Determination of the Water Absorption of Crude Rubber and of Vulcanized Rubber

1940 ◽  
Vol 13 (2) ◽  
pp. 400-407
Author(s):  
J. W. van Dalfsen
Keyword(s):  
Special Reference ◽  
Water Absorption ◽  
Vulcanized Rubber ◽  
Method Of Determination ◽  
Determination Methods

Abstract In the introduction the purpose of the investigation is described which is the development of a method suitable for the determination of the water absorption of crude and vulcanized rubber, and which, in conjunction with ash and nitrogen determinations is especially adapted to the testing of purified rubber. The conditions which affect the results of water determinations are reviewed, with special reference to the formulas of Taylor and Kemp, which make it possible, within certain limits, to compare results obtained by different determination methods. The reasons for selecting the foregoing method of determination of water absorption are described. It is pointed out that water absorption depends to different degrees on the time of vulcanization. In the rubber-sulfur mixture which was chosen, the influence of the degree of vulcanization is small, so that it is sufficient to vulcanize all types of rubber for the same length of time. At the same time it is shown that the results obtained by immersion of rubber for 7 and 25 hours at 80° C. still sufficiently agree with the values computed from the formulas of Taylor and Kemp. A method of measuring water absorption is described in detail. The question arises to what extent rubber manufacturers may use this method, in conjunction with ash and nitrogen determinations, method for estimating the quality of purified rubber. Rubber manufacturers are urged to give their opinion of this proposed method. Some other method will be considered if it should appear that manufacturers prefer this other method.

scholarly journals FAKTOR – FAKTOR YANG MEMPENGARUHI KUALITAS HASIL KERJA AUDITOR INTERNAL

2017 ◽  
Vol 8 (2) ◽  
pp. 331-350
Author(s):  
Aulia Afridzal ◽  
Helminsyah ◽  
Yusrawati JR Simatupang
Keyword(s):  
Internal Auditor ◽  
Method Of Determination ◽  
Model Study ◽  
Negative Effect ◽  
Positive Effect ◽  
Banda Aceh ◽  
Research Show ◽  
Variable Quality

This study tested the influence of accountability audit, knowledge and motivation to the quality of the work of the internal auditor. The respondents in this study is the auditor of the Inspektorat Pemerintah Kabupaten Aceh Besar and Kota Banda Aceh. The number of Auditors in this study as many as 37 Auditors. Method of determination of the sample used in this study was the census, while the method of data processing by means of multiple linear regression. The results of this research show that the whole variable (accountability, audit and motivation knowledge) together positive effect to the quality of the work of Auditors. Partially negative effect accountability to the quality of the work of Auditors, audit knowledge and motivation of the positive effect of the quality of the work of Auditors. This is shown by the value of R2 of 0.129 or 12.9%. This tells us that the variable accountability audit, knowledge and motivation affects the variable quality of the work the auditor amounted to 12.9%, while the rest of 87.1% are affected by other factors which are not formulated in the model study These.   Abstrak Penelitian ini menguji pengaruh akuntabilitas, pengetahuan audit dan motivasi terhadap kualitas hasil kerja auditor internal. Responden dalam penelitian ini adalah para auditor yang bekerja pada Inspektorat Pemerintah Kabupaten Aceh Besar dan Kota Banda Aceh. Jumlah auditor dalam penelitian ini sebanyak 37 auditor. Metode penentuan sampel yang digunakan dalam penelitian ini adalah sensus, sedangkan metode pengolahan data dengan cara regresi linear berganda. Hasil penelitian ini menunjukkan bahwa seluruh variabel (akuntabilitas, pengetahuan audit dan motivasi) secara bersama-sama berpengaruh positif terhadap kualitas hasil kerja auditor. Secara parsial akuntabilitas berpengaruh negatif terhadap kualitas hasil kerja auditor, pengetahuan audit dan motivasi berpengaruh positif terhadap kualitas hasil kerja auditor. Hal ini ditunjukkan oleh nilai R2 sebesar 0,129 atau 12,9%. Ini menjelaskan bahwa variabel akuntabilitas, pengetahuan audit dan motivasi mempengaruhi variabel kualitas hasil kerja auditor sebesar 12,9%, sedangkan sisanya sebesar 87,1% dipengaruhi oleh faktor-faktor lainnya yang tidak dirumuskan dalam model kajian ini. Kata kunci: Akuntabilitas, Pengetahuan Audit, Motivasi dan Kualitas Hasil Kerjaauditor

Methods for Determination of Rubber to Cord Bond Strength

1959 ◽  
Vol 32 (3) ◽  
pp. 898-906
Author(s):  
R. V. Uzina ◽  
L. S. Gromova ◽  
S. A. Vasil'eva
Keyword(s):  
Bond Strength ◽  
Laboratory Method ◽  
Single Thread ◽  
Vulcanized Rubber ◽  
Pull Out ◽  
Cord Fabric ◽  
Fabric Structures

