On the Optimum Detection of Surface Chemical Compounds

1985 ◽  
pp. 943-953
Author(s):  
Terje Lund
Keyword(s):  
Chemical Compounds ◽  
Surface Chemical ◽  
Optimum Detection

scholarly journals Body-Surface Compounds in Buckfast and Caucasian Honey Bee Workers (Apis Mellifera)

2014 ◽  
Vol 58 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Aneta Strachecka ◽  
Grzegorz Borsuk ◽  
Jerzy Paleolog ◽  
Krzysztof Olszewski ◽  
Milena Bajda ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Body Surface ◽  
Gel Electrophoresis ◽  
Protein Concentration ◽  
Polyacrylamide Gel Electrophoresis ◽  
Chemical Compounds ◽  
The Body ◽  
Surface Chemical ◽  
Surface Compounds ◽  
Honey Bee Workers

Abstract Body-surface chemical compounds were studied in 1-day-old nest workers and foragers both in Buckfast and Caucasian bees. The workers of these two age-castes were sampled twice in each of two consecutive years. Body-surface lipids were determined by means of gas chromatography, with a GCQ mass spectrometer. Protein concentrations and activities on the body surface were examined in bee cuticle rinsings obtained from worker bees according to the methods of Lowry, of Anson, and of Lee and Lin. Protease and protease inhibitor activities were determined. Polyacrylamide gel electrophoresis was performed. Caucasian bees, particularly foragers, had more lipids, but Buckfast bees (two age-castes) had more proteins on their body surfaces. A total of 17 alkane types (C17 - C33), 13 alkene types (C21 - C33), 21 esters (C12 - C32), and a phenol (C14) were detected in both races. Alkene C33 was detected only in Caucasian bees. More alkanes, esters, and phenols were found in Caucasian 1-day-old nest workers and foragers than in these age-castes of Buckfast bees. The protein concentration and protease inhibitor activities were lower in Caucasian bees that had higher protease activities. These values corresponded with specific numbers and widths of the electrophoretic bands.

scholarly journals Образование и стабильность поверхностных химических соединений при взаимодействии бериллия с поверхностью (101 0) Re

2022 ◽  
Vol 64 (1) ◽  
pp. 134
Author(s):  
Е.В. Рутьков ◽  
Н.Р. Галль
Keyword(s):  
Activation Energy ◽  
Thermal Desorption ◽  
Multilayer Film ◽  
Chemical Compounds ◽  
Specific Adsorption ◽  
Surface Chemical ◽  
Temperature Range

It is shown that the adsorption of Be on Re (1010) in the temperature range of 850-950 K leads to the formation of specific adsorption states - surface chemical compounds (SC) of ReBe stoichiometry with a concentration of adsorbed Be atoms of ~ 1.4 • 1015 cm-2. A multilayer film of beryllium (3-4 layers) is destroyed upon heating, and at 900 K all Be atoms leave the surface into the bulk of rhenium, except those that are part of the SC; atoms from the SC, in turn, actively dissolve at T> 1050-1150 K. This corresponds to a decrease in the activation energy of dissolution upon the formation of SC from about 3.3 to 2.7 eV. Thermal desorption of beryllium takes place only at T> 2100 K due to the emergence of Be atoms dissolved in the bulk of the metal onto the surface.

Electron-acceptor properties of silicon atoms in surface chemical compounds

1978 ◽  
Vol 14 (5) ◽  
pp. 495-500 ◽  
Author(s):  
E. F. Voronin ◽  
V. A. Tertykh ◽  
V. M. Ogenko ◽  
A. A. Chuiko
Keyword(s):  
Electron Acceptor ◽  
Chemical Compounds ◽  
Surface Chemical

scholarly journals Physicochemically modified peat by thermal and oxidation processes as an active material for purification of wastewaters from certain hazardous pollutants

2017 ◽  
Vol 71 (4) ◽  
pp. 299-306
Author(s):  
Jelena Purenovic ◽  
Marjan Randjelovic ◽  
Milan Momcilovic ◽  
Milovan Purenovic ◽  
Novica Stankovic ◽  
...  
Keyword(s):  
Active Material ◽  
Chemical Compounds ◽  
Adsorption Properties ◽  
Batch Adsorption ◽  
Surface Chemical ◽  
Oxidation Processes ◽  
Different Types ◽  
Odor Removal ◽  
Hazardous Pollutants ◽  
Colloidal Sulphur

The physicochemical modification of peat through thermal and oxidation processes was carried out, in order to obtain new, inexpensive and active material for purification of different types of waters. During the modification, surface chemical compounds of Shilov type were formed. Batch adsorption properties and suitability of physicochemically modified peat (PCMP) for odor removal were tested in aqueous solutions of H2S and colloidal sulphur. Additionally, PCMP was tested in the removal of As(V) which is hazardous ingredient in contaminated waters. Possible mechanisms of pollutants binding include interactions, which lead to formation of adducts and clathrates. All these processes are elucidated in detail. The results showed that the obtained material can be used for the removal of sulphide, colloidal sulphur and As(V) from different types of waters.

