Influence Of Different Conditions Research Articles

Influence of the storage conditions of embryo culture media on mouse development.

The culture of preimplantation embryos in vitro is an important method for human and mouse reproductive technology. This study aims to investigate the influence of different conditions of culture media on the preimplantation stage of mouse embryos cultured in vitro, and monitor the post-implantation development of new mice after embryo transfer to surrogate females. We demonstrated here that mouse embryos cultured in vitro in fresh M16, KSOM, Global, and HTF embryo culture media from one cell to the blastocyst stage and the subsequent embryo transfer to surrogate females are able to proceed through post-implantation development and, after birth, develop into healthy mice. However, culture of embryos in differently aged media shows various (often unpredictable) results. To find the optimal storage conditions of culture media, we suggest that the freezing and long-term storage of these media at - 80°C will not influence the quality of the media. To test this hypothesis, we grew embryos from one cell to blastocysts in vitro in the selected media after thawing and subsequently transferring them to surrogate females. Embryo culture in these four media after thawing does not affect preimplantation and postnatal mouse development. Thus, we have shown that storage of embryo culture media at low temperature (- 80°C) does not impact the quality of the media, and subsequently, it can be used for the culture of embryos for the full preimplantation period, the same as in fresh media.

An experimental investigation and multiphysics simulation of thermoelectric temperature controller for AWG chips

The refractive index of silicon-based waveguide materials is highly sensitive to temperature and stress, and the effective refractive index of the waveguide varies with temperature changes. Thus, it is critical to reduce the temperature dependence of Arrayed Waveguide Grating (AWG) devices and to precisely control the center wavelength of AWGs. In this study, the thermoelectric cooler (TEC) was designed and fabricated to control the temperature of the thermal AWG chip, which did not require any material replacement or reprocessing of the AWG chip. Different magnitudes and polarities of voltage are applied to the TEC to regulate its operational state (heating or cooling). A multiphysics simulation model of a thermal AWG device is established and validated through transient and steady-state experiments. This study investigated the influence of different conditions (input voltage, environmental temperature) on the temperature and maximum stress of the AWG chip. A conformal TEC was designed and its performance was compared with that of the square TEC. The energy consumption of the conformal TEC was also tested and analyzed. The results show that in a 25 °C ambient environment, the TEC can control the temperature of the AWG chip in the range of 1.5–78.3 °C, significantly expanding the current operational temperature range of 65.0–85.0 °C when using Positive Temperature Coefficient (PTC) heaters. Under the same conditions, when using the conformal TEC as the temperature control device, the temperature gradient on the AWG chip is reduced by 1.37 °C during cooling and 2.80 °C during heating. The maximum stress value in the core layer is always lower, with a maximum reduction of 3.61 MPa. TEC can set the ideal operating temperature of the AWG chip according to the actual operating environment of the product, which reduces the energy consumption of TEC. A comparison is made between the average power consumption of the conformal TEC and the PTC heater under two operating conditions: a 25 °C constant-temperature environment and a natural environment. The average power consumption can be reduced by up to 97.87 % and 93.02 %, respectively. This study holds significant guidance for solving the temperature dependence problem of AWG devices and the application of thermoelectric coolers in the field of optical communication.

In situ investigation of the thermal characteristics of microwave resonance-induced focused hotspots in dimers for improving microwave heating uniformity

Microwave hotspots or thermal runaway is a long-standing challenge that severely limits the uniformity of microwave heating. In particular, the evolvement process and suppression methods of focused hotspots in high permittivity dimers are still not clear. In this work, thermal imaging was used to in situ track the microwave hotspots of grape dimers with different gaps and shapes in a multi-mode microwave oven. Two thermal characteristics of microwave resonance-induced focused hotspots, gap sensitivity and shape selectivity, were found. Finite element simulation verified the experimental results and calculated the influence of different conditions on the heating uniformity and the enhanced electric field. The results indicated that gap can gradually weaken the enhanced electric field between grapes and rapidly improve the heating uniformity by approximately 30 times. For dimers of different shapes in contact, the sharper the contact area, the more pronounced the focused hotspots. Moreover, the heating uniformity raises with increasing shape factor n, and when n = ∞, it is improved by about 35 times compared with n = 1. In addition, the enhanced electric field, which exhibits complexity due to microwave scattering interaction between grapes, was analyzed. These findings provide two strategies for improving the heating homogeneity of dimers or particle systems.

