scholarly journals A New Techniques to Calculate the Efficiency of Electric High Voltage Network in Basra

Author(s):  
Qais Mohammed Aish ◽  
Wathiq Rafa Abed
Keyword(s):  
Radiocarbon ◽  
1970 ◽  
Vol 12 (2) ◽  
pp. 590-598 ◽  
Author(s):  
V. R. Switsur ◽  
M. A. Hall ◽  
R. G. West

The University of Cambridge Radiocarbon Dating Laboratory has been completely rebuilt and modernized, incorporating new techniques developed here for the various stages of measurements. Sample radioactivity is measured in gas proportional counters after conversion to highly purified CO2. Four counters are mounted within a single anticoincidence shield consisting of plastic scintillation material. This is surrounded by a graded cosmic ray shield of low radioactive steel, boron loaded wax, and finally, about 16 tons of ancient low radioactive lead blocks. The electronics are all solid state devices except for the stabilized high voltage supplies.


2009 ◽  
Vol 17 (5) ◽  
pp. 730-736 ◽  
Author(s):  
Nara Fernanda Braz da Silva Leal ◽  
Hélio Humberto Angotti Carrara ◽  
Karina Franco Vieira ◽  
Cristine Homsi Jorge Ferreira

Breast cancer is the second most frequent cancer among women. Surgery is part of the therapeutic process to prevent metastases, but it can also cause some complications, including lymphedema. Physiotherapy contributes to its treatment, using different techniques that have been developed over the years. This systematic literature review aims to present physiotherapy modalities applied for lymphedema therapy. The literature review was conducted using textbooks and Lilacs, Pubmed and Scielo databases, from 1951 to 2009. Physiotherapy resources used for lymphedema treatment include complex decongestive therapy (CDT), pneumatic compression (PC), high voltage electrical stimulation (HVES) and laser therapy. The analyzed literature shows that better results are obtained with combined techniques. CDT is the most used protocol, and its association with PC has demonstrated efficacy. The new techniques HVES and laser present satisfactory results.


1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.


Author(s):  
L. D. Ackerman ◽  
S. H. Y. Wei

Mature human dental enamel has presented investigators with several difficulties in ultramicrotomy of specimens for electron microscopy due to its high degree of mineralization. This study explores the possibility of combining ion-milling and high voltage electron microscopy as a means of circumventing the problems of ultramicrotomy.A longitudinal section of an extracted human third molar was ground to a thickness of about 30 um and polarized light micrographs were taken. The specimen was attached to a single hole grid and thinned by argon-ion bombardment at 15° incidence while rotating at 15 rpm. The beam current in each of two guns was 50 μA with an accelerating voltage of 4 kV. A 20 nm carbon coating was evaporated onto the specimen to prevent an electron charge from building up during electron microscopy.


Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.


Author(s):  
L. E. Thomas ◽  
J. S. Lally ◽  
R. M. Fisher

In addition to improved penetration at high voltage, the characteristics of HVEM images of crystalline materials are changed markedly as a result of many-beam excitation effects. This leads to changes in optimum imaging conditions for dislocations, planar faults, precipitates and other features.Resolution - Because of longer focal lengths and correspondingly larger aberrations, the usual instrument resolution parameter, CS174 λ 374 changes by only a factor of 2 from 100 kV to 1 MV. Since 90% of this change occurs below 500 kV any improvement in “classical” resolution in the MVEM is insignificant. However, as is widely recognized, an improvement in resolution for “thick” specimens (i.e. more than 1000 Å) due to reduced chromatic aberration is very large.


Author(s):  
T. Mukai ◽  
T. E. Mitchell

Radiation-induced homogeneous precipitation in Ni-Be alloys was recently observed by high voltage electron microscopy. A coupling of interstitial flux with solute Be atoms is responsible for the precipitation. The present investigation further shows that precipitation is also induced at thin foil surfaces by electron irradiation under a high vacuum.


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