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Conservation laws,Lie symmetries,self adjointness,and soliton solutions for the Selkov–Schnakenberg system

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Communications in theoretical Physics 2024年第2期76卷 29-44页

作者： Kashif Ali Aly r Seadawy Syed t r rizvi Noor Aziz Department of Mathematics COMSATS University IslamabadLahore CampusPakistan Mathematics Department Faculty of ScienceTaibah UniversityAl-Madinah Al-Munawarah41411Saudi Arabia

In this article,we explore the famous Selkov–Schnakenberg(SS)system of coupled nonlinear partial differential equations(PDEs)for Lie symmetry analysis,self-adjointness,and conservation ***,miscellaneous soliton solutions like dark,bright,periodic,rational,Jacobian elliptic function,Weierstrass elliptic function,and hyperbolic solutions of the SS system will be achieved by a well-known technique called sub-ordinary differential *** these results are displayed graphically by 3D,2D,and contour plots.

关键词： Selkov-Schnakenberg system Lie symmetry analysis conservation laws adjointness integrability

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Basis for the diversity and extent in loss of digestible nutrients created by dietary phytin: Emphasis on fowl and swine

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Animal Nutrition 2024年第1期16卷 422-428页

作者： Edwin t.Moran Michael r.Bedford Poultry Science Department Auburn University AB Vista Woodstock Court Blenheim Road

Phytin is the Ca2+-Mg2+-K+salt of phytic acid that is created and deposited in the aleurone layer and/or germ of grains and legumes. Its high presence in feedstuffs for fowl and swine diets results in it being a universal and significant impediment to optimum performance. Phytin impairs gastrointestinal recovery of a wide array of nutrients, the effect varying with the nutrient concerned. On exposure to low pH during gastric digestion, phytin dissociates into phytic acid and solubilized Ca2+. Even at low gastric pH,phytic acid is negatively charged which forms the basis of its anti-nutritive behavior. Pepsinogen has extensive basic amino acids on its activation peptide that are presented as cations at low pH which are targeted by pepsin for activation. Partially crystalized Ca2+near the enzyme?s active site further stabilizes its newly formed structure. thus, phytic acid appears to interfere with gastric digestion by several mechanisms; interfering with pepsinogen activation by binding to the polypeptide?s basic amino acids;coordinating free Ca2+, destabilizing pepsin; binding some dietary proteins directly, further compromising gastric proteolysis. Upon digesta attaining neutrality in the duodenum, Ca2+and other cations rebind with accessible anions, phytic acid being a significant contender. Phytate not only binds free cations but can also strip them from enzymes(e.g. Ca2+, Zn2+) which reduces their structural resistance to autolysis and ability as co-factors(e.g. Zn2+) to increase enzyme activity. Goblet cells initially employ Ca2+as an electronic shield between mucin layers enabling granule formation and cell storage. After mucin granule release, Ca2+is progressively displaced by Na+to free the viscous mucins enabling its translocation. Mucin entangles with the glycocalyx of adjacent enterocytes thereby constructing the unstirred water layer（USWL）. Excessive removal of Ca2+from mucin by phytic acid increases its fluidity facilitating its loss from the USWL with

关键词： Digestive enzyme Calcium Endogenous protein Mucin Phytin

Getting the Most Out of Every training Day: the Influence of Instructors on Self-regulated Learning During Firefighter Leadership Courses

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International Journal of Disaster risk Science 2024年第3期15卷 332-345页

作者： Stefan r?seler Micha Hilbert Guido Hertel Meinald t.thielsch Department of Psychology University of Münster

Leadership courses in the fire services are highly challenging, and they can seriously exhaust trainees and hamper their selfregulated learning efforts(for example, setting goals, focusing attention, seeking feedback). We theorize that experiences of failure or overload can curtail trainees' available energy resources on subsequent training days, which, in turn, should affect trainees' learning efforts. Given instructors' central role in leadership courses, we hypothesize that supportive and humble instructor behaviors decrease experiences of failure and overload and, thus, increase self-regulated learning. Moreover, we argue that supportive instructor behavior may amplify the positive effects of high energy resources, while humble behavior may alleviate the negative impact of low resource levels. We tested preregistered hypotheses with 118 firefighters participating in two-week leadership courses at a German fire academy. the participants completed short web-based questionnaires before and after classes each day. Multilevel analyses confirmed that perceived daily supportive and humble instructor behavior predicted trainees' reports of daily self-regulated learning activity. Notably, this effect was independent from positive effects of trainees' reported energy resources in the morning. Supportive and humble behavior did not moderate the eff ect of energy resources. Our findings suggest that instructors play a crucial role in facilitating effective learning under challenging training conditions. Furthermore, we offer implications for leaders in fire services, who often conduct trainings with their subordinates.

