Geothermal energy resources and development in Iran

Interest in geothermal energy originated in Iran when James R. McNitt, a United Nations geothermal expert, visited the country in December 1974. In 1975, a contract among the Ministry of Energy, ENEL (Entes Nazionale per L’Energia Elettrica) of Italy and TB (Tehran Berkeley) of Iran was signed for geothermal exploration in the north-western part of Iran. In 1983, the result of investigations defined Sabalan, Damavand, Khoy-Maku and Sahand regions as four prospected geothermal sites in north-western Iran.From 1996 to 1999, a countrywide geothermal energy resource exploration project was carried out by Renewable Energy Organization of Iran (SUNA) and 10 more potential areas were indicated additionally.Geothermal potential site selection using Geographic Information System (GIS) was carried out in Kyushu University in 2007. The results indicated 8.8% of Iran as prospected geothermal areas in 18 fields.Sabalan as a first priority of geothermal potential regions was selected for detailed explorations. Since 1995, surface exploration and feasibility studies have been carried out and five promising areas were defined. Among those prospective areas, Northwest Sabalan geothermal filed was defined for detailed exploration to justify exploration drilling and to estimate the reservoir characteristics and capacity.From 2002 to 2004, three deep exploration wells were drilled for evaluation of subsurface geological conditions, geothermal reservoir assessment and response simulation. Two of the wells were successful and a maximum temperature of 240 °C at a depth of 3197 m was recorded. As a result of the reservoir simulation, a 55-MW power plant is projected to be installed in the Sabalan field as a first in geothermal power generation. To supply the required steam for the geothermal power plant (GPP) 17 deep production and reinjection wells are planned to be drilled this year.     

Properties of GaN epitaxial layers grown at high growth rates by metalorganic chemical vapor deposition

GaN epitaxial layers were grown at high growth rates by increasing the input trimethylgallium (TMG) flow rate while keeping the NH₃ flow rate constant in metalorganic chemical vapor deposition. The electrical and optical properties of the grown layers have been investigated. With the increasing TMG flow rate, the electron concentration tends to decrease gradually and the Hall mobility decreases significantly. Considering the temperature dependence of the Hall mobility and the correlation between the Hall mobility and the electron concentration, it has been indicated that the more acceptors are incorporated and consequently the compensation ratio becomes higher with increasing the TMG flow rate. Photoluminescence measurements have revealed that the intensity ratio of the bound exciton emission to the 2.2 eV band emission, which is assumed to correlate to carbon or Ga vacancies, was decreased with increasing the TMG flow rate. It might be reasonable to take a lot of acceptor incorporation to explain the degradation of the electrical and optical properties in the samples grown at high growth rates by increasing the TMG flow rate.     

Discharge luminescence and discharge magnitude in treeing degradation

This paper describes results of the discharge luminescence and discharge magnitude measurements performed on the insulation materials exposed to partial discharge. Polymethyl methacrylate (PMMA) with an artificial needle shape void were used as the treeing specimens. The discharge luminescence is observed by image intensifier, and the luminous image is processed by computer. At the same time, the discharge magnitude distribution in relation to phase angle of the applied voltage was measured by a partial discharge measuring system. The mechanism of electric treeing was discussed by not only the measurement of the discharge pulses but also the local luminescence intensity of partial discharge. As a result, the luminescence intensity analysis showed the relation between tree growing length and void length when maximum luminescence intensity moved from the void area to the tree area. Both tree growth and maximum luminescence intensity at the tree area increase with constant ratio. The discharge luminescence intensity at the tree area increases significantly depending on the discharge magnitude in the specific phase angle area in positive and negative.     

Developing the geothermal resources map of Iran

Geothermal exploration involves a high degree of uncertainty and financial risk, and requires reliable exploration data to constrain development decisions. The paper describes a geothermal exploration and resource identification method that is based on building a map of potential geothermal resource areas by combining geological, geochemical and geophysical datasets; it is a powerful tool for visualizing new and existing data during decision-making processes. By performing suitability analysis and geothermal area identification, and by establishing criteria to define geothermal resources with development potential, a map of Iran was constructed highlighting 18 promising areas.     

