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Patterned platinum counter electrodes for dye-sensitized solar cells (DSSCs) were formed using neutralized platinum precursor pastes and a screen-printing method. Hydrogen hexachloroplatinate (IV) hexahydrate was used as a platinum precursor. Hexylene glycol was used as a solvent for the precursor and lithium hydroxide dissolved in ethylene glycol monomethyl ether was used as a neutralizing agent to prepare neutralized pastes. The results suggest that approximation of the energy from dipolar intermolecular forces between molecules, as represented by one of the Hansen solubility parameters, is an important factor for avoiding liquid–liquid phase separation in this case. The surface of the platinum layers exhibited a two-dimensional structure of fine particles (5–10 nm) with a ∼99.5% coverage rate. Consequently, the photoelectric conversion performance of DSSCs fabricated using the printed platinum counter electrodes was nearly equivalent to that fabricated using a sputtered platinum counter electrode, which is often used as a reference electrode.

This paper addresses the characteristics of capacitive-type epidermal moisture measurements using disposable electrode films fabricated by a screen-printing method. The disposable electrode films were composed of substrates, comb-shaped electrode layers, and insulating layers. The epidermal moisture measurement obtained higher gain by optimization of the finger width of the comb-shaped electrode layer. The gain and accuracy of measurements were also improved by changing the insulating layer that covered the comb-shaped electrode layer to the striped-pattern type instead of the conventional solid-filling type. This epidermal moisture measuring instrument reduces the cleaning process of the electrode film that directly contacts the skin, simplifies the handling of the devices, and ensures hygienic operation.

We have characterized a non-contact measurement system to concentrations of electrolytic solutions using a sensor film that is pasted on the outer surface of the solution vessel. This sensor film has asymmetrically sized circular electrodes printed facing each other on the both faces of substrate, and operates as a mutual-capacitive sensor. This measurement system shows the response depend on the strength of the electrolyte dissociation. In addition, it is found that the resolution and the sensing range could be controlled by adjusting the frequency of the applied voltage in the range from 10 kHz to 1 MHz.

Organic light emitting devices, in particular, properties of polymer light-emitting transistors with printed electrodes and bilayer printed devices with in-plane emission have been investigated and discussed. The semitransparent device based on poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT) with Ag-nanowire source/drain and transparent carbon nanotube gate electrodes exhibits ambipolar and light-emitting characteristics. For the devices with oriented poly(9,9-dioctylfluorene) (F8) films, enhanced electron and hole field-effect mobilities have been achieved by aligning the polymer chains parallel to the transport direction. The bilayer device using F8BT lower layer and oriented F8 upper layer with the channel direction parallel to the polymer orientation exhibits improved EL intensity and higher external quantum efficiency than that with the channel direction perpendicular to the polymer chains orientation. The optical pulses of more than 100 Hz frequency are generated by directly modulating a bilayer device with an in-plane emission pattern.

We describe a flexible capacitance-type sensor that can detect an approaching human without contact, fabricated by developing and applying duplex conductive-ink printing to a film substrate. The results of our calculations show that the difference in size between the top and bottom electrodes of the sensor allows for the spatial extension of the electric field distribution over the electrodes. Hence, such a component functions as a proximity sensor. This thin and light device with a large form factor can be arranged at various places, including curved surfaces and the back of objects such that it is unnoticeable. In our experiment, we attached it to the back of a bed and found that our device successfully detected the breathing of a subject on the bed without contacting his body. This should contribute to reducing the physical and psychological discomfort among patients during medical checks, or when their condition is being monitored.

Titanium dioxide (TiO2) pastes containing secondary particle with varying sizes are prepared by modulating the dispersion time of the dispersion liquid. The appearances, mesoscopic structures, and transmission spectra of the TiO2 layers constructed using these pastes depend on the sizes of the secondary particles. However, the dye-sensitized solar cells (DSSCs) constructed using different pastes show similar photoelectric conversion performances despite the different mesoscopic structures and transmission properties of the TiO2 layers. The DSSCs based on the experimental TiO2 pastes show lower photoelectric conversion efficiencies compared with the DSSC constructed using a commercially available reference paste. These results suggest that the primary TiO2 particles have a greater influence on the photoelectric conversion performance of the DSSC than the secondary particles. The incident photon-to-current conversion efficiency spectra of the DSSCs based on the TiO2 pastes exhibit a slight dependence on wavelength. Thus, it is possible that minor light-scattering effects resulting from the mesoscopic structure of TiO2 occur in the DSSCs constructed using the pastes. These results indicate that TiO2 pastes with fixed primary particle sizes but different secondary particle sizes can be used to change the appearance or design of DSSCs without affecting their photoelectric conversion performance.

