Estimation of the power of mechanical losses in the engine, transmission and wheels of car on the stand with running drums

The efficiency of a car is considered through the amount of energy loss spent on transmission from the engine to the driving wheels of the car. Analytical and experimental methods for assessing mechanical losses are analyzed. The advantages and disadvantages of road and bench tests of a car in free run modes are indicated. A description of the diagnostic equipment - a stand with running drums, used to simulate the movement of a car in laboratory conditions is given. The components of the necessary measuring equipment for recording the speed and torque on the wheels of a car are considered. The list of primary measuring sensors and main transducers is indicated, which transmit information to the computer. The results of the car run-out on the stand are given: the change in the instantaneous speed from time to time. The primary assessment of the regression model is made and the values of the coefficients are obtained by the method of least squares of deviations of the vehicle speed. A mathematical model for the subsequent processing of experimental data has been developed. The purpose of mathematical modeling is to separate mechanical losses by power units separately for the engine, transmission and car wheels. An assessment was made of the amount of energy losses in the stand itself with running drums. The characteristic of the stand has been obtained, which must be taken into account in the measurement procedure. The results of experimental studies for the GAZ-31029 car are presented. The results of the influence of the technical condition of transmission units and vehicle wheels on the value of the power of mechanical losses are presented. Car tire pressure studies have been conducted. The graphical dependences of the power of mechanical losses depending on the speed of the car are obtained. Recommendations have been developed for diagnosing the general condition of the vehicle by the amount of mechanical losses at the stand with running drums. The ways of further improvement of the method are given. The main conclusions based on the research results are formulated.

Estimated Biomass Loss Caused by the Vaia Windthrow in Northern Italy: Evaluation of Active and Passive Remote Sensing Options

Windstorms are a major disturbance factor for European forests. The 2018 Vaia storm, felled large volumes of timber in Italy causing serious ecological and financial losses. Remote sensing is fundamental for primary assessment of damages and post-emergency phase. An explicit estimation of the timber loss caused by Vaia using satellite remote sensing was not yet undertaken. In this investigation, three different estimates of timber loss were compared in two study sites in the Alpine area: pre-existing local growing stock volume maps based on lidar data, a recent national-level forest volume map, and an novel estimation of AGB values based on active and passive remote sensing. The compared datasets resemble the type of information that a forest manager might potentially find or produce. The results show a significant disagreement in the different biomass estimates, related to the methods used to produce them, the study areas characteristics, and the size of the damaged areas. These sources of uncertainty highlight the difficulty of estimating timber loss, unless a unified national or regional European strategy to improve preparedness to forest hazards is defined. Considering the frequent impacts on forest resources that occurred in the last years in the European Union, remote sensing-based surveys targeting forests is urgent, particularly for the many European countries that still lack reliable forest stocks data.

How COVID-19 Infection can Alter the Sex Hormones in Hospitalized Patients? A Longitudinal Study in Iran

Background: There is some evidence about alteration of sex hormones in patients with COVID-19 infection. This study aimed to evaluate the levels of sex hormones in female and male patients with COVID-19 during hospitalization and one month after discharge. Methods: The levels of sex hormones including estradiol, progesterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), total testosterone, and free testosterone were measured in 162 female and male patients with COVID-19 infection during hospitalization and one month after discharge. A demographic questionnaire and a checklist were used to collect the data. The ANCOVA test was used to compare the level of hormones in patients with severe and moderate disease. Results: In the primary assessment, 162 patients were assessed for serum levels of sex hormones, while a month after discharge, only 69 patients provided consent for assessment, and nine had passed away. During hospitalization, female patients with severe disease had an elevated level of estradiol (407.70±623.37 pg/mL) in comparison to those with a moderate disease (213.78±407.17 pg/mL). The levels of progesterone and LH were high during hospitalization, but there was a decrease in these levels after discharge. The reduction in the level of FSH in patients with severe disease was greater than in patients with moderate disease, which increased after discharge. While the level of testosterone decreased during hospitalization, the alteration of free testosterone was negligible in male patients.Conclusion: In this study, we observed alteration in sex hormones (increased level of estrogen, progesterone, LH and reduction in the level of FSH and total testosterone) in female and male patients, with the alteration being greater in the latter. Due to the attrition of patients in follow-up period, more studies are needed to confirm these results.