Mass transfer research on solid-liquid separation of extracted coal tar residue based on diffusion model

A large amount of coal tar residue (CTR) produced in the process of coal coking and tar processing is recognized as hazardous industrial waste with a high carbon content and strong carcinogenic polycyclic aromatic hydrocarbons. Through solvent extraction, CTR can be separated into economically valuable tar and fixed carbon, and waste recycling can be realized. In this paper, a mathematical model of CTR solid-liquid extraction is established based on a diffusion model and experiments, and the mass transfer law, mass transfer equation, and influence of different conditions of solid-liquid separation of CTR from toluene extraction are studied. First, the empirical formula is used to derive the change in the mass transfer coefficient kf outside the particles during extraction, and the kf gradually decreases as the extraction progresses. The particle swarm optimization is used to obtain the best effective diffusion coefficient Deff, inside the particles, which is 9.65 × 10−14 m2/s. The effective diffusion coefficient, Deff, was determined and corrected based on experimental data. A second-order function was fitted to describe the variation of Deff with temperature. MATLAB software was used to solve the model the concentration change law and extraction law during extraction were obtained. According to the model simulation, the influence of different conditions such as agent residue ratio, stirring speed, particle radius, and temperature on the extraction process is calculated.

Cleaning and upgrading of low-rank coal using a novel rotary triboelectric separator with the polyvinyl chloride as friction medium

In this work, a novel laboratory rotary triboelectric separator was designed for the beneficiation of low-rank coal using polyvinyl chloride as the friction medium. The friction charge polarity of the different components in the low-rank coal was determined by charge-to-mass ratio measurements. The separation performance of the rotary triboelectric separator was investigated by separating the simulated materials. The surface properties of the simulated minerals were analyzed using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The influence of different conditions on the separation of low-rank coal was studied using rotation speed, feed rate and plate voltage as variables. Under the optimum operating conditions, the ash removal rates of 0.25–0.5 mm, 0.125–0.25 mm and −0.125 mm low-rank coals were 50.05 %, 61.88 % and 25.56 %, respectively. Inductively coupled plasma mass spectrometry (ICP-MS) analysis of the separated products indicated that several harmful trace elements (i.e., Cd, Cr, Pb and Sb) were removed distinctly. Our results will provide an effective way for the separation and upgrading of low-rank coal.

Forecast of 241Am Migration from a System of Deep Horizontal Boreholes

Highly radioactive materials classified as high-level nuclear waste (HLW) of atomic power engineering should be disposed of deeply underground in special geological disposal facilities (GDFs), which can be of either shaft or borehole type. The advantages of borehole-type GDFs result from smaller volumes of mining operations, a simpler construction technology, shorter construction time and cost. This allows us to consider them as an alternative to shaft-type GDFs. The parts of the boreholes in which waste containers should be placed can be both vertical and horizontal. Computer simulation of the migration of radionuclides from a group of parallel horizontal boreholes into the biosphere made it possible to conclude that horizontal GDF boreholes have significant advantages over vertical ones. We determined a forecast of 241Am migration by a method of mathematical modelling of 241Am release from vitrified HLW disposed of in several horizontal drillholes. The maximum concentrations of americium in the near-surface groundwater above the repository are calculated depending on the number of boreholes, the depth of their location and the distance between them, the permeability of rocks and the time of waste storage prior to disposal. Influence of different conditions on the safety of a GDF of borehole type is estimated. Calculations show that the heat generated by HLW causes a weaker groundwater convection near horizontal boreholes compared to vertical boreholes of the same capacity. In addition to that, at an equal thickness of the rock layer separating the HLW from the surface, the geothermal temperature of the host rocks in the near field of a horizontal borehole will be lower than the average geothermal temperature near a vertical borehole. As a result, the rate of radionuclides leaching from the waste forms by groundwaters will also be lower in the case of horizontal boreholes.

Strong pyroelectric enhancement induced by the evolution of PNRs in paraelectric-phase KTN crystals

KTa1−xNbxO3 crystals exhibit excellent piezoelectric, ferroelectric, and electro-optical properties near the phase transition point, owing to the evolution of polar nanoregions (PNRs). This paper discusses the physical properties of the PNRs in three characteristic temperature ranges and analyzes the dielectric relaxation properties of the crystals. The effects of different heating rates and initial temperatures on the pyroelectric effect are discussed, and the influence of small electric fields on increasing the pyroelectric coefficient is investigated. The polarization characteristics of the crystal were obtained according to the change in the pyroelectric performance, and the influence of different conditions on the dynamic response of the PNRs was analyzed. It is proposed that the evolution of PNRs, induced by external coupling with an internal electric field, significantly affects macroscopic performance.

