Isolated mitral valve replacement with Guangdong-Ⅰ porcine bioprostheses in rheumatic heart valve disease: analysis of 166 cases with long-term follow-up

Objective To study the long-term effects of mitral valve replacement with bioprostheses in rheumatic heart valve disease. Methods 166 patients with rheumatic heart valve disease underwent isolated mitral valve replacement from Jan. 1978 to Dec. 1985. 79 Patients were male and 87 female. Patients’ age ranged from 11 to 53 years [mean (29.4 ± 9.9) years]. The patients were classified into two groups: group 1 (age【 30 years) included 84 patients, group 2 (age≥30 years) 82 cases. Mean CTR is 0.68 *0.08. Most patients were in NYHA function class Ⅲ-Ⅳ. 76. 3% of patients had atrial fibrillation. 6 patients had pre-operative cerebral vascular accidents. Postoperative deaths were excluded. Follow-up extended from 0.4 year to 19.4 years. Results Actuarial estimate of survival rate at 14 years is (52.5 ± 7.0)%. Heart function was improved to class Ⅰ - Ⅱ in most of patients. Late structural valve deterioration occurred in 89 patients. Among them, 59 were re-operated. Actuarial estimate of freedom from

Theoretical Analysis on Thermal Choking in Expanding RBCC Duct

A one-dimensional theoretical model was adopted in this paper to describe and analyze the flow in an expanding RBCC(rocket based combined cycle)duct.It can be concluded that the expanding angle,heating amount and distribution of heating play crucial roles on the thermal choking.They mainly influence the acceleration of flow,the position of choking throat and the total pressure loss.In order to fulfill the transition of subsonic flow to supersonic flow in the expanding RBCC duct,the heating amount has to change from a bigger value to a smaller one along the duct.When the thermal choking occurs in the RBCC duct,the moderate expanding angle,proper heating amount and distribution of heating are necessary for the best performance of RBCC combustor.Adopting the RBCC duct with smaller expanding angles anterior and bigger expanding angles posterior has positive effects on the thermal choking and flexibility of selecting heating method,and can restrain the negative effect of the combustion on the inlet also.

Dynamical Analysis of DC Shunt Motor Powered by PV Generator Using Perturbation and Observation as MPPT Technique

This paper presents the perturbation and observation (P & O) algorithm as maximum power point tracking (MPPT) method for the dynamical analysis of DC shunt motor fed by photovoltaic generator at different solar irradiance levels. At each solar intensity, the maximum power point of current/voltage (I/V) characteristic of the PV generator is achieved by perturbation and observation algorithm. The nonlinear behavior of (I/V) characteristics of the PV generator at various solar intensities and the magnetization curve of the ferromagnetic material of the DC shunt motor are described by high order polynomial mathematical expression. The dynamical analysis of the DC shunt motor fed by PV generator at different solar intensity has been carried out, also the dynamical analysis of DC shunt motor is investigated at a step change in solar intensity levels with fixed load at motor.

Simulation and Experimental Analysis of Vortex Tube Using Steel Material

Experimental and computational fluid dynamics (CFD) are investigated through the vortex tube system. The benefit of vortex tube is a counter flow type tube, which has further designed and fabricated for investigation. The whole set up is consisting of a simple device that can separate a single stream of compressed air into two streams;one is at high temperature and the other is lower temperature following an inlet gas stream. The advantages of this tube are their compactness, safety, and low equipment cost mainly used in cooling and heating applications. This study addressed three-dimensional flows;the domain is using computational fluid dynamics (CFD) method and experimental approach to optimize the direction of RHVT. Through the CFD analysis, the best cold end diameter (dc), number of nozzles, and the best parameters for obtaining the highest hot gas temperature and lowest cold gas temperature were obtained and verified by experimental procedures.

Screw Analysis of Head Broken in Process

The screw defective products is found in process course. The most important defect is the head broken so it will be paid attention to. In this paper the kind of process is analyzed so that the work harding is the main cause, which is concluded. The present paper is to cause skilled worker and related engineer′s attention and advices.