We have performed the homoepitaxial growth of high-crystalline quality Aluminium nitride (A1N) epilayers by the ammonia-gas source (GS) molecular-beam epitaxy method using the hydride vapor-phase epitaxy (HVPE) grown A1N thin layers as substrates. Surface morphologies and step-bunching structures of the homoepitaxially grown A1N epilayers were evaluated using in situ reflection high-energy electron diffraction (RHEED) patterns and scanning probe microscopy. It is noted that the step height of several monolayers was achieved on the surface of homoepitaxial layers. The homoepitaxial A1N thin films had the same or improved crystalline quality compared with the HVPE-grown A1N layers from X-ray rocking curve measurements, and its optical properties were investigated using cathodoluminescence measurements. Excitonic emission, which originates from the A free-exciton transition, was clearly observed in the present high-quality homoepitaxial A1N epilayers.

We have performed the homoepitaxial growth of GaN layers by reactive molecular-beam epitaxy (MBE) on both sides (Ga- and N-faces) of the bulk GaN single crystals prepared by the pressure-controlled solution growth (PC-SG) method. High-crystalline-quality GaN layers, which showed a narrow full-width at half maximum (FWHM) for the (002) plane in X-ray rocking curve measurements and no dark spot in the cathodoluminescence images, were obtained both on the Ga- and N-faces. It was indicated that the incorporation mechanism of residual impurities and/or defects is different between the homoepitaxial layers on the Ga- and N-faces, and that a larger amount of residual donors and nonradiative recombination centers existed in the homoepitaxial layer on the N-face. In addition, our results suggest that the poor quality of N-polarity GaN epilayers grown by conventional MBE is caused not only by the high density of nanometric inversion domains (IDs) in the N-polarity matrix, but also by polarity-related effects.

Undoped-GaN, Mg-doped GaN, undoped-AlGaN, and undoped-AlInGaN epilayers have been grown on bulk GaN single crystals with single polar surfaces by radio-frequency molecular-beam epitaxy method. The full-widths at half maximum of X-ray diffraction peaks taken from GaN epilayers were very small. When the growth was carried out only on Ga-faces of bulk GaN single crystals, p-GaN epilayers without any post-treatments and AlGaN epilayers on higher Al composition were obtained. Photoluminescence (PL) spectra at different temperatures ranged from 8 to 300 K were measured for the undoped-Al0.10In0.05Ga0.85N epilayer on Ga-face. The PL intensity of undoped-Al0.10In0.05Ga0.85N epilayer at RT was only 1 order of magnitude smaller than that at 8 K, indicating localization effects by In atoms. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

In0.05Al0.10Ga0.85N epilayers and Al0.10Ga0.90N epilayers have been grown on bulk GaN single crystals and GaN templates by radio-frequency (RF) molecular-beam epitaxy (MBE). Photoluminescence (PL) spectra at different temperatures ranged from 8 to 300 K were measured for these epilayers. The decreasing rates of PL peak intensity of the In0.05Al0.10Ga0.85N epilayers were smaller than those of the Al0.10Ga0.90N epilayers. The fluctuations of emission intensities were not observed in the In0.05Al0.10Ga0.85N epilayers by cathodoluminescence observations at 77 K. Our results indicate that In-related effects exist in InAlGaN quaternary alloys on substrates with low-dislocation densities, however, expect that the localization effect related to In-segregation is weak.

Lattice polarity of GaN epilayers grown on N-faces of bulk GaN single crystals has been investigated. The determinations of lattice polarity have been carried out by observation of surface reconstruction and surface morphology change by alkaline etching. As a result, it is found that GaN epilayers grown on N-faces using In-doped GaN buffer layers have Ga-polarity; on the other hand, GaN epilayers grown on N-faces using high-temperature (HT) AlN buffer layers have N-polarity. These results suggest that In-doping has the role of reversing the polarity of the GaN epilayers from N- to Ga-polarity, whereas HT-AlN buffer layers itself do not act as the layer reversing the polarity from N- to Al-polarity.

