Thermal degradation during composite fabrication is the main impediment for the wide use of agro-based fibers as filler and reinforcement in engineering thermoplastic composites. Different thermal, chemical and physical techniques (e.g., alkali, steam explosion and retting) aiming to increase the fiber-matrix adhesion or reduce the plant fibers water absorption have been presented in the literature. However, there have been very few attempts to solve the difficulties associated with processing engineering thermoplastics with plant fibers. Most of these attempts involved the use of additives (such as plasticizers and salts) to lower the polymers processing temperature and plant fibers with inherent higher thermal stability (such as Curaua and cellulose). Despite all these efforts, no important progress has been achieved. Therefore, to explore the full potential of wheat straw and expand its use in commercial applications, an experimental study was carried out to develop different methodologies to improve the thermal stability of wheat straw fiber. In this thesis, most attention is given to wheat straw because of the relevance and potential of entering the market as commercial filler today. It is reported here that the thermal stability and chemical composition of wheat straw do not seem to significantly vary with wheat straw type and cultivation region. For example, the main thermal degradation of wheat straw samples starts in a narrow window of temperature which goes from 220.8 to 237.8 °C and from 224.8 to 238.1 °C for air and nitrogen atmospheres, respectively. On the other hand, lignin and inorganic materials are the wheat straw components with the highest relative variation. In addition, it is showed here that silane modification is an efficient method to increase the temperature of degradation of wheat straw. The highest improvements were achieved with chlorosilane modifiers and combinations of alkoxysilane and chlorosilane modifiers. In fact, the silane treated samples have lower thermal degradation during the fabrication of composites with polyamide-6. It is observed here that the extruded and injection molded composites containing silane treated wheat straw samples have significant smaller thermal degradation than those utilizing untreated wheat straw samples. Equally important, it seems that the mechanical properties of the composites are not affected by the addition of silane treated samples in comparison with untreated wheat straw. In addition, another efficient treatment method is presented in this thesis. This method employs ultraviolet light to modify and improve the thermal stability of wheat straw. This method offers important economical and environmental benefits. Significant improvements (e.g., 40 ºC increase on the temperature at 2% of weight loss) were achieved after treatment for short periods of time (up to 15 minutes) and without the use of any pre-treatment or production of toxic by-products. This treatment method represents a novel application for ultraviolet light with potential for industrial use.

Les techniques de l'éco-construction répondent au besoin de réduire l'empreinte environnementale du secteur de la construction grâce à l'utilisation de ressources de proximité (filières courtes), sans transformation énergivore et grâce à la capacité de régulation thermo-hydrique des parois. La terre crue seule ou associée à de la paille fait office de symbole. Mais ses caractéristiques variables selon son origine, le long temps de séchage, et de faibles résistances mécaniques sont des freins à son utilisation. L'association de la terre avec des adjuvants biosourcés, tel que l'amidon déjà utilisé dans la fabrication de plaque de plâtre, représente une voie intéressante d'amélioration des performances. La thèse a pour objectif d'étudier l'influence de l'amidon sur le comportement physico-mécanique de la terre seule ou mélangée à de la paille. L'application envisagée des formules est la préfabrication de produits de construction non-porteurs. Les formulations incluent des fines argilo-calcaires (FAC), de la chènevotte ou des anas de lin, et différents amidons. La première partie de la thèse porte sur les mélanges terre-amidon. Des essais au viscosimètre ont défini le comportement rhéologique des mélanges de type Bingham modifié et ont montré une augmentation de la thixotropie. A l'état durci, les résistances mécaniques ont été meilleures avec l'amidon. La deuxième partie porte sur des mélanges terre-paille-amidon. L'amidon améliore l'ouvrabilité et les résistances mécaniques mesurées selon différentes conditions de stockage. A l'échelle d'un carreau, les performances mécaniques, thermiques, et acoustiques de certaines formules sont comparables à celles de carreaux de plâtre. / The eco-construction responds to the need to reduce the environmental footprint in the sector of construction through the use of proximity resources (e.g. earth, straw, etc.), without energy-intensive transformation and through the thermohydric regulation capacity of walls. Raw earth alone or in association with straw is a symbol. But variable characteristics according to its origin, a long drying time and low mechanical strengths are brakes to its use. Earth material in association with biosourced admixtures such as starch, already used in the manufacturing of plasterboard, represents an interesting way to improve its performances.The thesis aims to study the influence of starch on the physico-mechanical behavior of the earth alone or with straw. The intended application of the study is the prefabrication of non-load-bearing construction products. The designed mixes include quarry fines (QF), hemp or flax straw and various starches.The first part of this work deals with earth-starch mixes. Viscometer tests were defined modified Bingham as the rheological behavior of mixes and showed an increase in thixotropy. In hardened state, the mechanical strengths are better with starch.The second part deals with earth-straw-starch mixes. Starch improves the workability and the mechanical strengths measured under different storage conditions. At the scale of a block, the mechanical, thermal and acoustic performances of some mixes are comparable to those of plaster blocks.

