Electric road vehicles - overview, concepts and research at Reutlingen university

The paper details the architecture of fully electrified vehicles as well as their new electronic systems. Examples of up-to-date electrical passenger cars are given. A very important question, that is the environmental foot-print of electrical vehicles compared to conventional ones, is examined. A research project is introduced where a fleet of two-wheeled vehicles is available for day-to-day use. Research on vehicles, software for fleet management and battery range prediction is described.В данной статье привeдены подробные сведения о принципе работы электрифицированных транспортных средств, а также описаны их новые электрические системы. Показан примеры уже существующих электрических пассажирских транспортных средств. Рассмотрено влияние электрифицированного транспорта на окружающую среду в сравнении с обычными видами транспорта. Приведен проект исследований, в рамках которого для ежедневного использования существует парк двух колесных электрифицированных транспортных средств. Описаны исследования, непосредственно связанные с электрифицированным транспортом, определением точного времени разряда батареи, а также программным обеспечением, позволяющим управлять парком таких транспортных средств.У статті наведено докладні відомості щодо принципів роботи електрифікованих транспортних засобів, а також описано їх нові електричні системи. Показано приклади вже існуючих електричних пасажирських транспортних засобів. Розглянуто вплив електрифікованого транспорту на навколишнє середовище у порівнянні із звичайними видами транспорту. На- ведено проект досліджень, у рамках якого існує парк двоколісних електрифікованих транспортних засобів для щоденного використання. Описано дослідження, безпосередньо пов'язані із електрифікованим транспортом, визначенням точного часу розряду батареї, а також програмним забезпеченням, що дозволяє керувати парком таких транспортних засобів

Characterization of high-temperature PbTe p-n junctions prepared by thermal diffusion and by ion-implantation

We describe here the characteristics of two types of high-quality PbTe p-n-junctions, prepared in this work: (1) by thermal diffusion of In4Te3 gas (TDJ), and (2) by ion implantation (implanted junction, IJ) of In (In-IJ) and Zn (Zn-IJ). The results, as presented here, demonstrate the high quality of these PbTe diodes. Capacitance-voltage and current-voltage characteristics have been measured. The measurements were carried out over a temperature range from ~ 10 K to ~ 180 K. The latter was the highest temperature, where the diode still demonstrated rectifying properties. This maximum operating temperature is higher than any of the earlier reported results. The saturation current density, J0, in both diode types, was ~ 10^-5 A/cm2 at 80 K, while at 180 K J0 ~ 10^-1 A/cm2 in TDJ and ~ 1 A/cm2 in both ion-implanted junctions. At 80 K the reverse current started to increase markedly at a bias of ~ 400 mV for TDJ, and at ~550 mV for IJ. The ideality factor n was about 1.5-2 for both diode types at 80 K. The analysis of the C-V plots shows that the junctions in both diode types are linearly graded. The analysis of the C-V plots allows also determining the height of the junction barrier, the concentrations and the concentration gradient of the impurities, and the temperature dependence of the static dielectric constant. The zero-bias-resistance x area products (R0Ae) at 80 K are: 850 OHMcm2 for TDJ, 250 OHMcm2 for In-IJ, and ~ 80 OHMcm2 for Zn-IJ, while at 180 K R0Ae ~ 0.38 OHMcm2 for TDJ, and ~ 0.1 OHMcm2 for IJ. The estimated detectivity is: D* ~ 10^10 cmHz^(1/2)/W up to T=140 K, determined mainly by background radiation, while at T=180 K, D* decreases to 108-107 cmHz^(1/2)/W, and is determined by the Johnson noise

Photothermal effect in narrow band gap PbTe semiconductor

In this paper we report the observation of photothermal effect in PbTe p-n junction. The effect is expressed in photosignal generation due to illumination by 100 ns pulse CO(2) laser with photon energy less than PbTe forbidden gap

Development of high-precision hardware and software tools for automated determination of the characteristics of thermoelectric devices

