Generation characteristics of 100 kW PV system with various tilt angle and direction arrays

We report analysis about generation data of a 100 kW PV system. The system consists of seven polycrystalline silicon arrays and three thin-film arrays. The rated power of each array is 10 kW. Thin-film is made of tandem structure comprising amorphous silicon and microcrystalline silicon. For each array, tilt angles are arranged in 10°, 20° or 30°. And directions are facing due south, south-south east 30° and south-south west 30°.We have been analyzing generation data of the system since 2007 to understand the influence of system arrangement. The knowledge we have got until now is below.

(a)

Seasonal annealing occurs in thin-film arrays because thin-film cells contain amorphous silicon. Thus, theoretically, as for reduction of conversion efficiency in high temperature season, reduction of thin-film arrays is smaller than polycrystalline’s. We analyzed the ratio of seasonal generation energy (kWh) by using measured data of the system. Generation energy ratio in summer of thin-film is larger than polycrystalline’s. This is same trend as the theory.

(b)

There is a simulated data of solar irradiation that had been calculated by using meteorological data of 30 years. According to this simulated data, optimum condition of the system is arranged in tilt angle of 28.4° and facing due south. (The system is situated at latitude 33° north.) And simulation data shows that yearly irradiation decreases as tilt angle and direction become far from optimum condition. We analyzed yearly generation energy of each array in the system. Each array’s reduction percentages of generated energy from optimum condition were smaller than simulation value.

     

Organic solvent based TiO<Subscript>2</Subscript> dispersion paste for dye-sensitized solar cells prepared by industrial production level procedure

In order to prepare the TiO₂ liquid dispersions for the electrodes of dye-sensitized solar cells with industrial mass production level at a reasonable cost, the present study investigates the preparation of TiO₂ liquid dispersions by a general industrial dispersion technique using readily available P25. To determine the TiO₂ dispersion offering the best light–electricity energy conversion efficiency, the suitability of various types of solvents and resins for use in TiO₂ dispersion are tested. In general, organic solvent based TiO₂ dispersions are found to allow the formation of more uniform thin films in comparison with water-based dispersions. A preparation using ethyl cellulose as the resin and the terpineol as the solvent is found to exhibit the best conversion efficiency. We have also found that using two kinds of resins of different molecular weights gave rise to better efficiency. Among 26 metal compounds tested in this study, the best metal dopant was Ag. XRD and XPS measurements confirm that the Ag exists as metal Ag and silver oxide.     

Structural and Textural Quality of Kinu-Tofu Frozen-then-Thawed at High-Pressure

To determine effects of high-pressure thawing on quality of high-pressure frozen tofu, kinu-tofu (soybean curd) was frozen 90 min at ca ?20°C at 100 MPa (ice I), 200 MPa (liquid phase), 340 MPa (ice III), 400, 500 or 600 MPa (ice V), then thawed at the same pressure. Texture and structure of this tofu (D) were compared with high-pressure-frozen tofu thawed at atmospheric pressure (A: 90 min frozen; B: 90 min frozen then 2 days at ?30°C; C: 160 min frozen). When tofu was frozen at 200- 500 MPa, ice crystals were largest to smallest in B > A and C > D; pore size of D was the same as untreated tofu. Results indicated ice crystals never grew when frozen at 200–500 MPa. Growth occurred during reduction of pressure at ca ?20°C, frozen storage or while thawing at atmospheric pressure due to phase transition.     

Biofunctional calcium titanate coating on titanium by simple chemical treatment process using calcium-hydroxide slurry—Effects of the heating temperatures

The present study investigates the effect of the heating temperature on the characteristics of the surface layer in a simple treatment process using calcium-hydroxide slurry. Furthermore, biofunctions of the treated titanium surfaces, such as bioactivity in a simulated body fluid and corrosion resistance under a bio-environment, are also investigated. Our treatment process using calcium-hydroxide slurry is as follows: a titanium substrate is buried in calcium hydroxide slurry, and the slurry is then heated in air. The calcium hydroxide slurry was prepared by mixing of calcium hydroxide powder and water. When treated at heating temperature beyond 873 K, a crystallized calcium titanate coating is formed on a titanium substrate and further, the thickness increases with the increase of heating temperature. On the crystallized calcium titanate coating, calcium phosphate is precipitated in a simulated body fluid; therefore, the treated titanium surface has bioactivity. Furthermore, anodic current density of the treated surface is 10–10³ times lower than that of the non-treated surface.     

