Interference and diffraction experiment using 3D printing and Arduino

Abstract Here, we present a 3D printed experimental apparatus that students can use to acquire interference and diffraction quantitative data from light passing through a single or double-slit experiment. We built a linear screw stage with a multiturn potentiometer connected to its leadscrew as a position sensor. Using an Arduino, we collected light intensity data (from a photodiode mounted in the linear stage) as a function of position. The apparatus is a low-cost and compact alternative with data acquisition to optics physics laboratories.</jats:p

Lipase-catalyzed ethanolysis of jatropha curcas l. oil assisted by ultrasonication

Transesterification of non-edible oils using immobilized lipase is a promising process for biodiesel production. Thus, this study aimed to evaluate the enzymatic transesterification of the non-edible Jatropha curcas oil for FAEE production under ultrasound irradiation in a solvent-free system. The effects of enzyme concentration, water concentration, molar ratio of ethanol to oil and ultrasound power on the FAEE conversion have been evaluated. The results show that enzyme concentration and irradiation power have a positive significant effect on FAEE conversion, where an increase in these variables leads to higher conversions. Conversion above 54% of FAEE was achieved with 1.5 hours of reaction time using ultrasound irradiation, reducing reaction time by at least 3 times, when compared with the same experimental conditions without ultrasound irradiation. Results showed that ultrasound can improve reaction conversion mainly by enhancing the mass transfer between the constituents of the reactions

Lipase-Catalyzed Glycerolysis of Soybean and Canola Oils in a Free Organic Solvent System Assisted by Ultrasound

This work shows new and promising experimental data of soybean oil and canola oil glycerolysis using Novozym 435 enzyme as catalyst in a solvent-free system using ultrasound bath for the emulsifier, monoglyceride (MAG), and diacylglycerol (DAG) production. The experiments were conducted in batch mode to study the influence of process variables as temperature (40 to 70&nbsp;°C), immobilized enzyme content (2.5 to 10&nbsp;wt%, relative to substrates), molar ratio glycerol/oil (0.8:1 to 3:1), agitation (0 to 1200&nbsp;rpm) and ultrasound intensity (0 to 132&nbsp;W cm−2). Highest yields of DAG+MAG (75&nbsp;wt%) were obtained with molar ratio glycerol/canola oil 0.8:1, 70&nbsp;°C, 900&nbsp;rpm, 120&nbsp;min of reaction time, 10&nbsp;wt% of enzyme concentration, and 52.8&nbsp;W cm−2 of ultrasound intensity. When soybean oil was used, the best results in terms of DAG+MAGs (65&nbsp;wt%) were using molar ratio of glycerol/soybean oil 0.8:1, 70&nbsp;°C, 900&nbsp;rpm, 90&nbsp;min of reaction time, 10&nbsp;wt% of enzyme content, and 40&nbsp;% of ultrasound intensity (52.8&nbsp;W cm−2). The results showed that the lipase-catalyzed glycerolysis in a solvent-free system with ultrasound bath can be a potential route for high content production of DAGs and MAGs

Techno-economic assessment of benzyl benzoate clean production using conventional heating or microwaves

Benzyl benzoate is an important anti-scabies agent, so finding sustainable production processes is essential. This work involved the techno-economic assessment of benzyl benzoate production in a solventless system with conventional heating or microwave-assisted. The proposed processes' conditions were optimized by transesterifying methyl benzoate and benzyl alcohol in a solventless system using the Lipozyme 435 lipase as the catalyst. The optimized conditions were an es ter/alcohol molar ratio of 1:6, a temperature of 73 °C, and enzyme loading of 10% and 16% (w/w), for conventional heating and microwave-assisted, respectively. Under these conditions, the two reactions reached conversions greater than 90% in 24 h and 82% in 7 h. The tests on lipase reusability showed that the ester production remains stable for up to 4 use cycles. Gas chromatog raphy and proton NMR confirmed that benzyl benzoate could be produced biocatalytically, and a high purity can be obtained by simple distillation. The economic analysis of the process showed that the total capital investment was favorable, suggesting a promising investment opportunity. Furthermore, a production total cost showed a favorable positive net present value and returned on investment for benzyl benzoate production. Hence, the proposed clean production of benzyl benzoate can be considered for industrial scale-up

Partial characterization of lipases produced by a newly isolated Penicillium sp in solid state and submerged fermentation: A comparative study

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The aim of this research was the partial characterization of enzymatic extracts produced by a newly isolated Penicillium sp. in submerged (SmF) and solid state fermentation (SSF). The partial characterization of the crude enzymatic extract obtained by SSF and SmF systems showed optimum activity at pH 5.5 and 47 degrees C, and pH 7.0 and 37 degrees C, respectively (15.17 U/mL and 11.28 U/mL). The crude enzymatic extracts obtained by SmF and SSF presented the best stability at pH from 4.9 to 8.5 and temperature from 25 degrees C to 35 degrees C and pH 7.0 and 25 degrees C, respectively. These results confirm the interesting potential of SSF, because, besides the higher activities obtained in this system, the half-life time at 25 degrees C was higher than that observed for the lipase extract obtained in the SmF system. (C) 2009 Elsevier Ltd. All rights reserved42915571560Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)IntecnialCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

A review on lipase-catalyzed reactions in ultrasound-assisted systems

The named "green chemistry" has been receiving increasing prominence due to its environmentally friendly characteristics. The use of enzymes as catalysts in processes of synthesis to replace the traditional use of chemical catalysts present as main advantage the fact of following the principles of the green chemistry. However, processes of enzymatic nature generally provide lower yields when compared to the conventional chemical processes. Therefore, in the last years, the ultrasound has been extensively used in enzymatic processes, such as the production of esters with desirable characteristics for the pharmaceutical, cosmetics, and food industry, for the hydrolysis and glycerolysis of vegetable oils, production of biodiesel, etc. Several works found in the open literature suggest that the energy released by the ultrasound during the cavitation phenomena can be used to enhance mass transfer (substrate/enzyme), hence increasing the rate of products formation, and also contributing to enhance the enzyme catalytic activity. Furthermore, the ultrasound is considered a "green" technology due to its high efficiency, low instrumental requirement and significant reduction of the processing time in comparison to other techniques. The main goal of this review was to summarize studies available to date regarding the application of ultrasound in enzyme-catalyzed esterification, hydrolysis, glycerolysis and transesterification reactions