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Unconfined compressive strength of MICP and EICP treated sands subjected to cycles of wetting-drying,freezing-thawing and elevated temperature:Experimental and EPR modelling

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第5期15卷 1226-1247页

作者： isaac Ahenkorah Mizanur Rahman Rajibul Karim Simon Beecham WSP Golder WA6003Australia UniSA STEM University of South AustraliaMawson LakesSA5095Australia

Microbial-induced carbonate precipitation(MICP)and enzyme-induced carbonate precipitation(EICP)are two bio-cementation techniques,which are relatively new methods of ground *** both techniques share some similarities,they can exhibit different overall behaviours due to the differences in urease enzyme sources and treatment *** paper presented 40 unconfined compressive strength(UCS)tests of MICP and EICP treated sand specimens with similar average calcium carbonate(CaCO3)content subjected to cycles of wetting-drying(WD),freezing-thawing(FT)and elevated temperature(fire resistance test e FR and thermogravimetric analysis e TG).The average CaCO3 content after a certain number of WD or FT cycles(ACn)and their corresponding UCS(qn)reduced while the mass loss *** EICP treated sand specimens appeared to exhibit a lower resistance to WD and FT cycles than MICP treated specimens possibly due to the presence of unbonded or loosely bonded CaCO3 within the soil matrix,which was subsequently removed during the wetting(during WD)or thawing(during FT)*** test and TG analysis showed a significant loss of mass and reduction in CaCO3 content with increased temperatures,possibly due to the thermal decomposition of CaCO3.A complete deterioration of the MICP and EICP treated sand specimens was observed for temperatures above 600*** observed behaviours are complex and theoretical understanding is far behind to develop a constitutive model to predict ***,a multi-objective evolutionary genetic algorithm(GA)that deals with pseudo-polynomial structures,known as evolutionary polynomial regression(EPR),was used to seek three choices from millions of polynomial *** best EPR model produced an excellent prediction of qn with a minimum sum of squares error(SSE)of 2.392,mean squared error(MSE)of 0.075,root mean square error(RMSE)of 0.273 and a maximum coefficient of determination of 0.939.

关键词： Bio-cementation Enzyme-induced carbonate precipitation (EICP) Microbial-induced carbonate precipitation (MICP) Calcium carbonate Urease enzyme

The gravity field and gravity data reduction across the continental area of Nigeria

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Geodesy and Geodynamics 2023年第3期14卷 304-320页

作者： Oluwatimilehin B.Balogun isaac B.Osazuwa Department of Geosciences Mountain Top UniversityPrayer CityOgun StateNigeria Department of Geophysics Federal UniversityOye-EkitiEkiti StateNigeria

This research presents the variation of the gravity field and associated gravity field components over the continental area of Nigeria to provide data for geoscience research,geodetic and engineering works,aerodynamic studies and deep crustal *** positions and elevations were observed at 58 of the 59 base stations of the Primary Gravity Network of Nigeria(PGNN),whose absolute gravity values had been accurately *** absolute gravity values were plotted against their respective positions to reveal the distribution pattern and strength of the gravity field within the study *** gravity values at each base station were generated using the Somigliana's *** free-air gravity and free-air anomaly gravity values were generated with respect to the World Geodetic System 1984(WGS84)ellipsoid using GPS-derived elevation ***,the perturbing potential,free-air gravity with respect to the geoid,and the indirect effects were *** average of the indirect effects was used to adjust the WGS84 gravity formula to produce a gravity formula that better approximates the geoid across the continental area of Nigeria,compatible with the heights measured relative to the geoid,which can serve as a reference for establishing a vertical height *** Bouguer gravity and Bouguer gravity anomalies across Nigeria revealed a“trans-southern gravity high strip”interpreted to be associated with mantle *** new major mega-lineaments related to mantle upwelling were mapped.A batholith province trending NWeSE was delineated,occurring from north central Nigeria to the north western region and containing closures of“Bouguer gravity lows”interpreted as batholiths.A separate closure of“Bouguer gravity low”was detected at Azare,north eastern Nigeria,which may be due to the presence of intrusive granitic *** is recommended that the mantle structure beneath“the trans-southern gravity high strip”,“delineated batholith province”and“isolat

关键词： Absolute gravity Continental Nigeria landmass Primary gravity network of Nigeria(PGNN) WGS84 ellipsoid Indirect effect Height datum

Cardiogenic shock:approaching the truth

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Journal of Geriatric Cardiology 2022年第2期19卷 95-97页

作者： isaac Llaó Albert Ariza-Solé Cardiology Department Intensive Cardiac Care UnitBellvitge University HospitalL’Hospitalet de LlobregatBarcelonaSpain

Cardiogenic shock(CS)is a severe clinical condition characterized initially by reduced cardiac output with abnormal organ perfusion which commonly leads to a multiorgan *** expansion of cardiac critical care units,development of reperfusion networks and progress of mechanical circulatory support(MCS),mortality of CS due to acute myocardial infarction(AMI)remains as high as 40%−50%.[1]Clinical outcomes in non-AMI patients are less established but remains similarly disappointing.

