Influence of Sampling on the Quality of Analyses with Emphasis on Powders

1973 ◽  
Vol 17 ◽  
pp. 44-67 ◽  
Author(s):  
C. L. Grant ◽  
P. A. Pelton
Keyword(s):  
Bulk Material ◽  
Sampling Error ◽  
Total Error ◽  
Particulate Material ◽  
Large Share ◽  
Bulk Properties ◽  
Analytical Error ◽  
Analytical Result

Sampling is a necessary part of the chemical analysis of particulate matter where the objective is to characterize bulk properties since it is usually undesirable or impossible to test an entire lot. The sample must be a miniature replica of the bulk material at least in respect to those features being tested. In other words, the sample must be representative to permit extrapolation from the sample to the bulk.There is error associated with sampling particulate material, but this sampling error is only one component of the total error associated with an analytical result. Sample preparation and determination of the property being tested are two other major sources of error, These three errors combine as the squares of their standard deviations, i.e., their variances, to produce the total analytical error. Very often, sampling error is the largest of the three and, therefore, contributes a disproportionately large share to the total error.

Nonsampling vs. Sampling Errors in Survey Research

1982 ◽  
Vol 46 (2) ◽  
pp. 114-123 ◽  
Author(s):  
Henry Assael ◽  
John Keon
Keyword(s):  
Survey Data ◽  
Sampling Error ◽  
Total Error ◽  
Sampling Errors ◽  
Validity And Reliability ◽  
Consistent Finding ◽  
Survey Error ◽  
Research Designs ◽  
Nonsampling Error

To increase the validity and reliability of survey data, one must minimize total error and its components, sampling and nonsampling error. This article examines and empirically compares the components of total survey error for several research designs and data collection methods. The consistent finding is that nonsampling error is the major contributor to total survey error, while random sampling error is minimal. On this basis guidelines for improving quality of survey data are provided.

Determination of Physical and Mechanical Properties of Quarries Dos Bocas Mouths and Mine Copeto for High Resistance Concretes

2018 ◽  
Vol 4 (2) ◽  
pp. 33
Author(s):  
Lucia Katherine Macías Sánchez ◽  
Eduardo Humberto Ortiz Hernández ◽  
Luis Santiago Quiroz Fernández ◽  
Wilter Enrique Ruiz Párraga
Keyword(s):  
High Resistance ◽  
Bulk Material ◽  
Soil Mechanics ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Fine Aggregate ◽  
Santo Domingo ◽  
Technical Specifications

The importance of the use, the type and the correct quality of the aggregate (aggregate) cannot be underestimated. Thin and coarse aggregates occupy about 60% to 80% of the volume of the concrete (70% to 85% of the mass) and strongly influence the properties both in the fresh and hardened state, in the proportions of the mixture and the economy of the concrete. Due to the great importance of the quality of the materials that must be used for high strength concretes, this research has been conducted to determine if the aggregates of the Dos Bocas and Copeto quarries meet the requirements outlined in the standards MOP-001 - F- 2002 for high resistance concretes. The bulk material was taken from the Dos Bocas quarry located in Puerto Cayo, Province of Manabí, and the fine aggregate was obtained from the Copeto Mine that is located in the Santo Domingo sector, Santo Domingo de los Tsáchilas Province. The tests executed in the Laboratory of Soil Mechanics, consisted in determining the quality index of the aggregate, calculating the maximum percentage of mass wear, determination of minimum and maximum percentages that pass through the standard sieves, volumetric mass, absorption and surface moisture. For a better understanding and interpretation of the results obtained from the different tests. We proceeded to graphically represent each of them for the two types of aggregates, allowing us to compare the property of each material with its respective specification, as mentioned in the Technical Specifications of the Ministry of Public Works MOP-001 - F- 2002.

scholarly journals Quantifying uncertainty in climatological fields from GPS radio occultation: an empirical-analytical error model

2011 ◽  
Vol 4 (9) ◽  
pp. 2019-2034 ◽  
Author(s):  
B. Scherllin-Pirscher ◽  
G. Kirchengast ◽  
A. K. Steiner ◽  
Y.-H. Kuo ◽  
U. Foelsche
Keyword(s):  
Radio Occultation ◽  
Sampling Error ◽  
Total Error ◽  
Statistical Error ◽  
Error Component ◽  
Error Model ◽  
Atmospheric Parameters ◽  
Analytical Error ◽  
Low Latitudes ◽  
Analytical Error Model

