Classification of Geothermal Energy Resources in Japan Applying Exergy Concept

Higher demand for energy consumption and importance of environmental issues has encouraged researchers and policy makers to consider renewable energies more seriously. Geothermal resources are a green energy source that can make a considerable contribution in some countries. Japan has the third ranking geothermal energy potential, and its geothermal electricity production is currently eighth in the world. Since the nature of geothermal resources dictates its method of utilization, it is important to categorize available resources. There is no consensus on classification of geothermal resources. Most scientists, from geologist to engineers, agree on the term temperature. However, temperature or enthalpy alone cannot describe the nature of fluids; they can have same temperature with different phases, such as saturated water or saturated steam. Using exergy for resource classification benefits their comparison, according to their ability to do work. In this paper, exergetic classification of geothermal resources was applied to 18 under‐operating geothermal power plants in Japan. Six geothermal fields have high exergy resources according to their SExI values in excess of 0.5. The remaining geothermal fields in Japan are classified in the medium resources zone. Classification results can be used by decision makers as a reference for future geothermal development. Copyright © 2012 John Wiley & Sons, Ltd.     

Optimizing the design of large-scale ground-coupled heat pump systems using groundwater and heat transport modeling

In order to predict the long-term performance of large-scale ground-coupled heat pump (GCHP) systems, it is necessary to take into consideration well-to-well interference, especially in the presence of groundwater flow. A mass and heat transport model was developed to simulate the behavior of this type of system in the Akita Plain, northern Japan. The model was used to investigate different operational schemes and to maximize the heat extraction rate from the GCHP system.     

Tracheoplasty with an intercostal pedicle flap for tracheal neurilemmoma--a case report

PURPOSE: Negative pressure pulmonary oedema (NPPE) is a well-recognized but rare complication secondary to upper airway obstruction such as laryngeal spasm during emergence from general anaesthesia. Cauterization of the second and third thoracic sympathetic ganglia is a treatment for hyperhidrosis of the hands. We report a case of NPPE induced by direct suctioning of the endotracheal tube adapter during thoracic sympathetic ganglionectomy without recognized upper airway obstruction. CLINICAL FEATURES: A 19-yr-old otherwise healthy, non-smoking man was scheduled for elective bilateral chest endoscopic ablation of the second and third thoracic sympathetic ganglion for hyperhidrosis of the hands under general anaesthesia. To view and cauterize the ganglion with the endoscope, the surgeon requested cessation of positive pressure ventilation. As the surgeon could not satisfactorily visualize the target ganglia, he requested brief application of wall suction via the ETT tube adapter. A pressure of -100 mmHg was generated which lasted for three to four seconds. The goal was to reduce further the lung volume by increasing the pneumothorax produced by the endoscope. The patient developed negative pressure pulmonary oedema without upper airway obstruction. CONCLUSION: This case demonstrated that intrathoracic negative pressure generated by direct ETT adapter suctioning may produce pulmonary oedema similar to that induced by laryngeal spasm during the emergence of general anaesthesia.     

The absence of corpus luteum formation alters the endocrine profile and affects follicular development during the first follicular wave in cattle

We previously established a bovine experimental model showing that the corpus luteum (CL) does not appear following aspiration of the preovulatory follicle before the onset of LH surge. Using this model, the present study aimed to determine the profile of follicular development and the endocrinological environment in the absence of CL with variable nadir circulating progesterone (P(4)) concentrations during the oestrous cycle in cattle. Luteolysis was induced in heifers and cows and they were assigned either to have the dominant follicle aspirated (CL-absent) or ovulation induced (CL-present). Ultrasound scanning to observe the diameter of each follicle and blood collection was performed from the day of follicular aspiration or ovulation and continued for 6 days. The CL-absent cattle maintained nadir circulating P(4) throughout the experimental period and showed a similar diameter between the largest and second largest follicle, resulting in co-dominant follicles. Oestradiol (E(2)) concentrations were greater in the CL-absent cows than in the CL-present cows at day -1, day 1 and day 2 from follicular deviation. The CL-absent cows had a higher basal concentration, area under the curve (AUC), pulse amplitude and pulse frequency of LH than the CL-present cows. After follicular deviation, the CL-absent cows showed a greater basal concentration, AUC and pulse amplitude of growth hormone (GH) than the CL-present cows. These results suggest that the absence of CL accompanying nadir circulating P(4) induces an enhancement of LH pulses, which involves the growth of the co-dominant follicles. Our results also suggest that circulating levels of P(4) and E(2) affect pulsatile GH secretion in cattle.     

