We consider a single-server retrial queueing system where retrial time is inversely proportional to the number of customers in the system. A necessary and sufficient condition for the stability of the system is found. We obtain the Laplace transform of virtual waiting time and busy period. The transient distribution of the number of customers in the system is also obtained.

Polysilsesquioxanes (PSSQs) with the empirical formula (RSiO3/2)n have become very important as low-dielectric insulators for copper interconnects in the next-generation logic devices, but the detailed structure-property relationships were completely lacking. We have investigated the microstructure and functional properties of PSSQs with varying alkyl substituents and also PSSQ copolymers. As a result, significant advances have been made in the scientific understanding of PSSQ structures and significant improvements of key properties such as the crack resistance, mechanical modulus and hardness, and incorporation of nanometer-sized (<4 nm) porosity for ultra-low dielectric constants (<2.0).

The purpose of the present study was to characterize the Ca2+ channels in smooth muscle cells from human stomach and to examine the effects of osmotic swelling on the channel activity. Ca2+ channel current with either Ca2+ or Ba2+ as charge carrier was recorded from freshly isolated smooth muscle cells using the conventional whole-cell patch clamp technique. The degree of cell swelling as a result of hypotonic challenge was monitored using a video image analysis system. The changes in intracellular Ca2+ concentration ([Ca2+]i) were measured by microfluorimetry. The pharmacological and voltage activation profile suggests a typical dihydropyridine-sensitive L-type Ca2+ current. Cell swelling, induced by hypotonic challenge, enhanced the amplitude of currents through L-type Ca2+ channels without significant effects on steady-state voltage dependency. After treatment with the L-type Ca2+ channel agonist Bay K 8644 (0.1-2 µM), no further significant increase in calcium channel current or corresponding [Ca2+]i transients were provoked by the swelling. The above results demonstrated that the presence of L-type Ca2+ current in smooth muscle cells of the human stomach and the augmentation of the current are closely associated with the volume increase resulting from hypotonic swelling. Experimental Physiology (2000) 85.5, 497-504.

Nickel thin films were deposited with Ni(C5H5)2 \NiCp2, bis(cyclopentadienyl)nickel, nickelocene]/H2 at various temperatures and H2/Ar ratios. The deposition rate, resistivity, purity, crystal structure, and surface morphology of the nickel film were investigated. Also, thermal analysis was done to find out the dissociation characteristics of NiCp2, and Fourier transform infrared spectroscopy diagnostics were carried out to study the gas phase reaction kinetics of NiCp2. Nickel films deposited at higher temperatures (>225 °C) had high carbon content and high resistivity. At higher temperatures, thermal decomposition of NiCp2 and subsequent decomposition of Cp induced a large amount of carbon incorporation into the film. At lower temperatures (<190 °C), the slow dissociation of NiCp led to some extent of carbon incorporation in the film. Nickel films deposited at around 200 °C showed carbon content lower than 5% and lower resistivity because of the effective dissociation of Ni–Cp and desorption of Cp from the surface. Nickel films deposited with hydrogen addition showed higher purity, crystallinity, and lower resistivity due to the removal of the carbon on the surface.

Processible poly(methylsilsesquioxane)s (PMSSQs) were prepared in THF solution under nitrogen atmosphere in the presence of HCl catalyst. It was found that various reaction parameters such as concentration, temperature, reaction time, the amount of water, and the amount of acid catalyst could affect the molecular weight and the amount of functional end groups of PMSSQ samples. Thin films prepared from our PMSSQ samples by spin-coating followed by curing to 420°C exhibited a much better crack resistance than those presented in the literature, while the dielectric constant remained practically the same, i.e., ca. 2.7.