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关键词： Cellulose  

摘要： Cellulose was extracted from sugarcane bagasse and treated with electrohydrodynamic (EHD) device. The EHD-treated and non-treated cellulose fibers were added to whipping cream at three levels of 0.5%, 1%, and 1.5% wt/wt. Whipped cream was prepared using different fat concentrations (25%, 30%, and 35% wt/wt). Analysis of physicochemical properties showed that increasing cellulose and fat concentrations increased viscosity, firmness, overrun, and stability against syneresis in whipped cream. Superior textural and color quality (greater whiteness index and lower yellowness index) were observed in whipped cream samples contained modified cellulose compared to those consisting non-modified cellulose at each fat level. The sample prepared with 1.5% of modified cellulose and 30% of fat exhibited preferable stability, textural, and color properties compared to those contained 0.5%-1.5% non-modified cellulose and 35% fat. The current study showed that EHD-treated cellulose fiber with improved textural properties could be used in fat-reduced cream. Novelty impact statement Cellulose was extracted from sugarcane bagasse and treated with electrohydrodynamic device. The physically modified cellulose enhanced the stability, texture, and color of whipped cream as fat replacer.

关键词： 3D bioprinting   biofabrication   gelatin   pectin   scaffolds   tissue engineering  

摘要： Developing biomaterial formulations with specific biochemical characteristics and physical properties suitable for bioprinting of 3D scaffolds is a pivotal challenge in tissue engineering. Therefore, the design of novel bioprintable formulations is a continuously evolving research field. In this work, the authors aim at expanding the library of biomaterial inks by blending two natural biopolymers: pectin and gelatin. Cytocompatible formulations are obtained by combining pectin and gelatin at different ratios and using (3-glycidyloxypropyl)trimethoxysilane (GPTMS) as single crosslinking agent. It is shown that the developed formulations are all suitable for extrusion-based 3D bioprinting. Self-supporting scaffolds with a designed macroporosity and micropores in the bioprinted struts are successfully obtained by combining extrusion-based bioprinting and freeze-drying. The presence of gelatin in these formulations allows for the modulation of porosity, of water uptake and of scaffold stiffness in respect to pure pectin scaffolds. Results demonstrate that these new biomaterial formulations, processed with this specific approach, are promising candidates for the fabrication of tissue-like scaffolds for tissue regeneration.

关键词： Biodiesel  

摘要： In the present research, biodiesels were prepared from Mahua and Jatropha oil by two-step transesterification. The physicochemical characteristics (viz. density, acid value, iodine value, kinematic viscosity, cloud-pour point, fire-flash point) of prepared biodiesels were evaluated. Finally, the prepared biodiesels were blended with mineral diesel in different proportion and physicochemical characteristics of blended dual biofuel sample blends were also evaluated in order to determine the best blend. The results revealed that the dual biofuel samples met the requirements of EN-14214 (Europe standards), ASTM D-6751 (USA standards) and IS-15607 (India standards). A set of regression equations were also formulated, this mathematical model revealed that different physicochemical properties had high values of the regression coefficient (R2) up to 0.986 for various proportions of blend samples. The obtained results have shown that the pre-treatment process can effectively reduce the free fatty acid value to less than 1% for biodiesels. Further, the values of density and kinematic viscosity were found to be better for sample blends B10, B20, and B30, while B40 was on the upper-end limit and B50 was found to be out of limit range. Furthermore, it was concluded that the sample blends B30 (with 15% blending of each biodiesel) and B40 (with 20% blending of each biodiesel) had better properties and can be used further to test their fuel combustion characteristics on a diesel engine. © 2020 King Saud University

