Discrimination between natural and HPHT-treated type IIa diamonds using photoluminescence spectroscopy

We have performed low-temperature (8 K) photoluminescence (PL) measurements on 71 natural and 12 high-pressure-and-high-temperature (HPHT)-treated type IIa diamonds. The GR1, NV⁰, NV^?, H4, and H3 defect center PL signals are compared. Some distinct differences in the PL lineshape, intensity, and appearance of side-band PL signals are observed. Furthermore, we processed 6 of the natural diamond samples with the HPHT treatment to investigate the effect of the treatment on the PL spectrum. By systematically analyzing the differences in the PL spectra, we developed a scheme to discriminate natural and HPHT-treated diamonds with 99% validity.     

Optimization of inverted bulk heterojunction polymer solar cells

We have successively fabricated inverted bulk heterojunction polymer solar cells employing ZnO and MoO₃ as electron and hole selective layers, respectively. The device structure is ITO/ZnO/P3HT: PCBM/MoO₃/Al. Differently from conventional polymer solar cells, ITO and Al work as electron and hole collecting electrodes in this inverted structure, respectively. We have found the optimal thickness of ZnO and MoO₃ to be 100 nm and 5 nm, respectively. The highest PCE was obtained to be 3.32% under AM 1.5 illumination at 1,000W/m², which is the highest PCE of inverted solar cells reported previously in the literature.     

The optimal composition of the filter-media for coping with daily flow-rate fluctuation

The fluctuation of inlet flow in a water treatment plant can change the filtration rate abruptly and ultimately reduce the filtration performance by leaking the detained particles in filter media. The surface wave, occurring in the intake well by the fluctuation of inlet flow, reaches the filtration process in a very short time (about 10 minutes), which makes it impossible to control the filtration rate stably. In this study the authors evaluated the effect of daily flow-rate fluctuation on the performance of sand filtration process, and the dual media composition was proposed to improve the filtration performance. Comparative column tests were carried out for the various dual media, such as sand and anthracite compositions. From the results of column tests, dual media with the composition of sand 45 cm and anthracite 30 cm is more effective than the single media with sand in filtration process. In addition, irrespective of dual media composition, the managing ability to cope with that fluctuation tends to be weak at the end of allowable filtration duration time.     

A study on the formation of photochemical air pollution and the allocation of a monitoring network in Busan

The characteristics of concentration variations for dust, O₃, and its precursors in Busan, South Korea were analyzed on the basis of pollution data from 19 stations during 2005. The objectives of these analyses were (i) to observe the ozone precursor concentrations under various conditions, (ii) to examine the mechanism of high [O₃] episode development, (iii) to examine the formation of photochemical aerosols, (iv) to observe the spatial distribution of high [O₃] occurrence over time, and (v) to observe the spatial distributions of temperature and wind speed over the whole area of Busan on high [O₃] episode days. The ratio of initial [NO₂] to initial [NO], O₃ dosage, and O₃ formation/hazard potential were established as relevant parameters on which to base allocation of monitoring stations according to each regional type, and criteria based on these parameters were determined for reallocating stations over the Busan area according to various regional types based on monitoring purposes. It was found that the current allocations of stations for investigating photochemical pollution do not reflect the areas where high O₃ occurs and areas where it is desirable to measure O₃ and its precursors flowing out of the target area. Therefore, based on these criteria, reallocated monitoring stations according to each regional type were suggested.     

Ruthenium(II)‐ or Rhodium(III)‐Catalyzed Grignard‐Type Addition of Indolines and Indoles to Activated Carbonyl Compounds

The ruthenium(II)‐ or rhodium(III)‐catalyzed pyrimidinyl‐directed Grignard‐type C−H additions of N‐heterocycles with activated aldehydes and ketones are described. A cationic ruthenium catalyst and sodium acetate additive in dichloroethane as solvent were found to be optimal catalytic system for the construction of C‐7 alkylated indolines. In sharp contrast, a cationic rhodium complex allows the generation of C‐2 alkylated indoles and pyrroles as well as C‐1 alkylated carbazoles. The site‐selective C−H functionalization of these heterocyclic scaffolds could be an important asset towards the development of novel bioactive compounds.