A Genre Analysis of Online English Job Advertisement

In the recent years, posting online job advertisements has become a major way for a growing number of multinational cor-porations to publicize their employment information and to recruit job seekers. Nevertheless, the language and space of online jobadvertisement are uneven, which may affect the companies to attract and communicate with the potential candidates. Based on thetheoretical framework of moves and steps analysis suggested by Swales(1990) and Bhatia(2004), the study aims to explore thestructural pattern of this genre and to examine the lexico-grammatical features of each move and step. After analyzing four piecesof job advertisements retrieved from different recruiting websites, the study reveals that there are six moves in the whole structureof online job advertisement, among these, three moves are obligatory, named: establishing credential, introducing the position, to-gether with specifying required qualifications, skills, and experiences. Meanwhile, in each move, the positive adjectives, verbs, andfirst person are frequently used to serve the promotional function, and therefore to intensify the communicative purpose. The studymay contribute to the application of genre analysis in business English teaching, and also be instructive to the reading and writingof online job advertisement.

Design Optimization of Cam &Follower Mechanism of an Internal Combustion Engine for Improving the Engine Efficiency

The current cam and follower mechanism in four stroke internal combustion engine employs a flat follower. In this work an attempt is made to change the flat face of follower to a curved face follower, so that the required point contact can be achieved. As line contact between existing cam and follower mechanism results in high frictional losses which results in low mechanical efficiency. It is observed that the frequency of vibration in the existing and modified cam and follower mechanism remains almost same. The finite element approach is used to perform the analysis.

Differences in Morphological, Physiological and Growth Traits between Two Endemic Subspecies of <i>Brassica rupestris</i>Raf.: Implications for Their Conservation

The goal of this work was to analyze the phenological and physiological responses of Brassica rupestris Raf. subsp. hispida Raimondo & Mazzola and Brassica rupestris Raf. subsp. rupestris to environmental factors also in consideration of global change. We used seedlings of the two subspecies originated from wild plants from the natural habitats in Sicily and cultivated in the Botanical Garden of Rome. Leaf morphological and physiological traits and growth dynamic were analyzed as well as the response to an imposed water stress experiment. The results underlined a higher relative growth rate in plant height (RGRH, cm·cm-1·d-1) in B. rupestris subsp. rupestris also attested by the highest plant height (H, cm), leaf area (LA, cm2), specific leaf area (SLA, cm·g-1), total leaf area per plant (TLA, cm2) and total plant dry mass (PDM, g plant-1). Moreover, the significantly highest net photosynthetic rates (A, μmol CO2 m-2·s-1) during the study period of this subspecies was related to the high Chlorophyll content (Chl, SPAD units). B. rupestris subsp. rupestris was also the most tolerant subspecies to imposed water stress showing the highest relative water content (RWC, %), A and water use efficiency (WUE, μmol·mmol-1).

Systematic Biological Upgrade of a Urea Fertilizer Effluent Treatment Plant Using GPS

The use of modeling and simulation has developed into a critical tool for the sustainable management of wastewater, especially when it comes to replicating the complex biochemical procedures required for fertilizer effluent treatment, which calls for a significant amount of wastewater-related data. The biological improvement of a urea fertilizer effluent via GPS* simulation was carried out in this work using a methodical process. Using established analytical techniques, temperature, total suspended solids (TSS), biochemical oxygen demand (BOD), total phosphorus (T/), chemical oxygen demand (COD), total nitrogen (TN), total nitrate (NO3), electric conductivity (EC), turbidity, residual chlorine, urea, NH3, and heavy metals (Cu, Cd, Cr, Pb, Ni, and Fe) were assessed. The research revealed that the measured values from the fertilizer factory outfall effluent had high concentrations of all the physicochemical water quality indicators, with the exception of TSS, PO4-, SO4-, and NO3-. These concentrations are higher compared to the authorized limits or suggested values by the Federal Environmental Protection Agency (FEPA). To improve the therapy biologically, however, a modeling and simulation program (GPS-X, version 8.0) was used with the physicochemical information gathered from the studied sample. The results of the treated water simulation showed that the concentrations of BOD5 and COD had been significantly reduced by 35% and 44%, respectively. Additionally, it was discovered that total phosphorus (TP), nitrate (N), and total nitrogen (TN) were all within the permitted FEPA limit. The results revealed good treatment performance of the wastewater with increasing concentration of acetic acid and sodium hydroxide. Hence, the results of this research work identify the need for proper treatment of fertilizer industry effluents prior to their release into the environment.

