Experimental investigation of the work of a ploughing aggregate, operating according to the system ‘push- pull’

ArticleThe use of ploughing machine - and - tractor aggregates, operating according to the principle of ‘push - pull’ , finds increasing application in the world since it allows ensuring the stability of the movement and the depth of ploughing, reduction of the energy indicators. The aim of this experimental study is to determine under field conditions the dynamic and ope rational technological parameters of the ploughing machine - and - tractor aggregate, operating according to the ‘push - pull’ system. This aggregate was an integral ploughing - tillage wheeled HTZ 16131 tractor, in front of which there was mounted a two - bottom pl ough, and at the rear – four - bottom ploughs. This aggregate has satisfactory path parameters of the movement during the execution of the technological process of ploughing. The oscillations of the furrow path for this aggregate are of a low - frequency natur e and are concentrated in a rather narrow frequency range (0...50 m - 1 ). At the operating speed of 2.0 m ∙ s - 1 it is 0...0.16 Hz. The maximum value of the mutual correlation function between the input impact (the turning angle of the driven wheels of the aggr egating tractor) and the output value – its relative bearing is positive and reaches a value of 0.88. Stability of the ploughing depth for the aggregate according to the ‘2 + 4’ scheme is ± 1.65 cm 2 , which is normally the smaller value of the same indicato r for a serial ploughing aggregate (± 1.98 cm 2 )

Метод графов связи в задачах математического моделирования брахистохроны при наличии сил трения и сопротивления среды

Методом графів зв’язку встановлені основні геометричні параметри брахістохрон за наявності сил тертя та опору середовища, що дозволяє оптимізувати конструктивні параметри самоскидного бункера та мінімізувати витрати часу на його повне випорожнення.Basic geometrical brashistishrone parameters under condition of friction force environmental resistance presence are determined using connected graph method, which allows to improve design factors of skips and minimize time out unloading.Методом связных графов определены основные геометрические параметры брахистохрон при наличии сил трения и сопротивления среды, что позволяет оптимизировать конструктивные параметры самосвального бункера и минимизировать время выгрузки

Точные решения задач колебаний упругих механических систем при наличии сухого и нелинейно-вязкого трения

Здійснено математичне моделювання коливань пружних механічних систем за наявності сухого і (нелінійно) в’язкого тертя. Для побудованих моделей визначено точні аналітичні рішення.The mathematical modeling of the mechanical elastic systems’ oscillations with the coulomb and (nonlinear) viscous frictions is realized. One may obtain the accurate analytical solution for the constructed models.Осуществлено математическое моделирование колебаний упругих механических систем при наличии сухого и (нелинейно) вязкого трения. Для построенных моделей определены точные аналитические решения

Experimental investigation of the work of a ploughing aggregate, operating according to the system "push-pull"

The use of ploughing machine-and-tractor aggregates, operating according to the principle of - , finds increasing application in the world since it allows ensuring the stability of the movement and the depth of ploughing, reduction of the energy indicators. The aim of this experimental study is to determine under field conditions the dynamic and operational technological parameters of the ploughing machine-and-tractor aggregate, operating according to the - system. This aggregate was an integral ploughing-tillage wheeled HTZ 16131 tractor, in front of which there was mounted a two-bottom plough, and at the rear four-bottom ploughs. This aggregate has satisfactory path parameters of the movement during the execution of the technological process of ploughing. The oscillations of the furrow path for this aggregate are of a low-frequency nature and are concentrated in a rather narrow frequency range (0 50 m-1). At the operating speed of 2.0 m s-1 it is 0 0.16 Hz. The maximum value of the mutual correlation function between the input impact (the turning angle of the driven wheels of the aggregating tractor) and the output value its relative bearing is positive and reaches a value of 0.88. Stability of the ploughing depth for the aggregate according to the + scheme is 1.65 cm2, which is 1.98 cm2

Synchronization in G0/G1 enhances the mitogenic response of cells overexpressing the human insulin receptor A isoform to insulin

