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CFD evaluation of pressure drop across a 3-D filter housing for industrial gas turbine plants

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Frontiers in Energy 2016年第2期10卷 192-202页

作者： Fidelis i. ABAM Samuel o. EFFioM olayinka S. oHUNAKiN Department of Mechanical Engineering Michael Okpara University ofAgriculture Umudike Umuahia 02155 Nigeria Department of Mechanical Engineering Cross River University ofTechnology Calabar 540252 Nigeria Department of Mechanical Engneering Covenant Universiy Ota 11 O01Nigeria

This paper investigated the flow distribution and total pressure drop across a designed 3-D filter housing integrated with a 3-stage filtration system using computa- tional fluid dynamics （CFD）. The filter housing model was proposed for a heavy-duty industrial gas turbine plant operating at an average ambient temperature of 20℃.The pressure drops across the classes of filters were 652.8 Pa, 2692.2 Pa, 887.8 Pa, 776.2 Pa and 2304.2 Pa for i-GB, GB-GA, GA-FA, FA-HA, and HA-o, respectively. The results obtained indicated an acceptable total pressure drop of 7.2% for the entire filter housing before filter clean-up. Although the CFD simulation result shows that small outlet flow velocity and transonic flows exist at the outlet of the filter housing, the designed filter housing was proved compatible with the studied GT, for inlet flow conditions between 600≤ Wair≤610 kg/s and 60≤Vair≤70 m/s for the air flow rate and velocity, respectively. Furthermore, the designed filter housing could be adopted for the studied GT and locations of Usan and Maiduguri in Nigeria, and other locations with similar environmental conditions.

关键词： computational fluid dynamics (CFD) pressure drop flow distribution filter housing gas turbine

Measurement of mass attenuation coefficients,effective atomic numbers,and electron densities for different parts of medicinal aromatic plants in low-energy region

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Nuclear Science and Techniques 2018年第10期29卷 200-209页

作者： M.i.Sayyed F.Akman i.H.Geccbesler H.o.Tekin Department of Physics University of TabukTabuk 009662Saudi Arabia Department of Electronic Communication Technology Vocational School of Technical SciencesBingo¨l University12000 Bingo¨lTurkey Department of occupational Health and Safety Faculty of Health ScienceLaboratory of Natural Product ResearchBingo¨l University12000 Bingo¨lTurkey Department of Radiotherapy Uskdar University34662 I stanbulTurkey

The mass attenuation coefficients(l/q) for different parts(root, flower, stem, and leaf) of three medicinal aromatic plants(Teucrium chamaedrys L. subsp. sinuatum,Rheum ribes, and Chrysophthalmum montanum) were measured using an ^(241)Am photon source in a stable geometry and calculated using the Monte Carlo N-Particle Transport Code System-extended(MCNPX) code and the WinXCoM program. The experimental and theoretical MCNPX and WinXCoM values exhibited good *** measured mass attenuation coefficient values were then used to compute the effective atomic number(Z_(eff))and electron density(N_E) of the samples. The results reveal that S1-S(stem of Teucrium chamaedrys L. subsp. sinuatum) has the highest values of l/q and Zeff.

关键词： Medicinal Aromatic plant MCNPX code Mass attenuation coefficient Photon WinXCoM

Structural evolution, optoelectrical and corrosion properties of electrodeposited Wo_3 integration on Zn-Tio_2 electrolyte for defence super application

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Defence Technology（防务技术） 2018年第5期14卷 396-402页

作者： A.A.Daniyan L.E.Umoru o.S.i.Fayomi A.P.i.Popoola Department of Materials Science and Engineering Obafemi Awolowo University Department of Chemical Metallurgical and Materials Engineering Tshwane University of Technology Department of Mechanical Engineering Covenant University

Multifunctional nano composite coatings of Zn-Tio_2-Wo_3 were deposited electrolytically on mild steel(MS) from Zn bath, having Zn^(2+) ions and uniform dispersion of Tio_2 and Wo_3 nano particulates. The electrical, optical and corrosion resistance characteristics of the electrocodeposited coatings were assessed by Keithley 2400 Series Source meter with Multimeters, Newport Solar Simulator and a PGSTAT30 Autolab potentiostat respectively. The morphological characteristics of the composite coatings were characterized by scanning electron microscope(SEM) equipped with energy dispersive spectrometer(EDS). The result revealed that the electrocodeposits showed good stability and Zn-Tio_2-Wo_3 nanocomposite deposits displayed enhanced microstructural qualities, good electrical conductivity and exhibited enriched corrosion resistance.

