Дисертації з теми "Polypropylene Effect of temperature on"
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Snyder, Joseph Timothy II. "The effect of compressive biaxial orientation on the low-temperature toughness and pre-fracture damage of polypropylene." Case Western Reserve University School of Graduate Studies / OhioLINK, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=case1056558280.
Повний текст джерелаGuclu, Mehmet. "Light Stability And The Effect Of Temperature On Mechanical Properties Of Polypropylene / Poly(ethylene-vinyl-acetate) Blends." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608535/index.pdf.
Повний текст джерелаs modulus of the blends decreased with increasing drawing temperature and EVA content. The stress at break values of the blends slightly increased with EVA whereas decreased with drawing temperature. The percent strain at break values of the blends were found to increase abruptly by increasing EVA content and drawing temperature. These changes in the mechanical properties are the indication of compatibility. The impact tests were performed only at 0°
C, 25°
C and the impact strength increased with the temperature and EVA content, but none of the samples were broken at higher testing temperatures. The effect of stabilizer was very obvious because stabilizer-free samples failed after 400 hours whereas, the samples with stabilizer resisted up to 750 hours. Elongation values of the samples decreased because of increasing brittleness by UV irradiation. We also observed chain stiffening effect by crosslinking in all samples upon UV irradiation. Thermal analysis of the blends of the drawn samples showed an increasing trend of crsytallinity with increasing drawing temperature. Increasing drawing temperature made polymer chains more flexible because of the increasing chain mobility. These flexible chains were then oriented in one direction during tensile testing and therefore uniaxial crystallization occurred. The morphology of impact and tensile tests samples were also analyzed by scanning electron microscope (SEM). The fibrillation of pure PP is higher than the fibrillation of the blends.
Hayakawa, N., T. Kobayashi, M. Hazeyama, T. Takahashi, K. Yasuda, and H. Okubo. "Partial discharge inception characteristics of LN/sub 2//polypropylene laminated paper composite insulation system for high temperature superconducting cables." IEEE, 2005. http://hdl.handle.net/2237/6846.
Повний текст джерелаMansour, Marwan. "Experimental tests on the effect of temperature on the short term behavior of FRC beams." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
Знайти повний текст джерелаMagagula, Sifiso Innocent. "The effect of organic peroxides on the molecular composition of heterophasic ethylene-propylene impact copolymers." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97850.
Повний текст джерелаENGLISH ABSTRACT: Heterophasic ethylene-propylene copolymers, also known as impact polypropylene (PP) copolymers (IPCs) or heterophasic copolymers (HECOs), are a unique group of polyolefins produced through the copolymerisation of ethylene and propylene, with the aim of improving the impact properties of the PP homopolymer at low temperatures. Therefore, this polymer comprises of a PP homopolymer matrix with a dispersed rubbery copolymer phase. Due to their unique properties, HECO polymers have become commercially important materials, with a wide range of applications. Therefore a fundamental understanding of the processes and chemistry that affects their final macroscopic properties needs to be expanded. The main focus of this investigation was to understand why specific organic peroxides influence or interact differently with the various phases of HECO polymers, in order to utilize their properties to obtain HECO polymers with optimal and desired properties. Two HECO polymers with different ethylene contents were fractionated into three fractions (30, 100 and 130 °C), using preparative temperature rising elution fractionation (P-TREF). Each individual TREF fraction was degraded with two different types of organic peroxides, and then characterised using four different analytical tools. The changes in the molecular structures of the different fractions were investigated by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The changes in comonomer sequence distributions were investigated by carbon 13 nuclear magnetic resonance spectroscopy (13C-NMR). Moreover, the degradation of the different fractions was investigated by high temperature size exclusion chromatography (HT-SEC). The investigation showed that the HECO polymers with different ethylene contents were uniquely altered. It was evident that the ethylene content influenced the degradation behaviour of the HECO polymers. The ability of the peroxide to affect certain regions of the HECO polymer more than others is highly dependent upon its miscibility with certain regions of the HECO polymers. The “visbreaking” efficiency of a specific organic peroxide appears to be primarily dependent on the number of “peroxy” groups it contains in its molecular structure. Stellenbosch University https://scholar.sun.ac.za
