Garteur Group on Ground Vibration Testing: Results From the Test of a Single Structure by 12 Laboratories in Europe

1997 ◽  
Author(s):  
Etienne Balmès ◽  
Jan R. Wright
Keyword(s):  
State Of The Art ◽  
Ground Vibration ◽  
Structure Design ◽  
Modal Characteristics ◽  
Common Structure ◽  
Single Structure ◽  
The Common ◽  
Vibration Tests ◽  
Main Activity

Abstract In an effort to assess state of the art methodologies for the experimental determination of modal characteristics, 12 European groups, most of them working in the area of aircraft ground vibration tests for flutter certification, participated in a GAR-TEUR action group whose main activity was to have independent tests of a single representative structure. Design considerations for the common structure are first detailed. Estimates of frequency response functions and modal characteristics are then compared and show a level of consistency that is much higher than those reported in previous similar exercises.

Mechanism of interference with the Jaffé reaction for creatinine.

1987 ◽  
Vol 33 (7) ◽  
pp. 1129-1132 ◽  
Author(s):  
M H Kroll ◽  
N A Roach ◽  
B Poe ◽  
R J Elin
Keyword(s):  
Carbonyl Group ◽  
Equilibrium Constants ◽  
Molar Absorptivity ◽  
Reaction Products ◽  
Cyclic Ketones ◽  
Common Structure ◽  
Aliphatic Ketones ◽  
Rate Of Reaction ◽  
The Common

Abstract We investigated the mechanism of the Jaffé reaction for determination of creatinine by studying the spectrophotometric, kinetic, and equilibrium properties of the reaction of picrate with creatinine and with cyclic and aliphatic ketones. Absorbance spectra for the reaction products of picrate with all the ketones were superimposable with that of creatinine (Amax, 490 nm). Cyclic ketones not containing nitrogen had a molar absorptivity less than half that of creatinine and equilibrium constants approximately 0.01 that of creatinine. Aliphatic ketones, except for benzylacetone, had molar absorptivities similar to that of creatinine, but all of these compounds had equilibrium constants approximately a tenth or less that of creatinine. The common structure for all of the compounds reacting with picrate is the carbonyl group. The variable magnitude of interference for aliphatic and cyclic ketones is ascribable to the different rate constants, molar absorptivities, and equilibrium constants as compared with creatinine. Structures adjacent to the carbonyl group significantly affect the absorptivity and equilibrium constant, but steric hindrance is the major factor affecting the rate of reaction. We postulate that the carbonyl group is required for the Jaffé reaction, and we suggest a mechanism for the reaction.

FEATURES OF SIMULATING THE FORCE ACTIONS FROM A DAMAGED ENGINE AT GROUND VIBRATION TESTS OF AN AIRPLANE

2016 ◽  
Vol 47 (6) ◽  
pp. 649-663
Author(s):  
Regina Vladimirovna Leonteva ◽  
Vsevolod Igorevich Smyslov
Keyword(s):  
Ground Vibration ◽  
Vibration Tests

The Determination of the Noise Pollution in a Production Hall and the Diseases Produced by It

2018 ◽  
Vol 69 (4) ◽  
pp. 875-880
Author(s):  
Oana Roxana Chivu ◽  
Ovidiu Mederle ◽  
Augustin Semenescu ◽  
Ileana Mates ◽  
Claudiu Babis ◽  
...  
Keyword(s):  
Risk Factor ◽  
Human Body ◽  
Noise Level ◽  
Noise Pollution ◽  
Protective Measures ◽  
Work Program ◽  
Specialized Equipment ◽  
Chemical Products ◽  
Main Activity

The paper describes how to determine the noise in a production hall where there are production machines and equipment. The chosen plant is a production unit where filling of the polyurethane foam tubes is performed. The main activity is the production of professional insulators and wholesale of other products from the same range enumerating the following: wholesale chemical products; production of professional insulators; trade in chemicals and chemical industry. The recommended maximum admissible value for a normal 8h work program is 85 dB (A). The objective is to determine the level of noise in the factory and how it acts as a physical professional risk factor and its effects on the human body. The way in which the proposed objective was achieved was to determine the value of the noise level with the specialized equipment. Following the determinations that will be presented in the following chapters, appropriate protective measures have been taken.

scholarly journals The Degree of Oxidation of Graphene Oxide

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 560
Author(s):  
Alexandra Carvalho ◽  
Mariana C. F. Costa ◽  
Valeria S. Marangoni ◽  
Pei Rou Ng ◽  
Thi Le Hang Nguyen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Ab Initio ◽  
State Of The Art ◽  
High Accuracy ◽  
Precise Determination ◽  
Photoemission Spectroscopy ◽  
Pristine Graphene ◽  
X Ray ◽  
Degree Of Oxidation

