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Journal of Central South University 2013年第12期20卷 3697-3714页

作者： J.o.okeniyi I.o.oladele I.J.Ambrose S.o.okpala o.M.omoniyi C.A.Loto A.P.I.Popoola Mechanical Engineering Department Covenant University Chemical Metallurgical and Materials Engineering Department Tshwane University of Technology

Corrosion test data were measured using non-destructive electrochemical techniques and analysed for studying inhibition effectiveness by different concentrations of NazCr207 on the corrosion of concrete steel-rehar in NaC1 and in H2So4 media. For these, specifications of ASTM G16-95 R04 were combined with the normal and the Gumbel probability density functions as model analytical methods for addressing issues of conflicting reports of inhibitor effectiveness that had generated concerns. Results show that reinforced concrete samples admixed with concentrations having 4 g （0.012 7 tool）, 8 g （0.025 4 mol） and 6 g （0.019 l tool） NaaCr207 exhibited, in that order, high inhibition effectiveness, with respective efficiency, r/, of （90.46±1.30）%, （88.41＋2.24）% and （84.87±4.74）%, in the NaC1 medium. These exhibit good agreements within replicates and statistical methods for the samples. Also, optimal inhibition effectiveness model in the H2So4 medium was exhibited by 8 g （0.025 4 mol） Na2Cr207 concentration having r/=（78.44±1.10）%. These bear implications for addressing conflicting test data in the study of effective inhibitors for mitigating steel-rebar corrosion in aggressive environments.

关键词： corrosion inhibitor effectiveness saline/marine and industrial/microbial environments concrete steel-rebar normal andGumbel probability distribution functions Kolmogorov-Smirnov statistics tests of significance

Structural and superconducting properties in Y_(0.6)Gd_(0.4)Ba_2(Nb)Cu_3o_(7-y) cuprates doped with niobium

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Journal of Rare Earths 2012年第3期30卷 241-244页

作者： M. Yilmaz o. Dogan A. K. Education Faculty Department of Physics Konya University

Polycrystalline YBa2Cu3o7-y （YBCo） and Y0.6Gd0.4Ba2-xNbxCu3o7-y （YGBNCo） compounds with 0≤x≤0.225 were synthesized using standard solid state reaction technique. The structure for all samples was characterized by X-ray difference （XRD） and scanning electron microscopy （SEM）. The transport properties were measured by the （FPP） method in the temperature range from 70 to 130 K. As the Nb content in the samples increased, a diffused phase indicating a niobium perovskite phase and a small amount of unidentified phase appeared. With the increase of Nb content, the superconducting transition temperature Tconset increased slowly with x≤0.125, and then it remained unchanged or slowly decreased with 0.125≤x≤0.225. It could be found that there was a slow decrease of zero-resistance temperature, Tcoffset, with the increase of Nb content. The larger transition width might result from the YBa2Nbo6 phase, impurity and unidentified phases of the sample due to the Nb doping.

关键词： Y0.6Gd0.4Ba2Cu3o7-y cuprates Gd and Nb co-doping structural and superconducting properties rare earths

A Comparative Analysis of Anxiety and Depression among Glaucoma and Cataractous Patients in Southwest Nigeria

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open Journal of ophthalmology 2021年第2期11卷 105-133页

作者： A. C. okudo o. E. babalola A. T. ogunro Eye Foundation Hospital Abuja Nigeria Rachel Eye Center Garki Abuja Nigeria

Background: Glaucoma is the leading cause of irreversible blindness worldwide. An appreciable proportion of glaucoma patients have been found to have hidden psychiatric disorders that often go undetected. Anxiety and ... 详细信息

ong>Background:ong> Glaucoma is the leading cause of irreversible blindness worldwide. An appreciable proportion of glaucoma patients have been found to have hidden psychiatric disorders that often go undetected. Anxiety and depression have been found to be major contributors to these psychological issues. This present study aims to compare the prevalence of anxiety and depression amongst glaucoma and cataract patients and to identify risk factors for anxiety and depression amongst these patients. ong>Materials and Methods:ong> A comparative crossectional study was carried out among 197 Primary open Angle Glaucoma (PoAG) patients and 197 controls (non-PoAG patients that have no ocular disorder other than cataract) attending Deseret Community Vision Institute, Ijebu Imushin, ogun state from 1st of April to 31st May 2014. PoAG was defined as patients with open anterior chamber angles based on gonioscopy, pale and cupped discs (Cup: Disc ratio ≥ 0.4), and corresponding visual field defects with or without an elevated intraocular pressure. Cataract was defined as patients with opacification of the crystalline lens in either or both eyes. The Hospital Anxiety and Depression Scale (HADS) was used to assess anxiety and depression among the participants. Data were analyzed using SPSS Version 20 using Chi-square, Independent student T-test and Logistic regression. ong>Results:ong> The mean age of glaucoma subjects was 62.24 years and the cataract subjects was 64.2 years. There was a male preponderance with a male: female ratio of 1.5:1. Anxiety as defined by the HADS was seen in 35.5% of glaucoma patients and 21.8% of the cataract patients but there was no statistically significant difference after controlling for sociodermographic and clinical characteristics on logistic regression. The risk factors for anxiety among the glaucoma participants were those younger than 60 (oR 2.9, 95% CI: 1.3 - 6.5 p = 0.009) and those with severe glaucoma (oR 9.5, 9