AFRIKAANSE OPSOMMING: Heterofase etileen-propileen ko-polimere, ook bekend as impak PP ko-polimere (IPCS) of heterofase ko-polimere (HECO), is 'n unieke groep poliolefiene geproduseer deur die ko-polimerisasie van etileen en propileen, met die doel op die verbetering in die impak eienskappe van die PP homopolimeer by lae temperature. Hierdie polimeer bestaan dus uit 'n PP homopolimeer matriks met 'n verspreide rubberagtige ko-polimeer fase. As gevolg van hul unieke eienskappe, is HECO polimere van kommersiële belang, met 'n wye verskeidenheid van toepassings. 'n Fundamentele begrip van die prosesse en chemie wat die finale makroskopiese eienskappe beïnvloed moet dus uitgebrei word. Die hooffokus van hierdie ondersoek was om te verstaan waarom spesifieke organiese peroksiede verskillende invloede en interaksies met die verskillende fases van HECO polimere het, om sodoende van hul eienskappe gebruik te maak om HECO polimere te verkry met optimale en gewenste eienskappe. Twee HECO polimere met verskillende etileen inhoud was gefraksioneer in drie fraksies (30, 100 en 130 °C), met behulp van preparatiewe temperatuur styging eluering fraksionering (P-TREF). Elke individuele TREF fraksie was gedegradeer met twee verskillende tipes organiese peroksiede en daarna gekarakteriseer deur vier verskillende analitiese metodes. Die veranderinge in molekulêre strukture van die verskillende fraksies was geondersoek met behulp van Fourier transform infrarooi spektroskopie (FTIR) en differensiële skandering kalorimetrie (DSC). Die veranderinge in ko-monomeer volgorde distribusie was bestudeer deur middel van kern magnetiese resonans spektroskopie (KMR). Verder was die degradasie van die verskillende fraksies met behulp van hoë temperatuur grootte uitsluitingschromatografie (HT-SEC) bestudeer. Die ondersoek het getoon dat die HECO polimere met verskillende etileen inhoud uniek gedegradeer was. Dus is dit duidelik genoeg dat die etileen inhoud die degradasie gedrag van die HECO polimere beïnvloed het. Die vermoë van die peroksied om sekere areas van die HECO polimeer meer as ander te beïnvloed is hoogs afhanklik van die mengbaarheid met sekere areas van die HECO polimere. Die "visbreking" doeltreffendheid van 'n spesifieke organiese peroksiede is meestal afhanklik van die aantal "peroksie" groepe in die molekulêre struktuur.
Nguyen, Duy Cuong. "Caractérisation de l'interface fibre/matrice : application aux composites polypropylène/chanvre." Thesis, Troyes, 2016. http://www.theses.fr/2016TROY0009/document.
Повний текст джерелаAgro-composites are increasingly studied and applied to various industries over recent years due to good mechanical properties compared to conventional composites especially in terms of specific values. However, since low adhesion between the hydrophilic fiber and hydrophobic matrix, which occurs one of the main breaks modes in this kind of material, the characterization of the interface becomes a key problem. For investigation of this issue, existing methods show limitation for reasons of complexity (in preparation, in principle) and of cost. In this study, we developed a « pull-out ». In particular, the real fiber geometry of the plant fiber was taken into the calculation of mechanical properties of interface using a tomography inspired method. By checking the effective temperature of the molding then varying it, we studied the effect of this processing parameter to mechanical properties of fibre/matrix interface and determined the optimal conditions. The developed experimental protocol is applied to aged interfaces in order to clarifying the evolution of interfacial properties during the aging time to relative humidity. After four weeks, the interfacial shear strength and the shear modulus of the interface were greatly reduced while the shear deformation at the rupture was greatly increased
Jones, Andrew Paul. "Novel approaches to high temperature stabilisation of polypropylene." Thesis, Manchester Metropolitan University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.545931.
Повний текст джерелаSchildmeyer, Andrew Joseph. "Temperature and time dependent behaviors of a wood-polypropylene composite." Online access for everyone, 2006. http://www.dissertations.wsu.edu/Thesis/Summer2006/a%5Fschildmeyer%5F072006.pdf.
Повний текст джерелаMoeiri-Farsi, M. H. "Effects of autoclave temperatures on properties of cementitious based matrices reinforced with randomly orientated polypropylene fibres." Thesis, University of Salford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336075.
Повний текст джерелаHaniche, Rachid. "Contribution à l’étude des bétons portés en température / Evolution des propriétés de transfert : Etude de l’éclatement." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0155/document.
