ОБОСНОВАНИЕ ОСНОВНЫХ ПАРАМЕТРОВ ПЕРСПЕКТИВНЫХ УБОРОЧНЫХ МАШИН ФРЕЗЕРНОГО ТОРФА

Main directions of further modernization of УМПФ-type milling peat machines have been determined on the basis of complex analysis pertaining to application of these machines. Their modernization presupposes successful solution of national economy problem which is to increase a portion of local kinds of fuel in the power engineering balance of the Republic. One of the prospective peat machine diagram proposes to use a wheel propeller with a narrow back axle and front placement of removing and transporting element tool in relation to a bunker while applying a flight conveyer. Using this machine it is possible to obtain an improvement in indices of reliable operation of units, reduction in specific amount of metal per structure, reduction in power consumption in accomplishment of technological operation, higher productivity. First two directions of modernization provide for partial changes in some components of the machine and these tasks are successfully solved at repair and maintenance shops of peat enterprises. The third direction, that is development of milling peat machine of new generation, requires involvement of design organizations and machine-building plants. На основе комплексного анализа применения уборочных машин фрезерного торфа типа УМПФ определены основные пути их дальнейшей модернизации для успешного решения народнохозяйственной проблемы по увеличению доли местных видов топлива в энергетическом балансе республики. В одной из перспективных схем уборочной машины предлагается использовать колесный движитель с узкой задней осью, а также переднее расположение уборочно-транспортирующего рабочего органа по отношению к бункеру с использованием скребкового конвейера. При этом достигаются улучшение показателей надежности работы агрегатов, снижение металлоемкости конструкции и энергоемкости выполнения технологической операции, повышение производительности.Первые два пути модернизации предусматривают частичное изменении отдельных составных частей машины и успешно реализуются в ремонтно-механических мастерских торфопредприятий. Третье направление – разработка уборочной машины фрезерного торфа нового поколения – требует привлечения проектных организаций и машиностроительных заводов

СПЕЦИФИКА И НАПРАВЛЕНИЯ УЛУЧШЕНИЯ ДИНАМИКИ ТОРМОЖЕНИЯ АКТИВНЫХ ТРАКТОРНЫХ ПОЕЗДОВ

The paper considers an important problem in improvement of  braking dynamics potential as part of the overall tractor train dynamics consisting of  an all-wheel drive tractor and heavy-duty trailers which are either locally manufactured or developed with the participation of the paper’s authors. The trailers have a mechanical drive for their wheels from the tractor engine. The trains are intended for transportation peat, organic fertilizers and various loads in  forest exploitation and under other complicated soil and climatic and road conditions where there is justified necessity to activate the trailer wheels.Methodological tools have been developed with the purpose to analyze an influence of the blocked inter-double-reduction axle drive of an active tractor train on distribution of braking forces in double-reduction axles with due account of the heavy-duty peat trailer specificity. Theoretical provisions for wheeled vehicles have been developed with regard to the braking application specificity of active tractor trains with mechanical multi-path drive for wheels of a multi-double-reduction axle propulsion device. The paper presents calculation and theoretical data in order to estimate  distribution of specific braking forces in the double-reduction axle links of the active tractor train when the blocked inter-double-reduction axle drive of the tractor and trailer wheels is switched on and also in the case when the tractor engine is involved in braking process and a clutch coupling is switched-on.Sequence of the calculation formula has been completely carried out in the paper. They represent clear design and operational parameters of the active tractor train. Such approach has made it possible to realize them in the form of a software application which is convenient for analysis of the braking process pertaining to the investigated objects in order to select means for improvement of braking dynamics, rational parameters of multi-path wheel drive and tire completing of the active tractor train under design. The proposed information has a theoretical and practical value for specialists who are involved in development of new machine-tractor units for transport application in peat extraction, forestry, and agriculture.Статья посвящена важной проблеме улучшения потенциала тормозной динамики как части общей динамики тракторных поездов в составе полноприводного трактора и выпущенных промышленностью или создаваемых с участием авторов большегрузных прицепов, имеющих механический привод на колеса прицепа от двигателя трактора. Они предназначены  для перевозки торфа, органических удобрений, различных грузов на лесоразработках и в других сложных почвенно-климатических и дорожных условиях, в которых оправдана активизация колес прицепов.Разработан методический инструментарий для анализа влияния блокированного межмостового привода колес активного тракторного поезда на распределение тормозных сил по мостам с учетом специфики большегрузных прицепов-торфовозов. При решении задачи развиты положения теории колесных машин применительно к специфике торможения активного тракторного поезда с механическим разветвленным приводом колес многомостового движителя. Получены расчетно-теоретические выражения для оценки распределения удельных тормозных сил по мостам звеньев активного тракторного поезда при включенном блокированном межмостовом приводе колес трактора и прицепа, а также в случае участия в тормозном процессе двигателя трактора при включенной муфте сцепления.В полной мере выполнена последовательность расчетных выражений, включающих в явном виде конструктивные и эксплуатационные параметры активного тракторного поезда. Это позволило реализовать их в виде программного приложения, удобного для анализа процесса торможения исследуемых объектов при выборе средств улучшения динамики торможения, рациональных параметров разветвленного привода колес  и комплектации шинами проектируемого активного тракторного поезда. Изложенный материал  имеет теоретическое значение и представляет практический интерес для разработчиков новых машинно-тракторных агрегатов транспортного назначения для торфоразработок, лесного и сельского хозяйства

