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ZnCl2 Enhanced Acid Hydrolysis of Pretreated Corncob for Glucose Production:Kinetics,thermodynamics and Optimization Analysis

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Journal of bioresources and bioproducts 2019年第3期4卷 15-24页

作者： A I ADEOGUN b E AGbOOLA M A IDOWU t A SHIttU Department of Chemistry Federal University of AgricultureAbeokuta Department of Food Science and technology Federal University of AgricultureAbeokuta

the biomass of agricultural wastes as a source of fermentable sugars for biofuels production will address the food security and environmental preservation *** wastes are rich in lignocellulosic materials which can be hydrolyzed into fermentable ***,low sugar yield and high energy consumption are some of the challenges faced in the process of *** study investigated the low-cost corncob substrate for glucose production by dilute sulphuric acid hydrolysis in the presence of ZnCl_(2) at temperatures below 100℃after pretreatment with 10%*** dependent hydrolysis data were analyzed by Saeman model,thermodynamic parameters were obtained using Erying and Arrhenius equations while box-behnken model(Design Expert 6.0 version)was used for experimental *** the substrate concentration increased from 50 mg/L to 150 mg/L,glucose yield increased from 10.4 mg/g to 14.6 mg/g for pretreated corncob while an increase from 3.4 mg/g to 8.6 mg/g was noted for untreated *** hydrolysis rate constant was two orders of magnitude higher than the degradation rate *** parameters revealed endothermic process with positive Gibb’s free energy of hydrolysis having average values of 84.76 kJ/mol and 79.87 kJ/mol for pretreated and untreated samples *** optimum yield from the model was found to be 177.44 mg/g with 3.94%H_(2)SO_(4) and 0.43 mol/L ZnCl_(2) for 200 g/L compared with optimum yield of 46.37 mg/g obtainable without ZnCl_(2).the results of this study showed that the alkaline pretreatment of corncob increased the accessibility of cellulose from the solid fraction and increase glucose production.

关键词： hydrolysis Saeman’s model Erying equation box behnken model design expert alkaline pretreatment

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Stability of aneurysm solutions in a fluid-filled elastic membrane tube

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Acta Mechanica Sinica 2012年第4期28卷 1209-1218页

作者： A. t. Irichev Y.-b. Fu Steklov Mathematical Institute Gubkina Str. 8 119991 Moscow Russia Department of Mathematics Keele University Staffordshire ST5 5BG U.K.

When a hyperelastic membrane tube is inflated by an internal pressure, a localized bulge will form when the pressure reaches a critical value. As inflation continues the bulge will grow until it reaches a maximum size after which it will then propagate in both directions to form a hat-like profile. the stability of such bulging solutions has recently been studied by neglecting the inertia of the inflating fluid and it was shown that such bulging solutions are unstable under pressure control. In this paper we extend this recent study by assuming that the inflation is by an inviscid fluid whose inertia we take into account in the stability analysis. this reflects more closely the situation of aneurysm forma- tion in human arteries which motivates the current series of studies. It is shown that fluid inertia would significantly reduce the growth rate of the unstable mode and thus it has a strong stabilizing effect.

关键词： Aneurysms Localized bulging Stability bi- furcation

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Cooling rates in the shock veins of chondrites: constraints on the (Mg,Fe)_2SiO_4 polymorph transformations

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Science China Earth Sciences 1998年第5期41卷 522-528页

作者：陈鸣谢先德 A.ElGoresy b.Wopenka t.G.Sharp 1. Guangzhou Institute of Geochemistry Chinese Academy of Sciences 510640 Guangzhou China 2. Max-Planck-Institutfür Kernphysik 69029 Heidelberg Germany 3. Department of Earth and Planetary Sciences Washington University M063130 St.Louis USA 4. Department of Geology Arizona State University 85287-1404 Tempe AZ USA

the occurrence of γ phase, a high\|pressure polymorph of olivine （α phase）, in the shock veins of Si\| xiangkou chondrite was due to a greater cooling rate （>10 000℃·s -1 ） in the veins. because γ phase partially reverted to β phase and no back\|transformation from β phase to α phase took place, the shock veins of Peace River chondrite with a cooling rate of 1 000\2 000℃·s -1 contain a great amount of β phase. In the shock veins of Mbale chondrite with a cooling rate of the majority of γ phase reverted to α phase. the heat dissipation in shock veins took place after a stage of shock compression of chondrite parent body, and the parent body was broken into fragmental pieces. Cooling rate in the shock veins constrained the back\|transformations of （Mg,Fe）\-2SiO\-4 high\|pressure polymorphs.

关键词： chondrite shock vein (Mg Fe)\-2SiO\-4 polymorph transformation cooling rate.

