Stimularea artificială a motilităţii tractului gastrointestinal cu nanoparticule semiconductoare.

Articolul se referă la nanomedicină, în special, la tractul gastrointestinal (TGI), în cazurile când motilitatea normală este perturbată din diverse motive. Metoda nouă permite stimularea la distanţă a motilităţii gastrice, duodenale, intestinale prin implantarea nanoparticulelor semiconductoare în peretele tractului digestiv şi excitate cu câmp ultrasonor din exterior. Nanoparticulele semiconductoare permit extinderea gamei de metode miniinvazive destinate stimulării artifi ciale a motilităţii TGI şi nu provoacă necroză în locul de aplicare. Nanostructurile în baza GaN au un rol important în procesul de stimulare a motilităţii TGI acţionând în calitate de microbaterii ce adaugă potenţialul electric necesar pentru a genera contracţia tactului gastrointestinal

Dizajniranje in analiza termičnega modeliranja notranjosti električnega avtobusa

The heating, ventilation and air-conditioning (HVAC) system represents the main auxiliary load for any type of bus. Being the most significant energy-consuming auxiliary load for the electric bus, it must be given special attention in an electric bus system design. To study the heat transfer and thermal optimization for passenger comfort in the electric bus computer-aided design (CAD) is used. The geometry of an electric bus interior is designed considering the main components of the vehicle: passenger cabin, driver’s cabin, windows, walls, and seats. Materials of the same type as those used in the real bus are considered for the geometry model. Based on the heat transfer theory, a thermal model and simulations are made for the heat transfer inside the electric bus. The simulated data are compared with measurement data, and based on these, it can be concluded that the thermal model of the electric bus can be validated and used further for a wide variety of thermal simulation types.Sistem ogrevanja, prezračevanja in klimatizacije (HVAC) predstavlja glavno dodatno obremenitev za vse vrste avtobusov. Ker gre za sistem z največjo porabo energije pri električnem avtobusu, mu moramo posvetiti posebno pozornost pri dizajniranju električnega avtobusa. Pri študiji prenosa toplote in optimizaciji v smislu udobja potnikov smo uporabili računalniško podprto dizajniranje (CAD). Postavitev notranjosti električnega avtobusa je zasnovana glede na glavne komponente vozila: prostor za potnike, prostor za voznika, okna, stene in sedeže. V oblikovanem modelu so uporabljeni materiali iste vrste kot v realnih avtobusih. Na podlagi teorije o prenosu toplote smo naredili model in simulacije prenosa toplote znotraj električnega avtobusa, nakar smo primerjali podatke iz simulacije s podatki iz meritev. Iz izvlečkov omenjene primerjave lahko zaključimo, da je termični model električnega avtobusa mogoče validirati in nadalje uporabiti za najrazličnejše termične simulacije

CHARACTERISTICS OF REFUSALS IN LOW-VOLTAGE DISTRIBUTION SYSTEMS

This paper focuses on the determination of the characteristics of refusals in low voltage electrical distribution systems. In order to solve this problem, the phenomena of occurrence of refusals in low-voltage electrical distribution systems, conditioned by different influencing factors, processed and mathematically modelled. The main results of the research consist in establishing the static characteristics of the refusals, the mathematical models that determine the occurrence of the cause phenomena and the parameters that characterize the distributions of the refusals, depending on the occurrence per system, depending on the occurrence per season, depending of interruptions duration and the number of affected consumers. The significance of the results obtained consists in solving a number of problems faced by the operating services of electrical distribution systems, concerning the assurance of reliability of operation, providing the possibility of forecasting and preventing the occurrence of the phenomena of occurrence of refusals, which enable the justified planning of prophylactic measures and ensuring the reliability level

Integration of a Self-Excited Induction Generator in a Low Power Multisource Remote Site

In this paper a comprehensive analysis and a testing process are proposed for investigation of a self-excited induction generator working as integrated source in a low power multisource remote site. For its integration, a reliable scheme is defined and several tests are carried out with a laboratory test bench to evaluate the induction generator stability. The analysis defines a preferential operation area for each machine and the testing process reveals the evolution of the voltage stability during transients by a comparative study between autonomous mode and a mode where the induction generator is connected to a multisource DC bus. In order to avoid the voltage collapsing and the demagnetization of the machine it is necessary to identify its parameters and to define its operating working area where the best stability can be obtained as well as the limits of the load variation. The analytical model used to provide the working area is presented in the paper and also the experimental results which show the significant incensement of the load variation interval for the self-excited induction generator connected to a multisource site