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This study describes a measuring system for mass spectrometry, consisting of a glow discharge ionization source for soft plasma ionization and a time-of-flight mass spectrometer, to detect toxic volatile organic compounds rapidly and easily. It is the most important to determine how the complicated fragmentation of such compounds can be suppressed to occur so as to recognize the mass spectra of the volatile organic compounds as their fingerprints. The novelty of this work is that the optimal discharge condition for the soft plasma ionization–time-of-flight mass spectrometer system could be selected, so that the parent mass peak of analyte molecules could be observed both with high sensitivity and with little or no fragmentation of them. Use of air gas at a pressure of 1000 Pa provided the most favorable result for these criteria, whereas, in a previous report, the soft plasma ionization source operating with argon at a pressure of 346 Pa had yielded additional mass peaks of the fragmented species...

Durability of an organic–inorganic nanocomposite electrolyte membrane prepared by mixing hydrophilic fumed silica particles of an average size of 7 nm with Nafion ionomer was studied for the mitigation of chemical degradation of the membrane caused by trace radial species in polymer electrolyte fuel cells (PEFCs). Infrared (IR) spectroscopy indicated that the peak of C−F, S−O and C−O−C bands were not shifted to the higher wavenumber with an addition of 1 wt.% hydrophilic silica to the Nafion matrix. This suggests that hydrophilic silica had a catalyst activity for the decomposition of hydrogen peroxide and reduced the membrane degradation by trace radicals attack. Quantum chemical calculations (QCCs) using a model ionomer of trifluoromethanesulfonate (TFMS) and a model nanoparticle of Si(OH) 4 also implied that the nanoparticle was able to trap H, OH and OOH radical species before attacking the ionomer. The hydration of TFMS that induces deprotonation of sulfonic acid group in TMFS and formation of hydronium anion was confirmed also in the presence of trace radicals due to the ability of Si(OH) 4 to trap H radical.

In this works, we investigated the behavior of S-containing compounds from durian wastes in liquid and solid phases after the hydrothermal gasification, using ICP–OES and an HPLC–SEC/TOF-MS. Ion chromatography and XRD analysis were also done to support the finding. The results suggest that the organo sulfur compounds were degraded into inorganic species and remaining in liquid and solid state. The decomposition process was increased by the addition of Ca(OH)2 as an alkali reagent.

In our previous work, a method entitled “2D Visualization” was proposed to diagnose CH4/H2 plasmas and successfully applied to demonstrate the profile of CH radicals that dominated the microstructure of the resultant films. To synthesize higher density carbon electrodes for lithium-ion batteries, N2 was employed as a reaction control gas to enrich the density of CH in this present study. Two-dimensional distribution of CH radicals in the plasma was successfully reconstructed by means of spectroscopic visualization. Emission intensities of spontaneous radiation arising from CH in the plasma were captured by a CCD camera through an optical band-pass filter with a transmission wavelength of 430 nm. Surface morphology of the obtained electrode was observed using scanning electron microscope (SEM). Correlation between the plasma condition as well as the feeding gas condition and the morphology of the target surface is discussed. It was clarified that CH density in the CH4/N2 plasma was higher than that in CH4/H2 plasma and strongly depends on nitrogen molar ratio in the feeding gas, and that surface morphology of the target was controlled not only by the density of carbon-containing species such as CH but also by their excitation temperature in the plasma.

The behavior of fuel air mixing and combustion continues to be of prime importance in all kinds of combustion systems as this leads to improvements in combustion efficiency, formation and emission of trace pollutants, and size and dimensions of the combustion chamber. A detailed examination of flame requires close examination of the various ongoing physico-chemical properties as well as detailed stable and short lived chemical species in a combustion system. In this paper, an isotope shift/planer laser-induced fluorescence (IS/PLIF) method is developed that is based on the distinct excitation wavelengths of rotational lines of OD radicals that are displaced from the OH radicals due to their isotope shift. We provide visualization of the spatial distributions of fluorescent emissions from OH and OD for their application in unraveling the complex feature of flames from the view of a comprehensive insightful analysis. Note that OH is typically an intermediate specie in combustion reactions. However, OD molecules are produced from the dissociation reaction of deuterium oxide (D2O) upon injection into a flame. The information obtained from the LIF profiles provided useful information in our quest to examine the fate of mixing between fuel and air during combustion.

