Laboratory Simulation of Oxidative Aging of Asphalt

2009 ◽  
pp. 138-138-11
Author(s):  
GM Memon ◽  
BH Chollar
Keyword(s):  
Laboratory Simulation ◽  
Oxidative Aging

Laboratory Simulation of Lunar Luminescence

1962 ◽  
Vol 14 ◽  
pp. 441-444 ◽  
Author(s):  
J. E. Geake ◽  
H. Lipson ◽  
M. D. Lumb
Keyword(s):  
Science And Technology ◽  
Laboratory Simulation ◽  
The Moon ◽  
Physics Department ◽  
Luminescent Spectrum

Work has recently begun in the Physics Department of the Manchester College of Science and Technology on an attempt to simulate lunar luminescence in the laboratory. This programme is running parallel with that of our colleagues in the Manchester University Astronomy Department, who are making observations of the luminescent spectrum of the Moon itself. Our instruments are as yet only partly completed, but we will describe briefly what they are to consist of, in the hope that we may benefit from the comments of others in the same field, and arrange to co-ordinate our work with theirs.

EVALUASI PROGRAM PEMODELAN DAN SIMULASI LABORATORIUM KIMIA PADA MAHASISWA CALON GURU

EDUSAINS ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 201-211
Author(s):  
Yenni Kurniawati ◽  
Yuni Fatisa
Keyword(s):  
Mixed Method ◽  
Random Sampling ◽  
Sample Selection ◽  
Product Evaluation ◽  
Thinking Skills ◽  
Laboratory Simulation ◽  
Input Process ◽  
Improvement Program ◽  
Chemistry Students ◽  
Process Product

Abstract Modeling and laboratory simulation can help overcome of cost obstacle, time, safety and other constraints in laboratory experiments. Many skills also had the opportunity to be fostered and promoted, especially in connection with the construction of thinking skills. However, the implementation of this program required an evaluation, in order to decided whether the program will be continuing or not, in addition its needed to found the focused of on overall quality of learning in order to make a recommendation in the decision making. This research was conducted by the mixed-method approached with triangulation design, in order to evaluate the effectiveness, problems or any obstacles of the implementation of the program. The population in this study was the third semester of pre-service chemistry students at UIN Syarif Kasim Sultan Riau, which was supported by lecturers, assistant laboratory and staf. The sample selection was done using random sampling techniques. Program evaluation in this study was conducted by the CIPP model (Context, Input, Process, Product). The results showed that the program was running quite effective when viewed from the overall average grades. The evaluation about context, inputs, processes and products had the good and very good score, in which the evaluation score of context and input, get the better score than process and product evaluation. This study recommends to be a continuing improvement program of modeling and simulation laboratories, both as an exercise before the experiments or replace the real experiments. Keywords: modeling; simulation lab; chemistry experiment Abstrak Pemodelan dan simulasi laboratorium dapat membantu mengatasi kendala biaya, waktu, alasan keselamatan dan kendala lainnya dalam praktikum di laboratorium kimia. Beragam kemampuan lain juga berkesempatan untuk ditumbuh-kembangkan terutama dalam kaitannya dengan konstruksi berfikir. Meskipun demikian, implementasi pelaksanaan program ini memerlukan evaluasi, guna memutuskan apakah program ini layak dilanjutkan ataukah tidak, selain karena diperlukannya penemuan terhadap fokus peningkatan kualitas pembelajaran secara menyeluruh guna menghasilkan rekomendasi dalam menentukan keputusan. Penelitian ini dilakukan dengan menggunakan pendekatan mixed-method desain triangulasi, guna mengevaluasi sebab-sebab efektifitas, kendala ataupun kegagalan pelaksanaan program. Populasi dalam penelitian ini adalah mahasiswa semester III jurusan Pendidikan Kimia UIN Sultan Syarif Kasim Riau, yang didukung oleh dosen, asisten laboratorium dan laboran dan pemilihan sampel dilakukan menggunakan teknik random sampling. Evaluasi program dalam penelitian ini dilakukan menggunakan model CIPP (Context, Input, Process, Product). Hasil penelitian menunjukkan bahwa program ini berjalan cukup efektif jika dilihat dari rata-rata keseluruhan nilai, mulai dari context, input, proses dan produk yang berada pada skor baik dan sangat baik, di mana skor evaluasi context dan input, lebih baik dibanding proses dan produk. Penelitian ini memberikan rekomendasi untuk terus meningkatkan penggunaan pemodelan dan simulasi laboratorium kimia, baik sebagai latihan sebelum praktikum maupun menggantikan praktikum yang sesungguhnya. Kata Kunci: pemodelan; simulasi laboratorium; praktikum kimia  Permalink/DOI: http://dx.doi.org/10.15408/es.v8i2.4394  

