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On p-convergent Operators on Banach Lattices

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Acta Mathematica Sinica,English Series 2018年第5期34卷 873-890页

作者： Elroy D.ZEEKOEi Jan h.FOURiE Unit for Business Mathematics and informatics North-West University (NWU)

The notion of a p-convergent operator on a Banach space was originally introduced in 1993 by Castillo and SAnehez in the paper entitled ＂Dunford-Pettis-like properties of continuous vector function spaces＂. in the present paper we consider the p-convergent operators on Banach lattices, prove some domination properties of the same and consider their applications （together with the notion of a weak p-convergent operator, which we introduce in the present paper） to a study of the Schur property of order p. Also, the notion of a disjoint p-convergent operator on Banach lattices is introduced, studied and its applications to a study of the positive Schur property of order p are considered.

关键词： p-convergent operator disjoint p-convergent operator weak p-convergent operator Schur property of order p positive Schur property of order p

An experimental study of the synergistic effects of BMiM-BF_4,BMiM-DCA and TEACi aqueous solutions on methane hydrate formation

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Petroleum Science 2019年第2期16卷 409-416页

作者： Ali Rasoolzadeh Jafar Javanmardi Amir h.Mohammadi Department of Chemical Engineering Shiraz University of Technology institut de Recherche en Genie Chimique et Petrolier (iRGCP) Discipline of Chemical Engineering School of Engineering University of KwaZulu-Natal Howard College Campus

in this work, the effects of three ionic liquids(iLs), namely, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium dicyanamide and tetraethyl-ammonium chloride, on methane hydrate formation and dissociation kinetic parameters were studied. The kinetic parameters including the initial rate of hydrate formation, hydrate stability at atmospheric pressure and hydrate storage capacity were evaluated. The experimental measurements were performed in an initial pressure range of 3.5-7.1 MPa. it was found that both of iLs with imidazolium-based cation increase the initial methane hydrate formation rate while the iL with ammonium-based cation leads to a decrease in the initial methane hydrate formation rate. it was also interpreted from the results that all of the three studied iLs decrease methane hydrate stability at atmospheric pressure and increase methane hydrate storage capacity. Finally, both of iLs with imidazolium-based cations were found to have higher impacts on decreasing hydrate stability at atmospheric pressure and increasing the methane hydrate storage capacity than the applied iL with ammonium-based cation.

关键词： Storage capacity Gas hydrate initial rate ionic liquids Natural gas

Physicomechanical Properties of Sustainable Wood Plastic Composites of Tropical Sawdust and Thermoplastic Waste for Possible Utilization in the Wood industry

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Journal of Sustainable Bioenergy Systems 2023年第4期13卷 149-171页

作者： Jude i. Duruaku Patrick A. C. Okoye Theresa U. Onuegbu Valentine i. Onwukeme Nkechi h. Okoye Joseph O. Nwadiogbu Department of Pure and industrial Chemistry Nnamdi Azikiwe University Awka Nigeria Department of Pure and industrial Chemistry Chukwuemeka Odumegwu Ojukwu University Uli Nigeria

This work investigated and quantified the physicomechanical properties of flat-pressed wood plastic composites produced with recycled polyethylene terephthalate, recycled polyethylene and sawdust derived from selected tropical timbers, namely, Nauclea diderrichii, Brachystegia eurycoma, Erythrophleum suaveolens and Prosopis africana, for possible utilization in the wood industry. The compounding of the polymer blends of the precursor plastics, namely recycled PET (rPET) and recycled PE (rPE) with the sawdust (SD) from the selected timbers to produce the desired wood rPET/rPE composites was carried out via the flat press method. The characterization of the physicomechanical properties of the wood plastic composites (WPCs) produced, such as the density, hardness, flexural strength, ultimate tensile strength, elongation %, thickness swelling and water absorption capacity was carried out using methods based mainly on the European Committee for Standardization (CEN) and the American Society for Testing Materials (ASTM) standards. The results of the investigation on the resultant composites indicated that changes in the SD content affected the density of flat-pressed WPCs in line with literature. Generally, it was observed that as wood dust increased and PET content decreased, the density of composites decreased with some deviations as expected probably due to the anisotropic nature of the wood fillers. The analysis of variance (ANOVA) revealed that there was a statistically significant variation in the wood composites of Nuclea diderichii based on the physicomechanical values as the p-value (0.020) obtained was less than the critical level of α = 0.05. it was also observed that the composite, Wood 1 Sample 5 (W1S5) which was composed of 40% rPE, 40% rPET and 20% SD (derived from Nuclea diderichii), had the highest percentage elongation (26.84%);the highest flexural strength (14.995 N/mm2) and possibly the least carbon footprint in the env