Lab measurements and Monte Carlo simulations have been carried out for the evaluation of the Straw-type detectors used in the NA62 experiment at CERN. In addition, analyses of experiment data was used in corrections to improve the reconstruction of particle tracks, ultimately leading to improved resolution of the detector system as a whole. 97.7 percent of the Straws were aligned to within 30 microns, quantified as the deviation from zero of the mean of the inherent residual distribution of each Straw. A drift time dependence on where along the Straw the particle ionized have been corrected for; before the correction the dependence was as big as 6 ns. A radius-drift time relation based on the leading edge timing distribution has been deduced and implemented. Upon implementation artifacts from the piecewise fits used became evident. An alternative approach using residuals has been put forward.

Master of Science / Department of Animal Sciences and Industry / Dale A. Blasi / Drought conditions in the past have created a shortage of prairie hay and other grass hays that are used as roughage sources for receiving and growing beef diets. Historically, wheat straw and other cereal crop residue has been discounted as a feedstuff due to its low nutrient content. Chemical methods, including ammonia application, can improve the feeding value of cereal crop residue while constraining costs. While there are studies that show the efficacy of utilizing ammoniated wheat straw in beef cow and maintenance diets, limited data are available characterizing the feeding value of ammoniated wheat straw in receiving and growing diets. The objective of these two studies were to evaluate cattle growth and diet digestibility for receiving and growing diets containing either wheat straw (STRW), anhydrous ammonia treated wheat straw (AMMN), or a prairie hay and alfalfa blend (CONT) at 30% inclusion. Exp. 1 utilized 288 crossbred steers (271 kg) randomized to 8 pens per treatment and fed their respective test diets for 56 d and a common diet for 14 d to equalize gastrointestinal tract fill. No effect of straw ammoniation was observed on final bodyweight (BW), average daily gain (ADG), dry matter intake (DMI), or gain to feed (G:F) (P > 0.31). The 56-d BW, ADG, and G:F for CONT were significantly different from both STRW and AMMN (P < 0.001). Exp. 2 utilized 6 ruminally fistulated Holstein heifers (288 kg) in a replicated 3 × 3 Latin square design. There were no observed differences between AMMN and STRW in dry matter (DM), organic matter (OM), or ADF intake (P > 0.57) although CONT differed significantly from both straw treatments in DM, OM, and ADF intake (P < 0.05). Digestibility of DM, OM, and ADF were not different between AMMN and STRW (P > 0.43), where as CONT and STRW were different (P < 0.05). Anhydrous ammonia treatment of wheat straw had no effect on ruminal VFA concentration (P > 0.32). Ruminal pH was not affected by anhydrous ammonia application (P = 0.32), but STRW and CONT were different (P < 0.05). Fluid passage rate was not different among the three treatments (P = 0.33). Wheat straw is a suitable replacement for ammoniated wheat straw at 30% inclusion in receiving and growing diets that contain 40% of dietary DM as wet corn gluten feed. Further research is necessary to determine the effect of varying levels of wheat straw and ammoniated wheat straw in conjunction with wet corn gluten feed and other by-product feeds in receiving and growing diets in order to capitalize on performance and efficiency gains while constraining costs.

