Low cost, light weight, recyclability, and high specific strength of natural fibres make them a good replacement for synthetic fibre such as glass in fibre reinforced plastics (FRP). Green and ecofriendly source of these fibres offer less reliance on oil sources. However, their moisture uptake ability, low thermal stability and quality variations are some disadvantages that restrict their use. Biodegradable polymers or biopolymers such as polylactic acid polymers (PLA) are polyesters of lactic acid, and originally made from renewable agricultural raw materials e.g. corn starch. Development of new composite products from the existing renewable resources has a strong potential to bring a new biodegradable composite material suitable for the automotive and packaging industry to replace non-renewable petroleum based plastics. These biodegradable composites could degrade completely in soil or by composting process and do not emit any toxic or harmful components. The purpose of this work is to investigate the effects of increasing natural fibre content, and also adding Biomax modifier on the mechanical properties of poly lactic acid. PLA was reinforced with two different kinds of sustainable natural fibres, cotton, and jute fibres respectively. Biomax strong 120 was used as modifier for PLA/natural fibre composites in order to improve the impact strength and toughness properties. Mixtures of different fibre mass proportions as reinforcement, and PLA as a base resin with modifier additive were compounded in a twin-screw extruder. The extruded materials were processed in a novel compression moulding system to produce test samples. Composites without any modifier content were also produced under the same conditions and used as reference materials. iv Addition of plant fibres to the PLA reduces the composites flexural strength, while improves the elastic modulus significantly, compared to neat PLA. PLA 3001D based composites containing 40% jute fibre exhibited the highest stiffness (5.9 GPa) amongst the composites. Investigation of the impact properties of the composites showed that increasing fibre mass proportion leads to an increase in the impact strength of the composites. The impact strength of the PLA/cotton composite is more promising than PLA/Jute composites. The most significant result is that addition of even 3% Biomax Strong 120 had a positive effect on the impact properties of the specimens. Analysis of the rheological properties of the composites demonstrates that the cotton fibre reinforced PLA has higher complex viscosity than Jute fibre reinforced PLA composites. The DSC results explain that the crystallization temperature increases with increasing the jute fibre content. Furthermore composite‟s microstructure was monitored using Scanning Electron Microscope (SEM). A better adhesion between the cotton fibres and the PLA matrix than jute fibres and PLA was observed in the SEM images. / UOIT

Light-weight aggregate has been used successfully for structural and non-structural applications, and its most common use has been in light-weight concrete. Limited research has been done on light-weight grout though and there are no standards in place. The research performed in this study is intended to increase the knowledge of light-weight grout specifically made with expanded shale aggregate. The research presented herein is a pilot study and consists of preliminary aggregate and grout testing that resulted in the mix design of six grout types: three fine grout designs and three coarse grout designs. Conventional normal-weight aggregate was employed in the first grout mix. A light-weight aggregate batch was made with the same material proportions, as well as the same target water-cement (w/c) ratio and cement content. The weight of the cement was increased by 30 percent in the third grout type of each set to determine the effect on strength. The slump, component temperature, unit weight, air content, segregation, cement content, w/c ratio, and compressive strength for each grout type was gathered throughout testing. Correlations between grout testing results are examined and discussed. In addition, the effectiveness of expanded shale grout, other light-weight grouts, and normal-weight grout with respect to compressive strength to cement content ratio are determined. Results of the testing show that all six grout types studied in this research reached the minimum 28-day strength of 13.8 MPa (2000 psi) ASTM standard. In addition, the results indicate that the cement content in expanded shale light-weight grout would need to be increased to reach comparable compressive strengths to that of the normal-weight grout. The comparison between the compressive strength to cement content ratio of the different grouts indicate that normal-weight grout is more efficient. In addition, light-weight grout made with blast furnace slag grout is slightly more efficient than that made with expanded shale; however, this observation was only possible after several crucial assumptions were made about an existing blast furnace slag study. These strength-cement ratios do not account, however, for the benefits of reduced dead loads, improved thermal insulation, and improved sound insulation that could potentially influence the choice of the material used in and the life-cycle cost of the construction. Additional research should be done to verify the results of the ratios and the assumptions made herein. Furthermore, a life-cycle analysis needs to be conducted before a definite conclusion is made about which type grout is more efficient.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / To meet challenging constraints on telemetry system weight and volume, a custom Light-Weight Instrumentation System was developed to collect vehicle environment and dynamics on a short-duration exo-atmospheric flight test vehicle. The total telemetry system, including electronics, sensors, batteries, and a 1 watt transmitter weighs about 1 kg. Over 80 channels of measurement, housekeeping, and telemetry system diagnostic data are transmitted at 128 kbps. The microcontroller-based design uses the automotive industry standard Controller Area Network to interface with and support in-flight control functions. Operational parameters are downloaded via a standard asynchronous serial communications interface. The basic design philosophy and functionality is described here.

