Decarbonising power generation in China—Is the answer blowing in the wind?

This paper examines the current situation of wind industry development, evaluates the potentials of GHG mitigation and identifies the key determinants of scaling up wind power deployment in China. China has doubled its wind capacity every year for the past 4 years, the total installed capacity reached 12 Gigawatts (GW) and surpassed the 10-GW target 2 years ahead of schedule in the national plan for renewable energy development [38], [71], [87],and would reach 100–120 GW by 2020 according to the government’s new energy plan. It may become the biggest wind power generation and wind turbines manufacturing country of the world in the next years if the abundant wind resources and enormous domestic market can be harnessed with appropriate policies and efficient technology. The recent positive move in vigorous development of wind power in China implies that the total installed capacity will far exceed the targets of the government’s 2007 renewable energy plan. However, the prosperous Chinese wind market has also revealed some worrisome signals and weakness [28], [58], such as low capacity factor and frequent outage of wind farms, inadequate grid infrastructure, long distance transmission, low quality of turbines, adverse price bidding, nepotism in wind farm developer selection process and regulatory uncertainty and policy inconsistency which all conspire to hinder effective power generation in the massively new installed wind capacities. A coherent policy framework is required for creating enabling environment for accelerating wind energy penetration and state-of-art technology deployment in the country. It is argued that institutional, financial and technical capacity will need to be cemented to exploit the huge potentials of wind resources to meet the rapidly growing demand for electricity in China in the coming decades with minimised environmental implications.     

Characteristics of the Mach Disk in the Underexpanded Jet in which the Back Pressure Continuously Changes with Time

When the high-pressure gas is exhausted to the vacuum chamber from the nozzle, the underexpanded supersonic jet contained with the Mach disk is generally formed. The eventual purpose of this study is to clarify the unsteady phenomenon of the underexpanded free jet when the back pressure continuously changes with time. The characteristic of the Mach disk has been clarified in consideration of the diameter and position of it by the numerical analysis in this paper. The sonic jet of the exit Mach number Me=1 is assumed and the axisymmetric conservational equation is solved by the TVD method in the numerical calculation. The diameter and position of the Mach disk differs with the results of a steady jet and the influence on the continuously changing of the back pressure is evidenced from the comparison with the case of steady supersonic jet.     

Renewables in Africa—meeting the energy needs of the poor

This paper presents estimates of renewables energy technologies disseminated in sub-Sahara Africa and evaluates the potential of renewables in meeting the energy needs of Africa's poor. Using data mainly from eastern and southern Africa, the paper examines five major renewable energy technologies, namely: (i) large-scale biomass energy; (ii) small-scale biomass energy (iii) solar photovoltaic; (iv) solar thermal; and (v) wind. It then evaluates how suitable each renewable energy technology is to meet the energy needs of the urban and rural poor. The paper ends with key measures that could encourage the large-scale dissemination of renewable energy technologies to the poor in Africa.     

What causes the change in energy demand in the economy?: The role of technological change

This paper proposes a simple and theoretically clear approach to the estimation of technological change in a multisector general equilibrium framework. This study employs the Multiple Calibration Decomposition Analysis (MCDA) to evaluate technological change that is responsible for changes in energy use and carbon dioxide emissions in the Japanese economy in the oil crises period from 1970 to 1985. The MCDA serves as an elementary way of separating structural change due to technological change from that due to price substitution effects, capturing the interdependence among economic sectors. The empirical result provides a better understanding of the effects on the economy of technological change in that significant period.     

Marangoni Convection in the LiCaAIF_6 Crystal Growth by the Czochralski Technique

Numerical simulation of the mixed convection induced by buoyancy, crystal rotation, and also unbalanced surface tension at the melt-gas interface is conducted by means of the finite volume method in the model of the Czochralski crystal growth. The role of Marangoni convection in the heat and mass transfer is investigated by the comparison of the models with and without surface tension included, and our results indicate that Marangoni convection plays an important role in the heat and mass transfer near the interface of melt and crystal, and also the convection structure.     

