Cellulose is a potential source of nano-material not only because it possesses excellent mechanical and optical properties, but also because it is environmentally benign. In this study, nanofibres derived from wheat straw, an agriculture residue, was utilized in producing flexible and optically transparent nanocompostie films. The composites were produced using a bi-phase impregnation technique that coats the dried nanofibre films with clear polyurethane acrylate resins using UV radiation induced curing. The nanocomposite films thus produced possess excellent tensile properties (161MPa in strength and 9GPa in Young’s Modulus), superior thermal stability (above 300°C), low coefficient of thermal expansion (8-9ppm/K), good light transparency (80%), excellent flexibility and abrasion resistance. These nanocomposite films are aimed to replace the conventional glass substrates made in batches to a polymer based substrates that can be efficiently produced in a roll-to-roll process for the base of the future flexible flat panel displays.

When two or more individual materials combine to form a new material with improved characteristics, a composite is created. The two major components in a thermoplastic composite are the polymer, such as polypropylene (PP), and the filler, such as minerals like calcium carbonate and talc, or agricultural crop by-products like wheat straw, soy hull and soy stems. The main advantages of using agricultural fillers (AgFillers) in polypropylene are cost reduction and modulus improvement, without drastically increasing the specific gravity of the composite. These properties can be further enhanced by subjecting the composite to the bulk orientation process, in which the polymer chains align to give superior strength to the material, while the presence of polar AgFillers contributes to a reduction in material density. The objective of this research was to systematically study the relationships between the components and properties of AgFiller-PP composites, and their contributions to property modifications. Three types of AgFillers, wheat straw (WS), soy hulls (SH) and soy stems (SS) were studied, along with two PP types, virgin PP (vPP) and recycled PP (rPP), and mixtures of the two PP types. Non-oriented composites with a composition ratio of 40 wt% AgFiller to 60 wt% PP were tested for their morphology, chemical, thermal, rheological and mechanical properties. Similar properties of oriented composites with 20 wt% wheat straw filler and 80 wt% PP were also examined. The type of AgFiller was found to play a significant role in determining the rheological and mechanical properties of non-oriented AgFiller-PP composites. Scanning electron microscopy (SEM) showed that AgFillers had the tendancy to align lengthwise when subjected to the extrusion process. Depending on the fiber alignment within the filler with respect to the lengthwise direction of the filler, each AgFiller contributed differently to the composites’ properties. Stem-based AgFillers like WS and SS had fiber alignment parallel to the lengthwise direction, and the composites created had higher viscosity and higher flexural modulus. On the other hand, shell-based AgFillers like SH had fiber alignment perpendicular to the filler’s length, and were found to have less contribution to viscosity increase. Fourier transform Infrared (FTIR) spectroscopy using attenuated total reflectance (ATR) technique showed that a skin layer of PP congregated on the surface of all the non-oriented AgFiller-PP composites, regardless of the AgFiller used. The main contribution of PP polymer type was to the rheological properties of non oriented AgFiller-PP composites. The presence of rPP also appeared to slightly improve the immiscibility between polar AgFillers and nonpolar PP polymer, according to SEM image analysis. The viscosity of the composites decreased linearly with increasing amount of rPP, because the rPP tested had significantly lower viscosity than the vPP chosen. No statistically significant conclusions could be drawn on the mechanical property changes due to large experimental variance that existed in the data. Bulk orientation of AgFiller-PP composites was shown to provide significant reduction in the material’s density as well as improvement in physical properties. Experimental results of oriented wheat straw-PP composites showed that wheat straw was highly comparable, perhaps even more superior, to wood fibers as filler for oriented PP composites. The ability to produce oriented wheat straw-PP composites using the same technology and conditions as producing oriented wood-plastic composites affirmed the feasibility for commercialization of oriented wheat straw-PP composites, and by means contributing to setting a milestone in the scientific research of AgFiller-thermoplastic biocomposites.

