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Sample records for high performance small-scale

  1. High-Performance Small-Scale Solvers for Moving Horizon Estimation

    Frison, Gianluca; Vukov, Milan; Poulsen, Niels Kjølstad

    2015-01-01

    implementation techniques focusing on small-scale problems. The proposed MHE solver is implemented using custom linear algebra routines and is compared against implementations using BLAS libraries. Additionally, the MHE solver is interfaced to a code generation tool for nonlinear model predictive control (NMPC...

  2. Big Data solutions on a small scale: Evaluating accessible high-performance computing for social research

    Murthy, Dhiraj; Bowman, S. A.

    2014-01-01

    Though full of promise, Big Data research success is often contingent on access to the newest, most advanced, and often expensive hardware systems and the expertise needed to build and implement such systems. As a result, the accessibility of the growing number of Big Data-capable technology solutions has often been the preserve of business analytics. Pay as you store/process services like Amazon Web Services have opened up possibilities for smaller scale Big Data projects. There is high dema...

  3. Big Data solutions on a small scale: Evaluating accessible high-performance computing for social research

    Dhiraj Murthy

    2014-11-01

    Full Text Available Though full of promise, Big Data research success is often contingent on access to the newest, most advanced, and often expensive hardware systems and the expertise needed to build and implement such systems. As a result, the accessibility of the growing number of Big Data-capable technology solutions has often been the preserve of business analytics. Pay as you store/process services like Amazon Web Services have opened up possibilities for smaller scale Big Data projects. There is high demand for this type of research in the digital humanities and digital sociology, for example. However, scholars are increasingly finding themselves at a disadvantage as available data sets of interest continue to grow in size and complexity. Without a large amount of funding or the ability to form interdisciplinary partnerships, only a select few find themselves in the position to successfully engage Big Data. This article identifies several notable and popular Big Data technologies typically implemented using large and extremely powerful cloud-based systems and investigates the feasibility and utility of development of Big Data analytics systems implemented using low-cost commodity hardware in basic and easily maintainable configurations for use within academic social research. Through our investigation and experimental case study (in the growing field of social Twitter analytics, we found that not only are solutions like Cloudera’s Hadoop feasible, but that they can also enable robust, deep, and fruitful research outcomes in a variety of use-case scenarios across the disciplines.

  4. Solar-driven Joule cycle reciprocating Ericsson engines for small scale applications. From improper operation to high performance

    Stanciu, Dorin; Bădescu, Viorel

    2017-01-01

    Highlights: • New dynamic model for parabolic trough collector (PTC) coupled to Ericsson engine (EE). • Design procedure of the PTC-EE system which avoid malfunction. • Variation of PTC-EE system performance during a day for different engine rotation speeds. • Strategy to switch between different rotation speeds to maximize daily output work. - Abstract: The paper focuses on a Joule cycle reciprocating Ericsson engine (JCREE) coupled with a solar parabolic trough collector (PTC). A small scale application located at mid Northern Hemisphere latitude (44°25″N) is considered. A new dynamic (time-dependent) model is developed and used to design the geometry and estimate the performance of the PTC-JCREE system under the most favorable weather conditions (i.e. summer day and clear sky). The paper brings two main contributions. First, specific constraints on the design parameters have been identified in order to avoid improper JCREE operation, such as gas under-compression in the compressor cylinder and gas over-compression and/or over-expansion in the expander cylinder. Second, increasing the work generated per day requires using a proper strategy to switch between different rotation speeds. Specific results are as follows. For the (reference) constant engine rotation speed 480 rpm, the output work per day is 39,270 kJ and the overall efficiency is 0.134. The output work decreases by increasing the rotation speed, since the operation interval during a day diminishes. A better operation strategy is to switch among three rotation speed values, namely 480, 540 and 600 rpm. In this case the output work is 40,322 kJ and the overall efficiency is 0.137. The performance improvement is quite small and the reference constant rotation speed 480 rpm may be a suitable choice, easier to use in practice. For both the constant and variable rotation speed strategies, the overall efficiency is almost constant along the effective operation time interval, which is from 8:46 to

  5. Analysis of small-scale rotor hover performance data

    Kitaplioglu, Cahit

    1990-01-01

    Rotor hover-performance data from a 1/6-scale helicopter rotor are analyzed and the data sets compared for the effects of ambient wind, test stand configuration, differing test facilities, and scaling. The data are also compared to full scale hover data. The data exhibited high scatter, not entirely due to ambient wind conditions. Effects of download on the test stand proved to be the most significant influence on the measured data. Small-scale data correlated resonably well with full scale data; the correlation did not improve with Reynolds number corrections.

  6. Small-scale tunnel test for blast performance

    Felts, J E; Lee, R J

    2014-01-01

    The data reported here provide a validation of a small-scale tunnel test as a tool to guide the optimization of new explosives for blast performance in tunnels. The small-scale arrangement consisted of a 2-g booster and 10-g sample mounted at the closed end of a 127 mm diameter by 4.6-m long steel tube with pressure transducers along its length. The three performance characteristics considered were peak pressure, initial energy release, and impulse. The relative performance from five explosives was compared to that from a 1.16-m diameter by 30-m long tunnel that used 2.27-kg samples. The peak pressure values didn't correlate between the tunnels. Partial impulse for the explosives did rank similarly. The initial energy release was determined from a one-dimensional point-source analysis, which nearly tracked with impulse suggesting additional energy released further down the tunnel for some explosives. This test is a viable tool for optimizing compositional variations for blast performance in target scenarios of similar geometry.

  7. Macroscopic High-Temperature Structural Analysis Model of Small-Scale PCHE Prototype (II)

    Song, Kee Nam; Lee, Heong Yeon; Hong, Sung Deok; Park, Hong Yoon

    2011-01-01

    The IHX (intermediate heat exchanger) of a VHTR (very high-temperature reactor) is a core component that transfers the high heat generated by the VHTR at 950 .deg. C to a hydrogen production plant. Korea Atomic Energy Research Institute manufactured a small-scale prototype of a PCHE (printed circuit heat exchanger) that was being considered as a candidate for the IHX. In this study, as a part of high-temperature structural integrity evaluation of the small-scale PCHE prototype, we carried out high-temperature structural analysis modeling and macroscopic thermal and elastic structural analysis for the small-scale PCHE prototype under small-scale gas-loop test conditions. The modeling and analysis were performed as a precedent study prior to the performance test in the small-scale gas loop. The results obtained in this study will be compared with the test results for the small-scale PCHE. Moreover, these results will be used in the design of a medium-scale PCHE prototype

  8. Performance analysis of small-scale experimental facility of TWDEC

    Kawana, Ryoh; Ishikawa, Motoo; Takeno, Hiromasa; Yamamoto, Takayoshi; Yasaka, Yasuyoshi

    2008-01-01

    The objective of the present paper is to analyze small-scale experimental facilities of TWDEC (Travelling Wave type Direct Energy Converter) and to propose a modification in regard to a measuring device of the facilities by means of numerical simulation with the axisymmetrical two-dimensional approximation (a PIC method). The numerical simulation has given the following results: (1) tendency of the numerical results agree with the experimental results on the measured deceleration efficiency, (2) the deceleration efficiency measured in the experiment will increase if the radius of Faraday cup installed in the experiment increases and (3) the wave of condensation and rarefaction of measured electric charge density, which is averaged in the r-direction below the radius of Faraday cup, is not formed enough with a small radius of Faraday cup because of the r component of electric field which is induced by the electrode geometry

  9. Performance evaluation of granular activated carbon system at Pantex: Rapid small-scale column tests to simulate removal of high explosives from contaminated groundwater

    Henke, J.L.; Speitel, G.E. [Univ. of Texas, Austin, TX (United States). Dept. of Civil Engineering

    1998-08-01

    A granular activated carbon (GAC) system is now in operation at Pantex to treat groundwater from the perched aquifer that is contaminated with high explosives. The main chemicals of concern are RDX and HMX. The system consists of two GAC columns in series. Each column is charged with 10,000 pounds of Northwestern LB-830 GAC. At the design flow rate of 325 gpm, the hydraulic loading is 6.47 gpm/ft{sup 2}, and the empty bed contact time is 8.2 minutes per column. Currently, the system is operating at less than 10% of its design flow rate, although flow rate increases are expected in the relatively near future. This study had several objectives: Estimate the service life of the GAC now in use at Pantex; Screen several GACs to provide a recommendation on the best GAC for use at Pantex when the current GAC is exhausted and is replaced; Determine the extent to which natural organic matter in the Pantex groundwater fouls GAC adsorption sites, thereby decreasing the adsorption capacity for high explosives; and Determine if computer simulation models could match the experimental results, thereby providing another tool to follow system performance.

  10. Performance evaluation of granular activated carbon system at Pantex: Rapid small-scale column tests to simulate removal of high explosives from contaminated groundwater

    Henke, J.L.; Speitel, G.E.

    1998-08-01

    A granular activated carbon (GAC) system is now in operation at Pantex to treat groundwater from the perched aquifer that is contaminated with high explosives. The main chemicals of concern are RDX and HMX. The system consists of two GAC columns in series. Each column is charged with 10,000 pounds of Northwestern LB-830 GAC. At the design flow rate of 325 gpm, the hydraulic loading is 6.47 gpm/ft 2 , and the empty bed contact time is 8.2 minutes per column. Currently, the system is operating at less than 10% of its design flow rate, although flow rate increases are expected in the relatively near future. This study had several objectives: Estimate the service life of the GAC now in use at Pantex; Screen several GACs to provide a recommendation on the best GAC for use at Pantex when the current GAC is exhausted and is replaced; Determine the extent to which natural organic matter in the Pantex groundwater fouls GAC adsorption sites, thereby decreasing the adsorption capacity for high explosives; and Determine if computer simulation models could match the experimental results, thereby providing another tool to follow system performance

  11. The Impact of Micro-Finance on the Performance of Small-Scale ...

    The Impact of Micro-Finance on the Performance of Small-Scale Enterprises: A Comparison of ... PROMOTING ACCESS TO AFRICAN RESEARCH ... the impact that the study-MFIs are making on their SMEs-client in the Wa Municipality.

  12. Performance of small-scale photovoltaic systems and their potential for rural electrification in Ethiopia

    Stutenbaeumer, Ulrich; Negash, Tesfaye; Abdi, Amensisa [Addis Ababa Univ., Dept. of Physics, Addis Ababa (Ethiopia)

    1999-09-01

    The performance of small-scale stand-alone photovoltaic systems is tested under the climatic conditions of Addis Ababa, Ethiopia. With climatic data obtained at a station in the Rift Valley, the photovoltaic systems performance is estimated for those climatic conditions. The economics of small-scale stand-alone photovoltaic system applications under Ethiopian conditions are analysed. The potential of photovoltaics for the rural electrification of Ethiopia is discussed. (Author)

  13. High-Temperature Structural Analysis of a Small-Scale PHE Prototype under the Test Condition of a Small-Scale Gas Loop

    Song, K.; Hong, S.; Park, H.

    2012-01-01

    A process heat exchanger (PHE) is a key component for transferring the high-temperature heat generated from a very high-temperature reactor (VHTR) to a chemical reaction for the massive production of hydrogen. The Korea Atomic Energy Research Institute has designed and assembled a small-scale nitrogen gas loop for a performance test on VHTR components and has manufactured a small-scale PHE prototype made of Hastelloy-X alloy. A performance test on the PHE prototype is underway in the gas loop, where different kinds of pipelines connecting to the PHE prototype are tested for reducing the thermal stress under the expansion of the PHE prototype. In this study, to evaluate the high-temperature structural integrity of the PHE prototype under the test condition of the gas loop, a realistic and effective boundary condition imposing the stiffness of the pipelines connected to the PHE prototype was suggested. An equivalent spring stiffness to reduce the thermal stress under the expansion of the PHE prototype was computed from the bending deformation and expansion of the pipelines connected to the PHE. A structural analysis on the PHE prototype was also carried out by imposing the suggested boundary condition. As a result of the analysis, the structural integrity of the PHE prototype seems to be maintained under the test condition of the gas loop.

  14. GENDER DIFFERENTIALS IN FACTORS AFFECTING PERFORMANCE OF SMALL-SCALE ENTERPRISES IN LAGOS STATE – NIGERIA

    Yusuff Olabisi Sherifat

    2013-05-01

    Full Text Available There is a lack of empirical data segregation on factors affecting gender as the variable of interest. However, previous research had indicated several factors that affect business performances among small-scale enterprise owners. Using feminist theory and a descriptive survey research design, data were collected from fifty (50 small-scale enterprise owners that were purposively chosen across the study area. The findings show that the factors that were significant for female were significantly different from male. For female small scale enterprise owners, marital status (64% Age of Children (68%, Role Model/ advisors (58% were significant factors that affect their business performance. For male small-scale enterprise owners, Friends (70%, a lack of Government support (80%, inability to display innovativeness (78% and Risk-Taking (84% were significant for male. Lack of availability of capital and finances were significant for the two. Other factors that affect performance include friends, inadequate training and business location. Adequate knowledge of factors that affect gender enterprise performance will go a long way in alleviating these problems. Small-scale enterprises should be supported for poverty alleviation, especially among women and for the nation’s economic development

  15. STATISTICAL EVALUATION OF SMALL SCALE MIXING DEMONSTRATION SAMPLING AND BATCH TRANSFER PERFORMANCE - 12093

    GREER DA; THIEN MG

    2012-01-12

    The ability to effectively mix, sample, certify, and deliver consistent batches of High Level Waste (HLW) feed from the Hanford Double Shell Tanks (DST) to the Waste Treatment and Immobilization Plant (WTP) presents a significant mission risk with potential to impact mission length and the quantity of HLW glass produced. DOE's Tank Operations Contractor, Washington River Protection Solutions (WRPS) has previously presented the results of mixing performance in two different sizes of small scale DSTs to support scale up estimates of full scale DST mixing performance. Currently, sufficient sampling of DSTs is one of the largest programmatic risks that could prevent timely delivery of high level waste to the WTP. WRPS has performed small scale mixing and sampling demonstrations to study the ability to sufficiently sample the tanks. The statistical evaluation of the demonstration results which lead to the conclusion that the two scales of small DST are behaving similarly and that full scale performance is predictable will be presented. This work is essential to reduce the risk of requiring a new dedicated feed sampling facility and will guide future optimization work to ensure the waste feed delivery mission will be accomplished successfully. This paper will focus on the analytical data collected from mixing, sampling, and batch transfer testing from the small scale mixing demonstration tanks and how those data are being interpreted to begin to understand the relationship between samples taken prior to transfer and samples from the subsequent batches transferred. An overview of the types of data collected and examples of typical raw data will be provided. The paper will then discuss the processing and manipulation of the data which is necessary to begin evaluating sampling and batch transfer performance. This discussion will also include the evaluation of the analytical measurement capability with regard to the simulant material used in the demonstration tests. The

  16. Development and performance evaluation of frustum cone shaped churn for small scale production of butter.

    Kalla, Adarsh M; Sahu, C; Agrawal, A K; Bisen, P; Chavhan, B B; Sinha, Geetesh

    2016-05-01

    The present research was intended to develop a small scale butter churn and its performance by altering churning temperature and churn speed during butter making. In the present study, the cream was churned at different temperatures (8, 10 and 12 °C) and churn speeds (35, 60 and 85 rpm). The optimum parameters of churning time (40 min), moisture content (16 %) and overrun (19.42 %) were obtained when cream was churned at churning temperature of 10 °C and churn speed of 60 rpm. Using appropriate conditions of churning temperature and churn speed, high quality butter can be produced at cottage scale.

  17. Small-scale integrated demonstration of high-level radioactive waste processing and vitrification using actual SRP waste

    Woolsey, G.B.; Baumgarten, P.K.; Eibling, R.E.; Ferguson, R.B.

    1981-01-01

    A small-scale pilot plant for chemical processing and vitrification of actual high-level waste has been constructed at the Savannah River Laboratory (SRL). This fully integrated facility has been constructed in six shielded cells and has eight major unit operations. Equipment performance and processing characteristics of the unit operations are reported

  18. Small-scale demonstration of high-level radioactive waste processing and solidification using actual SRP waste

    Okeson, J.K.; Galloway, R.M.; Wilhite, E.L.; Woolsey, G.B.; Ferguson, R.B.

    1980-01-01

    A small-scale demonstration of the high-level radioactive waste solidification process by vitrification in borosilicate glass is being conducted using 5-6 liter batches of actual waste. Equipment performance and processing characteristics of the various unit operations in the process are reported and, where appropriate, are compared to large-scale results obtained with synthetic waste

  19. Performance of small-scale aero-derivative industrial gas turbines derived from helicopter engines

    Barinyima Nkoi

    2013-12-01

    Full Text Available This paper considers comparative assessment of simple and advanced cycle small-scale aero-derivative industrial gas turbines derived from helicopter engines. More particularly, investigation was made of technical performance of the small-scale aero-derivative engine cycles based on existing and projected cycles for applications in industrial power generation, combined heat and power concept, rotating equipment driving, and/or allied processes. The investigation was done by carrying out preliminary design and performance simulation of a simple cycle (baseline two-spool small-scale aero-derivative turboshaft engine model, and some advanced counterpart aero-derivative configurations. The advanced configurations consist of recuperated and intercooled/recuperated engine cycles of same nominal power rating of 1.567 MW. The baseline model was derived from the conversion of an existing helicopter engine model. In doing so, design point and off-design point performances of the engine models were established. In comparing their performances, it was observed that to a large extent, the advanced engine cycles showed superior performance in terms of thermal efficiency, and specific fuel consumption. In numerical terms, thermal efficiencies of recuperated engine cycle, and intercooled/recuperated engine cycles, over the simple cycle at DP increased by 13.5%, and 14.5% respectively, whereas specific fuel consumption of these cycles over simple cycle at DP decreased by 12.5%, and 13% respectively. This research relied on open access public literature for data.

  20. Small Scale Mixing Demonstration Batch Transfer and Sampling Performance of Simulated HLW - 12307

    Jensen, Jesse; Townson, Paul; Vanatta, Matt [EnergySolutions, Engineering and Technology Group, Richland, WA, 99354 (United States)

    2012-07-01

    The ability to effectively mix, sample, certify, and deliver consistent batches of High Level Waste (HLW) feed from the Hanford Double Shell Tanks (DST) to the Waste treatment Plant (WTP) has been recognized as a significant mission risk with potential to impact mission length and the quantity of HLW glass produced. At the end of 2009 DOE's Tank Operations Contractor, Washington River Protection Solutions (WRPS), awarded a contract to EnergySolutions to design, fabricate and operate a demonstration platform called the Small Scale Mixing Demonstration (SSMD) to establish pre-transfer sampling capacity, and batch transfer performance data at two different scales. This data will be used to examine the baseline capacity for a tank mixed via rotational jet mixers to transfer consistent or bounding batches, and provide scale up information to predict full scale operational performance. This information will then in turn be used to define the baseline capacity of such a system to transfer and sample batches sent to WTP. The Small Scale Mixing Demonstration (SSMD) platform consists of 43'' and 120'' diameter clear acrylic test vessels, each equipped with two scaled jet mixer pump assemblies, and all supporting vessels, controls, services, and simulant make up facilities. All tank internals have been modeled including the air lift circulators (ALCs), the steam heating coil, and the radius between the wall and floor. The test vessels are set up to simulate the transfer of HLW out of a mixed tank, and collect a pre-transfer sample in a manner similar to the proposed baseline configuration. The collected material is submitted to an NQA-1 laboratory for chemical analysis. Previous work has been done to assess tank mixing performance at both scales. This work involved a combination of unique instruments to understand the three dimensional distribution of solids using a combination of Coriolis meter measurements, in situ chord length distribution

  1. Performance assessment of cogeneration and trigeneration systems for small scale applications

    Angrisani, Giovanni; Akisawa, Atsushi; Marrasso, Elisa; Roselli, Carlo; Sasso, Maurizio

    2016-01-01

    Highlights: • Indices and methods to assess the performance of polygeneration systems. • Index to evaluate the economic feasibility of trigeneration system is introduced. • Thermo-economic analysis is performed considering three commercial cogenerators. • Sensitivity analysis varying reference electric efficiency for European Countries. • Sensitivity analysis varying environmental and economic parameters. - Abstract: Cogeneration and trigeneration systems can contribute to the reduction of primary energy consumption and greenhouse gas emissions in residential and tertiary sectors, by reducing fossil fuels demand and grid losses with respect to conventional systems. To evaluate the performance of these systems, several indices and assessment methodologies can be used, due to the high complexity of such systems, which can consist of several energy conversion devices and can perform bidirectional interactions with external electric and thermal grids. In this paper, a review of the available indices and methodologies to assess the performances of polygeneration systems is provided. An index (TSS_t_r_i) aimed to assess the economic feasibility of a trigeneration system is also introduced and discussed. This activity started in the framework of the International Energy Agency Annex 54 project (“Integration of Micro-Generation and Related Energy Technologies in Buildings”), where research groups shared their expertise about methods applied in each Country to evaluate the performance of polygeneration systems. It was concluded that a thermo-economic analysis comparing the performance of a polygeneration system with those of a reference benchmark scenario, is a very suitable assessment method. Some of the reviewed methodologies are then applied to small scale commercial cogenerators. The sensitivity analysis is performed considering different reference average values of electric efficiency, unitary natural gas and electricity prices, and emission factors for

  2. Performance estimation of Tesla turbine applied in small scale Organic Rankine Cycle (ORC) system

    Song, Jian; Gu, Chun-wei; Li, Xue-song

    2017-01-01

    Highlights: • One-dimensional model of the Tesla turbine is improved and applied in ORC system. • Working fluid properties and system operating conditions impact efficiency. • The influence of turbine efficiency on ORC system performance is evaluated. • Potential of using Tesla turbine in ORC systems is estimated. - Abstract: Organic Rankine Cycle (ORC) system has been proven to be an effective method for the low grade energy utilization. In small scale applications, the Tesla turbine offers an attractive option for the organic expander if an efficient design can be achieved. The Tesla turbine is simple in structure and is easy to be manufactured. This paper improves the one-dimensional model for the Tesla turbine, which adopts a non-dimensional formulation that identifies the dimensionless parameters that dictates the performance features of the turbine. The model is used to predict the efficiency of a Tesla turbine that is applied in a small scale ORC system. The influence of the working fluid properties and the operating conditions on the turbine performance is evaluated. Thermodynamic analysis of the ORC system with different organic working fluids and under various operating conditions is conducted. The simulation results reveal that the ORC system can generate a considerable net power output. Therefore, the Tesla turbine can be regarded as a potential choice to be applied in small scale ORC systems.

  3. Performance of a Small-scale Treatment Wetland for Treatment of Landscaping Wash Water

    Thompson, R. J.; Fayed, E.; Fish, W.

    2011-12-01

    A large number of lawn mowers and related equipment must be cleaned each day by commercial landscaping operations and state and local highway maintenance crews. Washing these devices produces wastewater that contains high amounts of organic matter and potentially problematic nutrients, as well as oil and grease and other chemicals and metals that come from the machinery itself. Dirty water washes off the mowers, flows off the pavement and into nearby storm drains without any kind of treatment. A better idea would be to collect such wastewater, retain it in an appropriate catchment such as an engineered wetland where natural processes could break down any pollutants in the wash water, and allow the water to naturally evaporate or percolate into the soil where it could recharge ground water resources safely. This research examines the performance of a small-scale treatment wetland tailored to remove nitrogen from landscaping wash water by incorporating both aerobic and anaerobic phases. Contaminants are analyzed through physical and chemical methods. Both methods involve collection of samples, followed by standardized, validated analytical laboratory tests for measuring total solids, total kjeldahl nitrogen, nitrates, total and dissolved phosphorus, COD, BOD, oil and grease, and metals (Zn and Cu). High levels of total solids, total kjeldahl nitrogen, nitrates, total and dissolved phosphorus, COD, BOD, oil and grease are found. Zinc and copper levels are low. Wetland treatment removes 99% total solids, 77% total kjeldahl nitrogen, 100% nitrates, 94% total phosphorus, 86% dissolved phosphorus, 94% COD, 97% BOD, and 76% oil and grease. The results will be a critical step towards developing a sustainable low-energy system for treating such wastewater that could be used by private landscaping companies and government agencies.

  4. Emergy Perspectives on the Environmental Performance and Sustainability of Small-Scale Gold Production Systems in Ghana

    Ernest Frimpong Asamoah

    2017-11-01

    Full Text Available Small-scale gold mining is an important component of the Ghanaian economy but it has also caused enormous damage to local ecosystems. In this paper, an emergy analysis was conducted in Ghana to assess the environmental performance and the relative sustainability of two artisanal and small-scale gold production systems: alluvial “dig and wash” and underground “ghetto” mines. Results show that both production systems have high environmental impacts, as indicated by an environmental loading ratio (ELR of 4.31 and environmental sustainability index (ESI of 0.33 for the alluvial system and 2.53 and 0.52 for the underground system, respectively. Concerning the international trade balance, the emergy exchange ratios of the two systems are both lower than one, at, 0.23 and 0.33 for the alluvial and underground systems, respectively, indicating a significant amount of resource loss to foreign regions. This study could assist in the regulation of the small-scale mining sector bearing in mind the unsustainable nature of their activities. In addition, supporting miners to consider land rehabilitation ethics is urgently needed.

  5. Fluid flow measurements of Test Series A and B for the Small Scale Seal Performance Tests

    Peterson, E.W.; Lagus, P.L.; Lie, K.

    1987-12-01

    The degree of waste isolation achieved by a repository seal system is dependent upon the fluid flow characteristics, or permeability, of the seals. In order to obtain meaningful, site-specific data on the performance of various possible seal system components, a series of in situ experiments called the Small Scale Seal Performance Tests (SSSPT) are being conducted at the Waste Isolation Pilot Plant (WIPP). This report contains the results of gas flow, tracer penetration, and brine flow tests conducted on concrete seals in vertical (Test Series A) and horizontal (Test Series B) configurations. The test objectives were to evaluate the seal performance and to determine if there existed scaling effects which could influence future SSSPT designs. 3 refs., 77 figs

  6. Performance of a small-scale turbojet engine fed with traditional and alternative fuels

    Badami, M.; Nuccio, P.; Pastrone, D.; Signoretto, A.

    2014-01-01

    Highlights: • One synthetic fuel, one bio-fuel blend and one traditional kerosene were tested on a small-scale turbojet. • The three fuels were characterized and their chemical and physical specifications were compared. • The experimental results, in term of CO, UHC and NO x emissions, are discussed. • Emissions are compared with CFD analysis and semi-empirical equations found in literature. - Abstract: The growing use of aeronautical fuels, together with the increasing attention towards reduced environmental impact technologies, are driving governments and aeronautical companies to search for alternative aeronautical fuels to petroleum based kerosene. Analysis and measurements on real aeronautical turbines are complex and expensive; for this reason the use of parts of real engines or small size turbojets can be very interesting for research activities. The present paper describes the results of an experimental and numerical activity, regarding the influence of alternative fuels on the performance in term of emissions, on a small-scale turbojet engine with a nominal thrust of 80 N at 80,000 rpm. Three different fuels, a traditional Jet-A kerosene, a synthetic Gas To Liquid (GTL) fuel and a blend of 30% Jatropha Methyl Ester (JME) and 70% Jet-A, were tested. The experimental results, in term of CO, UHC and NO x emissions, are discussed and compared with results obtained from CFD analysis and from semi-empirical equations found in literature

  7. Small-Scale High Temperature Melter-1 (SSHTM-1) Data Package. Appendix B

    NONE

    1996-03-01

    This appendix provides the data for Alternate HTM Flowsheet 2 (Glycolic Acid) melter feed preparation activities in both the laboratory- and small-scale testing. The first section provides an outline of this appendix. The melter feed preparation data are presented in the next two main sections, laboratory melter feed preparation data and small-scale melter feed preparation data. Section 3.0 provides the laboratory data which is discussed in the main body of the Small-Scale High Temperature-1 (SSHTM-1) Data Package, milestone C95-02.02Y. Section 3.1 gives the flowsheet in outline form as used in the laboratory-scale tests. This section also includes the ``Laboratory Melter Feed Preparation Activity Log`` which gives A chronological account of the test in terms of time, temperature, slurry pH, and specific observations about slurry appearance, acid addition rates, and samples taken. The ``Laboratory Melter Feed Preparation Activity Log`` provides a road map to the reader by which all the activity and data from the laboratory can be easily accessed. A summary of analytical data is presented next, section 3.2, which covers starting materials and progresses to the analysis of the melter feed. The next section, 3.3, characterizes the off-gas generation that occurs during the slurry processing. The following section, 3.4, provides the rheology data gathered including gram waste oxide loading information for the various slurries tested. The final section, 3.5, includes data from standard crucible redox testing. Section 4.0 provides the small-scale data in parallel form to section 3.0. Section 5.0 concludes with the references for this appendix.

  8. Addendum to ''Test Plan: Small-Scale Seal Performance Tests (SSSPT)''

    Finley, R.E.

    1992-01-01

    This document describes activities that are intended to update the data base of fluid flow measurements made on expansive salt concrete (ESC) seals as part of the Small-Scale Seal Performance Tests (SSSPT). The original plans for the SSSPT experiments are described by Stormont (1985a and 1985b). These seals have previously been tested with brine and gas during the early stages (less than 450 days) after emplacement. The purpose of this Test Plan Addendum is to detail the activities necessary to, update the gas and brine measurements previously performed on the SSSPT Series A and Series B seals and to identify the key personnel responsible for implementing these activities. This addendum describes a limited undertaking and does NOT change the scope of the original test plan

  9. Experimental performance of a piston expander in a small- scale organic Rankine cycle

    Oudkerk, J. F.; Dickes, R.; Dumont, O.; Lemort, V.

    2015-08-01

    Volumetric expanders are suitable for more and more applications in the field of micro- and small-scale power system as waster heat recovery or solar energy. This paper present an experimental study carried out on a swatch-plate piston expander. The expander was integrated into an ORC test-bench using R245fa. The performances are evaluated in term of isentropic efficiency and filling factor. The maximum efficiency and power reached are respectively 53% and 2 kW. Inside cylinder pressure measurements allow to compute mechanical efficiency and drown P-V diagram. A semi-empirical simulation model is then proposed, calibrated and used to analyse the different sources of losses.

  10. The Impact of Micro-Finance on the Performance of Small-Scale ...

    2014-10-02

    Oct 2, 2014 ... Department of Planning and Management ... Keywords: Small-scale Enterprises, Micro-Financing, Micro-Credit, Sales Revenue, .... The Wa Municipality is often acclaimed as a private-sector business enclave in the Upper.

  11. Thermal performance of a small-scale loop heat pipe for terrestrial application

    Chung, Won Bok; Boo, Joon Hong

    2004-01-01

    A small-scale loop heat pipe with polypropylene wick was fabricated and tested for its thermal performance. The container and tubing of the system was made of stainless steel and several working fluids were used to see the difference in performance including methanol, ethanol, acetone, R134a, and water. The heating area was 35 mm x 35 mm and there were nine axial grooves in the evaporator to provide a vapor passage. The pore size of the polypropylene wick inside the evaporator was varied from 0.5 m to 25 m. The size of condenser was 40 mm (W) x 50 mm (L) in which ten coolant paths were provided. The inner diameter of liquid and vapor transport lines were 2.0 mm and 4.0 mm, respectively and the length of which were 0.5 m. The PP wick LHP was operated with methanol, acetone, and ethanol normally. R134a was not compatible with PP wick and water was unsuitable within operating limit of 100 .deg. C. The minimum thermal load of 10 W (0.8 W/cm 2 ) and maximum thermal load of 80 W (6.5 W/cm 2 ) were achieved using methanol as working fluid with the condenser temperature of 20 .deg. C with horizontal position

  12. A high-frequency sonar for profiling small-scale subaqueous bedforms

    Dingler, J.R.; Boylls, J.C.; Lowe, R.L.

    1977-01-01

    A high-resolution ultrasonic profiler has been developed which permits both laboratory and field studies of small-scale subaqueous bedforms. The device uses a 2.5-cm diameter piezoelectric ceramic crystal pulsed at a frequency of 4.5 MHz to obtain vertical accuracy and resolution of at least 1 mm. Compared to other small-scale profiling methods, this ultrasonic technique profiles the bottom more accurately and more rapidly without disturbing the bedforms. These characteristics are vital in wave-dominated nearshore zones where oscillatory flow and low visibility for the most part have stymied detailed bedform studies. In the laboratory the transducer is mounted directly to an instrument carriage. For field work the transducer housing is mounted in a 2 m long aluminum frame which is situated and operated by scuba divers. Observations using the device include ripple geometry and migration, the suspension height of sand during sheet flow, and long-term erosion/deposition at a point. ?? 1977.

  13. Overview of the EU small scale mock-up tests for ITER high heat flux components

    Vieider, G.; Barabash, V.; Cardella, A.

    1998-01-01

    This task within the EU R and D for ITER was aimed at the development of basic manufacturing solutions for the high heat flux plasma facing components such as the divertor targets, the baffles and limiters. More than 50 representative small-scale mock-ups have been manufactured with beryllium, carbon and tungsten armour using various joining technologies. High heat flux testing of 20 of these mock-ups showed the carbon mono-blocks to be the most robust solution, surviving 2000 cycles at absorbed heat fluxes of up to 24 MW m -2 . With flat armour tiles rapid joint failures occurred at 5-16 MW m -2 depending on joining technology and armour material. These test results serve as a basis for the selection of manufacturing options and materials for the prototypes now being ordered. (orig.)

  14. Small-Scale Metal Tanks for High Pressure Storage of Fluids

    London, Adam (Inventor)

    2016-01-01

    Small scale metal tanks for high-pressure storage of fluids having tank factors of more than 5000 meters and volumes of ten cubic inches or less featuring arrays of interconnected internal chambers having at least inner walls thinner than gage limitations allow. The chambers may be arranged as multiple internal independent vessels. Walls of chambers that are also portions of external tank walls may be arcuate on the internal and/or external surfaces, including domed. The tanks may be shaped adaptively and/or conformally to an application, including, for example, having one or more flat outer walls and/or having an annular shape. The tanks may have dual-purpose inlet/outlet conduits of may have separate inlet and outlet conduits. The tanks are made by fusion bonding etched metal foil layers patterned from slices of a CAD model of the tank. The fusion bonded foil stack may be further machined.

  15. Ultrastrong ductile and stable high-entropy alloys at small scales.

    Zou, Yu; Ma, Huan; Spolenak, Ralph

    2015-07-10

    Refractory high-entropy alloys (HEAs) are a class of emerging multi-component alloys, showing superior mechanical properties at elevated temperatures and being technologically interesting. However, they are generally brittle at room temperature, fail by cracking at low compressive strains and suffer from limited formability. Here we report a strategy for the fabrication of refractory HEA thin films and small-sized pillars that consist of strongly textured, columnar and nanometre-sized grains. Such HEA pillars exhibit extraordinarily high yield strengths of ∼ 10 GPa--among the highest reported strengths in micro-/nano-pillar compression and one order of magnitude higher than that of its bulk form--and their ductility is considerably improved (compressive plastic strains over 30%). Additionally, we demonstrate that such HEA films show substantially enhanced stability for high-temperature, long-duration conditions (at 1,100 °C for 3 days). Small-scale HEAs combining these properties represent a new class of materials in small-dimension devices potentially for high-stress and high-temperature applications.

  16. Inside the small-scale composting of kitchen and garden wastes: Thermal performance and stratification effect in vertical compost bins.

    Arrigoni, Juan Pablo; Paladino, Gabriela; Garibaldi, Lucas Alejandro; Laos, Francisca

    2018-06-01

    Decentralized composting has been proposed as a best available practice, with a highly positive impact on municipal solid wastes management plans. However, in cold climates, decentralized small-scale composting performance to reach thermophilic temperatures (required for the product sanitization) could be poor, due to a lack of critical mass to retain heat. In addition, in these systems the composting process is usually disturbed when new portions of fresh organic waste are combined with previous batches. This causes modifications in the well-known composting evolution pattern. The objective of this work was to improve the understanding of these technical aspects through a real-scale decentralized composting experience carried out under cold climate conditions, in order to assess sanitization performance and to study the effects of fresh feedstock additions in the process evolution. Kitchen and garden organic wastes were composted in 500 L-static compost bins (without turning) for 244 days under cold climate conditions (Bariloche, NW Patagonia, Argentina), using pine wood shavings in a ratio of 1.5:1 v: v (waste: bulking agent). Temperature profile, stability indicators (microbial activity, carbon and nitrogen contents and ratio) and other variables (pH and electrical conductivity), were monitored throughout the experience. Our results indicate that small-scale composting (average generation rate of 7 kg d -1 ) is viable under cold weather conditions, since thermophilic sanitization temperatures (> 55 °C) were maintained for 3 consecutive days in most of the composting mass, according to available USEPA regulations commonly used as a reference for pathogens control in sewage sludge. On the other hand, stability indicators showed a differentiated organic matter degradation process along the compost bins height. Particularly, in the bottommost composting mix layer the process took a longer period to achieve compost stability than the upper layers, suggesting

  17. Economic performance of small scale hydroelectric power plants: `Results center`; Desempenho economico de PCH`s: centro de resultados

    Cipoli, Jose Adolfo; Silva, Jose Paulo Mendes [Companhia Paulista de Forca e Luz (CPFL), Campinas, SP (Brazil)

    1995-12-31

    This work presents the experience concerning the creation of an imaginary company named `CPFL Generator`, composed by 20 small scale hydroelectric power plants. The main idea of the project is to analyse the economic performance of each unit individually and the group as a company, enabling to a better quality management 3 refs., 1 fig., 7 tabs.

  18. Performance improvement of small-scale rotors by passive blade twist control

    Lv, Peng; Prothin, Sebastien; Mohd Zawawi, Fazila; Bénard, Emmanuel; Morlier, Joseph; Moschetta, Jean-Marc

    2015-01-01

    A passive twist control is proposed as an adaptive way to maximize the overall efficiency of the small-scale rotor blade for multifunctional aircrafts. Incorporated into a database of airfoil characteristics, Blade Element Momentum Theory is implemented to obtain the blade optimum twist rates for hover and forward flight. In order to realize the required torsion of blade between hover and forward flight, glass/epoxy laminate blade is proposed based on Centrifugal Force Induced Twist concept. ...

  19. Automated High-Speed Video Detection of Small-Scale Explosives Testing

    Ford, Robert; Guymon, Clint

    2013-06-01

    Small-scale explosives sensitivity test data is used to evaluate hazards of processing, handling, transportation, and storage of energetic materials. Accurate test data is critical to implementation of engineering and administrative controls for personnel safety and asset protection. Operator mischaracterization of reactions during testing contributes to either excessive or inadequate safety protocols. Use of equipment and associated algorithms to aid the operator in reaction determination can significantly reduce operator error. Safety Management Services, Inc. has developed an algorithm to evaluate high-speed video images of sparks from an ESD (Electrostatic Discharge) machine to automatically determine whether or not a reaction has taken place. The algorithm with the high-speed camera is termed GoDetect (patent pending). An operator assisted version for friction and impact testing has also been developed where software is used to quickly process and store video of sensitivity testing. We have used this method for sensitivity testing with multiple pieces of equipment. We present the fundamentals of GoDetect and compare it to other methods used for reaction detection.

  20. Design of a small scale boiler package for testing high moisture content biofuels

    Proctor, Andrew

    2005-07-01

    This report presents the results of a project to design a prototype, small-scale boiler (0.88 MWth output) to enable clean and efficient combustion of high moisture content (>30%) biomass fuels. The boiler was based on an open bottom smoke tube design, modified to incorporate water tubes in the combustion chamber running from front to back. These were added to support refractory bricks to create an extra pass in the boiler combustion chamber such that the reflected heat from the refractory increased the rate of evaporation of moisture from the fuel. A chain grate stoker was employed. The combustion tests involved three biofuels: wood pellets with a low moisture content (8-10%) (to provide combustion rates for a commercially proven biofuel); wood chips from forestry waste with a 30-40% moisture content; and spent mushroom compost with 70-75% moisture. The tests on the wood chips required a number of modifications to the fuel feeding system and to the boiler in order to achieve limited success and the tests with the mushroom compost were unsuccessful due to the combination of the high moisture content and the fuel's low calorific value. Experience gained with the wood chips suggested a number of improvements for a future boiler design. As well as describing the experimental work and test results, the report offers an economic analysis (capital costs, fuel costs, running costs) of the scheme.

  1. High-Temperature Structural Analysis of a Small-Scale Prototype of a Process Heat Exchanger (IV) - Macroscopic High-Temperature Elastic-Plastic Analysis -

    Song, Kee Nam; Hong, Sung Deok; Park, Hong Yoon

    2011-01-01

    A PHE (Process Heat Exchanger) is a key component required to transfer heat energy of 950 .deg. C generated in a VHTR (Very High Temperature Reactor) to a chemical reaction that yields a large quantity of hydrogen. A small-scale PHE prototype made of Hastelloy-X was scheduled for testing in a small-scale gas loop at the Korea Atomic Energy Research Institute. In this study, as a part of the evaluation of the high-temperature structural integrity of the PHE prototype, high-temperature structural analysis modeling, and macroscopic thermal and elastic-plastic structural analysis of the PHE prototype were carried out under the gas-loop test conditions as a preliminary qwer123$ study before carrying out the performance test in the gas loop. The results obtained in this study will be used to design the performance test setup for the modified PHE prototype

  2. Life cycle assessment of small-scale high-input Jatropha biodiesel production in India

    Pandey, Krishan K.; Pragya, Namita; Sahoo, P.K.

    2011-01-01

    Highlights: → NEB and NER of high input Jatropha biodiesel system was higher than those of low input. → These values further increase on including the energy content of the co-products, and in the further years. → Maximum energy use was during oil extraction, followed by oil processing and fertilizer use. → Allocation of resources at right time and with proper care increase the overall system productivity. -- Abstract: In the current scenario of depleting energy resources, increasing food insecurity and global warming, Jatropha has emerged as a promising energy crop for India. The aim of this study is to examine the life cycle energy balance for Jatropha biodiesel production and greenhouse gas emissions from post-energy use and end combustion of biodiesel, over a period of 5 years. It's a case specific study for a small scale, high input Jatropha biodiesel system. Most of the existing studies have considered low input Jatropha biodiesel system and have used NEB (Net energy balance i.e. difference of energy output and energy input) and NER (Net energy ratio i.e. ratio of energy output to energy input) as indicators for estimating the viability of the systems. Although, many of them have shown these indicators to be positive, yet the values are very less. The results of this study, when compared with two previous studies of Jatropha, show that the values for these indicators can be increased to a much greater extent, if we use a high input Jatropha biodiesel system. Further, when compared to a study done on palm oil and Coconut oil, it was found even if the NEB and NER of biodiesel from Jatropha were lesser in comparison to those of Palm oil and Coconut oil, yet, when energy content of the co-products were also considered, Jatropha had the highest value for both the indicators in comparison to the rest two.

  3. The impact of component performance on the overall cycle performance of small-scale low temperature organic Rankine cycles

    White, M.; Sayma, A. I.

    2015-08-01

    Low temperature organic Rankine cycles offer a promising technology for the generation of power from low temperature heat sources. Small-scale systems (∼10kW) are of significant interest, however there is a current lack of commercially viable expanders. For a potential expander to be economically viable for small-scale applications it is reasonable to assume that the same expander must have the ability to be implemented within a number of different ORC applications. It is therefore important to design and optimise the cycle considering the component performance, most notably the expander, both at different thermodynamic conditions, and using alternative organic fluids. This paper demonstrates a novel modelling methodology that combines a previously generated turbine performance map with cycle analysis to establish at what heat source conditions optimal system performance can be achieved using an existing turbine design. The results obtained show that the same turbine can be effectively utilised within a number of different ORC applications by changing the working fluid. By selecting suitable working fluids, this turbine can be used to convert pressurised hot water at temperatures between 360K and 400K, and mass flow rates between 0.45kg/s and 2.7kg/s, into useful power with outputs between 1.5kW and 27kW. This is a significant result since it allows the same turbine to be implemented into a variety of applications, improving the economy of scale. This work has also confirmed the suitability of the candidate turbine for a range of low temperature ORC applications.

  4. Life cycle analysis of small scale pellet boilers characterized by high efficiency and low emissions

    Monteleone, B.; Chiesa, M.; Marzuoli, R.; Verma, V.K.; Schwarz, M.; Carlon, E.; Schmidl, C.; Ballarin Denti, A.

    2015-01-01

    Highlights: • LCA was performed on innovative small scale pellet boilers. • Pellet boilers impacts were compared to oil and natural gas boilers impacts. • Both literature and experimental data were used for life cycle analysis. • The environmental impact due to all life cycle phases was envisaged. • Sensitivity tests evidenced realistic ways for pellet boilers impact reduction. - Abstract: This study focuses on the environmental impact assessment through Life Cycle Analysis (LCA) of two innovative 10 kW pellet boilers. In particular, the second boiler represents a technological evolution of the first one developed to improve its performance in terms of efficiency and environmental impact. For both boilers, emission factors measured during laboratory tests (full load tests and specific load cycle tests representative of real life boiler operation) have been used as input data in the life cycle analysis. The SimaPro software (v.8.0.4.30) was used for the LCA and the ReCiPe Midpoint method (European version H) was chosen to assess the environmental impact of all boilers (according to LCA ISO standards). In addition, the ReCiPe Endpoint method was used to compare the final results of all 5 boilers with literature data. The pelletisation process represented the most relevant share of the overall environmental impact followed by the operational phase, the manufacturing phase and the disposal phase. A sensitivity analysis performed on the most efficient pellet boiler evidenced the variation of the boiler’s environmental impact as a function of PM10 and NO X emission factors with respect to emission factors monitored during boiler full load operation. Moreover, the reduction of the boiler’s weight and the adoption of new electronic components led to a consistent reduction (−18%) of its environmental impact with respect to the previous technology. A second LCA has been carried on for a 15 kW oil boiler, a 15 kW natural gas boiler and a 15 kW pellet boiler

  5. Effects of shade and input management on economic performance of small-scale Peruvian coffee systems

    Jezeer, Rosalien E.|info:eu-repo/dai/nl/374336865; Ferreira Dos Santos, Maria Joao|info:eu-repo/dai/nl/371571979; Boot, René G.A.|info:eu-repo/dai/nl/069412928; Junginger, Martin|info:eu-repo/dai/nl/202130703; Verweij, Pita A.|info:eu-repo/dai/nl/145431843

    2018-01-01

    Tropical agroforestry systems provide a number of ecosystem services that might help sustain the production of multiple crops, improve farmers’ livelihoods and conserve biodiversity. A major drawback of agroforestry coffee systems is the perceived lower economic performance compared to high-input

  6. DHS small-scale safety and thermal testing of improvised explosives-comparison of testing performance

    Reynolds, J G; Hsu, P C; Sandstrom, M M; Brown, G W; Warner, K F; Phillips, J J; Shelley, T J; Reyes, J A

    2014-01-01

    One of the first steps in establishing safe handling procedures for explosives is small-scale safety and thermal (SSST) testing. To better understand the response of improvised materials or homemade explosives (HMEs) to SSST testing, 16 HME materials were compared to three standard military explosives in a proficiency-type round robin study among five laboratories-two DoD and three DOE-sponsored by DHS. The testing matrix has been designed to address problems encountered with improvised materials-powder mixtures, liquid suspensions, partially wetted solids, immiscible liquids, and reactive materials. More than 30 issues have been identified that indicate standard test methods may require modification when applied to HMEs to derive accurate sensitivity assessments needed for developing safe handling and storage practices. This paper presents a generalized comparison of the results among the testing participants, comparison of friction results from BAM (German Bundesanstalt für Materi-alprüfung) and ABL (Allegany Ballistics Laboratory) designed testing equipment, and an overview of the statistical results from the RDX (1,3,5-Trinitroperhydro-1,3,5-triazine) standard tested throughout the proficiency test.

  7. Small scale thermal violence experiments for combined insensitive high explosive and booster materials

    Rae, Philip J [Los Alamos National Laboratory; Bauer, Clare L [AWE, UK; Stennett, C [DCMT SHRIVENHAM, UK; Flower, H M [AWE, UK

    2010-01-01

    A small scale cook-off experiment has been designed to provide a violence metric for both booster and IHE materials, singly and in combination. The experiment has a simple, axisymmetric geometry provided by a 10 mm internal diameter cylindrical steel confinement up to 80 mm in length. Heating is applied from one end of the sample length creating pseudo 1-D heating profile and a thermal gradient across the sample(s). At the opposite end of the confinement to the heating block, a machined groove provides a point of rupture that generates a cylindrical fragment. The displacement of the external face of the fragment is detected by Heterodyne Velocimetry. Proof of concept experiments are reported focusing on HMX and TATB formulations, and are described in relation to confinement, ullage and heating profile. The development of a violence metric, based upon fragment velocity records is discussed.

  8. Small-scale sediment transport patterns and bedform morphodynamics: New insights from high resolution multibeam bathymetry

    Barnard, Patrick L.; Erikson, Li H.; Rubin, David M.; Kvitek, Rikk G.

    2011-01-01

    New multibeam echosounder and processing technologies yield sub-meter-scale bathymetric resolution, revealing striking details of bedform morphology that are shaped by complex boundary-layer flow dynamics at a range of spatial and temporal scales. An inertially aided post processed kinematic (IAPPK) technique generates a smoothed best estimate trajectory (SBET) solution to tie the vessel motion-related effects of each sounding directly to the ellipsoid, significantly reducing artifacts commonly found in multibeam data, increasing point density, and sharpening seafloor features. The new technique was applied to a large bedform field in 20–30 m water depths in central San Francisco Bay, California (USA), revealing bedforms that suggest boundary-layer flow deflection by the crests where 12-m-wavelength, 0.2-m-amplitude bedforms are superimposed on 60-m-wavelength, 1-m-amplitude bedforms, with crests that often were strongly oblique (approaching 90°) to the larger features on the lee side, and near-parallel on the stoss side. During one survey in April 2008, superimposed bedform crests were continuous between the crests of the larger features, indicating that flow detachment in the lee of the larger bedforms is not always a dominant process. Assessment of bedform crest peakedness, asymmetry, and small-scale bedform evolution between surveys indicates the impact of different flow regimes on the entire bedform field. This paper presents unique fine-scale imagery of compound and superimposed bedforms, which is used to (1) assess the physical forcing and evolution of a bedform field in San Francisco Bay, and (2) in conjunction with numerical modeling, gain a better fundamental understanding of boundary-layer flow dynamics that result in the observed superimposed bedform orientation.

  9. High-Efficiency Small-Scale Combined Heat and Power Organic Binary Rankine Cycles

    Costante Mario Invernizzi

    2018-04-01

    Full Text Available Small-CHP (Combined Heat and Power systems are generally considered a valuable technological option to the conventional boilers, in a technology developed context. If small-CHP systems are associated with the use of renewable energies (biomass, for example they could play an important role in distributed generation even in developing countries or, in any case, where there are no extensive electricity networks. Traditionally the considered heat engines for micro- or mini-CHP are: the gas engine, the gas turbine (with internal combustion, the steam engine, engine working according to the Stirling and to the Rankine cycles, the last with organic fluids. In principle, also fuel cells could be used. In this paper, we focus on small size Rankine cycles (10–15 k W with organic working fluids. The assumed heat source is hot combustion gases at high temperature (900–950 ∘ C and we assume to use only single stages axial turbines. The need to work at high temperatures, limits the choice of the right organic working fluids. The calculation results show the limitation in the performances of simple cycles and suggest the opportunity to resort to complex (binary cycle configurations to achieve high net conversion efficiencies (15–16%.

  10. Hybrid magnet devices for molecule manipulation and small scale high gradient-field applications

    Humphries, David E [El Cerrito, CA; Hong, Seok-Cheol [Seoul, KR; Cozzarelli, legal representative, Linda A.; Pollard, Martin J [El Cerrito, CA; Cozzarelli, Nicholas R [Berkeley, CA

    2009-01-06

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetizable molecular structures and targets. Also disclosed are hybrid magnetic tweezers able to exert approximately 1 nN of force to 4.5 .mu.m magnetic bead. The maximum force was experimentally measured to be .about.900 pN which is in good agreement with theoretical estimations and other measurements. In addition, a new analysis scheme that permits fast real-time position measurement in typical geometry of magnetic tweezers has been developed and described in detail.