关键词： Wood Plastic Composites Density Water Absorption Capacity Cellulose Sustainability Recycle Waste

STUDY ON MORPhOLOGY OF ChROMiUM iN ChiLLED Cu-0.14%-2.0%Cr ALLOYS

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Acta Metallurgica Sinica(English Letters) 2004年第5期17卷 655-660页

作者： h.W.Yang Z.K.Fan SchoolofMaterialScienceandEngineering Xi＇anUniversityofTechnologyXi＇an710048China SchoolofMaterialScienceandEngineering Xi＇anUniversityofTechnologyXi＇an710048China

The morphology of chromium in chilled Cu-Cr alloys with 0.14%-2.0% Cr has been studied. The results showed that eutectic Cr phase takes a fibrous shape, and pre-eutectic Cr is dendritic in the studied chilled Cu-Cr alloy. During solute treatment of the eutectic and super-eutectic Cu-Cr alloys, only part of chromium particles dissolved in copper phase, some fiber and dendritic chromium still remained. Forging before solute treatment can reduce the size of primary Cr particles, which benefits the aging structure.

关键词： morphology of Cr Cu-Cr alloy chilling forging

Experimental investigation and prediction of wear behavior of cotton fiber polyester composites

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Friction 2017年第2期5卷 183-193页

作者： hiral h.PARiKh Piyush P.GOhiL Department of Mechanical Engineering School of Science and Engineering Navrachana University Vadodara 391410 India Department of Mechanical Engineering Faculty of Technology & Engineering the MS University of Baroda Kalabhavan Vadodara 390001 India

The cotton fiber reinforced polyester composites were fabricated with varying amount of graphite fillers (0,3,5 wt.％) with a hand lay-up *** tests were planned by using a response surface (Box Behnken method) design of experiments and conducted on a pin-on-disc machine (POD) test *** effect of the weight percentage of graphite content on the dry sliding wear behavior of cotton fiber polyester composite (CFPC) was examined by considering the effect of operating parameters like load,speed,and sliding *** wear test results showed the inclusion of 5 wt.％ of graphite as fillers in CFPC increase wear resistance compared to 3 wt.％ of graphite *** graphite fillers were recommended for CFPC to increase the wear resistance of the material.A scanning electron microscope (SEM) was used to study the wear *** predict the wear behavior of the composite material,comparisons were made between the general regression technique and an artificial neural network (ANN).The conformation test results revealed the predicted wear with the ANN was acceptable when compared with the actual experimental results and the regression mathematical models.

关键词： wear composites cotton fiber reinforced polyester composites artificial neural network pin-on-disc

Effect of Soil Water Repellency on Energy Partitioning Between Soil and Atmosphere:A Conceptual Approach

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Pedosphere 2014年第4期24卷 498-507页

作者： h.SChONSKY A.PETERS G.WESSOLEK Department of Soil Conservation Institute of EcologyTechnical University of BerlinD-10587 Berlin(Germany)

Water repellency(WR) is a phenomenon known from many soils around the world and can occur in arid as well as in humid climates;few studies,however,have examined the effect of soil WR on the soil-plant-atmosphere energy *** aim of our study was to estimate the effects of soil WR on the calculated soil-atmosphere energy balance,using a solely model-based *** made out evapotranspiration to have the largest influence on the energy balance;therefore the effect of WR on actual evapotranspiration was *** achieve this we used climate data and measured soil hydraulic properties of a potentially water-repellent sandy soil from a site near Berlin,Germany.A numerical 1D soil water balance model in which WR was incorporated in a straightforward way was applied,using the effective cross section *** were carried out with vegetated soil and bare *** simulation results showed a reduction in evapotranspiration of 30-300 mm year^(-1)(9%-76%) at different degrees of WR compared to completely wettable soil,depending on the severity degree of soil *** energy that is not being transported away by water vapor(i.e.,due to reduced evapotranspiration) had to be transformed into other parts of the energy balance and thus would influence the local climate.

