scholarly journals ASSESSMENT OF APPLES' DAMAGE IN CONTAINERS WHEN TRANSPORTING THEM ON ROADS WITH DIFFERENT SURFACES

2020 ◽  
pp. 113-121
Author(s):  
А.А. СИМДЯНКИН ◽  
Л.П. БЕЛЮ
Keyword(s):  
Kinetic Energy ◽  
Rear Axle ◽  
Absolute Humidity ◽  
The Body ◽  
Crushed Stone ◽  
Calculation Methods ◽  
Fruit Damage ◽  
Biological Decomposition ◽  
Cartesian Coordinate ◽  
Classical Calculation

Проблема и цель. Целью настоящего исследования является оценка влияния расположения в кузове автомобиля ящиков с яблоками сорта «Айдаред», устойчивыми к повреждениям, на изменение скорости колебаний отдельных плодов в декартовой системе координат при движении транспортного средства по дорогам с различным покрытием и с различной скоростью. Методология. В качестве объекта исследований были выбраны яблоки, уложенные в стандартный ящик, размещаемый в трех положениях в кузове автомобиля «Форд Транзит». Измерения проводились на дорогах с тремя различными типами покрытий – асфальт, щебень и грунт на скоростях автомобиля, находящихся в диапазоне 20-50 км/ч. При проведении исследований использован метод замера ускорений в трех направлениях встроенным в смартфон акселерометром с установленным на нем программным обеспечением «Измеритель вибрации 1.3.6 APK», а также классические расчетные методы, позволяющие определить скорость яблока и его кинетическую энергию. Результаты. Выявлено наилучшее (с точки зрения повреждаемости плодов) расположение ящиков с яблоками – между осями автомобиля, и наихудшее – над задней осью. Приведена оценка вероятных повреждений плодов на основе расчета изменения их кинетической энергии при движении автомобиля. Определено изменение влажности плодов во времени при имитации получасовой перевозки яблок по щебеночной дороге со скоростью 20 км/ч. Установлено, что зафиксированное повышение абсолютной влажности плодов (более, чем на 10 %) существенно ускорит процессы биологического разложения, и даже дополнительное охлаждение не сможет существенно замедлить этот процесс. Заключение. На основании проведенных исследований рекомендуется избегать дорог с грунтовым и щебеночным покрытием в период их неудовлетворительного состояния, а при невозможности избежать таких участков использовать низкую скорость движения (не выше 20 км/ч), располагая ящики между осями автомобиля. Problem and purpose. The purpose of this study is to assess the efect of the location of boxes with Idared apples, resistant to damage, in the car body on the change in the vibration speed of individual fruits in a Cartesian coordinate system when a vehicle moves on roads with diferent surfaces and at diferent speeds. Methodology. Apples in a standard box placed in three positions in the body of a “Ford Transit” car were chosen as the object of the research. The measurements were carried out on roads with three diferent types of surface – asphalt, crushed stone and soil at vehicle speeds of 20-50 km/h. During the research measuring accelerations was done with the help of an accelerometer built into a smartphone with "Vibration Meter 1.3.6 APK" software installed on it. Besides the classical calculation methods allowing to determine the speed of an apple and its kinetic energy were used. Results. The best (in terms of fruit damage) location of boxes with apples is found and that was between the axles of the car, and the worst ones were above the rear axle. The estimation of probable damage to fruits based on the calculation of changes in their kinetic energy when driving a car was given. The change of fruit moisture was determined when simulating a half-hour transportation of apples along a gravel road at a speed of 20 km/h. It was found that the recorded increase in the absolute humidity of fruits (more than 10%) signifcantly accelerated the processes of biological decomposition. And even additional cooling could not signifcantly slow down this process. Conclusions. Based on the conducted research it is recommended to avoid roads with dirt and crushed stone surfaces during their unsatisfactory condition. If it is impossible to avoid such sections a driver should use a low speed (no higher than 20 km/h) placing boxes between the axles of the car.