Assessing the Public Lighting with Solar Panels in the Sub Saharan Countries in Africa： Yaounde Case Study

Located in central Africa, Cameroon offers a wealth of solar power opportunity. The public lighting in the capital city Yaounde is an example of solar energy promotion. The purpose of this paper is among other things aiming at assessing the solar energy resources of central Africa and making sure it can be used optimally at least for public lighting. Based on the knowledge from data collected and field experience for three years, the authors will assess the implementation of the technology and show how the use of solar energy can solve some problems in the city of Yaounde even when the area is grid connected. This paper will also identify actions for improved access to sustainable, friendly, affordable solar energy services to users, as well as a significant improvement of energy infrastructure and energy efficiency in the city. The authors will also address issues on identified obstacles for the promotion of solar energy in order to help the cities in sub Saharan countries to develop a vision aiming at developing good solar energy policy and better contribute to fight against poverty and climate change.     

Electrochemical investigation of the Bunsen reaction in the sulfur–iodine cycle

The Bunsen reaction, as a part of the sulfur–iodine thermochemical cycle, was studied using an electrochemical cell. The effects of current density, operating temperature, H₂SO₄ concentration in the anolyte, HI concentration and I₂/HI molar ratio in the catholyte were explored. Both the H₂SO₄ in anolyte and the HI in catholyte were concentrated during electrolysis. Increasing current density amplified this H₂SO₄ and HI concentration, while the other operating parameters also varied the anolyte and catholyte concentration. The transport properties of the cation exchange membrane were examined. The electrode current efficiency remained close to 100% for most runs except those at high current density. Both the average cell voltage and the heat equivalent of electric energy were determined at different conditions.     

High-temperature effects of the surrounding rocks around the combustion space area in SMFM-CRIP — A case study in China

Although the industrial experiments “strip mining-face mining” gasifier retreat control gas injection underground gasification process (SMFM-CRIP) have been completed, the existing issues of its rock movement and control become a critical bottleneck restricting large-scale production and application. Moreover, in the SMFM-CRIP process, the essential question of studying the rock movement is to master the high-temperature effect of the surrounding rock around the underground burned area. In view of the lack of research on this fundamental problem, this paper used the indoor experiments, theoretical analysis, and numerical simulation to research high-temperature effect of the surrounding rock around the combustion space area in SMFM-CRIP. The conclusions are as follows: (1) SMFM-CRIP can sufficiently extract the components of carbon in coal and the solid waste such as ash left in the goaf to realize green mining. (2) In the SMFM-CRIP experimental area, the scopes of temperature influence have limits on the mechanical properties of overlying strata on both sides of the coal wall of combustion space area. (3) The temperature influence in the SMFM-CRIP experimental area on the roof, both sides of the coal wall, and the floor of the combustion space area did not exceed 16.7, 8.7, and 13.6 m, respectively. These results provide important data and guidance for the future design of SMFM-CRIP’s large-scale production.     

Windfarming in India—the desired policy recast

The Indian wind energy programme suffered a recent setback after being placed third in terms of total installed capacity of wind electricity in the world. This paper submits, based on analysis of field performance data, that the falling profitability of private windfarm operation in the country today can hardly attract large scale investment in the private sector. It further suggests that a right choice of wind electric generators with an optimum rated wind speed will improve the windfarm performance. The steps to be adopted by the government agencies in order to ensure the desired growth of the wind industry in the country have also been suggested. These in turn invite certain changes in the present windfarm development policy of the country.     

