scholarly journals Experimental research on mass determination of non-metal weights

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 23
Author(s):  
M. Hu ◽  
J. Wang ◽  
C. Cai ◽  
R. Zhong ◽  
K. Jiao ◽  
...  
Keyword(s):  
Mass Measurement ◽  
Mass Determination ◽  
Measuring Process ◽  
Pm 2.5 ◽  
Metal Material ◽  
Buoyancy Correction ◽  
The Stability ◽  
Definition Of ◽  
Silicon Spheres

With the revision of the definition of the kilogram, more and more weights made of non-metal material, such as silicon spheres and PM 2.5 film, need to be determined with high accuracy. As conventional mass is commonly used in mass metrology, this paper discusses the mass-measuring process for silicon and PM 2.5 film. Electrostatic eliminators are used to eliminate the electrostatic effects of non-metal material to improve the stability of mass measurement. Due to the big difference of weights’ densities, the air buoyancy correction and its uncertainty evaluation are also conducted.

An Archaeological Approach to the Study of Cultural Stability

1955 ◽  
Vol 11 ◽  
pp. 32-57 ◽  
Author(s):  
Emil W. Haury ◽  
Robert L. Rands ◽  
Albert C. Spaulding ◽  
Walter W. Taylor ◽  
Raymond H. Thompson ◽  
...  
Keyword(s):  
Stability Problem ◽  
Significant Contribution ◽  
Time Perspective ◽  
Problem Area ◽  
Cultural Development ◽  
Instability Problem ◽  
Long Span ◽  
The Stability ◽  
Definition Of

The study of cultural stability requires a knowledge of cultural development over a reasonably long span of time. The definition of this time perspective is one of the major contributions of archaeology to the study of culture. The archaeologist therefore should be in a position to make a significant contribution to the appraisal of the stability problem itself. However, the lack of a commonly accepted anthropological definition of the concept of cultural stability imposes semantic difficulties which hinder the determination of practical limits for the stability- instability problem area. Moreover, the nature of the data available to the archaeologist conditions the kind of contribution he can make.

Improved Quantitation of Cephalin-Cholesterol Flocculation Test

1964 ◽  
Vol 10 (9) ◽  
pp. 781-788 ◽  
Author(s):  
Robert G Martinek ◽  
Elvira Vimba ◽  
Joseph D Mann
Keyword(s):  
Barium Sulfate ◽  
Quantitative Method ◽  
Turbidimetric Method ◽  
Flocculation Test ◽  
Laboratory Procedures ◽  
The Stability ◽  
Definition Of

Abstract A rapid turbidimetric method for the determination of cephalin-cholesterol flocculation is described. Greater specificity and photometric sensitivity have been achieved along with adequate precision. The test is standardized with the conventional barium sulfate turbidity standards used for other laboratory procedures. Definition of results in turbidity units is proposed, and photometric standardization of the cephalin-cholesterol emulsion described. The stability of the emulsion is elucidated. Comparison is made with a previously described quantitative method.

Measurement of the molar mass of the 28Si-enriched silicon crystal (AVO28) with HR-ICP-MS

2015 ◽  
Vol 30 (12) ◽  
pp. 2449-2458 ◽  
Author(s):  
Tongxiang Ren ◽  
Jun Wang ◽  
Tao Zhou ◽  
Hai Lu ◽  
Yuan-jing Zhou
Keyword(s):  
Crucial Role ◽  
Molar Mass ◽  
Mass Measurement ◽  
Accurate Determination ◽  
Silicon Crystal ◽  
Avogadro Constant ◽  
Icp Ms ◽  
Definition Of

Accurate molar mass measurement of the highly 28Si-enriched crystal (AVO28) plays a crucial role in the accurate determination of the Avogadro constant and thus the new definition of the kilogram.

scholarly journals Mass spectrometric characterization of nicked fragments of the β-subunit of human chorionic gonadotropin

1997 ◽  
Vol 43 (7) ◽  
pp. 1172-1181 ◽  
Author(s):  
Chuanliang Liu ◽  
Larry D Bowers
Keyword(s):  
Mass Measurement ◽  
Human Leukocyte ◽  
Mass Determination ◽  
Β Subunit ◽  
Leukocyte Elastase ◽  
Human Leukocyte Elastase ◽  
Direct Mass Measurement ◽  
Oligosaccharide Structures