Chemical degradation products of a Nafion membrane on the catalyst interface of polymer electrolyte fuel cell (PEFC) by hydrogen and oxygen feeding into the anode were studied by high-performance liquid chromatography (HPLC). An acidic solution of pH 5.3 was obtained after the anode reaction and 5.0 × 10− 6 mol·l− 1 of hydrogen fluoride was detected by HPLC. Degradation mechanisms of the ionomer induced by trace radical species were simulated by means of quantum chemical calculations using a model side chain terminal of trifluoromethanesulfonate (TFMS). The results indicate that H radicals and OH radicals generated by the reaction on the interface induce the production of hydrogen fluoride, carbonyl fluoride and sulfonic acids. The bond dissociation energies (BDE) of C S and C F bond in TFMS are calculated to be 214.5 and 569.6 kJ·mol− 1, respectively. It was clarified that the degradation of TFMS is affected not only by BDE but also by the behavior of fluorine atoms.

The divertor region is among the most important section of nuclear fusion reactors. In order to investigate the behavior of deuterium in divertor plasmas, emission profiles of the Balmer series lines of deuterium atoms, molecular bands of D 2 and CD intensities have been two-dimensionally visualized with a CCD camera fitted with a bandpass filter, using a test system, the Nagoya Divertor Simulator II (NAGDIS-II). It has been clarified that profiles of emission from deuterium atoms and excitation temperature varied significantly with changes of the discharge current. From profiles of the ratio of the atomic emission intensity to the deuterium molecular emission, the increase in the dissociation fraction of deuterium molecule with the increase of the discharge current has been confirmed. Two dimensional visualization of the divertor plasma is a promising method for studies in nuclear fusion science.

Hydrothermal process has been applied for effective production of Hydrogen from biowastes. In this study hydrothermal process for production of valuable Hydroxylapatitefrom chicken manure containing phosphorus was focused on. Conditions of 400?C and 26 - 27 MPa with addition of 1 mmol Ca(OH)2 were determined as the optimal by using O-phospho-DL-serine as a model compound. Afterwards, the real biowaste containing phosphorous, chicken manure was processed under the same conditions. Formation of a Hydroxylapatite; in the solid residue was confirmed from X-ray diffraction (XRD) patterns, after purification. It was found that 27.9% of P in the chicken manure was converted to Hydroxylapatite. With the use of acetic acid as a chemical purification medium, Hydroxylapatite was obtained.

Plasma-enhanced chemical vapor deposition (PECVD) is among the promising processes to synthesize advanced materials. Carbon films of sp2 with different micro-structures (wall-like/pole-like) are attractive for battery electrodes and have been synthesized from different methane + hydrogen plasmas. To clarify the interaction between plasma and a substrate target surface, an attempt to visualize the intermediate species CH was made in this work. Visible spectra (VIS-spectra) of the spontaneous optical emission from the plasmas were recorded by a multi-channel spectrometer to elucidate reaction mechanisms during the deposition process. The overall spectroscopic emission intensity from the methane-lean plasma was much higher than that from the methane-rich plasma. However, the emission intensity of CH radical in the methane-rich plasma was slightly higher than that in the methane lean one. In addition, two-dimensional spectroscopic images of CH radicals generated in the plasmas were captured using a CCD camera fitted with an optical band-pass filter at 430 nm. It was found that the negative bias voltage was responsible for a turbostratic in the deposited films.

In this work is presented online monitoring of gasification of durian (Durio zibethinus), onion (Allium cepa L.) and garlic (Allium sativum L.) as real biomasses containing sulfuric compounds, in sub and near critical water (250, 300 and 350 °C) by Lithium Ion Attachment Mass Spectrometry. Seven sulfuric compounds were detected in the resulting gas phase: H2S, ethanethiol, 1-propanethiol, methyl phenyl disulfide, propyl disulfide, diethyl trisulfide and dipropyl trisulfide gases. Allicin and alliin were successfully detected from onion and garlic samples. The effect of the subcritical conditions used on the release of sulfur heteroatomic compounds from real biomass was examined. Ca(OH)2 was adopted as an alkali reagent to suppress the emission of sulfuric compounds to the gas phase. Extraction was promoted and decomposition processes were observed for durian when Ca(OH)2 was added. For onion and garlic samples the decomposition process was prevailing with the addition of Ca(OH)2.