Estimating the offshore wind resources of the State of Ceará in Brazil

The onshore wind power is consolidated; the challenge is to reach the same level of maturity for offshore exploitation. Brazil has no offshore wind power plants and there are few studies in this direction. This paper aims to estimate the offshore wind resources in the State of Ceará, in Brazil. The investigation uses a mesoscale atmospheric computer model, the Regional Atmospheric Modeling System (RAMS), with horizontal resolution of 2 km, which estimates the offshore average wind speed, average wind direction, power density and turbulence taking into account the bathymetry data and navigation routes along the coast of Ceará. The wind potential was evaluated in three representative periods, La Niña, El Niño and Neutral year, analyzing the dry and rainy season for each period. The results indicate an average wind speed above 8 m/s and power density above 720 W/m² no matter the period evaluated, in the dry season. The predominant wind direction in the observed dry periods was from East to West and the turbulence intensity is smaller during dry season of El Niño. Besides, the bathymetry of the State of Ceará is shallow and the large ships route is far beyond the coast, offering no danger to future endeavors.     

Equilibrium potential for the electrochemical Bunsen reaction in the sulfur–iodine cycle

The electrochemical Bunsen reaction was carried out in an electrochemical cell, where the anodic and cathodic compartments were separated by a Nafion 117 membrane. The equilibrium potential of the cell was experimentally measured and theoretically modeled. The effect of electrolyte concentration and temperature was explored. An increase in SO₂ or I₂ concentration reduced the equilibrium potential, whereas increasing H₂SO₄ or HI concentration had a contrary effect. The cell equilibrium potential decreased with increasing temperature. The derived theoretical equilibrium potential model was verified by the experimental data. The regression parameters M and Z in the model were independent of electrolyte concentration, but M decreased and Z kept constant with increasing temperature. An empirical equilibrium potential formula was proposed based on the theoretical and experimental results. The good reproducibility of this formula for measured data indicated its feasibility to estimate the equilibrium potential and also its guidance for optimizing the electrochemical Bunsen reaction.     

Stability Investigation on the Thin Films in Capillary

IntroductionDuring inveshgation of the Phase-change heattrallsfer process in small-scale stl'UCtUI'es, it has beenfound that, because of geometrical restrichon, the thenliquid film formed on a flat solid base is sighficant to thewhole heat bosfer system due to its considerably largearea and high average heat tnmsfer coeffident which is10~l(X) bines Iaper than those in other par'tSt']. and 18tabwork[2] showed uns thermOPhysical phenomenon alsoedestS in a capiliny UP to now, more and moreres…     

Study on the Effects of Flow in the Volute Casing on the Performance of a Sirocco Fan

The flow at the exit from the runner blade of a centrifugal fan with forward curved blades (a sirocco fan) sometimes separates and becomes unstable. We have conducted many researches on the impeller shape of a sirocco fan, proper inlet and exit blade angles were considered to obtain optimum performance. In this paper, the casing shape were decided by changing the circumferential angle, magnifying angle and the width, 21 sorts of casings were used. Performance tests, inner flow velocity and pressure distributions were measured as well. Computational fluid dynamic calculations were also made and compared with the experimental results. Finally, the most suitable casing shape for best performance is considered.     

Comparison of the evolution of energy intensity in Spain and in the EU15. Why is Spain different?

Energy intensity in Spain has increased since 1990, while the opposite has happened in the EU15. Decomposition analysis of primary energy intensity ratios has been used to identify which are the key sectors driving the Spanish evolution and those responsible for most of the differences with the EU15 energy intensity levels. It is also a useful tool to quantify which countries and economic sectors have had most influence in the EU15 evolution. The analysis shows that the Spanish economic structure is driving the divergence in energy intensity ratios with the EU15, mainly due to strong transport growth, but also because of the increase of activities linked to the construction boom, and the convergence to EU levels of household energy demand. The results can be used to pinpoint successful EU strategies for energy efficiency that could be used to improve the Spanish metric.     

Influences of the Exhaust Flow on the Boundary Layer Flow on the Wafer Surface in Spin Coating System

Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped resist scatters outward and reattaches to the film surface. So, the scattered resist is removed by the exhaust flow generated at the gap between the wafer edge and the catch cup. It is seriously concerned that the stripes called Ekman spiral vortices appears on the disk in the case of high rotating speed and the film thickness increases near the wafer edge in the case of low rotating speed, because it prevent the formation of uniform film. The purpose of this study is to make clear the generation mechanism of Ekman spiral vortices and the influence of exhaust flow on it Moreover the influence of the catch cup geometry on the wafer surface boundary layer flow is investigated.     

