Дисертації: "Slag resistance"

1

Wang, Xidong. "Synthesis of AlON and MgAlON Ceramics and Their Chemical Corrosion Resistance." Doctoral thesis, KTH, Materials Science and Engineering, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3120.

Повний текст джерела

Анотація:

In view of the excellent mechanical, chemical and opticalproperties, AlON (Aluminum oxynitride) as well as MgAlON(Magnesium Aluminum oxynitride) have drawn the attention ofmaterials scientists in past decades. In this thesis,thermodynamic properties, synthesis and corrosion resistance tooxygen and slag of AlON and MgAlON ceramics have beeninvestigated.

Gibbs energy of AlON and MgAlON with different compositionsand temperatures were estimatedby using thermodynamicquasi-parabola rule. Phase stability diagrams of Al-O-N andMg-Al-O-N systems at different conditions have been calculated.On the basis of thermodynamic analysis, AlON and MgAlONceramics were synthesized by hot-press sintering andcharacterized by XRD, TEM and HREM analyses. An X-raydiffraction standard file of MgAlON is suggested and sent toJCPDS.

The density of AlON synthesized was 3.63g/cm³, about 97.8% of its theoretical density. Thedensity of MgAlON is 3.55 g/cm³. Fracture toughness of AlON and MgAlON is 3.96 and4.06 MPa.m^1/2. Three-point bending strength of AlON and MgAlONare 248 and 268 MPa, respectively, at room temperature andkeeps very high until 1723K. However the strength drops 189 and202 MPa for AlON and MgAlON, respectively, at 1723K. Thefracture section of AlON and MgAlON were examined and found tobe a mixed fracture of intercrystalline and cleavage fracturefor AlON and a mixed intercrystalline and transcrystallinefracture for MgAlON.

Oxidation experiments of AlON and MgAlON and a comparison ofthe oxidation behavior of AlON, MgAlON, O'SiAlON-ZrO₂and NB-ZCM have been carried out. Undernon-isothermal oxidation conditions, oxidation of AlON exhibitstwo steps with a "S"-shaped curve due to the phasetransformation of oxidation product. As temperature increases,the oxidation product, γ -Al₂O₃formed at lower temperatures will transform intoα-Al₂O₃. Due to the differences in the molar volumesbetween α-Al₂O₃and γ -Al₂O₃, cracks are likely to be formed in the productlayer promoting further oxidation. MgAlON, O'SiAlON-ZrO₂and NB-ZCM show only one step with paraboliccurves.

Isothermal oxidation experiments of AlON, MgAlON,O'SiAlON-ZrO₂and NB-ZCM have been carried out in thetemperature range of 1373-1773K. At lower temperatures, MgAlONshows the best resistance to oxidation. But at highertemperatures, such as 1773K, AlON shows the best resistance tooxidation. O'SiAlON-ZrO₂shows very good oxidation resistance in the lowtemperature range up to 1673K. But, as the temperature goes upabove 1673K, there is liquid phase produced during theoxidation process. Gas bubbles are also formed in the productlayer causing the flaking-off of some parts of the productlayer. Therefore its oxidation rate increases greatly astemperature rises to 1673K. In the case of BN-ZCM ceramics, dueto the evaporation of B₂O₃, the oxidation resistance seems to be poorest. Thechemical reaction activation energies for the initial stage ofoxidation of AlON, MgAlON, O'SiAlON-ZrO₂and BN-ZCM are 218, 330, 260 and 254 kJ/molerespectively. And the activation energies at the laterdiffusion controlling stages are 227, 573, 367 and 289 kJ/molefor AlON, MgAlON, O'SiAlON-ZrO₂and BN-ZCM respectively.

The roughness of the oxidation sample surfaces has beenmeasured by Atomic Force Microscope. As the temperatureincreases, the degrees of roughness of AlON and MgAlON surfacesincrease slightly due to the growth of crystal grain. Theroughness degree of BN-ZCM increases greatly because of theevaporation of B₂O₃. However the roughness of O'SiAlON-ZrO₂decreases as the temperature increases from 1473Kto 1673K. The main reason is that the liquid phase (glass)produced during the oxidation process at high temperatures suchas 1673K and 1773K. The roughness degree of MgAlON, AlON,O'SiAlON-ZrO₂and BN-ZCM are 234, 174, 75 and 63 nm respectivelyat 1473K, and 297, 284, 52 and 406 nm respectively at1673K.

Experiments of corrosion of AlON by CaO-MgO-"FeO"-Al₂O₃-SiO₂slags were conducted in the temperature range of1693-1753K under static conditions as well as under forcedconvection. XRD, SEM-EDS and TEM analyses on the corrodedsamples were carried out.

The results showed that the diffusion was therate-controlling step in the initial stage of the corrosion.Thereafter, the slag formation (the product layer dissolvinginto the liquid slag) became more and more important. Thisaspect was further confirmed by fractal dimension analysis ofthe interface. The overall activation energy for the corrosionprocess with slag No.1 was evaluated to be 1002 kJ. Adding"FeO" to the slag greatly enhanced the corrosion rate probablydue to the reaction of the sample with "FeO".

Key words:AlON, MgAlON, Thermodynamics, Synthesis,Oxidation, Slag corrosion

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Chan, Chen-Feng. "Influence of additives and atmosphere on microstructural evolution and slag resistance of Alâ‚‚Oâ‚ƒ-SiC-C refractories." Thesis, University of Sheffield, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391039.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Hassan, Husseen, and Abdifatah Sahal. "Experimental Tests of Pre - placed Aggregate Concrete for Concrete Repairs." Thesis, KTH, Betongbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-278540.

Повний текст джерела

Анотація:

Since a large part of the hydropower structures in Sweden was built in the 1950s and 1960s, many of them are slowly but surely exhibiting deterioration. The hydropower companies are facing big challenges and are consequently investing in effective repairing methods since a hydropower structure failure could pose serious consequences and dangers to people, the environment, and the community. Many structures within hydropower are made of concrete and the demands on the new supplementing concrete are high. Concrete with the potential to meet these high demands is the pre-placed aggregate concrete, which has shown promising results regarding its mechanical properties in previous studies. For this reason, this type of concrete is of interest to investigate. The focus has not been on optimizing the pre-placed aggregate concrete for full-scale productions. Instead, the main objectives of this master thesis were to study and analyze the mechanical properties of this type of concrete, such as shrinkage, compressive strength, splitting tensile strength, freeze-thaw resistance and moreover investigate parameters of importance in the mix design to obtain a homogenous and easy flowing grout that successfully could fill the voids between the coarse aggregates. The investigations were carried out by laboratory experiments in the research and laboratory facilities of Vattenfall in Älvkarleby. The mix design of the grout was developed using the methods and requirements stated in the American Society for Testing and Materials, ASTM standards, and The Swedish Institute for Standards, SiS. A total of 15 grout-mixes were made. However, only the last five were used to cast specimens as the air content was insufficient in the first ten. The results indicated that it is necessary to replace the air-entraining admixture with microspheres in order for the pre-placed aggregate concrete to meet the requirements in exposure class XF3 and XC4. The scaling of the pre-placed aggregate concrete was less than 0.1 kg/m2 at 56 cycles, and thus, the freeze-thaw resistance was classed as very good. Moreover, the use of slag considerably reduced the bleeding of the grout and also improved the casting results. However, on the other hand, it increased the shrinkage of the pre-placed aggregate concrete. An efficiency factor of 0.6 proved to be too low since the compressive strength of the specimen with slag was approximately 50 % higher than the ones without. Furthermore, the shrinkage of the pre-placed aggregate concrete was after 63 days found to be lower than that of the conventional concrete. Also, the compressive strength of the pre-placed aggregate concrete without slag proved to be approximately 15 % lower than that of conventional concrete. Additionally, vibration during casting was found to increase the compressive strength of the pre-placed aggregate concrete and also improved the casting results. Low bleeding, combined with a high discharge time of approximately 45 seconds for 1.7 liters of grout, generated the best casting results. The results from the investigations have shown that this type of concrete has great potential. However, actions and further investigations should be made to see whether changing the fine aggregate size to a smaller one improves the ability of the grout to penetrate the voids between the coarse aggregates. Moreover, pump injection of the grout should be tested instead of pouring it over the coarse aggregates to see whether it improves the casting results and the mechanical properties.
Då en stor del av vattenkraftsdammarna i Sverige byggdes på 1950 och 1960-talet börjar många av dessa sakta men säkert brytas ner. Vattenkraftföretagen står inför stora utmaningar och investerar följaktligen i effektiva reparationsmetoder då dammbrott skulle kunna få allvarliga konsekvenser för människor, den omgivande miljön och för samhället. Flertalet konstruktioner inom vattenkraften är gjorda av betong och kraven på den nya kompletterande betongen är höga. En betong med potentialen att möta och uppfylla dessa höga krav är injekteringsbetongen som i tidigare studier uppvisat lovande resultat beträffande dess mekaniska egenskaper. Med anledning av detta är injekteringsbetongen av intresse att undersöka. Fokus har inte varit på att optimera injekteringsbetongen i syfte att genomföra fullskaliga försök. Istället har huvudsyftet med detta examensarbete varit att studera och analysera injekteringsbetongens mekaniska egenskaper såsom krympning, tryckhållfasthet, spräckhållfasthet, frostbeständighet samt undersöka viktiga parametrar i skapandet av ett homogent och lättflytande cementbruk som med god framgång kunde fylla ut hålrummen mellan grova ballasten. Undersökningarna utfördes genom laboratorieförsök på Vattenfalls betonglaboratorium i Älvkarleby. Vidare har skapandet och utvecklandet av bruket utförts i enlighet med metoder och krav angivna i American Society for Testing and Materials, ASTM standards, samt i Svenska institutet för Standarder, SiS. Totalt gjordes 15 bruksblandningar, dock användes enbart de sista fem till gjutning av provkroppar då lufthalten visade sig vara för låg i dem första tio. Resultaten indikerade på att det är nödvändigt att ersätta luftporbildare med mikrosfärer för att erhålla en lufthalt som uppfyller kraven för betong i exponeringsklass XF3 samt XC4. Injekteringbetongens avflagning efter 56 dygn var mindre än 0.1 kg/m2 och frostbeständigheten kunde därmed klassas som mycket god. Användningen av slagg minskade cementbrukets vattenseparation avsevärt och bidrog även till förbättrade gjutresultat. Dock bidrog det å andra sidan till en ökad krympning hos injekteringsbetongen. En effektivitetsfaktor på 0.6 visade sig vara för låg då injekteringsbetongen med slagg hade en cirka 50 % högre tryckhållfasthet än dem utan. Dessutom visade sig injekteringsbetongens krympning vara mindre än den konventionella betongens efter 63 dagar. Tryckhållfastheten hos injekteringsbetongen utan slagg uppvisade även en cirka 15 % lägre tryckhållfasthet än den konventionella betongens. Vibrering under gjutning visade sig höja tryckhållfastheten hos injekteringsbetongen samt förbättra gjutresultaten. En låg vattenseparation i kombination med en flödestid på cirka 45 sekunder för 1.7 liter bruk visade sig ge bästa gjutresultaten. Resultaten från laboratorieförsöken har visat på att injekteringsbetongen besitter stor potential. Dock bör ytterligare undersökningar genomföras för att bedöma huruvida en mindre ballastfraktion för sanden påverkar brukets förmåga att penetrera den grova ballasten. Vidare bör bruket pumpas in istället för att hällas över den grova ballasten, detta för att se huruvida gjutresultaten samt de mekaniska egenskaperna hos injekteringsbetongen skulle förbättras.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Anttila, S. (Severi). "Influence of minor elements on some weldability issues of intermediate purity stabilized ferritic stainless steels." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526219738.