<p>The purpose of this study was to develop an analytical model that could be used by the designers of a rotary feeding and cutting system (RFCS) to identify the power demand of the RFCS with limited or no required field or laboratory data. Two separate RFCS were investigated, incorporated with either a low-speed cutting process (LSCP) or a high-speed cutting process (HSCP). The results from the laboratory and field trials were used to create and validate the analytical model.</p> <p>Laboratory tests were completed with the LSCP RFCS and these concluded that counter-knife sharpness, serrations and bevel angle all had significant effects on the specific energy required by the LSCP RFCS when processing cereal straw and alfalfa. The specific energy required by the LSCP RFCS, while processing cereal straw, increased by 0.35 kWâh/tonne (or 96%) when the sharpness of the counter-knives decreased from 0.13 to 0.63 mm (where the sharpness was recorded by the leading-edge-width of the counter-knives). With the same decrease in sharpness, the specific energy required by the LSCP RFCS while processing alfalfa increased by 0.04 kWâh/tonne (or 32%). The specific energy required by the LSCP RFCS while processing cereal straw with sharp counter-knives (counter-knives with a leading edge width of 0.13 mm) increased by 0.11 kWâh/tonne (or 51%) when serrated counter-knives were used instead of un-serrated counter-knives. However, counter-knife serrations did not have a significant effect on the specific energy demand of the LSCP RFCS when sharp counter-knives were used to process alfalfa. The increase in bevel angle from 15 to 90&#x00B0; caused the specific energy required to process cereal straw and alfalfa to approximately triple. The moisture content of alfalfa also had a significant effect on the specific energy required to process alfalfa with the LSCP RFCS. The specific energy demand of the LSCP RFCS was at a maximum when alfalfa at a moisture content of 53% on a wet basis (w.b.) was processed and decreased slightly (approximately 0.04 kWâh/tonne or 10%) when dryer and wetter alfalfa was processed.</p> <p>Field tests were completed with the HSCP RFCS and it was concluded that in general, there was a direct relationship between the specific energy required by the HSCP RFCS and the moisture content of the straw, counter-knife engagement and throughput. Further, it was also concluded that the specific energy requirements of the HSCP RFCS were more sensitive to counter-knife engagement when higher moisture content straw was processed. Depending on the type of chopper used, the specific energy required by the HSCP RFCS increased anywhere from 0.15 to 0.77 kWâh/tonne (or 22 to 61%) when the counter-knife engagement was increased from 0 to 100% (or fully removed to fully engaged). Again, depending on the type of chopper used, when the moisture content of the straw processed by the chopper increased from approximately 7 to 25% w.b. the specific energy required by the chopper increased by 0.14 to 0.96 kWâh/tonne (or 28 to 84%). The effect of throughput on the specific energy demand of the HSCP RFCS was dependent on the type of chopper used. For one of the choppers, an increase in throughput from 10.5 to 13.5 tonne/h caused the specific energy required by the HSCP RFCS to increase by 0.24 kWâh/tonne (or 35%); however for a different chopper, an increase in throughput from 12 to 13 tonne/h caused the specific energy demand of the HSCP RFCS to decrease by 0.16 kWâh/tonne (or 19%).</p> <p>The analytical model was validated using a subset of the data that were collected while employing each cutting device under field conditions and the data collected with the use of a custom-designed material properties test stand. The output of the analytical model fell within the 95% confidence interval of the measured power demand for each of the rotary feeding and cutting systems, and the analytical model was therefore deemed sufficiently accurate.</p> <p>Based on the analytical model, the total power demand of both the LSCP and HSCP rotary feeding and cutting systems was largely attributed to the power required to transport plant material. Further, the power required to transport the plant material along the sides of the counter-knives was much greater than the power required to transport the plant material along the rotor bed and along the leading edge of the tines. Because of the excessive power required to transport plant material along the sides of the counter-knives, three techniques were identified as potential strategies to decrease the power demand of the RFCS. The first technique involved removing half of the tines from the RFCS, and modifying the remaining tines to decrease the amount of plant material that is entrapped between sides of the counter-knives and the tines. The second technique involved coating the inside surface of the tines with a baked Teflon, to decrease the coefficient of friction between the plant material and the RFCS. The third technique involved reshaping the counter-knives, to decrease the surface area over which plant material was transported along the side of the counter-knives. According to the analytical model, employing any of the three techniques would result in the total power demand of the RFCS to decrease by 15 to 26%. </p> <p>For the HSCP RFCS, a stochastic model was developed to identify which of the four choppers tested during field trials would have the best performance when subjected to the same operating conditions. The chopper with the best performance was the WR chopper as its use resulted in the minimum geometric mean length of material exiting the combine harvester while also consuming the least amount of specific energy.</p>