Moving Cage: Vibration, Sonification and the Quanta of Time

2021 ◽  
Vol 46 (2) ◽  
pp. 169-183
Author(s):  
MARCUS CHENG CHYE TAN
Keyword(s):  
Kinetic Energy ◽  
The Body ◽  
Dance Movements ◽  
Politics Of The Body

Dear John is an experimental choreomusical work that reinterprets Cage's works while advancing his ideas of sound as sonic events and embodied choreography. In this episodic work, improvised movement unfolds to a soundscape of defamiliarized instruments, sound devices and sonicities of macro- and micro-movements. The correspondence and (in)congruence between dance movements and music's kinetic energy become the means to examine a politics of the body and sound, of music on movement. Additionally, in this ‘auditory architecture’ the quanta of time, its relations and (lack of) unity are exposed. This article then examines the intersubjective interplay of movement and music, body and sonicity; it considers the resonance of the performing body as intermaterial vibration and how this invites a sonic politics of relational possibility. The article will then also investigate the ways in which the interaction of motion and music, movement and stillness engenders experiences of time's indeterminacy and elasticity.

scholarly journals Elaboration of an Expert System for Sizing, Designing and Verifying Flexible Pavements

2020 ◽  
Vol 30 (3) ◽  
pp. 94-121
Author(s):  
Nadjet Bouacha ◽  
Mouloud Belachia
Keyword(s):  
Expert System ◽  
The Body ◽  
Design Calculation ◽  
Complex Data ◽  
Data Loss ◽  
Calculation Methods ◽  
System Generator ◽  
Subsequent Degradation ◽  
Executable Programs ◽  
Made In

Abstract The use of expert systems in the world of civil engineering, and in particular for roads, has become a necessity for the reason of the particularity, complexity, and diversity of the influencing parameters at the level of the design calculation, the latter of which represents the major source of subsequent degradation. This system consists of proposing a tool for helping the user firstly to size the body of the roadway, with several analytical methods and models (Pre-project, Boussinesq, Westgaard, and Burmister), and secondly, to offer different design possibilities (thickness and type of the material) that make up the layers. Lastly, it is to calculate the stresses and strains in order to compare them with admissible limits. The management of a knowledge base of complex natures (words, sentences, numbers, symbols, tables, calculation methods, equations, conditions, etc.) requires an adequate methodology which goes beyond the simple use of the technology but enables you to imagine the process of regrouping this mass of complex data and classifying the data, which can then be integrated into a database or spreadsheets and external programs designed with code compatible with the expert system generator. Our contribution relates initially to the formulation, organization, and preparation of the algorithms, and then the starting of the programs in order to conceive fully executable programs, the latter of which we can call the expert system. The validation of such a system was made as the work progressed, changes were made in the formulation of the rules, and the order and orientation of the data in the knowledge that the advantage of this type of system is the possibility of permanently reinforcing the database with human expertise in the field, or in books, especially so that we can avoid data loss due to illnesses, retirement, etc.

Experimental and numerical investigation of railroad vehicle braking dynamics

2009 ◽  
Vol 223 (3) ◽  
pp. 255-267
Author(s):  
C Mellace ◽  
A P Lai ◽  
A Gugliotta ◽  
N Bosso ◽  
T Sinokrot ◽  
...  
Keyword(s):  
Equations Of Motion ◽  
The Body ◽  
Computer Algorithms ◽  
Coordinate Systems ◽  
State Equations ◽  
Relative Coordinates ◽  
Linear State ◽  
Cartesian Coordinate ◽  
Railroad Vehicle ◽  
Braking Dynamics

One of the important issues associated with the use of trajectory coordinates in railroad vehicle dynamic algorithms is the ability of such coordinates to deal with braking and traction scenarios. In these algorithms, track coordinate systems that travel with constant speeds are introduced. As a result of using a prescribed motion for these track coordinate systems, the simulation of braking and/or traction scenarios becomes difficult or even impossible. The assumption of the prescribed motion of the track coordinate systems can be relaxed, thereby allowing the trajectory coordinates to be effectively used in modelling braking and traction dynamics. One of the objectives of this investigation is to demonstrate that by using track coordinate systems that can have an arbitrary motion, the trajectory coordinates can be used as the basis for developing computer algorithms for modelling braking and traction conditions. To this end, a set of six generalized trajectory coordinates is used to define the configuration of each rigid body in the railroad vehicle system. This set of coordinates consists of an arc length that represents the distance travelled by the body, and five relative coordinates that define the configuration of the body with respect to its track coordinate system. The independent non-linear state equations of motion associated with the trajectory coordinates are identified and integrated forward in time in order to determine the trajectory coordinates and velocities. The results obtained in this study show that when the track coordinate systems are allowed to have an arbitrary motion, the resulting set of trajectory coordinates can be used effectively in the study of braking and traction conditions. The results obtained using the trajectory coordinates are compared with the results obtained using the absolute Cartesian-coordinate-based formulations, which allow modelling braking and traction dynamics. In addition to this numerical validation of the trajectory coordinate formulation in braking scenarios, an experimental validation is also conducted using a roller test rig. The comparison presented in this study shows a good agreement between the obtained experimental and numerical results.

