Thermal comfort and productivity - Evaluation of workplace environment in a task conditioned office

The environment of workplace in an office involved in creative work was evaluated in 2005 and 2006. The M Company has installed partition based task/ambient conditioning systems (TAC) and several environment-friendly systems, such as double-skin and thermal-storage structures. It was intended to investigate the influence of the worker's behavior and task conditioning on worker's thermal comfort and productivity. In this survey, immediate thermal environment and worker's behavior were measured, and occupants' surveys of thermal comfort and feeling of fatigue were conducted. We found that both activity level of occupant and exposed thermal environment is greatly different one by one. It is suggested that an increase in metabolic rate according to worker's behavior influenced on their thermal comfort. Based on the knowledge obtained from this investigation, needs for TAC are discussed.     

Transition-Metal-Catalyzed Highly Regio- and Stereoselective Co-Polymerization of Dialkynylbenzene with Benzenedithiol Leading to Poly（Phenylene Vinylene Sulfide）

Co-polymerization of dialkynylbenzene with benzenedithiol proceeds regio- and stereoselectively in the presence of transition metal catalysts, affording the corresponding poly（phenylene vinylene sulfide） in good yield. In the presence of palladium acetate as catalyst, Markovnikov addition takes place selectively, whereas chlorotris（triphenylphosphine）rhodium-catalyzed reaction affords anti-Markovnikov adduct with excellent regio- and stereoselectivity.     

Hysteresis phenomena on the crystal lattice of Ti0.8Zr0.2Mn1.5 in the hydrogenation and dehydrogenation process

The crystal structure changes in the hydrogenation and dehydrogenation process have been investigated by the in-situ synchrotron X-ray diffraction measurement to elucidate the mechanism of hysteresis phenomena in equilibrium hydrogen pressure. The hysteresis phenomena were observed on the crystal lattice. The lattice constants and volume of α-phase (hydrogen solid solution) and β-phase (hydride) in the dehydrogenation process with lower equilibrium pressure were smaller than those in the hydrogenation process with higher equilibrium pressure. This phenomenon is opposite to the general relationship between the lattice volume and the equilibrium pressure. The hysteresis phenomenon was also observed in the diffraction peak widths. The peak widths of β-phase in the dehydrogenation process were wider than those in the hydrogenation process. The hysteresis phenomena may be related to lattice defects and the hydrogen content in crystalline regions.     

Increasing the thermostability of Flavobacterium meningosepticum glycerol kinase by changing Ser329 to Asp in the subunit interface region

The thermostability enhancement of Flavobacterium meningosepticumglycerol kinase (FGK) by random mutagenesis in the subunit interfaceregion was investigated. A single Escherichia coli transformant,which produced a more thermostable glycerol kinase than theparent enzyme, was obtained. The nucleotide sequence of thegene of the mutant enzyme (FGK2615) was determined, and thefour amino acid replacements were identified as Glu327 to Asp,Ser329 to Asp, Thr330 to Ala and Ser334 to Lys. Although theproperties of FGK2615 were fundamentally similar to those ofthe parent enzyme, the thermostability and K_m for ATP had changed.The thermostability of FGK2615 was apparently increased; thetemperature at which the enzyme activity is inactivated by 50%for a 30-min incubation of FGK2615 was determined to be 72.1°Cwhich was 3.1°C higher than that of the parent FGK. Fouradditional mutants each having a single amino acid replacement(Glu327 to Asp, Ser329 to Asp, Thr330 to Ala and Ser334 to Lys)were prepared and their thermostability and K_m for substrateswere evaluated. The effect of the substitution of Ser329 toAsp is discussed.     

Choking phenomena of sonic nozzles at low Reynolds numbers

The choking phenomena of sonic nozzles were investigated for the Reynolds number range from 40 to 30 000 for nitrogen gas. The results showed that the critical back pressure ratio is a function of the Reynolds number only, with different characteristics for different nozzle shapes. In ISO-type toroidal-throat Venturi nozzles, the minimum Reynolds number satisfying the choking condition is about 40 and the critical back pressure ratio is only about 0.05 at this minimum Reynolds number. It was also found that the critical back pressure ratio has a local minimum value around Re_th=4000 and that the local maximum value is around Re_th=10 000 due to the change in characteristics of the boundary layer in the diffuser. On the other hand, the critical back pressure ratio in quadrant nozzles decreases monotonically with decreasing Reynolds number, unlike the former nozzle, and the minimum Reynolds number necessary for choking is estimated to be approximately the same as that in the Venturi nozzle.     

Mechanism of N2O decomposition over a Rh black catalyst studied by a tracer method: The reaction of N2O with O(a)

N₂O decomposition on an unsupported Rh catalyst has been studied using tracer technique in order to reveal the reaction mechanism. N₂¹⁶O was pulsed onto ¹⁸O/oxidized Rh catalyst at 220°C and desorbed O₂ molecules (m/e=32,34,36) were monitored by means of mass spectrometer. The ¹⁸O fraction in the desorbed dioxygen was the same value as that on the surface oxygen. The result shows that the O₂ molecules desorb via Langmuir–Hinshelwood mechanism, i.e., the desorption of dioxygen through the recombination of adsorbed oxygen. On the other hand, TPD measurements in He showed that desorption of oxygen from the Rh black catalyst occurred at the higher temperatures. Therefore, reaction-assisted desorption of oxygen during N₂O decomposition reaction at the low temperature was proposed.     