Cytochemical analysis of mast cell granules after poly-dl-lysine action

1978 ◽  
Vol 36 (2) ◽  
pp. 278-279
Author(s):  
R. Courtoy ◽  
L.J. Simar ◽  
J. Christophe
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Chemical Compounds ◽  
Cellular Membrane ◽  
Thin Sections ◽  
Organic Bases ◽  
Ferric Thiocyanate ◽  
Cytochemical Analysis ◽  
Mast Cell Granule ◽  
Amine Liberation

Several chemical compounds induce amine liberation from mast cells but do not necessarily provoque the granule expulsion. For example, poly-dl-lysine induces modifications of the cellular membrane permeability which promotes ion exchange at the level of mast cell granules. Few of them are expulsed but the majority remains in the cytoplasm and appears less dense to the electrons. A cytochemical analysis has been performed to determine the composition of these granules after the polylysine action.We have previously reported that it was possible to demonstrate polyanions on epon thin sections using a cetylpyridinium ferric thiocyanate method. Organic bases are selectively stained with cobalt thiocyanate and the sulfhydryle groups are characterized with a silver methenamine reaction. These techniques permit to reveal the mast cell granule constituents, i.e. heparin, biogenic amines and basic proteins.

Growth of near noble metal Pd and Pt thin film silicides morphology and structure

1984 ◽  
Vol 42 ◽  
pp. 498-499
Author(s):  
E. I. Alessandrini ◽  
M. O. Aboelfotoh
Keyword(s):  
Noble Metals ◽  
Annealing Temperature ◽  
Chemical Compounds ◽  
Barrier Properties ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Stable Chemical ◽  
Metal Thickness ◽  
Amorphous Si ◽  
Si Films

Considerable interest has been generated in solid state reactions between thin films of near noble metals and silicon. These metals deposited on Si form numerous stable chemical compounds at low temperatures and have found applications as Schottky barrier contacts to silicon in VLSI devices. Since the very first phase that nucleates in contact with Si determines the barrier properties, the purpose of our study was to investigate the silicide formation of the near noble metals, Pd and Pt, at very thin thickness of the metal films on amorphous silicon.Films of Pd and Pt in the thickness range of 0.5nm to 20nm were made by room temperature evaporation on 40nm thick amorphous Si films, which were first deposited on 30nm thick amorphous Si3N4 membranes in a window configuration. The deposition rate was 0.1 to 0.5nm/sec and the pressure during deposition was 3 x 10 -7 Torr. The samples were annealed at temperatures in the range from 200° to 650°C in a furnace with helium purified by hot (950°C) Ti particles. Transmission electron microscopy and diffraction techniques were used to evaluate changes in structure and morphology of the phases formed as a function of metal thickness and annealing temperature.

Analytical Electron Microscopy of Ion-Implanted Metals

1985 ◽  
Vol 43 ◽  
pp. 282-285
Author(s):  
D.I. Potter ◽  
M. Ahmed ◽  
K. Ruffing
Keyword(s):  
Electron Microscopy ◽  
Ion Implantation ◽  
Friction And Wear ◽  
Analytical Electron Microscopy ◽  
Chemical Compositions ◽  
Surface Chemical ◽  
Near Surface ◽  
The Past ◽  
Analytical Electron ◽  
Property Changes

Ion implantation, used extensively for the past decade in fabricating semiconductor devices, now provides a unique means for altering the near-surface chemical compositions and microstructures of metals. These alterations often significantly improve physical properties that depend on the surface of the material; for example, catalysis, corrosion, oxidation, hardness, friction and wear. Frequently the mechanisms causing these beneficial alterations and property changes remain obscure and much of the current research in the area of ion implantation metallurgy is aimed at identifying such mechanisms. Investigators thus confront two immediate questions: To what extent is the chemical composition changed by implantation? What is the resulting microstructure? These two questions can be investigated very fruitfully with analytical electron microscopy (AEM), as described below.

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