scholarly journals Road holding ability of machine-tractor unit during plowing

2020 ◽  
Vol 1 (6) ◽  
pp. 41-49
Author(s):  
I.P. Troyanovskaya ◽  
◽  
A.O. Zhakov ◽  
Keyword(s):  
Mathematical Theory ◽  
Shear Force ◽  
Lateral Displacement ◽  
Lateral Forces ◽  
Straight Line ◽  
Controlled Motion ◽  
Draft Resistance ◽  
External Forces ◽  
Vehicle Movement ◽  
Line Movement

The discrepancy between the working width of the plow and the width of the tractor leads to asymmetry of the arable units. The geometry of the share surface of the reversible plow contributes to the generation of lateral forces on the working tool. All this contributes to the imbalance of the working body and the deviation of the tractor from straight-line movement during plowing. To maintain a straight line, the driver has to correct the vehicle movement every 5-10 meters, which makes him more tired. To study the causes of lateral slip of the plowing unit, a mathematical model was built. It consists of the equations of controlled motion and equations of uncontrolled shift of the tractor under the action of external forces from the plow. The description of the force interaction of the propeller with the ground is based on the mathematical theory of friction, taking into account anisotropy and elastic properties in contact. On the basis of the passive shear model, the hodograph of the maximum force shifting the tractor from the side of the working tool is constructed. It has been established that the shear force reaches its maximum adhesion value only in the case of trans-lational shear, when its line of action passes through the center of gravity of the tractor. In all other cases, the shift (pull) of the tractor is carried out by a force of a lower value. The features and as-sumptions of the model are formulated in relation to the tracked and wheeled tractors. As a result, it was found that regardless of the direction of the lateral displacement of the plow draft resistance, the tractor is pulled towards the plowed field. The result of the numerical experiment showed that the main reason for the drift of the wheeled arable unit is the different type of soil along the sides of the tractor, but not the displacement of the plow traction resistance.

scholarly journals Directional stability of an agricultural tractor

2021 ◽  
Vol 49 (2) ◽  
pp. 456-462
Author(s):  
Irina Troyanovskaya ◽  
A. Zhakov ◽  
O. Grebenshchikova ◽  
S. Voinash ◽  
E. Timofeev
Keyword(s):  
Mathematical Theory ◽  
Shear Force ◽  
Lateral Displacement ◽  
Lateral Forces ◽  
Straight Line ◽  
The Difference ◽  
External Forces ◽  
Agricultural Tractor ◽  
Line Movement ◽  
Moldboard Plow

The discrepancy between the plow width and the tractor width leads to the asymmetry of plowing units. The geometry of the plowshare surface of the moldboard plow contributes to the generation of lateral forces on the working tool. All this leads to the imbalance of the tool and the deviation of the tractor from straight-line movement during plowing. To maintain straight-line movement, the driver has to adjust the machine every 5-10 meters, which is highly tiresome. To study the causes of lateral slips of the plowing unit, we constructed a mathematical model, which consists of the equations of controlled movement and equations of the tractor's uncontrolled shear under the action of external forces from the plow. The description of the force interaction of the drive with the ground is based on the mathematical theory of friction, taking into account anisotropy and elastic properties in contact. Based on the passive shear model, we constructed a hodograph diagram of the maximum tractor shear force from the side of the working tool. We found that the shear force reaches its maximum friction value only in the case of a translational shear, when its line of action passes through the tractor's center of gravity. In all other cases, the shift (slip) of the tractor is caused by a lower force. We formulated the features and assumptions of the model as applied to caterpillar and wheeled tractors. As a result, we found that, regardless of the direction of the lateral displacement of the plow's traction resistance, the tractor is slipped towards the plowed field. The result of the numerical experiment showed that the main reason for the slip of the wheeled plowing unit is the difference in soils along the sides of the tractor but not the deviation of the plow traction resistance.

scholarly journals Determination of Optimum Position of Shear Wall in an Irregular Building for Zone III & IV

2019 ◽  
Vol 9 (1) ◽  
pp. 174-183
Keyword(s):  
Comparative Study ◽  
Lateral Displacement ◽  
Shear Walls ◽  
Shear Wall ◽  
Lateral Stiffness ◽  
Base Shear ◽  
Modeling And Analysis ◽  
Lateral Forces ◽  
Optimum Position ◽  
External Forces

