Hydrothermal Growth of Vertical ZnO Nanorods

Vertically aligned, single crystalline ZnO nanorods with a high packing density and diameter of ∼60 nm have been successfully synthesized via a low-temperature hydrothermal route on glass substrates pre-deposited with a ZnO seeding layer. The seeding layer exhibits an epitaxial effect on the growth and alignment of the ZnO nanorods. This epitaxial effect can arise from two considerations, namely the crystalline orientation and surface roughness of the seeding layer, which can be controlled by the curing temperature. The ZnO seeding layer that was cured at 350°C exhibited a preferred (0002) crystalline orientation of wurtzite hexagonal structure and a low surface roughness. It was demonstrated to promote the vertical growth of ZnO nanorods. The ZnO nanorods grew in an almost linear relationship with hydrothermal time up to 8 h, but thereafter started to dissolve as the reaction time extended beyond 8 h, due to competition from the homogeneous nucleation of ZnO microparticles in the solution.     

Lipopolysaccharide induces sickness behaviour in rats by a vagal mediated mechanism

A 52-year-old man was hospitalized for a right adrenal tumor which had been incidentally found by abdominal CT scan for examination of colon cancer. Laboratory and endocrine findings were within the normal limits except for increased urinary concentrations of noradrenaline and dopamine. Adrenal angiography revealed that the feeding artery of the tumor was the inferior suprarenal artery. Adrenal venous blood sampling studies detected no abnormalities in the concentrations of catecholamine, cortisol or aldosterone. Right adrenalectomy was performed and the tumor was histologically diagnosed as ganglioneuroma. Ganglioneuroma is a benign tumor originating from the sympathetic nerve ganglion. The adrenal origin of the tumor is relatively rare and 60 cases of adrenal ganglioneuroma including our case have been reported in Japan.     

Virologic diagnosis of an outbreak of epidemic hemorrhagic conjunctivitis by an indirect immunofluorescence technique. Cuba.1989

The causative agent of an hemorrhagic conjunctivitis outbreak was assessed through the study of 18 conjunctival exudates using the indirect immunofluorescence technique and isolation in cell culture of human embryo fibroblasts. In addition, 395 paired serum samples were studied and Enterovirus 70 was found to be responsible for the outbreak.     

Images of technology and creativity: in opposition or harmonywithin technical communications programs?

Recent exit interviews of Clarkson University graduates majoring in technical communications revealed that students have a clear hierarchy of worth that places technology at the top because of its supposed objectivity. Further, students opposed technology to creativity, which they took to be the domain of writing. The author asks several pointed questions aimed at probing how technical communication curricula can show students that creativity and reason can be in harmony and help them better understand their own talents and skills     

Purification and proteic characterization of a Cuban strain of the hepatitis A virus

The testicular toxicities of gallium arsenide (GaAs), indium arsenide (InAs) and arsenic trioxide (As2O3) were examined by repetitive intratracheal instillation using hamsters. GaAs (7.7 mg/kg) and As2O3 (1.3 mg/kg) were instilled twice a week a total of 16 times and InAs (7.7 mg/kg) was instilled a total of 14 times. GaAs caused testicular spermatid retention and epididymal sperm reduction, though the degrees were less severe than those in rats shown in our previous experiment. InAs and As2O3 did not show any testicular toxicities. Serum arsenic concentration in GaAs-treated hamsters was less than half of that in As2O3-treated hamsters in which no testicular toxicities were found. Serum molar concentration of gallium was 32-times higher than that of arsenic in GaAs-treated hamsters. Therefore gallium may play a main role in the testicular toxicity of GaAs in hamsters.     

Epitaxy of noble metals and (111) surface superstructures of silicon and germanium II: Study after annealing

We have studied by LEED, RHEED and REM the growth mode, after annealing, of Ag and Au on the (111) cleavage faces of Si and Ge and the surface superstructures induced by these deposits. It is generally admitted that three-dimensional growth occurs after completion of an ordered adsorption phase, which would account for the superstructure patterns observed. Having defined the domain of existence of each superstructure as a function of coverage ratio and temperature we are led to question the classical models previously proposed.     

Variable Digital Filter With Group Delay Flatness Specification or Phase Constraints

In this paper, we consider the design of finite-impulse response variable digital filters (VDFs) with variable cutoff frequency or variable fractional delay. We propose the design of VDFs with minimum integral squared error and constraints on the maximum error deviation in conjunction with flatness group delay specification or phase constraints. These specifications allow the VDFs to have approximately linear phase, especially in the passband. As these specifications are required to be satisfied for all the filters generated by the VDF with controllable spectral characteristics, the linear constraints resulting from the flatness specification are relaxed to inequality constraints. To make the optimization problem tractable for the phase constrained problem, suitable approximations are employed in the paper. The design problem is formulated as an optimization problem with a quadratic cost function and infinite number of constraints. A numerical scheme with adaptive grid step size is proposed for solving the optimization problem.     

Parameterization of the angular response of 2.54-cm photomultiplier tubes

Photomultiplier tubes are used widely in nuclear and particle physics for the detection of light. There is, however, a certain amount of debate in the literature as to how to parameterize the photocathode and how to describe the angular dependence of the photomultiplier response function. I outline a method for parameterizing a photocathode in terms of its thickness tau and complex refractive index ?. These parameters are measured for a pair of 2.54-cm photomultiplier tubes and used to predict the response as a function of angle. Comparison of this function with experimental data shows a clear correlation.