Effects of annealing ambient on ferroelectric properties and surface chemistry of sol–gel derived Bi3.25La0.75Ti3O12 thin films

In this work, Bi_3.25La_0.75Ti₃O₁₂ (BLT) thin films were prepared by sol–gel coatings followed by rapid thermal annealing in Ar or O₂ ambient. The correlation among annealing ambient, ferroelectric characteristics and surface chemistry of the BLT thin films were investigated. The BLT thin film annealed in Ar showed weaker crystallization, less dense surface and smaller polarization value than that annealed in O₂. After 10⁹ cycles, the remnant polarization of the BLT film annealed in Ar decreased to 83.5 % of the initial value while it remained 89.5 % for the sample annealed in O₂. X-ray photoelectron spectroscopy results indicated the inferior fatigue characteristics of the sample annealed in Ar was the comprehensive result of oxygen vacancies vicinity to Bi and Ti ion in the thin film.     

Polymerization of ethylene using zirconocenes supported on swellable cation-exchanged fluorotetrasilicic mica

Supported catalysts consisting of Cp₂ZrCl₂ and cation-exchanged fluorotetrasilicic mica (Mⁿ⁺-mica, Mⁿ⁺ = Na⁺, Mg²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺) were prepared and employed in the ethylene polymerization or ethylene/1-hexene copolymerization in the presence of R₃Al. The catalysts consisting of swellable Mg²⁺-mica and Zn²⁺-mica (both calcined at 200 °C) and Cp₂ZrCl₂ displayed high activity for the polymerization reaction. By contrast, when Mg²⁺-mica and Zn²⁺-mica were calcined above 250 °C, the swellability was lost, and the activities of Cp₂ZrCl₂ supported on these non-swellable micas were significantly reduced. The relationship between the activity and swellability of mica was clearly observed both in ethylene polymerizations employing (n-BuCp)₂ZrCl₂ in place of Cp₂ZrCl₂ and in ethylene/1-hexene copolymerizations using Cp₂ZrCl₂. The role of Mⁿ⁺-mica for the activation of the metallocene complex was investigated by surface observation using a scanning electron microscope and by XRD measurements of the catalysts after polymerization of ethylene for a short time. The results of the surface observations indicated that polyethylene was produced on the edges of Mⁿ⁺-mica lamellas at the initial stage of the polymerization. The XRD measurements show that the regularity of the stacked lamellas was immediately lost at this stage. The catalyst prepared by removing free Cp₂ZrCl₂ (i.e., unsupported Cp₂ZrCl₂, Cp₂ZrCl₂ dissolved into the catalyst slurry) showed extremely low activity, suggesting that the most of the active sites were formed through the reactions of Mⁿ⁺-mica and free Cp₂ZrCl₂. These results indicate that the lamellas of Mⁿ⁺-mica are peeled off at the initial stage of the polymerization and that exposed metal cations react with free-Cp₂ZrCl₂ to form additional active species. The swellability of Mⁿ⁺-mica strongly affects the formation of additional active sites, and therefore the supported catalysts based on non-swellable Mⁿ⁺-mica displayed only low activities.     