Measurement of odour after in vitro or in vivo ingestion of raw or heated garlic, using electronic nose, gas chromatography and sensory analysis

The possibility of characterising the garlic odour in in vitro and in vivo was demonstrated using the newly developed electronic nose, based on an array of metal oxide semiconductor sensors. Two grams of raw and heat‐treated garlic, and breath odour after eating 2 g of raw garlic and heat‐treated garlic were analysed with an electronic nose. Furthermore, calculation of F‐value (odour quality) and S‐value (odour strength) demonstrated distinct odour differences between the samples, and that the electronic nose could differentiate between the various garlic associated odours corresponding to the different origins (in vivo or in vitro), or to the different processing (raw or heat‐treated). The correlation between gas chromatography and sensory analysis was also discussed in order to identify the volatile compounds in the sample, and to investigate the association with the response of human perception to the samples. Results showed that odour sensor data were easier to obtain and were well correlated with both types of instrument.     

Fitting graphs and numerical tables for a single parameterrepresentation of the shape of programme sound signal distributions

In order to represent the statistical character of a sound signal simply and with a single parameter, numerical tables and graphs of theoretical distributions for the estimation of a parameter called the shape parameter of the distribution are presented. The theoretical distributions are based on a statistical model of broadcast signals which was derived from the analysis of variations in measured distribution. The statistical functions dealt with are PDFs (probability density functions) and CDFs (cumulative distribution functions) for instantaneous amplitude and power, for RMS-valued intensity fluctuations, and for one-minute mean powers and peak powers. A list of the values of the shape parameter estimated for CCIR data is given, from which almost all the CCIR data can be reproduced by using the theoretical distribution curves and the numerical tables presented     

Editorial

The first seawater desalination plant by electrodialysis in the world started its operation in September, 1974 at Noshima island of Hofu city, Yamaguchi Prefecture, Japan. The capacity of the plant is 120 m³/day and the plant has been supplying fresh water from the sea for the 800 inhabitants of the island. Batchwise operation is utilized to simplify the process because of its relatively small capacity, but the operation is fully automatic to supply fresh water continuously using a storage of proper capacity. The water cost is relatively high but lower than that of conventional distillation processes of the same capacity.     

Comparison of Three Particle Number Concentration Calibration Standards Through Calibration of a Single CPC in a Wide Particle Size Range

We carried out a set of experiments to compare three particle number concentration standards (NCSs) by calibrating the same condensation particle counter (CPC) unit (Model 3772, TSI Inc., Shoreview, MN, USA). The standards were, in the order of operation size range, the primary NCS of the National Institute of Advanced Industrial Science and Technology (AIST, Japan), the Single Charged Aerosol Reference (SCAR) (Finland), and the Inkjet Aerosol Generator (IAG) of AIST. The results obtained with the 3 standards were found to agree at all overlapping particle sizes within the uncertainty limits. The relative expanded uncertainties varied between 0.6% and 2.6%, depending on the size and standard, while the overall agreement between the standards was within 0.5%. The observed consistency of the results is an important step toward establishing internationally coherent particle NCSs. As a result, the CPC 3772 was successfully calibrated in a particularly wide size range, approximately from 10 nm to 10 μm. The results indicate that the CPC can be considered as a practical tool for calibrating particle number concentration up to 1 μm. In general, the particle number concentration can be measured up to 2.5 μm without a significant decrease of the detection efficiency. By attaching an appropriate size-classifying inlet, the CPC could be used even for measuring the total number concentration for particles smaller than 2.5 μm, in parallel with the PM_2.5 mass measurement. Above this particle diameter, the detection efficiency gradually decreased and reached 50% at about 10 μm.

Copyright 2012 American Association for Aerosol Research     

Muscular sarcoidosis

A 57-year-old woman with sarcoid nodules in muscles of the lower leg was reported. A star-shaped low signal intensity in the lesion on MR imaging, supposedly corresponding to fibrous scar, appears characteristic of this condition, although its specificity is still uncertain.