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Cattaneo-Christov heat flux model for third-grade fluid flow towards exponentially stretching sheet

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Applied Mathematics and Mechanics(English Edition) 2016年第6期37卷 761-768页

作者： S.A.SHEHZAD F.M.AbbASI t.HAYAt b.AHMAD Department of Mathematics Comsats Institute of Information TechnologySahiwal 57000Pakistan Department of Mathematics Comsats Institute of Information TechnologyIslamabad 44000Pakistan Department of Mathematics Quaid-i-Azam UniversityIslamabad 44000Pakistan NAAM Research Group Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia

the Cattaneo-Christov heat flux in the two-dimensional （2D） flow of a third- grade fluid towards an exponentially stretching sheet is investigated. the energy equation is considered through thermal relaxation. Similarity transformations are accounted to obtain the ordinary differential systems. the converted non-dimensional equations are solved for the series solutions. the convergence analysis of the computed solutions is reported. the graphical results of the velocity and temperature profiles are plotted and elaborated in detail. the results show that the thermal relaxation enhances the temper- ature gradient while reduces the temperature profile.

关键词： steady flow third-grade fluid Cattaneo-Christov heat flux exponentiallystretching sheet

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Effects of variable fluid properties on the thin film flow of Ostwald-de Waele fluid over a stretching surface

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Journal of Hydrodynamics 2013年第1期25卷 10-19页

作者： VAJRAVELU K. PRASAD K. V. RAJU b. t. Department of Mathematics Department of Mechanical Material and Aerospace Engineering University of Central Florida Department of Mathematics Central College Campus Bangalore University

We investigate, in this paper, the effects of thermo-physical properties on the flow and heat transfer in a thin film of a power-law liquid over a horizontal stretching surface in the presence of a viscous dissipation. the fluid properties, namely the fluid viscosity and the fluid thermal conductivity, are assumed to vary with temperature. Using a similarity transformation, the governing partial differential equations with a time dependent boundary are converted into coupled non-linear Ordinary Differential Equations （ODEs） with variable coefficients. Numerical solutions of the coupled ODEs are obtained by a finite difference scheme known as the Keller-box method. Results for the velocity and temperature distributions are presented graphically for different values of the pertinent parameters. the effects of unsteady parameter on the skin friction, the wall temperature gradient and the film thickness are presented and analyzed for zero and non-zero values of the temperature-dependent thermo-physical properties. the results obtained reveal many interesting features that warrant further study on the non-Newtonian thin film fluid flow phenomena, especially the shear-thinning phenomena.

关键词： thin film flow variable fluid properties viscous dissipation finite difference method

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On the pressure and stress singularities induced by steady flows of incompressible viscous fluids

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Acta Mechanica Sinica 2009年第4期25卷 451-462页

作者： G.b.Sinclair X.Chi t.I-P.Shih Department of Mechanical Engineering Louisiana State University Department of Aerospace Engineering Iowa State University

Design for structural integrity requires an appreciation of where stress singularities can occur in structural configurations. While there is a rich literature devoted to the identification of such singular behavior in solid mechanics, to date there has been relatively little explicit identification of stress singularities caused by fluid flows. In this study, stress and pressure singularities induced by steady flows of viscous incompressible fluids are asymptotically identified. this is done by taking advantage of an earlier result that the Navier-Stokes equations are locally governed by Stokes flow in angular corners. Findings for power singularities are confirmed by developing and using an analogy with solid mechanics. this analogy also facilitates the identification of flow-induced log singularities. both types of singularity are further confirmed for two global configurations by applying convergence-divergence checks to numerical results. Even though these flow-induced stress singularities are analogous to singularities in solid mechanics, they nonetheless render a number of structural configurations singular that were not previously appreciated as such from identifications within solid mechanics alone.

关键词： Incompressible viscous fluids Navier-Stokes equations Fluid-structure interactions Stress singularities

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Review of micromachining of ceramics by etching

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中国有色金属学会会刊：英文版 2009年第B09期19卷 1-16页

作者： H.t.tING K.A.AbOU-EL-HOSSEIN H.b.CHUA School of Engineering and Science Curtin University of Technology (Sarawak Campus) Department of Mechatronics Nelson Mandela Metr opolitan University

In the last two decades, there has been an enormous surge in interest in ceramic materials and, as a result, there have been significant advances in their development and applications. their inherent properties, such as capability of operating at temperatures far above metals, high level of hardness and toughness, low coefficient of thermal expansion and high thermal conductivity rendered ceramics to be one of the leading engineering materials. Many research works have been conducted in the past few years on machining of advanced ceramics using different processing methods in order to obtain a better surface roughness, higher material removal rate and improved tool life. Micromachining using chemical etching is one of those methods that do not involve the problem of tool life and direct tool-work piece contact. However, only a few research works have been done on micromachining of ceramics using chemical etching. Hence, study of chemical machining of advanced ceramics is still needed as the process has found wide application in the industry because of its relative low operating costs. In this work, we summarize the recent progresses in machining of different types of advanced ceramics, material processing methods such as wet etching and dry etching, and finally the prospects for control of material removal rate and surface quality in the process of ceramic micromachining.