We developed a new printing method called “screen-offset printing.” This method is the combination of screen printing and transfer printing techniques; ink is first screen-printed on a silicone blanket, and the ink is then transferred from the blanket onto a substrate. Such a procedure allows the formation of patterns with highly rectangular cross sections and finer patterns than can be achieved by conventional screen printing. In the present paper, we explain the details of this process and analyze its efficacy by comparing the experimental results of screen-offset printing with those of conventional screen printing. Further, we introduce a currently developing automated screen-offset printing machine and demonstrate the formation of fine patterns 20 µm in width.

The DSSC sub-module of 120 mm 2 which has high temperature durability was fabricated. The durability was tested under 85 °C for 1000 h; at the end of the test the conversion efficiency was retained over 95% of the initial one. The high temperature durability was realized using the improved sealant, protective material of collecting grids and the new ruthenium-complex dye J2 which was developed by SIIT. By the same way the larger size module was developed.

We performed the epitaxial growth of Al-rich Al1-xInxN (x

Additive-type printing techniques such as gravure-offset printing and screen printing are effective for low-cost and ecofriendly electrode pattern formation. Gravure-offset printing is effective for fine pattern formation with widths on the order of 10–20 µm, whereas screen printing is effective for the formation of large-area patterns. However, it is difficult to simultaneously form fine and large-area patterns using these printing techniques. In this study, we demonstrate that fine (minimum width of 15 µm) and medium- as well as large-area patterns can be formed simultaneously using our developed screen-offset printing technique, which is a combination of screen printing on a silicone blanket and transfer printing from the blanket to a substrate. Furthermore, we demonstrate the application of our method to printing on adhesive materials, which allows electrode formation without applying heat to the film substrate.

The growth of homoepitaxial GaN, AlGaN layers, and GaN/AlGaN multiple quantum wells (MQWs) on Ga- and N-faces of bulk GaN single crystal substrates prepared by pressure-controlled solution growth (PC-SG) has been performed by radio-frequency molecular-beam epitaxy (RF-MBE). It was determined that homoepitaxial GaN layers grown on both Ga- and N-faces had good crystallinity with narrow full-width at half maximum (FWHM) of 150 and 94 arcsec for the (0002) plane and 119 and 106 arcsec for the (10-12) plane in x-ray rocking curve measurements, respectively. Crack-free AlGaN epilayers with Al mole fraction up to 30% were obtained on both faces. AlGaN epilayers on Ga-faces with higher Al mole fraction than those on N-faces under the same Al flux condition were obtained. Furthermore, phase separation existed only in the AlGaN epilayers grown on N-faces. The 5 K photoluminescence spectra for the GaN/AlGaN MQW structures grown on Ga-faces at peak energy of 3.419 to 3.686 eV can be obtained by varying the well thickness from 18 to 2 ML.

Screen-offset printing combines screen-printing on a silicone blanket with transference of the print from the blanket to a substrate. The blanket absorbs organic solvents in the ink, and therefore, the ink does not disperse through the material. This prevents blurring and allows fine patterns with widths of a few tens of micrometres to be produced. However, continuous printing deteriorates the pattern's shape, which may be a result of decay in the absorption abilities of the blanket. Thus, we have developed a new technique for refreshing the blanket by substituting high-boiling-point solvents present on the blanket surface with low-boiling-point solvents. We analyse the efficacy of this technique, and demonstrate continuous fine pattern formation for 100 screen-offset printing processes.

Ratio of peak to total efficiencies for Ge detectors with six different relative efficiencies (er) to a 3 in×3 in NaI (Tl) detector has been measured as functions of gamma-ray energy and of source-detector distance.The ratio is simply fitted to a linear equation of In er in the range of 200 to 2000 keV gammaray energy. The parametric coefficients of the equation are also found to have a simple relation against gamma-ray energy.