Повний текст джерелаThe study of the behaviour of concrete at high temperatures is of great importance to determine the stability and strength of concrete structures in fire conditions. Spectacular fires, these last years, showed that the concrete could be very strongly solicited. Thus it appears that to ensure a very good behaviour of the concrete at temperature it is saved people and reduced the expenses of immobilisation and repair of the damaged structures. The aims of the present work, by the experimental study, are to provide a better comprehension of the involved phenomena during the exposure to the high temperatures of the high performance concretes (HPC). It focuses, in particular, on the fluids transfers (permeability) and the study of the thermal instability (spalling) of high performance concrete. The thesis work was conducted on high-performance concrete (80 MPa) with 5% silica fume (low permeability material to improve durability), and different amount of polypropylene fibres. The use of polypropylene fibres (PP) is regarded as an effective technical solution to improve the behaviour of the HPC at fire conditions, in particular thanks to the physical phenomena appearing at the temperatures lower than 200°C. Our work is concerned, initially, on the characterization of the evolution of physical properties (porosity, mass loss), thermal properties (conductivity and diffusivity) and mechanical properties (compressive strength and tensile) and the sorption isotherms. The second part concerns the study of the evolution of the permeability, as a main property characterising the hydrous transfers inside the concrete exposed to temperature. An experimental study is conducted concerning the evolution of the permeability of concrete as a function of temperature (up to 200 ° C). The studied parameters are: the type of concrete (with and without fibres), two types and geometry of fibres, the nature of the fluid (air and vapour) and the measurement methods (residual and under temperature). The experimental results shows that the existing fibres generate a most important permeability beyond 150°C and that the obtained results, by residual or under temperature measurements, may be related to the operating procedures. Finally, in the last part an investigation on the spalling phenomenon related to the material compositions is conducted. A new experimental method of investigation of the sensitivity of the formulations to thermal instability is proposed: the study of spherical specimens exposed in high temperatures. This method will be compared to the traditional methods of investigation. The analysis of the test results makes to discuss the thermal instability causes and to characterize the concrete properties at high temperatures, important data to modelling
Abu-Zurayk, R. A. R. "The effect of processing on structure and properties of polypropylene/clay nanocompsites." Thesis, Queen's University Belfast, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515684.
Повний текст джерелаCampbell, P. M. S. "The effect of nickel oxime chelates on the thermal and photochemical stability of polypropylene." Thesis, University of Ulster, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378966.
Повний текст джерелаKhoathane, MC, OC Vorster, and ER Sadiku. "Hemp Fiber-Reinforced 1-Pentene/Polypropylene Copolymer: The Effect of Fiber Loading on the Mechanical and Thermal Characteristics of the Composites." SAGE, 2008. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000586.
Повний текст джерелаKalyanam, Sriram. "Effect of silane coupling agents on the mechanical properties of glass polypropylene composites." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/8563.
Повний текст джерелаRichardson, Alan Elliott. "An investigation into the effect of polypropylene fibres on the durability of concrete." Thesis, University of Newcastle Upon Tyne, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500949.
Повний текст джерелаSadiku, E. R. "The effect of physical ageing on the structural and mechanical characteristics of polypropylene." Thesis, University of Strathclyde, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372099.
Повний текст джерелаMarsh, M. G. "The effect of a temperature gradient on high temperature fretting wear." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267625.
Повний текст джерелаFrancois, heude Alexandre. "Kinetic modeling of the polypropylene photothermal oxidation." Phd thesis, Ecole nationale supérieure d'arts et métiers - ENSAM, 2014. http://pastel.archives-ouvertes.fr/pastel-01069008.
Повний текст джерелаKanbur, Yasin. "Conductive Polymer Nanocomposites Of Polypropylene And Organic Field Effect Transistors With Polyethylene Gate Dielectric." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613312/index.pdf.
