Surface distortion features on indented CaF2 cleavages

Surface distortion features around static indents on the cleavages of CaF₂ single crystals have been investigated by multiple beam interference technique. At room temperature microcracks around such indents nucleate at the sinking in regions. Fizeau fringe patterns (around indents at 200° C) revealed a transition from a three-fold to a six-fold material flow.     

Study of solvents for butadiene extraction by gas chromatography

Six solvents have been studied by GLC for separation of 1,3-butadiene from C₄-olefins having close boiling points. Infinite dilution activity coefficients and partition coefficients of five olefins have been determined in these solvents by conventional GLC-technique at 30 °C. Relative volatilities of olefins in solvents have been calculated and on this basis the solvents have been compared.     

Effects of maternal ethanol consumption on hepatic lipid biosynthesis in foetal and neonatal rats

Effects of prolonged maternal ethanol consumption were studied on hepatic lipid content, on the rates of fatty acid synthesis and on the activities of enzymes involved in fatty acid synthesis in the livers of foetal and suckling neonatal rats. Prolonged maternal ethanol consumption resulted in a significant increase in the contents of hepatic total lipids, triacylglycerols and plasma unesterified fatty acids in foetal and neonatal rats. Studies in vitro with 3H2O showed that maternal ethanol consumption did not result in a significant change in its rate of incorporation into lipid fractions of foetal and neonatal livers. The rates of fatty acid synthesis showed a pronounced decrease immediately after birth, compared with the foetal stage, but increased in the adult animals. On the other hand, the highest rates of lipid oxidation were observed in the neonatal stage. Maternal ethanol consumption resulted in a significant decrease in the rates of [14C]palmitate oxidation to 14CO2 by both the foetal and neonatal livers. Maternal ethanol consumption did not result in an increase in the activities of any of the lipid-synthesizing enzymes tested throughout the period of development. Although increased fatty acid synthesis does not seem to be the mechanism for the accumulation of these lipids, decreased oxidation of the lipids may be partly responsible for the lipid accumulation.     

Study of a chemically amplified resist for X-ray lithography by Fourier transform infrared spectroscopy

Future applications of microelectromechanical systems (MEMS) require lithographic performance of very high aspect ratio. Chemically amplified resists (CARs) such as the negative tone commercial SU-8 provide critical advantages in sensitivity, resolution, and process efficiency in deep ultraviolet, electron-beam, and X-ray lithographies (XRLs), which result in a very high aspect ratio. In this investigation, an SU-8 resist was characterized and optimized for X-ray lithographic applications by studying the cross-linking process of the resist under different conditions of resist thickness and X-ray exposure dose. The exposure dose of soft X-ray (SXR) irradiation at the average weighted wavelength of 1.20 nm from a plasma focus device ranges from 100 to 1600 mJ/cm(2) on the resist surface. Resist thickness varies from 3.5 to 15 mum. The cross-linking process of the resist during post-exposure bake (PEB) was accurately monitored using Fourier transform infrared (FT-IR) spectroscopy. The infrared absorption peaks at 862, 914, 972, and 1128 cm(-1) in the spectrum of the SU-8 resist were found to be useful indicators for the completion of cross-linking in the resist. Results of the experiments showed that the cross-linking of SU-8 was optimized at the exposure dose of 800 mJ/cm(2) for resist thicknesses of 3.5, 9.5, and 15 microm. PEB temperature was set at 95 degrees C and time at 3 min. The resist thickness was measured using interference patterns in the FT-IR spectra of the resist. Test structures with an aspect ratio 3:1 on 10 microm thick SU-8 resist film were obtained using scanning electron microscopy (SEM).     

Soft X-ray Imaging using a Neon Filled Plasma Focus X-ray Source

A 3 kJ Mather-type UNU/ICTP plasma focus device with neon filling is used, for the first time, as a soft X-ray source for imaging of thin biological samples including insects. A charge-coupled-device (CCD) based pinhole projection system, placed in a differentially pumped chamber, is used for radiography using neon soft X-rays. The image brightness, contrast and resolution have been optimized by varying soft X-ray yield, pinhole size, camera chamber length and X-ray filters. The system can simply be modified for table-top soft X-ray microscopy of thin biological samples.     

A Magnetic Electron Analyzer for Plasma Focus Electron Energy Distribution Studies

The paper describes the construction of a magnetic electron analyzer for pulsed beam electron energy distribution studies. The single shot information is obtained using a NMOS linear image sensor. Both the energetical and the sensitivity calibration were performed using careful numerical simulations. For simplicity, the signals can be read on an oscilloscope, and they are transmitted via an optic fiber, which allows the analyzer to work while connected to high voltage. The analyzer was successfully implemented on a 15 kV/3 kJ plasma focus device and was used to study the electron energy distribution in the 30–660 keV range..     

Optimize Task Allocation in Cloud Environment Based on Big-Bang Big-Crunch

Wireless Personal Communications - Efficient resource allocation is indispensable in the current scenario of a service-oriented computing paradigm. Instance allocation to the host and the task...     

Microencapsulation of a eutectic PCM using in situ polymerization technique for thermal energy storage

In the present work, microencapsulated phase change material (M-PCM) has been synthesized with eutectic mixture (75% SA + 25% CA) as core and melamine formaldehyde (MF) as shell using in situ polymerization. Advanced instrumental techniques like field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR), particle size analyzer (PSA), thermogravimetric/differential thermal analysis (TG/DTA), differential scanning calorimetry (DSC), and thermal conductivity analyzer (TCi) were used to characterize the synthesized M-PCM, and impact of effective parameters like pH and agitator speed on the encapsulation process was also elucidated. Results obtained reveal that at the optimized pH (3.2) and agitator speed (1500 rpm) M-PCM possess smooth surface morphology, spherical in shape with particle size of 10.41 μm. Based on FT-IR analysis, it was observed that the synthesized M-PCM was uniformly encapsulated by MF resin with eutectic mixture in the core. The encapsulation process results in the improvement of the thermal stability of eutectic mixture, it increases from 202.5 to 212.3°C, and the encapsulation efficiency of the M-PCM is found to be 85.3%. The melting point and latent heat of fusion of M-PCM were found to be 34.5°C and 103.9 kJ/kg, respectively.