<p>Lättviktsskivor till möbelindustrin har varit ett omskrivet tema i olika branschtidningar den sista tiden.</p><p>Detta examensarbete beskriver och undersöker en ny konstruktion av en lättviktsskiva i massivt trä.</p><p>Lättviktsskivan är uppbyggd som en sandwichkonstruktion i tre skikt. Ytskikten består av 6 mm tjocka</p><p>limfogar och kärnmaterialet av profilerade distanser. Materialet är furu och lättviktsskivan har en</p><p>densitet på 320 kg/m3 vid 39 mm tjocklek. Utifrån kontakter med utvalda tillverkare och användare av</p><p>skivmaterial, samt genom tester, har denna konstruktion granskas och förslag på förbättringar har tagits</p><p>fram. Den ursprungliga distansen som var sammansatt av två halvor med centrumhål har ersatts av en</p><p>massiv distans med en liknande profilering. Vid företagskontakter framkom det en viss tveksamhet till</p><p>synliga fingerskarvar på synliga ytor, vilka den ursprungliga prototypen uppvisade. Med det som</p><p>utgångspunkt presenteras det ett förslag till olika kvaliteter till synliga respektive osynliga och dolda</p><p>ytor vid undersökning av estetiska och produktionstekniska aspekter.</p> / <p>Light-weight panels to the furniture industry have been a well documented task in line papers the last</p><p>time. This work describes and studies a new type of a construction of a light-weight panel in massive</p><p>wood. The light-weight panel in massive wood is built like a sandwich construction in three levels. The</p><p>outer layers are made of 6 mm thick massive wood glue panels and the core material by profiled</p><p>distances. Material is pine and the light-weight panel has a density of 310–332 kg/m3. Out of contacts</p><p>with selected producers and users of board materials, as in combination with tests, has this construction</p><p>been checked and purposes for improvements have been stated. The original distances, which were put</p><p>together by two parts including a centre hole have been replaced by a type of distance in massive wood</p><p>with a similar profiling. In contacts with companies has a slightly reserve been shown to finger-joints</p><p>on visible surfaces, which the originally prototype had. I conclusion with this presents a suggestion for</p><p>different kinds of qualities for visible and not visible respectively and hidden surfaces in conclusion</p><p>with the investigation of aesthetically and production technically aspects.</p>

The mechanical and mesoscopic structural properties of rigid cellular foam made of polystyrene have been investigated. Basic properties (e.g., density, total and available porosity, permeability, surface area, isotropicity, and cell size and cell wall thickness distributions) were measured. In most cases, alternative methods were used to determine which methods were most appropriate for the type of samples we studied. Standard compression and deflection mechanical tests were performed. The stress-strain curves and related mechanical properties were found to agree with standard cellular structural models of open-cell foams. We investigated the effects of small (~<5 atm) hydrostatic stress applied to foam samples for long periods of time (~one day). We observed large changes (up to a factor of three) in the stress-strain diagrams, Young's modulus, elastic collapse stress, ultimate strength, resilience, Poisson's ratio, permeability, penetration depth, and available porosity. Effects were most pronounced above 2 atm applied pressure differential, but were observed even for 1 atm loads. Short-term exposure to loads up to ten times as large did not cause comparable changes. These changes were interpreted as resulting from observed changes in the mesoscopic structure occurring near the surface using standard cellular structural models. This work was originally motivated by applications of foam as an inflating agent and structural component of fiber-epoxy composite tubular struts to be used in innovative space structures. The key recommendations of this study, regarding such applications, are to closely monitor the effects on the mechanical properties of polystyrene foam of: (1) cell structure and density inhomogeneities, and (2) pressure differentials which may be encountered during deployment and curing.

