Propoxylated Fatty Thiazole,Pyrazole, Triazole,and Pyrrole Derivatives with Antimicrobial and Surface Activity

Lauric acid and propylene oxide were used to modify four biologically active heterocycles (thiazole, pyrazole, triazole, and pyrrole) to synthesize 17 new surfactants. The chemical structures of these surfactants were confirmed using infrared and ¹H, and ¹³C nuclear magnetic resonance (NMR) spectroscopy. The surfactants all show good surface activity, low critical micelle concentration (CMC) values, high cloud points, and tight interfacial packing. All showed antimicrobial activity on both bacteria and fungi. In addition, biodegradation testing demonstrated significant breakdown within seven days.     

Experimental and theoretical study for the determination of thermal conductivity of porous building material made with pumice and tragacanth

In this study, porous solid materials were produced with mixture combinations of materials such as tragacanth, cement, and pumice aggregate. Thermal conductivities of the produced materials were determined using hot wire methodology. The thermal conductivities of the produced samples ranged from 0.433 to 0.177 W/mK, depending on pumice diameter, pumice, tragacanth, and cement rates. A new model was developed to determine the effective thermal conductivities of the produced samples. The thermal conductivities obtained by the measurements were compared to the ones predicted by the model. The predicted values deviated as 1–31% from the measured values. It was finally shown that the experimental results were in good agreement to the predicted results.     

Nonhypothesis Analysis of a Mutagenic Soybean (Glycine max [L.]) Population for Protein and Fatty‐Acid Composition

Soybean is a major source of oil for food, feed, and biofuel production. Mutagenesis is a tool for creating unique traits useful in breeding programs. The aim of this study is to use nonhypothesis statistical testing methods to make decisions about a mutagenic population. To this end, a total of 1037 mutation lines and 28 wild‐type lines were analyzed for fatty‐acid composition and protein content. Principal component analysis (PCA) was used to analyze the fatty acid profile, multivariate analysis of variance (MANOVA) to build a selection model for seed weight per plant and weight per 10 seeds, and clustering in conjunction with power analysis to determine the minimum number of individuals needed to create a MANOVA selection model for the oil to protein content. Five of the 35 possible entries were identified by PCA analysis for stearic acid and four of 16 possible entries for oleic acid. Interestingly, most of the selected mutants were validated genetically. In fact, selected mutants with high seed stearic acid or high seed oleic acid contents were verified to carry mutations on GmFAD2‐1A, GmFAD2‐1B, and GmSACPD‐C genes. This shows a promising method of identifying smaller portion of the population to screen for desired mutations.     

Fabrication of ceramic nanofibers using polydimethylsiloxane and polyacrylonitrile polymer blends

Nanofibers with several hundred of nanometers were successfully fabricated using electrospinning process and a mixture of two types of polymers which are: polydimethylsiloxane and polyacrylonitrile as precursors. After stabilization and carbonization at 1000 °C, three phases which are: silicon carbide (SiC), carbon, and oxy‐SiC were presented. Spectroscopic and microscopic techniques had confirmed the presence of nanocrystalline SiC and turbostratic carbons. These phases formed an intertwined network at the nanometric scale. In addition, the resulted fibers showed a core‐skin effect with skin richer in carbon and a core mainly dominated by silicon‐based phases in the form SiC or Si? O? C ceramics. A significant improvement was observed in both tensile strength and elastic modulus in these hybrid fibers. In term of crystallography, these nanofibers seem to exhibit similar microstructure that was observed in Nicalon fiber. However, it was difficult to determine the ratio of these phases and their influence on the physical properties of these hybrid fibers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45967.     

A carbon nanotube-based composite for the thermal control of heat loads

Design optimization of an encapsulated carbon composite thermal control (TC) system is presented. The composite TC system consists of multiple phase change materials (PCM) doped with carbon nanotubes and enclosed in a casing of carbon/carbon composite sheets. Using the concept of global thermal resistance an analytical model was formulated to predict the transient temperature distribution through the composite system. The temperature data was then used to estimate maximum energy storage and heat dissipation rates. A substantial reduction in weight and size of the TC composite was observed corresponding to the optimized design. The use of carbon nanotubes both as additives with optimal loading and as a thermal interface material significantly reduced the maximum junction temperatures for different constant power loads for the multiple PCM composite as compared to its original size used for the experimental work. The optimized composite minimized the total thermal resistance through the composite sample and thereby increased its thermal response as indicated by approximately 4 times increase in the heat dissipation rate.     

Preparation of high pure α-Al2O3 nanoparticles at low temperatures using Pechini method

A Pechini process was successfully used to synthesize alpha-alumina (98.95% mass fraction) at relatively low calcination temperature (925 °C). The synthesis of these nanoparticles was carried out using a polymer prepared from citric acid and ethylene glycol by the melt blending method. This polymer worked as a chelating agent for aluminum cations. The final products were produced after a dual-stages thermal treatment. The resulting α-alumina consisted of nanoparticles of 8–16 nm in diameters with a surface area (～8 m² g^?1). The mass fraction of α-alumina was dependent on the concentration of aluminum salt and polymer precursor's solutions, while the surface area of the final product was dependent on the mass fraction of θ-alumina.     

Microencapsulation of hazelnut oil through spray drying

This study was performed to investigate the influence of air inlet temperature (AIT) on the microencapsulation of hazelnut oil by spray drying. Encapsulated powders were analyzed for moisture content, powder yield, surface oil, encapsulation efficiency (EE), bulk density, and particle morphology. The obtained results demonstrated that moisture content, surface oil, and bulk density decreased by 37.8, 27.5, and 33%, respectively as AIT increased from 140 to 220°C. However, powder yield and encapsulation efficiency increased considerably with the rise in AIT. Higher EEs of about 75–80% were observed in this study.     

Improved catalytic activity by catalase immobilization using γ‐cyclodextrin and electrospun PCL nanofibers

Nanofibrous structures are promising for biocatalyst immobilization due to their large surface area which facilitates the enzyme attachment, stability, ease of separation, and fine porous structure. There is limited research available on the change in enzyme activity following interaction with cyclodextrin. In this study, catalase enzyme was immobilized into nanofibrous structures by various techniques, with and without γ‐CD addition, and the enzymatic activity of catalase was evaluated. In addition, catalase‐γ‐CD complex containing PEO polymer solution was electrospun in between PCL nanofibrous layers as a newly developed technique. The enzyme immobilized nanofibrous structures were characterized by SEM, XRD, and FT‐IR analysis methods. Among all the activity tests, best enzyme activity was recorded with catalase‐γ‐CD physical mixture encapsulated PCL nanofibrous layers. Moreover, the test results indicated that the use of cyclodextrin in immobilization process considerably improves the catalytic activity of the enzyme. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44404.