检索结果-南通市图书馆

Kinetics and mechanistic investigation of epoxide/cO2 cycloaddition by a synergistic catalytic effect of pyrrolidinopyridinium iodide and zinc halides

在线全文

学校读者我要写书评

暂无评论

Journal of Energy chemistry 2019年第10期28卷 35-42页

作者： Abdul Rehman Valentine c. eze M.F.M.Gunam Resul Adam Harvey School of Engineering Merz CourtNewcastle UniversityNewcastle Upon Tyne NE1 7RUUK Department of chemical and Polymer Engineering University of Engineering and Technology LahoreFaisalabad CampusPakistan

Formation of styrene carbonate (Sc) by the cycloaddition of cO2 to styrene oxide (SO) catalysed by pyrrolidinopyridinium iodide (PPI) in combination with zinc halides (Zncl2, ZnBr2 and ZnI2) was investigated. complete conversion of the SO to Sc was achieved in 3 h with 100% selectivity using 1/0.5 molar (PPI/ZnI2) catalyst ratio under mild reaction conditions i.e., 100℃ and 10 bar cO2 pressure. The synergistic effect of ZnI2 and PPI resulted in more than 7-fold increase in reaction rate than using PPI alone. The cycloaddition reaction demonstrated the first-order dependence with respect to the epoxide, cO2 and catalyst concentrations. Moreover, the kinetic and thermodynamic activation parameters of Sc formation were determined using the Arrhenius and Eyring equations. The positive values of △H(42.8 kJ mol^-1) and △G(102.3 kJ mol^-1) revealed endergonic and chemically controlled nature of the reaction, whereas the large negative values of △S(-159.4 J mol^-1 K^-1) indicate a highly ordered activated complex at the transition state. The activation energy for Sc formation catalyzed by PPI alone was found to be 73.2 kJ mol^-1 over a temperature range of 100-140℃, which was reduced to 46.1 kJ mol^-1 when using PPI in combination with ZnI2 as a binary catalyst. Based on the kinetic study, a synergistic acid-based reaction mechanism was proposed.

关键词： cycloaddition cO2 utilization cyclic carbonates Homogeneous catalysis Activation energy

Prevalence of parasitemia and associated immunodeficiency among HIV—malaria co—infected adult patients with highly active antiretroviral therapy

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2013年第2期6卷 148-152页

作者： caroline Edijana Omoti chiedozie K.Ojide Patrick V.Lofor Emeka eze Joy c eze Department of Haematology and Blood Transfusion University of Benin Teaching HospitalBenin CityNigeria Department of Medical Microbiology University of Benin Teaching HospitalBenin CityNigeria Department of Internal Medicine University of Benin Teaching HospitalBenin CityNigeria

Objective:To investigate the malaria parasitemia,cD4~+ cell counts and some haematological indices among HIV-malaria co-infected adult patients with highly active antiretroviral therapy (HAART).Methods:A total of 342 adult HIV positive subjects were recruited at the consultant outpatient HIV/AIDS *** of Benin Teaching Hospital,Benin city,Nigeria between June 2011 to November *** samples were taken for malaria parasite count,cD4~+ cell count and other haematological ***:Out of the 342 adult HIV positive subjects a total of 254 patients(74.3%) were found to have malaria *** incidence of malaria parasitemia increased with advancing clinical stage of HIV infection and this was statistically significant(P=0.002).There was no statistical significance when gender was compared with the HIV-malaria status(P>0.05).Of the 254 co-infected patients,134(52.8%) had high parasitemia (>1.25×10~9/L).Sixty patients were found to be hyperparasitemic(>2.5 parasites/L).There was a significant association between cD4~+ cell count and having significant parasitemia(Pco-infected patients had cD4~+ cell count≤200/μL,and majority(44.9%) of this population also had significant *** and thrombocytopenia were not significantly associated with HIV-malaria co-infection(P>0.05).conclusions:The prevalence of parasitemia is high among the HIV/AIDS infected patients.