Recycling has proven not only to address today’s economical, environmental and social issues, but also to be imperative for the sustainability of human technology. The current thesis has investigated the feasibility of a new philosophy for Recycling (Alloying-Recycling) using steel 1020 and aluminum 6061T6. The study was limited to the metallurgical aspects only and has highlighted the potential of recycled alloys made of recycled aluminum and steel to exhibit substantially increased wear resistance and strength-to-weight ratio as compared to initial primary materials. Three alloy-mixtures are considered: TN3 (5wt% 1020 +95wt% 6061T6); TN5 (0.7wt% 1020 + 99.3wt% 6061T6); and TN4 (10wt% 6061T6 + 90wt% 1020). A Tucker induction power supply system (3kW; 135-400 kHz) is used to melt the alloy mixtures for casting in graphite crucibles. Heat treatment of the cast samples is done using a radiation box furnace. Microscopy, Vickers hardness and pin-on-disc abrasive wear tests are performed. Casting destroyed the initial microstructures of the alloys leading to a hardness reduction in the as-cast and solution heat-treated aluminum rich samples to 60 Hv from 140 Hv. Ageing slightly increased the hardness of the cast samples and provided a wear resistance two times higher than that of the initial 6061T6 material. On the steel rich side, the hardness of the as-cast TN4 was 480 Hv, which is more than twice as high as the initial hardness of steel 1020 of 202 Hv; this hints to strong internal and residual stress, probably martensite formation during fast cooling following casting. Solution heat treatment lowered the hardness to the original value of steel 1020, but provided about ten (10) times higher wear resistance; this suggests higher ductility and toughness of normalised TN4 as compared to 1020. In addition, TN4 exhibits about 25% weight reduction as compared to 1020. The actual recycling process and the effect of non-metallic impurities shall be investigated in future works. Also, the casting and heat treatment processes need to be improved.

Recycling has proven not only to address today’s economical, environmental and social issues, but also to be imperative for the sustainability of human technology. The current thesis has investigated the feasibility of a new philosophy for Recycling (Alloying-Recycling) using steel 1020 and aluminum 6061T6. The study was limited to the metallurgical aspects only and has highlighted the potential of recycled alloys made of recycled aluminum and steel to exhibit substantially increased wear resistance and strength-to-weight ratio as compared to initial primary materials. Three alloy-mixtures are considered: TN3 (5wt% 1020 +95wt% 6061T6); TN5 (0.7wt% 1020 + 99.3wt% 6061T6); and TN4 (10wt% 6061T6 + 90wt% 1020). A Tucker induction power supply system (3kW; 135-400 kHz) is used to melt the alloy mixtures for casting in graphite crucibles. Heat treatment of the cast samples is done using a radiation box furnace. Microscopy, Vickers hardness and pin-on-disc abrasive wear tests are performed. Casting destroyed the initial microstructures of the alloys leading to a hardness reduction in the as-cast and solution heat-treated aluminum rich samples to 60 Hv from 140 Hv. Ageing slightly increased the hardness of the cast samples and provided a wear resistance two times higher than that of the initial 6061T6 material. On the steel rich side, the hardness of the as-cast TN4 was 480 Hv, which is more than twice as high as the initial hardness of steel 1020 of 202 Hv; this hints to strong internal and residual stress, probably martensite formation during fast cooling following casting. Solution heat treatment lowered the hardness to the original value of steel 1020, but provided about ten (10) times higher wear resistance; this suggests higher ductility and toughness of normalised TN4 as compared to 1020. In addition, TN4 exhibits about 25% weight reduction as compared to 1020. The actual recycling process and the effect of non-metallic impurities shall be investigated in future works. Also, the casting and heat treatment processes need to be improved.

Lättviktsskivor till möbelindustrin har varit ett omskrivet tema i olika branschtidningar den sista tiden. Detta examensarbete beskriver och undersöker en ny konstruktion av en lättviktsskiva i massivt trä. Lättviktsskivan är uppbyggd som en sandwichkonstruktion i tre skikt. Ytskikten består av 6 mm tjocka limfogar och kärnmaterialet av profilerade distanser. Materialet är furu och lättviktsskivan har en densitet på 320 kg/m3 vid 39 mm tjocklek. Utifrån kontakter med utvalda tillverkare och användare av skivmaterial, samt genom tester, har denna konstruktion granskas och förslag på förbättringar har tagits fram. Den ursprungliga distansen som var sammansatt av två halvor med centrumhål har ersatts av en massiv distans med en liknande profilering. Vid företagskontakter framkom det en viss tveksamhet till synliga fingerskarvar på synliga ytor, vilka den ursprungliga prototypen uppvisade. Med det som utgångspunkt presenteras det ett förslag till olika kvaliteter till synliga respektive osynliga och dolda ytor vid undersökning av estetiska och produktionstekniska aspekter. / Light-weight panels to the furniture industry have been a well documented task in line papers the last time. This work describes and studies a new type of a construction of a light-weight panel in massive wood. The light-weight panel in massive wood is built like a sandwich construction in three levels. The outer layers are made of 6 mm thick massive wood glue panels and the core material by profiled distances. Material is pine and the light-weight panel has a density of 310–332 kg/m3. Out of contacts with selected producers and users of board materials, as in combination with tests, has this construction been checked and purposes for improvements have been stated. The original distances, which were put together by two parts including a centre hole have been replaced by a type of distance in massive wood with a similar profiling. In contacts with companies has a slightly reserve been shown to finger-joints on visible surfaces, which the originally prototype had. I conclusion with this presents a suggestion for different kinds of qualities for visible and not visible respectively and hidden surfaces in conclusion with the investigation of aesthetically and production technically aspects.