Co2+-Substitution Effect in Ce-TZP/La M-type Hexaferrite Composites

A Ce-TZP/platelike La(Co(Fe_0.9Al_0.1)₁₁)O₁₉ composite was synthesized in situ while sintering from a mixture of Ce-TZP, La(Fe_0.9Al_0.1)O₃, Fe₂O₃, Al₂O₃, and CoO powders. Platelike La(Co(Fe_0.9Al_0.1)₁₁)O₁₉ crystals were grown in a dense Ce-TZP matrix after sintering at temperatures of 1200°–1350°C. The temperature range for sintering Ce-TZP/La(Fe,Al)₁₂O₁₉ composites was expanded widely by substituting Co²⁺ ions for Fe²⁺ ions in its structure. The highest value of the bending strength of the Ce-TZP/La(Co(Fe_0.9Al_0.1)₁₁)O₁₉ composites was 880 MPa, which was higher than that of the Ce-TZP/La(Fe,Al)₁₂O₁₉ composite (780 MPa) and Ce-TZP (513 MPa). The saturation magnetization of the Ce-TZP/La(Co(Fe_0.9Al_0.1)₁₁)O₁₉ composite was a constant value of 7.7 emu/g after the composite was sintered at 1200°–1350°C.     

Catalytic decomposition of N2O over supported Rh catalysts: effects of supports and Rh dispersion

The study of catalytic decomposition of nitrous oxide to nitrogen and oxygen over Rh catalysts supported on various supports (USY, NaY, Al₂O₃, ZrO₂, FSM-16, CeO₂, La₂O₃) showed that the activities of Rh/Al₂O₃ and Rh/USY (ultrastable Y zeolite) catalysts were comparable to or higher than the other catalysts reported in the literatures. The catalytic activity of N₂O decomposition was sensitive not only to the Rh dispersion but also to the preparation variables such as the Rh precursors and the supports used. A pulsed N₂O experiment over a Rh/USY catalyst suggested that the catalytic N₂O decomposition occurs on oxygen-covered surface and that O₂ may be freed on collision of N₂O molecules with the adsorbed oxygen atoms.     

Polymeric ionic liquid membranes as electrolytes for lithium battery applications

A new kind of polymeric ionic liquid (PIL) membrane based on guanidinium ionic liquid (IL) with ester and alkyl groups was synthesized. On addition of guanidinium IL, lithium salt, and nano silica in the PIL, a gel PIL electrolyte was prepared. The chemical structure of the PIL and the properties of gel electrolytes were characterized. The ionic conductivity of the gel electrolyte was 5.07 × 10⁻⁶ and 1.92 × 10⁻⁴ S cm⁻¹ at 30 and 80 °C, respectively. The gel electrolyte had a low glass transition temperature (T _g ) under −60 °C and a high decomposition temperature of 310 °C. When the gel polymer electrolyte was used in the Li/LiFePO₄ cell, the cell delivered 142 mAh g⁻¹ after 40 cycles at the current rates of 0.1 C and 80 °C.     

Comparative study of carbon-supported Pt/Mo-oxide and PtRu for use as CO-tolerant anode catalysts

Carbon-supported Pt/Mo-oxide catalysts were prepared, and the reformate tolerances of Pt/MoOx/C and conventional PtRu/C anodes were examined to clarify the features and differences between these catalysts. Fuel cell performance was evaluated under various reformate compositions and operating conditions, and the CO concentrations at the anode outlet were analyzed simultaneously using on-line gas chromatography. Pt/MoOx showed better CO tolerance than PtRu with CO(80 ppm)/H₂ mixtures, especially at higher fuel utilization conditions, which is mainly due to the higher catalytic activity of Pt/MoOx for the water-gas shift (WGS) reaction and electro-oxidation of CO. In contrast, the CO₂ tolerance of Pt/MoOx was much worse than that of PtRu with a CO₂(20%)/H₂ mixture. The results of voltammetry indicated that the coverage of adsorbates generated by CO₂ reduction on Pt/MoOx was higher than that on PtRu, and therefore, the electro-oxidation of H₂ is partly inhibited on Pt/MoOx in the presence of 20% CO₂. With CO(80 ppm)/CO₂(20%)/H₂, the voltage losses of Pt/MoOx and PtRu are almost equal to the sum of the losses with each contaminant component. Although the adsorbate coverage on Pt/MoOx increases in the presence of 20% CO₂, CO molecules in the gas phase could still adsorb on Pt through an adsorbate ‘hole’ to promote WGS or electro-oxidation reactions, which leads to a reduction in the CO concentration under CO/CO₂/H₂ feeding conditions.