Повний текст джерелаs and fullerenes were surface functionalized with HNO3 : H2SO4 before composite preparation. The CNT and fullerene content in the composites were varied as 0.5, 1.0, 2.0 and 3.0 % by weight. For the composites which contain surface modified CNT and fullerene four different compatibilizers were used. These were selected as TritonX-100, Poly(ethylene-block-polyethylene glycol), Maleic anhydride grafted Polypropylene and Cetramium Bromide. The effect of surface functionalization and different compatibilizer on mechanical, thermal and electrical properties were investigated. Best value of these properties were observed for the composites which were prepared with maleic anhydride grafted polypropylene and cetramium bromide. Another aim of this study is to built and characterize transistors which have polyethylene as dielectric layers. While doing this, polyethylene layer was deposited on gate electrode using vacuum evaporation system. Fullerene , Pentacene ve Indigo were used as semiconductor layer. Transistors work with low voltage and high on/off ratio were built with Aluminum oxide - PE and PE dielectrics.
Lufitha, Mundel. "Effect of substrate temperature on coating adhesion." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58842.pdf.
Повний текст джерелаMitchell, Angela. "The effect of temperature on starch synthesis." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243060.
Повний текст джерелаPhillips, Lisa Elaine. "The effect of low temperature on Salmonella." Thesis, University of Exeter, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286534.
Повний текст джерелаPrasad, Renee Priya. "The effect of rearing temperature on performance of Trichogramma sibericum at ambient temperature." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ51451.pdf.
Повний текст джерелаCheruthazhekatt, Sadiqali. "Novel multidimensional fractionation techniques for the compositional analysis of impact polypropylene copolymers." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80118.
Повний текст джерелаENGLISH ABSTRACT: Impact Polypropylene Copolymers (IPCs) are extremely complex materials, consisting of a mixture of polypropylene homopolymer and copolymers having different comonomer (ethylene) contents and chemical composition distributions. IPC can only be effectively analysed by multidimensional analytical approaches. For this, initially, the individual components have to be separated according to any of their molecular characteristics, either by chemical composition distribution (CCD) or molar mass distribution (MMD), followed by further analysis of these separated fractions with conventional analytical techniques. The combination of preparative temperature rising elution fractionation (TREF) with several other analytical techniques have been reported for the thorough characterization of this material. However, even the combinations of these methods were of limited value due to the complex nature of this polymer. Therefore, novel analytical approaches are needed for a more detailed compositional analysis of IPCs. This work describes a number of multidimensional analytical techniques that are based on the combination of fractionation and hyphenated techniques. Firstly, preparative TREF was combined with high temperature size exclusion chromatography-FTIR (HT SEC-FTIR), HT SEC-HPer DSC (High Performance Differential Scanning Calorimetry) and high temperature two-dimensional liquid chromatography (HT 2D-LC) for the comprehensive analysis of a typical impact polypropylene copolymer and one of its midelution temperature TREF fractions. HT SEC-FTIR analysis provided information regarding the chemical composition and crystallinity as a function of molar mass. Thermal analysis of selected SEC fractions using a novel DSC method - High Speed or High Performance Differential Scanning Calorimetry (HPer DSC) - that allows measuring of minute amounts of material down to micrograms, yielded the melting and crystallization behaviour of these fractions which is related to the chemical heterogeneity of this complex copolymer. High temperature 2D-LC analysis provided the complete separation of this TREF fraction according to the chemical composition of each component along with its molar mass distribution. In a second step, the compositional characterization by advanced thermal analysis (HPer DSC, Flash DSC 1, and solution DSC) of the TREF-SEC fractions was extended to all semi-crystalline and higher temperature TREF fractions. By applying HPer DSC at scan rates of 5−200°C/min and Flash DSC 1 at scan rates of 10−1000°C/s, the metastability of one of the fractions was studied in detail. DSC measurements of TREF-SEC cross-fractions at high scan rates in p-xylene successfully connected reversely to the slow scan rate in TREF elution, if corrected for recrystallization. Finally, the exact chemical structure of all HT HPLC separated components was determined by coupling of HT HPLC with FTIR spectroscopy via an LCTransform interface. This novel approach revealed the capability of this hyphenated technique to determine the exact chemical composition of the individual components in the complex TREF fractions of IPCs. The HT HPLC–FTIR results confirmed the separation mechanism in HPLC using a solvent gradient of 1-decanol/TCB and a graphitic stationary phase at 160°C. FTIR analysis provided information on the ethylene and propylene contents of the fractions as well as on the ethylene and propylene crystallinities.
