The complex permittivity (
ε′–
jε″), complex permeability (μ′–
jμ″) and microwave absorption properties of ferrite–polymer composites prepared with different ferrite ratios of 50%, 60%, 70% and 80% ...in polyurethane (PU) matrix have been investigated in X-band (8.2–12.4
GHz) frequency range. The M-type hexaferrite composition BaCo
+2
0.9Fe
+2
0.05Si
+4
0.95Fe
+3
10.1O
19 was prepared by solid-state reaction technique, whereas commercial PU was used to prepare the composites. At higher GHz frequencies, ferrite's permeabilities are drastically reduced, however, the forced conversion of Fe
+3 to Fe
+2 ions that involves electron hopping, could have increased the dielectric losses in the chosen composition. We have measured complex permittivity and permeability using a vector network analyzer (HP/Agilent model PNA E8364B) and software module 85071. All the parameters
ε′,
ε″,
μ′ and
μ″ are found to increase with increased ferrite contents. Measured values of these parameters were used to determine the reflection loss at various sample thicknesses, based on a model of a single-layered plane wave absorber backed by a perfect conductor. The composite with 80% ferrite content has shown a minimum reflection loss of −24.5
dB (>99% power absorption) at 12
GHz with the −20
dB bandwidth over the extended frequency range of 11–13
GHz for an absorber thickness of 1.6
mm. The prepared composites can fruitfully be utilized for suppression of electromagnetic interference (EMI) and reduction of radar signatures (stealth technology).
Elephantiasis of the lower limb is one of the most troublesome and common manifestation of filariasis. It is a very old problem in India, as Manu described it as an obstacle to the invitation of a ...Priest to annual remembrance festivities ("Shradha karma"): and Sushruta, the father Indian Surgery, described it as "Shleepada". Price (1984) has described the history of elephantiasis in great detail.
The objective of this paper is to present a seismic evaluation procedure based on an energy balance concept. The method is based on a framework that utilizes energy demand and capacity diagrams. The ...skeleton force–displacement (capacity) curve of the structure is converted into an energy capacity plot that is superimposed over the corresponding energy demand plot for a given hazard level to determine the expected peak displacement demand. First, the energy balance concept as applied in the seismic design of structures is discussed. Next, the underlying theory and framework for carrying out seismic evaluation are presented. The analysis procedure is then applied to an example three-story moment frame structure to estimate the displacement demands. The results obtained from the proposed procedure are then evaluated and compared with the results from nonlinear dynamic analysis as well as those from other well-established nonlinear static procedures. Observations regarding the accuracy of different nonlinear static procedures are discussed. The results show that the proposed method can be used effectively to estimate the response under a given ground motion.
Summary 1. Collagen sheet is very useful in preventing exogenous infection. 2. It promotes rapid epithelization in thickness raw areas, by protecting it from infection and the sheet is ultimately ...cost off. 3. Solit thickness skin grafts do not take up in cases of partial thickness skin loss. The wound epitheli it casts off. 4. Ointment dressings are prone to infection (57%) and they need frequent charges unlike collagen sheet. 5. Small, clean, full thickness raw areas covered with collagen sheet take lesser time to heal completaly (28 days), compared to those treated with conventional dressings (35-45 days).
Utility Of Collagen Sheet As Skin Substitute Bhatnagar, Dr. S. K.; Krishnan, Dr. R.; Goel, Dr. T. C. ...
Indian Journal of Plastic Surgery/Indian journal of plastic surgery,
02/2024, Letnik:
14, Številka:
1
Journal Article
Two types of composite samples were prepared using dielectric particulates such as BaTiO
3, polyaniline and conducting carbon in polyurethane matrix. One of the composite samples contains synthesized ...BaTiO
3 and polyaniline, while the other sample using, the commercial ingredients. Structural properties of both synthesized and commercial BaTiO
3 and polyaniline have been investigated. Complex permittivity
(
ε
r
′
-
j
ε
r
″
)
and microwave absorption properties of the prepared composites were studied in X-band (8.2–13.5
GHz). An optimized composite sample with synthesized BaTiO
3 and polyaniline has shown a maximum reflection loss of −25
dB (>99% power absorption) at 11.2
GHz with a bandwidth (full frequency width at half of the maximum response) of 2.7
GHz in a sample thickness of 2.5
mm. The measured absorption values have been validated by theoretical calculations. Materials can find applications in suppression of electromagnetic interference (EMI) and reduction of radar signature.
Circumcision and Socio-Medical Ethics Goel, T. C.; Dalela, D.; Agarwal, P. K.
Indian Journal of Plastic Surgery/Indian journal of plastic surgery,
08/2023, Letnik:
20, Številka:
2
Journal Article
Until now, micrometer-scale or larger crystals of the III-V semiconductors have not been grown at low temperatures for lack of suitable crystallization mechanisms for highly covalent nonmolecular ...solids. A solution-liquid-solid mechanism for the growth of InP, InAs, and GaAs is described that uses simple, low-temperature (≤203°C), solution-phase reactions. The materials are produced as polycrystalline fibers or near-single-crystal whiskers having widths of 10 to 150 nanometers and lengths of up to several micrometers. This mechanism shows that processes analogous to vapor-liquid-solid growth can operate at low temperatures; similar synthesis routes for other covalent solids may be possible.