关键词： climate effective cross section evapotranspiration soil-atmosphere energy balance soil hydraulic property water balance

Changes in Seasonal Patterns of Temperature and Precipitation in China During 1971-2000

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Advances in Atmospheric Sciences 2007年第3期24卷 459-473页

作者：宋连春 A.J.CANNON P.h.WhiTFiELD institue of Arid Meteorology China Meteorological Administration Department of Earth and Ocean Sciences University of British Columbia VancouverBritish Columbia V6T 1Z2Canada Meteorological Service of CanadaEnvironment Canada#201-401 Burrard Street VancouverBritish Columbia V6C 3S5Canada Meteorological Service of Canada Environment Canada #201-401 Burrard Street VancouverBritish Columbia V6C 3S5Canada

Many studies have shown evidence for significant changes in surface climate in different regions of the world and during different seasons over the past 100 years. Based on daily temperature and precipitation data from 720 climate stations in China, cluster analysis was used to identify regions in China that have experienced similar changes in the seasonal cycle of temperature and precipitation during the 1971-2000 climate normal period. Differences in 11-day averages of daily mean temperature and total precipitation between the first （1971-1985） and second （1986-2000） halves of the record were analyzed using the Mann- Whitney U test and the global κ-means clustering algorithm. Results show that most parts of China experienced significant increases in temperature between the two periods, especially in winter, although some of this warming may be attributable to the urban heat island effect in large cities. Most of western China experienced more precipitation in 1986-2000, while precipitation decreased in the Yellow River valley. Changes in the summer monsoon were also evident, with decreases in precipitation during the onset and decay phases, and increases during the wettest period.

关键词： κ-means clustering seasonality trends temperature precipitation China

Application of mesoporous silica nanocontainers as an intelligent host of molybdate corrosion inhibitor embedded in the epoxy coated steel

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Progress in Natural Science:Materials international 2017年第2期27卷 261-267页

作者： A.Keyvani M.Yeganeh h.Rezaeyan Department of Metallurgy and Materials Engineering Faculty of Technology and EngineeringShahrekord University Department of Materials Science and Engineering Faculty of EngineeringShahid Chamran University of Ahvaz School of Metallurgy and Materials Engineering College of EngineeringUniversity of Tehran

in this study, mesoporous silica served as a host for corrosion inhibitor. This material could adsorb and release corrosion inhibitor in different aqueous media. however, the extent of corrosion inhibitor release in the alkaline media was higher. By dispersing 1 wt% mesoporous silica loaded with sodium molybdate in the epoxy layer, a protective composite coating was produced. The corrosion properties of the composite coatings were assessed by electrochemical impedance spectroscopy. Results showed higher corrosion resistance of epoxy/mesoporous silica loaded with inhibitor in the Na Cl media for eight weeks of immersion in comparison with epoxy/mesoporous silica. Corrosion inhibitors released from nano-containers in the response to corrosion damage at the interface zone.

关键词： Mesoporous silica Epoxy Corrosion inhibitor EiS

Effects of a novel isoflavonoid from the stem bark of Alstonia scholaris against fructose-induced experimental cataract

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Journal of integrative Medicine 2019年第5期17卷 374-382页

作者： Pranay Soni Rajesh Choudhary Surendra h.Bodakhe Department of Pharmacology Institute of Pharmaceutical SciencesGuru Ghasidas Vishwavidyalaya

Objective: The present study investigated the anticataract activity of a novel isoflavonoid, isolated from stem bark of Alstonia scholaris, against fructose-induced experimental ***: The bioactivity of fractions extracted from A. scholaris, an isolated isoflavonoid(ASii) was screened using in vitro(goat lens) and in vivo(albino rats) experimental cataract models. For the in vivo evaluation, albino rats(12–15 weeks old) were divided into five groups(n = 6). Group i(normal)received 0.3% carboxymethyl cellulose solution(10 m L/[kgád], p.o.). Group ii(control) received 10%(w/v)fructose solution in their drinking water. Groups iii–V received ASii at three different doses, 0.1, 1.0 and10 mg/(kgád), concurrently with 10%(w/v) fructose solution. Treatment was given daily for 8 consecutive weeks. During the protocol, systolic blood pressure, diastolic blood pressure, blood glucose level and lenticular opacity were monitored at 2-week intervals. Pathophysiological markers(catalase, superoxide dismutase, glutathione peroxidase, reduced glutathione and malondialdehyde) in eye lenses were examined at the end of the 8-week treatment ***: The results of in vitro study showed that A. scholaris extract and the active fraction(A3) reduced the lenticular opacity as compared to toxic control group. The in vivo study showed that 8-week administration of ASii(0.1, 1.0 and 10 mg/[kgád], p.o.) led to significant reduction in blood pressure and blood glucose level and retarded the initiation and evolution of cataractogenesis, compared to the fructoseinduced cataract model control. Additionally, ASii treatment led to significant improvement in lens antioxidants(catalase, superoxide dismutase, glutathione peroxidase and reduced glutathione) and decreased lens malondialdehyde, compared to the control group(group ii).Conclusion: Results revealed that administration of ASii played a crucial role in the reduction of cataract formation in diabetic and hypertensive models.

关键词： isoflavonoid Oxidative stress Alstonia scholaris hypertension Diabetes Cataract