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Gastroenterology Report 2020年第6期8卷 487-489,I0003页

作者： joseph w.nunoo-mensah Mariam Rizk Department of Colorectal Surgery King’s College Hospital Foundation NHS TrustLondonSE59AEUK

Natural-orifice specimen-extraction surgery(NOSES)for colorectal disease is not a new surgical procedure,although its lack of penetration into common colorectal surgical practice may make it a relatively new *** et al.[1]were among the first to report the extraction of a colectomy specimen through the vagina in 1991 and,shortly thereafter,Franklin et al.[2]published the first report of partial colectomy with naturalorifice specimen extraction(NOSE)via the *** then,there have been several publications on the extraction of both malignant and benign colonic diseases from the caecum to the distal rectum through natural-orifice extraction *** procedures such as laparoscopic cholecystectomy,which was introduced in 1985 and rapidly diffused into the surgical community over a 2-to 3-year period,the dispersion of NOSES has not been equivocal[3].As there are several reasons why some new surgical innovations may be taken up more quickly than others,the adoption curves of new procedures can take many ***,the tipping point that describes the onset of the peak rate of diffusion of the new technology usually occurs after the first 10%–20%of users have adopted it[3].From a global perspective,the adoptions curve for NOSES has not obtained a peak rate of diffusion and appears to have arrested in the developmental and explorative phase of innovation[3].

关键词： orifice colorectal Stewart

Trend Analysis of Exchange Rate of the Ghana Cedi against the US Dollar Using Time Series

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Open Journal of Statistics 2023年第5期13卷 734-745页

作者： Francis Ayiah-mensah Prince Arthur-nunoo joseph Acquah John Awuah Addor Department of Mathematics Statistics and Actuarial Science Faculty of Applied Sciences Takoradi Technical University Takoradi Ghana Department of Mathematical Sciences University of Mines and Technology Tarkwa Ghana

Exchange rate volatility or its stability is a key determinant of the state of a country’s economy. The Ghana cedi’s performance against the US dollar in recent times has been the worse in the past decade. This has resulted in high inflation, high cost of living and high cost of production in Ghana. Despite the recent economic recovery growth, the cedi continues to strife in high rate of exchange against the dollar. This study examines and models a trend, and makes predictions of future rates of the cedis against the US dollar. Methodology: The study used a 13-year data of exchange rates of Ghana cedi and the US dollar spanning from 2010 to mid-2023 from the Bank of Ghana’s economic data on exchange rates, Ghana Stock Exchange and the world Bank. The ARIMA and SARIMA models were used to model the trends and for forecasting, taking into the consideration the asymmetric and seasonal effect of the data. Results: The outputs show that, the Ghana cedi will continue to rise but steadily against the US dollar for the remaining months of 2023 except in December, and continue to decline afterwards through into 2024. Conclusion: The cedi continues to weaken in value and the strength of its purchasing power. A weaker currency depicts a “junk” economy which affects its foreign investment. As the US dollar continues to rise, the Government and policy makers must implement effective policies to stabilize its rise against the cedi. Export of commodities must increase in addition to import restrictions to balance trade deficit and to strengthen the Ghana Cedi.

关键词： Ghana Cedi US Dollar Ghana Stock Exchange Inflation Exchange Rates

Supporting farmer-managed irrigation systems in the Shigar valley, Karakorum： Role of the government and Aga Khan Rural Support Programme

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Journal of Mountain Science 2017年第10期14卷 2064-2081页

作者： joseph K.w.HILL Department of Rural Management Xavier Institute of Social Sciences (XISS) Dr Gamil Bulcke Path Post Box 7 Ranchi- 834001 India

Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era records shows that over a century ago government agencies undertook irrigation support projects. In the past three decades,government agencies and the non-government agency Aga Khan Rural Support Programme(AKRSP), which channels foreign funds into the region, have actively engaged in the provision of irrigation support. This article seeks to explore whether such projects support or undermine farmer-managed irrigation systems and the complex institutional arrangements that underpin them. Field research using ethnographic and participatory methods was conducted in spring 2013 in the upper Shigar valley, Skardu district, GilgitBaltistan. The findings show that irrigation development is a political activity that involves village-based actors, religious leaders, local politicians,and government and non-government *** agencies operate in a largely top-down,engineering mode, their larger projects limited to villages suffering water scarcity. The local government provides small funds for renovation work of FMIS,though allocation of funds is highly politicized. Nongovernment agencies, for a variety of reasons including donor-funding cycles, apply a one-size-fitsall ‘participatory' model in an attempt to socially engineer rules and institutions. In communities divided by factionalism the use of such external models that stress formation of committees are unlikely to yield positive results, and could instead contribute to undermining the very systems they seek to support. This research argues that irrigation interventions should take care to build upon the rich and complex social arrangements that have sustained FMIS through the centuries.

