scholarly journals Mathematical Model Describing the Influence of Geometrical Parameters of Multichannel Dies on the Limit Force of Dry Ice Extrusion Process

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3317
Author(s):  
Jan Górecki ◽  
Krzysztof Talaśka ◽  
Krzysztof Wałęsa ◽  
Dominik Wilczyński ◽  
Dominik Wojtkowiak
Keyword(s):  
Mathematical Model ◽  
Compressive Force ◽  
Extrusion Process ◽  
Physical Characteristics ◽  
Geometrical Parameters ◽  
Actual Measurement ◽  
Dry Ice ◽  
Measurement Results ◽  
The Difference

The article presents a formulated mathematical model that enables the determination of the required compressive force in the extrusion process of dry ice employing multichannel dies. This is the main parameter in the piston-based dry ice extrusion process. The indicated model was developed for the purpose of further improvement of the energy efficiency of this extrusion process. It allows for the determination of the value of compressive force by accounting for 12 variables related to the geometrical parameters of the die and the physical characteristics of dry ice. Furthermore, the paper also provides descriptions of the empirical study methodologies together with the results. These were carried out in order to determine the difference between the results of mathematical modeling and actual measurement results. The final part of the article presents the results of the analysis of the mathematical model’s sensitivity to the change of the physical characteristics of dry ice. The formulated tool may be employed to adapt the geometric parameters of the die in order to obtain the desired compressive force value and dry ice granulation with reduced energy consumption.

scholarly journals The influence of geometrical parameters of the forming channel on the boundary value of the axial force in the agglomeration process of dry ice

2019 ◽  
Vol 254 ◽  
pp. 05001 ◽  
Author(s):  
Jan Górecki ◽  
Ireneusz Malujda ◽  
Dominik Wilczyński
Keyword(s):  
Carbon Dioxide ◽  
Low Temperature ◽  
Axial Force ◽  
Environmental Conditions ◽  
Main Parameter ◽  
Geometrical Parameters ◽  
Dry Ice ◽  
Agglomeration Process ◽  
Boundary Force

The article presents the results of study on the influence of geometrical parameters of the forming channels on axial force which is the main parameter of the agglomeration process of dry ice in the piston method. During research, the material was agglomerated utilizing different dies. The material is characterized by low temperature and sublimation under standard environmental conditions. The study focuses on determining the influence of geometrical parameters of the conical and cylindrical sections of the forming chamber which influence the value of yield stress in the carbon dioxide agglomeration process. The determination of the value of boundary force is the basis for formulating the construction assumptions which shall be the basis for designing and constructing the dry ice compaction and pelletization machine.

Infinite-dilution activity coefficients by comparative ebulliometry: A model of ebulliometer and the experimental equipment and procedure

1986 ◽  
Vol 51 (7) ◽  
pp. 1393-1402 ◽  
Author(s):  
Vladimír Dohnal ◽  
Marcela Novotná
Keyword(s):  
Mathematical Model ◽  
Activity Coefficients ◽  
Infinite Dilution ◽  
Calibration Error ◽  
Simple Mathematical Model ◽  
Experimental Equipment ◽  
Infinite Dilution Activity Coefficients ◽  
The Difference ◽  
Major Factors

The ebulliometric technique for determination of infinite-dilution activity coefficients is examined. A simple mathematical model of ebulliometer is formulated to derive and analyze corrections accounting for the difference between the composition of the ebulliometer charge and that of the equilibrium liquid. Our own experimental equipment employing the comparative ebulliometric setup is described along with the measuring procedure and calibration. Error analysis is carried out identifying major factors limiting the accuracy of the determination.

scholarly journals Methodology for determining the parameters of drilling mode for directional straight sections of well using screw downhole motors

2020 ◽  
Vol 241 ◽  
pp. 105 ◽  
Author(s):  
V. Litvinenko ◽  
M. Dvoinikov
Keyword(s):  
Mathematical Model ◽  
Stable Operation ◽  
Geometrical Parameters ◽  
Directional Drilling ◽  
Optimal Parameters ◽  
Combined Method ◽  
Steady State Operation ◽  
Drilling String ◽  
Simultaneous Rotation

Article presents results of study on possibility of increasing the efficiency of drilling directional straight sections of wells using screw downhole motors (SDM) with a combined method of drilling with rotation of drilling string (DS). Goal is to ensure steady-state operation of SDM with simultaneous rotation of DS by reducing the amplitude of oscillations with adjusting the parameters of drilling mode on the basis of mathematical modeling for SDM – DS system.Results of experimental study on determination of extrema distribution of lateral and axial oscillations of SDM frame depending on geometrical parameters of gerotor mechanism and modes ensuring stable operation are presented.Approaches to development of a mathematical model and methodology are conceptually outlined that allow determining the range of self-oscillations for SDM – DS system and boundaries of rotational and translational wave perturbations for a heterogeneous rod with an installed SDM at drilling directional straight sections of well. This mathematical model of SDM – DS system's dynamics makes it possible to predict optimal parameters of directional drilling mode that ensure stable operation of borehole assembly.  