An experiment involving three feeding trials was conducted to study the effect of substituting chopped wheat straw for alfalfa in diets for lactating dairy cows. The results of these trials have shown that in complete mixed diets or diets containing long alfalfa hay, replacement of half of the alfalfa in rations containing 45% roughage for lactating dairy cows with chopped wheat straw does not adversely affect DM intake or milk yield and increase milk fat percentage. Replacing half of the long alfalfa with chopped alfalfa also apparently improved lactational performance although not as dramatically as that of chopped straw. Ammoniation of wheat straw did not improve the performance response by lactating cows. Inclusion of chopped straw in the diets seemed to enhance the efficiency of milk production. Higher ruminal acetate:propionate ratios and increased digestibility of ether extract resulted from feeding straw. Digestibility of other nutrients were generally either not affected or were depressed by straw feeding. Increasing the chopped wheat straw level to 75% of the roughage resulted in lower DM intake and milk yield and negative body weight gains but higher milk fat levels. It did not appear that maintenance of constant ADF level in a dairy ration regardless of roughage level was the solution to the maintenance of milk fat levels. Thus it has been indicated that under the conditions of this experiment a combination of chopped alfalfa and wheat straw can be used successfully in complete mixed rations for high producing dairy cows. For the most part all productive parameters measured were improved by the addition of straw and by the feeding of complete mixed diets. This was especially true for milk fat which, from a dairyman's viewpoint, is very important because of its impact on milk pricing. It would also have a direct bearing on management by reducing labor costs through elimination of labor intensive handling of long alfalfa. Mechanical handling of complete mixed rations is relatively easier and cheaper.

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Lauko eksperimentas buvo vykdomas nuo 1999 metų pagal šią schemą: A veiksnys: Šiaudų įterpimas: šiaudai pašalinti (-Š), šiaudai susmulkinti ir paskleisti (+Š). B veiksnys: Žemės dirbimo sistemos. Eksperimentas buvo atliktas Lietuvos žemės ūkio universiteto bandymų stotyje. Eksperimentas vykdytas 2010 metais. Atlikus tyrimus nustatyta, kad šiaudų įterpimas ir žemės dirbimo sistemos neturėjo esminės įtakos piktžolių daigų skaičiui. Daugiausiai daugiamečių piktžolių daigų rasta sekliai purentuose variantuose, o mažiausiai – tiesiogiai sėjant į neįdirbtą dirvą. Trumpaamžių piktžolių daigų kiekiui esminės įtakos turėjo šiaudų paskleidimas (+Š). Trumpaamžių piktžolių daigų skaičius buvo 43 procentais mažesnis nei dirvoje, kur šiaudai buvo pašalinti (-Š). Nustatyta, kad šiaudų paskleidimas neturėjo esminės įtakos vasarinių rapsų piktžolėtumui, nustatytam prieš derliaus nuėmimą. Esminių skirtumų buvo rasta skirtingose žemės dirbimo sistemose, sekliai purentuose laukeliuose. Palyginus seklųjį purenimą kultivatoriumi plokščiapjūviais noragėliais ir lėkštiniais padargais (KL) bei seklųjį purenimą rotoriniu kultivatoriumi (RK) su giliu arimu (kontrolė) (GA), piktžolių kiekis