关键词： Farmer-managed irrigation systems Institutional arrangements Government Aga Khan Rural Support Programme Shigar valley Karakorum

Design and Implementation of Smart Power Voltage and Frequency Synchroniser in Power Distribution System

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Journal of Power and Energy Engineering 2023年第4期11卷 1-16页

作者： Isaac Kofi mensah Prah joseph Cudjoe Attachie Electrical and Electronic Engineering Department University of Mines and Technology Tarkwa Ghana

Voltage and frequency are usually considered and assessed independently in the design and operation of electrical networks. However, these two are linked. Each and every malfunctioning electrical system has an impact on both voltage and frequency. This paper presents the opportunity for monitoring the distributed electrical energy by means of a system that monitors, controls, and provides a breakpoint based on high or low voltage and frequency tripping mechanism that avoids any damage to the load. The designed system comprised a switch mode power supply (SMPS), a direct digital synthesizer (DDS), and PIC16F876A microcontroller techniques for stable voltage and frequency outputs. Proteus design suite version 8.11 software and Benchcope SDS1102CN were used for modeling and simulation. The hardware prototype was implemented at a telecom cell site for data capturing and analysis. Test results showed that the implementation of the prototype provided stable and constant outputs of 222 V/50 Hz and 112 V/60 Hz which constituted 99% and 99.8% efficiency for voltage and frequency performance respectively. The paper also discusses different technologies that can be adopted by the system to mitigate voltage and frequency effects on customer appliances.

关键词： Switch Mode Power Supply Direct Digital Synthesis Pulse width Modulation H-Bridge Mosfet Microcontroller Filtering and Rectification

Effect of Switching Devices on Power Quality and Transient Voltage Suppression Using Capacitor Bank Model

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Journal of Power and Energy Engineering 2022年第5期10卷 77-89页

作者： Isaac Kofi mensah Prah joseph Cudjoe Attachie Electrical and Electronic Engineering Department University of Mines and Technology Tarkwa Ghana

The main purpose of the electrical power system is to transport and distribute energy generated by the central power plants in a safe and reliable manner to the customer premises. Most of the electrical equipment is exposed within the open which suggests they can be vulnerable to lightning strikes, road dwindling, windstorms, and a few engineering activities with the potential of causing different degrees of damage to the electrical equipment. One of the ways to guard the equipment is to deploy switching devices. However, the operations of most of these switching devices produce oscillatory transient in the electrical transmission and distribution systems which result in voltage, current, and frequency fluctuations in the load. This paper investigates the effect of switching devices on power quality and proposes a positive sequence voltage power transient suppression technique that can spontaneously improve the distorted voltage at the instant of capacitor switching using the capacitor line model as a case study. MATLAB/Simulink software was utilized for the analysis on an electrical network model with bus voltages of 69 kV/12.47 kV and 480 V. The results showed that, during switching operations, the positive sequence voltage power detector block produces ripple-free accurate results.

关键词： Capacitor Banks Inrush Current Laplace Transform Power Quality Posi-tive Sequence Switching Transient Voltage

Turbulent lock release gravity current

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Science China(Technological Sciences) 2001年第5期44卷 449-462页

作者：陈国谦 joseph H.w.Lee National Laboratory for Turbulence Research Department of Mechanics Peking University Beijing 100871China

The time evolution of a turbulent lock release gravity current, formed by a finite volume ofhomogeneous fluid released instantaneously into another fluid of slightly lower density, was studied byexperimental measurements of the density structure via elaborate digital image processing and by a nu-merical simulation of the flow and mixing using a two-equation turbulence model. The essential fact thatthe gravity current passes through an initial slumping phase in which the current head advances steadilyand a second self-similar phase in which the front velocity decreases like the negative third power of thetime after release is satisfactorily presented by the laboratory observation. An overall entrainment ratioproportional to the distance from the release point is found by the numerical simulation. The renormal-ization group (RNG) k- ε model for Reynolds-stress closure is validated to characterize the gravitycurrent with transitional and localized turbulence.

关键词： turbulence modeling, gravity current, environmental hydraulics.

Positron imaging systems for studying particulate, granular and multiphase flows

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Particuology 2012年第2期10卷 146-153页

作者： Thomas w.Leadbeater David J.Parker joseph Gargiuli Positron Imaging Centre University of BirminghamEdgbastonBirmingham B152TTUKa

The University of Birmingham has pioneered and adapted the use of the medical imaging technique known as positron emission tomography （PET） to the study of particulate, granular and multiphase flows in industrial and physical processes, This paper provides a review of the PET and complimentary positron emission particle tracking （PEPT） techniques and details their application to the study of particulate sys- tems, The current state of the art, recent developments and example results from many of the applications to which these techniques have been applied are highlighted.