When two or more individual materials combine to form a new material with improved characteristics, a composite is created. The two major components in a thermoplastic composite are the polymer, such as polypropylene (PP), and the filler, such as minerals like calcium carbonate and talc, or agricultural crop by-products like wheat straw, soy hull and soy stems. The main advantages of using agricultural fillers (AgFillers) in polypropylene are cost reduction and modulus improvement, without drastically increasing the specific gravity of the composite. These properties can be further enhanced by subjecting the composite to the bulk orientation process, in which the polymer chains align to give superior strength to the material, while the presence of polar AgFillers contributes to a reduction in material density. The objective of this research was to systematically study the relationships between the components and properties of AgFiller-PP composites, and their contributions to property modifications. Three types of AgFillers, wheat straw (WS), soy hulls (SH) and soy stems (SS) were studied, along with two PP types, virgin PP (vPP) and recycled PP (rPP), and mixtures of the two PP types. Non-oriented composites with a composition ratio of 40 wt% AgFiller to 60 wt% PP were tested for their morphology, chemical, thermal, rheological and mechanical properties. Similar properties of oriented composites with 20 wt% wheat straw filler and 80 wt% PP were also examined. The type of AgFiller was found to play a significant role in determining the rheological and mechanical properties of non-oriented AgFiller-PP composites. Scanning electron microscopy (SEM) showed that AgFillers had the tendancy to align lengthwise when subjected to the extrusion process. Depending on the fiber alignment within the filler with respect to the lengthwise direction of the filler, each AgFiller contributed differently to the composites’ properties. Stem-based AgFillers like WS and SS had fiber alignment parallel to the lengthwise direction, and the composites created had higher viscosity and higher flexural modulus. On the other hand, shell-based AgFillers like SH had fiber alignment perpendicular to the filler’s length, and were found to have less contribution to viscosity increase. Fourier transform Infrared (FTIR) spectroscopy using attenuated total reflectance (ATR) technique showed that a skin layer of PP congregated on the surface of all the non-oriented AgFiller-PP composites, regardless of the AgFiller used. The main contribution of PP polymer type was to the rheological properties of non oriented AgFiller-PP composites. The presence of rPP also appeared to slightly improve the immiscibility between polar AgFillers and nonpolar PP polymer, according to SEM image analysis. The viscosity of the composites decreased linearly with increasing amount of rPP, because the rPP tested had significantly lower viscosity than the vPP chosen. No statistically significant conclusions could be drawn on the mechanical property changes due to large experimental variance that existed in the data. Bulk orientation of AgFiller-PP composites was shown to provide significant reduction in the material’s density as well as improvement in physical properties. Experimental results of oriented wheat straw-PP composites showed that wheat straw was highly comparable, perhaps even more superior, to wood fibers as filler for oriented PP composites. The ability to produce oriented wheat straw-PP composites using the same technology and conditions as producing oriented wood-plastic composites affirmed the feasibility for commercialization of oriented wheat straw-PP composites, and by means contributing to setting a milestone in the scientific research of AgFiller-thermoplastic biocomposites.

Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on Jan. 11, 2010. Major professor: Daniel C. Jansen. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree [of] Master of Science in Civil and Environmental Engineering." "December 2009." Includes bibliographical references (p. 176-180).

The focus of this study was to determine the effects of pretreatment of wheat straw by superheated steam (SS) alone or in combination with boiling water (BW) on biomass structure and yields of fermentation products (cell mass and fermentation end-products) by Clostridium thermocellum. Different cultivars of wheat straw were ground to a particle size less than 355 µm, and exposed to the following methods of pretreatment: i) 15 min soaking in 119 °C boiling water under absolute pressure of 193 kPa, followed by processing with SS at atmospheric pressure at different temperatures and retention times; ii) 15 min processing with SS at atmospheric pressure; and iii) 15 min soaking in 119 °C boiling water under absolute pressure of 193 kPa. Processing with SS was conducted at a variety of temperatures in the range of 180-220 °C. The severity of pretreatment was expressed through a treatment severity factor as a measure of harshness of treatment. Pretreatment combinations of boiling water with superheated steam at different retention times inside the SS chamber were also investigated. Wheat straw samples were then used as substrates in fermentation reactions with C. thermocellum. The most noticeable effects on biomass structure and fermentation were observed at the highest severity factor of 6.5, corresponding to 15 min pretreatment with boiling water followed by 15 min treatment with SS at 220˚C. This pretreatment provided the maximum increase in percentage of contribution of amorphous cellulose (% CAC), and the highest fermentation yield in terms of hydrogen, carbon dioxide, and ethanol production. / October 2015