关键词： Anxiety Depression Glaucoma Cataract

Effect of Media Material on Biogas Production

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World Journal of Engineering and Technology 2017年第3期5卷 540-549页

作者： o. T. oginni o. L. Rominiyi B. A. Adaramola S. A. babalola Department of Mechanical Engineering Ekiti State University Ado-Ekiti Nigeria Department of Mechanical and Mechatronics Engineering Afe Babalola University (ABUAD) Ado-Ekiti Nigeria

The paper investigates the effects of the quantity of media materials with simple appraisal on biogas yields between hard and soft wood subjected to the same atmospheric condition in the Ado-Ekiti, Nigeria, between october 2009 and June 2010. Sixteen digesters were used and the mechanical grinding of cassava peels was done in a clean mortar and pestle. Specific grammes of cow dung and cassava peels (200 g, 150 g, 100 g and 50 g) were seeded with four substrates (woods) mixed up with 1200 cm3 of distilled water respectively. The appropriate ratios of the prepared slurries were transferred into different digesters for bio-degradation process which is third-fourth full with the aid of a funnel, and the tubes were passed into a measuring cylinder as a gas collector?inverted over acidified water in a plastic vessels. The volume of biogas produced ranged from 6964 cm3 to 13,185 cm3 by Mahogany, and Iroko ranged from 5340 cm3 to 10,250 cm3 were obtained for both hard woods used. Likewise, the volumes of gas produced by soft woods were from 2465 cm3 to 6445 cm3 by?obeche and 3430 cm3 to 6990cm3 by Araba. The results showed that, the highest percentage of the seedling media materials (33% each) on the substrates (cassava peel and cow dung) produced the highest biogas with 2800 cm3 of Mahogany, 2400 cm3 of Iroko, 1200 cm3 of Araba and 1130 cm3 of obeche woods respectively. It was established that, the rate of biogas yields is directly proportional to the quantity of the seedling materials to obtain a reliable results as an alternative renewable energy.

关键词： Biogas Media Materials Anaerobic Hard and Soft Woods Slurry

Direct Air Carbon Capture Takes Baby Steps-Giant Strides Are Needed Sean o’Neill

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Engineering 2022年第1期8卷 3-5页

作者： Sean o’Neill 机构不详

In September 2021,the world’s largest industrial plant to pull carbon dioxide(Co_(2))directly out of the atmosphere officially became operational in *** and built by the Zurich,Switzerland-based company Climeworks,it... 详细信息

关键词： remove store permanent

Evaluation of Fresh and Hardened Properties of Self-Compacting Concrete

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open Journal of Civil Engineering 2015年第1期5卷 1-7页

作者： oladipupo S. olafusi Adekunle P. Adewuyi Abiodun I. otunla Adewale o. babalola Department of Civil Engineering College of Engineering Federal University of Agriculture Abeokuta Nigeria

This paper compared the rheological properties and compressive strengths of self-compacting concrete (SCC) and conventional cement concrete. The flowability and segregation resistance of freshly mixed concrete specimens were examined by the V-funnel apparatus, while the characteristics of passing ability were investigated with the L-box apparatus. Cylindrical concrete specimens of 100 mm diameter × 200 mm length were investigated for compressive strength. The rheological properties of SCC are incomparable with those of the conventional concrete due to their diverse testing methods and characteristics of individual flow. The compressive strength results of hardened concrete showed that SCC gained strength slowly compared to the conventional cement concrete due to the presence of admixtures and its 28 days strength was lower than conventional cement concrete, but SCC eventually had potentials of higher strength beyond 90 days. Finally, the effect of water-cement ratio on the plastic properties of self-compacting concrete was quite negligible compared to conventional concrete.

关键词： Concrete Self-Compacting Concrete V-Funnel L-Box Density Compressive Strength

Phytochemical Screening of Two Tropical Moss Plants: <i>Thidium gratum</i>P. Beauv and <i>Barbula indica</i>Brid Grown in Southwestern Ecological Zone of Nigeria

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American Journal of Analytical Chemistry 2012年第12期3卷 836-839页

作者： Adedeji o. Adebiyi Ayodele A. oyedeji Elijah E. Chikwendu olubunmi A. Fatoke Department of Chemistry Education Science Ekiti State University Ado Ekiti Nigeria Department of Plant Science Ekiti State University Ado Ekiti Nigeria

Chemical tests were carried out on the aqueous extracts of the air-dried powders of two tropical moss plants, Thidium gratum and Barbula indica using standard procedures, to identify the phytochemical constituents. The extracts were screened for the presence and quantities of alkaloids, flavonoids, phenols, saponins and steroids with a view to assess their therapeutic values in ethnomedicine. The results of the phytochemical screening revealed the presence of alkaloids, flavonoids, phenols, saponins and steroids in varying quantities in the two moss plants but there was absence of phenol in Barbula indica. These results suggest that the two moss plants can be veritable and potential source of useful drugs in treatment of ailments.