Повний текст джерела

Анотація:

Abstract Stabilized ferritic stainless steel grades are attractive alternatives to common austenitic grades in sheet metal applications. Compared with older unstabilized ferritic grades, the mechanical and corrosion properties are usually improved. The impurity level, mainly the amount of interstitial carbon and nitrogen, plays an important role in these steels. There are notable issues in the welding of these steels, the most apparent difference to austenitic steels is the susceptibility to brittle failure. This research focused on the influence of minor elements, especially aluminium, calcium, silicon, titanium, niobium, nitrogen and oxygen, on the weldability of modern intermediate purity level stabilized ferritic stainless steels. The research proceeded in several stages. At first, the general characteristics and performance data about the welds in currently manufactured 11 to 21 mass percent chromium ferritic stainless steels in Europe was obtained. The research then focused on novel high chromium stabilized ferritic stainless steels. Lastly, the influence of various steelmaking practices on weldability were investigated. The results showed that in stabilized ferritic stainless steels, slag islands are frequently seen in the molten weld pools. These islands can have many origins, e.g. deoxidation, calcium treatment and stabilization practices, and they can be roughly assessed from the chemical composition of the steel. The nature and the influence of these slags varies and can be related to irregularities in the weldability and molten metal fluid flow. Large grain size and titanium carbonitride particles impair the toughness of the heat-affected zone. Generally, stabilization with niobium is preferred. However, solely niobium stabilized steel welds run the risk of forming coarse columnar grains in welds deteriorating some of the properties. A breakdown of the columnar grains is possible to achieve in autogenous welds with minor titanium and aluminium alloying, provided that small amounts of nitrogen and oxygen are induced from the shielding gas. However, grain refinement may not improve the properties, if it is accomplished with an increase in the total interstitial content
Tiivistelmä Stabiloidut ferriittiset ruostumattomat teräkset soveltuvat korvaamaan tavanomaisia austeniittisia ruostumattomia teräksiä ohutlevysovelluksissa. Näillä teräksillä keskeiset mekaaniset ja korroosio-ominaisuudet ovat usein paremmat kuin varhaisilla, stabiloimattomilla ferriittisillä teräksillä. Hiili ja typpi ovat näissä teräksissä kuitenkin epäpuhtauksia. Toisin kuin austeniittiset teräkset, ferriittiset teräkset ovat alttiita haurasmurtumalle, erityisesti hitsatuissa rakenteissa. Tässä väitöstutkimuksessa keskityttiin mikroseosaineiden ja epäpuhtauksien vaikutukseen keskipuhtaiden stabiloitujen ferriittisten teräslajien hitsauksessa. Tutkimus kohdistui erityisesti alumiinin, kalsiumin, piin, titaanin, niobin, typen ja hapen vaikutuksiin. Aluksi tutkittiin kaupallisten terästen hitsien keskeisiä ominaisuuksia. Tämän jälkeen tutkittiin uusia ns. korkeakromisia stabiloituja ferriittisiä teräslajeja. Lopuksi tutkittiin teräksen valmistuksen vaikutuksia stabiloitujen ferriittisten ruostumattomien terästen hitsattavuuteen. Tutkituilla teräksillä hitsauksen aikana muodostui runsaasti kuonalauttoja. Näillä kuonilla on monta alkuperää, esim. deoksidointi, kalsiumkäsittely ja stabilointiaineet. Hitsien kuonaisuutta voidaan karkeasti arvioida teräksen kemiallisen koostumuksen perusteella. Muodostuvilla kuonilla on useita vaikutuksia hitsauksessa, mm. epäjatkuvuuksiin ja sulan virtauksiin. Hitsauksessa muodostuva suuri raekoko ja stabiloinnin titaanikarbonitridipartikkelit heikentävät oleellisesti hitsin muutosvyöhykkeen sitkeyttä. Stabilointi käyttäen pääasiassa niobia on toivottavaa, mutta jos stabilointiin käytetään vain niobia, tulee hitsin mikrorakenteesta karkea ja hitsin ominaisuudet voivat heikentyä. Karkean mikrorakenteen hienontaminen on mahdollista käyttäen suojakaasuna argonia, jossa on hieman typpeä ja happea, mikäli teräkseen on seostettu hieman alumiinia ja titaania. Raerakenteen hienontaminen ei kuitenkaan yksiselitteisesti paranna hitsin ominaisuuksia, mikäli hienontaminen saavutetaan kasvattamalla epäpuhtauspitoisuutta tarpeettoman korkeaksi

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Sampaio, Soares Luis Fernando. "Influence of slab continuity on punching resistance." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/48011.

Повний текст джерела

Анотація:

This research addresses the design of reinforced concrete flat slabs for punching shear. Flat slabs are two way spanning slabs without downstand beams that are directly supported by columns. The thickness of flat slabs is typically governed by considerations of either deflection control or punching shear for which there is still no widely accepted theoretical treatment. The research seeks to develop a better understanding of the effects of in-plane restraint and flexural continuity on the punching resistance of flat slabs. The overriding aim is to determine whether flexural continuity is sufficient to explain the satisfactory performance of existing flat slabs which appear punching shear deficient when assessed against test data from isolated punching shear specimens. The influence of slab continuity on punching resistance is assessed through analysis of test data, nonlinear finite element analysis (NLFEA) and fib MC2010 Level of Approximation (LoA) IV which is based on the Critical Shear Crack Theory (CSCT) of Muttoni. The CSCT relates shear resistance to the width of the so-called ‘critical shear crack’ which depends on slab rotation. MC2010 has four LoA of which I to III are intended for design. Punching resistance is normally determined from tests on isolated slab-column specimens which are intended to simulate behaviour within the elastic line of contraflexure for radial moments, although the benefits of continuity on punching shear strength is well known. MC2010 LoA IV, which uses nonlinear finite element analysis to determine the slab rotation, is used to investigate and develop a better understanding of the influence of continuity on the punching shear resistance of flat slabs at edge and internal columns. The FE model is calibrated against relevant test data from both isolated and continuous specimens. Parametric studies are presented which show the superseded UK design code BS8110 to require significantly less punching shear reinforcement than EC2 (2004) and MC2010 LoA II which give reasonable strength predictions for isolated internal column punching specimens. Despite this, slabs designed to BS8110 have performed satisfactorily for many years. MC2010 LoA IV is used to show that punching resistance at internal columns can be increased significantly by restraint from the surrounding slab. The increase in punching resistance due to continuity is shown to be sufficient to explain the satisfactory performance of flat slabs designed to BS8110 at internal columns. However, the strength increase is variable and, in the case of uniformly loaded slabs, already largely included in BS8110 and EC2. The research also considers the influence of slab continuity on punching resistance at edge columns. Parametric studies are developed to examine the influence of shear force eccentricity, flexural reinforcement distribution between support and span, and modelling assumptions on the punching resistance of flat slabs at edge columns. Relating the punching resistance at edge columns to the elastic unbalanced moment as done in MC2010 LoA II and III is shown to be overly conservative for continuous slabs. The ACI 318 and EC2 practice of making the design punching resistance independent of the unbalanced moment is reviewed and shown to be reasonable particularly for continuous slabs. MC2010 LoA IV is shown to be a powerful tool for assessment, however the predictions for the method are very sensitive to the modelling assumptions and boundary conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Šimko, Lukáš. "Vliv ohybového namáhání na elektrické vlastnosti alkalicky aktivovaných struskových kompozitů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372061.

Повний текст джерела

Анотація:

Ordinary concrete is the most commonly used building material, but nowadays the requirements for low energy consumption, durability of structures together with their easy diagnostics as well as ecological production raises. This thesis deals with cement and aluminosilicate composites with content of conductive fillers, which allows to monitor the change in electrical properties, most commonly electrical resistance in dependence on mechanical stress. In the experimental part of the thesis, test beams were produced based on alkali-activated slag with content of carbon nanotubes, graphite powder, carbon black and carbon fibre. The beams were subjected to flexural loading in a three-point bending configuration and the shift in electrical resistance was monitored.

