Thesis--Tekniska högskolan, Stockholm. / Extra t.p., with thesis statement, inserted. Bibliography: p. 121-124.

No description available.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 127-142).

Thesis (MScFor)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: The retention of filler particles and drainage are important aspects of papermaking. A number of important paper properties depend in the quality and quantity of filler retained in the paper. Fines, fillers and pulp fibres all have a negative charge and are kept apart by electrostatic forces. This causes a decrease in the effectiveness of cationic retention aids thereby causing a high cationic demand. This in turn implies that the retention of fines and filler particles in a formed sheet is not efficient, especially in the presence of anionic trash. In order to improve printability, print quality and dimensional stability, a large percentage of mineral pigments / fillers either in the form of internal loading or external coating should be added. It was found that coflocculation of fines and filler particles resulted in an even distribution of filler particles in the form of miero-flocs and the filler retention was maintained. Opacity was improved without much reduction in paper strength. An increased filler content without coflocculation of fines reduced sheet strength properties. The filler particles interfered with the development of fibre-to-fibre bonds and occupied spaces that otherwise might have contained fibres. This study showed that the most beneficial effect of coflocculation of filler with fines was obtained, with regards to paper strength, opacity, filler retention and printability, when the charge of the fibre furnish was maintained at -0.1 leu with the 0.1% addition of cationic PAM retention aid. / AFRIKAANSE OPSOMMING: Twee belangrike aspekte van papiervervaardiging is die retensie van vulstowwe en ontwatering. 'n Aantal belangrike papiereienskappe is afhanklik van die hoeveelheid en kwaliteit van vulstowwe wat in papier voorkom. Veselpuin, vulstowwe en pulp-vesels is almal negatief gelaai, gevolglik verseker elektrostatiese kragte dat hierdie deeltjies los van mekaar bly. Laasgenoemde verminder die doeltreffendheid van kationiese retensiemiddels en dit gee aanleiding tot 'n hoë kationiese aanvraag. Die retensie van veselpuin en vulstof deeletjies in papier is gewoonlik nie voldoende in die teenwoordigheid van anioniese afvalkomponente nie. Om aan papier verbeterde drukeienskappe, drukkwaliteit en dimensionele stabiliteit te gee, moet 'n groot persentasie minerale pigmente en/of vulstowwe as 'n interne lading of eksterne bestryking voorsien word. Daar is bevind dat kot1okkulasie van fynstowwe en vulstofdeeltjies, 'n egalige verspreiding van vulstof-partikels as mikro-t1okke tot gevolg het en dat vulstof-retensie op aanvaarbare vlakke behou is. Ook is ondeurskynendheid verbeter sonder 'n beduidende verswakking in die papiersterkte. 'n Toename in vulstofinhoud, sonder kot1okkulasie van fynstowwe, het die papier sterkte-eienskappe verlaag. Vulstofdeeltjies bëinvloed die ontwikkeling van vesel-tot-vesel binding. Hierdie deeltjies beset ruimtes wat andersins deur vesels benut sou word. Hierdie studie het getoon dat die voordeligste effek van kot1okkulasie van vulstowwe met fynstowwe verkry is, ten opsigte van papiersterkte, ondeurskynendheid, vulstof retensie en drukeienskappe, wanneer die lading van die pulpsuspensie by -0.1 leu gehou was met 'n byvoeging van 0.1% kationiese PAM retensie-hulpmiddel.

This research consists of experimental load tests and numerical simulations of structural steel connections with various filler materials to study the effect of non-steel fillers on the connection strength. Non-steel fillers are used in the steel connections to provide thermal insulation by reducing thermal bridging. Eight specimens having steel and polypropylene filler plates of various thicknesses were tested in the laboratory. The collected data were compared to a Finite Element Analysis (FEA) using ABAQUS to validate the numerical results. After validation, three parametric studies were conducted using ABAQUS to provide insight into general behavior of connections with a variety of fillers that could be used as thermal breaks. In addition, an extreme case of having air gaps instead of alternative fillers was also considered. The Research Council on Structural Connections (RCSC 2014) suggests a reduction in the bolt shear strength when undeveloped fillers with a thickness of more than 0.25 inch are used while using any non-steel material is prohibited due the limited research available. Most research studies have investigated the mechanical behavior of thermal breaks in either end-plate moment connections or slip-critical connections. No data is available for thermal breaks in bearing-type connections up to failure. This research aims to study the effects of filler material properties such as modulus of elasticity and strength on bolt strength, as well as investigate whether the current equation in RCSC 2014 is applicable for alternative filler materials like polypropylene that has less than 0.5% of the steel modulus of elasticity and less than 10% of steel strength.