Near-infrared diffuse tomography was used in order to observe dynamic behaviour of flowing gases by measuring the 3D distributions of composition and temperature in a weakly scattering packed bed reactor, subject to wall effects and non-isothermal conditions. The technique was applied to the vapour phase hydrogen isotopic exchange reaction in a hydrophobic packing of low aspect ratio made of platinum on styrene divinyl benzene sulphonate copolymer resin. The results of tomography revealed uneven temperature and composition maps of water and deuterated water vapours in the core-packed bed and in the vicinity of the wall owing to flow maldistribution. The dynamic lag between the near-wall water vapour and deuterated water vapour compositions were observed suggesting that the convective transfer which was significant near the wall at the start, owing to high porosity, was also effective at large conversions.

Near-infrared diffuse tomography was used in order to observe dynamic behaviour of flowing gases by measuring the 3D distributions of composition and temperature in a weakly scattering packed bed reactor, subject to wall effects and non-isothermal conditions. The technique was applied to the vapour phase hydrogen isotopic exchange reaction in a hydrophobic packing of low aspect ratio made of platinum on styrene divinyl benzene sulphonate copolymer resin. The results of tomography revealed uneven temperature and composition maps of water and deuterated water vapours in the core-packed bed and in the vicinity of the wall owing to flow maldistribution. The dynamic lag between the near-wall water vapour and deuterated water vapour compositions were observed suggesting that the convective transfer which was significant near the wall at the start, owing to high porosity, was also effective at large conversions.

Two-photon excited laser-induced fluorescence (LIF) spectra of argon atom were successfully observed in a Grimm-style glow discharge tube, which has widely been applied to depth profiling of the elemental composition on various film-like samples by emission spectrometry. The LIF signal of an argon atomic line at 641.63 nm was observed when the glow discharge argon plasma was illuminated by a pulsed Ti:sapphire laser radiation of 7–10 mJ/pulse at 753.39 or 795.66 nm without focusing of the laser beam.

燃焼火炎から発光する赤外光を，バンドパスフィルターで波数選択した後に，サーモグラフィーを用いて分光イメージング画像として取得した．二酸化炭素と一酸化炭素に由来する赤外発光バンドに着目し，それぞれの波数における分光イメージング画像を温度補正した後に，標準添加法によって絶対濃度分布を算出した．赤外発光分光によってその場分析した絶対濃度の値は，排ガスのガスクロマトグラフィー（GC）分析結果と良い一致を示した．この分析結果から，燃焼火炎中の二酸化炭素濃度と一酸化炭素濃度の比を二次元プロットすることによって，完全燃焼領域と不完全燃焼領域を明確に示すことに成功した．

The method to visualize two-dimensional (2D) distributions of heavy metals in refuse-derived fuel (RDF) combustion flame by using 2D atomic absorption spectrometry (2D-AAS) was studied. In-situ monitoring of the heavy metal vaporization was performed to gather useful information on the reduction of their emissions. The RDF sample was burned on a burner with an O2/N2 gas mixture being supplied from the bottom. Easily vaporized metals such as mercury (Hg) and cadmium (Cd) present in the RDF flame were measured by 2D-AAS. In order to measure the atomic absorption of lead (Pb), a sub-burner supplying O2 was placed in the RDF flame. O2 reacts with unburned gases in the RDF flame, increasing the flame temperature locally. Consequently, atomic absorption of Pb became measurable, and its 2D profiles were obtained by mapping. In addition, quantitative analyses of Hg and Cd contained in the RDF were made using the standard addition method without any pretreatments.

