Experimental results with mobile antennas having cross-polarizationcomponents in urban and rural areas

The receiving performance of mobile antenna systems that have vertical and horizontal elements at the 920-MHz band has been investigated by measurements in both rural and urban areas in Japan. Three types of inverted-F antennas for a car and three types of antenna elements, a monopole, a bent-slot and an inverted-F antenna, for portable equipment were used in the experiments. The average received power and its probability density function are obtained as the parameter to evaluate the performance of antenna systems. The performances of the bent-slot antenna system for portable equipment and the inverted-F antenna system mounted on a car are compared with those of the monopole or dipole antenna systems used as reference antennas. A notable increase in the average received power has been observed in operation in an urban area where the field distributes randomly and consists of cross-polarized components     

Production and detection of fission-induced neutrons following fast neutron direct interrogation to various dry materials containing 235U

For better nuclear material accountancy, we had developed a non-destructive assay system dedicated to uranium waste drums (JAWAS-N: JAEA Waste Assay System at Ningyo-toge). The system is based on a fast neutron direct interrogation (FNDI) method. To clarify the characteristics of the FNDI method and the performance of JAWAS-N, experimental and computational mock-up tests were carried out using various dry materials that contained known amounts of natural uranium. As a result, linearity between the die-away time (τ₂) and the counts of fast neutrons attributed to ²³⁵U fission was confirmed. Moreover, the MCNP simulation was performed to discuss the radial and axial dependences of ²³⁵U fission probability, neutron detection efficiency, and sensitivity on uranium distributions in the drum. The simulation results agreed with the empirical results reported in a previous paper, providing valuable information on the practice of FNDI-based uranium determination. Furthermore, the nominal detection limits of natural uranium in JAWAS-N were estimated to be 15, 4, and 2 g for τ₂ = 0.2, 0.3, and 0.4 msec, respectively. The findings obtained here will contribute to the implementation of the FNDI method to assess the quantities of ²³⁵U in actual uranium waste drums.     

Development of apparatus for electro-flotation

A new apparatus for electro-flotation has been developed by using the impeller of stirred tank as electrode(s). The principle of this apparatus reported is that the gas bubbles generated by electrolysis float the flocs while flocculation is promoted by the rotation of electrode(s). The collection efficiency of this apparatus for tap water containing blue ink of 10^?3m³/M³ in concentration has been discuss by using various electrode(s) and changing the rotation speed of the electrode(s).     

Urinary bladder carcinoma was induced in a patient treated with cyclophosphamide for malignant lymphoma

A major responsibility of any Quality Assurance Unit (QUA) is to ensure data integrity. Errors made during data entry can lead to many problems in the study review process and decrease the quality, accuracy, and overall efficiency of data management. One technique that can reduce the number of data entry errors in computer data sets is the use of a dual entry data system. Currently available software allows creation of customized data entry screens that either closely resemble or duplicate the data collection forms used during studies. Two data entry operators enter data into two independent data sets. The use of an on-screen display that resembles the data collection form reduces the potential for keypunch errors. The two data sets can then be electronically compared. The comparison reports differences between the two data sets. When differences exist, the correct values can be determined by reference to the original data sheets and the two data files can then be corrected. Theoretically, the only key punch errors that will exist after making these corrections are when the two independent entry operators make the same exact data entry error. Typically, the time required for two people to enter data is minimal compared to the time required to manually identify and correct data entry discrepancies. With error-free data entry, we have found that electronic data quality, accuracy, and audit efficiency are improved at every subsequent step of data management, analysis, quality assurance auditing, and report generation.     

Formation of hydrogen-capped polyynes by laser ablation of C60 particles suspended in solution

Laser ablation of C₆₀ particles suspended in hexane or methanol solution has been studied using a Nd:YAG laser (266, 355, 532, and 1064 nm). Insoluble product analysis by Raman spectroscopy showed that C₆₀ particles transformed to graphite-like ones. On the other hand, soluble product analysis by HPLC coupled with UV absorption spectroscopy and GC/MS demonstrated that linear hydrogen-capped polyynes (C_nH₂: n=8, 10, 12) were formed. The dominant C_nH₂ polyyne was C₈H₂ in all cases. The relative abundance of polyynes decreased with increasing wavelength of the Nd:YAG laser, except for 266-nm irradiation in hexane, where the relative abundance of polyynes at 355 nm was greater than that at 266 nm. It was therefore concluded that photochemical processes are more important than thermal ones for the formation of polyynes. The relative abundance of polyynes in hexane was greater than that in methanol. The dependence of relative abundance of polyynes on the particles concentration, laser irradiation time, and laser power was measured in order to obtain information on formation mechanism of polyynes. These results and reported laser photochemical processes of C₆₀ molecules in the gas phase suggested that C₂ radicals produced from C₆₀ are polymerized and hydrogenated to form C₈H₂ and much smaller amounts of C₁₀H₂ and C₁₂H₂.     

