The contribution of ear photosynthesis to grain filling in wheat (Triticum aestivum L.) is not well known. The main objective of this work was to evaluate this contribution through three different experimental approaches: (1) ear photosynthesis was reduced by removing awns or shading the ears (in combination with a defoliation treatment), (2) grain weight per ear was compared in an 'all shaded' crop versus plants where only the vegetative parts were shaded ('ear emerging'), and (3) ear photosynthesis was reduced with DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea), a specific inhibitor of photosystem II. In field experiments in La Plata (Argentina), cultivars Klein Escudo and BioINTA 3000 were subjected to awn removal and ear shading treatments, with or without severe defoliation, and to 'a...
SUMMARYThe aim of this study was to determine middle ear pressure changes during the operation performed under anaesthesia induced by isoflurane or desflurane. This was a prospective,...Full Text Available
The present volume provides standardized energy balance sheets expressed in a common unit of tons of oil equivalent for all OECD Countries. It covers the years 1970 to 1982 year by year and includes many revisions and additions to data previously published. The balances in the present volume are based on data published in OECD Energy Statistics 1971-1981 and OECD Energy Statistics 1981-1982. Tables for each OECD Country include production, import, export, consumption by the different industries, transportation, agriculture, residential sector of the different energies: solid fuels, petroleum, gas, nuclear power and hydroelectricity.
During the 1990's, natural gas was the energy source with the fastest rate of growth in the world energy balance. Nevertheless, recent evolutions of the energy context, in particular in terms of prices, have had a rather strong impact on the progress of the different energy sources penalizing gas a little. Beyond this competition between energies, which may increase, the medium-term perspectives of natural gas development is in keeping with an environment full of uncertainties. This article presents: the world supply and demand prospects for 2010-2015 (impact of high gas prices on other energy sources, occurrence of production constraints, political decisions of producing countries and world gas industry balance), trends on main markets (North America, Europe, Asia-Oceania), and international trade. (J.S.)
A survey on electric power and on energy balance especially primary and final energy (gas oil, kerosene,solar energy...) has been implemented in Lebanon in 1993. Results and economic impact of energy consumption and energy production are given in statistics and tables. 10 figs.
ObjectiveTo address the characteristics of hearing loss in patients with Turner syndrome (TS), we evaluated hearing levels of patients with TS and analyzed causative factors.Study designThirty-three patients with TS (8 to 40 years of age) were studied through the use of audiological measurements, and causative factors were explored.ResultsTwenty cases (35 of 66 ears tested) showed high-frequency (8 kHz) sensory neural hearing loss (HFQ-SNHL). Fifteen cases (26 ears) and 15 cases (24 ears) of the impaired 20 cases were unresponsive to distortion-product otoacoustic emissions and transient-evoked otoacoustic emissions, respectively. HFQ-SNHL showed little relation to the history of middle ear infection and puberty, although middle ear infections were seen in 11 of the 20 cases. The hearing t...
The growth of a middle ear cholesteatoma behind a normal tympanic membrane is a rate though possible event. In such cases, CT may provide useful information for diagnosis. The results are presented of a CT study carried out on 14 patients affected with unilateral conductive hearing loss and with normal tympanic membrane. CT allowed the diagnosis of meddle ear cholesteatoma to be made in all cases. All patients were treated with surgery: 8 of them underwent tympanoplasty and 6 explorative tympanotomy. While the diagnosis of cholesteatoma was confirmed in 13 patients, in 1 case tympanosclerosis was diagnosed. CT diagnosis of middle ear cholesteatoma is based on the demonstration of a low-density soft-tissue mass, in association with bone erosion or ossicular dislocation. The author emphasizes the difficulty of a CT diagnosis of cholesteatoma in the patients with middle ear soft-tissue masses in the ...
The economic benefits of supplemental fuel injections depend, in part, on the coke replacement ratio. An assessment of the accuracy with which blast furnace coke rate may be measured and a determination of the key drivers of coke rate uncertainty are offered, to provide guidance for experiments in high-rate gas injection. Using statistical analysis tools, an expression for the measurement error associated with the various terms of blast furnace carbon balance is developed. Coke rate calculations based on the material balance are most sensitive to coke carbon content and to proper tracking of hot metal tapping schedule.
Kawasaki Heavy Industries, Ltd. has developed a gas turbine combined cycle and cogeneration plant computer aided engineering (CAE) system, which creates cycle heat balance automatically on given configurations of gas turbines, heat recovery boilers, steam turbines and auxiliaries. The system can predict the performance of the plant as a function of control set points, loads, process steam requirements and ambient conditions, which enables accurate and fast design of gas turbine combined cycle and cogeneration plants. (author)
The fundamental principles of coal gasification are discussed including the reactions, their course and influencing parameters. Said principles are illustrated considering heat balance as well as process performance. Coal gasification processes are presented which are under development on a pilot plant scale or which are approved on an industrial scale.
CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the ...
BackgroundThe endoscopic endonasal transsphenoidal approach (EETA) to the pituitary is performed by ear, nose, and throat (ENT) surgeons in collaboration with neurosurgeons but also...Full Text Available
... Ready-to-Eat (MRE) VIII operational ration was evaluated at a field training exercise (Market Square II) with troops of the 82nd Airborne Division. ...
With the help of heat balance equation and high temperature thermodynamic function, the calibration relation of jet temperature with discharge power, gas flow rate was obtained for nitrogen thermal plasma. It was shown that the results were agreed with the principle of similarity. The jet temperature was a function of Peff/f, instead of a general two variables function of Peff and f, which were effective discharge power and working gas flow rate, respectively. A related discussion has been given; it will be referable to thermal plasma applications. (authors)
We report the performance of a commercial recuperated micro gas turbine on biomass producer gas and mixtures of biomass producer gas with natural gas. The biomass producer gas, obtained by gasification at 850{sup o}C with air at atmospheric pressure, contains about 7% H2, 17% CO, 15% CO2, 4% CH4, 2% other hydrocarbons, 2% H2O, and a balance of N2 and Ar from air. It has a net heating value of about 6 MJ/(Nm{sup 3}). The micro gas turbine delivers full power (30 kW{sub e}) on gas mixtures with a net heating value of at least 15 MJ/(Nm{sup 3}). For gas of lower heating value, the maximum fuel gas flow allowed by the fuel control unit limits the attainable power. At reduced power, the lower limit for stable operation is a net heating value of about 8 MJ/(Nm{sup 3}). The gross ...
When withdrawing a fluid sample (for additional chromatographic analyses) from an apparatus operated at a reduced pressure, a typical syringe proves to be ineffective (even if it is equipped with a gas tight plunger). It simply does not create enough pressure differential to remove a fluid sample from a reduced pressure environment. We encountered such a situation as part of efforts to extend the operation of the advanced distillation curve protocol to reduced pressures. The problem was solved by the development of a pressure balance syringe that allows reliable and precise sampling from an apparatus operating at sub-ambient pressures. This new device uses an external vacuum source to evacuate a syringe barrel, allowing a user to withdraw fluid samples from environments with pressures as low as 0.5kPa. To demonstrate the operation of the newly developed device, distillate analyses were performed on two fluids at low pressure: a predefined ...
Bis(imido) uranium(VI) trans- and cis-dichalcogenate complexes with the general formula U(NtBu)2(EAr)2(OPPh3)2 (EAr = O-2-tBuC6H4, SPh, SePh, TePh) and U(NtBu)2(EAr)2(R2bpy) (EAr = SPh, SePh, TePh) (R2bpy = 4,4'-disubstituted-2,2'-bipyridyl, R = Me, tBu) have been prepared. This family of complexes includes the first reported monodentate selenolate and tellurolate complexes of uranium(VI). Density functional theory calculations show that covalent interactions in the U-E bond increase in the trans-dichalcogenate series U(NtBu)2(EAr)2(OPPh3)2 as the size of the chalcogenate donor increases and that both 5f and 6d orbital participation is important in the M-E bonds of U-S, U-Se, and U-Te complexes.
Prior to 1978, the Wilsonville Advanced Coal Liquefaction facility material balance surrounded only the thermal liquefaction unit and involved analyses of only the slurry stream and individual gas streams. The distillate solvent yield was determined by difference. Subsequently, several modifications and additional process units were introduced to this single unit system. With the inclusion of the deashing unit in 1978 and the catalytic hydrogenation unit in 1981, the process has evolved into a sophisticated two-stage coal liquefaction process and has the potential for various modes of integration. This report presents an elemental balancing procedure and a simplified presentation format that is sufficiently flexible to meet current and future needs. The development of the elemental balancing technique and the relevant computer programs to handle the calculations have been addressed. This will be useful ...
This paper consists of two parts. Part 1 deals with the thermodynamic and thermoeconomic methodology of a trigeneration (TRIGEN) system with a rated output of 6.5 MW gas-diesel engine while the application of the methodology is presented in Part 2. The system has been installed in the Eskisehir Industry Estate Zone in Turkey. Thermodynamic methodology includes the relations and performance parameters for energy and exergy analysis, while thermoeconomic methodology covers the cost balance relations, cost of products and thermodynamic inefficiencies, relative cost difference and exergoeconomic factor. (author)
Gasification and hydrogenation are the two basic routes for coal processing. Accounts are given of various low-temperature processes in coal gasification route A: air separation, removal of sour gas by the Rectisol process, liquid nitrogen washing, the material balance and utility consumption of these processes, plus low-temperature gas separation, partial condensation and methane washing. There are also accounts of the low-temperature processes involved in gasification route B: i.e., in the indirect coal liquefaction and direct liquefaction carried out in the Sasol II and III processes. (3 refs.) (In Japanese)
When withdrawing a fluid sample (for additional chromatographic analyses) from an apparatus operated at a reduced pressure, a typical syringe proves to be ineffective (even if it is equipped with a gas tight plunger). It simply does not create enough pressure differential to remove a fluid sample from a reduced pressure environment. We encountered such a situation as part of efforts to extend the operation of the advanced distillation curve protocol to reduced pressures. The problem was solved by the development of a pressure balance syringe that allows reliable and precise sampling from an apparatus operating at sub-ambient pressures. This new device uses an external vacuum source to evacuate a syringe barrel, allowing a user to withdraw fluid samples from environments with pressures as l...
This paper reports on steam injection cycle which is similar to supplementary fired combined cycle, but for the utilized steam medium produced by HRSG, its temperature is higher and pressure is lower than in the combined cycle. In comparison with the thermodynamic advantage of the two cycles, a clear understanding of physical concept can be gotten simply by energy balance. The difference of total power output between them is subtraction of enthalpy difference of exhaust steam and feed water of HRSG in steam injection cycle from the rejected heat by water coolant of condenser in combined cycle, when using the identical gas turbine and the same amount of total fuel consumption. In general case, formulas and data are given to indicate this comparison by the ratio of steam mass flow supplied by HRSG of the two cycles. The analysis of Cheng Cycle Series 7 is applied as an example to give the practical result.
Commercially available melter technologies were tested during 1994-95 as part of a multiphase program to test candidate technologies for vitrification of the low-level waste (LLW) stream to be derived from retrieval and pretreatment of Hanford Site tank wastes. Seven vendors were selected for Phase 1 testing to demonstrate vitrification of a high sodium content liquid LLW simulant. The tested melter technologies included four Joule-heated melters, a carbon electrode melter, a combustion melter, and a plasma melter. Various dry and slurry melter feed preparation processes were also tested. Various feed material samples, product glass samples, and process offgas streams were characterized to provide data for evaluation of process decontamination factors and material mass balances for each vitrification technology. This report describes the melter mass balance evaluations and results for six of the Phase 1 LLW melter vendor demonstration tests.
The purpose of this study was to assess the agreement between rectal temperature and infrared emission detection (IRED). The specificity and sensitivity, the positive predictive value and the negative predictive value were calculated. It was a prospective, observational and unblinded study. Thermoscan-pro-1 was used to collect pairs of data in 41 patients, all hospitalised on an acute geriatric ward during a 4-month period. 41% of the patients were febrile. The 'bias' between rectal and tympanic measurement (left ear) was -0.64 degree C (d) and the standard deviation 0.58 degree C (s). The '95% Confidence Interval' for the bias was -0.82 degree C and -0.46 degree C. The '95% limits of agreement' between the rectal measurement and the tympanic measurement (left ear) was -1.78 degrees C and 0.50 degree C. Regression analysis taught us that bias was increasing with increasing temperature. If we take into account one measurement with the IRED ...
Auditory neurons in the superior colliculus (SC) respond preferentially to sounds from restricted directions to form a map of auditory space. The development of this representation is shaped...Full Text Available
The sensations of sound and motion generated by the inner ear are controlled by the brain through extensive centripetal innervation originating within the brain stem. In the semicircular canals, brain...Full Text Available
... hearing protection since you play, sit or stand near loud instruments and speakers. Here are a few ... piper's calling you to join him" Led Zeppelin (Robert Plant), "Stairway to Heaven" "My ears are ringin' ...
Precondition for the low-NO operation of gas turbine burners is the generation of as homogeneous as possible a gaseous fuel/air mixture. Such a burner behavior can be achieved by selective adaptation of the flow and injection. A computing model is introduced that calculates the dynamically balanced GASs/droplet flow through numerical solution of the transport equations in a curved orthogonal coordinate system. The feedback reaction of the fuel droplets to the gas phase is considered by source terms and/or sink terms. Test computations were carried out for comparison with analytical solutions from the flow mechanics and validated by comparison with measurement results. Droplet motion and evaporation were checked by means of published experimental results on single droplets. For the validation of the developed computing technique, model tests were carried out with water in place of fuel. It is pointed out that the choice of ...
The major driver to enhance the efficiency of the simple gas turbine cycle has been the increase in process conditions through advancements in materials and cooling methods. Thermodynamic cycle developments or cycle integration are among the possible ways to further enhance performance. The current paper presents the possibilities and advantages from the LOTHECO natural gas-fired combined cycle concept. In the LOTHECO cycle, low-temperature waste heat or solar heat is used for the evaporation of injected water droplets in the compressed air entering the gas turbine's combustion chamber. Following a description of this innovative cycle, its advantages are demonstrated by comparison between different gas turbine power generation systems for small and large-scale applications, including thermodynamic and economic analysis. A commercial gas turbine (ALSTOM GT10C) has been selected and ...
The energy price volatility model suggests that some of the proposed natural gas programs can contribute to energy price stability. The sector most vulnerable to fuel price variations is, of course, the transportation sector. The most effective strategy to achieve energy pace stability is to reduce petroleum consumption in this sector. The natural gas vehicle program is therefore recommended as potentially important and worthy of further consideration. At this point, distinguishing the merits of various subprograms is not feasible. This result farther supports the conclusion that the DOE`s energy R&D portfolio is not efficiently balanced and an increase in oil and gas research should be a high priority. The DOE has responded favorably and has significantly increased its proposed research with the explicit objective of displacing oil in the transportation sector. The enhanced research and development ...
A numerical model was developed to simulate the combined effects of heat transfer, magnetite oxidation, and NO{sub x} formation in a grate-kiln furnace for taconite pellet induration. Heat transfer from the flame in the kiln was described by the net radiation method. The shrinking core model was used to account for magnetite oxidation on the grate. A novel approach to oxidation of tumbling pellets in a kiln was derived. The Zeldovich mechanism was used to predict thermal NO generation. Temperature fluctuations in the gas streams were estimated with a clipped Gaussian probability density function. The thermal energy balances and mass balances resulted in coupled systems of first-order differential equations, which were solved numerically. The model is capable of predicting NO production and magnetite oxidation in agreement with observation of plant performance. Although the design of the grate-kiln system is for efficient ...
Melting in a cokeless cupola furnace fuelled with natural gas is a novel, energy-saving and environment-friendly process. In order to be able to monitor the processes inside the furnace with detailed mass and heat balances, an experimental furnace with an efficient measuring system was constructed in the framework of a research project financed by the BMFT and Messrs. Eisenwerke Dueker GmbH und Co. KG, Laufach, Germany. (orig./HS) [Deutsch] Das Schmelzen im kokslosen erdgasgefeuerten Kupolofen ist ein neues, energiesparendes und umweltfreundliches Verfahren. Um die Vorgaenge im Ofen mit umfassenden Stoff- und Waermebilanzen erfassen zu koennen, ist im Rahmen eines vom BMFT und der Firma Eisenwerke Dueker GmbH und Co. KG, Laufach, finanzierten Forschungsvorhabens, ein Versuchsofen mit umfangreicher Messeinrichtung gebaut worden. (orig./HS)
The vacuum system of the XVTS (X-Ray Vacuum Transport System) for the LCLS (Linac Coherent Light Source) XTOD (X-ray Transport, Optics and Diagnostics) system has been analyzed and configured by the Lawrence Livermore National Laboratory's NTED (New Technologies Engineering Division) as requested by the SLAC/LCLS program. The system layout, detailed analyses and selection of the vacuum components for the XTOD tunnel section are presented in this preliminary design report. The vacuum system was analyzed and optimized using a coupled gas load balance model of sub-volumes of the components to be evacuated. Also included are the plans for procurement, mechanical integration, and the cost estimates.
Sessions covered economic and management, advance control technologies (including pulverized coal dynamic balancing-activator and control strategy by B. DeMarcy and X.Ollat), nuclear technologies, environmental (including purge considerations for seasonal SCR systems by D.P. Evely, NOx and heat rate supervisory control at NRG-Huntley operations by G Lange, comparison of gypsum dewatering technologies at flue gas desulfurization plants by B.A. Perlmutter, beta gauge particulate monitoring by J.L. Arnold), improving performance at nuclear power plants, network security, and emerging applications.
This is the first report about a relevant and compiled information on the Mexican Energy Sector. It was realized in one volume by the University Energy Program of the National Autonomous University of Mexico and it comprises information for the period 1996-1997. In the chapter 1 there are presented the numbers of hydrocarbon reserves. Chapter 2 treats about production, events and its results. Likewise chapter 3 shows information about the typical Installations for petroleum, gas and electricity including through of the nuclear energy. In the chapter 4, named Energy Consumption, is presented a National energy balance for 1996 and, finally there are a sections about the prices, the rates and a glossary to facilitate its understanding. (Author)
When energetic heavy ions traverse a medium, the amount of energy deposited by the ions is closely related to their effective charges. The charge-state fractions of these beams are obtained by solving rate equations for the electron loss and capture processes. By assuming local balance between electron loss and capture, the charge-state distributions, the averge equilibrium charge q, and other properties are obtained as functions of the incident beam velocity. The LET (linear energy transfer) of Ne and Ar ions with energies between 0.01 and 100 MeV/amu is calculatedted using their average equilibrium charge.
Energy projects are extremely capitalistic and the costs involved have a significant weight on the balance sheets of companies. This paper describes the general rules of financing policies used by companies from the natural gas and petroleum industries: constraints (external and financial markets, partnership, warranties..); implication of financiers; risk analysis (political (nationalization, civil or military troubles, difficult transfer of profits outside the project..), financial (property developer, nature of the project, delay, cost overruns, performance, market..)); financial instruments (proper funds and debt, bankers and insurers, loans etc..). These rules are illustrated with several examples of recent projects of gas pipelines and exploitation of oil fields abroad. (J.S.)
Chromium nitride thin films were deposited on SA-304 stainless steel substrates by using direct-current reactive magnetron sputtering. The influence of process conditions such as nitrogen content in the fed gas, substrate temperature, and different sputtering gases on microstructural characteristics of the films was investigated. The films showed (200) preferred orientation at low nitrogen content (< 30%) in the fed gas. The formation of Cr_2N and CrN phases was observed when 30% and 40% N_2 were used, with a balance of Ar, respectively. Field emission scanning electron microscopy and atomic force microscopy were used to characterize the morphology and surface topography of the thin films, respectively. Microhardness tests showed a maximum hardness of 16.95 GPa for the 30% nitrogen content.
Co-combustion of chicken litter with coal was performed in a laboratory-scale fluidized bed combustor to investigate the effect of chicken litter addition on the partitioning behavior of mercury. Gaseous total and elemental mercury concentrations in the flue gas were measured online, and ash was analyzed for particle-bound mercury along with other elemental and surface properties. The mercury mass balance was between 85 and 105%. The experimental results show that co-combustion of chicken litter decreases the amount of elemental and total mercury in the gas phase. Mercury content in fly ash increases with an increasing chicken litter share. 22 refs., 6 figs., 5 tabs.
The report gives background design data for a specific copper smelter. The data is sufficiently detailed to allow air pollution control system engineering studies to be conducted. These studies will be concerned primarily with lean SO/sub 2/ streams that currently are not being captured. Physical layout of the smelter and the surrounding area is presented, along with existing control equipment. Ductwork that would be considered for future system tie-in is defined. Emissions from operating equipment, gas flow rates, temperatures, sulfur balance, and a process flow sheet are included. Utilities, stack dimensions, footing requirements, and solid waste handling are defined. Available area for new control equipment, gas characteristic variation, and potential new control equipment installation problems are discussed. Portions of this document are not fully legible. (GRA)
The report gives background design data for a specific copper smelter. The data is sufficiently detailed to allow air pollution control system engineering studies to be conducted. These studies will be concerned primarily with lean SO/sub 2/ streams that currently are not being captured. Physical layout of the smelter and the surrounding area is presented, along with existing control equipment. Ductwork that would be considered for future system tie-in is defined. Emissions from operating equipment, gas flow rates, temperatures, sulfur balance, and a process flow sheet are included. Utilities, stack dimensions, footing requirements, and solid waste handling are defined. Available area for new control equipment, gas characteristic variation, and potential new control equipment installation problems are discussed. (GRA)
Gas storage is a critical element in the natural gas industry. Producers, transmission and distribution companies, marketers, and end users all benefit directly from the load balancing function of storage. The unbundling process has fundamentally changed the way storage is used and valued. As an unbundled service, the value of storage is being recovered at rates that reflect its value. Moreover, the marketplace has differentiated between various types of storage services and has increasingly rewarded flexibility, safety, and reliability. The size of the natural gas market has increased and is projected to continue to increase towards 30 trillion cubic feet over the next 10 to 15 years. Much of this increase is projected to come from electric generation, particularly peaking units. Gas storage, particularly the flexible services that are most suited to electric loads, is crucial in ...
This presentation outlined the energy policy in the United States and its impact on frontier development in Alaska, deepwater offshore fields and in the western oil shale resources. The energy strategy focuses on technologies that increase domestic production from existing resources as well as technologies that create new sources of energy. In addition to emphasizing the cooperation between Canada and the United States in ensuring energy supply security and stability, this paper discussed the importance of overall bilateral trade between the 2 countries. It was noted that Canada is the United State's most secure and reliable energy partner and is the number 1 supplier of imported oil, natural gas, electricity and uranium. The Bush administration's energy policy is based on the mandate to supply stable, reliable, secure, affordable and environmentally sound energy for the country's growing economy. The energy strategy focuses on increasing ...
A mathematical model of a mineral melting cupola furnace for stone wool production has been developed for improving cupola operation. The 1-D, first-engineering-principles model includes mass and heat balances for the gas phase, five solid phases, and four liquid phases. The gas and solid/liquid phases flow countercurrently. Seven chemical reactions account for the conversions of coke, iron oxide, limestone, and gaseous species. The heterogeneous reactions of coke conversion are limited by both kinetics and mass transport. Heat transfer between phases is modeled including both convection and radiation. The model predicts gas concentrations; mass flow rates; and temperature profiles of the solid, melt, and gas in the cupola, as well as heat loss to the water-cooled walls. Inputs to the model include the coke, rock, and blast air properties, the blast air amount, and the coke ...
The increasing diffusion of small-scale energy systems within the distributed generation (DG) paradigm is raising the need for studying the environmental impact due to the different DG solutions in order to assess their sustainability. Addressing the environmental impact calls for building specific models for studying both local and global emissions. In this framework, the adoption of natural gas-fueled DG cogeneration technologies may provide, as a consequence of cogeneration enhanced overall energy efficiency and of natural gas relatively low carbon content, a significant reduction of global impact in terms of CO2 emissions with respect to the separate production of electricity and heat. However, a comprehensive evaluation of the DG alternatives should take into account as well the impact due to the presence of plants spread over the territory that could increase the local pollution, in particular due to CO and NOx, and thus could worsen the ...
Electrical power is generated by steam turbines (steam being produced by coal, oil, gas or nuclear reactors), hydro units, gas turbines, internal combustion engines, jet engines, and pumped storage plants. Nuclear Power Plants generate only 15% of the total electrical power in the US. Nuclear Power Plants being cheaper to run are generally base loaded. The pumped-storage and gas turbine plants have ideal characteristics for peaking duty. In the pumping mode, pumped storage plants are used to provide additional system load and in the generating mode, they supply reactive power during peak load demands. Gas turbine plants have higher running costs, but are used as peaking units with a fast start capability. Fossil power plants need a minimum of 1 hour to stabilize expansion in the boiler and turbine generator. Due to a more competitive power supply market due to deregulation, most of the utilizes plan ...
Due to the advantages of the flexibility and economics in exploration and production of offshore liquefied natural gas (LNG), the floating production storage and offloading unit for liquefied natural gas (LNG-FPSO) has attracted wide attentions in recent years. The offloading system for LNG transportation from LNG-FPSO to LNG carrier is one of the most important parts in LNG-FPSO. The influences of the main parameters such as the mass flow rate and the height difference of the pipeline. on the performance of LNG offloading in offshore associated gas fields were investigated. A model based on a typical offshore LNG offloading system was first established and simulations were conducted. The governing equations were then used to evaluate the effects of parameters together with the simulation results. It was found that there was an economic mass flow rate for practical design on balance of the cost in pump ...
We investigate the thermodynamic and chemical structure of the intracluster medium (ICM) across a statistical sample of 20 galaxy clusters analysed with the Chandra X-ray satellite. In particular, we focus on the scaling properties of the gas density, metallicity and entropy and the comparison between clusters with and without cool cores (CCs). We find marked differences between the two categories except for the gas metallicity, which declines strongly with radius for all clusters (Z ~ r^{-0.31}), outside ~0.02 r500. The scaling of gas entropy is non-self-similar and we find clear evidence of bimodality in the distribution of logarithmic slopes of the entropy profiles. With only one exception, the steeper sloped entropy profiles are found in CC clusters whereas the flatter slope population are all non-CC clusters. We explore the role of thermal conduction in stabilizing the ICM and conclude that this mechanism alone is ...
The presented paper describes the formulation of the fractional mass balances which are used to calculate the concentration and size distribution of char in the balance cells of a circulating fluidized bed boiler. In case of using the shrinking core model additionally the distribution of conversion of the char particles is calculated. Basically two reaction models (a shrinking particle and a shrinking core model) are available to describe the combustion process. The model considers all essential physico/chemical phenomena (primary fragmentation, attrition, mass transfer to gas phase) which have to be taken into account for the description of the combustion process. The model is part of an overall simulation program for circulating fluidized bed boilers. This engineering simulator has been developed to return the main performance parameters of such systems like temperature along the furnace height, size distribution of ...
In this study the greenhouse impact of the total Finnish forest sector was considered, which means that the estimated emissions and sink effects from exported forest products were also included. The forest biomass is and seems to be in the next decades the most important factor in the carbon balance of the total forest sector. The development alternatives of forest industries and waste management practices has still a remarkable influence on the greenhouse impact of the Finnish forest sector. The waste management practices in the future has an important influence on the emissions but the exact net greenhouse impact of the landfills is still uncertain. However, the methane emissions from existing landfills can be reduced essentially by gas recovery. Increased incineration and energy recovery of wood waste (and replacing fossil fuel use by it) is also a future alternative for reducing the greenhouse effects in the forest sector. The sequestration ...