AFRIKAANSE OPSOMMING: Impak Polipropileen Kopolimere (IPKe) is uiters komplekse materiale, bestaande uit 'n mengsel van polipropileen homopolimeer en kopolimere met verskillende komonomeer (etileen) inhoud en chemiese samestelling verspreiding. IPKe kan slegs doeltreffend ontleed word deur multidimensionele analitiese benaderings te volg. Hiervoor moet die individuele komponente aanvanklik eers geskei word volgens enige van hul molekulêre eienskappe, hetsy deur die chemiese samestelling verspreiding (CSV) of molêre massa verspreiding (MMV), gevolg deur 'n verdere ontleding van hierdie geskeide fraksies met konvensionele analitiese tegnieke. Die kombinasie van voorbereidings temperatuur-verhogings eluasie fraksionering (TVEF) met verskeie ander analitiese tegnieke is gerapporteer vir die deeglike karakterisering van hierdie materiaal. Maar selfs die kombinasies van hierdie metodes was van beperkte waarde as gevolg van die komplekse aard van hierdie polimeer. Daarom word nuwe analitiese benaderings benodig vir 'n meer gedetailleerde komposisionele ontleding van IPKe. Hierdie studie beskryf 'n aantal multidimensionele analitiese tegnieke wat gebaseer is op die kombinasie van fraksionering en gekoppelde tegnieke. Eerstens is voorbereidings TVEF gekombineer met hoë temperatuur grootte-uitsluitingschromatografie-FTIR (HT GUC-FTIR), HT GUC-HPer DSK en hoë temperatuur twee-dimensionele vloeistof chromatografie (HT 2D-VC) vir die omvattende ontleding van 'n tipiese impak polipropileen kopolimeer en een van sy mid-eluasie temperatuur TVEF fraksies. HT GUC-FTIR analiese het inligting verskaf met betrekking tot die chemiese samestelling en kristalliniteit as 'n funksie van molêre massa. Termiese analiese van geselekteerde GUC fraksies deur gebruik te maak van 'n nuwe-DSK metode - Hoë Spoed of Hoë Prestasie Differensïele skandeer kalorimetrie (HPer DSK) - wat die meting van klein hoeveelhede materiaal tot by mikrogram hoeveelhede toelaat, het die smelt en kristallisasie gedrag van hierdie fraksies bepaal wat verwant is aan die chemiese heterogeniteit van hierdie komplekse kopolimeer. Hoë temperatuur 2D-LC analiese het die volledige skeiding van hierdie TVEF fraksie volgens die chemiese samestelling van elke komponent saam met die molêre massa verspreiding moontlik gemaak. In 'n tweede stap, is die komposisionele karakterisering deur gevorderde termiese analiese (HPer DSK, Flash DSK 1 en oplossing DSK) van die TVEF-GUC fraksies uitgebrei na alle semi-kristallyne en hoër temperatuur TVEF fraksies. Deur die gebruik van HPer DSK, teen ’n skandeerspoed van 5-200°C / min, en Flash DSK 1, teen ’n skandeerspoed van 10-1000°C / s, is die meta-stabiliteit van een van die fraksies in detail bestudeer. DSK metings van TVEF-GUC kruis-fraksies by 'n hoë skandeeerspoed in p-xyleen het suksesvol omgekeerd verbind aan die stadige skandeerspoed in TVEF eluasie, wanneer gekorrigeer vir dekristallisatie. Ten slotte is die presiese chemiese struktuur van al die HT HPVC geskeide komponente bepaal deur die koppeling van HT HPVC met FTIR spektroskopie deur middel van 'n LC-transform-koppelvlak. Hierdie nuwe benadering het die vermoë van die gekoppelde tegniek om die presiese chemiese samestelling van die individuele komponente in die komplekse TVEF fraksies of IPKe te bepaal aan die lig gebring. Die HT HPVC-FTIR resultate het die skeidingsmeganisme in HPVC bevestig deur die gebruik van ’n oplosmiddelgradiënt van 1-dekanol/TCB en 'n graphitiese stasionêre fase by 160°C. FTIR analiese verskaf inligting in verband met die etileen en propileen inhoud van die fraksies sowel as die etileen en propileen krystalliniteit.
Lisy, Frederick Joseph. "Effect of orientation on properties of reinforced polypropylene and evaluation of materials with scanning acoustic microscopy." Case Western Reserve University School of Graduate Studies / OhioLINK, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=case1060794951.
Повний текст джерелаHoza, Adam. "Effect of Ethylene and Propylene on Performance of Ziegler - Natta Catalyst in Stopped - Flow Polymerization." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-320775.
