Zinc determination in Tannat wine by direct injection onto graphite tube: Electrothermal AAS as an alternative to flame AAS

2017 ◽  
Vol 135 ◽  
pp. 239-244 ◽  
Author(s):  
Alicia Mollo ◽  
Alexandra Sixto ◽  
Lucía Falchi ◽  
Mariela Medina ◽  
Moisés Knochen
Keyword(s):  
Direct Injection ◽  
Graphite Tube ◽  
Zinc Determination ◽  
Electrothermal Aas

Ultrastructure of melanocyte-keratinocyte interactions and pigment transfer in vitro

1978 ◽  
Vol 36 (2) ◽  
pp. 650-651
Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo
Keyword(s):  
Direct Injection ◽  
Skin Pigmentation ◽  
Freeze Fracture ◽  
Pigment Granule ◽  
Time Lapse ◽  
Ultrastructural Level ◽  
Lanthanum Tracer ◽  
A Cell

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.

SPRAY CHARACTERISTICS IN A DIRECT-INJECTION DIESEL ENGINE

1996 ◽  
Vol 6 (1) ◽  
pp. 95-109 ◽  
Author(s):  
H. C. Yang ◽  
Hong Sun Ryou ◽  
Y. T. Jeong ◽  
Young Ki Choi
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Spray Characteristics ◽  
Direct Injection Diesel Engine

DEVELOPMENT OF A DIRECT INJECTION GAS-HYBRID ROCKET SYSTEM USING GLYCIDYL AZIDE POLYMER

2019 ◽  
Vol 18 (2) ◽  
pp. 157-170
Author(s):  
Yutaka Wada ◽  
S. Hatano ◽  
Ayana Banno ◽  
Yo Kawabata ◽  
Hiroshi Hasegawa ◽  
...  
Keyword(s):  
Direct Injection ◽  
Hybrid Rocket ◽  
Glycidyl Azide Polymer ◽  
Rocket System ◽  
Glycidyl Azide

X-ray fluorescence determination of zinc sulfate in acidic zinc plating electrolyte

2020 ◽  
Vol 86 (10) ◽  
pp. 18-22
Author(s):  
K. N. Vdovin ◽  
K. G. Pivovarova ◽  
N. A. Feoktistov ◽  
T. B. Ponamareva
Keyword(s):  
Zinc Sulfate ◽  
Zinc Coating ◽  
Electrolyte Composition ◽  
Complexometric Titration ◽  
X Ray ◽  
Fluorescence Determination ◽  
Zinc Plating ◽  
Zinc Determination

Zinc sulfate is the main component in the composition of the acidic zinc plating electrolyte. Deviation in the electrolyte composition from the optimum content leads to destabilization of the electrolysis process and deteriorate the quality of the resulting zinc coating. The proper quality of a zinc coating obtained by galvanic deposition can be ensured only with timely monitoring and adjustment of the electrolyte composition. A technique of X-ray fluorescence determination of zinc (in terms of zinc sulfate) in an acidic zinc plating electrolyte is proposed. The study was carried out using an ARL Quant’X energy dispersive spectrometer (Thermo Fisher Scientific, USA) with a semiconductor silicon-lithium detector. The features of the spectrometer design are presented. The optimal parameters of excitation and detection of zinc radiation were specified when the electrolyte sample was diluted 1:1000. The ZnKα1 line was used as an analytical line. The plotted calibration graph is linear, the correlation coefficient being 0.999234. The results of zinc determination according to the developed method were compared with the data of the reference method of complexometric titration to prove the reliability of the procedure. The results are characterized by good convergence and accuracy. The proposed method of X-ray fluorescence zinc determination in a zinc plating electrolyte equals complexometric titration in the limiting capabilities and even exceeds the latter in terms of the simplicity of sample preparation and rapidity. The developed method of X-ray fluorescence determination of zinc is implemented in analysis of the electrolyte used in the continuous galvanizing unit at «METSERVIS LLC».

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