  11. Impact of Metadata on Full-text Information Retrieval Performance: An Experimental Research on a Small Scale Turkish Corpus

    Çağdaş Çapkın

    2016-12-01

    Full Text Available Information institutions use text-based information retrieval systems to store, index and retrieve metadata, full-text, or both metadata and full-text (hybrid contents. The aim of this research was to evaluate impact of these contents on information retrieval performance. For this purpose, metadata (MIR, full-text (FIR and hybrid (HIR content information retrieval systems were developed with default Lucene information retrieval model for a small scale Turkish corpus. In order to evaluate performance of this three systems, “precision - recall” and “normalized recall” tests were conducted. Experimental findings showed that there were no significant differences between MIR and FIR in mean average precision (MAP performance. On the other hand, MAP performance of HIR was significantly higher in comparison to MIR and FIR. When information retrieval performance was evaluated as user-centered, the “normalized recall” performances of MIR and HIR were significantly higher than FIR. Additionally, there were no significant differences between the systems in retrieved relevant document means. Processing different types of contents such as metadata and full-text had some advantages and disadvantages for information retrieval systems in terms of term management. The advantages brought together in hybrid content processing (HIR and information retrieval performance improved.

  12. Energetics of small scale turbulence in the lower stratosphere from high resolution radar measurements

    J. Dole

    2001-08-01

    Full Text Available Very high resolution radar measurements were performed in the troposphere and lower stratosphere by means of the PROUST radar. The PROUST radar operates in the UHF band (961 MHz and is located in St. Santin, France (44°39’ N, 2°12’ E. A field campaign involving high resolution balloon measurements and the PROUST radar was conducted during April 1998. Under the classical hypothesis that refractive index inhomogeneities at half radar wavelength lie within the inertial subrange, assumed to be isotropic, kinetic energy and temperature variance dissipation rates were estimated independently in the lower stratosphere. The dissipation rate of temperature variance is proportional to the dissipation rate of available potential energy. We therefore estimate the ratio of dissipation rates of potential to kinetic energy. This ratio is a key parameter of atmospheric turbulence which, in locally homogeneous and stationary conditions, is simply related to the flux Richardson number, Rf .Key words. Meteorology and atmospheric dynamics (turbulence – Radio science (remote sensing

  13. Energetics of small scale turbulence in the lower stratosphere from high resolution radar measurements

    J. Dole

    Full Text Available Very high resolution radar measurements were performed in the troposphere and lower stratosphere by means of the PROUST radar. The PROUST radar operates in the UHF band (961 MHz and is located in St. Santin, France (44°39’ N, 2°12’ E. A field campaign involving high resolution balloon measurements and the PROUST radar was conducted during April 1998. Under the classical hypothesis that refractive index inhomogeneities at half radar wavelength lie within the inertial subrange, assumed to be isotropic, kinetic energy and temperature variance dissipation rates were estimated independently in the lower stratosphere. The dissipation rate of temperature variance is proportional to the dissipation rate of available potential energy. We therefore estimate the ratio of dissipation rates of potential to kinetic energy. This ratio is a key parameter of atmospheric turbulence which, in locally homogeneous and stationary conditions, is simply related to the flux Richardson number, Rf .

    Key words. Meteorology and atmospheric dynamics (turbulence – Radio science (remote sensing

  14. High-z objects and cold dark matter cosmogonies - Constraints on the primordial power spectrum on small scales

    Kashlinsky, A.

    1993-01-01

    Modified cold dark matter (CDM) models were recently suggested to account for large-scale optical data, which fix the power spectrum on large scales, and the COBE results, which would then fix the bias parameter, b. We point out that all such models have deficit of small-scale power where density fluctuations are presently nonlinear, and should then lead to late epochs of collapse of scales M between 10 exp 9 - 10 exp 10 solar masses and (1-5) x 10 exp 14 solar masses. We compute the probabilities and comoving space densities of various scale objects at high redshifts according to the CDM models and compare these with observations of high-z QSOs, high-z galaxies and the protocluster-size object found recently by Uson et al. (1992) at z = 3.4. We show that the modified CDM models are inconsistent with the observational data on these objects. We thus suggest that in order to account for the high-z objects, as well as the large-scale and COBE data, one needs a power spectrum with more power on small scales than CDM models allow and an open universe.

  15. A method for high throughput bioelectrochemical research based on small scale microbial electrolysis cells

    Call, Douglas F.

    2011-07-01

    There is great interest in studying exoelectrogenic microorganisms, but existing methods can require expensive electrochemical equipment and specialized reactors. We developed a simple system for conducting high throughput bioelectrochemical research using multiple inexpensive microbial electrolysis cells (MECs) built with commercially available materials and operated using a single power source. MECs were small crimp top serum bottles (5mL) with a graphite plate anode (92m 2/m 3) and a cathode of stainless steel (SS) mesh (86m 2/m 3), graphite plate, SS wire, or platinum wire. The highest volumetric current density (240A/m 3, applied potential of 0.7V) was obtained using a SS mesh cathode and a wastewater inoculum (acetate electron donor). Parallel operated MECs (single power source) did not lead to differences in performance compared to non-parallel operated MECs, which can allow for high throughput reactor operation (>1000 reactors) using a single power supply. The utility of this method for cultivating exoelectrogenic microorganisms was demonstrated through comparison of buffer effects on pure (Geobacter sulfurreducens and Geobacter metallireducens) and mixed cultures. Mixed cultures produced current densities equal to or higher than pure cultures in the different media, and current densities for all cultures were higher using a 50mM phosphate buffer than a 30mM bicarbonate buffer. Only the mixed culture was capable of sustained current generation with a 200mM phosphate buffer. These results demonstrate the usefulness of this inexpensive method for conducting in-depth examinations of pure and mixed exoelectrogenic cultures. © 2011 Elsevier B.V.

  16. Morocco - Small-Scale Fisheries

    Millennium Challenge Corporation — The final performance evaluation roadmap for the Small-Scale Fisheries Project (PPA-MCC) is developed using a grid constructed around indicators relating to Project...

  17. Performance measurement of a new concept reciprocating piston expander (RPE using a newly developed small-scale dynamometer unit

    Mohamad MNA

    2017-01-01

    Full Text Available This paper presents the progress of a small-scale dynamometer prototype development for performance measurement of a reciprocating piston expander (RPE. Since the available dynamometer systems in the market are limited to specific applications that require for the customization, their price normally very expensive. Since the current study on the RPE required a dynamometer unit, therefore, a new and cheaper dynamometer prototype that was suitable for RPE application has been developed. Using air as RPE working fluid, a case study has been carried out to measure its performance at different inlet fluid conditions, i.e., within 20°C–140°C and 3–5 bars. The results observed that the performance of RPE was proportionally increased to the increased of inlet fluid pressure and temperature. The maximum brake power produced was 27 Watt when the RPE operated at 140°C, 5 bars and the speed of 820 rpm. It also revealed that the changes in the pressure of inlet fluid can give significant change on the performance of the RPE due to its direct relation to the RPE actual rotating force. Although the RPE and dynamometer seem good being adapted to each other, both of them require some improvements to ensure both systems well operated and reliable.

  18. Classification of Small-Scale Eucalyptus Plantations Based on NDVI Time Series Obtained from Multiple High-Resolution Datasets

    Hailang Qiao

    2016-02-01

    Full Text Available Eucalyptus, a short-rotation plantation, has been expanding rapidly in southeast China in recent years owing to its short growth cycle and high yield of wood. Effective identification of eucalyptus, therefore, is important for monitoring land use changes and investigating environmental quality. For this article, we used remote sensing images over 15 years (one per year with a 30-m spatial resolution, including Landsat 5 thematic mapper images, Landsat 7-enhanced thematic mapper images, and HJ 1A/1B images. These data were used to construct a 15-year Normalized Difference Vegetation Index (NDVI time series for several cities in Guangdong Province, China. Eucalyptus reference NDVI time series sub-sequences were acquired, including one-year-long and two-year-long growing periods, using invested eucalyptus samples in the study region. In order to compensate for the discontinuity of the NDVI time series that is a consequence of the relatively coarse temporal resolution, we developed an inverted triangle area methodology. Using this methodology, the images were classified on the basis of the matching degree of the NDVI time series and two reference NDVI time series sub-sequences during the growing period of the eucalyptus rotations. Three additional methodologies (Bounding Envelope, City Block, and Standardized Euclidian Distance were also tested and used as a comparison group. Threshold coefficients for the algorithms were adjusted using commission–omission error criteria. The results show that the triangle area methodology out-performed the other methodologies in classifying eucalyptus plantations. Threshold coefficients and an optimal discriminant function were determined using a mosaic photograph that had been taken by an unmanned aerial vehicle platform. Good stability was found as we performed further validation using multiple-year data from the high-resolution Gaofen Satellite 1 (GF-1 observations of larger regions. Eucalyptus planting dates

  19. A method for high throughput bioelectrochemical research based on small scale microbial electrolysis cells

    Call, Douglas F.; Logan, Bruce E.

    2011-01-01

    There is great interest in studying exoelectrogenic microorganisms, but existing methods can require expensive electrochemical equipment and specialized reactors. We developed a simple system for conducting high throughput bioelectrochemical

  20. Experimental study on the thermal performance of a small-scale loop heat pipe with polypropylene wick

    Boo, Joon Hong; Chung, Won Bok

    2005-01-01

    A small-scale Loop Heat Pipe (LHP) with polypropylene wick was fabricated and tested for investigation of its thermal performance. The container and tubing of the system were made of stainless steel and several working fluids were tested including methanol, ethanol, and acetone. The heating area was 35 mm x 35 mm and nine axial grooves were provided in the evaporator to provide vapor passages. The pore size of the polypropylene wick inside the evaporator was varied from 0.5 μm to 25 μm. The inner diameter of liquid and vapor transport lines were 2.0 mm and 4.0 mm, respectively and the length of which were 0.5 mm. The size of condenser was 40 mm (W) x 50 mm (L) in which ten coolant paths were provided. Start-up characteristics as well as steady-state performance was analyzed and discussed. The minimum thermal load of 10 W (0.8W/cam 2 ) and maximum thermal load of 80 W (6.5 W/cm 2 ) were achieved using methanol as working fluid with the condenser temperature of 20 deg. C with horizontal position

  1. Small scale denitrification variability in riparian zones: Results from a high-resolution dataset

    Gassen, Niklas; Knöller, Kay; Musolff, Andreas; Popp, Felix; Lüders, Tillmann; Stumpp, Christine

    2017-04-01

    Riparian zones are important compartments at the interface between groundwater and surface water where biogeochemical processes like denitrification are often enhanced. Nitrate loads of either groundwater entering a stream through the riparian zone or streamwater infiltrating into the riparian zone can be substantially reduced. These processes are spatially and temporally highly variable, making it difficult to capture solute variabilities, estimate realistic turnover rates and thus to quantify integral mass removal. A crucial step towards a more detailed characterization is to monitor solutes on a scale which adequately resemble the highly heterogeneous distribution and on a scale where processes occur. We measured biogeochemical parameters in a spatial high resolution within a riparian corridor of a German lowland river system over the course of one year. Samples were taken from three newly developed high-resolution multi-level wells with a maximum vertical resolution of 5 cm and analyzed for major ions, DOC and N-O isotopes. Sediment derived during installation of the wells was analyzed for specific denitrifying enzymes. Results showed a distinct depth zonation of hydrochemistry within the shallow alluvial aquifer, with a 1 m thick zone just below the water table with lower nitrate concentrations and EC values similar to the nearby river. Conservative parameters were consistent inbetween the three wells, but nitrate was highly variable. In addition, spots with low nitrate concentrations showed isotopic and microbial evidence for higher denitrification activities. The depth zonation was observed throughout the year, with stronger temporal variations of nitrate concentrations just below the water table compared to deeper layers. Nitrate isotopes showed a clear seasonal trend of denitrification activities (high in summer, low in winter). Our dataset gives new insight into river-groundwater exchange processes and shows the highly heterogeneous distribution of

  2. Small-Scale Coal-Biomass to Liquids Production Using Highly Selective Fischer-Tropsch Synthesis

    Gangwal, Santosh K. [Southern Research Institute, Durham, NC (United States); McCabe, Kevin [Southern Research Institute, Durham, NC (United States)

    2015-04-30

    The research project advanced coal-to-liquids (CTL) and coal-biomass to liquids (CBTL) processes by testing and validating Chevron’s highly selective and active cobalt-zeolite hybrid Fischer-Tropsch (FT) catalyst to convert gasifier syngas predominantly to gasoline, jet fuel and diesel range hydrocarbon liquids, thereby eliminating expensive wax upgrading operations The National Carbon Capture Center (NCCC) operated by Southern Company (SC) at Wilsonville, Alabama served as the host site for the gasifier slip-stream testing/demonstration. Southern Research designed, installed and commissioned a bench scale skid mounted FT reactor system (SR-CBTL test rig) that was fully integrated with a slip stream from SC/NCCC’s transport integrated gasifier (TRIGTM). The test-rig was designed to receive up to 5 lb/h raw syngas augmented with bottled syngas to adjust the H2/CO molar ratio to 2, clean it to cobalt FT catalyst specifications, and produce liquid FT products at the design capacity of 2 to 4 L/day. It employed a 2-inch diameter boiling water jacketed fixed-bed heat-exchange FT reactor incorporating Chevron’s catalyst in Intramicron’s high thermal conductivity micro-fibrous entrapped catalyst (MFEC) packing to efficiently remove heat produced by the highly exothermic FT reaction.

  3. Assessment of off-design performance of a small-scale combined cooling and power system using an alternative operating strategy for gas turbine

    Han, Wei; Chen, Qiang; Lin, Ru-mou; Jin, Hong-guang

    2015-01-01

    Highlights: • We develop an off-design model for a CCP system driven by gas turbine. • An alternative operating strategy is proposed to improve the system performance. • Off-design performance of the combined cooling and power system (CCP) is enhanced. • Effects of both the different operating strategy are analyzed and compared. • Performance enhancement mechanism of the proposed operating strategy is presented. - Abstract: A small-scale combined cooling and power (CCP) system usually serves district air conditioning apart from power generation purposes. The typical system consists of a gas turbine and an exhaust gas-fired absorption refrigerator. The surplus heat of the gas turbine is recovered to generate cooling energy. In this way, the CCP system has a high overall efficiency at the design point. However, the CCP system usually runs under off-design conditions because the users’ demand varies frequently. The operating strategy of the gas turbine will affect the thermodynamic performance of itself and the entire CCP system. The operating strategies for gas turbines include the reducing turbine inlet temperature (TIT) and the compressor inlet air throttling (IAT). A CCP system, consisting of an OPRA gas turbine and a double effects absorption refrigerator, is investigated to identify the effects of different operating strategies. The CCP system is simulated based on the partial-load model of gas turbine and absorption refrigerator. The off-design performance of the CCP system is compared under different operating strategies. The results show that the IAT strategy is the better one. At 50% rated power output of the gas turbine, the IAT operating strategy can increase overall system efficiency by 10% compared with the TIT strategy. In general, the IAT operating strategy is suited for other gas turbines. However, the benefits of IAT should be investigated in the future, when different gas turbine is adopted. This study may provide a new operating

  4. Industrial clusters and social networks and their impact on the performance of micro- and small-scale enterprises: evidence from the handloom sector in Ethiopia

    Ali, M.A.

    2012-01-01

    This study empirically investigates how clustering and social networks affect the performance of micro- and small-scale enterprises by looking at the evidence from Ethiopia. By contrasting the performance of clustered micro enterprises with that of dispersed ones, it was first shown that

  5. Development of a versatile high-temperature short-time (HTST) pasteurization device for small-scale processing of cell culture medium formulations.

    Floris, Patrick; Curtin, Sean; Kaisermayer, Christian; Lindeberg, Anna; Bones, Jonathan

    2018-07-01

    The compatibility of CHO cell culture medium formulations with all stages of the bioprocess must be evaluated through small-scale studies prior to scale-up for commercial manufacturing operations. Here, we describe the development of a bespoke small-scale device for assessing the compatibility of culture media with a widely implemented upstream viral clearance strategy, high-temperature short-time (HTST) treatment. The thermal stability of undefined medium formulations supplemented with soy hydrolysates was evaluated upon variations in critical HTST processing parameters, namely, holding times and temperatures. Prolonged holding times of 43 s at temperatures of 110 °C did not adversely impact medium quality while significant degradation was observed upon treatment at elevated temperatures (200 °C) for shorter time periods (11 s). The performance of the device was benchmarked against a commercially available mini-pilot HTST system upon treatment of identical formulations on both platforms. Processed medium samples were analyzed by untargeted LC-MS/MS for compositional profiling followed by chemometric evaluation, which confirmed the observed degradation effects caused by elevated holding temperatures but revealed comparable performance of our developed device with the commercial mini-pilot setup. The developed device can assist medium optimization activities by reducing volume requirements relative to commercially available mini-pilot instrumentation and by facilitating fast throughput evaluation of heat-induced effects on multiple medium lots.

  6. Investigation on catalytic gasification of high-ash coal with mixing-gas in a small-scale fluidised bed

    Chen, X.; Zhang, J.; Lin, J. [Fuzhou University, Fuzhou (China)

    2005-10-15

    The experimental study on the Yangquan high-ash coal catalytic gasification with mixing gas by using solid alkali or waste liquid of viscose fiber as the catalyst in a small-scale fluidized bed with 28 mm i.d. was carried out. The loading saturation levels of two catalysts in Yangquan high-ash coal are about 6%. Under the gasification temperature ranging from 830 to 900{sup o}C and from 900 to 920{sup o}C, the apparent reaction order of Yangquan high-ash coal with respect to the unreacted carbon fraction approximates to 2.3 and 1/3 for the non-catalyst case, respectively. Also, the different values of apparent reaction order in the two temperature ranges are presented for the case with 3% solid alkali catalyst loaded. At the low temperature ranging from 830 to 860{sup o}C, the apparent reaction order of catalytic gasification is 1 since enough active carbon sites on the coal surface are formed during the catalytic gasification by solid alkali. But at the high temperature ranging from 860 to 920{sup o}C, the sodium carbonate produced by the reaction of solid alkali with carbon dioxide can be easily fused, transferred and re-distributed, which affects the gasification reaction rate, and the apparent reaction order of catalytic gasification is reduced to 1.3. 10 refs., 9 figs., 4 tab s.

  7. Small scale optics

    Yupapin, Preecha

    2013-01-01

    The behavior of light in small scale optics or nano/micro optical devices has shown promising results, which can be used for basic and applied research, especially in nanoelectronics. Small Scale Optics presents the use of optical nonlinear behaviors for spins, antennae, and whispering gallery modes within micro/nano devices and circuits, which can be used in many applications. This book proposes a new design for a small scale optical device-a microring resonator device. Most chapters are based on the proposed device, which uses a configuration know as a PANDA ring resonator. Analytical and nu

  8. Structure of small-scale standing azimuthal Alfven waves interacting with high-energy particles in the magnetosphere

    Klimushkin, D.Yu.

    1998-01-01

    The effect of bounce-drift instability on the structure of small-scale azimuthal Alfven waves in the magnetosphere is studied with allowance for the curvature of the geomagnetic field lines. The pressure of the background plasma is assumed to be zero. As early as 1993, Leonovich and Mazur showed that Alfven waves with m>>1, being standing waves along magnetic field lines, propagate, at the same time, across the magnetic surfaces. As these waves propagate through the magnetosphere, they interact with a group of high-energy particles and, thereby, are amplified with a growth rate dependent on the radial coordinate, i.e., a coordinate perpendicular to the magnetic sheaths. Near the Alfven resonance surface, the growth rate approaches zero, and the waves are damped completely due to the energy dissipation in the ionosphere. As the growth rate increases, the maximum of the wave amplitude is displaced to the Alfven resonance region and the most amplified waves are those whose magnetic field vectors oscillate in the azimuthal direction. Among the waves excited in a plasma resonator that is formed near the plasmapause, the most amplified are those with radial polarization

  9. Mercury exposure in a high fish eating Bolivian Amazonian population with intense small-scale gold-mining activities.

    Barbieri, Flavia Laura; Cournil, Amandine; Gardon, Jacques

    2009-08-01

    Methylmercury exposure in Amazonian communities through fish consumption has been widely documented in Brazil. There is still a lack of data in other Amazonian countries, which is why we conducted this study in the Bolivian Amazon basin. Simple random sampling was used from a small village located in the lower Beni River, where there is intense gold mining and high fish consumption. All participants were interviewed and hair samples were taken to measure total mercury concentrations. The hair mercury geometric mean in the general population was 3.02 microg/g (CI: 2.69-3.37; range: 0.42-15.65). Age and gender were not directly associated with mercury levels. Fish consumption showed a positive relation and so did occupation, especially small-scale gold mining. Hair mercury levels were lower than those found in Brazilian studies, but still higher than in non-exposed populations. It is necessary to assess mercury exposure in the Amazonian regions where data is still lacking, using a standardized indicator.

  10. Integrating Science-Based Co-management, Partnerships, Participatory Processes and Stewardship Incentives to Improve the Performance of Small-Scale Fisheries

    Kendra A. Karr

    2017-10-01

    Full Text Available Small scale fisheries are critically important for the provision of food security, livelihoods, and economic development for billions of people. Yet, most of these fisheries appear to not be achieving either fisheries or conservation goals, with respect to creating healthier oceans that support more fish, feed more people and improve livelihoods. Research and practical experience have elucidated many insights into how to improve the performance of small-scale fisheries. Here, we present lessons learned from five case studies of small-scale fisheries in Cuba, Mexico, the Philippines, and Belize. The major lessons that arise from these cases are: (1 participatory processes empower fishers, increase compliance, and support integration of local and scientific knowledge; (2 partnership across sectors improves communication and community buy-in; (3 scientific analysis can lead fishery reform and be directly applicable to co-management structures. These case studies suggest that a fully integrated approach that implements a participatory process to generate a scientific basis for fishery management (e.g., data collection, analysis, design and to design management measures among stakeholders will increase the probability that small-scale fisheries will implement science-based management and improve their performance.

  11. High altitude artisanal small-scale gold mines are hot spots for Mercury in soils and plants

    Terán-Mita, Tania A.; Faz, Angel; Salvador, Flor; Arocena, Joselito M.; Acosta, Jose A.

    2013-01-01

    Mercury releases from artisanal and small-scale gold mines (ASGM) condense and settle on plants, soils and water bodies. We collected soil and plant samples to add knowledge to the likely transfer of Hg from soils into plants and eventually predict Hg accumulation in livestock around ASGM in Bolivia. Mean contents of Hg in soils range from 0.5 to 48.6 mg Hg kg −1 soil (5× to 60× more compared to control sites) and exceeded the soil Hg threshold levels in some European countries. The Hg contents ranged from 0.6 to 18 and 0.2 to 28.3 mg Hg kg −1 leaf and root, respectively. The high Hg in Poaceae and Rosaceae may elevate Hg accumulation into the food chain because llama and alpaca solely thrive on these plants for food. Erosion of soils around ASGM in Bolivia contributes to the Hg contamination in lower reaches of the Amazon basin. - Highlights: ► Hg in soils ranged from 0.5 to 48.6 mg Hg kg −1 soil, and at least 5× to 60× more than control sites. ► Plants near gold mines exceed the 0.1 mg Hg kg −1 plant material European limit for feed quality. ► Camelids feeding on plants with high Hg may elevate Hg levels in foods (meats) for the miners. ► Soils with high Hg can be significant Hg sources to the contamination of the Amazon basin. - Mean contents of Hg in soils were at least 5× to 60× more compared to Hg in control sites, and the high Hg in Poaceae and Rosaceae may elevate Hg into the food chain.

  12. High-temperature hydrogen-air-steam detonation experiments in the BNL small-scale development apparatus

    Ciccarelli, G.; Ginsburg, T.; Boccio, J.; Economos, C.; Finfrock, C.; Gerlach, L.; Sato, K.; Kinoshita, M.

    1994-08-01

    The Small-Scale Development Apparatus (SSDA) was constructed to provide a preliminary set of experimental data to characterize the effect of temperature on the ability of hydrogen-air-steam mixtures to undergo detonations and, equally important, to support design of the larger scale High-Temperature Combustion Facility (HTCF) by providing a test bed for solution of a number of high-temperature design and operational problems. The SSDA, the central element of which is a 10-cm inside diameter, 6.1-m long tubular test vessel designed to permit detonation experiments at temperatures up to 700K, was employed to study self-sustained detonations in gaseous mixtures of hydrogen, air, and steam at temperatures between 300K and 650K at a fixed initial pressure of 0.1 MPa. Hydrogen-air mixtures with hydrogen composition from 9 to 60 percent by volume and steam fractions up to 35 percent by volume were studied for stoichiometric hydrogen-air-steam mixtures. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air gas mixture temperature, in the range 300K-650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The hydrogen-air detonability limits for the 10-cm inside diameter SSDA test vessel, based upon the onset of single-head spin, decreased from 15 percent hydrogen at 300K down to between 9 and 10 percent hydrogen at 650K. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments

  13. Experimental Validation of a Numerical Model for Three-Dimensional High-Speed Railway Bridge Analysis by Comparison with a Small-Scale Model

    Sneideris, J.; Bucinskas, Paulius; Agapii, L.

    2015-01-01

    The aim of this paper is to perform dynamic analysis of a multi-span railway bridge interacting with the underlying soil. A small-scale model of a bridge structure is constructed for experimental testing and the results are compared with a computational model. The computational model in this paper...... dimensional 10-degrees-of-freedom system. The subsoil model utilizes Green’s function for a horizontally layered half-space. The small-scale experimental model consists of bridge deck, columns and footings which are made from Plexiglas. An electric vehicle travels along the bridge deck on a track to simulate...

  14. Performance of small-scale dairy farms in the highlands of central Mexico during the dry season under traditional feeding strategies.

    Martínez-García, Carlos Galdino; Rayas-Amor, Adolfo Armando; Anaya-Ortega, Juan Pablo; Martínez-Castañeda, Francisco Ernesto; Espinoza-Ortega, Angélica; Prospero-Bernal, Fernando; Arriaga-Jordán, Carlos Manuel

    2015-02-01

    In Mexico, small-scale dairy systems (SSDS) represent over 78 % of dairy farms and contribute with 37 % of national milk production; however, they face high feeding costs. The objective of this study was to assess the performance of SSDS during the dry season in terms of milk yields, milk composition and feeding costs under traditional feeding strategies, to identify areas of opportunity for improving their profitability. The information was collected from 22 SSDS every month during dry season. Feeds were classified in quality forages (QF), supplements (SU) and straws (ST). Two factors were identified: factor 1-a positive relationship among QF, SU, milk yield and ration cost and factor 2-represented straw usage. Four feeding strategies were identified: (1) low-cost feeding strategy; (2) home-grown feeding strategy; (3) high-cost feeding strategy; and (4) straw-based feeding strategy. There were differences (P  0.05) differences among feeding strategies for fat and protein contents in milk. It is concluded that to improve performance and profitability and enhance sustainability in SSDS, farmers should base feeding strategies on home-grown quality forages, as it was the case in group 2 which showed lower feeding cost and better milk yield. It is also recommended to increase the inclusion of quality forages like grazing pastures and maize silages during the dry season and to avoid the inclusion of straws.

  15. The effects of the small-scale DM power on the cosmological neutral hydrogen (HI) distribution at high redshifts

    Sarkar, Abir; Sethi, Shiv K.; Mondal, Rajesh; Bharadwaj, Somnath; Das, Subinoy; Marsh, David J.E.

    2016-01-01

    The particle nature of dark matter remains a mystery. In this paper, we consider two dark matter models—Late Forming Dark Matter (LFDM) and Ultra-Light Axion (ULA) models—where the matter power spectra show novel effects on small scales. The high redshift universe offers a powerful probe of their parameters. In particular, we study two cosmological observables: the neutral hydrogen (HI) redshifted 21-cm signal from the epoch of reionization, and the evolution of the collapsed fraction of HI in the redshift range 2 < z < 5. We model the theoretical predictions of the models using CDM-like N-body simulations with modified initial conditions, and generate reionization fields using an excursion set model. The N-body approximation is valid on the length and halo mass scales studied. We show that LFDM and ULA models predict an increase in the HI power spectrum from the epoch of reionization by a factor between 2–10 for a range of scales 0.1 < k < 4 Mpc −1 . Assuming a fiducial model where a neutral hydrogen fraction x-bar HI  = 0.5 must be achieved by z = 8, the reionization process allows us to put approximate bounds on the redshift of dark matter formation z f  > 4 × 10 5 (for LFDM) and the axion mass m a  > 2.6 × 10 −23  eV (for ULA). The comparison of the collapsed mass fraction inferred from damped Lyman-α observations to the theoretical predictions of our models lead to the weaker bounds: z f  > 2 × 10 5 and m a  > 10 −23  eV. These bounds are consistent with other constraints in the literature using different observables; we briefly discuss how these bounds compare with possible constraints from the observation of luminosity function of galaxies at high redshifts. In the case of ULAs, these constraints are also consistent with a solution to the cusp-core problem of CDM

  16. High-temperature hydrogen-air-steam detonation experiments in the BNL small-scale development apparatus

    Ciccarelli, G.; Ginsberg, T.; Boccio, J.; Economos, C.; Finfrock, C.; Gerlach, L.; Sato, K.

    1994-01-01

    The Small-Scale Development Apparatus (SSDA) was constructed to provide a preliminary set of experimental data to characterize the effect of temperature on the ability of hydrogen-air-steam-mixtures to undergo detonations and, equally important, to support design of the larger-scale High-Temperature Combustion Facility (HTCF) by providing a test bed for solution of a number of high-temperature design and operational problems. The SSDA, the central element of which is 10-cm inside diameter, 6.1-m long tubular test vessel designed to permit detonation experiments at temperatures up to 700K, was employed to study self-sustained detonations in gaseous mixtures of hydrogen, air, and steam at temperature between 300K and 650K at a fixed pressure of 0.1 MPa. Detonation cell size measurements provide clear evidence that the effect of hydrogen-air gas mixture temperature, in the range 300K to 650K, is to decrease cell size and, hence, to increase the sensitivity of the mixture to undergo detonations. The effect of steam content, at any given temperature, is to increase the cell size and, thereby, to decrease the sensitivity of stoichiometric hydrogen-air mixtures. The one-dimensional ZND model does a very good job at predicting the overall trends in the cell size data over the range of hydrogen-air-steam mixture compositions and temperature studied in the experiments. Experiments were conducted to measure the rate of hydrogen oxidation in the absence of ignition sources at temperatures of 500K and 650K, for hydrogen-air mixtures of 15% and 50%, and for a mixture of equimolar hydrogen-air and 30% steam at 650K. The rate of hydrogen oxidation was found to be significant at 650K. Reduction of hydrogen concentration by chemical reaction from 50 to 44% hydrogen, and from 15 to 11% hydrogen, were observed on a time frame of minutes. The DeSoete rate equation predicts the 50% experiment very well, but greatly underestimates the reaction rate of the lean mixtures

  17. Rolling at small scales

    Nielsen, Kim L.; Niordson, Christian F.; Hutchinson, John W.

    2016-01-01

    The rolling process is widely used in the metal forming industry and has been so for many years. However, the process has attracted renewed interest as it recently has been adapted to very small scales where conventional plasticity theory cannot accurately predict the material response. It is well....... Metals are known to be stronger when large strain gradients appear over a few microns; hence, the forces involved in the rolling process are expected to increase relatively at these smaller scales. In the present numerical analysis, a steady-state modeling technique that enables convergence without...

  18. Design, Development and Performance Evaluation of a Small Scale Solar Assisted Paddy Dryer for on Farm Processing

    Sidrah Ashfaq

    2016-04-01

    Full Text Available With the continued escalation in population growth and the expansion of international food trade and demand of high quality product for food security at low cost has created considerable interest in the development of new post-harvest technologies. This is particularly important for developing countries where post-harvest losses of cereals are between 10-20% and of fruits and vegetables as high as 20- 100% A new solar assisted paddy dryer with central air distribution model (along the length of drying chamber has been developed. Due to this distinct feature of the dryer high drying rate was achieved during the drying processes .Other components of the dryer are perforated drying chamber, blower and flat plat solar air collector. Dryer was evaluated using 100kg of freshly harvested paddy at 23.78% moisture content (wb. Performance evaluation results showed that the mean drying rate of the solar assisted paddy dryer was 0.87kg/hr per for every 100kg, whereas 0.46kg/hr was the sun drying rate comparatively. The faster drying rate of the dryer reveals its suability to dry the paddy for its safe storage moisture content rapidly. By using the solar assisted paddy dryer, approximately 50% saving in time was also achieved as compared with the traditional sun drying method. Solar assisted paddy dryer took 10hr for drying the 100kg paddy up to 14%, while sun drying method dried paddy up to 13.89% in 19 hours. Cost analysis also showed that, by using solar assisted paddy dryer we candry good quality paddy at low cost as compared with the open sun drying method. For development of agriculture in the rural areas, commercial size of the solar assisted paddy dryer can be amplified and produced at community level.

  19. Small-scale integrated demonstration of high-level radioactive waste processing and vitrification using actual SRP waste

    Ferguson, R.B.; Woolsey, G.B.; Galloway, R.M.; Baumgarten, P.M.; Eibling, R.E.

    1980-01-01

    Experiments have been made to demonstrate the feasibility of immobilizing SRP high-level waste in borosilicate glass. Results to date are encouraging. Equipment performance and processing characteristics for solidifying small batches of actual SRP waste have agreed well with previous experience with small- and large-scale tests synthetic waste, and with theoretical predictions

  20. Application of laboratory data from small-scale simulators to human performance issues in the nuclear industry

    Spettell, C.M.

    1986-01-01

    Laboratory analogs of nuclear power plant tasks were simulated on personal computers in two experimental studies. Human performance data were collected during each experimental study. The goal of the first experiment was to validate a quantitative model of dependence among human errors during testing, calibration, and maintenance activities. This model, the Multiple Sequential Failure (MSF) model (NUREG/CR-2211) has been used to quantify dependent human error failure probabilities for human reliability analyses in Probabilistic Risk Assessments (PRAs). The goal of the second experiment was to examine the relationship among psychological and behavioral characteristics of individuals and their performance at controlling a simulated nuclear power plant. These studies demonstrated the usefulness of the experimental psychology approach for validating models of human performance at nuclear power plant tasks

  1. Small-scale sediment transport patterns and bedform morphodynamics: New insights from high-resolution multibeam bathymetry

    Barnard, P.L.; Erikson, L.H.; Kvitek, R.G.

    2011-01-01

    New multibeam echosounder and processing technologies yield sub-meter-scale bathymetric resolution, revealing striking details of bedform morphology that are shaped by complex boundary-layer flow dynamics at a range of spatial and temporal scales. An inertially aided post processed kinematic (IAPPK) technique generates a smoothed best estimate trajectory (SBET) solution to tie the vessel motion-related effects of each sounding directly to the ellipsoid, significantly reducing artifacts commonly found in multibeam data, increasing point density, and sharpening seafloor features. The new technique was applied to a large bedform field in 20-30 m water depths in central San Francisco Bay, California (USA), revealing bedforms that suggest boundary-layer flow deflection by the crests where 12-m-wavelength, 0.2-m-amplitude bedforms are superimposed on 60-m-wavelength, 1-m-amplitude bedforms, with crests that often were strongly oblique (approaching 90??) to the larger features on the lee side, and near-parallel on the stoss side. During one survey in April 2008, superimposed bedform crests were continuous between the crests of the larger features, indicating that flow detachment in the lee of the larger bedforms is not always a dominant process. Assessment of bedform crest peakedness, asymmetry, and small-scale bedform evolution between surveys indicates the impact of different flow regimes on the entire bedform field. This paper presents unique fine-scale imagery of compound and superimposed bedforms, which is used to (1) assess the physical forcing and evolution of a bedform field in San Francisco Bay, and (2) in conjunction with numerical modeling, gain a better fundamental understanding of boundary-layer flow dynamics that result in the observed superimposed bedform orientation. ?? 2011 Springer-Verlag (outside the USA).

  2. Economic and Environmental Performances of Small-Scale Rural PV Solar Projects under the Clean Development Mechanism: The Case of Cambodia

    Ellen De Schepper

    2015-09-01

    Full Text Available The two core objectives of the Clean Development Mechanism (CDM are cost-effective emission reduction and sustainable development. Despite the potential to contribute to both objectives, solar projects play a negligible role under the CDM. In this research, the greenhouse gas mitigation cost is used to evaluate the economic and environmental performances of small-scale rural photovoltaic solar projects. In particular, we compare the use of absolute and relative mitigation costs to evaluate the attractiveness of these projects under the CDM. We encourage the use of relative mitigation costs, implying consideration of baseline costs that render the projects profitable. Results of the mitigation cost analysis are dependent on the baseline chosen. To overcome this drawback, we complement the analysis with a multi-objective optimization approach, which allows quantifying the trade-off between economic and environmental performances of the optimal technologies without requiring a baseline.

  3. Optimizing the performance of small-scale organic Rankine cycle that utilizes a single-screw expander

    Ziviani, D.; Gusev, S.; Lecompte, S.; Groll, E.A.; Braun, J.E.; Horton, W.T.; Broek, M. van den; De Paepe, M.

    2017-01-01

    Highlights: • A total of 102 steady-state points with R245fa and SES336 have been collected. • R245fa led to 10% higher power output despite lower expander isentropic efficiency. • The ORC running with SES36 presented a better matching between expander and cycle. • The theoretical matching between expander volume ratio and cycle efficiency is determined. • Steady-state performance maps are used to build a feed-forward controller. - Abstract: This paper deals with the operation and optimization of a down-scaled industrial organic Rankine cycle (ORC) for low-grade waste heat recovery. The system is a sub-critical regenerative ORC with a nominal power output of 11 kW. The ORC unit has been assembled using off-the-shelf components including three identical plate heat exchangers, a liquid receiver, a multi-stage centrifugal pump and a single-screw compressor adapted to operate as an expander. The experimental results are used to evaluate the influence of the expander performance on the behavior of the ORC system at nominal and part-load conditions. The matching between the volumetric expander and the system operating conditions is also analyzed. Results showed that in the case of SES36, both the expander efficiency and system performance were maximized for a pressure ratio between 7 and 9. In the case of R245fa, while the system efficiency achieved values similar to SES36, but the expander maximum isentropic efficiency was 17% lower. Two analyses are carried out to optimize the operation of the ORC unit with R245fa. At first, the insights gained by analyzing the experimental data are used to evaluate the theoretical matching between volumetric expander and the system maximum efficiency in terms of the Second Law of thermodynamics. Secondly, a control-oriented steady-state cycle model based on empirical correlations calibrated on the experimental results is developed. The model is used to implement a feed-forward control strategy based on predetermined steady

  4. Optimum performance of the small scale open and direct solar thermal Brayton cycle at various environmental conditions and constraints

    Le Roux, W.G.; Bello-Ochende, T.; Meyer, J.P. [Department of Mechanical and Aeronautical Engineering, University of Pretoria, (South Africa)

    2011-07-01

    The energy of the sun can be transformed into mechanical power through the use of concentrated solar power systems. The use of the Brayton cycle with recuperator has significant advantages but also raises issues such as pressure loss and low net power output which are mainly due to irreversibilities of heat transfer and fluid friction. The aim of this study is to optimize the system to generate maximum net power output. Thermodynamic and dynamic trajectory optimizations were performed on a dish concentrator and an off-the-shelf micro-turbine and the effects of wind, solar irradiance and other environmental conditions and constraints on the power output were analyzed. Results showed that the maximum power output is increased when wind decreases and irradiance increases; solar irradiance was found to have a more significant impact than wind. This study highlighted the factors which impact the power generation of concentrated solar power systems so that designers can take them into account.

  5. Small-Scale Morphological Features on a Solid Surface Processed by High-Pressure Abrasive Water Jet

    Can Kang

    2013-08-01

    Full Text Available Being subjected to a high-pressure abrasive water jet, solid samples will experience an essential variation of both internal stress and physical characteristics, which is closely associated with the kinetic energy attached to the abrasive particles involved in the jet stream. Here, experiments were performed, with particular emphasis being placed on the kinetic energy attenuation and turbulent features in the jet stream. At jet pressure of 260 MPa, mean velocity and root-mean-square (RMS velocity on two jet-stream sections were acquired by utilizing the phase Doppler anemometry (PDA technique. A jet-cutting experiment was then carried out with Al-Mg alloy samples being cut by an abrasive water jet. Morphological features and roughness on the cut surface were quantitatively examined through scanning electron microscopy (SEM and optical profiling techniques. The results indicate that the high-pressure water jet is characterized by remarkably high mean flow velocities and distinct velocity fluctuations. Those irregular pits and grooves on the cut surfaces indicate both the energy attenuation and the development of radial velocity components in the jet stream. When the sample is positioned with different distances from the nozzle outlet, the obtained quantitative surface roughness varies accordingly. A descriptive model highlighting the behaviors of abrasive particles in jet-cutting process is established in light of the experimental results and correlation analysis.

  6. Small-Scale Morphological Features on a Solid Surface Processed by High-Pressure Abrasive Water Jet.

    Kang, Can; Liu, Haixia

    2013-08-14

    Being subjected to a high-pressure abrasive water jet, solid samples will experience an essential variation of both internal stress and physical characteristics, which is closely associated with the kinetic energy attached to the abrasive particles involved in the jet stream. Here, experiments were performed, with particular emphasis being placed on the kinetic energy attenuation and turbulent features in the jet stream. At jet pressure of 260 MPa, mean velocity and root-mean-square (RMS) velocity on two jet-stream sections were acquired by utilizing the phase Doppler anemometry (PDA) technique. A jet-cutting experiment was then carried out with Al-Mg alloy samples being cut by an abrasive water jet. Morphological features and roughness on the cut surface were quantitatively examined through scanning electron microscopy (SEM) and optical profiling techniques. The results indicate that the high-pressure water jet is characterized by remarkably high mean flow velocities and distinct velocity fluctuations. Those irregular pits and grooves on the cut surfaces indicate both the energy attenuation and the development of radial velocity components in the jet stream. When the sample is positioned with different distances from the nozzle outlet, the obtained quantitative surface roughness varies accordingly. A descriptive model highlighting the behaviors of abrasive particles in jet-cutting process is established in light of the experimental results and correlation analysis.

  7. The relationship between small-scale and large-scale ionospheric electron density irregularities generated by powerful HF electromagnetic waves at high latitudes

    E. D. Tereshchenko

    2006-11-01

    Full Text Available Satellite radio beacons were used in June 2001 to probe the ionosphere modified by a radio beam produced by the EISCAT high-power, high-frequency (HF transmitter located near Tromsø (Norway. Amplitude scintillations and variations of the phase of 150- and 400-MHz signals from Russian navigational satellites passing over the modified region were observed at three receiver sites. In several papers it has been stressed that in the polar ionosphere the thermal self-focusing on striations during ionospheric modification is the main mechanism resulting in the formation of large-scale (hundreds of meters to kilometers nonlinear structures aligned along the geomagnetic field (magnetic zenith effect. It has also been claimed that the maximum effects caused by small-scale (tens of meters irregularities detected in satellite signals are also observed in the direction parallel to the magnetic field. Contrary to those studies, the present paper shows that the maximum in amplitude scintillations does not correspond strictly to the magnetic zenith direction because high latitude drifts typically cause a considerable anisotropy of small-scale irregularities in a plane perpendicular to the geomagnetic field resulting in a deviation of the amplitude-scintillation peak relative to the minimum angle between the line-of-sight to the satellite and direction of the geomagnetic field lines. The variance of the logarithmic relative amplitude fluctuations is considered here, which is a useful quantity in such studies. The experimental values of the variance are compared with model calculations and good agreement has been found. It is also shown from the experimental data that in most of the satellite passes a variance maximum occurs at a minimum in the phase fluctuations indicating that the artificial excitation of large-scale irregularities is minimum when the excitation of small-scale irregularities is maximum.

  8. Suppression of small-scale self-focusing of high-power laser beams due to their self-filtration during propagation in free space

    Ginzburg, V. N.; Kochetkov, A. A.; Potemkin, A. K.; Khazanov, E. A.

    2018-04-01

    It has been experimentally confirmed that self-cleaning of a laser beam from spatial noise during propagation in free space makes it possible to suppress efficiently the self-focusing instability without applying spatial filters. Measurements of the instability increment by two independent methods have demonstrated quantitative agreement with theory and high efficiency of small-scale self-focusing suppression. This opens new possibilities for using optical elements operating in transmission (frequency doublers, phase plates, beam splitters, polarisers, etc.) in beams with intensities on the order of a few TW cm‑2.

  9. Relationship between human resource ability and market access capacity on business performance. (case study of wood craft micro- and small-scale industries in Gianyar Regency, Bali)

    Sukartini, N. W.; Sudarmini, N. M.; Lasmini, N. K.

    2018-01-01

    The aims of this research are to: (1) analyze the influence of Human Resource Ability on market access capacity in Wood Craft Micro and Small Industry; (2) to analyze the effect of market access capacity on business performance; (3) analyze the influence of Human Resources ability on business performance. Data were collected using questionnaires, interviews, observations, and literature studies. The resulting data were analyzed using Struture Equation Modeling (SEM). The results of the analysis show that (1) there is a positive and significant influence of the ability of Human Resources on market access capacity in Wood Craft Micro-and Small-Scale Industries in Gianyar; (2) there is a positive and significant influence of market access capacity on business performance; and (3) there is a positive and significant influence of Human Resource ability on business performance. To improve the ability to access the market and business performance, it is recommended that human resource ability need to be improved through training; government and higher education institutions are expected to play a role in improving the ability of human resources (craftsmen) through provision of training programs

  10. Drift motions of small-scale irregularities in the high-latitude F region: An experimental comparison with plasma drift motions

    Ruohoniemi, J.M.; Greenwald, R.A.; Baker, K.B.; Villain, J.P.; McCready, M.A.

    1987-01-01

    On the evening of January 6, 1986, coordinated observations were carried out with the Johns Hopkins University Applied Physics Laboratory HF coherent scatter radar at Goose Bay, Labrador, and the SRI International incoherent scatter radar at Sondre Stromfjord, Greenland. The common field of view comprised a section of high-latitude F region ionosphere centered on the great circle plane between the radar sites. Over a 40-min period, the HF radar observed strong backscatter from small-scale (13.9 m) field-aligned irregularities. The bulk line-of-sight drift velocity of the irregularities is deduced from the backscatter data. The returns collected simultaneously with the incoherent scatter radar are processed for estimates of the mean line-of-sight ion velocity. Approximately 100 distinct comparisons are possible between the two sets of velocity estimates. Reversals exceeding 1,000 m/s are present in both. In this paper, the authors demonstrate a correspondence between the measured irregularity and ion drifts that is consistent with the supposition that the motion of the irregularities is dominated by convective drift of the ambient plasma. This indicates that the small-scale irregularities detected by HF radars in the high-latitude F region can serve as tracers of ionospheric convective drift

  11. Just in Time Strategy and Financial Performance of Small Scale Industry in Ogun State: A Study of ADO-ODO/OTA Local Government

    Patrick Amaechi Egbunike

    2017-10-01

    Full Text Available Many manufacturing firms have decided to implement just in time technique as a strategic cost management to survive and remain competitive in their business environment. The study examines how just in time technique has assisted in reducing inventory cost management and improve the firm profit level. The specific objective is to ascertain the influence of purchases and sales on return on equity of small scale manufacturing industry. Survey design was used for the study. Sample frame was purposively selected for convenience sake. Data was collected though secondary source. Regression analysis was employed to analyze the data. The study found positive relationship between just in time implementation and profit level of small scale business industry. We recommend other small scale businesses that have not started implementing just in time strategy to start the strategy. We encourage future researcher to examine the efficiency of just in time strategy among petty small scale trader in our urban centers.

  12. Antimicrobials in small-scale urban pig farming in a lower middle-income country - arbitrary use and high resistance levels.

    Ström, G; Boqvist, S; Albihn, A; Fernström, L-L; Andersson Djurfeldt, A; Sokerya, S; Sothyra, T; Magnusson, U

    2018-01-01

    Administration of antimicrobials to food-producing animals is regarded as a major contributor to the overall emergence of resistance in bacteria worldwide. However, few data are available on global antimicrobial use and resistance (AMR) in livestock, especially from low- and middle-income countries. We conducted a structured survey of 91 small-scale pig farms in the urban and peri-urban areas of Phnom Penh, Cambodia, to assess the farmers' knowledge, attitudes and practices related to antimicrobial use in their pig production. Commensal Escherichia coli was isolated from three healthy pigs from each farm ( n  = 261) and susceptibility testing was performed against 14 antimicrobials, using broth microdilution. Univariable logistic regression and generalized linear mixed models were used to investigate potential associations between farm characteristics, management factors and resistance to different types of antimicrobials. We found a widespread and arbitrary use of antimicrobials, often based on the farmer's own judgment. Around 66% of the farmers reported frequently self-adjusting treatment duration and dosage, and 45% had not heard about the term 'antimicrobial resistance'. The antimicrobials most commonly mentioned or kept by the farmers were amoxicillin, tylosin, gentamicin and colistin. Around 37% used a feed concentrate that contained antimicrobials, while antimicrobials for humans were used as a last-line treatment by 10% of the farmers. Commensal E. coli exhibited high prevalence of resistance to several antimicrobials considered to be of critical importance for human medicine, including ampicillin, ciprofloxacin and colistin, and multidrug-resistance was found in 79% of the samples. Higher prevalence of resistance was observed on farms that administered prophylactic antimicrobials and on farms that treated the entire group or herd in the event of disease. The widespread and arbitrary use of antimicrobials in pig farming in Cambodia is highly worrisome

  13. Development of a High-Fidelity Model for an Electrically Driven Energy Storage Flywheel Suitable for Small Scale Residential Applications

    Mustafa E. Amiryar

    2018-03-01

    Full Text Available Energy storage systems (ESS are key elements that can be used to improve electrical system efficiency by contributing to balance of supply and demand. They provide a means for enhancing the power quality and stability of electrical systems. They can enhance electrical system flexibility by mitigating supply intermittency, which has recently become problematic, due to the increased penetration of renewable generation. Flywheel energy storage systems (FESS are a technology in which there is gathering interest due to a number of advantages offered over other storage solutions. These technical qualities attributed to flywheels include high power density, low environmental impact, long operational life, high round-trip efficiency and high cycle life. Furthermore, when configured in banks, they can store MJ levels of energy without any upper limit. Flywheels configured for grid connected operation are systems comprising of a mechanical part, the flywheel rotor, bearings and casings, and the electric drive part, inclusive of motor-generator (MG and power electronics. This contribution focusses on the modelling and simulation of a high inertia FESS for energy storage applications which has the potential for use in the residential sector in more challenging situations, a subject area in which there are few publications. The type of electrical machine employed is a permanent magnet synchronous motor (PMSM and this, along with the power electronics drive, is simulated in the MATLAB/Simulink environment. A brief description of the flywheel structure and applications are given as a means of providing context for the electrical modelling and simulation reported. The simulated results show that the system run-down losses are 5% per hour, with overall roundtrip efficiency of 88%. The flywheel speed and energy storage pattern comply with the torque variations, whilst the DC-bus voltage remains constant and stable within ±3% of the rated voltage, regardless of

  14. On the Accuracy of the Conjugation of High-Orbit Satellites with Small-Scale Regions in the Ionosphere

    Safargaleev, V. V.; Safargaleeva, N. N.

    2018-03-01

    The degree of uncertainty that arises when mapping high-orbit satellites of the Cluster type into the ionosphere using three geomagnetic field models (T89, T98, and T01) has been estimated. Studies have shown that uncertainty is minimal in situations when a satellite in the daytime is above the equatorial plane of the magnetosphere at the distance of no more than 5 R E from the Earth's surface and is projected into the ionosphere of the northern hemisphere. In this case, the dimensions of the uncertainty region are about 50 km, and the arbitrariness of the choice of the model for projecting does not play a decisive role in organizing satellite support based on optical observations when studying such large-scale phenomena as, e.g., WTS, as well as heating experiments at the EISCAT heating facility for the artificial modification of the ionosphere and the generation of artificial fluctuations in the VLF band. In all other cases, the uncertainty in determining the position of the base of the field line on which the satellite is located is large, and additional information is required to correctly compare the satellite with the object in the ionosphere.