Port Logistics in West and Central Africa: A Strategic Development under Globalization

The main idea of this study is to provide help to West and Central Africa port logistics authorities in making, evaluating and realizing their decisions on port development/management, all in an effort to guaranty port efficiency and operational brilliance to profit the different ports, their hinterlands and their related clients. Consequently, an examination is made as far as port sector is concerned, with an ever more demanding enhancement in operational efficiency. Moreover, a past research on West and Central Africa Ports, as well as an overview on port logistics was made, making it possible to determine what has been done (prospects) and what is still to be done (ineffectiveness), in prospective of a more reformed and efficient port. One of the principles of this paper is also to confer all the aspects that operate as obstacles to the WCA port’s improvement and development;using thus the evaluation model called EWCA (Evaluation of West and Central Africa Ports), which gives a descriptive analysis of the present situation of the latter’s port logistics, including the aid of multiple regression model to determine an impact of explanatory variables on the study probability. Applying the method of strategic development, this paper thus deals with exploring typical problems and quandaries of West and Central Africa ports. The findings suggested how to fight back or overcome the constrictions and strangulations;enabling West and Central Africa port logistics attain their desired strategic development aims, despite the ineffectiveness. Tremendous efforts were made, giving a vital shoot on African economy and development;even though there is still a lot to do, for the data and variables showed how the port logistics augment and descend frequently without a long period of stability.

IML信息安全策略风险评估模型与应用研究

随着企业信息化战略的不断深入与拓展,增强信息安全意识与建立信息安全体系也成为广泛共识。信息安全策略是决定信息化战略成败的关键之举。基于全面系统风险分析与评估(Overall System Risk Analysis&Valuation)理念的IML信息安全策略取得了长足发展。从集约性风险(Intensivism Risk)多极性风险(Multipolar Risk)和层次性风险(Layers Risk)三方面高效地评估信息安全策略风险成为其核心特点。本文将深入探讨IML信息安全策略风险评估模型及其主要新应用。

Construction and application of Markov model for followup data

Objective: To construct Markov model for clinical follow up data and predict the number of survivals and deaths. Methods: The state of patients was classified into survival. death and censorship. The weighted least squares method was used for estimating parameters. Results: Markov model for survival analysis of follow--up data was presented. By using an example, the transition probability matrices were obtained and the number of survivals and deaths at each observation point was predicted respectively. Conclusion: Markov model constructed in the present study to analyze clinical follow up data could be used as effective supplemention for life table analysis.

Mechanisms of the Deterioration of the Wall Reliefs at Shenhur Temple, Upper Egypt and Concepts for Conservation

The Roman Period temple of Isis at Shenhur was built and enhanced amid the rule of Augustus (30 BCE-14 CE) through that of Trajan (98-117 CE). It was built of two sorts of local limestone and decorated with reliefs. Examination of conservation state uncovered that it was collapsed and only partly preserved and it disposed of some still buried rooms. The temple is exposed to different deteriorations processes created by internal and external stresses because of the mineral composition of the building materials, atmosphere variables, salts crystallization and groundwater. In this study, the deterioration problems of the wall reliefs were examined for the aim of its conservation. For this purpose, the chemical, physical and structural characterization were performed by means of X-Ray Diffraction (XRD) and observation of thin section by transmitted light optical microscopy (LOM), polarized microscope, Scanning Electron Microscope (SEM) attached with EDX and thermogravimetric (DTA & TGA). Additionally, microbiological study and chemical analyses of ground water were carried out. Results demonstrated that the deterioration of Shenhur was because of the forceful activity of the environment agents and soluble salts such as chlorides and sulphates. These results and information allowed that the identification of the types of salts and deterioration features might be used in the future for conservation purposes.

Study on Plant Management Information System Based on Intranet for HongHe Cigarette Factory

Accompanying with the development of computer technology and network technology, enterprises have built their Intranet. This paper is dealing with how to construct the plant management information system based on Intranet, and lays emphasis on the subsystem division using structural system analysis and design method.

The Impact of Different Graduate Programs on Evaluating Chinese Graduate Schools

：The traditional evaluation on Chinese graduate schools usually focus on the comprehensivefactors of master's and doctoral programs. This paper attempts to test a hypothesis on the relationshipbetween graduate programs and the ratings of Chinese graduate schools. The educational evaluation historyboth in the U.S. and in China is briefly reviewed and compared. A case study is performed by using part ofthe graduate schools' data from Chinese polytechnic universities in 1994. The comprehensive factors thataffect the graduate schools' scale are examined. The result indicates that different graduate programs doaffect graduate schools' ratings. Two comprehensive factors are obtained from several indicators representingmaster's scale and doctoral scale respectively. The paper also intends to help provide a new evaluationmethod in ranking graduate schools' scale.