Diffractive optics as beam-shaping elements for plastics laser welding

David Grewell and Avraham Benetar, "Diffractive Optics As Beam Shaping Elements For Plastics Laser Welding," Optical Engineering, 46(11), 118001, (2007). http://dx.doi.org/10.1117/1.2802588</p

Scale-up and Technology Transfer of Protein-based Plastic Products

Over the last number of years researchers at ISU have been developing protein based plastics from soybeans, funded by Soy Works Corporation. These materials have been characterized and the processing of these materials into prototype products has been demonstrated. A wide range of net-shape forming processes, including but not limited to extrusion, injection molding and compression molding have been studied. Issues, including technology transfer, re-formulation and product consistency, have been addressed partially during this contract. Also, commercial-scale processing parameters for protein based plastic products were designed, but not yet applicable in the industry. Support in the trouble shooting processing and the manufacturing of protein based plastic products was provided by Iowa State University during the one year contract

Enhancing Biodiesel Production from Soybean Oil Using Ultrasonics

Our objective was to determine the effect of ultrasonics on biodiesel production from soybean oil. In this study, ultrasonic energy was applied in two different modes: pulse and continuous sonication. Soybean oil was mixed with methanol and a catalytic amount of sodium hydroxide, and the mixture was sonicated at three levels of amplitude (60, 120, and 180 μmpp) in pulse mode (5 s on/25 s off). In the continuous mode, the same reaction mixture was sonicated at 120 μmpp for 15 s. The reaction was monitored for biodiesel yield by stopping the reaction at selected time intervals and analyzing the biodiesel content by thermogravimetric analysis (TGA). The results were compared to a control group, in which the same reactant composition was allowed to react at 60 °C for intervals ranging from 5 min to 1 h without ultrasonic treatment. It was observed that ultrasonic treatment resulted in a 96% by weight isolated yield of biodiesel in less than 90 s using the pulse mode, compared to 30−45 min for the unsonicated control sample with comparable yields (83−86%). In the pulse mode, the highest yield (96%) was obtained by sonicating the mixture at 120 μmpp amplitude. In the continuous sonication mode, the highest biodiesel yield was 86% by weight, which was obtained in 15 s

Evaluation of Effects of Ultrasonic Pretreatment on Biogas Production Potential from Corn Ethanol By-products

This paper reviews the biochemical methane potential (BMP) production from anaerobic digestion of corn-ethanol by-products including dried distiller grain with solubles (DDGS), centrifuge solids, thin stillage, and corn-syrup as well as evaluating the effects of ultrasonic pretreatment on biogas production from these feedstocks. Ultrasonic pretreatment was applied with three amplitude settings of 33% (52.8 µm pp ), 66% (105.6 µm pp ), and 100% (160 µm pp ) as well as five time settings of 10, 20, 30, 40, and 50 seconds, respectively, to each of the four by-products before setting up a bench top BMP trial. Biogas production was measured and analyzed for methane content and accumulated methane production. Without ultrasound pretreatment, corn-syrup had the highest methane production potential (408 ml/g VS added) compare to the other by-products. Methane production was increased by 25 and 12% for the ultrasound pretreated DDGs samples and solids samples, respectively, compared with untreated samples. The ultrasonic pretreatment of ethanol co-products was shown to increase methane production from the anaerobic digestion of these products. The ultrasonic pre-treatment of solids co-products (DDGS and centrifuge solids) was far more effective than on liquid co-products (syrup and thin stillage). An energy balance showed that ultrasonic pretreatment of DDGS provided 70% more energy than was required to operate the ultrasonic unit. An energy balance for other co-products however, indicated that the ultrasonic pre-treatment required more energy than was generated by the process in terms of additional biogas production

Effect of Acetylation on the Mechanical and Thermal Properties of Soy Flour Elastomers

Biobased fillers were utilized as components in soy-elastomer composites. Soy flour is lightweight, low cost, and high strength, which makes it an ideal alternative to petroleum-derived fillers. However, poor interfacial adhesion and low dispersion within the polymer matrix are limiting factors for composite performance. Soy flour chemically pretreated by acetylation was compounded with synthetic rubber elastomers. In general, soy flour (as received) concentration in the composite is proportional to the ultimate strength. However, soy-elastomer composites with acetylated filler performed similar to the neat elastomer. In addition, the pretreated composite\u27s thermal stability increased and exhibited less phase seperation compared to the untreated composites