The 10th Biennial Hatter Cardiovascular Institute workshop: cellular protection—evaluating new directions in the setting of myocardial infarction, ischaemic stroke, and cardio-oncology

Due to its poor capacity for regeneration, the heart is particularly sensitive to the loss of contractile cardiomyocytes. The onslaught of damage caused by ischaemia and reperfusion, occurring during an acute myocardial infarction and the subsequent reperfusion therapy, can wipe out upwards of a billion cardiomyocytes. A similar program of cell death can cause the irreversible loss of neurons in ischaemic stroke. Similar pathways of lethal cell injury can contribute to other pathologies such as left ventricular dysfunction and heart failure caused by cancer therapy. Consequently, strategies designed to protect the heart from lethal cell injury have the potential to be applicable across all three pathologies. The investigators meeting at the 10th Hatter Cardiovascular Institute workshop examined the parallels between ST-segment elevation myocardial infarction (STEMI), ischaemic stroke, and other pathologies that cause the loss of cardiomyocytes including cancer therapeutic cardiotoxicity. They examined the prospects for protection by remote ischaemic conditioning (RIC) in each scenario, and evaluated impasses and novel opportunities for cellular protection, with the future landscape for RIC in the clinical setting to be determined by the outcome of the large ERIC-PPCI/CONDI2 study. It was agreed that the way forward must include measures to improve experimental methodologies, such that they better reflect the clinical scenario and to judiciously select combinations of therapies targeting specific pathways of cellular death and injury

Distinct cardioprotective mechanisms of immediate, early and delayed ischaemic postconditioning

Cardioprotection against ischaemia/reperfusion injury in mice can be achieved by delayed ischaemic postconditioning (IPost) applied as late as 30 min after the onset of reperfusion. We determined the efficacy of delayed IPost in a rat model of myocardial infarction (MI) and investigated potential underlying mechanisms of this phenomenon. Rats were subjected to 20, 30 or 45 min of coronary artery occlusion followed by 120 min of reperfusion (I/R). Immediate and early IPost included six cycles of I/R (10/10 s) applied 10 s or 10 min after reperfusion onset. In the second series of experiments, the rats were subjected to 30 min of coronary occlusion followed by IPost applied 10 s, 10, 30, 45 or 60 min after the onset of reperfusion. Immediate and early IPost (applied 10 s or 10 min of reperfusion) established cardioprotection only when applied after a period of myocardial ischaemia lasting 30 min. Delayed IPost applied after 30 or 45 min of reperfusion reduced infarct sizes by 36 and 41 %, respectively (both P < 0.01). IPost applied 60 min after reperfusion onset was ineffective. Inhibition of RISK pathway (administration of ERK1/2 inhibitor PD-98059 or PI3K inhibitor LY-294002) abolished cardioprotection established by immediate IPost but had no effect on cardioprotection conferred by early IPost. Blockade of SAFE pathway using JAK/STAT inhibitor AG490 had no effect on the immediate or early IPost cardioprotection. Blockade of mitochondrial KATP (mitoKATP) channels (with 5-Hydroxydecanoate) abolished cardioprotection achieved by immediate and early IPost, but had no effect on cardioprotection when IPost was applied 30 or 45 min into the reperfusion period. Immediate IPost increased phosphorylation of PI3K-AKT and ERK1/2. Early or delayed IPost had no effect on phosphorylation of PI3K-AKT, ERK1/2 or STAT3. These data show that in the rat model, delayed IPost confers significant cardioprotection even if applied 45 min after onset of reperfusion. Cardioprotection induced by immediate and early postconditioning involves recruitment of RISK pathway and/or mitoKATP channels, while delayed postconditioning appears to rely on a different mechanism