Baigiamajame darbe analizuojamas sapropelio kaip rišiklio panaudojimas termoizoliacinių sapropelio-šiaudų plokščių gamyboje. Šiems tyrimams buvo pasirinktas užpelkėjusio Dobilios ežero, esančio Kauno rajone, organinis sapropelis. Bandiniai buvo gaminami su skirtingu sapropelio-šiaudų kiekiu juose ir formuojami specialioje tyrimams pagamintoje formoje. Suformuotų bandinių masė buvo apie 130g. Suformuotų bandinių sapropelio kiekis kito nuo 15% iki 35%. Presavimo slėgis buvo 0,25; 0,5; 0,75; 1,0 MPa. Buvo nustatomas tiriamų bandinių, tankis atsparumas lenkimui ir gniuždymui, taip pat apskaičiuojamas šiluminis laidumas. Raktiniai žodžiai: sapropelis, šiaudai, plokštelės, lenkimas, gniuždymas, stipris. / This Master Thesis analyses the appliance of sapropel as a binder in a heat insulation plate production. For the research was chosen a silt of a waterlogged lake Dobilė, located in Kaunas region. All samples were formed with specially made form for research. Every sample had different quantity of sapropel and strawdust. Forming weight of samples were approx 130g. A chosen quantity of sapropel variated from 15 to 35 percents in a sample. The mix of sapropel and strawdust in a form was pressed by 0,25; 0,5; 0,75; 1,0 MPa pressure. During the research samples were analysed their resistance to compression and flexure, estimated sample density and thermal conductivity. Keywords: binder, sapropel, plate, compression, flexure, straw.

Magistrantūros studijų baigiamajame darbe pateikiami pasėlio sudygimo, tankumo, piktžolėtumo tyrimo duomenys skirtingo intensyvumo žemės dirbimo, padengimo šiaudais ir žaliąja trąša laukeliuose. Stacionarus dviejų veiksnių eksperimentas vykdomas nuo 1999 metų. Tyrimai buvo vykdomi nuo 2011 - 2012 m. Eksperimentas buvo vykdomas pagal tokią schemą: A veiksnys: Šiaudų įterpimas: šiaudai pašalinti (-Š), šiaudai susmulkinti ir paskleisti (+Š). B veiksnys: Žemės dirbimo sistemos. Atlikus tyrimus nustatyta, kad miežių daigų skaičiui trečią dieną nuo dygimo pradžios esminės įtakos turėjo žemės dirbimo intensyvumas. Fone, kur šiaudai buvo susmulkinti ir paskleisti (+Š) esmingai didesnis daigų skaičius, palyginti su giliu arimu (GA), nustatytas laukeliuose, kurie buvo sekliai purenti kultivatoriumi plokščiapjūviais noragėliais ir lėkštiniais padargais (KL) ir laukeliuose su žaliąja trąša (ŽTRK). Fone be šiaudų (-Š), palyginus su giliu arimu (GA), esmingai daugiau miežių daigų sudygo sekliai artuose (SA), sekliai purentuose kultivatoriumi plokščiapjūviais noragėliais ir lėkštiniais padargais (KL) ir neįdirbtos ražienos (ND) laukeliuose. Dešimtąją dieną nuo dygimo pradžios, tiek fone su susmulkintais ir paskleistais šiaudais, tiek fone be šiaudų esmingai mažiau miežių daigų rasta laukeliuose, kurie buvo sekliai purenti rotoriniu kultivatoriumi (RK). Fone su šiaudais taip pat esminiai skirtumai nustatyti laukeliuose kur sėta į neįdirbtą ražieną (ND). Produktyvių stiebų skaičiui neturėjo... [toliau žr. visą tekstą] / Master's thesis presents data of a study of crop germination, density, weed and earthworm population in fields varying in intensity of tillage, straw and green fertilizer coverage. Stationary two-factor experiment is being carried out since 1999. Studies were carried out from 2011 – 2012 . The experiment was carried out according to the following scheme: factor A: Straw incorporation: straw removal (-Š), straw shredded and spread out (+ Š). Factor B: tillage systems. The research found that the number of barley sprouts on the third day from the beginning of germination is essentially influenced by tillage intensity. In area, where the straw were chopped and spread (+Š) substantially increased the number of sprouts in comparison with deep plowing (GA), has been determined in the fields that have been consistently levelled using harrow tines and flatcutting disc implements (KL). Area without straw (-Š) in comparison with deep ploughing (GA), substantially more barley seeds germinated in shallow ploughed (SA), shallow tine cultivator tines and flatcutting disc implements (KL) and the uncultivated stubble (ND) fields. Tenth day after the beginning of germination area with chopped or spread straw and area without straw in the background substantially less barley plants found in fields that have been consistently leveled harrow (RK). In the area with straw as well as in the area where sown in no-till stubble (ND) substantial differences were dicovered. Number of productive stems... [to full text]