Under typical conditions found in Pressurized Fluidized Bed Combustion (PFBC), the calcination reaction of limestones is thermodynamically inhibited, and the sorbent reacts with SO{sub 2} by a direct mechanism. Direct sulfation reactivity of different Spanish sorbents was studied by high-pressure thermogravimetric analysis. It was found that the physical structure of the surface of the particles influence the sulfation behaviour of the sorbents. Total pore volume and pore surface area correlated well with the reactivity of the sorbents. Temperatures between 800 and 925{degree}C, and pressure between 12 and 25 bar, promoted an increase in reactivity, while the gas composition had no effect when changed from 15% CO{sub 2}, 3% O{sub 2}, 0.5% SO{sub 2}, balance N{sub 2} to 12% CO{sub 2}, 7% O{sub 2}, 0.5% SO{sub 2}, balance N{sub 2}. It was found that the unreacted shrinking core model could not satisfactorily describe the ...
Recognizing the importance of energy as a vital component in economic development, the Taiwanese government has been continuously revising its energy policy, seeking to balance economic development, energy supply, and environmental protection (3E). Some measures, in an attempt to achieve the 3E balance, were previously implemented in Taiwan; nevertheless, some unresolved issues departing from certain core principles of Taiwan's sustainable energy policy and an international initiative for a low carbon society remain. The aim of this paper is to examine the energy supply and demand structure of Taiwan and the present status of individual energy carriers (including coal, petroleum, natural gas and electricity). In addition, it investigates the current energy policy framework and its implementation in Taiwan, identifies unresolved issues regarding sustainable energy development, and formulates key policy solutions for certain ...
Results of an investigation aiming to study the effects of the burner cap design factors on flame stability are presented in this paper. Flame stability is an essential part of the operation of all domestic burners, including natural gas-fired cooktops. At high thermal inputs flame lifts are encountered above certain levels of primary aeration, whereas flashback only takes place at low thermal inputs, due to natural gas low flame speed, above certain levels of primary aeration. In this work, flame lift limits were measured at 3.3 kW thermal input and the highest primary aeration above which flame lifts started to become visible was the stability limit at this thermal input. Around 60% primary aeration was desired to minimize pollutant emissions. Turndown tests were done at 40% primary aeration. The `Factorial Experimental Design` method with statistical analysis was used. This enabled detection of interactions between factors as well as the ...
This paper presents part-load evaluation of a natural gas-fired chemical looping combustion (CLC) combined cycle with CO2 capture. The novel combined cycle employs an air-based gas turbine, a CO2-turbine and a steam turbine cycle. In this combined cycle, the CLC reactors replace combustion chamber of the gas turbine. The proposed combined cycle has a net plant efficiency of about 52.2% at full-load, including CO2 compression to 200 bar. The part-load evaluation shows that reducing the load down to 60% results in an efficiency drop of 2.6%-points. However, the plant shows better relative part-load efficiency compared to conventional combined cycles. The pressure in CLC-reduction and -oxidation reactors is balanced by airflow control, using a compressor equipped with variable guide vanes. A combination of control strategies is discussed for plant start-up and shutdown and for part-load when airflow ...
This study is part of a greater project from IPT (Sao Paulo's Institute of Technology), which foresaw an energetic use for elephant-grass (Pennisetum purpureum). Biomass gasification is an sustainable option for energy supply, which presents low pollutants emission rate and allows - through the global cycle of growing and consumption of feedstock (vegetables), a balance between consumption and production of carbonic gas, preventing an increase of the carbonic gas levels in the atmosphere. A gasifier was built with internal diameter of 400 mm and total height of 4600 mm . The equipment was tested for gasification of elephant-grass (Pennisetum purpureum) at a 100 kg/h rate. The equipment was tested and some constructive faults were detected. In the countryside, this biomass is commonly used for cattle feeding It was evaluated an adequate diesel-electric-generator. to work at hybrid regime, using 70% biomass ...
An approximate analyzing model was developed to predict the azimuth of zigzag streamline, the distribution ratio between two neighboring layers and the radial distribution among the layers of the gas passing through the shaft of blast furnace loaded in layers. The theoretical basis of the approximate analysis is composed of the material balance derived from the assumption that any stream line surrounded with two streamlines is isolated and no material transfer occurs through the tube wall, and of the energy theory that the stream tube and passage are formed so that the total pressure drop in the whole system is the minimum. The effects of the apparent angle of repose between two layers, the packing volume and the passage resistance on the non-uniform flow in the layer were evaluated on the basis of the model. The result calculated by the approximate analysis agrees with the result by the numerical analysis based on the equations of continuity ...
Norway is privileged with extensive resources of natural gas, oil and hydropower. Location of gas fired combined cycle (CC) power plants in Norway offers advantages due to the availability of natural gas from the Norwegian continental shelf and fairly low ambient temperatures, giving high fuel-to-electricity conversion efficiency. The continental shelf provides large storage capacity for CO{sub 2} in deep saline aquifers and in drained gas fields. In this paper the results of extensive work on CO{sub 2} capture carried out during the last years by Statoil in co-operation with several engineering contractors, are presented. The goal has been to develop a commercially viable concept for a combined cycle power plant including CO{sub 2} capture and sequestration. The main concept is based on CO{sub 2} capture from exhaust gas from a combined cycle power plant, using absorption by amine ...
This report presents the operating results for Run 243 at the Advanced Coal Liquefaction R and D Facility in Wilsonville, Alabama. This run was made in an Integrated Two-Stage Liquefaction (ITSL) mode using Illinois 6 coal from the Burning Star mine. The primary objective was to demonstrate the effect of a dissolver on the ITSL product slate, especially on the net C/sub 1/-C/sub 5/ gas production and hydrogen consumption. Run 243 began on 3 February 1983 and continued through 28 June 1983. During this period, 349.8 tons of coal was fed in 2947 hours of operation. Thirteen special product workup material balances were defined, and the results are presented herein. 29 figures, 19 tables.
The effects of the fluctuations of the Thai economy of the country's petroleum industry and the outlook for the future are discussed. Thailand witnessed enormous economic growth during the 1980s and the first part of the 1990s, but events since 1997 have caused it to stutter. However, the petroleum industry remains buoyant with measures to stimulate gas and oil production and moves to privatise and deregulate energy markets. Key statistics for Thailand, historical demand trends for petroleum, the impact of the 1997 Asian economic crisis, regulation of the Thai oil market, crude and condensate production levels, refinery capacity, new entrants to the refinery sector, the Thai refinery expansion programme, the product trade balance, the challenges of fuel reformulation and demand scenarios are considered.
Available in abstract form only. Full text of publication follows: In this study. simulation of carbon dioxide absorption by Sodium Hydroxide solution in a packed bed has been investigated. At first, mass and energy balances were applied around a differential height of the bed. So, the governing equations were obtained. Surface renewal theory by Danckwerts was used to represent the mass transfer operation Finally, by changing the operating parameters like solvent temperature, inlet gas composition pressure and height of the bed, the effect of these parameters on the absorption and the composition of carbon dioxide in exit stream have been investigated. (authors)
Using air as a carrier gas is common in humidification?dehumidification desalination processes. A computer program was written using mass and energy balances for modeling the process behavior. The parameters considered in this work were inlet air and fresh water recycle temperatures, inlet air flow rate, saline water and fresh water recycle flow rates, and saline water to air flow ratio. Results of simulation showed that increasing inlet air and fresh water recycle flow rate increases fresh water production. It was also found that heating the inlet air to humidification column or cooling the inlet water to dehumidification column increases the production rate but increasing water to air flow ratio in a humidifier leads to a lower production rate. The predicted effects of the parameters on ...
Main driver of the operation costs of agricultural biogas plants are substrate costs. The assessment of the biogas potential of different crops is carried out after ensiling and related to the DM content of the silage. This is insufficient for practical economic calculation due to prior dry mass losses during ensiling and aerobic deterioration. By the use of balancing trials process related dry mass losses can be estimated. In dependence of the deterioration time methane losses of 7,2 - 25,9% were evaluated. The methane losses match with the dry mass losses calculated according to Honig. (orig.)
Ten subjects balanced their own body or a mechanically equivalent unstable inverted pendulum by hand, through a compliant spring linkage. Their balancing process was always characterized by repeated...Full Text Available
Mucociliary transport so critical in nasal, paranasal sinus, and middle ear physiology is impaired in chronic sinsusitis and otitis media by factors such as increased mucus viscoelasticity, decreased ciliary area, and primary or secondary ciliary immotility. We reviewed the pathophysiology of primary ciliary dyskinesia, otitis media with effusion, chronic sinusitis, and allergic rhinitis in terms of mucociliary transport. Subjects with primary ciliary dyskinesia may experience recurrent middle ear infection, chronic airway infection, predominantly lower-lobe bronchiectasis, male sterility, or situs inversus. Primary ciliary dyskinesia is sometimes difficult to diagnose in cases without situs inversus. Nasal nitric oxide concentration in such patients decreases, although why is unclear. Mutations may involve dynein arm intermediate chain 1 (DNAI1) or dynein arm heavy chain 5 (DNAH5). Mucociliary clearance decreases more in those with otitis ...
DescriptionThis project is part of the BBSRCs special initiative on plant and microbial metabolomics. The project will primarily focus on the trichothecene mycotoxin producing Ascomycete fungus Fusarium graminearum (Fg) which causes ear blight disease of small grain cereals. The project aims to explore the metabolome of various wild-type and single gene deletion Fg strains and to compare some of these with the identical gene mutation in the budding yeast, S. cerevisiae (Sc) and the saprophytic filamentous [continued...
A proton exchange membrane fuel cell (PEMFC) must maintain a balance between the hydration level required for efficient proton transfer and excess liquid water that can impede the flow of gases to the electrodes where the reactions take place. Therefore, it is critically important to understand the two-phase flow of liquid water combined with either the hydrogen (anode) or air (cathode) streams. In this paper, we describe the design of an in situ test apparatus that enables investigation of two-phase channel flow within PEMFCs, including the flow of water from the porous gas diffusion layer (GDL) into the channel gas flows; the flow of water within the bipolar plate channels themselves; and the dynamics of flow through multiple channels connected to common manifolds which maintain a uniform pressure differential across all possible flow paths. These two-phase flow effects have been studied at relatively low operating ...
By increasing the price of crude oil and natural gas and the decline in their stock a possibility of more intense use of coal reserves as a feedstock not only for energy purposes but also as a feedstock source for other industries, mainly chemical and steel industry, is opening up. At present brown coal exploited in the Czech Republic is explicitly burned in the power sources of various outputs. Coal pyrolysis under the defined conditions may be an outstanding way of non-energetic brown coal processing. The target of our work was to determine the behaviour of various types of brown coal from the North Bohemian Basin under the pyrolysis up to the temperature 750{sup o}C. At the same time, qualitative parameters of the pyrolysis products in dependence on the features of the input brown coal were observed. Various types of brown coal were used for the pyrolysis tests differing mainly in the content of ash, sulphur and tar. Within the work mass ...
Products of a power plant flue gas desulfurization scrubber are discharged into a pond as sludge consisting of calcite (initial delta13C 3.2-3.8 per thousand), gypsum (initial delta34S 7.6-8.6 per thousand), and aqueous solution. Reducing conditions exist below a boundary that appears to move vertically as a function of changes in pond water level. Under reducing conditions, bacteria partially reduce aqueous sulfate to low-delta34S sulfide, consuming organic carbon and generating low-delta13C bicarbonate. Under oxidizing conditions, sulfide is converted to sulfate, leading to calcite dissolution, gypsum precipitation, and isotopic re-equilibration of remaining calcite with dissolved bicarbonate near the pond surface. The gypsum has delta34S near 6 per thousand, and calcite has delta13C as low as -1.7 per thousand; the changes from initial values correspond to predictions based on isotopic balance and reaction stoichiometry. The pond largely ...
The lipid obtained by the toluene extraction of a dried raw Atlanta sewage sludge by the Soxhlet method, was pyrolyzed over activated alumina at atmospheric pressure. A range of weight hourly space velocities (WHSV) from 0.22-1.60/h and a range of temperatures from 400-480[degree]C were selected. A 70 wt % yield of light liquid hydrocarbons was obtained at a WHSV of 0.46/h and 450[degree]C. The sulfur and nitrogen contents of the pyrolysis products were much lower than products from direct liquefaction of sludge. Infrared spectra and [sup 13]C nuclear magnetic resonance confirmed the absence of carbonyl groups in the products. Gas chromatography showed a uniform hydrocarbon chain length distribution across the C[sub 7] to C[sub 17] mass range. The gas product consisted mainly of carbon dioxide and hydrocarbons. Lauric acid was used as a model to study the decarboxylation. The effects of catalyst loading and catalyst moisture content were ...
Two important greenhouse gases, CO{sub 2} and CH{sub 4}, are closely connected to the carbon cycling of wetlands. Although virgin wetlands are mostly carbon accumulating ecosystems, major proportion of the CO{sub 2} bound annually in photosynthesis is released back to the atmosphere. Main portion of the carbon cycling in wetlands is quite fast while a small proportion of carbon diffusing from soil is released from organic matter, which may be ten thousand years old. Methane is formed in the anaerobic layers of wetlands, from where it is released gradually to the atmosphere. The decomposition in anaerobic conditions is very slow, which means that usually only a few percent of the annual carbon cycling takes place as methane. Research on CO{sub 2} fluxes of different virgin and managed peatlands was the main topic of this project during the first phase of SILMU. The measurements were made during two seasons in varying conditions in c. 30 study sites. In the second phase of SILMU the ...
A thermal and economic study, carried on by using the first and second law of thermodynamics concepts demonstrated the economic feasibility of the cogeneration system, and proposed modifications to be done in the studied cryogenic plant, a typical T-240 NA MPL3 plant. The thermodynamic analysis showed that the second law efficiency of the processes could be improved, together with a 12% electric energy consumption reduction. Four cogeneration schemes were analyzed with both the first and second laws of thermodynamics and, then, the economic analysis was performed. Rankine, Brayton, Otto and Combined gas-steam basic cycles were used in this analysis.The combined gas-steam cycle was shown to be more economically feasible than others. Thermal and electric loads were well balanced, resulting in a higher second law efficiency. Although the initial investment for the modification was higher, the savings resulted to be higher, ...
In relation to considerations on composition of gas produced by coal gasification, the HYCOL hydrogen generation process data were analyzed. From the fact that CO concentration (Y) decreases linearly with CO2 concentration (X), element balance of gasification of reacted coal was used to introduce a reaction analysis equation. The equation includes a term of oxygen excess {Delta}(amount of oxygen consumed for combustion of CO and H2 in excess of the theoretical amount), derived by subtracting the stoichiometric oxygen amount used to gasify coal into CO and H2 from the consumed oxygen amount. The {Delta} can be used as a reference to oxygen utilization efficiency. An equation for the {Delta} was introduced. Also introduced was a term for steam decomposition amount derived by subtracting the generated steam from the supplied steam. These terms may be used as a clue to permeate into the gasifying reaction process. This suggestion was discussed by ...
This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the ...
As part of The International Northern Sea Route Programme (INSROP), Subprogram III, Trade and Commercial Shipping, a study has been made concerning seaborne export of liquefied petroleum gas (LPG) from the Northern Russia, especially the West Siberian fields in Tyumen. The main purpose of the total project III.0703, part 2 and this study is to evaluate the economic viability of seaborne export from this area to the European region, mainly with the use of a special ice-strengthened LPG vessel, constructed and designed for such seaborne operations. This study concentrates on both seaborne LPG transportation, the demand and supply for seaborne LPG in the world and marine transportation of LPG from the West Siberian fields. Another purpose is to see which regions are potential exporters, importers and buyers of seaborne export of LPG from Tyumen. Currently large quantities of liquefied gas are flared off at the West Siberian fields due to ...
Oregon State University (OSU) and the Pacific Northwest National Laboratory (PNNL) were funded by the U.S. Department of Energy to conduct research focused on resolving the key technical issues that limited the deployment of efficient and extremely compact microtechnology based heat actuated absorption heat pumps and gas absorbers. Success in demonstrating these technologies will reduce the main barriers to the deployment of a technology that can significantly reduce energy consumption in the building, automotive and industrial sectors while providing a technology that can improve our ability to sequester CO{sub 2}. The proposed research cost $939,477. $539,477 of the proposed amount funded research conducted at OSU while the balance ($400,000) was used at PNNL. The project lasted 42 months and started in April 2001. Recent developments at the Pacific Northwest National Laboratory and Oregon State University suggest that the performance of ...
CT and MRI of acquired abnormalities of the inner ear and cerebello-pontine angle present themselves with very typical findings. The imaging should be adapted to the pathology looked for and either CT or MRI should be used alone or in combination.CT, especially high resolution CT (HRCT), provides an excellent bone contrast, while MRI has a much superior soft tissue contrast. Acute inflammatory changes of the inner ear are solely depicted by contrast-enhanced MRI. HRCT excellently depicts osseous changes of the inner ear and cerebellopontine angle such as chronic ossifying labyrinthitis occurring after acute labyrinthitis, otosclerotic or traumatic changes. Tumorous changes not yielding to bony changes are best delineated by MRI. Posttraumatic hemorrhage and chronic fibrotic changes within the labyrinth are depicted by MRI, only. In conclusion HRCT and MRI are excellent methods to delineate acquired abnormalities of the ...
In conjunction with the US Enviromental Protection Agency sponsored Shawnee test program, Bechtel National, Inc., and the Tennessee Valley Authority jointly developed a computer model capable of projecting preliminary design and economics for lime- and limestone-scrubbing flue gas desulfurization systems. The model is capable of projecting relative economics for spray tower, turbulent contact absorber, and venturi-spray tower scrubbing options. It may be used to project the effect on system design and economics of variations in required SO/sub 2/ removal, scrubber operating parameters (gas velocity, liquid-to-gas (L/G) ration, alkali stoichiometry, liquor hold time in slurry recirculation tanks), reheat temperature, and scrubber bypass. It may also be used to evaluate alternative waste disposal methods or additives (MgO or adipic acid) on costs for the selected process. Although the model is not intended to project the ...
A Lurgi baseline study was requested by the DOE/GRI Operating Committee of the Joint Coal Gasification Program for the purpose of updating the economics of earlier Lurgi coal gasification plant studies for the production of substitute natural gas (SNG) based on commercially advanced technologies. The current study incorporates the recent experience with large size Lurgi plants in an effort to improve capital and operating costs of earlier plant designs. The present coal gasification study is based on a mine mouth plant producing 250 billion Btu (HHV) per day of SNG using the Lurgi dry bottom coal gasification technology. A Western subbituminous coal was designated as the plant food, obtained from the Rosebud seam at Colstrip, Montana. This study presents the detailed description of an integrated facility which utilizes coal, air, and water to produce 250 billion Btu (HHV) per day of SNG. The plant consists of coal handling and preparation, twenty-six Lurgi dry ...
US Department of Energy (DOE) Order 5820.2A (DOE, 1988) requires performance assessments on all new and existing low-level radioactive waste (LLW) disposal sites. An integral part of performance assessment is estimating the fluxes of radioactive gases such as radon-220 and radon-222. Data needs pointed out by mathematical models drive site characterization. They provide a logical means of performing the required flux estimations. Thorium-230 waste, consisting largely of thorium hydroxide and thorium oxides, has been approved for disposal in shallow trenches and pits at the LLW Radioactive Waste Management Site in Area 5 of the Nevada Test Site. A sophisticated gas transport model, CASCADR8 (Lindstrom et al., 1992b), was used to simulate the transport and fate of radon-222 from its source of origin, nine feet below a closure cap of native soil, through the dry alluvial earth, to its point of release into the atmosphere. CASCADR8 is an M-chain ...
'The use of personal protective clothing that covers the head is a common practice in many industries. Such personal protective clothing will impact the sound pressure level and the frequency content of sounds to which the wearer will be exposed. The use of such clothing, then, may impact speech and alarm audibility. A measure of the impact of such clothing is its insertion loss. Insertion loss measurements were performed on four types of personal protective clothing in use by Westinghouse Savannah River Company personnel which utilize cloth and plastic hood configurations to protect the head. All clothing configurations tested at least partially cover the ears. The measurements revealed that insertion loss of the items tested was notable at frequencies above 1000 Hz only and was a function of material stiffness and acoustic flanking paths to the ear. Further, an estimate of the clothing''s noise reduction rating ...
A field study was conducted to investigate the absorption of various elements into oats and carrots cultivated in brown forest soil after three years' applications of chemical fertilizer and two types of sewage sludge compost mixed with sawdust (SD compost) or rice husk (RH compost). The results obtained in this study are summarized as follows. 1) The application of SD compost led to a significant increase on the concentrations of Mn, Zn, Ag and Ba in oat root, of Zn and Br in oat shoot, of Cl and Zn in oat ears, of Mg, Sc, Mn, Zn, Br, Ba and La in carrot peel, of Mn, Fe, Co and Zn in carrot edible portion and of Na, Sc, Mn, Fe, Co and Sm in carrot shoot. 2) The application of RH compost increased the concentrations of Mn, Zn, and Ag in oat root, of K, Cr, Mn, Zn and Br in oat shoot, of Zn and Br in oat ears, of Mg, Mn and Br in carrot peel, of Cl, Mn, Zn and Br in carrot edible portion and of Na, Mn, Zn, Br and Sm in carrot shoot. (author)
This report presents the operating results for Run 244 at the Advanced Coal Liquefaction R and D Facility in Wilsonville, Alabama. This run was made in an all-distillate Integrated Two-Stage Liquefaction (ITSL) mode using Illinois 6 coal from the Burning Star mine. The primary objective was to demonstrate the effects of temperature programming an aged catalyst batch on the ITSL product slate, especially on the net C/sub 1/-C/sub 5/ gas production and hydrogen consumption. Other objectives were to demonstrate the effect of fresh catalyst addition and to age the catalyst batch for an extended run with catalyst addition and withdrawal. Run 244 began on 4 July 1983 and continued through 27 September 1983. During this period, 182.9 tons of coal was fed in 1872 hours of operation. Seven special product workup material balances and two hydrotreater balances were defined, and the results are presented herein. From 27 to 30 ...
The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas will be described in this paper. The pre- and postoperative imaging of the temporal bone was performed with HRCT and MRI. HRCT and MRI were performed in the axial and coronal plane. MRI was done with T2 weighted and T1 weighted sequences both before and after the intravenous application of contrast material. All imaging findings were confirmed clinically or surgically. The preoperative cholesteatoma-caused complications depicted by HRCT included bony erosions of the ossicles, scutum, facial canal in the middle ear, tympanic walls including the tegmen tympani, and of the labyrinth. The preoperative cholesteatoma-caused complications depicted by MRI included signs indicative for labyrinthitis, and brain abscess. Postoperative HRCT depicted bony erosions caused by recurrent ...
We irradiated proton beams on the ears of rabbits and the Harding-Passey mouse melanoma and observed their morphological change. We used 52 MeV proton beams from the INS-FM cyclotron. We adjusted the energy of the proton beams to be at the plateau part of the Bragg curve, at the half-way point of the Bragg peak, and at the Bragg peak. The amount of radiation was 5000rad in each case. The Harding-Passey mouse melanoma was transplanted into the subcutan of a three week old mouse. In this experiment, we used tumors, the diameter of which grew up to 1.5-2cm in 2-3 weeks after the transplantation. Using the jroscope, we observed both lightly and severely damaged cells. Using proton irradiation with the Bragg peak located at depth of 1mm in the rabbit's ears, we studied the change in the tissue. Irradiated epidermis fell off and was eroded because of radiation damage, but the rear surface of the rabbit's ears ...
Throughout the 1990's to year 2000, energy integration, and particularly natural gas integration, was seen as a major goal in the southern cone of South America. The regional perspective for energy was related to an even more challenging objective - Latin American economic integration, which was quickly moving forward by the constitution of Mercosur, the free trade zone built by Argentina, Brazil, Uruguay and Paraguay, and also having Bolivia and Chile as special partners. Mercosur was getting stronger and becoming a successful political project. Trade conflicts existed, but they were considered normal and nobody would disagree about the viability of Mercosur. By the beginning of the 21. century, the economic integration process in South America was already advancing timidly as compared to the impetus from the beginning of 1990's. Mercosur started facing complex and almost insurmountable challenges after the numerous global financial crises (from 1998 to 2003) had ...
A virtual balancing axis arrangement is described for multi-cylinder reciprocating piston machines for effectively balancing out imbalanced forces and minimizing residual imbalance moments acting on the crankshaft of such machines without requiring the use of additional parallel-arrayed balancing shafts or complex and expensive gear arrangements. The novel virtual balancing axis arrangement is capable of being designed into multi-cylinder reciprocating piston and crankshaft machines for substantially reducing vibrations induced during operation of such machines with only minimal number of additional component parts. Some of the required component parts may be available from parts already required for operation of auxiliary equipment, such as oil and water pumps used in certain types of reciprocating piston and crankshaft machine so that by appropriate location and dimensioning in accordance with the ...
Proper balance control is a key aspect of acitivities of daily living. The aim of this study was to determine the contribution of body weight to predict balance stability. The balance stability of 59 male subjects with BMI ranging from 17.4 to 63.8kg/m2 was assessed using a force platform. The subjects were tested with and without vision. A stepwise multiple regression analysis was used to determine the independent effect of body weight, age, body height and foot length on balance stability (i.e., mean speed of the center of foot pressure). With vision, the stepwise multiple regression revealed that body weight accounted for 52% of the variance of balance stability. The addition of age contributed a further 3% to explain balance control. Without vision, body weight accounted for 54% of the...
This report presents the operating results for Run 245 at the Advanced Coal Liquefaction R and D Facility in Wilsonville, Alabama. This run was made in an all-distillate Integrated Two-Stage Liquefaction (ITSL) mode using Illinois 6 coal from the Burning Star mine. The primary run objective was to obtain steady-state ITSL performance by replacing spent HTR reactor catalyst with fresh, sulfided catalyst. Secondary objectives were to maintain an all-distillate (minimum resid production) product slate and to demonstrate the effects of catalyst addition on the net gas production and hydrogen consumption. Run 245 began on 7 November, 1983, and continued through 12 February, 1984. During this period, 179.0 tons of coal was fed in 2045 hours of operation. Eight special product workup material balances were defined, and the results are presented herein. 6 references, 28 figures, 20 tables.
The possibility of a positive agricultural use of flue gas filter ash from brown coal power plants is investigated. The suggested measure is mixing ash dump surfaces with extremely acidic spoil bank soils, which balances the high pH value of the alkaline ash and contributes to improved nutrient and soil sorptive conditions. Optimum quantity of spoil bank sands in the mixture with ash is between 10% and 40%. The optimum quantity must be determined for each type of ash considering improvement of soil chemical conditions and water retention capacity. Filter ash properties vary widely; the required amount of spoil bank sand added to investigated ash surfaces near 3 brown coal power plants was between 25% and 30% of the mixture. The same favourable soil and ash mixture can be produced by adding 60% to 75% filter ash to acidic raw spoil bank soil surfaces forming a top soil layer in a thickness of minimum 60 cm. Tests of plant growth showed high crop ...
Considering the present situation of thermal energy in Romania and having in view the fact that Romania is a Kyoto protocol signatory state one estimates that the development of the nuclear energy will have a promising growth. According with the statement of the National Energetic Observer, Romania became a net energy resource importer for the past 30 years and the estimations about the future are not optimistic. The finite reserves of fossil fuel (coal and natural gas), the gradual reduction of their share in the national energy balance with a tendency to become insignificant after 2025, as well as the present situation of the thermal power plants which are already beyond their operation life, all these indicate the nuclear energy as being the most reliable and sustainable future source for thermal energy production. Having in view these circumstances the paper aims at a short presentation of the existing nuclear solutions for district ...
The mining and energy industry is under assault today for reasons that have less to do with alleged technical failures and much more to do with ethical complaints about a rate of growth in population that industrial products from mining resources have made possible. The political agendas of Western industrialized nations have been driven during the past quarter century by those whose social philosophy advocates a new ethic of biocentric equality, whereby humans must be forced to being `living as if Nature mattered`. A Green ethic requires that `a violent, plundering humankind` must abandon its alleged rape of the earth and derive its ethical norms from pre-existing ecosystemic harmonies to preserve a fragile and precarious balance existing in Nature. From the perspective of history, there is nothing new about such complaints, current complaints about the use of fossil fuels and pollution from mining, echo similar complaints in past periods. Current Green thinking ...
