42 research outputs found
The impact of the kinematic parameters of bounce and pitch motions of sprung mass on wheeled vehicles handling
The impact of the kinematic parameters of bounce and pitch motions of wheeled vehicles’ (WVs’) sprung mass (SM) with non-linear power characteristics of the cushion system on vehicles handling is studied. The dependence of the critical value of the dynamic steering angle of directive wheels on the amplitude of bounce and pitch motions and the kinematic parameters of motion is developed. It is proven that the limit value of the dynamic steering angle of directive wheels is reduced during acceleration, and vice versa (it increases during braking, while the bounce and pitch motions are significantly reduced)
Study of Power Parameters of Forming Profile Elliptical Screw Workpieces
Based on the power-saving technologies, the design of an installation for coiling elliptical screw workpieces is worked out. Theoretical dependences for determining power and structural parameters of coiling a screw profile workpiece (SPW) on the elliptical mandrel are developed with consideration of the material grade specification and the parameters of technological equipment. The dependences of the moment value of SPW bending to the elliptical mandrel on its rotation angle, thickness and width are defined. The challenge is to develop the progressive methods of manufacturing augers and their sub-type - L-shaped auger spirals (LSAS) with high precision geometrical dimensions Computer simulation of the tape workpiece winding process on ellipse mandrel with initial conditions, displacements, deformations and stresses that arising in the material of tape workpice after applying the simulated efforts to it, was shown. Given simulation showed ranges where maximum stresses of tension and compression arising in material of tape workpiece, and made it possible to determine the minimum radius of curvature during winding, which is advisable to take at least 20 mm
Improvement of the organizational-economic mechanism of resource-saving at the machine building enterprise
The characteristic of the resource-saving at the machine-building enterprise has been presented. The complexity and system of the resource-saving control, as well as reasonableness of the development of the efficient organizational economic resource-saving mechanism have been interpreted. It was testified that the basis of the successful activity strategy in the resource-saving at the local machine-building enterprises is the efficient application of the available resources according to the requirement of the manufacturing products. Efficiency of such control can result from the proper application of the resourcenomy levers as a new science. Innovation chain of investigation of the resource-saving control problems from the point of view of resourcenomy has been proposed. Determination of the most efficient ways of setting up the organizational economic mechanism of resource-saving basing on the qualitative and quantitative factors of the resources application, using the resourcenomy techniques and taking into account the possibility to provide the enterprise with technologies, staff, control system, as well as the influence of each of the factors of the outside and inside environment of the enterprise, has been presented
Взаємодія видів транспорту: методичні вказівки до виконання лабораторних робіт для студентів ОКР «Бакалавр» спеціальності 6.070101 "Транспортні технології (автомобільний транспорт)"
Зростання чисельності населення та задоволення його природного прагнення у підвищенні добробуту потребуй розвитку суспільного виробництва для більш широкого випуску товарів за обсягом та номенклатурою. Випуск товарів пов'язаний з перевезенням сировини до місць переробки, її переміщенням у процесі виробництва i транспортуванням готової продукції до місць споживання. Об'єкти виробництва та споживання, як правило, розташовані у різних місцях, а потреба у готовій продукції може виникнути негайно або через певний проміжок часу. Тому сфери виробництва та споживання розірвані у просторі i часі. Випуск товарів неможливий без забезпечення виробництва робітниками, доставку яких з місць проживання виконує транспорт. Крім цього, транспорт задовольняє потреби людей на переміщення з освітніми та культурно - побутовими цілями, заклади яких віддалені від місць проживання. Отже, призначення транспорту є надання послуг пов'язаних з переміщенням вантажів та пасажирів у просторі часу.
