scholarly journals Study of the characteristics of external noise of dual-powered electric locomotive

2019 ◽  
Vol 78 (2) ◽  
pp. 105-113
Author(s):  
M. Yu. NOSKOV ◽  
N. S. NESTEROV ◽  
Yu. A. KHLOBYSTOV
Keyword(s):  
Experimental Studies ◽  
Alternating Current ◽  
External Noise ◽  
The Body ◽  
Constant Current ◽  
Sound Insulation ◽  
Stationary Mode ◽  
Electric Locomotive ◽  
Regulatory Requirements ◽  
Sound Levels

The article presents the results of tests of a freight dual-system electric locomotive 2EV120 when operating in stationary mode and moving at normalized speed. In the course of conducting experimental studies of the sound level of external noise during operation of a locomotive at a constant and alternating current, exceeding the regulatory requirements at individual observation points was found, and it was noticed that the operation of the traction transformer is the main source of increased noise, the main component of which is air in this case. It has been established that in the sound field formed around an electric locomotive operating in the parking lot, the distribution of sound levels is uneven. An example, given in the article, describes the distribution of sound levels when an electric locomotive is operated on alternating current before and after the application of noise protection measures. In the process of testing, a set of organizational and technical measures was developed, the implementation of which reduced the external noise of the electric locomotive 2EV120 as a whole to the regulatory requirements. In particular, to reduce the noise from the operation of the traction transformer, as one of the options, it is proposed to install a shielding device in its sub-body part, the minimum efficiency of which was 4.2 dBA. Analysis of the regulatory margin for external noise showed that its value at the observation point located opposite one of the operating traction transformers equipped with a shielding device is minimal. One of the reasons for this in this case is the sound energy penetrating through the body covering of a large area, generated by the work of the locomotive's internal equipment. In order to increase the regulatory margin when the 2EV120 electric locomotive is operating at a constant current, the authors propose the following: to strengthen the sound insulation capacity of the thin-walled body plating of the electric locomotive by installing a double-wall sound-insulating structure with sound-absorbing material inside it.

Results of tests on the indicator of external noise of electric locomotives in the standing time

2017 ◽  
Vol 76 (5) ◽  
pp. 301-305 ◽  
Author(s):  
M. Yu. Noskov ◽  
M. M. Ginshparg ◽  
N. S. Nesterov
Keyword(s):  
Spectral Composition ◽  
Sound Field ◽  
Alternating Current ◽  
External Noise ◽  
Stationary Mode ◽  
Frequency Range ◽  
Electric Locomotive ◽  
Standing Time ◽  
Test Loop ◽  
Absorbing Material

The authors of the Test Loop of the JSC “VNIIZhT” had conducted tests of mainline electric locomotives intended for handling freight trains on sections of the road electrified with alternating current at a voltage of 25 kV (electric locomotives of an alternating current). Tests were conducted in terms of the level of external noise at the standing time. The results of tests of AC electric locomotive, which was in a stationary mode, are presented in terms of the external noise index, and a methodology for performing these tests is described. As a result of the conducted researches, the article establish the main sources of external noise in the operation of AC electric locomotives (fans intended for cooling electrical equipment and traction motors, air compressors, traction transformers, etc.), its actual values, as well as the nature of the sound field around electric locomotives. The analysis of the obtained sound field made it possible to identify the points where the excess of the standard noise values (more than 65 dBA) is observed. It is proposed to bring the technical condition of the equipment, such as traction transformer, converter and cooling module of the traction engine of the power compartment of an electric locomotive in accordance with the normative documentation. The repeated measurements of the external noise level after technical completion did not reveal the excess of its normative values in accordance with the regulatory documentation. In order to provide a normative margin in terms of the external noise of an electric locomotive, it is proposed to use sound-absorbing material in the construction of its body. It is recommended to perform an experimental study of the spectral composition of the noise of the equipment of an electric locomotive operating at the standing time and the resulting external noise at points located outside and around the locomotive in order to calculate the acoustic characteristics of sound-absorbing materials. Sound absorbing material is expedient to be selected depending on the frequency range in which the greatest excess is observed above the maximum permissible values using known empirical and semi-empirical dependences, on the basis of which it is possible to preliminary determine its sound-absorbing properties in the frequency range established by regulatory documents. After equipping the power compartment of the locomotive with soundproof materials, tests on the evaluation of the external noise of an electric locomotive at standing should be repeated.