Trauma

Primary assessment in trauma: ABCDE?, Airway?, Breathing?, Circulation?, Secondary survey?, Chest trauma?, Abdominal trauma?, Head trauma?, Spinal trauma?, Limb trauma?, Burns?, Pregnant trauma patients?, Paediatric trauma?

Assessment of medical students’ clinical performance using high-fidelity simulation: comparison of peer and instructor assessment

Background High-fidelity simulators are highly useful in assessing clinical competency; they enable reliable and valid evaluation. Recently, the importance of peer assessment has been highlighted in healthcare education, and studies using peer assessment in healthcare, such as medicine, nursing, dentistry, and pharmacy, have examined the value of peer assessment. This study aimed to analyze inter-rater reliability between peers and instructors and examine differences in scores between peers and instructors in the assessment of high-fidelity-simulation-based clinical performance by medical students. Methods This study analyzed the results of two clinical performance assessments of 34 groups of fifth-year students at Ajou University School of Medicine in 2020. This study utilized a modified Queen’s Simulation Assessment Tool to measure four categories: primary assessment, diagnostic actions, therapeutic actions, and communication. In order to estimate inter-rater reliability, this study calculated the intraclass correlation coefficient and used the Bland and Altman method to analyze agreement between raters. A t-test was conducted to analyze the differences in evaluation scores between colleagues and faculty members. Group differences in assessment scores between peers and instructors were analyzed using the independent t-test. Results Overall inter-rater reliability of clinical performance assessments was high. In addition, there were no significant differences in overall assessment scores between peers and instructors in the areas of primary assessment, diagnostic actions, therapeutic actions, and communication. Conclusions The results indicated that peer assessment can be used as a reliable assessment method compared to instructor assessment when evaluating clinical competency using high-fidelity simulators. Efforts should be made to enable medical students to actively participate in the evaluation process as fellow assessors in high-fidelity-simulation-based assessment of clinical performance in situations similar to real clinical settings.

Magnetic Resonance Imaging in Diagnosis of Complications of Renal and Ureteral Injuries in Different Periods of Traumatic Disease

The aim of this study was to evaluate the effectiveness of MRI in diagnosing combined renal and ureteral injuries at different periods of traumatic disease (TD). Methods and Results: We analyzed the results of diagnostics and treatment of 139 patients (80 women and 59 men) with renal and ureteral injuries aged between 18 and 72 years. There were 67(48.2%) patients in the period of acute reaction to trauma, 40(28.8%) patients with early manifestations, and 32(23%) patients in the period of late manifestations. In 127(91.4%) patients, an urgent plain abdominal X-ray was performed without any preliminary preparation. USI of the abdominal and retroperitoneal space was performed in 108(77.7%) patients in the stage of the primary assessment of renal injury as it was a rapid non-invasive investigation. A whole-body MSCT was performed in 131(94.2%) patients, using the nonionic contrast agents Ultravist (350mg I/ml) and Omnipaque (350mg I/ml). MRI was performed in 125(89.9%) patients, including cases of pregnancy and a medical history of allergies. Contrast-enhanced MSCT had a high diagnostic efficiency in assessing complications in kidney and ureteral injuries at different periods of TD (accuracy of 89.2% for acute reaction, 88.8% for early manifestations, and 89.5% for late manifestations). MRI of the kidneys and ureters was indicated in periods of early and late manifestations of TB to detect renal complications in cases with a discrepancy between clinical manifestations and the results obtained by ultrasound and MSCT (accuracy of 87.5% for early manifestations and 89.9% for late manifestations).

Hypothermia in Trauma

Hypothermia in trauma patients is a common condition. It is aggravated by traumatic hemorrhage, which leads to hypovolemic shock. This hypovolemic shock results in a lethal triad of hypothermia, coagulopathy, and acidosis, leading to ongoing bleeding. Additionally, hypothermia in trauma patients can deepen through environmental exposure on the scene or during transport and medical procedures such as infusions and airway management. This vicious circle has a detrimental effect on the outcome of major trauma patients. This narrative review describes the main factors to consider in the co-existing condition of trauma and hypothermia from a prehospital and emergency medical perspective. Early prehospital recognition and staging of hypothermia are crucial to triage to proper care to improve survival. Treatment of hypothermia should start in an early stage, especially the prevention of further cooling in the prehospital setting and during the primary assessment. On the one hand, active rewarming is the treatment of choice of hypothermia-induced coagulation disorder in trauma patients; on the other hand, accidental or clinically induced hypothermia might improve outcomes by protecting against the effects of hypoperfusion and hypoxic injury in selected cases such as patients suffering from traumatic brain injury (TBI) or traumatic cardiac arrest.