关键词： Diary study Fire services Instructor behavior Leadership training resource investment

Mathematical modelling of ball and plate system with experimental and correlation function-based model validation

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Control theory and technology 2024年第2期22卷 326-341页

作者： t.r.Dil Kumar S.J.Mija Department of Electrical Engineering National Institute of Technology CalicutKozhikode673601KeralaIndia

the ball and plate system is an inherently nonlinear under actuated benchmark system used for validating the performance of various control schemes. A mathematical model depicting the dynamics close to that of the system is very much required for such a test bed. In this correspondence, the complete nonlinear model, a simplified nonlinear model, and a linearized model of the ball and plate system are developed. the system comprises a ball and plate mechanism and a rotary servo unit. the ball and plate mechanism is modelled using the Euler–Lagrange method, whereas the rotary servo subsystem is modelled from the first principles. the nonlinear model of the combined system is developed by including the dynamics of the servo motor with gear and rolling resistance between the ball and the plate. the simplified nonlinear model of the system is obtained with suitable assumptions. the model is linearized around the operating point using the Jacobian. the validity of the developed models is investigated through correlation function analysis. the open-loop response of the three models, viz., nonlinear, simplified nonlinear, and linearized models, is analyzed in the MAtLAB/Simulink platform. Since the open-loop system is unstable, the experimental validation of the model is performed with a double-loop PSO (particle swarm optimization) PID control scheme.

关键词： Ball and plate system Correlation function Model validation Particle swarm optimization(PSO) PSO PID controller

Aerodynamics of a tandem-Bladed Axial Compressor rotor under Circumferential Distortion at Different rotational Speeds

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Journal of thermal Science 2024年第4期33卷 1340-1356页

作者： Amit KUMAr Jerry t.JOHN A.M.PrADEEP r.A.DAKKErMANS Dragan KOZULOVIC Department of Aerospace Engineering Indian Institute of Technology BombayMumbai400076India Department of Automotive and Aeronautical Engineering Hamburg University of Applied Sciences20099HamburgGermany Institute of Jet Propulsion Bundeswehr University Munich85577NeubibergGermany

For most aircraft engines,inflow distortion is *** distortion is known to degrade the aerodynamic performance and stable operating limits of a *** rotor configuration is an arrangement that effectively controls the growth of the boundary layer over the suction surface of the ***,a higher total pressure rise can be achieved through this unconventional design approach involving the splitting of the blade into forward and aft *** is expected that the effect of inlet flow distortion would be more severe for a tandem-rotor design due to the greater flow turning inherent in such ***,this aspect needs to be thoroughly *** present study discusses the effect of circumferential distortion on the tandem-rotor at different rotational ***-annulus rANS simulations using ANSYS CFX are used in the present *** performance of the rotor at a particular flow coefficient and different rotational speeds is *** total pressure and efficiency are observed to drop at lower mass flow rates under the influence of circumferential *** loss region in each blade passage is mainly associated with the blade wake,tip leakage vortex,secondary flow,and boundary ***,their contribution varies from passage to passage,particularly in the distorted *** the lower span,the wake width is found to be higher than that at a higher *** to the redistribution of the mass flow,the circumferential extent reduces at a higher *** the undistorted sector,the strength of the tip leakage vortex is significantly higher at the design rotational speed than at lower *** distortion near the tip region promotes an early vortex breakdown even at the design operating *** adversely affects the total pressure,efficiency,and stall *** clean flow conditions,this phenomenon is only observed near the stall *** the design operating condition,the breakdown of the forward rotor tip l

关键词： tandem rotor circumferential distortion loss tip leakage vortex vortex breakdown diffusion factor aerodynamics of compressor blade

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Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu t.W.Huang K.Jiang C.N.Wu H.Peng P.C.hen r.Li H.B.Zhuo C.t.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