关键词：陶瓷材料化学蚀刻表面粗糙度机械加工过程陶瓷加工刀具寿命材料去除率高温作业

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toughening of Epoxy Resin with Solid Amine terminated Poly(ethy-lene glycol) benzoate and Effect of Red Mud Waste Particles

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Journal of Materials Science & technology 2008年第2期24卷 272-278页

作者： b.C.Samanta t.Maity S.Dalai A.K.banthia Department of Chelnistrv and Chemical technology Vidyasagar UniversityMidnapore-721102India Materials Science Centre Indian Institute of TechnologyKharagpur-721302India

An investigation was carried out to modify the toughness of triethylene tetramine cured DGEbA （diglycidyl ether of bisphenol-A） resin using solid amine terminated poly （ethylene glycol） benzoate （AtPEGb） as modifier with and without red mud waste particles. the solid AtPEGb modifier synthesized from the acid catalyzed esterification reaction of poly （ethylene glycol）（PEG） and 4-amino benzoic acid was characterized by Fourier transform infrared spectroscopy （Ft-IR） and ^1H-NMR （nuclear magnetic resonance） spectroscopies, viscosity measurements, and solubility parameter calculation. the unfilled and red mud waste filled modified epoxy networks were evaluated with impact, adhesive, tensile, flexural and thermal properties by differential scanning calorimetry （DSC）, thermogravimetric （tG） and dynamic mechanical analysis （DMA）. the effect of modifier concentration and red mud waste particles on toughening behavior was also investigated. the optimum properties were obtained at 12.5 phr （parts per hundred parts of resin） concentration of the modifier. the AtPEGb modified cured epoxy was thermally stable up to 315℃. the morphology on fracture surfaces of cured epoxy was also analyzed by scanning electron microscopy （SEM）.

关键词： Epoxy toughness Adhesive Morphology

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titanate Nanorods Modified with Nanocrystalline ZnS Particles and their Photocatalytic Activity on Pollutant Removal

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Journal of Materials Science & technology 2016年第11期32卷 1122-1128页

作者： G.Naudin t.Entradas b.barrocas O.C.Monteiro Faculte de Chimie Universite Pierre et Marie Curie (UPMC) Batiment F 3e etage 4 placeJussieu 75005 Paris France Centro de Quimica e bioquimica Faculdade de Ciencias Universidade de Lisboa 1749-016 Lisboa Portugal

Aiming to produce materials with enhanced photocatalytic properties, the synthesis of new crystalline nanocomposites by combining titanate nanorods（tNR） with ZnS nanocrystallites is described in this *** tNR modification was accomplished by an in situ nucleation and growth process of ZnS *** diethyldithiocarbamate was used as the metal chalcogenide precursor. the prepared materials were structural, morphological and optical characterized by X-ray diffraction, transmission electron microscopy and high resolution transmission electron microscopy, energy dispersive spectroscopy and powder diffuse reflectance spectra. Crystalline Zn S nanoparticles were obtained as a homogeneous and continuous layer, covering completely the tNR surface. the application of these new nanocomposite materials on photocatalytic degradation of pollutants was investigated. First, the evaluation of hydroxyl radical formation, using the terephthalic acid as probe, was studied. Afterwards, the adsorption and photodegradation of safranine-t, used here as a model pollutant molecule, was investigated. the obtained data indicate that the prepared nanocomposites have potential to be used as photocatalysts for organic pollutant *** best removal results（97% removal） were obtained using the 0.01 Zn S/HtNR sample as catalyst（0.2 g/L; 10 ppm safranin-t solution） with a combination of a low dye adsorption（20%） and a high dye photocatalytic degradation（77%）.

关键词： Nanocomposite materials Surface modification Photocatalysis Adsorption ability Optical properties

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Miniaturized antenna design for communication establishment of peer-to-peer communication in the oil pipelines

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Petroleum Research 2021年第3期6卷 291-302页

作者： E.b.Priyanka S.thangavel t.Kalavathidevi Department of Automobile Engineering Kongu Engineering CollegeErode638060India Department of Mechatronics Engineering Kongu Engineering CollegeErode638060India Department of Electronics and Instrumentation Engineering Kongu Engineering CollegeErode638060India

In the oil pipeline world,wireless automation plays an important role through integrated electronic technology in antenna design for robust *** technology gets evaluated by its power consumption and compactness to afford a better solution to real-world problems with better sophistication to adopt a modernized wireless *** that,the Iot(Internet of things)technology plays a predominant role by combining with Artificial Intelligence to optimize and revolute the characterization of data *** the data communication is initiated,the main contributor to the transmission is the miniaturized antenna holding different types in its structure and *** acquires the required radio spectrum channel with the advanced multi coding modulating technique by utilizing token ring mesh topology for the data transfer with acquired data *** chapter describes the design and fabrication of a miniaturized antenna using MEMS technology(Micro-Electro-Mechanical System)and its different types using INtELLISUItE software to get suited for better communication in oil *** on the application,it also enumerates the choices of micro or nanoantennas with its specification upholding data adopting techniques with modulation schemes to support Iot applications.

关键词： Antenna MEMS Channel width Optimization Oil pipelines and Iot

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