A zirconium alloy comprising from 0.8 to 1.6wt% of Sn, from 0.17 to 0.25wt% of Fe, from 0.15 to 0.25wt% of Cr and from 0.01 to 0.08wt% of Ni and Si at a concentration of 120ppm or lower as an impurity and the balance of Zr is melted into cast pieces and then subjected to an #beta# annealing. It is controlled so as to satisfy Fe + Cr + Ni #<=# 0.52wt%. Then, rolling and annealing are applied so that the total heat injection amount #SIGMA#A_i to the materials is within a range of from 1 x 10"-"1"9 to 1 x 10"-"1"7. #SIGMA#A_i = #SIGMA#t_i #centre dot# exp(-Q/RT_i), in which t_i represents processing time (hour) at an ith heat treatment step after the #beta# annealing, T_i represents a processing temperature (K) in the step i. Q represents an activating energy, R represents a gas constant, and Q/R 40,000. (I.N.).
The share of peat in the primary energy supply in Finland in 1996 was about 6.5 % and the area used for peat production was about 535 km"2, corresponding to about 0.5 % of the original peatland area of Finland. Fuel peat production is hence a significant form of using natural resources. About 1.4 % of the total peatland area has been reserved for peat production. Approximately 95 % of the peat excavated in Finland is used as fuel peat, and 5 % as horticultural peat. As raw material and fuel peat can be considered to be slowly renewable material. The environmental impacts of fuel peat production, transportation and peat combustion were evaluated in this research by methods used in life-cycle assessment. Preparation and production phases of peat production areas, fuel peat transportation to power plants, combustion of peat in power plants, and disposal of the ashes formed the basis for the investigation. Data collected in 1994-1996 was used as the basic material in the research. Special ...
Increasingly stringent pollution regulations have spurred a broad interest in the reduction of engine emissions. Two strategies can be considered: after-treatment or engine emissions reduction. For Diesel engines, after-treatment has a high cost induced by the required technology and implementation issues. In this context, the Highly Premixed Combustion combustion mode (HP C) has emerged as a topic of major interest in recent years. It represents one of the most promising ways for new generation of CI engines using high Exhaust Gas Recirculation (EGR) rates. Experimentation on the test bench brought the proof of significant emission reduction. However, actual vehicle implementation implies frequent transient which fall far beyond steady state experimentation on the test bench. Several key challenges have to be addressed. With this combustion technology; accurate torque balancing at all engine modes is a requirement. Even slight unbalance ...
Cu/YSZ cermet (40 and 60 vol.% Cu powder with balance YSZ) is a more economical cathode material than the conventional Ni/YSZ cermet for high temperature electrolysis (HTE) of water vapor and it was successfully fabricated by high-energy ball-milling of Cu and YSZ powders, pressing into pellets (o 13 mm x 2 mm) and subsequent sintering process at 700 deg. C under flowing 5%-H{sub 2}/Ar gas. The Cu/YSZ composite material thus fabricated was characterized using various analytical tools such as XRD, SEM, and laser diffraction and scattering method. Electrical conductivity of sintered Cu/YSZ cermet pellets thus fabricated was measured by using 4-probe technique for comparison with that of conventional Ni/YSZ cermets. The effect of composite composition on the electrical conductivity was investigated and a marked increase in electrical conductivity for copper contents greater than 40 vol.% in the composite was explained by percolation threshold. ...
This article describes a methodology to determine the best strategy in an open bid, where oil and gas fields are the targets for exploration. Based upon the previous bid rounds for a given specific area - the Campos Basin, for that matter -, the data were statistically treated to fit a probability density function, modelling the value of bids offered by the competing companies. By means of techniques and concepts pertaining to Game Theory a balance matrix was built for values of bids made by companies as a function of the company alone in assumed bid rounds. At the end of each british auction, participants of this simultaneous game, using the rationality principle, aimed at winning the tender on the oil field aimed for, through the use of better answers with respect to its rival competitor. The game goal was maximize return on investment purchase in the decisions of lease blocks purchases in the auctions, or to try minimize its opponents gains. ...
The overall objective of this research work was to prepare hydrocracking catalysts using amorphous silica-alumina (ASA) supports in combination with USY and {beta}-zeolites. Three supports: namely silica-alumina, USY and {beta}-zeolites were selected to prepare the extrudates using AP-1 as a binder, while two metal pairs: namely Ni-W and Ni-Mo were loaded on the extrudates through co-impregnation using incipient wetness technique. The catalysts were then calcined at 550C for 2h. The catalysts were tested in a fixed-bed flow reaction system for their activity, using desulfurized vacuum gas oil (DS-VGO) as a feedstock. The catalytic evaluation results of the catalysts showed that {beta}-zeolite alone and in combination with the ASA used in this study, has a potential as a support for developing heavy oil hydrocracking catalysts. A balance of weak and strong acidities of {beta}-zeolite provides control cracking, while high surface area and bigger ...
Coal demineralization mechanism and its optimum condition were studied by hydrothermal reaction between Ca(OH)2 and quartz as a coal demineralization model. In experiment, the mixture of powder quartz and Ca(OH)2 water slurry was subjected to reaction in an autoclave under spontaneous pressure at 175-340{degree}C. After dried in N2 gas atmosphere at 105{degree}C, the reaction product was analyzed by X-ray diffraction, thermo-balance and differential thermal analysis. In measurement of quartz conversion, the specimen was analyzed by X-ray diffraction after removal of bound water by heat treatment at 850{degree}C. The mixture of clean coal deashed by NaOH and a fixed amount of quartz was also used as specimen for experiment. As the experimental result, dicalcium silicate hydrate was mainly produced at 175{degree}C, and the product changed into xonotlite through tobermorite by longer treatment at higher temperature. For complete reaction of ...
ObjectivesThe specific objectives of the research are to: 1. Determine the concentrations of N2O, NO and NO2 in tropical coastal waters in relation to nutrients and salinities. 2. Determine, with excess nitrate present, the potential for nitrate reduction and denitrification in sediments along tropical estuaries, and whether NO, NO2, N2O, N2 or NH4+ are significant products. 3. Establish the balance between denitrification, nitrate ammonification and anammox in tropical estuarine sediments, relative to [continued...]DescriptionThe coastal zone is extremely important in the biogeochemical processes which control the natural cycle of elements of the Earth. In particular, the coastal zone contributes significantly to the nitrogen cycle, removing nitrogen washed in from the land by rivers and so reducing its fertilizing impact on the coastal seas. However, these removal processes, driven by microorganisms, also contribute to the formation of nitrogen gases, some of ...
Low pressure silane plasmas are known for their ability to synthesize silicon nanoparticles via gas phase nucleation. While in the past this particle formation has often been considered from the viewpoint of a contamination problem in semiconductor processing, we here describe a silane low pressure plasma that enables the synthesis of highly oriented, cubic-shaped silicon nanocrystals with a rather monodisperse size distribution. These silicon nanocubes have successfully been used in the manufacture of single nanoparticle vertical transistors. We discuss the advantages of this new paradigm of building nanoelectronic devices. The plasma synthesis process is characterized in more detail than in prior work. The particle nucleation, growth and shape evolution are studied. Results indicate that the process provides two spatially distinct zones: a diffuse plasma for particle growth and a constricted plasma zone for particle annealing. Measurements of the plasma ion ...
Alter both oil crisis, of 1973 and 1979, a bad effect of the elevated costs and continuously increment of the oil prices was noted, for this reason, the interest for renewable energies sources widely available in developing countries was increased. All over the world, governments have formulated main objectives for energies savings and search for friendly technologies, taking into account the effects related with the environment. The imminent scarcity of fossil fuels has made humanity the rational use of primary energies, as a result of these; new plants with improved technology have been conceived taking into account energy savings and efficiency improvement. In this context, biomass gasification technologies are important, since they consist in techniques of parallel production of electricity and heat from just one fuel. This work consists in the development of a gasifier down draft of 100 kW for an internal combustion engine, which includes its sizing process and its energy ...
Disposable nappies (diapers) have been satisfactorily demineralized and used for the collection of excreta from infants and young children during mineral and trace metal balances. It was possible to...Full Text Available
Subjects covered in this section are: (1) PCAST panel promotes energy research cooperation; (2) Letter issued by ANS urges funding balance in FFTF restart consideration and (3) FESAC panel releases report on priorities and balance.
Ghil, M., B. Shkoller, and V. Yangarber, 1977: A balanced diagnostic system compatible with a barotropic prognostic model. M. Weather. Rev. , 105, 1223- 1238, ...
Mass Balance and Present-day Antarctic Rebound and Gravity Change. Erik R. Ivins , Eric Rignot, Xiaoping Wu, Carol A. Raymond (JPLKaltech, 300-233,4800 Oak ...
Provides standardized energy balance sheets expressed in a common unit of tons of oil equivalent for all OECD countries as well as the regions: OECD total, IEA, North America, Pacific, OECD Europe, EEC and Yugoslavia.
Understanding the pathogenesis of obesity is now more important than ever, given the remarkable world-wide epidemic. This paper explores the potential role of core temperature in energy balance, and...Full Text Available
based sensors, and a host of other scientific ... and change the balance between incoming and outgoing energy. ..... have launched on a larger rocket, flown in ...
Summary: Analysis of biological networks requires assessing the statistical significance of network-based predictions by using a realistic null model. However, the existing network null model, switch randomization, is unsuitable for metabolic networks, as it does not include physical constraints and generates unrealistic reactions. We present JMassBalance, a tool for mass-balanced randomization and analysis of metabolic networks. The tool allows efficient generation of large sets of randomized networks under the physical constraint of mass balance. In addition, various structural properties of the original and randomized networks can be calculated, facilitating the identification of the salient properties of metabolic networks with a biologically meaningful null model. Availability and Imp...
A whole sequence of the parameters of the combined heat and power system (KWK) is described which enables a comparison between the electricity and heat demand of a consumer and the energy availability through a combined heat and power system. Proceeding from this, a thermodynamic model of a steam and gas process with combined heat and power is introduced which is based on an exergetic balancing of the subsystems of the process. In this way, the varying thermodynamic quality of the energy flows occuring in the process will be taken into consideration so that the results of the model correspond in any case with the second law of thermodynamics. (orig.) [Deutsch] Es wird ein vollstaendiger Satz von Kenngroessen der Kraft-Waerme-Kopplung (KWK) beschrieben, mit dessen Hilfe der Strom- und Waermebedarf eines Verbrauchers mit der Energiebereitstellung durch eine KWK-Anlage verglichen werden kann. Darauf aufbauend wird ein thermodynamisches Modell des ...
The design of separation devices, particularly for solvent-based selective removal of H{sub 2}S from CO{sub 2}, requires an accurate mathematical model. Unfortunately, this requirement for high accuracy is often in conflict with the need for efficient computation. The addition of more and more complicated analyses, such as a move from Henry's law to a method incorporating gas and liquid activities for computing vapor liquid equilibria, may give a more accurate solution, but only at the cost of decreased computational efficiency. The efforts in this work have been directed toward two goals. The first was to develop an accurate mathematical model for the aqueous methyldiethanolamine (MDEA) system. The steady-state packed column model developed in this work has been tested with data from Schubert (1988) to verify its accuracy. The second goal was to modify the model to improve its computational efficiency. Areas such as vapor-liquid equilibrium calculations, ...
Restructured power markets require concepts not only for extending the lifetime of existing plants, but also concepts for reducing the life-cycle costs of existing older steam power plants in order to remain competitive with the most modern and advanced power generation technology such as combined cycle power plants. Out of the broad range of methods to extend service life and increase availability, and to increase power output and efficiency, this paper focuses on full repowering. Full repowering replaces the old fired boiler with gas turbine(s) and heat-recovery steam generators (HRSG) as heat input to the existing bottoming cycle and reuses the steam turbine (ST) condenser and further balance of plant (BOP) equipment. The potential offered by this concept is demonstrated. Repowering and modernization projects are executed if they result in economic benefits for the operator. Investment decisions need to be prepared based on an estimate or ...
In this study, considering that Hg(2+) in wet flue gas desulfurization (FGD) systems can easily be reduced and then released into atmosphere, causing secondary pollution, the researches about Hg(2+) reduction and Hg(0) re-emission mechanism were carried out. The effects of several experimental parameters on the reduction were studied, including initial pH, temperature, and concentrations of Cl(-) and S(IV). Our experimental results indicated that Cl(-) had a restraining effect on the Hg(2+) reduction and Hg(0) re-emission, after 24h reaction, only 20.5% of Hg(2+) was reduced with 100mM Cl(-) in simulated desulfurization solution. Cl(-) can slow Hg(2+) reduction and Hg(0) re-emissions dramatically through changing reaction mechanism, with formation of new intermediate: ClHgSO(3)(-), which can decompose to Hg(0), but much more slowly than Hg(SO(3))(2)(2-) or HgSO(3). Simulating the conditions of the practical application (initial pH 5, T=50 degrees C, S(IV)=5 mM, ...
Using infra-red (IR) thermography, power loads onto the MKII Gas-Box divertor targets have been investigated in Type-I ELMy H-Mode plasmas at JET in medium current discharges (Ip = 2.6 MA and BT = 2.7 T). Heat fluxes are calculated from the measured divertor target tile surface temperatures taking into account the influence of co-deposited surface layers on tile surfaces. This is particularly important when estimating the energy deposition during transient events such as ELMs. Detailed energy balance analysis is used, both from IR and tile embedded thermocouples, to demonstrate an approximately constant ELM-averaged in/out divertor target asymmetry of ?0.55 and to show that the ELM in/out energy deposition ratio ranges from 1 : 1 to 2 : 1. The inter-ELM in/out ratio is close to the ELM-averaged value at low pedestal collisionalities and decreases down to values close to zero when the inner target plasma detaches at the highest pedestal ...
Due to the 'novel forest diseases' the political parties of the Federal Republic of Germany unanimously attend to the reduction of emissions. The transportation sector is considered to be a major emission source. A study discussed in the publication abstracted did therefore aim at giving a detailed account and description of the recently ratified technical requirements and tax credits expected to reduce vehicle exhaust gas air pollution. Moreover, the study researches into the regulations' importance as to the low emission properties of individual automobiles. Based on the results obtained the study arrives at assumptions as to emissions to be expected from the transportation sector. It tries to assess the financial import with respect to the individual citizen, overall internal revenues and federal motor vehicle taxes. The introductory chapter is followed by a review of emissions caused by vehicle exhaust gases along with a description ...
Delayed endolymphatic hydrops (DEH) is a unique disorder characterized by fluctuating otologic symptoms in the setting of preexisting unilateral deafness. The symptoms include aural fullness, fluctuating hearing, and/or episodes of vertigo similar to those observed in Meniere disease and may occur ipsilateral or contralateral to the previously deafened ear. In most reported cases, the unilateral deafness has been a profound sensorineural hearing loss with a sudden onset that has been variously attributed to bacterial or viral labyrinthitis, acoustic or cranial trauma, otosclerosis, and congenital CMV infection. Familial occurrence of the syndrome has not previously been reported in the literature. In this report, we describe two possible familial instances of delayed DEH. These patients ra...
The dipteran parasitoids Therobia leonidei and Homotrixa alleni (Tachinidae) use acoustic cues to locate their calling tettigoniid (Ensifera, Orthoptera) hosts. The sexually dimorphic tympanal organs of both fly species are located at the prosternum. For comparison a homologous chordotonal organ in the non-hearing fly Phormia regina, Meigen (Phoridae) is also described. The scolopidial sense organs of the ears have approximately 180 sensory cells in Th. leonidei and 250 cells in H. alleni. Interspecific analysis indicates that the cell number and arrangement might be genus specific in Tachinidae. The mononematic scolopidia, each with one sensory cell, are of different sizes and insert at the tympanal membrane. Large scolopidial units (diameter of sensory cells up to 50??m) extend longitudi...
Investigations were conducted at Los Alamos National Laboratory to quantify the extent of migration of depleted uranium away from firing sites. Extensive sampling of air particles, soil, sediment, and water was conducted to establish the magnitude of uranium contamination throughout one watershed. The uranium source term was estimated, and mass balance calculations were performed to compare the percentage of migrated uranium with original expenditures. Mass balance calculations can be powerful in identification of the extent of waste migration and used as an aid in planning future waste investigations.
This work reviews the differences in fuel economy between two direct injection diesel engine versions through the use of a First Law energy balance and a Second Law availability balance. Both experimental data and simulated results are used in the analysis. The use of an engine simulation allowed the important processes in each engine to be analyzed and a Second Law effectiveness calculated. The availability balances and effectiveness values are used to determine the effect of major engine components on the fuel economy. A comparison is also made with an ideal engine with selected perfect or reversible processes.
Patients rely on their primary care physician to manage multiple, often chronic medical conditions that require prescription medications. Balancing the risk to benefit of treatments can be challenging...Full Text Available
... animal through a mask by isoflurane and maintained by a balanced anesthesia, which consisted of an intramuscular injection of Innovar-vet (0.11 ...
Astron. J., 82, 890-901, doi:10.1086/112143. Ghil, M., B. Shkoller, and V. Yangarber, 1977: A balanced diagnostic system compatible with a barotropic prognostic model....
Sep 5, 2008 ... Russia. The six-component balance for blunt models aerodynamic force measurement in shock tunnel. Lu Zhiquo, Liu Hongshan, Zhang Yan ...
A new controlled-clearance pressure balance is under development with the aim of improving the hydraulic high-pressure standard up to 1 GPa. This pressure balance consists of three parts: (i) a pressure generation device up to 1 GPa, (ii) a weight-loading unit which can load/unload weights automatically and independently, (iii) a controlled-clearance piston-cylinder which is designed to allow the jacket pressure to be applied independently. Some adjustments were made for loading heavy weights on/off the piston safely, keeping them in balance, then generating the pressure stably. Stability of the generated pressure was checked for several piston-cylinders, and it was found that pressure fluctuation was less than a few parts per million. The jacket pressure coefficient of a 500 MPa controlled-clearance piston-cylinder was precisely evaluated as a function of both the system pressure and the jacket pressure.
A precise technique for studying coal liquefaction in a 200 cc stirred-batch-autoclave has been developed. Reaction pressures of up to 4000 psig and temperatures of up to 850/sup 0/F can be employed. The slurry temperature in the autoclave is controlled within 2/sup 0/F by raising or lowering the autoclave which is partially submerged in a sandbath; hence the name: Variable Submergence Temperature Control (VaSTeC). Heatup and cooldown are achieved in 5 and 2 minutes, respectively. A mini-scale vacuum distillation procedure was developed for measurement of 1000/sup 0/F-distillate with a repeatability of 0.3%. About 99% material balance is routinely obtained in the autoclave runs. The following yield repeatabilities have been demonstrated (MAF coal basis):H/sub 2/ cons. (0.1%), C/sub 1/ to C/sub 3/ gas (0.3%), C/sub 4/-1000/sup 0/F distillate (2.4%), and unconverted carbon (0.5%). The autoclave can simulate the yield slate of the thermal ...
A new air injection process called toe-to-heel air injection (THAI) has been developed to achieve very stable combustion performance in heavy oil wells by controlling gas override. In the THAI process, injected air migrates preferentially to the combustion front into a horizontal producer well by the oxygen diffusional gradient created under steady state conditions. This is possible because of the balance between the stoichiometric oxygen flux needed to burn the fuel (coke) laid down ahead of the combustion front and the removal of downstream combustion gases and mobilised fluids. This study involved a numerical simulation of the THAI process to increase the understanding of the processes involving fluid flow, heat transfer and chemical reactions taking place during in situ combustion. Two tests were conducted involving one dry and one wet combustion using heavy Wolf Lake Oil. The objective was to determine if the behaviour of the oil could be ...
The mass deployment of electric and plug-in hybrid electric vehicles (EVs and PHEVs) that rely on low greenhouse gas (GHG) emission electricity generation has great potential to significantly reduce the consumption of petroleum and other high CO2-emitting transportation fuels. The vision of the Electric and Plug-in Hybrid (EV/PHEV) Vehicles Roadmap is to achieve by 2050 the widespread adoption and use of EVs and PHEVs, which together represent more than 50% of annual LDV (light duty vehicle) sales worldwide. In addition to establishing a vision, this roadmap sets strategic goals to achieve it, and identifies the steps that need to be taken to accomplish these goals. This roadmap also outlines the roles and collaboration opportunities for different stakeholders and shows how government policy can support the overall achievement of the vision. The strategic goals for attaining the widespread adoption and use of EVs and PHEVs worldwide by 2050 cover the development of ...
The research project's objective is to create a decision help for owners of residential buildings for several families regarding the renewal of decentralized heating and warm water preparation systems in the flats. The focus lies on a comparison of the costs of typical systems on the basis of a full cost calculation. This is done by taking into consideration the intentions of residential building companies like the reduction of additional costs to be paid by the tenants (both for social reasons and to make the flats easier to rent), low investment costs, low maintenance costs, energy saving, tenants' claims for comfort and acceptance by the tenants, economical reasons, especially regarding flats fully amortized (activation in the balance sheet). In addition to the quantitative comparison, the advantages and disadvantages of the different systems were also compared to one another from the qualitative point of view. [German] Ziel des ...
Discussions regarding the use of wood fuels for commercial energy production in the Netherlands began in the 1990's. The main reasons for using wood fuel are: the political demand for using renewable energy, the need to reduce CO_2 emissions, and the lack of markets for surplus timber. Only 10 % of the area of Holland is forested. Therefore, early thinning and cleaning are important management tools for improving growth and producing better quality timber. The energy potential from early thinning and plantation cleaning could be between 400 000 and 570 000 dry tons annually. The Netherlands has not experience in harvesting energy wood. However, through the International Energy Agency/Bioenergy Agreement, knowledge gained in other countries, especially Denmark, Sweden and Finland, is being transferred to Holland. In 1996, there have been made field tests with Danish equipment. Although there are few technical barriers to wood fuel in the Netherlands, the economics of wood fuels ...
As part of the studies on coal utilization basics, considerations were given on quantification of sulfur forms of coal and the pyrolysis behavior of sulfur compounds. With the temperature raising oxidation method, a thermo-balance was connected directly to a mass analyzer, and the coal temperature was raised at a rate of 5{degree}C per minute and gasified. Peak division was performed on SO2 and COS production to derive sulfur forms of coal. Using the slow-speed pyrolysis method, production rates of H2S, COS, SO2 and mercaptans were measured at a temperature raising rate of 20{degree}C per minute. Sulfur content in char was also measured. With the quick pyrolysis method, a Curie point pyrolyzer was connected directly to a gas chromatograph, by which secondary reaction is suppressed, and initial pyrolytic behavior can be tracked. All kinds of coals produce a considerable amount of SO2 in the slow-speed pyrolysis, but very little in the quick ...
When a plasma becomes contaminated by foreign particles, generically referred to as dust, the result is called a dusty plasma. At the present time there is a great deal of interest in dusty plasmas because of their roles in terrestrial and extra-terrestrial processes - semiconductor processing, high temperature fusion experiments, stellar formation and the rings of Saturn. This thesis is concerned with the role of dust in processing type plasmas. In the following experiments, artificial dust is introduced into a parallel electrode plasma chamber. Ions and electrons in the plasma charge the dust particles and they become suspended in the plasma due to the balancing of electric and gravitational forces. By illuminating the suspended dust with laser light and using an extremely high speed camera fitted with a macro lens to look at the scattered light, the dust particles are observed directly. Specially written computer software is then able to track and analyse the ...
The study of tropospheric kinetics underlies global change because key greenhouse gases are photochemically active. Modeling of tropospheric chemistry on a global scale is essential because some indirect greenhouse gases are short-lived and interact in a non-linear fashion. It is also extremely challenging, however; the global change grid is extensive in both the physical and temporal domains, and critical lower atmospheric species include the organics and their oxidized derivatives, which are numerous. Several types of optimization may be incorporated into kinetics modules to enhance their ability to simulate the complete lower atmospheric gas phase chemical system. (1) The photochemical integrator can be accelerated by avoiding matrix and iterative solutions and by establishing families. Accuracy and mass conservation are sacrificed in the absence of iteration, but atom balancing is restorable post hoc. (2) Chemistry can be arranged upon the ...
The liquefaction reaction system of an NEDOL process coal liquefaction 1t/d PSU was opened and checked to investigate the cause of the rise of differential pressure between liquefaction reactors of the PSU. The liquefaction test at a coal concentration of 50 wt% using Tanito Harum coal was conducted, and it was found that the differential pressure between reactors was on the increase. By the two-phase flow pressure loss method, deposition thickness of deposit in pipelines was estimated at 4.4mm at the time of end operation, which agreed with a measuring value obtained from a {gamma} ray. The rise of differential pressure was caused by deposit formation in pipelines connecting reactors. The main component of the deposit is calcite (CaCO3 60-70%) and is the same as the usual one. It is also the same type as the deposit on the reactor wall. Ca in coal ash is concerned with this. To withdraw solid matters deposited in the reactor, there are installed pipelines for the withdrawal at the ...
'Energy Nation Norway' looks at Norway as an energy nation from both a national and an international perspective. Its purpose is to provide a basis for political and industrial decisions relating to the petroleum industry. The report is particular concerned with the petroleum sector, besides considering the Norwegian energy cluster from a broader perspective. The energy cluster has been and will continue to be a crucial vehicle for economic growth and the development of wealth in Norway. These are the report's main conclusions: The petroleum industry has played a significant part in Norway's economic development, the side-effects of which have benefited the country's entire population. The world's economic growth and wealth development require energy. In the next few decades oil and gas will continue to form a large part of the world's energy consumption. Norway has great opportunities and competitive ...
The Economic Analysis (EA) report is written to address the impacts of this proposed Effluent Limitation Guidelines and Standards for Synthetic-Based and Other Non-Aqueous Drilling Fluids. Currently, effluent guidelines pertaining to the discharge of drilling fluids address two specific types of fluids: Oil-based drilling fluids (OBFs) that use diesel and mineral oil, which are prohibited from being discharged; and Water-based drilling Fluids (WBFs), which can be discharged subject to meeting certain discharge requirements, including a sheen test and an aqueous toxicity test, in certain limited offshore regions. Section Two presents sources of data, Section Three presents the industry profile, Section Four discusses the regulatory costs of options under consideration for the proposed rulemaking, and Section Five discusses the impacts of the proposed rule on firms, well drilling, and production, and also briefly discusses secondary impacts such as those on employment, output, inflation, ...
Shut Down System - 2 (SDS - 2) of TAPP-3 and 4 works on the principle of rapid injection of gadolinium nitrate poison solution into bulk moderator in calandria using high pressure helium to shut down the reactor. This is a new system, in the context of Indian PHWRs, designed, engineered, commissioned and being operated in TAPP-3 and 4. The system design incorporates passive features such as floating polyethylene ball with ball-ball seat arrangement and locked open isolation ball valves with key interlock arrangement. This arrangement eliminates active valves downstream of poison tanks during SDS - 2 actuation. A series parallel arrangement of fast acting pilot controlled air operated valves, which keep the high pressure helium isolated from poison tanks in poised state, are the only active components. During commissioning and initial period of operation of TAPP-4, problems were encountered and were resolved by suitable modifications and the same were incorporated in TAPP-3. Measurement ...
A relational database capable of storing and manipulating the large volumes of data on air toxic metals has been developed for the Center for Air Toxic Metals at the Energy and Environmental Research Center (EERC) of the University of North Dakota. The database provides information to researchers, managers, and operations personnel to aid in their decision making and long-term planning of issues related to air toxic metals. A personal computer-based graphical user interface is used to access the data located on a UNIX workstation at the EERC. With security codes and software issued by the EERC and an Internet service provider in place, the database can be accessed externally through the Internet. Currently the database contains over 3000 analytical measurements from nine full-scale systems and several bench-scale operations. Data are available on gas, solid, and liquid stream samples as well as relevant engineering parameters, including process data. Data will be ...
