Abstract: The direct conversion of benzene to phenol by hydroxylation with hydrogen peroxide was carried out over catalysts containing iron impregnated on activated carbon. Iron was impregnated on various surface modified activated carbons. The catalyst that was made by treating activated carbon with nitric acid, that was treated thermally in the presence of nitrogen at 600 °C and impregnated with 5 wt.% iron, gave a phenol yield of 20%. It was found that the synergistic interactions of surface groups and the impregnated iron have enhanced the performance of these catalysts.

Abstract: Coconut shell, being a good carbon precursor and having a regular porous structure, was chosen for pro- duction of carbonic materials in this work. Metal doping on the coconut char was used to develop catalytic centers for hydrocarbon cracking and thereby obtain a product with good microporosity. Magnesium, calcium, cobalt, copper and nickel doping on the coconut char was done by soaking the coconut char in the aqueous solutions of the respective metal salt and further calcining. The characterization of the product samples was done by the measurement of surface area, adsorption capacity of CO 2, N2, CH4, and SEM analysis. The micro pore area obtained by using CO 2 adsorption at 298 K was found to be >400 m 2 /g for samples prepared from coconut char impregnated with metal. The adsorption capacity of magnesium-doped sample was found to be 98 mg/g, whereas that for a sample prepared from non-im- pregnated coconut char was 55 mg/g. SEM analysis was conducted to study the morphology and nature of the samples prepared.

Abstract: Gas hydrates, or more generally clathrate hydrates, are a type of inclusion compound and take the form of nonstoichiometic solid crystalline materials formed from water and small guest molecules. Under sufficient pressure of the guest material and at specific temperatures, 3D hydrate structures are formed by the stacking of polyhedral cages of hydrogenbonded water molecules. Suitably sized guest molecules are enclathrated in cages and their presence stabilizes the compounds formed. Although the guest molecules are physically enclosed within the cages, there are no direct chemical bonds between host water molecules and guest molecules. In general gas hydrates form three distinct structural families known as structure I (sI), structure II (sII), and structure H (sH), which differ in the combination of cage types required to build a 3D structure. In addition, there are a variety of more complex clathrate hydrate structures, labeled as types III–VII and structure T (sT). It is clear that many of the physical attributes of gas hydrates remain unknown and thus need to be examined in more detail. The gas hydrates are of particular interest in the fields of energy research and environmental science because of the possible applications for the storage of natural gas, sequestration of CO2 in the deep ocean, [5] and separation of greenhouse gases from flue gas. It is noteworthy that for lowering the pressure of hydrate formation without significant reduction of the capacity to store CH4, the use of sH hydrate was suggested. [7]

Abstract: The direct conversion of benzene to phenol by hydroxylation with hydrogen peroxide was carried out over catalyst containing various transition metals impregnated on activated carbon. Iron and vanadium impregnated catalysts gave better yields of phenol compared to copper impregnated catalysts. The activity of transition metals supported on activated carbon catalyst in the production of phenol was V > Fe > Cu. In addition to the role of transition metals in catalyzing the hydroxylation reaction, the hydrophobic nature of the activated carbon surface and also the surface acidity and basicity seems to have enhanced the performance of these catalysts.

Abstract: The objective of this study is to detect faults due to multiple element failures in HVAC systems occurring concurrently. To classify and detect single as well as multiple faults, measurements were made of supply air temperature, OA-damper position, supply fan pressure, indoor temperature and airflow rate in a variable air volume heating ventilating and air conditioning test facility. Experimental results show that three types of patterns emerge in the analysis of multi-fault problems. To solve the multi-fault problem, a new strategy based on pattern classification and the use of residual ratios is presented. It is shown that the residual ratio can be used to diagnose and accurately identify and detect multiple-faults occurring in HVAC systems. Copyright © 2005 John Wiley & Sons, Ltd.

Abstract: Molybdenum based mixed oxide containing Mo0.65V0.25W0.10 was investigated for the partial oxidation of methanol. The structural property and catalytic activity of the mixed oxide catalyst was studied by surface area (BET), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD). The thermal activation of the catalyst resulted increase in the conversion of methanol and the selectivity to formaldehyde. The thermal activation of the MoVW mixed oxide in nitrogen atmospheres induces partial crystallization of a Mo5O14-type oxide at 813 K. The SEM images of the thermally activated catalyst show needle like particles. These particles were agglomerates of platelet-like crystallites of a few hundreds of nanometers in size. SEM and EDX techniques show that the mixed oxide is characterized by an inhomogeneous elemental distribution on the length scale of a few microns. XRD of the thermally activated catalyst showed a nanocrystalline material identified as a mixture of Mo5O14, MoO3 and MoO2-type MoVW oxides. The catalytic activity of the MoVW mixed oxide show a good conversion of methanol and selectivity to formaldehyde.

Abstract: This paper evaluates the performance of ventilation for the removal of indoor pollutants as a function of ventilation rate and the number of occupants in a test room and school classroom. An experimental apparatus consists of a test room, a tracer gas supply system, a gas detector, and a fan for ventilation air supply with a controller. The ventilation performance is evaluated in a step-down method based on ASTM Standard E741-83 using CO2 gas as a tracer gas in the test room of 35 m3. For the ventilation air flow rate of 1.0 ACH, a recommended ventilation flow rate of Korea school standard for acceptable indoor air quality in the case of one person, CO2 gas concentration decreases up to 55% within 50 minutes without occupancy and increases up to 75% in the case of one occupant. Also indoor air quality at the school classroom is investigated experimentally.