关键词： Thermogravimetric analysis  

摘要： The study evaluated the effect of fluidized bed drying (FBD) and freeze-drying (FD) on physicochemical, nutritional, thermal, and structural properties of Moringa oleifera. The leaves' and flowers' powder was prepared by FBD at 50 celcius outlet temperature and FD at -50 celcius, while seeds were germinated at 25 celcius for 96 hr and dried. Seeds were also subjected to a fermentation process using Lactiplantibacillus plantarum culture. FD Moringa leaves and flowers had better retention in terms of nutrition and antioxidant activities. In the case of seeds, fermented ones indicated better quality in terms of physicochemical, thermal, and structural properties. Germination and fermentation improved the glass transition temperature of seeds. Thermogravimetric analysis curves of FD-dried leaves, flowers, and seeds shifted to higher onset temperature at 243.5, 272.9, and 210.2 celcius with mass loss of 29.31%, 36.83%, and 33.11%, respectively. X-ray diffraction pattern revealed similar shapes with different dried powders. The fermented seeds exhibited a higher crystallinity index (21.47%). Novelty impact statement The processing operations like germination and fermentation coupled with freeze and fluidized bed drying can enhance the nutritional value, antioxidant activity, phenolic content, ascorbic acid, glass transition temperature value, and crystallinity index of the Moringa oleifera powder, which can be used as a functional ingredient in the development of novel foods and pharmaceuticals.

关键词： Gadolinium orthoferrite   Nanoparticles   Co-precipitation   Free impinging-jets microreactor   Micromixing   Material design  

摘要： A free impinging-jets microreactor (FIJMR) was successfully used for the ultrafast co-precipitation of gadolinium and iron(III) hydroxides and subsequent production of fine GdFeO3 nanoparticles via precipitate heat treatment in the air. The effects of the concentration of Gd3+ and Fe3+ ions (c = 0.001-0.1 mol/L), the temperature of the reaction solutions (t = 0-50 degrees C), the flow rate of the solutions (Q(j) = 100-400 mL/min) and the jets impingement angle (2 theta = 90-1801 on the mixing mode and nanoparticle size were comprehensively analyzed. The impact of co-precipitation parameters was discussed in detail from both physicochemical and hydrodynamic points of view. It was shown that the FIJMR co-precipitation resulted in isometric GdFeO3 nanoparticles with variable average size (< D > = 22.8-40.6 nm) and size distribution variance (FWHM = 19.7-32.2 nm). The optimal parameters were found to be c = 0.01 mol/L, t = 0 degrees C, Q(j) = 200 mL/min and 2 theta = 90 degrees and allowed to produce ultrafine GdFeO3 nanoparticles (< D > = 22.8 nm) with narrow size distribution (FWHM = 20.5 nm), unified morphology, high visible-light absorption and superparamagnetic behavior. Based on these results, FIJMR-assisted co-precipitation was concluded to be an efficient and prospective method for the physicochemical design and production of advanced functional nanopowders.

关键词： Plasma-activated water   Tomato   Antibacterial  

摘要： A new technique, plasma activated water (PAW), was used to inactivate bacteria on the tomato surface. The PAW was generated at 60 Watts (W) for 20 min using air flow rates at 6 or 10 standard liter per min (slm) with 1 or 2 plasma jet(s). Tomatoes inoculated with Salmonella Typhimurium, Escherichia coli, or Listeria monocytogenes were treated by the PAW for 30, 60, 90, 120, 150, 180 or 210 s. Significantly higher reductions (p < 0.05) of bacterial populations were obtained with 2 plasma jets. More than 5 log reductions of S. Typhimurium, E. coli, and L. monocytogenes were obtained when treated with 2 acting plasma jets for 30, 180, and 210 s, respectively. When treatment time increased, lower values of pH and higher values of oxidative reduction potential, nitrite, nitrate, ozone, and peroxide were obtained. An analysis of the electron paramagnetic resonance confirmed the generation of reactive oxygen species in PAW. This study showed that PAW was effective against bacteria on tomato surfaces and offered evidences for the antibacterial mechanism of PAW.

关键词： atmosphere over ocean   aerosol   black carbon   elemental and organic carbon   elemental and isotopic composition  

摘要： We discuss the physicochemical characteristics of aerosol over seas of the North Atlantic and Arctic Ocean, measured in the 80th cruise and two preceding (67th and 71st) cruises of RV Akademik Mstislav Keldysh. Most aerosol characteristics (concentrations of aerosol, black carbon, elemental and organic carbon, elemental composition) are shown to be larger in the atmosphere of the Baltic and North Seas as compared to the Norwegian and Barents Seas. The isotopic composition of carbon in aerosol samples was dominated by light isotopes, indicating the predominant effect from combustion of oil products and natural gas.

