Development of a new heterojunction structure (ACJ -HIT) and its application to polycrystalline silicon solar cells

A new solar cell structure named HIT (Heterojunction with Intrinsic Thin layer) has been developed based on new artificially constructed junction (ACJ) technology. In this structure a non-doped a-Si thin layer was inserted between the p(a-Si)/n(c-Si) heterojunction, improving the output characteristics and achieving a conversion efficiency of 18.1%. This structure was applied to cast polycrystalline silicon solar cells of a practical size. A high conversion efficeincy of 13.6% was obtained with a cell size of 10 cm × 10 cm using various technologies, including hydrogen plasma passivation.     

Compositional Dependence of Normal Spectral Emissivity of Molten Cu-Fe Alloy

Metallurgical and Materials Transactions B - Normal spectral emissivity of molten Cu-Fe alloy with different compositions was measured at the wavelength of 807 nm using an electromagnetic...     

Direct Observation of Pure Cu and Cu-Ag Anode Passivation in H2SO4-CuSO4 Aqueous Solution by Channel Flow Double Electrode and Optical Microscopy

Metallurgical and Materials Transactions B - The dissolution and passivation of pure Cu and Cu-5 wt pct Ag anodes in H2SO4-CuSO4 electrolyte were investigated by a direct...     

Contamination levels of PCDDs, PCDFs and Co-PCBs in commercial baby foods in Japan

To examine dioxin contamination in commercial baby foods in Japan, congener analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) were performed on 102 varieties of baby foods obtained from supermarkets in 2001-2002. The toxic equivalent quantity (TEQ) levels for dioxins in samples ranged from < 0.001 to 0.135 pg-TEQ/g wet weight when undetected or trace levels of congeners were taken as zero. Among 102 samples tested, 26 samples exceeded 0.010 pg-TEQ/g. The highest TEQ value was for "sardine, vegetables" (0.135 pg-TEQ/g), followed by "Japanese radish (daikon), sardine" (0.080 pg-TEQ/g). Thus, dioxins were detected at low levels in baby foods containing animal products such as fishes and/or dairy products.     

Sonochemical decomposition of perfluorooctane sulfonate and perfluorooctanoic acid

Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are shown to be globally distributed, environmentally persistent, and bioaccumulative. Although the toxicities of these compounds were reported, the cleanup procedure from the environment is not developed because of their inertness. In this report the sonochemical degradations of PFOS and PFOA to the products through the fission of the perfluorocarbon chains were observed and the half-life times of the PFOS and PFOA degradations under an argon atmosphere determined to be 43 and 22 min, respectively. The shortening of perfluorocarbon chain of PFOS and PFOA leads to the lowering of the toxicity in view of the decrease of the persistence, and the technique would contribute to the remediation of the environmental pollution by these compounds.     

Direct Formation of Crystalline Gadolinium-Doped Ceria Powder via Polymerized Precursor Solution

Synthesis of Ce_0.9Gd_0.1O_1.95 (CGO) powder from a polymeric precursor solution containing a mixture of nitrates, nitric acid, and ethylene glycol was investigated with emphasis on the effect of polymerization of the precursor solution on the crystallization and morphology of the derived solid intermediate and the final oxide powder. It is shown for the first time in this work that the solid intermediate derived from the polymerized solution is present in the form of well-crystallized cerium-gadolinium formate solid solution, Ce_{1− x} Gd _x (HCOO)₃, exhibiting anisotropic growth. Further polymerization of the precursor solution resulted in the direct formation of loosely agglomerated nanoscaled CGO oxide powder from the polymerized solution at temperatures as low as 130°C.     

Probability distributions of gas hydrate formation

Induction time distributions for gas hydrate formation were measured for gas mixtures of methane + propane at pressures up to 11.3 MPa using a high‐pressure automated lag time apparatus (HP‐ALTA). Measurements were made at subcooling temperatures between 4.3 and 13.5 K and, while isothermal induction times between 0 and 15,000 s were observed, the median isothermal induction times for the distributions ranged from 100 to 4000 s. A hyperbolic relationship between median induction time and subcooling was used to correlate the data. A graphical interpretation is presented that relates the two types of data that can be acquired by using the HP‐ALTA in one of two modes to study hydrate formation: induction time distributions at constant subcooling and formation temperature distributions observed during linear cooling ramps. The equivalence of these two modes provides a robust method for studying the variation of formation phenomena in different hydrate systems. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2640–2646, 2013     

Short-term irradiation behavior of minor actinide doped uranium plutonium mixed oxide fuels irradiated in an experimental fast reactor

A fuel irradiation program is being conducted using the experimental fast reactor ‘Joyo’. Two short-term irradiation tests in the program were completed in 2006 using a uranium and plutonium mixed oxide fuel which contains minor actinides (MA-MOX fuel). The objective of the tests is the investigation of early thermal behavior of MA-MOX fuel such as fuel restructuring and redistribution of minor actinides. Three fuel pins which contained MA-MOX: 2% neptunium and 2% americium doped uranium plutonium mixed oxide (Am,Pu,Np,U)O_2−x fuel were supplied for testing. The first test was conducted with high-linear heating rate of approximately 430 W cm⁻¹ for only 10 min. After the first test, one fuel pin was removed for examinations. Then the second test was conducted with the remaining two pins at nearly the same linear power for 24 h. In these tests, two oxygen-to-metal molar ratios were used for fuel pellets as a test parameter. Non-destructive and destructive post-irradiation examinations results are discussed with early on the behavior of the fuel during irradiation.     

Pial Vessel-Associated Microglia/Macrophages Increase in Female Dahl-SS/Jr Rats Independent of Pregnancy History

As the resident immune cells of the central nervous system, microglia have a wide range of functions such as surveillance, phagocytosis, and signaling through production of chemokines and cytokines. Recent studies have identified and characterized macrophages residing at the meninges, a series of layers surrounding the brain and spinal cord. While perivascular microglia within the brain parenchyma increase following chronic hypertension, there are no reports of changes at the meninges, and specifically, associated with the pial vasculature. Thus, we used female Sprague Dawley and Dahl salt-sensitive (SS/Jr) rat brains, stained for ionized calcium-binding adapter molecule (Iba1), and characterized microglia/macrophages associated with pial vessels in the posterior brain. Results indicate that Iba1⁺ pial vessel-associated microglia (PVAM) completely surrounded the vessels in brains from the Dahl-SS/Jr rats. PVAM density was significantly higher and distance between PVAMs lower in Dahl-SS/Jr compared to the Sprague Dawley rat brains. Pregnancy history did not affect these findings. While the functional role of these cells are not known, we contextualize our novel findings with that of other studies assessing or characterizing myeloid cells at the borders of the CNS (meninges and choroid plexus) and perivascular macrophages and propose their possible origin in the Dahl-SS/Jr model of chronic hypertension.