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Johnston, Katherine Ann. "Biochemical mechanisms of resistance of potato cultivars to slug attack." Thesis, University of Newcastle Upon Tyne, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254057.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Deva, Yashika Poorvi. "Slug flow induced corrosion studies using electrochemical noise measurements." Ohio : Ohio University, 1995. http://www.ohiolink.edu/etd/view.cgi?ohiou1179513355.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Lindeman, Harriet. "Spoken Resistance: Slam Poetry Performance as a Diasporic Response to Discursive Violence." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/scripps_theses/1032.

Повний текст джерела

Анотація:

This project foregrounds the work and perspectives of spoken word poets of Middle Eastern and North African (MENA) descent in connection to the NYC slam poetry scene. I trace the parallel racialization of MENA diaspora communities in the US and the development of slam poetry as a space for raising “othered” voices. Through ethnographic analysis, I consider slam poetry as a site of intersectional struggle, arguing that the engagement of MENA diaspora poets with this scene reveals the ways in which poetry both constitutes resistance to discursive violence through representation and works to mobilize audiences against tangible structures of violence.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Nguyen, Tien Dung. "Apport des aluminates de calcium vis-à-vis de la résistance à l'eau des sulfates de calcium hydratés." Thesis, Lyon, INSA, 2012. http://www.theses.fr/2012ISAL0002.

Повний текст джерела

Анотація:

Les sulfates de calcium sont des matériaux économiques et écologiques. Pourtant leur utilisation dans le domaine de la construction est assez limitée du fait de leur sensibilité à l’eau. La capacité des ciments alumineux (CAC) à diminuer la sensibilité à l’eau des sulfates de calcium ainsi que les mécanismes d’insensibilisation ont été étudiés. L’insensibilisation à l’eau des sulfates de calcium a été réalisée par ajout de faibles quantités de ciment alumineux (≤ 30%). Quatre sulfates de calcium de nature différente : gypse, hémi-hydrate α et β, anhydrite synthétique ont été étudiés. L’étude des mécanismes d’insensibilisation à l’eau des sulfates de calcium par ajout du ciment Fondu, menée à différentes analyses de la microstructure : IR, DRX, ATD-TG, MEB, a mis en évidence deux approches : la formation de l’ettringite insoluble et la formation du gel d’AH3 qui colle les grains de sulfate de calcium soluble. La nature des phases cristallochimiques du ciment alumineux a des influences sur les caractéristiques mécaniques, la sensibilité à l’eau ainsi que la durabilité des mélanges [sulfate de calcium / CAC]. L’étude des mélanges [anhydrite synthétique / laitier / CAC] offrent des perspectives intéressantes notamment concernant le développement des liants à faible empreinte CO2
Calcium sulphate materials are economical and ecological. But their use in the construction is quite limited because of their sensibility to water. The capacity of aluminate cement (CAC) to decrease the water sensibility of calcium sulphate and the mechanisms of insensibilisation were investigated. Waterproofing of gypsum base materials was carried out by addition of small amounts of aluminate cement (≤ 30%). Different nature of calcium sulphates : gypsum, hemihydrate α and β, synthetic anhydrite was studied. The study of mechanisms of insensibilisation to water of calcium sulphate by adding cement Fondu, with different analysis of microstructure : IR, DRX, ATD-TG, MEB, revealed two approaches : formation of ettringite insoluble and formation of gel AH3 that stick soluble grains of calcium sulphate. The nature of phases of aluminate cement has influences on the mechanical properties, sensibility to water and durability of mixtures [calcium sulphate / CAC]. The studies of mixtures [synthetic anhydrite / slag / CAC] offer interesting perspectives for the development of binders with low imprint CO2

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Повшук, Василь Володимирович. "Нанозміцнені периклазовуглецеві вогнетриви для футерівки конвертерів з використанням комплексного антиоксиданту". Thesis, НТУ "ХПІ", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/37726.

Повний текст джерела

Анотація:

Дисертація на здобуття наукового ступеня кандидата технічних наук (доктора філософії) за спеціальністю 05.17.11 – технологія тугоплавких неметалічних матеріалів (161 – Хімічні технології та інженерія). – Національний технічний університет "Харківський політехнічний інститут", Харків, 2018. Дисертація присвячена розробці складів та основних технологічних параметрів отримання нанозміцнених периклазовуглецевих вогнетривів для різних зон футерівки конвертера з заданими показниками фізико-механічних властивостей і підвищеною стійкістю до дії шлаку та до окиснення. У роботі теоретично обґрунтовано і експериментально доведено можливість одержання нанозміцнених периклазовуглецевих вогнетривів шляхом синтезу наповненої наночастинами β-SiC та NiO вуглецевої матриці-основи заданої структури периклазовуглецевих вогнетривів і забезпечення її максимальної струк-турної міцності за рахунок використання оптимальних співвідношень золь-гель добавок, що модифікують фенолформальдегідну смолу, і компонентів прекурсорів нікелевого антиоксиданту. Визначено технологічні параметри одержання периклазовуглецевих вогнетривів із заданими фізико-механічними властивостями на засаді плавленого периклазу і різною кількістю графіту, шляхом використанням ЕТС-40 або його золю та солей нікелю для створення комплексного антиоксиданту Аl + SiC + Ni(NiO), що забезпечує підвищену стійкість до окиснення за рахунок утворення щільного шару із наночастин β-SiC та Ni(NiO) навколо часток графіту, розроблено безвипалювану технологію та склади магнезіального флюсу для плавки сталі в конвертері з відходів периклазовуглецевих вогнетривів футеровок конвертерів, які сприяють прискоренню наведення шлаку в конвертері та підвищенню стійкості футерівки конвертера.
Thesis for the degree of candidate of technical sciences (Ph.D.) in specialty 05.17.11 – technology of refractory nonmetallic materials (161 – chemical technologies and engineering). – National Technical University "Kharkov Polytechnic Institute", Kharkov, 2018. The thesis is devoted to the development of compositions and basic techno-logical parameters for the preparation of nano-reinforced periclase-carbon refractories for various zones of converter lining with prescribed parameters of physical and mechanical properties and increased resistance to slag and oxidation. The possibility of obtaining nano-reinforced periclase-carbon refractories by synthesis of the carbon-matrix matrix of a given structure of periclase-carbon refractories filled with nanoparticles β-SiC and NiO and ensuring its maximum structural strength due to the use of optimum sol-gel admixtures for modifying the phenol-formaldehyde resin is theoretically substantiated and experimentally proved pre-cursor components of a nickel antioxidant. The technological parameters for the production of periclase-carbon refractories with specified physic-mechanical properties based on fused periclase with different amounts of graphite were determined using ETS-40 or its sol and nickel salts to create a complex antioxidant Al + SiC + Ni(NiO), which provides enhanced resistance to oxidation due to the formation of a dense layer of β-SiC and Ni(NiO) nanoparticles around graphite particles, a non-combustion technology and magnesia flux formulations for melting steel in a converter from waste periclase-carbon refractories lining of converters that accelerate guidance in the converter slag and improve the sustainability of the converter lining.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Повшук, Василь Володимирович. "Нанозміцнені периклазовуглецеві вогнетриви для футерівки конвертерів з використанням комплексного антиоксиданту". Thesis, НТУ "ХПІ", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/37701.

Повний текст джерела

Анотація:

Дисертація на здобуття наукового ступеня кандидата технічних наук (доктора філософії) за спеціальністю 05.17.11 – технологія тугоплавких неметалічних матеріалів (161 – Хімічні технології та інженерія). – Національний технічний університет "Харківський політехнічний інститут", Харків, 2018. Дисертація присвячена розробці складів та основних технологічних параметрів отримання нанозміцнених периклазовуглецевих вогнетривів для різних зон футерівки конвертера з заданими показниками фізико-механічних властивостей і підвищеною стійкістю до дії шлаку та до окиснення. У роботі теоретично обґрунтовано і експериментально доведено можливість одержання нанозміцнених периклазовуглецевих вогнетривів шляхом синтезу наповненої наночастинами β-SiC та NiO вуглецевої матриці-основи заданої структури периклазовуглецевих вогнетривів і забезпечення її максимальної струк-турної міцності за рахунок використання оптимальних співвідношень золь-гель добавок, що модифікують фенолформальдегідну смолу, і компонентів прекурсорів нікелевого антиоксиданту. Визначено технологічні параметри одержання периклазовуглецевих вогнетривів із заданими фізико-механічними властивостями на засаді плавленого периклазу і різною кількістю графіту, шляхом використанням ЕТС-40 або його золю та солей нікелю для створення комплексного антиоксиданту Аl + SiC + Ni(NiO), що забезпечує підвищену стійкість до окиснення за рахунок утворення щільного шару із наночастин β-SiC та Ni(NiO) навколо часток графіту, розроблено безвипалювану технологію та склади магнезіального флюсу для плавки сталі в конвертері з відходів периклазовуглецевих вогнетривів футеровок конвертерів, які сприяють прискоренню наведення шлаку в конвертері та підвищенню стійкості футерівки конвертера.
Thesis for the degree of candidate of technical sciences (Ph.D.) in specialty 05.17.11 – technology of refractory nonmetallic materials (161 – chemical technologies and engineering). – National Technical University "Kharkov Polytechnic Institute", Kharkov, 2018. The thesis is devoted to the development of compositions and basic techno-logical parameters for the preparation of nano-reinforced periclase-carbon refractories for various zones of converter lining with prescribed parameters of physical and mechanical properties and increased resistance to slag and oxidation. The possibility of obtaining nano-reinforced periclase-carbon refractories by synthesis of the carbon-matrix matrix of a given structure of periclase-carbon refractories filled with nanoparticles β-SiC and NiO and ensuring its maximum structural strength due to the use of optimum sol-gel admixtures for modifying the phenol-formaldehyde resin is theoretically substantiated and experimentally proved pre-cursor components of a nickel antioxidant. The technological parameters for the production of periclase-carbon refractories with specified physic-mechanical properties based on fused periclase with different amounts of graphite were determined using ETS-40 or its sol and nickel salts to create a complex antioxidant Al + SiC + Ni(NiO), which provides enhanced resistance to oxidation due to the formation of a dense layer of β-SiC and Ni(NiO) nanoparticles around graphite particles, a non-combustion technology and magnesia flux formulations for melting steel in a converter from waste periclase-carbon refractories lining of converters that accelerate guidance in the converter slag and improve the sustainability of the converter lining.