Late Ordovician Mass Extinction: Earth, fire and ice

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National Science review 2024年第1期11卷 51-65页

作者： David A.t.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

the Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. these symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

Preparation of microparticles and nanoparticles using membrane-assisted dispersion,micromixing,and evaporation processes

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Particuology 2024年第1期84卷 30-44页

作者： Goran t.Vladisavljevic Chemical Engineering Department Loughborough UniversityLoughboroughLeicestershire LE113TUUnited Kingdom

Synthetic microporous membranes are increasingly used for energy-efficient and controlled production of micro-and nanoparticles and micro-and nanoemulsions with tuneable morphology and physico-chemical properties through various micromixing,emulsification,and evaporation *** emul-sification processes,the membrane pores are used for dispersed phase injection and size-controlled generation of droplets and droplet-templated *** micromixing processes,membrane is utilised as a micromixer for mixing two miscible liquids,usually solvent and antisolvent-rich solutions,which leads to the creation of supersaturation and subsequent nanoprecipitation or *** mem-brane evaporation processes,membrane is used to prevent phase dispersion while allowing efficient molecular diffusion of solvent and/or antisolvent vapour through gas-filled *** dispersion processes can be operated continuously by decoupling shear stress on the membrane surface from cross flow using tube insets,flow pulsations,swirling flow,membrane oscillations or membrane *** generation and solidification can be performed continuously in a single pass by connecting membrane module with a downstream *** dispersion processes can be used for pro-duction of nanoparticles such as nanovesicles(liposomes,micelles,ethosomes,and niosomes),nanogels,polymeric,lipid and metallic nanoparticles,and *** main advantages of membrane-assisted particle generation are in low energy consumption,controlled geometry and hydrodynamic conditions at the microscale level,flexible throughput due to modular and scalable design of membrane devices,and a wide choice of available microporous membranes with various wall porosities,wetta-bilities,pore sizes,and pore morphologies to suit different applications.

关键词： Nanoparticles Microparticles Nanoemulsions Microemulsions Microporous membrane Crystallisation Flash nanoprecipitation Emulsification Zero liquid discharge

A concise review on surface and structural modification of porous zeolite scaffold for enhanced hydrogen storage

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Chinese Journal of Chemical Engineering 2024年第6期70卷 33-53页

作者： B.A.Abdulkadir r.S.r.Mohd Zaki A.t.Abd Wahab S.N.Miskan Anh-tam Nguyen Dai-Viet N.Vo H.D.Setiabudi Centre for research in Advanced Fluid&Processes Universiti Malaysia Pahang Al-Sultan AbdullahLebuh Persiaran Tun Khalil YaakobGambangPahang 26300Malaysia Faculty of Chemical&Process Engineering technology Universiti Malaysia Pahang Al-Sultan AbdullahLebuh Persiaran Tun Khalil YaakobGambangPahang 26300Malaysia Center of Excellence for Green Energy and Environmental Nanomaterials(CE@GrEEN) Nguyen Tat Thanh University300A Nguyen Tat ThanhDistrict 4Ho Chi Minh City 755414Viet Nam

Investigating zeolites as hydrogen storage scaffolds is imperative due to their porous nature and favorable physicochemical ***,the storage capacity of the unmodified zeolites has been rather unsatisfactory(0.224%-1.082%(mass))compared to its modified ***,the contemporary focus on enhancing hydrogen storage capacities has led to significant attention towards the utilization of modified zeolites,with studies exploring surface modifications through physical and chemical treatments,as well as the integration of various active *** enhanced hydrogen storage properties of zeolites are attributed to the presence of aluminosilicates from alkaline and alkaline-earth metals,resulting in increased storage capacity through interactions with the charge density of these ***,there is a great demand to critically review their role such as well-defined topology,pore structure,good thermal stability,and tunable hydrophilicity in enhanced hydrogen *** article aimed to critically review the recent research findings based on modified zeolite performance for enhanced hydrogen *** of the factors affecting the hydrogen storage capacities of zeolites that can affect the rate of reaction and the stability of the adsorbent,like pressure,structure,and morphology were studied,and ***,future perspectives,recommendations,and directions for modified zeolites were discussed.

关键词： Zeolites Hydrogen storage Surface modification Adsorption Active metal

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