Hydrogen gas has successfully been produced from biomass by hydrothermal gasification. Various alkaline additives have been found to increase the hydrogen yield. However, studies have not yet been done on pollutants that would be produced in the hydrothermal gasification with real biomass waste containing hetero-atoms such as S, N, and P elements. Studies have also yet to be done on finding ways to suppress the formation of pollutants. For this purpose, l -cysteine containing hetero-atoms S and N, and O-phospho- dl -serine with P, were selected as pure test samples. The objective was to determine the optimum conditions for the suppression of the pollutants produced in the hydrothermal gasifications, while effectively generating hydrogen. Phosphate ion was found in the liquid phase after the gasification of O-phospho- dl -serine with and without additive at 400 °C. Phosphorus compounds were not detected in the gas phase. When a large quantity of Ca(OH)2 was added, phosphorus compounds were precipitated in the solid phase. Hydrogen gas yields were increased and other gases were suppressed by using the additive. These results were same as those of chicken manure. The test samples were used to determine the optimum conditions of 400 °C, 21 MPa, and the Ca(OH)2 additive. NH 4 + was mainly produced in liquid phase by using the model sample of l -cysteine. With the addition of Ca(OH)2, the yields of SO2 and H2S are significantly decreased. NO 2 - and NO 3 - were detected at trace levels. The main gas produced was hydrogen and the generation of CO2 gas was efficiently suppressed. These optimum conditions were then applied to real biowastes, cow dung. Hydrogen production increased and was found to be mainly in the gas phase, while there was negligible generation of pollutants, with these were in the gas phase. H2S were detected at trace levels. NO was not recorded, and production of other gases were suppressed by using the additive. Nitrogen in the sample was trapped as NH 4 + in the liquid phase.

Biomass gasification using supercritical water is a promising way to produce hydrogen gas. However, this method might release toxic heteroatomic compounds. It is therefore important to clarify reaction pathways for efficiently obtaining hydrogen gas and suppressing environmental burden. L-cysteine was adopted for a test reagent containing sulfur and determination of the sulfur compound reaction pathways was studied by Li + -ion attachment mass spectrometry. It was found that H 2 S, CO, CO 2 , SO, SO 2 and SO 3 gasses were released at high concentrations in the gas phase during the hydrothermal reaction. By adding Ca(OH) 2 as alkali, the pathway of these gasses were, however, suppressed into the liquid phase so that the toxic emissions to the gas phase could be avoided.

Hydrogen gas and the valuable material hydroxylapatite have successfully been produced from biomass wastes by hydrothermal gasification. However, it was expected that toxic compounds might be produced through the reaction. It was therefore important to clarify whether toxic compounds were synthesized in hydrothermal gasification of biowastes since dioxins are categorized among the most toxic compounds for humans. This is particularly true of biomass wastes containing hetero-atoms in organic matrices. In this study, formation of the dioxins polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and certain dioxin-like polychlorinated biphenyls (PCBs) were examined. Chicken manure and cattle manure were tested as real biowastes for hydrothermal gasification and the produced compounds in the liquid and solid phases were analyzed for detection of dioxins by gas chromatography/mass spectrometry (GC/MS). The total toxic equivalent quantities (the total TEQ) of dioxins produced by the hydrothermal gasification were found to be much lower than regulation levels in Japan require and therefore the products require no additional post treatments.

In order to investigate dynamic plasma behaviors in scrape-off layer (SOL) regions, such as ELMs and plasma blobs, we have developed a 4-channel high-speed camera equipped with four interference filters to obtain 2D successive images of spectral intensity of He I emission lines at 667.8 nm, 706.5 nm and 728.1 nm in addition to HeII at 656.0 nm. By using calculated results based on a Collisional Radiative (CR) model for He, the intensity ratios of the He I lines (728.1/706.5 and 667.8/706.5), provides 2D distributions of the electron temperature and density. The 2D profiles of electron density and temperature reconstructed from 2D images of He I emission lines taken in a small tokamak, HYBTOK-II were compared with those measured with the triple probe in order to evaluate the accuracy of this diagnostics. Electron density and temperature measured with the 4-channel high-speed camera are in good agreement with those obtained with the triple probe (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A time-of-flight mass spectrometry (TOFMS) with a newly laboratory-made sampling cone interface fitted to an atmospheric pressure chemical ionization (APCI) positive ion source was successfully applied to easy, rapid on-line measurements of nanoparticles and components generated during combustion. The mass spectra for smoke from a mosquito coil ranged up to m/z 1202, corresponding to 1.2 nm with the carboneous material density as graphite 2.2 g cm−3. Typical m/z peaks were assigned to such synthetic pyrethroids, as d-allethrin and d-tetramethrin, at m/z 303 and 332, respectively. A specific pattern with a peak-to-peak interval of 74 was recognized in the higher mass range. The interval of 74 was confirmed by measuring with a standard silica solution in a positive ion mode using a conventional APCI interface under the same APCI conditions. The mass spectrum of the silica solution had a pattern with peak interval of 44 which was assigned to SiO. These results indicate that the pattern with an interval of 74 in the mass spectrum of the mosquito coil smoke is sample-derived peak. We assumed that the interval of m/z 74 is assigned to identified as triacetylene (1,3,5-hexatriyne) that is generated during the combustion.

