The purpose of the present study is to determine the effect of three "non-rinse" washing compounds upon the tensile strength of cotton percale, in order to have some basis for recommendation as to use when teaching laundering to homemaking students and homemakers.

Erodibility is an important factor in studies of geomorphology. Along with other factors such as climate, time, and tectonics, it contributes to the shape and evolution of landscapes. Several methods exist to quantify erodibility that examine rock mass properties such as fracture characteristics and strength of intact rock. These systems can be used to predict such varied properties as the slope of a rock mass, the geometry of bedrock channels, and the likelihood and type of potential slope failures. Yet, these systems are limited by shortcomings such as subjectivity, limited calibration, and failing to produce reasonable predictions of slope when rocks are mechanically or chemically weak. To address these and additional issues, original and modified versions of three erodibility rating indices are applied in a variety of lithologic, climatic, and erosional environments. Ratings are compared to topography for calibration purposes and to examine whether erodibility and topography will correlate in all environments studied. Several of the techniques tested are successful at improving ratings' correlation to topography in slowly eroding landscapes, while other landscapes do not correlate to ratings. A new adjustment factor for chemically weak rocks further improves this correlation in certain environments. Finally, suggestions are made for the future use of erodibility indices that incorporate specific techniques and alterations from the study as well as general impressions from use. / Master of Science

Alumina-titanium diboride (Al2O3-TiB2) composites have high temperature, wear, and impact resistance that could be useful in high performance applications. Determining the effect of processing parameters on relative bond strength and effective plasticity may contribute to optimization and predictability of performance in the Al2O3-TiB2 system. Al2O3-TiB2 composites were obtained from a collection of samples that were created during a separate ongoing research program being conducted by Dr. Kathryn V. Logan. The Logan samples were initially formed by hot pressing powders produced using Self-Propagating High Temperature synthesis (SHS) of Al, TiO2, and B2O3 powders or manual mixing (MM) of Al2O3 and TiB2 powders. Samples were then fractured using standard single edge notched beam (SENB) fracture toughness testing. The obtained fractured surfaces were examined using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). Relative amounts of transgranular and intergranular fracture of Al2O3 and TiB2 grains were determined. Transgranular fracture was used as a measure of relative bond strength. Other samples were obtained from the Logan collection to conduct nano-indentation measurements on polished sample surfaces in Al2O3 grains and in TiB2 grains. Indent locations were verified using SEM. Reduced modulus, final displacements, and fracture toughness for indents in Al2O3 grains and in TiB2 grains were determined from nano-indentation curves. Reduced modulus was used as a measure of relative bond strength. Final displacement and fracture toughness were used as measures of relative effective plasticity. Analysis of Variance (ANOVA) using Taguchi arrays was conducted using the powder processing factor (SHS vs. MM) and the predominant microstructure factor (TiB2 grains surrounding Al2O3 grains vs. TiB2 grains distributed amongst Al2O3 grains) when examining the effect of processing parameters on relative bond strength as measured by amount of transgranular fracture. Analysis of Variance (ANOVA) using Taguchi arrays was conducted using the powder processing factor (SHS vs. MM), the predominant microstructure factor (TiB2 grains surrounding Al2O3 grains vs. TiB2 grains distributed amongst Al2O3 grains), and the indented phase factor (Al2O3 vs. TiB2) when examining the effect of processing parameters on relative bond strength as measured by nano-indentation reduced modulus and both measures of relative effective plasticity. Powder processing was significant for the relative bond strength measures, but was not significant for the relative effective plasticity measures. Predominant microstructure was significant for all measures except relative effective plasticity as measured by fracture toughness, for which none of the factors and interactions were significant. The interaction between powder processing and predominant microstructure was significant for most of the relative bond strength measures and for relative effective plasticity as measured by final displacements. Indented phase was significant for the nano-indentation measures except nano-indentation fracture toughness, although the significance for nano-indentation fracture toughness was just below the critical level. The interaction between powder processing and indented phase and the interaction between predominant microstructure and indented phase were only significant for the relative bond strength measure using nano-indentation reduced modulus. The interaction between powder processing, predominant microstructure, and indented phase was significant for the nano-indentation measures except nano-indentation fracture toughness. The optimum level for powder processing was predominantly manual mixing. The optimum level for predominant microstructure was predominantly TiB2 grains surrounding Al2O3 grains. The optimum level for indented phase was predominantly TiB2. / Master of Science

This thesis deals with the relationship between form and strength in architecture. The proposed building is a Kindergarten which unites issues of shape, physics, and habitat. The roof is vaulted and the walls are curved for lateral resistance and in order to make folds scaled to a child. These physical moves work towards the theme of the Kindergarten: a place for the transition between home and school. / Master of Architecture