  15. Quantifying small-scale spatio-temporal variability of snow stratigraphy in forests based on high-resolution snow penetrometry

    Teich, M.; Hagenmuller, P.; Bebi, P.; Jenkins, M. J.; Giunta, A. D.; Schneebeli, M.

    2017-12-01

    Snow stratigraphy, the characteristic layering within a seasonal snowpack, has important implications for snow remote sensing, hydrology and avalanches. Forests modify snowpack properties through interception, wind speed reduction, and changes to the energy balance. The lack of snowpack observations in forests limits our ability to understand the evolution of snow stratigraphy and its spatio-temporal variability as a function of forest structure and to observe snowpack response to changes in forest cover. We examined the snowpack under canopies of a spruce forest in the central Rocky Mountains, USA, using the SnowMicroPen (SMP), a high resolution digital penetrometer. Weekly-repeated penetration force measurements were recorded along 10 m transects every 0.3 m in winter 2015 and bi-weekly along 20 m transects every 0.5 m in 2016 in three study plots beneath canopies of undisturbed, bark beetle-disturbed and harvested forest stands, and an open meadow. To disentangle information about layer hardness and depth variabilities, and to quantitatively compare the different SMP profiles, we applied a matching algorithm to our dataset, which combines several profiles by automatically adjusting their layer thicknesses. We linked spatial and temporal variabilities of penetration force and depth, and thus snow stratigraphy to forest and meteorological conditions. Throughout the season, snow stratigraphy was more heterogeneous in undisturbed but also beneath bark beetle-disturbed forests. In contrast, and despite remaining small diameter trees and woody debris, snow stratigraphy was rather homogenous at the harvested plot. As expected, layering at the non-forested plot varied only slightly over the small spatial extent sampled. At the open and harvested plots, persistent crusts and ice lenses were clearly present in the snowpack, while such hard layers barely occurred beneath undisturbed and disturbed canopies. Due to settling, hardness significantly increased with depth at

  16. Energy, Exergy and Performance Analysis of Small-Scale Organic Rankine Cycle Systems for Electrical Power Generation Applicable in Rural Areas of Developing Countries

    Suresh Baral

    2015-01-01

    Full Text Available This paper introduces the concept of installing a small-scale organic Rankine cycle system for the generation of electricity in remote areas of developing countries. The Organic Rankine Cycle Systems (ORC system uses a commercial magnetically-coupled scroll expander, plate type heat exchangers and plunger type working fluid feed pump. The heat source for the ORC system can be solar energy. A series of laboratory tests were conducted to confirm the cycle efficiency and expander power output of the system. Using the actual system data, the exergy destruction on the system components and exergy efficiency were assessed. Furthermore, the results of the variations of system energy and exergy efficiencies with different operating parameters, such as the evaporating and condensing pressures, degree of superheating, dead state temperature, expander inlet temperature and pressure ratio were illustrated. The system exhibited acceptable operational characteristics with good performance under a wide range of conditions. A heat source temperature of 121 °C is expected to deliver a power output of approximately 1.4 kW. In addition, the system cost analysis and financing mechanisms for the installation of the ORC system were discussed.

  17. Enhancing the Productivity of High Value Crops and Income Generation with Small-Scale Irrigation Technologies in Kenya. Final Report 2009-2013

    2014-02-01

    The project was implemented by the Kenya Agricultural Research Institute in collaboration with key irrigation stakeholders including Horticultural Crops Development Authority (HCDA), G North and Son limited, Kenya Irrigation and Drainage Association (KIDA), Jomo Kenyatta University of Agriculture and Technology (JKUAT), Greenbelt Movement and Ministry of Agriculture. The objective was to develop and pilot test appropriate irrigation systems (methods and related water/nutrient management practices) for small-scale farmers for increasing yield, quality of high value crops and farmers income to improved livelihood. The project built on earlier work on low head drip irrigation in Kenya involving KARI led promotion among the peri-urban and rural communities. The Equipment used include Neutron Probe Hydroprobe, Ammonium Sulphate Fertilizers (5% a.e), drip irrigation kits, MoneyMaker irrigation pumps, Pessl imetos weather station, SDEC tensimetre and tensiometers), Venturi injectors, among others.

  18. High-performance small-scale solvers for linear Model Predictive Control

    Frison, Gianluca; Sørensen, Hans Henrik Brandenborg; Dammann, Bernd

    2014-01-01

    , with the two main research areas of explicit MPC and tailored on-line MPC. State-of-the-art solvers in this second class can outperform optimized linear-algebra libraries (BLAS) only for very small problems, and do not explicitly exploit the hardware capabilities, relying on compilers for that. This approach...

  19. Transient simulation of a solar heating system for a small-scale ethanol-water distillation plant: Thermal, environmental and economic performance

    Vargas-Bautista, Juan Pablo; García-Cuéllar, Alejandro Javier; Pérez-García, Santiago L.; Rivera-Solorio, Carlos I.

    2017-01-01

    Highlights: • Thermal simulation of a small solar ethanol distillation plant is performed. • The optimum collector area is obtained for two different thermal collectors types. • Higher solar fraction was found for parabolic trough collectors. • Economic analysis is performed for different scenarios to evaluate feasibility. - Abstract: The thermal, environmental and economic performance of a small-scale ethanol distillation system, where solar energy is used as primary energy source, was studied. Two different concentrations of ethanol at the feed stream (5 wt.% and 10 wt.%) were analysed to obtain a distillate product of 95 wt.% ethanol (hydrous ethanol). Evacuated tube solar collectors (ETC) and parabolic trough collectors (PTC) were considered for the solar heating system. A case of study for a specific geographical place (Monterrey, México) was developed herein to evaluate the solar ethanol distillation system; the results can be extended to other locations, weather conditions and operational parameters. The thermal results from the simulation showed that through an adequate selection of the solar collector area and an appropriate sizing of the different equipment of the solar distillation system, PTC represents a better option where energy savings of 80% and 71% can be achieved for 5 wt.% and 10 wt.% ethanol at the feed stream, respectively. However, the economic feasibility of the solar distillation system is achieved using ETC for a price of hydrous ethanol of 1.75 USD/L and a feed stream of 10 wt.% ethanol, reaching an internal rate of return (IRR) of 18.8% and payback period of 5.2 years. As an important technical result, selected ETC presented advantages over PTC where an average distillate product of 3.6 and 3.4 ml at 95 wt.% ethanol can be obtained per unit of solar energy (kW h) captured per area (m"2) of solar collector using 5 wt.% and 10 wt.% ethanol at the feed stream, respectively (36% more than PTC). The reduction of greenhouse gases (GHG

  20. Climate SPHINX: High-resolution present-day and future climate simulations with an improved representation of small-scale variability

    Davini, Paolo; von Hardenberg, Jost; Corti, Susanna; Subramanian, Aneesh; Weisheimer, Antje; Christensen, Hannah; Juricke, Stephan; Palmer, Tim

    2016-04-01

    The PRACE Climate SPHINX project investigates the sensitivity of climate simulations to model resolution and stochastic parameterization. The EC-Earth Earth-System Model is used to explore the impact of stochastic physics in 30-years climate integrations as a function of model resolution (from 80km up to 16km for the atmosphere). The experiments include more than 70 simulations in both a historical scenario (1979-2008) and a climate change projection (2039-2068), using RCP8.5 CMIP5 forcing. A total amount of 20 million core hours will be used at end of the project (March 2016) and about 150 TBytes of post-processed data will be available to the climate community. Preliminary results show a clear improvement in the representation of climate variability over the Euro-Atlantic following resolution increase. More specifically, the well-known atmospheric blocking negative bias over Europe is definitely resolved. High resolution runs also show improved fidelity in representation of tropical variability - such as the MJO and its propagation - over the low resolution simulations. It is shown that including stochastic parameterization in the low resolution runs help to improve some of the aspects of the MJO propagation further. These findings show the importance of representing the impact of small scale processes on the large scale climate variability either explicitly (with high resolution simulations) or stochastically (in low resolution simulations).

  1. Just in Time Strategy and Financial Performance of Small Scale Industry in Ogun State: A Study of ADO-ODO/OTA Local Government

    Patrick Amaechi Egbunike; Osazee Graham Imade

    2017-01-01

    Many manufacturing firms have decided to implement just in time technique as a strategic cost management to survive and remain competitive in their business environment. The study examines how just in time technique has assisted in reducing inventory cost management and improve the firm profit level. The specific objective is to ascertain the influence of purchases and sales on return on equity of small scale manufacturing industry. Survey design was used for the study. Sample frame was purpo...

  2. High-resolution monitoring across the soil-groundwater interface - Revealing small-scale hydrochemical patterns with a novel multi-level well

    Gassen, Niklas; Griebler, Christian; Stumpp, Christine

    2016-04-01

    Biogeochemical turnover processes in the subsurface are highly variable both in time and space. In order to capture this variability, high resolution monitoring systems are required. Particular in riparian zones the understanding of small-scale biogeochemical processes is of interest, as they are regarded as important buffer zones for nutrients and contaminants with high turnover rates. To date, riparian research has focused on influences of groundwater-surface water interactions on element cycling, but little is known about processes occurring at the interface between the saturated and the unsaturated zone during dynamic flow conditions. Therefore, we developed a new type of high resolution multi-level well (HR-MLW) that has been installed in the riparian zone of the Selke river. This HR-MLW for the first time enables to derive water samples both from the unsaturated and the saturated zone across one vertical profile with a spatial vertical resolution of 0.05 to 0.5 m to a depth of 4 m b.l.s. Water samples from the unsaturated zone are extracted via suction cup sampling. Samples from the saturated zone are withdrawn through glass filters and steel capillaries. Both, ceramic cups and glass filters, are installed along a 1" HDPE piezometer tube. First high resolution hydrochemical profiles revealed a distinct depth-zonation in the riparian alluvial aquifer. A shallow zone beneath the water table carried a signature isotopically and hydrochemically similar to the nearby river, while layers below 1.5 m were influenced by regional groundwater. This zonation showed temporal dynamics related to groundwater table fluctuations and microbial turnover processes. The HR-MLW delivered new insight into mixing and turnover processes between riverwater and groundwater in riparian zones, both in a temporal and spatial dimension. With these new insights, we are able to improve our understanding of dynamic turnover processes at the soil - groundwater interface and of surface

  3. Gas-permeable ethylene bags for the small scale cultivation of highly pathogenic avian influenza H5N1 and other viruses in embryonated chicken eggs

    McCurdy Kimberly S

    2010-01-01

    Full Text Available Abstract Background Embryonated chicken eggs (ECE are sometimes used for the primary isolation or passage of influenza viruses, other viruses, and certain bacteria. For small-scale experiments with pathogens that must be studied in biosafety level three (BSL3 facilities, inoculated ECE are sometimes manipulated and maintained in small egg incubators within a biosafety cabinet (BSC. To simplify the clean up and decontamination of an egg incubator in case of egg breakage, we explored whether ethylene breather bags could be used to encase ECE inoculated with pathogens. This concept was tested by determining embryo survival and examining virus yields in bagged ECE. Results Virus yields acceptable for many applications were attained when influenza-, alpha-, flavi-, canine distemper-, and mousepox viruses were propagated in ECE sealed within ethylene breather bags. Conclusions For many small-scale applications, ethylene breather bags can be used to encase ECE inoculated with various viruses.

  4. Multi-wavelength high-resolution observations of a small-scale emerging magnetic flux event and the chromospheric and coronal response

    Vargas Domínguez, Santiago; Kosovichev, Alexander; Yurchyshyn, Vasyl, E-mail: svargas@bbso.njit.edu [Big Bear Solar Observatory, NJIT, 40386 North Shore Lane, Big Bear City, CA 92314-9672 (United States)

    2014-10-20

    State-of-the-art solar instrumentation is now revealing magnetic activity of the Sun with unprecedented temporal and spatial resolutions. Observations with the 1.6 m aperture New Solar Telescope (NST) of the Big Bear Solar Observatory are making next steps in our understanding of the solar surface structure. Granular-scale magnetic flux emergence and the response of the solar atmosphere are among the key research topics of high-resolution solar physics. As part of a joint observing program with NASA's Interface Region Imaging Spectrograph (IRIS) mission on 2013 August 7, the NST observed active region NOAA 11,810 in the photospheric TiO 7057 Å band with a resolution of pixel size of 0.''034 and chromospheric He I 10830 Å and Hα 6563 Å wavelengths. Complementary data are provided by the Solar Dynamics Observatory (SDO) and Hinode space-based telescopes. The region displayed a group of solar pores, in the vicinity of which we detect a small-scale buoyant horizontal magnetic flux tube causing granular alignments and interacting with the preexisting ambient field in the upper atmospheric layers. Following the expansion of distorted granules at the emergence site, we observed a sudden appearance of an extended surge in the He I 10830 Å data (bandpass of 0.05 Å). The IRIS transition region imaging caught ejection of a hot plasma jet associated with the He I surge. The SDO/HMI data used to study the evolution of the magnetic and Doppler velocity fields reveal emerging magnetic loop-like structures. Hinode/Ca II H and IRIS filtergrams detail the connectivities of the newly emerged magnetic field in the lower solar chromosphere. From these data, we find that the orientation of the emerging magnetic field lines from a twisted flux tube formed an angle of ∼45° with the overlying ambient field. Nevertheless, the interaction of emerging magnetic field lines with the pre-existing overlying field generates high-temperature emission regions and boosts the

  5. Small-scale household biogas digesters

    Bruun, Sander; Jensen, Lars Stoumann; Khanh Vu, Van Thi

    2014-01-01

    There are a number of advantages to small-scale biogas production on farms, including savings on firewood or fossil fuels and reductions in odour and greenhouse gas emissions. For these reasons, governments and development aid agencies have supported the installation of biogas digesters. However......, biogas digesters are often poorly managed and there is a lack of proper distribution systems for biogas. This results in methane being released inadvertently through leaks in digesters and tubing, and intentionally when production exceeds demand. As methane has a global warming potential 25 times greater......% of the produced biogas is released, depending on the type of fuel that has been replaced. The limited information available as regards methane leaking from small-scale biogas digesters in developing countries indicates that emissions may be as high as 40%. With the best estimates of global numbers of small...

  6. Small-scale classification schemes

    Hertzum, Morten

    2004-01-01

    Small-scale classification schemes are used extensively in the coordination of cooperative work. This study investigates the creation and use of a classification scheme for handling the system requirements during the redevelopment of a nation-wide information system. This requirements...... classification inherited a lot of its structure from the existing system and rendered requirements that transcended the framework laid out by the existing system almost invisible. As a result, the requirements classification became a defining element of the requirements-engineering process, though its main...... effects remained largely implicit. The requirements classification contributed to constraining the requirements-engineering process by supporting the software engineers in maintaining some level of control over the process. This way, the requirements classification provided the software engineers...

  7. Small-scale fisheries bycatch jeopardizes endangered Pacific loggerhead turtles.

    S Hoyt Peckham

    2007-10-01

    Full Text Available Although bycatch of industrial-scale fisheries can cause declines in migratory megafauna including seabirds, marine mammals, and sea turtles, the impacts of small-scale fisheries have been largely overlooked. Small-scale fisheries occur in coastal waters worldwide, employing over 99% of the world's 51 million fishers. New telemetry data reveal that migratory megafauna frequent coastal habitats well within the range of small-scale fisheries, potentially producing high bycatch. These fisheries occur primarily in developing nations, and their documentation and management are limited or non-existent, precluding evaluation of their impacts on non-target megafauna.30 North Pacific loggerhead turtles that we satellite-tracked from 1996-2005 ranged oceanwide, but juveniles spent 70% of their time at a high use area coincident with small-scale fisheries in Baja California Sur, Mexico (BCS. We assessed loggerhead bycatch mortality in this area by partnering with local fishers to 1 observe two small-scale fleets that operated closest to the high use area and 2 through shoreline surveys for discarded carcasses. Minimum annual bycatch mortality in just these two fleets at the high use area exceeded 1000 loggerheads year(-1, rivaling that of oceanwide industrial-scale fisheries, and threatening the persistence of this critically endangered population. As a result of fisher participation in this study and a bycatch awareness campaign, a consortium of local fishers and other citizens are working to eliminate their bycatch and to establish a national loggerhead refuge.Because of the overlap of ubiquitous small-scale fisheries with newly documented high-use areas in coastal waters worldwide, our case study suggests that small-scale fisheries may be among the greatest current threats to non-target megafauna. Future research is urgently needed to quantify small-scale fisheries bycatch worldwide. Localizing coastal high use areas and mitigating bycatch in

  8. Small-scale fisheries bycatch jeopardizes endangered Pacific loggerhead turtles.

    Peckham, S Hoyt; Maldonado Diaz, David; Walli, Andreas; Ruiz, Georgita; Crowder, Larry B; Nichols, Wallace J

    2007-10-17

    Although bycatch of industrial-scale fisheries can cause declines in migratory megafauna including seabirds, marine mammals, and sea turtles, the impacts of small-scale fisheries have been largely overlooked. Small-scale fisheries occur in coastal waters worldwide, employing over 99% of the world's 51 million fishers. New telemetry data reveal that migratory megafauna frequent coastal habitats well within the range of small-scale fisheries, potentially producing high bycatch. These fisheries occur primarily in developing nations, and their documentation and management are limited or non-existent, precluding evaluation of their impacts on non-target megafauna. 30 North Pacific loggerhead turtles that we satellite-tracked from 1996-2005 ranged oceanwide, but juveniles spent 70% of their time at a high use area coincident with small-scale fisheries in Baja California Sur, Mexico (BCS). We assessed loggerhead bycatch mortality in this area by partnering with local fishers to 1) observe two small-scale fleets that operated closest to the high use area and 2) through shoreline surveys for discarded carcasses. Minimum annual bycatch mortality in just these two fleets at the high use area exceeded 1000 loggerheads year(-1), rivaling that of oceanwide industrial-scale fisheries, and threatening the persistence of this critically endangered population. As a result of fisher participation in this study and a bycatch awareness campaign, a consortium of local fishers and other citizens are working to eliminate their bycatch and to establish a national loggerhead refuge. Because of the overlap of ubiquitous small-scale fisheries with newly documented high-use areas in coastal waters worldwide, our case study suggests that small-scale fisheries may be among the greatest current threats to non-target megafauna. Future research is urgently needed to quantify small-scale fisheries bycatch worldwide. Localizing coastal high use areas and mitigating bycatch in partnership with small-scale

  9. Intelligent Network Flow Optimization (INFLO) prototype : Seattle small-scale demonstration report.

    2015-05-01

    This report describes the performance and results of the INFLO Prototype Small-Scale Demonstration. The purpose of : the Small-Scale Demonstration was to deploy the INFLO Prototype System to demonstrate its functionality and : performance in an opera...

  10. management and growth paradox of rural small-scale industrial

    User

    Keywords: Rural Small-Scale Industries, firm growth, management, proprietors, workforce ... veloping countries as a solution to the problem of scarcity .... In the analysis logistic regression sta- ..... of imported raw materials such as high cost and.

  11. A Guide to Bundling Small-scale CDM Projects

    Mariyappan, J.; Bhardwaj, N.; De Coninck, H.; Van der Linden, N.

    2005-07-01

    Small-scale renewable energy and energy efficiency projects that fit the development needs of many developing countries, can potentially be supported via the Clean Development Mechanism (CDM), one of the Kyoto Protocol's flexible mechanisms for tackling climate change. However, there is concern that due to high transaction costs, as well as many existing barriers, very few investments will be made in small-scale projects, which are often the most suitable development option in countries such as India. In view of this, the 'bundling' together of appropriate small-scale projects on a regional basis has been proposed as a way in which funding can be leveraged from international sources and transaction costs reduced. IT Power, IT Power India and the Energy research Centre of the Netherlands (ECN) are carrying out a 2-year project to establish the capacity within India to enable individual small scale projects to be bundled as a single CDM project. Overall objectives are to develop the necessary institutional capabilities to formulate and implement small scale CDM projects in India; to provide a guide on how to bundle small scale projects under the CDM in developing countries; and to raise the awareness of the potential for investment in small scale energy projects which can gain funding through the CDM

  12. Novel, cost-effective configurations of combined power plants for small-scale cogeneration from biomass: Feasibility study and performance optimization

    Amirante, Riccardo; Tamburrano, Paolo

    2015-01-01

    Highlights: • A cheap small combined cycle for cogeneration from biomass is proposed. • An optimization procedure is utilized to explore its potential. • Two configurations employing two different heat exchangers are considered. • The maximum electrical efficiency is 25%, the maximum overall efficiency is 70%. • The operation in load following mode is effective for both configurations. - Abstract: The aim of this paper is to demonstrate that, thanks to recent advances in designing micro steam expanders and gas to gas heat exchangers, the use of small combined cycles for simultaneous generation of heat and power from the external combustion of solid biomass and low quality biofuels is feasible. In particular, a novel typology of combined cycle that has the potential both to be cost-effective and to achieve a high level of efficiency is presented. In the small combined cycle proposed, a commercially available micro-steam turbine is utilized as the steam expander of the bottoming cycle, while the conventional microturbine of the topping cycle is replaced by a cheaper automotive turbocharger. The feasibility, reliability and availability of the required mechanical and thermal components are thoroughly investigated. In order to explore the potential of such a novel typology of power plant, an optimization procedure, based on a genetic algorithm combined with a computing code, is utilized to analyze the trade-off between the maximization of the electrical efficiency and the maximization of the thermal efficiency. Two design optimizations are performed: the first one makes use of the innovative “Immersed Particle Heat Exchanger”, whilst a nickel alloy heat exchanger is used in the other one. After selecting the optimum combination of the design parameters, the operation in load following mode is also assessed for both configurations

  13. Partition Efficiency of High-Pitch Locular Multilayer Coil for Countercurrent Chromatographic Separation of Proteins Using Small-Scale Cross-Axis Coil Planet Centrifuge and Application to Purification of Various Collagenases with Aqueous-Aqueous Polymer Phase Systems

    Shinomiya, Kazufusa; Kobayashi, Hiroko; Inokuchi, Norio; Nakagomi, Kazuya; Ito, Yoichiro

    2010-01-01

    Partition efficiency of the high-pitch locular multilayer coil was evaluated in countercurrent chromatographic (CCC) separation of proteins with an aqueous-aqueous polymer phase system using the small-scale cross-axis coil planet centrifuge (X-axis CPC) fabricated in our laboratory. The separation column was specially made by high-pitch (ca 5 cm) winding of 1.0 mm I.D., 2.0 mm O.D. locular tubing compressed at 2 cm intervals with a total capacity of 29.5 mL. The protein separation was performed using a set of stable proteins including cytochrome C, myoglobin, and lysozyme with the 12.5% (w/w) polyethylene glycol (PEG) 1000 and 12.5% (w/w) dibasic potassium phosphate system (pH 9.2) under 1000 rpm of column revolution. This high-pitch locular tubing yielded substantially increased stationary phase retention than the normal locular tubing for both lower and upper mobile phases. In order to demonstrate the capability of the high-pitch locular tubing, the purification of collagenase from the crude commercial sample was carried out using an aqueous-aqueous polymer phase system. Using the 16.0% (w/w) PEG 1000 – 6.3% (w/w) dibasic potassium phosphate – 6.3% (w/w) monobasic potassium phosphate system (pH 6.6), collagenase I, II, V and X derived from Clostridium hystolyticum were separated from other proteins and colored small molecular weight compounds present in the crude commercial sample, while collagenase N-2 and S-1 from Streptomyces parvulus subsp. citrinus were eluted with impurities at the solvent front with the upper phase. The collagenase from C. hystolyticum retained its enzymatic activity in the purified fractions. The overall results demonstrated that the high-pitch locular multilayer coil is effectively used for the CCC purification of bioactive compounds without loss of their enzymatic activities. PMID:21869859

  14. Partition Efficiency of High-Pitch Locular Multilayer Coil for Countercurrent Chromatographic Separation of Proteins Using Small-Scale Cross-Axis Coil Planet Centrifuge and Application to Purification of Various Collagenases with Aqueous-Aqueous Polymer Phase Systems.

    Shinomiya, Kazufusa; Kobayashi, Hiroko; Inokuchi, Norio; Nakagomi, Kazuya; Ito, Yoichiro

    2011-01-01

    Partition efficiency of the high-pitch locular multilayer coil was evaluated in countercurrent chromatographic (CCC) separation of proteins with an aqueous-aqueous polymer phase system using the small-scale cross-axis coil planet centrifuge (X-axis CPC) fabricated in our laboratory. The separation column was specially made by high-pitch (ca 5 cm) winding of 1.0 mm I.D., 2.0 mm O.D. locular tubing compressed at 2 cm intervals with a total capacity of 29.5 mL. The protein separation was performed using a set of stable proteins including cytochrome C, myoglobin, and lysozyme with the 12.5% (w/w) polyethylene glycol (PEG) 1000 and 12.5% (w/w) dibasic potassium phosphate system (pH 9.2) under 1000 rpm of column revolution. This high-pitch locular tubing yielded substantially increased stationary phase retention than the normal locular tubing for both lower and upper mobile phases. In order to demonstrate the capability of the high-pitch locular tubing, the purification of collagenase from the crude commercial sample was carried out using an aqueous-aqueous polymer phase system. Using the 16.0% (w/w) PEG 1000 - 6.3% (w/w) dibasic potassium phosphate - 6.3% (w/w) monobasic potassium phosphate system (pH 6.6), collagenase I, II, V and X derived from Clostridium hystolyticum were separated from other proteins and colored small molecular weight compounds present in the crude commercial sample, while collagenase N-2 and S-1 from Streptomyces parvulus subsp. citrinus were eluted with impurities at the solvent front with the upper phase. The collagenase from C. hystolyticum retained its enzymatic activity in the purified fractions. The overall results demonstrated that the high-pitch locular multilayer coil is effectively used for the CCC purification of bioactive compounds without loss of their enzymatic activities.

  15. Development of small scale cluster computer for numerical analysis

    Zulkifli, N. H. N.; Sapit, A.; Mohammed, A. N.

    2017-09-01

    In this study, two units of personal computer were successfully networked together to form a small scale cluster. Each of the processor involved are multicore processor which has four cores in it, thus made this cluster to have eight processors. Here, the cluster incorporate Ubuntu 14.04 LINUX environment with MPI implementation (MPICH2). Two main tests were conducted in order to test the cluster, which is communication test and performance test. The communication test was done to make sure that the computers are able to pass the required information without any problem and were done by using simple MPI Hello Program where the program written in C language. Additional, performance test was also done to prove that this cluster calculation performance is much better than single CPU computer. In this performance test, four tests were done by running the same code by using single node, 2 processors, 4 processors, and 8 processors. The result shows that with additional processors, the time required to solve the problem decrease. Time required for the calculation shorten to half when we double the processors. To conclude, we successfully develop a small scale cluster computer using common hardware which capable of higher computing power when compare to single CPU processor, and this can be beneficial for research that require high computing power especially numerical analysis such as finite element analysis, computational fluid dynamics, and computational physics analysis.

  16. Spatiotemporal bioeconomic performance of artificial shelters in a small-scale, rights-based managed Caribbean spiny lobster (Panulirus argus fishery

    Maren Headley

    2017-03-01

    Full Text Available This study presents a bioeconomic analysis of artificial shelter performance in a fishery targeting a spiny lobster meta-population, with spatially allocated, individual exclusive benthic property rights for shelter introduction and harvest of species. Insights into fishers’ short-run decisions and fishing strategies are also provided. Spatiotemporal bioeconomic performance of shelters located in ten fishing areas during four seasons was compared using two-way ANOVAs and Pearson correlations. Results show that there was spatiotemporal heterogeneity in bioeconomic variables among fishing areas, with mean catch per unit effort (CPUE, kg shelter–1 ranging from 0.42 kg to 1.3 kg per trip, mean quasi-profits of variable costs per shelter harvested ranging from USD6.00 to USD19.57 per trip, and mean quasi-profits of variable costs ranging from USD338 to USD1069 per trip. Positive moderate correlations between shelter density and CPUE (kg shelter–1 km–2 were found. Bioeconomic performance of the shelters was influenced by spatiotemporal resource abundance and distribution, fishing area location in relation to the port, shelter density, heterogeneous fishing strategies and the management system. The results provide empirical information on the spatiotemporal performance of shelters and fishing strategies and can contribute to management at the local-scale of a meta-population distributed throughout the Caribbean Sea and Gulf of Mexico.

  17. Trajectory planning and trajectory tracking for a small-scale helicopter in autorotation

    Taamallah, Skander; Bombois, Xavier; Van den Hof, Paul M.J.

    2017-01-01

    The design of a high-performance guidance and control system for a small-scale helicopterUnmanned Aerial Vehicle (UAV), with an engine OFF flight condition (i.e. autorotation), is known to be a challenging task. It is the purpose of this paper to present a Trajectory Planning (TP) and Trajectory

  18. ITER baffle module small-scale mock-ups: first wall thermo-mechanical testing results

    Severi, Y.; Giancarli, L.; Poitevin, Y.; Salavy, J.F.; Le Marois, G.; Roedig, M.; Vieider, G.

    1998-01-01

    The EU-home team is in charge of the R and D related to the ITER baffle first wall. Five small-scale mock-ups, using Be, CFC and W tiles and different armour/heat-sink material joints under development, have been fabricated and thermomechanically tested in FE200 (Le Creusot) and JUDITH (Juelich) electron beam facilities. The small-scale mock-ups have been submitted to thermo-mechanical fatigue tests (up to failure using accelerating techniques). The objective was to determine the performances of the armour material joints under high heat flux cycles. (orig.)

  19. Small scale soft x-ray lasers

    Skinner, C.H.; DiCicco, D.S.; Kim, D.; Voorhees, D.; Suckewer, S.

    1990-01-01

    The widespread application of soft x-ray laser technology is contingent on the development of small scale soft x-ray lasers that do not require large laser facilities. Progress in the development of soft x-ray lasers pumped by a Nd laser of energy 6-12J is reported below. Application of an existing soft x-ray laser to x-ray microscopy has begun. A soft x-ray laser of output energy 1-3 mJ at 18,2 nm has been used to record high resolution images of biological specimens. The contact images were recorded on photoresist which was later viewed in a scanning electron microscope. The authors present a composite optical x-ray laser microscope design

  20. Small-scale eruptive filaments on the quiet sun

    Hermans, L.M.; Martin, S.F.

    1986-01-01

    A study of a little known class of eruptive events on the quiet sun was conducted. All of 61 small-scale eruptive filamentary structures were identified in a systematic survey of 32 days of H alpha time-lapse films of the quiet sun acquired at Big Bear Solar Observatory. When fully developed, these structures have an average length of 15 arc seconds before eruption. They appear to be the small-scale analog of large-scale eruptive filaments observed against the disk. At the observed rate of 1.9 small-scale eruptive features per field of view per average 7.0 hour day, the rate of occurence of these events on the sun were estimated to be greater than 600 per 24 hour day.. The average duration of the eruptive phase was 26 minutes while the average lifetime from formation through eruption was 70 minutes. A majority of the small-scale filamentary sturctures were spatially related to cancelling magnetic features in line-of-sight photospheric magnetograms. Similar to large-scale filaments, the small-scale filamentary structures sometimes divided opposite polarity cancelling fragments but often had one or both ends terminating at a cancellation site. Their high numbers appear to reflect the much greater flux on the quiet sun. From their characteristics, evolution, and relationship to photospheric magnetic flux, it was concluded that the structures described are small-scale eruptive filaments and are a subset of all filaments

  1. Cold dark matter: Controversies on small scales.

    Weinberg, David H; Bullock, James S; Governato, Fabio; Kuzio de Naray, Rachel; Peter, Annika H G

    2015-10-06

    The cold dark matter (CDM) cosmological model has been remarkably successful in explaining cosmic structure over an enormous span of redshift, but it has faced persistent challenges from observations that probe the innermost regions of dark matter halos and the properties of the Milky Way's dwarf galaxy satellites. We review the current observational and theoretical status of these "small-scale controversies." Cosmological simulations that incorporate only gravity and collisionless CDM predict halos with abundant substructure and central densities that are too high to match constraints from galaxy dynamics. The solution could lie in baryonic physics: Recent numerical simulations and analytical models suggest that gravitational potential fluctuations tied to efficient supernova feedback can flatten the central cusps of halos in massive galaxies, and a combination of feedback and low star formation efficiency could explain why most of the dark matter subhalos orbiting the Milky Way do not host visible galaxies. However, it is not clear that this solution can work in the lowest mass galaxies, where discrepancies are observed. Alternatively, the small-scale conflicts could be evidence of more complex physics in the dark sector itself. For example, elastic scattering from strong dark matter self-interactions can alter predicted halo mass profiles, leading to good agreement with observations across a wide range of galaxy mass. Gravitational lensing and dynamical perturbations of tidal streams in the stellar halo provide evidence for an abundant population of low-mass subhalos in accord with CDM predictions. These observational approaches will get more powerful over the next few years.

  2. Small-Scale Renewable Energy Converters for Battery Charging

    Mohd Nasir Ayob

    2018-03-01

    Full Text Available This paper presents two wave energy concepts for small-scale electricity generation. In the presented case, these concepts are installed on the buoy of a heaving, point-absorbing wave energy converter (WEC for large scale electricity production. In the studied WEC, developed by Uppsala University, small-scale electricity generation in the buoy is needed to power a tidal compensating system designed to increase the performance of the WEC in areas with high tides. The two considered and modeled concepts are an oscillating water column (OWC and a heaving point absorber. The results indicate that the OWC is too small for the task and does not produce enough energy. On the other hand, the results show that a hybrid system composed of a small heaving point absorber combined with a solar energy system would be able to provide a requested minimum power of around 37.7 W on average year around. The WEC and solar panel complement each other, as the WEC produces enough energy by itself during wintertime (but not in the summer, while the solar panel produces enough energy in the summer (but not in the winter.

  3. Airfoil optimization for noise emission problem on small scale turbines

    Gocmen, Tuhfe; Ozerdem, Baris [Mechanical Engineering Department, Yzmir Institute of Technology (Turkey)

    2011-07-01

    Wind power is a preferred natural resource and has had benefits for the energy industry and for the environment all over the world. However, noise emission from wind turbines is becoming a major concern today. This study paid close attention to small scale wind turbines close to urban areas and proposes an optimum number of six airfoils to address noise emission concerns and performance criteria. The optimization process aimed to decrease the noise emission levels and enhance the aerodynamic performance of a small scale wind turbine. This study determined the sources and the operating conditions of broadband noise emissions. A new design is presented which enhances aerodynamic performance and at the same time reduces airfoil self noise. It used popular aerodynamic functions and codes based on aero-acoustic empirical models. Through numerical computations and analyses, it is possible to derive useful improvements that can be made to commercial airfoils for small scale wind turbines.

  4. Biomass for energy - small scale technologies

    Salvesen, F.; Joergensen, P.F. [KanEnergi, Rud (Norway)

    1997-12-31

    The bioenergy markets and potential in EU region, the different types of biofuels, the energy technology, and the relevant applications of these for small-scale energy production are reviewed in this presentation

  5. Small scale structure on cosmic strings

    Albrecht, A.

    1989-01-01

    I discuss our current understanding of cosmic string evolution, and focus on the question of small scale structure on strings, where most of the disagreements lie. I present a physical picture designed to put the role of the small scale structure into more intuitive terms. In this picture one can see how the small scale structure can feed back in a major way on the overall scaling solution. I also argue that it is easy for small scale numerical errors to feed back in just such a way. The intuitive discussion presented here may form the basis for an analytic treatment of the small structure, which I argue in any case would be extremely valuable in filling the gaps in our resent understanding of cosmic string evolution. 24 refs., 8 figs

  6. Chemical Transfer (Single Small-Scale) Facility

    Federal Laboratory Consortium — Description/History: Chemistry laboratoryThe Chemical Transfer Facility (CTF)  is the only U.S. single small-scale  facility, a single repository for the Army’s...

  7. Biomass for energy - small scale technologies

    Salvesen, F; Joergensen, P F [KanEnergi, Rud (Norway)

    1998-12-31

    The bioenergy markets and potential in EU region, the different types of biofuels, the energy technology, and the relevant applications of these for small-scale energy production are reviewed in this presentation

  8. A threshold-voltage model for small-scaled GaAs nMOSFET with stacked high-k gate dielectric

    Chaowen, Liu; Jingping, Xu; Lu, Liu; Hanhan, Lu; Yuan, Huang

    2016-02-01

    A threshold-voltage model for a stacked high-k gate dielectric GaAs MOSFET is established by solving a two-dimensional Poisson's equation in channel and considering the short-channel, DIBL and quantum effects. The simulated results are in good agreement with the Silvaco TCAD data, confirming the correctness and validity of the model. Using the model, impacts of structural and physical parameters of the stack high-k gate dielectric on the threshold-voltage shift and the temperature characteristics of the threshold voltage are investigated. The results show that the stacked gate dielectric structure can effectively suppress the fringing-field and DIBL effects and improve the threshold and temperature characteristics, and on the other hand, the influence of temperature on the threshold voltage is overestimated if the quantum effect is ignored. Project supported by the National Natural Science Foundation of China (No. 61176100).

  9. A threshold-voltage model for small-scaled GaAs nMOSFET with stacked high-k gate dielectric

    Liu Chaowen; Xu Jingping; Liu Lu; Lu Hanhan; Huang Yuan

    2016-01-01

    A threshold-voltage model for a stacked high-k gate dielectric GaAs MOSFET is established by solving a two-dimensional Poisson's equation in channel and considering the short-channel, DIBL and quantum effects. The simulated results are in good agreement with the Silvaco TCAD data, confirming the correctness and validity of the model. Using the model, impacts of structural and physical parameters of the stack high-k gate dielectric on the threshold-voltage shift and the temperature characteristics of the threshold voltage are investigated. The results show that the stacked gate dielectric structure can effectively suppress the fringing-field and DIBL effects and improve the threshold and temperature characteristics, and on the other hand, the influence of temperature on the threshold voltage is overestimated if the quantum effect is ignored. (paper)

  10. The Multifractal Structure of Small-Scale Artificial Ionospheric Turbulence

    Vybornov F. I.

    2013-03-01

    Full Text Available We present the results of investigation of a multifractal structure of the artificial ionospheric turbulence when the midlatitude ionosphere is affected by high-power radio waves. The experimental studies were performed on the basis of the SURA heating facility with the help of radio sounding of the disturbed region of ionospheric plasma by signals from the Earth’s orbital satellities. In the case of vertical radio sounding of the disturbed ionosphere region, the measured multipower and generalized multifractal spectra of turbulence coincide well with similar multifractal characteristics of the ionosperic turbulence under the natural conditions. In the case of oblique sounding of the disturbance region at small angles between the line of sight to the satellite and the direction of the Earth’s magnetic field, a nonuniform structure of the small-scale turbulence with a relatively narrow multipower spectrum and small variations in the generalized multifractal spectrum of the electron density was detected.

  11. Verification of small-scale water vapor features in VAS imagery using high resolution MAMS imagery. [VISSR Atmospheric Sounder - Multispectral Atmospheric Mapping Sensor

    Menzel, Paul W.; Jedlovec, Gary; Wilson, Gregory

    1986-01-01

    The Multispectral Atmospheric Mapping Sensor (MAMS), a modification of NASA's Airborne Thematic Mapper, is described, and radiances from the MAMS and the VISSR Atmospheric Sounder (VAS) are compared which were collected simultaneously on May 18, 1985. Thermal emission from the earth atmosphere system in eight visible and three infrared spectral bands (12.3, 11.2 and 6.5 microns) are measured by the MAMS at up to 50 m horizontal resolution, and the infrared bands are similar to three of the VAS infrared bands. Similar radiometric performance was found for the two systems, though the MAMS showed somewhat less attenuation from water vapor than VAS because its spectral bands are shifted to shorter wavelengths away from the absorption band center.

  12. Small scale combined woodgas power plant

    Gulbis, V.

    2003-01-01

    As a first attempt to introduce biomass gasification technology in Latvia at the Faculty of Engineering of Latvia University of Agriculture an integral small scale combined heat and power (CHP) system based on a used Russian-made diesel-alternator set with electrical output 100 kWe was developed. The diesel is converted to dual fuel gas engine, using producer gas as the main fuel and gas oil as pilot fuel. To get sufficiently clean (tar content ≤ 250 mg/m 3 ) woodgas for using in IC engine a downdraft type of gasifier was chosen designed and constructed on the IMBERT gasifier principles. The test runs of the first experimental model showed that the engine does not develop expected power because of high resistance of gasifier and gas cleaning system does not work sufficiently enough. There was rather high level of tar content in woodgas because the temperature in the reduction zone was low. Calculations were carried out and new technological scheme of gasification system was worked out, introducing innovative ideas aimed on improving the working parameters (author)

  13. Small scale affinity purification and high sensitivity reversed phase nanoLC-MS N-glycan characterization of mAbs and fusion proteins.

    Higel, Fabian; Seidl, Andreas; Demelbauer, Uwe; Sörgel, Fritz; Frieß, Wolfgang

    2014-01-01

    N-glycosylation is a complex post-translational modification with potential effects on the efficacy and safety of therapeutic proteins and known influence on the effector function of biopharmaceutical monoclonal antibodies (mAbs). Comprehensive characterization of N-glycosylation is therefore important in biopharmaceutical development. In early development, e.g. during pool or clone selection, however, only minute protein amounts of multiple samples are available for analytics. High sensitivity and high throughput methods are thus needed. An approach based on 96-well plate sample preparation and nanoLC-MS of 2- anthranilic acid or 2-aminobenzoic acid (AA) labeled N-glycans for the characterization of biopharmaceuticals in early development is reported here. With this approach, 192 samples can be processed simultaneously from complex matrices (e.g., cell culture supernatant) to purified 2-AA glycans, which are then analyzed by reversed phase nanoLC-MS. Attomolar sensitivity has been achieved by use of nanoelectrospray ionization, resulting in detailed glycan maps of mAbs and fusion proteins that are exemplarily shown in this work. Reproducibility, robustness and linearity of the approach are demonstrated, making use in a routine manner during pool or clone selection possible. Other potential fields of application, such as glycan biomarker discovery from serum samples, are also presented.

  14. Spatial and temporal small-scale variability of nitrogen mobilization in a forest ecosystem with high N deposition in NW-Germany.

    Lorz, Carsten; Eissner, Christel; Lethmate, Jürgen; Schneider, Birgit

    2010-02-01

    For conifer stands in NW-Germany with high DIN load (23-35 kg N ha(-1) a(-1)) and a long history of nitrogen export the risk of N mobilization were investigated. Ammonium is the most mobilized N species, pointing towards either conditions not favoring nitrification or, more likely - under the dominant aerobic conditions - a very high amount of ammonium in the forest floor. Independence of net nitrification and net ammonification from each other indicates the existence of two separate systems. The nitrifying system depends very much on biotic conditions - as a function of energy and moisture - and seems not to be directly related to N deposition. In contrast, for the ammonification system (Oe horizon) a correlation with the sum of ammonium deposition three months prior to sampling was found. However, the role of disturbance, i.e. nitrogen export, during the last centuries and the role of recovery of the N balance during the last 150 years is still not clear. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  15. Design and Modelling of Small Scale Low Temperature Power Cycles

    Wronski, Jorrit

    he work presented in this report contributes to the state of the art within design and modelling of small scale low temperature power cycles. The study is divided into three main parts: (i) fluid property evaluation, (ii) expansion device investigations and (iii) heat exchanger performance......-oriented Modelica code and was included in the thermo Cycle framework for small scale ORC systems. Special attention was paid to the valve system and a control method for variable expansion ratios was introduced based on a cogeneration scenario. Admission control based on evaporator and condenser conditions...

  16. Design of High-Efficiency and Low-Cost Six-Phase Permanent Magnet Synchronous Generator for Direct-Drive Small-Scale Wind Power Application

    M. E. Moazzen

    2017-06-01

    Full Text Available Permanent magnet synchronous generators (PMSG have a huge potential for direct-drive wind power applications. Therefore, optimal design of these generators is necessary to maximize their efficiency and to reduce their manufacturing cost and total volume. In this paper, an optimal design of a six-phase 3.5 KW direct-drive PMSG to generate electricity for domestic needs is performed. The aim of optimal design is to reduce the manufacturing cost, losses and total volume of PMSG. To find the best design, single/multi-objective design optimization is carried out. Cuckoo optimization algorithm (COA is adopted to solve the optimization problem. Comparison between the results of the single-objective and multi-objective models shows that simultaneous optimization of manufacturing cost, losses and total volume leads to more suitable design for PMSG. Finally, finite-element method (FEM is employed to validate the optimal design, which show a good agreement between the theoretical work and simulation results.

  17. Self-similarity of high-pT hadron production in cumulative processes and violation of discrete symmetries at small scales (suggestion for experiment)

    Tokarev, M.V.; Zborovsky, I.

    2009-01-01

    The hypothesis of self-similarity of hadron production in relativistic heavy ion collisions for search for phase transition in a nuclear matter is discussed. It is offered to use the established features of z-scaling for revealing signatures of new physics in cumulative region. It is noted that selection of events on centrality in cumulative region could help to localize a position of a critical point. Change of parameters of the theory (a specific heat and fractal dimensions) near to a critical point is considered as a signature of new physics. The relation of the power asymptotic of ψ(z) at high z, anisotropy of momentum space due to spontaneous symmetry breaking, and discrete (C, P, T) symmetries is emphasized

  18. Digging up your dirt. High school students combine small-scale respiration and soil carbon measurements with satellite imagery in hands-on inquiry activities.

    Kemper, K.; Throop, H.

    2015-12-01

    One of the greatest impacts on the global carbon cycle is changes in land use. Making this concept relevant and inquiry-based for high school students is challenging. Many are familiar with reconstructing paleo-climate from ice core data, but few have a connection to current climate research. Many students ask questions like 'What will our area be like in 20 years?' or 'How much does planting trees help?' while few have the scientific language to engage in a discussion to answer these questions. Our work connects students to climate change research in several ways: first, teacher Keska Kemper engaged in field research with Dr. Heather Throop creating a 'teacher in the field' perspective for students in the classroom. Dr. Throop met with Keska Kemper's students several times to develop an inquiry-based field study. Students predicted and then measured rates of respiration between different soil types in an urban park close to their school. Students then could compare their results from Portland, Oregon to Throop's work across a rain gradient in Australia. Discussions about percent tree cover and soil carbon helped students see connections between land use changes and changes in carbon cycling. Last, students examined satellite imagery to determine percent tree cover and numberss of trees to compare to soil carbon in the same region. Students were able to examine imagery over the last 30 years to visualize land use changes in the greater Portland area.

  19. Small Scale Foundries in Ghana: The challenges

    Anthony ANDREWS

    2012-08-01

    Full Text Available Small Scale Foundries (SSFs have been in existence for several years in Ghana. The industry has created several jobs for the people of Ghana and has minimized the burden on government to find ways of disposing scrap metals generated within the country. While scrap metals are still being exported, the quantity exported has decreased as a result of recycling by foundrymen in producing various parts. The government of Ghana has not paid special attention to this industry. Nevertheless, individuals and private investors are heavily involved in producing several thousands of tonnes of castings annually generating revenue for the government through taxation as well as helping with metal waste disposal. Metal cast products are sold both locally and internationally to neighbouring countries. The industry is however faced with numerous challenges. These include quality issues due to lack of technical know-how, access to funding from both government and private financial institutions and foundry waste management. To promote this industry, government and private financial institutions must be encouraged to come on board. Policies must be established and proper training programme developed to improve and promote this technology. This could go a long way in reducing the high unemployment rate in Ghana.

  20. Lessons from Small-scale Standardised Testing of English Reading ...

    The superior performance by the public school can partly be explained by teachers teaching experience, most of them have been teaching for more than ten years and greater community support for the school. It is recommended that data produced through small-scale standardised testing should be used by school ...

  1. Small-scale dynamo at low magnetic Prandtl numbers

    Schober, Jennifer; Schleicher, Dominik; Bovino, Stefano; Klessen, Ralf S.

    2012-12-01

    The present-day Universe is highly magnetized, even though the first magnetic seed fields were most probably extremely weak. To explain the growth of the magnetic field strength over many orders of magnitude, fast amplification processes need to operate. The most efficient mechanism known today is the small-scale dynamo, which converts turbulent kinetic energy into magnetic energy leading to an exponential growth of the magnetic field. The efficiency of the dynamo depends on the type of turbulence indicated by the slope of the turbulence spectrum v(ℓ)∝ℓϑ, where v(ℓ) is the eddy velocity at a scale ℓ. We explore turbulent spectra ranging from incompressible Kolmogorov turbulence with ϑ=1/3 to highly compressible Burgers turbulence with ϑ=1/2. In this work, we analyze the properties of the small-scale dynamo for low magnetic Prandtl numbers Pm, which denotes the ratio of the magnetic Reynolds number, Rm, to the hydrodynamical one, Re. We solve the Kazantsev equation, which describes the evolution of the small-scale magnetic field, using the WKB approximation. In the limit of low magnetic Prandtl numbers, the growth rate is proportional to Rm(1-ϑ)/(1+ϑ). We furthermore discuss the critical magnetic Reynolds number Rmcrit, which is required for small-scale dynamo action. The value of Rmcrit is roughly 100 for Kolmogorov turbulence and 2700 for Burgers. Furthermore, we discuss that Rmcrit provides a stronger constraint in the limit of low Pm than it does for large Pm. We conclude that the small-scale dynamo can operate in the regime of low magnetic Prandtl numbers if the magnetic Reynolds number is large enough. Thus, the magnetic field amplification on small scales can take place in a broad range of physical environments and amplify week magnetic seed fields on short time scales.

  2. Small-scale dynamo at low magnetic Prandtl numbers.

    Schober, Jennifer; Schleicher, Dominik; Bovino, Stefano; Klessen, Ralf S

    2012-12-01

    The present-day Universe is highly magnetized, even though the first magnetic seed fields were most probably extremely weak. To explain the growth of the magnetic field strength over many orders of magnitude, fast amplification processes need to operate. The most efficient mechanism known today is the small-scale dynamo, which converts turbulent kinetic energy into magnetic energy leading to an exponential growth of the magnetic field. The efficiency of the dynamo depends on the type of turbulence indicated by the slope of the turbulence spectrum v(ℓ)∝ℓ^{ϑ}, where v(ℓ) is the eddy velocity at a scale ℓ. We explore turbulent spectra ranging from incompressible Kolmogorov turbulence with ϑ=1/3 to highly compressible Burgers turbulence with ϑ=1/2. In this work, we analyze the properties of the small-scale dynamo for low magnetic Prandtl numbers Pm, which denotes the ratio of the magnetic Reynolds number, Rm, to the hydrodynamical one, Re. We solve the Kazantsev equation, which describes the evolution of the small-scale magnetic field, using the WKB approximation. In the limit of low magnetic Prandtl numbers, the growth rate is proportional to Rm^{(1-ϑ)/(1+ϑ)}. We furthermore discuss the critical magnetic Reynolds number Rm_{crit}, which is required for small-scale dynamo action. The value of Rm_{crit} is roughly 100 for Kolmogorov turbulence and 2700 for Burgers. Furthermore, we discuss that Rm_{crit} provides a stronger constraint in the limit of low Pm than it does for large Pm. We conclude that the small-scale dynamo can operate in the regime of low magnetic Prandtl numbers if the magnetic Reynolds number is large enough. Thus, the magnetic field amplification on small scales can take place in a broad range of physical environments and amplify week magnetic seed fields on short time scales.

  3. The Phenomenology of Small-Scale Turbulence

    Sreenivasan, K. R.; Antonia, R. A.

    I have sometimes thought that what makes a man's work classic is often just this multiplicity [of interpretations], which invites and at the same time resists our craving for a clear understanding. Wright (1982, p. 34), on Wittgenstein's philosophy Small-scale turbulence has been an area of especially active research in the recent past, and several useful research directions have been pursued. Here, we selectively review this work. The emphasis is on scaling phenomenology and kinematics of small-scale structure. After providing a brief introduction to the classical notions of universality due to Kolmogorov and others, we survey the existing work on intermittency, refined similarity hypotheses, anomalous scaling exponents, derivative statistics, intermittency models, and the structure and kinematics of small-scale structure - the latter aspect coming largely from the direct numerical simulation of homogeneous turbulence in a periodic box.