Abstract. Due to the measurement principle of the radio occultation (RO) technique, RO data are highly suitable for climate studies. RO profiles can be used to build climatological fields of different atmospheric parameters like bending angle, refractivity, density, pressure, geopotential height, and temperature. RO climatologies are affected by random (statistical) errors, sampling errors, and systematic errors, yielding a total climatological error. Based on empirical error estimates, we provide a simple analytical error model for these error components, which accounts for vertical, latitudinal, and seasonal variations. The vertical structure of each error component is modeled constant around the tropopause region. Above this region the error increases exponentially, below the increase follows an inverse height power-law. The statistical error strongly depends on the number of measurements. It is found to be the smallest error component for monthly mean 10° zonal mean climatologies with more than 600 measurements per bin. Due to smallest atmospheric variability, the sampling error is found to be smallest at low latitudes equatorwards of 40°. Beyond 40°, this error increases roughly linearly, with a stronger increase in hemispheric winter than in hemispheric summer. The sampling error model accounts for this hemispheric asymmetry. However, we recommend to subtract the sampling error when using RO climatologies for climate research since the residual sampling error remaining after such subtraction is estimated to be only about 30% of the original one or less. The systematic error accounts for potential residual biases in the measurements as well as in the retrieval process and generally dominates the total climatological error. Overall the total error in monthly means is estimated to be smaller than 0.07% in refractivity and 0.15 K in temperature at low to mid latitudes, increasing towards higher latitudes. This study focuses on dry atmospheric parameters as retrieved from RO measurements so for context we also quantitatively explain the difference between dry and physical atmospheric parameters, which can be significant at altitudes below about 6 km (high latitudes) to 10 km (low latitudes).

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.

Fluctuations of Annual Precipitation and Water Resources Quality in Ukraine

2016 ◽  
Vol 10 (4s) ◽  
pp. 621-629
Author(s):  
Valentina Pidlisnyuk ◽  
◽  
John Harrington JR ◽  
Yulia Melnyk ◽  
Yuliya Vystavna ◽  
...  
Keyword(s):  
Water Resources ◽  
Surface Waters ◽  
Precipitation Amount ◽  
Ion Concentration ◽  
Annual Precipitation ◽  
Resource Quality ◽  
Phosphate Ion ◽  
Regional Trends

The article focuses on examining the influence of fluctuations in annual precipitation amount on the quality of surface waters. Water quality was estimated with data on BOD, COD and phosphate–ion concentration within five selected regions of Ukraine. Analysis of the precipitation data (1991 – 2010) showed different regional trends. Using the statistics, determination of the interconnection between precipitation amount and water resources quality were done. The obtained regularities and associated uncertainties can be used for prediction of changes in water resource quality and as a guide for future adaptation to possible climate change.

POTENSI PENGEMBANGAN SADE SEBAGAI DESA WISATA LOMBOK

2016 ◽  
Vol 20 (2) ◽  
pp. 69-82
Author(s):  
W. Suprihatin ◽  
H. Hailuddin
Keyword(s):  
Analytical Hierarchy Process ◽  
Environmental Aspect ◽  
Priority Level ◽  
Highest Weight ◽  
Local Tradition ◽  
Tourist Village ◽  
Hierarchy Process ◽  
Initial Pattern

The background of the problems in this study is the decreasing quality of Sade hamlet amid rising tourist arrivals. From the environmental aspect, the conditions of the hamlet began to decline, in which the initial pattern of Sade has started a lot of changes towards the deficient and began to leave the local tradition. One effort to improve the condition of Sade hamlet in social, cultural and the environmental aspect is through the formulation of a sustainable structuring, the presence and identity maintaining and making a sustainable Tourism Village. Through analysis of AHP (Analytical Hierarchy Process) by collecting the perceptions of some experts through interviews and questionnaires, obtained by weighting the priority of the experts, namely the preservation of culture as an element of priority-level goals to be achieved in the development of Sade Hamlet as a tourist village at 0,476. While the determination of the level of the main criteria in the achievement of these objectives is the highest weight while maintaining a typical village environment at 0.319. Priority strategies that get the highest weight of the experts is that Sade Hamlet Revitalization with a priority weighting of 0.583. The second priority is the relocation of Hamlet at 0.235. Lowest weighting or last priority is Replication Sade Hamlet at 0.182.

Automation of selected brazes' dynamic properties in high-temperatures' measurement process

2013 ◽  
Vol 18 (2-3) ◽  
pp. 33-41
Author(s):  
Dominik Sankowski ◽  
Marcin Bakala ◽  
Rafał Wojciechowski
Keyword(s):  
Surface Tension ◽  
High Temperatures ◽  
Dynamic Properties ◽  
Automatic Measurement ◽  
Measurement Methodology ◽  
Joining Process ◽  
Wetting Force ◽  
Research Grant

Abstract The good quality of several manufactured components frequently depends on solidliquid interactions existing during processing. Nowadays, the research in material engineering focuses also on modern, automatic measurement methods of joining process properties, i.a. wetting force and surface tension, which allows for quantitative determination of above mentioned parameters. In the paper, the brazes’ dynamic properties in high-temperatures’ measurement methodology and the stand for automatic determination of braze’s properties, constructed and implmented within the research grant nr KBN N N519 441 839 - An integrated platform for automatic measurement of wettability and surface tension of solders at high temperatures, are widely described

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