In this work, a high-accuracy setup was developed for the characterization of thermoelectric devices in the temperature range of 300-900 K. The output parameters of the thermoelectric devices, including the thermoelectric efficiency Z, Seebeck coefficient S, and internal resistance r, were measured. A technique, block diagram, and computer tools for automated measurement and preliminary processing of experimental data were developed for automated studies of the properties of semiconductor materials and thermoelectric power conversion modules. The developed tools were shown to have high efficiency. The complexity of the process of measuring the main electrical parameters of semiconductor materials was significantly reduced, and the accuracy of the obtained results was increased

Minority carrier transport in p-ZnO nanowires

In this work, we explore the minority carrier diffusion length in zinc oxide nanowires, using the electron beam-induced current technique. Systematic measurements as a function of temperature were performed on p-type, Sb-doped ZnO film, containing a 4 mu m thick nanowire layer. The minority carrier diffusion length exhibits a thermally activated increase with the energy of 74 +/- 5 meV. Electron beam irradiation also causes the diffusion length increase with the activation energy of 247 +/- 10 meV, likely related to Sb(Zn)-2V(Zn) acceptor-complex

Compositionally Graded Organic–Inorganic Nanocomposites for Enhanced Thermoelectric Performance

Thermoelectric generators (TEGs) operate in the presence of a temperature gradient, where the constituent thermoelectric (TE) material converts heat into electricity via the Seebeck effect. However, TE materials are characterised by a thermoelectric figure of merit (ZT) and/or power factor (PF), which often has a strong dependence on temperature. Thus, a single TE material spanning a given temperature range is unlikely to have an optimal ZT or PF across the entire range, leading to inefficient TEG performance. Here, we demonstrate compositionally graded organic-inorganic nanocomposites, where the composition of the TE nanocomposite is systematically tuned along the length of the TEG, in order to optimise the PF along the applied temperature gradient. The nanocomposite composition can be dynamically tuned by an aerosol-jet printing method with controlled in-situ mixing capability, thus enabling the realisation of such compositionally graded thermoelectric composites (CG-TECs). We show how CG-TECs can be realised by varying the loading weight percentage of Bi2Te3 nanoparticles or Sb2Te3 nanoflakes within an organic conducting matrix using bespoke solution-processable inks. The enhanced energy harvesting capability of these CG-TECs from low-grade waste heat (<100 °C) is demonstrated, highlighting the improvement in output power over single-component TEGs

Polimerne mješavine obložene Eudragitom: Potencijalni sustav za kontroliranu peroralnu isporuku teofilina

