National Standards of Impulse Electrical Voltage of the Russian Federation and the Republic of Belarus: Additional Comparisons

Measurement Techniques - This article discusses supplementary comparison results of initial national standards of the impulse electrical voltage, which resulted in confirmation of the accuracy of...     

National Standards of the Harmonic Coefficient Unit of the Russian Federation and the Republic of Belarus: Results of Comparisons

Measurement Techniques - The article presents the results of supplementary comparisons of the national standards of the harmonic coefficient unit of the Russian Federation (VNIIFTRI) and the...     

Chemical and sorption heat engines: State of the art and development prospects in the Russian Federation and the Republic of Belarus

The basic principles of operation of chemical and adsorption heat engines have been described. The advantages and new aspects of their application have been considered. A review of the state of the art in sorption technologies in different countries, as well as of the features of their application in Russia and Belarus is given. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 1, pp. 19–48, January–February, 2008.     

Comparisons of mathematics achievement of grade 8 students in the United States and the Russian Federation

Using the Mantel-Haenszel (MH) Procedure, we analyzed data for 7,087 American and 4,022 Russian Grade 8 students from the Third International Mathematics and Science Study (TIMSS) to compare mathematics achievement in the two countries on each of the 124 multiple-choice items. The results of the analyses indicate that the performance of the students on individual multiple-choice mathematics items vary by country. The results also suggest that the relationship between country and item performance differ as a function of content area. A total score of a country's achievement does not provide the whole picture of achievement dynamics; it averages out potentially important information on student achievement and the causes of their performance relative to other countries. The dynamics of achievement across countries will not be revealed unless the analyses are done at the item level.     

The Algorithm for Processing Key Comparisons to Establish Equivalence between National Standards

To establish equivalence between national standards, it is proposed to consider a priori the key comparisons made as regards the selection of data belonging to a single population. It is also proposed to estimate reference values as arithmetic means or medians. All national standards are recognized as equivalent with these values for the uncertainties established from the comparisons.     

The Results of the CCQM-K9 Key International Comparisons of National Standards of pH Measurements

A summary of the first CCQM-K9 key international comparisons of pH measurements to assess the level of the national standards of ten countries is presented. It is shown that there is good agreement between the results obtained within the limits of the measurement uncertainty declared by the participants.     

Prospects for employing heat pumps in the Republic of Belarus

A brief analysis of the possibilities of employing sorption heat pumps in the Republic of Belarus is given. Primary consideration is given to the light-duty heat pumps used for air-conditioning systems with automatic switching from the heating to the cooling state (air/water). One important component of sorption heat pumps is the low-temperature power source, which strongly influences the design of the heat pump in terms of economy and environmental protection.__________Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 78, No. 1, pp. 23–34, January–February, 2005.     

Status and prospects of hydrogen power engineering in the Republic of Belarus

Consideration is given to modern problems of development of scientific research in the field of hydrogen power engineering in the Republic of Belarus, the lines of investigations, and the prospects and problems facing research organizations. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 1, pp. 4–7, January–February, 2008.     

Ratio Comparisons of Impedance Standards

The application of a readily assembled comparator circuit, previously used in the comparison calibration of inductive and resistive voltage dividers, has been extended to cover the comparison of impedance standards. As an example requiring the most stringent performance from the circuit, the comparison of four-terminal inductance standards and their absolute determination in terms of the unit of capacitance have been studied. A data-reduction procedure has been devised to utilize a partial set of pair-wise comparison measurements to establish the absolute scale of inductance from 10 henrys to 500 ?H. A realistic assessment of system errors has been incorporated in the data reduction, which establishes the absolute accuracy at approximately 0.003 percent over the whole range. Determination of the quality factor Q of the inductors to better than 0.2 percent has also resulted from these measurements, principally at 1 kHz.     

Regional Maintenance of the Volt Using NBS Volt Transfer Techniques

In cooperation with five industrial standards laboratories, the National Bureau of Standards (NBS) studied the feasibility of establishing a regional volt maintenance and surveillance program in the greater Los Angeles, Calif., area. The objectives were to improve surveillance, to reduce dependence on NBS, and to have each laboratory maintain its unit of voltage to within 1 ppm of the U. S. legal volt. A two-phase program was established, the first to characterize the five laboratories and the second to carry out the surveillance. After 3 years all laboratories were found to be maintaining their unit to within better than 1 ppm of the U. S. legal volt.     

Results of Comparisons of the Working Standards of Frequency Deviation

The results of comparisons of six working standards of frequency deviation, carried out using a new comparator, are considered.     

Effect of the Organic and Mineral Constituents of Sapropels from Belarus Republic on the Selective Sorption of Radiocesium

The radiocesium interception potential (RIP) characterizing the ability of a sorbent to retain ¹³⁷Cs⁺ cations in the presence of competing K⁺ or NH₄⁺ cations [RIP(K) or RIP(N)] under the conditions controlled by selective sorption was determined for various materials. RIP(K) (mg-equiv kg^–1) is 44–720 and 260–1200, and RIP(N), 21–189 and 96–250 for sapropels of the organic and silica types, respectively. For sapropels of the organic type, the selectivity coefficient K_s(N/K) for the ¹³⁷Cs-selective sorption sites varies from 2.1 to 3.8, and for silica sapropels (Lake Dobeevskoe) it reaches 4.5–4.8, suggesting the presence of illite-type particles, which significantly influence the ¹³⁷Cs uptake by these types of sapropels. The highest RIP(K) values for the sapropels studied are reached at the organic to mineral matter ratios in the interval 0.43–0.61.     

Identification and Handling of Discrepant Measurements in Key Comparisons

In a key comparison one or several measurement objects are circulated among a number of laboratories, each of which measures the quantities represented by the objects. In order to compare the measurement results obtained by the participating laboratories, the values represented by the circulated objects have to be established. These values, known as the key comparison reference values, and their associated uncertainties can easily be calculated by the method of least squares from the measurement results provided by the participating laboratories. Since this method requires that the measurement results be mutually consistent, a hypothesis that sometimes has to be rejected at a reasonable level of significance, a procedure for identification and handling of discrepant measurements is needed. In this paper such a procedure is suggested. It is demonstrated that although a key comparison reference value is attracted to a discrepant measurement result that has an uncertainty much smaller than the remaining results, the suggested procedure is able to identify this discrepant result. It is also demonstrated that the exclusion of a discrepant measurement result from the calculation of the reference values does not amplify the discrepancy of that result. As the discrepant result is not excluded from the comparison itself, the exclusion of the result in the calculation of the reference values should therefore be uncontroversial.     

New Feature: History of Science. Now The Russian Federation

This is the first in a series of articles that will appear within the ESHS pages of Centaurus. The articles will follow an interview format and feature junior and senior researchers who will reflect on the situation of History of Science in their country.