  4. Small scale smugglers in Tamaulipas, Mexico

    Simón Pedro Izcara Palacios

    2013-07-01

    Full Text Available Small-scale part-time smugglers are embedded in the migrant community itself. They work in the United States for several months before returning to their place of origin to organize, with the help of several assistants, a small group of migrants, who are transported where the coyotes themselves are going. This article analyses small-scale smuggling carried out by Tamaulipas' polleros, who transport to the United States, one or a few times per year, migrants from their hometowns or other neighboring areas in order to be employed in the farming sector.

  5. Cassini RTG's -- Small scale module tests

    Kelly, C.E.; Klee, P.M.

    1994-01-01

    The Cassini spacecraft, scheduled for a 1997 launch to Saturn, will be powered by three GPHS RTGs (General Purpose Heat Source Radioisotope thermoelectric Generators). The RTGs are the same type as those powering the Galileo and Ulysses spacecraft. Three new converters (F-6, F-7, and F-8) are to be built and one converter (F-2) remaining from the GPHS program will be used. F-6 and F-7 are to be fueled and F-8 serves as a spare converter. In addition, the back-up RTG (F-5) from the Ulysses launch, which is still fueled, will serve as the Cassini back-up RTG. The new RTGs will have a lower fuel loading than in the past and will provide a minimum of 276 watts each at B.O.M. (beginning of mission). The mission length is 10.75 years, at which time these RTGs will provide a minimum of 216 watts and a possible extension to 16 years when the power will be 199 watts. This paper discusses tests performed to date to confirm the successful re-establishment of the unicouple production at Martin Marietta. This production line, shut down 10 years ago, has been restarted and over 1,500 unicouples have been produced to date. Confirmation will be primarily obtained by the performance of three small scale converters in comparison with previously tested modules from the Multi Hundred Watt (MHW) (Voyager) and GPHS (Galileo, Ulysses) programs. Test results to date have shown excellent agreement with the data base

  6. Development of a small-scale computer cluster

    Wilhelm, Jay; Smith, Justin T.; Smith, James E.

    2008-04-01

    An increase in demand for computing power in academia has necessitated the need for high performance machines. Computing power of a single processor has been steadily increasing, but lags behind the demand for fast simulations. Since a single processor has hard limits to its performance, a cluster of computers can have the ability to multiply the performance of a single computer with the proper software. Cluster computing has therefore become a much sought after technology. Typical desktop computers could be used for cluster computing, but are not intended for constant full speed operation and take up more space than rack mount servers. Specialty computers that are designed to be used in clusters meet high availability and space requirements, but can be costly. A market segment exists where custom built desktop computers can be arranged in a rack mount situation, gaining the space saving of traditional rack mount computers while remaining cost effective. To explore these possibilities, an experiment was performed to develop a computing cluster using desktop components for the purpose of decreasing computation time of advanced simulations. This study indicates that small-scale cluster can be built from off-the-shelf components which multiplies the performance of a single desktop machine, while minimizing occupied space and still remaining cost effective.

  7. Nitrate-nitrogen removal with small-scale reverse osmosis ...

    The nitrate-nitrogen concentration in water supplied to clinics in Limpopo Province is too high to be fit for human consumption (35 to 75 mg/ℓ NO3-N). Therefore, small-scale technologies (reverse osmosis, ion-exchange and electrodialysis) were evaluated for nitrate-nitrogen removal to make the water potable (< 10 mg/ℓ ...

  8. Climate change adaptation strategies by small-scale farmers in ...

    Mburu

    SPSS) ... were financial constraints (93.4%), lack of relevant skills (74.5%) and lack of ... Key words: Climate change, small-scale farmers, adaptation strategies. ... investment in irrigation infrastructure, high post-harvest ..... 72.0 School drop out.

  9. A feasibility and implementation model of small-scale hydropower ...

    Large numbers of households and communities will not be connected to the national electricity grid for the foreseeable future due to high cost of transmission and distribution systems to remote communities and the relatively low electricity demand within rural communities. Small-scale hydropower used to play a very ...

  10. Atomistic Simulations of Small-scale Materials Tests of Nuclear Materials

    Shin, Chan Sun; Jin, Hyung Ha; Kwon, Jun Hyun

    2012-01-01

    Degradation of materials properties under neutron irradiation is one of the key issues affecting the lifetime of nuclear reactors. Evaluating the property changes of materials due to irradiations and understanding the role of microstructural changes on mechanical properties are required for ensuring reliable and safe operation of a nuclear reactor. However, high dose of neuron irradiation capabilities are rather limited and it is difficult to discriminate various factors affecting the property changes of materials. Ion beam irradiation can be used to investigate radiation damage to materials in a controlled way, but has the main limitation of small penetration depth in the length scale of micro meters. Over the past decade, the interest in the investigations of size-dependent mechanical properties has promoted the development of various small-scale materials tests, e.g. nanoindentation and micro/nano-pillar compression tests. Small-scale materials tests can address the issue of the limitation of small penetration depth of ion irradiation. In this paper, we present small-scale materials tests (experiments and simulation) which are applied to study the size and irradiation effects on mechanical properties. We have performed molecular dynamics simulations of nanoindentation and nanopillar compression tests. These atomistic simulations are expected to significantly contribute to the investigation of the fundamental deformation mechanism of small scale irradiated materials

  11. Microcredit Loan Repayment Default among Small Scale ...

    The model is applied to primary data from a survey of 200 small scale entrepreneurs in the Upper West Region of Ghana. Results show that enterprise size, interest rate, loan duration, level of profit and loan amount are the simultaneous determinants of probability and rate of default. The study recommends that the National ...

  12. Small Scale Regenerative Desulfurization of Biogas

    Linders, M.J.G.; Stille, L.C.; Miedema, M.C.; Groenestijn, J.W. van; Goetheer, E.L.V.

    2016-01-01

    The application of small scale biogas digesters to supply biogas to households in developing countries is well established. The biogas is used for different applications, amongst other cooking. Generally, no further treatment of the biogas is applied. Hydrogen Sulfide (H2S) is present in varying

  13. Why small-scale cannabis growers stay small: five mechanisms that prevent small-scale growers from going large scale.

    Hammersvik, Eirik; Sandberg, Sveinung; Pedersen, Willy

    2012-11-01

    Over the past 15-20 years, domestic cultivation of cannabis has been established in a number of European countries. New techniques have made such cultivation easier; however, the bulk of growers remain small-scale. In this study, we explore the factors that prevent small-scale growers from increasing their production. The study is based on 1 year of ethnographic fieldwork and qualitative interviews conducted with 45 Norwegian cannabis growers, 10 of whom were growing on a large-scale and 35 on a small-scale. The study identifies five mechanisms that prevent small-scale indoor growers from going large-scale. First, large-scale operations involve a number of people, large sums of money, a high work-load and a high risk of detection, and thus demand a higher level of organizational skills than for small growing operations. Second, financial assets are needed to start a large 'grow-site'. Housing rent, electricity, equipment and nutrients are expensive. Third, to be able to sell large quantities of cannabis, growers need access to an illegal distribution network and knowledge of how to act according to black market norms and structures. Fourth, large-scale operations require advanced horticultural skills to maximize yield and quality, which demands greater skills and knowledge than does small-scale cultivation. Fifth, small-scale growers are often embedded in the 'cannabis culture', which emphasizes anti-commercialism, anti-violence and ecological and community values. Hence, starting up large-scale production will imply having to renegotiate or abandon these values. Going from small- to large-scale cannabis production is a demanding task-ideologically, technically, economically and personally. The many obstacles that small-scale growers face and the lack of interest and motivation for going large-scale suggest that the risk of a 'slippery slope' from small-scale to large-scale growing is limited. Possible political implications of the findings are discussed. Copyright

  14. Small-scale soft-bodied robot with multimodal locomotion

    Hu, Wenqi; Lum, Guo Zhan; Mastrangeli, Massimo; Sitti, Metin

    2018-02-01

    Untethered small-scale (from several millimetres down to a few micrometres in all dimensions) robots that can non-invasively access confined, enclosed spaces may enable applications in microfactories such as the construction of tissue scaffolds by robotic assembly, in bioengineering such as single-cell manipulation and biosensing, and in healthcare such as targeted drug delivery and minimally invasive surgery. Existing small-scale robots, however, have very limited mobility because they are unable to negotiate obstacles and changes in texture or material in unstructured environments. Of these small-scale robots, soft robots have greater potential to realize high mobility via multimodal locomotion, because such machines have higher degrees of freedom than their rigid counterparts. Here we demonstrate magneto-elastic soft millimetre-scale robots that can swim inside and on the surface of liquids, climb liquid menisci, roll and walk on solid surfaces, jump over obstacles, and crawl within narrow tunnels. These robots can transit reversibly between different liquid and solid terrains, as well as switch between locomotive modes. They can additionally execute pick-and-place and cargo-release tasks. We also present theoretical models to explain how the robots move. Like the large-scale robots that can be used to study locomotion, these soft small-scale robots could be used to study soft-bodied locomotion produced by small organisms.

  15. Degradation mechanisms of small scale piping systems

    Bartonicek, J.; Koenig, G.; Blind, D.

    1996-01-01

    Operational experience shows that many degradation mechanisms can have an effect on small-scale piping systems. We can see from the analyses carried out that the degradation which has occurred is primarily linked with the fact that these piping systems were classified as being of low safety relevance. This is mainly due to such components being classified into low safety relevance category at the design stage, as well as to the low level of operational monitoring. Since in spite of the variety of designs and operational modes the degradation mechanisms detected may be attributed to the piping systems, we can make decisive statements on how to avoid such degradation mechanisms. Even small-scale piping systems may achieve guaranteed integrity in such cases by taking the appropriate action. (orig.) [de

  16. Small-scale tearing mode in tokamaks

    Ivanov, N.V.

    1983-01-01

    Considerations are given on the possible effect of small-scale tearing mode with m >> 1 on the plasma electron thermal conductivity in a tokamak. The estimate of the electron thermal conductivity coefficient is obtained. Calculation results are compared with experimental data. The calculated dependence of radial distribution of electron temperature is shown to vary weakly with the tn(m 2 /m 1 ) alteration everywhere, except for the vicinity of point r approximately 0

  17. Performance evaluation of small scale internal combustion engine with mixtures for diesel oil-palm oil; Avaliacao do desempenho do motor de combustao interna de pequeno porte com misturas oleo diesel - oleo de dende

    Seye, Omar; Souza, Rubem Cesar Rodrigues [Universidade Federal do Amazonas (CDEAM/UFAM), Manaus, AM (Brazil). Centro de Desenvolvimento Energetico Amazonico], Emails: Seye62omar@yahoo.com, rcsouza@internext.com.br

    2006-07-01

    This work aims at the performance evaluation of the Cummins 4B -3.9, an internal combustion engine of maximum power 75 hp (56.6 kW) for small scale power generation, burning different mixtures of diesel fuel and palm oil. The palm oil in nature is mixed manually, what unfortunately will influence the engine performance as it hinders the combustion. The test protocol will include the biodiesel, later on. The emissions were assessed for several proportions of mixture diesel/palm oil covering the strip from 0 to 20% and the results were compared to the engine performance when it operates with diesel only. The motor is coupled to a dynamometer, whose operation consists of the acceleration and deceleration of water in order to simulate the effect of a load being applied to the motor. The system is controlled by the software LT commander that allows the start up and the shutdown of the engine from the screen of the computer that also monitors the following parameters as speed of rotation of the motor (RPM), applied torque (N-m), potency (hp), temperature of the lubricating oil, temperature of the water in the entrance and exit of the motor, and temperature of the environment (deg C), pressures of the lubricating oil and of opening of the injector (mBar). While a flow meter coupled to the piping measures the consumption of fuel, the gas analyzer ECHO Line 6000 it monitors the concentration and temperature of carbon monoxide (CO) (ppm), nitric oxide (NO) (ppm), nitrogen dioxide (NO{sub 2}), (ppm), sulfur dioxide (SO{sub 2}) (ppm) and Oxygen (O{sub 2}) (%) in the exhaust gases. This equipment also determines the combustion parameters as excess of air and the efficiency. The technical results present the efficiency variation, the pressure of the fuel, monoxide carbon, NOx emissions, Oxygen content in the exhaust gases, for the different mixture proportions. Furthermore, the results of economic viability show generation cost values of US$ 135,66/MWh for the motor operating

  18. Fabrication and testing of small scale mock-ups of ITER shielding blanket

    Hatano, Toshihisa; Sato, Satoshi; Suzuki, Satoshi; Yokoyama, Kenji; Furuya, Kazuyuki; Kuroda, Toshimasa; Enoeda, Mikio; Takatsu, Hideyuki; Ohara, Yoshihiro [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    1998-12-01

    Small scale mock-ups of the primary first wall, the baffle first wall, the shield block and a partial model for the edge of the primary first wall module were designed and fabricated incorporating most of the key design features of the ITER shielding blanket. All mock-ups featured the DSCu heat sink, the built-in SS coolant tubes within the heat sink and the SS shield block. CFC tiles was used as the protection armor for the baffle first wall mock-up. The small scale shield block mock-up, integrated with the first wall, was designed to have a poloidal curvature specified in the ITER design. Fabrication routes of mock-ups were decided based on the single step solid HIP of DSCu/DSCu, DSCu/SS and SS/SS reflecting the results of previous joining techniques development and testing. For attaching the CFC tiles onto DSCu heat sink in the fabrication of the baffle first wall mock-up, a two-step brazing was tried. All mock-ups and the partial model were successfully fabricated with a satisfactory dimensional accuracy. The small scale primary first wall mock-up was thermo-mechanically tested under high heat fluxes of 5-7 MW/m{sup 2} for 2500 cycles in total. Satisfactory heat removal performance and integrity of the mock-up against cyclic high heat flux loads were confirmed by measurement during the tests and destructive examination after the tests. Similar high heat flux tests were also performed with the small scale baffle first wall mock-up under 5-10 MW/m{sup 2} for 4500 cycles in total resulting in sufficient heat removal capability and integrity confirmed by measurements during the tests. (author)

  19. Fabrication and testing of small scale mock-ups of ITER shielding blanket

    Hatano, Toshihisa; Sato, Satoshi; Suzuki, Satoshi; Yokoyama, Kenji; Furuya, Kazuyuki; Kuroda, Toshimasa; Enoeda, Mikio; Takatsu, Hideyuki; Ohara, Yoshihiro

    1998-12-01

    Small scale mock-ups of the primary first wall, the baffle first wall, the shield block and a partial model for the edge of the primary first wall module were designed and fabricated incorporating most of the key design features of the ITER shielding blanket. All mock-ups featured the DSCu heat sink, the built-in SS coolant tubes within the heat sink and the SS shield block. CFC tiles was used as the protection armor for the baffle first wall mock-up. The small scale shield block mock-up, integrated with the first wall, was designed to have a poloidal curvature specified in the ITER design. Fabrication routes of mock-ups were decided based on the single step solid HIP of DSCu/DSCu, DSCu/SS and SS/SS reflecting the results of previous joining techniques development and testing. For attaching the CFC tiles onto DSCu heat sink in the fabrication of the baffle first wall mock-up, a two-step brazing was tried. All mock-ups and the partial model were successfully fabricated with a satisfactory dimensional accuracy. The small scale primary first wall mock-up was thermo-mechanically tested under high heat fluxes of 5-7 MW/m 2 for 2500 cycles in total. Satisfactory heat removal performance and integrity of the mock-up against cyclic high heat flux loads were confirmed by measurement during the tests and destructive examination after the tests. Similar high heat flux tests were also performed with the small scale baffle first wall mock-up under 5-10 MW/m 2 for 4500 cycles in total resulting in sufficient heat removal capability and integrity confirmed by measurements during the tests. (author)

  20. Small-scale rural bakery; Maaseudun pienleipomo

    Alkula, R.; Malin, A.; Reisbacka, A.; Rytkoenen, A.

    1997-12-31

    The purpose of the study was to clarify how running a small-scale bakery can provide a farming enterprise with its primary or secondary source of livelihood. A questionnaire and interviews were conducted to clarify the current situation concerning small-scale rural bakeries. The experimental part of the study looked into different manners of production, devices used in preparing and processing of doughs, and baking of different kinds of pastries in different types of ovens in laboratory conditions. Based on the results obtained, solutions serving as examples were formulated for small-scale bakeries run with various modes and methods of production. Additionally, market reviews were conducted concerning appropriate equipment for small-scale bakeries. Baking for commercial purposes on the farm is still something new as ca. 80 % of the enterprises covered by the study had operated for no more than five years. Many entrepreneurs (ca. 70 %) expressed a need for supplementary knowledge from some field related to baking. Rural bakeries are small-scale operations with one-person enterprises amounting to 69 % and two-person enterprises to 29 %. Women are primarily responsible for baking. On average, the enterprises baked seven different products, but the amounts baked were usually small. In the experimental part of the study, loaves of rye bread were baked using five different types and sizes of oven accommodating 5-22 loaves of rye bread at the one time. The oven type was found not to affect bread structure. The energy consumption for one ovenful varied between 2.4 and 7.0 kWh, i.e. 0.25-0.43 kWh per kilo. When baking rolls (30-140 rolls at a time), the power consumption varied between 1.2 and 3.5 kWh, i.e. 0.32-0.53 kWh per kilo. The other devices included in the comparative study were an upright deep-freezer, a multi-temperature cabinet and a fermenting cabinet. Furthermore, making rolls by hand was compared to using a machine for the same job, and likewise manual

  1. Philippines: Small-scale renewable energy update

    NONE

    1997-12-01

    This paper gives an overview of the application of small scale renewable energy sources in the Philippines. Sources looked at include solar, biomass, micro-hydroelectric, mini-hydroelectric, wind, mini-geothermal, and hybrid. A small power utilities group is being spun off the major utility, to provide a structure for developing rural electrification programs. In some instances, private companies have stepped forward, avoiding what is perceived as overwhelming beaurocracy, and installed systems with private financing. The paper provides information on survey work which has been done on resources, and the status of cooperative programs to develop renewable systems in the nation.

  2. Adopting small-scale production of electricity

    Tengvard, Maria; Palm, Jenny (Linkoeping Univ., Dept. of Technology and Social Change, Linkoeping (Sweden)). e-mail: maria.tengvard@liu.se

    2009-07-01

    In Sweden in 2008, a 'new' concept for small-scale electricity production attracted massive media attention. This was mainly due to the efforts of Swedish company Egen El, which is marketing small-scale photovoltaics (PVs) and wind turbines to households, both homeowners and tenants. Their main selling point is simplicity: their products are so easy to install that everyone can do it. Autumn 2008 also saw IKEA announce that within three years it would market solar panels. How, then, do households perceive these products? Why would households choose to buy them? How do households think about producing their own electricity? Analysis of material based on in-depth interviews with members of 20 households reveals that environmental concerns supply the main motive for adopting PVs or micro wind power generation. In some cases, the adopting households have an extensively ecological lifestyle and such adoption represents a way to take action in the energy area. For some, this investment is symbolic: a way of displaying environmental consciousness or setting an example to others. For still others, the adoption is a protest against 'the system' with its large dominant actors or is a way to become self-sufficient. These microgeneration installations are rejected mainly on economic grounds; other motives are respect for neighbours and difficulties finding a place to install a wind turbine.

  3. Evaluation of remotely sensed actual evapotranspiration data for modeling small scale irrigation in Ethiopia.

    Taddele, Y. D.; Ayana, E.; Worqlul, A. W.; Srinivasan, R.; Gerik, T.; Clarke, N.

    2017-12-01

    The research presented in this paper is conducted in Ethiopia, which is located in the horn of Africa. Ethiopian economy largely depends on rainfed agriculture, which employs 80% of the labor force. The rainfed agriculture is frequently affected by droughts and dry spells. Small scale irrigation is considered as the lifeline for the livelihoods of smallholder farmers in Ethiopia. Biophysical models are highly used to determine the agricultural production, environmental sustainability, and socio-economic outcomes of small scale irrigation in Ethiopia. However, detailed spatially explicit data is not adequately available to calibrate and validate simulations from biophysical models. The Soil and Water Assessment Tool (SWAT) model was setup using finer resolution spatial and temporal data. The actual evapotranspiration (AET) estimation from the SWAT model was compared with two remotely sensed data, namely the Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectrometer (MODIS). The performance of the monthly satellite data was evaluated with correlation coefficient (R2) over the different land use groups. The result indicated that over the long term and monthly the AVHRR AET captures the pattern of SWAT simulated AET reasonably well, especially on agricultural dominated landscapes. A comparison between SWAT simulated AET and AVHRR AET provided mixed results on grassland dominated landscapes and poor agreement on forest dominated landscapes. Results showed that the AVHRR AET products showed superior agreement with the SWAT simulated AET than MODIS AET. This suggests that remotely sensed products can be used as valuable tool in properly modeling small scale irrigation.

  4. Small scale structure formation in chameleon cosmology

    Brax, Ph.; Bruck, C. van de; Davis, A.C.; Green, A.M.

    2006-01-01

    Chameleon fields are scalar fields whose mass depends on the ambient matter density. We investigate the effects of these fields on the growth of density perturbations on sub-galactic scales and the formation of the first dark matter halos. Density perturbations on comoving scales R<1 pc go non-linear and collapse to form structure much earlier than in standard ΛCDM cosmology. The resulting mini-halos are hence more dense and resilient to disruption. We therefore expect (provided that the density perturbations on these scales have not been erased by damping processes) that the dark matter distribution on small scales would be more clumpy in chameleon cosmology than in the ΛCDM model

  5. Appendix - A small scale research review

    Larsen, Lea Lund

    over two questions asked in the abstract concerning workshop C - Effects of teacher training in lifelong learning - at the current ASEM conference. At first it is asked what do we already know about teacher training effects in relation to adult learners? This will be identified by a search...... for systematic reviews in the international This will be identified by a search for systematic reviews in the international clearinghouses and afterwards by a small scale mapping done in the pedagogic databaseERIC. The second question sounds: which methods can be used to measure the effects of teacher...... training? This will be illustrated by describing a research design in progress at the National Centre of Competence Development, DK, regarding a program where teachers are taught Cooperative Learning as a pedagogical and didactical method. This appendix concerns the first question. In search for empiric results concerning: What do...

  6. New markets for small-scale hydro

    Maurer, E.A.

    1997-01-01

    The market for small and medium sized hydro-electric power plant is more attractive than ever. The boom in Europe has increasingly spread to the emerging countries, and here too small hydro plays an important ecological role. In addition to new plant rehabilitation of 'historical' plant is now a major factor. The last few years have seen a market shift from single machine components to complete plant and systems, requiring a strategy re-think on the part of larger companies. Following the influx of private capital into the power industry, business conditions have also undergone a thorough transformation. In place of 'fast money', hydro power offers the prospect of earning longer-term, sustainable money'. The term small-scale hydro-electric power (or simply 'small hydro') is used slightly differently depending on the country and market. Here, it is used to denote plant with turbines up to 10 MW. (Author)

  7. Small Scale Hydrocarbon Fire Test Concept

    Joachim Søreng Bjørge

    2017-11-01

    Full Text Available In the oil and gas industry, hydrocarbon process equipment was previously often thermally insulated by applying insulation directly to the metal surface. Fire protective insulation was applied outside the thermal insulation. In some cases, severe corrosion attacks were observed due to ingress of humidity and condensation at cold surfaces. Introducing a 25 mm air gap to prevent wet thermal insulation and metal wall contact is expected to solve the corrosion issues. This improved insulation methodology does, however, require more space that may not be available when refurbishing older process plants. Relocating structural elements would introduce much hot work, which should be minimized in live plants. It is also costly. The aim of the present study is therefore to develop a test concept for testing fire resistance of equipment protected with only air-gap and thermal insulation, i.e., without the fire-protective insulation. The present work demonstrates a conceptual methodology for small scale fire testing of mockups resembling a section of a distillation column. The mockups were exposed to a small-scale propane flame in a test configuration where the flow rate and the flame zone were optimized to give heat flux levels in the range 250–350 kW/m2. Results are presented for a mockup resembling a 16 mm thick distillation column steel wall. It is demonstrated that the modern distance insulation in combination with the heat capacity of the column wall indicates 30+ minutes fire resistance. The results show that this methodology has great potentials for low cost fire testing of other configurations, and it may serve as a set-up for product development.

  8. Aerodynamics of small-scale vertical-axis wind turbines

    Paraschivoiu, I.; Desy, P.

    1985-12-01

    The purpose of this work is to study the influence of various rotor parameters on the aerodynamic performance of a small-scale Darrieus wind turbine. To do this, a straight-bladed Darrieus rotor is calculated by using the double-multiple-streamtube model including the streamtube expansion effects through the rotor (CARDAAX computer code) and the dynamicstall effects. The straight-bladed Darrieus turbine is as expected more efficient with respect the curved-bladed rotor but for a given solidity is operates at higher wind speeds.

  9. Small-scale irradiated fuel electrorefining

    Benedict, R.W.; Krsul, J.R.; Mariani, R.D.; Park, K.; Teske, G.M.

    1993-01-01

    In support of the metallic fuel cycle development for the Integral Fast Reactor (IFR), a small scale electrorefiner was built and operated in the Hot Fuel Examination Facility (HFEF) at Argonne National Laboratory-West. The initial purpose of this apparatus was to test the single segment dissolution of irradiated metallic fuel via either direct dissolution in cadmium or anodic dissolution. These tests showed that 99.95% of the uranium and 99.99% of the plutonium was dissolved and separated from the fuel cladding material. The fate of various fission products was also measured. After the dissolution experiments, the apparatus was upgraded to stady fission product behavior during uranium electrotransport. Preliminary decontamination factors were estimated for different fission products under different processing conditions. Later modifications have added the following capabilities: Dissolution of multiple fuel segments simultaneously, electrotransport to a solid cathode or liquid cathode and actinide recovery with a chemical reduction crucible. These capabilities have been tested with unirradiated uranium-zirconium fuel and will support the Fuel Cycle Demonstration program

  10. Hoopa Valley Small Scale Hydroelectric Feasibility Project

    Curtis Miller

    2009-03-22

    This study considered assessing the feasibility of developing small scale hydro-electric power from seven major tributaries within the Hoopa Valley Indian Reservation of Northern California (http://www.hoopa-nsn.gov/). This study pursued the assessment of seven major tributaries of the Reservation that flow into the Trinity River. The feasibility of hydropower on the Hoopa Valley Indian Reservation has real potential for development and many alternative options for project locations, designs, operations and financing. In order to realize this opportunity further will require at least 2-3 years of intense data collection focusing on stream flow measurements at multiple locations in order to quantify real power potential. This also includes on the ground stream gradient surveys, road access planning and grid connectivity to PG&E for sale of electricity. Imperative to this effort is the need for negotiations between the Hoopa Tribal Council and PG&E to take place in order to finalize the power rate the Tribe will receive through any wholesale agreement that utilizes the alternative energy generated on the Reservation.

  11. Intelligent Network Flow Optimization (INFLO) prototype : Seattle small-scale demonstration plan.

    2015-01-01

    This report describes the INFLO Prototype Small-Scale Demonstration to be performed in Seattle Washington. This demonstration is intended to demonstrate that the INFLO Prototype, previously demonstrated in a controlled environment, functions well in ...

  12. Simulating Small-Scale Experiments of In-Tunnel Airblast Using STUN and ALE3D

    Neuscamman, Stephanie [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glenn, Lewis [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schebler, Gregory [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McMichael, Larry [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glascoe, Lee [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-09-12

    This report details continuing validation efforts for the Sphere and Tunnel (STUN) and ALE3D codes. STUN has been validated previously for blast propagation through tunnels using several sets of experimental data with varying charge sizes and tunnel configurations, including the MARVEL nuclear driven shock tube experiment (Glenn, 2001). The DHS-funded STUNTool version is compared to experimental data and the LLNL ALE3D hydrocode. In this particular study, we compare the performance of the STUN and ALE3D codes in modeling an in-tunnel airblast to experimental results obtained by Lunderman and Ohrt in a series of small-scale high explosive experiments (1997).

  13. Small scale imaging using ultrasonic tomography

    Zakaria, Z.; Abdul Rahim, R.; Megat Ali, M.S.A.; Baharuddin, M.Y.; Jahidin, A.H.

    2009-01-01

    Ultrasound technology progressed through the 1960 from simple A-mode and B-mode scans to today M-mode and Doppler two dimensional (2-D) and even three dimensional (3-D) systems. Modern ultrasound imaging has its roots in sonar technology after it was first described by Lord John Rayleigh over 100 years ago on the interaction of acoustic waves with media. Tomography technique was developed as a diagnostic tool in the medical area since the early of 1970s. This research initially focused on how to retrieve a cross sectional images from living and non-living things. After a decade, the application of tomography systems span into the industrial area. However, the long exposure time of medical radiation-based method cannot tolerate the dynamic changes in industrial process two phase liquid/ gas flow system. An alternative system such as a process tomography systems, can give information on the nature of the flow regime characteristic. The overall aim of this paper is to investigate the use of a small scale ultrasonic tomography method based on ultrasonic transmission mode tomography for online monitoring of liquid/ gas flow in pipe/ vessel system through ultrasonic transceivers application. This non-invasive technique applied sixteen transceivers as the sensing elements to cover the pipe/ vessel cross section. The paper also details the transceivers selection criteria, hardware setup, the electronic measurement circuit and also the image reconstruction algorithm applied. The system was found capable of visualizing the internal characteristics and provides the concentration profile for the corresponding liquid and gas phases. (author)

  14. Small-Scale Combined Heat and Power Plants Using Biofuels

    Salomon-Popa, Marianne [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Technology

    2002-11-01

    In this time period where energy supply and climate change are of special concern, biomass-based fuels have attracted much interest due to their plentiful supply and favorable environmental characteristics (if properly managed). The effective capture and continued sustainability of this renewable resource requires a new generation of biomass power plants with high fuel energy conversion. At the same time, deregulation of the electricity market offers new opportunities for small-scale power plants in a decentralized scheme. These two important factors have opened up possibilities for small-scale combined heat and power (CHP) plants based on biofuels. The objective of this pre-study is to assess the possibilities and technical limitations for increased efficiency and energy utilization of biofuels in small size plants (approximately 10 MWe or lower). Various energy conversion technologies are considered and proven concepts for large-scale fossil fuel plants are an especially important area. An analysis has been made to identify the problems, technical limitations and different possibilities as recognized in the literature. Beyond published results, a qualitative survey was conducted to gain first-hand, current knowledge from experts in the field. At best, the survey results together with the results of personal interviews and a workshop on the role of small-scale plants in distributed generation will serve a guideline for future project directions and ideas. Conventional and novel technologies are included in the survey such as Stirling engines, combustion engines, gas turbines, steam turbines, steam motors, fuel cells and other novel technologies/cycles for biofuels. State-of-the-art heat and power plants will be identified to clarify of the advantages and disadvantages as well as possible obstacles for their implementation.

  15. Occurrence of Eimeria species parasites on small-scale commercial chicken farms in Africa and indication of economic profitability.

    Kimberly M Fornace

    Full Text Available Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa.

  16. Occurrence of Eimeria Species Parasites on Small-Scale Commercial Chicken Farms in Africa and Indication of Economic Profitability

    Fornace, Kimberly M.; Clark, Emily L.; Macdonald, Sarah E.; Namangala, Boniface; Karimuribo, Esron; Awuni, Joseph A.; Thieme, Olaf; Blake, Damer P.; Rushton, Jonathan

    2013-01-01

    Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa. PMID:24391923

  17. Occurrence of Eimeria species parasites on small-scale commercial chicken farms in Africa and indication of economic profitability.

    Fornace, Kimberly M; Clark, Emily L; Macdonald, Sarah E; Namangala, Boniface; Karimuribo, Esron; Awuni, Joseph A; Thieme, Olaf; Blake, Damer P; Rushton, Jonathan

    2013-01-01

    Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa.

  18. Atmospheric dispersion modelling over complex terrain at small scale

    Nosek, S.; Janour, Z.; Kukacka, L.; Jurcakova, K.; Kellnerova, R.; Gulikova, E.

    2014-03-01

    Previous study concerned of qualitative modelling neutrally stratified flow over open-cut coal mine and important surrounding topography at meso-scale (1:9000) revealed an important area for quantitative modelling of atmospheric dispersion at small-scale (1:3300). The selected area includes a necessary part of the coal mine topography with respect to its future expansion and surrounding populated areas. At this small-scale simultaneous measurement of velocity components and concentrations in specified points of vertical and horizontal planes were performed by two-dimensional Laser Doppler Anemometry (LDA) and Fast-Response Flame Ionization Detector (FFID), respectively. The impact of the complex terrain on passive pollutant dispersion with respect to the prevailing wind direction was observed and the prediction of the air quality at populated areas is discussed. The measured data will be used for comparison with another model taking into account the future coal mine transformation. Thus, the impact of coal mine transformation on pollutant dispersion can be observed.

  19. Small-Scale Smart Grid Construction and Analysis

    Surface, Nicholas James

    The smart grid (SG) is a commonly used catch-phrase in the energy industry yet there is no universally accepted definition. The objectives and most useful concepts have been investigated extensively in economic, environmental and engineering research by applying statistical knowledge and established theories to develop simulations without constructing physical models. In this study, a small-scale version (SSSG) is constructed to physically represent these ideas so they can be evaluated. Results of construction show data acquisition three times more expensive than the grid itself although mainly due to the incapability to downsize 70% of data acquisition costs to small-scale. Experimentation on the fully assembled grid exposes the limitations of low cost modified sine wave power, significant enough to recommend pure sine wave investment in future SSSG iterations. Findings can be projected to full-size SG at a ratio of 1:10, based on the appliance representing average US household peak daily load. However this exposes disproportionalities in the SSSG compared with previous SG investigations and recommended changes for future iterations are established to remedy this issue. Also discussed are other ideas investigated in the literature and their suitability for SSSG incorporation. It is highly recommended to develop a user-friendly bidirectional charger to more accurately represent vehicle-to-grid (V2G) infrastructure. Smart homes, BEV swap stations and pumped hydroelectric storage can also be researched on future iterations of the SSSG.

  20. Concepts for Small-Scale Testing of Used Nuclear Fuel

    Marschman, Steven Craig [Idaho National Lab. (INL), Idaho Falls, ID (United States); Winston, Philip Lon [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    This report documents a concept for a small-scale test involving between one and three Boiling Water Rector (BWR) high burnup (HBU) fuel assemblies. This test would be similar to the DOE funded High Burn-Up (HBU) Confirmatory Data Project to confirm the behavior of used high burn-up fuel under prototypic conditions, only on a smaller scale. The test concept proposed would collect data from fuel stored under prototypic dry storage conditions to mimic, as closely as possible, the conditions HBU UNF experiences during all stages of dry storage: loading, cask drying, inert gas backfilling, and transfer to an Independent Spent Fuel Storage Installation (ISFSI) for multi-year storage.

  1. The development for small scale soft X-ray spectrometer

    Sun Kexu; Jiang Shaoen; Yi Rongqing; Cui Yanli

    2004-12-01

    For the development of small-scale soft X-ray spectrometer, first, some small-scale soft X-ray detection elements are developed, it is included GaAs irradiated with neutron, GaAs irradiated with proton, multi-layer mirror, plane mirror and small scale X-ray diode et al. Soft X-ray spectrometers built of multi-layer mirror-GaAs (with neutron irradiation), and plane mirror-small-scale XRD, and plane mirror-GaAs (with proton irradiation) are prepared. These spectrometers are examined in Shen Guang-II laser facility, and some external estimation are given. (authors)

  2. Small-Scale Shock Testing of Propellants and Ingredients

    Dawley, S

    2004-01-01

    .... The use of small-scale gap testing to evaluate the shock sensitivity of individual propellant ingredients and propellant formulations is a valuable method for experimentally establishing shock...

  3. An accurate and computationally efficient small-scale nonlinear FEA of flexible risers

    Rahmati, MT; Bahai, H; Alfano, G

    2016-01-01

    This paper presents a highly efficient small-scale, detailed finite-element modelling method for flexible risers which can be effectively implemented in a fully-nested (FE2) multiscale analysis based on computational homogenisation. By exploiting cyclic symmetry and applying periodic boundary conditions, only a small fraction of a flexible pipe is used for a detailed nonlinear finite-element analysis at the small scale. In this model, using three-dimensional elements, all layer components are...

  4. Integrated bioenergy conversion concepts for small scale gasification power systems

    Aldas, Rizaldo Elauria

    Thermal and biological gasification are promising technologies for addressing the emerging concerns in biomass-based renewable energy, environmental protection and waste management. However, technical barriers such as feedstock quality limitations, tars, and high NOx emissions from biogas fueled engines impact their full utilization and make them suffer at the small scale from the need to purify the raw gas for most downstream processes, including power generation other than direct boiler use. The two separate gasification technologies may be integrated to better address the issues of power generation and waste management and to complement some of each technologies' limitations. This research project investigated the technical feasibility of an integrated thermal and biological gasification concept for parameters critical to appropriately matching an anaerobic digester with a biomass gasifier. Specific studies investigated the thermal gasification characteristics of selected feedstocks in four fixed-bed gasification experiments: (1) updraft gasification of rice hull, (2) indirect-heated gasification of rice hull, (3) updraft gasification of Athel wood, and (4) downdraft gasification of Athel and Eucalyptus woods. The effects of tars and other components of producer gas on anaerobic digestion at mesophilic temperature of 36°C and the biodegradation potentials and soil carbon mineralization of gasification tars during short-term aerobic incubation at 27.5°C were also examined. Experiments brought out the ranges in performance and quality and quantity of gasification products under different operating conditions and showed that within the conditions considered in the study, these gasification products did not adversely impact the overall digester performance. Short-term aerobic incubation demonstrated variable impacts on carbon mineralization depending on tar and soil conditions. Although tars exhibited low biodegradation indices, degradation may be improved if the

  5. Medium/small-scale computers HITACHI M-620, M-630, and M-640 systems: the aim of development and characteristics

    Oshima, N; Saiki, Y; Sunaga, K [Hitachi, Ltd., Tokyo (Japan)

    1990-10-01

    The medium/small-scale HITACHI M-620, M-630, and M-640 computer systems are outlined. Every system is featured by the configuration usable as a medium or small-scale host computer in offices, the function connectable with large-scale host computers, the performance of 5-50 times those of conventional office computers, easy operation and fast processing. As features of the hardware, the one-board CPU and small integrated cubicle structure containing the CPU board, high-speed large-capacity magnetic disk storage device, various kinds of controllers and others are illustrated. As features of the software, the OS (VOS K) featured by the virtual data space control (VDSA) and relational database (RDB) functions, EAGLE/4GL (effective approach to achieving high level software productivity/4th generation language), STEP (self training environmental support program) and simple end user language ACE3/E2 are outlined. 7 figs.

  6. Small scale wind energy harvesting with maximum power tracking

    Joaquim Azevedo

    2015-07-01

    Full Text Available It is well-known that energy harvesting from wind can be used to power remote monitoring systems. There are several studies that use wind energy in small-scale systems, mainly with wind turbine vertical axis. However, there are very few studies with actual implementations of small wind turbines. This paper compares the performance of horizontal and vertical axis wind turbines for energy harvesting on wireless sensor network applications. The problem with the use of wind energy is that most of the time the wind speed is very low, especially at urban areas. Therefore, this work includes a study on the wind speed distribution in an urban environment and proposes a controller to maximize the energy transfer to the storage systems. The generated power is evaluated by simulation and experimentally for different load and wind conditions. The results demonstrate the increase in efficiency of wind generators that use maximum power transfer tracking, even at low wind speeds.

  7. Technical efficiency of small-scale fishing households in Tanzanian ...

    This paper examines the technical efficiency of Tanzanian small-scale fishing households, based on data from two coastal villages located near Bagamoyo and Zanzibar, using a stochastic frontier model with technical inefficiency. The estimated mean technical efficiency of small-scale fishing households was 52%, showing ...

  8. Economic Analysis of Small Scale Fish Pond Production in Oguta ...

    What are the costs and returns of small-scale fishpond enterprises? What problems hinder the development of small-scale fishpond production? Data were collected with the aid of structured questionnaires and interviews. Descriptive statistics, gross margin and likert scale were employed in data analysis. Gross margin ...

  9. Transaction Cost Of Borrowing Among Small Scale Farmers In ...

    The study examined transaction cost of borrowing among small scale farmers in Rivers State, Nigeria. Data was collected with the aid of structured questionnaire from 109 randomly selected small scale farmers in the study area. Data analysis was by frequency, percentage and mean. It was found that farmers mostly ...

  10. Economic efficiency among small scale poultry farmers in Imo State ...

    ... household size and extension, were found to be the significant factors that account for the observed variation in efficiency among the small scale poultry farmers. Keywords: economic efficiency, small scale poultry farmers, stochastic frontier production model. International Journal of Agriculture and Rural Development Vol.

  11. Undermining the myths about small-scale mining

    Verbrugge, B.L.P.; Besmanos, B.

    2015-01-01

    Along with many other countries, in recent decades the Philippines –have witnessed a dramatic expansion of small-scale mining (SSM), mostly (but not exclusively)in the form of small-scale gold mining. As can be seen in the graph below (figure 1), official gold production fromSSM has

  12. Emissions from small scale biomass combustion - Research needs

    Gustavsson, L.; Karlsson, M.L.; Larfeldt, J.; Leckner, B.

    1994-01-01

    Earlier investigations have shown that small scale biomass combustion leads to unacceptable emissions in the air. The most important problem is high levels of unburnt hydrocarbons. This report analyzes which are the most important reasons to these emissions and which research efforts that are necessary to increase the knowledge about the combustion processes, thereby promoting the development of environmentally feasible equipment. The following factors are defined as most crucial to emission levels: size of combustion chamber, air excess ratio, means of combustion air supply, mixing between air and fuel, transient events, and fuel quality. It is concluded that both basic and research within the area is needed. More specific, research in the form of systematic analysis of best available technology, reactor experiments, compilation of knowledge about relevant basic combustion processes, mathematical modelling as well as development of measurement techniques are called for. 15 refs, 11 figs, 1 tab

  13. Small scale tests on the progressive retreat of soil slopes

    Voulgari, Chrysoula; Utili, Stefano; Castellanza, Riccardo

    2015-04-01

    In this paper, the influence due to the presence of cracks on the morphologic evolution of natural cliffs subject to progressive retreat induced by weathering is investigated through small scale laboratory tests. Weathering turns hard rocks into soft rocks that maintain the structure of the intact rocks, but are characterised by higher void ratios and reduced bond strengths; soft rocks are transformed into granular soils generally called residual soils. A number of landslides develop in slopes due to weathering which results in the progressive retrogression of the slope face and the further degradation within the weathering zone. Cracks, that are widely present, can be a result of weathering and they can cause a significant decrease in their stability, as they provide preferential flow channels which increase the soil permeability and decrease the soil strength. The geological models employed until now are mainly empirical. Several researchers have tried to study the stability of slopes through experimental procedures. Centrifuge modelling is widely used to investigate the failure of slopes. Small scale tests are also an important approach, in order to study the behaviour of a slope under certain conditions, such as the existence of water, as they allow the observation of the infiltration processes, the movement of the weathering front, deformation and failure. However, the deformation response of a slope subject to weathering is not yet thoroughly clarified. In this work, a set of experiments were conducted to investigate weathering induced successive landslides. Weathering was applied to the slope model by wetting the slope crest through a rainfall simulator device. The moisture content of the soil during the tests was monitored by soil moisture sensors that were buried inside the slope model. High resolution cameras were recording the behaviour of the slope model. GeoPIV was used to analyse the frames and obtain the deformations of the slope model during the

  14. Rural electrification in Malaysia via small scale biomass gasifier

    Zainal Alimuddin Zainal Alauddin

    2000-01-01

    It is the government of Malaysia's vision to see that the rural community is not left behind in its endeavour to be an industrialised nation in the year 2020. The standard of living in the rural areas is very far different from that in the urban areas. To obtain equality the standard of living of the rural folks need to be ungraded. This is done largely by electrification. Electricity has been in the past the catalyst for development and raising the standard of living of the poor. Electricity supplied by the nation's electricity company might not reach all remote areas and therefore there must be a means to provide alternative electrical supply to these places. Present method employ the use of diesel generator sets to provide electricity. The availability of biomass source of supply in the rural areas could be effectively exploited to provide alternative source of energy via a gasification system to run a reciprocating engine coupled to a generator to generated electricity. A small-scale biomass gasification generator set in the range of 2-5 kW is suitable to provide electrical supply to a typical house in the rural area. The present use of biomass source of energy is in its utilisation to provide source of heat for cooking. Several tests have been conducted and the performance is very good. Alternatively another medium scale system generating about 50-20O kW would be suitable for a typical village having about 50 houses. A small-scale system has been developed in USM to provide 5 kW of electrical power. The system used a petrol engine and produces an overall efficiency of 7% with a specific consumption of about 3 kg/kWh. The biomass material used is wood. However for application in the rural areas the biomass material will depend on the type available. A further 50 kW system is being develop in USM. (Author)

  15. Accelerating research into bio-based FDCA-polyesters by using small scale parallel film reactors.

    Gruter, Gert-Jan M; Sipos, Laszlo; Adrianus Dam, Matheus

    2012-02-01

    High Throughput experimentation has been well established as a tool in early stage catalyst development and catalyst and process scale-up today. One of the more challenging areas of catalytic research is polymer catalysis. The main difference with most non-polymer catalytic conversions is the fact that the product is not a well defined molecule and the catalytic performance cannot be easily expressed only in terms of catalyst activity and selectivity. In polymerization reactions, polymer chains are formed that can have various lengths (resulting in a molecular weight distribution rather than a defined molecular weight), that can have different compositions (when random or block co-polymers are produced), that can have cross-linking (often significantly affecting physical properties), that can have different endgroups (often affecting subsequent processing steps) and several other variations. In addition, for polyolefins, mass and heat transfer, oxygen and moisture sensitivity, stereoregularity and many other intrinsic features make relevant high throughput screening in this field an incredible challenge. For polycondensation reactions performed in the melt often the viscosity becomes already high at modest molecular weights, which greatly influences mass transfer of the condensation product (often water or methanol). When reactions become mass transfer limited, catalyst performance comparison is often no longer relevant. This however does not mean that relevant experiments for these application areas cannot be performed on small scale. Relevant catalyst screening experiments for polycondensation reactions can be performed in very efficient small scale parallel equipment. Both transesterification and polycondensation as well as post condensation through solid-stating in parallel equipment have been developed. Next to polymer synthesis, polymer characterization also needs to be accelerated without making concessions to quality in order to draw relevant conclusions.

  16. Small-scale nuclear fusion needs investors

    Kasteren, J. van.

    1985-01-01

    The only Dutch high-risk research company 'Convector' needs money. In the beginning of October, investors could put at most five million Dutch florins in a highly disputed project for the development of a thermonuclear reactor, based on the principle of globular lightnings. (G.J.P.)

  17. Dark matter self-interactions and small scale structure

    Tulin, Sean; Yu, Hai-Bo

    2018-02-01

    We review theories of dark matter (DM) beyond the collisionless paradigm, known as self-interacting dark matter (SIDM), and their observable implications for astrophysical structure in the Universe. Self-interactions are motivated, in part, due to the potential to explain long-standing (and more recent) small scale structure observations that are in tension with collisionless cold DM (CDM) predictions. Simple particle physics models for SIDM can provide a universal explanation for these observations across a wide range of mass scales spanning dwarf galaxies, low and high surface brightness spiral galaxies, and clusters of galaxies. At the same time, SIDM leaves intact the success of ΛCDM cosmology on large scales. This report covers the following topics: (1) small scale structure issues, including the core-cusp problem, the diversity problem for rotation curves, the missing satellites problem, and the too-big-to-fail problem, as well as recent progress in hydrodynamical simulations of galaxy formation; (2) N-body simulations for SIDM, including implications for density profiles, halo shapes, substructure, and the interplay between baryons and self-interactions; (3) semi-analytic Jeans-based methods that provide a complementary approach for connecting particle models with observations; (4) merging systems, such as cluster mergers (e.g., the Bullet Cluster) and minor infalls, along with recent simulation results for mergers; (5) particle physics models, including light mediator models and composite DM models; and (6) complementary probes for SIDM, including indirect and direct detection experiments, particle collider searches, and cosmological observations. We provide a summary and critical look for all current constraints on DM self-interactions and an outline for future directions.

  18. Hydriding and dehydriding characteristics of small-scale DU and ZrCo beds

    Chung, Dongyou; Lee, Jungmin; Koo, Daeseo [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Chung, Hongsuk, E-mail: hschung1@kaeri.kr [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, Ki Hwan [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kang, Hyun-Goo; Chang, Min Ho [National Fusion Research Institute, 113 Gwahakro, Yuseong, Daejeon 305-333 (Korea, Republic of); Camp, Patrick [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Jung, Ki Jung; Cho, Seungyon; Yun, Sei-Hun; Kim, Chang Shuk [National Fusion Research Institute, 113 Gwahakro, Yuseong, Daejeon 305-333 (Korea, Republic of); Yoshida, Hiroshi [Fusion Science Consultant, 3288-10 Sakado-cho, Mito-shi 310-0841, Ibakaki-ken (Japan); Paek, Seungwoo; Lee, Hansoo [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of)

    2013-10-15

    Highlights: • We have designed and fabricated a twosome small-scale getter bed for a comparison of ZrCo with DU on the hydriding/dehydriding properties. • We provide preliminary experimental results of our ZrCo and DU beds. -- Abstract: With the development of fusion technology, it will be necessary to store large amounts of tritium during the nuclear fusion fuel cycle. Stable metal tritides are viewed as potential candidates for the high-density storage of tritium. Metal tritide formers offer a safe and convenient method for tritium storage. For the storage, supply, and recovery of hydrogen isotopes, zirconium cobalt (ZrCo) and depleted uranium (DU) have been extensively proposed. Thus, we have designed and fabricated two identical small-scale getter beds for a comparison of ZrCo with DU on the hydriding/dehydriding properties. After the powderization of the metals, the hydriding/dehydriding performance at different stoichiometries of ZrCo and DU was measured. We provide preliminary experimental results of our ZrCo and DU beds.

  19. High performance homes

    Beim, Anne; Vibæk, Kasper Sánchez

    2014-01-01

    Can prefabrication contribute to the development of high performance homes? To answer this question, this chapter defines high performance in more broadly inclusive terms, acknowledging the technical, architectural, social and economic conditions under which energy consumption and production occur....... Consideration of all these factors is a precondition for a truly integrated practice and as this chapter demonstrates, innovative project delivery methods founded on the manufacturing of prefabricated buildings contribute to the production of high performance homes that are cost effective to construct, energy...

  20. Small-scale spatial cognition in pigeons.

    Cheng, Ken; Spetch, Marcia L; Kelly, Debbie M; Bingman, Verner P

    2006-05-01

    Roberts and Van Veldhuizen's [Roberts, W.A., Van Veldhuizen, N., 1985. Spatial memory in pigeons on the radial maze. J. Exp. Psychol.: Anim. Behav. Proc. 11, 241-260] study on pigeons in the radial maze sparked research on landmark use by pigeons in lab-based tasks as well as variants of the radial-maze task. Pigeons perform well on open-field versions of the radial maze, with feeders scattered on the laboratory floor. Pigeons can also be trained to search precisely for buried food. The search can be based on multiple landmarks, but is sometimes controlled by just one or two landmarks, with the preferred landmarks varying across individuals. Findings are similar in landmark-based searching on a computer monitor and on a lab floor, despite many differences between the two kinds of tasks. A number of general learning principles are found in landmark-based searching, such as cue competition, generalization and peak shift, and selective attention. Pigeons also learn the geometry of the environment in which they are searching. Neurophysiological studies have implicated the hippocampal formation (HF) in avian spatial cognition, with the right hippocampus hypothesized to play a more important role in the spatial recognition of goal locations. Most recently, single-cell recording from the pigeon's hippocampal formation has revealed cells with different properties from the classic 'place' cells of rats, as well as differences in the two sides of the hippocampus.

  1. Comparison of the performances of land use regression modelling and dispersion modelling in estimating small-scale variations in long-term air pollution concentrations in a Dutch urban area.

    Beelen, R.M.J.; Voogt, M.; Duyzer, J.; Zandveld, P.; Hoek, G.