A novel technique of spectroscopic imaging using a near-infrared (NIR) laser sheet beam was developed for visualization of liquid water in a proton-exchange membrane (PEM) sandwiched between two opaque electrodes set in a polymer electrolyte fuel cell (PEFC). In-plane two-dimensional distribution of water in the thin membrane was clearly visualized during the fuel cell operation. Under the condition of fuel feeding into the PEFC without humidification, water was generated by the fuel cell reaction in the whole electrode area. In contrast, under the condition of fuel feeding with humidification, the PEM got wet in the vicinity of a gas flow field locally.

Temperature-dependent infrared (IR) spectra of a Nafion membrane were measured over a temperature range from 30 to 320 °C. The obtained spectra were analyzed using perturbation-correlation moving-window two-dimensional (PCMW2D) correlation spectroscopy and quantum chemical calculations (QCC). Three-step structural changes in Nafion ionomer induced by temperature were revealed. Dehydration of the ionomer is dominant below 60 °C. Protonation of sulfonate group in the side chain terminal occurs around 100 °C. Thermal degradation of the chains starts above 280 °C.

Results are presented here on the detection of unstable species formed in flames using a novel Laser Ionization Mass Spectrometry (LIMS) system. The chemical species generated in atmospheric pressure flames were directly introduced into a mass spectrometer operated at high vacuum conditions using a newly developed interface, in which the ionization was induced by laser irradiation. Optimum conditions for the experimental conditions were investigated in order to obtain mass spectra with adequate signal to noise (S/N) ratios. In addition, the distribution profiles of various species in the flame was measured and visualized. The distribution of OH profiles was also measured under the same conditions using Planer Laser Induced Fluorescence (PLIF) diagnostics. The results showed that the profiles of OH distribution by LIMS were in good agreement with those obtained using PLIF diagnostics.

The nitridation of titanium (Ti) caused by a Q-switched Nd:YAG laser under nitrogen gas atmosphere was investigated in situ using X-ray photoelectron spectroscopy (XPS). A laser having a wavelength of 1064 nm and 532 nm (SHG mode) was irradiated on a titanium substrate in an atmosphere-controlled chamber, and the substrate was then transported to an XPS analysis chamber without exposing it to air. The characteristics of the surface layer strongly depend on the laser power. When the power is relatively low, a titanium dioxide layer containing a small amount of nitrogen is formed on the substrate. Laser irradiation beyond a certain laser power is required to obtain a stoichiometric titanium nitride (TiN) layer. A TiN layer and an oxynitride layer with a TiO x N y -like structure are formed as the topmost and the lower surface layer, respectively, when the laser power exceeds this threshold value. The threshold laser power strongly depends on the wavelength of the laser, and this threshold value for the 532-nm laser is quite lower than that for the 1064-nm laser.

Optogalvanic (OG) spectra of argon in the visible to near-infrared spectral region between 735 and 850 nm were investigated using a Grimm-style glow-discharge tube, which has been widely used to obtain depth profiles of the elemental composition on various film-like samples. About 49 lines of one-photon and two-photon OG peaks were observed with a pulsed Ti:sapphire laser; these peaks were precisely assigned. Two-photon OG spectra of argon were easily observed without focusing the pulsed laser irradiation to more than 1 mJ. The excitation mechanisms of the observed argon OG spectra could be classified into 3 types: single-photon transition, two-photon transition, and two-photon stepwise transition. In addition, a pseudo-resonant effect was also found to be effective. The argon lines observed in this experiment are suitable as convenient calibration wavelength markers of pulsed tunable laser radiation.