Повний текст джерелаKakireddy, Veera Raghava R. "Effect of temperature on copper chemical mechanical planarization." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0001973.
Повний текст джерелаGriškevičius, Mečislavas. "High Temperature Effect On Resistance Of Timber Structures." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2010. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20101119_134602-29128.
Повний текст джерелаDisertacijoje nagrinėjami pušinės ir ąžuolinės medienos stipruminių savybių pokyčių temperatūriniai sąryšiai bei medinių centriškai gniuždomų liaunų elementų elgsena veikiant aukštesnėms temperatūroms. Pagrindiniai tyrimo objektai yra Lietuvos spygliuočių ir lapuočių medienos savybių pokyčiai didėjant temperatūrai ir centriškai gniuždomų liaunų medinių elementų elgsenos veikiant kaitrai eksperimentiniai tyrimai bei rezultatų lyginamoji analizė. Darbe spręsti tokie pagrindiniai uždaviniai: gauti eksperimentinius duomenis apie aukštos temperatūros poveikį skirtingos natūralios – pušinės ir ąžuolinės – medienos savybėms, atlikti centriškai gniuždomų liaunų medinių elementų elgsenos ugnyje tyrimus. Atsižvelgiant į tyrinėtą tikrovišką gaisro poveikį patikslinti esamą EN 1995-1-2 medinių liaunų gniuždomų elementų atsparumo ugniai skaičiavimo metodiką. Disertaciją sudaro įvadas, penki skyriai, bendrosios išvados, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai ir du priedai. Pirmasis skyrius skirtas literatūros apžvalgai. Jame pateikta darbų, kuriuose nagrinėjamas aukštesnės temperatūros veikiamos medienos, stipruminių savybių mažėjimas ir kuriuose pateikiami gaisro sąlygomis gniuždomų medinių elementų laikomosios galios tyrimų rezultatai. Pabaigoje formuluotos išvados ir disertacijos tikslai ir uždaviniai. Antrajame skyriuje pateikta medienos stipruminių savybių aukštesnėse temperatūrose tyrimo metodika ir sukurtų nestandartinių bandymo įrenginių schemos... [toliau žr. visą tekstą]
Huang, Yan, and 黃燕. "Temperature dependent hall effect: studies ofGaN on sapphire." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B42577068.
Повний текст джерелаHarvey, Roy Edward. "The effect of high temperature on yeast fermentations." Thesis, Heriot-Watt University, 1988. http://hdl.handle.net/10399/1000.
Повний текст джерелаMcGinnity, Frank A. "The effect of temperature on engine gas dynamics." Thesis, Queen's University Belfast, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241518.
Повний текст джерелаParks, Olivia Waverly. "Effect of water temperature on cohesive soil erosion." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/49663.
Повний текст джерелаeffect of water temperature on cohesive soil erosion should be explored. The objectives of this study are to: determine the effect of water temperature on the erosion rates of clay; determine how erosion rates vary with clay mineralogy; and, explore the relationship between zeta potential and erosion rate. Samples of kaolinite- and montmorillonite-sand mixtures, and vermiculite-dominated soil were placed in the wall of a recirculating flume channel using a vertical sample orientation. Erosion rate was measured under a range of shear stresses (0.1-20 Pa) for a period of five minutes per shear stress at water temperatures of 12, 20, and 27�"C. The zeta potential was determined for each clay type at the three testing temperatures and compared to mean erosion rates. The kaolinite erosion rate doubled when the temperature increased from 12 to 20�"C, and erosion of vermiculite samples tripled when the temperature increased from 20 to 27�"C. The montmorillonite samples generally eroded through mechanical failure rather than fluvial erosion, and the limited fluvial erosion of the montmorillonite-sand mixture was not correlated with water temperature. The data suggest correlation between zeta potential and erosion rate; however, due to the small sample size (n=3), statistically significant correlation was not indicated. Research should continue to explore the influence of water temperature on cohesive soil erosion to better understand the influence of clay mineralogy. Due to the high degree of variability in cohesive soil erosion, multiple replications should be used in future work. The vertical sample orientation enabled discrimination between fluvial erosion and mass wasting and is recommended for future studies.
Master of Science
Doluweera, D. G. Sumith Pradeepa. "Effect of Weak Inhomogeneities in High Temperature Superconductivity." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1227215152.
