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Vasile Andrei, Cornel Marin and Alexis Negrea

Abstract

According to the IWA norms, the water loss category includes also the apparent loss water due to measurement errors of the water meters used at the connections. This paper presents the experimental results obtained during two years of registrations in TARGOVISTE’s Water Company network. A program for verifying the water meters used for connections has been implemented according to a statistical distribution, depending on the number of appliances and their dimensions. Using a theoretical simulation model, calibrated on the basis of the actual reference flows measured on the metrology approved measuring stand, a procedure was developed to assess the level of deviations in the fully metered water distribution network. Depending on the values of deviations and flows actually recorded by the meters in the distribution network, it was possible to estimate the percentage of the losses from the actually used water meters.

Open access

Ghiţă Bârsan, Vasile Năstăsescu and Vlad-Andrei Bârsan

Abstract

The paper is based on the experience gained in creating eLearning courses to keep the student’s interest high, to encourage them to study additional materials in order to achieve the level of complexity proposed by the discipline objectives. The combination of specific gaming-techniques with simulation elements has been combined into designing the e-learning content. The degree of motivation and the interest in the discipline were appreciated by comparing the results obtained by students attending a blending-learning to those students who did the didactic activities in the traditional way. At present, there is a decrease in students’ interest in technical subjects. On one hand, the complexity of these disciplines is high, and moreover, in order for the students to achieve the didactic objectives of the discipline, they must make a sustained effort and combine the individual study with the explanations in the classroom.

Open access

Nicolae Vasile, Bogdan Tene, Andrei Nedelschi, Nicolae Fidel and Ionuţ Craiu

Abstract

The paper deals with the concept of autonomy of electrical systems, which is becoming more and more present, in the context in which the electric-non-electric relation existing on the market is constantly changing in favor of electricity. The factors influencing this trend come from imposing the principles of Sustainable Development, the exhaustiveness of fossil forms of energy, technological advances in the electrical and electronic components industry and their connection with computers. Evolution of Smart Grid, Smart Grid, Smart City, Smart Building, Smart Transport, etc. provides a global electronic system that will power and control most of the economic activity.

Open access

Russu Eliza, Mureşan Adrian Vasile, Cordoş Bogdan Andrei, Cotoi Ovidiu Simion and Copotoiu Constantin

Abstract

Objective: Starting with the ‘Vinyon-N-revolution’ of the 50’s, there has been a constant interest in understanting tissue integration, or the so-called graft healing process, as well as its relationship with infection. In this study we present an experimental animal model designed to assess tissue integration of different graft materials, and their reaction to the presence of infection.

Methods: Synthetic grafts (knitted Dacron®, woven Dacron®, silver-impregnated Dacron® and Gore-Tex®) were implanted subfascially in the interscapular region of Wistar rats. Animals were divided into a control group and an infected group, with infection induced using bacterial suspensions of standard strains of Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli. Implants were retrieved at 2 and 4 weeks postoperatively in the control group and at 1, 2 and 3 weeks postoperatively in theinfected group. Retrieved grafts were assessed bacteriologically and morpho-pathologically.

Results: All microorganisms produced clinically evident infections, with positive blood cultures in case of E. coli. Staphylococci produced more massive infections on Dacron® grafts, except for the silver-impregnated version, while E. coli produced more significant infections on Gore-Tex® grafts. Morpho-pathologically Dacron® grafts behaved poorly, with ocassional complete structural compromise, and no difference between the conventional and the silver-impregnated type. The Gore-Tex® graft showed a consistent structural resistance throughout the study period.

Conclusions: Although the silver-impregnated graft inhibited bacterial growth, it was poorly tolerated by the host tissue. In contrast, Gore-Tex® grafts showed more massive infection, especially with E. coli, but kept their structural integrity surprisingly well.

Open access

Eliza Russu, Adrian Vasile Mureșan, Bogdan Andrei Cordoș, Constantin Copotoiu and Ovidiu Simion Cotoi

Abstract

Objective: Tissue integration of vascular grafts partially depends on the host response to injury, which immediately begins after implantation and restoration of the circulation. In an infected environment, the inflammation changes the incorporation patterns. The aim of the study was to observe the tissue incorporation process, in a normal and an infected environment. Methods: We have created an experimental model by performing subfascial implantation of four types of vascular grafts, in rats (woven Dacron®, knitted Dacron®, silver coated Dacron® and expanded Polytetrafloroethylene - ePTFE) and by infecting some of them with three different bacterial strains. We have retrieved the noninfected grafts at two and four weeks after implantation, whilst the infected ones at one, two and three weeks. Results: Detailed microscopic appearences were analysed. The control and infected groups were compared. Statistical significance was calculated for various corelations. Conclusions: The morphopathological findings showed that the ePTFE graft’s structure was best preserved. Statistical significance existed between the bacterial strain and the degree of inflammation. The silver coated Dacron® was not shown to be superior to the knitted Dacron®. The poorest incorporation was the one of the woven Dacron®.

Open access

Alina Scridon, Marcel Perian, Teodor Grigoraş, Vasile Bogdan Halaţiu, Adriana Vântu, Alkora Ioana Balan, Ionela Alexandra Cosma, Asmaa Carla Barmou, Bogdan Andrei Finascu, Diana Lavinia Moldovan, Dan Alexandru Cozac and Răzvan Constantin Şerban