关键词： Nano-composite Electrocodeposition Corrosion Conductivity and resistance

Systematic experimental study of the temperature dependence of viscosity and rheological behavior of water-based drilling fluids with nano-additives

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Petroleum 2023年第4期9卷 534-544页

作者： A.V.Minakov M.i.Pryazhnikov E.i.Mikhienkova Y.o.Voronenkova Siberian Federal University KrasnoyarskRussia Kutateladze institute of Thermophysics SB RASNovosibirskRussia

The paper presents the results of a systematic study of the influence of nano-additives of various concentrations,average sizes and composition on the temperature dependence of the viscosity and rheological behavior of water-based drilling *** compositions of drilling fluids,such as water suspensions of various clay solutions and gammaxan-based polymer solutions,were *** nanoparticles of silicon and aluminum oxides were used as nano-additives at concentrations ranging from 0.25 to 3 wt%.The average nanoparticle size varied from 10 to 151 *** temperature of drilling fluids varied from 25℃ to 80℃.it is shown that the addition of nanoparticles to drilling fluids leads to a significant change in their rheological properties depending on the *** was found that with increasing temperature,the yield stress and consistency index of drilling fluids with nanoparticles increase,while the behavior index,on the contrary,*** behavior depends on the size of the *** the particle size increases,their influence on the temperature dependence of the drilling fluids’viscosity *** general,it is shown that the addition of nanoparticles makes the viscosity of drilling fluid more stable with regard to the *** is an essential fact for practical application.

关键词： Drilling fluid Nano-additive Viscosity Rheology Temperature

Seasonal variations and the influence of geomembrane liners on the levels of PBDEs in landfill leachates,sediment and groundwater in Gauteng Province,South Africa

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Emerging Contaminants 2017年第2期3卷 76-84页

作者： i.V.Sibiya o.i.olukunle o.J.okonkwo Tshwane University of Technology Department of EnvironmentalWater and Earth SciencesPrivate Bag X680PretoriaSouth Africa

in the present study,the seasonal concentrations of polybrominated diphenyl ethers(PBDEs)in leachate and sediment samples,and the influence of geomembrane liners on PBDE levels and the extent of their infiltration into groundwater on selected landfill sites in Gauteng Province,South Africa were *** and sediment samples were collected from seven operational landfill sites namely:Goudkoppies,Robinson Deep,Marie Louis,Soshanguve,onderstepoort,Hatherly and Garankuwa from Johannesburg and Pretoria,in winter and *** samples were collected from monitoring boreholes from two landfill ***-liquid and Soxhlet extraction techniques were employed for the extraction of leachate and groundwater,and sediment respectively using *** extracted samples were subjected to column clean up and,thereafter,analysed using gas chromatographyemass spectroscopy(GC-MS).PBDEs selected for the study were:BDE-17,-28,-47,-100,-99,-153,-154,-183 *** P9PBDE concentrations in leachate samples for winter and summer ranged from 0.316e1.36 ng L-1 and 0.560e1.08 ng L-1 *** P9 PBDE concentrations obtained for sediment in winter and summer were 3.00e4.91 ng g-1 and 2.50e3.71 ng g-1 *** samples exhibited higher(poncentrations for both leachate and sediment samples compared to summer *** trend was attributed to high precipitation rate in summer which may have infiltrated into the landfills,subsequently diluting the leachate and sediment *** contrast,the winter period is generally dry and PBDEs are,therefore,more likely to be *** concentrations of PBDEs in leachate and sediment samples were higher in landfill sites with geomembrane liners compared to those without *** samples taken from the vicinity of selected landfill sites without geomembrane liners exhibited high concentrations of P9PBDEs,indicating possible migration of PBDEs from landfill site into ***

关键词： Seasonal trend PBDEs concentrations Landfill leachates Sediment Groundwater Geomembrane liners

Advances in non-thermal technologies for whole and minimally processed apple fruit–A review

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Food Bioscience 2022年第6期50卷 1367-1381页

作者： Nandi E.Nyamende Gunnar o.Sigge Zinash A.Belay Rebogile R.Mphahlele ayodeji B.oyenihi Asanda Mditshwa Zaharan M.Hussein oluwafemi James Caleb Department of Food Science Faculty of AgriSciencesStellenbosch UniversityPrivate Bag X1Stellenbosch7602South Africa Agri-Food Systems and omics Laboratory Post-Harvest and Agro-Processing Technologies (PHATs)Agricultural Research Council (ARC) Infruitec-NietvoorbijPrivate Bag X5026Stellenbosch7599South Africa Post-Harvest and Agro-Processing Technologies (PHATs) ARC - Tropical and Sub-tropical CropsPrivate Bag X11208Mbombela1200South Africa Functional Foods Research Unit Faculty of Applied SciencesCape Peninsula University of TechnologyBellville CampusP.O.Box 1906Bellville7535South Africa School of Agriculture Earth and Environmental SciencesCollege of AgricultureEngineering and ScienceUniversity of KwaZulu-Natal (PMB-Campus)Private Bag X01Scottsville3209South Africa Department of Applied Sciences College of Science and Technical EducationMbeya University of Science and TechnologyP.O.Box 131MbeyaTanzania Africa institute for Postharvest Technology Faculty of AgriSciencesStellenbosch UniversityPrivate Bag X1Stellenbosch7602South Africa