Abstract In selecting methods for determination of rubber to cord bond strength it is necessary to consider the factors which are subject to variation in the system— the type of cord, the composition of the vulcanized rubber, or the composition of the impregnant. The selection (composition) of the methods of assessment of bond strength was carried out in the present study while keeping the type of cord and the rubber compositions constant ; only the composition of the impregnant was varied. Up to the present there has been no single laboratory method for evaluating rubber to cord bond strength for the determination of the service quality of rubber-fabric structures. The bond strength in such a system is assessed in the majority of cases by the use of a series of methods. The existing methods may be systematized according to the nature of the deformation (static or dynamic), the nature of the specimen (with single thread of cord or with cord fabric) and so on. We adopted the following classification of methods: 1). Determination of bond strength of a single thread of cord with the rubber; 2). Determination of bond strength of rubber to fabric model specimens. Determination of bond strength of a single thread of cord with rubber is an exceptionally widely used type of testing in the rubber industry. It is based either on the principle of stripping of a single thread of cord from the rubber under pressure, or on the principle of pull-out of a thread of cord from a rubber specimen.

scholarly journals Performance verification and measurement uncertainty estimation for the determination of sodium chloride in butter

2019 ◽  
Vol 23 ◽  
pp. 26
Author(s):  
Thalita Cristhina de Lima Moura ◽  
Beatriz Galdino Ribeiro ◽  
Paulo Roberto Salomão David ◽  
Alex Leandro Andrade de Lucena ◽  
Marcelo Farias de Andrade ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Limit Of Quantification ◽  
Performance Verification ◽  
Reagent Purity ◽  
Brazilian Legislation ◽  
Method Of Determination ◽  
Coefficients Of Variation ◽  
Measurement Uncertainty Estimation

The minimum parameters of identity and quality of butters in Brazil are governed by the Ministry of Agriculture, Livestock and Supply. From them it is possible to carry out the performance verification of the methodologies to guarantee the results reliability. Thus, the objective of this study was to analyze the performance of the method of determination of NaCl in butter, based on ISO 1738:2004, evaluating accuracy, precision and the limit of quantification (LOQ). The precision was obtained since the coefficients of variation found in the tests were lower than the Horwitz value. The accuracy was approved as a consequence of the confirmation of the proficiency having as provider the FAPAS. The LOQ of 0.41g of NaCl/100g of butter was established by evaluating the accuracy and the recovery in a NaCl content determination test, using a solution prepared with Certified Reference Material. To assure quality, the uncertainty associated with the NaCl measurement was also estimated, through the evaluation of the possible sources of uncertainty, among which were: weighing, analyzer, glassware and the reagent purity, with a measurement uncertainty of 0.03g NaCl/100g of sample. Finally, it was verified the conformity of the NaCl content in commercial samples according to the Brazilian legislation.

A New Method of Determination of Fillers in Vulcanized Rubber

1940 ◽  
Vol 13 (4) ◽  
pp. 931-935
Author(s):  
R. A. Hublin
Keyword(s):  
Filler Content ◽  
New Method ◽  
Vulcanized Rubber ◽  
Method Of Determination ◽  
Classic Method ◽  
Solution Methods

Abstract A new reagent, o-nitroanisol, makes it possible to determine the total filler content of vulcanized rubber much more rapidly and more precisely than heretofore. In addition, the procedure is easier than that of the classic method. It would therefore be desirable if the method of determining fillers by solution of the rubber, which can now be carried out so easily, were to be used in many cases in place of incineration methods, which, in spite of being rapid, are very inaccurate, and also if the new method were to be used in place of the ordinary, relatively inconvenient solution methods.

Tingkat Pemahaman Kompetensi Guru Pada Mahasiswa Pendidikan Geografi Sebagai Calon Guru Geografi

2020 ◽  
Vol 21 (1) ◽  
pp. 102-117
Author(s):  
Novia Zalmita ◽  
Muhajirah Muhajirah ◽  
Abdul Wahab Abdi
Keyword(s):  
Prospective Teachers ◽  
Prospective Teacher ◽  
Quantitative Description ◽  
Population Data ◽  
Geography Education ◽  
Teacher Competence ◽  
Education Department ◽  
Long Time

One that influences human resource indicators is education. The teacher is a profession as a job of academic specialization in a relatively long time in college. Understanding related to teacher competence is very important to have by a prospective teacher because it can affect the quality of performance as a professional teacher. The teacher's competence is known as pedagogic, professional, social and personality competencies. The issue in this study is how the competency of the teacher of the Department of Geography Education FKIP Unsyiah as a prospective teacher of geography? The purpose of this study was to determine the competence of teachers in the Department of Geography Education FKIP Unsyiah as prospective geography teachers. Quantitative description approach is used in this study to find answers to the issue. The population in this study were students of the Department of Geography Education FKIP Unsyiah class of 2015 and 2016 who had been declared to have passed the Micro Teaching and Magang Kependidikan 3 course totaling 50 people. Because the population is small and can be reached, the determination of the sample using total sampling techniques so that the sample in this study is the whole population. Data collection is done by distributing test questions to respondents. The data was analyzed using the descriptive statistics percentage formula. The results of the study indicate that the level of teacher competence of Geography Education Department students as prospective teachers is in the moderate category, namely as many as 22 respondents (44%). A total of 12 respondents (24%) were in the high category, 15 respondents (30%) were in the low category and 1 respondent (2%) were in the very low category.

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