Geothermal applications in Turkey

Geothermal energy is mostly utilised in direct applications in Turkey. The equivalent of 61,000 residences are currently heated by geothermal fluids. A total of 665 MW_t is utilised for space heating of residential, public and private property, and 565,000 m² of greenhouses. Geothermal fluids are also used in 195 spas (327 MW_t), bringing the total direct use capacity to 992 MW_t. ORME Geothermal Inc. has completed the engineering design of a geothermal district heating system that serves the equivalent of nearly 300,000 residences. A total of 170 geothermal fields have been explored so far in Turkey. At Kizildere a single-flash power plant with 20.4 MW_e installed capacity is integrated with a factory producing liquid CO₂ and dry-ice. A binary cycle power plant with an installed capacity of 25 MW_e will be constructed shortly at Aydin/Germencik. The proven geothermal heat capacity, according to data from existing geothermal wells and natural discharges, is 3132 MW_t (I. Akkus, MTA General Directorate, oral communication, January 2003).     

Overall Investigation of Poly (Phenylene Sulfide) from Synthesis and Process to Applications—A Review

Poly (phenylene sulfide) (PPS) is one kind of high‐performance polymer with high thermal stability that can be used widely in different industrial domains. However, according to an investigation of the literature, few reviews have comprehensively focused on the continuous development of PPS applications in the past decade. To meet this demand, this paper provides an overall investigation of PPS polymer and PPS‐based composites from synthesis and process to applications. Briefly, this paper introduces PPS materials according to the following topics. First, the molecular weight distribution and morphology of PPS, as well as their reinforced parts, are introduced. Afterward, the topic is focused on the synthesis, process, and blending of PPS. In the next part, this paper investigates the key points regarding PPS as a high‐performance polymer, focusing on the aspect of thermal behavior and mechanical properties. Finally, PPS composite applications are emphasized and overviewed from a wide range of aspects.     

Experimental and numerical study of the sweep effect on three-dimensional flow downstream of axial flow fans

The purpose of this work is to study the influence of the axial flow fan sweep on the downstream turbulent flow. The fans studied are three low-pressure and low-Mach-number axial flow fans, with respectively a radial, a forward and a backward sweep. Experimental and computational fluid dynamics (CFD) investigations are carried out on three fans, and the results are compared. The CFD method is a three-dimensional (3D) Reynolds average Navier–Stokes (RANS) numerical simulation with the Reynolds stress model (RSM) as the turbulence model. It allows us to compute the Reynolds stress tensor components. Unsteady velocity measurements are carried out downstream of the fans with hot-wire anemometry. The values of the three velocity components of the flow and the six components of the Reynolds stress tensor obtained from experiments and simulations are compared. Overall performances are also measured to validate the design and fan simulation. It appears that a forward sweep decreases the radial component of the velocity whereas a backward sweep increases this component. Moreover, the sweep has a significant influence on the turbulent kinetic energy downstream of the fan.     

Randomized, prospective, controlled study comparing radical prostatectomy alone and neoadjuvant androgen withdrawal in the treatment of localized prostate cancer. Canadian Urologic Oncology Group

PURPOSE: A prospective, multicenter, randomized study was done to test the hypothesis that neoadjuvant androgen withdrawal decreases the incidence of positive margins following radical prostatectomy for localized prostate cancer. MATERIALS AND METHODS: Observations were made of 213 patients randomized to undergo radical prostatectomy alone (101) or to receive a 12-week course of 300 mg. cyproterone acetate daily followed by surgery (112). Groups were similar at baseline in terms of clinical stage, serum prostate specific antigen and Gleason score. Of 192 patients available for efficacy analysis 9 had stage T1b, 8 stage T1c, 63 stage T2a, 36 stage T2b and 76 stage T2c disease. RESULTS: One or more positive surgical margins were found in 59 of 91 patients (64.8%) in the surgery only group compared to 28 of 101 (27.7%) in the cyproterone acetate group (p = 0.001). Patients who received preoperative therapy had a statistically significantly lower rate of apical margin involvement than those who did not (17.8 versus 47.8%, respectively, p < 0.0001). There was no statistically significant difference in surgical (p = 0.8645) or postoperative (p = 0.173) complications between the 2 groups. CONCLUSIONS: Neoadjuvant androgen withdrawal with a 12-week course of 300 mg. cyproterone acetate daily results in a lower rate of positive margins without adversely affecting postoperative recovery. The impact on patient survival will be determined by long-term followup.     

Value of imaging in the assessment of malignant fibrous histiocytoma of the soft tissues

Malignant fibrous histiocytoma (MFH) is a rare and potentially highly malignant sarcoma. The authors report 6 cases of MFH in various sites: two in the chest wall, one in the pelvis, two in the gluteal zones and one on the scalp. Ultrasonography and computed tomography were the main imaging methods used in the assessment of the structure and extension of the tumor. A poor prognosis was noted in four cases: death within a few months in the two thoracic sites, recurrence in the pelvic and scalp lesions, radical surgery allowed recovery in two cases. A review of the literature showed that MRI and CT are complementary in the initial staging and follow-up of these patients.     

Compact 1.55 /spl mu/m room-temperature optically pumped VCSEL using photonic crystal mirror

Reported is the first realisation of a novel vertical cavity surface emitting laser (VCSEL), in which one of the Bragg mirrors is entirely replaced by a single-layer photonic crystal mirror (PCM). The presence of the PCM considerably enhances the vertical compactness of the device. Room-temperature singlemode laser emission has been obtained at 1.55 mum by optical pumping (pulsed regime), with a threshold power around 15 mW     

Implementation of surface tension force in fluid flow during reactive rotational molding

During Reactive Rotational Molding (RRM), it is very important to predict the fluid flow in order to obtain the piece with homogeneous shape and high quality. This prediction may be possible by simulation the fluid flow during rotational molding. In this study we have used a mixture of isocyanate and polyol as reactive system. The kinetic rheological behaviors of thermoset polyurethane are investigated in anisothermal conditions. Thanks to these, rheokinetik model of polyurethane was identified. Then, to simulate the RRM, we have applied Smoothed Particles Hydrodynamics (SPH) method which is suited method to simulate the fluid flow with free surface such as occurs at RRM. Modelling and simulating reactive system flow depend on different parameters; one of them is the surface tension of reactive fluid. To implement force tension surface, the interface between polymer and air is dynamically tracked by finding the particles on this border. First, the boundary particles are detected by free-surface detection algorithm developed by Barecasco, Terissa and NAA [1, 2] in two and three dimension. Then, analytical and geometrical algorithms have been used for interface reconstructions. The aim of this work is the implementation of surface tension force in the SPH solver applied to RRM. To illustrate that, we used novel and simple geometric algorithm fitting circle and fitting sphere, in two and three dimensional configurations, respectively. The model has been validated using a well-known dam break test case which covered the experimental data.     

Stability of linear time-delay systems

The sufficient condition of stability of linear system with delay in the form of frequency equality is received. Efficiency of the received criterion is shown on examples.     

Integrated thermal-fluidic I/O interconnects for an on-chip microchannel heat sink

Power dissipation in microprocessors will reach a level that necessitates chip-level liquid cooling in the near future. An on-chip microfluidic heat sink can reduce the thermal interfaces between an IC chip and the convective cooling medium. Through wafer-level processing, integrated thermal-fluidic I/O interconnects enable on-chip microfluidic heat sinks with ultrasmall form factor at low-cost. This letter describes wafer-level integration of microchannels at the wafer back-side with through-wafer fluidic paths and thermal-fluidic input/output interconnection for future generation gigascale integrated chips.