padidėjo 1,5 ir 1,6 karto. Daugiamečių piktžolių esmingai padidėjo laukeliuose, kur buvo sekliai arta (SA). Šiaudų paskleidimas turėjo esminės įtakos trumpaamžių piktžolių kiekiui. Dirvoje su šiaudais, palyginus su laukeliais be šiaudų, trumpaamžių piktžolių sumažėjo 1,3 karto. Esmingai trumpaamžių piktžolių kiekis... [toliau žr. visą tekstą] / Field experiment was carried out since 1999, as follows: Factor A: Insert a straw: straw removal (-S), straw, shredded and spread (+S). Factor B: tillage systems. The experiment was carried out in Lithuanian University of Agriculture Experimental Station. The experiment was conducted in 2010. It was determined that straw incorporation and tillage system had no significant effect on the number of weed seedlings. Most perennial weed seedlings found in shallow scratch in the treatments, while at least - when sown directly into uncultivated soil. Short-lived weed seedlings had a substantial impact on the quantity of straw spreading (+S). Short-lived weed seedling density was 43 percent lower than in the soil, where straw was removed (-S). It was found that the spreading of straw had no significant effect on weed control in spring rape, before the harvest. Significant differences were found in different tillage systems, shallow scratch boxes. Compared shallow scarification autum cultivator tines and implements Disc (KL) and a rotary cultivator shallow scarification (RK) with deep plowing (control) (GA), weeds grew 1.5 and 1.6 times. Perennial weeds has increased substantially in the fields, where it was shallow plowing (SA). Spreading straw had a substantial impact on short amount of weed. The soil with straw, as compared with the boxes without straw, weeds, fallen short 1.3 times. Substantially short amount of weeds growing through tillage systems. Studies have shown that both... [to full text]

Research goal. We seek to validate optimal composition of straw biomass fuel and energy efficiency of straw utilization for energy needs, to assess straw biomass fuel preparation technology in respect to energy efficiency, and to determine emissions that are generated during straw combustion. Research objectives. The following objectives were planned to reach the goal of the research: 1) Process analysis of preparation of biomass fuel (pellets and briquettes) for burning, 2) Validation of mixture of lime additive (CaO) into straw biomass fuel, 3) Property analysis of prepared biomass fuel, 4) Measurement and assessment of emissions generated while burning straw biomass fuel, 5) Assessment of energy consumption by straw pellet production equipment. / Tyrimų tikslas. Pagrįsti šiaudų biokuro optimalios sudėties paruošimo ir panaudojimo energinėms reikmėms efektyvumą, atlikti šiaudų biokuro paruošimo technologijos energinį vertinimą ir nustatyti deginimo metu išskiriamas emisijas. Tyrimų uždaviniai. Tyrimų tikslui pasiekti numatyta: 1) Atlikti šiaudų biokuro (briketų ir granulių) paruošimo deginimui technologinę analizę; 2) Pagristi kalkių priedo (CaO) įmaišymo į šiaudų biokuro sudetį tikslingumą; 3) Ištirti pagaminto šiaudų biokuro savybes; 4) Nustatyti ir įvertinti šiaudų biokuro deginimo metu išskiriamas emisijas; 5) Įvertinti šiaudų granulių gamybos technologinės įrangos energijos sanaudas.