The National Institute of Materials Science (NIMS) has utilized the in-house alloy design program to develop a 5{sup th} generation Ni-base single crystal superalloy, TMS-196 with superior high temperature creep, thermo mechanical fatigue (TMF) and oxidation resistance by incorporating further ruthenium (Ru) and chromium (Cr) content over the compositions of 4{sup th} generation superalloys. With Ru additions in advanced superalloys to enhance phase stability, higher content of refractory elements can be accommodated to provide further strengthening; the associated oxidation resistance can be improved by the increase in Cr additions. In present article, TMS-196 has been subjected to cyclic/isothermal oxidation tests at 1100 C and 900 C, creep at conditions between 800 C{proportional_to}1100 C/137MPa{proportional_to}735MPa and TMF cycles. Preliminary studies indicate that the surface of oxidized TMS-196 can exhibit continuous alumina layer attributing good oxidation resistance similar ...
The most striking achievement in magnetic fusion experiments during last few years was the discovery of plasma detachment from material targets, a much needed effect for plasmas with high power fusion parameters. Due to the very low heat loads on the targets observed in these regimes and potentially low erosion of the targets, detached regimes look attractive from the International Thermonuclear Experimental Reactor (ITER) design point of view. Thus the author has experimental proof for the possibility for a co-existence of fusion relevant hot plasma in the core and a low temperature partly ionized plasma at the edge of magnetic fusion device. Although somewhat similar behavior of edge plasma was considered theoretically even before plasma detachment was found experimentally, it was not clear in the beginning how these theoretical and experimental findings would fit together. Now, after a few years of intensive additional experimental and theoretical studies, a self-consistent physical ...
Developing safe, reliable, cost-effective, and efficient hydrogen-electricity co-generation systems is an important step in the quest for national energy security and minimized reliance on foreign oil. This project aimed to, through materials research, develop a cost-effective advanced technology cogenerating hydrogen and electricity directly from distributed natural gas and/or coal-derived fuels. This advanced technology was built upon a novel hybrid module composed of solid-oxide fuel-assisted electrolysis cells (SOFECs) and solid-oxide fuel cells (SOFCs), both of which were in planar, anode-supported designs. A SOFEC is an electrochemical device, in which an oxidizable fuel and steam are fed to the anode and cathode, respectively. Steam on the cathode is split into oxygen ions that are transported through an oxygen ion-conducting electrolyte (i.e. YSZ) to oxidize the anode fuel. The dissociated hydrogen and residual steam are exhausted from the SOFEC cathode and ...
DescriptionChanges in glacier mass balance are critically influenced by the distribution of snow accumulation at the start of the melt season, but models of the winter season lag seriously behind those of the melt season. The overall aim is to test physically-based models of the spatial and temporal evolution of the winter snowpack at a temperate ice cap (Langjokull, Iceland), to assess how effectively and also how efficiently they capture variation in winter accumulation. A three-step modelling approach i [continued...
Ultrafine grained steels with different carbon contents were produced through warm caliber rolling and evaluated for their stress-strain behavior along with the reduction in area. It was found that the reduction in area-tensile strength balance is far better than the conventional ferrite+pearlite steels and even superior to bainitic steels for all materials tested in the present study.
The role of high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) in the diagnosis of preoperative and postoperative complications caused by acquired cholesteatomas will be described in this paper. The pre- and postoperative imaging of the temporal bone was performed with HRCT and MRI. HRCT and MRI were performed in the axial and coronal plane. MRI was done with T2 weighted and T1 weighted sequences both before and after the intravenous application of contrast material. All imaging findings were confirmed clinically or surgically. The preoperative cholesteatoma-caused complications depicted by HRCT included bony erosions of the ossicles, scutum, facial canal in the middle ear, tympanic walls including the tegmen tympani, and of the labyrinth. The preoperative cholesteatoma-caused complications depicted by MRI included signs indicative for labyrinthitis, and brain abscess. Postoperative HRCT depicted bony erosions caused by recurrent ...
The invention relates to a method for purifying a gas mixture containing at least one undesirable gas compound utilizing certain sulfonamide or sulfamide solvents.
Theoretical prediction of nuclear masses is analyzed as a pattern recognition problem on the N-Z plane. A global pattern is observed by plotting the differences between measured masses and Liquid Drop Model (LDM) predictions. After unfolding the data by removing the smooth LDM mass contributions, the remaining microscopic effects have proved difficult to model, although they display a striking pattern. These deviations carry information related to shell closures, nuc]ear deformation and the residual nuclear interactions. In the present work the more than 2000 known nuclear masses are studied as an array in the N-Z plane viewed through a mask, behind which the approximately 7000 unknown unstable nuclei that can exist between the proton and neutron drip lines are hidden. We show here that employing a Fourier transform deconvolution method these by masses can be predicted with similar accuracy than standard methods. We believe that a more general approach needs to be ...
Theoretical prediction of nuclear masses is analyzed as a pattern recognition problem on the N-Z plane. A global pattern is observed by plotting the differences between measured masses and Liquid Drop Model (LDM) predictions. After unfolding the data by removing the smooth LDM mass contributions, the remaining microscopic effects have proved difficult to model, although they display a striking pattern. These deviations carry information related to shell closures, nuc]ear deformation and the residual nuclear interactions. In the present work the more than 2000 known nuclear masses are studied as an array in the N-Z plane viewed through a mask, behind which the approximately 7000 unknown unstable nuclei that can exist between the proton and neutron drip lines are hidden. We show here that employing a Fourier transform deconvolution method these by masses can be predicted with similar accuracy than standard methods. We believe that a more general approach needs to be ...
There is increasing use of radiofrequency radiation (RFR) in industry for communications, welding, security, radio, medicine, navigation etc. It has been recognised for some years that RFR may interact with cardiac pacemakers and steps have been taken to prevent this interference. It is less well recognised that other metallic implants may also act as antennas in an RFR field and possibly cause adverse health effects by heating local tissues. There are a large and increasing number of implants having metal components which may be found in RFR workers. These implants include artificial joints, rods and plates used in orthopaedics, rings in heart valves, wires in sutures, bionic ears, subcutaneous infusion systems and (external) transdermal drug delivery patches"1. The physician concerned with job placement of such persons requires information on the likelihood of an implant interacting with RFR so as to impair health. The following outlines the approach developed in ...
Experiments were conducted to confirm the isotropic spatial resolution of multislice CT with a 0.5 mm slice thickness. Isotropic spatial resolution means that the spatial resolution in the transaxial plane (X-Y plane) and that in the longitudinal direction (Z direction) are equivalent. To obtain point spread function (PSF) values in the X-Y-Z directions, three-dimensional voxel data were obtained by helical scanning of a bead phantom. The modulation transfer function (MTF) values were then obtained by three-dimensional Fourier transform of the PSF. Evaluation of the spatial resolution in the X-Y-Z directions by the MTF values showed that the spatial resolution in the Z direction does not depend on the reconstruction kernel used. It was also found that the spatial resolution in the Z direction, as compared with that in the X-Y plane, is superior with the standard kernel for the abdomen and is inferior with the high-definition kernel for the ears/bones. By performing ...
Gemini North adaptive optics imaging spectroscopy is presented for the Galactic ultra-compact HII (UCHII) region K3-50A. Data were obtained in the K-band using the Near-infrared Integral Field Spectrograph (NIFS) behind the facility adaptive optics module ALTAIR in natural guide star mode. The NIFS data cube reveals a complex spatial morphology across the 0.1 pc scale of the 3'' UCHII region. Comparison of the nebular emission to Cloudy ionization models shows that the central source must have an effective temperature between about 37000 K and 45000 K with preferred values near 40000 K. Evidence is presented for sharp density variations in the nebula which are interpreted as a clearing of material nearest the central source. High excitation lines of FeIII and SeIV show that the ionization of the nebula clearly changes with distance from the central source. A double lobed kinematic signature (+/- 25 kms) is evident in the Br gamma line map which may be related to the larger scale ...
A mathematical interaction model, validated by experimental results, was developed to modeling the metal uptake by plants and induced growth decrease, by knowing metal in soils. The model relates the dynamics of the uptake of metals from soil to plants. Also, two types of relationships are tested: total and available metal content. The model successfully fitted the experimental data and made it possible to predict the threshold values of total mortality with a satisfactory approach. Data are taken from soils treated with Cd and Ni for ryegrass (Lolium perenne, L.) and oats (Avena sativa L.), respectively. Concentrations are measured in the aboveground biomass of plants. In the latter case, the concentration of metals in different parts of the plants (tillering, shooting and earing) is also modeled. At low concentrations, the effects of metals are moderate, and the dynamics appear to be linear. However, increasing concentrations show nonlinear behaviors. - The model ...
Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager ('Vision', Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of 6 images/s and an ...
To analyze and review the most common focal lesions of the external auditory canal (EAC), describing the computed tomography (CT) findings. The CT images of EAC were reviewed in a series of 167 patients. Abnormal findings were recorded in 13 cases. The CT images were correlated with otoscopic and/or intraoperative findings. There were four cases of osteoma (one located outside the EAC); all of which were treated surgically, as was the one case of exostosis. Six patients presented debris in EAC, coinciding with clinical evidence of external otitis. There were two cholesteatomas derived from EAC, one of them secondary to survery to treat osteoma. On patient was diagnosed as having a basal cell carcinoma of the ear, extending to EAC, but refused to undergo surgery. Five patients presented small triangular laminae of dense bone arising from the upper wall of the EAC which were defined as abnormal variants of the fusion of the temporal squamous epithelium to the ...
The difference of NH_4"+-N/NO_3"--N nutrition between hybrid and conventional rice varieties at the late growth stage was studied by using "1"5N-tracer technique. The results showed that the nitrate fertilizer utilization efficiency by the hybrid rice after anthesis was 7.8% higher than that by the ordinary rice variety, and the nitrate fertilizer recovery fraction by the former was 13.2% greater than that by the latter. The varietal difference in NO_3"--N uptake and utilization was almost twice as that in NH_4"+-N. It was also showed that "1"5N distribution in ear of the hybrid rice was about 20% greater than that of the conventional variety, but there were no obvious differences between NO_3"--N and NH_4"+-N. However, "1"5N distribution in the lower node leaves and root was found to be significant higher with NO_3"--N than that with NH_4"+-N in both rice varieties, particularly in the hybrid rice. Compared with NH_4"+-N, NO_3"--N top-dressing before anthesis was ...
In this work the calculation of the average precipitation in the Quito River basin, state of Choco, Colombia, is presents through diverse techniques, among which are those suggested by Thiessen and those based on the isohyets analysis, in order to select the one appropriate to quantification of rainwater available to the basin. Also included is an estimation of the error with which the average precipitation in the zone studied is fraught when measured, by means of the methodology proposed by Gandin (1970) and Kagan (WMO, 1966), which at the same time allows to evaluate the representativeness of each one of the stations that make up the rain gauge network in the area. The study concludes with a calculation of the hydrologic balance for the Quito river basin based on the pilot procedure suggested in the UNESCO publication on the study of the South America hydrologic balance, from which the great contribution of rainfall to a greatly enhanced ...
The article examines the limits and challenges small powers face when they adjust to systemic changes. Specifically, this article discusses the Philippines' conduct of a diplomatic strategy of equi balancing between the USA and China. In this strategy, the Philippines enhances and deepens its security relations with its strategic ally, the USA and at the same time, obtains economic assistance and politico diplomatic concessions from East Asia's emergent power, China. The Philippines' diplomatic gambit, however, is restrained by its formal alliance with the USA and its chronic territorial dispute with China over the Spratly Islands. At present, several developments are undermining Manila's efforts in playing this balancing game with Washington and Beijing. These are: the Philippines' passiv...
A publication on Norwegian gas and gas export. The content is wide spread from use of gas in daily life via sub sea pipeline repair systems to an overview over tomorrows gas fields. (AG)
During organogenesis, net growth of tissues is determined by a balance between proliferation, hypertrophy, and apoptotic death. Human fetal bladder outflow obstruction is a major cause of end-stage...Full Text Available
The dwelling is equipped with solar collectors which heat the air circulating in the cavity walls and the space beneath the floors. The thermal aspects of such a building are described. Heat balance, losses, heating by the sun in different seasons are described. Different measures taken to reduce the energy losses are described.
The ability to enter a hypometabolic state upon restriction of caloric intake is pivotal for animal survival: balancing the energy budget in endotherms can be a real struggle when food is not...Full Text Available
The erosion phenomena of coastal regions in Italy and in the world is remarkable from the environmental point of view. Are showed activities of mechanical defense and numerical models to solve complex problem.
The authors introduce the above electric car. They deal particularly with the vehicle concept, the energy consumption and the emission balance. (orig.).
Theoretically, the outcome of World War II in Europe hung in the balance as the Allies poured onto the Normandy beachhead. Following the June 6, 1944 invasion, the Allies continue to come ashore, massively building up men and material inside the beachhead...
Adipose tissue is central to the regulation of energy balance. Two functionally different types of fat are present in mammals: white adipose tissue (WAT), the primary site of triglyceride storage,...Full Text Available
BackgroundMaintenance of healthy bone requires the balanced activities of osteoclasts (OCs), which resorb bone, and osteoblasts, which build bone. Disproportionate action of OCs...Full Text Available
Specific criteria have been developed based on computerized dynamic posturography (CDP) to assist clinicians in identifying patients with psychogenic balance problems (Cyr and Cevette, Full Text Available
Diamagnetic samples placed in a strong magnetic field and a magnetic field gradient experience a magnetic force. Stable magnetic levitation occurs when the magnetic force exactly counter balances...Full Text Available
The cytokine interleukin-7 (IL-7) has essential growth activities that maintain the homeostatic balance of the immune system. Little is known of the mechanism by which IL-7 signaling regulates metabolic...Full Text Available
1. Interactions of pyrazole and ethanol were studied in three laboratory test procedures. They included sleeping time in mice, rotor rod balance in rats and lever pressing behaviour of rats. 2....Full Text Available
As the IC Information Sharing Executive (IC ISE), my main focus today concerns classified information--and, in particular, information that is derived from intelligence sources and methods, or information that is reflected in the analytic judgments and as...
The importance of a properly functioning and well-balanced immune system for maintaining health has become strikingly evident over the past decades. Roughly since World War II, there has been an apparent...Full Text Available
Background and AimsMany plants reproduce both clonally and sexually, and the balance between the two modes of reproduction will vary among populations. Clonal reproduction was characterized...Full Text Available
We analyze transport through conical channels due to the difference in particle concentration on the two sides of the membrane. Because of the detailed balance, fluxes of non-interacting particles...Full Text Available
The report deals with the energy consumption of traffic and its emissions of hazardous substances into the air, and stresses the advantages of the electric car with respect to energy consumption and noise generation. 5 figs., 3 refs.
The amount of phosphorus contained in food as food additives is currently increasing and a high intake of phosphorus can cause various diseases. To determine the effects of a prolonged high phosphorus...Full Text Available
Prophylactic knee braces are designed to prevent and reduce the severity of ligamentous injuries to the knee. Conflicting evidence is reported concerning their efficacy. The purpose of this study was...Full Text Available
This report contains the study on the dynamic characteristics of Wolsung fuel rod and on the dynamic balancing of rotating machinery to evaluate the performance of nuclear reactor components. The study on the dynamic characteristics of Wolsung fuel rod wa...
Modifications of the design and calibration procedure of a diffusion porometer permit determinations of stomatal resistance which agree well with results obtained by leaf energy balance. The energy...Full Text Available
Mass balance relations, valid for any counterflow system, are derived and applied to a central core model of the renal medulla, in which descending Henle's limbs (DHL), ascending Henle's limbs (AHL),...Full Text Available
General balance laws and constitutive relations are developed for convective hydrothermal geothermal reservoirs. A fully interacting rock-fluid system is considered; typical rock-fluid interactions involve momentum and energy transfer, and the dependence ...
A balanced application of chemiosmosis to plant mitochondria is presented. Electron transport carriers are sequenced to achieve proton translocation across the inner membrane. The processes of proton translocation, use, and release are integrated to yield a description of the effective proton gradient available for metabolite transport and ATP synthesis. 27 references, 6 figures.
Carbon dioxide is a waste product of aerobic cellular respiration in all aerobic life forms. PaCO2 represents the balance between the carbon dioxide produced and that eliminated. Hypocapnia...Full Text Available
CSV consists of a very complex of molecules and demonstrates significant cellular activities capable of stimulating immune functions in vivo. The purpose of this study was to analyze the effects of...Full Text Available
Adjuvant therapy aims to prevent outgrowth of residual disease but can induce serious side effects. Weighing conflicting treatment effects and communicating this information with patients is not elementary....Full Text Available
The heating history of a droplet during its flight can be divided into two phases: (a) the initial phase when evaporation, although it occurs, does not change the heat balance of the droplet much (the case considered in our previous paper and (b) the final phase when the cooling due to evaporation balances the heat flux from the plasma. The later phase is considered in Chen's comment. In our reply, a very straightforward consideration demonstrates that even in the final phase of the droplet flight, the 'rocket' effect can be significant. (reply)
In the 1988 February issue of this magazine the units olf and decipol were introduced. Olf is a measure for the pollution load and decipol for the indoor air quality. This article discusses a new ventilation theory which is quantified by the new indoor air quality thermal comfort balance based on the units olf and decipol. This balance requires more ventilation air than for the present regulations. It takes into account all pollution sources. 2 figs., 9 refs., 3 tabs.
This paper represents a parametric study of the amplification factor to account for rebound effects in the Energy Balance Method. Of the 66 distinct cases we chose for our parametric study, the amplification factor of 1.1 seems sufficient except in four borderline cases where the carbon steel pipes are small or have very small gaps between the pipes and the pipe whip restraints. We conclude that the amplification factor generally decreases as the parameters gap size, hinge-to-break distance and overhang increase.
We investigate the parametrization issue for discrete-time stable all-pass multivariable systems by means of a Schur algorithm involving a Nudelman interpolation condition. A recursive construction of balanced realizations is associated with it, that possesses a very good numerical behavior. Several atlases of charts or families of local parametrizations are presented and for each atlas a chart selection strategy is proposed. The last one can be viewed as a nice mutual encoding property of lossless functions and turns out to be very efficient. These parametrizations allow for solving optimization problems within the fields of system identification and optimal control.
Resistance and tolerance are two types of host defense mechanisms that increase fitness in response to fungi. Several genetic polymorphisms in pattern recognition receptors, most remarkably Toll-like receptors (TLRs), have been described to influence resistance and tolerance to aspergillosis in distinct clinical settings. TLRs on dendritic cells pivotally contribute in determining the balance between immunopathology and protective immunity to the fungus. Epithelial cells also contribute to this balance via selected TLRs converging on indoleamine-2,3-dioxygenase (IDO). Studies in experimental hematopoietic transplantation confirmed the dichotomy of pathways leading to resistance and tolerance to the fungus providing new insights on the relative contribution of the hematopoietic/nonhematopoi...
A gas diffusion semiconductor electrode and solar cell and a process for gaseous fixation, such as nitrogen photoreduction, CO/sub 2/ photoreduction and fuel gas photo-oxidation are described. The gas diffusion photosensitive electrode has a central electrolyte porous matrix with an activated semiconductor material on one side adapted to be in contact with an electrolyte and a hydrophobic gas diffusion region on the opposite side adapted to be in contact with a supply of molecular gas.
The book tries about the International and national aspects, natural gas situation, production, consumption, prices, demand projection, energetic plans, norms and laws of the natural gas in Colombia
This document provides information on the supply and disposition of natural gas to a wide audience. The 1996 data are presented in a sequence that follows natural gas from it`s production to it`s end use.
The origin of natural gas in the Japanese oil and gas fields are geochemically studied. Samples are taken from structural natural gas, surface gas seepage, water-dissolved natural gas and coal-field gas of the Japan Sea coast area. The origins of primary hydrocarbons are classified into bacteria gas and thermogenic gas, the latter being subclassified into gas in oil production zone with the per million deviation of the carbon isotope (/sup 13/C/sup 1/) of methane less than -35 and those gases with maturity higher than this. Surface gas seepage is subjected to migration and bacterial oxidation. Coal gas is similar to oil gas. The CO/sub 2/ concentration is 0 - 2% and /sup 13/CO/sub 2/ deviations from -30 - +30. The origin can be barely ...
Many older homes are equipped with mercury-containing gas regulators that reduce the pressure of natural gas in the mains to the low pressure used in home gas piping. Removal of these regulators can...Full Text Available
Sewage gas or biogas as a product of anaerobic digestion contains methane and carbon dioxide as its main components. Biogas is scrubbed off carbon dioxide in absorption columns and purified to natural-gas quality. The purified gas then is piped to the gas pressure control station and fed into the public network. Description of process and plant is given.
We report the performance of a micro gas turbine on biomass producer gas and mixtures of biomass producer gas with natural gas. The micro gas turbine delivers full power on gas mixtures with a heating value of at least 15 MJ/Nm{sup 3}. For gas of lower heating value, the maximum fuel gas flow limits the attainable power. The lower limit for stable operation is about 8 MJ/Nm{sup 3}. The gross efficiency of the micro gas turbine depends on output power but not on the gas heating value, within our measurement accuracy. Above 70% of full power, emissions of CO and NO are 40 and 10 times lower than those of a gas engine of similar size. At part load below 70% of full power, the micro gas turbine burner switches to a different operating mode ...
The most effective way to generate electricity out of biomass is the gasification and the use of the gas in a gas engine. The conversion of the organic carbon with the gasification of biomass is higher than 95 %. Depending on the gasification concept, the efficiency of gasifiers is found between 70 and 90 %. If the pyrolysis gas is used in a gas engine, an electric efficiency of about 26 % referring to the primary amount of energy can be obtained. With efficient gas cleaning (cleaning for tar and dust), pyrolysis gas is well qualified for engine combustion. Through modern state of engine controlling there are ways to have complete control of the fluctuations in the gas composition. Furthermore, the minor calorific value of offered wood gas poses no problem for turbo charged lean-burn gas engines. ...
This patent describes an electrodeless lamp. It comprises: a microwave cavity; a source of microwaves in communication with the cavity; a lamp envelope containing a plasma-forming medium mounted within the microwave cavity; a gas manifold for feeding gas to at least one gas passageway for directing a stream of gas to the outer surface of the envelope; a gas leak passageway leading from the gas manifold; a conductive mesh assembly for retaining microwaves within the cavity and permitting light to be emitted from the cavity. The assembly including gas flow blocking means for preventing the flow of gas through the gas leak passageway when the screen is in place in the lamp; and means for shutting off the source of microwaves when the gas pressure in the manifold drops below a ...
Pre-stacking depth migration treatment is studied for the estimation of the fold configuration from seismic survey cross sections. The estimation of a velocity structure is necessary for the execution of such treatment, and the utilization of structural-geological knowledge is required for its interpretation. The concept of balanced cross section in relation to the fault-bend fold constructs a stratum structure model under conditions that the deformation during fold and fault formation is a planar strain, that there is no change in volume due to deformation, and that a fold is a parallel fold. In addition to the above geometric and kinetic approach, there is another fold formation process simulation model using a Newtonian fluid for study from the viewpoint of dynamics. This simulation stands on the presumption that the boundary contains a ramp that had been in presence before fold formation and that an incompressible viscous matter is mounted on the top surface. ...
The heavy dependence on nuclear power eventually raise the issues of an efficient utilization of uranium resources, which Korea presently imports from abroad, end of a spent fuel storage. From the viewpoint that sodium-cooled fast Reactors (SFRs) have the potential of an enhanced safety by utilizing inherent safety characteristics, trans-uranics (TRU) reduction and resolving the spent fuel storage problems through a proliferation-resistant actinide recycling. SFRs are sure to be most promising nuclear power operation. The Korea Atomic Energy Research Institute (KAERI) has been developing SFR design technologies since 1997. And nowadays, the preliminary heat balance of the demonstration SFR is calculated. However, in order to verify design condition of the NSSS, it is necessary to set the heat balance and the conceptual design for BOP of the SFR as a part of the SFR design technique development business. Moreover, in order to confirm whether the ...
The working hypothesis of the research was that the soil of boreal forests is a large carbon store and the amount of C is still increasing in young soils, like in the forest soils of Finland, which makes these soils important sinks for atmospheric CO{sub 2}. Since the processes defining the soil C balance, primary production of plants and decomposition, are dependent on environmental factors and site properties, it was assumed that the organic carbon pool in the soil is also dependent on the same factors. The soil C store is therefore likely to change in response to climatic warming. The aim of this research was to estimate the C balance of forest soil in Finland and predict changes in the balance in response to changes in climatic conditions. To achieve the aim (1) intensive empirical experimentation on the density of C in different pools in the soil and on fluxes between the pools was done was done, (2) the effect of site ...
Appendices to this summary consist of twelve individual status reports that will be available through the National Technical Information Service (NTIS) in the United States and of course limited copies will be available through NATO. The twelve report titles which are appendices to the summary are: (A) Status Report on the Limestone/Sludge Flue Gas Desulfurization Process; (B) Status Report on the Lime/Sludge Flue Gas Desulfurization Process; (C) Status Report on the Double Alkali/Sludge Flue Gas Desulfurization Process; (D) Status Report on the Sea Water Scrubbing Flue Gas Desulfurization Process; (E) Status Report on the Limestone/Gypsum Flue Gas Desulfurization Process; (F) Status Report on the Lime/Gypsum Flue Gas Desulfurization Process; (G) Status Report on the Double Alkali/Gypsum Flue Gas Desulfurization Process; (H) Status Report on ...
Nineteen lesion mimic mutants (xsl1-19) of japonica rice Xiushui11 were obtained by ?-rays irradiation treatment. All mutants belonged to whole life lesion mimic. Lesion mimic of mutants didn't largen after tillering stage, leaves didn't wither, and no effect on the plants exsert spikes and seed. When the highest temperature in day exceeded 32 degree C in seedling stage, lesion mimic of all mutant expect xsl19 disappeared. Under 32 degree C, lesion mimic would appear gradually, and symptoms weren't inhibited by high temperature after 5 leaf stage. The plant heights of all lesion mimic mutants were 47.56-63.54 cm in the tillering stage, and that of CK was 83.75 cm; but the dwarf phenomenon of mutants only appeared before tillering stage, and didn't affect plant heights finally; the heading dates of mutants were the same to the CK, the ear length of all mutants were 9.43-15.19 cm, and that of CK was 16.41 cm; the total grain quantity per spike of all mutants were ...
An abundance of waste corn, a key food of many wildlife species, has helped make possible the widespread success of wildlife management in the United States over the past half century. We found waste corn post harvest in Nebraska declined by 47% from 1978 to 1998 due primarily to improvements in combine headers resulting in a marked decline in ear loss. The reduction in waste coincided with major declines in fat storage by sandhill cranes and white-fronted geese during spring migration. Sandhill cranes, northern pintails, white-fronted geese, and lesser snow geese avoided soybeans while staging in spring in the Rainwater Basin Area and Central Platte River Valley. These findings and other literature suggest soybeans are a marginal food for wildlife particularly during periods of high energy requirements. Soybean acreage has increased by 600% in the United States since 1950 and now comprises nearly one-quarter of the nation>'s cropland. With over 80% of the ...
The Archean core of the Laramide Wind River uplift records evidence of at least three major granitoid-forming episodes. The oldest, the Dry Creek gneiss (DCG), was emplaced by 2.8 Ga and occupies the northeastern part of the range. Mafic, pelitic and ultramafic inclusions occur in the DCG. Elsewhere in the Wind River Mountains there is evidence for crustal components as old as 3.8 Ga. The Bridger batholith (BB), intruded at 2.67 Ga, is found in the west-central Wind River Mountains. The Wind River batholith (WRB) refers to the youngest Late Archean granodiorites and granites which are found throughout the range and includes granitoids previously name the Louis Lake, Bears Ears, Popo Agie, and Middle Mountain intrusions. Although granitoids of the Wind River batholith have been dated at 2.63 and 2.55 Ga, they are considered together here because there is a complete gradation in rock type and because definite intrusive contacts are scarce. The DCG, BB, and WRB each ...