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Includes bibliographical references. / by Kwai-Yung Benjamin Su. / Sc.D.

Dissertation (Ph.D.)--Auburn University, 2009. / Abstract. Includes bibliographic references.

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references.

Submitted in fulfilment of the requirements for the degree of Master of Engineering: Mechanical Engineering, Department of Mechanical Engineering, Faculty of Engineering and the Built Environment, Durban University of Technology, Durban, South Africa. 2017. / In this study, the fatigue life of fiber reinforced composite (FRC) materials system was investigated. A nano-filler was used to increase the service life of the composite structures under cyclical loading since such structures require improved structural integrity and longer service life. Behaviour of glass fiber reinforced composite (GFRC) enhanced with various weight percentages (1 to 5 wt. %) of Cloisite 30B montmorillonite (MMT) clay was studied under static and fatigue loading. Epoxy clay nanocomposite (ECN) and hybrid nanoclay/GFRC laminates were characterised using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The mechanical properties of neat GFRC and hybrid nanoclay/GFRC laminates were evaluated. Fatigue study of the composite laminates was conducted and presented using the following parameter; matrix crack initiation and propagation, interfacial debonding, delamination and S–N relationship. Residual strength of the materials was evaluated using DMA to determine the reliability of the hybrid nanoclay/GFRC laminates. The results showed that ECN and hybrid nanoclay/GFRC laminates exhibited substantial improvement in most tests when compared to composite without nanoclay. The toughening mechanism of the nanoclay in the GFRC up to 3 wt. % gave 17%, 24% and 56% improvement in tensile, flexural and impact properties respectively. In the fatigue performance, less crack propagations was found in the hybrid nanoclay/GFRC laminates. Fatigue life of hybrid nanoclay/GFRC laminate was increased by 625% at the nanoclay addition up to 3 wt. % when compared to neat GFRC laminate. The residual strength of the composite materials revealed that hybrid nanoclay/GFRC showed less storage modulus reduction after fatigue. Likewise, a positive shift toward the right was found in the tan delta glass transition temperature (Tg) of 3 wt. % nanoclay/GFRC laminate after fatigue. It was concluded that the application of nanoclay in the GFRC improved the performance of the material. The hybrid nanoclay/GFRC material can therefore be recommended mechanically and thermally for longer usage in structural application. / M

The paper industry utilizes fillers either to reduce the cost or to provide desired functional or end-use properties of paper products. However, there are disadvantages associated with higher filler loadings beyond a certain level, which reduces paper strength. The present study focused on improving the physical property of filled papers. Three methods of structuring fillers were designed; precipitation with starch, complexation with starch and fatty acid, and regeneration with cellulose. Because cellulose and starch have hydroxyl groups on the chemical structure, the hydrogen bonding between fillers and wood fibers is assumed to be occurred by structuring fillers. For starch application, we used two different approaches; salt precipitation and fatty acid complexation. The cooked starch can be precipitated by certain salt solutions such as (NH4)2SO4. Also, the cooked starch can be complexed with fatty acid to produce an insoluble crystalline structure. When starch composites with clay made by both methods were put into the furnish as fillers, dramatic strength improvement was achieved such as 100-200% gains in tensile strength. This is due to the strong bonding between clay fillers and wood fibers, which is determined by Z-directional tensile strength. One of advantages is that using the starch-fatty acid complex has an inherent water repellent property, sizing effect. For cellulose as a bonding material, N-methylmorpholine-N-oxide was used as a solvent to dissolve the cellulose. The advantage of using this method is that we can use the low grade cellulose. The physical properties of the cellulose coated clay handsheets were significantly improved, but optical properties such as brightness and opacity were inferior to the hadnsheets filled with starch-clay composites due to relatively large particle size. In order to model the strength improvement by the composite filler, BDT theory, which is a modified Pages Equation, was used. After calculating the factors such as surface area and specific bond strength, the model matched well with the experimental results. Using this model, the tensile strength improvement could be predicted in terms of the change of bond strength and composite size.