Intraarterial chemotherapy combined with radiation therapy for advanced cancer of the uterine cervix

The results of intraarterial chemotherapy (IACT) combined with definitive radiation therapy for 23 advanced and bulky carcinomas of uterine cervix are reported. IA-CT with cisplatin 50 mg and doxorubicin 30 mg was administered by one shot method in bilateral internal iliac arteries. The protocol consisted of one to three treatment session every 3 weeks. Nine of eleven patients with clinical stage III achieved a complete local response (82%), and the 3- and 5-year survival in these cases were 72% and 72%, respectively. These results were superior to the response (58%), 3- and 5-year survivals (68%, 58%) obtained in 19 patients treated mainly with radiation therapy alone. The side effect of grade 2 and 3 for the intestine, such as ileus and hemorrhagic colitis, was noted in 3 patients (15%). In addition, 3 of 8 patients with radical surgery and postoperative radiation therapy after IA-CT developed insufficient fracture of pelvic bone. These complications accompanied by IA-CT combined with radiation therapy and/or surgery increased slightly, compared with that by the previous therapy without IA-CT, but were not critical. The results suggest that IA-CT following radiation therapy is effective to improve the prognosis of patients with Stage III cervical cancer.     

Sequential Circuits with Combinational Test Generation Complexity under Single-Fault Assumption

We show that the test generation problem for all single stuck-at faults in sequential circuits with internally balanced structures can be reduced into the test generation problem for single stuck-at faults in combinational circuits. In our previous work, we introduced internally balanced structures as a class of sequential circuits with the combinational test generation complexity. However, single stuck-at faults on some primary inputs, called separable primary inputs, corresponded to multiple stuck-at faults in a transformed combinational circuit. In this paper, we resolve this problem. We show how to generate a test sequence and identify undetectability for single stuck-at faults on separable primary inputs.     

Patch-clamp analysis of the mechanism of PACAP-induced excitation in rat supraoptic neurones

In neurosecretory cells of the supraoptic nucleus (SON) of rats, pituitary adenylate cyclase activating polypeptide (PACAP) causes an increase in [Ca2+]i, and stimulates somatodendritic vasopressin (VP) release. In this report, to elucidate the ionic mechanism of the action of PACAP, membrane potentials and ionic currents were measured from SON neurones in slice preparations or from dissociated SON neurones. In the current clamp mode, PACAP depolarized membrane potentials of both phasic and non-phasic neurones and increased the firing rate. Moreover, simultaneous measurements of membrane potentials and [Ca2+]i revealed that the membrane depolarization correlated well with increases in [Ca2+]i. In the voltage-clamp mode, PACAP induced inward currents at a holding potential of -70 or -80 mV in a dose-dependent manner and the time course of the currents was similar to that of the PACAP-induced membrane depolarization. The averaged reversal potential of the PACAP-induced currents obtained from dissociated SON neurones was -33 mV, which was close to the reversal potential of non-selective cation currents in SON neurones. The currents were rapidly and reversibly inhibited by a cation-channel blocker, gadolinium. Analysis of synaptic inputs into SON neurones in slice preparations revealed that PACAP had little or no effects on the frequency of spontaneous excitatory and inhibitory postsynaptic currents. These results suggest that pituitary adenylate cyclase activating polypeptide (PACAP) activates PACAP receptors in the postsynaptic membrane of the supraoptic nucleus (SON) neurones, and that the activation of PACAP receptors leads to opening of non-selective cation channels, depolarization of the membrane potential, and increase in the firing rate in SON neurones. Such mechanisms may account for the PACAP-induced increase in [Ca2+]i and vasopressin (VP) release observed in SON neurones.     

Interlayer dissolution of montmorillonite observed by internal refraction interferometry

Dissolution behavior of a clay mineral such as montmorillonite is one of the most important phenomena for a long-term safety of high-level radioactive waste disposal. Dissolution rates of aggregated montmorillonite samples in basic solutions at room temperature were investigated in flow-through experiments by using internal refraction interferometry with an enhanced phase-shift interferometry. Conventional solution analysis methods cannot measure the effects of dissolution occurring within the interlayer of montmorillonite. Internal refraction interferometry can measure the crystal dissolution of montmorillonite, including both the dissolution of the outer surface and the interlayer of montmorillonite. The dissolution rate of montmorillonite in the interlayer was first observed. It was slower than the dissolution rate of outer surface. As the number of the montmorillonite crystal laminations increased, the montmorillonite dissolution rate in the interlayer decreased. Montmorillonite dissolution rates showed limited dependence on pH in the alkaline solutions. This can be explained by the effect of the laminated structure of montmorillonite crystal on the dissolution rate, especially in highly alkaline solution.