Study of thermal regeneration of spent activated carbons: Thermogravimetric measurement of various single component organics loaded on activated carbons

Thermogravity analysis of the activated carbons loaded with 32 different single component organics showed that TGA curves could be classified into three distinct groups with regard to their shapes. The organics that belong to Group (I) are rather volatile and TGA curves can be explained by equdibrium desorption model. Group (II) organics are relatively easy to decompose and TGA curves were interpreted in terms of first-order cracking kinetics. The parameters included in these models were obtained from the measured TGA curves by utilizing half desorbed temperature T_{$\text{1}\text{2}$} and reciprocal slope of TGA at T_{$\text{1}\text{2}$}, ΔT. Group (III) consists of phenol, β-naphtol, lignin etc. and gave high residuals on activated carbons after heating up to 800°C. This suggests that these organics are the ones that are critical to the ordinary thermal regeneration method.A rough classification of organics into these groups was done by using the boiling point and the aromatic carbon content.     

IR transparency of the glass of ZnCl2-KBr-PbBr2 system

IR transparency and some properties of halide glass of composition 48ZnCl₂-48KBr-4PbBr₂ (mol%) have been investigated as the basic study on the development of IR glass fiber for CO₂ gas laser. The glass transition temperature Tg, crystallization temperature T_c, softning temperature T_s, and linear thermal expansion coefficient α of the glass were found to be 45–46°C, 100°C, 54°C, and 570×10^?7 / °C, respectively. The refractive index of the glass for He-Ne laser emission (632.8 nm) was about 1.63. The amount of impurity which decreases the transmissibility for CO₂ laser beam due to the absorption in the wavelength region 10–11 μm could be reduced by preparing the glass from a batch containing NH₄ Cl under reactive atmosphere of CCl₄ or CBr₄ in a glove box filled with He gas of dew point ?62～ ?45°C. The minimum value of absorption loss of the glass for CO₂ gas laser measured by laser calorimetry was about 20 dB/m.     

Photochemical Reaction in a Reduced Soda-Lime-Silica Glass Containing Ce3+ and As3

The photochemical reaction between Ce³⁺ and As³⁺ in a reduced 16Na₂O. ¹1CaO.73SiO₂ glass (mol%) was examined by exposing it to an Xe or Hg arc. In addition to Ce⁴⁺, a paramagnetic As(II)OS center having C_2v symmetry and a trapped electron center were identified by ESR. The As(II)O defect is the origin of the unidentified ESR signal which correlates with the discoloration of a borosilicate glass developed for solar energy application .     

A multilingual ontology for infectious disease surveillance: rationale, design and challenges

A lack of surveillance system infrastructure in the Asia-Pacific region is seen as hindering the global control of rapidly spreading infectious diseases such as the recent avian H5N1 epidemic. As part of improving surveillance in the region, the BioCaster project aims to develop a system based on text mining for automatically monitoring Internet news and other online sources in several regional languages. At the heart of the system is an application ontology which serves the dual purpose of enabling advanced searches on the mined facts and of allowing the system to make intelligent inferences for assessing the priority of events. However, it became clear early on in the project that existing classification schemes did not have the necessary language coverage or semantic specificity for our needs. In this article we present an overview of our needs and explore in detail the rationale and methods for developing a new conceptual structure and multilingual terminological resource that focusses on priority pathogens and the diseases they cause. The ontology is made freely available as an online database and downloadable OWL file.     

Chemical Design and Thin Film Preparation of p-Type Conductive Transparent Oxides

Chemical design to find a new transparent conductive oxide having p-type conductivity has been proposed. Following the chemical design, we have selected CuGaO₂ and CuAlO₂ as candidate materials. CuGaO₂ thin films were prepared on silica glass substrates by RF sputtering method. The optical band gap of the film was estimated to be 3.4 eV. Positive sign of Seebeck coefficient demonstrated the p-type conductivity of the film. The dc conductivity of the film was 5.6 × 10^–3S·cm^-1 and the activation energy was 0.22 eV at room temperature. Because of rough texture of the film, the observed conductivity was not an intrinsic property of the material. Further, CuAlO₂ thin films were prepared by laser ablation. The film deposited in O₂ atmosphere of 1.3 Pa at 690°C showed higher optical transmission in visible and near-infrared regions than previously reported. Contribution of Cu 3d components to upper edge of valence band in CuGaO₂ and CuAlO₂ were confirmed by photoemission spectroscopic measurements.     

A first-principles study on water flow through single-walled carbon nanotubes using artificial neural network method

Ab initio molecular dynamics simulations are done to elucidate the electronic structure and properties of water/single-walled carbon nanotubes (SWCNTs) systems. The artificial neural network (ANN) approach and statistical methods are then used to model and analyze these properties. The ANN method substantially speeds up the ab initio electronic structure calculations and has superior accuracy in mimicking the results of such calculations. We aim to understand the effects of CNT chirality, temperature, and CNT flexibility on the water diffusion inside SWCNTs. In this regard, the CNT is fixed implies that the position of CNT is kept constant during the diffusion process. Statistical analysis of results shows that there is a nonmonotonic variation of diffusion length of water with respect to the CNT chirality. However, an increase in temperature and rigid CNTs accelerate the water diffusion.     

Transparent Conducting Oxides Based on the Spinel Structure

The structural characteristics of spinel (from both theoretical and experimental viewpoints) that are advantageous for producing transparent conducting oxide (TCO) materials are considered. A working hypothesis is presented for finding new TCO materials with spinel structure. Results of tight-binding energy-band calculations reveal the formation of extended conduction bands in selected TCOs. This is a necessary criterion for n -type TCOs containing cations with d ¹⁰ s ⁰ electronic configuration. Discovery of some transparent conducting spinels, namely MgIn₂O₄, CdGa₂O₄, and ZnGa₂O₄, provides experimental confirmation for the formation of extended conduction bands. Li⁺-, He⁺-, and H⁺-ion implantations into MgIn₂O₄ films have been performed to explore a new technique to generate electron carriers. Carrier generation in implanted MgIn₂O₄ films has been verified from electrical conductivity and optical absorption measurements. Implanted Li⁺ ions have been observed to occupy vacant tetrahedral cation interstices in the spinel lattice. Each Li⁺ ion releases an electron to the conduction band upon occupying this tetrahedral vacancy. Observations suggest that the ion implantation technique is effective and feasible for carrier generation in TCO materials.     

The effect of segregation and partial order on the thermodynamics of (1 1 1) antiphase boundaries in Ni3Al

Thermodynamic properties of thermal and a-thermal (1 1 1) antiphase boundaries (APB) in Ni₃Al are computed from first-principles. The effect of off-stoichiometry, partial disordering and segregation are evaluated and a rough estimate of the vibrational contribution to the antiphase boundary energy is given. Although the vibrational effect is found to be small, the configurational effects are large, so that at non-zero temperature and in off-stoichiometric Ni₃Al the antiphase boundary energy (APBE) may be only half of that in perfectly ordered stoichiometric Ni₃Al at zero temperature. This result points to a discrepancy between electronic structure calculations and experimental measurements.