Radar Propagation Medium

2021 ◽  
pp. 127-158
Author(s):  
Bassem R. Mahafza
Keyword(s):  
Author(s):  
Paul Eric B. Parañal

Abstract This paper presents a new fail mechanism for laser-marking induced die damage. Discovered during package qualification, silica spheres – commonly used as fillers in the molding material, was shown to act as a propagation medium that promote the direct interaction of the scribing laser beam and the die surface. Critical to the understanding of the fail mechanism is the deprocessing technique devised to allow layer by layer examination of the metallization and passivation layers in an encapsulated silicon die. The technique also made possible the inspection of the molding compound profile directly on top of the affected die area.


2016 ◽  
Vol 11 (2) ◽  
pp. 150-155
Author(s):  
R. Troian ◽  
D. Dragna ◽  
C. Bailly ◽  
M.-A. Galland

Modeling of acoustic propagation in a duct with absorbing treatment is considered. The surface impedance of the treatment is sought in the form of a rational fraction. The numerical model is based on a resolution of the linearized Euler equations by finite difference time domain for the calculation of the acoustic propagation under a grazing flow. Sensitivity analysis of the considered numerical model is performed. The uncertainty of the physical parameters is taken into account to determine the most influential input parameters. The robustness of the solution vis-a-vis changes of the flow characteristics and the propagation medium is studied.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Aline Machado de Castro ◽  
Mariana Martins Pereira Teixeira ◽  
Daniele Fernandes Carvalho ◽  
Denise Maria Guimarães Freire ◽  
Leda dos Reis Castilho

This work aimed at investigating the simultaneous production of amylases and proteases by solid-state fermentation (SSF) of babassu cake using Aspergillus awamori IOC-3914. By means of experimental design techniques and the desirability function, optimum inoculum conditions (C/N ratio of propagation medium, inoculum age, and concentration of inoculum added to SSF medium) for the production of both groups of enzymes were found to be 25.8, 28.4 h, and 9.1 mg g−1, respectively. Significant influence of both initial C/N ratio and inoculum concentration was observed. Optimum amylolytic activities predicted by this multiresponse analysis were validated by independent experiments, thus indicating the efficacy of this approach.


Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 650
Author(s):  
Gennady V. Golubkov ◽  
Mikhail I. Manzhelii ◽  
Alexandr A. Berlin ◽  
Lev V. Eppelbaum ◽  
Alexey A. Lushnikov ◽  
...  

The main problems of remote sensing of the Earth’s surface within the frequency range 1.2–1.6 GHz are discussed. They are related to the resonant quantum properties of the radio wave propagation medium in the lower ionosphere. It is shown that, for the passive remote sensing, the main source is incoherent microwave radiation of the D and E ionospheric layers in the decimeter range. For the first time, a theoretically grounded principally new scheme of measurements is suggested. The scheme assumes that the radiation source exists below the satellite orbit and accounts for the fact that two types of radiation (direct and reflected) reach the satellite sensor. The separation of the respective fluxes is a serious problem that should be solved for the correct interpretation of the measurements. The question is raised regarding the correct calibration of measuring equipment, depending on the current state of the ionosphere.


1940 ◽  
Vol 18c (11) ◽  
pp. 566-577
Author(s):  
N. H. Grace ◽  
J. L. Farrar ◽  
J. W. Hopkins

Dormant Norway spruce cuttings were collected in mid-November and treated with talc dusts containing two separate phytohormone chemicals, indolylacetic and naphthylacetic acids, in three concentrations, 0, 1000, and 5000 p.p.m., alone, and in combination with cane sugar and an organic mercurial disinfectant. Treated cuttings were planted immediately in outside frames in sand and a mixture of sand and peat in equal proportions. They were removed for examination 10 months later. Phytohormone treatment, except with the 5000 p.p.m. concentration of naphthylacetic acid, which was injurious, increased the number of cuttings rooted, the number and length of roots, the number of surviving cuttings, and the number of rooted cuttings with new growth. There were also marked effects on the initiation and development of new growth. The admixture of peat in the propagation medium improved rooting and development of new growth, particularly in certain of the phytohormone treatments. Only about 50% of the controls rooted in both sand and sand-peat, while the 5000 p.p.m. concentration of indolylacetic acid effected 68% rooting in sand and 82% in sand-peat.Both cane sugar and organic mercury significantly affected a number of the responses. However, the effects were comparatively small and depended, for the most part, on interactions with phytohormone treatments and media. Organic mercury increased the number of cuttings rooted by about 6%.


1991 ◽  
Vol 6 (4) ◽  
pp. 235-238
Author(s):  
S. KERKYRAS ◽  
R. L. REUBEN ◽  
W.K.D. BORTHWICK

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