Yes / Test results of nine recycled aggregate concretes and a control concrete using only natural aggregates are reported. The recycled aggregates used were classified into three different types according to their measured specific gravity and water absorption, namely, RG I for recycled coarse aggregate having a specific gravity of 2.53 and water absorption of 1.9%; RG III for recycled coarse aggregate having a specific gravity of 2.4 and water absorption of 6.2%; and RS II for recycled fine aggregate having a specific gravity of 2.36 and water absorption of 5.4%. The replacement levels of both recycled coarse and fine aggregates were 30, 50, and 100% in separate mixtures. Slump loss and the amount of bleeding with time were recorded for fresh concrete. Compressive and tensile strengths, moduli of rupture and elasticity, and unrestrained shrinkage strain were also measured for hardened concrete. The properties of fresh and hardened concrete tested, together with a comprehensive database reported in the literature, were evaluated with respect to the relative water absorption of aggregates combining the quality and volume of recycled aggregates used. In addition, the properties of hardened concrete with different replacement levels and quality of recycled aggregates were compared with the design equations of ACI 318-05 and empirical equations proposed by Oluokun for natural aggregate concrete, whenever possible. Test results clearly showed that the properties of fresh and hardened concrete containing recycled aggregates were dependent on the relative water absorption of aggregates. In addition, the moduli of rupture and elasticity of recycled aggregate concrete were lower than the design equations specified in ACI 318-05, when the relative water absorption of aggregates is above 2.5% and 3.0%, respectively.

Yes / Engineered Cementitious Composites (ECC) is a material which possesses advanced self-healing properties. Although the self-healing performance of ECC has been revealed in numerous studies, only small-scale, laboratory-size specimens have been used to assess it under fixed laboratory conditions and curing techniques. In order to evaluate the effect of intrinsic self-healing ability of ECC on the properties of structural-size, large-scale reinforced-beam members, specimens with four different shear span to effective depth (a/d) ratios, ranging from 1 to 4, were prepared to evaluate the effects of shear and flexural deformation. To ensure a realistic assessment, beams were cured using wet burlap, similar to on-site curing. Each beam was tested for mechanical properties including load-carrying capacity, deflection capacity, ductility ratio, yield stiffness, energy absorption capacity, and the influence of self-healing, by comparing types of failure and cracking. Self-healed test beams showed higher strength, energy absorption capacity and ductility ratio than damaged test beams. In test beams with an a/d ratio of 4 in which flexural behavior was prominent, self-healing application was highly successful; the strength, energy absorption capacity and ductility ratios of these beams achieved the level of undamaged beams. In addition, flexural cracks healed better, helping recover the properties of beams with predominantly flexural cracks rather than shear cracks. / The authors gratefully acknowledge the financial assistance of the Scientific and Technical Research Council (TUBITAK) of Turkey provided under Project: MAG-112M876 and the Turkish Academy of Sciences, Young Scientist Award program. The second author would also like to acknowledge the financial support of TÜBITAK for the 2219 Scholarship.

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The aim of this thesis was to investigate the difference between containerboard materials strength and stiffness properties in tension and compression, how the mechanisms behind compressive and tensile properties are affected by the relative humidity of the ambient air and how the relative humidity affects the compressive response of the fibre network. These properties are used to predict the lifetime performance of corrugated boxes and to prevent early collapses of the boxes and thereby waste or harm of the transported goods inside. The work also discusses the methods used to evaluate the different properties and how reliable the results are. The experimental part includes testing of linerboard and fluting materials from both virgin and recycled fibres, which have been conditioned at 50% and 90% relative humidity. The compression tests were filmed to evaluate if different compression failure modes can be related to the strength and stiffness of the material. The results indicated that the compressive strength and stiffness differ from the strength and stiffness values in tension at 90% relative humidity. Compressive strength is lower in both 50% and 90% relative humidity compared with the tensile strength. However, the compression stiffness shows a higher value than the tensile stiffness at 90% relative humidity. The study of the method for evaluating the compressive behaviour of the paper does not present a complete picture on what type of failure the paper actually experience.