The experimental analysis on the influence of different conditions in microchannel on critical heat flux and boiling starting point

The experimental analysis on the influence of different conditions in microchannel on critical heat flux and boiling starting point

Causal Conditional Hidden Markov Model for Multimodal Traffic Prediction

Multimodal traffic flow can reflect the health of the transportation system, and its prediction is crucial to urban traffic management. Recent works overemphasize spatio-temporal correlations of traffic flow, ignoring the physical concepts that lead to the generation of observations and their causal relationship. Spatio-temporal correlations are considered unstable under the influence of different conditions, and spurious correlations may exist in observations. In this paper, we analyze the physical concepts affecting the generation of multimode traffic flow from the perspective of the observation generation principle and propose a Causal Conditional Hidden Markov Model (CCHMM) to predict multimodal traffic flow. In the latent variables inference stage, a posterior network disentangles the causal representations of the concepts of interest from conditional information and observations, and a causal propagation module mines their causal relationship. In the data generation stage, a prior network samples the causal latent variables from the prior distribution and feeds them into the generator to generate multimodal traffic flow. We use a mutually supervised training method for the prior and posterior to enhance the identifiability of the model. Experiments on real-world datasets show that CCHMM can effectively disentangle causal representations of concepts of interest and identify causality, and accurately predict multimodal traffic flow.

A Mesoscale Simulation Approach to Study the Flow Field in an Axial Granular Bed Filter

In an axial granular bed filter (GBF), a new mesoscale simulation approach is obtained by combining the macroscopic calculation models, i.e., the equations of the total pressure drop and dust-removal efficiency into the porous media model and the source term of the conservation equations. After grid-dependent tests and experimental validation, the effects of different conditions, i.e., granular bed height L, superficial gas velocity ug, dust diameter dp, dust concentration cp, granular diameter dg, initial bed voidage ε0, and filtration time t, on the pressure drop and dust-removal efficiency are investigated. The results show that the pressure drop is related to the inertial and viscous resistance terms, which increase with increasing L, ug, cp and t and decreasing ε and dg. The dust-removal efficiency is related to the Reynolds number, effective Stokes number, and equivalent granular diameter ratio. It increases with increasing L, ug, dp and t (small values), and decreasing cp, ε, and dg. Moreover, the influence of different conditions coincides well with dust-removal efficiency in relevant studies, which further demonstrates the accuracy of the mesoscale simulation approach. With the application of this method, the flow field can also be obtained easily and quickly, which is expected to provide a reference for the simulation study of GBF.

A finite element analysis of different postures and intra-abdominal pressures for the uterine ligaments in maintaining the normal position of uterus

Uterine prolapse is a common gynecological disease, which seriously affects the quality of life and physical and mental health of elderly women. The aim of this study was to analyze the influence of different conditions (intra-abdominal pressure (IAP) and posture) on stress and displacement of uterine ligaments using the finite element method, and evaluate the contribution of uterine ligaments on uterus. The three-dimensional (3D) models of retroverted uterus and its accessory ligaments were established, loads and constraints were set in ABAQUS software, and the stress and displacement of uterine ligaments were calculated. The uterine displacement increased with the increase of IAP, and then the stress and displacement of each uterine ligament also increased. The uterine displacement was in the order of forward < upright < backward with different postures, and USL, CL and RL got larger values when the body was backward, while BL got a larger value when the body was forward. With the same condition, the stress of the uterine ligaments was in the order of USL > BL > CL > RL, and the displacement of the ligaments was in the order of BL > RL > USL > CL. The contribution of each uterine ligament changing with different IAP and postures was studied through finite element analysis, and the research results were consistent with the clinical data, which can provide a basis for exploring the mechanism of uterine prolapse.