In-Plane Asymmetries on the Ge(111)-c(2×8) Surface Mapped with the Scanning Tunneling Microscope

1992 ◽  
Vol 295 ◽  
Author(s):  
P. Molinàs-Mata ◽  
J. Zegenhagen ◽  
M. Böhringer ◽  
N. Takeuchi ◽  
A. Selloni
Keyword(s):  
Local Density ◽  
Experimental Studies ◽  
Surface States ◽  
Small Sample ◽  
Constant Current ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Low Energy Electron ◽  
Tunneling Currents ◽  
Insight Into

AbstractWe report on new experimental studies of the Ge(111)-c(2×8) reconstruction performed with low-energy electron diffraction. (LEED) and scanning tunneling microscopy (STM). Weak quarter-order reflections are present in the c(2 × 8) LEED pattern in agreement with previous observations and results of ab initio calculations. In order to gain insight into the predicted splitting of dangling bond states, we compare constant current topographs (CCT's) performed at high-tunneling currents (40.nA) with first-principles calculations of the local density of states (LDOS) 1Å above the surface adatoms and obtain good qualitative agreement. We finally discuss to what extent the STM CCT's at high tunneling currents (small sample-tip distances (STD)) are sensitive to surface states outside the Г point.

Experimental Studies on Diesel Engine with Piston Crown Modification Using an Optimum Alternative Fuel

2015 ◽  
Vol 813-814 ◽  
pp. 830-835
Author(s):  
Akkaraju H. Kiran Theja ◽  
Rayapati Subbarao
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Air Gap ◽  
The Body ◽  
Injection Timing ◽  
Positive Trend ◽  
Piston Crown ◽  
Karanja Oil

The drawbacks associated with bio-fuels can be minimized by making modifications to combustion chamber. Modification of combustion chamber is achieved by providing an air gap in between the crown and the body of the piston with the top crown made of low thermal conductivity material. Experimentation is carried on a diesel engine with brass as piston crown material and karanja as test fuel, which is found to be a better alternative fuel based on the tests carried out prior to modification. Investigations are carried out on the performance of the engine with modified combustion chamber consisting of air gap insulated piston with 2 mm air gap with brass crown when fuelled with karanja oil. Comparative studies are made between the two configurations of engine with and without modification at an injection timing of 29obTDC. Performance, heat balance and emission plots are made with respect to brake power. Fuel consumption increased with modification. The mechanical and volumetric efficiencies are similar in both the cases. Indicated and brake thermal efficiencies got reduced with modification. But, it is good to see that HC and CO emissions are showing positive trend. Thus, the present investigation hints the possibility of improvements while making piston modification and providing air gap insulation.

Late Stage Decomposition of Embalmed Cadavers

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Pilar Mata Tutor ◽  
Catherine Villoria Rojas ◽  
María Benito Sánchez
Keyword(s):  
Soft Tissue ◽  
Late Stage ◽  
Good Condition ◽  
Experimental Studies ◽  
The Body ◽  
Health Law ◽  
External Appearance ◽  
Intrinsic Factors ◽  
Preservation Technique ◽  
Extrinsic And Intrinsic Factors

Decomposition is a natural process that begins approximately four minutes after death and continues until the body is degraded to simpler biochemical components which are gradually recycled back to the environment. This process is dependent on extrinsic and intrinsic factors. Embalming is a chemical preservation technique that aims to preserve the external appearance of the body in good condition for an indeterminate period. In Spain, there is a lack of experimental studies carried out to analyse the variables that affect decomposition in embalmed bodies, therefore, in accordance with the conclusions reached by previous authors, it is hypothesised that embalmed bodies show quantifiable characteristics during the late stage decomposition which distinguish them from control, unembalmed, cadavers. An anthropological and statistical analysis was performed on 14 individuals from Cementerio Sur de Madrid exhumed after ten years according to the Mortuary Health Law of the Autonomous Region of Madrid. The preliminary results obtained showed that there is a qualitative and statistically significant relationship between the variables evaluated, being the presence or absence of soft tissue the most notable difference. The mortuary or thanatopraxy treatments performed before the burial and the microenvironmental conditions of the burial positively influence the soft tissue preservation on embalmed bodies. These results contribute to the understanding about the decomposition rate of an embalmed cadavers in cemeteries, and the related extrinsic variables.