Повний текст джерелаPack, Jessica Spencer. "Effect of Localized Temperature Change on Vigilance Performance." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1429286666.
Повний текст джерелаPorter, Heidi S. "The effect of febrile temperature on Plasmodium falciparum /." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd2225.pdf.
Повний текст джерелаTakahashi, Junji 1951. "Effect of high temperature on lettuce seed development." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276828.
Повний текст джерелаPorter, Heidi Sue. "The Effect of Febrile Temperature on Plasmodium falciparum." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/1573.
Повний текст джерелаXiong, Bijin. "Contribution to the study of elastic and plastic deformation mechanisms of polyethylene and polypropylene as a function of microstructure and temperature." Thesis, Lyon, INSA, 2014. http://www.theses.fr/2014ISAL0120/document.
Повний текст джерелаThe mechanical properties of semicrystalline polymers in relation to microstructure have been the subject of a large number of studies. However, there are still some unresolved issues, for instance, plastic deformation mechanisms in elevating temperature, intrinsic properties of interlamellar amorphous phase, local stress distribution in spherulites etc. The aim of this thesis is to address these issues in the case of PE and PP in different temperatures. A series of PE and PP samples with wide range of microstructures thanks to various thermal treatments were characterized by DSC, SAXS, WAXS and Raman spectroscopy. In elastic domain, the local strain εlocal in equator and polar regions of spherulites were measured by in situ SAXS. The ratio is a constant which only depends on drawing temperature. This ratio was used in a mechanical modelling as a transition factor from mesoscopic to macroscopic scale. Furthermore, the apparent modulus of the interlamellar amorphous phase Ma was estimated by the measured local stress and strain. The Ma of PE was found to be in the range 250 - 500 MPa which is surprisingly high comparing with the modulus of bulk rubbery PE. In the plastic domain, cavitation, martensitic transformation and crystal shear were observed by in situ SAXS and WAXS and their respective strain onsets were shown to be strongly dependent on crystallite thickness and temperature. It was found that competition exists between these plastic mechanisms. With increasing temperature, cavitation gradually disappears and martensitic transformation is delayed. A map for the onset of these plastic mechanisms was produced. In addition, the fibrillar structure induced by drawing at different temperature was studied by in situ SAXS. The long period and diameter of micro-fibrils proved to be dependent on the drawing temperature and also the initial structure via the melting-recrystallization and fragmentation-rearrangement mechanism. Similar investigations were performed with PP
Chaishome, Jedsada. "The effect of processing parameters on the mechanical properties of vacuum formed flax fibre reinforced polypropylene composites." Thesis, University of Nottingham, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.594739.
Повний текст джерелаWang, Kui. "Characterization and modeling of the thermomechanical behavior of polypropylene-based composites : effect of recycling and filler content." Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-00962217.
Повний текст джерелаBellam, Balaji Anand. "Effect of e-beam sterilization on polypropylene/ethylene propylene diene monomer and ethylene vinyl acetate thermoplastic elastomer." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/52484/.
Повний текст джерелаKhatua, Sourav. "Effect of Accelerated Corrosion on the Bond Strength of Corrosion Resistant Reinforcing Bars Embedded in Concrete." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1513944280521728.
Повний текст джерелаKirca, Onder. "Temperature Effect On Calcium Aluminate Cement Based Composite Binders." Phd thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607454/index.pdf.
Повний текст джерелаCalmunger, Mattias. "Effect of temperature on mechanical response of austenitic materials." Thesis, Linköpings universitet, Konstruktionsmaterial, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-73748.
Повний текст джерелаNaperalsky, Michael E. "Effect of post-exercise environmental temperature on glycogen resynthesis." The University of Montana, 2009. http://etd.lib.umt.edu/theses/available/etd-06052009-115319/.
Повний текст джерелаChang, Chia-Wei, and 張家維. "Temperature/Moisture Effect on Bending Fatigue Strength of Glass/Polypropylene/Aluminum Foam Sandwich Structures." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/18583303239687497381.