    2010-01-01

    The performance of a Land Use Regression (LUR) model and a dispersion model (URBIS - URBis Information System) was compared in a Dutch urban area. For the Rijnmond area, i.e. Rotterdam and surroundings, nitrogen dioxide (NO2) concentrations for 2001 were estimated for nearly 70 000 centroids of a

  2. A Small-Scale Low-Cost Gas Chromatograph

    Gros, Natasa; Vrtacnik, Margareta

    2005-01-01

    The design and application of a small-scale portable gas chromatograph for learning of the basic concepts of chromatography is described. The apparatus consists of two basic separable units, which includes a chromatographic unit and an electronic unit.

  3. Resource-Use Efficiency in Rice Production Under Small Scale ...

    acer

    specific objectives of the study were to determine resource use efficiency, describe ... economic level. ... this key variable with a view to stepping ... focused on small-scale irrigation systems for ... farmers were assumed to be operating under.

  4. Contributions of Small-Scale Community-Owned Infrastructure (SCI ...

    Contributions of Small-Scale Community-Owned Infrastructure (SCI) and Asset ... Descriptive analysis was employed to explain access to productive rural ... for asset maintenance and replacement; support targeted value chains given the ...

  5. Strengthening industry-research linkage for small scale industrial ...

    Strengthening industry-research linkage for small scale industrial development in Ghana - the relevance of scientific and technological information. ... Journal of Applied Science and Technology. Journal Home · ABOUT · Advanced Search ...

  6. Financing small scale wind energy projects in the UK

    Mitchell, Catherine

    1993-01-01

    This paper shows how wind energy projects in the UK have obtained finance. It attempts to list the financing options open to small scale developments and to note any likely problems which may occur. (UK)

  7. The hazardous nature of small scale underground mining in Ghana

    K.J. Bansah

    2016-01-01

    Full Text Available Small scale mining continues to contribute significantly to the growth of Ghana's economy. However, the sector poses serious dangers to human health and the environment. Ground failures resulting from poorly supported stopes have led to injuries and fatalities in recent times. Dust and fumes from drilling and blasting of ore present health threats due to poor ventilation. Four prominent small scale underground mines were studied to identify the safety issues associated with small scale underground mining in Ghana. It is recognized that small scale underground mining in Ghana is inundated with unsafe acts and conditions including stope collapse, improper choice of working tools, absence of personal protective equipment and land degradation. Inadequate monitoring of the operations and lack of regulatory enforcement by the Minerals Commission of Ghana are major contributing factors to the environmental, safety and national security issues of the operations.

  8. The Hetex small-scale hydro plant

    Guentert, P.; Boller, F.; Wanner, A.

    2006-01-01

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at the 400 kW small hydroelectric power plant (SHP) installed on the Aabach stream in Niederlenz, Switzerland. With a maximum water-flow of 4.5 m 3 /s, the turbine can produce about 1.5 GWh of electricity per year. In spring 2005, bearing damage necessitated substantial renovation to the turbine and the generator. This study examines the state of the rest of the plant noted during maintenance work. It also focuses on the feeding of the electricity produced into the grid, the effects of increased residual water-flow, the option of using the Hallwilersee lake as a buffer, upstream flood evacuation and the possibility of green electricity certification. The calculation of the amount of water available is discussed. Due to inconsistent data, a corrected flow-duration curve was used. For the local river authorities, the through passage for fish from the Aare river up to the Hallwilersee has a high priority. The Hetex SHP weir is one of nine barriers to a direct connection. The planning of a fish-pass to be built in 2006 is discussed

  9. Evaluation of real-time operating system for small-scale embedded systems

    Dayang Norhayati Abang Jawawi; Rosbi Mamat

    1999-01-01

    In this paper, the performance of some real-time operating systems for small-scale embedded systems are evaluated based on some criteria. The evaluation is performed qualitatively and quantitatively. The evaluation results based on a case study on an engineering application will be presented. (author)

  10. Cost analysis of enzymatic biodiesel production in small-scaled packed-bed reactors

    Budzaki, S.; Miljic, G.; Sundaram, S.; Tisma, M.; Hessel, V.

    2017-01-01

    A cost analysis of enzymatic biodiesel production in small-scaled packed-bed reactors using refined sunflower oil is performed in this work. A few enzymatic micro-flow reactors have so far reached a performance close to gram-scale, which might be sufficient for the pharmaceutical industry. This

  11. High Performance Marine Vessels

    Yun, Liang

    2012-01-01

    High Performance Marine Vessels (HPMVs) range from the Fast Ferries to the latest high speed Navy Craft, including competition power boats and hydroplanes, hydrofoils, hovercraft, catamarans and other multi-hull craft. High Performance Marine Vessels covers the main concepts of HPMVs and discusses historical background, design features, services that have been successful and not so successful, and some sample data of the range of HPMVs to date. Included is a comparison of all HPMVs craft and the differences between them and descriptions of performance (hydrodynamics and aerodynamics). Readers will find a comprehensive overview of the design, development and building of HPMVs. In summary, this book: Focuses on technology at the aero-marine interface Covers the full range of high performance marine vessel concepts Explains the historical development of various HPMVs Discusses ferries, racing and pleasure craft, as well as utility and military missions High Performance Marine Vessels is an ideal book for student...

  12. Catalytic reduction of emissions from small scale wood combustion. State of the art

    Hargitai, T.; Silversand, F.A. [Katator AB, Lund (Sweden)

    1998-12-31

    Small-scale combustion of big-fuel often results in excessive emissions of volatile organic compounds (VOC), polyaromatic compounds (PAM) and carbon monoxide (CO). These compounds have a negative impact on human health and urban air quality. The predominant volatile organic compounds present in flue gases from big-fuel combustion are propylene, ethylene, butadiene, methanol, ethanol, methane, phenol and benzene. The poor combustion performance of some wood stoves has in certain cases led to legislation against small-scale combustion of big-fuel in urban areas. Catalytic cleaning is one very efficient way of decreasing the environmental impacts of big-fuel combustion. Several studies concerning catalytic purification of flue gases from big-fuel combustion have been presented over the years. Several problems must be addressed when designing a catalyst for this application: Clogging problems from deposition of ashes and particulates in the catalyst; Catalyst poisoning by sulphur, phosphorus, alkali metals etc.; Catalyst fouling due to deposition of ashes and particulates; Catalyst overheating at high flue-gas temperatures and Poor catalyst performance during start-up Most studies have been focused on monolith-type catalysts and- the conversion of CO, VOC and PAH typically is above 80 %. The observed problems are associated with increased pressure drop due to catalyst clogging and decreased catalyst performance due to fouling and poisoning. In most cases precious metals, preferably Pt. have been used as active combustion catalyst. Precious metals have a high activity for the combustion of CO and hydrocarbons and a fair stability against poisoning with compounds present in flue gases from big-fuel, e.g. sulphur and alkali metals. The majority of the studies on precious metals have been focused on Pt. Rh and Pd, which are especially active in catalytic combustion. Some metal oxides are used in catalytic combustion, especially at low temperatures (e.g. in VOC abatement

  13. High performance systems

    Vigil, M.B. [comp.

    1995-03-01

    This document provides a written compilation of the presentations and viewgraphs from the 1994 Conference on High Speed Computing given at the High Speed Computing Conference, {open_quotes}High Performance Systems,{close_quotes} held at Gleneden Beach, Oregon, on April 18 through 21, 1994.

  14. Development of small-scale peat production; Pienturvetuotannon kehittaeminen

    Erkkilae, A.; Kallio, E. [VTT Energy, Jyvaeskylae (Finland)

    1997-12-01

    The aim of the project is to develop production conditions, methods and technology of small-scale peat production to such a level that the productivity is improved and competitivity maintained. The aim in 1996 was to survey the present status of small-scale peat production, and research and development needs and to prepare a development plan for small-scale peat production for a continued project in 1997 and for the longer term. A questionnaire was sent to producers by mail, and its results were completed by phone interviews. Response was obtained from 164 producers, i.e. from about 75 - 85 % of small-scale peat producers. The quantity of energy peat produced by these amounted to 3.3 TWh and that of other peat to 265 000 m{sup 3}. The total production of energy peat (large- scale producers Vapo Oy and Turveruukki Oy included) amounted to 25.0 TWh in 1996 in Finland, of which 91 % (22.8 TWh) was milled peat and 9 % (2.2 TWh) of sod peat. The total production of peat other than energy peat amounted to 1.4 million m{sup 3}. The proportion of small-scale peat production was 13 % of energy peat, 11 % of milled peat and 38 % of sod peat. The proportion of small-scale producers was 18 % of other peat production. The results deviate clearly from those obtained in a study of small-scale production in the 1980s. The amount of small-scale production is clearly larger than generally assessed. Small-scale production focuses more on milled peat than on sod peat. The work will be continued in 1997. Based on development needs appeared in the questionnaire, the aim is to reduce environmental impacts and runoff effluents from small- scale production, to increase the efficiency of peat deliveries and to reduce peat production costs by improving the service value of machines by increasing co-operative use. (orig.)

  15. Seismic detection method for small-scale discontinuities based on dictionary learning and sparse representation

    Yu, Caixia; Zhao, Jingtao; Wang, Yanfei

    2017-02-01

    Studying small-scale geologic discontinuities, such as faults, cavities and fractures, plays a vital role in analyzing the inner conditions of reservoirs, as these geologic structures and elements can provide storage spaces and migration pathways for petroleum. However, these geologic discontinuities have weak energy and are easily contaminated with noises, and therefore effectively extracting them from seismic data becomes a challenging problem. In this paper, a method for detecting small-scale discontinuities using dictionary learning and sparse representation is proposed that can dig up high-resolution information by sparse coding. A K-SVD (K-means clustering via Singular Value Decomposition) sparse representation model that contains two stage of iteration procedure: sparse coding and dictionary updating, is suggested for mathematically expressing these seismic small-scale discontinuities. Generally, the orthogonal matching pursuit (OMP) algorithm is employed for sparse coding. However, the method can only update one dictionary atom at one time. In order to improve calculation efficiency, a regularized version of OMP algorithm is presented for simultaneously updating a number of atoms at one time. Two numerical experiments demonstrate the validity of the developed method for clarifying and enhancing small-scale discontinuities. The field example of carbonate reservoirs further demonstrates its effectiveness in revealing masked tiny faults and small-scale cavities.

  16. Small-scale variability in tropical tropopause layer humidity

    Jensen, E. J.; Ueyama, R.; Pfister, L.; Karcher, B.; Podglajen, A.; Diskin, G. S.; DiGangi, J. P.; Thornberry, T. D.; Rollins, A. W.; Bui, T. V.; Woods, S.; Lawson, P.

    2016-12-01

    Recent advances in statistical parameterizations of cirrus cloud processes for use in global models are highlighting the need for information about small-scale fluctuations in upper tropospheric humidity and the physical processes that control the humidity variability. To address these issues, we have analyzed high-resolution airborne water vapor measurements obtained in the Airborne Tropical TRopopause EXperiment over the tropical Pacific between 14 and 20 km. Using accurate and precise 1-Hz water vapor measurements along approximately-level aircraft flight legs, we calculate structure functions spanning horizontal scales ranging from about 0.2 to 50 km, and we compare the water vapor variability in the lower (about 14 km) and upper (16-19 km) Tropical Tropopause Layer (TTL). We also compare the magnitudes and scales of variability inside TTL cirrus versus in clear-sky regions. The measurements show that in the upper TTL, water vapor concentration variance is stronger inside cirrus than in clear-sky regions. Using simulations of TTL cirrus formation, we show that small variability in clear-sky humidity is amplified by the strong sensitivity of ice nucleation rate to supersaturation, which results in highly-structured clouds that subsequently drive variability in the water vapor field. In the lower TTL, humidity variability is correlated with recent detrainment from deep convection. The structure functions indicate approximately power-law scaling with spectral slopes ranging from about -5/3 to -2.

  17. Small-scale electric generators for arctic applications

    Lamp, T.R.

    1995-01-01

    Forest fires that have endangered remote US Air Force sites equipped with radioisotope thermoelectric generators (RTGs) has prompted the assessment of power generating systems as substitutes for RTGs in small scale (10--120 watt) applications. A team of scientists and engineers of the US Air Forces' Wright Laboratory conductd an assessment of electrical power technologies for use by the Air Force in remote, harsh environments. The surprisingly high logistics costs of operating fossil fuel generators resulted in the extension of the assessment to non-RTG sites. The candidate power sources must operate unattended for long periods at a high level of operational reliability. Selection of the optimum power generation technology is complicated and heavily driven by the severe operating environment and compounded by the remoteness of the location. It is these site-related characteristics, more than any other, that drive the selection of a safe and economical power source for Arctic applications. A number of proven power generation technologies were evaluated. The assessment concluded that RGTs are clearly the safest, most reliable, and most economical approach to supplying electrical power for remote, difficult to assess locations. The assessment also indicated that the logistics costs associated with combustion driven generator systems could be substantially reduced through the use of conversion technologies which have been previously developed for space power applications. copyright 1995 American Institute of Physics

  18. A comparison of working in small-scale and large-scale nursing homes: A systematic review of quantitative and qualitative evidence.

    Vermeerbergen, Lander; Van Hootegem, Geert; Benders, Jos

    2017-02-01

    Ongoing shortages of care workers, together with an ageing population, make it of utmost importance to increase the quality of working life in nursing homes. Since the 1970s, normalised and small-scale nursing homes have been increasingly introduced to provide care in a family and homelike environment, potentially providing a richer work life for care workers as well as improved living conditions for residents. 'Normalised' refers to the opportunities given to residents to live in a manner as close as possible to the everyday life of persons not needing care. The study purpose is to provide a synthesis and overview of empirical research comparing the quality of working life - together with related work and health outcomes - of professional care workers in normalised small-scale nursing homes as compared to conventional large-scale ones. A systematic review of qualitative and quantitative studies. A systematic literature search (April 2015) was performed using the electronic databases Pubmed, Embase, PsycInfo, CINAHL and Web of Science. References and citations were tracked to identify additional, relevant studies. We identified 825 studies in the selected databases. After checking the inclusion and exclusion criteria, nine studies were selected for review. Two additional studies were selected after reference and citation tracking. Three studies were excluded after requesting more information on the research setting. The findings from the individual studies suggest that levels of job control and job demands (all but "time pressure") are higher in normalised small-scale homes than in conventional large-scale nursing homes. Additionally, some studies suggested that social support and work motivation are higher, while risks of burnout and mental strain are lower, in normalised small-scale nursing homes. Other studies found no differences or even opposing findings. The studies reviewed showed that these inconclusive findings can be attributed to care workers in some

  19. Small-Scale Spray Releases: Additional Aerosol Test Results

    Schonewill, Philip P.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, G. N.; Mahoney, Lenna A.; Tran, Diana N.; Burns, Carolyn A.; Kurath, Dean E.

    2013-08-01

    One of the events postulated in the hazard analysis at the Waste Treatment and Immobilization Plant (WTP) and other U.S. Department of Energy (DOE) nuclear facilities is a breach in process piping that produces aerosols with droplet sizes in the respirable range. The current approach for predicting the size and concentration of aerosols produced in a spray leak involves extrapolating from correlations reported in the literature. These correlations are based on results obtained from small engineered spray nozzles using pure liquids with Newtonian fluid behavior. The narrow ranges of physical properties on which the correlations are based do not cover the wide range of slurries and viscous materials that will be processed in the WTP and across processing facilities in the DOE complex. To expand the data set upon which the WTP accident and safety analyses were based, an aerosol spray leak testing program was conducted by Pacific Northwest National Laboratory (PNNL). PNNL’s test program addressed two key technical areas to improve the WTP methodology (Larson and Allen 2010). The first technical area was to quantify the role of slurry particles in small breaches where slurry particles may plug the hole and prevent high-pressure sprays. The results from an effort to address this first technical area can be found in Mahoney et al. (2012a). The second technical area was to determine aerosol droplet size distribution and total droplet volume from prototypic breaches and fluids, including sprays from larger breaches and sprays of slurries for which literature data are largely absent. To address the second technical area, the testing program collected aerosol generation data at two scales, commonly referred to as small-scale and large-scale. The small-scale testing and resultant data are described in Mahoney et al. (2012b) and the large-scale testing and resultant data are presented in Schonewill et al. (2012). In tests at both scales, simulants were used to mimic the

  20. Responsive design high performance

    Els, Dewald

    2015-01-01

    This book is ideal for developers who have experience in developing websites or possess minor knowledge of how responsive websites work. No experience of high-level website development or performance tweaking is required.

  1. High Performance Macromolecular Material

    Forest, M

    2002-01-01

    .... In essence, most commercial high-performance polymers are processed through fiber spinning, following Nature and spider silk, which is still pound-for-pound the toughest liquid crystalline polymer...

  2. Techno-economic feasibility study of the integration of a commercial small-scale ORC in a real case study

    Cavazzini, G.; Dal Toso, P.

    2015-01-01

    Highlights: • The integration of a small-scale commercial ORC in a real case study was analyzed. • The possibility of recovering the waste heat produced by an ICE was considered. • A semi-empirical steady-state model of the commercial small scale ORC was created. • Both direct and indirect costs was considered in the business model. • The ORC integration was not economically feasible due to increased indirect costs. - Abstract: The ORC certainly represents a promising solution for recovering low-grade waste heat in industries. However, the efficiency of commercial small-scale ORC solutions is still too low in comparison with the high initial costs of the machine and the lack of simulation models specifically developed for commercial ORC systems prevents industries from defining an accurate business model to correctly evaluate the ORC integration in real industrial processes. This paper presents a techno-economic feasibility analysis of the integration of a small-scale commercial ORC in a real case study, represented by a highly-efficient industrial distillery. The integration is aimed at maximizing the electricity auto-production by exploiting the heat produced by an internal combustion engine, already partially recovered in internal thermal processes. To analyze the influence of the ORC integration on the industrial processes, a semi-empirical steady-state model of the commercial small scale ORC was created. The model made it possible to simulate the performance of the commercial ORC within a hypothetical scenario involving the use of the heat from the cooling water and from the exhaust gases of the internal combustion engine. A detailed thermo-dynamic analysis has been carried out to study the effects of the ORC integration on the plant’s energy system with particular focus on the two processes directly affected by ORC integration, namely vapor production and the drying process of the grape marc. The analysis highlighted the great importance in the

  3. Small-scale field-aligned currents observed by the AKEBONO (EXOS-D) satellite

    Fukunishi, H.; Oya, H.; Kokubun, S.; Tohyama, F.; Mukai, T.; Fujii, R.

    1991-01-01

    The EXOS-D fluxgate magnetometer data obtained at 3,000-10,000 km altitude have shown that small-scale field-aligned currents always exist in large-scale region 1, region 2, cusp and polar cap current systems. Assuming that these small-scale field-aligned currents have current sheet structure, the width of current sheet is estimated to be 5-20 km at ionospheric altitude. By comparing the magnetometer data with charged particle and high frequency plasma wave data simultaneously obtained from EXOS-D, it is found that small-scale currents have one-to-one correspondence with localized electron precipitation events characterized by flux enhancement over a wide energy range from 10 eV to several keV and broadband electrostatic bursts occasionally extending above local plasma frequencies or electron cyclotron frequencies

  4. Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration

    Green, David W.; Lee, Jung-Seok; Jung, Han-Sung

    2016-01-01

    The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a “water-tight” barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachment complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia, and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organizing cell–cell connections, cell–matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption, and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis. PMID:26903872

  5. Small Scale Turbopump Manufacturing Technology and Material Processes

    Alvarez, Erika; Morgan, Kristin; Wells, Doug; Zimmerman, Frank

    2011-01-01

    As part of an internal research and development project, NASA Marshall Space Flight Center (MSFC) has been developing a high specific impulse 9,000-lbf LOX/LH2 pump-fed engine testbed with the capability to throttle 10:1. A Fuel Turbopump (FTP) with the ability to operate across a speed range of 30,000-rpm to 100,000-rpm was developed and analyzed. This small size and flight-like Fuel Turbopump has completed the design and analysis phase and is currently in the manufacturing phase. This paper highlights the manufacturing and processes efforts to fabricate an approximately 20-lb turbopump with small flow passages, intricately bladed components and approximately 3-in diameter impellers. As a result of the small scale and tight tolerances of the hardware on this turbopump, several unique manufacturing and material challenges were encountered. Some of the technologies highlighted in this paper include the use of powder metallurgy technology to manufacture small impellers, electron beam welding of a turbine blisk shroud, and casting challenges. The use of risk reduction efforts such as non-destructive testing (NDT) and evaluation (NDE), fractography, material testing, and component spin testing are also discussed in this paper.

  6. Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration

    David William Green

    2016-02-01

    Full Text Available The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a water-tight barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachement complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement.. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organising cell-cell connections, cell-matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis.

  7. Numerical simulation of a small-scale biomass boiler

    Collazo, J.; Porteiro, J.; Míguez, J.L.; Granada, E.; Gómez, M.A.

    2012-01-01

    Highlights: ► Simplified model for biomass combustion was developed. ► Porous zone conditions are used in the bed. ► Model is fully integrated in a commercial CFD code to simulate a small scale pellet boiler. ► Pollutant emissions are well predicted. ► Simulation provides extensive information about the behaviour of the boiler. - Abstract: This paper presents a computational fluid dynamic simulation of a domestic pellet boiler. Combustion of the solid fuel in the burner is an important issue when discussing the simulation of this type of system. A simplified method based on a thermal balance was developed in this work to introduce the effects provoked by pellet combustion in the boiler simulation. The model predictions were compared with the experimental measurements, and a good agreement was found. The results of the boiler analysis show that the position of the water tubes, the distribution of the air inlets and the air infiltrations are the key factors leading to the high emission levels present in this type of system.

  8. Impact of small-scale structures on estuarine circulation

    Liu, Zhuo; Zhang, Yinglong J.; Wang, Harry V.; Huang, Hai; Wang, Zhengui; Ye, Fei; Sisson, Mac

    2018-05-01

    We present a novel and challenging application of a 3D estuary-shelf model to the study of the collective impact of many small-scale structures (bridge pilings of 1 m × 2 m in size) on larger-scale circulation in a tributary (James River) of Chesapeake Bay. We first demonstrate that the model is capable of effectively transitioning grid resolution from 400 m down to 1 m near the pilings without introducing undue numerical artifact. We then show that despite their small sizes and collectively small area as compared to the total channel cross-sectional area, the pilings exert a noticeable impact on the large-scale circulation, and also create a rich structure of vortices and wakes around the pilings. As a result, the water quality and local sedimentation patterns near the bridge piling area are likely to be affected as well. However, when evaluating over the entire waterbody of the project area, the near field effects are weighed with the areal percentage which is small compared to that for the larger unaffected area, and therefore the impact on the lower James River as a whole becomes relatively insignificant. The study highlights the importance of the use of high resolution in assessing the near-field impact of structures.

  9. Performance Evaluation of a Small Scale Modular Solar Trigeneration System

    Handong Wang

    2014-01-01

    Full Text Available In order to improve the efficiency of solar thermal power (STP system, a novel modular system combining cooling, heating, and power generation (CCHP is proposed and introduced in this work. This modular CCHP system can simultaneously provide 10 kW electricity, −15~5°C coolant, and 60°C hot water to meet the requirements of cooling, heating, and electricity in a general family or other fields. The flow chart and working process of the modular system are introduced, based on which the energy and exergy efficiencies at the CCHP and STP operation modes are primarily evaluated and discussed. The results show that when the output electricity is constant, the overall efficiencies of energy and exergy of the system operating at the CCHP mode are 9.37 times and 2.62 times as big as those of the system operating at the STP mode, respectively. Thus, the modular solar thermal CCHP system can improve the energy and exergy efficiencies. Furthermore, calculation shows that both the overall energy and exergy efficiencies decrease with increase of inlet vapor temperature at given inlet vapor pressure, but both the efficiencies increase with increase of inlet vapor pressure at given inlet temperature.

  10. Catalytically supported reduction of emissions from small-scale biomass furnace systems

    Hartmann, Ingo; Lenz, Volker; Schenker, Marian; Thiel, Christian; Kraus, Markus; Matthes, Mirjam; Roland, Ulf; Bindig, Rene; Einicke, Wolf-Dietrich

    2011-01-01

    The increased use of solid biomass in small combustion for generating heat from renewable energy sources is unfortunately associated with increased emissions of airborne pollutants. The reduction is possible on the one hand by the use of high-quality modern furnaces to the latest state of the art. On the other hand, several promising approaches method for retrofitting small-scale furnaces are currently being developed that will allow an effective emission reduction by the subsequent treatment of the exhaust gas. The overview of current available emission control technologies for small-scale biomass combustion plants shows that there is still considerable need for research on the sustainable production of heat from solid biofuels. The amendment to the 1st BImSchV provides a necessary drastic reduction of discharged pollutants from small-scale biomass furnaces. When using the fuel wood in modern central heating boilers the required limits can be met at full load. However, dynamic load changes can cause brief dramatic emission increases even with wood central heating boilers. Firebox and control optimization must contribute in the future to a further reduction of emissions. The typical simple single-room fireplaces like hand-fed wood stoves are suitable under type test conditions to comply the limit values. By contrast, in practical operation, the harmful gas emissions be exceeded without secondary measures normally. The performed experimental investigations show that a reduction of both CO and of organic compounds by catalytic combustion is possible. In addition to developing specially adapted catalysts, it is necessary to provide additional dust separation by combined processes, since conventional catalysts are not suitable for deposition and retention of particulate matter or would lose their activity due to dust accumulation on the active surface, when the catalyst would act as a filter at the same time. To enable sufficiently high reaction temperatures and thus a

  11. A review of mercury exposure among artisanal small-scale gold miners in developing countries

    Kristensen, Anders Kasper Bruun; Thomsen, Jane Frølund; Mikkelsen, Sigurd

    2014-01-01

    Extraction of gold using mercury has been a way out of poverty for millions of people in developing countries. Artisanal small-scale gold mining (ASGM) has expanded during the last decades and is often carried out under primitive conditions. Thus, workers in this industry may be exposed to high...... levels of mercury and suffer from toxic effects from mercury exposure. The objective of this review was to provide an outline of the studies available on elemental mercury exposure among artisanal small-scale gold miners....

  12. Small-Scale Bullying Prevention Discussion Video for Classrooms: A Preliminary Evaluation

    Migliaccio, Todd; Raskauskas, Juliana

    2013-01-01

    Bullying has been shown to be negatively related to both academic performance and attendance among students. The present study examined a small-scale bullying intervention using a video-discussion model. Eighty-one students in grades 4 through 6 completed pre- and posttests examining gains in knowledge of bullying and responses to it. Results…

  13. Energy transfers and magnetic energy growth in small-scale dynamo

    Kumar, Rohit Raj; Verma, Mahendra K.; Samtaney, Ravi

    2013-01-01

    In this letter we investigate the dynamics of magnetic energy growth in small-scale dynamo by studying energy transfers, mainly energy fluxes and shell-to-shell energy transfers. We perform dynamo simulations for the magnetic Prandtl number Pm = 20

  14. Estimating the “Forgone” ESVs for Small-Scale Gold Mining Using Historical Image Data

    Ernest Frimpong Asamoah

    2017-10-01

    Full Text Available Ghana’s economic development relies largely on the mining industry, but the ecological cost is very high, particularly for the small-scale sector. To ascertain and give an account of the ecological pressures from the small-scale gold mining sector, we quantified and appraised the ecosystems (land cover types degradation due to mining land use along portions of the renowned Pra River basin of Ghana. The study classified and analysed high-quality Landsat image data (1986–2016 to monitor processes and changes in the river basin and adopted the Ecosystem Service Value (ESV model to quantify the forgone value in monetary term. The results revealed that the initial ESV of 17.69 million US$ in 1986 increased to 18.40 million US$ in 2002 for the study landscape with the small-scale mining sector accounting for 8.4% of the trade-off costs. The expansion of forest areas and its higher value coefficient (VC was, however, prevalent and this resulted in a net positive change during this period. However, in 2016, out of the total ESV of 14.63 million US$ obtained, the small-scale mining activities accounted for 36.8% of the trade-off costs. The substantial increase in trade-off costs with a subsequent decrease in ESV in the study landscape, following the intensification of small-scale gold mining, indicates that their activities have been degrading the watershed ecosystem and are, therefore, unsustainable. The study affirms the need for policymakers/government to review the laws, particularly on post-mining monitoring schemes to deter illegal miners and support the registered small-scale miners who are willing to implement land rehabilitation activities.

  15. Engineering development for a small-scale recirculator experiment

    Newton, M.A.; Deadrick, F.J.; Hanks, R.L.; Hawkins, S.A.; Holm, K.A.; Kirbie, H.C.; Karpenko, V.P.; Nattrass, L.A.; Longinotti, D.B.

    1995-01-01

    Lawrence Livermore National Laboratory (LLNL) is evaluating the physics and technology of recirculating induction accelerators for heavy-ion inertial-fusion drivers. As part of this evaluation, the authors are building a small-scale recirculator to demonstrate the concept and to use as a test bed for the development of recirculator technologies. System designs have been completed and components are presently being designed and developed for the small-scale recirculator. This paper discusses results of the design and development activities that are presently being conducted to implement the small-scale recirculator experiments. An, overview of the system design is presented along with a discussion of the implications of this design on the mechanical and electrical hardware. The paper focuses primarily on discussions of the development and design of the half-lattice period hardware and the advanced solid-state modulator

  16. CO2-impacts of a small-scale consumers levy

    1995-02-01

    Because of a number of developments (altered budgets of Dutch ministries and implementation of environmental policy plans of energy distribution companies in the Netherlands) the 1993 analyses of the effects of a small-scale consumer levy on the emission of CO 2 are updated. First, attention is paid to the conservation impetus as a result of an increase of the energy price for small-scale consumers. Next, the effects that can occur as a consequence of the presently suggested form of the levy (in particular, the exemption of renewable energy and waste heat) are discussed. Subsequently, the alterations of other policy tools, that are necessary in case a higher effectiveness of conservation measures is realized, are dealt with. The direct effect of a higher energy price on the saving behavior of the small-scale consumers is calculated by means of the CENECA-model. 4 tabs., 1 appendix, 8 refs

  17. Small scale wood combustion in Germany. Recent research and trends

    Maier, H.; Unterberger, S.; Hein, K.R.G. [Institute of Process Engineering and Power Plant Technology, University of Stuttgart (Germany)

    1998-12-31

    To reduce Europe`s greenhouse gas emission CO{sub 2} it is a challenging task utilising biomass fuels as there are wood or wood residues from the forest industry. The utilisation can be done either in commercially operated medium (> 50 kWth) or full scale (> 1 MWth) decentralised heat and power stations or in small scale (< 50 kWth) domestic heating systems. In small scale heating systems untreated wood logs, wood briquette or wood pellets and in few cases wood chips are used. The present market in Germany is focused on the use of wood logs. Presently, the use of wood pellets in small scale automatically operated boilers < 15 kW especially for low energy houses is discussed more and more. Since 1980 the installation of new wood fired small scale domestic heating systems reached a significant size due to the interest of the customers to have a alternative inhouse heating system and to increase the living comfort. In 1994 the amount of sold small scale heaters in Germany were in total about 133.258 units. The thermal power of in 1994 sold units is estimated of about 1350 MW which is a significant size in total with regard to domestic heating purposes. Since few years there is a clear market trend in Germany towards the installation of open fire stoves. Due to this trend in Germany and the design characteristic of open fire stoves using huge glass doors of glass windows it is very difficult to achieve a further reduction of emissions like CO and unburned volatile hydrocarbons (VOC). In the text the requirements for modern small scale wood fired stoves in Germany as well as the actual stage and trend of research and development (R and D) are discussed 4 refs.

  18. Still Another Book of Small-Scale Motets

    Rodríguez-Garcia, Esperanza

    2016-01-01

    UID/EAT/00693/2013 PTDC/CPC-MMU/0314/2014 ‘Still another book of small-scale motets: Sebastián Raval’s Motecta (1600)’ Lodovico Viadana’s Cento concerti ecclesiastici (Venice: Giacomo Vincenti, 1602), a collection of small-scale motets with basso continuo, is still considered ‘chronologically the first publication to include a basso continuo with sacred vocal music’. It has become the epitome of the advent of the Baroque in Italian sacred music. But, as has been argued in recent times, ...

  19. Gas explosion characterization, wave propagation (small-scale experiments)

    Larsen, G.C.

    1985-01-01

    A number of experiments have been performed with blast waves arising from the ignition of homogeneous and well defined mixtures of methane, oxygen and nitrogen, contained within spherical balloons with controlled initial dimensions. In the initial small scale experiments pressure characteristics, ground reflection phenomena and pressure distribution on box like obstacles were studied. Both configurations with one box and two closely spaced boxes have been considered, and a wave-wave interaction phenomenom was observed in the case of closely spaced obstacles. Main emphasis has been placed on the half scale field experiments. In these, the maximum flame speed has been of the order of 100 m/s, resulting in positive peak pressures of 50-100.10 2 Pa in 5 - 10 m distance from the source. The explosion process was found to be reasonable symmetric. The attenuation of the blast wave due to vegetation and the influence of obstacles as banks, walls and houses on the pressure field have been investigated. The presence of the bank and the house was felt in a zone with a length corresponding to a typical dimension of the obstacles, whereas the overall pressure field is shown to be unaffected by the type of obstacles and vegetation investigated. For the wall and house, reflection factors have been established, and some variation over the surface has been measured. The scatter of the pressure measurements is estimated for stable, neutral and unstable atmospheric conditions, and an attempt to determine the ground reflection factor has been performed. Finally the accelerations of a house exposed to the blast wave have been examined

  20. Clojure high performance programming

    Kumar, Shantanu

    2013-01-01

    This is a short, practical guide that will teach you everything you need to know to start writing high performance Clojure code.This book is ideal for intermediate Clojure developers who are looking to get a good grip on how to achieve optimum performance. You should already have some experience with Clojure and it would help if you already know a little bit of Java. Knowledge of performance analysis and engineering is not required. For hands-on practice, you should have access to Clojure REPL with Leiningen.

  1. Small scale combustion of solid biofuels; Smaaskalig foerbraenning av fasta biobraenslen

    2010-12-15

    The purpose of this assignment is to explore the need and the consequences of giving municipalities more power to intervene in the case of individual plants of local heating creates a nuisance in the surrounding areas as high emissions of hazardous air pollutants. The mission does not include an analysis of general instruments for small-scale combustion of biofuels

  2. High Performance Concrete

    Traian Oneţ

    2009-01-01

    Full Text Available The paper presents the last studies and researches accomplished in Cluj-Napoca related to high performance concrete, high strength concrete and self compacting concrete. The purpose of this paper is to raid upon the advantages and inconveniences when a particular concrete type is used. Two concrete recipes are presented, namely for the concrete used in rigid pavement for roads and another one for self-compacting concrete.

  3. High performance polymeric foams

    Gargiulo, M.; Sorrentino, L.; Iannace, S.

    2008-01-01

    The aim of this work was to investigate the foamability of high-performance polymers (polyethersulfone, polyphenylsulfone, polyetherimide and polyethylenenaphtalate). Two different methods have been used to prepare the foam samples: high temperature expansion and two-stage batch process. The effects of processing parameters (saturation time and pressure, foaming temperature) on the densities and microcellular structures of these foams were analyzed by using scanning electron microscopy

  4. The UNDP/World Bank monitoring program on small scale biomass gasifiers (BTG's experience on tar measurements)

    Knoef, H.A.M. [Biomass Technology Group BTG, Enschede (Netherlands)

    2000-07-01

    By the time that small-scale biomass gasifiers were 'rediscovered' and promoted for use in developing countries (1970s), UNDP and the World Bank were well aware of the pitfalls of previous attempts to diffuse decentralized energy technologies. Therefore they decided to initiate a technology assessment programme before endorsing and/or stimulating a widespread gasifier introduction programme in developing countries. On July 1, 1983, the UNDP/WB worldwide Small-scale biomass gasifier monitoring was initiated, which was to {sup c}ollect uniform data on the actual field performance, economics, safety and public acceptability of biomass gasifiers currently operating in developing countries{sup .} For the UNDP/WB program BTG developed a tar measuring protocol which was used at twenty gasifiers worldwide (Indonesia, Philippines, Brazil, Mali, Seychelles, Vanuatu and Burundi). Other parameters monitored include pressure and temperatures at various spots, gasflow, fuel consumption, lubrication oil analyses, gas-composition analyses, emission measurements. The seven year programme showed that most of donor funded projects failed, mainly because there was not sufficient commitment from involved parties. National programs on the utilization of loca available biomass resources mostly failed because the fuel did not suit the requirements of gasifier reactor. In case of proper project design/set-up most of the small scale biomass gasifiers operated without major problems. Examples of such projects are the ones in Balong and Majalengka (Indonesia) Onesua (Vanuatu), Espara Feliz (Brazil) and Dogofiry (Mali). A motivated team of technicians, operators, managers is one the most important items within this respect. Most of the heat gasifiers are installed commercially and are much more successful compared to the subsidized power gasifiers. Local manufactured gasifiers are generally constructed of low quality materials causing frequent technical problems. However, locally

  5. High performance conductometry

    Saha, B.

    2000-01-01

    Inexpensive but high performance systems have emerged progressively for basic and applied measurements in physical and analytical chemistry on one hand, and for on-line monitoring and leak detection in plants and facilities on the other. Salient features of the developments will be presented with specific examples

  6. Danish High Performance Concretes

    Nielsen, M. P.; Christoffersen, J.; Frederiksen, J.

    1994-01-01

    In this paper the main results obtained in the research program High Performance Concretes in the 90's are presented. This program was financed by the Danish government and was carried out in cooperation between The Technical University of Denmark, several private companies, and Aalborg University...... concretes, workability, ductility, and confinement problems....

  7. High performance homes

    Beim, Anne; Vibæk, Kasper Sánchez

    2014-01-01

    . Consideration of all these factors is a precondition for a truly integrated practice and as this chapter demonstrates, innovative project delivery methods founded on the manufacturing of prefabricated buildings contribute to the production of high performance homes that are cost effective to construct, energy...

  8. Foliage and Grass as Fuel Pellets–Small Scale Combustion of Washed and Mechanically Leached Biomass

    Jan Hari Arti Khalsa

    2016-05-01

    Full Text Available The high contents of disadvantageous elements contained in non-woody biomass are known to cause problems during small and large scale combustion, typically resulting in a higher risk of slagging, corrosion, and increased emissions. Mechanically leaching the respective elements from the biomass through a sequence of process steps has proven to be a promising solution.The florafuel process used here is comprised of size reduction followed by washing and subsequent mechanical dewatering of the biomass. Densification of the upgraded biomass into standardized pellets (Ø 6mm enables an application in existing small-scale boilers. The presented combustion trials investigated the performance of pellets made from leached grass, foliage and a mixture of both in two small-scale boilers (<100 kWth with slightly different technology (moving grate versus water-cooled burner tube during a 4-h measurement period. Emissions were in accordance with German emissions standards except for NOx (threshold is 0.50 g/m3 in the case of pure grass pellets (0.51 g/m3 and particulate matter (PM in all but one case (foliage, 13–16 mg/m3. An electrostatic precipitator (ESP unit installed with one of the boilers successfully reduced PM emission of both the grass and mixture fuel below the threshold of 20 mg/m3 (all emission values refer to 13 vol.% O2, at standard temperature and pressure (STP. Bottom ash composition and grate temperature profiles were analyzed and discussed for one of the boilers.

  9. Road network selection for small-scale maps using an improved centrality-based algorithm

    Roy Weiss

    2014-12-01

    Full Text Available The road network is one of the key feature classes in topographic maps and databases. In the task of deriving road networks for products at smaller scales, road network selection forms a prerequisite for all other generalization operators, and is thus a fundamental operation in the overall process of topographic map and database production. The objective of this work was to develop an algorithm for automated road network selection from a large-scale (1:10,000 to a small-scale database (1:200,000. The project was pursued in collaboration with swisstopo, the national mapping agency of Switzerland, with generic mapping requirements in mind. Preliminary experiments suggested that a selection algorithm based on betweenness centrality performed best for this purpose, yet also exposed problems. The main contribution of this paper thus consists of four extensions that address deficiencies of the basic centrality-based algorithm and lead to a significant improvement of the results. The first two extensions improve the formation of strokes concatenating the road segments, which is crucial since strokes provide the foundation upon which the network centrality measure is computed. Thus, the first extension ensures that roundabouts are detected and collapsed, thus avoiding interruptions of strokes by roundabouts, while the second introduces additional semantics in the process of stroke formation, allowing longer and more plausible strokes to built. The third extension detects areas of high road density (i.e., urban areas using density-based clustering and then locally increases the threshold of the centrality measure used to select road segments, such that more thinning takes place in those areas. Finally, since the basic algorithm tends to create dead-ends—which however are not tolerated in small-scale maps—the fourth extension reconnects these dead-ends to the main network, searching for the best path in the main heading of the dead-end.

  10. Üstverinin Tam-Metin Bilgi Erişim Performansı Üzerindeki Etkisi: Küçük Ölçekli Türkçe Külliyat Üzerinde Deneysel Bir Araştırma / Impact of Metadata on Full-text Information Retrieval Performance: An Experimental Research on a Small Scale Turkish Corpus

    Çapkın, Çağdaş

    2016-01-01

    Information institutions use text-based information retrieval systems to store, index and retrieve metadata, full-text, or both metadata and full-text (hybrid) contents. The aim of this research was to evaluate impact of these contents on information retrieval performance. For this purpose, metadata (MIR), full-text (FIR) and hybrid (HIR) content information retrieval systems were developed with default Lucene information retrieval model for a small scale Turkish corpus. In order to evaluate ...

  11. Small-Scale Helicopter Automatic Autorotation : Modeling, Guidance, and Control

    Taamallah, S.

    2015-01-01

    Our research objective consists in developing a, model-based, automatic safety recovery system, for a small-scale helicopter Unmanned Aerial Vehicle (UAV) in autorotation, i.e. an engine OFF flight condition, that safely flies and lands the helicopter to a pre-specified ground location. In pursuit

  12. Risk management strategies utilized by small scale poultry farmers ...

    Birds can only tolerate narrow temperature changes; therefore, poultry flocks are vulnerable to climate induced risk. This study investigated risk management strategies utilized by small scale poultry farmers in Oyo state. A total of 118 respondents were sampled using multi stage sampling procedure. Interview schedule was ...

  13. Effects of artisanal small-scale gold mining on fisheries ...

    Artisanal Small-scale Gold Mining (ASGM) has direct and indirect impacts on fisheries management. These impacts are mainly about the quality of the water where fish lives, ownership of the surrounding waters, land and human health. This study was carried out in two landing sites of Wagusu and Riskis Kogwari in ...

  14. Characteristics of small-scale palm oil production enterprise in ...

    The study examined characteristics of small-scale palm oil production enterprise in Anambra State, Nigeria. All the palm oil producers in Anambra State formed the population of the study. Multi-stage sampling technique was used to select 120 respondents for the study. Data were collected from primary source through ...

  15. Productivity and production efficiency among small scale irrigated ...

    The study examined productivity and production efficiency among small scale irrigated sugarcane farmers in Niger State, Nigeria using a stochastic translog frontier function. Data for the study were obtained using structured questionnaires administered to 100 randomly selected sugarcane farmers from Paiko and Gurara ...

  16. Productive Efficiency of Small Scale Sawmilling Industries in Mufindi ...

    A structured questionnaire was used to collect data from 80 small-scale sawmills in Mufindi District. Data were analysed using descriptive as well as quantitative methods. Technical, scale and allocative efficiency score of sawmills were computed using data envelopment analysis programme developed by Coelli. Censored ...

  17. Economic Analysis of Small Scale Egg Production in Gombe Local ...

    This study was conducted to determine the economic profitability of small-scale egg production in Gombe L.G.A. Gombe State. Data were collected from 36 famers using simple random sampling technique. The data collected were analyzed using descriptive statistics, gross margin and farm financial ratio analysis. The study ...

  18. Small-scale Aquaculture to Strengthen Food Security in Cambodia ...

    Small-scale Aquaculture to Strengthen Food Security in Cambodia (CIFSRF) ... for their families' consumption in the same ponds as large fish, which can be sold for income. ... The project also studies opportunities to scale up the model for broader use ... Assessing improvements in nutrition outcomes following agricultural ...

  19. New perspectives in small-scale fisheries management: challenges ...

    This is in response to the recognition that conventional fisheries management is not equipped to deal with the complexities, uncertainties and challenges prevalent in small-scale fishery systems. Consequently, a new fisheries paradigm is emerging based on the principles and ideas underpinning systems thinking, ...

  20. Development and utilization of spring water in small scale supply ...

    Development and utilization of spring water in small scale supply scheme for the Kogi State Polytechnic, Lokoja, central Nigeria. Joseph Omada. Abstract. No Abstract. Journal of Mining and Geology 2005, Vol. 41(1): 131-135. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL ...

  1. Agricultural Credit Utilization among Small Scale Women Farmers in ...

    ... monitor regularly the disbursement of agricultural loan to women farmers at the appropriate planning season with reasonable interest charge and that extension agents should ensure that the loan is utilized for only agricultural purposes. Key words: Credit utilization, small-scale farmer's income generation, Niger State.

  2. Responsible and Sustainable Tourism : Strengthening Small-Scale ...

    Responsible and Sustainable Tourism : Strengthening Small-Scale ... to work with the Costa Rican association of small and medium tourism enterprises of the ... as the hub of a network of small service providers operating within the model. ... marketing and outreach, distance learning, and the integration of services that are ...

  3. Training needs of small scale poultry farmers on improved ...

    Poultry business is a job opportunity for numerous for earning income and ... needs of the small scale commercial poultry farmers to improve poultry production ... strategies (88%) while only 24.1% of the respondents need training on types of ...

  4. A Success Story of Organizing Small Scale Farmers in Kenya

    Buch-Hansen, Mogens

    2012-01-01

    , but not least to be used in PES schemes. The article emphasizes vertical integration and production diversification, enabling market conditions, and democratization as the main factors in KTDA’s success that could possibly be replicated in promoting small scale farmers participating in the post-Kyoto carbon...

  5. Designing of network planning system for small-scale manufacturing

    Kapulin, D. V.; Russkikh, P. A.; Vinnichenko, M. V.

    2018-05-01

    The paper presents features of network planning in small-scale discrete production. The procedure of explosion of the production order, considering multilevel representation, is developed. The software architecture is offered. Approbation of the network planning system is carried out. This system allows carrying out dynamic updating of the production plan.

  6. Work related injuries and associated factors among small scale ...

    Objective: This study aims to assess the magnitude of work related injury and associated factors among small scale industrial workers in Mizan-Aman town, Bench Maji Zone, Southwest Ethiopia. Method: A cross-sectional study design was conducted from February to May, 2016. Data was collected using a structured face to ...

  7. Development of small-scale fisheries in Yemen: An exploration

    Wagenaar, A.; Haese, D' M.F.C.

    2007-01-01

    Yemen is one of the poorest countries in the world. The development of its fishery sector is increasingly being mentioned as a source of livelihood creation. The aims of this paper are to: (a) provide an overview of the institutional environment in which small-scale fishermen in Yemen operate; (b)

  8. Smoke emissions in small-scale burning of wood

    Tuomi, S.

    1993-01-01

    The article is based on research carried out in Finland and Sweden on the subject of emissions of smoke in the small-scale burning of wood and the factors affecting it. Due to incomplete combustion, small-scale burning of wood is particularly typified by its emissions of solid particles, carbon monoxide, hydrocarbons and PAH compounds. Included among factors influencing the volume of emissions are the load imposed on the heating device, the manner in which the fuel is fed into the firebox, fuel quality, and heating device structure. Emissions have been found to be at their minimum in connection with heating systems based on accumulators. Emissions can be significantly reduced by employing state-of-the-art technology, appropriate ways of heating and by dry fuel. A six-year bioenergy research programme was launched early in 1993 in Finland. All leading research institutions and enterprises participate in this programme. Reduction of emissions has been set as the central goal in the part dealing with small-scale burning of wood. Application of catalytic combustion in Finnish-made heating devices is one of the programmes development targets. Up to this date, the emissions produced in the small-scale burning of wood are not mentioned in official regulations pertaining to approved heating devices. In Sweden tar emissions are applied as a measure of the environmental impact imposed by heating devices

  9. 2010 Thin Film & Small Scale Mechanical Behavior Gordon Research Conference

    Dr. Thomas Balk

    2010-07-30

    Over the past decades, it has been well established that the mechanical behavior of materials changes when they are confined geometrically at least in one dimension to small scale. It is the aim of the 2010 Gordon Conference on 'Thin Film and Small Scale Mechanical Behavior' to discuss cutting-edge research on elastic, plastic and time-dependent deformation as well as degradation mechanisms like fracture, fatigue and wear at small scales. As in the past, the conference will benefit from contributions from fundamental studies of physical mechanisms linked to material science and engineering reaching towards application in modern applications ranging from optical and microelectronic devices and nano- or micro-electrical mechanical systems to devices for energy production and storage. The conference will feature entirely new testing methodologies and in situ measurements as well as recent progress in atomistic and micromechanical modeling. Particularly, emerging topics in the area of energy conversion and storage, such as material for batteries will be highlighted. The study of small-scale mechanical phenomena in systems related to energy production, conversion or storage offer an enticing opportunity to materials scientists, who can provide new insight and investigate these phenomena with methods that have not previously been exploited.

  10. Assessment of Small-scale Buffalo Milk Dairy Production-A Premise for a Durable Development

    Marian MIHAIU

    2012-05-01

    Full Text Available Buffalo husbandry is an important source of income for a number of small-scale producers in Romania that is why an assessment of its products quality is much needed for improvement and evaluation of their vulnerability to international competition. In order to ascertain possible developments in the buffalo dairy sector and to broadly identify areas of intervention that favor small-scale dairy producers, the study examined the potential to improve buffalo milk production by evaluating its authenticity and hygienic quality. The methods used involved the molecular testing (PCR-technique for identifying cow, sheep or goat DNA in the dairy products samples collected from the small-scale producers market. The hygienic quality of these samples was determined through classical microbiology methods, highly developed techniques (Trek System and PCR for bacterial species confirmation. The results showed that a high percent (65%, from the products found were adulterated with other species milk, mostly cow milk. The most commonly falsified buffalo dairy products were the cheese and the traditional product telemea. The prevalence of the bacterial species identified belonged to Listeria innocua and Listeria welshmeri. The conclusion of this study is the need of a durable development system in this particular dairy chain to improve and assure the authenticity and quality of the small-scale producers products and their reliability for the consumers.

  11. Assessment of Small-scale Buffalo Milk Dairy Production-A Premise for a Durable Development

    Marian MIHAIU

    2012-05-01

    Full Text Available Buffalo husbandry is an important source of income for a number of small-scale producers in Romania that is why an assessment of its� product�s quality is much needed for improvement and evaluation of their vulnerability to international competition. In order to ascertain possible developments in the buffalo dairy sector and to broadly identify areas of intervention that favor small-scale dairy producers, the study examined the potential to improve buffalo milk production by evaluating its authenticity and hygienic quality. The methods used involved the molecular testing (PCR-technique for identifying cow, sheep or goat DNA in the dairy products� samples collected from the small-scale producers market. The hygienic quality of these samples was determined through classical microbiology methods, highly developed techniques (Trek System and PCR for bacterial species confirmation. The results showed that a high percent (65%, from the products found were adulterated with other species milk, mostly cow milk. The most commonly falsified buffalo dairy products were the cheese and the traditional product �telemea�. The prevalence of the bacterial species identified belonged to Listeria innocua and Listeria welshmeri. The conclusion of this study is the need of a durable development system in this particular dairy chain to improve and assure the authenticity and quality of the small-scale producers� products and their reliability for the consumers.