A produção comercial dos surfactantes ocorre principalmente por síntese química a partir do petróleo. A via biotecnológica se apresenta como uma alternativa promissora por possibilitar a utilização de biomassas vegetais, ricas em carboidratos a exemplo da palha de cana-de-açúcar. Assim, esta biomolécula torna-se mais competitiva comercialmente em relação aos surfactantes químicos, obtendo um processo biossustentável e biodegradável. Microrganismos isolados da Antártica apresentam potencial para a produção destas biomoléculas, uma vez que em condições extremas de sobrevivência estas poderiam ser produzidas em concentrações elevadas. Assim, este estudo avaliou a produção de biossurfactante em hidrolisado hemicelulósico de palha de cana-de-açúcar (HHPC) a partir de leveduras da Antártica, além da caracterização parcial da biomolécula e testes de estabilidade da emulsão. Inicialmente foram avaliadas 24 leveduras, cultivadas em frascos Erlenmeyer de 50 mL em meio semi-definido contendo xilose ou glicose como fontes de carbono, a 25ºC, 150 rpm, por até 72 horas. As propriedades emulsificante e tensoativa do bioproduto foram avaliadas e as culturas que apresentaram resultados satisfatórios para ambas as propriedades e consumo de xilose superior ou igual a 80% foram selecionadas para cultivo em meio formulado com HHPC. Das 24 leveduras testadas, três foram selecionadas para cultivo em hidrolisado: Cryptococcus laurentii (L62), Cryptococcus adeliensis (L95) e Rhodotorula mucilaginosa (L52). Destas, a levedura Cryptococcus adeliensis (L95) se destacou por apresentar produção de biomoléculas com maior propriedade emulsificante e tensoativa. Para esta levedura o consumo de xilose em meio semi-definido e em HHPC bem como o índice de emulsificação nas diferentes condições foram semelhantes. O biossurfactante produzido por Cryptococcus adeliensis (L95) foi caracterizado como glicolipídeo. Diferentes métodos de extração desta biomolécula foram testados, no entanto, estes não apresentaram diferença significativa. A estabilidade da emulsão obtida do sobrenadante de L95 em HHPC foi determinada em distintas condições físico-químicas, sendo que esta foi estável a pH extremamente baixo (2,00), baixas temperaturas (0oC e 4oC) e elevada concentração salina (10% m/V). Estes resultados são promissores considerando o potencial de aplicação de biossurfactantes em biorremediação bem como insumos nos mais diversos segmentos industriais, os quais necessitam de biomoléculas que resistam às mais diversas condições ambientais. Desta forma nesta pesquisa foi possível inferir que a biomassa de palha de cana pode ser destinada à obtenção de biossurfactantes a partir de leveduras da Antártica, destacando a relevância da pesquisa quanto à inovação biotecnológica. / The commercial production of surfactants occurs mainly by chemical synthesis from petroleum. The biotechnological pathway is considered as a promising alternative because it allows the use of vegetable biomass, rich in carbohydrates such as sugarcane straw. Thus, this biomolecule becomes more commercially competitive with respect to the chemical surfactants, obtaining a biodegradable process. Microorganisms isolated from Antarctica have the potential to produce these biomolecules, since under extreme conditions of survival, these could be produced in higher concentrations. In this way, this study aims to evaluate the biosurfactant production in sugarcane straw hemicellulosic hydrolysate from Antarctic yeasts, in addition to the partial characterization of the biomolecule and stability tests of the emulsion. Initially, 24 yeasts were evaluated, grown in 50 mL Erlenmeyer flasks in semi-defined medium with xylose or glucose as carbono sources, at 25ºC, 150 rpm, up to 72 hours. The emulsifying and surfactante properties of the bioproduct were evaluated, and the cultures that had satisfactory results for both properties and xylose consumption higher or equal to 80% were selected to be cultivated in a medium formulated with sugarcane straw hemicellulosic hydrolysate (SSHH). In the 24 yeasts tested, three were selected to be cultivated in the hydrolysed: Cryptococcus laurentii (L62), Cryptococcus adeliensis (L95) and Rhodotorula mucilaginosa (L52). Among these C. adeliensis (L95) was distinguished by the production of biomolecules with higher emulsifying and tensoactive properties. For this yeast, the xylose consumption in semi-defined medium and in SSHH, as well as the emulsification index under diferente conditions were similar. The biosurfactant produced by C. adeliensis (L95) was characterized as glycolipid. Different methods of extraction of this biomolecule were tested, however, these did not have significant difference. The emulsion stability obtained from the C. adeliensis (L95) supernatant in SSHH was determined under different physicochemical conditions, which was stable at extremely low pH (2,00), low temperatures (0oC and 4oC) and high saline concentration (10% m/v). These results are interesting considering the potential of the biosurfactants application in bioremediation and inputs for several industrial segments, which require biomolecules that resist to the most diverse environmental conditions. In this research, it was concluded that sugarcane straw biomass can be used to obtain biosurfactants from Antarctic yeasts, consequently highlighting the research relevance regarding to the biotechnological innovation.