Thesis (MScPhysio)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Muscle weakness is a problem for many young people with spastic cerebral palsy (CP). Many studies have reported that selective strength-training programs can improve muscle strength. However, most of these studies are of single group design and do not adequately control for confounding variables. Objective: To determine the impact of a comprehensive strength training program targeting multiple muscle groups on adolescents with CP, using basic inexpensive free weights and resistance devices. Method: A randomised clinical trial evaluated the effects of an eight-week strength-training program on 31 independently ambulant adolescents with spastic CP, with or without walking aids, from Eros School (19 males, 12 females; mean age 16 years 1 month; range 13 - 18 years). The Kin-Com dynamometer, 3-D gait analysis, the Economy of Movement test and a questionnaire was used to evaluate selected muscle strength, the degree of crouch gait, free walking velocity and stride length, energy consumption during walking and perceptions of body image and functional competence. Twenty one subjects took part in the strength-training program and were compared with 10 control subjects. Results were analysed using repeated measures ANOVA and bootstrap analysis. Results: Compared with the control, significant improvement in the degree of crouch as measured by the sum of the ankle, knee and hip angles at midstance (p=0.05) and perceptions of body image (p=0.01) were noted for the experimental group. Significant trends were also noted for isometric knee extension muscle strength at 30° as well as for hip abduction at 10° and 20°. Walking efficiency, -velocity and stride length remained unchanged as well as perceptions of functional ability. Conclusion: A strength-training program targeting multiple muscle groups including upper and lower limbs as well as the trunk, can lead to changes in muscle strength and improve the degree of crouch gait with improved perception of body image. Successful participation in such a program at school may motivate children with CP to continue with home-based basic strength training. Strength training alone did not decrease oxygen consumption during walking and inclusion of aerobic exercise is recommended. / AFRIKAANSE OPSOMMING: Spierswakheid is 'n probleem vir baie jong mense met serebrale verlamming (SV). Navorsing het getoon dat selektiewe versterkende oefenprogramme selektiewe spiere kan versterk, maar die meeste studies bestaan uit 'n enkel groep met onvoldoende beheer oor verstrengelde veranderlikes. Doel: Om die impak van 'n omvattende versterkende oefenprogram met basiese, goedkoop gewigte en weerstandsaparaat wat vele spiergroepe teiken, op adolesente met spastiese SV te evalueer. Metodologie: Die effekte van 'n agt weke lang versterkende oefenprogram is op 31 onafhanklik mobiel adolesente met spastiese SV, met of sonder loophulpmiddel, van Eros Skool deur middel van 'n ewekansige kliniese proef geevalueer (19 manlike, 12 vroulike deelnemers; gemiddelde ouderdom 16 jaar 1 maand; omvang 13 - 18 jaar). Die Kin-Com dinamometer, "3-D gait analysis", die "Economy of Movement" toets en 'n vraelys is gebruik om geselekteerde spiersterkte, die hoeveelheid knie fleksie gesien in die onderste ledemaat tydens loop, loopspoed en treelengte, energieverbruik tydens loop asook persepsies van liggaamsbeeld en funksionelevermoë te evalueer. Een en twintig het in die versterkende oefenprogram deelgeneem en is met 10 kontrole deelnemers vergelyk. Resultate is met behulp van herhaalde metings "ANOVA" en "bootstrap analysis" geanaliseer. Resultate: In vergelyking met die kontrole groep, het die experimentele groep betekenisvolle verbetering getoon in die hoeveelheid fleksie gesien in die ondersteledemaat (p=0.05) soos bereken deur die som van die enkel-, knie- en heuphoek in midstaan fase tydens loop, asook in liggaamspersepsie (p=0.01). Beduidenisvolle tendense is ook gesien by die experimentele groep vir isometriese knie ekstensie spiersterkte by 30° asook vir heup abduksie by 10° en 20°. Energieverbruik tydens loop asook loopspoed en treelengte was onveranderd asook persepsie van funksionele vermoë. Gevolgtrekking: 'n Versterkende oefenprogram wat verskeie spiergroepe teiken, insluitende die onderste en boonste ledemate asook die romp, kan lei tot In verbetering in spiersterkte, minder fleksie in die onderste ledemate tydens loop asook 'n verbetering in ligaamspersepsie. Suksesvolle deelname aan so 'n program op skool, mag kinders dalk motiveer om In basiese versterkende oefenprogram tuis voort te sit. Versterkende oefening alleen het geen vermindering in suurstofverbruik tydens loop veroorsaak en die insluit van aerobiese oefening word aanbeveel.

Conventional fiber reinforced polymers (FRPs) require polymers such as epoxies that are not biodegradable, which have a significant impact on the environment. The first phase of the thesis aims at replacing conventional polymers with sustainable bio-polymers. The tensile mechanical properties of glass-FRP (GFRP) laminates using two types of organic furfuryl alcohol bio-resins extracted from renewable resources, such as corncobs, were investigated. Results are compared to control specimens fabricated using conventional epoxy resin. It was shown that by careful selection of viscosity of bio-resin, and type and dosage of catalyst, similar mechanical properties to epoxy-GFRP can be achieved. The second and third phases consisted of durability testing of the bio-resin GFRP. A total of 160 tension coupons and 81 unconfined and confined concrete cylinders wrapped with bio-resin-GFRP were studied. Conditioning was achieved by immersion of the specimens in saline solutions with 3% salt concentration, at 23, 40 and 55 degrees Celcius, for up to 300 days. Specimens were compared to epoxy-GFRP specimens aged in the same environment. Deterioration was quantified by tensile testing of the coupons and compression testing of the cylinders at various stages of exposure. The bio-resin-GFRP showed 33% less tensile strength retention than the epoxy-GFRP. The epoxy-GFRP and bio-resin-GFRP wrapped cylinders had the same un-aged confined axial compressive strength (fcc’), essentially a strengthening ratio (fcc’/fc’) of 2.24. After 300 days, the (fcc’/fc’) ratio retentions for the bio-resin-GFRP was 73% at all temperatures. Using the Arrhenius model, it was predicted that 61% retention in tensile strength of the bio-resin-GFRP and 65% retention of the compressive strength of wrapped cylinders would occur after 100 years in an environment with a mean annual temperatures of 10 degrees Celcius. / Thesis (Master, Civil Engineering) -- Queen's University, 2013-08-24 00:02:25.683