Для реалізації свого призначення транспорт має розвинену інфраструктуру, яка складається з специфічних інфраструктур окремих видів транспорту. При цьому кожний вид транспорту виділяє окремі види сполучень (магістральні, місцеві, тощо), які забезпечуються відповідним рухомим складом i транспортними технологіями. У загальному випадку процес доставки вантажів і пасажирів включає в себе перевезення як з участю різних видів транспорту, так i у межах одного виду транспорту з виконанням різних видів сполучення. Отже, предметом взаємодії видів транспорту є розгляд відносин, які виникають при доставці вантажів i пасажирів різними видами транспорту або різними видами сполучень у межах одного виду транспорту
Organization of the Six-Cylinder Tractor Diesel Working Process
The purpose of the work is the organization of the six-cylinder diesel engines (with a power of 116 and 156 kW) working process with exhaust gas recirculation. The following systems and components were used in the experimental configuration of the engine: Common Rail BOSСH accumulator fuel injection system with an injection pressure of 140 MPa equipped with electro-hydraulic injectors with 7-hole nozzle and a 500 mm3 hydraulic flow; direct fuel injection system with MOTORPAL fuel pump with a maximum injection pressure of 100 MPa, equipped with MOTORPAL and AZPI five-hole nozzle injectors; two combustion chambers with volumes of 55 and 56 cm3 and bowl diameters of 55 and 67.5 mm; cylinder heads providing a 3-4 swirl ratio for Common Rail system, 3.5-4.5 for mechanical injection system; recirculation rate was set by gas throttling before the turbine using original design rotary valve. The tests were conducted at characteristic points of the NRSC cycle: minimum idle speed 800 rpm, maximum torque speed 1600 rpm, rated power speed 2100 rpm. It is established: achievement of emission standards for the 116 kW diesel engine is possible with the use of direct-acting fuel equipment and a semi-open combustion chamber; on the 156 kW diesel - using the Low Cost type common Rail fuel supply system and an open combustion chamber
Metabolic changes from liver regeneration after metastatic colorectal cancer surgery
Background. The pathological effect of the surgical ischemia-reperfusion technique is a cause for the development of liver damage and occurrence of acute liver failure during the postoperative period in cancer patients after major resection as well as after transplantation. Despite the urgency of the problem, most of the pathological processes that accompany the above-mentioned conditions are still only incompletely studied.
Objective. To investigate the mechanisms of the damaging effects of stress reaction after liver resection, to evaluate the functional state of residual liver tissue and to find ways to influence the regeneration and apoptosis of the resected liver, which in the future would make the liver surgery safer.
Methods. The results of treatment of 15 patients with colorectal cancer (mCRC) and liver metastases, who had undergone surgery in the period from December 2015 to November 2016 at the National Cancer Institute. Determination of the state of the detoxifying function of hepatocytes and the coupling of biological oxidation and phosphorylation in the mitochondria of hepatocytes were performed by electron paramagnetic resonance at the temperature of liquid nitrogen.
Results. It has been found that the levels of the oxidized and low-spin forms of cytochrome P-450 in the catalytic cycle of the detoxification system were 0.33 ± 0.08 relative units and 1.11 ± 0.13 relative units, respectively (the normal levels are 0.59 ± 0.03 relative units and 2.56 ± 0.02 relative units). Also, an increase registered in the levels of formation of complexes of NO-FeS-proteins up to the values of 0.33 ± 0.08 relative units (the normal level is 0.14 ± 0.07). We believe that such changes are the cause of disturbances in the energy function of mitochondria and the formation of cell hypoxia, which correlates with an increase of lactate levels in tissue of the future liver remnant. The liver remnant levels are > 2.00 mM/g·tissue, while the normal is 1.80 ± 0.26 mm/g·tissue. This confirms the functioning of hepatocytes under hypoxic conditions.
Conclusions. In the residual liver tissue, we have found a decrease in detoxification system deficiency and the energy supply of hepatocytes. In hepatocytes of the future liver remnant, reprogramming of the metabolism of mitochondria from oxidative phosphorylation in glycolysis is registered, resulting in the formation of cell hypoxia and an increase in levels of lactate and superoxide radicals. To assess the degree of ALF in the postoperative period, we suggest use of the levels of lactate, the activity of cytochrome P-450, the levels of formation of complexes of NO and FeS-proteins in mitochondria ETC and the generation rate of SR as the markers
Metabolic changes from liver regeneration after metastatic colorectal cancer surgery
Background. The pathological effect of the surgical ischemia-reperfusion technique is a cause for the development of liver damage and occurrence of acute liver failure during the postoperative period in cancer patients after major resection as well as after transplantation. Despite the urgency of the problem, most of the pathological processes that accompany the above-mentioned conditions are still only incompletely studied.
