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In this paper is presented experimental investigation of dynamic characteristics of electromagnetic contactor with Hightemperature superconductive (HTS) coil in liquid nitrogen. Transient characteristics of armature dynamics and current during electromagnet switching are presented and analysed. HTS coil could provide reduced electric energy consumption in long term operation by active coil resistance reduction, improving this way electromagnetic contactor energy efficiency. Estimation of electromagnetic contactor with HTS-2G coil energy consumption is also presented.

New results on the effect of TiO2 on Pd/La2O3-CeO2-Al2O3 systems for catalytic oxidation of methane in the presence of H2O and SO2 have been received. Low-temperature N2-adsorption, XRD, SEM, HRTEM, XPS, EPR and FTIR techniques were used to characterize the catalyst. The presence of Ce3+ on the catalytic surface and in the volume near the lantana was revealed by EPR and XPS. After aging, the following changes are observed: (i) agglomeration of the Pd-clusters (from 8 nm to 12 nm); (ii) transformation of part of the TiO2 from anatase to larger particles of rutile; and (iii)—the increase in PdO/Pd—ratio above its optimum. The modification by Ti of the La2O3-CeO2-Al2O3 system leads to higher resistance towards the presence of SO2 most likely due to the prevailing formation of unstable surface sulfites instead of thermally stable sulfates. Based on kinetic model calculations, the reaction pathway over the Pd/La2O3-CeO2-TiO2-Al2O3 catalyst follows the Mars–van Krevelen mechanism. For evaluation of the possible practical application of the obtained material, a sample of Pd/La2O3-CeO2-TiO2-Al2O3, supported on rolled aluminum-containing stainless steel (Aluchrom VDM®), was prepared and tested. Methane oxidation in an industrial-scale monolithic reactor was simulated using a two-dimensional heterogeneous reactor model. [ABSTRACT FROM AUTHOR]

Introduction: Prostate carcinoma (PC) is the second most diagnosed cancer in men worldwide. Prostate tissue in needle biopsy expresses a wide variety of architectural patterns some of which are difficult to interpret. Immunohistochemical markers, such as AMACR, p63 and 34βE12 that are currently used in diagnosing prostate cancer, are of great value, but often their interpretation is ambiguous. In 2005 Tomlins et al. identified an emerging marker, erythroblastosis E26 rearrangement gene (ERG), which is a member of the family of genes encoding erythroblast-transformation specific transcription factors (ETS) with frequent expression in PC.

Use-wear studies have identified a long-lasting system of agricultural practices (harvesting) from the very beginning of the Early Neolithic in Bulgaria. For almost two millennia during the Neolithic and Chalcolithic (6th and 5th millennia BC), the archaeological evidence suggests the use of sickle elements based on blade segments and tools on blades inserted obliquely in a curved handle - the well-known Karanovo type of sickle. Post-Chalcolithic times are marked by a shift in the harvesting toolkit. This paper focuses on agricultural toolkits from three recently discovered and excavated sites in north Bulgaria: Oreshets near Belogradchik, Rasovo near Montana, and Chavdartsi in Lovech district. The sites are multilayered, the flint assemblages presented here belong to the LBA (Oreshets and Chavdartsi) and LBA/EIA (Rasovo). No structures or features directly associated with the flint artefacts were identified, but the assemblages exhibit most (if not all) of the characteristics of the BA and post-BA agricultural repertoire. This repertoire includes varieties of denticulates (mainly blades) which from the beginning of the BA became diagnostic finds and marked a momentous shift from the preceding style of sickle. During the BA sickle inserts and blades were increasingly shaped through truncation and backing, both of which aided the accommodation of the implements in grooved handles and handheld tool manipulation. As an innovation, the emergence of which is difficult to fix chronologically within the BA, large, curved blades (ca 15 cm) appear in the agricultural toolkit during the LBA, with reminiscent use in the EIA as well. [ABSTRACT FROM AUTHOR]

Conventional robotic systems in agriculture are driven by operator control or are those that move along an established path. Unfortunately, however, in the field an established path is a very conditional concept. It is not possible to fix the route along which the robot will move, because different crops alternate on the same field. It is necessary to assess whether the robot is taking samples from the terrain and the crop, whether it will perform a plant protection event or other type of operation. Plant protection operations are accompanied by a constant change in the mass of the agricultural robot. During the operation, the mass of the sprayed solution decreases. This change leads to a decrease in its resistance. In order to be able to design an agricultural robot, it is necessary to establish its stability in different terrains. This article discusses the main points in determining the longitudinal sustainability of agricultural robots. Dependencies for the conditions of sustainability of the agricultural robot when climbing and descending are derived. The article is an overview and helps to determine the robot's resilience faster. [ABSTRACT FROM AUTHOR]

Problem Statement and Purpose: Soccer is a sport characterized by high intensity and duration. The energy needed to play a soccer match is provided by aerobic metabolism. Therefore, it is important to determine such parameters as oxygen consumption and maximal oxygen consumption in soccer players. The aim of the study is to track the changes in the functional indicators of professional soccer players during the spring half-season and to give recommendations for changes in the training plan to increase their performance and reduce fatigue at the end of the season. Approach: The study involved 13 professional soccer players and was conducted in the period January - June. Functional examination of respiration - spirometry and determination of gas exchange parameters during exercise - spiroergometry were performed twice at the beginning and at the end of the period. Results: The spirometry data of the subjects showed values close to the predicted values. The decrease in values at the end of the spring half-season is probably due to the fatigue accumulated during this period. Although the values show a decrease in the parameters, there is no statistically significant difference in the two measurements of the Tifno index, but there is a statistically significant difference in the decrease in VC (Wilcoxon signed rank test, p value = 0.04) and FEO1 (Wilcoxon signed rank test, p value = 0.0002). The fact that even the indicators at the beginning of the study are to some extent underestimated, shows the accumulation of fatigue in the players and the need to rethink the overall training plan with corresponding individual approaches to each soccer player in order to optimize the training-recovery ratio. There was a slight increase (statistically insignificant) in mean VO2max and VO2max/kg during the spring half-season, indicating that training resulted in an increase in aerobic capacity. This is an indication that conditioning training is producing the desired result and can be carried out without any major changes. Conclusions: The benefit of periodic medical and functional examinations of football players is mainly in two directions. First, it provides information about the current state of health of the athlete under study and his fitness to participate in training and sports competitions. And, secondly, it enables the coach, analyzing the results, to assess the specific functional capabilities of the football players, to make changes in the training schedule and specific exercises, to pay attention to recovery and to apply an individual approach to each specific case in order to improve specific indicators. [ABSTRACT FROM AUTHOR]