Silicon and phosphorus contents in polished and unpolished rice planted in a district of high incidence of amyotrophic lateral sclerosis (ALS) have been determined by neutron activation and X-ray fluorescence methods, and compared with those from control areas. In the neutron activation analysis, beta-ray spectra of 32P produced by the 31P(n, gamma)32P reaction on polished and unpolished rice were measured with a low background beta-ray spectrometer. In the X-ray fluorescence analysis, characteristic X-rays were analyzed with a wavelength dispersive X-ray fluorescence spectrometer. Silicon contents in polished and unpolished rice from the ALS area are 42 micrograms.g-1 and 370 micrograms.g-1, respectively, and the corresponding phosphorus contents are 1,210 micrograms.g-1, and 3,370 micrograms.g-1, respectively. The data for ALS area are equal to those for the control area within standard deviation.

Angular distributions of recoil 8 Li in the 9 Be(π - , π N ) 8 Li reaction have been measured at P beam (π - )=1.0, 3.0, and 4.0 GeV/c with solid state track detector (SSTD). At 1.0 and 3.0 GeV/c, the heavy-fragment knockout process explains the major feature of the data, whereas at 4.0 GeV/c a characteristic sideways peaking is observed at around θ 1ab ≃30°. The latter phenomenon shows that another effects must begin to occur at around 4.0 GeV/c. The 12 C, 14 N, 16 O→ 8 Li, 8 B spallation reactions by π - mesons (background reactions) have also been measured. They are mainly due to the intra-nuclear cascade and evaporation process.

Cross sections of negative-pion-induced reactions in 9Be, 12C and 19F have been measured at energies between 0.4 and 1.9 GeV by detecting the induced radioactivity. The excitation function of the 9Be(π−, πN)8Li reaction and those of the 12C(π−, π−n)11C and 19F(π−, π−n)18F reactions exhibit T = 1 2 resonances at Eπ = 0.6 and 0.9 GeV and a T = 3 2 resonance at 1.3 GeV. The resonance peaks are broadened apparently by the Fermi motion of the struck nucleon in the nucleus. The cross-section ratio σ( 9 Be (π − , π N ) 8 Li / σ π − p , where σπ−p is the free particle over the Fermi momentum, decreases rather monotonically like that for the (p, pn) reaction with increasing incident energy, while the ratios of σ(π − , π − n) σ π − n for the 12C(π−), π−n11C and 19F(π−, π−n)18F reactions are enhanced around Eπ = 0.6 GeV. This enhancement is explained partly by the charge exchange of the nucleon emitted from the Δ-particle formed through the decay of the T = 1 2 isobar. However, another mechanism should be needed to understand the enhancement of the (π−, π−n) reaction cross section around 0.6 GeV. The excitation functions for the 9 Be 6 He , 12 C ( 8 B , 8 Li ) and 12 C 6 He reactions indicate that the initial pion-nucleon.

Summary Content of calcium, manganese and aluminum in CNS tissue was measured by neutron activation analysis in four ALS and three control cases with the following results: (1) The increase in calcium and aluminum contents in CNS tissue of ALS cases were found with localization of these metals in the degenerated areas of ALS while manganese content showed no significant difference between ALS and controls. (2) Two of the four ALS cases showed a positive correlation between calcium and manganese and the other two ALS cases between calcium and aluminum, while all three control cases showed no correlation between these metals. (3) These findings suggest that the degenerative changes in ALS may be due to soft tissue calcification with interaction of other metals such as aluminum, manganese, and so on. (4) The importance of the possibility of aluminum participation in a calcifying process producing degeneration was emphasized in terms of the etiology of ALS.

The π + and π − momentum spectrum of the reaction γ p → ππ N have been measured at lab angles 20°, 40°, 60° and 90° and photon energies 0.744, 0.844, 0.944 and 1.044 GeV with a magnetic spectrometer using the photon subtraction method. Both spectra show a peak corresponding to the production of the πΔ(1236) state. The analysis has been carried out with amplitudes for the quasi two-body process γ p → πΔ (1236) and a phase-space background so as to reproduce both π + and π − spectra. The ratio of cross sections σ ( γ p → π + Δ 0 )/ ( γ p → π − Δ ++ ) is found to vary 0.0 to 1.8, depending on kinematical conditions.