It has been previously stated that the minimum physiological recommendations for the indispensable amino acids in health adults, as proposed by FAO/WHO/UNU in 1985, are far too low, except for the methionine. An amino acid stable isotopic kinetic study was conducted to seek further experimental support to this hypothesis. Twenty healthy young men received an l-amino acid based diet, supplying 140 mg N.kg"-"1.d"-"1, patterned on egg protein for 1 week, then for 3 weeks either i) a pattern based on current international recommendations (FAO diet, n=7), ii) a the tentative Laboratory of Human Nutrition of the Massachusetts Institute of Technology, new amino acid recommendation pattern (MIT diet, n=7) or iii) again the egg hen pattern (EGG diet, n=6). All subjects were again studied for one final, consecutive week of the egg diet. At the end of the initial week, at the first and third week with the three experimental diets,and after three days following the return of the egg diet, an 8 h ...
Gas hydrates have impacted the oil and gas industry since 1934, when they were first found to plug pipelines. Today we know that in deep oceans and in permafrost, very substantial gas reserves are present in hydrated form. Concerns are being raised about in situ dissociation for both energy and greenhouse implications upon methane release. In Japan work is underway to consider the storage of carbon dioxide, concentrated in clathrates. This talk will deal with some basic questions. Why should we be interested in gas hydrates? What are gas hydrates? How do gas hydrates form? How might hydrates impact on the energy/environmental picture?
This book discusses the progress and problems of current interest in gaseous dielectrics and their use, with special emphasis on insulation in high-voltage transmission lines and substations. Topics covered include: basic physics of gaseous dielectrics; basic mechanisms; gas decomposition, reactions and toxicity; diagnostics and field probes; gases and mixtures for GIS transformers and circuit breakers; gaseous media for discharge chemistry and etching/corona; gas engineering for pulsed power and switching; gas breakdown under steep-fronted voltages; new developments in gas-insulated equipment and gas handling; gas/insulator interface/flashover; and quality control in testing gas-insulated equipment. Contains approximately 85 papers.
Reliable and consistent characterization of the stable isotope composition of atmospheric water vapour and its temporal variability are important prerequisites to the wider application of isotope mass balance methods in atmospheric and water balance studies. A new approach is proposed which utilizes standard class-A evaporation pans, which have sufficient volume to buffer short-term transient variations in atmospheric conditions, justifying the assumption of constant kinetic isotopic fractionation effects in concert with precisely measured temperature and relative humidity to derive vapour isotopic composition. The results of the studies suggest that isotopic sampling of existing, conventionally operated class-A evaporation pans could offer a straightforward and cost-effective solution to the problem of documenting the shifting isotopic distribution in atmospheric moisture
This presentation deals with innovation in teaching and understanding of thermodynamic principles. Key features of the approach being advocated are: (a) postulation of the existence of entropy, (b) explicitly associating energy transfers with other transports, (c) stating the 2nd Law in terms of Gibbs' available-energy, (d) systematic use of software such as EES. The paper outlines and elaborates upon an introductory course. Major headings in the course are: basic concepts: properties, additive properties and balances, primitive properties, energy, 1st Law. entropy, elementary academic applications of balances, available-energy, second law, exergy, thermostatic property relations, EES. Applications to processes, fluid flow, Heat transfer, thermochemical. Applications to devices, single-pro...
Several researchers have investigated morphological changes on the south-eastern Mediterranean coast during the late Holocene. However, very few of these studies include quantitative data covering the last 200?years. In this study, topographical maps, nautical charts and aerial photographs are used to estimate the shoreline migrations and beach?nearshore sand balance over the last 200?years in Haifa Bay, Israel, the northernmost final depositional sink of the Nile littoral cell. The findings reflect two main periods. During the first period, between 1799 and 1928, human intervention along the bay?s coast was negligible, a significant coastal expansion of ?50 to 150?m (averages of 0.4?1.2?m/year) was measured, and sand accumulation was estimated at ?70,000?m3 annually in the beach?nearshore...
We study the spike statistics of neurons in a network with dynamically balanced excitation and inhibition. Our model, intended to represent a generic cortical column, comprises randomly connected excitatory and inhibitory leaky integrate-and-fire neurons, driven by excitatory input from an external population. The high connectivity permits a mean field description in which synaptic currents can be treated as gaussian noise, the mean and autocorrelation function of which are calculated self-consistently from the firing statistics of single model neurons. Within this description, a wide range of Fano factors is possible. We find that the irregularity of spike trains is controlled mainly by the strength of the synapses relative to the difference between the firing threshold and the postfiring reset level of the membrane potential. For moderately strong synapses, we find spike statistics very similar to those observed in primary visual cortex.
The general objective of this workshop is to investigate and discuss methods by which uncertainties in mass balance models for toxics in the Great Lakes may be reduced. As described by the workshop prospectus, this paper is focused on problems of reducing (and quantifying) uncertainty as they relate to in situ field observations/system response measurements for the establishment of initial conditions, boundary conditions, calibration/confirmation data sets, and model post-audit data sets.'' I have taken this description to refer not only to the evaluation of uncertainty in the field observations themselves, but also to the uncertainty associated the analyses of in situ observations as they interact in the overall modeling process. Thus, I will be concerned here with quantification and reduction of uncertainty both (1) as they may be applied to descriptions of the system that is being modeled and (2) as they may be associated with model ...
A computer modelling has been developed for the calculation of mass balance of monazite ore break-down by alkali process at Rare Earth Research and Development Center. The process includes the following units : ore digestion by concentrate NaOH, dissolution of digested ore by HCl, uranium and thorium precipitation and crystallization of Na3PO4 which is by-product from this process. The model named RRDCMBP was prepared in Visual Basic language. The modelling program can be run on personal computer and it is interactive and easy to use. User is able to choose any equipment in each unit process and input data to get output of mass balance results. The model could be helpful in the process analysis for the further process adjustment and development.
"1"0"1Mo is one of the key nuclides in diagnosing fission burn-up. However, it's difficult to measure its nuclear decay data due to its short half-life. Present study concerns in the measurements of #gamma#-ray emission probabilities, P_#gamma#, of "1"0"1Mo and "1"0"1Tc using the balance of scheme method and the entire process recording. The P_#gamma# of "1"0"1Mo by the entire process recording is about 5% lower than that by using the balance of scheme method. The P_#gamma# of "1"0"1Tc using the two methods agree each other very well. So, it seems the #gamma#-ray emission probabilities as well as measurement method still need study further for "1"0"1Mo. (authors)
Many of the vulnerabilities to Energy Access, Energy Security, and Environmental Sustainability result from impediments to reaching a global demand-supply balance, as well as local balances, for various energy sources and carriers. Vulnerabilities result from multiple reasons: regional imbalances of energy production and consumption, the bulky character of the majority of energy fuels, the virtual necessity of electricity consumption following its production, among others. To detect and prioritize respective 'bottlenecks' across energy carriers, they have to be measured. In this report, production, consumption, exports, and imports were measured across all major energy carriers for seven key regions of the world for three time frames-2008, 2020, and 2050. Imbalances between production and consumption form bottlenecks in each region.
Ozone plays a critical role in both the chemistry and radiation balance of the troposphere. Understanding the factors controlling tropospheric ozone levels is critical to our understanding of a variety of issues in global chemistry and climate change. Chlorine atoms have the potential to contribute significantly to the ozone balance in the free troposphere. They can react directly with ozone or alternately, with organics and may actually lead to the formation of ozone in the presence of sufficient NO. Reactions of alkali halides in sea salt particles are a potential source of atomic chlorine, hence reactions of these alkali halides, especially those producing precursors to atomic chlorine, are of great interest. Finally, the mechanisms, intermediates and products of the Cl-biogenic reactions are unknown; these could serve as unique markers of chlorine atom chemistry in the troposphere, and hence are important to define.
The characteristics of the local magnetic shear, a quantity associated with high-mode-number ballooning mode stability, are considered in heliotron/torsatron devices that have a large Shafranov shift. The local magnetic shear is shown to vanish even in the stellarator-like region in which the global magnetic shear is positive. The reason for this is that the degree of the local compression of the poloidal magnetic field on the outer side of the torus, which maintains the toroidal force balance, is reduced in the stellarator-like region of global magnetic shear because the global rotational transform in heliotron/torsatron systems is a radially increasing function. This vanishing of the local magnetic shear is a universal property in heliotron/torsatron systems with a large Shafranov shift since it results from toroidal force balance in the stellarator-like global shear regime that is inherent to such systems.
The possible physical linkage between galactic cosmic rays intensity and the Earth's cloud cover is discussed using the analysis of the first indirect aerosol effect (Twomey effect) and its experimental representation as the dependence of average cloud droplet effective radius on aerosol index characterizing the aerosol concentration in the atmospheric air column of unit section. It is shown that the basic kinetic equation of the Earth's climate energy-balance model is described by the bifurcation equation (with respect to the temperature of the Earth's surface) in the form of fold catastrophe with two governing parameters defining the variations of insolation and Earth's magnetic field (or galactic cosmic rays intensity in the atmosphere), respectively. The principle of hierarchical climatic models construction, which consists in the structural invariance of balance equations of these models evolving on the different time scales, is described. ...
Even if there have been efforts to validate remote-sensing-based energy balance models, which provide evapotranspiration (ET) maps over a large spatial scale, few studies have been conducted to validate their performance in Korea. In this study, surface energy balance fluxes including ET were estimated and inter-compared with two different models using the Landsat-5 Thematic Mapper (TM) image over a watershed scale in Korea. While there were larger spatial discrepancies for net radiation, soil heat and sensible heat fluxes on a pixel-by-pixel basis between the two models, relatively smaller spatial discrepancies for the latent heat flux and daily ET were detected. The spatial discrepancies for the daily ET were larger in low topography and dense vegetation ranges. Despite the different par...
Of the many energy-conservation options available to the design engineer, a system-management approach is recommended as one that will effect maximum benefits to the owner. Systems management includes energy-conscious consideration of design criteria, design details, installation, testing and balancing, and operation. It requires the informed participation of the design engineer, contractor, testing and balancing (TAB) engineer, and owner/operator. Within limits, almost every component of HVAC systems offers an opportunity to conserve energy. Many of these impact energy determinants such as system static pressure, system total air flow, or the quantity of outside air. A few design considerations for energy conservation in a simple system and the impact that the TAB work has on these are illustrated. Particular attention is devoted to the energy impact of systems management, makeup air, and system static pressure.
Abstract The present study makes use of a detailed water balance to investigate the hydrological status of a peatland with a basal clay-rich layer overlying an aquifer exploited for drinking water. The aim is to determine the influence of climate and groundwater extraction on the water balance and water levels in the peatland. During the two-year period of monitoring, the hydrological functioning of the wetland showed a hydric deficit, associated with a permanent unsaturated layer and a deep water table. At the same time, a stream was observed serving as a recharge inflow instead of draining the peatland, as usually described in natural systems. Such conditions are not favourable for peat accumulation. Field investigations show that the clay layer has a high hydraulic conductivity (from 11...
Abstract A 3-month, open-label, single-center study was conducted to determine whether a uniquely formulated and physiologically balanced topical treatment serum containing multiple growth factors, cytokines, peptides, antioxidants and depigmenting agents could improve the visible signs of facial photodamage. Thirty-seven females, aged 32-55 years, with mild to severe, fine and coarse peri-ocular wrinkles were enrolled and completed the study. Subjects applied the treatment serum to the face twice daily for 3 months in conjunction with a basic skincare regimen. Clinical evaluations of photodamage were performed at baseline and months 1, 2 and 3. Cutometer measurements and subject self-assessment questionnaires were also conducted during the study. Clinical evaluations showed statistically ...
Given a double complex $X$ there are spectral sequences with the $E_2$ terms being either H$_I$ (H$_{II}(X))$ or H$_{II}($H$_I (X))$. But if $H_I(X)=H_{II}(X)=0$ both spectral sequences have all their terms 0. This can happen even though there is nonzero (co)homology of interest associated with $X$. This is frequently the case when dealing with Tate (co)homology. So in this situation the spectral sequences may not give any information about the (co)homology of interest. In this article we give a different way of constructing homology groups of $X$ when H$_I(X)=$H$_{II}(X)=0$. With this result we give a new and elementary proof of balance of Tate homology and cohomology.
The assessment and control of fetal exposure to radiation in the workplace is an issue that is complicated by both biological and political/social ramifications. As a result of the dramatic increase in the number of women employed as radiation workers during the past 10 years, many facilities using radioactive materials have instituted fetal protection programs with special requirements for female radiation workers. It is necessary, however, to ensure that any fetal protection program be developed in such a way as to be nondiscriminatory. A study has been initiated whose purpose is to balance the political/social and the biological ramifications associated with occupational protection of the developing embryo/fetus. Several considerations are involved in properly balancing these factors. These considerations include appropriate methods of declaring the pregnancy, training workers, controlling the dose to the embryo/fetus, measuring and ...
This work describes how a general, process-based mass-balance model (CoastMab) for phosphorus for coastal areas may be used as a tool to estimate realistic values of "natural" or preindustrial reference levels of key bioindicators in coastal science, including the Secchi depth, a standard measure of water clarity, the chlorophyll-a concentration, an operational measure of phytoplankton biomass and the concentration of cyanobacteria, a measure of the concentration of harmful algae. The CoastMab-model is an ecosystem model giving monthly predictions to achieve seasonal variations of basin-wide properties. The selected case-study area, the Gulf of Riga, is sensitive to nutrient loading because of its shallowness and low openness towards the Baltic Proper. The morphometry of any coastal area, ...
Gas hydrates are crystalline substances composed of water and gas, in which a solid-water-lattice accommodates gas molecules in a cage-like structure. Gas hydrates are globally widespread in permafrost regions and beneath the sea in sediment of outer continental margins. While methane, propane, and other gases can be included in the clathrate structure, methane hydrates appear to be the most common in nature. The amount of methane sequestered in gas hydrates is probably enormous, but estimates are speculative and range over three orders of magnitude from about 100,000 to 270,000,000 trillion cubic feet. The amount of gas in the hydrate reservoirs of the world greedy exceeds the volume of known conventional gas reserves. Gas hydrates also represent a significant drilling and production hazard. A fundamental question ...
Gas hydrates are crystalline substances composed of water and gas, in which a solid-water-lattice accommodates gas molecules in a cage-like structure. Gas hydrates are globally widespread in permafrost regions and beneath the sea in sediment of outer continental margins. While methane, propane, and other gases can be included in the clathrate structure, methane hydrates appear to be the most common in nature. The amount of methane sequestered in gas hydrates is probably enormous, but estimates are speculative and range over three orders of magnitude from about 100,000 to 270,000,000 trillion cubic feet. The amount of gas in the hydrate reservoirs of the world greedy exceeds the volume of known conventional gas reserves. Gas hydrates also represent a significant drilling and production hazard. A fundamental question ...
The situation of natural gas in the Federal Republic of Germany is described, with particular emphasis on the advantages and consequences of natural gas supply. The brochure discusses the role of natural gas on the energy market, the reliability of natural gas supply, the environmental impacts, the energy-saving effect of natural gas, natural gas prices, the competitive strength of the German gas industry, and the long-term reliability of natural gas supply. (orig.) [German] Die Situation des Erdgases in der Bundesrepublik Deutschland wird beschrieben, wobei die wichtigsten Vorteile und Auswirkungen der Erdgasversorgung besonders hervorgehoben werden. Es geht um die Stellung des Erdgases im Energiemarkt, die Sicherheit der Energieversorgung, Umweltschutz, Energieeinsparung durch Erdgaseinsatz, Erdgaspreise, ...
Effects of combustion conditions on the critical calorific value of flame blowout were reported for low calorific gas on the assumption of using coal derived gaseous fuel. Further, calculations of adiabatic flame temperature by using chemical equilibrium calculation were conducted in order to get a possibility of increasing exit gas temperature of gas turbine combustor to 1,300 C for low calorific value gas fuel. As a result, effects of (1) fuel composition, (2) preheating fuel temperature, (3) calorific value, and (4) combustion air velocity and fuel nozzle diameter, on the critical calorific values of flame blowout were clarified. In increasing exit gas temperature of gas turbine combustor to 1,300 C when using low calorific value gas fuel, it is essential to get an advanced cooling technology for the gas turbine ...
The genetic type, source and charging history of natural gas in the Yulin gas field in the Ordos Basin have been studied by combining the carbon isotopic composition of natural gas and geochemical characteristics of light hydrocarbons with carbon isotope fractionation model results and fluid inclusion analysis. The carbon isotopic composition of methane and ethane in the Yulin gas field is relatively enriched in {sup 13}C with {delta}{sup 13}C{sub 1} values ranging from - 35.3 permille to - 29.8 permille (average value = - 32.4 permille) and {delta}{sup 13}C{sub 2} ranging from - 26.3 permille to - 23.5 permille (average value = - 24.8 permille). The C{sub 7} light hydrocarbons are predominated by methylcyclohexane, accounting for 65.8% to 80.9% (average value = 71.6%), which is characteristic of coal-derived gas. Furthermore, the gas geochemistry indicates ...
The production, principal applications, characteristics and properties, advantages of the gas natural is showed. A sectorial overview of the ceramic industry and the utilization of the natural gas in the ceramic industry is presented. The expectations are systematized and the impact of the natural gas utilization in the ceramic industry is evaluated. Some conclusions are withdrawn and recommendations suggested.
A combined gas/steam turbine process includes a high-pressure furnace and a high pressure gasification unit with a mounted upstream of a combustion chamber there is a gas turbine with a waste heat system. Combustion heat which is not needed to heat the flue gas to combustion temperature is released from the furnace and transferred to ths combustion air going into the combustion chamber.
Nomographs have been developed to simplify site performance estimates for various types of gas turbine engines used for industrial applications. The nomographs can provide valuable data for engineers to use for an initial appraisal of projects where gas turbines are to be considered. General guidelines for the selection of gas turbines are also discussed. In particular, site conditions that influence the performance of gas turbines are described.
The budding natural gas markets in East Europe attract a great deal of interest from natural gas industries in the Western countries. Dutch companies, institutions and the government, too, are active in this market. So far the results have not been spectacular. An analysis is made of the present situation and the Dutch approach
This article puts the case for coal fired combined cycle gas turbine (CCGT) power plants. The need to gasify the coal for the CCGT, use of fluidised bed combustors or gasification systems, the difference in prices of coal and natural gas, and coal and natural gas reserves are discussed. (UK)
Natural gas is essential to the world economy. Gas now accounts for almost a quarter of OECD primary energy requirements and is expected to become the second most important fuel in the world in the next decade. Industrial and residential consumers increasingly rely on natural gas to keep their houses warm, their lights on and their factories running. Meanwhile the gas industry itself has entered a new phase. Where gas used to be restricted to regional markets, it is now increasingly traded on a global scale. While gas production and transport requires long-term investment, now it is optimised on a short-term basis. Demand continues to grow, but local gas production has become much more expensive. How should we react? How will demand be satisfied? What changes are required to promote flexibility and trade? What are the implications for ...
Mist eliminators for flue gas desulphurisation units remove liquid droplets entrained in the flue gas leaving the SO/sub 2/-absorber vessels. The commercial designs currently available are described.
The purpose of this project was to build a long-range, parallel hybrid gas/electric vehicle capable of driving beyond the communter capabilities of series hybrid vehicles. It was envisioned that since the gas engine would be able to independently propel t...
... (I still say no to bags though if I can, even if it means the bus driver looks at me funny when I get on balancing a pie and bread roll on top of 18 better-than-half-price recycled toilet rolls - as happened on Tuesday night.) I know some cloth/nylon bags are designed to fold up tightly - either with poppers or a bag to keep them neat - so ...
Volume four contains calculations for: Borrow areas--site evaluation; temporary facilities--material quantities; embankment quantities--excavation and cover materials; Burro Canyon site excavation quantities--rippable and unrippable materials; site restoration--earthwork quantities and seeding; and bid schedule quantities and material balance.
The maximum fissile fuel production capacity of three conceptual fusion breeder systems is examined on the basis of the dominant isotopic-balance processes. Compact relationships involving system power output, plasma and energy multiplication, and parameters which describe the fuel cycle and neutron spectrum in the blanket are established. It is found that the fusion breeder, as characterized herein, possesses a substantial fissile fuel breeding capacity the extent of which is governed primarily by the neutron spectrum in the conversion blanket and the break-even condition of the plasma.
The authors solve the two-dimensional stefan problem of solidification in a half-space, where the heat flux at the wall is a slightly varying function of positioning along the wall, by means of a large Stefan number approximation (which turns out to be equivalent to a small time solution), and then by means of the Heat Balance Integral Method, which is valid for all time, and which agrees with the large Stefan number solution for small times. A representative solution is given for a particular form of the heat flux perturbation.
This paper presents the Asian landscape with its regional balances and imbalances and its changes after September 11 and subsequent events. The nuclear posture and the role of nuclear weapons inside the China-India-Pakistan triangle is analyzed with respect to the US non-proliferation policy and its expanding military presence over the Asian continent. (J.S.)
Land plants must balance CO2 assimilation with transpiration in order to minimize drought stress and maximize their reproductive success. The ratio of assimilation to transpiration is called...Full Text Available
Global angular momentum balance suggests that the neutron stars in Be/X-ray binaries are not spinning in equilibrium. This requires an X-ray lifetime ''approx <'' 10"5 yr, and suggests that there are many 'dead' Be/X-ray binaries in the Galaxy. Some of these may be turned up as millisecond radio pulsars with Be star companions. (author).
This EPRI sponsored report describes factors that influence the selection of drives in process industry. These factors include economics, safety aspects, speed control and the plant steam balance. Since the economics play a key-role in the decision, this report provides a quick way of estimating the economics of replacing steam turbines with electric motors. The tools to carry out economic analyses have been provided in the form of graphs and nomographs for quick estimation.
Although the U.S. aerospace industry continues to be the leading positive contributor to the balance of trade among all merchandise industries, it is experiencing significant changes whose implications may not be well understood. Increasing U.S. collabora...
... News In Practice UK work Key facts & information Mass Balance Projects Resources & Library Technical Area Contacts Site Map Benchmarking solvent waste in the UK furniture manufacturing industry OrganisationBritish Furniture Manufacturers Ltd Project ReportSolvent Waste in Furniture Manufacturing Website: www.bfmenvironment.co.uk Return to list RSWT | Website Design Quiet Storm Solutions Ltd Please consider upgrading your browser! If you can see this ...
Substantial damages at main components of steam turbines do not have to result inevitably in an exchange of the components concerned. Rather a preliminary or final repair is possible which also considers the cause of the damage. An important condition with the technically complex questions is an appropriate qualification and experience of all involved persons. The common task of operators, manufacturers and insurance companies is to preserve the balance from costs, expenditure of time and risk.
The purpose of this paper is to describe instrumentation and control (I C) system improvements at Experimental Breeder Reactor 11 (EBR-11). The improvements are focused on three objectives; to keep the reactor and balance of plant (BOP) I C systems at a high level of reliability, to provide diagnostic systems that can provide accurate information needed for analysis of fuel performance, and to provide systems that will be prototypic of I C systems of the next generation of liquid metal reactor (LMR) plants.
The purpose of this paper is to describe instrumentation and control (I&C) system improvements at Experimental Breeder Reactor 11 (EBR-11). The improvements are focused on three objectives; to keep the reactor and balance of plant (BOP) I&C systems at a high level of reliability, to provide diagnostic systems that can provide accurate information needed for analysis of fuel performance, and to provide systems that will be prototypic of I&C systems of the next generation of liquid metal reactor (LMR) plants.
Water transport in the ionomeric membrane, typically Nafion{reg_sign}, has profound influence on the performance of the polymer electrolyte fuel cell, in terms of internal resistance and overall water balance. In this work, high resolution neutron imaging of the Nafion{reg_sign} membrane is presented in order to measure water content and through-plane gradients in situ under disparate temperature and humidification conditions.
This publication presents 5 years (1990--94) of summary financial data and current year detailed financial data on the major publicly owned electric utilities. Generator and nongenerator summaries are presented. Composite tables present: Aggregates of income statement and balance sheet data, financial indicators, electric operation and maintenance expenses, electric utility plant, number of consumers, sales of electricity, and operating revenue, and electric energy account data.
In November 1998, President Clinton charged the National Bioethics Advisory Commission with the task of conducting a thorough review of the issues associated with human stem cell research, balancing all ethical and medical considerations. The President's ...
The creation of a methodology about the Ecobalance of the main plastic materials manufactured in Europe is very helpful for many questions relating with these matters. This methodology is necessary for the EC and most of its members. It is important that these analysis have available, precise and up-to-date information. In order that these dates are well-known, the european industry of plastics recognised and started an ambitious project two years ago and now we can see the first results.
An austenitic alloy having good thermal stability and resistance to sodium corrosion at 700.degree. C. consists essentially of 35-45% nickel 7.5-14% chromium 0.8-3.2% molybdenum 0.3-1.0% silicon 0.2-1.0% manganese 0-0.1% zirconium 2.0-3.5% titanium 1.0-2.0% aluminum 0.02-0.1% carbon 0-0.01% boron and the balance iron.
This is a patent for a device to increase compaction of the loaded batch in a coking chamber that assures a balanced compaction of the batch from the upper to the bottom layer. The leveling rod has a device on the external end that causes the rod to shift vertically and bring pressure on the material and the pressing attachment. Opposite the loading hoppers of the coking chambers there are guides that ensure the rod will be sunk perpendicularly into the loaded material.
The metabolism of organic matter in the coastal regions of the ocean may significantly affect the oceanic carbon budget. This paper describes the high percentage (30%) of oceanic oxidation that occurs in coastal areas and the impact of this metabolism on the carbon cycle and climate of earth. Organic metabolism in the ocean appears to be a source of carbon dioxide release into the atmosphere. Oxidation in the coastal zone is of special interest, as it is likely influenced by anthropogenic activity. Recommendations for future research on this topic are proposed. 129 refs., 2 figs., 6 tabs.
Three book reviews and five essays address the problems of governing coastal regions. The books reviewed and the articles covered the institutions and programs involved in resource management, the balance of local and state interests in coastal conservation and developments, a consensus on coastal planning issues, and a growing trend in state-local collaborative planning. Four of the articles pertain to California, and one focuses on programs in Maine, Rhode Island, and Washington. 135 references. (DCK)
''Climates of the Oceans'' deals with the atmosphere over the world oceans and provides a treatment not only of the climatic elements such as temperature, pressure, wind, precipitation etc., but also of the circulation of the atmosphere and its changes throughout the year. The connection between sea and overlying air is examined through studies of the water and heat balance. Numerous maps and tables illustrate the elements and their fluctuations over the water and on islands and coasts.
Equations are compiled for thermal balance in which for simplification, no consideration is made for heat conductivity along the axis of the cable and dependence of losses, heat capacitance and heat conductivity on temperature. Equations are modeled on a transistor analog calculator 42 TA. The solution to the task on the computer produced values of maximum temperature on the cable and coordinates of the point of maximum overheating. Using the analog model, one can study other parameters of the thermal mode.
This work provides an overview of existing plants in Europe and describes the substrates being used. It focuses on the individual farm-scale and community plants, as these are the two main types now being built. It also describes plants currently under construction, especially in Germany and Denmark, where the major efforts are focused. A description of how the technique has developed over the past few years, its current state of development, the motivation and economic balance, and the substrate characteristics, is presented.
Absorption of the excimer laser radiations of 193-nm argon fluorine and 308-nm xenon chloride in balanced salt solution, sodium hyaluronate, and human cadaver eyes was measured. The absorption of these materials as considerably different for the two wavelengths; we found that 308-nm light experienced much less absorption than the 193-nm light. The extinction coefficient (k) for 308 nm was k = 0.19/cm for balanced salt solution and k = 0.22/cm for sodium hyaluronate. In contrast to this, the extinction coefficient for 193 nm was k = 140/cm for balanced salt solution and k = 540/cm for sodium hyaluronate. Two 1-day-old human phakic cadaver eyes showed complete absorption with both wavelengths. Using aphakic eyes, incomplete absorption was noted at the posterior pole with 308 nm and complete absorption was noted with 193 nm. The extinction in the anterior part of aphakic eyes (the first 6 mm) was 4.2/cm for 308 nm, meaning ...