Stiffness is the property of the structure that is responsible for absorbing the external forces. For the case a multistory building, when the height of the building increases, the lateral stiffness of the building decreases. With low lateral stiffness, the building becomes more vulnerable to lateral forces like wind and earthquake. In order to prevent the structure from damage from the lateral forces, lateral stiffness is induced in the structure by means of shear walls. With the introduction of shear wall, we observe a considerable decrement in lateral displacement and increase in base shear. The resistance of lateral forces in terms of magnitude by shear wall depends on its location in the building. In this paper, a G+15 storey building is considered. The building is irregular in nature (T shaped). A comparative study is done to obtain the optimum position of shear wall in the structure. For optimization, the total length of the shear wall in the structure is kept constant. The whole modeling and analysis is done by ETABS v. 2016. The comparative study is done on the basis of base shear, storey displacement & storey drift. The above values are calculated by the dynamic approach of analysis of building subjected to seismic loading.

scholarly journals Evaluación de la motilidad espermática a través del sistema C.A.S.A de semen caprino criopreservado bajo diferentes medios diluyentes

Respuestas ◽  
2013 ◽  
Vol 18 (2) ◽  
pp. 16-27
Author(s):  
Leonardo Hernández-Corredor ◽  
Alexander Nivia-Osuna ◽  
Daniel Hernández-Villamizar ◽  
Jorge Alexander Rubio-Parada ◽  
Armando Quintero-Moreno
Keyword(s):  
Lateral Displacement ◽  
Egg Yolk ◽  
Computer Assisted ◽  
Complete Medium ◽  
Sperm Analysis ◽  
Straight Line ◽  
Nitrogen Vapor ◽  
Computer Assisted Sperm Analysis ◽  
The University ◽  
Casa System

 El estudio evaluó la motilidad espermática y su efecto postdescongelación en semen caprino, en dos medios comerciales (Andromed® y TwoStep®) y diferentes protocolos de congelación (medio completo, con adicción del 10% de yema de huevo, semen centrifugado y sobrenadante seminal), se utilizaron machos de la raza alpina de la Universidad Francisco de Paula Santander Ocaña, el semen fue colectado con electroeyaculador, una vez los medios terminados y parte de los contenidos seminales enteros o centrifugados mezclados, se estabilizó por 2 horas, se envasó en pajillas de 0,5 cc y se congela en vapores de nitrógeno por 10 minutos, las pajillas se llevaron al laboratorio de Andrología de la Universidad del Zulia y por medio del sistema C.A.S.A.(Computer Assisted Sperm Análisis) se evaluaron los parámetros de motilidad como velocidad curvilínea (VCL), velocidad rectilínea (VSL), velocidad lineal (VAP), índice de linealidad (LIN), índice de rectitud (STR), índice de oscilación (ALH), Amplitud media del desplazamiento lateral de la cabeza del espermatozoide (BCF), los datos fueron analizados por medio del procedimiento GLM de SAS versión 9.0; los mejores índices de motilidad (VCL, ALH, BCF) fueron expresados enel tratamiento de contenido seminal centrifugado en medio Andromed®. (p≤0,001))La mejor progresividad espermática (VSL,LIN,STR)se presentó el tratamiento de Semen completo de caprino, criopreservado en medio comercial TwoStep®. ABSTRACT  The study evaluated the effect sperm motility and sperm post-thawing in goats, two commercial means (Andromed ® and Two Step ®) and different freezing protocols (complete medium with 10% addition of the egg yolk, semen centrifuged supernatant and seminal ), we used males of the Alpine race of the University Francisco de Paula Santander Ocaña, semen was collected with electroejaculator once finished media and part of the whole and centrifuged seminal contents mixed, stabilized by two hours, packed in 0.5 cc straws and frozen in nitrogen vapor for 10 min, the straws were taken to the laboratory of Andrology at the University of Zulia and through CASA system (Computer Assisted Sperm Analysis) were evaluated motility parameters such as curvilinear velocity (VCL), straight line velocity (VSL), linear velocity (VAP), linearity index (LIN), straightness index (STR) Oscillation Index (ALH ) average amplitude of the lateral displacement of the sperm head (BCF), the data were analyzed by the GLM procedure of SAS version 9.0, the highest rates of motility (VCL, ALH, BCF) were expressed in the treatment of seminal content centrifugation Andromed ® medium. (p ≤ 0.001)) The best progressive sperm (VSL, LIN, STR) will present the full Semen treatment goats, cryopreserved at Two Step ® commercial medium.Keywords: semen, buck, Andromed, Two step.