ラットの成長期から成熟期にわたって, カゼイン飼料または市販飼料と30%ショ糖水および水の選択摂取が, いかに体重変化をもたらすかを観察するために, ラットを6週齢から28週齢まで飼育し, その間, ショ糖水の投与および中断を繰り返し, 総エネルギー摂取量, 体重, 飲水量, 尿中成分の変化を調べ, 次の結果を得た。1) ラットのショ糖水投与による総エネルギー摂取量および体重の増加は, いずれの飼料を与えた場合にも観察された。その体重増加は, 成長期後に大きい傾向を示した。この時, ラットは総エネルギーの50～60%をショ糖水から摂取した。ラットはカゼイン飼料より市販飼料に高い嗜好性を示した。2) ショ糖水の投与を中断した場合の体重変化は, 成長期ではショ糖水投与時に比べわずかな増加を示したにすぎず, 成長期後では約1g/日の減少を示した。3) ショ糖水投与によって, ショ糖水からとる水の量が多くなり, 飲料水の摂取量は減少し, 総飲水量ではショ糖水群と無ショ糖水群間で有意差はなかった。4) ショ糖水群では無ショ糖水群に対して, たん白質摂取量および尿中排泄尿素窒素量が有意に減少し, クレアチニンの尿中排泄量, およびアラントインと尿酸の合計の尿中排泄量は, ショ糖水投与直後に一過性の有意な増加を示した。

Introduced is the activities of the Joint Research Project Team on Thorium Fuel organized by mainly university researchers in Japan and supported by the Ministry of Education, Science and Culture for seven years since 1980. Four major groups were organized; (1) nuclear data, reactor physics and design, (2) nuclear fuel, (3) down stream and (4) biological effects of thorium.The first group covered measurements and analysis on nuclear data of thorium related nuclides, experiment and analysis on nuclear characteristics of thorium containing cores, basic engineering on a thorium molten salt reactor, and designs of several types of reactors. Fabrication and irradiation tests of thorium oxide fuel, and basic studies on new type thorium fuels (e.g. carbide and nitride) were studied by the second group. The third group covered the use of solutions in reprocessing of spent fuel, behavior of fission products, immobilization of high level radioactive waste, and continuous reprocessing for a molten salt reactor. The fourth group performed the trace study for patients who had been intravascularly injected with thorotrast for diagnosis of war injuries during the Second World War.

Metal analysis of calcium, manganese, aluminum and copper in CNS tissue samples of degenerative CNS disease cases (six Japanese ALS, three Japanese Alzheimer disease, four Guam PD, one Guam ALS) using neutron activation analysis, was conducted with following results: Five of six Japanese ALS cases, two of three Japanese Alzheimer disease cases and all of four Guam PD cases showed a high content of calcium and aluminum in CNS tissue with a significant positive correlation between calcium and aluminum and/or between calcium and manganese. These findings suggest a possible process of metal-induced soft tissue calcification with interaction of other di- and/or trivalent cations such as aluminum, manganese in CNS tissue of these degenerative CNS diseases.

京都大学原子炉実験所において,昭和48,49年度に「環境試料の放射化分析専門研究会」が持たれた.この専門研究会では,環境生物試料に対する原子炉中性子放射化分析の適用性を探究する目的をもって,その道の専門家より構成される11研究グループの協同の下に,NBSの生物標準試料Orchard LeavesとBovine Liverの相互比較分析を実施した.我が国において利用可能な,すべての原子炉,すなわち,京大原子炉実験所KUR原子炉,立教大学TRIGA-II原子炉,及び原研JRR-2,JRR-3,JRR-4原子炉が中性子照射に用いられた.分析は大部分が非破壊放射化分析により実施され,短寿命核種は短時間照射{(1～10)m}により,中・長寿命核種は長時間照射{(1～290(h}により,多元素同時定量が行われた.各グループより提出されたOrchard Leaves及びBovine Liverの分析結果を,それぞれTable 2及び3に示した.この結果に基づいて,今回の相互比較分析の精度を,それぞれTable 4及び5に示した. Orchard Leavesについては精度数%ないし30%で合計23元素が定量可能である. Bovine Liverについては,同じく精度数%ないし30%で合計13元素が定量可能である.以上の諸元素に対する研究グループの平均値はNBSの保証値又は参考値とよく一致している.これによって,環境生物試料の多元素ルーチン分析における放射化分析の有用性が示されたといえる.

