Determining electrical losses of the traction drive of electric train based on a synchronous motor with excitation from permanent magnets

Iдентифiковано параметри iнвертора напруги тягового приводу на базi синхронного двигуна зi збудженням вiд постiйних магнiтiв. Синтезовано iмiтацiйну модель тягового приводу, що дозволяє отримати миттєвi значення електричних втрат в iнверторi та двигунi. Проаналiзовано залежнiсть електричних витрат вiд швидкостi руху поїзда та тактової частоти iнвертора

The efficiency of using synthesized fertilizers via foliar feeding and drip irrigation in various soil and climatic zones of the Republic of Armenia

In the current research paper, a new water-soluble combined fertilizer (WCF) is introduced, the composition of which is determined via the agrochemical composition of the soils of Armenia, and besides, its effectiveness has been further investigated. It has been established that when applying the recommended fertilizer through foliar feeding or soaking the seeds, the yield is significantly increased and its quality is improved. Under the impact of WCF, the yield increase compared to the NPK variant was as follows: for winter wheat under non-irrigated conditions – 5.1 c/ha, for tomato – 49 c/ha, for grapevine – 20 c/ha, while when using 20:20:20 the increase in yield capacity was 10.0 c/ha, 3.7 c/ha, and 8.0 c/ha, respectively

Justification of the Structure of the Electric Traction Drive of the Electric Locomotive for Railway Quarry Transport

Purpose. The study is aimed at substantiating the structure and determining the main parameters of the traction electric drive of an electric locomotive for railway quarry transport, taking into account its modes of operation. Methodology. The research was carried out by means of mathematical modeling, which included solving the traction problem and evaluating the parameters of the energy exchange processes between the components of the traction electric drive. The simulation was carried out for the movement of the train along the track section and during shunting, which differ significantly in their mathematical description. During simulation of movement along the track section, the traction problem was solved using recommendations for traction calculations for train operation. A simplified model was developed to simulate movements during shunting. Determination of the parameters of the traction electric drive components is carried out by analyzing the processes of energy exchange in the traction electric drive based on the power balance. During the studies, it was assumed that the on-board energy storage in the traction mode feeds the traction electric motors of the booster section. In the electrodynamic braking mode, the energy accumulator stores energy from all traction electric motors of the electric locomotive. Findings. The authors obtained time dependences of the parameters that characterize the train movement at all stages of the cycle «empty half passage – loading – loaded half passage – unloading» (on the example of an electric locomotive for PJSC «Ferrexpo Poltava Mining»). The analysis of the obtained dependencies made it possible to determine the parameters of the main components of the traction electric drive for the proposed storage operation scenario. It was established that the energy capacity of the energy storage should be 250 kWh for one movement cycle. The energy storage power is 6000 kW. Originality. The authors of this paper for the first time proposed the structure of the traction electric drive of an electric locomotive for quarry railway transport, in which the electric motors of the control electric locomotive are powered from the catenary network, and the electric motors of the booster section are powered from the energy accumulator and are included in the operation at a load that exceeds 50% of the nominal one. Practical value. The practical value lies in the developed mathematical models of movement and energy exchange processes, which can be applied to the study of traction electric drives of vehicles of various purposes

Right heart function interacts with left ventricular remodeling after CRT: A pressure volume loop study

Cardiolog

Anhedonic-like traits and lack of affective deficits in 18-month-old C57BL/6 mice: Implications for modeling elderly depression.

The prevalence of depression increases with aging. We hypothesized that like humans, old animals exhibit anhedonic-like behavior, along with signs of behavioral despair. In rodents, anhedonia, a reduced sensitivity to reward, which is listed as a core feature of major depression in the DSM-IVR, can be measured by a decrease in intake of and preference for sweet solutions. Here, sucrose intake, forced swimming, immobility in the modified tail suspension test, novelty exploration, grooming, anxiety and locomotor activity were compared in naive 3- and 18-month-old male C57BL/6 mice. The absolute amounts and the ratio of consumed 1% sucrose solution to water intake was significantly smaller in 18-month-old mice than in 3-month-old mice. The consumption of 5%-sucrose solution requiring high levels of drinking effort, novelty exploration in two setups and grooming behavior in the splash test were reduced in older animals. Analysis of other behaviors suggested that the above-mentioned signs of anhedonic-like traits were unlikely to be attributable to the potential effect of aging on metabolic needs for water, taste perception, motor capabilities or the induction of essential anxiety and neophobia. A 4-week treatment with the antidepressant imipramine (7mg/kg/day) or dimebon, a compound with suggested neuroprotective proneurogenic properties (1mg/kg/day) restored sucrose intake and preference in 18-month-old mice. Meanwhile, young and old mice showed no differences in the parameters of behavioral despair evaluated in the forced swim and modified tail suspension tests. Thus, the behavioral profile of aged mice parallels that of humans with elderly depression, in whom the symptoms of hedonic deficits typically outweigh affective disturbances. The assessment of anhedonic-like traits with the sucrose preference test in 18-month-old mice will be useful in preclinical studies of elderly depression