关键词： cardiac mortality acute

The role of cellular and molecular neuroimmune crosstalk in gut immunity

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Cellular & Molecular Immunology 2023年第11期20卷 1259-1269页

作者： Daping Yang Nicole Almanzar isaac M.Chiu Department of Immunology Harvard Medical SchoolBostonMA02115USA

The gastrointestinal tract is densely innervated by the peripheral nervous system and populated by the immune *** two systems critically coordinate the sensations of and adaptations to dietary,microbial,and damaging stimuli from the external and internal microenvironment during tissue homeostasis and *** brain receives and integrates ascending sensory signals from the gut and transduces descending signals back to the gut via autonomic *** regulate intestinal immune responses through the action of local axon reflexes or through neuronal circuits via the gut-brain *** neuroimmune crosstalk is critical for gut homeostatic maintenance and disease *** this review,we discuss the roles of distinct types of gut-innervating neurons in the modulation of intestinal mucosal *** will focus on the molecular mechanisms governing how different immune cells respond to neural signals in host defense and *** also discuss the therapeutic potential of strategies targeting neuroimmune crosstalk for intestinal diseases.

关键词： Neuroimmunology Neuroimmune Host defense Gut Sensory

Output Second-order Sliding-mode Control for a Gecko Biomimetic Climbing Robot

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Journal of Bionic Engineering 2019年第4期16卷 633-646页

作者： David Cruz-Ortiz Mariana Ballesteros-Escamilla isaac Chairez Alberto Luviano SEPl UPIITAInstitute Politecnico NationalAv.Institute Politecnico National 258007340Mexico Bioprocesses Department UPIBIInstitute Politecnico NationalAv.Acueducto 55007340Mexico

The aim of this study is to propose the output controller to solve the execution of the gait sequence for Gecko Bio-inspired Robotic Devices (GBRDs).The Twisting Controller (TC) serves as basis of the tracking trajectory designed *** TC uses both the tracking error and its estimated derivative,which is calculated by a set of distributed Super-Twisting Algorithms (STAs).Each STA is implemented as a robust and exact *** output-based controller structure corresponds to a sort of decentralized form for robotic ***,each articulation is controlled by an independent TC.A set of proposed references trajectories reproduce the gait cycle of a Real Gecko-Lizard (RG-L).The reference trajectories are proposed as the superposition of sigmoid functions ful-filling the conditions of the Bezzier *** simulations evaluate the GBRD movement enforced by the suggested controller in the horizontal as well as the vertical *** own 3D printed GBRD is the experimental platform aimed to test the distributed *** controlled vacuum pumps are used to adhere the GBRD to the wall surfaces.A set of experimental validations confirm the robustness and the reliability of the proposed controller when its performance is compared with classical output feedback controllers.

关键词： gecko robot biomimetic output-based controller twisting controller Super-Twisting Algorithm(STA)

Potential of organic waste to energy and bio-fertilizer production in Sub-Saharan Africa:a review

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Waste Disposal and Sustainable Energy 2023年第3期5卷 259-267页

作者： isaac Rubagumya Allan John Komakech Isa Kabenge Nicholas Kiggundu Department of Agricultural and Biosystems Engineering Makerere UniversityP.O.Box 7062KampalaUganda

Many growing cities of Sub-Saharan Africa(SSA)are marred by the inefficient collection,management,disposal and reuse of organic *** purpose of this study was to review and compare the energy recovery potential as well as bio-fertilizer perspective,from the organic waste volumes generated in SSA *** on computations made with a literature review,we find that the amount of organic wastes varies across countries translating to differences in the energy and bio-fertilizer production potentials across *** wastes generated in SSA can potentially generate about 133 million GWh of energy per *** organic waste to bio-fertilizer production potentials range from 11.08 million tons to 306.26 million tons *** has the highest energy and bio-fertilizer potential among the SSA countries with a total per capita of 630 MWh/year and 306.26 million tons,*** challenges and technical considerations for energy and bio-fertilizer approaches in the management of organic waste in SSA have also been *** study is of help to the readers and strategic decision makers in understanding the contribution of bioenergy and bio-fertilizer to achieving sustainable development goals,namely,7(Affordable and Clean Energy)and 13(Climate Action)in SSA.