We have previously reported the hydration structure of a poly(2-methoxyethyl acrylate) (PMEA) antithrombogenic material. In the present study, the hydration structure of a 2-methoxyethyl acetate (MEAc) model monomer for PMEA was explored by means of attenuated total reflection infrared (ATR-IR) spectroscopy and differential scanning calorimetry (DSC). Water in MEAc does not show an evidence for cold crystallization by DSC, while it was found by ATR-IR spectroscopy that MEAc has a hydration structure similar to that of PMEA at a functional group level. Three different types of hydrated water, tightly bound water, loosely bound water and scarcely bound water, were identified in MEAc, as well as PMEA. It was suggested from the present study that the localized and concentrated water cluster having the three types of hydration structure on the surface of PMEA plays an important role in the biocompatibility.

Hydrogen-bond structures in poly(2-hydroxyethyl methacrylate) (PHEMA) were investigated by infrared (IR) spectroscopy and quantum chemical calculations (QCC). A monomer of 2-hydroxyethyl methacrylate (HEMA) and model compounds of methyl acetate (MA) and methanol (MeOH) were also used. Evidences for OH⋯O C and OH⋯OH types of hydrogen-bonds were observed in an IR spectrum of a PHEMA solid. It was estimated from the present study that 47.3% of OH groups on the PHEMA side chain terminal are engaged in the OH⋯O C type of hydrogen-bond, while the rest contributes to the OH⋯OH type of hydrogen-bond.

Subcritical water (SCW) extraction of citrus pomaces (CPs) was carried out, and antioxidant activity and nutraceutical compound levels of the SCW extracts were evaluated in detail. At first, CP samples were subjected to the SCW extraction under various conditions focusing on the extraction temperature and time. Consequently, the highest total phenol contents, radical scavenging activity, and reducing power were found when extraction was carried at 200°C and 1.4 MPa for 60 min. Furthermore, the amounts of three kinds of polymethoxylated flavones (sinensetin, nobiletin, and tangeretin) in the SCW extracts also showed the highest values under this condition. These results indicate that SCW is an effective medium for the fast and highly efficient extraction of the antioxidants and nutraceutical compounds from CPs.

The surface reaction on titanium due to pulsed Nd:YAG laser irradiation in a nitrogen atmosphere was investigated using X-ray photoelectron spectroscopy (XPS). The laser, with a wavelength of 532 nm (SHG mode), was irradiated on a titanium substrate in an atmosphere-controlled chamber, and then the substrate was transported to an XPS analysis chamber without exposure to air. This in situ XPS technique makes it possible to clearly observe the intrinsic surface reaction. The characteristics of the surface layer strongly depend on the nitrogen gas pressure. When the pressure is 133 kPa, an oxynitride and a stoichiometric titanium nitride form the topmost and lower surface layers on the titanium substrate, respectively. However, only a nonstoichiometric titanium oxide layer containing a small amount of nitrogen is formed when the pressure is lower than 13.3 kPa. Repetition of laser shots promotes the formation of the oxide layer, but the formation is completed within a few laser shots. After the initial structure is formed, the chemical state of the surface layer is less influenced by the repetition of laser shots.

Lithium (Li) ion attachment mass spectrometry (IAMS) is a highly sensitive method for detecting volatile organic compounds (VOCs) without fragmentation in real-time. We have therefore developed a novel IAMS system for direct determination of trace amounts of VOCs by modifying the sampling cone interface. This technique was successfully applied to in situ analysis of human breath. It was shown that the concentrations of acetone in 7 healthy subjects ranged from 0 (not detectable) to 28.5 ppbv (parts per billion by volume) after a 15-hour overnight fast. The detection limit (3σ) is 0.55 ppbv for acetone and the relative standard deviation (RSD) is less than 9.7%. These results demonstrate that the newly developed IAMS system provides simple, rapid, and sensitive measurements of trace amounts of acetone in human breath, and that the system is promising for early diagnosis of diabetes.

A system with Li+ ion attachment (IA) ionization has been developed for the direct detection of intermediates formed in burning flames by mass spectrometry. Dimethyl ether (DME) among alternative fuels was selected as a test substance to examine the capability of the system. As a result, intermediates generated in a premixed DME-air flame were directly detectable as Li+ adduct ions. By moving the burner on an X-Y stage, spatial distribution profiles of different species, including unburned DME and formaldehyde, were obtained for three types of flames: diffusion, partially premixed, and premixed. Copyright © 2008 John Wiley & Sons, Ltd.