An External Focus of Attention Improves Stability After a Perturbation During a Dynamic Balance Task

2015 ◽  
Vol 3 (2) ◽  
pp. 74-90 ◽  
Author(s):  
Scott W. Ducharme ◽  
Will F.W. Wu
Keyword(s):  
Lateral Displacement ◽  
Dynamic Balance ◽  
Attentional Focus ◽  
Focus Of Attention ◽  
External Information ◽  
External Focus ◽  
Balance Task ◽  
Straight Line ◽  
Focus Condition ◽  
Focus Strategies

An external focus of attention has been shown to improve balance measures during static postural tasks. The purpose of this study was to evaluate the effects of different attentional focus strategies in response to a perturbation while performing a dynamic balance task. Participants (n = 29) performed a dynamic balance task that consisted of stepping onto an uneven surface while attempting to continuously walk in a straight line. The orientation of the surface was unknown to the participants. During the external focus conditions, participants were instructed to focus on the surface they walked on. During the internal focus conditions, participants were instructed to focus on keeping their body over their feet. Analyses revealed that the external focus condition exhibited significantly less lateral displacement from the intended walking line following the perturbation (4.56 ± 2.56 cm) than the internal (5.61 ± 2.89 cm, p = .019) and baseline (6.07 ± 2.6 cm, p = .004) conditions. These data indicate that participants were more resilient to the perturbing surface when their attention was focused on external information. Thus, participants were able to respond to a perturbation more effectively when utilizing an external focus of attention.

scholarly journals Relatively semi-conservative replication and a folded slippage model for simple sequence repeats

2020 ◽  
Author(s):  
Zhongyang Tan ◽  
Hongxi Zhang ◽  
Douyue Li ◽  
Xiangyan Zhao ◽  
Saichao Pan ◽  
...  
Keyword(s):  
Current Theory ◽  
Bond Stability ◽  
Straight Line ◽  
Wide Range ◽  
Open Standard ◽  
Geometric Space ◽  
External Forces ◽  
Almost All ◽  
Simple Sequence

Abstract BackgroundSimple sequence repeats (SSRs) are found ubiquitously in almost all genome, and their formation mechanism is ambiguous yet.ResultsHere, the SSRs were analyzed in 55 randomly selected segments of genomes from a fairly wide range of species, with introducing more open standard for extensively mining repeats. A high percentage of repeats were discovered in these segments, which is inconsistent with the current theory suggested that repeats tend to disappear over long-term evolution. Therefore, a mechanism is most probably responsible for continually producing repeats during replication to balance continuous repeat disappearance, which may makes the replicating process relatively semi-conservative. To improve the current straight-line slippage model, we proposed a folded slippage model involving the geometric space of nucleotides and hydrogen bond stability to explain the high-percent SSR occurrence, which can describe SSR expansion and contraction more reasonably. And analysis of external forces in the folding template strands suggested that the microsatellites tend to expand than contract.ConclusionOur research may provide implements for contributions of microsatellites to genome evolution and complement semi-conservative replication.

Life expectancy and life energy according to Evo-SETI theory

2018 ◽  
Vol 18 (1) ◽  
pp. 36-46 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Mathematical Theory ◽  
Physical Phenomenon ◽  
Living Organism ◽  
Strict Sense ◽  
Power Curve ◽  
The Sun ◽  
Normalization Condition ◽  
Straight Line ◽  
Least Energy ◽  
Living Creature