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Rapolu, Prakash. "Capillarity Effect on Two-phase Flow Resistance in Microchannels." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1204082574.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Cliff, Kevin Terry. "A study of membrane swelling and transport mechanisms in solvent resistant nanofiltration." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/9112.

Повний текст джерела

Анотація:

Recently a large amount of interest has developed around separating out impurities of small size; pertinent examples are found within fuel and solvent processing. For such applications a leading candidate process is nanofiltration. This thesis focuses on SRNF (solvent resistant nanofiltration) composite membranes consisting of a dense polymer active layer bonded to a stronger, but ultimately more porous, support layer. The composite membranes that have been produced during the course of this work consist of a PDMS (polymdimethylsiloxane) active layer bonded to a commercially available support layer of PAN (polyacrylonitrile). To create the membrane a monomer was spread over the support layer and then polymerised to form the matrix which was responsible for separation. Commercially, either heat or radiation is often applied to cause polymerisation, however the membranes in the current work have been formed by the used of a homogeneous catalyst. This thesis investigates the transport and separation dynamics of the produced membranes for a series of fuel simulants composed of organometallics and poly-nuclear aromatic solutes dissolved in aromatic and alkane solvents. Membrane composition and the extent of polymer swelling were found to be the two key factors which had the greatest influence on solvent flux and solute rejection. By increasing catalyst concentration it was found that the dual effects of increased rejection and reduced flux occurred, with the converse also being true. The effective pore size of the membrane could also be controlled by varying the catalyst amount during manufacture as this directly affected the limit of crosslinking which formed. Polymer swelling was the most pronounced using solvents with a solubility parameter close to that of the polymer. The membrane transport mechanism was most accurately forecast by the solution diffusion model for flux predictions and the convection diffusion model for rejection predictions, however all the models tried were in close agreement. This was postulated to be due to the swelled polymer matrix which allows for both convective and diffusive transport to occur.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Perera, Upul. "Seismic performance of concrete beam-slab-column systems constructed with a re-usable sheet metal formwork system /." Connect to thesis, 2009. http://repository.unimelb.edu.au/10187/4835.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Janoušek, Petr. "Vývoj kompozitů na bázi anorganických pojiv určených pro extrémní aplikace." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-225913.

Повний текст джерела

Анотація:

The topic of this master's thesis is the development of composite materials based on inorganic binders for use in extreme conditions. It means especially geopolymeric or alkali activated materials (AAM) based composites. The theoretical part of this thesis summarizes knowledges about the development and use of alkali-activated materials, their structure and mechanisms of their formation. It also deals with the applicable raw materials for AAM and their exciters, which are in particular water glass and sodium hydroxide. There also have been a summary of the effects of high temperatures and chemicals on the mechanical properties of AAM and the requirements of standard EN 1504-3 for repairing materials. The task of the practical part was to develop a repair mortar for concrete structures based on AAM so that its production was as simple as possible, ie one-component materials. Gradually six recipes have been develeoped. Test specimens made from these recipes have been putted to selected tests according to the requirements of ČSN EN 1504-3.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Fox, David Christopher Alexander. "The fire performance of restrained polymer-fibre-reinforced concrete composite slabs." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/17998.

Повний текст джерела

Анотація:

Composite slab flooring systems for steel-framed buildings consist of a profiled steel deck and a cast in-situ slab. The slab traditionally includes a layer of light gauge steel mesh reinforcement. This mesh is placed near the surface, which controls the early-age cracking caused by concrete drying and shrinkage. The steel mesh also performs a vital structural role at high temperatures. Structural fire tests and numerical investigations over the last 15 years have established that the mesh can provide enhanced fire resistance. A load-carrying mechanism occurs in fire with the mesh acting as a tensile catenary, spanning between perimeter supports. This structural mechanism is currently utilised regularly in the performance-based fire engineering design of steel-framed buildings. In a recent development, this mesh can be removed by using concrete with dispersed polymer fibre reinforcement to form the composite slab. The polymer-fibre-reinforced concrete (PFRC) is poured onto the deck as normal, and the fibres resist early crack development. For developers this technique has several advantages over traditional reinforcing mesh, such as lower steel costs, easier site operations and faster construction. However, to date the fire resistance of such slabs has been demonstrated only to a limited extent. Single element furnace tests with permissible deflection criteria have formed the basis for the fire design of such slabs. But these have not captured the full fire response of a structurally restrained fibre-reinforced slab in a continuous frame. The polymer fibres dispersed throughout the slab have a melting point of 160ºC, and it is unclear how they contribute to overall fire resistance. In particular, there has been no explanation of how such slabs interact with the structural perimeter to maintain robustness at high deflections. This project was designed to investigate the structural fire behaviour of restrained polymer-fibre-reinforced composite slabs. An experimental series of six slab experiments was designed to investigate the effects of fibre reinforcement and boundary restraint. A testing rig capable of recording the actions generated by the heat-affected slab was developed and constructed. Model-scale slab specimens were tested with different reinforcement and perimeter support conditions, to establish the contributions to fire resistance of the polymer fibres and applied structural restraint.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Aalto, Jonatan, and Elisabeth Neuman. "Comparison of Punching Shear Design Provisions for Flat Slabs." Thesis, KTH, Betongbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215631.

Повний текст джерела

Анотація:

Abstract A new generation of EN 1992-1-1 (2004) also known as Eurocode 2 is under development and currently there is a set of proposed provisions regarding section 6.4 about punching shear, PT1prEN 1992-1-1(2017). It was of interest to compare the proposal with the current punching shear design provisions. The aim of this master thesis was to compare the punching shear resistance obtained in accordance with both design codes. Furthermore the eect of some parameters on the resistance was to be compared. It was also of interest to evaluate the userfriendliness of the proposal. In order to meet the aim, a case study of a real 　at slab with drop panels was performed together with a parametric study of a pure ctive 　at slab. The parametric study was performed for inner, edge and corner columns in the cases prestressed, without and with shear reinforcement. It was concluded that the distance av from the column axis to the contra 　exural location has a big in　uence on the punching shear resistance. The factor ddg considering concrete type and aggregate properties also has a big impact on the resistance. The simplied estimation of av according to 6.4.3(2) in PT1prEN 1992-1-1 (2017) may be inaccurate in some cases. The length b0 of the control perimeter has a larger eect on the resistance in EN 1992-1-1 (2004) than in PT1prEN 1992-1-1 (2017). In PT1prEN 1992-1-1 (2017), studs located outside the second row has no impact on the resistance. The tensioning force in a prestressed 　at slab has a larger in　uence on the resistance in PT1prEN 1992-1-1 (2017) than in EN 1992-1-1 (2004). Furthermore, the reinforcement ratio is increased by the tendons, and thus aect the resistance in PT1prEN 1992-1-1 (2017). Clearer provisions for the denition of the support strip bs for corners and ends of walls are needed in PT1prEN 1992-1-1 (2017). It may be questionable if the reduction of the perimeter for a large supported area in accordance with 6.4.2(4) in PT1prEN 1992-1-1 (2017) underestimates the resistance v in some cases. Considering the work-load with PT1prEN 1992-1-1 (2017), more parameters are included. However, they may not require that much eort to obtain. Keywords: Punching shear, resistance, concrete, 　at slab, design provisions, Eurocode 2, case study, parametric study, shear reinforcement, prestressed vi

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Lehoťák, Roman. "Návrh betonové konstrukce s ohledem na požární odolnost." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2021. http://www.nusl.cz/ntk/nusl-444631.

Повний текст джерела

Анотація:

The diploma thesis deals with the analysis of internal forces and the design of the reinforcement of a reinforced concrete monolithic slab, a reinforcing wall and a column in the 1st floor of a dairy hall building. The fire resistance of selected structures was taken into account during dimensioning. The calculation of the internal forces was performed by the finite element method in Dlubal RFEM 5.24.

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Zápotočný, David. "Návrh betonové konstrukce s ohledem na požární odolnost." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409785.

Повний текст джерела

Анотація:

Diploma thesis deals with design of selected parts of reinforced concrete construction of a multi-storey building with respect of fire resistance. The proposed elements are reinforced concrete locally suported ceiling slab, selected column and wall. These structures are located in the storage hall on the 1st underground floor. Different variants of structural design are consulted and compared in this work. The calculation of internal forces is performed in the calculation software Scia Engineer 19.1. The thesis includes a structural design as well as drawings. The construction is designed according to ČSN EN standarts.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Jindra, Daniel. "Stanovení požární odolnosti konstrukcí." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392030.

Повний текст джерела

Анотація:

Possibilities of modeling non-linear behavior of concrete within standard room temperatures and increased fire-load values using FEM software ANSYS are studied. Temperature dependences of material models are considered. Fire resistance of reinforced concrete and concrete-steel composite construction is analyzed. Fire loads are defined in accordance with relevant standards. Non-linear structural transient analyses are calculated after temperatures were determined by transient thermal analyses. Results obtained from analyses of simple reinforced concrete structure are compared with approach of isotherm 500 °C method.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Van, der Merwe Johann Eduard. "Rocking shear wall foundations in regions of moderate seismicity." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1957.