Apples are rich sources of bioactive compounds(e.g.,anthocyanins,flavanols,flavonols,and antioxidant activity),and micronutrients(e.g.,vitamins,zinc,and iron)that are essential for normal human body *** compounds in apples help to regulate immune responses and protect against chronic diseases by neutralizing and eliminating cellular free *** fruit production is ranked second globally,which has economic *** conventional industry practice of using chlorine-based chemical disinfectants has been discouraged based on public health concerns,and by strict policies limiting chemical residues on fresh or minimally processed ready to eat ***,the aim of this review is to provide a critical assessment on the status of emerging non-thermal technologies such as cold plasma,pulsed electric fields,ozone,electrolyzed water,and edible coatings for the whole and minimally processed apple fruit *** influence of these non-thermal technologies on microbial decontamination,preservation of bioactive compounds,and overall quality of apples during storage is *** addition,based on extensive report on various studies about non-thermal technologies for *** review concluded that future investigations should focus on balancing the decontamination performance of these non-thermal technologies with the preservation of essential nutritional quality attributes,providing guidance for the apple fruit industry.

关键词： Malus domestica Electrolyzed water Plasma activated water Pulsed electric fields ozone Fruit quality

Modeling microwave drying kinetics and moisture diffusivity of Mabonde banana variety

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international Journal of Agricultural and Biological Engineering 2014年第6期7卷 107-113页

作者： Adewale o.omolola Afam i.o.Jideani Patrick F.Kapila Department of Food Science and Technology School of AgricultureUniversity of VendaThohoyandou 0950South Africa Department of Agricultural and Rural Engineering School of AgricultureUniversity of VendaThohoyandou 0950South Africa

This study investigates the microwave drying kinetics of thin layer Mabonde banana variety(MBV)at power levels between 100 and 300 *** mathematical drying models:Wang and Singh,Verma,Two-term,Page,Two term exponential,and Logarithmic models were fitted to experimental drying data obtained from the *** statistical consistency of the models was determined using statistical parameters including coefficient of determination,mean bias error,root mean square error,and reduced Chi *** migration from banana slices was described using the Fick’s diffusion *** effective diffusivity was *** results indicated that drying took place largely in the falling rate *** time required to reduce the moisture of banana to a certain level was dependent on the microwave output,being the longest at 100 W and shortest at 300 *** effective moisture diffusivity increased with increasing microwave power with values at 4.89×10^(-10),1.09×10^(-9) and 1.69×10^(-9) m^(2)/s at 100,200,and 300 W,*** Wang and Singh model gave the best results for the description of thin layer drying of MBV.

关键词： Mabonde banana variety microwave drying models drying kinetics effective moisture diffusivity

on a Subordination Result of a Subclass of Analytic Functions

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Advances in Pure Mathematics 2017年第11期7卷 641-646页

作者： Risikat ayodeji Bello Department of Mathematics and Statistics College of Pure and Applied Science Kwara State University Malete Nigeria

in this paper, we investigate a subordination property and the coefficient inequality for the class M(1, b), The lower bound is also provided for the real part of functions belonging to the class M(1, b).

关键词： Analytic Function Univalent Function Hadamard Product Subordination

Quantitative Evaluation of Cyber-Attacks on a Hypothetical School Computer Network

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Journal of information Security 2019年第3期10卷 103-116页

作者： Akinjide A. Akinola Adeyemi A. Adekoya Ayoade o. Kuye Abiodun ayodeji University of Lagos Lagos Nigeria Virginia State University Petersburg VA USA University of Port Harcourt Port Harcourt Nigeria Nuclear Power Plant Development Directorate Nigeria Atomic Energy Commission Abuja Nigeria

This paper presents the attack tree modeling technique of quantifying cyber-attacks on a hypothetical school network system. Attack trees are constructed by decomposing the path in the network system where attacks are plausible. Considered for the network system are two possible network attack paths. one network path represents an attack through the internet, and the other represents an attack through the Wireless Access Points (WAPs) in the school network. The probabilities of success of the events, that is, 1) the attack payoff, and 2) the commitment of the attacker to infiltrate the network are estimated for the leaf nodes. These are used to calculate the Returns on Attacks (RoAs) at the Root Nodes. For Phase i, the “As is” network, the RoA values for both attack paths, are higher than 7 (8.00 and 9.35 respectively), which are high values and unacceptable operationally. in Phase ii, countermeasures are implemented, and the two attack trees reevaluated. The probabilities of success of the events, the attack payoff and the commitment of the attacker are then re-estimated. Also, the Returns on Attacks (RoAs) for the Root Nodes are re-assessed after executing the countermeasures. For one attack tree, the RoA value of the Root Node was reduced to 4.83 from 8.0, while, for the other attack tree, the RoA value of the Root Node changed to 3.30 from 9.35. RoA values of 4.83 and 3.30 are acceptable as they fall within the medium value range. The efficacy of this method whereby, attack trees are deployed to mitigate computer network risks, as well as using it to assess the vulnerability of computer networks is quantitatively substantiated.

关键词： Cyber-Attack Quantitative Vulnerability Assessment Attack Trees Return on Attack Countermeasures