     

Effect of substituted alkyl groups on textural properties of ORMOSILs

A series of organically modified silica gels (ORMOSILs) with different alkyl groups such as methyl, ethyl, propyl, phenyl and octyl groups was investigated to determine the effect of substituted alkyl groups on the textural properties such as surface area, total pore volume, microporosity and hydrophobicity. Gelation time increased with increasing volume of alkyl groups. As-synthesized xerogels showed a systematic decrease in surface areas and total pore volumes and increase in microporosities with an increase in the volume of alkyl groups. All the ORMOSILs exhibited similar surface areas and total pore volumes after calcination at 500°C for 1 d. Increase in microporosities was observed in all the calcined xerogels. This study suggests that the primary particle sizes of pure silica cores are not affected by the size of the alkyl group, while their connectivity decreases with increasing volume of alkyl groups in the acid–base catalysed system of alkyltrimethoxysilane–tetramethylorthosilicate.     

Effect of heating temperature on dielectric properties of Pb(Zr,Ti)O3 [PZT] fibers

Ferroelectric Pb(Zr_0.53Ti_0.47)O₃ fibers were reproducibly fabricated by sol-gel technique using triethanolamine (TEA) complexed alkoxide. The phase transition from pyrochlore to perovskite took place about 400°C and a stable single perovskite phase was obtained at 550°C. PZT gel fibers spun through nozzle were heat-treated at 700°C, and at 1000°C for 1 h to certify the effect of heat-treatment temperature on the electrical properties. The PZT fibers had elliptical cross sections with diameter of 72 m–92 m, and dense microstructure was obtained by heating at 1000°C. In the PZT fibers heat-treated at 1000°C, a distinguishable relative permittivity peak and a pyroelectric current peak were observed at their Curie temperature. The P-E hysteresis loops of the crystalline PZT fibers were also observed.     

A perturbation analysis on solid polymer surfaces

A linear stability model was formulated to analyze the perturbation of solid polymer surfaces. Surface energy and thermal stress were considered as the main variables. The surface tends to more unstable as the temperature increase. This is interpreted as the dominancy of the lattice vacancy diffusion over surface mass diffusion and the increase in thermal stress.     

TSAT is a better predictor than ferritin of hemoglobin response to Epoetin alfa in US dialysis patients

Clinical guidelines recommend concurrent treatment of anemia in end‐stage renal disease with erythropoiesis‐stimulating agents (ESAs) and iron. However, there are mixed data about optimal iron supplementation. To help address this gap, the relationship between iron markers and hemoglobin (Hb) response to ESA (Epoetin alfa) dose was examined. Electronic medical records of 1902 US chronic hemodialysis patients were analyzed over a 12‐month period between June 2009 and June 2010. The analysis included patients who had at least one Hb value during each 4‐week interval for four consecutive intervals (k ? 2, k ? 1, k, and k + 1; k is the index interval), received at least one ESA dose during intervals k ? 1 or k, had at least one transferrin saturation (TSAT) value at interval k, and at least one ferritin value during intervals k ? 2, k ? 1, or k. Effect modification by TSAT and ferritin on Hb response was evaluated using the generalized estimating equations approach. Patients had a mean (standard deviation) age of 62 (15) years; 41% were Caucasian, 34% African American, 65% had hypertension, and 39% diabetes. Transferrin saturation, but not ferritin, had a statistically significant (P < 0.05) modifying effect on Hb response. Maximum Hb response was achieved when TSAT was 34%, with minimal incremental effect beyond these levels. Of the two standard clinical iron markers, TSAT should be used as the primary marker of the modifying effect of iron on Hb response to ESA. Long‐term safety of iron use to improve Hb response to ESA warrants further study.