关键词： Positron emission particle tracking (PEPT)Particle dynamicsMulti-phase flow measurement

Angiosperm phylogeny inferred from sequences of four mitochondrial genes

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Journal of Systematics and Evolution 2010年第6期48卷 391-425页

作者： Tory A.HENDRY joseph w.BROwN Geordan T.HUDSON Department of Ecology and Evolutionary Biology University of Michigan

An angiosperm phylogeny was reconstructed in a maximum likelihood analysis of sequences of four mitochondrial genes,atp1,matR,nad5,and rps3,from 380 species that represent 376 genera and 296 families of seed *** is largely congruent with the phylogeny of angiosperms reconstructed from chloroplast genes atpB,matK,and rbcL,and nuclear 18S *** basalmost lineage consists of Amborella and Nymphaeales(including Hydatellaceae).Austrobaileyales follow this clade and are sister to the mesangiosperms,which include Chloranthaceae,Ceratophyllum,magnoliids,monocots,and *** the exception of Chloranthaceae being sister to Ceratophyllum,relationships among these five lineages are not well *** eudicots,Ranunculales,Sabiales,Proteales,Trochodendrales,Buxales,Gunnerales,Saxifragales,Vitales,Berberidopsidales,and Dilleniales form a basal grade of lines that diverged before the diversification of rosids and *** rosids,the COM(Celastrales-Oxalidales-Malpighiales) clade is sister to malvids(or rosid II),instead of to the nitrogen-fixing clade as found in all previous large-scale molecular analyses of *** and Caryophyllales are members of an expanded asterid *** study shows that the mitochondrial genes are informative markers for resolving relationships among genera,families,or higher rank taxa across *** low substitution rates and low homoplasy levels of the mitochondrial genes relative to the chloroplast genes,as found in this study,make them particularly useful for reconstructing ancient phylogenetic relationships.A mitochondrial gene-based angiosperm phylogeny provides an independent and essential reference for comparison with hypotheses of angiosperm phylogeny based on chloroplast genes,nuclear genes,and non-molecular data to reconstruct the underlying organismal phylogeny.

关键词： angiosperm homoplasy mitochondrial gene molecular evolutionary rate phylogeny rosids.

The History of Chinese Mathematics-the Founding of the IHNS(CAS)-and the True Story of a wrong Diagram in SCC Volume 3

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Chinese Annals of History of Science and Technology 2018年第2期2卷 86-128页

作者： joseph w.Dauben PhD Program in History The Graduate CenterThe City University of New YorkNY 10016US

The Institute for the History of Natural Sciences in Beijing celebrated the sixtieth anniversary of its founding in 1957 with an international symposium devoted to“China and the world in the Global History of Science and Technology.”2 This contribution to that symposium focuses on the roles that historians of mathematics,East and west,have played in bringing the importance of mathematics in China to the attention of the world at *** concludes by discussing a controversy surrounding the diagram and purported“proof”given in the ancient mathematical classic,the Zhoubi suanjing周髀算經(Mathematical classic of Zhou’s gnomon),of the gou-gu theorem that appeared in volume 3 of joseph Needham’s Science and Civilisation in China,published in 1959.

关键词： Institute for the History of Natural Sciences ⅢICHCS Beijing(1974) Zhu Kezhen Li Yan Qian Baocong Yan Dunjie joseph Needham ⅧICHS Milan(1956) Zhoubi suanjing

Enhanced apoptosis in post-liver transplant hepatitis C:Effects of virus and immunosuppressants

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world Journal of Gastroenterology 2012年第18期18卷 2172-2179页

作者： Eu Jin Lim Ruth Chin Peter w Angus joseph Torresi Liver Transplant Unit Austin HospitalHeidelbergVictoria 3084Australia Department of Medicine University of MelbourneAustin HealthHeidelbergVictoria 3084Australia Department of Infectious Diseases Austin HospitalHeidelbergVictoria 3084Australia

Hepatitis C(HCV)-infected patients have a poorer survival post-liver transplantation compared to patients transplanted for other indications,since HCV recurrence post-transplant is universal and commonly follows an aggressive *** is increasing evidence that in the non-transplant setting,induction of hepatocyte apoptosis is one of the main mechanisms by which HCV drives liver inflammation and fibrosis,and that HCV proteins directly promote *** studies have shown that post-liver transplant,there is a link between high levels of HCV replication,enhanced hepatocyte apoptosis and the subsequent development of rapidly progressive liver *** the responsible mechanisms remain unclear,it is likely that immunosuppressive drugs play an important *** is well known that immunosuppressants impair immune control of HCV,thereby allowing increased viral *** there is also evidence that immunosuppressants may directly induce apoptosis and this may be facilitated by the presence of high levels of HCV *** HCV and immunosuppressants may synergistically interact to further enhance apoptosis and drive more rapid *** findings suggest that modulation of apoptosis within the liver either by changing immunosuppressive therapy or the use of apoptosis inhibitors may help prevent fibrosis progression in patients with post-transplant HCV disease.

关键词： Hepatitis C Liver transplantation Apoptosis Immunosuppressive agents transforming growth factor-β