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In this article, we find a lower bound for the blow-up time of solutions to some nonlinear parabolic equations under Robin boundary conditions in bounded domains of Rn  

We consider the chemotaxis system:. {ut=δu-∇;{dot operator}(uχ(v)∇;v)+f(u),x∈Ω,t>0,vt=δv-v+ug(u),x∈Ω,t>0, under homogeneous Neumann boundary conditions in a bounded domain Ω⊂Rn, n≥ 1, with smooth boundary and function f is assumed to generalize the logistic source:. f(u)=au-bu2,u≥0, with a>0,b>0. Moreover, χ( s) and g( s) are nonnegative smooth functions and satisfy:. χ(s)≤κ script(1+θ symbols)k,s≥0, with some κ script>0,θ symbol>0 and k>1,g(s)≤h0(1+hs)δ,s≥0,withh0>0,h≥0,δ≥0. We prove that for all positive values of κ script, a and b, classical solutions to the above system are uniformly-in-time bounded. This result extends a recent result by C. Mu, L. Wang, P. Zheng and Q. Zhang (2013)... 

This paper deals with the blow-up of solutions to some nonlinear divergence form parabolic equations with nonlinear boundary conditions. We obtain a lower bound for the blow-up time of solutions in a bounded domain Ω⊆Rn, n≥. 3. L'article traite d'un problème d'explosion des solutions d'équations paraboliques non linéaires sous forme de divergence, avec des conditions aux limites non linéaires. On obtient une estimation d'une borne inférieure du temps d'explosion des solutions dans le cas d'un domaine borné Ω⊆Rn, n≥. 3  

This paper deals with the blow-up phenomena for a system of parabolic equations with nonlinear boundary conditions. We show that under some conditions on the nonlinearities, blow-up occurs at some finite time. We also obtain upper and lower bounds for the blow-up time when blow-up occurs. Copyright  

In this paper, we study the mathematical model proposed by Owen and Sherratt in 1997. We prove that the classical solutions to this model are uniformly-in-time bounded. © World Scientific Publishing Company  

This letter is concerned with the blow-up of the solutions to a semilinear parabolic problem with a reaction given by a variable exponent. Lower bounds for the time of blow-up are derived if the solutions blow up  

In this paper, we describe the design, development and preliminary evaluation of a novel animation tool for smartphones and tablets, with the goal of improving creativity and problem-solving ability among novice users, mainly young children. The user first draws the objects with markers and crayons on paper and takes a photo with their mobile or tablet to import their drawings into the app as game sprites. They then design their animation scene and point to a part of the character and selecting its animation type from existing buttons. Hence the selected part is animated in a vertex shader while ensuring a smooth transition with the non-pointed part. The results of a preliminary evaluation... 

A tanks-in-series model was applied for mathematical modeling of the unsteady state performance of 70 and 100 liters airlift bioreactor for the production of lactic acid by fermentation. A set of first-order differential equations for the material balances of micro-organism, substrate, product, and dissolved oxygen around hypothetically well mixed stages was solved simultaneously utilizing computer program in MATLAB. The kinetic model utilized considered the effect of two substrates (glucose and dissolved oxygen) on the growth rate. The effect of air velocity on the lactic acid production was investigated. Results of this model have been validated with experimental data  

One of the methods to increase the hardness of metals, mostly used in aerospace and automobile industries, where light parts with high strength is needed, is precipitation hardening. Nano-precipitates can strongly influence the mechanical properties of materials, especially in a dynamic case. In the present work, attempts have been made so as to make Nano-particles dynamically precipitate in IF steels. Investigating the structure by the means of SEM and AFM resulted in understanding that the precipitates were in nano-size. The micro-hardness of samples was measured as well. © BHR Group 2007 Industrial Processes for Nano and Micro Products  

Local educational institutions produce in-house English for Specific Purpose (ESP) materials according to the curriculum policies designated and developed by the Ministry of Higher Education In Iran. To this end, this book aims to be used in the Iranian setting at the tertiary level for undergraduate students majoring in Mechanical Engineering. Moreover, the style of English usage in this ESP textbook is American.
Regarding the content of the textbook, it has both thematic organizations in which the topics are relevant and includes sufficient treatment of the target language areas necessary for the students. The principle organizing approach of this textbook is theme-based. In addition,... 

The aim of this study is to employ feedback control loops to provide a stable forward dynamics simulation of human movement under repeated position constraint conditions in the environment, particularly during stair climbing. A ten-degrees-of-freedom skeletal model containing 18 Hill-type musculotendon actuators per leg was employed to simulate the model in the sagittal plane. The postural tracking and obstacle avoidance were provided by the proportional—integral—derivative controller according to the modulation of the time rate change of the joint kinematics. The stability of the model was maintained by controlling the velocity of the body's centre of mass according to the desired centre of... 

A combination of silica chloride and wet SiO2 was used as an effective deacetalizating agent for the conversion of acetals to their corresponding carbonyl derivatives under mild and heterogeneous condition  

Free Content Selective synthesis of conjugated enynes from α-arylalkynols using LiCl-Acidic Al2O3 under solvent-free conditions  

7H-benzimidazo[2,1-a]benz[de]isoquinolin-7-one compounds were prepared in a selective manner by reaction between o-phenylenediamines and appropriate 1,8-naphthalenedicarboxylic anhydrides using acidic alumina under microwave irradiation