Evaluating mitogenic signaling specifically through the human insulin receptor (IR) is relevant for the preclinical safety assessment of developmental insulin analogs. It is known that overexpression of IR sensitizes cells to the mitogenic effects of insulin, but it is essentially unknown how mitogenic responses can be optimized to allow practical use of such recombinant cell lines for preclinical safety testing. We constitutively overexpressed the short isoform of the human insulin receptor (hIR-A, exon 11-negative) in L6 rat skeletal myoblasts. Because the mitogenic effect of growth factors such as insulin is expected to act in G0/G1, promoting S-phase entry, we developed a combined topoinhibition + serum deprivation strategy to explore the effect of G0/G1 synchronization as an independent parameter in the context of serum deprivation, the latter being routinely used to reduce background in mitogenicity assays. G0/G1 synchronization significantly improved the mitogenic responses of L6-hIR cells to insulin, measured by 3H-thymidine incorporation. Comparison with the parental L6 cells using phospho-mitogen-activated protein kinase, phospho-AKT, as well as 3H-thymidine incorporation end points supported that the majority of the mitogenic effect of insulin in L6-hIR cells was mediated by the overexpressed hIR-A. Using the optimized L6-hIR assay, we found that the X-10 insulin analog was more mitogenic than native human insulin, supporting that X-10 exhibits increased mitogenic signaling through the hIR-A. In summary, this study provides the first demonstration that serum deprivation may not be sufficient, and G0/G1 synchronization may be required to obtain optimal responsiveness of hIR-overexpressing cell lines for preclinical safety testing

Стійкість руху секції машини для обробки парів в поздовжньо-вертикальній площині

EN: One of the tasks of using the black fallow in agricultural production is the weed control and the moisture conservation in the soil. Application of the most advanced soil cultivation technologies ensures preservation of no more than 75% of precipitations in the soil. To improve the state of this issue, we have developed a special machine for processing the black fallow. A mathematical model has been developed that describes the dynamics of the movement of the harrow section in a longitudinal-vertical plane, and its solution is given, which allows investigation of the impact of this or that design parameter upon the dynamics of the angle of rotation in time. The adequacy of the developed mathematical model is confirmed by special laboratory and field investigations of the created experimental machine. With rational design parameters the rotation angle of the harrow section in a longitudinal-vertical plane will not exceed – 3º, and the time of its exit to the equilibrium position will not exceed 16...17 s. UK: До основних завдань застосування парів в сільськогосподарському виробництві є боротьба з бур'янами та збереження ґрунтової вологи. Застосування найсучасніших технологій обробітку ґрунту забезпечує збереження в ґрунті не більше 75% вологи. Для поліпшення стану у даному питанні нами розроблена спеціальна ґрунтообробна машина для обробки парів та проведене її дослідження. Розроблено математичну модель, що описує динаміку руху боронувальної секції в поздовжньо-вертикальній площині і приведено його розв’язування, яке дозволяє визначати вплив того чи іншого конструктивного параметра на динаміку зміни в часі кута її повороту. Адекватність розробленої математичної моделі підтверджено спеціальними лабораторно-польовими дослідженнями на створеній експериментальній установці. Встановлено, що при раціональних конструктивних параметрах значення кута повороту боронувальної секції в поздовжньо-вертикальній площині не перевищить – 3º, а час її виходу в рівноважний стан не перевищить 16...17 c

Tiltu veidu uzbūves matemātiskā modeļa atbilstības eksperimentāla pārbaude praktiskai izmantošanai lauksaimniecības transporta sistēmā

EN: The article exposes the results of the mathematical simulation of the agricultural bridge equipment functioning. The mathematical models describing the functioning of the agricultural bridge equipment were checked for adequacy by comparing the theoretical and experimental amplitude-frequency characteristics of the oscillations of its heading angle and lateral displacement. It was established by the result of investigated characteristics’ quantitative assessment that a satisfactory coincidence of the theoretical and experimental results, as well as a positive result of checking the adequacy of the mathematical models of the vertical and the horizontal oscillations of the agricultural equipment indicate a possibility of their further use for solving scientific and practical problems. LV: Rakstā aprakstīta metodika, kas paredzēta lauksaimniecības tiltu veida aprīkojuma funkcionēšanas matemātiskās modelēšanas rezultātu atbilstības pārbaudei, izmantojot dinamisko sistēmu automātiskās regulēšanas teoriju. Lauksaimniecības tiltu veida aprīkojuma darbību raksturojošo matemātisko modeļu atbilstība tika pārbaudīta, salīdzinot teorētiskos un eksperimentālos amplitūdas frekvences raksturlielumus tā virziena leņķa svārstībām un sānu pārvietojumam. Ar izpētīto kvantitatīvā novērtējuma rezultātiem tika noskaidrots, ka ir apmierinoša teorētisko un eksperimentālo rezultātu sakritība, kā arī pozitīvs rezultāts, pārbaudot lauksaimniecības tehnikas vertikālo un horizontālo svārstību matemātisko modeļu piemērotību, norāda uz iespēju tos turpmāk izmantot zinātnisku un praktisku problēmu risināšanai