AbstractThis paper is profoundly innovative for the Evo-SETI (Evolution and SETI) mathematical theory. While this author's previous papers were all based on the notion of a b-lognormal, that is a probability density function in the time describing one's life between birth and ‘senility’ (the descending inflexion point), in this paper the b-lognormals range between birth and peak only, while a descending parabola covers the lifespan after the peak and down to death. The resulting finite curve in time is called a LOGPAR, a nickname for ‘b-LOGnormal and PARabola’. The advantage of such a formulation is that three variables only (birth, peak and death) are sufficient to describe the whole Evo-SETI theory and the senility is discarded forever and so is the normalization condition of b-lognormals: only the shape of the b-lognormals is kept between birth and peak, but not its normalization condition.In addition, further advantages exist:1) The notion of ENERGY becomes part of Evo-SETI theory. This is in addition to the notion of ENTROPY already contained in the theory as the Shannon Information Entropy of b-lognormals, as it was explored in this author's previous papers. Actually, the LOGPAR may now be regarded as a POWER CURVE, i.e. a curve expressing the power of the living being to which it refers. And this power is to be understood both in the strict sense of physics (i.e. a curve measured in Watts) and in the loose sense of ‘political power’ if the logpar refers to a Civilization.Then the integral in the time of this power curve is, of course, the ENERGY either absorbed or produced by the physical phenomenon that the LOGPAR is describing in the time. For instance, if the logpar shows the time evolution of the Sun over about 10 billion years, the integral of such a curve is the energy produced by the Sun over the whole of its lifetime. Or, if the logpar describes the life of a man, the integral is the energy that this man must use in order to live.2) The PRINCIPLE OF LEAST ENERGY, reminiscent of the Principle of Least Action, i.e. the key stone to all Physics, also enters now into the Evo-SETI Theory by virtue of the so-called LOGPAR HISTORY FORMULAE, expressing the b-lognormal's mu and sigma directly in terms of the three only inputs b, p, d. The optimization of the lifetime of a living creature, or of a Civilization, or of a star, is obtained by setting to zero the first derivative of the area under the logpar power curve with respect to sigma. That yields the best value of both mu and sigma fulfilling the Principle of Least Energy for Evo-SETI Theory.3) We also derive for the first time a few more mathematical equations related to the ‘adolescence’ (or ‘puberty’) time, i.e. the time when the living organism acquires the capability of producing offsprings. This time is defined as the abscissa of ascending inflection point of the b-lognormal between birth and peak. In addition, we prove that the straight line parallel to the time axis and departing from the puberty time comes to mean the ‘Fertility Span’ in between puberty and the EOF (End-Of-Fertility time), which is where the above straight line intersects the descending parabola. All these new results apply well to the description of Man as the living creature to which our Evo-SETI mathematical theory perfectly applies.In conclusion, this paper really breaks new mathematical ground in Evo-SETI Theory, thus paving the way to further applications of the theory to Astrobiology and SETI.

Theoretical Tire Model for Wear Progress of Tires with Tread Pattern Considering Two-Dimensional Contact Patch

2021 ◽  
Author(s):  
Y. Nakajima ◽  
S. Hidano
Keyword(s):  
Shear Force ◽  
Rolling Resistance ◽  
Slip Condition ◽  
Slip Angle ◽  
Two Dimensional ◽  
Tire Model ◽  
Slip Ratio ◽  
Contact Patch ◽  
Crown Shape ◽  
External Forces

ABSTRACT A new theoretical tire model for the wear progress of tires with tread block pattern is developed considering a two-dimensional contact patch. In the model, the wear energy is calculated from the shear force and pressure distribution in a two-dimensional contact patch that are changed with not only shear forces in a contact patch but also with the wear and irregular wear of tires. The fore–aft shear force in a contact patch consists of six mechanisms related to slip ratio, camber, contact between a tire and a road, barrel deformation of a loaded block, rolling resistance, and a rolling tire with rounded crown shape, whereas the lateral shear force consists of three mechanisms related to slip angle/camber, contact of a tire with rounded crown shape, and barrel deformation of a loaded block. The heel and toe irregular wear and the progress of irregular wear under pure slip condition qualitatively agree with the conventional knowledge of tire engineers. The expected wear energy is introduced to predict the wear progress under combined slip condition in the wear course. Using the vehicle dynamics to predict the tire force history, a histogram of external forces is obtained by transforming from it. Calculating wear energies by changing slip angle and slip ratio, the relation between external forces and the wear energy is expressed as the response surface. Multiplying the wear energy by the histogram, the expected wear energy distribution in a block is calculated. Assuming that the worn depth is proportional to the expected wear energy, the wear progress is predicted.

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