Subcooled Boiling in the Ultrasonic Field—On the Cause of Microbubble Emission Boiling

Subcooled quasi-pool boiling for water and for ethanol aqueous solutions of 10% by weight (10wt%) and 50wt% and ethanol in an ultrasonic field was experimentally performed for the upward flat heating surface of a copper block with 10 mm diameter under atmospheric conditions. Tested liquid subcooling was 15 K, 20 K, and 25 K for water and aqueous solutions of ethanol and 20 K, 30 K, and 40 K for 100wt% ethanol. At 20 K of liquid subcooling for water and ethanol aqueous solutions, no microbubble emission boiling (MEB) has been observed in quasi-pool boiling. Even if MEB occurs, the heat flux levels off and it turns easily to film boiling. In an ultrasonic field, MEB occurs remarkably. Then the heat flux increases to higher than the ordinary critical heat flux as observed in highly subcooled boiling. The experimental results show that the ultrasonic vibration introduces instability of the interface of liquid and vapor and accelerates MEB at 20 K of liquid subcooling for water and aqueous solutions of ethanol. At 15 K of liquid subcooling for water and aqueous solutions, no effect of ultrasonic vibration is observed. However, at 25K of liquid subcooling, the ultrasonic vibration extends MEB region to higher superheating of the heating surface for aqueous solutions of ethanol. The maximum heat flux in MEB decreases with increasing of ethanol concentration and becomes critical heat flux for 100wt% ethanol. No effect of ultrasonic vibration on boiling is observed for the 100wt% ethanol in these experiments.     

Numerical Simulation of the Supersonic Flows in the Second Throat Ejector —Diffuser Systems

INTRODUCTIONThe ejector system is a device which employs ahigh-velocity primary motive fluid to enirain and accelerate a slower moving secondary fluid. The resulting kinetic energy of the mixture is subsequently usedfor self-compression to a higher pressure, thus performing the function of a compressor. The ejectorsystem has lOng been applied to jet pumps, vacuumpumps, high-altitude simulators, V/STOLs, etc[lrv4],because of the major advantages of its structural simplicity and reliabili…     

Islet transplantation in multicenter networks:the GRAGIL example

Purpose of review The enthusiasm generated by the results of the Edmonton protocol of islet transplantation is inciting a great number of institutions to start such programs. However, the procedure of islet isolation and purification is costly, complex an     

The PCDD/PCDF Dioxin Releases in the Climate of Environment of Jordan in the Period （2000-2008）

Many environment problems of the full using of several categories of processing include mining, heat generators, direct combustion of forest fires, cement production, power plant, transport, medical waste. Dioxin/furan releases from these categories are one of these environment problems. Possible lines of reducing the PCDD/ PCDF （Polychlorinated dibenzo-para-dioxins/Polychlorinated dibenzofurans） releases from these categories are eluci- dated. The contribution of this paper is present the identification and estimation of the latest figure of dioxin/furan releases in the climate of environment of Jordan in the period 2000-2008 from the following categories （cement, aluminum, ceramic, medical waste, power plant, land fill, ferrous and non- ferrous metals, uncontrolled combustion process （biomass burning, waste burning, accidental fires in house, transport）. These finding shows the sign of growth of estimated PCDD/PCDF releases from categories which did not calculated and followed after 2003. The result shows the highest PCDD/PCDF release from landfill fires （62.75 g TEQ/year）, medical waste （8.8264 g TEQ/year）, and transport （3.0145 g TEQ/year）. Jordan seeks by next years, a reduction in total releases of dioxins and furans from sources resulting from human activity. This challenge will apply to the aggregate of releases to the air nationwide and of releases to the water within the Jordan area. Jordan should conduct air monitoring for dioxin in order to track fluctuations in atmospheric deposition levels.