Kinetic Study for Janus Green Dye Adsorption from Aqueous Solutions Using Iraqi Bauxite Clay and its Composite

Clays are considered important natural materials in the field of water purification, including bauxite clay (BAU) and its prepared and activated composite (BAU/CMC-AC) with carboxymethyl cellulose polymer. The ad-sorbent surfaces are characterized by FTIR and XRD techniques. The adsorp-tion of green janus (JG) from an aqueous solution with bauxite and its compo-site were studied under the influence of different conditions of the weight and size of adsorbed surface particles, contact time and temperature. The results were found to be: contact time (90, 45) min for maximum quantity adsorbed of (JG) dye on bauxite and its composite respectively. The experimental data were tested on pseudo 1st- and 2nd-order kinetic models. It was shown to apply more with the pseudo-2nd order kinetic model for both adsorbents. It also showed that the highest removal percentage were (78%, 88.5 %) for the bauxite surface and its composite (BAU, BAU/CMC-AC) at the preferred temperature

Cardiac hypertrophy simulations using parametric and echocardiography-based left ventricle model with shell finite elements

In our paper, we simulated cardiac hypertrophy with the use of shell elements in parametric and echocardiography-based left ventricle (LV) models. The hypertrophy has an impact on the change in the wall thickness, displacement field and the overall functioning of the heart. We computed both eccentric and concentric hypertrophy effects and tracked changes in the ventricle shape and wall thickness. Thickening of the wall was developed under the influence of concentric hypertrophy, while the eccentric hypertrophy produces wall thinning. To model passive stresses we used the recently developed material modal based on the Holzapfel experiments. Also, our specific shell composite finite element models for heart mechanics are much smaller and simpler to use with respect to conventional 3D models. Furthermore, the presented modeling approach of the echocardiography-based LV can serve as the basis for practical applications since it relies on the true patient-specific geometry and experimental constitutive relationships. Our model gives an insight into hypertrophy development in realistic heart geometries, and it has the potential to test medical hypotheses regarding hypertrophy evolution in a healthy and heart with a disease, under the influence of different conditions and parameters.

Job Burnout and Job Satisfaction among Healthcare Service Providers in a Daycare Center for Individuals with Autism Spectrum Disorders in Low-Resource Settings

Job satisfaction and burnout are components of job morale. In general, and among healthcare provider personnel, these are psychological factors of the job and under the influence of different conditions and the organizational management of the healthcare systems. Both job burnout and job satisfaction among healthcare service providers have received scant attention in the literature, particularly in the healthcare systems of the Kurdistan Region of Iraq (KRI) as one low- or middle-income country (LMIC). The burnout rate and job satisfaction in a daycare center for children with autism spectrum disorders were reviewed and measured using a sample consisting of 34 employees from three different sections. The Maslach Burnout Inventory-Third Edition (MBI-3) and the Job Descriptive Index (JDI) were used. The relationships between the two scales and their consisting factors were examined using Pearson Correlation and Chi-square test to understand the correlation and levels of significant difference between the expected and the observed frequencies. There was a significant negative correlation between job burnout and satisfaction with the job and some significant correlations between the factors of the scales. Lower levels of emotional exhaustion and depersonalization factors of the burnout scale were statistically correlated. It was shown that the personnel were mainly satisfied with their jobs through their choices in the four parts of the job satisfaction scale. Further investigations are needed to understand different contributing factors to job satisfaction and burnout among healthcare providers in KRI. The current study might highlight the importance of understanding the healthcare providers' perspectives on their careers.

THE PRODUCTIVITY OF THE FIRST CALVING COWS OF DIFFERENT CONDITIONS GROWING AND HOUSING

Introduction. The purpose of the work was to study the influence of different conditions of rearing and housing of the first calving cows on their productivity, reproductive capacity and stayability during lactation at the current stage of breeding. Materials and methods of research. The work was carried out based on the data of four breeding plants for the breeding of Ukrainian black and white dairy cows. The data of 3.610 first calving cows that calved during the last six years were analyzed. Statistical processing of the obtained data was carried out by the method of two-factor variance analysis using computer programs. During the analysis, the data were divided by the age of first fertilization and the average daily gain before fertilization. Only animals with a duration of lactation of more than 200 days were selected to determine productivity indicators for lactation. The stayability was determined for the first 10 months of lactation. In determining the probability of abortion and stillbirth, calvings with stillborn calves and abortions after which lactation began are taken into account. Research results. It was established that the live weight of first calving cows, regardless of the housing, increased proportionally to the intensity of their growing. In stall housing, the live weight of first servis that were fertilized at different ages had no significant differences, while in free stall housing, the first calving cows that were inseminated before the age of 470 days had an advantage of 12–19 kg. In terms of milk yield for 305 days of lactation, the first calving cow that were kept tethered and were fertilized at an earlier age exceeded the animals of other groups by 29–148 kg of milk, and those kept without tethering by 564–989 kg. Intensively reared animals produced 244–539 kg of milk more when tethered, and when tethered, this difference was significantly greater and amounted to 530–1081 kg, compared to first calving cow with an increase of less than 800 g. A reading has been established for the trend of increasing the milk yields from the changes in the first fertilization. The intensity of the growth of the heifers before the flooding also has a positive impact on their day milk yield. The probability of unsuccessful calving does not depend on the age of the first insemination in stall housing, but in free housing, animals that were inseminated before 470 days of age had 36–46% more unfavorable results with calving than those that were inseminated in older age The probability of abortion and the birth of a dead calf during stall housing heifers with different intensities of growing before fertilization also had no significant differences, and during free housing heifers with an average daily gain of more than 800 g had 7–9 more cases of unsuccessful calving, calculated on 100 animal compared to heifers with a lower intensity of growing. Conclusions. Increasing the intensity of raising heifers and reducing the age of first insemination contribute to increasing their productivity. It is necessary to carry out constant monitoring of repair youngsters for fatness and to prevent obesity. It leads to a decrease in reproductive capacity, unfavorable calving and, as a result, an increase in the probability of culling in the first lactation, especially in in free housing.