Galvanotropic Reactions of Polycelis nigra in Relation to Inherent Electrical Polarity

1927 ◽  
Vol 5 (1) ◽  
pp. 66-88
Author(s):  
J. ARMITAGE ROBERTSON
Keyword(s):  
Electrical Circuit ◽  
The Body ◽  
Constant Current ◽  
Forward Movement ◽  
Electrical Currents ◽  
Turning Mechanism ◽  
Electrical Polarity ◽  
Metabolic Activities ◽  
Physiological Gradients ◽  
A Current

The galvanotropic reactions of Polycelis nigra were investigated in constant and "intermittent" (that is, a current showing slight commutator ripple) electrical currents, varying in strength from one to about ten milliamperes. Galvanotropic reactions were most readily forthcoming at about 2 m.a. constant current, higher current strengths producing signs of discomfort or rigor, and intermittent current being slightly more effective in producing such disturbances than constant current. As a rule, Polycelis places itself longitudinally, with head facing the kathode, and moves thither by means of looping, its normal gliding motion being in abeyance. If facing the kathode on application of the current, it simply loops forward, but if moving parallel to the electrodes it turns its anterior end first, and then movesmore or less directly towards the kathode. If previously facing the anode, a turn in the direction of the kathode is usually accomplished only after more or less headwaving and apparent difficulty or hesitation. Decapitate animals, if facing the anode in the current, at some time or other almost invariably loop backwards to the kathode, tail foremost, for a varying number of times, before turning their anterior end to the kathode and orientating normally. This was never observed in normal animals. Decaudate animals behave like unmutilated individuals. Decapitate-and-decaudate Polycelis (middle-pieces) reactin the same manner as do decapitate specimens, i.e. show backward looping. Longitudinal halves of Polycelis are usually curved towards the injured side, and show little or no movement, either in or out of the current; it is supposed that this curvature is mechanical and the result of the injury. Higher amperages (above 2 m.a.) produce, progressively, cessation of forward movement with twisting and apparent discomfort, and, finally, flattening of the kathodic end of the body. This last reaction is often accompanied by various postures, presumably the result of arrested movement. An explanation of these reactions, in normal and unmutilated animals, is attempted, based on the supposed interaction of the experimental current with the external portion of an inherent electrical circuit. If this inherent circuit be obstructed it is suggested that the metabolic activities, with which it is apparently correlated, are to some extent upset. Further, that to avoid this derangement, and concomitant malaise, the animals orientate themselves so that the experimental current does not flow counter to the external portion of their inherent circuit; that the turning mechanism of the flanks which affects this orientation can be explained upon similar grounds; finally that backward looping can be explained as a transference of control or dominance to the tail end, due to the combined inhibitory action of mutilation and of a contrary experimental current upon the normal physiological gradients at the anterior end. A variety of points related to the theory, and some cases of galvanotropism bearing on the work, together with their theoretical explanations, are discussed.

EVALUATION OF TOXIOLOGICAL INDICATORS OF MONTHMORRILLONITE CLAY FOR THE PURPOSE OF USING THEM AS ALUMOSILICATE SOBENT AGAINST THE NEGATIVE EFFECT OF MYCOTOXINS ON THE BODY OF ANIMALS AND BIRDS

2021 ◽  
Vol 1 (1) ◽  
pp. 72-78
Keyword(s):  
Experimental Studies ◽  
The Body ◽  
Montmorillonite Clay ◽  
Test Substance ◽  
Negative Effects ◽  
Experimental Animals ◽  
Eyelid Edema ◽  
White Rats ◽  
Mucous Membranes ◽  
Negative Effect