Cardiotoxicity Associated with Chemotherapy Used in Gastrointestinal Tumours

Cardiotoxicity is a well-recognised side effect of cancer-related therapies with a great impact on outcomes and quality of life in the cancer survivor population. The pathogenesis of chemotherapy-induced cardiotoxicity in patients with gastrointestinal cancers involves various molecular mechanisms, and the combined use of various chemotherapies augments the risk of each drug used alone. In terms of cardiotoxicity diagnosis, novel biomarkers, such as troponins, brain natriuretic peptide (BNP), myeloperoxidases and miRNAs have been recently assessed. Echocardiography is a noninvasive imaging method of choice for the primary assessment of chemotherapy-treated patients to generally evaluate the cardiovascular impact of these drugs. Novel echocardiography techniques, like three-dimensional and stress echocardiography, will improve diagnosis efficacy. Cardiac magnetic resonance (CMR) can evaluate cardiac morphology, function and wall structure. Corroborated data have shown the importance of CMR in the early evaluation of patients with gastrointestinal cancers, treated with anticancer drugs, but further studies are required to improve risk stratification in these patients. In this article, we review some important aspects concerning the cardiotoxicity of antineoplastic drugs used in gastrointestinal cancers. We also discuss the mechanism of cardiotoxicity, the role of biomarkers and the imaging methods used in its detection.

Evaluation of the Brain Function State During Mild Cognitive Impairment Based on Weighted Multiple Multiscale Entropy

The mild cognitive impairment (MCI) stage plays an essential role in preventing the progression of older adults to Alzheimer's disease. In this study, neurofeedback training (NFT) is applied to improve MCI brain cognitive function. To assess the improvement effect, a novel algorithm called Weighted Multiple Multiscale Entropy (WMMSE) is proposed to extract and analyze the electroencephalogram (EEG) features of patients with MCI. To overcome the information loss problem of traditional multiscale entropy (MSE), WMMSE fully considered the correlation of the sequence and the contribution of each sequence to the total entropy. The experimental group composed of 39 patients with MCI was subjected to NFT for 10 days during two sessions. The control group included 21 patients with MCI without any intervention. The Lempel-Ziv complexity (LZC) was used for primary assessment, and WMMSE was used to accurately analyze the effect of NFT. The results show that the WMMSE values of F4, C3, C4, O1, and T5 channels post-NFT are higher compared with pre-NFT and significant differences (P < 0.05). Moreover, the cognitive subscale of the Montreal Cognitive Assessment (MoCA) results shows that the post-NFT score is higher than the pre-NFT in the vast majority of the patients with MCI and significant differences (P < 0.05). When compared with the control group, the WMMSE values of the experimental group increased in each channel. Therefore, the NFT intervention method contributes to brain cognitive functional recovery, and WMMSE can be used as a biomarker to evaluate the state of MCI brain cognitive function.

PRIMARY ASSESSMENT OF THE DEGREE OF TORREFACTION OF BIOMASS AGRICULTURAL CROPS

Biomass energy is an important component in the overall structure of renewable energy and has the greatest potential for increasing volumes. However, the peculiarities of the properties of agro-industrial residues are a significant disadvantage of their widespread use. The process of torrefaction allows to bring the characteristics of biofuel as close as possible to thermal coal. Different degree of heat treatment of biomass leads to a product with different heating value. Therefore, it is important to know the optimal mode of torrefaction, which will provide the best energy parameters of biofuels.Researches of torrefaction were carried out on the basis of educational and scientific laboratory "DAK GPS" of the State Agrarian and Engineering University in Podilia. The kinetics of the relative mass of different types of biomass at different processing temperatures was considered. The dependence of the degree of torrefaction on the heat treatment temperature is revealed. As shown by studies for most biomaterials of plant origin, we can distinguish the beginning of intensive transformation and its end, after which there is a sharp slowdown in weight loss, and, accordingly, and the energy density of the samples.