Sustained release (SR) dosage forms enable prolonged and continuous deposition of the drug in the gastrointestinal (GI) tract and improve the bioavailability of medications characterized by a narrow absorption window. In this study, a new strategy is proposed for the development of SR dosage forms for theophylline (TPH). Design of the delivery system was based on a sustained release formulation, with a modified coating technique and swelling features aimed to extend the release time of the drug. Different polymers, such as Carbopol 71G (CP), sodium carboxymethylcellulose (SCMC), ethylcellulose (EC) and their combinations were tried. Prepared matrix tablets were coated with a 5 % (m/m) dispersion of Eudragit (EUD) in order to get the desired sustained release profile over a period of 24 h. Various formulations were evaluated for drug concentration and in vitro drug release. It was found that the in vitro drug release rate decreased with increasing the amount of polymer. Coating with EUD resulted in a significant lag phase in the first two hours of dissolution in the acidic pH of simulated gastric fluid (SGF) due to decreased water uptake, and hence decreased driving force for drug release. Release became faster in the alkaline pH of simulated intestinal fluid (SIF) owing to increased solubility of both the coating and matrixing agents. The optimized formulation was subjected to in vivo studies in rabbits and the pharmacokinetic parameters of developed formulations were compared with the commercial (Asmanyl®) formulation. Asmanyl® tablets showed faster absorption (tmax 4.0 h) compared to the TPH formulation, showing a tmax value of 8.0 h. The cmax and AUC values of TPH formulation were significantly (p < 0.05) higher than those for Asmanyl®, revealing relative bioavailability of about 136.93 %. Our study demonstrated the potential usefulness of eudraginated polymers for the oral delivery of the sparingly soluble drug theophylline.Pripravci za produljeno oslobađanje (SR) omogućavaju produljeno i kontinuirano oslobađanje lijeka u gastrointestinalnom (GI) traktu i poboljšavaju bioraspoloživost lijekova s uskim apsorpcijskim prozorom. U radu se predlaže nova strategija za razvoj formulacija s produljenim oslobađanjem teofilina (TPH), koja se temelji na sustavu za produljeno oslobađanje, kojem je u svrhu produljenja vremena oslobađanja modificiran način oblaganja i bubrenja. Korišteni su različiti polimeri, kao što su Carbopol 71G (CP), natrijeva karboksimetilceluloza (SCMC), etilceluloza (EC) i njihove kombinacije. Pripravljene matriks tablete obložene su 5-postotnom (m/m) disperzijom Eudragita (EUD) kako bi se postiglo produljeno oslobađanje tijekom 24 h. U pripravljenim formulacijama određena je koncentracija lijeka i in vitro oslobađanje. Rezultati pokazuju da se povećanjem udjela polimera smanjuje brzina oslobađanja in vitro. Oblaganje s EUD značajno je produljilo lag fazu tijekom prva 2 sata otapanja u kiselom pH simuliranog želučanog soka (SGF). Naime, oblaganje usporava ulazak vode i tako smanjuje pogonsku silu za oslobađanje lijeka. Zbog povećane topljivosti obložnog sloja i matriksa u lužnatom mediju, oslobađanje u simuliranoj intestinalnoj tekućini (SIF) je brže. Optimizirana formulacija ispitana je in vivo na zečevima. Farmakokinetički parametri novih formulacija uspoređivani su s komercijalnim pripravkom Asmanyl®. Asmanyl® tablete pokazuju bržu apsorpciju (tmax 4,0 h) u odnosu na TPH formulaciju (tmax 8,0 h). cmax i AUC vrijednosti TPH formulacije bile su značajno (p < 0,05) više od onih za Asmanyl®, što ukazuje na relativnu bioraspoloživost od oko 136,93 %. Stoga smatramo da su polimeri obloženi eudragitom potencijalno korisni za oralnu upotrebu teško topljivog lijeka teofilina

Impact of forward bias injection on minority carrier transport in p-type ZnO nanowires

Minority carrier diffusion length in p-type Sb-doped ZnO nanowires was measured as a function of temperature and forward bias injection duration. The minority carrier diffusion length displays a thermally activated length increase with the energy of 144 +/- 5 meV. The forward bias injection exhibits an increase in diffusion length with the activation energy of 217 +/- 20 meV, indicating the possible involvement of a Sb(Zn)-2V(Zn) acceptor complex

ВЛИЯНИЕ ПРЕДОПЕРАЦИОННОГО НАЗНАЧЕНИЯ ЭНАЛАПРИЛА НА ТЕЧЕНИЕ АНЕСТЕЗИИ ПРИ ОБШИРНЫХ АБДОМИНАЛЬНЫХ ОПЕРАЦИЯХ У ПОЖИЛЫХ ПАЦИЕНТОВ

Objective: to evaluate the impact of preoperative use of angiotensin-converting enzyme inhibitors on hemodynamics in elderly patients. The use of enalapril on the day of surgery in patients lowly tolerant to transient hypoxia and hypercapnia was accompanied by hemodynamic instability during anesthesia and by the higher frequency of vasopressor usage. The hemodynamics of patients moderately tolerant to transient hypoxia and hypercapnia did not depend on the intake of enalapril. Цель работы - оценка влияния предоперационного применения ингибиторов ангиотензинпревращающего фермента на гемодинамику у пожилых пациентов. Приём эналаприла в день операции у пациентов с низкой толерантностью к транзиторной гипоксии и гиперкапнии сопровождался нестабильностью гемодинамики в течение анестезии и увеличением частоты применения вазопрессоров. Гемодинамика пациентов со средней толерантностью к транзиторной гипоксии и гиперкапнии не зависела от приёма эналаприла