The article presents the results of laboratory studies to assess the toxicological parameters of montmorillonite clay from the Pogadaevskoye deposit in the West Kazakhstan region in order to use them as an aluminosilicate sorbent in the composition of feeds that reduce the negative effects of mycotoxins on the body of animals and birds. The relevance of research is associated with the cultivation of healthy and highly productive animals and poultry in order to ensure the food security of the Republic of Kazakhstan.The studies carried out to assess the toxicological parameters of montmorillonite clay in order to use them as an aluminosilicate sorbent in experimental animals (rabbits and white rats) allowed the following results to be obtained: Visual study of the intensity of erythema when exposed to the test substance on the skin of rabbits showed their absence (0 points). The study of the intensity of edema (an increase in the thickness of the skin clutch of rabbits) when exposed to the test substance on the skin of rabbits showed no reaction (0 points). Studies evaluating the irritating effect of the test substances on the mucous membranes of the eyes of rabbits by symptoms of damage showed the absence of hyperemia (0 points). Weak eyelid edema (1 point), the minimum amount of discharge in the corner of the eye (1 point). The results of studies on the classification assessment of the test substance for the severity of the irritant effect on the eyes of rabbits showed that the average total score of the severity of the irritative effect corresponds to 1 point. A comprehensive analysis of the results obtained on the basis of scientific and experimental studies to assess the toxicological indicators of montmorillonite clay from the Pogadaevskoye deposit in relation to irritating effects on the skin and mucous membranes of experimental animals (rabbits) showed their harmlessness.

STATE OF AUTONOMIC REGULATION OF HEART RHYTHM IN YOUNG AND AGED RATS BEFORE AND AFTER APPLICATION OF DIFFERENT REGIMENS OF RHYTHMIC EXTREME COOLING

2020 ◽  
pp. 436-443
Author(s):  
В. В. Кулик ◽  
В. Г. Бабийчук
Keyword(s):  
Heart Rate ◽  
Metabolic Regulation ◽  
Experimental Studies ◽  
Autonomic Regulation ◽  
The Body ◽  
Total Power ◽  
Aged Rats ◽  
Cooling Mode ◽  
Adaptive Capabilities ◽  
Extreme Cold

В работе изучено влияние разных режимов ритмических экстремальных холодовых воздействий на состояние вегетативной регуляции сердечного ритма у молодых и старых крыс. По данным спектрального анализа вариабельности сердечного ритма установлено, что у молодых крыс использование температурных режимов ритмических экстремальных холодовых воздействий, РЭХВ (-120 °С; -120 °С; -120 °С) и (-60 °С; -120 °С; -120 °С) значительно повышало адаптационные возможности организма за счет активации собственных гомеостатических регуляторных систем. При этом комбинированный режим РЭХВ (-60 °С; -120 °С; -120 °С) оказался наиболее оптимальным для старых животных, поскольку его применение не сопровождалось чрезмерной активацией симпатико-адреналовой системы на ранних этапах экспериментальных исследований в отличие от режима (-120 °С; -120 °С; -120 °С). Кроме того, использование данного режима охлаждения способствовало статистически значимому увеличению показателей общей мощности спектра нейрогуморальной регуляции не столько за счет повышения активности гуморально-метаболического звена регуляции, преобладание которого характерно для пожилого возраста, сколько благодаря увеличению тонуса вегетативных центров, причем парасимпатические влияния на миокард превалировали над симпатическими. The influence of various rhythmic extreme cold effects on the state of autonomic regulation of heart rate in young and aged rats was studied. According to the spectral analysis of heart rate variability, it has been found that in young rats, using rhythmic extreme cold exposures (RECE) temperature regimens of (-120 °С; -120 °С; -120 °С) and (-60 °С; -120 °С; -120 °С) significantly increased adaptive capabilities of the body due to the activation of its own homeostatic regulatory systems. At the same time, the combined regimen of RECE (-60 °С; -120 °С; -120 °С) occurred to be the most optimal for aged animals, since its use was not accompanied with an excessive activation of sympathoadrenal system at the early stages of experimental studies, in contrast to the regimen (-120 °С; -120 °С; -120 °С). In addition, the use of this cooling mode contributed to a statistically significant increase in the total power of spectrum of neurohumoral regulation not so much due to a rise in activity of humoral-metabolic regulation link, the prevalence of which is characteristic of an old age, but due to an increase in the tone of vegetative centers, herewith the parasympathetic effects on the myocardium prevailed sympathetic ones.

CONSUMER PROPERTIES OF PASTA WITH POWDER FROM MARIGOLD INFLORESCENCES (TAGETES L.)