The Effect of Different Storage Conditions for Refilled Plastic Drink Bottles on the Concentration of Microplastic Release in Water

The demand for water consumption in plastic bottles has increased in recent years. Most consumers of this type of water think that it is well sterilized. This is due to the high level of propaganda that accompanies its production regarding the extent of its validity. It is also common to reuse these bottles for several times by filling it frequently for different uses, and their use for preserving and storing different types of liquids.&#x0D; This study is conducted for the purpose of detecting and evaluating the pollution caused by microplastics in plastic bottles filled with water for one time, as well as water bottles reused more than once. Moreover, it evaluates the effect of storage period and conditions on the abundance of microplastics when bottles are stored for different times and under the influence of different conditions (shade, cooling and freezing). The results of the study show the presence of fine microplastics in open bottled water exposed to different storage conditions. The highest concentration of microplastics is obtained in storage conditions under the influence of shade with a limit of (1050) microplastics / liter, while the lowest concentration is obtained at around (20) microplastics / liter. The highest concentration of microplastics is obtained in storage conditions under the influence of cooling, with a limit of (850) microplastics / liter, whereas, the lowest concentration is obtained in the range of (16) microplastics / liter. Under the influence of freezing, the highest concentration of microplastics is obtained in the range of (648) microplasics / liter, while the lowest concentration Is obtained in the range of (20) microplastics / liter.&#x0D; Through the results, it is noted that there is a noticeable gradient in the concentration of microplastics for the samples that have been studied. It is also noted that there is an increase in the concentration of microplastics with repeated reuse during continuous periods of time. It is recommended that more studies and research be conducted indicating the extent of the impact of microplastics on human health in addition to other environmental components with emphasis on finding treatment means to get rid of microplastics.

Green and efficient enantioseparation of amlodipine using a novel pairwise crystallization-circulating extraction coupling method aimed at in situ reuse of mother liquor

Diastereomeric crystallization is a widely used enantioseparation method, but its yield is low due to mother liquor waste. To realize in situ regeneration and reuse of mother liquor, a novel green pairwise crystallization-circulating extraction coupling (PC-CE) method was developed. By using two resolving agents (D-/L-tartaric acid), the two enantiomers (S-/R-amlodipine) of racemate were separately crystallized as S-D and R-L salts in two crystallizers. Moreover, by circulating extraction between the crystallizers, the accumulated R-enantiomer in the S-D salt crystallizer was transferred into the R-L salt crystallizer, and the accumulated S-enantiomer in the R-L salt crystallizer was transferred into the S-D salt crystallizer. Therefore, the enantiomeric excess (ee) of two mother liquors decreased to nearly 0%, and they returned to a racemic state and can be reused by supplementing raw materials. In contrast, conventional direct in situ reuse of mother liquor is infeasible due to the accumulation of non-target enantiomer. Theoretical analysis using ternary phase diagrams and experiments confirmed the above description. During the conventional direct in situ reuse of mother liquor process, the crystal ee values changed greatly. PC-CE can be used to form a stable and efficient cyclic operation for the mother liquors in situ reuse and the efficient crystallization enantioseparation. The influences of different conditions on the batch PC-CE process were studied. After reuse of mother liquor for 15 times, the two crystals with ee values of 98% ∼ 99% were consecutively obtained, and the overall yields were close to 100% except for the operating loss. Due to the in situ reuse of mother liquor, PC-CE is a green enantioseparation method and has practical application potential in many chiral resolution fields.