Temperature-dependent infrared (IR) spectra of a poly(vinyl alcohol) (PVA) film were analyzed by perturbation-correlation moving-window two-dimensional (PCMW2D) correlation spectroscopy. The PCMW2D correlation analysis revealed that there are two characteristic bands in the O–H stretching region, though only one broad feature is found in the original IR spectra. These two bands were assigned to bulk hydroxyl group on the PVA chain with hydrogen bonds, which appears at a lower wavenumber region, and residual hydroxyl group induced by thermal degradation, which appears at a higher wavenumber region. The lower wavenumber band changes below the melt temperature of PVA, while the higher wavenumber band changes above the melt temperature. Spectral variations in the C–H deformation bands region and those in the C O stretching bands region were also discussed from the results of the PCMW2D correlation analysis.

of fossil fuels. In this regard, thermoelectric power generation that can directly convert the thermal energy to electrical energy is one of the attractive methods. Skutterudite compounds of CoSb3 have been investigated as promising candidate materials for thermoelectric power generation. In this research, CoSb3 compounds were synthesized from raw metal powders by using a pulse discharge sintering process. To improve the thermoelectric properties, iron was doped as an element substituting for cobalt of the CoSb3 compound. The syntheses of FexCo1xSb3 were confirmed by x-ray diffraction analysis. The Seebeck coefficient, electric resistivity, and thermal conductivity were measured as the thermoelectric properties. Optimum content of iron was decided from the maximum thermoelectric figure of merit. Furthermore, filling of lanthanum into Fe0:1Co0:9Sb3 was attempted to decreasethethermalconductivity.Thelanthanum-filledFe0:1Co0:9Sb3 compoundsweresynthesizedfromrawmetal powders and LaSb powder by the pulse discharge sintering process. The optimum lanthanum content that leads to the maximum thermoelectric performance is discussed. The substitution of iron for cobalt improved the thermoelectric performance. The lanthanum-filling decreased the thermal conductivity at a low lanthanum content and led to higher thermoelectric performance in spite of low lanthanum content.

Thermoelectric power generation is a helpful method for harnessing waste thermal energy, particularly covering a middle temperature range between 500 and 800 K. A β-Zn 4 Sb 3 compound has become the focus of attention as a thermoelectric material applicable to thermoelectric power generation around 700 K. In this research, a method combining the mechanical alloying with the pulse discharge sintering was adopted to obtain the sintered compact of β-Zn 4 Sb 3 . Pure zinc and antimony powders were used as the starting material for mechanical alloying. These powders were mixed in the stoichiometry ratio of 4 to 3, or more Zn-rich. The mechanical alloying was carried out by planetary ball milling under conditions of fixed revolution speed and variable milling time. The influence of the milling time on the synthesis of β-Zn 4 Sb 3 was investigated. The sintering was executed at two sintering temperatures and under fixed conditions of sintering time, pressing pressure, and atmosphere. The influences of the sintering temperature of pulse discharge sintering on the polycrystalline grain size and the thermoelectric properties were also studied. The following results were clarified. The phases of ZnSb and Zn are easily obtained by mechanical alloying for 50 h or longer time. These phases change to a single phase of β-Zn 4 Sb 3 through pulse discharge sintering under the optimum condition of Zn-rich mixing. The sintered compact of β-Zn 4 Sb 3 with 1.17 of nondimensional figure of merit can be obtained at 673 K with the proposed mechanical alloying with pulse discharge sintering method.

Emisson spectra and time-resolved two-dimensional (2D) emission images of the electron-ion dielectronic recombination (i.e. a reversal process of auto-ionization) line of neutral Cu atoms, the selectively excited Cu ionic line, and normal Cu atomic line were observed for understanding the excitation mechanisms of Cu neutral and ionic lines in a low-pressure laser-induced plasma (LP-LIP) of Ar. From the observations, the number of charged particles around the emitting species seems to increase with increasing Ar pressure. Different time-resolved 2D emission images were observed among the selectively excited Cu ionic line and other Cu emission lines resulting from the different excitation mechanisms of the respective emission lines. Collisions of the second kind and electron-ion recombinations were found to be one of the major excitation mechanisms of Cu in Ar LP-LIP.