Phosphorus-33 is a useful radioisotope of phosphorus for biological and medical restarch, for its long half life (25.4d) and low β-ray energy (0.25MeV) compared with 32P (14.3d, 1.70MeV).Two methods of production of this radioisotope in carrier free state have been already reported. 33S (n, p) reaction with reactor neutrons and 34S (γ, p) reaction with γ-rays from electron linear accelerator. These methods however use natural targets, and the resulting 33P/32P ratio is low.The present report describes a method for producing high ratio 33P/32P by 37Cl (γ, α) reaction with γ-rays from an electron linear accelerator giving a maximum energy of 18 MeV. For target material, NaCl and NH4Cl are taken up. The 33P/32P ratio of the phosphorus fraction after chemical separation with cation and anion exchange columns is about 12/1 at the end of irradiation when using NaCl as torget.

A new method for the detection of alpha radionuclides on the electromigrated paper has been proposed. The method is based on the alpha particle track detector with celluloid films. Alpha irradiated films are etched in NaOH solution and are compared with the autoradiographs on X-ray films, whereby the alpha nuclides could be easily distinguished from the beta and gamma nuclides. The authors could confirm the half life of the nuclide from measurements of the number of alpha tracks. The method is applicable to the chemical investigation of alpha nuclides, such as actinide elements.

Excitation functions for the reactions Mn/ sup55/( alpha ,n)Co/sup 58/, 5/( alpha ,n)Mn/sup 55/ and hod using a stacked-foil technique, the alpha- particle energies rangnng from 10 to 40 Mev. Bombardments were made with the alpha-particle beam of 32 and 40 Mev from the 160 cm INSJ cyclotron. The beam was collected in a Faraday cup and measured by a current integrator. After bombardments, manganese, cobalt, and iron were chemically separated. The disintegration rates of product nuclei Co/sup 58/, Co/sup 57/, Co/sup 56/, and Mn/ sup 54/ were obtained by the gamma-ray scintillation spectrometry, while that of Mn/sup 56/ by a calibrated end-window type Geiger counter. The reaction cross section was found to agree with calculated value for a nuclear radius constant r/ sub 0/ of 1.7 x 10/sup -13/ cm. Competition between different reactions was analyzed in terms of the statistical model of nuclear reaction by use of a level density expression of mu = c expSTA2(aE)/sup 1/2!, and agreed with the calculated values for a = 2 Mev/sup -1/. (auth)

Excitation functions for the (α, p ), (α, n ), (α, p n ), (α, 2 n ), (α, p 2 n +α, 3 n ), (α, α n ), (α, α p n ) and (α, α2 n ) reactions on Fe 54 were measured by the activation method using a “stacked-foil” technique, the alpha-particle energies ranging from 10 MeV to 40 MeV. The predominance of proton emission over neutron emission has been observed. The ratios of σ(α, p )/σ(α, n ) and σ(α, p n )/σ(α, 2 n ) in the region of maximum yield were found to be 3.4 and 60, respectively. The ratio of σ(α, α p n )/σ(α, α2 n ) at 40 MeV was about 180. A small “knee” was observed at the incident alpha-particle energy of about 20 MeV in the excitation function for the (α, 2 n ) reaction. The total reaction cross section was found to agree with the value calculated from continuum theory for a nuclear radius constant r 0 of 1.7×10 -13 cm assuming a nuclear square well potential.

Excitation functions for the (α, p ) and (α, p n ) reactions on A 40 were measured by the activation method using a “modified stacked-foil” technique. The bombardments were made with an alpha-particle beam from the 160 cm INSJ cyclotron. The beam was collected in a Faraday cup and measured by a current integrator. The disintegration rates of product nuclei were determined by 4πβ-counting. The results were compared with the predictions based on the statistical model of nuclear reaction by use of a level density expression of the form ω= c exp [2( a E ) 1/2 ]. The experimental cross sections appear to agree with the calculated values for r 0 ≃1.1×10 -13 cm and a =1∼2 Mev -1 . The considerably low value of r 0 might indicate that the statistical model is not completely applicable.