Optimal Self-Propulsion of a Deformable Prolate Spheroid

1983 ◽  
Vol 27 (02) ◽  
pp. 121-130
Author(s):  
T. Miloh
Keyword(s):  
Kinetic Energy ◽  
Surface Deformation ◽  
Deformable Body ◽  
Large Degree ◽  
Prolate Spheroid ◽  
The Body ◽  
Deformation Pattern ◽  
Inviscid Fluid ◽  
Periodic Surface ◽  
Deformation Velocity

The problem of self-propulsion of an elongated deformable body moving in an infinite medium of inviscid fluid is considered in some detail. A prolate spheroid is chosen as a model shape, and a particular deformation pattern which maximizes the Froude efficiency is sought. The Froude efficiency in this context is defined by the ratio of the kinetic energy of the body to the total kinetic energy of the system comprising the body and the fluid. It is demonstrated that a body can propel itself from rest in a persistent manner even for a periodic surface deformation with zero mean which preserves both the volume and the location of its centroid. Under these constraints the induced forward velocity of the body is of 0(ε2) where ε is the amplitude of the deformation velocity. It is also demonstrated that for a persistent self-propulsion to exist the body should develop a large degree of skewness, resulting from the interaction between the two deformation components—one with fore-and-aft symmetry and one without. It is also essential that the symmetric and asymmetric deformation components should be out of phase.

scholarly journals Importance of Vehicle Body Elements and Rear Axle Elements for Describing Road Booming Noise

Vehicles ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 589-603
Author(s):  
Michael Herrmann ◽  
Rainer Jöst ◽  
Florian Kehl ◽  
Ali Özkan ◽  
Simon Pless ◽  
...  
Keyword(s):  
Rear Axle ◽  
Transfer Functions ◽  
Body Movement ◽  
Longitudinal Mode ◽  
Simulation Models ◽  
The Body ◽  
Vehicle Body ◽  
Coupled Modes ◽  
Low Frequencies ◽  
Body Components

For investigating influences of vehicle components on the acoustic comfort at low frequencies, e.g., the booming noise behavior of a vehicle, building a whole car simulation model is useful. To reduce the model’s complexity and to save resources in the validation process, we first identify relevant components before building the model. Based on previous studies, we focus on the vehicle’s body and the rear axle. In this paper, we analyze which axle and body elements are crucial for describing road booming noise. For this purpose, we use impact measurements to examine noise transfer functions of the body and a vibro-acoustical modal analysis to identify coupled modes between the body’s structure and the interior cavity. For investigating relevant force paths from the rear axle to the body, we used a chassis test bench. We identify the main transmission paths of road booming noise and highlight which axle and body components have an influence on them. Mainly the rear axle in its upright direction in combination with a rigid body movement of the rear tailgate coupled with the first longitudinal mode of the airborne cavity causes road booming noise. Furthermore, the rear axle steering, the active roll stabilization and the trim elements of the vehicle’s body are essential to describe road booming noise. The results can be used to set priorities in the validation of individual axle and body components for future simulation models. We found that the ventilation openings, the front seats, the headliner, and the cockpit of a vehicle have little influence on its noise transfer functions from the rear axle connection points to the driver’s ear between 20 and 60 Hz.

The Application of Eddy-Viscosity Stress Limiters for Modeling Cross-Flow Separation

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
P. A. Gregory ◽  
P. N. Joubert ◽  
M. S. Chong ◽  
A. Ooi
Keyword(s):  
Kinetic Energy ◽  
Skin Friction ◽  
Turbulent Kinetic Energy ◽  
Flow Separation ◽  
Eddy Viscosity ◽  
Cross Flow ◽  
The Body ◽  
Mean Flow ◽  
Viscosity Models ◽  
Experimental Apparatus