关键词： HIV Malaria HAART cD4~+

Optimization and kinetics of glucose production via enzymatic hydrolysis of mixed peels

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bioresources and Bioproducts 2020年第4期5卷 283-290页

作者： Michael U.Ude Ike Oluka Paul c.eze Engineering Research Development and Production Projects Development Institute(PRODA)EmeneEnugu StateNigeria Department of Agricultural and Bioresource Engineering Enugu State University of Science and Technology(ESUT)Enugu StateNigeria

The optimization and kinetics of glucose production via enzymatic hydrolysis of mixed peels were carried *** substrate was characterized using proximate analysis and *** process was optimized using response surface methodology while the kinetics of the hydrolysis was studied using Michealis-menten *** results obtained showed that the mixed peels have high hemicellulose content,hydrolysable carbohydrate and *** optimum conditions for glucose yield of 79%by enzymatic hydrolysis are temperature of 36℃,time of five days,pH of 4.55 and enzyme dosage of 0.428 g/50 *** hydrolysis obeyed Michealis-Menten kinetic model with spontaneous and feasible ***,the results have proved that mixed peels(cassava and potato peels)is a good substrate for glucose production and study of other waste peels as feed-stock is recommended.

关键词： Enzymatic hydrolysis Optimization Glucose cassava and potato peels

Some Estimates of the Maximum Modulus for Polynomials with Gaps

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Analysis in Theory and Applications 2019年第4期35卷 421-426页

作者： eze R.Nwaeze Department of Mathematics Tuskegee UniversityTuskegeeAL 36088USA

Let p(z)be a polynomial of degree n having some zeros at a point z0 ∈c with |z0|<1 and the rest of the zeros lying on or outside the boundary of a prescribed *** this brief note,we consider this class of polynomials ... 详细信息

Let p(z)be a polynomial of degree n having some zeros at a point z0 ∈c with |z0|cribed *** this brief note,we consider this class of polynomials and obtain some bounds for(max|z|=R|p(z)|)s in terms of (max|z|=1|p(z)|)s for any R≥1 and s∈N.

关键词： Polynomials maximum modulus zeros prescribed disk

Africa's Perspectives on china-Africa Relations and Forum on china-Africa cooperation(FOcAc)

在线全文

学校读者我要写书评

暂无评论

国际展望 2009年第2期1卷 48-61,132页

作者： Osita c.eze Professor and Director-General of Nigerian Institute of International Affairs

china is in Africa in a vigorous way,and doing business in several countries like Sudan,congo DRc,Angola,South Africa,and *** the short term,the relationship may appear to be mutually *** paper seeks to address the issue of Africa's perspectives on china-Africa Relations and the FOcAc and examine the concept of strategic partnerships,determine the state of china-Africa relations,examines FOcAc and draw conclusion as well as recommendation on possible ways and issues for future engageme...

关键词： Africa’s Perspectives on china-Africa Relations and Forum on china-Africa cooperation FOcAc

A Systematic Review on Antituberculosis Drug Discovery and Antimycobacterial Potential of Biologically Synthesized Silver Nanoparticles:Overview and Future Perspectives

在线全文

学校读者我要写书评

暂无评论

Infectious Microbes & Diseases 2022年第4期4卷 139-148页

作者： christian K.ezeh chibuzor N.eze Uju M.E.Dibua Stephen c.Emencheta Department of Microbiology University of NigeriaNsukkaEnugu StateNigeria Department of Pharmaceutical Microbiology University of NigeriaNsukkaEnugu StateNigeria

Rapid emergence and quick evolution of drug-resistant and aggressive mycobacterial strains have resulted in the present antimycobacterial drug crisis and the persistence of tuberculosis as a major public health ***/biological nanotechnologies constitute an interesting area of research for discovering antimycobacterial *** review focused on the biological(green)synthesis of silver nanoparticles(AgNPs)as an alternative source of antimycobacterial *** for this study were searched and screened from three electronic databases(Google Scholar,PubMed and ScienceDirect)following the Preferred Reporting Items for Systematic Reviews and Meta-analyses *** from in total 17 eligible studieswere reported in this systematic *** of the 17 studies used plants to fabricate AgNPs,whereas the remaining five studies used microorganisms(bacteria and/or fungi).Silver as part of silver nitrate(AgNO3)was themetal precursor reported for the synthesis of AgNPs in these *** nanoparticles were mostly spherical,with sizes ranging from12 *** minimum inhibitory concentrations varied between studies and were divided into three groups:(i)those more effective than the antibiotic(controls),(ii)those more effective than plant extracts,and(iii)those less effective than the antibiotic *** addition,little or no cytotoxicity effects were *** nanoparticles were also shown to be highly specific or selective toward mycobacterial *** systematic review highlights the antimycobacterial potential of biologically synthesized AgNPs,underscoring the possibility of discovering/developing new antimycobacterial agents using biological synthesis approaches with less toxicity and high selectivity.