2021 ◽  
Vol 40 (4) ◽  
pp. 102-112
Author(s):  
SHAPOVALOVA Nataliia ◽  
VEZHLIVTSEVA Svitlana ◽  
ANTIUSHKO Dmytro
Keyword(s):  
Raw Materials ◽  
Experimental Studies ◽  
The Body ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
Organoleptic Properties ◽  
Biological Value ◽  
Plant Raw Materials ◽  
Active Substances

Background. The deficiency of essential nutrients in the human body is the root cause of reduced efficiency, general resistance of the body to various diseases. That is an urgent problem in the context of the spread of coronavirus infection. In this regard, the search for opportunities to meet the needs of the population in food products that contain biologically active substances (BAS) through the use of high-value and at the same time available plant raw materials is extremely important. Marigolds attract special attention among such raw materials. The aim of the work is to study the chemical composition and evaluate the consumer properties of Tagetes L. varieties, zoned in the Kiev region, to prove the possibility of increasing the biological value of pasta by adding to their recipe powder from marigold inflorescences. Materials and methods. The object of research is pasta of B group (noodles). Inflorescences of marigolds of different varieties gathered during the flowering period in July-September 2019–2020 in the territory of Vasylkiv and Obukhiv districts of Kyiv region, Ukraine were used as enriching plant raw materials. The quality of finished pasta was assessed by organoleptic and physicochemical indexes (moisture content and titratable acidity). The content of mineral elements in the fine powder of marigold inflorescences was determined on the EXHERT-3L device, the quantitative composition and BAS identification – by spectrophotometric analysis on the device Specord-200 Analytic Jena UV-vis. The integrated quality index of pasta products was calculated taking into account the importance factors of individual indexes. Results. Comparing the obtained results, we can state that all the studied varieties – Gold Kopfen, Orange Flame, Hawaii, Equinox are characterized by high biological value, regardless of the area of collection. As a result of calculated and experimental studies it was determined that the addition of 7 % of the supplement does not provide the required supply of vitamins and minerals. Replacing the flour in the recipe by 20 % significantly improves the mineral composition, but deteriorates the taste and aromatic properties of pasta. The most optimal and rational amount of added additive is 15 %, as it improves the organoleptic properties of pasta and enriches their BAS. Conclusion. The usage of non-traditional vegetable raw materials, in particular powder from marigold inflorescences, which is rich in biologically active substances, allows not only to expand the range, improve the quality of finished products, but also increase the biological value of the product. The optimal amount of additive –powder from marigold inflorescences, was defined. It is 15 % by weight of flour in the production of noodles. This concentration allows not only to improve the organoleptic properties, but also to increase the content of biologically active substances – vitamins, micro- and macronutrients. The usage of non-traditional natural raw materials (powder from marigold inflorescences) allows to abandon artificial colorsand give the finished pasta a pleasant colorand aroma.

Effect of Abrasive Tools in Galvanomechanical Treatment on the Roughness of the Deposited Chromium Layer

2018 ◽  
Vol 284 ◽  
pp. 1178-1183 ◽  
Author(s):  
D.A. Zherebtcov ◽  
Oksana N. Gruba ◽  
K.R. Smolyakova
Keyword(s):  
Experimental Studies ◽  
The Body ◽  
Abrasive Tool ◽  
Chromium Layer ◽  
Pressing Force ◽  
Hard Chromium ◽  
Chromium Plating ◽  
Cylindrical Parts ◽  
Abrasive Tools

The article deals with the method of obtaining a hard chromium coating on details of the "body of rotation" type with the use of an abrasive tool. The influence of the composition and hardness of the elastic abrasive tool on the results of galvanomechanical chromium plating of rotating cylindrical parts has been studied. Binder compositions for an abrasive tool used to improve the roughness of the deposited chromium layer have been developed. A series of experimental studies has been carried out with chromium plating of steel cylindrical parts with simultaneous abrasive processing. Beforehand, an abrasive tool with previously developed binder formulations was manufactured. The obtained results of the influence of the characteristics of the abrasive tool and its pressing force on the chromium-plated part on the quality of the precipitated chromium made it possible to determine the optimum modes for obtaining a coating of the required thickness. Also, a suitable abrasive tool has been chosen to obtain a coating of proper quality.

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