The ability of eddy-viscosity models to simulate the turbulent wake produced by cross-flow separation over a curved body of revolution is assessed. The results obtained using the standard k−ω model show excessive levels of turbulent kinetic energy k in the vicinity of the stagnation point at the nose of the body. Additionally, high levels of k are observed throughout the wake. Enforcing laminar flow upstream of the nose (which replicates the experimental apparatus more accurately) gives more accurate estimates of k throughout the flowfield. A stress limiter in the form of Durbin’s T-limit modification for eddy-viscosity models is implemented for the k−ω model, and its effect on the computed surface pressures, skin friction, and surface flow features is assessed. Additionally, the effect of the T-limit modification on both the mean flow and the turbulent flow quantities within the wake is also examined. The use of the T-limit modification gives significant improvements in predicted levels of turbulent kinetic energy and Reynolds stresses within the wake. However, predicted values of skin friction in regions of attached flow become up to 50% greater than the experimental values when the T-limit is used. This is due to higher values of near-wall turbulence being created with the T-limit.

Gas Turbine Engine Test Cell Modeling

1990 ◽  
Author(s):  
D. Salinas ◽  
E. E. Cooper
Keyword(s):  
Kinetic Energy ◽  
Gas Turbine ◽  
Three Dimensional ◽  
Gas Turbine Engine ◽  
Test Cell ◽  
Dimensional System ◽  
Engine Test ◽  
Turbine Engine ◽  
Coordinate Model ◽  
Cartesian Coordinate

A numerical simulation of the aerothermal characteristics of a gas turbine engine test cell is presented. The three-dimensional system is modeled using the PHOENICS computational fluid dynamics code. Results predict the velocity field, temperatures, pressures, kinetic energy of turbulence, and dissipation rates of turbulent kinetic energy. Numerical results from two versions, a cartesian coordinate model and a body fitted coordinate model, are compared to experimental data. The comparison shows good quantitative and very good qualitative agreement, suggesting that numerical modeling would be useful in the preliminary design of gas turbine test facilities.

Gait style as an etiology to chronic postural pain. Part II. Postural compensatory process

1993 ◽  
Vol 83 (11) ◽  
pp. 615-624 ◽  
Author(s):  
HJ Dananberg
Keyword(s):  
Kinetic Energy ◽  
Sagittal Plane ◽  
Center Of Mass ◽  
Metatarsophalangeal Joint ◽  
Specific Pattern ◽  
The Body ◽  
First Metatarsophalangeal Joint ◽  
The Past ◽  
Compensatory Process ◽  
Methods Of Treatment

The body is designed to pull the center of mass over a single pivotal site formed by dorsiflexion of the first metatarsophalangeal joint. If this response dorsiflexion motion is blocked by functional hallux limitus, then the kinetic energy, which is created for this motion, must somehow be dissipated. The process by which this dissipation occurs creates a specific pattern of compensations which, in the past, has been seen as primary motions unrelated to sagittal plane blockade. These compensatory motions are described along with a brief section concerning the methods of treatment.

Die Pauli-Gleichung mit Differentialoperatoren für den Spin/ The Pauli Equation with Differential Operators for the Spin

1978 ◽  
Vol 33 (10) ◽  
pp. 1133-1150
Author(s):  
Eberhard Kern
Keyword(s):  
Angular Momentum ◽  
Rigid Body ◽  
Differential Operators ◽  
Spin Operator ◽  
Rigid Bodies ◽  
The Body ◽  
Wave Functions ◽  
Pauli Equation ◽  
Spin Eigenfunctions ◽  
Cartesian Coordinate

The spin operator s = (ħ/2) σ in the Pauli equation fulfills the commutation relation of the angular momentum and leads to half-integer eigenvalues of the eigenfunctions for s. If one tries to express s by canonically conjugated operators Φ and π = (ħ/i) ∂/∂Φ the formal angular momentum term s = Φ X π fails because it leads only to whole-integer eigenvalues. However, the modification of this term in the form s = 1/2 {π + Φ(Φ π) + Φ X π} leads to the required result.The eigenfunction system belonging to this differential operator s(Φ π) consists of (2s + 1) spin eigenfunctions ξm (Φ) which are given explicitly. They form a basis for the wave functions of a particle of spin s. Applying this formalism to particles with s = 1/2, agreement is reached with Pauli’s spin theory.The function s(Φ π) follows from the theory of rotating rigid bodies. The continuous spinvariable Φ = ((Φx , Φy, Φz) can be interpreted classically as a “turning vector” which defines the orientation in space of a rigid body. Φ is the positioning coordinate of the rigid body or the spin coordinate of the particle in analogy to the cartesian coordinate x. The spin s is a vector fixed to the body.

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