  12. Small-scale field evaluation of push-pull system against early- and outdoor-biting malaria mosquitoes in an area of high pyrethroid resistance in Tanzania [version 1; referees: 2 approved

    Arnold S. Mmbando

    2017-11-01

    Full Text Available Background: Despite high coverage of indoor interventions like insecticide-treated nets, mosquito-borne infections persist, partly because of outdoor-biting, early-biting and insecticide-resistant vectors. Push-pull systems, where mosquitoes are repelled from humans and attracted to nearby lethal targets, may constitute effective complementary interventions. Methods: A partially randomized cross-over design was used to test efficacy of push-pull in four experimental huts and four local houses, in an area with high pyrethroid resistance in Tanzania. The push-pull system consisted of 1.1% or 2.2% w/v transfluthrin repellent dispensers and an outdoor lure-and-kill device (odour-baited mosquito landing box. Matching controls were set up without push-pull. Adult male volunteers collected mosquitoes attempting to bite them outdoors, but collections were also done indoors using exit traps in experimental huts and by volunteers in the local houses. The collections were done hourly (1830hrs-0730hrs and mosquito catches compared between push-pull and controls. An. gambiae s.l. and An. funestus s.l. were assessed by PCR to identify sibling species, and ELISA to detect Plasmodium falciparum and blood meal sources. Results: Push-pull in experimental huts reduced outdoor-biting for An. arabiensis and Mansonia species by 30% and 41.5% respectively. However, the reductions were marginal and insignificant for An. funestus (12.2%; p>0.05 and Culex (5%; p>0.05. Highest protection against all species occurred before 2200hrs. There was no significant difference in number of mosquitoes inside exit traps in huts with or without push-pull. In local households, push-pull significantly reduced indoor and outdoor-biting of An. arabiensis by 48% and 25% respectively, but had no effect on other species. Conclusion: This push-pull system offered modest protection against outdoor-biting An. arabiensis, without increasing indoor mosquito densities. Additional experimentation

  13. High-Performance Networking

    CERN. Geneva

    2003-01-01

    The series will start with an historical introduction about what people saw as high performance message communication in their time and how that developed to the now to day known "standard computer network communication". It will be followed by a far more technical part that uses the High Performance Computer Network standards of the 90's, with 1 Gbit/sec systems as introduction for an in depth explanation of the three new 10 Gbit/s network and interconnect technology standards that exist already or emerge. If necessary for a good understanding some sidesteps will be included to explain important protocols as well as some necessary details of concerned Wide Area Network (WAN) standards details including some basics of wavelength multiplexing (DWDM). Some remarks will be made concerning the rapid expanding applications of networked storage.

  14. Sedimentary facies analysis of a high-frequency, small-scale, peritidal carbonate sequence in the Lower Jurassic of the Tripolis carbonate unit (central western Crete, Greece: Long-lasting emergence and fossil laminar dolocretes horizons

    Fotini A. Pomoni

    2016-07-01

    Full Text Available The study examines a Lower Jurassic (late Liassic cyclic lagoonal–peritidal stratigraphic unit outcropping in central western Crete (Tripolis unit, which corresponds to the eastern (internal part of the mainland Gavrovo-Tripolis platform, the most significant external platform of the Hellenides. The studied Tripolis carbonate sequence consists of meter-scale, shallowing-upward successions of restricted inner-carbonate platform facies, including cyclically repeated subtidal, intertidal and supratidal facies, that are separated by erosion surfaces (elementary cycles. Each cycle starts with relatively open-marine facies, which are overlain by shallower, more restricted facies (tidal flat progradation. The lithofacies association includes dolomitic intraclastic–peloidal–bioclastic wackestones–packstones/floatstones and grainstones/rudstones dominated by a restricted shallow-marine fauna (bivalves, gastropods, ostracods and seldom benthic foraminifers, representing a shallow subtidal to intertidal, moderately high-energy environment within an inner-platform setting (peritidal environment to restricted lagoon. This lithofacies association has been intermittently subaerially exposed and has undergone diagenetic processes in an inter- or supratidal environment, exhibiting features of vadose diagenesis and pedogenesis due to long-lasting exposure along certain horizons. The peritidal facies are capped by dolocretes controlled by root-activities (laminar dolocretes, peloidal–pisoid dolocretes and massive dolocretes, marking the end of each depositional cycle, and, thus, distinguishing the successive episodes of a prolonged subaerial exposure period and birth of paleosol horizons. Dolocretes consist a diagenetic facies, characterized by several vadose and pedogenic fabrics, including fenestral cavities with geopetal structures, “flower spar” to blocky sparry cement in primary pores, micritic coatings, crudely pelleted walls, alveolar

  15. Air pollution and economics: Alternate use of fuels in small scale industries

    Rao, B.P.S.; Pandit, V.I.

    1999-01-01

    In developing countries the problem of air pollution was recognized earlier, however, it has acquired a greater dimension due to the conventional use of low grade fuels like coal, baggase, rice husk, etc. having high sulphur and ash content. The industrial sources contribute about 30--40% of the total emissions. In India, the small scale industries (low investment group) contribute about 60--80% of the total industrial emissions. These industries are characterized with various environmental pollution problems due to cluster of small scale industries located in sensitive area; use of low grade fuel, primitive processing techniques without emission abatement facilities etc., thus leading to enormous pollution in an confined region. Acute need was felt to reduce the pollution problem associated with small scale industries by use of cleaner fuel so as to reduce the localized problem. The paper presents the emissions associated with use of coal/coke, natural gas, LPG, and propane along with the fuel cost for small scale industrial sector of Agra, Firozabad and Mathura region. The studies carried out would find applicability to meet the air pollution standards based on shift in fuel and associated cost

  16. Child Wasting in Emergency Pockets: A Meta-Analysis of Small-Scale Surveys from Ethiopia

    Chiara Altare

    2016-01-01

    Full Text Available Child undernutrition is a major public health concern in Ethiopia (stunting national prevalence: 44%; wasting: 10%, despite the overall improvement in child health status during the last decade. Hundreds of small-scale surveys are conducted in Ethiopia’s emergency pockets under ENCU’s supervision. We reviewed the evidence from small-scale surveys conducted between 2008 and 2013 with two objectives: to provide a summary estimate of wasting prevalence from emergency pockets and to examine reasons for variation in prevalence estimates. We created a dataset by combining data from the Complex Emergency Database, the Famine Early Warning System Network and the Armed Conflict Location Event Data. We conducted a meta-analysis of small-scale surveys using a random effects model with known within-study heterogeneity. The influence of survey covariates on estimated prevalence was investigated with meta-regression techniques. We included 158 surveys in the analysis. A high degree of heterogeneity among surveys was observed. The overall estimate of wasting prevalence was 10.6% (95% CI 9.8–11.4, with differences among regions and between residents and refugees. Meta-regression results showed that vaccination coverage, child mortality, diarrhea prevalence and food insecurity are significantly associated with wasting prevalence. Child care and displacement status were not. Aggregated analysis of small-scale surveys provides insights into the prevalence of wasting and factors explaining its variation. It can also guide survey planning towards areas with limited data availability.

  17. High performance data transfer

    Cottrell, R.; Fang, C.; Hanushevsky, A.; Kreuger, W.; Yang, W.

    2017-10-01

    The exponentially increasing need for high speed data transfer is driven by big data, and cloud computing together with the needs of data intensive science, High Performance Computing (HPC), defense, the oil and gas industry etc. We report on the Zettar ZX software. This has been developed since 2013 to meet these growing needs by providing high performance data transfer and encryption in a scalable, balanced, easy to deploy and use way while minimizing power and space utilization. In collaboration with several commercial vendors, Proofs of Concept (PoC) consisting of clusters have been put together using off-the- shelf components to test the ZX scalability and ability to balance services using multiple cores, and links. The PoCs are based on SSD flash storage that is managed by a parallel file system. Each cluster occupies 4 rack units. Using the PoCs, between clusters we have achieved almost 200Gbps memory to memory over two 100Gbps links, and 70Gbps parallel file to parallel file with encryption over a 5000 mile 100Gbps link.

  18. Leadership solves collective action problems in small-scale societies

    Glowacki, Luke; von Rueden, Chris

    2015-01-01

    Observation of leadership in small-scale societies offers unique insights into the evolution of human collective action and the origins of sociopolitical complexity. Using behavioural data from the Tsimane forager-horticulturalists of Bolivia and Nyangatom nomadic pastoralists of Ethiopia, we evaluate the traits of leaders and the contexts in which leadership becomes more institutional. We find that leaders tend to have more capital, in the form of age-related knowledge, body size or social connections. These attributes can reduce the costs leaders incur and increase the efficacy of leadership. Leadership becomes more institutional in domains of collective action, such as resolution of intragroup conflict, where collective action failure threatens group integrity. Together these data support the hypothesis that leadership is an important means by which collective action problems are overcome in small-scale societies. PMID:26503683

  19. Biofuels in Africa: growing small-scale opportunities

    Sulle, Emmanuel [Tanzania Natural Resources Forum (Tanzania, United Republic of); Fauveaud, Swan [Renewable Energy Group, Environment and Solidarity (France); Vermeulen, Sonja

    2009-11-15

    Global demand for climate-friendly transport fuels is driving vast commercial biofuels projects in developing countries. At the opposite end of the spectrum is small-scale bioenergy production. This offers a way for the poor to meet their energy needs and diversify their livelihoods without compromising food security or environmental integrity. Governments hope that it will be possible to combine the advantages of both large- and small-scale production of biofuels to generate energy security and GDP at the national level, while opening up local opportunities. In Africa, most governments are keen to attract foreign direct investment, and see big business as a strategic means of scaling up rural development. But there is a middle way. By encouraging business models that bridge large and small enterprise, African governments could show that commercial competition can go hand in hand with a range of real local benefits.

  20. Sustainability Metrics of a Small Scale Turbojet Engine

    Ekici, Selcuk; Sohret, Yasin; Coban, Kahraman; Altuntas, Onder; Karakoc, T. Hikmet

    2018-05-01

    Over the last decade, sustainable energy consumption has attracted the attention of scientists and researchers. The current paper presents sustainability indicators of a small scale turbojet engine, operated on micro-aerial vehicles, for discussion of the sustainable development of the aviation industry from a different perspective. Experimental data was obtained from an engine at full power load and utilized to conduct an exergy-based sustainability analysis. Exergy efficiency, waste exergy ratio, recoverable exergy ratio, environmental effect factor, exergy destruction factor and exergetic sustainability index are evaluated as exergetic sustainability indicators of the turbojet engine under investigation in the current study. The exergy efficiency of the small scale turbojet engine is calculated as 27.25 % whereas the waste exergy ratio, the exergy destruction factor and the sustainability index of the engine are found to be 0.9756, 0.5466 and 0.2793, respectively.

  1. Leadership solves collective action problems in small-scale societies.

    Glowacki, Luke; von Rueden, Chris

    2015-12-05

    Observation of leadership in small-scale societies offers unique insights into the evolution of human collective action and the origins of sociopolitical complexity. Using behavioural data from the Tsimane forager-horticulturalists of Bolivia and Nyangatom nomadic pastoralists of Ethiopia, we evaluate the traits of leaders and the contexts in which leadership becomes more institutional. We find that leaders tend to have more capital, in the form of age-related knowledge, body size or social connections. These attributes can reduce the costs leaders incur and increase the efficacy of leadership. Leadership becomes more institutional in domains of collective action, such as resolution of intragroup conflict, where collective action failure threatens group integrity. Together these data support the hypothesis that leadership is an important means by which collective action problems are overcome in small-scale societies. © 2015 The Author(s).

  2. Financing small-scale infrastructure investments in developing countries

    Daniel L. Bond; Daniel Platz; Magnus Magnusson

    2012-01-01

    In most developing countries a shortage of long-term, local-currency financing for small-scale infrastructure projects impedes local economic development. Inadequate fiscal transfers, little own source revenue and low creditworthiness make it difficult for local governments to fully fund projects on their own. This paper proposes the use of project finance as a means to attract financing from domestic banks and institutional investors. Donors can play a catalytic role by providing technical a...

  3. Managing Small-Scale Fisheries : Alternative Directions and Methods

    Managing Small-scale Fisheries va plus loin que le champ d'application de la gestion classique des pêches pour aborder d'autres concepts, outils, méthodes et ... Les gestionnaires des pêches, tant du secteur public que du secteur privé, les chargés de cours et les étudiants en gestion des pêches, les organisations et les ...

  4. Process improvement of knives production in a small scale industry

    Ananto, Gamawan; Muktasim, Irfan

    2017-06-01

    Small scale industry that produces several kinds of knive should increase its capacity due to the demand from the market. Qualitatively, this case study consisted of formulating the problems, collecting and analyzing the necessary data, and determining the possible recommendations for the improvement. While the current capacity is only 9 (nine), it is expected that 20 units of knife will produced per month. The processes sequence are: profiling (a), truing (b), beveling (c), heat treatment (d), polishing (e), assembly (f), sharpening (g) and finishing (h). The first process (a) is held by out-house vendor company while other steps from (b) to (g) are executed by in-house vendor. However, there is a high dependency upon the high skilled operator who executes the in -house processes that are mostly held manually with several unbalance successive tasks, where the processing time of one or two tasks require longer duration than others since the operation is merely relied on the operator's skill. The idea is the improvement or change of the profiling and beveling process. Due to the poor surface quality and suboptimal hardness resulted from the laser cut machine for profiling, it is considered to subst itute this kind of process with wire cut that is capable to obtain good surface quality with certain range levels of roughness. Through simple cutting experiments on the samples, it is expected that the generated surface quality is adequate to omit the truing process (b). In addition, the cutting experiments on one, two, and four test samples resulted the shortest time that was obtained through four pieces in one cut. The technical parameters were set according to the recommendation of machine standard as referred to samples condition such as thickness and path length that affect ed the rate of wear. Meanwhile, in order to guarantee the uniformity of knife angles that are formed through beveling process (c), a grinding fixture was created. This kind of tool diminishes the

  5. A computationally inexpensive CFD approach for small-scale biomass burners equipped with enhanced air staging

    Buchmayr, M.; Gruber, J.; Hargassner, M.; Hochenauer, C.

    2016-01-01

    Highlights: • Time efficient CFD model to predict biomass boiler performance. • Boundary conditions for numerical modeling are provided by measurements. • Tars in the product from primary combustion was considered. • Simulation results were validated by experiments on a real-scale reactor. • Very good accordance between experimental and simulation results. - Abstract: Computational Fluid Dynamics (CFD) is an upcoming technique for optimization and as a part of the design process of biomass combustion systems. An accurate simulation of biomass combustion can only be provided with high computational effort so far. This work presents an accurate, time efficient CFD approach for small-scale biomass combustion systems equipped with enhanced air staging. The model can handle the high amount of biomass tars in the primary combustion product at very low primary air ratios. Gas-phase combustion in the freeboard was performed by the Steady Flamelet Model (SFM) together with a detailed heptane combustion mechanism. The advantage of the SFM is that complex combustion chemistry can be taken into account at low computational effort because only two additional transport equations have to be solved to describe the chemistry in the reacting flow. Boundary conditions for primary combustion product composition were obtained from the fuel bed by experiments. The fuel bed data were used as fuel inlet boundary condition for the gas-phase combustion model. The numerical and experimental investigations were performed for different operating conditions and varying wood-chip moisture on a special designed real-scale reactor. The numerical predictions were validated with experimental results and a very good agreement was found. With the presented approach accurate results can be provided within 24 h using a standard Central Processing Unit (CPU) consisting of six cores. Case studies e.g. for combustion geometry improvement can be realized effectively due to the short calculation

  6. Manufacturing of small scale W monoblock mockups by hot radial pressing

    Visca, Eliseo; Testani, C.; Libera, S.; Sacchetti, M.

    2003-01-01

    In the frame of the European Technology R and D programme for International thermonuclear experimental reactor (ITER) and in the area of high heat flux plasma facing components (HHFC), representative small-scale mock-ups were manufactured and tested to compare different concepts and joining technologies (i.e. active brazing, hot isostatic pressing (HIPping), diffusion bonding, etc.). On the basis of the results obtained by thermal fatigue tests, the monoblock concept resulted to be the most robust one, particularly when the HIPping manufacturing technology is used. Within this programme, ENEA developed an alternative technique for manufacturing plasma-facing components with a monoblock geometry of the ITER machine. The basic idea of this technique, named hot radial pressing (HRP), is to perform a radial diffusion bonding between the cooling tube and the armour tile by pressurising the internal tube only and by keeping the process parameters within the range in which the thermo-mechanical properties of the copper alloys are not yet degraded. The HRP is performed by a standard furnace, in which only a section of the canister is heated. The manufacturing procedure and the results of the screening and fatigue thermal tests performed on the ENEA mock-ups are reported in this paper

  7. Empirical spatial econometric modelling of small scale neighbourhood

    Gerkman, Linda

    2012-07-01

    The aim of the paper is to model small scale neighbourhood in a house price model by implementing the newest methodology in spatial econometrics. A common problem when modelling house prices is that in practice it is seldom possible to obtain all the desired variables. Especially variables capturing the small scale neighbourhood conditions are hard to find. If there are important explanatory variables missing from the model, the omitted variables are spatially autocorrelated and they are correlated with the explanatory variables included in the model, it can be shown that a spatial Durbin model is motivated. In the empirical application on new house price data from Helsinki in Finland, we find the motivation for a spatial Durbin model, we estimate the model and interpret the estimates for the summary measures of impacts. By the analysis we show that the model structure makes it possible to model and find small scale neighbourhood effects, when we know that they exist, but we are lacking proper variables to measure them.

  8. The legalization of small scale mining in Colombia

    Alexandra Urán

    2013-11-01

    Full Text Available The following article presents conceptual and analytical elements that allow us to broaden the debate about the legalization of the mining in Colombia. Looking for items to be able to propose alternatives in order to consolidate a new mining process socially and environmentally sustainable, claiming the value of the ancestral practices and forms of the redistributive production. To this end, it is necessary to start with the discussion of the concepts of formalization and legality, so that we can generate a theoretical framework that will allow us to explore such delicate matter, we will continue to make the framework socio-political, in which it is based that strategy. Then there is a brief context of thereformulation of legal mining, focusing our attention particularly standards which involves or has effects on artisanal mining and/or small-scale mining. There we will find ourselves with a debate on the typology of the mining and the current difficulties to define schemasof legalization or formalization of small-scale mining in Colombia. To conclude with a proposal to formalize as a mechanism of transition to an administrative system - legislativethat will connect more effectively with the realities and skills of the ethnic communities that practice small-scale mining.

  9. a Model Study of Small-Scale World Map Generalization

    Cheng, Y.; Yin, Y.; Li, C. M.; Wu, W.; Guo, P. P.; Ma, X. L.; Hu, F. M.

    2018-04-01

    With the globalization and rapid development every filed is taking an increasing interest in physical geography and human economics. There is a surging demand for small scale world map in large formats all over the world. Further study of automated mapping technology, especially the realization of small scale production on a large scale global map, is the key of the cartographic field need to solve. In light of this, this paper adopts the improved model (with the map and data separated) in the field of the mapmaking generalization, which can separate geographic data from mapping data from maps, mainly including cross-platform symbols and automatic map-making knowledge engine. With respect to the cross-platform symbol library, the symbol and the physical symbol in the geographic information are configured at all scale levels. With respect to automatic map-making knowledge engine consists 97 types, 1086 subtypes, 21845 basic algorithm and over 2500 relevant functional modules.In order to evaluate the accuracy and visual effect of our model towards topographic maps and thematic maps, we take the world map generalization in small scale as an example. After mapping generalization process, combining and simplifying the scattered islands make the map more explicit at 1 : 2.1 billion scale, and the map features more complete and accurate. Not only it enhance the map generalization of various scales significantly, but achieve the integration among map-makings of various scales, suggesting that this model provide a reference in cartographic generalization for various scales.

  10. Flash hydropyrolysis of coal using a small scale of free fall reactor

    Miura, K.; Morozumi, F. [Kyoto University, Kyoto (Japan). Department of Chemical Engineering

    1998-07-01

    A small scale of high-pressure free fall reactor was developed for the flash hydropyrolysis of coal. Taiheiyo coal (a Japanese subbituminous coal) was pyrolysed under a high hydrogen pressure without difficulty by use of this reactor. The effect of gas atmosphere, residence time, pressure, and temperature on the product yield was examined in detail. A flash hydropyrolysis reaction model was developed based on the experimental data, and its validity was examined. 8 refs., 5 figs., 1 tab.

  11. High performance sapphire windows

    Bates, Stephen C.; Liou, Larry

    1993-02-01

    High-quality, wide-aperture optical access is usually required for the advanced laser diagnostics that can now make a wide variety of non-intrusive measurements of combustion processes. Specially processed and mounted sapphire windows are proposed to provide this optical access to extreme environment. Through surface treatments and proper thermal stress design, single crystal sapphire can be a mechanically equivalent replacement for high strength steel. A prototype sapphire window and mounting system have been developed in a successful NASA SBIR Phase 1 project. A large and reliable increase in sapphire design strength (as much as 10x) has been achieved, and the initial specifications necessary for these gains have been defined. Failure testing of small windows has conclusively demonstrated the increased sapphire strength, indicating that a nearly flawless surface polish is the primary cause of strengthening, while an unusual mounting arrangement also significantly contributes to a larger effective strength. Phase 2 work will complete specification and demonstration of these windows, and will fabricate a set for use at NASA. The enhanced capabilities of these high performance sapphire windows will lead to many diagnostic capabilities not previously possible, as well as new applications for sapphire.

  12. Passive Plasma Contact Mechanisms for Small-Scale Spacecraft

    McTernan, Jesse K.

    Small-scale spacecraft represent a paradigm shift in how entities such as academia, industry, engineering firms, and the scientific community operate in space. However, although the paradigm shift produces unique opportunities to build satellites in unique ways for novel missions, there are also significant challenges that must be addressed. This research addresses two of the challenges associated with small-scale spacecraft: 1) the miniaturization of spacecraft and associated instrumentation and 2) the need to transport charge across the spacecraft-environment boundary. As spacecraft decrease in size, constraints on the size, weight, and power of on-board instrumentation increase--potentially limiting the instrument's functionality or ability to integrate with the spacecraft. These constraints drive research into mechanisms or techniques that use little or no power and efficiently utilize existing resources. One limited resource on small-scale spacecraft is outer surface area, which is often covered with solar panels to meet tight power budgets. This same surface area could also be needed for passive neutralization of spacecraft charging. This research explores the use of a transparent, conductive layer on the solar cell coverglass that is electrically connected to spacecraft ground potential. This dual-purpose material facilitates the use of outer surfaces for both energy harvesting of solar photons as well as passive ion collection. Mission capabilities such as in-situ plasma measurements that were previously infeasible on small-scale platforms become feasible with the use of indium tin oxide-coated solar panel coverglass. We developed test facilities that simulate the space environment in low Earth orbit to test the dual-purpose material and the various application of this approach. Particularly, this research is in support of two upcoming missions: OSIRIS-3U, by Penn State's Student Space Programs Lab, and MiTEE, by the University of Michigan. The purpose of

  13. Experimental investigation of small-scale gasification of woody biomass

    Barrio, Maria

    2002-05-01

    A small-scale stratified down draft gasifier has been built and operated under stable conditions using wood pellets as fuel and air as gasification agent. The problems observed during the preliminary experiments have been described and explained; they are mainly related to the stability of the process. The stable operation of the gasifier has been characterised by the gas composition and the product gas tar and particle content. The biomass feeding rate has varied between 4,5 and 6,5 kg/h. The CO content of the product gas (23-26 % vol.) is higher than in similar gasifiers and the H{sub 2} content has been found to vary between 14 and 16 % vol. The tar content in the product gas (Ca. 3 g/Nm{sup 3}) is rather high compared with similar gasifiers. The temperature profile, together with other relevant parameters like the air-excess ratio, the air to fuel ratio and gas to fuel ratio have been calculated. The experiments show that the air excess ratio is rather constant, varying between 0,25 and 0,3. Experiments have been conducted with a gas engine using mixtures of CH{sub 4}, CO, H{sub 2}, CO{sub 2} and N{sub 2} as a fuel. NO{sub x} and CO emissions are analysed. The char gasification process has been studied in detail by means of Thermogravimetric Analysis. The study comprises the chemical kinetics of the gasification reactions of wood char in CO{sub 2} and H{sub 2}O, including the inhibition effect of CO and H{sub 2}. A kinetic model based on Langmuir-Hinshelwood kinetics has been found which relates the mass loss rate to the temperature, gas composition and degree of conversion for each reaction. The ratio CO/CO{sub 2} has been found to be a relevant parameter for reactivity. The gasification experiments in mixtures of CO{sub 2} and H{sub 2}O give reasons to believe that the rate of desorption for the complex C(O) varies depending on the gas mixture surrounding the char. It has been found that if the experimental data are obtained from separate H{sub 2}O/N{sub 2

  14. On the impact of non-sphericity and small-scale surface roughness on the optical properties of hematite aerosols

    Kahnert, Michael; Nousiainen, Timo; Mauno, Paeivi

    2011-01-01

    We perform a comparative modelling study to investigate how different morphological features influence the optical properties of hematite aerosols. We consider high-order Chebyshev particles as a proxy for aerosol with a small-scale surface roughness, and spheroids as a model for nonspherical aerosols with a smooth boundary surface. The modelling results are compared to those obtained for homogeneous spherical particles. It is found that for hematite particles with an absorption efficiency of order unity the difference in optical properties between spheres and spheroids disappears. For optically softer particles, such as ice particles at far-infrared wavelengths, this effect can be observed for absorption efficiencies lower than unity. The convergence of the optical properties of spheres and spheroids is caused by absorption and quenching of internal resonances inside the particles, which depend both on the imaginary part of the refractive index and on the size parameter, and to some extent on the real part of the refractive index. By contrast, small-scale surface roughness becomes the dominant morphological feature for large particles. This effect is likely to depend on the amplitude of the surface roughness, the relative significance of internal resonances, and possibly on the real part of the refractive index. The extinction cross section is rather insensitive to surface roughness, while the single-scattering albedo, asymmetry parameter, and the Mueller matrix are strongly influenced. Small-scale surface roughness reduces the backscattering cross section by up to a factor of 2-3 as compared to size-equivalent particles with a smooth boundary surface. This can have important implications for the interpretation of lidar backscattering observations.

  15. Advanced astigmatism-corrected tandem Wadsworth mounting for small-scale spectral broadband imaging spectrometer.

    Lei, Yu; Lin, Guan-yu

    2013-01-01

    Tandem gratings of double-dispersion mount make it possible to design an imaging spectrometer for the weak light observation with high spatial resolution, high spectral resolution, and high optical transmission efficiency. The traditional tandem Wadsworth mounting is originally designed to match the coaxial telescope and large-scale imaging spectrometer. When it is used to connect the off-axis telescope such as off-axis parabolic mirror, it presents lower imaging quality than to connect the coaxial telescope. It may also introduce interference among the detector and the optical elements as it is applied to the short focal length and small-scale spectrometer in a close volume by satellite. An advanced tandem Wadsworth mounting has been investigated to deal with the situation. The Wadsworth astigmatism-corrected mounting condition for which is expressed as the distance between the second concave grating and the imaging plane is calculated. Then the optimum arrangement for the first plane grating and the second concave grating, which make the anterior Wadsworth condition fulfilling each wavelength, is analyzed by the geometric and first order differential calculation. These two arrangements comprise the advanced Wadsworth mounting condition. The spectral resolution has also been calculated by these conditions. An example designed by the optimum theory proves that the advanced tandem Wadsworth mounting performs excellently in spectral broadband.

  16. Management of broadleaved weeds in small-scale in an on-farm perspective

    Ooro, P.A.; Kamwaga, J.N.; Kipkemoi, P.L.; Bor, P.K.; Mbanda, G.O.; Rogoncho; Ochieng', J.O.

    2001-01-01

    An on-farm trial was conducted at eight different sites in Rongai and Njoro areas of Nakuru district and only six of the sites were finally harvested. The study was mainly to evaluate different weed control methods to offer a variety of recommendations for small scale wheat farmers. Of the treatments tested Buctril Mc out performed all the treatments except for Ariane. Cultural methods of control seemed to be inferior to almost all the chemical control. (author)

  17. Utilization of Construction Waste Composite Powder Materials as Cementitious Materials in Small-Scale Prefabricated Concrete

    Cuizhen Xue; Aiqin Shen; Yinchuan Guo; Tianqin He

    2016-01-01

    The construction and demolition wastes have increased rapidly due to the prosperity of infrastructure construction. For the sake of effectively reusing construction wastes, this paper studied the potential use of construction waste composite powder material (CWCPM) as cementitious materials in small-scale prefabricated concretes. Three types of such concretes, namely, C20, C25, and C30, were selected to investigate the influences of CWCPM on their working performances, mechanical properties, ...

  18. Flow visualization and velocity measurement in a small-scale open channel using an electron microscope

    Yasuda, K; Sogo, M; Iwamoto, Y

    2013-01-01

    The present note describes a method for use in conjunction with a scanning electron microscope (SEM) that has been developed to visualize a liquid flow under a high-level vacuum and to measure a velocity field in a small-scale flow through an open channel. In general, liquid cannot be observed via a SEM, because liquid evaporates under the high-vacuum environment of the SEM. As such, ionic liquid and room temperature molten salt having a vapor pressure of nearly zero is used in the present study. We use ionic liquid containing Au-coated tracer particles to visualize a small-scale flow under a SEM. Furthermore, the velocity distribution in the open channel is obtained by particle tracking velocimetry measurement and a parabolic profile is confirmed. (technical design note)

  19. Thermal characteristics of various biomass fuels in a small-scale biomass combustor

    Al-Shemmeri, T.T.; Yedla, R.; Wardle, D.

    2015-01-01

    Biomass combustion is a mature and reliable technology, which has been used for heating and cooking. In the UK, biomass currently qualifies for financial incentives such as the Renewable Heat Incentive (RHI). Therefore, it is vital to select the right type of fuel for a small-scale combustor to address different types of heat energy needs. In this paper, the authors attempt to investigate the performance of a small-scale biomass combustor for heating, and the impact of burning different biomass fuels on useful output energy from the combustor. The test results of moisture content, calorific value and combustion products of various biomass samples were presented. Results from this study are in general agreement with published data as far as the calorific values and moisture contents are concerned. Six commonly available biomass fuels were tested in a small-scale combustion system, and the factors that affect the performance of the system were analysed. In addition, the study has extended to examine the magnitude and proportion of useful heat, dissipated by convection and radiation while burning different biomass fuels in the small-scale combustor. It is concluded that some crucial factors have to be carefully considered before selecting biomass fuels for any particular heating application. - Highlights: • Six biomass materials combustion performance in a small combustor was examined. • Fuel combustion rate and amount of heat release has varied between materials. • Heat release by radiation, convection and flue gasses varied between materials. • Study helps engineers and users of biomass systems to select right materials

  20. Precision for Smallholder Farmers: A Small-Scale-Tailored Variable Rate Fertilizer Application Kit

    Jelle Van Loon

    2018-03-01

    Full Text Available Precision agriculture technology at the hands of smallholder farmers in the developing world is often deemed far-fetched. Low-resource farmers, however, are the most susceptible to negative changes in the environment. Providing these farmers with the right tools to mitigate adversity and to gain greater control of the production process could unlock their potential and support rural communities to meet the increasing global food demand. In this study, a real-time variable rate fertilizer application system was developed and tested as an add-on kit to conventional farm machinery. In the context of low investment costs for smallholder farmers, high user-friendliness and easy installment were the main concerns for the system to be viable. The system used nitrogen (N-sensors to assess the plant nutrient status on the spot and subsequently adjust the amount of fertilizer deposited according to the plant’s needs. Test bench trials showed that the add-on kit performed well with basic operations, but more precision is required. Variability between N-sensors and metering systems, combined with power fluctuations, created inaccuracies in the resulting application rate. Nevertheless, this work is a stepping stone towards catalyzing the elaboration of more cutting-edge precision solutions to support small-scale farmers to become successful, high producing agro-entrepreneurs.

  1. Community-Weighted Mean Plant Traits Predict Small Scale Distribution of Insect Root Herbivore Abundance.

    Ilja Sonnemann

    Full Text Available Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content along transects in grasslands of different management intensity in three regions in Germany. We calculated community-weighted mean plant traits to test whether the functional plant community composition determines the small scale distribution of insect root herbivores. To analyze spatial patterns in plant species and trait composition and insect root herbivore abundance we computed Mantel correlograms. Insect root herbivores mainly comprised click beetle (Coleoptera, Elateridae larvae (43% in the investigated grasslands. Total insect root herbivore numbers were positively related to community-weighted mean traits indicating high plant growth rates and biomass (specific leaf area, reproductive- and vegetative plant height, and negatively related to plant traits indicating poor tissue quality (leaf C/N ratio. Generalist Elaterid larvae, when analyzed independently, were also positively related to high plant growth rates and furthermore to root dry mass, but were not related to tissue quality. Insect root herbivore numbers were not related to plant cover, plant species richness and soil water content. Plant species composition and to a lesser extent plant trait composition displayed spatial autocorrelation, which was not influenced by land use intensity. Insect root herbivore abundance was not spatially autocorrelated. We conclude that in semi-natural grasslands with a high share of generalist insect root herbivores, insect root herbivores affiliate with large, fast growing plants, presumably because of availability of high quantities of food. Affiliation of

  2. Techno-economic optimisation of three gas liquefaction processes for small-scale applications

    Nguyen, Tuong-Van; Rothuizen, Erasmus Damgaard; Elmegaard, Brian

    2016-01-01

    inventory. The present work investigates three configurations (single-mixed refrigerant, single and dual reverse Brayton cycles) for small-scale applications, which are optimised and evaluated individually. The influences of the refrigerant properties and process technologies are analysed, and the most...... promising cycle setups are identified. The findings illustrate the resulting trade-offs between the system performance and investment costs, which differ significantly with the type of refrigeration cycle. Although these configurations are suitable for small-scale applications, mixed-refrigerant processes...... thermodynamic models leads to relative deviations of up to 1% for the power consumption and 20% for the network conductance. Particular caution should thus be exercised when extrapolating the results of process models to the design of actual gas liquefaction systems....

  3. Energy transfers and magnetic energy growth in small-scale dynamo

    Kumar, Rohit Raj

    2013-12-01

    In this letter we investigate the dynamics of magnetic energy growth in small-scale dynamo by studying energy transfers, mainly energy fluxes and shell-to-shell energy transfers. We perform dynamo simulations for the magnetic Prandtl number Pm = 20 on 10243 grid using the pseudospectral method. We demonstrate that the magnetic energy growth is caused by nonlocal energy transfers from the large-scale or forcing-scale velocity field to small-scale magnetic field. The peak of these energy transfers moves towards lower wave numbers as dynamo evolves, which is the reason why the integral scale of the magnetic field increases with time. The energy transfers U2U (velocity to velocity) and B2B (magnetic to magnetic) are forward and local. Copyright © EPLA, 2013.

  4. Small-scale power plant potential in Finland

    Helynen, S.

    1993-01-01

    The presentation discusses the small-scale power plant potential in Finland. The study of the potential is limited to W-scale power plants producing both electric power and heat using solid fuels. The basic power plant dimensioning and electric power load determination is based on traditional boiler and gas turbine technology. The possible sites for power plants are communities using district heating, and industrialized sites needing process steam or heat. In 1990 70 % (17 TWh) of district heat was produced by gas turbines. Ten communities have an own back-pressure power plant, and 40 communities buy heat from industrial plants, owing back-pressure power generation. Additionally about 40 communes buy district heat from companies, owned by power companies and industry. Estimates of small-scale power plant potential has been made plant wise on the basis of district heat loads and industrial heat needs. The scale of the plants has been limited to scale 3 MWe or more. The choosing of the fuel depends on the local conditions. The cheapest indigenous fuels in many communes are industrial wood wastes, and both milled and sod peat. The potential of steam technology based small-scale power plants has been estimated to be about 50 plants in 1992/1993, the total power of which is 220-260 MW. The largest estimate is base situation, in which there would be energy cooperation between the communes and industry. The fuel used by the power plants would be about 5.4-6.6 TWh/a corresponding to 270-330 million FIM/a. The total investment costs of the plants would be about 2.0 billion FIM. The plants would employ about 250 persons, and the fuel supply (wood or peat) about 100 persons

  5. Examples of backreaction of small-scale inhomogeneities in cosmology

    Green, Stephen R.; Wald, Robert M.

    2013-06-01

    In previous work, we introduced a new framework to treat large-scale backreaction effects due to small-scale inhomogeneities in general relativity. We considered one-parameter families of spacetimes for which such backreaction effects can occur, and we proved that, provided the weak energy condition on matter is satisfied, the leading effect of small-scale inhomogeneities on large-scale dynamics is to produce a traceless effective stress-energy tensor that itself satisfies the weak energy condition. In this work, we illustrate the nature of our framework by providing two explicit examples of one-parameter families with backreaction. The first, based on previous work of Berger, is a family of polarized vacuum Gowdy spacetimes on a torus, which satisfies all of the assumptions of our framework. As the parameter approaches its limiting value, the metric uniformly approaches a smooth background metric, but spacetime derivatives of the deviation of the metric from the background metric do not converge uniformly to zero. The limiting metric has nontrivial backreaction from the small-scale inhomogeneities, with an effective stress energy that is traceless and satisfies the weak energy condition, in accord with our theorems. Our second one-parameter family consists of metrics which have a uniform Friedmann-Lemaître-Robertson-Walker limit. This family satisfies all of our assumptions with the exception of the weak energy condition for matter. In this case, the limiting metric has an effective stress-energy tensor which is not traceless. We emphasize the importance of imposing energy conditions on matter in studies of backreaction.

  6. Small-Scale Flat Plate Collectors for Solar Thermal Scavenging in Low Conductivity Environments

    Emmanuel Ogbonnaya

    2017-01-01

    Full Text Available There is great opportunity to develop power supplies for autonomous application on the small scale. For example, remote environmental sensors may be powered through the harvesting of ambient thermal energy and heating of a thermoelectric generator. This work investigates a small-scale (centimeters solar thermal collector designed for this application. The absorber is coated with a unique selective coating and then studied in a low pressure environment to increase performance. A numerical model that is used to predict the performance of the collector plate is developed. This is validated based on benchtop testing of a fabricated collector plate in a low-pressure enclosure. Model results indicate that simulated solar input of about 800 W/m2 results in a collector plate temperature of 298 K in ambient conditions and up to 388 K in vacuum. The model also predicts the various losses in W/m2 K from the plate to the surroundings. Plate temperature is validated through the experimental work showing that the model is useful to the future design of these small-scale solar thermal energy collectors.

  7. R high performance programming

    Lim, Aloysius

    2015-01-01

    This book is for programmers and developers who want to improve the performance of their R programs by making them run faster with large data sets or who are trying to solve a pesky performance problem.

  8. Interactive economic analysis of small-scale heating plant

    Landen, R.A.; Sanders, D.L.; Douglas, B.H.

    1998-11-01

    This report contains the work that has been undertaken by LRZ Limited in pursuance of this agreement. The potential for small-scale biomass heating systems is identified, and surrounding issues relating to acceptance are discussed. Such systems are described, and the origins of capital and running costs examined. A full review of the calculation methods for boiler plant size and fuel consumption is made, and subsequently expounded in four varying case studies. The results of this work are discussed, and the final development of the computer models is reviewed, incorporating further refinements to the method. Finally, data not contained in the text is incorporated in comprehensive appendices. (author)

  9. Small-scale generator opportunities in the competitive supply market

    Scrivener, G.

    1998-01-01

    The last franchises for electricity supply held by Public Electricity Suppliers are due to expire early in 1998. As a consequence from then on, after a phased start-up, all electricity consumers will be free to choose their supplier, completing the process of introducing competition into the electricity market which started in 1990 with the privatisation of the Industry. Then the framework by which the industry operates will become very different. This paper will review the changes to the operation of the market and assess the opportunities for small scale embedded generators post 1998. (Author)

  10. Thermodynamic comparison of three small-scale gas liquefaction systems

    Nguyen, Tuong-Van; Rothuizen, Erasmus Damgaard; Markussen, Wiebke Brix

    2017-01-01

    . The present work investigates three configurations suitable for small-scale applications because of their simplicity and compactness: the single-mixed refrigerant, single and dual reverse Brayton cycles. The impact of different feed compositions and refrigerant properties is analysed. A detailed assessment...... to be more efficient (1000-2000 kJ/kgLNG) than expander-based ones (2500-5000 kJ/kgLNG) over larger ranges of operating conditions, at the expense of a greater system complexity and higher thermal conductance (250-500kW/K against 80-160 kW/K). The results show that the use of different thermodynamic models...

  11. Development of small scale soft x-ray lasers

    Kim, D.; Suckewer, S.; Princeton Univ., NJ; Skinner, C.H.; Voorhees, D.

    1991-05-01

    At present rapid progress is being made in the application of soft x-ray lasers to fields such as microscopy and microlithography. A critical factor in the range of suitable applications is the scale and hence cost of the soft x-ray lasers. At Princeton, gain at 183 angstrom has been obtained with relatively low pump laser energies (as low as 6J) in a ''portable'' small-scale soft x-ray laser system. We will also discuss aspects of data interpretation and pitfalls to be avoided in measurements of gain in such systems. 14 refs., 7 figs

  12. Small scale pelletizing equipment for agriculture; Smaaskalig pelleteringsanlaeggning foer lantbruket

    Paulrud, Susanne (The Swedish Environmental Research Inst. Ltd., Stockholm (Sweden)); Wallin, Mikael (Sweden Powers Chippers AB, Boraas (Sweden))

    2009-06-15

    Refining agricultural raw materials is one way for farmers to increase the value of their products. For example, briquettes or pellets made from straw, reed canary grass or hemp can sell for a higher price than in loose or baled forms. The aim of this project was to develop and build a plant for small-scale production of pellets on the farm. Working together with the farmer, the plant would then be tested and adapted for small-scale production of pellets from straw, reed canary grass and hemp. The project also aimed to investigate and summarise suitable systems and solutions for breaking up bales in preparation for use in the pellets module. A pelleting system has been developed and built as a container module (measuring 6 x 2.80 x 2.50 m) by Sweden Power Chippers (SPC). The container system includes a fuel store with push floor, a grinder, an SPC pellet press (pp150, capacity 150 kg/hour for woodbased material), a conveyor belt and a cooling system. The practical operation of the plant was tested on two Swedish farms: Laattra gaard in Vingaaker and Ek gaard in Vara. The bales were broken up in preparation for pelleting using a straw mill of model Tomahawk 505M. The project has demonstrated that the SPC plant has the capacity to be used for agricultural pelleting of fuels from straw, canary reed grass and hemp. Some modification and continued adjustment of the feed system for the fuel remains to be done in order to optimise and ensure the reliability of the pelleting process. A certain amount of modifications to the plant is required to enable cost-effective transportation between different locations. Tests showed that each batch of fuel was unique, even from the same raw material, and that optimisation of the dies is necessary for each specific case. Training is required to run the plant. The farmers have been able to run the plant themselves, for example, starting up the plant, changing the sieve on the grinder, changing dies etc. In order for such small-scale

  13. Small-scale generator opportunities in the competitive supply market

    Scrivener, G. [Energy Technology Support Unit (ETSU), Harwell (United Kingdom)

    1998-07-01

    The last franchises for electricity supply held by Public Electricity Suppliers are due to expire early in 1998. As a consequence from then on, after a phased start-up, all electricity consumers will be free to choose their supplier, completing the process of introducing competition into the electricity market which started in 1990 with the privatisation of the Industry. Then the framework by which the industry operates will become very different. This paper will review the changes to the operation of the market and assess the opportunities for small scale embedded generators post 1998. (Author)

  14. Model Predictive Control for a Small Scale Unmanned Helicopter

    Jianfu Du

    2008-11-01

    Full Text Available Kinematical and dynamical equations of a small scale unmanned helicoper are presented in the paper. Based on these equations a model predictive control (MPC method is proposed for controlling the helicopter. This novel method allows the direct accounting for the existing time delays which are used to model the dynamics of actuators and aerodynamics of the main rotor. Also the limits of the actuators are taken into the considerations during the controller design. The proposed control algorithm was verified in real flight experiments where good perfomance was shown in postion control mode.

  15. Dimensional analysis of small-scale steam explosion experiments

    Huh, K.; Corradini, M.L.

    1986-01-01

    Dimensional analysis applied to Nelson's small-scale steam explosion experiments to determine the qualitative effect of each relevant parameter for triggering a steam explosion. According to experimental results, the liquid entrapment model seems to be a consistent explanation for the steam explosion triggering mechanism. The three-dimensional oscillatory wave motion of the vapor/liquid interface is analyzed to determine the necessary conditions for local condensation and production of a coolant microjet to be entrapped in fuel. It is proposed that different contact modes between fuel and coolant may involve different initiation mechanisms of steam explosions

  16. Small scale studies of production of fissium aerosols

    Lindqvist, O.; Rydberg, J.

    1983-02-01

    A small scale study concerning the production and analysis of fission product aerosols formed at various temperatures as a function of the chemical composition of the fissium/corium mixture at the source is presented. CsOH, CsJ and Te are the main aerosol components to be expected. The thermodynamic characterization of occuring Te-iodides and other phases is of great importance for reactor core meltdown chemistry and for the evaluation of the aerosol transport tests. Elemental iodine seems not to be released in significant amounts in reducing atmosphere. Analysis data concerning elements, phases, themral analysis and gases are presented. (G.B.)

  17. Public choice in water resource management: two case studies of the small-scale hydroelectric controversy

    Soden, D.L.

    1985-01-01

    Hydroelectric issues have a long history in the Pacific Northwest, and more recently have come to focus on developing environmentally less-obtrusive means of hydroelectric generation. Small-scale hydroelectric represents perhaps the most important of these means of developing new sources of renewable resources to lessen the nation's dependence on foreign sources of energy. Each potential small-scale hydroelectric project, however, manifests a unique history which provides a highly useful opportunity to study the process of collective social choice in the area of new energy uses of water resources. Utilizing the basic concepts of public choice theory, a highly developed and increasingly widely accepted approach in the social sciences, the politicalization of small-scale hydroelectric proposals is analyzed. Through the use of secondary analysis of archival public opinion data collected from residents of the State of Idaho, and through the development of the two case studies - one on the Palouse River in Eastern Washington and the other at Elk Creek Falls in Northern Idaho, the policy relevant behavior and influence of major actors is assessed. Results provide a useful test of the utility of public-choice theory for the study of cases of natural-resources development when public involvement is high.

  18. Climate change impacts and adaptations on small-scale livestock production

    Taruvinga, A.

    2013-06-01

    Full Text Available The paper estimated the impacts of climate change and adaptations on small-scale livestock production. The study is based on a survey of 1484 small-scale livestock rural farmers across the Eastern Cape Province of South Africa. Regression estimates finds that with warming, the probability of choosing the following species increases; goats, dual purpose chicken (DPC, layers, donkeys and ducks. High precipitation increases the probability of choosing the following animals; beef, goats, DPC and donkeys. Further, socio-economic estimates indicate that livestock selection choices are also conditioned by gender, age, marital status, education and household size. The paper therefore concluded that as climate changes, rural farmers switch their livestock combinations as a coping strategy. Unfortunately, rural farmers face a limited preferred livestock selection pool that is combatable to harsh climate which might translate to a bleak future for rural livestock farmers.

  19. Fractal properties and small-scale structure of cosmic string networks

    Martins, C.J.A.P.; Shellard, E.P.S.

    2006-01-01

    We present results from a detailed numerical study of the small-scale and loop production properties of cosmic string networks, based on the largest and highest resolution string simulations to date. We investigate the nontrivial fractal properties of cosmic strings, in particular, the fractal dimension and renormalized string mass per unit length, and we also study velocity correlations. We demonstrate important differences between string networks in flat (Minkowski) spacetime and the two very similar expanding cases. For high resolution matter era network simulations, we provide strong evidence that small-scale structure has converged to 'scaling' on all dynamical length scales, without the need for other radiative damping mechanisms. We also discuss preliminary evidence that the dominant loop production size is also approaching scaling

  20. Investigation of small-scale tokamak plasma turbulence by correlative UHR backscattering diagnostics

    Gusakov, E Z; Gurchenko, A D; Altukhov, A B; Bulanin, V V; Esipov, L A; Kantor, M Yu; Kouprienko, D V; Lashkul, S I; Petrov, A V; Stepanov, A Yu

    2006-01-01

    Fine scale turbulence is considered nowadays as a possible candidate for the explanation of anomalous ion and electron energy transport in magnetized fusion plasmas. The unique correlative upper hybrid resonance backscattering (UHR BS) technique is applied at the FT-2 tokamak for investigation of density fluctuations excited in this turbulence. The measurements are carried out in Ohmic discharge at several values of plasma current and density and during current ramp up experiment. The moveable focusing antennas set have been used in experiments allowing probing out of equatorial plane. The radial wave number spectra of the small-scale component of tokamak turbulence are determined from the correlation data with high spatial resolution. Two small-scale modes possessing substantially different phase velocities are observed in plasma under conditions when the threshold for the electron temperature gradient mode excitation is overcome. The possibility of plasma poloidal velocity profile determination using the UHR BS signal is demonstrated

  1. Biomedical device prototype based on small scale hydrodynamic cavitation

    Morteza Ghorbani

    2018-03-01

    Full Text Available This study presents a biomedical device prototype based on small scale hydrodynamic cavitation. The application of small scale hydrodynamic cavitation and its integration to a biomedical device prototype is offered as an important alternative to other techniques, such as ultrasound therapy, and thus constitutes a local, cheap, and energy-efficient solution, for urinary stone therapy and abnormal tissue ablation (e.g., benign prostate hyperplasia (BPH. The destructive nature of bubbly, cavitating, flows was exploited, and the potential of the prototype was assessed and characterized. Bubbles generated in a small flow restrictive element (micro-orifice based on hydrodynamic cavitation were utilized for this purpose. The small bubbly, cavitating, flow generator (micro-orifice was fitted to a small flexible probe, which was actuated with a micromanipulator using fine control. This probe also houses an imaging device for visualization so that the emerging cavitating flow could be locally targeted to the desired spot. In this study, the feasibility of this alternative treatment method and its integration to a device prototype were successfully accomplished.

  2. Biomedical device prototype based on small scale hydrodynamic cavitation

    Ghorbani, Morteza; Sozer, Canberk; Alcan, Gokhan; Unel, Mustafa; Ekici, Sinan; Uvet, Huseyin; Koşar, Ali

    2018-03-01

    This study presents a biomedical device prototype based on small scale hydrodynamic cavitation. The application of small scale hydrodynamic cavitation and its integration to a biomedical device prototype is offered as an important alternative to other techniques, such as ultrasound therapy, and thus constitutes a local, cheap, and energy-efficient solution, for urinary stone therapy and abnormal tissue ablation (e.g., benign prostate hyperplasia (BPH)). The destructive nature of bubbly, cavitating, flows was exploited, and the potential of the prototype was assessed and characterized. Bubbles generated in a small flow restrictive element (micro-orifice) based on hydrodynamic cavitation were utilized for this purpose. The small bubbly, cavitating, flow generator (micro-orifice) was fitted to a small flexible probe, which was actuated with a micromanipulator using fine control. This probe also houses an imaging device for visualization so that the emerging cavitating flow could be locally targeted to the desired spot. In this study, the feasibility of this alternative treatment method and its integration to a device prototype were successfully accomplished.

  3. Effects of thermal inflation on small scale density perturbations

    Hong, Sungwook E. [School of Physics, Korea Institute for Advanced Study, 85 Hoegiro, Seoul 130-722 (Korea, Republic of); Lee, Hyung-Joo; Lee, Young Jae; Stewart, Ewan D. [Department of Physics, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-338 (Korea, Republic of); Zoe, Heeseung, E-mail: swhong@kias.re.kr, E-mail: ohsk111@kaist.ac.kr, E-mail: noasac@kaist.ac.kr, E-mail: jcap@profstewart.org, E-mail: heezoe@dgist.ac.kr [School of Basic Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333 Techno jungang-daero, Daegu 711-873 (Korea, Republic of)

    2015-06-01

    In cosmological scenarios with thermal inflation, extra eras of moduli matter domination, thermal inflation and flaton matter domination exist between primordial inflation and the radiation domination of Big Bang nucleosynthesis. During these eras, cosmological perturbations on small scales can enter and re-exit the horizon, modifying the power spectrum on those scales. The largest modified scale, k{sub b}, touches the horizon size when the expansion changes from deflation to inflation at the transition from moduli domination to thermal inflation. We analytically calculate the evolution of perturbations from moduli domination through thermal inflation and evaluate the curvature perturbation on the constant radiation density hypersurface at the end of thermal inflation to determine the late time curvature perturbation. Our resulting transfer function suppresses the power spectrum by a factor 0∼ 5 at k >> k{sub b}, with k{sub b} corresponding to anywhere from megaparsec to subparsec scales depending on the parameters of thermal inflation. Thus, thermal inflation might be constrained or detected by small scale observations such as CMB distortions or 21cm hydrogen line observations.