Radon-222 has been measured in natural gas produced from experimental geopressured-geothermal test wells. Comparison with published data suggests that while radon activity of this unconventional natural gas resource is higher than conventional gas produced in the gulf coast, it is within the range found for conventional gas produced throughout the US. A method of predicting the likely radon activity of this unconventional gas is described on the basis of the data presented, methane solubility, and known or assumed reservoir conditions of temperature, fluid pressure, and formation water salinity.
BackgroundEmphysematous cholecystitis is a variant of acute cholecystitis which is generally caused by gas-forming organisms. Emphysematous cholecystitis may cause gas spreading...Full Text Available
... Accession Number : ADD135818. Title : Performance of Titanium in Flue Gas Desulfurization Scrubber Systems,. Descriptive Note : Journal Article,. ...
The properties of the ideal gas of classical (nonquantum) tachyons are considered. Starting from the definition of thermodynamic functions for this system, it may be found that tachyons and bradyons gases are similar. (AA).
A new surveillance system for Oil-Filled cable, which can provide continuous monitoring, using a newly developed optical gas sensor that can detect the concentration of the gas dissolved in the oil with extremely high sensitivity has been developed. It was proved that the degree of deterioration of the insulating oil can be detected by measuring C{sub 2}H{sub 2} and CH{sub 4} by investigating the relation between the degree of deterioration and amount of combustible gas generated. In order to detect extremely small amounts of gas, a new gas detecting method using absorption line of the gas using a frequency modulated technique has been developed. The gas detection ability was also confirmed by examination using a 66 kV of cable and the possibility of detection at an early stage is expected.
Rapid technology improvements, resulting in high efficiency, emissions reduction and low generation cost, are making gas turbines the generation technology of choice despite some recent reliability problems. The basic reason for the dominance is high efficiency. The rapid pace of gas-turbine technology improvement in the 1990s drove combined-cycle thermal efficiency to nearly 60 percent with natural gas as the fuel. It will probably go even higher after the year 2000. In addition, the gas-fired combined cycle is a bargain. With natural gas prices where they are right now, it is the least-cost generation operation for power producers with access to gas. Many will replace older, high-cost power plants with new gas-fired combined cycle power plants.
The oxygen production of a photosynthetic gas exchanger containing Chlorella pyrenoidosa (1% packed cell volume) was measured when various concentrations of carbon dioxide were present...Full Text Available
The purpose of this publication is to provide a better understanding of flue gas desulfurization. It provides brief answers to questions concerning its applicability, cost, effectiveness, and operation.
This bibliography contains 3920 references including abstracts, to information on the technology of flue gas desulfurization and denitrification. These references and others are included in the Department of Energy's Energy Data Base (EDB) through Decembe...
Tests to measure the maximum horsepower of commercial vehicles converted for use with natural gas fuel indicate a reduction of approximately 20% in horsepower compared with gasoline-driven vehicles. This reduction in horsepower resulting from the use of gas is due basically to the lower thermal efficiency of the cycle of natural gas compared with that of gasoline and to its lower volumetric efficiency, since natural gas is injected into the combustion chamber in gaseous form, unlike gasoline, in which part of the fuel entering the cylinder is in the liquid phase. Natural gas used as a fuel generates lower quantities of air pollutants, particularly unburned hydrocarbons (HCs) and carbon monoxide (CO). Despite the downside of reduced horsepower, the use of natural gas as a fuel for automotive vehicles equipped with Otto-cycle engines is economically viable owing ...
The natural gas industry has proposed an increase in the DOE gas R&D budget from about $100 million to about $250 million per year for each of the next 10 years. The proposal includes four programs: natural gas supplies, fuel cells, natural gas vehicles and stationary combustion systems. This paper is a qualitative assessment of the gas industry proposal and recommends a natural gas R&D strategy for the DOE. The methodology is a conceptual framework based on an analysis of market failures and the energy policy objectives of the DOE`s (1991) National Energy Strategy. This framework would assist the DOE in constructing an R&D portfolio that achieves energy policy objectives. The natural gas supply program is recommended to the extent that it contributes to energy price stability. Stationary combustion programs are supported on ...
Prepared to make housing project managers, maintenance engineering staff, and designers and architects of HUD - assisted and HUD - insured housing projects and mobile home parks aware of their responsibilities under the Natural Gas Pipeline Safety Act, this handbook provides technical guidance for the reduction of gas leaks and the handling of gas leak incidents in residential areas. The hazards of natural gas, concern over gas safety in residential areas, applicable codes and standards, and sources of information and help are reviewed, along with maintenance and engineering considerations relating to gas pipe failures, the detection of gas leaks, appliance servicing, and pipe installation, repair, and replacement. Housing management considerations are also examined, with attention to recordkeeping and reporting, emergency contingency ...
Gas Supplies of Interstate Natural Gas Pipeline Companies 1987 was prepared by the Reserves and Natural Gas Division, Office of Oil and Gas, Energy Information Administration (EIA). The publication provides information on the total reserves, production, and deliverability capabilities of the 87 interstate pipeline companies required to file the Federal Energy Regulatory Commission (FERC) Form 15, ''Interstate Pipeline's Annual Report of Gas Supply.'' This publication is the 25th in a series of annual reports on the total gas supplies of interstate pipeline companies since the inception of individual company reports to the Federal Power Commission (FPC) in 1964 for report year 1963. This publication provides information on the interstate pipeline companies' supply of natural gas during ...
The corrosion behavior of 304 stainless steel was characterized with cyclic voltammetry in a eutectic Li/K and Li/Na carbonate melt under anode and cathode gas of the molten-carbonate fuel cell (MCFC). The corrosion rate of 304 steel was determined in four different environments of the MCFC with electrochemical methods and from cross-sectional analysis of corrosion layers. These four environments were open-circuit and MCFC-load conditions both under anode and cathode gas. At open-circuit conditions corrosion was more severe under the oxidizing cathode gas then under the reducing anode gas. On the contrary, at load conditions corrosion was more severe under anode than under cathode gas. The anodic polarization under anode gas enhances corrosion, whereas the high anodic polarization under cathode gas leads to anodic protection. Corrosion ...
Full text: Chemical-technology approaches allowing to intensification the prevention processes of gas hydrates formation at motion of gas-liquid stream of natural gas in system natural gas well - gas wire have been worked up. Technological regimes of treatment of gas stream have been determined. Linear correlation dependences inhibitor electrolytes contained hydrated ions with different ion radii and charges of subgroups of alkali elements with one - type electron configuration were obtained. Important physico-chemical parameters of electrolytes have been determined: activity; coefficients of activity, viscosity, diffusion; density; heat capacity; heat conductivity; surface tension and freezing-point. The features of continuous influence of inhibitory factors on process of gas flow at low temperatures and relatively high pressure differences ...
The passive continental margin in the northern South China Sea is a weakly active area. It has been found to be favorable for large gas field development and also to be profitable for gas hydrate. The active faults, diapir structure, slump deposits, faults break of slopes, gas chimneys and sandstone of submarine fan, control the concentration of gas hydrate. Gas chimneys are widely distributed in the northern South China Sea. They supply the pathway for migration of deeper gas to gas hydrate stability zones especially in the basin of tectonic inactive zone. This paper discussed the geological structures of gas hydrate occurrence in gas fields and presented a detailed analysis of gas chimneys within the northern slope of the South China Sea. The paper described the geological ...
The paper deals with a model in which the motion of a gas in plasma accerators and high-curent discharges in the present of a skin effect is treated as expulsion by a 'magnetic piston' under the action of surface current flow. Specifically examined is the situation where the initial gas pressure is negligible in comparison with the magnetic pressure, and the motion of the gas may be treated as a self-simulating one. A system of hydrodynamic equations of the problem is derived and integrated by Adam's method. Results are plotted and discussed.
Gas contaminated with at least one noxious component, such as SO/sub 2/, HF or NOx, is scrubbed with a clear, calcium-containing, initially-basic washing liquid which also comprises the anion of a strong inorganic acid, that of a polybasic carboxylic acid and, optionally, that of a monobasic carboxylic acid. Apparatus is provided for scrubbing the gas, oxidizing produced calcium bisulfite to calcium sulfate, separating out and removing solids, and recirculating clarified liquid for scrubbing contaminated gas.
The Rayleigh scattering length has been calculated for rare-gas liquids in the ultraviolet for the frequencies at which they luminesce. The calculations are based on the measured dielectric constants in the gas phase, except in the case of xenon for which measurements are available in the liquid. The scattering length mayplace constraints on the design of some large-scale detectors, using uv luminescence, being proposed to observe solar neutrinos and dark matter. Rayleigh scattering in mixtures of rare-gas mixtures is also discussed.
The fission gas xenon bonded in bubbles, in pore, and in the lattice of mixed carbide fuels is measured by electron-probe microanalysis. Radial xenon distribution and release curves are determined and are calibrated by gas chromatography of the bonded fission gas and by burnup analysis in the respective pin sections of the irradiation experiments FR2 6A and 6C, Mol 11/K 2, and DFR 330/1. The results are correlated to the microstructure of the fuel, bonding medium, temperature, and burnup. (Auth.).
Analysis of the coke gas combustion porcess is presented. Standard kinetic relationships were utilized. Calculations were performed for coke gas with high and low content of H/sub 2/ and for blasting air 20 and 100/sup 0/C. Temperature relationships, composition of gas combustion products and release of nitrogen oxides were determined. Results are analyzed which will make it possible to control the composition of combustion products.
This thesis dealt with the metal-organic gas phase epitaxy with nitrogen as carrier gas. For this first by means of three-dimensional modelings of the epitaxy process the influence of the carrier gas on the processes was explained. The optimization of the growth parameter for the whole light-emitting-diode structure in double-hetero arrangement resulted that an a temperature of 770 C and a V/ III-ratio of 150 layers with a high crystal quality could be reached.
Plasma with a gas temperature below room temperature is not yet fully understood although it is expected to be an attractive tool for applications to material processing. In the present work, gas-temperature-dependent generation of a cryoplasma jet was studied. So far, we have generated a helium cryoplasma jet (296-5 K) under atmospheric pressure. At gas temperatures below 20 K, the helium excimer, He2, was observed clearly from by optical emission spectroscopy.
The gas composition of recent thermal waters is in perfect conformity with their geologic-tectonic positions. The composition of gas-liquid inclusions in the basic-hyperbasic xenoliths of basaltoid lavas depends on the depth from which xenoliths are supplied. (The depth is determined by using the methods of geological thermobarometers). By comparing available data the conclusion was drawn that the gas compositions of thermal waters reflect the depth of generation of deep fluid which heats them and depends on the penetration depth of the fluid-conducting fissure zones.
Spark ignition internal combustion engines perform satisfactorily when the fueled with biomass producer gas from a fluidized bed gasifier. Although power output is reduced compared to natural gas levels, full power recovery can be achieved with a relatively low level of supercharging. Important considerations are an adequate fuel delivery system and adquate gas cleaning. ref.
... harassment, incidental to construction and operation of an offshore liquefied natural gas (LNG) facility. Under the Marine Mammal Protection ... ...
The primary objective of this study is to assess the oil and gas potential of the West Siberian Basin of Russia. The study does not analyze the costs or technology necessary to achieve the estimates of the ultimate recoverable oil and gas. This study uses reservoir data to estimate recoverable oil and gas quantities which were aggregated to the field level. Field totals were summed to a basin total for discovered fields. An estimate of undiscovered oil and gas, from work of the US Geological Survey (USGS), was added to give a total basin resource volume. Recent production decline points out Russia`s need to continue development of its discovered recoverable oil and gas. Continued exploration is required to discover additional oil and gas that remains undiscovered in the basin.
Details of a 1 day conference designed to create more efficient interactions between the gas supply and electricity systems in Ontario and new models for gas supply and the electricity system were presented. Market efficiency, generators' perspectives on critical gas issues, an overview of the North American gas and an outline of issues concerning Ontario were discussed. A natural gas industry forecast and issues concerning marketers and producers were presented. The terms on which gas is bought and sold were discussed. Regulatory tools, cost allocation and issues relating to unbundling were also presented. Infrastructure needs were reviewed, as well as basic market structures. It was suggested that appropriate commercial service options need to be developed and approved, including cross-utility services.
The Department of Energy has proposed a rulemaking process to set minimum standards for the efficiency of gas ranges under the National Appliance Energy Conservation Act (NAECA). The Gas Research Institute is compiling information on annual household range gas usage in order to prepare a response to the proposed rulemaking. The data base from the Northern Illinois Gas residential load study provides recent information (data taken from 1990 through 1992) over a comprehensive study of household types and appliance and user characteristics (150 variables noted for each household). The stated Objective is to study the Northern Illinois Gas residential load study data base and to evaluate its effectiveness in predicting annual household gas usage.
Research was performed to assess the feasibility of barrier membrane substances, for use within mining or associated high risk environments, in restricting the diffusion transport of radon gas quantities. Specific tests were conducted to determine permeability parameters of a variety of membrane materials with reference to radon flow capabilities. Tests were conducted both within laboratory and in-situ emanation environments where concentrations and diffusion flows of radon gas were known to exist. Equilibrium radon gas concentrations were monitored in initially radon-free chambers adjacent to gas sources, but separated by specified membrane substances. Membrane barrier effectiveness was demonstrated to result in reduced emanation concentrations of radon gas within the sampling chamber atmosphere. Minimum gas concentrations were evidenced where the barrier ...
The light gain due to S/sub 2/ molecules in a supersonically cooled gas mixture is calculated. The S/sub 2/ molecules formed due to the recombination of the sulfur atoms, and the combustion gas mixture was preheated in a precombustion chamber. Optimal gas flow and nozzle parameters are found which correspond to the highest possible light gain using Cs/sub 2/-Ar and S/sub 2/-Ar gas mixtures. The steady state gas flow in the nozzle was calculated, taking into account the chemical reactions in the one-dimensional approximation. It is shown that the maximum gain values vary in the 0.0001-0.002 range for gas pressures in the precombustion chamber in the range 10-100 atm. The optimal initial relative concentration of Cs/sub 2/ molecules and S/sub 2/ molecules are given. 32 references.
The use of natural gas in China is still relatively immature, as gas production only supplies a low percentage of the domestic energy system. In contrast, Chinese economy mainly relies on coal with a 67% share of the total primary energy supply. The environmental impact from this high coal dependence is significant and planners have sought for cleaner energy sources. Natural gas is both cleaner and generally more efficient than coal and gas consumption is rising quickly due to these facts. The growth tendency indicates that natural gas will become an important substitution for coal in some parts of the Chinese primary energy consumption. To quantify this tendency, this paper uses a system dynamics model to create a possible outlook. The results show that the gas consumption in China will c...
Biomass gasification provides the potential to efficiently and economically produce a renewable source of a clean gaseous fuel suitable for power generation or synthesis gas (syngas) applications. An important side benefit of the use of biomass is the effective minimization of the primary greenhouse gas, carbon dioxide (CO{sub 2}), by providing a means to close-loop the CO{sub 2} cycle. However, high molecular weight hydrocarbon constituents (tar) in the product gas from gasification can complicate the downstream uses of the gas. This paper discusses both the development of a low cost, disposable catalyst system that can eliminate these heavy hydrocarbons from the gas and the use of the catalyst in conjunction with the Battelle high-throughput gasification process for power generation and synthesis applications. (author)
The presence of an extraneous light gas must be taken into account in consideration of centrifugal separation of uranium isotopes, when there is inevitable leakage of such a gas through the gas sealant and/or leaking in from the atmosphere. Consideration is first given to the influence of the presence of the light gas on the maximum separative power. Then the basic equation for isotope separation containing a light gas is derived from Hirschfelder's diffusion equations. This equation is solved and the separative performance is expressed in terms of the shape factor and reflux parameter. The formulas for expressing the flow configurations of the gases are obtained for a simple model in which inflow and outflow prevail throughout the centrifuge. The corresponding equation for a model in which the gases flow in two concentric thin streams is also derived. It is concluded that the ...
This report presents and discusses results from Task 5 of the study ''Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,'' performed at a full-scale commercial wallboard plant. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. The FGD process is used to control the sulfur dioxide emissions which would result in acid rain if not controlled. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies developed for power plants involve the capture of mercury in FGD systems. The objective of this study is to determine whether any mercury is released into the ...
This report summarises nearly 20 biosphere reports and gives a synthesis of the work performed within the SR-Site Biosphere project, i.e. the biosphere part of SR-Site. SR-Site Biosphere provides the main project with dose conversion factors (LDFs), given a unit release rate, for calculation of human doses under different release scenarios, and assesses if a potential release from the repository would have detrimental effects on the environment. The intention of this report is to give sufficient details for an overview of methods, results and major conclusions, with references to the biosphere reports where methods, data and results are presented and discussed in detail. The philosophy of the biosphere assessment was to make estimations of the radiological risk for humans and the environment as realistic as possible, based on the knowledge of present-day conditions at Forsmark and the past and expected future development of the site. This was achieved by using the best available ...
A patent is claimed for a process by which a low-hydrogen gas containing at least 90 percent by volume of methane which is suited for natural gas substitution is produced by transformation of vaporizable hydrocarbons with the aid of steam in the presence of a catalyst containing nickel, at temperatures of 350 to 600/sup 0/C and at increased pressure. Hydrocarbons and steam are supplied to the reaction in mixed form with recycle product gas. Per kilogramme of hydrocarbons to be converted in the high btu gas reactor, less than 1 kilogramme of fresh steam is needed. High btu gas is fed back from the high btu gas reactor to the input end of the same via a gas cycle comprising a cooler, a carbon dioxide absorption device, and a saturator. Between the carbon dioxide absorption device and the saturator a product gas is branched ...
The performance of the gas-jet transport system coupled to the RIKEN gas-filled recoil ion separator GARIS was investigated using 255No produced in the 238U(22Ne, 5n)255No reaction. Alpha particles of 255No separated with GARIS and transported by the gas-jet system were measured with a rotating wheel apparatus for ? spectrometry under low background condition. The high gas-jet efficiencies of about 75% were independent of the recoil ranges of 255No in the gas-jet chamber. The present results suggest that the GARIS/gas-jet system is a promising tool for the next-generation superheavy element chemistry: (1) the background radioactivities of unwanted reaction products are strongly suppressed, (2) the intense beam is absent in the gas-jet chamber and hence the high gas-jet efficiency is achieved, and (3) the beam-free ...
The purpose of this study is to identify the radiative heat transfer augmentation by a coaxial cylinder introduced in the infinite cylindrical pipe enclosing a participating gas. The gas is either a mixture of water vapor and carbon dioxide or gray. The gas is assumed to be homogeneous at a constant temperature, and has a refractive index of unity. All of the surfaces are opaque and gray, diffusely emitting and reflecting at a constant temperature. The effect of system diameter, diameter ratio, wall emittances, gas and surface temperatures, mixture component on heat transfer augmentation are studied by using the zone method with participating gas radiative properties evaluated from the weighted sum of gray gases model. From the radiative equilibrium condition, the installed wall temperature is formulated and calculated by the iteration method. If the medium is a gray ...
Visible smoke of exhaust gas from iron ore sintering plants spoil the scenery around the works. In this paper, the mechanism of formation of visible smoke is discussed by detailed analysis of the exhaust gas components and dust in the Oita No. 1 sintering plant. The main substance of visible smoke was mist condensing in the air during the cooling of exhaust gas that contained 0.1 ppm of sulfuric acid. Sulfuric acid is considered to raise the dew point and so facilitate mist condensation, and to lower the vaporization of visible mist containing sulfuric acid solution. Dust in the exhaust gas is also considered to act as nucleation sites for mist condensation. This proposed mechanism was confirmed by the test remixing SOx-rich gas with desulfurization gas in the Nagoya No. 3 sintering plant. Long trails of visible smoke were observed by remixing SOx-rich ...
Pressurized fluidized bed combustion (PFBC) is an emerging coal-fired, combined-cycle power generation technology nearing commercial status through several operating and planned demonstration plants throughout the world. Current-generation PFBC plants use ``ruggedized`` gas turbines that can tolerate dust loading common with conventional cyclone gas cleaning. The next generation of PFBC will apply advanced hot gas cleaning systems that will reuse the dust loading to low levels acceptable to high performance, industrial gas turbines. These advances should result in performance and cost advantages. This article examines the demonstration of PFBC technology at Tidd power station.
Sigma 1) examines ways to reduce the number of breakdowns of pressure-regulating stations and to minimize the energy consumed in warming the gas, 2) determines the optimal gas temperatures upstream from the pressure reduction, and 3) shows the dependence of energy consumption upon the water dewpoint. The method of calculating the optimal input temperature relies on Mollier's diagram. Tables and nomographs for natural gas and water dewpoint at 19/sup 0/F and 580 psi (-7/sup 0/C and 4 MPa) are useful in achieving the desired gas temperatures. Heating the regulators' control valves is important.
A study was conducted to examine the energy consumption in existing and new hog farming facilities and to analyse the potential for increased natural gas use in the Saskatchewan hog industry. Existing heating/cooling, ventilation and feed mill equipment choices offer possibilities for running on electricity, natural gas or propane. Energy costs are lowest when natural gas is used. To put the study in context, an overview of the Saskatchewan hog industry was provided. The potential increase in natural gas use in hog production by year 2005 was estimated. 10 refs., 6 tabs., 8 figs.
Increased use of natural gas has positive effects for the environment and the climate, because it primarily replaces petroleum products. Moreover, the natural gas does not pose a threat to bio fuel in Norway. But introducing CO2 taxes on natural gas will significantly increase the emission of greenhouse gases, concludes a report conducted by Norsk Energi (Norwegian Energy) on behalf of Norsk Naturgassforening (Norwegian Natural Gas Association) and Norsk Gassforum (Norwegian Gasforum). A brief presentation of the main conclusions in the report (ml)
National Power is building its first gas turbine combined cycle power station at Killingholme, situated to the south of the River Humber in the East of England. NEI ABB Gas Turbines Limited was awarded the turnkey contract in July 1990 to build a nominal 650 MW combined cycle power station based around three Asea Brown Boveri GT13E gas turbines. The project is outlined in this article. The plant is due for completion in July 1993. (author)
This article outlines the use of gasifiers during World War II and how, with soaring fuel prices, producer gas may provide an alternate energy path for agribusiness and farms today. In the last few years, the University of California has become a focus of producer gas research in the US. Biomass fuels used include crushed walnut shells, fruit pits, cereal straw and corn cobs. Particle size, moisture content and slagging create problems and the right kind of gas producer must be used to obtain reliable conversion to producer gas.
The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through February 1999.
The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through September 1999.
The waste tail gas fuel emitted from refinery plant in Taiwan e.g. catalytic reforming unit, catalytic cracking unit and residue desulfurization unit, was recovered and reused as a replacement fuel. In this study, it was slowly added to the fuel stream of a heater furnace to replace natural gas for powering a full-scale distillation process. The waste tail gas fuel contained on average 60 mol% of hydrogen. On-site experimental results show that both the flame length and orange-yellowish brightness decrease with increasing proportion of waste gas fuel in the original natural gas fuel. Moreover, the adiabatic flame temperature increases as the content of waste gas fuel is increased in the fuel mixture since waste gas fuel has a higher adiabatic flame temperature than that of natural gas. The complete replacement of natural ...
This paper provided an outline of the Canadian natural gas commodity market and a forecast for Canadian natural gas supply and prices for the 2007 winter heating season. Since 2001, steady demand growth and slow supply growth have contributed to higher North American natural gas commodity prices. The loss of natural gas supply due to hurricanes pushed North American natural gas commodity prices to record levels in 2005. Canadian natural gas production levels currently exceed domestic gas consumption. In 2005, Canada produced 16.5 billion cubic feet per day of marketable natural gas. Approximately 45 per cent was consumed domestically, and the remainder was exported to the United States. Despite high levels of drilling activity, production of natural gas from western Canada has flattened out since ...
A novel two-phase flow management process useful for active thermal power rejection in space is introduced. The process serves as a condenser in a Rankine cycle and is applicable for thermal energy management needs in low gravity environments. Benefit is derived from the ability to utilize the high specific energy transport capability of two-phase flow, while not requiring mass-intensive solutions nor complex control strategies to maintain design energy balance integrity. Initial design calculations for a hypothetical space vapor cycle demonstration experiment were done and a steady-state computer model of the novel condensing process was created and used to evaluate its potential to maintain the design energy balance of the experiment. The experiment (approximately 28 kg) was a supercritical organic thermal loop operating between 500 and 400 Kelvin at a mass flow of 1 grain per second; using R-113 as the working fluid and rejecting all of its ...
A study has been made of the reactor blockages occurring in the course of direct hydroliquefaction of Miike coal, Taiheiyo coal and Yallourn coal briquets in a tubular reactor. The liquefaction tests were carried out at 450 C under 24.6 MPa hydrogen pressure, with red mud and sulfur catalyst. From the observed balances for catalyst and coal ash, it was inferred that reactor blockages are due to sedimentation of catalyst and ash. The conditions for catalyst and coal ash run-off were determined after solvent and slurry flow rates had been altered to suit the type of coal being tested. It was found that ash run-off occurred more readily as the difference between the slurry flow velocity and the natural sedimentation velocity of red mud in the coal liquids increased. Even when ash run-off was occurring, however, the ash concentration of the slurry in the reactor was higher than the concentration in the feed slurry. This is taken as indicating that some of the solvent ...
At least quinary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise zirconium and/or hafnium in the range of 45 to 65 atomic percent, titanium and/or niobium in the range of 4 to 7.5 atomic percent, and aluminum and/or zinc in the range of 5 to 15 atomic percent. The balance of the alloy compositions comprise copper, iron, and cobalt and/or nickel. The composition is constrained such that the atomic percentage of iron is less than 10 percent. Further, the ratio of copper to nickel and/or cobalt is in the range of from 1:2 to 2:1. The alloy composition formula is: (Zr,Hf).sub.a (Al,Zn).sub.b (Ti,Nb).sub.c (Cu.sub.x Fe.sub.y (Ni,Co).sub.z).sub.d wherein the constraints upon the formula are: a ranges from 45 to 65 atomic percent, b ranges from 5 to 15 atomic percent, c ranges from 4 to 7.5 atomic percent, d comprises the balance, d.multidot.y is less than 10 atomic ...
When oxygen is limiting, animals can ferment glucose via several metabolic pathways varying in energetic efficiency and leading to various end products (such as lactate, succinate, or propionate). Because the pH dependence of H/sup +/ production by fermentation is opposite to that by hydrolysis of adenosine triphosphate formed in the fermentation, the total number of moles of protons generated is always two per mole of fermentable substrate. However, two and three times more adenosine triphosphate can be turned over per mole of protons produced in succinate and propionate fermentations, respectively, than in lactate fermentation. At its limit, this advantage would achieve the same balance between H/sup +/ production and H/sup +/ consumption during ATP cycling that is observed in aerobic metabolism, a situation observed in certain alcohol fermentations. Since proton balance during anaerobiosis is clearly adaptable, we consider possible impact ...
In the Energy Balance Analysis Model (Standard Review Plan (USNRC, 1981), Section 3.6.2, ''Determination of Rupture Locations and Dynamic Effects Associated with the Postulated Rupture of Piping''), time dependence is not considered, and a constant blowdown thrust force is assumed. This force includes an amplification factor of 1.1 to account for potential effects of rebound. Many of the assumptions used in establishing the acceptance criteria, as stated in the Standard Review Plan, were based on engineering judgment and logic intended to assure upper bound design rather than on a mechanistic assessment of actual pipe rupture phenomena and their effects. As a result of the current practice an exceedingly conservative design may be introduced. This report represents a parametric study of the amplification factor to account for rebound effects in the Energy Balance Method. Of the 71 distinct cases we chose for ...