Remote ischaemic conditioning: defining critical criteria for success—report from the 11th Hatter Cardiovascular Workshop

Abstract: The Hatter Cardiovascular Institute biennial workshop, originally scheduled for April 2020 but postponed for 2 years due to the Covid pandemic, was organised to debate and discuss the future of Remote Ischaemic Conditioning (RIC). This evolved from the large multicentre CONDI-2–ERIC–PPCI outcome study which demonstrated no additional benefit when using RIC in the setting of ST-elevation myocardial infarction (STEMI). The workshop discussed how conditioning has led to a significant and fundamental understanding of the mechanisms preventing cell death following ischaemia and reperfusion, and the key target cyto-protective pathways recruited by protective interventions, such as RIC. However, the obvious need to translate this protection to the clinical setting has not materialised largely due to the disconnect between preclinical and clinical studies. Discussion points included how to adapt preclinical animal studies to mirror the patient presenting with an acute myocardial infarction, as well as how to refine patient selection in clinical studies to account for co-morbidities and ongoing therapy. These latter scenarios can modify cytoprotective signalling and need to be taken into account to allow for a more robust outcome when powered appropriately. The workshop also discussed the potential for RIC in other disease settings including ischaemic stroke, cardio-oncology and COVID-19. The workshop, therefore, put forward specific classifications which could help identify so-called responders vs. non-responders in both the preclinical and clinical settings

Ischaemic conditioning and reperfusion injury

The 30-year anniversary of the discovery of 'ischaemic preconditioning' is in 2016. This endogenous phenomenon can paradoxically protect the heart from acute myocardial infarction by subjecting it to one or more brief cycles of ischaemia and reperfusion. Apart from complete reperfusion, this method is the most powerful intervention known for reducing infarct size. The concept of ischaemic preconditioning has evolved into 'ischaemic conditioning', a term that encompasses a number of related endogenous cardioprotective strategies, applied either directly to the heart (ischaemic preconditioning or postconditioning) or from afar, for example a limb (remote ischaemic preconditioning, perconditioning, or postconditioning). Investigations of signalling pathways underlying ischaemic conditioning have identified a number of therapeutic targets for pharmacological manipulation. Over the past 3 decades, a number of ischaemic and pharmacological cardioprotection strategies, discovered in experimental studies, have been examined in the clinical setting of acute myocardial infarction and CABG surgery. The results from many of the studies have been disappointing, and no effective cardioprotective therapy is currently used in clinical practice. Several large, multicentre, randomized, controlled clinical trials on cardioprotection have highlighted the challenges of translating ischaemic conditioning and pharmacological cardioprotection strategies into patient benefit. However, a number of cardioprotective therapies have shown promising results in reducing infarct size and improving clinical outcomes in patients with ischaemic heart disease

SUBSTANTIATION OF MAIN PARAMETERS OF PROSPECTIVE MILLING PEAT MACHINES

Main directions of further modernization of УМПФ-type milling peat machines have been determined on the basis of complex analysis pertaining to application of these machines. Their modernization presupposes successful solution of national economy problem which is to increase a portion of local kinds of fuel in the power engineering balance of the Republic. One of the prospective peat machine diagram proposes to use a wheel propeller with a narrow back axle and front placement of removing and transporting element tool in relation to a bunker while applying a flight conveyer. Using this machine it is possible to obtain an improvement in indices of reliable operation of units, reduction in specific amount of metal per structure, reduction in power consumption in accomplishment of technological operation, higher productivity. First two directions of modernization provide for partial changes in some components of the machine and these tasks are successfully solved at repair and maintenance shops of peat enterprises. The third direction, that is development of milling peat machine of new generation, requires involvement of design organizations and machine-building plants

Пути сокращения засоления и восстановления почв в районах производственной деятельности ОАО «Беларуськалий»

The article is a review of the prominent technical solutions regarding potash salt deposits mining. The article shows the efficiency of application of biological restoration of saline soil by using salt marsh plants