We show that the degree of oxidation of graphene oxide (GO) can be obtained by using a combination of state-of-the-art ab initio computational modeling and X-ray photoemission spectroscopy (XPS). We show that the shift of the XPS C1s peak relative to pristine graphene, ΔEC1s, can be described with high accuracy by ΔEC1s=A(cO−cl)2+E0, where c0 is the oxygen concentration, A=52.3 eV, cl=0.122, and E0=1.22 eV. Our results demonstrate a precise determination of the oxygen content of GO samples.

scholarly journals Characterization and Quantification of Selenoprotein P: Challenges to Mass Spectrometry

2021 ◽  
Vol 22 (12) ◽  
pp. 6283
Author(s):  
Jérémy Lamarche ◽  
Luisa Ronga ◽  
Joanna Szpunar ◽  
Ryszard Lobinski
Keyword(s):  
Mass Spectrometry ◽  
State Of The Art ◽  
Animal Health ◽  
Primary Standard ◽  
Selenoprotein P ◽  
Primary Standards ◽  
Analytical Approaches ◽  
Careful Investigation ◽  
Accurate Quantification

Selenoprotein P (SELENOP) is an emerging marker of the nutritional status of selenium and of various diseases, however, its chemical characteristics still need to be investigated and methods for its accurate quantitation improved. SELENOP is unique among selenoproteins, as it contains multiple genetically encoded SeCys residues, whereas all the other characterized selenoproteins contain just one. SELENOP occurs in the form of multiple isoforms, truncated species and post-translationally modified variants which are relatively poorly characterized. The accurate quantification of SELENOP is contingent on the availability of specific primary standards and reference methods. Before recombinant SELENOP becomes available to be used as a primary standard, careful investigation of the characteristics of the SELENOP measured by electrospray MS and strict control of the recoveries at the various steps of the analytical procedures are strongly recommended. This review critically discusses the state-of-the-art of analytical approaches to the characterization and quantification of SELENOP. While immunoassays remain the standard for the determination of human and animal health status, because of their speed and simplicity, mass spectrometry techniques offer many attractive and complementary features that are highlighted and critically evaluated.

Caged-electron States and Split-electron States in Endohedral Alkali C60

2021 ◽  
Author(s):  
yifan yang ◽  
Lorenz S Cederbaum
Keyword(s):  
State Of The Art ◽  
Electronic States ◽  
Electron States ◽  
The Common ◽  
High Level

The low-lying electronic states of neutral X@C60(X=Li, Na, K, Rb) have been computed and analyzed by employing state-of-the-art high level many-electron methods. Apart from the common charge-separated states, well known...

Computer Aided Design of Transmission Components of Liquid Stirred Tank

2011 ◽  
Vol 109 ◽  
pp. 711-714
Author(s):  
Ying Jiang ◽  
Jie Liu
Keyword(s):  
Computer Aided Design ◽  
Automatic Generation ◽  
Structure Design ◽  
Stirred Tank ◽  
Design System ◽  
Design Requirement ◽  
Design Efficiency ◽  
The Common ◽  
Aided Design ◽  
Develop System

Secondary develop system can realize design automation of the common parts, so that software system can automatically inquire the chart and get data, then this could really release design personnel and improve the design efficiency. By secondary develop system of stirred tank users can respectively carry on the design according to their own needs. So secondary develop system has the function of automatic generation graphics, and can generate CAD drawings complying with the design requirement, so it reflected the intelligent performance of the design system. Secondary develop system is able to complete the automatic design of common parts, and can greatly improve the quality and efficiency of design, so it has very important use value. This design realizes the function of automatic graphics generation of transmission of stirred tank, and can generate structure design of common belt wheel.

Clay-sealings from the Fayum

1906 ◽  
Vol 26 ◽  
pp. 32-45
Author(s):  
J. G. Milne
Keyword(s):  
Irregular Shape ◽  
The Common

During the excavations of Messrs. Hogarth Grenfell and Hunt for the Egypt Exploration Fund in the winter of 1895–6 on the site of Karanis (Kom Ushim) in the Fayum, a considerable number of clay-sealings were found, mainly in the cellars of the Roman houses. These were recently put in my hands for investigation and offer some interesting material.The sealings have evidently come from various kinds of articles: in many instances the clay is too much broken for any determination of the shape which it had taken to be possible; but among the better preserved pieces are examples from the mouths of bottles, some of which have been squeezed down into the neck like a cork, others placed over a linen covering, sometimes tied down with cord: others are from the flat sides of wooden boxes, often showing the marks of cord: others again from parcels of irregular shape, in some cases seemingly wrapped in papyrus. The common points of all are that they consist of lumps of Nile-mud, and that they have been impressed, while the clay was damp, with signets, which were presumably those of the merchants who forwarded the goods upon which the sealings were placed.

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