Influence of constructive features of cowshed on the formation of microclimate and qualitative indicators of milk

The state of the microclimate in the light-frame, reconstructed cowshed and milking parlor with a loose-box method of keeping a dairy herd in the spring was studied; the influence of different conditions and parameters of the microclimate on milk quality was investigated. It was found that the temperature in the reconstructed cowshed with forced milking in the hall by the milking machine «Yalynka» averaged 14.27 ± 2.105 ° C, while in the milking parlor the temperature was slightly higher than 16.38 ± 1.335 ° C. In the light frame cowshed the temperature was 12.24 ± 1.380 ° С, and in the milking zone of cows with the robotic installation almost without deviation 12.14 ± 1.715 ° С. Humidity and speed of air movement in the compared rooms was within the hygienic norms. Microbiological indicators of bacterial air pollution in both rooms correspond to hygienic norms, but in the reconstructed cowshed the number of colony-forming units in 1 m3 was higher. The largest number of colony-forming units in 1 m3 was recorded in the air of the milking parlor where the UDE-8 "Yalynka" unit is located due to insufficient ventilation, high humidity and temperature. Dispersion of the tiny drops from the cows udder in the air and other body limbs, equipment and fences when washing the milking parlor with water under pressure. In a light frame cowshed with free milking with a robotic unit at the ALC "Terezyne", the acidity of milk was 16.4 ± 0.64 ° T; the purity degree was according to the standard of the first group, the temperature 30 minutes after milking was 4.2 ± 0.57 ° C; microbial contamination of milk was on average 233.4 ± 8.64 thousand CFU / cm3; the titre of colon bacillus group was about one; the number of somatic cells was 376.9 ± 29 thousand / cm3, which ultimately corresponded to the highest grade according to DSTU 3662: 2018. When milking by the UDE-8 "Yalynka", the acidity of the obtained milk was 18.6 ± 0.42 ° T; the degree of purity according to the standard corresponded to the first group, the temperature 30 minutes after milking was 5.8 ± 0.71 ° C; microbial contamination of milk averaged 292.3 ± 12.3 thousand CFU / cm3; the titre of colon bacillus group was about one; the number of somatic cells was 465.7 ± 19 thousand / cm3, which ultimately corresponded to the first grade according to DSTU 3662: 2018. Therefore, the maintenance of the dairy herd in both light-frame and reconstructed premises allows to form a sufficiently comfortable sanitary and hygienic conditions. The increase in microbial contamination of milk obtained from cows in the milking parlor by UDE- 8 "Yalynka" is the result of insufficient operation of the ventilation system of the milking parlor and improper implementation of certain elements of preparation of animals for milking. Key words: light-frame cowshed, microclimate, milking parlor, milk quality.

A Closer Look at the Contact Conditions of a Block-on-Flat Wear Experiment

Specific wear rates of tribosystems always rely on the data obtained from wear experiments. Nonetheless, the events taking place during an experiment may often lead to wide variations and low repeatability of the results. In this work, the authors attempt to take a closer look into the dynamic contact conditions of a dry linearly reciprocating block-on-flat wear experiment. The finite element method and Archard’s wear model are used through COMSOL Multiphysics® 5.2a and LiveLink™ for MATLAB® software to model the wear and study the influence of different conditions of the block surface and alignment of the sample. Changes of the geometry of the block and the contact pressure are quantified for several back and forth motions, using an extrapolation scheme in the wear modelling methodology. The tracking of such changes allow a dynamic overview of how the block contact area and the contact pressure distribution change throughout time. The results show how the assumption of a constant contact area and use of a nominal contact pressure in calculating the wear rate in such experiments can be inappropriate, especially in the presence of roughness and misalignments of the block.

Development of physical qualities and increase of motivation in children of older preschool age in different conditions of preparation for passing trp regulations

The paper considers the possibilities of expanding the content of physical education activities by including tasks for improving physical qualities, intellectual abilities, motivation of preschoolers in the context of preparing for passing the TRP standards of the 1st level. The influence of the developed means on the motivation of children of senior preschool age to pass the TRP standards of the 1st stage was analyzed. The level of readiness of children of senior preschool age to pass the norms of the TRP of the 1st stage was revealed.Purpose - to reveal the influence of different conditions on the physical readiness of children of senior preschool age to pass the TRP standards.Methods and organization of the study. The developed means of preparing children for passing the TRP standards are focused on the child's understanding of causal relationships between facts. At preschool age, this means that the child develops not only physical qualities, but also intellectual abilities.