关键词： Alpine streams   Water temperature   Habitat templates   Metabolic activity  

摘要： The unique hydrology and physicochemistry of alpine streams provide an important influence on the structure and function of inhabiting biological communities. A substantial body of research exists on alpine streams across many regions of the globe (e.g. Europe, North and South America and Greenland). To date, however, there have been few studies investigating the environmental conditions present in alpine streams across the Japanese archipelago. The lack of information on alpine streams in Japan is problematic as unique regional climates, e.g. some of the highest levels of snowfall globally, are likely to have repercussions for morphological, hydrological, physicochemical and metabolic signatures, causing them to differ from those observed in other regions. In this study we compare the morphology, hydrology, physicochemistry and metabolic activity of snowmelt and groundwater fed streams in the Kamikochi region of the Japanese Alps. Stream discharge, water chemistry (major ions, silica, dissolved oxygen), water temperature and channel stability were measured over a period of 16 months in 2017-2018. Metabolic activity was determined using Resazurin-Resorufin (Raz-Rru) Smart Tracer and variation in the Raz transformation rate was assessed to understand the effects of hydrology and physicochemistry on ecosystem functioning. Snowmelt streams were characterised by higher variability of water temperature, water chemistry and stream discharge, both, within and between sites. Indeed, two of the snowmelt streams experienced no flow conditions for several periods and also floods. In comparison, water chemistry, water temperature and stream discharge in groundwater fed streams were more temporally stable. Metabolic activity was higher in one groundwater fed stream, attributed to significant growth of macrophytes. These findings indicate that the patterns of morphology, hydrology, physicochemistry and metabolic activity across streams in the Japanese Alps largely resemble those

关键词： The loess-soil   Soil sand content   Silt content   Organic matter   Electric conductivity   pH   BP neural network   Genetic algorithm  

摘要： The soil water characteristic curve is an important soil hydraulic property that governs soil water storage, availability, and has potential influences of hydrological and ecological processes in whole ecosystems. In order to obtain the soil water characteristic in a convenient and fast way, one hundred and three undisturbed Loess-soil samples were selected for the study. The results show that the BP neural network based on the genetic algorithm optimization model proposed in this paper can obtain the soil water characteristic curve from easily-obtained soil physical-chemical properties, with the prediction accuracy AEmean = 0.0213, REmean = 0.0752, and RMSEmean = 0.1378. The research results provide a basis for the further study of soil water holding capacity of undisturbed loess soil, and also provide a more accurate method for obtaining soil water characteristic curve.

关键词： Cellulose   Soybean hull   Bioremediation   Adsorption   Congo Red  

摘要： Textile industries represents one of the most pollutants industries due to the discharge of contaminated water into waterways. Around 20% of industrial water pollution arise from textile manufacture. Among the current remediation techniques, adsorption using agro-industrial wastes is emerging as an efficient tool. In this work, chemical semi-crystalline cellulose and its derivative functionalized with quaternary ammonium groups were assayed as adsorption beds. These adsorbents were physically characterized by Fourier transform infrared spectroscopy, X-ray diffraction, nitrogen adsorption to determine total surface area and differential scanning calorimetry. Applicability and efficiency of these biosorbers were assayed using Congo Red as a model textile dye which is an organic pollutant compound. Adsorption of this dye induced disorder onto the surface of cellulose modifying its morphology. The adsorption kinetics were studied, showing that the adsorption of the dye followed a pseudo-second order rate expression on both adsorbents. Different adsorption isotherm models were applied to describe the equilibrium isotherms. The empirical Freundlich model was found to be more suitable for both adsorbents. Adsorption capacities of the extracted and the cationized cellulose were 112 and 314 mg/g, respectively, therefore maximum adsorption capacity values (similar to 55 mg/g) were found to be much higher and adsorption times (20-90 min) were found to be much lower than the average of various Congo Red adsorbents produced from agro-industrial waste. A thermodynamic study showed that the adsorption of Congo Red onto cellulose and its cationic derivative was endothermic in nature (20.03 and 8.58 kJ/mol, respectively) with a positive entropic change.