scholarly journals Prediction of the Collapse of Necrotic Femoral Head by CT and X-Ray Examinations before Hip Replacement Based on Intelligent Medical Big Data

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yongwei Shang ◽  
Jianjie Xu ◽  
Ting Zhang ◽  
Zhihui Dong ◽  
Jiebing Li ◽  
...  
Keyword(s):  
Big Data ◽  
Femoral Head ◽  
Hip Replacement ◽  
Detection Methods ◽  
Actual Measurement ◽  
X Ray ◽  
Measurement Results ◽  
Tertiary Hospitals ◽  
The Difference ◽  
Medical Big Data

It was to explore the effect of the CT and X-ray examinations before the hip replacement to predict the collapse of the necrotic femoral head under the classification of medical big data based on the decision tree algorithm of the difference grey wolf optimization (GWO) and provide a more effective examination basis for the treatment of patients with the osteonecrosis of the femoral head (ONFH). From January 2019 to January 2021, a total of 152,000 patients with ONFH and hip replacement in the tertiary hospitals were enrolled in this study. They were randomly divided into two groups, the study sample-X group (X-ray examination results) and based-CT group (CT examination results)—76,000 cases in each group. The actual measurement results of the femoral head form the gold standard to evaluate the effect of the two groups of detection methods. The measurement results of X-ray and CT before hip replacement are highly consistent with the detection results of the physical femoral head specimens, which can effectively predict the collapse of ONFH and carry out accurate staging. It is worthy of clinical promotion.

Study on Hydraulic Energy-Recovering Workover Rig and the Simulation for Lifting the Pipestring

2006 ◽  
Vol 129 (2) ◽  
pp. 96-101 ◽  
Author(s):  
Zhang Lujun
Keyword(s):  
Mathematical Model ◽  
Potential Energy ◽  
Energy Saving ◽  
Simulation Analysis ◽  
Actual Measurement ◽  
Measurement Results ◽  
Vessel Volume ◽  
Simulation Results ◽  
The Mathematical Model ◽  
Special Working

In this paper, an advanced energy-saving petroleum machinery, the hydraulic energy-recovering workover rig, is researched. The equipped power of this rig is only one third of an ordinary rig, and this rig can also recover and reuse the potential energy which is released by the pipestring when lowered. The special working theory of this rig is introduced. An energy-saving analysis is conducted. Analysis shows that when lowering the pipestring which weighs 260kN, the energy recovered by this rig is about 240×106J. The mathematical model of lifting the pipestring is established and a simulation analysis is conducted. Through simulation, some conclusions are obtained: (1) the lighter the pipestring the shorter the pipestring lifting time; (2) the smaller the throttle valve path area the longer the pipestring lifting time; (3) the smaller the air vessel volume the shorter the pipestring lifting time. The actual measurement results prove that the simulation results are right.

scholarly journals Finite Element Simulation and Experimental Determination of Residual Stresses after Extrusion Process in Metal Matrix Composites

2005 ◽  
Vol 14 (4) ◽  
pp. 096369350501400
Author(s):  
G. Albertini ◽  
E. Girardin ◽  
A. Giuliani ◽  
D.E. Ilie ◽  
B.P. O'Donnell ◽  
...  
Keyword(s):  
Finite Element ◽  
Metal Matrix ◽  
Extrusion Process ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Element Simulation ◽  
The Difference ◽  
Two Phases

The introduction of reinforcement in a Metal Matrix causes micro-stresses which may prove to be very detrimental for the life of the component. Submitting the components to annealing thermal treatments introduces thermal mismatch stresses. They are generated during cooling due to the difference between the thermal expansion coefficient of the two phases. Finite Element Analysis has been performed to study this effect and the results have been experimentally validated by X-ray diffraction, SEM investigation and EDAX on an AA2009 + 25% SiCp extruded shaft for helicopters, simplified as a thin extruded tube.

scholarly journals Mathematical Model for Velocity Calculation of Three Types of Vehicles in the Case of Pedestrian Crash

2018 ◽  
Vol 68 (3) ◽  
pp. 95-110
Author(s):  
Hoxha Gëzim ◽  
Shala Ahmet ◽  
Likaj Ramë ◽  
Bajrami Xhevahir
Keyword(s):  
Mathematical Model ◽  
Accurate Determination ◽  
Geometrical Parameters ◽  
Vehicle Speed ◽  
Model Formulation ◽  
Vehicle Velocity ◽  
Pedestrian Accidents ◽  
Throw Distance ◽  
Front Profile