The determination of about 0.002 % Na in Pb metal by the CI curve method of the usual flamephotometric determination required about 2 days for its complicated procedures of removing the precipitate of PbSO4 and evaporating off the acids to dryness. A rapid method of determination based on the addition standard, linear extrapolation method carried out without removing the coexisting substances has been devised. The Pb as a principal constituent is removed as PbSO4instead of by spraying the sample solution because of the health hazard involved. Quantitative determinations of 3 kinds of Pb metal samples by this rapid method were carried out, and showed adequate accuracy. The results were in good agreement with those determined by heretofore known methods. An evaluation of the standard procedure of this method indicated that the time required for quantitative determination of a sample was 23hours by 2 analysts.

Excitation functions have been measured for a number of (p, xn), (p, pxn), (p, 2pxn) and (p, 3pxn) reactions of Ga69 and Ga71 with 13–56 MeV protons. The following peak cross-sections were determined: Ga69-(p, 2n)-465 mb, (p, 3n)-65 mb, (p, 4n)-7.2 mb, (p, pn)-420 mb, (p, p2n)-370 mb, (p, p3n)-193 mb, (p, αn)-134 mb, (p, 3p)-39 mb, (p, αpn)-42 mb; Ga71-(p, 3n)-600 mb, (p, 4n)-137 mb, (p, pn)-300 mb, (p, p3n)-240 mb, (p, α3n)-80 mb, (p, αp)-2.4 mb. The results have been compared with (1) statistical theory calculations, (2) cascade-evaporation calculations, and (3) a similar study of the reactions of Zn66+α-particles. It is concluded that the reactions exhibit both compound nuclear and direct interaction features with the latter being consistent with a cascade-evaporation mechanism. Values have been obtained for the total reaction cross-section of Ga69 and they are in agreement with continuum theory values for r0=1.4−1.5 fm.

Isomeric cross section ratios for reactions Mn 55 (α, n )Co, 58 m , g Fe 56 (α, p n )Co 58 m , g and Rb 85 (α, 2 n )Y 87 m , g were measured by the activation method using a stacked-foil technique. The experimental results of the energy dependence of σ m /σ g for Mn 55 (α, n )Co 58 m , g reaction were compared with the calculation using the square-well potential with the interaction radius parameter of r 0 =1.7 fermi and the energy level density parameter of a =2 MeV -1 in Fermi gas model. From the comparison, it seems that as the spin level density parameter either a constant value between σ=3 to σ=4 or the value dependent on nuclear temperature corresponding to 2σ 2 =14.4 T fits comparatively well in experimental results. However, the experimental result on this reaction shows that the σ m /σ g reaches a maximum value at about 25 MeV and then decrease. This behavior may be interpreted by a mechanism of direct interaction. The energy dependence of σ m /σ g for Fe 56 (α, p n )Co 59 m , g reaction qualitat...

Excitation functions for the ( alpha , pn), ( alpha , p2n), ( alpha , 3n), and ( alpha , alpha pn) reactions on Fe/sup 56/ and the ( alpha , alpha p) reaction on Fe/sup 57/ were measured by the activation method using a stacked- foil technique; the alpha -particle energies ranged from 17 to 40 Mev. The measured excitation functions for the alpha -particle reactions on Fe/sup 56/ were compared with those for the proton reactions on Co/sup 59/; the compound nucleus Ni/sup 60/ was the same for two cases. The comparison gives a test of the validity of compound nucleus theory. The ratios of corresponding cross sections seem to agree well with the theory (except in the case of resulting Co/ sup 57/). It may be seen that the two curves corresponding to the same residual nucleus in each case do not entirely coincide in energy. (auth)

Silicon and phosphorus contents in Pepperbush standard reference material were determined by neutron activation and X-ray fluorescence methods. In neutron activation analysis, β-ray spectra of 32P produced by 31P (n, γ) 32P reaction on Pepperbush and standard samples were measured by a low background β-ray spectrometer. In X-ray fluorescence analysis, the standard samples were prepared by mixing the Pepperbush powder with silicon dioxide and diammonium hydrogenphosphate. Characteristic X-rays from the samples were analyzed by a wavelength dispersive X-ray fluorescence spectrometer. From the β and X-ray intensities, silicon and phosphorus contents in Pepperbush were determined to be 1840±80 and 1200±50μg g-1, respectively.