The following parameters merit examination in determining the viability of process combinations: conceptual and technical soundness, environmental acceptability, energy balance, flexibility, costs, economic risk potential. The present contribution on this subject is not intended to take the place of or cover the scope of single-case studies. In practice, viability studies on process combinations have to deal with concrete plans involving precisely defined material flow balances, emissions, costs etc. The present paper therefore only presents the basic principles of this type of study. [Deutsch] Folgende Randbedingungen fuer sinnvolle Verfahrenskombinationen sind zu untersuchen: - konzeptionelle und technische Stimmigkeit, - Umweltvertraeglichkeit, - energetische Bilanz, - Flexibilitaet, - Kosten, - oekonomisches Risikopotential. Nun kann dieser Beitrag zum Thema keine Einzelfallbetrachtung ersetzen bzw. abdecken. Im Rahmen einer echten Pruefung ...
On June 19, 1998, after the first annual outage, Wolsung Unit 2 was shutdown at a controlled rate due to the continuous instability of Liquid Zone Control level. Investigation revealed that the Liquid Zone Control level instability was caused by water condensed inside the helium lines, generated from the moistened helium flow, especially, inside the helium balance header feed and bleed valve lines. It was found that improper installation of the diaphragm type isolation valves and the drain valve tap could easily contain the water inside the lines and be destined to form water traps causing the balance header pressure oscillation. After the lines were dried, Liquid Zone Control level instability was almost vanished, and approached the allowable equilibrium state. As the reactor power was increased, however, the zone level instability increased again. In order to compensate for the excessive, the Bulk Power Control Gain (Kp) was reduced to ...
The Pacific Northwest National Laboratory (PNNL) operates a number of research and development (R and D) facilities for the Department of Energy on the Hanford Site. According to DOE Order 5400.1, a Facility Effluent Monitoring Plan is required for each site, facility, or process that uses, generates, releases, or manages significant pollutants or hazardous materials. Three of the R and D facilities: the 325, 331, and 3720 Buildings, are considered major emission points for radionuclide air sampling and thus individual Facility Effluent Monitoring Plans (FEMPs) have been developed for them. Because no definition of ''significant'' is provided in DOE Order 5400.1 or the accompanying regulatory guide DOE/EH-0173T, this FEMP was developed to describe monitoring requirements in the DOE-owned, PNNL-operated facilities that do not have individual FEMPs. The remainder of the DOE-owned, PNNL-operated facilities are referred to as ...
All first-stage experimental tests were completed for Task 4 (and the Contract). The first-stage one-liter autoclave tests that were made were duplicates of Run 41-LA. The conditions used were chosen last quarter to reduce the cost of the first-stage of the process from those used at the conclusion of Task 3. Filtration and second-stage tests were made using the products of the first-stage tests. Post-second-stage filtration, tested as an alternative to interstage (pre-second- stage) filtration, resulted in low filtration rates. Different catalyst loadings and type and residence time for second-stage hydrotreating were explored. Longer residence times did not result in significantly more resid conversion. Higher catalyst loadings were more effective in converting the resid at the same residence time. The material and elemental balances for the first-stage were completed. The material and elemental balances for the second-stage were initiated.
In the development of the specific mathematical modeling for heavy and ultra heavy petroleum fractions in a molecular distiller is very important the definition of physical and chemical parameters as density and specific heat of the mixture, the enthalpy of vaporization, among others, since they are used in the energy balance. Information on these properties and their variation with temperature are found in the open literature for mixture with few components (simple mixtures). However, for multicomponent solutions consisting of complex mixtures such as oil and its heavy and ultraheavy fractions, available data are few, or are limited to low temperatures. The specific heat is an important property in the energy balance. This property can be measured by Differential Scanning Calorimetry (DSC), which gives results with great sensitivity and accuracy. This paper presents the variation of specific heat with the temperature of ultra-heavy oil ...
Energy expenditure (EE) of four adult men on a weight-maintenance diet was estimated by use of doubly labeled water, intake balance, and direct and indirect calorimetry. The doubly labeled water (2H218O) method was used to estimate free-living EE for 13 d. Metabolizable energy (ME) intake was used to estimate free-living EE for 1 wk. The subjects' 24-h EE was measured in a dual direct-indirect room calorimeter on 3 alternate days. Estimates of free-living EE as measured by ME intake and doubly labeled water indicate agreement between the two methods (mean difference +/- SEM, -1.04 +/- 0.63%). Measurements of EE with indirect and direct calorimetry are equivalent (mean difference 0.63 +/- 0.44%). The daily EE measured by doubly labeled water in these free-living adults over a 13-d period was 15.01% greater than the 24-h EE measured within the calorimeter.
The paper studied a possibility of estimating characteristics of coal liquefaction residue from liquefaction conditions in the case of fixing coal kind in the NEDOL process coal liquefaction PSU. Wyoming coal was used for the study, and the already proposed simplified liquefaction reaction models were used. Among material balances explained by the models, those of asphaltene, preasphaltene, THF insoluble matters are concerned with residue composition. Ash content is separately calculated from ash balance. Reaction velocity constants of simplified liquefaction reaction models which influence the residue composition were obtained by the multiple regression method from experimental results in the past. The estimation expression of residue viscosity was introduced from residue ash/composition. When the residue composition is estimated by the model from liquefaction conditions, and the residue viscosity is obtained using it, the higher the ...
A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling device causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides ...
A novel direct calculation method of response matrices on heterogeneous lattices by using the Monte Carlo method is proposed. These direct response matrices (DRMs) can be used in core calculations in place of the conventional homogenized lattice constants. The DRMs are formalized by four sub response matrices (sub-RMs) in order to respond to a core eigenvalue, k; thus the DRMs can be re-evaluated on each outer iteration in the core calculations. The sub-RMs can be evaluated by analyzing each neutron's trajectory from ordinary lattice calculations with the Monte Carlo code. Since these sub-RMs are calculated directly under an actual complex assembly geometry, i,e., without a homogenization process, intra-assembly heterogeneous effects can be reflected on global partial current balance calculations. With using two of the sub-RMs, which deal with neutron production probabilities for each fuel pin, and the obtained partial current balance, ...
In this paper, a mathematical model for a counterflow wet cooling tower is derived, which is based on one-dimensional heat and mass balance equations using the measured heat transfer coefficient. The balance equations are solved numerically to predict the temperature change of air and water, as well as the humidity as a function of the cooling tower high. Experimental measurements on two pilot-scale cooling towers were carried out in order to analyze the performance of different cooling tower filling materials. Also, the performance of other cooling tower elements, such as droplet separators and water spray nozzles, was investigated in the pilot experiments. The flow distribution, i.e. the velocity field, upstream to the filling material was predicted using the three-dimensional version of the computational fluid dynamics (CFD) code Fluent/UNS, version 4.2. The calculated flow fields are presented for different distances between the inlet of ...
Up to now the long range filaments have been considered as a balance between Kerr focusing and defocusing by plasma generation in the nonlinear focus. However, it is difficult to apply the above explanation of filamentation in far-field zone. There are basically two main characteristics which remain the same at these distances - the super broad spectrum and the width of the core, while the power in a stable filament drops to the critical value for self-focusing. At such power the plasma and higher-order Kerr terms are too small to prevent self-focusing. We suggest here a new mechanism for stable soliton pulse propagation in far-away zone, where the power of the laser pulse is slightly above the critical one, and the pulse comprises super-broad spectra. For such pulses the diffraction is not paraxial and an initially symmetric Gaussian pulse takes parabolic form at several diffraction lengths . The stable soliton propagation appears as a balance ...
In this study, e-waste flows of five large home appliances (color televisions, refrigerators, washing machines, personal computers, and air conditioners) in Vietnam are investigated. A social survey was performed to investigate the situation on using appliances in households as well as on the disposal of appliances by the first users. Future quantities of e-waste were estimated using a model that combines use of the Weibull distribution, the logistic function, and the population balance model. It was forecast that about 3.86 million appliances, or 114 000 tons, will be discarded in 2010, and about 17.2 million appliances, or 567 000 tons, in 2025, showing a rapid increase of e-waste in the near future.
The maximum fissile fuel production capacity of three conceptual fusion breeder systems is examined on the basis of the dominant isotopic-balance processes. Compact relationships involving system power output, plasma and energy multiplication, and parameters which describe the fuel cycle and neutron spectrum in the blanket are established. It is found that the fusion breeder, as characterized herein, possesses a substantial fissile fuel breeding capacity the extent of which is governed primarily by the neutron spectrum in the conversion blanket and the break-even condition of the plasma. (author).
A thermodynamic analysis of a hybrid geothermal heat pump system is carried out. Mass, energy, and exergy balances are applied to the system, which has a cooling tower as a heat rejection unit, and system performance is evaluated in terms of coefficient of performance and exergy efficiency. The heating coefficient of performance for the overall system is found to be 5.34, while the corresponding exergy efficiency is 63.4%. The effect of ambient temperature on the exergy destruction and exergy efficiency is investigated for the system components. The results indicate that the performance of hybrid geothermal heat pump systems is superior to air-source heat pumps.
As one of the evolutionary oldest parts of the brain, the diencephalon evolved to harmonize changing environmental conditions with the internal state for survival of the individual and the species. The pioneering work of physiologists and psychologists around the middle of the last century clearly demonstrated that the hypothalamus is crucial for the display of motivated behaviors, culminating in the discovery of electrical self-stimulation behavior and providing the first neurological hint accounting for the concepts of reinforcement and reward. Here we review recent progress in understanding the role of the lateral hypothalamic area in the control of ingestive behavior and the regulation of energy balance. With its vast array of interoceptive and exteroceptive afferent inputs and its equ...
This paper summarizes the U.S. Department of Energy R&D program in crystalline-silicon photovoltaic technology, which is jointly managed by Sandia National Laboratories and National Renewable Energy Laboratory. This program features a balance of basic an d applied R&D, and of university, industry, and national laboratory R&D. The goal of the crystalline-silicon R&D program is to accelerate the commercial growth of crystalline-silicon photovoltaic technology, and four strategic objectives were identified to address this program goal. Technical progress towards meeting these objectives is reviewed.
A simple theory for predicting the convective energy loss from side-facing cavity receivers in windless environments has been developed. The approach used is to determine the velocity distribution of the incoming air in the aperture plane (and thereby the rate of mass entrainment); and then to estimate the bulk temperature of the heated emerging air. The convective loss is then calculated from an energy balance. To illustrate this theory, numerical results applicable to the 2.15 meter cubic cavity being tested in the laboratory are provided.
In order to ensure a power balance in an electrical network a spinning reserve has to be capable of activation within seconds. However, because of the need to vary the fuel flow in the steam generator, the run-up of output takes minutes. The required capacity response is therefore achieved by storage of steam from the steam generator. In this process the turbine control valves come into action in a specific manner. The paper describes the importance of the initial reserve for unit capacity control. (orig.).
An important aspect, which has to be considered in terms of municipal solid waste (MSW) management, is the stage of collection. The emissions generated from these systems can arrive to values that are of the same order of magnitude of emissions from combustion of waste in waste-to-energy plants. The present work faces the problem of transport, from intermediate station to the center of final combustion, placing attention to the emissions from scenarios that has been selected between real systems of management. This analysis can lead to highlight some important elements that can be useful to minimize the impacts.
Abstract This study presents a review of distributed model predictive control (DMPC) strategies followed by recent studies conducted by the authors on the robustness of these strategies to model errors and a summary of future challenges in this area. The review identifies three key challenges for the successful application of DMPC: (i) the selection of optimal control structure for DMPC; (ii) the choice of a suitable coordination strategy among the controllers; and (iii) the robustness of DMPC strategies to model errors. Then, the study summarises recent developments related to the robustness of unconstrained and constrained DMPC algorithms. For the unconstrained case, a methodology that is based on the calculation of a performance index is proposed to balance the trade-off between perform...
Transplantation has emerged as the therapy of choice for many patients with end organ failure. One of the major goals is to tailor immunosuppressive therapy to the individual needs of every patient to balance the risk for rejection and over-immunosuppression. This will require diagnostic tools that can detect harmful processes in the allograft early, and that can be measured repeatedly. This review will consider recent advances in our understanding of the molecular nature of these processes and how this information is being utilized to design novel diagnostic assays to non-invasively monitor allografts. Highlighted is the need for large-scale prospective multi-centre studies to validate assays that show early promise in single centre studies.
The paper presents the integration of the SIMBAD space charge module in the UAL framework. SIMBAD is a Particle-in-Cell (PIC) code. Its 3-D Parallel approach features an optimized load balancing scheme based on a genetic algorithm. The UAL framework enhances the SIMBAD standalone version with the interactive ROOT-based analysis environment and an open catalog of accelerator algorithms. The composite package addresses complex high intensity beam dynamics and has been developed as part of the FAIR SIS 100 project.
Oman is an attractive and welcoming country, well-ordered and unpretentious. It has benefited from remarkable achievements of economic and social development since 1970. It now has a resource base that should be sufficient to keep it on continuing path of further development. However, the second 20-years of modern Oman will inevitable contain some testing challenges. These are centred in two main areas - the economic, where expenditure has already outstripped revenue and where firm controls are needed to maintain a reasonable balance; and the social, where the pressures from an increasingly literate and numerous population will demand changes to the autocratic traditional system of government. (author)
Nonlinear distortion added by the loudspeaker in a hearing aid lowers the signal-to-noise ratio and may degrade the hearing aid user's ability to understand speech. The balancedarmature- type loudspeakers, predominantly used in hearing aids, are inherently nonlinear devices, as any displacement of the loudspeaker diaphragm inevitably changes the magnetic and electrical characteristics of the loudspeaker. A numerical time-domain model capable of describing these nonlinearities is presented. By simulation it is demonstrated how the output distortion could potentially be reduced significantly through careful design of the mechanical properties of the armature.
A thermodynamic model was used to estimate enthalpy of solution of carbon dioxide (CO{sub 2}) in methyldiethanolamine (MDEA) aqueous solutions. The model was based on a set of equations for chemical equilibria, phase equilibria, charge, and mass balances. Non-ideality in the liquid phase was taken into account by interaction parameters fitted to (vapor + liquid) equilibrium data. The enthalpies of solution of CO{sub 2} were derived from the model using classical thermodynamic relations and were compared to experimental values obtained in previous works.
A thermodynamic model was used to estimate enthalpy of solution of carbon dioxide (CO_2) in methyldiethanolamine (MDEA) aqueous solutions. The model was based on a set of equations for chemical equilibria, phase equilibria, charge, and mass balances. Non-ideality in the liquid phase was taken into account by interaction parameters fitted to (vapor + liquid) equilibrium data. The enthalpies of solution of CO_2 were derived from the model using classical thermodynamic relations and were compared to experimental values obtained in previous works.
Menopause is characterized by the progressive reduction of estrogens resulting to cessation of menses. It is associated with an increase of cardiovascular risk factors such as hyperglycemia, hypertension, dyslipidemia and of abdominal and/or selective visceral fat mass deposition. Obesity, a modern day epidemic, is promoted by an obesogenic environment that interacts with the genetic background. The result is a positive energy balance materialized by the accumulation of the adipose tissue. This process is marked by great individual variation. Obesity is also associated with the presence of cardiovascular risk factors. In this review, the main pathophysiologic processes for the increase of obesity in menopause and the possible effects of pre-menopausal obesity regarding the cessation of ova...
Big Bang nucleosynthesis requires a fine balance between equations of state for photons and relativistic fermions. Several corrections to equation of state parameters arise from classical and quantum physics, which are derived here from a canonical perspective. In particular, loop quantum gravity allows one to compute quantum gravity corrections for Maxwell and Dirac fields. Although the classical actions are very different, quantum corrections to the equation of state are remarkably similar. To lowest order, these corrections take the form of an overall expansion-dependent multiplicative factor in the total density. We use these results, along with the predictions of Big Bang nucleosynthesis, to place bounds on these corrections.
In Nuclear Magnetic Resonance (NMR) imaging, contrast is dependent on the emission of radiofrequency waves by atomic nuclei, balanced by several parameters. The high information content of NMR images is due to the multiplicity of its parameters. However, this advantage introduces a difficulty in the interpretation of the contrast. There are three contrast parameters for each tissue: hydrogen nuclei density; relaxation time T1; relaxation time T2. Contrast may be enhanced towards any of these parameters by increasing the emission of radiowaves by atomic nuclei using particular pulse sequences.
Completion of the Phase III evaluation and comparison of salt disposition alternatives was supported with enhanced computer models and analysis for each case on the ''short list'' of four options. SPEEDUP(TM) models and special purpose models describing mass and energy balances and flow rates were developed and used to predict performance and production characteristics for each of the options. Results from the computational analysis were a key part of the input used to select a primary and an alternate salt disposition alternative.
Phelps N. A. Cluster or capture? Manufacturing foreign direct investment, external economies and agglomeration, Regional Studies.?This paper reviews the nature and significance of external economies associated with multinational enterprise (MNE) participation in the manufacturing industries of host economies. It argues that the balance of forces of internalization and externalization is currently skewed towards the former and the interests of MNEs rather than the latter and the interests of local and national communities and governments. A stylized comparison of developmental and competition state interventions in relation to MNEs and their foreign direct investment (FDI) suggests that in the absence of co-ordinated interventions by governments, there will commonly be a failure of t...
Air pollution abatement measures are being intensified at the moment: Power plants and district heating systems are being retrofitted with high-efficiency desulphurisation and NO/sub 2/ reduction systems, the 3rd amendment of the Clean Air Technical Guide sets more rigid emission limits, and unleaded petrol and catalysts will significantly reduce car exhaust emissions. The author presents pollutant balances from 1966 to 1982 to contradict the popular notion that pollutant emitters formerly failed to take preventive measures.
DescriptionRates of ice accumulation in Antarctica are not known well, yet they are fundamental to assessing the ice sheet mass balance. Past accumulation rates are less well defined. We are in a unique position to provide detailed accounts of accumulation in Antarctica. We will measure isochronous internal layering across the ice sheet, which can be readily identified in radar data that we hold. Internal layers will be traced to ice-cores (allowing dating) and across wide regions of the ice sheets. A nume [continued...
In this paper we present a new, accurate form of the heat balance integral method, termed the combined integral method (CIM). The application of this method to Stefan problems is discussed. For simple test cases the results are compared with exact and asymptotic limits. In particular, it is shown that the CIM is more accurate than the second order, large Stefan number, perturbation solution for a wide range of Stefan numbers. In the initial examples it is shown that the CIM reduces the standard problem, consisting of a PDE defined over a domain specified by an ODE, to the solution of one or two algebraic equations. The latter examples, where the boundary temperature varies with time, reduce to a set of three first order ODEs.
Lung transplantation has become an accepted option for many patients with end-stage pulmonary diseases. Anesthesia and surgery following lung transplantation may be required for various diseases that may affect both systemic organs and the transplanted graft. When a patient with a lung transplant undergoes surgery, there is the potential for interference with lung function, depending on the type of intervention and its anatomical site. Accurate preoperative evaluation, an understanding of the physiology of the transplanted lung, proper airway instrumentation, individualized management of intraoperative ventilation, and fluid balance are essential for a positive perioperative outcome.
The steady state ampacity is calculated for mixed electric power underground cable circuits in a single trench or ductbank. The methodology presented in this paper can be applied to any practical number of balanced, three phase circuits (each in trefoil, pipe or conduit) of different voltage classes, cable sizes, load currents and cable systems to located anywhere within a single trench or ductbank. The different thermal resistivities of the backfill or ductbank and the surrounding soil are taken into consideration. A practical example for 10 circuits in a trench is provided.
The humidification?dehumidification process is an interesting technique that has been adapted for water desalination. Previous works experimentally investigated desalination processes in the shell and tube columns, where the humidification and dehumidification were thermally coupled and simultaneously performed at the tube and shell sides, respectively. In this work, a comprehensive steady-state mathematical model was developed for such a humidification?dehumidification desalination process by taking into account the heat and mass balances on both sides of the desalting column, the mass transfer rate at the humidification side, and the heat transfer rate between the dehumidification side and humidification side. Meanwhile, the mass transfer coefficient at the humidification side and the to...
With the prevalence and development of GNSS technologies, location-based vehicle services (LBVS) have experienced a rapid growth in recent years. However, location is a sensitive and private piece of information, so the design and development of such services just take the clients' privacy concerns into account. In this paper, we propose a new electronic toll pricing system based on group signatures, which provides a strong guarantee for the clients' anonymity within groups. Our system achieves a balance between privacy and the communication overhead imposed upon the users.
The State of the Espirito Santo will become until the end of 2008, one of the main producers and natural gas exporters of Brazil, where, according to PETROBRAS, the State will produce about 20 million /day m{sup 3}, what it will go to contribute significantly for reduction of the dependence of the Bolivian gas, and still to give support to the natural gas sector in Brazil. The Intention of this work, is to identify proposals so that it has left of the gas produced in the State of the Espirito Santo, has a differentiated price. It does not make sensible the State to pay for the gas that is removed in its proper territory the same price that paid Sao Paulo for the gas that consumes imported of national Bolivia. With the markdown of the gas the State will be able to attract investments of great transport, to generate job and income and to ...
We have used the SINFONI integral field spectrograph to map the near-infrared K-band emission lines of molecular and ionised hydrogen in the central regions of two cool core galaxy clusters, Abell 2597 and Sersic 159-03. Gas is detected out to 20 kpc from the nuclei of the brightest cluster galaxies and found to be distributed in clumps and filaments around it. The ionised and molecular gas phases trace each other closely in extent and dynamical state. Both gas phases show signs of interaction with the active nucleus. Within the nuclear regions the kinetic luminosity of this gas is found to be somewhat smaller than the current radio luminosity. Outside the nuclear region the gas has a low velocity dispersion and shows smooth velocity gradients. There is no strong correlation between the intensity of the molecular and ionised gas emission and either the radio or ...
Nova Corporation and its related businesses are involved in natural gas production, gas pipelines, consulting services, and upgrading of natural gas into chemicals and plastics. Nova owns Alberta Gas Transmission Division, the primary gas transportation system in Alberta, with 11,400 miles of pipeline and total deliveries in 1992 of 3.4 trillion ft"3. Nova also owns 50% of Foothills Pipe Lines Ltd., one of Canada's largest carriers of exported gas, and 50% of TQM Pipeline Partnership, which transports natural gas in Quebec. Nova conducts its chemicals business through Novacor Chemicals Ltd., which has plants in Alberta, Ontario, Quebec, and the USA. Novacor's major petrochemicals are methanol, ethylene, propylene, and styrene and its major plastics are polystyrene, polypropylene, and polyethylene. Nova's gas-producing ...
Gas transmission pipelines are susceptible to both internal (gas side) and external (soil side) corrosion attack. Internal corrosion is caused by the presence of salt laden moisture, CO{sub 2}, H{sub 2}S, and perhaps O{sub 2} in the natural gas. Internal corrosion usually manifests itself as general corrosion. However, the presence of chlorides in entrained water also can lead to pitting corrosion damage. The electrochemical noise technique can differentiate general from localized corrosion and provide estimates of corrosion rates without external perturbation of the corroding system. It is increasingly being applied to field and industrial installations for in situ corrosion monitoring. It has been used here to determine its suitability for monitoring internal and external corrosion damage on gas transmission pipelines. Corrosion measurements were made in three types of environments: (1) aqueous ...
Short-lived fission gas release from fuel pellets during irradiation was investigated based on the experimental results of the gas-flow rigs irradiated in the Halden Heavy Water Reactor (HBWR). The release-to-birth (R/B) rates of short-lived fission gas were measured by means of gas-flow measurement during the irradiation experiments. Surface-to-volume (S/V) ratios of fuel pellets and diffusion coefficients of short-lived fission gas release were evaluated from the obtained (R/B) values. The increase of (S/V) ratio agreed well with the point where the fuel temperature exceeded the threshold of 1% fission gas release. This indicates that the interlinkage of fission gas bubbles occurred there. The evaluated diffusion coefficients scattered in the range between 10"-"2"3 and 10"-"1"7 m"2/s, and the effects of fuel type (UO_2 or MOX) were not ...
The European gas market is continuing to expand due to increased industrial, domestic and power generation demand. As a result of this demand, and the trend toward liberalization of the market, the need for storage of gas is also increasing. One key segment of the large scale storage of gas is underground storage, either in partially depleted gas or oil fields, naturally occurring caverns, aquifers and salt cavities. In most cases the gas produced after storage requires conditioning to meet the water of hydrocarbon dew point specification of the gas transmission system. For that reason export gas from storage will require gas conditioning in order to meet pipeline specifications. Adsorption as a feasible and reliable process will be presented in detail and especially in regards to hydrocarbon dew-pointing compared with ...
In the convolution/superposition algorithm, the energy spectrum should be modified to make the reconstructed dose distribution consistent with the measured dose distribution. The energy spectrum, which gives the best agreement, is not determined uniquely depending on the reconstruction procedure. In this report, the effects of the characteristics of the energy spectrum on the calculation accuracy are evaluated by comparing the percentage depth dose (PDD) and beam profiles for the reference energy spectrum with those calculated for the modified spectrum in order to optimize the energy spectrum modification procedure when 4 and 10 MV X-ray beams are used. Decreasing the number of energy bins brought a larger decrease rate in the computation accuracy than a decrease rate in computation time. Further, the decrease of the number of energy bins led to a change of the energy spectrum. The balance of the relative fluence weight in a each bin and its average energy, which ...
The K site near Seoul began landfilling in 1992. The landfilled wastes include municipal solid waste (66.4%), construction residues (20.4%), water and wastewater sludges (trace levels), and hazardous waste (trace levels). The water content of the municipal solid waste is very high (47.3%); as a result, the leachate level (average E.L.) of the landfill, the design value of which is 7.0 m, was measured at 10.3 m in January 1995 and is increasing. The increase of leachate level in the landfill site causes a problem with slope stability. The leachate level at each disposal stage divided by the intermediate cover layer was calculated with the HELP (Hydrologic Evaluation of Landfill Performance) model and calibrated with the data measured from February 1993 to June 1995. Also, the hydraulic conductivities of the waste layer and the intermediate cover layer in each stage were calibrated continuously with HELP model analysis. To verify these results, the total water ...
Pipeline leak detection technologies can be classified according to their specificity, such as their application to offshore or onshore installations or to multi-phase or single-phase flow regimes. They can also be classified according to the technology on which they are based. Available technologies can be categorized into the following 4 groups: (1) compensated mass balance, solving steady state equations which model a specific pipeline, known as real time mode (RTM), (2) the same as group 1, but solving transient equations, known as real time transient model (RTTM), (3) pressure wave behavior, and (4) statistical modeling. Hybrids schemes can also be found. Effective leak detection systems are needed to address the increasing transformation of very large crude cargo (VLCC) ships into floating production, storage and offloading (FPSO) systems. These operations make use of short and large diameters exporting lines, and often involve the use of hoses instead of ...
The upper range of the requirement for methionine plus cystine in healthy adults was proposed in 1985 by FAO/WHO/UNU to be 13 mg.kg body wt-1.d-1. To explore the validity of this estimate, five healthy, young adult men were given for 7 d a diet based on an L-amino acid mixture supplying 13 mg methionine.kg-1.d-1 (87 mumol.kg-1.d-1) without cystine. Constant intravenous infusions of L-[2H3-methyl-1-13C]methionine were given on days 5 and 7 while subjects were in the fed and postabsorptive states, respectively. Estimates were made of methionine oxidation, and daily methionine balance was derived from the intake-oxidation data. For the five subjects, methionine balances were -0.9, +0.7, +3.5, -3.1, and -3.8 mg kg-1.d-1, or -6, +5, +23, -21, and -26 mumol.kg-1.d-1. These findings lead to the conclusion that the upper range of the requirement for methionine plus cystine probably exceeds 13 mg.kg-1.d-1 in healthy young adults. The implications of ...