Повний текст джерела

Анотація:

Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: In regions of moderate seismicity it has been shown that a suitable structural system is created when designing the shear wall with a plastic hinge zone at the lower part of the wall, with the shear walls resisting lateral loads and all other structural elements designed to resist gravity loads. A suitably stiff foundation is required for the assumption of plastic hinge zones to hold true. This foundation should have limited rotation and should remain elastic when lateral loads are applied to the structure. Ensuring a foundation with a greater capacity than the shear wall results in excessively large shear wall foundations being required in areas of moderate seismicity for buildings with no basement level. This study aims to investigate the feasibility of reducing the size of shear wall foundations in areas of moderate seismicity for buildings with no basement level. The investigation is aimed at allowing shear wall foundation rocking and taking into account the contribution of structural frames to the lateral stiffness of the structure. An example building was chosen to investigate this possibility. Firstly, lateral force-displacement capacities were determined for a shear wall and an internal reinforced concrete frame of this investigated building. Nonlinear momentrotation behaviour was determined for the wall foundation size that would traditionally be required as well as for six other smaller foundations. The above capacity curves against lateral loads were then used to compile a simplified model of the structural systems assumed to contribute to the lateral stiffness of the building. This simplified model therefore combined the effect of the shear wall, internal frame and wall foundation. Nonlinear time-history analyses were performed on this simplified model to investigate the dynamic response of the structure with different wall foundation sizes. By assessing response results on a global and local scale, it was observed that significantly smaller shear wall foundations are possible when allowing foundation rocking and taking into account the contribution of other structural elements to the lateral stiffness of the building.
AFRIKAANSE OPSOMMING: Daar is reeds getoon dat ŉ voldoende strukturele sisteem verkry word in gebiede van gematigde seismiese risiko indien ŉ skuifmuur ontwerp word met ŉ plastiese skarnier sone naby die ondersteuning van die muur. Skuifmure word dan ontwerp om weerstand te bied teen laterale kragte met alle ander strukturele elemente ontwerp om gravitasie kragte te weerstaan. Vir die aanname van plastiese skarnier sones om geldig te wees word ŉ fondasie met voldoende styfheid benodig. Só ŉ fondasie moet beperkte rotasie toelaat en moet elasties bly wanneer laterale kragte aan die struktuur aangewend word. ŉ Fondasie met ŉ groter kapasiteit as dié van die skuifmuur lei daartoe dat uitermate groot fondasies benodig word in gebiede van gematigde seismiese risiko vir geboue met geen kelder vlak. Hierdie studie is daarop gemik om die moontlikheid van kleiner skuifmuur fondasies te ondersoek vir geboue met geen kelder vlak in gebiede van gematigde seismiese risiko. Die ondersoek het ten doel om skuifmuur fondasie wieg aksie toe te laat en die bydrae van strukturele rame tot die laterale styfheid van die struktuur in ag te neem. Eerstens is die laterale krag-verplasing kapasiteit van ŉ skuifmuur en ŉ interne gewapende beton raam van die gekose gebou bepaal. Nie-lineêre moment-rotasie gedrag is bepaal vir die skuifmuur fondasie grootte wat tradisioneel benodig sou word asook vir ses ander kleiner fondasie grotes. Die bogenoemde kapasiteit kurwes is gebruik om ŉ vereenvoudigde model van die strukturele sisteme wat aanvaar word om laterale styfheid tot die gebou te verleen, op te stel. Hierdie vereenvoudigde model kombineer gevolglik die effek van die skuifmuur, interne raam en skuifmuur fondasie. Nie-lineêre tydgeskiedenis analises is uitgevoer op die vereenvoudigde model ten einde die dinamiese reaksie van die struktuur te ondersoek vir verskillende fondasie grotes. Resultate is beoordeel op ŉ globale en lokale vlak. Daar is waargeneem dat aansienlik kleiner skuifmuur fondasies moontlik is deur wieg aksie van die fondasie toe te laat en die bydrae van ander strukturele elemente tot die laterale styfheid van die gebou in ag te neem.

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Dogru, Sedat. "Sycophant Wireless Sensor Networks Tracked By Sparsemobile Wireless Sensor Networks While Cooperativelymapping An Area." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615139/index.pdf.

Повний текст джерела

Анотація:

In this thesis the novel concept of Sycophant Wireless Sensors (SWS) is introduced. A SWS network is a static ectoparasitic clandestine sensor network mounted incognito on a mobile agent using only the agent&rsquo
s mobility without intervention. SWS networks not only communicate with each other through mobileWireless Sensor Networks (WSN) but also cooperate with them to form a global hybrid Wireless Sensor Network. Such a hybrid network has its own problems and opportunities, some of which have been studied in this thesis work. Assuming that direct position measurements are not always feasible tracking performance of the sycophant using range only measurements for various communication intervals is studied. Then this framework was used to create a hybrid 2D map of the environment utilizing the capabilities of the mobile network the sycophant. In order to show possible applications of a sycophant deployment, the sycophant sensor node was equipped with a laser ranger as its sensor, and it was let to create a 2D map of its environment. This 2D map, which corresponds to a height dierent than the follower network, was merged with the 2D map of the mobile network forming a novel rough 3D map. Then by giving up from the need to properly localize the sycophant even when it is disconnected to the rest of the network, a full 3D map of the environment is obtained by fusing 2D map and tracking capabilities of the mobile network with the 2D vertical scans of the environment by the sycophant. And finally connectivity problems that arise from the hybrid sensor/actuator network were solved. For this 2 new connectivity maintenance algorithms, one based on the helix structures of the proteins, and the other based on the acute triangulation of the space forming a Gabriel Graph, were introduced. In this new algorithms emphasis has been given to sparseness in order to increase fault tolerance to regional problems. To better asses sparseness a new measure, called Resistance was introduced, as well as another called updistance.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Jirka, Petr. "Penzion na cyklostezce." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227832.

Повний текст джерела

Анотація:

The subject of this thesis is a design of a newly built guesthouse on a bicycle path in the village Spálené Poříčí. The building is designed in a gently sloping terrain towards the west. The main entrance faces the south. It is an object without a basement and with two above ground floors. The structure of the building is a transverse wall system made of ceramic fittings. Other walls are also made of ceramic fittings. The entire building is based upon the stripe foundations and footings. Pension is covered in the part of the accommodation and in the restaurant part with a gable roof. For the restaurant, a terrace is designed on the west side of the building. In this thesis, static and building equipments are solved. The building is also evaluated in the terms of lighting, thermal, acoustic requirements and the fire safety of building is also solved.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Pivodová, Alena. "Návrh železobetonového objektu s ohledem na požadavky požární odolnosti." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392070.

Повний текст джерела

Анотація:

The diploma thesis deals with an analysis of internal forces of B4 reinforced construction of an office building. Analysis takes into account interaction with subsoil and when designing structural parts of the building, different requirements for fire resistance of a structure are taken into account. A Dlubal RFEM 5.17 program was used for finite element analysis, and model functionality verification was performer by using a summation of moments method. The thesis deals with the design and assessment of a point-supported slab, column, inner and external walls.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Touš, Jakub. "Sportovní areál." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227863.

Повний текст джерела

Анотація:

The main focus of this thesis is to design the expansion and modernization of a sport complex "U Jezu" for a sport club TJ Roztoky. This thesis is consisted of a study for a territorial agreement. In this study, there are indicated a formation of two playing fields with the artificial surfaces, beach volleyball court proposing two building objects as a base for the entire complex, which consists of garages, storages and a main building. A more detailed design was created for the main building. As the supporting structure of the object, the transverse wall system completed with outdoor columns supporting the cantilevered portion of the ceiling tiles, which are mainly unidirectionally reinforced concrete floor slabs. The supporting structure is based on the strip foundations. The designed building object has two-above ground floors and a ground floor, which will be created by embedding the building object into the hill side. The ground floor is designed for the relaxation and the leisure purposes. Moreover, there is also a technological equipment necessary for the operation of the facility. On the first above ground floor, there are designed locker rooms for athletes, a club room with a kitchen and an accommodation unit for a manager of the complex. The second floor is for the accommodation. There are designed rooms with lounge and office of the president of the sport club. Part of the second floor consists of a terrace. For the roofing, a flat roof with a single-classic sequence of layers is designed. In this thesis, the static is partially solved. Furthermore, the object is evaluated in the terms of lighting, acoustic and thermal requirements as well as requirements for the fire safety of buildings.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Forman, Daniel. "Základní škola." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226178.

Повний текст джерела

Анотація:

Thesis Theme is a primary school, namely the outbuilding primary school Havlíčkův Brod, Konečná 1884. I suggest first grade pavilion and pavilion with school canteen with kitchens. Pavilions are based on the footings. Pavilions are designed as a two-way system from the wall HELUZ. Construction of ceiling are from ferroconcrete slabs are cross reinforced, single-layer roof is flat with a classic sequence of layers. In addition to construction and process layout I solved also the statics of building in specialize of concrete structures. The following are also evaluated heat and acoustic requirements and requirements for fire safety of buildings. New pavilions are solved as wheelchair accessible. Pavilion of the first grade has two floors with 5 classes of stem, 1 vocational and 2 classes are earmarked for after-school clubs. This pavilion is connected to the connecting neck between the former pavilon A and pavilion B. Dining pavilion has one floor, which is divided in the school canteen and kitchen is connected to the connecting neck leading to the gym. The land is mildly sloping to the south side. All consstructions comply with the applicable standards and recommendations ČSN.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

LaBarca, Irene K. "Deicer scaling resistance of concrete containing slag cement." 2006. http://catalog.hathitrust.org/api/volumes/oclc/70222728.html.