  4. Small-scale engagement model with arrivals: analytical solutions

    Engi, D.

    1977-04-01

    This report presents an analytical model of small-scale battles. The specific impetus for this effort was provided by a need to characterize hypothetical battles between guards at a nuclear facility and their potential adversaries. The solution procedure can be used to find measures of a number of critical parameters; for example, the win probabilities and the expected duration of the battle. Numerical solutions are obtainable if the total number of individual combatants on the opposing sides is less than 10. For smaller force size battles, with one or two combatants on each side, symbolic solutions can be found. The symbolic solutions express the output parameters abstractly in terms of symbolic representations of the input parameters while the numerical solutions are expressed as numerical values. The input parameters are derived from the probability distributions of the attrition and arrival processes. The solution procedure reduces to solving sets of linear equations that have been constructed from the input parameters. The approach presented in this report does not address the problems associated with measuring the inputs. Rather, this report attempts to establish a relatively simple structure within which small-scale battles can be studied

  5. The case for small-scale domestic cannabis cultivation.

    Decorte, Tom

    2010-07-01

    The shift to (inter)regional production, trade and domestic cultivation has become an irreversible international trend. Until now, the focus of most empirical work has been on large-scale, commercially oriented and professionally organized segments of the cannabis industry, often based on police data and on the perspective of law enforcement agencies. This paper offers a review of recent Dutch-language research that focuses on cannabis cultivation. Empirical studies were identified through literature searches using relevant search terms and Web of Science, Elin, Social Science Research Network and Elsevier ScienceDirect. The paper presents the main findings of Dutch and Belgian empirical work on the factors that stimulated the import substitution process on the cannabis market, aspects related to quality and potency issues, typologies of cannabis growers, and (unintended) effects of pursued policies. In the light of this (selective) review the author offers some commentary and analysis concerning the claims made by different stakeholders, and concludes with some reflections on future research and on policy implications. The author outlines the importance of small-scale, independent or ideologically oriented cannabis cultivation as an under-researched market segment. The author also makes a case for greater toleration of small-scale cannabis cultivation, to secure the least worst of cannabis markets. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  6. PREDICTION OF POWER GENERATION OF SMALL SCALE VERTICAL AXIS WIND TURBINE USING FUZZY LOGIC

    Altab Hossain

    2009-01-01

    Full Text Available Renewable energy from the wind turbine has been focused for the alternative source of power generation due to the following advances of the of the wind turbine. Firstly, the wind turbine is highly efficient and eco-friendly. Secondly, the turbine has the ability to response for the changeable power generation based on the wind velocity and structural framework. However, the competitive efficiency of the wind turbine is necessary to successfully alternate the conventional power sources. The most relevant factor which affects the overall efficiency of the wind turbine is the wind velocity and the relative turbine dimensions. Artificial intelligence systems are widely used technology that can learn from examples and are able to deal with non-linear problems. Compared with traditional approach, fuzzy logic approach is more efficient for the representation, manipulation and utilization. Therefore, the primary purpose of this work was to investigate the relationship between wind turbine power generation and wind velocity, and to illustrate how fuzzy expert system might play an important role in prediction of wind turbine power generation. The main purpose of the measurement over the small scaled prototype vertical axis wind turbine for the wind velocity is to predict the performance of full scaled H-type vertical axis wind turbine. Prediction of power generation at the different wind velocities has been tested at the Thermal Laboratory of Faculty of Engineering, Universiti Industri Selangor (UNISEL and results concerning the daily prediction have been obtained.

  7. Life Cycle Inventory Analysis for a Small-Scale Trawl Fishery in Sendai Bay, Japan

    Kazuhito Watanabe

    2016-04-01

    Full Text Available A reduced environmental burden, while maintaining high quality and low cost, has become an important factor for achieving sustainability in the fisheries sector. The authors performed life cycle inventory (LCI analysis targeting the fish production for a small-scale trawl fishery including small trawlers operating in Sendai Bay, Japan. The average annual cumulative CO2 emissions for the small trawlers were 4.7 ton-CO2/ton-product and 8.3 ton-CO2/million Japanese yen (JPN. Total fuel consumption contributed to 97% of the global warming potential. The range of variation in the basic unit of CO2 for each small trawler was also elucidated. Energy conservation through lower fuel consumption is shown to be an effective measure for reducing CO2 in a small trawler fishery. Moreover, the authors examined the system boundary, the determination of the functional unit, and the allocation method of applying LCI analysis to fisheries. Finally, the economy and environment of small trawler fisheries are discussed as important factors for sustainable fisheries, and the life cycle approach is applied to a new fishery type in Japan.

  8. Progress towards a small-scale, automated optical thin-film production capability

    Drage, D.J.; Netterfield, R.P.; Dligatch, S.; Blenman, N.; Fairman, P.S.; Katsaros, A.; Preston, E.W.

    2000-01-01

    Full text: The Optical Thin-film group at CSIRO Telecommunications and Industrial Physics (CTIP) has, working over a number of years, built up considerable expertise in producing complex dielectric, multilayer thin-film designs to meet unusual and demanding optical performance specifications. At the same time the process of vacuum deposition of dielectric materials has been advanced, particularly by the development and use of ion-assisted deposition (IAD). Proposed modifications to our existing chamber (DB600) and the addition of a new, larger diameter chamber (DD750), presently under construction, will increase output and reliability while improving quality. We will describe the changes already made to the DB600 such as: the gridless ion source, in-situ ellipsometric monitoring along with spectrophotometric monitoring, full e-beam scan on the material source, complete source shuttering and reactive deposition of SiO 2 from thermally evaporated SiO. The effects of making these beneficial changes will be described. Further changes to be made to the DB600 include, replacing its diffusion pump with a cryo-pump and automatic control of the deposition process. All the changes described for the DB600 along with a positive drive system for rotation of the substrate holder, rod feed e-gun hearths, and multiple crystal monitor heads, will be included in the DD750 design which will also be described. We believe that these improvements will give us the capability of small-scale production of reproducible, high quality filters

  9. PREDICTION OF POWER GENERATION OF SMALL SCALE VERTICAL AXIS WIND TURBINE USING FUZZY LOGIC

    Altab Md. Hossain

    2009-12-01

    Full Text Available Renewable energy from the wind turbine has been focused for the alternative source of power generation due to the following advances of the of the wind turbine. Firstly, the wind turbine is highly efficient and eco-friendly. Secondly, the turbine has the ability to response for the changeable power generation based on the wind velocity and structural framework. However, the competitive efficiency of the wind turbine is necessary to successfully alternate the conventional power sources. The most relevant factor which affects the overall efficiency of the wind turbine is the wind velocity and the relative turbine dimensions. Artificial intelligence systems are widely used technology that can learn from examples and are able to deal with non-linear problems. Compared with traditional approach, fuzzy logic approach is more efficient for the representation, manipulation and utilization. Therefore, the primary purpose of this work was to investigate the relationship between wind turbine power generation and wind velocity, and to illustrate how fuzzy expert system might play an important role in prediction of wind turbine power generation. The main purpose of the measurement over the small scaled prototype vertical axis wind turbine for the wind velocity is to predict the performance of full scaled H-type vertical axis wind turbine. Prediction of power generation at the different wind velocities has been tested at the Thermal Laboratory of Faculty of Engineering, Universiti Industri Selangor (UNISEL and results concerning the daily prediction have been obtained.

  10. High performance work practices, innovation and performance

    Jørgensen, Frances; Newton, Cameron; Johnston, Kim

    2013-01-01

    Research spanning nearly 20 years has provided considerable empirical evidence for relationships between High Performance Work Practices (HPWPs) and various measures of performance including increased productivity, improved customer service, and reduced turnover. What stands out from......, and Africa to examine these various questions relating to the HPWP-innovation-performance relationship. Each paper discusses a practice that has been identified in HPWP literature and potential variables that can facilitate or hinder the effects of these practices of innovation- and performance...

  11. Global Burden of Disease of Mercury Used in Artisanal Small-Scale Gold Mining.

    Steckling, Nadine; Tobollik, Myriam; Plass, Dietrich; Hornberg, Claudia; Ericson, Bret; Fuller, Richard; Bose-O'Reilly, Stephan

    Artisanal small-scale gold mining (ASGM) is the world's largest anthropogenic source of mercury emission. Gold miners are highly exposed to metallic mercury and suffer occupational mercury intoxication. The global disease burden as a result of this exposure is largely unknown because the informal character of ASGM restricts the availability of reliable data. To estimate the prevalence of occupational mercury intoxication and the disability-adjusted life years (DALYs) attributable to chronic metallic mercury vapor intoxication (CMMVI) among ASGM gold miners globally and in selected countries. Estimates of the number of artisanal small-scale gold (ASG) miners were extracted from reviews supplemented by a literature search. Prevalence of moderate CMMVI among miners was determined by compiling a dataset of available studies that assessed frequency of intoxication in gold miners using a standardized diagnostic tool and biomonitoring data on mercury in urine. Severe cases of CMMVI were not included because it was assumed that these persons can no longer be employed as miners. Cases in workers' families and communities were not considered. Years lived with disability as a result of CMMVI among ASG miners were quantified by multiplying the number of prevalent cases of CMMVI by the appropriate disability weight. No deaths are expected to result from CMMVI and therefore years of life lost were not calculated. Disease burden was calculated by multiplying the prevalence rate with the number of miners for each country and the disability weight. Sensitivity analyses were performed using different assumptions on the number of miners and the intoxication prevalence rate. Globally, 14-19 million workers are employed as ASG miners. Based on human biomonitoring data, between 25% and 33% of these miners-3.3-6.5 million miners globally-suffer from moderate CMMVI. The resulting global burden of disease is estimated to range from 1.22 (uncertainty interval [UI] 0.87-1.61) to 2.39 (UI 1

  12. Small-Scale Spray Releases: Initial Aerosol Test Results

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2013-05-29

    rectangular slots. For the combination of both test stands, the round holes ranged in size from 0.2 to 4.46 mm. The slots ranged from (width × length) 0.3 × 5 to 2.74 × 76.2 mm. Most slots were oriented longitudinally along the pipe, but some were oriented circumferentially. In addition, a limited number of multi-hole test pieces were tested in an attempt to assess the impact of a more complex breach. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the much larger flow rates and equipment that would be required. This report presents the experimental results and analyses for the aerosol measurements obtained in the small-scale test stand. It includes a description of the simulants used and their properties, equipment and operations, data analysis methodologies, and test results. The results of tests investigating the role of slurry particles in plugging small breaches are reported in Mahoney et al. (2012). The results of the aerosol measurements in the large-scale test stand are reported in Schonewill et al. (2012) along with an analysis of the combined results from both test scales.

  13. Small-Scale Spray Releases: Initial Aerosol Test Results

    Mahoney, Lenna A.; Gauglitz, Phillip A.; Kimura, Marcia L.; Brown, Garrett N.; Kurath, Dean E.; Buchmiller, William C.; Smith, Dennese M.; Blanchard, Jeremy; Song, Chen; Daniel, Richard C.; Wells, Beric E.; Tran, Diana N.; Burns, Carolyn A.

    2012-11-01

    rectangular slots. The round holes ranged in size from 0.2 to 4.46 mm. The slots ranged from (width × length) 0.3 × 5 to 2.74 × 76.2 mm. Most slots were oriented longitudinally along the pipe, but some were oriented circumferentially. In addition, a limited number of multi-hole test pieces were tested in an attempt to assess the impact of a more complex breach. Much of the testing was conducted at pressures of 200 and 380 psi, but some tests were conducted at 100 psi. Testing the largest postulated breaches was deemed impractical because of the large size of some of the WTP equipment. This report presents the experimental results and analyses for the aerosol measurements obtained in the small-scale test stand. It includes a description of the simulants used and their properties, equipment and operations, data analysis methodologies, and test results. The results of tests investigating the role of slurry particles in plugging small breaches are reported in Mahoney et al. (2012). The results of the aerosol measurements in the large-scale test stand are reported in Schonewill et al. (2012) along with an analysis of the combined results from both test scales.

  14. A hysteretic model considering Stribeck effect for small-scale magnetorheological damper

    Zhao, Yu-Liang; Xu, Zhao-Dong

    2018-06-01

    Magnetorheological (MR) damper is an ideal semi-active control device for vibration suppression. The mechanical properties of this type of devices show strong nonlinear characteristics, especially the performance of the small-scale dampers. Therefore, developing an ideal model that can accurately describe the nonlinearity of such device is crucial to control design. In this paper, the dynamic characteristics of a small-scale MR damper developed by our research group is tested, and the Stribeck effect is observed in the low velocity region. Then, an improved model based on sigmoid model is proposed to describe this Stribeck effect observed in the experiment. After that, the parameters of this model are identified by genetic algorithms, and the mathematical relationship between these parameters and the input current, excitation frequency and amplitude is regressed. Finally, the predicted forces of the proposed model are validated with the experimental data. The results show that this model can well predict the mechanical properties of the small-scale damper, especially the Stribeck effect in the low velocity region.

  15. Impact of value chain governance on the development of small scale shrimp farmers in Vietnam

    T. M. H. Ho

    2016-06-01

    Full Text Available Purpose of this paper is to identify the tendency of shrimp value chain development and impact of its governance on the small scale shrimp farmers in Vietnam. Design/methodology/approach - Data from the shrimp farmers surveys in Mekong delta, Vietnam from 2008-2010 with the update information in 2014 were taken to analyse by the value chain analysis method. Findings – Traditional governance type of the shrimp value chain in the early state (before 2004 showed the different levels of coordination of farmers with collectors, among collectors, and collectors with processing plants. In this type of governance, trust and linkages are inextricably linked. However, they are not strong. The processing plants determine shrimp prices and quality requirement in the market while many collectors do not seem to be highly responsible for the quality of their products. To avoid this limitation, with the governmental support policy to improve farmers’ income, the processing plants set up a direct buying from farmers under contracts. These contracts led to a new governance type with an expectation of improving farmers' position. However, this model was broken due to several reasons including un-controlled shrimp raw material from small scale and individual farmers. Consequently, processors now tend to establish their own raw material zone to comply shrimp quality assurance, and eject the existence of farmers. This will lead small scale farmers to very difficult problems in finding the market. Poverty and social problems of small scale farmers might appear. The result recommends a greater strengthening and tightening of the value chain. Re-organizing shrimp farmers into legal teams or groups that help farmers to re-participate in the game with others actor in the chain is crucial. Research limitations/implications - The research mainly follows inductive approach in w

  16. [Qualitative evaluation of employer requirements associated with occupational health and safety as good practice in small-scale enterprises].

    Kuroki, Naomi; Miyashita, Nana; Hino, Yoshiyuki; Kayashima, Kotaro; Fujino, Yoshihisa; Takada, Mikio; Nagata, Tomohisa; Yamataki, Hajime; Sakuragi, Sonoko; Kan, Hirohiko; Morita, Tetsuya; Ito, Akiyoshi; Mori, Koji

    2009-09-01

    activities depended on "cost", "human resources", "time to perform", and "advisory organization". These results suggest that employer awareness of the relationship between good management and occupational health is essential to the implementation of occupational health and safety practices in small-scale enterprises.

  17. Conversion of fracture toughness testing values from small scale three point bending test specimens to small scale yielding state (SSY) by elastic-plastic stress analysis

    Ikonen, K.

    1993-07-01

    The report describes the work performed for achieving readiness to calculate fracture toughness dependence on dimension effects and loading conditions in fracture test specimens and real structures. In the report two- and three-dimensional computer codes developed and calculational methods applied are described. One of the main goals is to converse fracture toughness from small scale three point bending test specimens to case of a depth crack in plane strain i.e. to small scale yielding state (SSY) by numerical elastic-plastic stress analysis. Thickness effect of a test specimens and effect of a crack depth are separately investigated. Tests of three point bending specimens with and without sidegrooves and curved crack front are numerically simulated and experimental and computed results are compared. J-integral is calculated along crack front and also from force-deflection dependence of the beam. For the analyses the computing system was thoroughly automatized. Measuring capacity of three point bending test specimens was tried to evaluate. (orig.) (7 refs., 54 figs.)

  18. 2012 THIN FILM AND SMALL SCALE MECHANICAL BEHAVIOR GRS/GRC, JULY 21-27, 2012

    Balk, Thomas

    2012-07-27

    The mechanical behavior of materials with small dimension(s) is of both fundamental scientific interest and technological relevance. The size effects and novel properties that arise from changes in deformation mechanism have important implications for modern technologies such as thin films for microelectronics and MEMS devices, thermal and tribological coatings, materials for energy production and advanced batteries, etc. The overarching goal of the 2012 Gordon Research Conference on "Thin Film and Small Scale Mechanical Behavior" is to discuss recent studies and future opportunities regarding elastic, plastic and time-dependent deformation, as well as degradation and failure mechanisms such as fatigue, fracture and wear. Specific topics of interest include, but are not limited to: fundamental studies of physical mechanisms governing small-scale mechanical behavior; advances in test techniques for materials at small length scales, such as nanotribology and high-temperature nanoindentation; in-situ mechanical testing and characterization; nanomechanics of battery materials, such as swelling-induced phenomena and chemomechanical behavior; flexible electronics; mechanical properties of graphene and carbon-based materials; mechanical behavior of small-scale biological structures and biomimetic materials. Both experimental and computational work will be included in the oral and poster presentations at this Conference.

  19. Python high performance programming

    Lanaro, Gabriele

    2013-01-01

    An exciting, easy-to-follow guide illustrating the techniques to boost the performance of Python code, and their applications with plenty of hands-on examples.If you are a programmer who likes the power and simplicity of Python and would like to use this language for performance-critical applications, this book is ideal for you. All that is required is a basic knowledge of the Python programming language. The book will cover basic and advanced topics so will be great for you whether you are a new or a seasoned Python developer.

  20. High performance germanium MOSFETs

    Saraswat, Krishna [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)]. E-mail: saraswat@stanford.edu; Chui, Chi On [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Krishnamohan, Tejas [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Kim, Donghyun [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Nayfeh, Ammar [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States); Pethe, Abhijit [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)

    2006-12-15

    Ge is a very promising material as future channel materials for nanoscale MOSFETs due to its high mobility and thus a higher source injection velocity, which translates into higher drive current and smaller gate delay. However, for Ge to become main-stream, surface passivation and heterogeneous integration of crystalline Ge layers on Si must be achieved. We have demonstrated growth of fully relaxed smooth single crystal Ge layers on Si using a novel multi-step growth and hydrogen anneal process without any graded buffer SiGe layer. Surface passivation of Ge has been achieved with its native oxynitride (GeO {sub x}N {sub y} ) and high-permittivity (high-k) metal oxides of Al, Zr and Hf. High mobility MOSFETs have been demonstrated in bulk Ge with high-k gate dielectrics and metal gates. However, due to their smaller bandgap and higher dielectric constant, most high mobility materials suffer from large band-to-band tunneling (BTBT) leakage currents and worse short channel effects. We present novel, Si and Ge based heterostructure MOSFETs, which can significantly reduce the BTBT leakage currents while retaining high channel mobility, making them suitable for scaling into the sub-15 nm regime. Through full band Monte-Carlo, Poisson-Schrodinger and detailed BTBT simulations we show a dramatic reduction in BTBT and excellent electrostatic control of the channel, while maintaining very high drive currents in these highly scaled heterostructure DGFETs. Heterostructure MOSFETs with varying strained-Ge or SiGe thickness, Si cap thickness and Ge percentage were fabricated on bulk Si and SOI substrates. The ultra-thin ({approx}2 nm) strained-Ge channel heterostructure MOSFETs exhibited >4x mobility enhancements over bulk Si devices and >10x BTBT reduction over surface channel strained SiGe devices.

  1. High performance germanium MOSFETs

    Saraswat, Krishna; Chui, Chi On; Krishnamohan, Tejas; Kim, Donghyun; Nayfeh, Ammar; Pethe, Abhijit

    2006-01-01

    Ge is a very promising material as future channel materials for nanoscale MOSFETs due to its high mobility and thus a higher source injection velocity, which translates into higher drive current and smaller gate delay. However, for Ge to become main-stream, surface passivation and heterogeneous integration of crystalline Ge layers on Si must be achieved. We have demonstrated growth of fully relaxed smooth single crystal Ge layers on Si using a novel multi-step growth and hydrogen anneal process without any graded buffer SiGe layer. Surface passivation of Ge has been achieved with its native oxynitride (GeO x N y ) and high-permittivity (high-k) metal oxides of Al, Zr and Hf. High mobility MOSFETs have been demonstrated in bulk Ge with high-k gate dielectrics and metal gates. However, due to their smaller bandgap and higher dielectric constant, most high mobility materials suffer from large band-to-band tunneling (BTBT) leakage currents and worse short channel effects. We present novel, Si and Ge based heterostructure MOSFETs, which can significantly reduce the BTBT leakage currents while retaining high channel mobility, making them suitable for scaling into the sub-15 nm regime. Through full band Monte-Carlo, Poisson-Schrodinger and detailed BTBT simulations we show a dramatic reduction in BTBT and excellent electrostatic control of the channel, while maintaining very high drive currents in these highly scaled heterostructure DGFETs. Heterostructure MOSFETs with varying strained-Ge or SiGe thickness, Si cap thickness and Ge percentage were fabricated on bulk Si and SOI substrates. The ultra-thin (∼2 nm) strained-Ge channel heterostructure MOSFETs exhibited >4x mobility enhancements over bulk Si devices and >10x BTBT reduction over surface channel strained SiGe devices

  2. High Performance Computing Multicast

    2012-02-01

    A History of the Virtual Synchrony Replication Model,” in Replication: Theory and Practice, Charron-Bost, B., Pedone, F., and Schiper, A. (Eds...Performance Computing IP / IPv4 Internet Protocol (version 4.0) IPMC Internet Protocol MultiCast LAN Local Area Network MCMD Dr. Multicast MPI

  3. NGINX high performance

    Sharma, Rahul

    2015-01-01

    System administrators, developers, and engineers looking for ways to achieve maximum performance from NGINX will find this book beneficial. If you are looking for solutions such as how to handle more users from the same system or load your website pages faster, then this is the book for you.

  4. Economic feasibility of small scale button mushroom production in pakistan

    Tahir, A.; Hassan, S.

    2013-01-01

    Abstract:- Mushroom is widely cultivated as a proteineous vegetable in many countries of the world including Pakistan. Its cultivation requires less space, care, equipment and cost compared to many other crops and livestock. The present study was conducted in 2010 to estimate the profitability of small scale button mushroom production at National Agricultural Research Centre (NARC) Islamabad, Pakistan. The cost of production methodology was used for this study. The yield and gross return of mushroom was estimated at 155.6 kg ha and Rs.77,800 ha , respectively. The results indicated the fact that mushroom production is very much remunerative to its producers as it can give maximum net return by reducing their cost of production as its cultivation is dependent on the agricultural raw material which is cheaply available. (author)

  5. Numerical simulation of small scale soft impact tests

    Varpasuo, Pentti

    2008-01-01

    This paper describes the small scale soft missile impact tests. The purpose of the test program is to provide data for the calibration of the numerical simulation models for impact simulation. In the experiments, both dry and fluid filled missiles are used. The tests with fluid filled missiles investigate the release speed and the droplet size of the fluid release. This data is important in quantifying the fire hazard of flammable liquid after the release. The spray release velocity and droplet size are also input data for analytical and numerical simulation of the liquid spread in the impact. The behaviour of the impact target is the second investigative goal of the test program. The response of reinforced and pre-stressed concrete walls is studied with the aid of displacement and strain monitoring. (authors)

  6. A multi scale model for small scale plasticity

    Zbib, Hussein M.

    2002-01-01

    Full text.A framework for investigating size-dependent small-scale plasticity phenomena and related material instabilities at various length scales ranging from the nano-microscale to the mesoscale is presented. The model is based on fundamental physical laws that govern dislocation motion and their interaction with various defects and interfaces. Particularly, a multi-scale model is developed merging two scales, the nano-microscale where plasticity is determined by explicit three-dimensional dislocation dynamics analysis providing the material length-scale, and the continuum scale where energy transport is based on basic continuum mechanics laws. The result is a hybrid simulation model coupling discrete dislocation dynamics with finite element analyses. With this hybrid approach, one can address complex size-dependent problems, including dislocation boundaries, dislocations in heterogeneous structures, dislocation interaction with interfaces and associated shape changes and lattice rotations, as well as deformation in nano-structured materials, localized deformation and shear band

  7. Small-Scale Pellet Boiler with Thermoelectric Generator

    Moser, Wilhelm; Friedl, Guenther; Haslinger, Walter [Austrian Bioenergy Centre GmbH, Wieselburg (Austria); Hofbauer, Hermann [Vienna Univ. of Technology (Austria). Inst. of Chemical Engineering

    2006-07-15

    Pellet burners need auxiliary electrical power to provide CO{sub 2}-balanced heat in a comfortable and environment-friendly way. The idea is to produce this and some extra electricity within the furnace in order to save resources and to gain operation reliability and independency. Thermoelectric generators (TEGs) allow the direct conversion of heat to electrical power to a certain extent. They have the advantages of a maintenance-free long life and soundless operation without moving parts or any working fluid. A novel kind of decentralised small-scale biomass-based combined heat and power generation will be developed. The basic system allows grid-independent operation of automatically running biomass furnaces including fuel delivery from storage and circulating the cooling respectively heating water or air. The advanced system also provides electricity for network supply or for other electrical devices and is an additional benefit.

  8. Exergoeconomic analysis of small-scale biomass steam cogeneration

    Rodriguez Sotomonte, Cesar Adolfo; Lora, Electo Eduardo Silva [Universidade Federal de Itajuba, MG (Brazil)], e-mails: c.rodriguez32@unifei.edu.br, electo@unifei.edu.br; Venturini, Osvaldo Jose; Escobar, Jose Carlos [Universidad Federal de Itajuba, MG (Brazil)], e-mail: osvaldo@unifei.edu.br

    2010-07-01

    The principal objective of this work is to develop a calculation process, based on the second law of thermodynamics, for evaluating the thermoeconomic potential of a small steam cogeneration plant using waste from pulp processing and/or sawmills as fuel. Four different configurations are presented and assessed. The exergetic efficiency of the cycles that use condensing turbines is found to be around 11%, which has almost 3 percent higher efficiency than cycles with back pressure turbines. The thermoeconomic equations used in this paper estimated the production costs varying the fuel price. The main results show that present cost of technologies in a small-scale steam cycle cogeneration do not justify the implementation of more efficient systems for biomass prices less than 100 R$/t. (author)

  9. Small scale renewable solar energy and the best result project

    Bilbao, J.; Miguel, A.H.; Perez-Burgos, A.M. [Valladolid Univ. (Spain)

    2008-07-01

    The European Community has established programmes with different Projects in relation with the develop of an energy system according to de Kyoto objectives, improving energy efficiency, maintaining security supply and doubling the share of renewable energy use. The Best Result Project (Building and Energy Systems and Technology in Renewable Energy Sources Update and Linked Training), is financed by the European Commission, Intelligent Energy Agency (EIE) and the project objectives are to develop training and diffusion activities in the field of Renewable Energy Technology. The project aims to raise the renewable energy knowledge among suppliers and general public. The project activities are: basis and specialized training events, workshops, meetings, visits and e-learning common platform. The final objective is to extend the market of small scale RES applications in the building and energy sector through common and local activities addressing RES suppliers and consumers. (orig.)

  10. Optimal Combustion Conditions for a Small-scale Biomass Boiler

    Viktor Plaček

    2012-01-01

    Full Text Available This paper reports on an attempt to achieve maximum efficiency and lowest possible emissions for a small-scale biomass boiler. This aim can be attained only by changing the control algorithm of the boiler, and in this way not raising the acquisition costs for the boiler. This paper describes the experimental facility, the problems that arose while establishing the facility, and how we have dealt with them. The focus is on discontinuities arising after periodic grate sweeping, and on finding the parameters of the PID control loops. Alongside these methods, which need a lambda probe signal for proper functionality, we inroduce another method, which is able to intercept the optimal combustion working point without the need to use a lambda sensor.

  11. Pervasive Rise of Small-scale Deforestation in Amazonia.

    Kalamandeen, Michelle; Gloor, Emanuel; Mitchard, Edward; Quincey, Duncan; Ziv, Guy; Spracklen, Dominick; Spracklen, Benedict; Adami, Marcos; Aragão, Luiz E O C; Galbraith, David

    2018-01-25

    Understanding forest loss patterns in Amazonia, the Earth's largest rainforest region, is critical for effective forest conservation and management. Following the most detailed analysis to date, spanning the entire Amazon and extending over a 14-year period (2001-2014), we reveal significant shifts in deforestation dynamics of Amazonian forests. Firstly, hotspots of Amazonian forest loss are moving away from the southern Brazilian Amazon to Peru and Bolivia. Secondly, while the number of new large forest clearings (>50 ha) has declined significantly over time (46%), the number of new small clearings (<1 ha) increased by 34% between 2001-2007 and 2008-2014. Thirdly, we find that small-scale low-density forest loss expanded markedly in geographical extent during 2008-2014. This shift presents an important and alarming new challenge for forest conservation, despite reductions in overall deforestation rates.

  12. Design and analysis of tubular permanent magnet linear generator for small-scale wave energy converter

    Kim, Jeong-Man; Koo, Min-Mo; Jeong, Jae-Hoon; Hong, Keyyong; Cho, Il-Hyoung; Choi, Jang-Young

    2017-05-01

    This paper reports the design and analysis of a tubular permanent magnet linear generator (TPMLG) for a small-scale wave-energy converter. The analytical field computation is performed by applying a magnetic vector potential and a 2-D analytical model to determine design parameters. Based on analytical solutions, parametric analysis is performed to meet the design specifications of a wave-energy converter (WEC). Then, 2-D FEA is employed to validate the analytical method. Finally, the experimental result confirms the predictions of the analytical and finite element analysis (FEA) methods under regular and irregular wave conditions.

  13. Immediate and delayed recall of a small-scale spatial array.

    Tlauka, Michael; Donaldson, Phillip; Bonnar, Daniel

    2015-01-01

    The study examined people's spatial memory of a small-scale array of objects. Earlier work has primarily relied on short-retention intervals, and to date it is not known whether performance is affected by longer intervals between learning and recall. In the present investigation, university students studied seven target objects. Recall was tested immediately after learning and after an interval of seven days. Performance was found to be similar in the immediate and delayed conditions, and the results suggested that recall was facilitated by egocentric and intrinsic cues. The findings are discussed with reference to recent investigations that have shown task parameters can influence spatial recall.

  14. Emissions from small scale combustion of pelletized wood fuels

    Bachs, A.

    1998-01-01

    Combustion of wood pellets in small scale heating systems with an effect below 20 kW has increased. During the winter season 1995/96 1500 small plants for heating houses are estimated to be in operation. Stack emissions from three pellet burners and two pellet stoves have been studied at laboratory. Different pellet qualities were tested. When the fraction of fines increased also the NO x emissions increased with about 10 %. As reference fuel 8 mm pellets was used. Tests with 6 mm pellets gave, in most cases, significant lower emissions of CO and THC. Eleven stoves, burners and boilers were studied in a field test. The results show that all the plants generally have higher emissions in the field than during conditions when the plants are adjusted with a stack gas monitoring instrument. A conclusion is that it is difficult for the operator to adjust the plant without a monitoring instrument. The emissions from the tested plants give an estimation of stack gas emissions from small scale pellet plants. The difference between the 'best' and 'worst' technologies is big. The span of emissions with the best technology to the worst is given below. The interval is concerning normal combustion . During abnormal conditions the emissions are on a significant higher level: * CO 80-1 000 mg/MJ; * Tar 0,3-19 mg/MJ; * THC (as methane equivalents) 2-100 mg/MJ; * NO x 50-70 mg/W;, and * Dust emissions 20-40 mg/MJ. Emissions from pellets heating are lower than from wood combustion and the best technology is close to the emission from oil burners. Wood and pellets have the same origin but the conditions to burn them in an environmental friendly way differ. Combustion of pellets could be improved through improved control of the air and fuel ratio that will create more stable conditions for the combustion

  15. Real-Time Fabric Defect Detection Using Accelerated Small-Scale Over-Completed Dictionary of Sparse Coding

    Tianpeng Feng

    2016-01-01

    Full Text Available An auto fabric defect detection system via computer vision is used to replace manual inspection. In this paper, we propose a hardware accelerated algorithm based on a small-scale over-completed dictionary (SSOCD via sparse coding (SC method, which is realized on a parallel hardware platform (TMS320C6678. In order to reduce computation, the image patches projections in the training SSOCD are taken as features and the proposed features are more robust, and exhibit obvious advantages in detection results and computational cost. Furthermore, we introduce detection ratio and false ratio in order to measure the performance and reliability of the hardware accelerated algorithm. The experiments show that the proposed algorithm can run with high parallel efficiency and that the detection speed meets the real-time requirements of industrial inspection.

  16. design of a small scale wind generator for low wind speed areas

    USER

    Most small scale level wind turbine generators are directly driven system, variable speed, and partially ... the best solutions for small-scale wind power plants. Low-speed multi-pole PM generators ..... Designs of the Same Magnet Structure for.

  17. Safety trends in small-scale coal mines in developing countries with particular reference to China, India and Pakistan

    Jadoon, K.G.; Akbar, S.; Edwards, J.S.

    2004-01-01

    Small-scale mining for coal is practiced all over the world. But major proportions of these mines are located in developing countries in Asia. China, India and Pakistan are the main producers of coal from small- scale mines. Due to prevailing poor safety conditions in these mines, a large number of workers receive injuries ranging from minor to fatal. Gas explosions/outbursts, roof falls, material handling, etc. are the main causes of majority of accidents occurring in small-scale mines. In China, thousands of workers are killed due to gas explosions/outbursts every year. Lack of financial resources, inadequate education and training of workers, contractual labour systems and lack of commitment to improve safety and health are the reasons that mainly contribute to the poor safety performance in this sector of mining. (author)

  18. High performance proton accelerators

    Favale, A.J.

    1989-01-01

    In concert with this theme this paper briefly outlines how Grumman, over the past 4 years, has evolved from a company that designed and fabricated a Radio Frequency Quadrupole (RFQ) accelerator from the Los Alamos National Laboratory (LANL) physics and specifications to a company who, as prime contractor, is designing, fabricating, assembling and commissioning the US Army Strategic Defense Commands (USA SDC) Continuous Wave Deuterium Demonstrator (CWDD) accelerator as a turn-key operation. In the case of the RFQ, LANL scientists performed the physics analysis, established the specifications supported Grumman on the mechanical design, conducted the RFQ tuning and tested the RFQ at their laboratory. For the CWDD Program Grumman has the responsibility for the physics and engineering designs, assembly, testing and commissioning albeit with the support of consultants from LANL, Lawrence Berkeley Laboratory (LBL) and Brookhaven National laboratory. In addition, Culham Laboratory and LANL are team members on CWDD. LANL scientists have reviewed the physics design as well as a USA SDC review board. 9 figs

  19. Experimental, theoretical, and numerical studies of small scale combustion

    Xu, Bo

    Recently, the demand increased for the development of microdevices such as microsatellites, microaerial vehicles, micro reactors, and micro power generators. To meet those demands the biggest challenge is obtaining stable and complete combustion at relatively small scale. To gain a fundamental understanding of small scale combustion in this thesis, thermal and kinetic coupling between the gas phase and the structure at meso and micro scales were theoretically, experimentally, and numerically studied; new stabilization and instability phenomena were identified; and new theories for the dynamic mechanisms of small scale combustion were developed. The reduction of thermal inertia at small scale significantly reduces the response time of the wall and leads to a strong flame-wall coupling and extension of burning limits. Mesoscale flame propagation and extinction in small quartz tubes were theoretically, experimentally and numerically studied. It was found that wall-flame interaction in mesoscale combustion led to two different flame regimes, a heat-loss dominant fast flame regime and a wall-flame coupling slow flame regime. The nonlinear transition between the two flame regimes was strongly dependent on the channel width and flow velocity. It is concluded that the existence of multiple flame regimes is an inherent phenomenon in mesoscale combustion. In addition, all practical combustors have variable channel width in the direction of flame propagation. Quasi-steady and unsteady propagations of methane and propane-air premixed flames in a mesoscale divergent channel were investigated experimentally and theoretically. The emphasis was the impact of variable cross-section area and the flame-wall coupling on the flame transition between different regimes and the onset of flame instability. For the first time, spinning flames were experimentally observed for both lean and rich methane and propane-air mixtures in a broad range of equivalence ratios. An effective Lewis number

  20. Ionospheric response to variable electric fields in small-scale auroral structures

    B. S. Lanchester

    1998-10-01

    Full Text Available High time and space resolution optical and radar measurements have revealed the influence of electric fields on E-region electron density profiles in small-scale auroral structures. Large electric fields are present adjacent to auroral filaments produced by monoenergetic electron fluxes. The ionisation profiles measured within and beside the auroral filaments show the effects of plasma convection due to electric fields as well as the consequences of the response time to large and dynamic fluxes of energetic electrons. Without high-resolution optical measurements, the interpretation of the radar data is limited.Key words. Auroral ionosphere · Ionosphere-magnetosphere interactions · EISCAT

  1. Ionospheric response to variable electric fields in small-scale auroral structures

    B. S. Lanchester

    Full Text Available High time and space resolution optical and radar measurements have revealed the influence of electric fields on E-region electron density profiles in small-scale auroral structures. Large electric fields are present adjacent to auroral filaments produced by monoenergetic electron fluxes. The ionisation profiles measured within and beside the auroral filaments show the effects of plasma convection due to electric fields as well as the consequences of the response time to large and dynamic fluxes of energetic electrons. Without high-resolution optical measurements, the interpretation of the radar data is limited.

    Key words. Auroral ionosphere · Ionosphere-magnetosphere interactions · EISCAT

  2. Investigation of the feasibility of a small scale transmutation device

    Sit, Roger Carson

    This dissertation presents the design and feasibility of a small-scale, fusion-based transmutation device incorporating a commercially available neutron generator. It also presents the design features necessary to optimize the device and render it practical for the transmutation of selected long-lived fission products and actinides. Four conceptual designs of a transmutation device were used to study the transformation of seven radionuclides: long-lived fission products (Tc-99 and I-129), short-lived fission products (Cs-137 and Sr-90), and selective actinides (Am-241, Pu-238, and Pu-239). These radionuclides were chosen because they are major components of spent nuclear fuel and also because they exist as legacy sources that are being stored pending a decision regarding their ultimate disposition. The four designs include the use of two different devices; a Deuterium-Deuterium (D-D) neutron generator (for one design) and a Deuterium-Tritium (D-T) neutron generator (for three designs) in configurations which provide different neutron energy spectra for targeting the radionuclide for transmutation. Key parameters analyzed include total fluence and flux requirements; transmutation effectiveness measured as irradiation effective half-life; and activation products generated along with their characteristics: activity, dose rate, decay, and ingestion and inhalation radiotoxicity. From this investigation, conclusions were drawn about the feasibility of the device, the design and technology enhancements that would be required to make transmutation practical, the most beneficial design for each radionuclide, the consequence of the transmutation, and radiation protection issues that are important for the conceptual design of the transmutation device. Key conclusions from this investigation include: (1) the transmutation of long-lived fission products and select actinides can be practical using a small-scale, fusion driven transmutation device; (2) the transmutation of long

  3. The statistical analysis of energy release in small-scale coronal structures

    Ulyanov, Artyom; Kuzin, Sergey; Bogachev, Sergey

    We present the results of statistical analysis of impulsive flare-like brightenings, which numerously occur in the quiet regions of solar corona. For our study, we utilized high-cadence observations performed with two EUV-telescopes - TESIS/Coronas-Photon and AIA/SDO. In total, we processed 6 sequences of images, registered throughout the period between 2009 and 2013, covering the rising phase of the 24th solar cycle. Based on high-speed DEM estimation method, we developed a new technique to evaluate the main parameters of detected events (geometrical sizes, duration, temperature and thermal energy). We then obtained the statistical distributions of these parameters and examined their variations depending on the level of solar activity. The results imply that near the minimum of the solar cycle the energy release in quiet corona is mainly provided by small-scale events (nanoflares), whereas larger events (microflares) prevail on the peak of activity. Furthermore, we investigated the coronal conditions that had specified the formation and triggering of registered flares. By means of photospheric magnetograms obtained with MDI/SoHO and HMI/SDO instruments, we examined the topology of local magnetic fields at different stages: the pre-flare phase, the peak of intensity and the ending phase. To do so, we introduced a number of topological parameters including the total magnetic flux, the distance between magnetic sources and their mutual arrangement. The found correlation between the change of these parameters and the formation of flares may offer an important tool for application of flare forecasting.

  4. Quantifying seismic anisotropy induced by small-scale chemical heterogeneities

    Alder, C.; Bodin, T.; Ricard, Y.; Capdeville, Y.; Debayle, E.; Montagner, J. P.

    2017-12-01

    Observations of seismic anisotropy are usually used as a proxy for lattice-preferred orientation (LPO) of anisotropic minerals in the Earth's mantle. In this way, seismic anisotropy observed in tomographic models provides important constraints on the geometry of mantle deformation associated with thermal convection and plate tectonics. However, in addition to LPO, small-scale heterogeneities that cannot be resolved by long-period seismic waves may also produce anisotropy. The observed (i.e. apparent) anisotropy is then a combination of an intrinsic and an extrinsic component. Assuming the Earth's mantle exhibits petrological inhomogeneities at all scales, tomographic models built from long-period seismic waves may thus display extrinsic anisotropy. In this paper, we investigate the relation between the amplitude of seismic heterogeneities and the level of induced S-wave radial anisotropy as seen by long-period seismic waves. We generate some simple 1-D and 2-D isotropic models that exhibit a power spectrum of heterogeneities as what is expected for the Earth's mantle, that is, varying as 1/k, with k the wavenumber of these heterogeneities. The 1-D toy models correspond to simple layered media. In the 2-D case, our models depict marble-cake patterns in which an anomaly in shear wave velocity has been advected within convective cells. The long-wavelength equivalents of these models are computed using upscaling relations that link properties of a rapidly varying elastic medium to properties of the effective, that is, apparent, medium as seen by long-period waves. The resulting homogenized media exhibit extrinsic anisotropy and represent what would be observed in tomography. In the 1-D case, we analytically show that the level of anisotropy increases with the square of the amplitude of heterogeneities. This relation is numerically verified for both 1-D and 2-D media. In addition, we predict that 10 per cent of chemical heterogeneities in 2-D marble-cake models can

  5. Controls on sublithospheric small-scale convection on Curie depths

    Likerman, Jeremias; Zlotnik, Sergio; Chun-Feng, Li

    2017-04-01

    As the ocean lithosphere cools and thickens, its bottom layer goes unstable leading to sub-lithospheric small-scale convection (SSC). Since SSC was originally proposed, there have been considerable efforts regarding the understanding of the physics that rules the thermal instabilities of the SSC (e.g. Dumoulin et al, 1999; Solomatov and Moresi, 2000). Over the last several years, it is understood that the interaction between the plate movement and the SSC tends to form longitudinal (LRs or also called 'Richter rolls') and transverse rolls (TRs), of which the axis is parallel and perpendicular to the plate motion, respectively. The geometry of these rolls have been been recently inferred by Li et al (2013) using Curie depths from the North Atlantic as proxies for plates temperatures. They showed that Curie depths have a large oscillating and heterogeneous patterns that could be related to SSC. In the North Atlantic transverse rolls seem predominant. In this work we analyze, by means of 3D dynamical numerical simulations, the influence of SSC on the Curie depths patterns observed in the North Atlantic and Pacific plates. We investigate the behaviour of the Curie isotherms trying to determine if SSC is able to reproduce the observed data, and the influence of several poorly constrained rheological parameters. Our numerical simulations show that: a) using realistic laboratory-constrained rheologies and temperature it is possible to modify temperatures as low as those at Curie depths; b) transverse rolls are generated as well as longitudinal rolls on those isotherms; c) the spreading rate is a first order control on the developing of transverse rolls. References Dumoulin, C., Doin, M. P., & Fleitout, L. (1999). Heat transport in stagnant lid convection with temperature-and pressure-dependent Newtonian or non-Newtonian rheology. Journal of Geophysical Research: Solid Earth, 104(B6), 12759-12777. Li, C. F., Wang, J., Lin, J., & Wang, T. (2013). Thermal evolution of the

  6. Pervious concrete fill in Pearl-Chain Bridges: Using small-scale results in full-scale implementation

    Lund, Mia Schou Møller; Hansen, Kurt Kielsgaard; Truelsen, R.

    2016-01-01

    distribution and strength properties is determined for 800 mm high blocks cast in different numbers of layers, and (2) full-scale implementation in a 26 m long Pearl-Chain Bridge. With a layer thickness of 27 cm, the small-scale tests indicated homogenous results; however, for the full-scale implementation......Pearl-Chain Bridge technology is a new prefabricated arch solution for highway bridges. This study investigates the feasibility of pervious concrete as a filling material in Pearl-Chain Bridges. The study is divided into two steps: (1) small-scale tests where the variation in vertical void...

  7. Increased power to heat ratio of small scale CHP plants using biomass fuels and natural gas

    Savola, Tuula; Fogelholm, Carl-Johan

    2006-01-01

    In this paper, we present a systematic study of process changes for increased power production in 1-20 MW e combined heat and power (CHP) plants. The changes are simulated, and their economic feasibility evaluated by using existing small scale CHP case plants. Increasing power production in decentralised CHP plants that operate according to a certain heat demand could reduce the fuel consumption and CO 2 emissions per power unit produced and improve the feasibility of CHP plant investments. The CHP plant process changes were simulated under design and off design conditions and an analysis of power and heat production, investment costs and CO 2 emissions was performed over the whole annual heat demand. The results show that using biomass fuels, there are profitable possibilities to increase the current power to heat ratios, 0.23-0.48, of the small scale CHP plants up to 0.26-0.56, depending on the size of the plant. The profitable changes were a two stage district heat exchanger and the addition of a steam reheater and a feed water preheater. If natural gas is used as an additional fuel, the power to heat ratio may be increased up to 0.35-0.65 by integrating a gas engine into the process. If the CO 2 savings from the changes are also taken into account, the economic feasibility of the changes increases. The results of this work offer useful performance simulation and investment cost knowledge for the development of more efficient and economically feasible small scale CHP processes

  8. Latent hardening size effect in small-scale plasticity

    Bardella, Lorenzo; Segurado, Javier; Panteghini, Andrea; Llorca, Javier

    2013-07-01

    We aim at understanding the multislip behaviour of metals subject to irreversible deformations at small-scales. By focusing on the simple shear of a constrained single-crystal strip, we show that discrete Dislocation Dynamics (DD) simulations predict a strong latent hardening size effect, with smaller being stronger in the range [1.5 µm, 6 µm] for the strip height. We attempt to represent the DD pseudo-experimental results by developing a flow theory of Strain Gradient Crystal Plasticity (SGCP), involving both energetic and dissipative higher-order terms and, as a main novelty, a strain gradient extension of the conventional latent hardening. In order to discuss the capability of the SGCP theory proposed, we implement it into a Finite Element (FE) code and set its material parameters on the basis of the DD results. The SGCP FE code is specifically developed for the boundary value problem under study so that we can implement a fully implicit (Backward Euler) consistent algorithm. Special emphasis is placed on the discussion of the role of the material length scales involved in the SGCP model, from both the mechanical and numerical points of view.

  9. Latent hardening size effect in small-scale plasticity

    Bardella, Lorenzo; Panteghini, Andrea; Segurado, Javier; Llorca, Javier

    2013-01-01

    We aim at understanding the multislip behaviour of metals subject to irreversible deformations at small-scales. By focusing on the simple shear of a constrained single-crystal strip, we show that discrete Dislocation Dynamics (DD) simulations predict a strong latent hardening size effect, with smaller being stronger in the range [1.5 µm, 6 µm] for the strip height. We attempt to represent the DD pseudo-experimental results by developing a flow theory of Strain Gradient Crystal Plasticity (SGCP), involving both energetic and dissipative higher-order terms and, as a main novelty, a strain gradient extension of the conventional latent hardening. In order to discuss the capability of the SGCP theory proposed, we implement it into a Finite Element (FE) code and set its material parameters on the basis of the DD results. The SGCP FE code is specifically developed for the boundary value problem under study so that we can implement a fully implicit (Backward Euler) consistent algorithm. Special emphasis is placed on the discussion of the role of the material length scales involved in the SGCP model, from both the mechanical and numerical points of view. (paper)

  10. Small scale lithium-lead/water-interaction studies

    Kranert, O.; Kottowski, H.

    1991-01-01

    One current concept in fusion blanket design is to utilize water as the coolant and liquid lithium-lead as the breeding/neutron multiplier material. Considering the complex design of the blanket module, it is likely that a water leakage into the liquid alloy may occur due to a tube rupture provoking an intolerable pressure increase in the blanket module. The pressure increase is caused by the combined chemical and thermohydraulic reaction of lithium-lead with water. Experiments which simulate such a transient event are necessary to obtain information which is important for the blanket module design. The interaction has been investigated by conducting small-scale experiments at various injection pressures, alloy- and coolant temperatures. Besides using eutectic Li 17 Pb 83 , Li 7 Pb 2 , lithium and lead have been used. Among other results, the experiments indicate increasing chemical reaction with increasing lithium concentration. At the same time, the chemical reaction inhibits violent thermohydaulic reactions due to the attenuating effect of the hydrogen produced. The preliminary epxerimental results from Li 17 Pb 83 and Li 7 Pb 2 reveal that the pressure- and temperature transients caused by the chemical and thermohydraulic reactions lie within technically manageable limits. (orig.)

  11. Small-Scale Testing of Laterally Loaded Monopiles in Sand

    Thomassen, Kristina; Roesen, Hanne Ravn; Ibsen, Lars Bo

    2011-01-01

    of small-scale laboratory tests. Six quasi-static tests are conducted on piles with diameters of 40mm and 100mm and a slenderness ratio, L/D, of 5. To minimise scale effects, the tests are carried out in a pressure tank at various stress levels. From the obtained load-deflection relationships......In current designs of offshore wind turbines, monopiles are often used as foundation. The behaviour of the monopoles when subjected to lateral loading has not been fully investigated. In this paper, the behaviour of two non-slender piles in sand subjected to lateral loading are analysed by means...... it is revealed that the uncertainties of the results for the pile with a diameter of 40mm are large. The load-deflection relationships normalised as H/(L2Dγ’) and y/D indicate that the lateral load, H, is proportional to L2D. Comparison of the normalised load-deflection relationships for different stress levels...

  12. Small-scale dislocation plasticity in strontium titanate

    Stukowski, Alexander; Javaid, Farhan; Durst, Karsten; Albe, Karsten [Technische Universitaet Darmstadt (Germany)

    2016-07-01

    Strontium titanate (STO) is an optically transparent perovskite oxide ceramic material. In contrast to other ceramics, single crystal STO plastically deforms under ambient condition, without showing a phase transition or early fracture. This remarkable ductility makes it a prime candidate for different technological applications. However, while the mechanical behavior of bulk STO has been studied extensively using uniaxial compression testing techniques, little is known about the local, small-scale behavior and the details of dislocation-based nanoplasticity in this perovskite material. In this contribution we compare results obtained from new nanoindentation experiments and corresponding large-scale molecular dynamics simulations. The evolution of the plastic zone and dislocation structures that form underneath the indenter is investigated using etch-pit methods in experiments and a novel three-dimensional defect identification technique in atomistic computer models. The latter allows tracing the evolution of the complete dislocation line network as function of indentation depth, quantifying the activity of different slip systems, and correlating this information with the recorded load-displacement curves and hardness data.

  13. Impact of small-scale geometric roughness on wetting behavior.

    Kumar, Vaibhaw; Errington, Jeffrey R

    2013-09-24

    We examine the extent to which small-scale geometric substrate roughness influences the wetting behavior of fluids at solid surfaces. Molecular simulation is used to construct roughness wetting diagrams wherein the progression of the contact angle is traced from the Cassie to Wenzel to impregnation regime with increasing substrate strength for a collection of systems with rectangularly shaped grooves. We focus on the evolution of these diagrams as the length scale of the substrate features approaches the size of a fluid molecule. When considering a series of wetting diagrams for substrates with fixed shape and variable feature periodicity, we find that the diagrams progressively shift away from a common curve as the substrate features become smaller than approximately 10 fluid diameters. It is at this length scale that the macroscopic models of Cassie and Wenzel become unreliable. Deviations from the macroscopic models are attributed to the manner in which the effective substrate-fluid interaction strength evolves with periodicity and the important role that confinement effects play for substrates with small periodicities.