Depolymerization of Post-Consumer Polylactic Acid Products

Presented in this study is a novel recycling strategy for poly(lactic acid) (PLA) in which the depolymerization is rapidly promoted by the base–catalyzed hydrol–/alcohol–ysis of the terminal ester bonds under mild conditions. Post–consumer PLA water bottles were cut into approximately 6 × 2 mm plastic chips and heated to 50–60×C in water, ethanol, or methanol as the depolymerization medium. A variety of carbonate salts and alkaline metal oxides were screened as potential catalysts. High–power ultrasound was also investigated as a means to accelerate the PLA decomposition. Both mass loss and HPLC analysis of the treated suspensions showed that the conversion of PLA to lactic acid/lactic esters was achieved with yields over 90% utilizing either ultrasonics or a hot bath. It was found that the most rapid decomposition occurred in solution of sodium hydroxide in methanol at 50oC, in which maximum depolymerization was complete in 5 min. It was also seen that the degree of crystallinity affected the rate of depolymerization

Effect of Ultrasonic Pretreatment on Methane Production Potential from Corn Ethanol Coproducts

This article addresses the biochemical methane potential (BMP) production from anaerobic digestion of corn-ethanol coproducts including dried distiller grain with solubles (DDGS), distiller\u27s wet grains (DWG), thin stillage, and condensed distiller\u27s solubles (CDS) as well as evaluating the effects of ultrasonic pretreatment on methane production from these feedstocks. Ultrasonic pretreatment was applied with three amplitude settings of 33% (52.8 µmpp), 66% (105.6 µmpp), and 100% (160 µmpp) as well as five time settings (10, 20, 30, 40, and 50 s) to each of the four coproducts prior to conducting benchtop BMP trials. Ultrasonic pretreatment reduced mean particle size of DDGS and DWG by 45% and 43%, respectively. Without ultrasound pretreatment, CDS had the highest methane production potential (407 mL g-1 VS added) compared to the other coproducts. Ultrasonic pretreatment of DWG co-products (DDGS and DWG) resulted in greater increases in methane production than on liquid coproducts (CDS and thin stillage). Methane yields were increased by 25% and 12% for the ultrasound pretreated DDGS and DWG, respectively, compared with untreated samples. An energy balance for the DWG, thin stillage, and CDS coproducts indicated that ultrasonic pretreatment required more energy than was generated by the process in terms of additional biogas production. However, an energy balance for ultrasonic pretreatment of DDGS provided 70% more energy than was required to operate the ultrasonic unit

Function and Biodegradation in Soil of Bioplastic Horticultural Containers made of PLA-BioResTM Composites

Container-crops horticultural industries rely almost exclusively on petroleum-based plastic containers for modern production systems. Containers made of these materials fulfill all of the functions required during crop production, and perform better than containers made of clay, peat, and other natural materials, but the source of the plastic materials (fossil carbon), their lack of biodegradability, and their end-of-life disposal (97% end up in landfills) are major obstacles to sustainability. Although function and efficiency are among the most important aspects in determining the best materials for horticultural containers, there is no need for containers to persist in the environment for decades when their useful life cycle is only one month to three years depending on the plant species produced in them

Characterization of Ultrasonic Treatment of Ethanol Co-Products for Enhanced Biogas Production

This study evaluates the change in particle size of dry-milling corn ethanol co-products by using ultrasonic energy to increase the production of the biogas from the anaerobic digestion of ethanol dry-milling co-products, namely: dried distiller grain with solubles (DDGS), solids, thin stillage, and corn-syrup. The co-product samples were treated with various ultrasonic conditions and compared to non-treated samples (control sample). The ultrasonic amplitude was varied from 52.8 µm pp to 160 µm pp and the sonication time was varied from 10 to 50s. The samples were characterized with scanning electron and optical microscopy (SEM, OM) and particle distribution analysis (PDA). It was found that with solid/liquid suspensions (DDGS, solids), there was a significant decrease in particle size, increasing the surface area to volume ratio, to possibly enhance biogas yield during anaerobic digestion of these materials. In the case of thin stillage and corn syrup, the results were surprising in that an increase in particle size was seen

Novel Characterization Method of Biodiesel Produced from Soybean Oil using Thermogravimetric Analysis

The aim of this study was to demonstrate thermogravimetric analysis (TGA) as a potential method for monitoring biodiesel production. Soybean oil and commercial biodiesel were mixed in different proportions by weight. Mixtures of different biodiesel/soybean oil ratios were also created by interrupting a base-catalyzed transesterification process for producing biodiesel at various times. The mixtures produced by both approaches were analyzed with TGA. The results were then compared with data obtained by proton nuclear magnetic resonance spectroscopy ( 1HNMR spectroscopy). The relative weight losses in both sets of mixtures we generated correlated well to the proportion of biodiesel present in the sample. The results from both analytical methods were in good agreement and within a deviation of 5%. Thus, TGA is a simple, convenient and economical method for monitoring biodiesel production