SO2 SCRUBBING BY ULTRAFINE CA(OH)2 AEROSOL

The objective of the present study was to generate submicrometer calcium hydroxide aerosols and to investigate the effectiveness of such aerosols in sulfur capture. The effectiveness of SO₂ removal by Ca(OH)₂ aerosol has been investigated in an isothermal reactor. Ca(OH) ₂ aerosol was generated by a novel fluidizer system in which submicrometer-sized powders were entrained in gases. SO₂ was added to this aerosol to a concentration of 2000 ppm. The aerosol-SO₂ mixture was heated to 550°C-750°C in an isothermal tube reactor. The SO₂ removal efficiency, which varied from 20% to 70%, was determined to be a function of the aerosol concentration, reactor temperature and residence time. The fraction of aerosol reacted was not affected strongly by the aerosol concentration. The reaction kinetics were determined from the experimental data using a simple analytical model in which the rate is first order in both SO₂ and calcium hydroxide aerosol concentrations.     

Temporary bond—debond technology for high‐performance transistors on flexible substrates

Abstract— A processing technology based upon a temporary bond—debond approach has been developed that enables direct fabrication of high‐performance electronic devices on flexible substrates. This technique facilitates processing of flexible plastic and metal‐foil substrates through automated standard semiconductor and flat‐panel tool sets without tool modification. The key to processing with these tool sets is rigidifying the flexible substrates through temporary bonding to carriers that can be handled in a similar manner as silicon wafers or glass substrates in conventional electronics manufacturing. To demonstrate the power of this processing technology, amorphous‐silicon thin‐film‐transistor (a‐Si:H TFT) backplanes designed for electrophoretic displays (EPDs) were fabricated using a low‐temperature process (180°C) on bonded‐plastic and metal‐foil substrates. The electrical characteristics of the TFTs fabricated on flexible substrates are found to be consistent with those processed with identical conditions on rigid silicon wafers. These TFTs on plastic exhibit a field‐effect mobility of 0.77 cm²/V‐sec, on/off current ratio >10⁹ at Vds = 10 V, sub‐threshold swing of 365 mV/dec, threshold voltage of 0.49 V, and leakage current lower than 2 pA/μm gate width. After full TFT‐array fabrication on the bonded substrate and subsequent debonding, the flexible substrate retains its original flexibility; this enables bending of the EPD display without loss in performance.     

Determination of various impurities in synthetic diamond powder

Impurities in industrial synthetic diamond powder samples were analyzed by X-ray diffraction (XRD) and Flame Atomic Absorption Spectrometry (FAAS). Specimen for FAAS is required in solution form. Diamonds are chemically inert to most acids and alkalies. Carbon was removed as CO₂ on heating and estimated gravimetrically. The remaining residue was fused with di-lithium tetraborate and dissolved in nitric acid. Impurities such as Si, Al, Fe, Ca, Mg, W, Na, Co and Ni were then determined by FAAS. Crystalline phases of major impurities were identified by XRD.     

An introduction to the new degradation of polyvinyl chloride (PVC) shower hose

Recently, polyvinyl chloride (PVC) shower hoses have hardened throughout the eastern Shizuoka Prefecture, Japan. According to the elemental analysis results, the carbon and oxygen concentrations were much lower in the damaged hoses. These findings reveal that oxygen-containing, carbon-based plasticisers may leach from the damaged hose. As a result, the hoses lost flexibility after one year of use. The highest number of heterotrophic bacteria was detected by PCR-denaturing gradient gel electrophoresis in the shower water, and the bacterial DNA concentration was higher when hot water contacted the hose surface. I conclude that the plasticiser was leached from the stiffened hose through a bioaccumulation process.     

Computational intelligence for microarray data and biomedical image analysis for the early diagnosis of breast cancer

The objective of this paper was to perform a comparative analysis of the computational intelligence algorithms to identify breast cancer in its early stages. Two types of data representations were considered: microarray based and medical imaging based. In contrast to previous researches, this research also considered the imbalanced nature of these data. It was observed that the SMO algorithm performed better for the majority of the test data, especially for microarray based data when accuracy was used as performance measure. Considering the imbalanced characteristic of the data, the Naive Bayes algorithm was seen to perform highly in terms of true positive rate (TPR). Regarding the influence of SMOTE, a well-known imbalanced data classification technique, it was observed that there was a notable performance improvement for J48, while the performance of SMO remained comparable for the majority of the datasets. Overall, the results indicated SMO as the most potential candidate for the microarray and image dataset considered in this research.     

Year-round performance of an improved collector-cum-storage type solar water heater

Systematic studies have been carried out on collector-cum-storage type solar water heaters, and efforts were made to minimise heat losses so that this type of water heater can be used for getting hot water at 40°–45°C for taking baths in the early morning hours of the next day. This paper reports year round performace, the performance equation and economics of this new improved solar water heater. This heater can supply 100 litres of hot water at 60°–70°C in the afternoon, and 40°–45°C temperature can be retained till next day morning. Its efficiency is 70.1%.     

On the electrical resistivity and chemical etching of TiSi2 thin films sputtered from a composite target

The electrical resistivity of TiSi₂ thin films sputtered onto an oxidised Si substrate using a composite alloy target is studied. It is found that the as-deposited films show high resistivity. Annealing the films at an elevated temperature leads to a significant fall in the resistivity. An optimum sheet resistance of 2om tq⁻¹ is obtained after annealing at 800°C for 30 min in argon ambient. The effect of annealing temperature on resistivity is studied. The sheet resistance is also found to be affected by the magnitude of the substrate bias during film deposition. The data are given. The patterning of TiSi₂ thin films by wet chemical etching for device applications is described.