关键词： Sub-Saharan Africa Organic waste Energy production Bio-fertilizer production Challenges

Influence of technology transfer from universities on manufacturing firms'innovative performance

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International Journal of Innovation Studies 2023年第2期7卷 115-126页

作者： isaac Muiruri Gachanja Mount Kenya University P.O.Box 342-01000ThikaKenya

Technology transfer(TT)from universities to manufacturing firms is important for enhancing innovation performance(IP)and ultimately improving ***,TT is hampered by bureaucracy,inertia,inefficiency,cognitive dissonance,and low research and development *** purpose of this study is to examine the relationship between TT from universities to manufacturing firms and their *** study was conducted based on Megnigbeto's(2018)triple helix game theory.A mixed-method approach was *** independent variable was TT,measured in terms of technology spillover,networking,and the presence of accelerators and incubators within a firm's *** dependent variable was IP,measured through innovation output and innovation *** study used an explanatory sequential research *** target population was manufacturing firms in Kenya,identified using a multi-stage sampling *** data were collected using semi-structured questionnaires,interview schedules,and *** regressions,hierarchical multiple moderated regressions,structural equation modeling,and partial least squares were used to test the *** results indicate that TT from universities significantly influences IP in manufacturing *** are important intermediaries of TT in manufacturing firms in Kenya because of their improved IP and *** should create dynamic linkages with industries and adopt an engaged learning approach in their programs to create greater and more unique values for enhanced competitiveness and sustainable development.

关键词： Technology transfer Innovation performance Linkages and competitiveness

Antitumor and Antifungal Activities of Organic Extracts of Seacucumber Holothuria atra from the Southeast Coast of India

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Journal of Ocean University of China 2015年第1期14卷 185-189页

作者： Devaraj isaac DHINAKARAN Aaron Premnath LIPTON Center for Marine Science and Technology Manonmaniam Sundaranar University Marine Biotechnology Laboratory Central Marine Fisheries Research Institute

In phylum Echinodermata, the family Holothuridae is distinguished by its capacity of bioactive compounds. Sea cu- cumber Holothuria atra is commonly known as the lollyfish. The antifimgal activity was detected using agar well diffusion method against the various fungal strains such as Trichoderma viride, Aspergillus niger, Aspergillus flavis, Candida albicans and Penicillium chrysogenum. Relatively high antifungal activity was seen against Candida albicans at 100 μL-1 concentration of extracts. Zone of inhibition was measured at 18 mm of diameter. The anti-tumor activities were detected against the Vero and Hep2 cell lines using MTT assay. The cells were treated with H. atra extract at concentrations 0.078-10mg mL-1. The extract showed high proliferative activity against the Hep2 cells. The body wall extracts of sea cucumber （H. atra） showed effective antifungal and antitumor activities All these findings suggest that the extracts could be used for the development of drugs.

关键词： Holothuria atra MTT assay Vero cell lines Hep2 cell lines antifungal activity antitumor activity

Rapidity dependence of global polarization in heavy ion collisions

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Chinese Physics C 2021年第1期45卷 226-238页

作者： Zuo-Tang Liang Jun Song isaac Upsal Qun Wang Zhangbu Xu Institute of Frontier and Interdisciplinary Science Key Laboratory of Particle Physics and Particle Irradiation(MOE)Shandong UniversityQingdao 266237China Department of Physics Jining UniversityShandong 273155China Physics Department Brookhaven National LaboratoryUptonNew York 11973USA Department of Modem Physics University of Science and Technology of ChinaHefei 230026China

We use a geometric model for hadron polarization in heavy ion collisions with an emphasis on the rapidity *** model is based on the model of Brodsky,Gunion,and Kuhn,as well as the Bjorken scaling *** make predictions regarding the rapidity dependence of global Λ polarization in the collision energy range of 7.7-200 GeV by assuming the rapidity dependence of two parameters,κ and . The predictions can be tested by future beam-energy-scan experiments at the Relativistic Heavy Ion Collider of Brookhaven National Lab.

关键词： polarization orbital angular momentum relativistic heavy-ion collisions