Reactive molecular dynamic investigation of the oxidative aging impact on asphalt

2021 ◽  
Vol 279 ◽  
pp. 121298
Author(s):  
Yi Yang ◽  
Yixuan Wang ◽  
Jing Cao ◽  
Zengguang Xu ◽  
Yanlong Li ◽  
...  
Keyword(s):  
Molecular Dynamic ◽  
Oxidative Aging ◽  
Dynamic Investigation

scholarly journals How Small Molecules Affect the Thermo-Oxidative Aging Mechanism of Polypropylene: A Reactive Molecular Dynamics Study

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1243
Author(s):  
Fan Zhang ◽  
Yufei Cao ◽  
Xuan Liu ◽  
Huan Xu ◽  
Diannan Lu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Acetic Acid ◽  
Small Molecules ◽  
Aging Process ◽  
Experimental Studies ◽  
Hydroxyl Group ◽  
Oxidative Aging ◽  
Reactive Molecular Dynamics ◽  
Aging Mechanism ◽  
Effects Of Temperature

Understanding the aging mechanism of polypropylene (PP) is fundamental for the fabrication and application of PP-based materials. In this paper, we present our study in which we first used reactive molecular dynamics (RMD) simulations to explore the thermo-oxidative aging of PP in the presence of acetic acid or acetone. We studied the effects of temperature and oxygen on the aging process and discussed the formation pathways of typical small molecule products (H2, CO, CO2, CH4, C2H4, and C2H6). The effect of two infection agents, acetic acid and acetone, on the aging reaction was analyzed emphatically. The simulation results showed that acetone has a weak impact on accelerating the aging process, while acetic acid has a significant effect, consistent with previous experimental studies. By tracking the simulation trajectories, both acetic acid and acetone produced small active free radicals to further react with other fragment products, thus accelerating the aging process. The first reaction step of acetic acid is often the shedding of the H atom on the hydroxyl group, while the reaction of acetone is often the shedding of the H atom or the methyl. The latter requires higher energy at lower temperatures. This is why the acceleration effect of acetone for the thermo-oxidative aging of PP was not so significant compared to acetic acid in the experimental temperature (383.15 K).

Microstructural Control in Thick-Walled Nb-Ti-V Microalloyed Linepipe Steels

2004 ◽  
Vol 467-470 ◽  
pp. 223-228
Author(s):  
K.M. Banks
Keyword(s):  
Grain Size ◽  
Laboratory Simulation ◽  
Microalloyed Steels ◽  
Processing Parameter ◽  
Strip Rolling ◽  
Bearing Steels ◽  
Simulation Results ◽  
Linepipe Steels ◽  
Ferrite Grain Size ◽  
Microstructural Control

Various microstructure models for Nb-bearing steels were tested under industrial strip rolling conditions to establish a relationship between grain size and toughness in Ti-Nb-V microalloyed steels. For similar Nb contents, microstructure models for Nb steels were found to adequately describe recrystallisation kinetics in more complex Ti-Nb-V steels. For thick-walled linepipe (11.6mm), a minimum of 0.04%Nb is required to achieve adequate toughness. Retained strain was the dominant processing parameter factor affecting ferrite grain size. The predicted minimum amount of retained strain after the last pass required for sufficient grain refinement concurred with laboratory simulation results. For the rolling schedules investigated, metadynamic recrystallisation was predicted to occur during roughing, whilst static recrystallisation was predominant during finishing.

Laboratory Simulation of Thermal Convection in Rotating Planets and Stars

Science ◽  
1976 ◽  
Vol 191 (4222) ◽  
pp. 81-83 ◽  
Author(s):  
F. H. BUSSE ◽  
C. R. CARRIGAN
Keyword(s):  
Thermal Convection ◽  
Laboratory Simulation

Laboratory Simulation of Induction Tube Welding

1986 ◽  
Vol 23 (2) ◽  
pp. 159-165
Author(s):  
L. Hobson ◽  
A. Taylor ◽  
A. H. Woodcock
Keyword(s):  
Electrical Engineering ◽  
Measurement Techniques ◽  
Laboratory Scale ◽  
Laboratory Simulation ◽  
Laboratory Exercise ◽  
Tube Welding

An advanced laboratory exercise is outlined in which the industrial technique of induction tube welding is simulated on a laboratory scale. Details are given of the different measurement techniques used. This experiment may be used to introduce basic electrical engineering topics into engineering disciplines of all types.

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