关键词： Phytochemical Constituents Extracts Moss Plants Ethnomedicine Ailments

Reinforcement learning and A^(*)search for the unit commitment problem Patrick de Mars^(∗),Aidan o’Sullivan

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Energy and AI 2022年第3期9卷 172-181页

作者： Patrick de Mars Aidan o’Sullivan UCL Energy Institute United Kingdom

Previous research has combined model-free reinforcement learning with model-based tree search methodsto solve the unit commitment problem with stochastic demand and renewables generation. This approachwas limited to shallow search depths and suffered from significant variability in run time across probleminstances with varying complexity. To mitigate these issues, we extend this methodology to more advancedsearch algorithms based on A^(*) search. First, we develop a problem-specific heuristic based on priority list unitcommitment methods and apply this in Guided A^(*) search, reducing run time by up to 94% with negligibleimpact on operating costs. In addition, we address the run time variability issue by employing a novel anytimealgorithm, Guided IDA^(*), replacing the fixed search depth parameter with a time budget constraint. We showthat Guided IDA^(*) mitigates the run time variability of previous guided tree search algorithms and enablesfurther operating cost reductions of up to 1%.

关键词： Unit commitment Reinforcement learning Tree search Power systems

Comparison of Urea-Derived N_2o Emission from Soil and Soil-Plant System

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Pedosphere 2000年第3期10卷 207-212页

作者： CHENLIJUN o.VANCLEEMPUT 等 LaboratoryofEcologicalProcessofTraceSubstanceinTerrestrialEcosystem InstituteofAppliedEcologyTheChneseAcademyofSciencesShenyang110015China FacultyofAgriculturalandAppliedBiol

A pot experiment with a sandy loam soil and spring wheat as test crop was conducted to compare the N2o emission from soil system with plant cut off and from soil-plant system with plant kept. The results showed that after urea fertilizer applied, the N2o emission from soil and soil-wheat system decreased exponentially with time, and its total amount was 0.34%~0.63% and 0.33%~0.58% of applied urea-N respectively, no significant difference being found between these two systems. The N2o emission had a very significant negative relationship (P = 0.01) with the biomass of wheat plant. A combined application of urease inhibitor hydroquinone and nitrification inhibitor dicyandiamide could reduce the N2o emission by 50%~83% and 46%~74%, respectivelyl from soil and soil-wheat system. The N2o was mainly produced and emitted from soil, and the soil biochemical regulation, i.e., applying related inhibitors into soil could effectively diminish the urea derived N2o emission.

关键词： N2o emission soil soil-plant system ure

Electrolytic deposition of super-smart composite coating of Zn-V2o5-Nbo2 on low carbon steel for defence application

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Defence Technology（防务技术） 2018年第5期14卷 446-450页

作者： o.S.I.Fayomi L.R.Kanyane A.P.I.Popoola S.o.oyedepo Department of Chemical Metallurgical and Materials EngineeringTshwane University of TechnologyP.M.B.X680PretoriaSouth Africa Department of Mechanical Engineering Covenant UniversityP.M.B 1023OtaNigeria

Despite the massive usages of low carbon steel in automobile for engineering components, its corrosion and high friction coefficient in aggressive environment make it limited in service. This paper is aimed at modifying low carbon steel structural component with thin film composite for enhanced mechanical and corrosion properties. The steel structure was electrodeposited with Zn-V_2 o_5 and embedded with varied Nbo_2 weight concentration of 6-12 wt % based electrolyte. Scanning electron microscope(SEM) and high optical microscope was used to study the microstructural evolution of the fabricated coatings. The thermal stability of the fabricated coatings was studied in an isothermal furnace at 300 ℃ and 600 ℃ and further characterized using a high tech optical microscope. Potentiodynamic polarization technique was used to investigate the corrosion behavior of the composites in 3.65% NaCl. From the result, the effect of Nbo_2 on Zn-V_2 o_5-Nbo_2 was massive with improved crystal grain within the coatings lattices. The coating possesses strong metallurgical bonding and good corrosion resistance properties of about 0.315 mm/yr corrosion rate compare to 4.1 mm/yr of as-received sample. No doubt the impact of thermal shock on the resilient characteristics of the composite coating was moderate owing to the stable adherent properties of the deposited coatings.

关键词： Electrodeposition Low carbon steel Micro-hardness Thermal stability corrosion behavior Rare earth metal(REM)