Age-related change of technetium-99m-HMDP distribution in the skeleton

To understand age-related changes of whole-body and regional skeletal metabolism, it is important to investigate the mechanisms of age-related bone loss and to develop suitable treatments for it. Bone biopsies show metabolism of the particular site examined while biochemical markers for bone metabolism reflect total skeletal metabolism. Bone scintigraphy is a convenient and simple way to analyze whole-body and regional skeletal metabolism. We attempted to study and understand age-related changes in bone metabolism by quantifying the bone scan and correlating it with biochemical bone metabolic markers. METHODS: The whole-body skeletal uptake (WBSU) and tracer distribution pattern were studied in men and women by bone scintigraphy using 99mTc-hydroxy-methane-diphosphonate (HMDP). Bone scans were performed using a standard protocol and quantified by setting regions of interest (ROIs) on selected regions. WBSU and the skeletal distribution pattern were compared with simultaneously obtained serum biochemical markers. RESULTS: WBSU showed an increase with age in both sexes, but in women, uptake in the head and legs increased more relatively than in the thoracic region, while in men no such tendency was observed. Increase of WBSU and relative increase of uptakes in the head demonstrated a weak correlation with the serum levels of alkaline phosphatase and type 1 collagen metabolites. CONCLUSION: These results show an age-related increase of skeletal turnover and sex-dependent regional skeletal metabolism. The age-related changes seen in bone scintigrams might be a sign of progressive bone loss, reflecting changes in local bone metabolism.     

Improved crystallinity of ZnO thin films grown by the ‘Aurora PLD method’

An ‘Aurora PLD method,’ in which a magnetic field is applied to a plasma plume, was employed to grow ZnO films and to study the mechanism of crystal growth. In the Aurora PLD method, the ZnO target displayed a brighter plume in the vicinity of the magnet (near the substrate holder). The photoluminescence (PL) was double that of a conventionally PLD grown film when the Aurora PLD was used. Furthermore, when a method of Aurora PLD with Ar added was used, the PL intensity increased 3-4 times. Hall effect measurement revealed the reduction of the residual electron concentration due to Aurora PLD growth, suggesting the possible improvement of the crystallinity. These advantages of the Aurora PLD method were compared with respect to an elevated growth temperature of approximately 100 °C.     

Fabrication of high precision microstructure using ICP etching for capacitive inclination sensor

Capacitive inclination sensors have the advantage because it could easily provide a linear analog output with respect to inclination. Since the dimensions of the sensing region are very small, then this sensor is expected to be widely used in fields where efficient and reliable position control is a primary factor to be considered if this sensor could be mass produced at low cost. Therefore, we proposed fabrication process based on transfer to resin using mold. We successfully fabricated a micro capacitive inclination sensor by a combination of a resin forming method and a mold. The sensor consists of a gap distance of 80 μm between its electrodes. The sensor detects difference of capacitance, which varied with movement of silicone oil accompanying with inclination. When the sensor was inclined, linear analog output was obtained within the range of ?45 to +45°     

The reduction of pressure drop due to dust loading in a conventional cyclone

Experiments have been conducted to examine the effect of dust loading on pressure drop in a conventional cyclone. The presence of dust in the air stream reduced the cyclone pressure drop by as much as 30%, even at extremely low concentrations, such as 0.2 g/m³. In the range of 1.5–50 g/m³, the pressure drop ratio (the ratio of the pressure drop of dusty air to that of pure air with the same inlet velocity) was independent of dust concentration, and kept nearly constant; but it decreased as the concentration increased above 50g/m³. It was observed that the presence of dust reduced the tangential velocity. However the radii of a cross section of the cyclone, where the pressures are equal to those of the entrance and the exit, did not change noticeably. Calculating the pressure drop by integrating the term due to centrifugal force is also examined.     

Polynomial summaries of positive semidefinite kernels

Polynomials have proven to be useful tools to tailor generic kernels to specific applications. Nevertheless, we had only restricted knowledge for selecting fertile polynomials which consistently produce positive semidefinite kernels. For example, the well-known polynomial kernel can only take advantage of a very narrow range of polynomials, that is, the univariate polynomials with positive coefficients. This restriction not only hinders intensive exploitation of the flexibility of the kernel method, but also causes misuse of indefinite kernels. Our main theorem significantly relaxes the restriction by asserting that a polynomial consistently produces positive semidefinite kernels, if it has a positive semidefinite coefficient matrix. This sufficient condition is quite natural, and hence, it can be a good characterization of the fertile polynomials. In fact, we prove that the converse of the assertion of the theorem also holds true in the case of degree 1. We also prove the effectiveness of our main theorem by showing three corollaries relating to certain applications known in the literature: the first and second corollaries, respectively, give generalizations of the polynomial kernel and the principal-angle (determinant) kernel. The third corollary shows extended and corrected sufficient conditions for the codon-improved kernel and the weighted-degree kernel with shifts to be positive semidefinite.