Повний текст джерела

Анотація:

Thesis (M.S.)--University of Wisconsin--Madison, 2006.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 108-110).

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Wu, Chong Hao, and 吳崇豪. "Research on the Abrasion Erosion Resistance of Slag Concrete." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/55024361435235995473.

Повний текст джерела

Анотація:

碩士
國立中興大學
土木工程學系
92
Often staying in the aggressive environment a hydraulic concrete structure should have abrasion erosion resistance. The abrasion resistibility of concrete surface will govern the durability of hydraulic structures. In this research two new developed waterborne sand and gravel flow abrasion test apparatus were adopted for test that simulates the abrasion erosion of concrete that takes place in the field. The slag was added in concrete to improve the abrasion resistibility. Five water to binder ratios (w/cm) and four slag contents were selected for the mixture designs to make concrete specimens for abrasion test. Test results show that adding slag in concrete can obviously enhance its abrasion resistance. Concrete made with a w/cm ratio of 0.35, the abrasion erosion rate was the minimum for the 45% slag content namely, such a concrete has the best abrasion erosion resistibility.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Hsu, Chia-Chan, and 許家展. "Study of molten-slag corrosion resistance of magnesia-chrome brick." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/48268304763084860093.

Повний текст джерела

Анотація:

碩士
國立成功大學
材料科學及工程學系
89
This study simulated the work conditions in the smelting reduction processes for high corrosion between refractories and slags with high FeO content, low basicity 1and low carbon content1 at 1650℃. The relationship between test temperature, time and molten-slag corrosion, the corrosion resistance mechanism was discussed. The corrosion test was determined by using dynamic rotary slag corrosion and electric furnace static slag corrosion tests. The magnesia-chrome refractory specimens were investigated by X-ray diffraction, optical polarized microscope, scanning electron microscope (SEM), energy dispersive spectrometer (EDS), mapping, line scanning, scanning transmission electron microscope (STEM) and electron diffraction (ED) patterns after corrosion test. The excellent corrosion resistance with only 1% eroded area was obtained for the magnesia-chrome bricks after dynamic rotary slag corrosion test at 1650℃ for 9 cycles. The penetration layer of 20 mm formed in the magnesia-chrome bricks specimens. The open porosity about 4 % and pore size about 6μm in the penetration layer were lower and smaller than that of origin bricks. After electric furnace static slag corrosion test, XRD result shows that the MgO content in the penetration layer decreased with increasing test temperature and time. And further, it reacted with SiO2 and CaO to form CaMgSiO4 compound which was met and propagated along the crack into the slag. After electric furnace static slag corrosion test, a diffusion layer between magnesia-chrome brick and slag was formed. The thickness of diffusion layer increased with increasing test time. From TEM analysis, the diffusion layer was (Mg,Fe)(Al,Cr)2O4 solid solution which bounded well with MgCr2O4 phase.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Chen, Li-Hsiung, and 陳立雄. "Study of Grounding Resistance Reduction Using Granulated Blast-Furnace Slag." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/86299596908480309139.

Повний текст джерела

Анотація:

碩士
國立成功大學
電機工程學系
89
The granulated blast furnace slag is waste of the by-products of steel-making plant. It mostly applies in civil engineering、build engineering and build road now, it will be the major task of the environmentalism from now on that the granulated blast furnace slag is reclaimed in other domain. The characters of low resistivity and glue about the granulated blast furnace slag, can product glue under cement-hydrate catalyst, and it should be material of the grounding resistance reduction. This paper discuss the granulated blast furnace slag of main material of the grounding resistance reduction. According to the additives of the differnet proportion of water、cement and salt, its resistivity and clot strength are considered, the optimum combination is sought out. The finished product can be used in the grounding resistance reduction. And the grounding bar is buried in it, The proposed method is testified that achieve the purpose of reducing the grounding resistance effectively by measurement result.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Chen, Tsung-Rurng, and 陳聰榮. "Slag Resistance of AlO-SiC-C Blast Furnace Trough Castables." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/77700651985180221872.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Juan, Chun-Kai, and 阮俊凱. "Study on modify shear and bending resistance of steel- polyethylene slag HyFRC." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/89212949688694920868.

Повний текст джерела

Анотація:

碩士
國立中山大學
海洋環境及工程學系研究所
101
Concrete is the most used engineer material on the world. It is a brittle material, good in compression resistance but poor in tensile and bending resistance. Hence, we put fiber into concrete to modify its mechanical properties. A newer material is hybrid fiber reinforce concrete (HyFRC), it’s still under developing now. This study use hyper performance polyethylene fiber (Dyneema) and hooked-end steel fiber, to research the mechanical properties variety of concrete by different length of dyneema in the same hybrid fiber amount added. This study plan use dyneema length 2cm, 4cm, 6cm and 3cm steel fiber, and two different concrete W/B= 0.35(Air entrained &; Water-reducing added) and W/B=0.42.there are 6 sets of HyFRC and2 sets of OPC to compare the benefit by hybrid fiber. After tests we can get the compression stress of HyFRC is 10% more than OPC, and shear stress is over 30% than OPC and also can absorb more over 100% energy before failure. If fiber too long, it will agglomerate seriously and cause bleeding and segregation, it makes poor mechanical properties. At last, the conclusion of this study is the best polyethylene fiber length is 2cm and Air entrained &; Water-reducing added.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Peng, Sheng-Yang, and 彭勝暘. "The Abrasion Resistance of Cement Mortar Fabricated from Electric Arc Furnace Oxidizing Slag." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/31937262296543998265.

Повний текст джерела

Анотація:

碩士
國立聯合大學
土木工程與防災科技研究所
102
Electric arc furnace (EAF) oxidizing slag is a byproduct generated by the EAF steelmaking process. Approximately 1 million tons of oxidizing slag is produced each year in Taiwan. The oxidizing slag can be recycled after processing by using magnetic separation, crushing, and sieving. The processed oxidizing slag is typically used as backfill or roadbed material, providing low economic value. To enhance the economic benefits of oxidizing slag, this study adopted oxidizing slag as an abrasion-resistant material. This study first tested the basic physical properties of standard sand, oxidizing slag, natural sand, corundum, emery, emery MK2 and emery MK3, which involved water absorption, specific gravity, sieve analysis, Mohs hardness, and aggregate soundness testing. Second, based on the sieve analysis of five fine aggregate types and various material ratios as specified by Chinese National Standards (CNS) 1010, this study fabricated cement-mortar compressive blocks and abrasion-resistant plate specimens, tested mortar fluidity, and used standard sand as the control group to compare variations in the workability and compressive strength of varying fine aggregates of identical and diverse grades. In addition, this study employed X-ray diffraction (XRD) and scanning electron microscopy (SEM) to analyze the main components and microstructure of the material. Finally, based on the CNS 14792, a method for testing the abrasion resistance of concrete was adopted. This study fabricated cement plates and compared the 28-day abrasion resistance to investigate the abrasion rates of cement plates composed of various fine aggregates of different grades, and to analyze the difference in abrasion resistance between oxidizing slag and traditional abrasion-resistant material (such as emery and corundum). The feasibility and applicability of oxidizing slag used as abrasion-resistant material was evaluated.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Vassilev, Dimitre Georgiev. "Evaluation of Test Methods for De-icer Scaling Resistance of Concrete." Thesis, 2012. http://hdl.handle.net/1807/33570.

Повний текст джерела

Анотація:

The standard ASTM C672 de-icer salt scaling resistance test has been found to be overly aggressive to concretes containing slag cement. It was compared to the newly proposed ASTM WK9367 method, based on the Quebec BNQ test, as well as several modifications, including use of an accelerated curing regime developed in Virginia (VADOT). Sixteen concrete mixtures were studied using high-alkali cement, low-alkali cement, grade 100 slag and grade 120 slag with slag contents of 0%, 20%, 35% and 50%. Vinsol resin air-entraining admixture was compared to Micro Air®. Reducing the water cement ratio from 0.42 to 0.38 had the biggest impact on improving scaling resistance of slag concretes. In general, increased slag contents increased scaling regardless of the test method used. The Micro Air® admixture provided a lower air void actor and higher hardened air content compared to Vinsol resin.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Wan-HsinJao and 饒莞馨. "Comparative Study of Modified BOF Slag and Railway Ballast on Electrical Resistance and Carbon Footprint." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/38399492506687485701.

Повний текст джерела

Анотація:

碩士
國立成功大學
土木工程學系
103
Normally, railway ballast is made of crushed stone. But the resource is limited, so it would cause damage to the nature. If we can find the substitute for crushed stone, it would be benefit to sustainable development. In this paper, the applicability of BOF slag as railway ballast will be discussed. First, explain the production process and the classification of slag. Describe the physical properties and chemical properties of BOF salg. Then choose electrical resistance experiments to compare BOF slag with crushed stone. To inspect whether BOF slag conform the specification or not. At last, calculate the carbon emissions of BOF slag and crushed stone. After 7 months measurement, found that both of ballast resistance and rail insulation to earth of BOF slag is agree with the specification. But the electrical resistance is doubt that might be too large. According to the other experiment, found that the roadbed type will affect the resistance value. The carbon emission of BOF slag is slightly smaller than the crushed stone. And the carbon emission of transportation phase in the life cycle has the highest percentage.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Chang, Shao-Pu, and 張少璞. "Rutting Resistance of Asphalt Concrete Pavement with the Basic Oxygen Furnance Slag of Different Grain Sizes." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/03531920981697854113.