AbstractThis paper treats influencing factors in the determination of vehicles speed on the pedestrian crash moment according to pedestrian throw distance and formulates a mathematical model for vehicle speed determination. Vehicle speed is one of the highest causes of accidents. The mathematical model formulation (as the target of this paper) for velocity calculation, in the case of pedestrian accidents, presents great help and guidance to experts of this field when dealing with accident analysis that through accurate determination of this parameter to find other circumstances as close as possible to the technical process of pedestrian accidents. The target of this paper is to define a mathematical model formulation for vehicle velocity calculation in pedestrian crash moment depending on relevant parameters. For the purpose of model formulating, we have selected three cases of real accidents that involved vehicles (“Peugeot 307”, “VW Golf ” and “Mercedes E 220”) with different geometrical parameters of the front profile and pedestrians with different heights and weights. For regression analysis we used “R” and “SPSS” software, which enables the statistical analysis of the data and mathematical model formulation. Also, for analysis of impact of relevant factors, model formulation and model testing have used “Virtual Crash” and “PC Crash” software, which enables pedestrian-vehicle crash simulation using vehicles with real technical characteristics and various pedestrian characteristics. Inductive, comparative, and deductive methods are part of the research methods in this paper.

scholarly journals Analysis Of Form Coefficient For Measuring Gross Tonnage Of Wooden Ship Based On Domestic Meansurment Method Of Indonesia

2021 ◽  
Vol 3 (2) ◽  
pp. 165-171
Author(s):  
Habibi Amal ◽  
Syamsul Asri ◽  
Andi Ardianti ◽  
Suandar Baso
Keyword(s):  
Measurement Method ◽  
Processing Method ◽  
Volume Factor ◽  
Size And Shape ◽  
Data Processing Method ◽  
Measurement Results ◽  
Mathematical Equations ◽  
The Difference ◽  
Actual Size

Most of the traditional wooden boats in Sinjai and Bone Districts were measured using the domestic measurement method, ship owners with sizes <GT 7 and <GT 30 refused to verify their vessels. Ship owners feel disadvantaged in terms of policies, permits, landing fees, subsidized fuel rations and so on. This study aims to determine the characteristics of the size and shape of traditional wooden ships, analyze and compare the results of the calculation of the gross tonnage (GT) of the ship which is calculated based on the actual size and shape of the ship (real body) with the ship calculated using domestic measurement methods and compiling mathematical equations in determining the value of the ship volume factor based on the main size to calculate the GT. The data processing method was carried out by using the Slovin technique with a population of 49 ship data for the determination of the minimum sample and then entered into the interval class. The results showed that the traditional wooden ships in Sinjai and Bone Regencies have geometric characteristics that are not much different from one another, but the main sizes are quite varied. The larger the main size of the ship, the greater the difference in GT calculations when using the volume factor value based on the domestic measurement method compared to using the volume factor value generated by real body calculations. The formula for the volume factor value (Cb or f) = 0.238 Log ((LBH)1/3) + 0.5134 can be used to determine the volume factor, especially for ships operating in the Sinjai and Bone Regencies as well as an initial reference for measurements by measuring experts ship so that moderate measurement results are obtained.

scholarly journals QIBLA DIRECTION WITH THE CONSTELLATION (STUDY OF DETERMINATION OF QIBLA DIRECTION WITH GUBUG PENCENG)

2021 ◽  
Vol 2 (2) ◽  
pp. 162-193
Author(s):  
M Ihtirozun Ni'am ◽  
Muhammad Fiki Burhanuddin ◽  
Nizma Nur Rahmi
Keyword(s):  
Field Research ◽  
Central Point ◽  
The Sun ◽  
Naked Eye ◽  
Measurement Results ◽  
Numerical Research ◽  
The Difference

In the ethnography of Javanese society, Gubug penceng is used as a southern constellation. With a declination value of -63º 05’ 57”, the appearance of this gubug penceng is a bit unique, because it can only be observed by observers who are south of the tropic. However, with a magnitude value of 0.77 and a shape that is easy to remember, it makes the gubug becomes a star that is easily visible to the naked eye. The author here will examine the use of the gubug penceng for determining the direction of the Qibla. Previous writers will take into account the azimuth of the Qibla and the azimuth of the acrux star which is the brightest star in the constellation of the thinner, then determine the direction of the Qibla by referring to the difference between the azimuth acrux and the qibla. This research is a field research which is included in qualitative numerical research. The author will compare the results of the Qibla direction from this gubug penceng with the Qibla direction determined with the help of the azimuth of the Sun. The results of this study found that the gubug penceng can be used as a reference to determine the direction of the Qibla. The qibla direction of the measurement results is quite accurate, because the object of aiming is in the form of a central point of the star. The difference between the direction of the Qibla between using the reference hut is not more than 24 minutes, so the results are quite accurate.

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