An intensified integration of renewable energies and a more extensive use of combined heat and power lead to an increasingly decentralized power economy. Such an economy is characterized by the conversion of energy at the point of the energy demand and depending on the energy system, by the possibility of balancing the fluctuating supply of renewable energies. In the long run, there is no doubt that fuel cells will be part of such a sustainable and flexible energy concept. The scope of this dissertation includes an analysis of the flexibility of fuel cells in energy supply (1,5 kW{sub el}), an assessment of the potential to compensate for the fluctuating supply of wind energy by an aggregation of decentralized fuel cells and a participation as a contractor in the spot and balance energy markets. Therefore two fuel cells were monitored and tested in order to obtain their characteristics and distributions for the energy demand of households in ...
Geologically estimated natural gas resources are 500 Tcm. With the advance in geological science increase of estimated resources is expected. Natural gas reserves in 2000 have been proved to be around 165 Tcm. As it is known the reserves are subject to two constraints, namely: capital invested in the exploration and drilling technologies used to discover new reserves. The natural gas scarcity factor, i.e. ratio between available reserves and natural gas consumption, is around 300 years for the last 50 years. The new discovery of natural gas reserves has given rise to a new energy strategy based on natural gas. Natural gas utilization is constantly increasing in the last 50 years. With new technologies for deep drilling, we have come to know that there are enormous gas resources available at relatively low price. These ...
Geologically estimated natural gas resources are 500 Tcm. With the advance in geological science increase of estimated resources is expected. Natural gas reserves in 2000 have been proved to be around 165 Tcm. As it is known the reserves are subject to two constraints, namely: capital invested in the exploration and drilling technologies used to discover new reserves. The natural gas scarcity factor, i.e. ratio between available reserves and natural gas consumption, is around 300 years for the last 50 years. The new discovery of natural gas reserves has given rise to a new energy strategy based on natural gas. Natural gas utilization is constantly increasing in the last 50 years. With new technologies for deep drilling, we have come to know that there are enormous gas resources available at relatively low price. These ...
Two-phase flow in horizontal parallel channels has been experimentally investigated under fuel cell related operating conditions. Pronounced hysteresis is observed in the pressure drop versus flow characteristic curve when starting from either flooded or dry conditions. When gas is introduced into channels initially filled with water (flooded initial condition), both gas and liquid tend to flow predominantly in one channel at low gas or liquid flow velocities. As the gas flow velocity increases, even distribution of gas and liquid flow in both channels is observed, accompanied with a sudden decrease in the pressure drop. On the other hand, even gas and liquid flow distribution between both channels is found at comparatively lower gas flow velocities when starting with dry-gas flow conditions with liquid introduced into ...
A report is given of a meeting of the Netherlands Association for Energy Legislation (NEVER), which was held in Amsterdam, Netherlands, April 2006. After the meeting a presentation was made about the report 'Government involvement in liberalised gas markets. A welfare-economic analysis of the Dutch gas-depletion policy' of the Netherlands Bureau for Economic Policy Analysis (CPB). This report analyses the welfare effects of two major components of the Dutch gas-depletion policy: the offtake guarantee for small-fields gas and the cap on production from the Groningen field. After the presentation a reaction was given to the report. Both presentations give an overview of the governmental policy and insight in the effects.
A high-density gas jet supersonic nozzle is reported in this paper. The jitter and actuation time of the nozzle is determined by the pin discharge and laser spark radiation respectively. The jitter time of the nozzle is within 10 ?s with the backing pressure as high as 25 bar. With a nanosecond laser pulse focused on the gas jet about 1 mm below the nozzle, the actuation time is calculated to be about 15 ms by detecting the laser produced spark radiation, which reveals the existence of the gas jet and the relative gas density evolving with time. Consequently the gas density is estimated to be well above 1019 cm-3, compared with theoretical simulations from the nozzle parameters.
Some aspects of the PSO scheme for natural gas are examined critically. Two central arguments used for justifying the PSO subsidy scheme of natural gas and its distribution are reviewed; these include the 'smallholder argument' and the 'environmental argument'. The 'smallholder argument' claims that since Norway has the natural gas resources, it should also make use of the natural gas in the country, and not simply send the raw material to other countries. The 'environmental argument' states that natural gas compared to other fossil fuels such as coal and fuel oil, is a far cleaner alternative, thus an environmental-friendly alternative entitled to financial support. The arguments are critically examined by the author (ml)
We report on the discovery of kinematic shock signatures associated with a localized radio jet interaction in the merging Seyfert galaxy NGC 5929. We explore the velocity-dependent ionization structure of the gas and find that low-ionization gas at the interaction site is significantly more disturbed than high-ionization gas, which we attribute to a local enhancement of shock ionization due to the influence of the jet. The characteristic width of the broad low-ionization emission is consistent with shock velocities predicted from the ionization conditions of the gas. We interpret the relative prominence of shocks to the high density of gas in the nuclear environment of the galaxy and place some constraints of their importance as feedback mechanisms in Seyferts.
Natural gas is a promising alternative fuel to meet strict engine emission regulations in many countries. Natural gas engines can operate at lean burn and stoichiometric conditions with different combustion and emission characteristics. In this paper, the operating envelope, fuel economy, emissions, cycle-to-cycle variations in indicated mean effective pressure and strategies to achieve stable combustion of lean burn natural gas engines are highlighted. Stoichiometric natural gas engines are briefly reviewed. To keep the output power and torque of natural gas engines comparable to those of their gasoline or Diesel counterparts, high boost pressure should be used. High activity catalyst for methane oxidation and lean deNOx system or three way catalyst with precise air-fuel ratio control str...
An increasing share of natural gas supplies distributed to residential appliances in the U.S. may come from liquefied natural gas (LNG) imports. The imported gas will be of a higher Wobbe number than domestic gas, and there is concern that it could produce more pollutant emissions at the point of use. This report will review recently undertaken studies, some of which have observed substantial effects on various appliances when operated on different mixtures of imported LNG. While we will summarize findings of major studies, we will not try to characterize broad effects of LNG, but describe how different components of the appliance itself will be affected by imported LNG. This paper considers how the operation of each major component of the gas appliances may be impacted by a switch to LNG, and how this local impact may affect overall safety, performance and pollutant emissions.
The 575-mile Statpipe gas transportation system entails 191 miles of wet-gas line running from the Statfjord field across the Norwegian trench to the Karsto, Norway, conditioning plant and 384 miles of dry-gas line from Karsto, again across the trench, to the Heindal and Sleipner fields for final connection at Ekofisk with the Norpipe system for transport to Emden, West Germany. Special construction considerations include the 1000-ft-deep trench crossings, the rocky shore approach and departure, and the subsea tie-ins required at depths of up to 500 ft. The system has an initial annual design capacity of 186 billion CF of wet gas and 260 billion CF through the dry-gas line to Emden.
The Sulige gas field and the Yulin gas field are located in the north of the Ordos Basin. Reservoir pressure in the Sulige area is subnormal, whereas reservoirs in the Yulin area have normal hydrostatic pressure. This paper provides an explanation of this difference. The characteristics of reservoir sediment and formation water chemistry in the gas reservoirs of these two areas were analyzed. The results showed that both reservoirs have good sealing ability. Data of numerical simulation showed that tectonic uplift resulted in a great reduction in formation pressure in the northern Ordos Basin during the late Cretaceous period, and the decrease was greater in the Yulin gas field than in the Sulige gas field. However, because the total hydrocarbon-generating intensity of the Sulige area (<24...
The Granger instantaneous-causality test is applied to explore the potential causal relationships between wholesale electricity and natural-gas prices in California. The test shows these relationships to be bi-directional, and reveals California's electricity and natural-gas markets to be as inextricably intertwined as casual observation and theoretical considerations would suggest they ought to be. This meshing of markets exacerbated the effects of California's natural-gas crisis on the contemporaneous electricity crisis, while concurrently the electricity crisis may have contributed to the dysfunction in the national-gas market and helped to precipitate the natural-gas crisis. The finding supports an integrated approach, as opposed to a piecemeal approach, for formulating energy policy recommendations, not just in California but in the world at large. (author)
The Granger instantaneous-causality test is applied to explore the potential causal relationships between wholesale electricity and natural-gas prices in California. The test shows these relationships to be bi-directional, and reveals California's electricity and natural-gas markets to be as inextricably intertwined as casual observation and theoretical considerations would suggest they ought to be. This meshing of markets exacerbated the effects of California's natural-gas crisis on the contemporaneous electricity crisis, while concurrently the electricity crisis may have contributed to the dysfunction in the national-gas market and helped to precipitate the natural-gas crisis. The finding supports an integrated approach, as opposed to a piecemeal approach, for formulating energy policy recommendations, not just in California but in the world at large.
Barsebaeck 1 was closed on 30 November 1999. Barsebaeck's output of approximately 4 TWh per year will primarily be replaced by imports from coal-fired plants in Denmark and Germany. During the year, the closure of Swedish fossil-fired condensing power stations continued. With that, over 3,000 MW of peak-load power has been shut down during recent years. Consequently, situations entailing shortages of power can arise. On the deregulated electricity market, it is only the system operators that have a satisfactory overview of the overall electricity balance. The Swedish Power Association has thus lobbied the government as regards the need to elucidate Svenska Kraftnaet's responsibility. In a governmental decision from December, Svenska Kraftnaet was given the task of, among other things, monitoring the available capacity during peak loads and developing market instruments that can contribute to safeguarding the availability of power during peak ...
In this study the technical and economical possibilities of burning carbon monoxide (CO) of the flue gas and utilizing of the released heat in hot air cupola furnace used for melting have been studied. As basis for examining was burning of cleaned furnace...
The paper is an overview of utility flue gas desulfurization (FGD) technology and costs. The two commercially offered throwaway and salable product systems that are considered to be the most important for near-term (through 1990) SO2 control are: throwawa...
This patent describes a method of improving the S0{sub 2} scrubbing efficiency of flue gas desulfurization scrubbers. It comprises conducting the scrubbing operation in such scrubbers in the presence of an oil-soluble surfactant.
Gas turbine component protection remains essential but environmental regulations emphasize the gas-turbine efficiency. Heating and cooling are features often integrated into the GI air intake packages to provide the optimum operating conditions. This paper describes modern inlet air treatment systems and discusses their effectiveness. (author)
The structure of the skin in the epauletted fruit bat (Epomophorus wahlbergi) wing and body trunk was studied with a view to understanding possible adaptations for gas metabolism and...Full Text Available
The genetic type, source and charging history of natural gas in the Yulin gas field in the Ordos Basin have been studied by combining the carbon isotopic composition of natural gas and geochemical characteristics of light hydrocarbons with carbon isotope fractionation model results and fluid inclusion analysis. The carbon isotopic composition of methane and ethane in the Yulin gas field is relatively enriched in ^1^3C with d^1^3C1 values ranging from -35.3%% to -29.8%% (average value=-32.4%%) and d^1^3C2 ranging from -26.3%% to -23.5%% (average value=-24.8%%). The C7 light hydrocarbons are predominated by methylcyclohexane, accounting for 65.8% to 80.9% (average value=71.6%), which is characteristic of coal-derived gas. Furthermore, the gas geochemistry indicates that, although marine lime...
The Bureau of Mines performed chemical research to elaborate details of sulfur chemistry pertaining to the citrate flue gas desulfurization process in which sulfur dioxide (SO2), absorbed (as bisulfite ion) in a buffered sodium citrate solution, is reduce...
This report gives the results of a survey of operational flue gas desulfurization (FGD) systems on coal-fired utility boilers in the United States. The FGD systems installed on Units 1 and 2 at the Bruce Mansfield Station of the Pennsylvania Power Company...
A catalytic process for the oxidation of sulfur-containing gases , E.G., sulfur dioxide and simultaneous production of sulfuric acid wherein a sulfur-containing gas is reacted with an oxygencontaining gas in the presence of a catalyst comprising an iron group metal on a solid support comprising a zeolite in a silicaalumina matrix.
Gas exchange between the plant and the environment is severely hampered when plants are submerged, leading to oxygen and energy deficits. A straightforward way to reduce these shortages of oxygen and...Full Text Available
TSS (thermal swing sublimation) method was studied which uses vaporization heat and sensible heat of LNG for solidification and separation of CO2 gas in waste gases of LNG-fired combined cycle power generation system. In experiment, the mixed gas composed of CO2, H2O and N2 was used for simulating waste gas of LNG-fired combined cycle power generation systems, and the growth behavior of ice and dry ice was studied for developing dry ice making technology under low-temperature condition. As the experimental result, the following were clarified: various crystal structures depending on cooling temperature, the effect of gas flow rate on peeling of surface precipitated solids, and solidification characteristics of H2O/CO2 mixed gas. The growth rate of precipitated solid film thickness decreased with an increase in gas flow rate, while increased with CO2 ...
Limestone slurry needs to move efficiently through a complex process, meaning that selecting the right pumps and valves is critical. The article discusses factors to consider in selecting pumps and values for flue gas desulfurization process in coal-fired power plants. 2 photos.
The possibility has been explored of using a laser scattering technique to detect the imminent onset of rock activity associated with gas outbursts. The instrument described in this paper provides a sensitive, remote and rapid means of passively monitoring micro-seismic activity at the exposed face.
Petroleum is the unchallenged energy market leader in West Germany,having a share of 42%; natural gas accounts for 16-17%. West Germany imports 29% of its natural gas from the Soviet Union, 28% from the Netherlands, 14% from Norway, and 1% from Denmark. In West Germany many-branched natural gas distribution system is operated, equipped with a.o. 21 installations for underground storage which results in a great flexibility of the system. Because of the preferential treatment given to the use of coal as fuel for power plants the share of natural gas has decreased to the present 6% in the last ten years. In the indutrial sector the share is 18%. Strict air pollution abatement measures ('TA-Luft') favour the use of natural gas. However, duty has been levied on the use of natural gas per January 1st, 1989. For space heating of houses and commercial ...
The Monthly Energy Review provides an overview of the production, distribution, and consumption of energy derived from petroleum natural gas, coal, electricity, and nuclear energy. It also discusses oil and gas resource development, energy prices, and issues relevant to international energy markets.
This report presented some quick facts about oil and gas pipelines in Turkey and presented opportunities for trade. The key players and customers in the oil and gas sector were described along with an export check list. Turkey is looking into becoming an energy bridge between oil and gas producing countries in the Middle East, Central Asia and Europe. The oil and gas sectors are dominated by the Turkish Petroleum Corporation, a public enterprise dealing with exploration and production, and the State Pipeline Corporation which deals with energy transmission. They are also the key buyers of oil and gas equipment in Turkey. There are several pipelines connecting countries bordering the Caspian Sea. Opportunities exist in the areas of engineering consulting as well as contracting services for oil and gas pipeline transmission and distribution. Other opportunities ...
The report gives results of the measurement of dissolution rates of reagent CaCO3 and commercial limestones (9 types/19 grinds) at constant pH and solution composition by batch titration with HC1. Conditions were selected to simulate flue gas desulfurizat...
The influence of geometry and operating conditions of the centrifugal compressor stage on the radial gas force is determined on the basis of the theoretical method and calculation program using experimental boundary conditions.
... Radon gas concentrations are measured using instruments with calibrations traceable to the UK National Physical Laboratory and PTB, Germany. The primary facility is a 43 m3 walk-in chamber accessed by an airlock. Radon gas is maintained at a level in this chamber that is ...
The various steps of gas treatment in the Sasol II coal liquefaction plant are discussed: CO/sub 2/ removal, separation of the hydrocarbon fractions and the recirculated hydrogen by low-temperature decomposition, production of pure hydrogen by alternating pressure absorption.
Jeltes, R., Burghardt, E., and Breman, J. (1971). Brit. J. industr. Med., 28, 96-99. Gas chromatographic determination of phosgene and dichloroacetylene in air. Phosgene and dichloroacetylene...Full Text Available
An experimental investigation of heat transfer characteristics for various configurations of air jets impinging on the leading edge inner surface of a gas turbine blade wall is presented. Three configurations were investigated, namely a slot jet, a round ...
The goal of GRI's Gas Appliance Technology Center is to encourage the introduction of highly efficient, cost-effective, convenient gas appliances for residential and commercial gas users. The report covers activity at Battelle from February 1989 to April 1990 in broad support tasks, residential and commercial appliances, and residential space conditioning. Broad support tasks included the G/A/S Newsletter; the GATC InfoBase; and technology transfer, workshops, and GATC coordination. Residential appliance tasks included burner technology research, gas appliance venting, gas lighting, and plastics durability. Commercial appliance tasks included development of a commercial cooktop fuel/air mixing valve. Residential space conditioning tasks included a corrosion test method for gas appliances and vents, generic technology for condensing ...
This paper summarizes the current scientific and technological knowledge about greenhouse gas emissions from various agricultural practices and the manufacturing of food. The study also provides estimates that compare agriculture-related alternatives for reducing greenhouse gas emissions.
Legal aspects of using natural gas as boiler fuel for electric utilities are reviewed through one utility's challenges to the Power Plant and Industrial Fuel Use implementation. ASARCO vs. FPC, 1973, and City of Willcox vs. FPC are discussed. (PSB)
The report, generated by a computerized data base system, presents a survey of operational and planned domestic utility flue gas desulfurization (FGD) systems, operational domestic particle scrubbers, and Japanese coal-fired utility FGD installations. It ...
The report presents detailed technical information concerning application of flue gas desulfurization (FGD) systems to industrial boilers. The information was obtained by a survey of plant personnel, control system vendors, regulatory agencies, and consulting engineering firms. T...
The report discusses the capabilities of equipment vendors to supply and install the quantity of flue gas desulfurization systems required to meet alternative standards for coal-fired steam generators. It analyzes limiting factors affecting supply capabilities (such as the availa...
The effects of freeze-thaw cycling on the strength and durability of samples of compacted, stabilized, wet flue gas desulfurization (FGD) by-products are reported. The results of laboratory tests show a clear relationship between higher water contents and...
NO[sub x] emission legislation requirements for large-bore internal combustion engines have required engine manufacturers to continue to develop and improve techniques for exhaust emission reduction. This paper describes the development of the Cooper-Bessemer Clean Burn gas-diesel (dual-fuel) engine that results in NO[sub x] reductions of up to 92 percent as compared with an uncontrolled gas-diesel engine. Historically, the gas-diesel and diesel engine combustion systems have not responded to similar techniques of NO[sub x] reduction that have been successful on straight spark-ignited natural gas burning engines. NO[sub x] levels of a nominal 1.0 g/BHP-h, equal to the spark-ignited natural gas fueled engine, have been achieved for the gas-diesel and are described. In addition, the higher opacity exhaust plume characteristic of gas-diesel ...
Concentration of an amine solution for removal of hydrogen sulfides and carbon dioxide from natural gas, is tested by carbon dioxide absorption measurement in an apparatus allowing complete reaction to give reliable results.
The increasing price differential between natural gas and coal will create a demand for technology that can allow the displacement of natural gas with coal in power plants. Coal gasification is the standard approach suggested to allow coal to displace natural gas. However, the relatively high capital investment required for coal gasification will require fuel cost differentials higher than those anticipated in the near term before coal gasification replaces natural gas. One way of achieving shorter term displacement of natural gas by coal would be to develop technology that would allow coal to be used as the heat source for the endothermic reforming of natural gas. In a natural gas-fired combined cycle power plant, the endothermic heat of reforming, which would be provided by coal combustion, is recovered in the combined-cycle. Therefore, ...
At the St. Joe Minerals Corp.'s zinc smelter powerplant, an SO2 emission control program evolved into a cooperative program with the Bureau of Mines for installation and initial operation of a citrate process flue gas desulfurization demonstration plant. ...
The report describes a computer model developed by TVA to simulate the performance and determine the economics of coal cleaning, or coal cleaning combined with flue gas desulfurization (FGD), for power plant emission control processes over a wide range of user-specified condition...
The manual describes a combined coal-cleaning and flue gas desulfurization (FGD) computerized design and cost-estimate model and gives detailed procedures for using it. All inputs and outputs are described, as well as the various options available. Design and economic premises ar...
This project addresses the problem of flue gas desulfurization (FGD) sludge disposal to land. Specifically, the chemical species of FGD sludge constituents are thermodynamically modeled using the equilibrium constant approach, in an attempt to predict the constituent concentratio...
The report gives an initial assessment of the feasibility of disposing of flue gas desulfurization wastes in mines and in the ocean. The purpose of the assessment was to evaluate environmental, technical, regulatory, and economic aspects of the use of such disposal sites. Availab...
Crockford, G. W., Crowder, M., and Prestidge, S. P. (1972).Brit. J. industr. Med.,29, 378-386. A trace gas technique for measuring clothing microclimate...Full Text Available
In this paper we have proposed a novel gas turbine cycle with hydrogen-fueled chemical-looping combustion, and the system study on two hydrogen-fueled power plants, the new gas turbine cycle and an advanced gas turbine cycle with H{sub 2}/O{sub 2} combustion, has been investigated with the aid of exergy principle (EUD methodology). The hydrogen fueled chemical-looping combustion in the new gas turbine cycle consists of two successive reactions: hydrogen fuel is reacted with metal oxide (reduction of metal oxide), and then instead of air or pure oxygen, the reduced metal is successively oxidized by the saturated air. As a result, the new hydrogen-fueled gas turbine cycle has a breakthrough performance, with at least about 12 percentage-point higher efficiency compared to the gas turbine cycle with H{sub 2}/O{sub 2} combustion, and will be environmentally superior ...
Gas-fired combined cycle plant may be the norm when it comes to new plant but it comes in a variety of shapes and sizes. Samarinda uses aero-derivatives with the famous Rolls-Royce RB211 gas generator. (author)
The feasibility of producing a pocket-sized air contaminant monitor based upon a miniature gas chromatograph and an integrated microcomputer has been demonstrated and a practical design for the instrument is presented. This pocket-sized instrument is intended to be used as a pers...
Functional imaging of the pharynx used to be the domain of cineradiography, CT and ultrafast CT. The development of modern MRI techniques led to new access to functional disorders of the pharynx. The aim of this study was to implement a new MRI technique to examine oropharyngeal obstructive mechanisms in patients with obstructive sleep apnea (OSA). Sixteen patients suffering from OSA and 6 healthy volunteers were examined on a 1.5 T whole-body imager (`Vision`, Siemens, Erlangen Medical Engineering, Germany) using a circular polarized head coil. Imaging was performed with 2D flash sequences in midsagittal and axial planes. Patients and volunteers were asked to breathe normally through the nose and to simulate snoring and the Mueller maneuver during magnetic resonance imaging (MRI). Prior to MRI, all patients underwent an ear, nose and throat (ENT) examination, functional fiberoptic nasopharyngoscopy and polysomnography. A temporal resolution of 6 images/s and an ...
Apparatus and method for selective measurement of tritium oxide in an environment which may include other radioactive components and gamma radiation, the measurement including the selective separation of tritium oxide from a sample gas through a membrane into a counting gas, the generation of electrical pulses individually representative by rise times of tritium oxide and other radioactivity in the counting gas, separation of the pulses by rise times, and counting of those pulses representative of tritium oxide. The invention further includes the separate measurement of any tritium in the sample gas by oxidizing the tritium to tritium oxide and carrying out a second separation and analysis procedure as described above.
A high-voltage cathode initiates an electron emission, resulting in a reduction in the carbon dioxide concentration in exhaust gas from the burning of hydrocarbon fuel. Assuming that the observed carbon dioxide reduction is originated from the molecular decomposition, the energy needed for the endothermic reaction of this carbon dioxide reduction may stem primarily from the internal energy reduction in the exhaust gas in accordance of the first law of the thermodynamics. An oxygen increase due to the reduction in carbon dioxide in a discharge gas was observed in real time.
This report consists of three sections. The first section is a brief general overview of all the issues that impact the competition between natural gas and electricity in industrial applications. The second section of this report focus on the all the marketing issues and provides detail analysis of the status of these issues in Europe, Japan and United States. The third section of this report is a detail review of the current status of the competition between gas technologies and electro-technologies, it also make recommendation for developing new gas technologies. The fourth section is a contribution from M. Pettersson and S. Stenstroem, Sweden, on infrared dryers. (authors)
Makeup water is distilled internally in an amine gas treating unit by adding it to the reclaimer used to process a slipstream of lean amine from the stripper.
Experimental data on the gas holdup and the mean bubble size in a bubble column with a single nozzle was obtained for gas-molten salt systems of a eutectic mixture of LiCl (58 mol %)-KCl (42 mol %) and molten NaNO/sub 3/. The liquid-phase mass transfer coefficient K /SUB L/ was evaluated from the specific surface area a and the volumetric coefficient K /SUB L/ a data for oxygen and carbon dioxide absorption into molten NaNO/sub 3/. The dimensionless correlations of the performance of bubble columns for aqueous solutions can be extended to the gas-molten salt systems.
This dissertation deals with membrane gas absorption in the application of CO{sub 2} removal by aqueous alkanolamines, using microporous PTFE hollow fiber membranes. A new lab-scale apparatus was constructed and an extensive experimental study executed to determine the performance of the membrane gas absorber, with aqueous solutions of monoethanolamine (MEA) and methyldiethanolamine (MDEA) as absorbents. The important operation parameters CO{sub 2} partial pressure, gas velocity, liquid velocity, temperature and liquid CO{sub 2} loading were systematically varied within the range typically experienced in a process for exhaust gas CO{sub 2}-removal
This thesis dealt with the metal-organic gas phase epitaxy with nitrogen as carrier gas. For this first by means of three-dimensional modelings of the epitaxy process the influence of the carrier gas on the processes was explained. The optimization of the growth parameter for the whole light-emitting-diode structure in double-hetero arrangement resulted that an a temperature of 770 C and a V/ III-ratio of 150 layers with a high crystal quality could be reached.
Access for independents to retail gas markets was a central concern in European policy reform efforts in the 1990s. Upstream oil and gas companies reacted with strategic intentions of forward integration. By late 2004, forward integration was still weak, however. An important explanation of the gap between announced strategic re-orientation and actual strategy implementation lies in the political failure of EU member states to dismantle market barriers to entry for independents. Variations between companies in downstream strategy implementation are explained by variations in business opportunities and internal company factors.
Dimethyl methylphosphonate (DMMP), a chemical simulant of the nerve gas GB, was decontaminated with a nonthermal atmospheric pressure plasma. The decontamination efficiency was measured qualitatively by means of Fourier transform spectroscopy and quantitatively by means of gas chromatography. With helium gas only, 10g/m2 of DMMP on an aluminum surface was 99.9% decontaminated in 2min, furthermore, with the addition of 5% of oxygen gas, it was 99.99% decontaminated in 10min. Given the low input power (<100W) and temperature (<75degreeC), this plasma is eligible for nondestructive decontamination of almost all material surfaces.
The purpose of this work was to develop and evaluate a method of locating breached fuel within the Fast Flux Test Facility (FFTF) reactor based on the relative response of the delayed neutron monitors (DNM) located on each of the three primary sodium cooling loops. The primary method of location is the use of tag gas containing unique ratios of the noble gases xenon and krypton. Although the tag gas system works quite well, it is relatively expensive because of the costs of preparing and loading the gas into each fuel pin. Triangulation of DNM signals could potentially decrease tag gas costs while maintaining overall location reliability.
This paper is a quarterly report describing the use of a new soil gas collection device which allows the collection of soil gas in the field for later analysis in the laboratory. It describes the installation of this sampling device and the procedure for setting the probe, extraction of soil gas beneath the surface, and sealing of the soil gas for transport. The sites used for initial testing was the top of Yucca Mountain and Crystal Spring in Ash Meadows National Wildlife Refuge. The results from this initial test showed no volatile matter present in the soil at these locations.
The multicell proportional chambers at the backing calorimeter of the ZEUS experiment at the storage ring HERA are supplied with a gas mixture of Ar/CO[sub 2] by an open gas system. Flow proportional counters with the build-up [sup 55]Fe sources are used as gas system monitoring detectors. The ZEUS experiment is planned to collect data for about 10 years. Therefore, the lifetime of the Ar/CO[sub 2] mixture should be known. In this paper, the results of laboratory tests and preliminary measurements of the aging effects for monitoring counters are presented. ((orig.))