Повний текст джерела

Анотація:

碩士
國立中興大學
土木工程學系所
105
Abstract In Taiwan,the variation of urban and rural developmentand population clusterto the city cause the roads used with highly loading bearing capacityso it has tomaintain frequently for the past few years.This study uses the physical property of the Basic Oxygen Furnace Slagdesigns of mix proportion with its different grain sizes instead of part ofnatural gradation and analyses the differences and results for rutting resistance through the test data. First of all, itconduct two sets design of mix proportionwith 19mm nominal maximum size added by 43% of basic oxygen furnace slag of different grain sizes. Determining the curve of combined gradation of aggregate throughaggregatesieve analysis,specific gravity, water absorption , physical properties tests before the design of mix proportion .Moreover , itdecidedthe porosity and optimum oil content then checked the stability,the porosity between aggregate and asphalt filling rate in accordance with ASTM. Finally, conducting the retained strength and wheel-tracking tests analyzed the differences of data. In conclusion, itevaluated the influence for rutting resistance of dense grade asphalt concrete pavement with the basic oxygen furnace slag of different grain sizes. The results showed the total settlement of asphalt concrete , dynamic stability and deformation after adding the basic oxygen furnace have a betterbehavior. Using the AC3 and AC6 basic oxygen furnace (hereinafter to be referred as AC3 an AC6) instead of the natural gradation in the same grain size, the AC6 is better. It may be the reasonthe shape and rigidity of it blend into the asphalt concrete has higher ability of resistance deformation than the same grain sizes of the natural gradation. It suggests that it can use the AC6 with AC3 to enhance the ability of rutting resistance on the highly loading bearing capacity roads.

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Lin, Kuan-Ting, and 林冠婷. "The study in the pullout resistance of galvanized rebar embedded in concrete containing blast furnace slag and fly ash." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/15738692270033870944.

Повний текст джерела

Анотація:

碩士
國立高雄應用科技大學
土木工程與防災科技研究所
103
This study was to evaluate the pullout resistance of galvanized rebar in the concrete mixes containing pozzolanic materials, namely blast furnace slag and fly ash. Two concrete mixes were designed with 280 kgf/cm2 in the compressive strength and 0.5 in the water to cement ratio with 10%, 20%, and 30% of blast furnace slag or fly ash that were proportioned. Fresh and harden concrete properties of 7, 14, 28, 56, 91, and 120-days moist cured concrete cylinders were assessed. It has to be noted that regular and zinc-coated galvanized rebars were designed and embedded in the center of the concrete cylinders (φ10cm×20cm) for the pullout test. The test results of fresh concrete properties showed good workability of both concrete mixes containing pozzolanic materials. When more pozzolanic materials were added, concrete setting time, compressive strength, the velocity of ultrasonic wave, and electric resistance increased and the unit weight decreased. In addition, the force-displacement diagram of the pullout test in the galvanized rebar showed a rather higher slope in comparison with that of regular rebar in both concrete mixes containing pozzolanic materials, which may indicate a better pullout resistance in the use of galvanized rebar. The conclusions of this study provide a good reference of galvanized rebar resistance embedded in concrete containing blast furnace slag and fly ash.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Chang, Jiun-Ran, and 張鈞然. "CaCO3/Ca3(SiO4)O powder mixed with SiO2/modified desulfurization slag for improving theanti-corrosion and heat resistance ability of AZ91DMagnesium alloy." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/86155673215889778504.

Повний текст джерела

Анотація:

碩士
國立中興大學
材料科學與工程學系所
102
Magnesium alloys have low density and high strength/weight ratio. These characteristic make magnesium alloys being a potential candidates to replace steel and aluminum alloys in many structural and mechanical applications especially in vehicle application. However, magnesium alloy has high electrochemical activity, and therefore a poor corrosion resistance. Besides, magnesium alloys have poor mechanical properties at high temperature. Accordingly, usage of magnesium alloys are not yet widespread. In this study, using CaCO3/Ca3(SiO4)O powder mixed with SiO2 or modified desulfurization slag spraying on the surface of AZ91D. That could improve the anti-corrosion and heat resistance ability of AZ91D. The spray coating layer contain more SiO2 percentage which has better anti-corrosion and heat resistance ability. The result of experiment show that the spray coating layer’s containing 16 wt.% SiO2 thermal diffusivity is 2.9 mm2/s. After 96 hours salt spray test, the spray coating containing 16 wt.% SiO2 corrosion area less than 5%. The adhesion strength of spray coating layer containing 16 wt.% SiO2 is 0.92 MPa. By the result of cross cut test, the spray coating layer containing 16 wt.% SiO2 reached 4B level. On the other hand, the spray coating layer contain more modified desulfurization slag percentage has better anti-corrosion and heat resistance ability. The spray coating layer’s containing 16 wt.% SiO2 thermal diffusivity is 2.9 mm2/s. After the 96 hours salt spray test, the spray coating contains 24 wt.% modified desulfurization slag corrosion area less than 5%. The adhesion strength of spray coating layer containing 24 wt.% modified desulfurization slag is 1.18MPa. By the result of cross tape test the spray coating layer containing 24 wt.% modified desulfurization slag reached 4B level.

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Wang, Jun-Hong, and 王駿宏. "Spray coating of CaCO3/Ca3(SiO4)O slurry containing SiO2/modified desulfurization slag on AZ91D Mg alloy for improving the corrosion performance and the heat resistance of the alloy." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/91507866886936251391.

Повний текст джерела

Анотація:

碩士
國立中興大學
材料科學與工程學系所
103
In this study, CaCO3/Ca3(SiO4)O slurry containing different weight ratio of SiO2 and modified desulfurization slag, sprayed coating on AZ91D for improving the corrosion performance and the heat resistance of the alloy. The result of experiment show the corrosion performance of the spray-coated AZ91D is improved with increasing SiO2 content added into cement slurry. When the spray coating containing >12 wt.% SiO2, the corrosion performance of the spray-coated AZ91D is not enhanced and C-S-H (CaO-SiO2-H2O) gel is hindered self-repair. In addition, when 30 wt.% modified desulfurization slag added into containing 12 wt.%SiO2 cement slurry spray coating on AZ91D (C+12S+30M@AZ91D), the corrosion current density of the spray-coated AZ91D was decreased from 198 μAcm-2 (AZ91D) to 14.61 μAcm-2. The anti-salt spray time of C+12S+30M@AZ91D is improved to 144 hour. The corrosion resistance ability has elevated the phenomenon. After 48 hour of salt spray test, the C+12S+30M@AZ91D surface can be found the forming of CaO-CaCO3 dense layer. In heat resistance properties, the C+12S+30M@AZ91D surface on the coatedside was heated to 500 ℃, the tensile strength of C+12S+30M@AZ91D can be maintained at 204 MPa. The ignition temperature of C+12S+30M@AZ91D is increased from 580 ℃ (AZ91D) to 650 ℃. The time to onset burning at 735 ℃ of C+12S+30M@AZ91D can be increased from 45 second (AZ91D) to 89 second. The spray-coated AZ91D, the coating materials containing the 12 wt.% SiO2 cement slurry added with 30 wt.% modified desulfurization slag, can improve the corrosion performance and the heat resistance of AZ91D. After spray-coated on AZ91D, the density rising of the spray-coated AZ91D was maintained at <5 %.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Huang, Yong-Cheng, and 黃永承. "Study of Effluence-Resistant Mortar with Slag." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/98123920044440734659.

Повний текст джерела

Анотація:

碩士
國立雲林科技大學
營建工程系碩士班
101
The environment of Taiwan is hot and wet. When moisture permeates into concrete of structure, calcium hydroxide forms and is carried to the surface of concrete to form efflorescence. Agent of inhibitor for efflorescence was developed for retard calcium hydroxide and moisture. Slag of waste contains heavy metal. Cement products using slag of waste always have problems of diffusing of heavy metal and efflorescence. Agent of inhibitor for efflorescence is applied in this study to solve the problems.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Chin-ShouLin and 林晉守. "Effects of Slag Content on Drained Shear Resistances of Slag-MLS mixed Soils under Simple Shear Conditions." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/55mx8e.

Повний текст джерела

Анотація:

碩士
國立成功大學
土木工程學系
106
Taiwan is an island-type country. Due to its geographical location, the port is developing rapidly. The construction of the port is accompanied by problems such as silt accumulation in the port, the retreat of the surrounding coastline, and disappearance of the beach. Therefore, the dredging operation of the port and sand fill works around the port are environmental sustainability issues. This study uses the dredged sediment from the Mai-Liao harbor to add the BOF slag as a more anti-erosion and shear-resistant backfill material. The BOF slag is the by-product of the steelmaking industry, which has a high shear resistance and specific. The research content is to uniformly mix the Mai-Liao Sand (MLS) and the BOF slag in different ratios, calculate the pore parameters of the soil from the viewpoint of particle structure and prepare the specimen by water pluviation. We use consolidation drainage simple shear test to investigate the influence of different BOF slag content on the physical and mechanical properties of the dredged sediment form Mai-Liao harbor. And we prepare the specimen by layering the BOF slag method to investigate the difference in shear resistance between uniformly mix method and layered method. The results verify the feasibility of the BOF slag as a hybrid modified backfill material and provide a quantitative result as a reference for field application.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Diaz, Alfonso J. "Seismic resistance of fiber-reinforced slab-column connections." Thesis, 1991. http://hdl.handle.net/1911/13523.

Повний текст джерела

Анотація:

Three interior and three exterior fiber reinforced slab-column connections were subjected to gravity loads and then tested under lateral load simulating earthquake forces. Test results were compared to previous tests on non-fiber slab-column connections. Addition of steel fiber to the concrete matrix greatly increased the ductility and the energy dissipation capacity of all specimens. Fiber reinforcement also enhanced the shear capacity of interior connections. The failure mode switched from punching shear in interior connections with small amount or no fiber reinforcement to flexure failure in interior connections with higher fiber reinforcement ratios. Fiber reinforcement apparently did not improve the shear strength of exterior connections. The optimum amount of steel fiber found through the tests was between 50 and 100 pounds of fiber per cubic yard of concrete.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Chen, Cheng-Chung, and 陳政宗. "Effects of Slag Modifer on Mechanical Properties of Low Carbon Wear-Resistant Steels." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/7j2t74.