Повний текст джерела國立臺灣海洋大學
機械與機電工程學系
101
The goal of this thesis is to experimentally study the hygrothermal effect on the static and fatigue four-point bending strengths of the sandwich structures with glass/polypropylene faces and aluminum foam cores. Results show that under the conditions of fixed moderate humidity, the static and fatigue bending strengths of the studied sandwich beams decrease significantly as the environmental temperature increases. However, the effect of humidity is not evident on the strengths under controlled hygrothermal conditions. The relationship between the static bending strength and the temperature can be described using a liner function. Moreover, the Arrehenius models are successful to describe the relationship between the fatigue strength coefficients employed in the power laws of the S-N curves and the testing temperatures. The variation of the fatigue strength exponents with the testing temperature is not apparent based on the analysis of experimental data. The testing temperatures were found to have slight influence on the trend of stiffness degradation of the studied sandwich specimens. However, different trends of the stiffness degradation curves were observed when the specimens were fatigue tested under various hydgrothermal conditions. A prediction parameter based on the loading level was employed to correlate the experimental fatigue data obtained at various hygrothermal conditions, and good performance of the utilized parameter was observed.
Deng, D., Benjamin R. Whiteside, F. Wang, Keith Norris, and Z. Zhang. "Epitaxial growth and morphological characteristics of isotactic polypropylene/polyethylene blends: Scale effect and mold temperature." 2014. http://hdl.handle.net/10454/10052.
Повний текст джерелаThis study investigates the influence of length scale effects (micro- and macro-injection molded parts) and mold temperature on the epitaxial growth and morphological characteristics in injection-molded bars of isotactic polypropylene (iPP)/high-density polyethylene (HDPE) blends. After preparing the blends with an iPP content of 70 wt% via melt extrusion, the injection-molded bars were formed using both micro and conventional injection molding. Samples were subsequently prepared from the moulded components to allow investigation of the internal morphology using wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and polarized light microscopy (PLM). The results indicated that the matching of micro scale and appropriate mold temperature was most favorable for epitaxial crystallization. The micro-parts had a large fraction of shear layer compared with macro-parts. The SEM observations showed that the shear layer of the former consisted of a highly oriented shish-kebab structure. Moreover, the effects of different methods of injection molding on the morphological characteristics of the micro-parts and macro-parts in different layers were elucidated in detail using PLM and SEM.
Chen, Bo-Shiun, and 陳柏勳. "Pyrolysis of Polypropylene in a Fluidized Bed Reactor – Effects of the Reaction Temperature and Flow Rate of Steam on the Product Yields." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/10281504848015488099.
Повний текст джерела長庚大學
化工與材料工程研究所
97
Polypropylene (PP) was selected as fed material to study the product distribution of the pyrosis reaction carried out in a assembly gas-solid fluidized bed equipment. Super-heated steam was used as fluidized gas due to the less production of carbon black and the enhancement of H2 and CO yield. Experimental study of the effects of reaction temperature (500 , 550 and 600℃) and steam flow rate (19.54 - 37.85 g/min) on the solid residue , liquid yield , and gas yield was performed . The components and composition of the gas product were determined by gas chromatography. Experimental results showed that at steam flow rate of 19.54 g/min and reaction temperature of 600℃ , there are the minimum solid residue , minimum liquid yield , and the maximum gas yield , i.e. 0.71 wt% of solid residue , 5.20 wt% of liquid yield , and 76.81 wt% of gas yield. However , at the steam flow rate of 37.85 g/min and temperature of 500℃ , there are the highest solid residue , highest liquid yield , and the lowest gas yield , i.e. 2.88 wt% of solid residue , 20.13 wt% of liquid yield , and 62.21 wt% of gas yield , respectively. Experimental results also showed the effects of reaction temperature and steam flow rate on the gas chromatography of the pyrolysis of PP. The yield of the CH4 and the CO decrease with the increase of the flow rate of steam , but the yield of CO2 , C2H6 , and C2H4 are less influenced by the flow rate of steam. It also showed that increases the pyrolysis temperature , led to increases the various gas yield , i.e. H2 , CO , CO2 , C2H4 , C2H6 , and other gases.
Chahyadi, Ichwan Susanto. "Effect of maleated polypropylene on polypropylene-wood flour composites." 1989. http://catalog.hathitrust.org/api/volumes/oclc/20078460.html.
Повний текст джерелаTypescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 72-75).
Majithiya, Kamleshkumar M. "The Effect of Molecular Weight on Polypropylene Foaming." Thesis, 2012. http://hdl.handle.net/1807/32605.
Повний текст джерела