, fresh matter and dry matter), only root length decreased under such conditions. Peroxidase activity increased due to the longer period of storage in cold chamber, which was related to the senescence of seedlings. Despite the reduction in the success rate of seedlings, there was no decrease of vegetative developmental traits (except root length) analyzed in seeds/seedlings. Therefore, the storage in cold chamber is a viable instrument to extend the use of seeds for propagation of Euterpe edulis

Mestrado em Gestão e Conservação de Recursos Naturais - Instituto Superior de Agronomia / Universidade de Évora
Miscanthus x giganteus is a perennial grass, originated from hybridization between M. sinensis and M. sacchariflorus, identified as a suitable species for commercial production of bioenergy. Formal information on propagation under Mediterranean condition is, nevertheless, scarce. This study aimed to evaluate the influence of rhizome cold storage (4O C) and size on Miscanthus sprouting. Dormant rhizomes were obtained from an experimental plot at Tapada da Ajuda, Lisbon. Following cold storage, rhizomes were taken to the nursery to run the experiment. The experiment was conducted in a randomized block design with five replications, where factors were duration of cold storage (60 and 30 days, and a non-stored control), and length (greater than or lower than 10 cm) and diameter (higher or lower than 1 cm) of rhizome fragments. Results were assessed eight weeks after planting, allowing the conclusion that for optimized plant production under the environmental conditions of the experiment, rhizome fragments should have a diameter not less than 1 cm, length not less than 10 cm and the method of breaking dormancy must be cold storage for a period not exceeding four weeks at a temperature of 4OC.

The aim of this research was to develop a new harvest maturity index for highly coloured stone fruit that is not affected by seasonal or climatic factors. The judgement of commercial maturity is difficult with some cultivars of stone fruit because they develop intense skin pigmentation several days before they are ripe. Studies of the changes of the physiochemical and physiological parameters associated with ripening confirmed that no single measurement is suitable for the assessment of harvest maturity in the Japanese type plum cultivars(Prunus salicina Lindl). Two distinct patterns of ripening behaviour were identified. The cool storage (0 degrees Centigrade) responses of fruit harvested at three stages of maturity were examined. Total soluble proteins were extracted and separated from fruit during maturation and ripening using 2-dimensional gel electrophoresis. At least three proteins were first detected in fruit at optimum commercial harvest maturity. Since Gulfruby, Beauty and Rubyred (Japanese type plum cultivars) accumulated similar concentrations of aminocyclopropane-1-carboxylic acid(ACC), it was suggested that the suppressed-climacteric phenotype is the result of an impaired ability of the fruit to convert this compound to ethylene
Doctor of Philosophy (PhD) (Ph.D.)

The pharmaceutical market of remedies is actively developing in the direction of biotechnologies, due to the increase of using the targeted therapy in contrast to the conventional therapy, the increase of demand for monoclonal antibodies, the prescription of orphan medicines, vaccines and biosimilars [5]. Especial attention is foccused by medical immunobiological preparations (MIBPs) which are used for the immunoprophylaxis and the immunotherapy, and require the special storage conditions, videlicet the organization of storage, transportation and the usage with the help of the "cold chain". Therefore, pharmaceutical enterprises are taking additional measures to ensure the quality of their products from the beginning of the manufacture to the distribution of their products. A significant part of the MIBPs requires the storage conditions of a fairly narrow temperature interval from +2 ºС to +8 ºС, and the temperature of +5 ºС is optimal. Certain vaccines can be stored and transported at a temperature from -80 ° C to +2 ° C [4]. In Ukraine the requirements of the creation of a cold chain and abidance by the terms of storage and transportation of MIBP are regulated by certain regulatory documents [1, 2]. But definite complexities, such as the absence of common standard testing methodologies for insulated containers, refrigeration rooms, refrigerating equipment, carrier vehicles and temperature control devices, as also the lack of standard requirements for a temperature control system in the cold chain, require MIBP manufacturers to apply a scientific approach during the development of the "cold chain" in order to ensure the quality of their remedies [3]. The cooling elements, which are packed together with MIBP, take on an indispensable the role in providing and maintaining the established temperature regimes. Therefore, the efficacy of the cooling element has a direct critical influence on the preservation of the quality of medical remedies.

The primary objective of the research was to study the physiological and biochemical changes in Hass avocado fruit stored in different combination of oxygen and carbon dioxide concentrations at both 0 degrees and 5 degrees Centigrade (C), and to determine whether storage in controlled atmosphere (CA) can decrease the incidence of chilling injury (CI). A secondary objective was to identify possible correlations between CA, the incidence of CI, the activity of some ripening related enzymes and changes in proteins during ripening at 20 degrees C following storage at low temperatures. Fruit suffered no CI and ripened normally following CA storage for 3 weeks at both 0 degrees and 5 degrees C, then transferred to air for 6 days at 20 degrees C. CI symptoms did develop after CA storage for 6 and 9 weeks at 0 degrees C. Changes in proteins during ripening were analysed by 2D-PAGE. Some polypeptides were detected in unripe fruit but decreased with ripening. Polypeptides of 16.5, 25, 36 and 56 kD (kilo Dalton) were present early in ripening and their levels further increased during ripening. The appearance of three ripening related polypeptides with estimated molecular weights 80 kD (pI 3.6), 36 kD (pI 5.8) and 16.5 kD (pI 5.7) was observed in fruit at the climacteric stage. Three polypeptides with estimated molecular weights of 41 kD (pI7.8), 36 kD (pI 5.8) and 33 kD (pI 5.1) were found in air stored fruit but were not detected in fruit stored in CA. This research showed that CA did not ameliorate CI at 0 degrees C, instead storage at 0 degrees C caused a premature increase in ethylene production when the fruit were returned to air at 20 degrees C. In contrast, CA storage at 5 degrees C retarded ethylene production and ripening in fruit after it was returned to air at 20 degrees C.
Doctor of Philosophy (PhD)

Detta examensarbete handlar om undersökning av tre olika användningsfall inom datalagring; Cold Storage, High Performance Storage och Virtual Machine Storage. Rapporten har som syfte att ge en översikt över kommersiella distribuerade filsystem samt en djupare undersökning av distribuerade filsystem som bygger på öppen källkod och därmed hitta en optimal lösning för dessa användnings-fall. I undersökningen ingick att analysera och jämföra tidigare arbeten där jämförelser mellan pre-standamätningar, dataskydd och kostnader utfördes samt lyfta upp diverse funktionaliteter (snapshotting, multi-tenancy, datadeduplicering, datareplikering) som moderna distribuerade filsy-stem kännetecknas av. Både kommersiella och öppna distribuerade filsystem undersöktes. Även en kostnadsuppskattning för kommersiella och öppna distribuerade filsystem gjordes för att ta reda på lönsamheten för dessa två typer av distribuerat filsystem.Efter att jämförelse och analys av olika tidigare arbeten utfördes, visade sig att det öppna distribue-rade filsystemet Ceph lämpade sig bra som en lösning utifrån kraven som sattes som mål för High Performance Storage och Virtual Machine Storage. Kostnadsuppskattningen visade att det var mer lönsamt att implementera ett öppet distribuerat filsystem. Denna undersökning kan användas som en vägledning vid val mellan olika distribuerade filsystem.
In this thesis, a study of three different uses cases has been made within the field of data storage, which are as following: Cold Storage, High Performance Storage and Virtual Machine Storage. The purpose of the survey is to give an overview of commercial distributed file systems and a deeper study of open source codes distributed file systems in order to find the most optimal solution for these use cases. Within the study, previous works concerning performance, data protection and costs were an-alyzed and compared in means to find different functionalities (snapshotting, multi-tenancy, data duplication and data replication) which distinguish modern distributed file systems. Both commercial and open distributed file systems were examined. A cost estimation for commercial and open distrib-uted file systems were made in means to find out the profitability for these two types of distributed file systems.After comparing and analyzing previous works, it was clear that the open source distributed file sys-tem Ceph was proper as a solution in accordance to the objectives that were set for High Performance Storage and Virtual Machine Storage. The cost estimation showed that it was more profitable to im-plement an open distributed file system. This study can be used as guidance to choose between different distributed file systems.