Повний текст джерела

Анотація:

碩士
國立臺北科技大學
材料科學與工程研究所
97
An nvestigation on Slag modifier is added to low carbon wear- resistance steels in the high frequency induction furnace melting. Recelently there were two ways to do in the high frequency induction furnace melting. One iscalled SPAL(Surface Protective Air Liquide) procress, the other is Gas Diffuser procress .Generally peaking high frequency induction furnace is only melting but add Slag modifier can dorefining the same as steel making, There has refining procress too, Slag modifier is the same application as E.S.R(Elactroslag relting). The liquid metal can be purifying, It get good mechanical properties. We add Slag modifier some different quantity in the high frequency induction furnace melting to to low carbon wear- resistance steels It not only can increase liquid metal fluidity but also reduce gas hole, inclusion to get good mechanical properties. This is a creative way to do .The benefit is It can help operator simply to do his job also reduce cast cost ,we have done many material test to disscuss for example: the tensile strength test,hardness test,impact test ,S.E.M micrographs,XRD analtsis ect. iffuser),SPAL (Surface protection Air Liquid).

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Guo, Kaifeng, and 郭凱峰. "Study of Correlation of Transient Thermal Resistance across Multi-Layer Slab." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/59432530333825458394.

Повний текст джерела

Анотація:

碩士
國立屏東科技大學
車輛工程系所
102
In the study of heat transfer, the steady-state temperature distribution in a composite slab can be solved for using the thermal resistance. However, the one-dimensional transient heat conduction problems frequently encountered in the industry have not been tackled to predict the change din temperature over time simply based on a concept similar to the thermal resistance. Although the method of solution for time-dependent temperature variations within a composite slab has been developed for some time, its implementation is quite complex and cumbersome. This is even more difficult if the aforementioned method is to be adopted to fit the concept of thermal resistance. The purpose of this thesis is to develop a correlation that can be fast and conveniently adopted for the use of transient thermal resistance. This work employed ANSYS software to study the heat conduction phenomena in a composite slab with a finite thickness through the simulations of transient heat conduction through the slab. Later, the values of coefficients appeared in the correlation were determined using the curve fit function available in MATLAB software. For verification, the temperature distribution predicted via the correlation was then compared to the temperature values obtained from numerical simulation. After that, this thesis derived the equation for transient heat flux based the Fourier’s law and the distributions of the transient heat flux across the composite slab were also compared to those obtained numerically for validation. Once the feasibility of the correlation has been confirmed, the mathematical model for transient thermal resistance was successfully developed.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Akinwale, Abiodun Ebebezer. "The effect of South African quaternary supplementary cementitious blends on corrosion behaviour of concrete reinforcement in chloride and Sulphate media." Diss., 2018. http://hdl.handle.net/10500/25242.

Повний текст джерела

Анотація:

The aim of this study was to assess the strength, durability properties and corrosion resistance of concrete samples using supplementary cementitious blended materials. In this investigation, three supplementary concrete materials (SCMs) were used together with ordinary Portland Cement (OPC) to form cementitious blends at different proportions. The supplementary materials are silica fume (SF), ground granulated blast furnace slag (GGBS) and fly ash (FA). Sixteen (16) different proportions of the cementitious blends were produced. Tests carried out on concrete samples include slump test, compressive strength, oxygen permeability, sorptivity, porosity, chloride conductivity test, resistance to chloride and sulphate attack. The electrode potentials of tested samples were also observed using electrochemical measurements. Concrete specimens prepared with 10%, 20%, 30%, 40%, up to 60% of blended cements replacement levels were evaluated for their compressive strength at, 7, 14, 28, 90 and 120 days while the specimens were evaluated for durability tests at 28, and 90 days respectively. The results were compared with ordinary Portland cement concrete without blended cement. Voltage, and temperature measurements were also carried out to understand the quality of concrete. The corrosion performance of steel in reinforced concrete was studied and evaluated by electrochemical half-cell potential technique in both sodium chloride, and magnesium sulphate solutions respectively. The reinforced concrete specimens with centrally embedded 12mm steel bar were exposed to chloride and sulphate solutions with the 0.5 M NaCl and MgSO4 concentrations respectively. An impressed voltage technique was carried out to evaluate the corrosion resistance of the combination of quaternary cementitious blended cement, so as to get the combination with optimum performance. Improvement of strength, durability, and corrosion resistance properties of blended concrete samples are observed at different optimum percentages for binary, ternary and quaternary samples. The effect of cementitious blends is recognized in limiting the corrosion potential of the tested SCM concrete samples. Generally, the cementitious blends with limited quantity of SF to 10% have the potential to produce satisfactory concrete. These should however be used for low cost construction, where high quality concrete is not required.
Civil and Chemical Engineering
M. Tech. (Chemical Engineering)

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Du, Yong. "Seismic resistance of slab-column connections in non-ductile flat-plate buildings." Thesis, 1993. http://hdl.handle.net/1911/16619.

Повний текст джерела

Анотація:

In order to determine the seismic response of existing reinforced concrete non-ductile flat-plate buildings, four reinforced concrete slab-column connection subassemblies designed for gravity load only were built at half-scale of prototype structure, and tested at Ryon laboratory of the Rice University. Each specimen had two exterior and one interior connections. The variables included the presence of spandrel beam, magnitude of gravity load, and reinforcing arrangement. The behavior of entire subassemblies and the individual connections under the cyclic loading was studied in terms of failure mode, stiffness, ductility, shear capacity, and moment transfer capacity in the two loading directions. Based on the test results, a procedure to predict the flexural and shear strengths of the interior and exterior connections is recommended. A hysterestic model for non-ductile slab-column connections is proposed. This model reflects the unsymmetrical moment transfer behavior of non-ductile connections. Furthermore, the model is incorporated in a non-linear dynamic analysis program and a typical flat-plate building is analyzed to demonstrate the application of the analytical model.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

CHANG, TZU-HUA, and 張慈華. "Slug Confers Resistance to the Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/01807552049649278825.

Повний текст джерела

Анотація:

博士
國防醫學院
醫學科學研究所
99
Rationale: Non-small cell lung cancers carrying epidermal growth factor receptor (EGFR) mutations respond well to EGFR tyrosine kinase inhibitors (TKIs), but patients ultimately develop drug resistance and relapse. Although epithelial-mesenchymal transition (EMT) can predict resistance to EGFR TKIs, the molecular mechanisms are still unknown. Objectives: To examine the role of EMT regulators in resistance to gefitinib. Methods: The expression level of EMT regulators in gefitinib-sensitive cells (PC9) and gefitinib-resistant cells (PC9/gef) was determined using quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis. Molecular manipulations (silencing or overexpression) were performed to investigate the effects of EMT regulators on gefitinib resistance in vitro, and a xenograft mouse model was used for in vivo confirmation. In addition, cancer cells from fifty-four patients with malignant pleural effusions of lung adenocarcinoma were collected for analysis of EMT regulator mRNA by quantitative real-time RT-PCR. Results: Slug expression, but not that of snail, twist or zeb-1, was significantly increased in PC9/gef compared to PC9 cells. Slug knockdown in PC9/gef cells reversed resistance to gefitinib, and overexpression of Slug in PC9 cells protected cells from gefitinib induced-apoptosis. Silencing of Slug in gefitinib-resistant cells restored gefitinib-induced apoptosis primarily through Bim upregulation and activation of caspase-9. Slug enhanced tumor growth in a xenograft mouse model, even with gefitinib treatment. In clinical samples, Slug expression was significantly higher in cancer cells with resistance to EGFR TKIs than in treatment-naïve cancer cells. Conclusions: Slug contributes to the resistance to gefitinib and may be a potential therapeutic target for treating resistance to EGFR TKIs.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

CHOI, Sung-Min. "Fatigue Resistance of Angle Shape Shear Connector used in Steel-Concrete Composite Slab." Thesis, 2011. http://hdl.handle.net/2237/14871.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Cheng, Ching-Chia, and 鄭景家. "VEGF-C-induced slug expression contributes to acquired resistance of gefitinib in lung cancer." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/z497j3.

Повний текст джерела

Анотація:

碩士
中國醫藥大學
癌症生物學研究所碩士班
102
Lung cancer is one of the most common malignancies worldwide. Epidermal growth factor receptor (EGFR) regulates many biological functions including proliferation, anti-apoptosis and metastasis. A specific EGFR tyrosine kinase inhibitor, gefitinib (Iressa, ZD1839), has been developed to exhibit clinical efficacy in lung cancer patients. However, acquisition of resistance to gefitinib is also observed after treatment. It is critical and timely to understand the molecular mechanisms involved in gefitinib resistance. In this study, we found the RNA expression of VEGF-C was higher in gefitinib resistance PC9 (PC9/GR) cells than wild type PC9 (PC9/WT) cells. Knockdown the VEGF-C in PC9/GR cells re-sensitize to gefitinib; consistently, overexpression of VEGF-C in PC9/WT cells enhanced resistance to gefitinib. In additional, we also found that PC9/GR cells expressed high level of Slug more than PC9/WT cells and related to gefitinib resistance. Furthermore, overexpression of Slug in PC9/GR/shVEGF-C cells enhanced the resistance to gefitinib. Together, our study reveals a molecular mechanism link between Slug and VEGF-C, and provides evidence the Slug and VEGF-C is potential therapeutic targets in gefitinib-resistant lung cancer.

Стилі APA, Harvard, Vancouver, ISO та ін.

Дисертації з теми "Slag resistance"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями