Essential Elements of the Allochthonous Taurus Petroleum System

This study has been carried out to investigate the petroleum potential of the Allochthonous Taurus units in the central Taurus Belt region. For this, essential elements of the petroleum system, such as source rock, reservoir and seal rocks, traps and critical moment of the generation and accumulation have been studied. Organic matter rich shales and carbonates of the both the Carboniferous and Permian sequences are potential source rocks, whereas the Middle-Upper Carboniferous grainstones and sandstones with the Permian carbonates including Girvanella and algae are probable reservoir rocks in the Allochthonous Taurus petroleum system. Although trap formation processes are mostly related to the thrust faults that have been formed during the Eocene, the primary or depositional stratigraphic traps are more dominant than structural ones.     

Contact metasomatic and hydrothermal minerals in the SH2 deep well, Sabatini volcanic district, Latium, Italy

Metasomatic and hydrothermal minerals were logged throughout the SH2 geothermal well, which reached a depth of 2498 m in the Sabatini volcanic district. Below 460 m of volcanics, where the newly formed minerals were mainly chlorite, calcite and zeolites (mostly phillipsite), drilling entered the Allochthonous Flysch Complex. Evidence of the “Cicerchina facies” was found down to 1600 m depth. Starting from 1070 m, down to hole bottom, a contact metasomatic complex was defined by the appearance of garnet. Garnet together with K-feldspar, vesuvianite, wilkeite, cuspidine, harkerite, wollastonite and apatite prevail in the top part of the contact metasomatic complex. Vesuvianite and phlogopite characterize the middle part. Phlogopite, pyroxene, spinel and cancrinite predominate in the bottom part. The 1500 m thick metasomatic complex indicates the presence at depth of the intrusion of a trachytic magma which released hot fluids involved in metasomatic mineral-forming reactions. Minerals such as harkerite, wilkeite, cuspidine, cancrinite, vesuvianite and phlogopite indicate the intrusive melt had a high volatile content which is in agreement with the very high explosivity index of this volcanic district.The system is at present sealed by abundant calcite and anhydrite. It is proposed that most, if not all, of the sulphates formed after reaction of SO₂ with aqueous calcium species rather than from sulphates being remobilized from evaporitic (Triassic) rocks as previously inferred. The hypothesis of a CO₂-rich deep-derived fluid ascending through major fracture systems and contrasting cooling in the hottest areas of Latium is presented.     

Determination of Coal Rank by Fuzzy Logic: A Case Study of Coal from Central Anatolia,Turkey

Koyunagili coalfield in the Beypazari basin of the Central Anatolia was investigated and coal ranks were determined using fuzzy Mamdani model based on ASTM coal rank classification. This is a pilot study to investigate the applicability of the fuzzy model to determine the ranking of any coal seam. The Koyunagili coalfield, which is located at the southern part of the Beypazari basin, consists of the late Miocene coal seam within the tuffaceous rocks. The mineable coal seam is split by a 0.5–0.55 m thick clayey limestone into the upper (1.2–1.3 m thick) and lower (0.4 m thick) benches. A total of 28 profile coal samples from underground mines were collected. The samples have an average of 30.9% moisture (as-received), 23% ash yield, and 2.9% total sulphur and 4167 kcal/kg gross calorific value on an air-dried basis. Mean random reflectance values of huminite have an average of 0.34%, and show no differences across the coalfield. Coal ranking has been determined by the fuzzy Mamdani model. During processing, fixed carbon content (FCC), volatile matter values (VMV), calorific value (CV), and vitrinite/huminite reflectance (Ro %) parameters are inputs, and a total of 10 rules are used for the model. Modeling results are consistent with the previous studies.     

Appraisal of the Tokaanu–Waihi geothermal field and its relationship with the Tongariro geothermal field, New Zealand

Tokaanu–Waihi geothermal field is situated near the southern end of the Taupo Volcanic Zone, New Zealand. Neutral chloride thermal waters discharge at Tokaanu and Waihi in the north of the field on flat land between the andesite volcanoes Tihia and Kakaramea and the shore of Lake Taupo, while steam-heated thermal features occur at Hipaua on the northern flanks of Kakaramea. Electrical resistivity surveys have been made over the field using several different measurement techniques. In the north of the field where roads and tracks allow vehicle access, resistivity profiling using Schlumberger arrays with electrode spacings (AB/2) of 500 m and 1000 m show that Tokaanu, Waihi and Hipaua all lie within a continuous region of low apparent resistivity (5–20 Ωm) and are thus part of the same geothermal system. Along the eastern edge of the system there is a sharp transition to apparent resistivities greater than 100 Ωm in the cold surrounding region. Surveys on Lake Taupo using an equatorial bipole-bipole electrode array towed behind boats (spacing equivalent to AB/2=500 m) found that the low resistivity zone extends offshore by about 1 km. The steep, bush-clad, southern part of the field was surveyed with magnetotelluric (MT) resistivity measurements using both naturally occurring signals and the 50 Hz radiation from the power wires as sources. These measurements found low resistivities over the north-eastern slopes and around the summits of Tihia and Kakaramea, indicating thermal activity. However, the measurements were too widely spaced to allow the field boundary to be clearly delineated. Interpretation of the resistivity and other data suggests that the Tokaanu–Waihi thermal waters rise nearly vertically from a source deep beneath the elevated southwestern part of the field to the water table. These waters then flow north to discharge at the surface near Lake Taupo. Neighbouring geothermal systems, which occur at Tongariro about 18 km south of Tokaanu–Waihi, and at Motuoapa about 10 km to the northeast, are separated from the Tokaanu–Waihi field by high resistivity ground. This suggests that the thermal fluids discharging at the three fields do not have a common source, as has been suggested previously.     

Lithium in the McDermitt caldera,Nevada and Oregon

Anomalously high concentrations of lithium in fluviatile-lacustrine sediments near McDermitt, Nevada, may constitute a potential resource. These sediments are associated with a caldera about 45 km in diameter that is a result of volcanic activity, subsidence and sedimentation chiefly of Miocene age. The sediments originally were vitroclastic and now consist chiefly of authigenic zeolites, clay minerals, feldspar and quartz. Calcite occurs as thin beds, nodules and cement Gypsum is presnt but sparse.Most of the clay beds in the caldera contain 0.01–0.1% Li and have well above the average Li concentration for continental clays (0.006%) (Ronov et al.¹). Individual smectitic clay samples from the western and southern part of the caldera contain as much as 0.65% Li and are associated with analcime and K-feldspar. Two beds, each 0.6m thick, contain 0.35% Li. Clay samples from the northern part of the caldera contain as much as 0.36% Li, and are associated with clinoptilolite and erionite. The clay beds are thinner in the north; in one section a bed 0.3 m thick contains 0.36% Li, and in another section a bed 0.1 m thick contains 0.30% Li. Lithium is probably derived from volcanic material and then incorporated into the clay beds during alteration.     

Microstructural study of super Ni laminated composite/1Cr18Ni9Ti steel dissimilar welded joint

Abstract

Super Ni laminated composite and 1Cr18Ni9Ti stainless steel were welded by the tungsten inert gas process with the Cr25–Ni13 filler alloy. The microstructure, element distribution and phase formation near the fusion zone were evaluated by standard technique. Results indicated the formation of four main regions: the fusion transition region on the 1Cr18Ni9Ti steel side, the fusion transition region on the super Ni laminated composite side, a columnar crystal weld region and the weld centre region. The microstructure on either side of the weld was characterized by strong directionality and changed from columnar austenite to equiaxed austenite in the weld centre. A Ni, Fe and Cr element transition region, about 30 μm wide, was formed at the fusion zone on the super Ni side. The phase formed into welded zone was composed mainly of austenite, δ-Fe, γ-Ni(Cr, Fe) and FeNi intermetallic compounds.     

Optimizing the tilt angle of solar collectors

Solar collectors need to be tilted at the correct angle to maximize the performance of the system. In this paper, the annual solar fraction of the system (the fraction of energy that is supplied by solar energy) is used as an indicator to find the optimum inclination angles for a thermosyphon solar water heater installed in northern and southern parts of Jordan. Calculations are carried out using the powerful computer program TRNSYS (Transient System Simulation). The system is assumed to operate with a daily hot water load of 150 l at 55°C flowing during the day according to the widely used Rand consumption profile. The results show that the optimum inclination angle for the maximum solar fraction is about φ+(0→10°) for the northern region (represented by Amman) and about φ+(0→20°) for the southern region (represented by the town of Aqaba). These values are greater than those for maximum solar radiation (which is commonly used as an indicator) at the top of the collector by about 5 to 8°.     

Gravity changes in the Tauhara sector of the Wairakei–Tauhara geothermal field,New Zealand

Five microgravity surveys, done between 1972 and 2006, show that in the northern part of the Tauhara geothermal field there were large gravity decreases prior to 1985 associated with the expansion of steam zones resulting from pressure drawdown caused by fluid extraction at Wairakei. Since 1985 there have been gravity increases of up to 240 μgal in the northern part of Tauhara, corresponding to a mass increase of about 20 Mt. The gravity increases are centred near the unused deep well TH4, and are inferred to result mainly from resaturation of a deep steam zone due to a downflow of water in the well. We suggest that the water entered the well from a confined groundwater aquifer at a known casing break at 393 m depth and exited in the region of slotted casing at about 900–1000 m depth causing displacement of single-phase liquid upwards into the overlying steam zone. The average downflow rate is estimated to be about 110 t/h (30 kg/s); however, no downhole measurements in the well have been possible due to casing breaks. Simple modelling of the gravity data suggests the region of resaturation had the form of a cone of impression 150–250 m high and extending laterally for 1–2 km. Since 1985, gravity changes in the central and southern parts of the Tauhara field have been less than 50 μgal, indicating little net mass loss (<2 Mt), and hence little effect in this area from the continuing production at Wairakei. The subsidence centred near Crown Road has been attributed to compaction of a thin, elliptical lens of porous, thermally-altered volcanic deposits at shallow depth as a result of a water level decline in the near-surface, steam-heated groundwater aquifer. Gravity data (1994 onwards) at a point near the centre of the subsidence bowl show that, despite ground subsidence of about 0.55 m, there have been no significant gravity changes. One explanation for the absence of gravity changes is that the water lost from the near-surface aquifer has drained downwards increasing the saturation in part of a deeper, partly saturated layer.     

Determination of suitable types of solar cells for optimal outdoor performance in desert climate

To choose the most suitable solar cell for desert climate, measurements and analysis of the integrated spectral response (ISR) and the electrical power over 32 spectral bands for monocrystalline, polycrystalline and amorphous solar cells have been carried out in Helwan during several seasons under different environmental conditions. The results of ISR show that while the amorphous silicon solar cell is sensitive in the visible part of the spectrum with maximum sensitivity at wavelength (λ=0.522 μm), the polycrystalline silicon solar cell shows remarkable sensitivity in the infra-red region with maximum sensitivity at (λ=0.922 μm) and the monocrystalline silicon solar cell is more sensitive in the near infra-red spectrum with maximum value of sensitivity at (λ=0.704 μm). Deviations were found in the behavior between the ISR and the electrical output power in the measured bands.     

Numerical models to simulate heat and mass transfer at sharp interfaces in nucleate boiling

Abstract

This work describes a simulation technique for nucleate boiling that considers mass transfer with interfacial temperature gradients and a sharp interface. Interpolation functions estimate the temperature at points located in a direction normal to the interface. A linear temperature profile at the interface interpolates the temperature of the interface-cells. An interface-cells segregation algorithm avoids the interface smearing. Simulations with water at 6.2?K wall superheat show good agreement with the available experimental data on bubble growth rate. Results reveal large heat transfer coefficients over a 200?μm region near the interface. Analysis of the wall shear stress indicates an influence region around the bubble base of two-times the departure bubble diameter.     

三峡水库蓄水对库区降水量的影响分析

三峡大坝建成后库区水位上升,常年水面面积也将大幅增加,库区下垫面将发生变化,从而导致局地气候特征的变化。为了解三峡大坝对库区降水量的影响,基于三峡库区37个雨量站点1958-01-01~2008-12-31逐日有效降水量资料,采用气象诊断旋转正交经验函数(REOF)方法计算并分析了三峡库区和大坝南北部年均降水量、四季降水量的时空变化情况,并通过REOF模态图时间系数分析了建坝前后降水量的波动情况。结果发现,三峡水库运行后库区降水量存在一定的波动,三峡大坝在运行前45年与运行后6年的时间内,年均、四季整个库区与北部降水量差值波动幅度并不明显。     

Offshore wave energy resource assessment in the East China Sea

The offshore wave energy resource in the East China Sea (ECS) off the coast of the southern East China is assessed using wave buoy data covering the period of 2011−2013. It is found that the averaged offshore wave power was approximately 13 kW m⁻¹ in the region of interest. Most of the offshore wave energy in the ECS is contributed by the sea states with significant wave heights between 1.5 m and 3.5 m and with wave energy periods between 6 s and 8 s. Seasonal variations are detected in the wave characteristics of significant wave height and wave power. The predominant wave directions are mainly from the II quadrant and the IV quadrant, respectively, in winter and summer, in accordance with the monsoon characteristics in the ECS. Wave heights, periods and power are generally higher in winter and autumn, and weaker in spring and summer; however, extreme values occur in some summer and autumn months due to the extreme conditions caused by typhoons passing over this region. These extreme sea states do not contribute much to the total annual energy, mainly because of their low occurrence, but may bring risks to the wave energy converters.     

Assessment of ground thermal capacity for space cooling in Libya

We identify a number of passive techniques for space cooling, using the thermal capacity of the ground in traditional buildings. The techniques used involve completely or partially underground houses, thick walls, and floor slabs on the ground. Results show that the cooling potential of the floor varies from 0.2 MJ/m²-day in the region near the Mediterranean coast to 0.6 MJ/m²-day in the southern region of Libya.     

Characterization of the unsteady flow in the nacelle region of a modern wind turbine

A three‐dimensional Navier–Stokes solver has been used to investigate the flow in the nacelle region of a wind turbine where anemometers are typically placed to measure the flow speed and the turbine yaw angle. A 500 kW turbine was modelled with rotor and nacelle geometry in order to capture the complex separated flow in the blade root region of the rotor. A number of steady state and unsteady simulations were carried out for wind speeds ranging from 6 m s^?1 to 16 m s^?1 as well as two yaw and tilt angles. The flow in the nacelle region was found to be highly unsteady, dominated by unsteady vortex shedding from the cylindrical part of the blades, which interacted with the root vortices from each blade, generating high‐velocity gradients. As a consequence, the nacelle wind speed and the nacelle flow angle were found to vary significantly with the height above the nacelle surface. The nacelle anemometry showed significant dependence on both yaw and tilt angles with yaw errors of up to 10 degrees when operating in a tilted inflow. Copyright © 2010 John Wiley & Sons, Ltd.     

Numerical solution of three-dimensional rectangular submerged jets with the evidence of the undisturbed region of flow

ABSTRACT

The evolution of turbulent rectangular submerged free jets has been investigated numerically with a two-dimensional (2D) approach by the present authors and, by using the large eddy simulations (LES) at several Reynolds numbers. The average numerical results confirmed the presence of the undisturbed region of flow (URF) located between the slot exit and the beginning of the potential core region (PCR) previously observed experimentally at the University of Rome “Tor Vergata” by Gori and coworkers. The 2D study of the present authors carried out under the conditions previously investigated in the literature, showed that the URF has a self-similar behavior, and proposed a new law for the evolution of the momentum. The present paper extends the LES to three-dimensional (3D) rectangular submerged free jets, in the range from Re = 5,000 to Re = 40,000, showing that the self-similar behavior of URF is also present in the 3D numerical simulations, as well as in the PCR and in the fully developed region (FDR).     

Wind resource assessment of the Jordanian southern region

Wind data in terms of annual, seasonal and diurnal variations at Queira, which is located in the southern part of Jordan was studied and analyzed. For this purpose, long-term wind speed data for a period of 12 years (1990–2001) was used. The analysis showed that the seasonal and diurnal pattern of wind speed matches the electricity load pattern of the location. Higher winds of the order of 6 m/s and more were observed during both the summer months of the year (May–August) and peak hours (1100–1500) of the day. The wind duration availability is discussed as the number of hours during which the wind remained in certain wind speed intervals. The possibility of electricity generation from wind power at Queira was carried out using three different wind energy systems of sizes 100, 22 kW rated power, and a wind farm consisting of 25 small wind turbines; each of 4 kW rated power with hub heights of 20, 30, and 40 m. The energy production analysis showed higher production from the wind farm with a 20 m hub height than the production from the other two wind turbines. Similarly, the cost analysis showed that the lowest generation costs of 1 kWh were obtained for the wind farm compared to the other two wind turbines. The possibility of water pumping using the wind farm was also investigated. The results showed that water pumping using wind turbines is an appropriate alternative for the photovoltaic water pumping in the region.     

PASCOOL ELECTRONIC METAHANDBOOK,PEM⋆

In the PASCOOL research program, which is part of the European research project Joule II, one task was dedicated to the development of an interactive software that would summarise the result of the Pascool research program and show the applicability of passive cooling in Mediterranean countries. The aim was to encourage designers to make use of passive cooling strategies in existing and new buildings. Therefore, a software called PEM, Pascool Electronic Metahandbook was created. A selection of buildings from the southern European countries are presented in this software. These buildings had been previously monitored and simulated as a separate task within the Pascool program.

In addition, the software contains a climate database and simple predesign tools for dimensioning insulation and solar protection.

Version 1.2 of this software was completed in October 1995 and is available on CD-ROM.     

Performance of a solar ejector cooling-system in the southern region of Turkey

Performance variations of a solar-powered ejector cooling-system (SECS) using an evacuated-tube collector are presented for Antalya, Aydin, Konya and Urfa cities located in the southern region of Turkey by means of hourly and monthly average ambient temperature and solar radiation meteorological data. A SECS, based on a constant-area ejector flow model and using R-123, was considered. The cooling season and period were taken into account for the 6 months (May–October) and the hours 8:00–17:00, respectively. It was found that the evacuated-tube collector efficiency depending upon the ambient temperature and solar radiation within the day was remarkably varied. However, for all the cities, the cooling capacities of the SECS were very similar. When generator, condenser, and evaporator temperatures were taken, namely, 85 °C, 30 °C and 12 °C, the maximum overall coefficient of performance and the cooling capacity were obtained as 0.197 and 178.26 W/m², respectively, at 12:00 in August for Aydin. The evacuated-tube collector area per ton cooling was found to be around 21 m² at noontime in August for all the cities. Furthermore, at the off-design conditions, a performance map of the system was derived and discussed. It was determined that the SECS could be used for office-cooling purposes during the hours (8:00–15:00) in the southern region of Turkey.     

An Investigation on Transport Properties Near the Wall in Porous Media by Fractal Models

A comprehensive investigation on the wall effects on the transport properties, permeability, thermal conductivity, and thermal dispersion conductivity is performed, based on the fractal models for these properties and the porosity variations near the wall in porous media. The results show that the fractal models for transport properties of porous media can provide good agreement with the conventional models in the region near the wall in porous media. This indicates that the fractal models for transport properties of porous media also hold in the region near the wall in porous media if the wall effects are taken into account.     

A Numerical Study of the Thermal Entrance Effect in Miniature Thermal Conductivity Detectors

The microchannel flow in miniature TCDs (thermal conductivity detectors) is investigated numerically. Solutions based on the boundary-layer approximation are not very accurate near the channel inlet for low Reynolds numbers. As a result the full Navier-Stokes equations were solved to analyze the gas flow in a miniature TCD. The effects of channel size and inlet and boundary conditions on the heat transfer rate were examined. When the gas stream is not preheated, the distance for a miniature TCD to reach the conduction-dominant region is approximately two to three times the thermal entry length of a constant property pipe flow subject to a uniform thermal boundary condition. If the gas inlet temperature is in the vicinity of the mean gas temperature in the conduction-dominant region, the entrance length is much shorter and very close to that of a constant property pipe flow with uniform surface temperature or heat flux.