Prostaglandin F2alpha increases endothelial nitric oxide synthase in the periphery of the bovine corpus luteum: the possible regulation of blood flow at an early stage of luteolysis

Prostaglandin F(2)(alpha) (PGF(2)(alpha)) released from the uterus causes alterations in luteal blood flow, reduces progesterone secretion, and induces luteolysis in the bovine corpus luteum (CL). We have recently discovered that luteal blood flow in the periphery of the mature CL acutely increases coincidently with pulsatile increases in a metabolite of PGF(2)(alpha) (PGFM). In this study, we characterized changes in regional luteal blood flow together with regional alterations in endothelial nitric oxide synthase (eNOS) expression during spontaneous luteolysis and in response to PGF(2)(alpha). Smooth muscle actin-positive blood vessels larger than 20 microm were observed mainly in the periphery of mature CL. PGF(2)(alpha) receptor was localized to luteal cells and large blood vessels in the periphery of mid-CL. PGF(2)(alpha) acutely stimulated eNOS expression in the periphery but not in the center of mature CL. Injection of the NO donor S-nitroso-N-acetylpenicillamine into CL induced an acute increase in luteal blood flow and shortened the estrous cycle. In contrast, injection of the NOS inhibitor l-NAME into CL completely suppressed the acute increase in luteal blood flow induced by PGF(2)(alpha) and delayed the onset of luteolysis. In conclusion, PGF(2)(alpha) has a site-restricted action depending on not only luteal phase but also the region in the CL. PGF(2)(alpha) stimulates eNOS expression, vasodilation of blood vessels, and increased luteal blood flow in periphery of mature CL. Furthermore, the increased blood flow is mediated by NO, suggesting that the acute increase in peripheral blood flow to CL is one of the first physiological indicators of NO action in response to PGF(2)(alpha).     

Immunodeficiency with increased immunoglobulin M associated with growth hormone insufficiency

Growth hormone deficiency associated with hypogammaglobulinemia has been reported only in a few publications. Our patient was a male with recurrent episodes of infections. Serum immunoglobulin (Ig) G was extremely low although IgM concentration was much greater than the normal limit. Growth hormone responses to insulin, 1-Dopa and growth hormone-releasing hormone were low. The mean growth hormone concentration during sleep was less than the normal limit. These results are consistent with hyper-IgM immunodeficiency associated with growth hormone deficiency. The mode of transmission appears to be autosomal dominant. This combination has not been reported previously.     

Electrodialytic recovery process of metal finishing waste water

A study for electrodialytic recovery of waste water was made in the nickel electroplating process. By the use of the electrodialysis equipment, rinsing waste water is desalted and reused for rinsing, while nickel salt is concentrated and recovered to the plating bath. Although conventional electiodialysis equipment is able to apply in this process, proper pretreatment and suitably designed operation condition of the electrodialysis unit are needed for a long term stable operation.     

Numerical modeling of the Momotombo geothermal system, Nicaragua

The Momotombo geothermal field, Nicaragua, has been under commercial production since 1983; presently it has an installed capacity of 77 MWe. A three-dimensional, porous-media numerical model of the system was developed and calibrated using the code iTOUGH2, and was utilized to study the response of the geothermal reservoir under different fluid production and injection scenarios. Satisfactory agreements were obtained between measured and computed discharge enthalpies and flow rates for most of the shallow wells. The model also qualitatively reproduced the pressure drawdowns measured in selected wells.     

Fiber-linked Faraday effect current sensor by use of a flint glass cell with dielectric-coated retardation-compensated total reflection surfaces

A new type of Faraday effect optical current transformer has been developed that uses a single block of square flint glass with dielectric-coated total reflection surfaces as the sensing element. Numerical calculation has shown that the coating of two dielectric layers of 45.59-nm-thick Ta2O5 and 448.35-nm-thick SiO2 films on a flint glass surface produces zero retardation total reflection for the 45 degrees incident angle of light at lambda = 840 nm with great incident angle, wavelength, and film thickness tolerances. A fiber-linked current transformer has been constructed and experimentally demonstrated to exhibit high isolation from surrounding currents as well as high stability against mechanical disturbances.