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关键词： Lubricant additive   Friction coefficient   Adhesive wear   Microalgae   Alternative energy  

摘要： Hydrogen fuel offers a cleaner fuel alternative to fossil fuel due to more efficient burning as well as reduces the environmental and health issues brought by fossil fuel usage. In engine application, regardless of either pure hydrogen or in combination with air or/and other biofuel, all the moving parts are exposed to friction and wear, and lubricant is used to minimize friction and wear for optimum operation. Thus, in this study, the use of microalgae oil as an alternative biolubricant is evaluated from the physicochemical and tribological aspects. It is found that modified microalgae oil (MMO) has demonstrated great anti-friction and anti-wear potential, particularly the 10% modified microalgae oil blend (MMO-10). The coefficient of friction is reduced (up to 10.1%) and significant reductions of wear loss and surface roughness are obtained in comparison to pure poly-alpha-olefin. Lubricant's heat dissipation is also enhanced with MMO addition, demonstrating great prospect for MMO for hydrogen-powered engine utilization. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： Drug delivery carrier   Graphene oxide   Self-role up   Nanocarrier  

摘要： Efficient cellular endocytosis is indispensable for a drug delivery system. Graphene oxide (GO) is attracting considerable attention owing to its unique properties. However, GO tends to aggregate in physiological aqueous solutions and thus stabilization through functional molecules needs to be introduced. This research suggests a new strategy for utilizing GO as a drug carrier without a complicated surface modification process. A needle-like GO nanocarrier is developed through a conformational change of GO sheets in the cell growth medium with the aids of salt ions. A high surface area and sufficient number of functional groups of GO ensure the accumulation of doxorubicin hydrochloride (DOX) on the GO sheets. The drug loading capacity is measured through UV-vis spectroscopy. DOX-loaded GO sheets are visualized using confocal images and an AFM analysis. The conformational change and cellular uptake mechanism are studied with the help of TEM. The cytotoxicity and cellular uptake of the DOX-loaded GO needles are investigated on human dermal fibroblast (HDF) cells and the HeLa cancer cell line. GO needles demonstrate good biocompatibility of below a 100 mu g/mL concentration, whereas DOX-loaded GO needles show a better anti-cancer capability than free DOX treatment owing to the enhanced cellular endocytosis of a 1D needle structure. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

关键词： Pea   protein   composition   physicochemical property   functional food  

摘要： Field pea is one of the most important leguminous crops over the world. Pea protein is a relatively new type of plant proteins and has been used as a functional ingredient in global food industry. Pea protein includes four major classes (globulin, albumin, prolamin, and glutelin), in which globulin and albumin are major storage proteins in pea seeds. Globulin is soluble in salt solutions and can be further classified into legumin and vicilin. Albumin is soluble in water and regarded as metabolic and enzymatic proteins with cytosolic functions. Pea protein has a well-balanced amino acid profile with high level of lysine. The composition and structure of pea protein, as well as the processing conditions, significantly affect its physical and chemical properties, such as hydration, rheological characteristics, and surface characteristics. With its availability, low cost, nutritional values and health benefits, pea protein can be used as a novel and effective alternative to substitute for soybean or animal proteins in functional food applications.

关键词： Adsorbed film thickness   Hashin model   K-B-G* parameter   Filler critical concentration  

摘要： The blend of asphalt binder and mineral filler forms asphalt mastic and the investigation of physicochemical interaction between them is significant to study the rheological properties of asphalt mixture. The interfacial physicochemical effect can be directly evaluated by the adsorbed film thickness between filler and binder. Therefore, the study proposed new methods based on Hashin model and K-B-G* parameter to calculate the adsorbed film thickness and the results were within 0.14 mu m for different asphalt mastics. Additionally, the effects of asphalt binder and mineral filler characteristics on adsorbed film thickness were also investigated in this study. The results showed that asphalt binder with higher polar components content can form thicker adsorbed film with mineral filler particles. And the order of adsorbed film thickness of different mineral filler with asphalt binder from thick to thin was fly ash, hydrated lime and limestone. Furthermore, the study investigated the existence of filler critical concentration to provide proper ratio of mineral filler to asphalt binder for asphalt mixture design. (C) 2020 Published by Elsevier Ltd.