Thermal energy production by hydrothermal oxidation of ethanol in sub-critical water is experimentally studied as a fundamental research to develop a new concept of combustion system. Experiments proves that the moderate exothermic combustion occurs by hydrothermal oxidation of ethanol in sub-critical water and its conversion depends on the preheating temperature and the concentration of oxidizer. For lower concentration of oxidizer, the hydrothermal decomposition reaction of ethanol is dominant and methane, carbon monoxide and hydrogen are produced. For higher concentration of oxidizer, the hydrothermal oxidation reaction of ethanol is dominant and carbon dioxide is produced as well as thermal energy up to 576 kJ/kg. The reaction kinetics of the hydrothermal oxidation of ethanol in sub-critical water is also obtained.

The molecular structure of lipids in whole bacteria cells was characterized in detail by using two different and complementarily direct analyses; thermally assisted hydrolysis and methylation-gas chromatography (THM-GC) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) combined with on-probe sample pretreatment. First, THM-GC in the presence of tetramethylammonium hydroxide (TMAH) was applied to compositional analysis of the fatty acid components of lipids in whole bacterial cells. On the resulting chromatograms, a series of fatty acid components in bacterial lipids were clearly observed as resolved peaks of their methyl esters. The fatty acid compositions determined on the basis of the peak intensities were in good agreement with those obtained by the conventional technique involving solvent extraction of the lipids in the samples. Furthermore, MALDI-MS combined with the on-probe sample treatment, using 2,5-dihydroxybenzoic acid (DHB) and sodium iodide (NaI) as matrix and cationization reagents, respectively, was used to detect intact phospholipids directly from whole bacterial cells. The MALDI spectra thus obtained showed an array of ions generated from bacterial phospholipids, such as phosphatidylethanolamines (PEs) and phosphatidylglycerols (PGs). Finally, the bacterial lipids were comprehensively characterized in terms of the acyl groups and the molecular structures by taking both of the results obtained by THM-GC and MALDI-MS into consideration.

Cryogenic gas chromatography (GC) combined with isotope labeling was applied to discriminative determination of hydrogen gas formed through consecutive CO2 reforming of methane and water–gas shift reaction. First, hydrogen gas was obtained by using a tandem reaction system, where reforming and shift reaction occurred consecutively. Here, D2O instead of H2O was used for shift reaction to label hydrogen gas generated there. Then, the resulting hydrogen isotopes were analyzed by a cryogenic GC system, in which an oven temperature was maintained at −196 °C by immersing a separation column into liquid nitrogen. On the chromatograms, the peaks of H2 and D2 generated from reforming and shift reaction, respectively, were clearly observed as well-separated peaks. Based on their peak intensities, hydrogen gas formed through the tandem reaction system was precisely determined with differentiating its sources.

Two types of OH radicals exist in a mixture of CH4–H2 fueled flame, which are produced respectively from CH4-air and H2-air combustion reactions. We have devised a new diagnostics tool for planar laser-induced fluorescence (PLIF) spectroscopy using isotope shift (herein called IS/PLIF spectroscopy). This diagnostics was applied to separately visualize two-dimensional (2-D) distributions of net (not absolute) OH radical fluorescence intensities produced from CH4–O2-air and H2–O2-air combustion reactions in a CH4–H2–O2-air premixed flame. In result, the OH radical produced from H2–O2-air combustion reaction appeared on upstream side of the inner flame as compared to that produced from CH4–O2-air combustion reaction. Since OH radical is one of chain carriers in combustion reactions, this indicates that H2 tends to react at more upstream location than CH4 in the CH4–H2 mixture flame. This tendency is attributable to the fact that H2 differs from CH4 in the high burning velocity and extended flammability limit.

High-throughput near-infrared imaging was used to distinguish catalyst activity for low-temperature methane steam-reforming. Geminal hydroxyls of reduced ceria were depicted during methane reforming at 673 K. The changes in absorbance maps under various water partial pressures showed evidence of formate intermediate formations without redox exchanges. Higher resolution was observed in absorbance change images than that of thermal images obtained from catalyst surface self-emissions. The experimental results illustrated higher activity of pure rhodium catalyst than that of bimetallic ones, likely because of the high dispersion of rhodium on the catalyst support. Moreover, the reaction was accelerated when high surface area silica was added because more reduced sites were exposed. Our filter bandwidths limited our interest in band-shift distribution of geminal hydroxyl band during the reduction process. (c) 2005 American Institute of Chemical Engineers.