Abstract We describe the use of an HPLC/MS technique for the characterization of nicked fragments of hCG β-subunit. After reductive alkylation of the nicked hCG β-subunit with vinylpyridine, endoproteinase Glu-C or trypsin was used to digest the protein to produce peptides that could be analyzed by HPLC/electrospray ionization MS. Human leukocyte elastase digestion was used to produce an experimentally nicked hCG. Two nicking sites were observed, between amino acids 42Thr and 43Arg and between 44Val and45Leu. The former site has not been previously reported for elastase digestion. The structures of the fragments were confirmed by HPLC/MS after removal of the oligosaccharide by direct mass measurement and by mass determination of their proteolytic digests. Without the glycopeptidase treatment, the microheterogeneity of the two N-linked oligosaccharides could be deduced from the spectra of the proteolytic fragments. Nicking with elastase was found to alter the oligosaccharide structures. Nicked β-subunit samples isolated from the urine of choriocarcinoma patients were also analyzed and the location of the nicking site(s) agreed with that determined by classical techniques. Important differences in the oligosaccharide structures were also observed in these samples, including the presence of triantennary oligosaccharides not found in hCG from healthy subjects. These findings demonstrate the potential of HPLC/MS for characterization of glycoprotein standard preparations.

scholarly journals An HPLC and UHPLC-HRMS Approach to Study PSMA-11 Instability in Aqueous Solution

2020 ◽  
Author(s):  
ANTONELLA IUDICELLO ◽  
Filippo Genovese ◽  
Valentina Di Iorio ◽  
Gianfranco Cicoria ◽  
Stefano Boschi
Keyword(s):  
Analytical Method ◽  
Radiochemical Purity ◽  
Time Dependent ◽  
Dependent Manner ◽  
Compound Structure ◽  
High Affinity ◽  
Secondary Compound ◽  
The Stability ◽  
Definition Of

Abstract Background. Stability of precursors and reagents are of utmost importance for developing a suitable, fast and routinely reproducible analytical method for the quality control of radiopharmaceuticals, for the validation of the analytical method itself, as well as for radiolabeling procedure. During the validation of the analytical method used for the determination of chemical and radiochemical purity of an injectable solution of 68Ga-PSMA-11, a trend to instability of the PSMA-11 standard, the same used as a precursor in the radiosynthesis of 68Ga-PSMA11, has been found. This instability led to the formation of a secondary compound in a time-dependent manner. The formation of this compound made difficult the validation of the analytical method and influenced the radiolabeling yield, by increasing free 68Ga which, obviously, decreased the final yield.Results. The nature of this compound was investigated by adding chelators, such as EDTA, to PSMA-11 solutions and by using the combination of UHPLC-HRMS. The results led to the definition of the secondary compound structure, as natFe-PSMA-11, from the combination of the high affinity chelator HBED-CC, present in the molecule of PSMA-11, and environmental Fe(III).Conclusions. Strategies to reduce the risk of low radiolabeling yields and to increase the stability of the standards were also discussed.

Mass Measurement of 1-kg Silicon Spheres for Determination of the Avogadro and Planck Constants

2015 ◽  
Vol 64 (6) ◽  
pp. 1527-1532 ◽  
Author(s):  
Shigeki Mizushima ◽  
Naoki Kuramoto ◽  
Kazunaga Ueda ◽  
Kenichi Fujii
Keyword(s):  
Mass Measurement ◽  
Avogadro And Planck Constants ◽  
Silicon Spheres

Mass determination of silicon spheres used for the Avogadro project

Measurement ◽  
2007 ◽  
Vol 40 (7-8) ◽  
pp. 785-790 ◽  
Author(s):  
Michael Borys ◽  
Michael Gläser ◽  
Michael Mecke
Keyword(s):  
Mass Determination ◽  
Silicon Spheres

Postmodern More

Moreana ◽  
2003 ◽  
Vol 40 (Number 153- (1-2) ◽  
pp. 219-239
Author(s):  
Anne Lake Prescott
Keyword(s):  
Human Language ◽  
Thomas More ◽  
The Stability ◽  
Definition Of ◽  
Recent Critic

Thomas More is often called a “humanist,” and rightly so if the word has its usual meaning in scholarship on the Renaissance. “Humanist” has by now acquired so many different and contradictory meanings, however, that it needs to be applied carefully to the likes of More. Many postmodernists tend to use the word, pejoratively, to mean someone who believes in an autonomous self, the stability of words, reason, and the possibility of determinable meanings. Without quite arguing that More was a postmodernist avant la lettre, this essay suggests that he was not a “humanist” who stalks the pages of much recent postmodernist theory and that in fact even while remaining a devout Catholic and sensible lawyer he was quite as aware as any recent critic of the slipperiness of human selves and human language. It is time that literary critics tightened up their definition of “humanist,” especially when writing about the Renaissance.

Sign in / Sign up

Export Citation Format

Share Document