The goal of the present work is to improve shale reservoir stimulation treatment by using ultra light weight proppants in fracturing fluids. Slickwater has become the most popular fracturing fluid for fracturing shales in recent times because it creates long and skinny fractures and it is relatively cheap. The problem with slickwater is the high rate of settling of common proppants, e.g. sand, which results in propped fractures which are much smaller than the original fractures. Use of gels can help in proppant transport but introduce large formation damage by blocking pores in nano-darcy shales. Gel trapping in the proppant pack causes reduction in permeability of the proppant pack. The light weight proppants which can easily be transported by slickwater and at the same time be able to provide enough fracture conductivity may solve this problem. Three ultra light weight proppants (ULW1, ULW2, and ULW3) have been studied. The mechanical properties of the proppant packs as well as single proppants have been measured. Conductivity of proppant packs has been determined as a function of proppant concentration and confining stress at an average Barnett shale temperature of 95oC. The crush strengths of all the three proppant packs are higher than typical stresses encountered (e.g., Barnett). ULW1 and ULW2 are highly deformable and do not produce many fines. ULW3 has a higher Young’s modulus and produces fines. Conventionally, the proppant conductivity decreases with decreasing proppant concentration and increasing confining stress. But in cases of ULWs, for a partial monolayer, conductivity can be as large as that of a thick proppant pack. The settling velocity is the lowest for ULW1, intermediate for ULW2 and the highest for ULW3. This work contributes new mechanical, conductivity, and settling data on three ultra light weight proppants. Application of light weight proppants in stimulation treatments in shale reservoirs can lead to large propped fractures, which can improve the productivity of fractured shale reservoirs. / text

Recycling has proven not only to address today’s economical, environmental and social issues, but also to be imperative for the sustainability of human technology. The current thesis has investigated the feasibility of a new philosophy for Recycling (Alloying-Recycling) using steel 1020 and aluminum 6061T6. The study was limited to the metallurgical aspects only and has highlighted the potential of recycled alloys made of recycled aluminum and steel to exhibit substantially increased wear resistance and strength-to-weight ratio as compared to initial primary materials. Three alloy-mixtures are considered: TN3 (5wt% 1020 +95wt% 6061T6); TN5 (0.7wt% 1020 + 99.3wt% 6061T6); and TN4 (10wt% 6061T6 + 90wt% 1020). A Tucker induction power supply system (3kW; 135-400 kHz) is used to melt the alloy mixtures for casting in graphite crucibles. Heat treatment of the cast samples is done using a radiation box furnace. Microscopy, Vickers hardness and pin-on-disc abrasive wear tests are performed. Casting destroyed the initial microstructures of the alloys leading to a hardness reduction in the as-cast and solution heat-treated aluminum rich samples to 60 Hv from 140 Hv. Ageing slightly increased the hardness of the cast samples and provided a wear resistance two times higher than that of the initial 6061T6 material. On the steel rich side, the hardness of the as-cast TN4 was 480 Hv, which is more than twice as high as the initial hardness of steel 1020 of 202 Hv; this hints to strong internal and residual stress, probably martensite formation during fast cooling following casting. Solution heat treatment lowered the hardness to the original value of steel 1020, but provided about ten (10) times higher wear resistance; this suggests higher ductility and toughness of normalised TN4 as compared to 1020. In addition, TN4 exhibits about 25% weight reduction as compared to 1020. The actual recycling process and the effect of non-metallic impurities shall be investigated in future works. Also, the casting and heat treatment processes need to be improved.