Crossed‐beam apparatus for simultaneous spectrophotometric observation and microwave exposure of biochemical samples

1975 ◽  
Vol 46 (10) ◽  
pp. 1344-1349 ◽  
Author(s):  
John W. Allis ◽  
Claude M. Weil ◽  
David E. Janes
Keyword(s):  
Microwave Exposure ◽  
Spectrophotometric Observation

Processing strategy for high strength Ni-based hybrid composite clad on SS 316L steel through microwave heating

2021 ◽  
pp. 095440542110213
Author(s):  
Sarbjeet Kaushal ◽  
Satnam Singh ◽  
Dheeraj Gupta
Keyword(s):  
Sliding Wear ◽  
Steel Surface ◽  
Steel Substrate ◽  
Microstructural Analysis ◽  
High Strength ◽  
Phase Changes ◽  
Microwave Exposure ◽  
Pull Out ◽  
316L Steel ◽  
Microwave Applicator

Processing of nickel-based high strength composites and alloys is a difficult and thought-provoking task. In this work, a strategy of heating through microwaves radiation is utilized to process the high strength hybrid Ni-based composite clad on SS 316L steel surface containing 15% (WC-8Co) and 5% Mo. The premixed composite powder was placed on the steel surface and irradiated with domestic microwave applicator having 2.45 GHz fixed frequency and 900 W power. The hybrid clad was successfully developed within 12–15 min of microwave exposure. The processed clad was subjected to various metallurgical and mechanical characterizations to understand the microstructures and phase changes. Microstructural analysis study revealed that the clad of ∼0.85 mm thickness was obtained and presence of dispersed reinforced particles of WC-8Co and Mo in nickel matrix were observed. Some inter-metallic phases of W2C, Ni2Mo4C, Ni4W and NiSi2 were observed in the clad. The average microhardness of the composite clad was712 ± 58 HV. The microwave processed clad exhibited a flexural strength of 852 ± 6 MPa with deformation index of 35 × 10−5 mm/N. Further, the sliding wear study revealed that the sliding velocity of 1.0 m/s favoured the formation of oxide tribo layers. The various mechanisms of wear revealed by the analysis of worn-out surfaces were abrasion, adhesion, surface pull-out and deformation of surfaces. The microwave processed clad revealed significant improvement in wear resistance in comparison to the steel substrate.

Microwave carbonization of cotton fiber for the production of carbon materials

2021 ◽  
Vol 11 ◽  
pp. 54-68
Author(s):  
E. V. Matveev ◽  
◽  
A. I. Gajdar ◽  
B. A. Lapshinov ◽  
A. V. Mamontov ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Fiber Surface ◽  
Thermal Method ◽  
Surface Layers ◽  
Cotton Lint ◽  
Microwave Exposure ◽  
Carbonization Process ◽  
Fiber Wall ◽  
Physico Chemical ◽  
Transverse Fractures

This article presents the results of comparative studies of the structural and physico-chemical features of cotton lint samples carbonized by the microwave method and the standard (thermal) method. The dependences of the temperature change of the samples during the microwave carbonization process are obtained. The heterogeneity of the morphology of the fiber surface along the cross-section of the microwave carbonized sample was revealed. It is shown that the structure of the surface layers is characterized by two mechanisms of fiber destruction: numerous brittle transverse fractures and coloring of the fibers in places of swellings (a sharp increase in their diameter) and fluffing of the surface into convoluted fibrils with a transverse size of 50 – 300 nm due to the destruction of the outer layers of the secondary fiber wall. In the central region, the destruction of fibers occurs by the formation of longitudinal interfibrillary slits and the delamination of the secondary fiber wall, which leads to the formation of pores with dimensions of 50 – 200 nm. It is established that during the microwave carbonization process, the central part of the sample is almost completely freed from impurities that are deposited on the fibers of the surface layers. It is shown that the integral adsorption capacity of the microwave carbonized sample is higher than the adsorption capacity of the sample carbonized by the thermal method (126 mg/g and 47 mg/g, respectively). It was found that during microwave exposure more than 10 minutes, regions with an adsorption capacity of ~ 350 – 450 mg/g appear in the carbonized material, that is comparable to the capacity of samples activated by the standard method.

scholarly journals Cell nucleus and membrane recovery after exposure to microwaves

2011 ◽  
Vol 65 (1-2) ◽  
pp. 13-20 ◽  
Author(s):  
Yuriy Shckorbatov ◽  
Vladimir Pasiuga ◽  
Nicolay Kolchigin ◽  
Valentin Grabina ◽  
Dmitry Ivanchenko ◽  
...  
Keyword(s):  
Membrane Permeability ◽  
Cell Nucleus ◽  
Trypan Blue ◽  
Initial Level ◽  
Chromatin Condensation ◽  
Buccal Cells ◽  
Cell Plasma Membrane ◽  
Plasma Membrane Permeability ◽  
Microwave Exposure ◽  
Cell Plasma

Cell nucleus and membrane recovery after exposure to microwaves Cells of human buccal epithelium of six male donors were exposed to microwave radiation (frequency f = 36.64 GHz, power density W = 0.1, 1 and 4 W/m2). Exposure time was 10 seconds. The state of chromatin in cell nucleus was estimated by a number of heterochromatin granules after staining with 2% orcein in 45% acetic acid. Permeability of cell membranes was estimated by percentage of unstained cells after 5 min of staining the cells with vital dyes trypan blue (0.5%) and indigocarmine (5 mM). Cell exposure to microwaves induced chromatin condensation (increase of the number of heterochromatin granules) and increase of membrane permeability to trypan blue and indigocarmine. Isolated human buccal cells demonstrated the ability to recover after microwave exposure. The number of heterochromatin granules decreased to its initial level after 0.5 hour (W = 0.1 W/m2) and 2 hours (W = 1 and 4 W/m2) after cell exposure. Cell plasma membrane permeability recovered later — after 1 hour and 3 hours post exposure, respectively.

Application of 1H-NMR-based metabolomics for detecting injury induced by long-term microwave exposure in Wistar rats’ urine

2012 ◽  
Vol 404 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Li-Feng Wang ◽  
Xiang-Jun Hu ◽  
Rui-Yun Peng ◽  
Shui-Ming Wang ◽  
Ya-Bing Gao ◽  
...  
Keyword(s):  
1H Nmr ◽  
Wistar Rats ◽  
Microwave Exposure
Sign in / Sign up

Export Citation Format

Share Document