No description available.

Thermoplastic composites using natural fibres are studied intensively and widely used in applications including automotive, packaging, consumer goods and construction. Good balance of mechanical properties, processability and low cost are great advantages of these materials on top of the environmental benefits. Recently, there have been various efforts to amplify the positive effects on the environment by replacing the conventional polymers by bio-derived renewable polymers in the composites. Recent studies conducted from our research group showed competitiveness of plant fibre-thermoplastic composites. Implementing the promising results and experience, a new composite design using renewable polyethylene as the matrix material was studied. This polyethylene is a renewable thermoplastic that was derived from sugar cane ethanol. The objectives of this study were to employ renewable high density polyethylene (HDPE) into composites using wheat straw and flax fibre to extend the range of properties of the HDPE while keeping the amount of renewable content to nearly 100%. The chemical resistance of these materials has not been reported before and it was investigated here by measuring and comparing the properties before and after accelerated chemical ageing. Both wheat straw and flax fibre had two different grades in size. Each of them was compounded with HDPE and additives (antioxidant and coupling agent) in a co-rotating twin screw extruder. The concentrations of fibres were varied from 0 to 30 wt-%. Then, injection molded samples were prepared for measurement of properties: tensile, flexural, impact tests. The effects of reinforcing fibre size were studied first. Both length and aspect ratio were considered. For both types of fibre composites, a general trend was observed. There was no clear evidence of improvements in flexural (strength and modulus) and tensile (strength, percentage elongation at break) properties with respect to the change in fibre size. However, impact (IZOD impact strength, Gardner impact failure energy) properties showed some improvements. This result was due to no substantial difference in size and aspect ratios in post-processed fibres that were actually residing in the matrix. There were remarkable improvements in flexural strength and modulus when the fibre content increased. However, minor decreases in tensile properties were observed. Furthermore, the impact properties were very sensitive to the concentration of fibres. As the fibre concentration went up, there were significant decreases in both IZOD impact strength and Gardner impact failure energy. Chemical resistance of these composites was studied by exposing them in six different chemical solutions (hydrochloric acid, acetic acid, sodium hydroxide, ethyl alcohol, industrial detergent, water) for up to thirty days. The increase in weight and leaching behaviour was observed. As the fibre content increased within the composites, the weight gain was more rapid during chemical ageing. Because there were more fibres exposed on the surface after chemical ageing, it is likely that they contributed to the higher flux of liquids (used for chemical ageing) inside the sample. Among the physical properties, tensile properties were most susceptible to the chemical ageing. One possible reason could be due to the exposed surface area to volume ratio, which was the highest in tensile bars and therefore faster mass transfer taking place into the matrix per volume. Finally, morphological study using scanned electron spectroscopy (SEM) revealed the damage on the surface when exposed to the chemicals. The fibres on the surface had been leached out in the sodium hydroxide solution leaving empty spaces. The fractured surface was also monitored via SEM. Though there was not enough evidence of strong interfacial interactions between the fibre and the polymer, good dispersions were observed.