关键词： Triphenylamine derivatives   doping   DFT   molecular structure   optoelectronic properties   chemical reactivity parameters  

摘要： In this study, the molecule 2-cyano-3-[4(diphenylamino)phenyl] acrylic acid (L0) was doped with a potassium atom at two different positions to obtain LK(1) and LK(2). The three molecules were studied using DFT (B3LYP) and HF methods, with the basic sets 6-31G(d,p) and 6-311G(d,p). From our results, we observed that energy gap at the B3LYP level is smaller in the doped molecules LK(1) (2.842-3.074 eV) and LK(2) (2.758-2.850 eV) compared to the virgin molecule L0 (3.194-3.226 eV). The energy gap value for each molecule is smaller when the 6-31G(d,p) basis set is used. The dipole moment, average polarizability, first-order hyperpolarizability, refractive index, electric susceptibility, dielectric constant increased considerably in the doped molecules, especially in LK(2). These results show that LK(1) and LK(2) are good candidates for applications in nonlinear optical materials and photovoltaic devices compared to L0.

关键词： Hard fats   physicochemical properties   thermal properties   confectionery products  

摘要： Hard fats, obtained from liquid oils by different fat modification techniques, are composed of high-melting-point triacylglycerols (TAGs) that can be used as alternatives to improve the functional characteristics of lipid systems. These low-cost industrial products are regarded as raw materials in lipid technology. They can behave as modifiers in crystallization processes, acting as preferential nuclei for ordering crystal lattices and inducing specific polymorphic patterns because of their homogeneous TAGs. Adding hard fats, such as mango, illipe, kokum, sal, shea, rambutan, palm oil, palm kernel oil, and sunflower oil, into other oils is beneficial as it increases their compatibility for uses in fat-based products, especially confectionery products. The addition of hard fats has a significant effect on the rate of crystallization, significantly decreasing the induction time for nucleation and leading to a higher hardness, and increases the thermal resistance for applications in fat-based products. The aim of this article is to review the changes in the physicochemical and thermal properties of hard fats and their mixtures obtained by fractionation, enzymatic interesterification and blending, which broaden their applicability in the food industry.

关键词： Internal combustion engine   Nanoparticles   Physico-chemical characterization   Mass spectrometry   Emission modeling  

摘要： Particulate emissions from on-road motor vehicles are the focus of intensive current research due to the impact of the ambient particulate matter (PM) levels on climate and human health. Constant improvement in engine technology has led to significant decrease in the number and mass of emitted PM, but particular concern is raised nowadays by the ultrafine particles. In this context, there is a critical lack of certification procedures for the measurement of the smallest-size (<23 nm) particulate matter emissions. To support the engine development process as well as future certification procedures, a measurement technology for sub-23 nm particles must be designed. The development of a reliable measurement procedure entails understanding the formation and evolution of particles from the engine to the tailpipe via multiple analytical techniques and theoretical simulations. We present here extensive experimental characterization of ultrafine particles emitted by a gasoline direct injection single-cylinder engine as particle generator. The particles were sampled using a cascade impactor which allows size-separation into 13 different size bins. Chemical characterization of the collected size-selected particles was performed using mass spectrometry, which gives access to detailed molecular information on chemical classes of critical interest such as organosulphates, oxygenated hydrocarbons, nitrogenated hydrocarbons, metals, or polycyclic aromatic hydrocarbons. Additionally, the morphology of the emitted particles was probed with atomic force (AFM) and scanning electron microscopy (SEM). Tip-Enhanced Raman Spectroscopy (TERS) was applied for the first time to sub-10 nm combustion-generated particles to gather information on their nanostructure. The extensive database built from these multiple experimental characterizations has been used as input of a theoretical approach to simulate and validate engine out-emissions. These studies were performed in the framework of the H20

关键词： Pyroconversion   Response surface methodology   Digestibility   Available starch   Dietary fiber   Physicochemical properties  

摘要： This study optimizes the pyrodextrinization of yam (Dioscorea sp.) starch isolated from tubers grown in Brazil to produce a yellow pyrodextrin with the lowest enzymatically available starch (AS) content and color difference (Delta E) index. At 140 degrees C (fixed heating temperature), the effects of acid concentration (0.65- 2.99 g of HCl/kg of starch) and incubation time (53- 307 min) on the response variables were evaluated using a response surface methodology. Some physicochemical characteristics were also determined on pyrodextrins. Both factors negatively affected the AS content, although positively influenced the Delta E (P < 0.05). The yellow pyrodextrin produced with 1.82 g/kg and heating for 307 min, presented physicochemical properties similar to the commercial pyrodextrins from potato starch, with 46.6 % of AS, 24.5 of Delta E, high solubility and very low viscosity. The pyrodextrinization caused a decrease of 30 - 54 % in AS content (P < 0.05), making these yam pyrodextrins a promising material for water-soluble and very low viscous dietary fiber.