关键词： antimycobacterial activity silver nanoparticles cytotoxicity biological synthesis tuberculosis mycobacterial

Status of congenital Heart Defects in Nigeria: The Role of cardiac Surgery

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of cardiovascular Surgery 2019年第7期9卷 63-72页

作者： Ikechukwu A. Nwafor John c. eze National cardiothoracic center of Excellence University of Nigeria Teaching Hospital Ituku-Ozalla Nigeria

Background: Unlike in developed countries, the delivery of cardiovascular services to children born with congenital heart defects in Nigeria is inadequate. There are problems at both pediatric and adult ages with high morbidity and mortality on account of inadequate surgical care. Objective: To determine the status of congenital defects and assess the impact of foreign cardiac missionary missions vis-à-vis the effects on the magnitude as well as on the educational program for the local cardiac team. Materials and Method: In the last 5.5 years, Foreign cardiac Surgery missions were reinstituted at National cardiothoracic center of Excellence, Enugu, Nigeria. The participants performed cardiac interventions on a variety of patients with cHD. We performed a retrospective review of this endeavor. Patients’ demographics, number of patients, age ranges, types of cHD and clinical evaluation methodology were obtained from our hospital’s record department. We also assessed types of cardiac interventions, outcome and challenges and the impacts of the foreign cardiac surgery missions. Results:?During the study period, a total of 72 children with cHD were evaluated. They were 39 males and 33 females. The age ranged between 0 - 10 years in children and 41 - 50 years in the adult. We studied both simple and complex anomalies. A VSD was the commonest (n = 22, 27.16%). conclusion: Foreign congenital cardiac surgery missions were not able to provide adequate services for the care of cHD that require cardiac surgery both in terms of reduction in magnitude as well as adequate educational program for the local cardiac team. Thus infants, in particular, suffer an early death. The need for governmental support to develop a comprehensive program to care for these patients is essential in Nigeria and other developing countries.

关键词： Status Heart congenital International Mission

Typical Hydraulic Properties of Deep Aquifers of Niger Delta from Pumping Test Data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2017年第11期5卷 139-148页

作者： S. A. Ngah c. L. eze Institute of Geosciences and Space Technology Rivers State University Port Harcourt Nigeria

The hydraulic properties of deeper coastal Plain Sands, which form the main aquifer in the Niger Delta, were investigated around Eleme, Rivers State. The intent was to find out if frequent well failure was as a result of the aquifer not having enough transmitting capacity to sustain the huge withdrawal necessary for Eleme and its environs where demand for groundwater withdrawal is very high because Eleme axis serves as a major industrial axis of River State or whether the frequent well failure was due to inefficient well construction practice. constant discharge pumping tests were conducted in 8 deep borehole (250 - 310 m). Data generated during the test were analysed using cooper-Jacob’s straight line method. The calculated transmissivity of the aquifers ranged from 1324 m2/day - 5815 m2/day. These values when compared with transmissivity values elsewhere indicate that the aquifers in the study area have excellent water yielding properties, plotting within the range of “Very Good” in water transmitting capacity scale. coefficient of permeability ranged from 13.65 m/d - 59.9 m/d. coefficient of Storage ranged from 28.2 × 10-5 - 29.1 × 10-5 while the Specific capacities of the wells ranged from 48.75 3 - 78.13 m3/d/m. It is concluded that the deep aquifers of the Niger Delta do possess the capacity to produce and sustain large groundwater withdrawal. It is further recommended that competent drilling contractors be engaged in deep well construction in the area.

关键词： Deep Aquifers. Hydraulic Properties coastal Plain Sands Eleme Niger Delta

Analysis of Variance in an Unbalanced Two-Way Mixed Effect Interactive Model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Statistics 2016年第2期6卷 310-319页

作者： F. c. eze E. U. Nwankwo Department of Statistics Nnamdi-Azikiwe University Awka Nigeria

The expected mean squares for unbalanced mixed effect interactive model were derived using Brute Force Method. From the expected mean squares, there are no obvious denominators for testing for the main effects when the factors are mixed. An expression for F-test for testing for the main effects was derived which was proved to be unbiased.

关键词： Mixed Model Expected Mean Squares Unbalanced Data