Objective. To investigate the mechanisms of the damaging effects of stress reaction after liver resection, to evaluate the functional state of residual liver tissue and to find ways to influence the regeneration and apoptosis of the resected liver, which in the future would make the liver surgery safer.
Methods. The results of treatment of 15 patients with colorectal cancer (mCRC) and liver metastases, who had undergone surgery in the period from December 2015 to November 2016 at the National Cancer Institute. Determination of the state of the detoxifying function of hepatocytes and the coupling of biological oxidation and phosphorylation in the mitochondria of hepatocytes were performed by electron paramagnetic resonance at the temperature of liquid nitrogen.
Results. It has been found that the levels of the oxidized and low-spin forms of cytochrome P-450 in the catalytic cycle of the detoxification system were 0.33 ± 0.08 relative units and 1.11 ± 0.13 relative units, respectively (the normal levels are 0.59 ± 0.03 relative units and 2.56 ± 0.02 relative units). Also, an increase registered in the levels of formation of complexes of NO-FeS-proteins up to the values of 0.33 ± 0.08 relative units (the normal level is 0.14 ± 0.07). We believe that such changes are the cause of disturbances in the energy function of mitochondria and the formation of cell hypoxia, which correlates with an increase of lactate levels in tissue of the future liver remnant. The liver remnant levels are > 2.00 mM/g·tissue, while the normal is 1.80 ± 0.26 mm/g·tissue. This confirms the functioning of hepatocytes under hypoxic conditions.
Conclusions. In the residual liver tissue, we have found a decrease in detoxification system deficiency and the energy supply of hepatocytes. In hepatocytes of the future liver remnant, reprogramming of the metabolism of mitochondria from oxidative phosphorylation in glycolysis is registered, resulting in the formation of cell hypoxia and an increase in levels of lactate and superoxide radicals. To assess the degree of ALF in the postoperative period, we suggest use of the levels of lactate, the activity of cytochrome P-450, the levels of formation of complexes of NO and FeS-proteins in mitochondria ETC and the generation rate of SR as the markers
Intelligent transport systems in the context of resource saving
Интеллектуальные транспортные системы обычно рассматриваются как базовая технология для постоянного снижения дорожно-транспортных происшествий и повышения эффективности трафика.
Согласно исследованию, существующие интеллектуальные транспортные системы не только обеспечивают значительное сокращение выбросов парниковых газов, экономию топлива, время проезда, но и не маргинализируют мобильность граждан.Intelligent transport systems are usually considered as a basic technology to continuously reduce traffic accidents and increase the efficiency of traffic. According to the study, the existing intelligent transport systems not only provide a significant reduction in greenhouse gas emissions, fuel economy, travel time, but also do not marginalize the stability of citizens
Establishing the range of variability of the skull structures in adulthood
One of the most relevant direction of modern craniological anatomy ̶ is an individual variability of the shape, size, position and relations of skull’s regions and their structures. The research was conducted on craniometric study of 100 coherent and fragmented skull’s bones included in the collections of human anatomy department in Kharkiv National Medical University. For facial skull studies used different measuring instruments and devices: dividers, set of facial lines, protractors, goniometer.In adulthood people of our region there is a direct dependence on the morphological type of the structures of the head and certain indicators of the cranial, altitude-longitudinal and altitude-latitudinal indexes. Most often, there are males with expanded and rounded forms of the skull with a predominance of moderate head size, that is relate them to the brachicranial type of the skull’s structure. The middle group consists of males and females who have a classical middle form of the head, and belong to the mesomorphic structure of the skull. The smallest group consists of adulthood people with a narrow and elongated form of the head, referred to the dolichocranial type of skull structure