  14. Structures and Intermittency in Small Scales Solar Wind Turbulence

    Sahraoui, Fouad; Goldstein, Melvyn

    2010-01-01

    Several observations in space plasmas have reported the presence of coherent structures at different plasma scales. Structure formation is believed to result from nonlinear interactions between the plasma modes, which depend strongly on their phase synchronization. Despite this important role of the phases in turbulence, very limited work has been devoted to study the phases as potential tracers of nonlinearities in comparison with the wealth of literature on power spectra of turbulence where phases are totally missed. The reason why the phases are seldom used is probably because they usually appear to be completely mixed (due to their dependence on an arbitrary time origin and to 2π periodicity). To handle the phases properly, a new method based on using surrogate data has been developed recently to detect coherent structures in magnetized plasmas [Sahraoui, PRE, 2008]. Here, we show new applications of the technique to study the nature (weak vs strong, self-similar vs intermittent) of the small scale turbulence in the solar wind using the Cluster observations.

  15. Small-scale structure in the diffuse interstellar medium

    Meyer, D.M.

    1990-01-01

    The initial results of a study to probe the small-scale structure in the diffuse interstellar medium (ISM) through IUE and optical observations of interstellar absorption lines toward both components of resolvable binary stars is reported. The binaries (Kappa CrA, 57 Aql, 59 And, HR 1609/10, 19 Lyn, and Theta Ser) observed with IUE have projected linear separations ranging from 5700 to 700 Au. Except for Kappa CrA, the strengths of the interstellar absorption lines toward both components of these binaries agree to within 10 percent. In the case of Kappa CrA, the optically thin interstellar Mg I and Mn II lines are about 50 percent stronger toward Kappa-2 CrA than Kappa-1 CrA. Higher resolution observations of interstellar Ca II show that this difference is concentrated in the main interstellar component at V(LSR) = 9 + or - 2 km/s. Interestingly, this velocity corresponds to an intervening cloud that may be associated with the prominent Loop I shell in the local ISM. Given the separation (23 arcsec) and distance (120 pc) of Kappa CrA, the line strength variations indicate that this cloud has structure on scales of 2800 AU or less. 21 refs

  16. Small-scale fixed wing airplane software verification flight test

    Miller, Natasha R.

    The increased demand for micro Unmanned Air Vehicles (UAV) driven by military requirements, commercial use, and academia is creating a need for the ability to quickly and accurately conduct low Reynolds Number aircraft design. There exist several open source software programs that are free or inexpensive that can be used for large scale aircraft design, but few software programs target the realm of low Reynolds Number flight. XFLR5 is an open source, free to download, software program that attempts to take into consideration viscous effects that occur at low Reynolds Number in airfoil design, 3D wing design, and 3D airplane design. An off the shelf, remote control airplane was used as a test bed to model in XFLR5 and then compared to flight test collected data. Flight test focused on the stability modes of the 3D plane, specifically the phugoid mode. Design and execution of the flight tests were accomplished for the RC airplane using methodology from full scale military airplane test procedures. Results from flight test were not conclusive in determining the accuracy of the XFLR5 software program. There were several sources of uncertainty that did not allow for a full analysis of the flight test results. An off the shelf drone autopilot was used as a data collection device for flight testing. The precision and accuracy of the autopilot is unknown. Potential future work should investigate flight test methods for small scale UAV flight.

  17. Hydropower harvesting from a small scale reciprocating system

    Malla, Ramesh B.; Shrestha, Binu; Bagtzoglou, Amvrossios; Drasdis, Jonathon [Department of Civil and Environmental Engineering, University of Connecticut, 261 Glenbrook Road, Storrs, CT 06269-2037 (United States); Johnson, Paul [eGen LLC, 1084 Shennecossett Road, Groton, CT 06340 (United States)

    2011-05-15

    Conventional hydropower systems that can take advantage of low head movement of water require substantial flow rates. However, these systems cannot harvest hydro energy from small sources of water with low head and low discharge, such as streams and creeks. The reciprocating hydropower system discussed in this paper can harvest power from such low flow discharge and low head sources. This paper presents a detailed proof-of-concept study of the hydropower model, including the underlining theoretical principles. Laboratory test results demonstrating the dependence of the lift force in the reciprocating small scale hydropower model as a function of flow velocity, size and rotational speed of the cylinder and comparison of the results with a previous study are also included. Two methods of power harvesting from the output displacement obtained from the hydropower system are discussed. The first employs electromagnetic induction principles and the other is based on a linear inertial generator using a conventional second order spring mass damper system. Finally, results from a finite element analysis of the hydropower system are presented and facilitate future design of the structural aspects of the housing for the reciprocating cylinder. (author)

  18. Social Norms of Cooperation in Small-Scale Societies.

    Fernando P Santos

    2016-01-01

    Full Text Available Indirect reciprocity, besides providing a convenient framework to address the evolution of moral systems, offers a simple and plausible explanation for the prevalence of cooperation among unrelated individuals. By helping someone, an individual may increase her/his reputation, which may change the pre-disposition of others to help her/him in the future. This, however, depends on what is reckoned as a good or a bad action, i.e., on the adopted social norm responsible for raising or damaging a reputation. In particular, it remains an open question which social norms are able to foster cooperation in small-scale societies, while enduring the wide plethora of stochastic affects inherent to finite populations. Here we address this problem by studying the stochastic dynamics of cooperation under distinct social norms, showing that the leading norms capable of promoting cooperation depend on the community size. However, only a single norm systematically leads to the highest cooperative standards in small communities. That simple norm dictates that only whoever cooperates with good individuals, and defects against bad ones, deserves a good reputation, a pattern that proves robust to errors, mutations and variations in the intensity of selection.

  19. Social Norms of Cooperation in Small-Scale Societies.

    Santos, Fernando P; Santos, Francisco C; Pacheco, Jorge M

    2016-01-01

    Indirect reciprocity, besides providing a convenient framework to address the evolution of moral systems, offers a simple and plausible explanation for the prevalence of cooperation among unrelated individuals. By helping someone, an individual may increase her/his reputation, which may change the pre-disposition of others to help her/him in the future. This, however, depends on what is reckoned as a good or a bad action, i.e., on the adopted social norm responsible for raising or damaging a reputation. In particular, it remains an open question which social norms are able to foster cooperation in small-scale societies, while enduring the wide plethora of stochastic affects inherent to finite populations. Here we address this problem by studying the stochastic dynamics of cooperation under distinct social norms, showing that the leading norms capable of promoting cooperation depend on the community size. However, only a single norm systematically leads to the highest cooperative standards in small communities. That simple norm dictates that only whoever cooperates with good individuals, and defects against bad ones, deserves a good reputation, a pattern that proves robust to errors, mutations and variations in the intensity of selection.

  20. Catalytic heat exchangers for small-scale production of hydrogen - feasibility study

    Silversand, F [Catator AB, Lund (Sweden)

    2002-02-01

    A feasibility study concerning heat-exchanger reactors in small-scale production of hydrogen has been performed on the request of Svenskt Gastekniskt Center AB and SWEP International AB. The basic idea is to implement different catalysts into brazed plate-type heat exchangers. This can be achieved by installing catalytic cylinders in the inlet-and outlet ports of the heat exchangers or through treatment of the plates to render them catalytically active. It is also possible to sandwich catalytically active wire meshes between the plates. Experiments concerning steam reforming of methanol and methane have been performed in a micro-reactor to gather kinetic data for modelling purposes. Performance calculations concerning heat exchanger reactors have then been conducted with Catator's generic simulation code for catalytic reactors (CatalystExplorer). The simulations clearly demonstrate the technical performance of these reactors. Indeed, the production rate of hydrogen is expected to be about 10 nm{sup 3}/h per litre of heat exchanger. The corresponding value for a conventional steam-reforming unit is about 1 nm{sup 3}/h or less per litre of reactor volume. Also, the compactness and the high degree of integration together with the possibilities of mass production will give an attractive cost for such units. Depending on the demands concerning the purity of the hydrogen it is possible to add secondary catalytic steps like water-gas shifters, methanation and selective oxidation, into a one-train unit, i.e. to design an all-inclusive design. Such reactors can be used for the supply of hydrogen to fuel cells. The production cost for hydrogen can be cut by 60 - 70% through the utilisation of heat exchanger reactors instead of conventional electrolysis. This result is primarily a result of the high price for electricity compared to the feed stock prices in steam reforming. It is important to verify the performance calculations and the simulation results through experimental

  1. Catalytic heat exchangers for small-scale production of hydrogen - feasibility study

    Silversand, F. [Catator AB, Lund (Sweden)

    2002-02-01

    A feasibility study concerning heat-exchanger reactors in small-scale production of hydrogen has been performed on the request of Svenskt Gastekniskt Center AB and SWEP International AB. The basic idea is to implement different catalysts into brazed plate-type heat exchangers. This can be achieved by installing catalytic cylinders in the inlet-and outlet ports of the heat exchangers or through treatment of the plates to render them catalytically active. It is also possible to sandwich catalytically active wire meshes between the plates. Experiments concerning steam reforming of methanol and methane have been performed in a micro-reactor to gather kinetic data for modelling purposes. Performance calculations concerning heat exchanger reactors have then been conducted with Catator's generic simulation code for catalytic reactors (CatalystExplorer). The simulations clearly demonstrate the technical performance of these reactors. Indeed, the production rate of hydrogen is expected to be about 10 nm{sup 3}/h per litre of heat exchanger. The corresponding value for a conventional steam-reforming unit is about 1 nm{sup 3}/h or less per litre of reactor volume. Also, the compactness and the high degree of integration together with the possibilities of mass production will give an attractive cost for such units. Depending on the demands concerning the purity of the hydrogen it is possible to add secondary catalytic steps like water-gas shifters, methanation and selective oxidation, into a one-train unit, i.e. to design an all-inclusive design. Such reactors can be used for the supply of hydrogen to fuel cells. The production cost for hydrogen can be cut by 60 - 70% through the utilisation of heat exchanger reactors instead of conventional electrolysis. This result is primarily a result of the high price for electricity compared to the feed stock prices in steam reforming. It is important to verify the performance calculations and the simulation results through

  2. Mixing of Process Heels, Process Solutions and Recycle Streams: Small-Scale Simulant

    Kaplan, D.I.

    2001-01-01

    The overall objective of this small-scale simulant mixing study was to identify the processes within the Hanford Site River Protection Project - Waste Treatment Plant (RPP-WTP) that may generate precipitates and to identify the types of precipitates formed. This information can be used to identify where mixtures of various solutions will cause precipitation of solids, potentially causing operational problems such as fouling equipment or increasing the amount of High Level Waste glass produced. Having this information will help guide protocols for flushing or draining tanks, mixing internal recycle streams, and mixing waste tank supernates. This report contains the discussion and thermodynamic chemical speciation modeling of the raw data

  3. Evaluation of measurement uncertainty for purity of a monoterpenic acid by small-scale coulometry

    Norte, L. C.; de Carvalho, E. M.; Tappin, M. R. R.; Borges, P. P.

    2018-03-01

    Purity of the perylic acid (HPe) which is a monoterpenic acid from natural product (NP) with anti-inflammatory and anticancer properties was analyzed by small-scale coulometry (SSC), due to the low availability of HPe on the pharmaceutic market and its high cost. This work aims to present the evaluation of the measurements uncertainty from the purity of HPe by using SSC. Coulometric mean of purity obtained from 5 replicates resulted in 94.23% ± 0.88% (k = 2.06, for an approximately 95% confidence level). These studies aim in the future to develop the production of certified reference materials from NPs.

  4. The small-scale species mobility in calcareous grasslands - example from southern Poland

    Wojciech Bąba

    2011-01-01

    Full Text Available In this paper I use the different measures of species mobility to describe the fine small-scale dynamics of calcareous grassland built mainly by perennial species and developed in the highly heterogeneous habitat of calcareous rocks. The community showed the low dynamics on a plot-scale (100 m2 and a high one on the scale of 1 m2. However, the studied species differed greatly in calculated indices: turnover rate, (T; 6-64, residence time (RT; 0.5-21.8 y and carousel time (CT; 4-420 y as well as the observed tendency to persistence on the spots (PERSIST and their re-colonisation (AGAIN. This allowed to distinguish the three groups of species: (1 "core species" characterized by high frequency and low T and high CT and RT values, which determine the low dynamics of a community on the plot scale, (2 species with intermediate mobility rate and (3 the group with high mobility rate. The observed cumulative frequencies of all the studied species (CFobs were much lower than expected under the random re-assignation model (CFRR. Moreover, they were also lower than those predicted by random immigration model (CFRI. The results showed that the "complex carousel" model rather than "single carousel" one explained better the small-scale dynamics of calcareous grasslands.

  5. To What Extent Do Improved Practices Increase Productivity of Small-Scale Rice Cultivation in A Rain-fed Area? : Evidence from Tanzania

    Yuko Nakano; Yuki Tanaka; Keijiro Otsuka

    2014-01-01

    This paper investigates the impact of training provided by a large-scale private farm on the performance of surrounding small-scale rice farmers in a rain-fed area in Tanzania. We found that the training effectively enhances the adoption of improved rice cultivation practices, paddy yield, and profit of rice cultivation by small-holder farmers. In fact, the trainees achieve paddy yield of 5 tons per hectare on average, which is remarkably high for rain-fed rice cultivation. Our results sugges...

  6. On Spatial Resolution in Habitat Models: Can Small-scale Forest Structure Explain Capercaillie Numbers?

    Ilse Storch

    2002-06-01

    Full Text Available This paper explores the effects of spatial resolution on the performance and applicability of habitat models in wildlife management and conservation. A Habitat Suitability Index (HSI model for the Capercaillie (Tetrao urogallus in the Bavarian Alps, Germany, is presented. The model was exclusively built on non-spatial, small-scale variables of forest structure and without any consideration of landscape patterns. The main goal was to assess whether a HSI model developed from small-scale habitat preferences can explain differences in population abundance at larger scales. To validate the model, habitat variables and indirect sign of Capercaillie use (such as feathers or feces were mapped in six study areas based on a total of 2901 20 m radius (for habitat variables and 5 m radius sample plots (for Capercaillie sign. First, the model's representation of Capercaillie habitat preferences was assessed. Habitat selection, as expressed by Ivlev's electivity index, was closely related to HSI scores, increased from poor to excellent habitat suitability, and was consistent across all study areas. Then, habitat use was related to HSI scores at different spatial scales. Capercaillie use was best predicted from HSI scores at the small scale. Lowering the spatial resolution of the model stepwise to 36-ha, 100-ha, 400-ha, and 2000-ha areas and relating Capercaillie use to aggregated HSI scores resulted in a deterioration of fit at larger scales. Most importantly, there were pronounced differences in Capercaillie abundance at the scale of study areas, which could not be explained by the HSI model. The results illustrate that even if a habitat model correctly reflects a species' smaller scale habitat preferences, its potential to predict population abundance at larger scales may remain limited.

  7. ARCADE small-scale docking mechanism for micro-satellites

    Boesso, A.; Francesconi, A.

    2013-05-01

    The development of on-orbit autonomous rendezvous and docking (ARD) capabilities represents a key point for a number of appealing mission scenarios that include activities of on-orbit servicing, automated assembly of modular structures and active debris removal. As of today, especially in the field of micro-satellites ARD, many fundamental technologies are still missing or require further developments and micro-gravity testing. In this framework, the University of Padova, Centre of Studies and Activities for Space (CISAS), developed the Autonomous Rendezvous Control and Docking Experiment (ARCADE), a technology demonstrator intended to fly aboard a BEXUS stratospheric balloon. The goal was to design, build and test, in critical environment conditions, a proximity relative navigation system, a custom-made reaction wheel and a small-size docking mechanism. The ARCADE docking mechanism was designed against a comprehensive set of requirements and it can be classified as small-scale, central, gender mating and unpressurized. The large use of commercial components makes it low-cost and simple to be manufactured. Last, it features a good tolerance to off-nominal docking conditions and a by-design soft docking capability. The final design was extensively verified to be compliant with its requirements by means of numerical simulations and physical testing. In detail, the dynamic behaviour of the mechanism in both nominal and off-nominal conditions was assessed with the multibody dynamics analysis software MD ADAMS 2010 and functional tests were carried out within the fully integrated ARCADE experiment to ensure the docking system efficacy and to highlight possible issues. The most relevant results of the study will be presented and discussed in conclusion to this paper.

  8. Small Scales Structure of MHD Turbulence, Tubes or Ribbons?

    Verdini, A.; Grappin, R.; Alexandrova, O.; Lion, S.

    2017-12-01

    Observations in the solar wind indicate that turbulent eddies change their anisotropy with scales [1]. At large scales eddies are elongated in direction perpendicular to the mean-field axis. This is the result of solar wind expansion that affects both the anisotropy and single-spacecraft measurments [2,3]. At small scales one recovers the anisotropy expected in strong MHD turbulence and constrained by the so-called critical balance: eddies are elongated along the mean-field axis. However, the actual eddy shape is intermediate between tubes and ribbons, preventing us to discriminate between two concurrent theories that predict 2D axysimmetric anisotropy [4] or full 3D anisotropy [5]. We analyse 10 years of WIND data and apply a numerically-derived criterion to select intervals in which solar wind expansion is expected to be negligible. By computing the anisotropy of structure functions with respect to the local mean field we obtain for the first time scaling relations that are in agreement with full 3D anisotropy, i.e. ribbons-like structures. However, we cannot obtain the expected scaling relations for the alignment angle which, according to the theory, is physically responsible for the departure from axisymmetry. In addition, a further change of anisotropy occurs well above the proton scales. We discuss the implication of our findings and how numerical simulations can help interpreting the observed spectral anisotropy. [1] Chen et al., ApJ, 768:120, 2012 [2] Verdini & Grappin, ApJL, 808:L34, 2015 [3] Vech & Chen, ApJL, 832:L16, 2016 [4] Goldreich & Shridar, ApJ, 438:763, 1995 [5] Boldyrev, ApJL, 626:L37, 2005

  9. Introduction of an energy efficiency tool for small scale biomass gasifiers – A thermodynamic approach

    Vakalis, S.; Patuzzi, F.; Baratieri, M.

    2017-01-01

    Highlights: • Analysis of plants for electricity, heat and materials production. • Thermodynamic analysis by using exergy, entransy and statistical entropy. • Extrapolation of a single efficiency index by combining the thermodynamic parameters. • Application of methodology for two monitored small scale gasifiers. - Abstract: Modern gasification plants, should be treated as poly-generation facilities because, alongside the production of electricity and heat, valuable or waste materials streams are generated. Thus, integrated methods should be introduced in order to account for the full range and the nature of the products. Application of conventional hybrid indicators that convert the output into monetary units or CO_2 equivalents are a source of bias because of the inconsistency of the conversion factors and unreliability of the available data. Therefore, this study introduces a novel thermodynamic-based method for assessing gasification plants performance by means of exergy, entransy and statistical entropy. A monitoring campaign has been implemented on two small scale gasifiers and the results have been applied on the proposed method. The energy plants are compared in respect to their individual thermodynamic parameters for energy production and materials distribution. In addition, the method returns one single value which is a resultant of all the investigated parameters and is a characteristic value of the overall performance of an energy plant.

  10. Small-scale topography modulates elevational α-, β- and γ-diversity of Andean leaf beetles.

    Thormann, Birthe; Ahrens, Dirk; Espinosa, Carlos Iván; Armijos, Diego Marín; Wagner, Thomas; Wägele, Johann W; Peters, Marcell K

    2018-03-09

    Elevational diversity gradients are typically studied without considering the complex small-scale topography of large mountains, which generates habitats of strongly different environmental conditions within the same elevational zones. Here we analyzed the importance of small-scale topography for elevational diversity patterns of hyperdiverse tropical leaf beetles (Coleoptera: Chrysomelidae). We compared patterns of elevational diversity and species composition of beetles in two types of forests (on mountain ridges and in valleys) and analyzed whether differences in the rate of species turnover among forest habitats lead to shifts in patterns of elevational diversity when scaling up from the local study site to the elevational belt level. We sampled beetle assemblages at 36 sites in the Podocarpus National Park, Ecuador, which were equally distributed over two forest habitats and three elevational levels. DNA barcoding and Poisson tree processes modelling were used to delimitate putative species. On average, local leaf beetle diversity showed a clear hump-shaped pattern. However, only diversity in forests on mountain ridges peaked at mid-elevation, while beetle diversity in valleys was similarly high at low- and mid-elevation and only declined at highest elevations. A higher turnover of species assemblages at lower than at mid-elevations caused a shift from a hump-shaped diversity pattern found at the local level to a low-elevation plateau pattern (with similar species numbers at low and mid-elevation) at the elevational belt level. Our study reveals an important role of small-scale topography and spatial scale for the inference on gradients of elevational species diversity.

  11. Modeling the small-scale dish-mounted solar thermal Brayton cycle

    Le Roux, Willem G.; Meyer, Josua P.

    2016-05-01

    The small-scale dish-mounted solar thermal Brayton cycle (STBC) makes use of a sun-tracking dish reflector, solar receiver, recuperator and micro-turbine to generate power in the range of 1-20 kW. The modeling of such a system, using a turbocharger as micro-turbine, is required so that optimisation and further development of an experimental setup can be done. As a validation, an analytical model of the small-scale STBC in Matlab, where the net power output is determined from an exergy analysis, is compared with Flownex, an integrated systems CFD code. A 4.8 m diameter parabolic dish with open-cavity tubular receiver and plate-type counterflow recuperator is considered, based on previous work. A dish optical error of 10 mrad, a tracking error of 1° and a receiver aperture area of 0.25 m × 0.25 m are considered. Since the recuperator operates at a very high average temperature, the recuperator is modeled using an updated ɛ-NTU method which takes heat loss to the environment into consideration. Compressor and turbine maps from standard off-the-shelf Garrett turbochargers are used. The results show that for the calculation of the steady-state temperatures and pressures, there is good comparison between the Matlab and Flownex results (within 8%) except for the recuperator outlet temperature, which is due to the use of different ɛ-NTU methods. With the use of Matlab and Flownex, it is shown that the small-scale open STBC with an existing off-the-shelf turbocharger could generate a positive net power output with solar-to-mechanical efficiency of up to 12%, with much room for improvement.

  12. Villacidro solar demo plant: Integration of small-scale CSP and biogas power plants in an industrial microgrid

    Camerada, M.; Cau, G.; Cocco, D.; Damiano, A.; Demontis, V.; Melis, T.; Musio, M.

    2016-05-01

    The integration of small scale concentrating solar power (CSP) in an industrial district, in order to develop a microgrid fully supplied by renewable energy sources, is presented in this paper. The plant aims to assess in real operating conditions, the performance, the effectiveness and the reliability of small-scale concentrating solar power technologies in the field of distributed generation. In particular, the potentiality of small scale CSP with thermal storage to supply dispatchable electricity to an industrial microgrid will be investigated. The microgrid will be realized in the municipal waste treatment plant of the Industrial Consortium of Villacidro, in southern Sardinia (Italy), which already includes a biogas power plant. In order to achieve the microgrid instantaneous energy balance, the analysis of the time evolution of the waste treatment plant demand and of the generation in the existing power systems has been carried out. This has allowed the design of a suitable CSP plant with thermal storage and an electrochemical storage system for supporting the proposed microgrid. At the aim of obtaining the expected energy autonomy, a specific Energy Management Strategy, which takes into account the different dynamic performances and characteristics of the demand and the generation, has been designed. In this paper, the configuration of the proposed small scale concentrating solar power (CSP) and of its thermal energy storage, based on thermocline principle, is initially described. Finally, a simulation study of the entire power system, imposing scheduled profiles based on weather forecasts, is presented.

  13. Evaluation of process costs for small-scale carbon dioxide removal from natural gas. Topical report, September 1989-December 1989

    Changela, M.K.; Reading, G.J.; Echterhoff, L.W.

    1991-08-01

    The report establishes the cost of producing pipeline quality gas on a small scale from high carbon dioxide subquality natural gas. Two processing technologies are evaluated: conventional diethanolamine (DEA) absorption and membrane separation. Comparison of the established costs shows both capital and operating cost advantages for small-scale membrane applications. Membranes offer higher cost savings at low feed flow rates and high carbon dioxide feed contents. Membranes are produced in modules, thus they do not exhibit economies of scale. This works to their advantage for removing carbon dioxide on a small scale. Processing costs for amine systems are more sensitive to economies of scale, and thus decrease more rapidly than for membranes at higher feed flow rates. The report shows that membranes have a definite market niche within the natural gas processing arena. For economic reasons, membranes will likely become the technology of choice for small-scale systems that treat high carbon dioxide content natural gas streams. However, amines will continue to service large-scale systems and applications where deep carbon dioxide removal is required. A related report (GRI Report No. GRI-91/0093 entitled, 'Technical Evaluation of Hybrid Membrane/DEA Modeling') shows that hybrid systems, the integration of membranes and amines, also offer the potential to lower processing costs

  14. Resolving the Circumstellar Environment of the Galactic B[e] Supergiant Star MWC 137 from Large to Small Scales

    Kraus, Michaela; Nickeler, Dieter H. [Astronomický ústav, Akademie věd České republiky, v.v.i., Fričova 298, 251 65 Ondřejov (Czech Republic); Liimets, Tiina [Tartu Observatory, 61602 Tõravere, Tartumaa (Estonia); Cappa, Cristina E.; Duronea, Nicolas U. [Instituto Argentino de Radioastronomía, CONICET, CCT-La Plata, C.C.5., 1894, Villa Elisa (Argentina); Cidale, Lydia S.; Arias, Maria L. [Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, 1900, La Plata (Argentina); Gunawan, Diah S.; Maravelias, Grigoris; Curé, Michel [Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Av. Gran Bretaña 1111, Casilla 5030, Valparaíso (Chile); Oksala, Mary E. [California Lutheran University, Department of Physics, Thousand Oaks, CA 91360 (United States); Fernandes, Marcelo Borges [Observatório Nacional, Rua General José Cristino 77, 20921-400 São Cristovão, Rio de Janeiro (Brazil); Santander-García, Miguel, E-mail: michaela.kraus@asu.cas.cz [Observatorio Astronómico Nacional (IGN), C/Alfonso XII 3, E-28014, Madrid (Spain)

    2017-11-01

    The Galactic object MWC 137 has been suggested to belong to the group of B[e] supergiants. However, with its large-scale optical bipolar ring nebula and high-velocity jet and knots, it is a rather atypical representative of this class. We performed multiwavelength observations spreading from the optical to the radio regimes. Based on optical imaging and long-slit spectroscopic data, we found that the northern parts of the large-scale nebula are predominantly blueshifted, while the southern regions appear mostly redshifted. We developed a geometrical model consisting of two double cones. Although various observational features can be approximated with such a scenario, the observed velocity pattern is more complex. Using near-infrared integral-field unit spectroscopy, we studied the hot molecular gas in the vicinity of the star. The emission from the hot CO gas arises in a small-scale disk revolving around the star on Keplerian orbits. Although the disk itself cannot be spatially resolved, its emission is reflected by the dust arranged in arc-like structures and the clumps surrounding MWC 137 on small scales. In the radio regime, we mapped the cold molecular gas in the outskirts of the optical nebula. We found that large amounts of cool molecular gas and warm dust embrace the optical nebula in the east, south, and west. No cold gas or dust was detected in the north and northwestern regions. Despite the new insights into the nebula kinematics gained from our studies, the real formation scenario of the large-scale nebula remains an open issue.

  15. Resolving the Circumstellar Environment of the Galactic B[e] Supergiant Star MWC 137 from Large to Small Scales

    Kraus, Michaela; Nickeler, Dieter H.; Liimets, Tiina; Cappa, Cristina E.; Duronea, Nicolas U.; Cidale, Lydia S.; Arias, Maria L.; Gunawan, Diah S.; Maravelias, Grigoris; Curé, Michel; Oksala, Mary E.; Fernandes, Marcelo Borges; Santander-García, Miguel

    2017-01-01

    The Galactic object MWC 137 has been suggested to belong to the group of B[e] supergiants. However, with its large-scale optical bipolar ring nebula and high-velocity jet and knots, it is a rather atypical representative of this class. We performed multiwavelength observations spreading from the optical to the radio regimes. Based on optical imaging and long-slit spectroscopic data, we found that the northern parts of the large-scale nebula are predominantly blueshifted, while the southern regions appear mostly redshifted. We developed a geometrical model consisting of two double cones. Although various observational features can be approximated with such a scenario, the observed velocity pattern is more complex. Using near-infrared integral-field unit spectroscopy, we studied the hot molecular gas in the vicinity of the star. The emission from the hot CO gas arises in a small-scale disk revolving around the star on Keplerian orbits. Although the disk itself cannot be spatially resolved, its emission is reflected by the dust arranged in arc-like structures and the clumps surrounding MWC 137 on small scales. In the radio regime, we mapped the cold molecular gas in the outskirts of the optical nebula. We found that large amounts of cool molecular gas and warm dust embrace the optical nebula in the east, south, and west. No cold gas or dust was detected in the north and northwestern regions. Despite the new insights into the nebula kinematics gained from our studies, the real formation scenario of the large-scale nebula remains an open issue.

  16. High Performance Networks for High Impact Science

    Scott, Mary A.; Bair, Raymond A.

    2003-02-13

    This workshop was the first major activity in developing a strategic plan for high-performance networking in the Office of Science. Held August 13 through 15, 2002, it brought together a selection of end users, especially representing the emerging, high-visibility initiatives, and network visionaries to identify opportunities and begin defining the path forward.

  17. Using a small scale wireless sensor network for model validation. Two case studies

    Lengfeld, Katharina; Ament, Felix [Hamburg Univ. (Germany). Meteorological Inst.; Zacharias, Stefan [Deutscher Wetterdienst, Freiburg im Breisgau (Germany)

    2013-10-15

    In this paper, the potential of a network consisting of low cost weather stations for validating microscale model simulations and for forcing surface-atmosphere-transfer-schemes is investigated within two case studies. Transfer schemes often do not account for small scale variabilities of the earth surface, because measurements of the atmospheric conditions do not exist in such a high spatial resolution to force the models. To overcome this issue, in this study a small scale network of meteorological stations is used to derive measurements in high spatial and temporal resolution. The observations carried out during the measurement campaign are compared to air temperature and specific humidity simulations of the mesoscale atmospheric model FOOT3DK (Flow Over Orographically-Structured Terrain - 3 Dimensional Model (Koelner Version)). This comparison indicates that FOOT3DK simulates either air temperature or specific humidity satisfactorily for each station at the lowest model level, depending on the dominating land use class within each grid cell. The influence of heterogeneous forcing and vegetation on heat flux modelling is studied using the soil-vegetation-atmosphere transfer scheme TERRA. The observations of the measurement campaign are used as input for four different runs with homogeneous and heterogeneous forcing and vegetation. Heterogeneous vegetation reduces the bias between the grid cells, heterogeneous forcing reduces the random error for each grid cell. (orig.)

  18. Experimental evidence of widespread regions of small-scale plasma irregularities in the magnetosphere

    Holmgren, G.; Kintner, P.M.

    1990-01-01

    Small-scale (≤ 1 km) plasma irregularities have previously been observed in situ from the E region to an altitude of 8,000 km. In this paper the authors report results from the Viking plasma wave experiments which extends the measurements of high-latitude irregularities in two ways: (1) they have acquired electron density fluctuation measurements up to an altitude of 13,500 km and (2) for the first time a measurement technique was used that made a phase velocity deduction possible from in situ measurements. The spacecraft was equipped with two spatially separated Langmuir probes, each with an ability to measure relative probe current fluctuations with frequencies from dc to about 400 Hz. Under certain assumptions the current fluctuations could be interpreted as relative plasma density fluctuations, δn e /n e . Data from this interferometric instrument has been used to infer the distribution and nature of plasma irregularities along Viking orbits. It is demonstrated that the interferometric technique offers great advantages compared to single point measurements in this kind of study. It is shown that the observed small-scale plasma irregularities are nondispersive and convecting with the background plasma. They exhibit a power law frequency spectrum as observed in the satellite reference frame. The spectral index varies with location. An attempt to map source regions by identifying regions of high power and shallow spectrums is made

  19. Sediment depositions upstream of open check dams: new elements from small scale models

    Piton, Guillaume; Le Guern, Jules; Carbonari, Costanza; Recking, Alain

    2015-04-01

    numbers that the flows tend to adopt? New small scale model experiments have been undertaken focusing on depositions processes and their related hydraulics. Accurate photogrammetric measurements allowed us to better describe the deposition processes3. Large Scale Particle Image Velocimetry (LS-PIV) was performed to determine surface velocity fields in highly active channels with low grain submersion4. We will present preliminary results of our experiments showing the new elements we observed in massive deposit dynamics. REFERENCES 1.Armanini, A., Dellagiacoma, F. & Ferrari, L. From the check dam to the development of functional check dams. Fluvial Hydraulics of Mountain Regions 37, 331-344 (1991). 2.Piton, G. & Recking, A. Design of sediment traps with open check dams: a review, part I: hydraulic and deposition processes. (Accepted by the) Journal of Hydraulic Engineering 1-23 (2015). 3.Le Guern, J. Ms Thesis: Modélisation physique des plages de depot : analyse de la dynamique de remplissage.(2014) . 4.Carbonari, C. Ms Thesis: Small scale experiments of deposition processes occuring in sediment traps, LS-PIV measurments and geomorphological descriptions. (in preparation).

  20. Small-scale geodiversity and dirt road management, Ede (NL)

    van den Ancker, Hanneke; Jungerius, Pieter Dirk

    2016-04-01

    A large part of the countryside roads on the Pleistocene sands of The Netherlands are dirt roads. Most are footpaths, but a small percentage are relatively heavily used by motorized vehicles. These latter roads are a cause subject of debate. Puddles and potholes develop during periods of wet weather, while dust whirls from the roads form during spells of dry weather as do washboard ripples. They cause problems for people living along these roads and tourists (walkers and bikers. The community of Ede (NL), like many other communities on the sand, wants to keep its 80 km of dirt roads because of the natural values they harbour as well as for their characteristic landscape quality and cultural heritage value. A part of the dirt roads in Ede is heavily used. In 2009, the community of Ede developed a decision model to support management of the dirt roads. Ede acknowledges that each dirt road is unique and asks for a tailor-made solution. Road maintenance measures include grading, making a camber, digging pits, applying loam or sandy loam. If problems become too large, one-way traffic can be an option. In more and more cases the dirt roads are barred for motorized through traffic (Gemeente Ede, 2009). As a reconnaissance we have studied the dirt roads of the Horabos/Horalaan over the last year. Incidentally we looked at other parts of the main Horalaan and the footpaths in the adjacent forest of Hoekelum. All dirt roads lie near the top of a Saalian push-moraine in which the upper course of dry valleys are present. Some results of the reconnaissance: - Most dirt roads sections in the Horabos lie lower than the surrounding terrain; - The problems develop in a short period of time during special weather conditions; - Certain dirt road sections e.g. those sections crossing a slight depression are quickly developing potholes; - Even a small slope of the road (differences that have consequences for its maintenance. Knowledge of geodiversity of the terrain and study of small-scale

  1. A greenhouse type solar dryer for small-scale dried food industries: Development and dissemination

    Janjai, Serm [Solar Energy Research Laboratory, Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom 73000 (Thailand)

    2012-07-01

    In this study, a greenhouse type solar dryer for small-scale dried food industries was developed and disseminated. The dryer consists of a parabolic roof structure covered with polycarbonate sheets on a concrete floor. The system is 8.0m in width, 20.0m in length and 3.5m in height, with a loading capacity about 1,000kg of fruits or vegetables. To ensure continuous drying operation, a 100kW-LPG gas burner was incorporated to supply hot air to the dryer during cloudy or rainy days. Nine 15-W DC fans powered by three 50-W PV modules were used to ventilate the dryer. This dryer was installed for a small-scale food industry at Nakhon Pathom in Thailand to produce osmotically dehydrated tomato. To investigate its performance, the dryer was used to dry 3 batches of osmotically dehydrated tomato. Results obtained from these experiments showed that drying air temperatures in the dryer varied from 35 C to 65 C. In addition, the drying time for these products was 2-3 days shorter than that of the natural sun drying and good quality dried products were obtained. A system of differential equations describing heat and moisture transfers during drying of osmotically dehydrated tomato was also developed. The simulated results agreed well with the experimental data. For dissemination purpose, other two units of this type of dryer were constructed and tested at two locations in Thailand and satisfactory results were obtained.

  2. Development of small-scale electroplating system for Ni-63 electroplating onto Ni foil

    Kim, Jin Joo; Choi, Sang Mu; Son, Kwang Jae; Hong, Jintae

    2016-01-01

    Betavoltaic battery is a device that converts the decay energy of beta-emitting radioisotopes into electric energy. Ni-63 is pure betaemitter with a low energy spectrum and significantly long half-life of 100.1 years and thus is widely used as the power source of betavoltaic battery. There are several methods for the formation of a Ni deposit onto a semiconductor such as electroplating, electroless plating, and chemical vapor deposition. In this study, small-scale radioisotope electroplating system was designed and fabricated to perform electroplating with a small amount of plating buffer and minimum exposure of radioactive materials. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery. In this study, an electroplating system for small-scale Ni electroplating was designed and manufactured. The process for the fabrication of a Ni-63 foil as the energy source of a betavoltaic battery was developed using the minimum concentration of Ni. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery

  3. Development of small-scale electroplating system for Ni-63 electroplating onto Ni foil

    Kim, Jin Joo; Choi, Sang Mu; Son, Kwang Jae; Hong, Jintae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Betavoltaic battery is a device that converts the decay energy of beta-emitting radioisotopes into electric energy. Ni-63 is pure betaemitter with a low energy spectrum and significantly long half-life of 100.1 years and thus is widely used as the power source of betavoltaic battery. There are several methods for the formation of a Ni deposit onto a semiconductor such as electroplating, electroless plating, and chemical vapor deposition. In this study, small-scale radioisotope electroplating system was designed and fabricated to perform electroplating with a small amount of plating buffer and minimum exposure of radioactive materials. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery. In this study, an electroplating system for small-scale Ni electroplating was designed and manufactured. The process for the fabrication of a Ni-63 foil as the energy source of a betavoltaic battery was developed using the minimum concentration of Ni. These procedures and the manufactured electroplating device can be applied to radioactive Ni-63 electroplating for the fabrication of a betavoltaic battery.

  4. Small scale biomass heating systems: Standards, quality labelling and market driving factors - An EU outlook

    Verma, V.K.; De Ruyck, J.; Bram, S.

    2009-01-01

    In the present study a comparative evaluation of several existing quality labels and standards for small scale biomass heating systems (BHS) and the biomass fuels they use was performed. With the introduction of pellet fuels, biomass heating technology achieved enough maturity to successfully compete with oil/gas heating devices in terms of ease of use, utilization of energy and pollutant emissions. From indoor air quality and related health risks point of view, quality labelling of both BHS and fuel they use leads to stricter emissions, efficiency and safety requirements as compared to National and EU standards. Several measures supporting this green energy market in the active countries (Sweden, Nordic countries, Germany, France and Austria) were investigated. It was found that policies and financial incentives such as the Finance Law (2005-2009) in France and Market Incentives Programme (1999-2006) in Germany are the most successful. German regulations and quality label (Blue Angel) provide the stringent quality requirements for residential BHS. In Belgium, Wallonia is the most active region for biomass energy utilization (83.5 MW for residential heating in 2007). A quality label for small scale BHS however does not yet exist. An equivalent label (Optimaz) exists for oil fired residential boilers. Emphasis has been placed upon using Optimaz as a reference and to compare with other existing quality labels. As a result, an effort had been made to move ahead in the preliminary study for development of a quality label for Belgian. (author)

  5. Wind energy potential in Chile: Assessment of a small scale wind farm for residential clients

    Becerra, Miguel; Morán, José; Jerez, Alejandro; Cepeda, Francisco; Valenzuela, Miguel

    2017-01-01

    Highlights: • An assessment of a small scale wind farm was carried out. • Two Chilean locations were selected, which are geographically dissimilar. • The software tool selected for the project’s evaluation was HOMER. • All the project’s financial evaluations were negative. • Government policy tools and their applications were discussed. - Abstract: This work presents a techno-financial evaluation of two Chilean locations with promising wind potential: Laguna Verde placed in the central region of the country, and Porvenir in the southern region. A small scale wind farm was studied, considering a nominal electrical production capacity of 90 kW. This facility is comprised of three wind turbine models, all available in the national market. Currently, the tariff method used in Chile is the net billing scheme, where the energy bought and sold to the grid has different prices. The study is based on 300 hypothetical residential households. The software tool used to perform the assessment was the Hybrid Optimization of Multiple Energy Resources (HOMER). For all the scenarios the results showed a Net Present Cost (NPC), instead of a financial profit from the proposed projects. A sensitivity analysis was also carried out. From the group of variables studied, the NPC exhibited itself as more sensitive to the price of buying energy from the grid and to the annual average wind speed. Finally, a few government policies and their applications are discussed.

  6. An improved reactor system for small-scale fuel processing - the Optiformer concept

    Silversand, Fredrik; Karlsson, Charlotte (Catator AB, Lund (Sweden))

    2008-08-15

    Catator AB (CAT) has evaluated a revised design of the previously described Ultraformer concept. In comparison to the original Ultraformer, the new reformer concept (Optiformer) shows enhanced performances with respect to thermo-mechanic durability and conversion efficiencies. The unit is also easy to manufacture and ordinary high-temperature steel alloys may be used. The new concept is based on a helix-shaped tubular heat-exchanger reactor designed by ICI Caldaie (ICI) fitted with CATs proprietary wire-mesh catalyst. The concept has currently been evaluated for production rates between 0.5 and 30 nm3/hr of hydrogen and this report describes a detailed study of a unit for small-scale CHP-applications. Such systems will involve a fuel processor together with a suitable fuel cell, e.g. a solid-oxide fuel cell (SOFC) or a high-temperature PEFC (HT-PEFC). The evaluations performed in this study indicate stable operation over a wide window of capacities with negligible emissions of hydrocarbons. Since it is possible to operate the redesigned unit at a higher temperature (>900 deg C) than the original Ultraformer unit (750- 800 deg C), the conversion degree is much higher for thermo-dynamical reasons. The redesigned unit contains all necessary structures for vaporization, recuperation, effect supply and gas purification in a highly integrated structure. Furthermore, the unit is equipped with an internal insulation and a cooling jacked to reduce the skin temperature of the unit. The reactor has undergone about 100 full thermal cycles without any thermo-mechanical issues or catalyst degradation. Natural gas and different kerosene qualities have so far been evaluated with respect to conversion degree and possible slip of hydrocarbons. The conversion degree at rated load (100%) was above 99%, which enable us to reach superior efficiencies. If the unit were to be used together with a SOFC, the WGS-step could be omitted, reducing the size and weight further from about 2.2 l

  7. Handbook for Small-Scale Densified Biomass Fuel (Pellets) Manufacturing for Local Markets.

    Folk, Richard L.; Govett, Robert L.

    1992-07-01

    Wood pellet manufacturing in the Intermountain West is a recently founded and rapidly expanding energy industry for small-scale producers. Within a three-year period, the total number of manufacturers in the region has increased from seven to twelve (Folk et al., 1988). Small-scale industry development is evolving because a supply of raw materials from small and some medium-sized primary and secondary wood processors that has been largely unused. For the residue producer considering pellet fuel manufacturing, the wastewood generated from primary products often carries a cost associated with residue disposal when methods at-e stockpiling, landfilling or incinerating. Regional processors use these methods for a variety of reasons, including the relatively small amounts of residue produced, residue form, mixed residue types, high transportation costs and lack of a local market, convenience and absence of regulation. Direct costs associated with residue disposal include the expenses required to own and operate residue handling equipment, costs for operating and maintaining a combustor and tipping fees charged to accept wood waste at public landfills. Economic and social costs related to environmental concerns may also be incurred to include local air and water quality degradation from open-air combustion and leachate movement into streams and drinking water.

  8. RADAR upper hybrid resonance scattering diagnostics of small-scale fluctuations and waves in tokamak plasmas

    Bulyiginskiy, D.G.; Gurchenko, A.D.; Gusakov, E.Z.; Korkin, V.V.; Larionov, M.M.; Novik, K.M.; Petrov, Yu.V.; Popov, A.Yu.; Saveliev, A.N.; Selenin, V.L.; Stepanov, A.Yu.

    2001-01-01

    The upper hybrid resonance (UHR) scattering technique possessing such merits as one-dimensional probing geometry, enhancement of cross section, and fine localization of scattering region is modified in the new diagnostics under development to achieve wave number resolution. The fluctuation wave number is estimated in the new technique from the scattering signal time delay measurements. The feasibility of the scheme is checked in the proof of principal experiment in a tokamak. The time delay of the UHR scattering signal exceeding 10 ns is observed. The small scale low frequency density fluctuations are investigated in the UHR RADAR backscattering experiment. The UHR cross-polarization scattering signal related to small scale magnetic fluctuations is observed. The lower hybrid (LH) wave propagation and both linear and nonlinear wave conversion are investigated. The small wavelength (λ≤0.02 cm) high number ion Bernstein harmonics, resulting from the linear wave conversion of the LH wave are observed in a tokamak plasma for the first time

  9. Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields

    Chitta, L. P.; Peter, H.; Solanki, S. K.; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Riethmüller, T. L.; Noort, M. van [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Rodríguez, J. Blanco [Grupo de Astronomía y Ciencias del Espacio, Universidad de Valencia, E-46980 Paterna, Valencia (Spain); Iniesta, J. C. Del Toro; Suárez, D. Orozco [Instituto de Astrofísica de Andalucía (CSIC), Apartado de Correos 3004, E-18080 Granada (Spain); Schmidt, W. [Kiepenheuer-Institut für Sonnenphysik, Schöneckstr. 6, D-79104 Freiburg (Germany); Pillet, V. Martínez [National Solar Observatory, 3665 Discovery Drive, Boulder, CO 80303 (United States); Knölker, M., E-mail: chitta@mps.mpg.de [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

    2017-03-01

    How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the solar corona. To address the above question, we use high-resolution line-of-sight magnetic field data from the Imaging Magnetograph eXperiment instrument on the Sunrise balloon-borne observatory and coronal observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory of an emerging active region. We find that the coronal loops are often rooted at the locations with minor small-scale but persistent opposite-polarity magnetic elements very close to the larger dominant polarity. These opposite-polarity small-scale elements continually interact with the dominant polarity underlying the coronal loop through flux cancellation. At these locations we detect small inverse Y-shaped jets in chromospheric Ca ii H images obtained from the Sunrise Filter Imager during the flux cancellation. Our results indicate that magnetic flux cancellation and reconnection at the base of coronal loops due to mixed polarity fields might be a crucial feature for the supply of mass and energy into the corona.

  10. Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields

    Chitta, L. P.; Peter, H.; Solanki, S. K.; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Riethmüller, T. L.; Noort, M. van; Rodríguez, J. Blanco; Iniesta, J. C. Del Toro; Suárez, D. Orozco; Schmidt, W.; Pillet, V. Martínez; Knölker, M.

    2017-01-01

    How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the solar corona. To address the above question, we use high-resolution line-of-sight magnetic field data from the Imaging Magnetograph eXperiment instrument on the Sunrise balloon-borne observatory and coronal observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory of an emerging active region. We find that the coronal loops are often rooted at the locations with minor small-scale but persistent opposite-polarity magnetic elements very close to the larger dominant polarity. These opposite-polarity small-scale elements continually interact with the dominant polarity underlying the coronal loop through flux cancellation. At these locations we detect small inverse Y-shaped jets in chromospheric Ca ii H images obtained from the Sunrise Filter Imager during the flux cancellation. Our results indicate that magnetic flux cancellation and reconnection at the base of coronal loops due to mixed polarity fields might be a crucial feature for the supply of mass and energy into the corona.

  11. Small Scale Yielding Correction of Constraint Loss in Small Sized Fracture Toughness Test Specimens

    Kim, Maan Won; Kim, Min Chul; Lee, Bong Sang; Hong, Jun Hwa

    2005-01-01

    Fracture toughness data in the ductile-brittle transition region of ferritic steels show scatter produced by local sampling effects and specimen geometry dependence which results from relaxation in crack tip constraint. The ASTM E1921 provides a standard test method to define the median toughness temperature curve, so called Master Curve, for the material corresponding to a 1T crack front length and also defines a reference temperature, T 0 , at which median toughness value is 100 MPam for a 1T size specimen. The ASTM E1921 procedures assume that high constraint, small scaling yielding (SSY) conditions prevail at fracture along the crack front. Violation of the SSY assumption occurs most often during tests of smaller specimens. Constraint loss in such cases leads to higher toughness values and thus lower T 0 values. When applied to a structure with low constraint geometry, the standard fracture toughness estimates may lead to strongly over-conservative estimates. A lot of efforts have been made to adjust the constraint effect. In this work, we applied a small-scale yielding correction (SSYC) to adjust the constraint loss of 1/3PCVN and PCVN specimens which are relatively smaller than 1T size specimen at the fracture toughness Master Curve test

  12. Experimental Study of a Small Scale Hydraulic System for Mechanical Wind Energy Conversion into Heat

    Tadas Zdankus

    2016-07-01

    Full Text Available Significant potential for reducing thermal energy consumption in buildings of moderate and cold climate countries lies within wind energy utilisation. Unlike solar irradiation, character of wind speeds in Central and Northern Europe correspond to the actual thermal energy demand in buildings. However, mechanical wind energy undergoes transformation into electrical energy before being actually used as thermal energy in most wind energy applications. The study presented in this paper deals with hydraulic systems, designed for small-scale applications to eliminate the intermediate energy transformation as it converts mechanical wind energy into heat directly. The prototype unit containing a pump, flow control valve, oil tank and piping was developed and tested under laboratory conditions. Results of the experiments showed that the prototype system is highly efficient and adjustable to a broad wind velocity range by modifying the definite hydraulic system resistance. Development of such small-scale replicable units has the potential to promote “bottom-up” solutions for the transition to a zero carbon society.

  13. Small scale CHP: Alternative integration forms in the Danish energy system

    Boeg, Rasmus; Gatautis, Ramunas; Engberg Pedersen, Thomas; Schmidt, Rune; Ravn, Hans F.

    2003-01-01

    In Denmark, introduction of small scale combined heat and power (CHP) plants were part of the energy policy during the 1990's. Thus, the installed electricity capacity on this type of units multiplied approximately ten times during this decade, to constitute more than 2000 MW in 2000, or around 20% of total installed electricity capacity. The motivation for this development was mainly energy savings due to the relatively high thermal efficiency in combined production, and the associated reduction of emissions. The remuneration for the electricity delivered to the electrical network was in part based on a feed in tariff. The construction of the tariff reflected estimated benefits to the electrical system. With the liberalisation of the electricity markets this arrangement has been questioned, and it has been suggested that the differentiated payment to local CHP should be based on electricity market prising. For Denmark this would imply that the local CHP should trade the electricity on the Nordpool electricity spot market. This paper analyses parts of these two alternative ways of economic arrangements in relation to small scale CHP. First it describes the development and status till now. Then it analyses the production patterns and associated economic consequences of a change from the tariff based system to a market system. (BA)

  14. RavenDB high performance

    Ritchie, Brian

    2013-01-01

    RavenDB High Performance is comprehensive yet concise tutorial that developers can use to.This book is for developers & software architects who are designing systems in order to achieve high performance right from the start. A basic understanding of RavenDB is recommended, but not required. While the book focuses on advanced topics, it does not assume that the reader has a great deal of prior knowledge of working with RavenDB.

  15. Caught in the Same Net? Small-Scale Fishermen's Perceptions of Fisheries Interactions with Sea Turtles and Other Protected Species

    Aliki Panagopoulou

    2017-06-01

    Full Text Available Small-scale fisheries are responsible for high numbers of animals caught as bycatch, such as turtles, cetaceans, and seals. Bycatch and its associated mortality is a major conservation challenge for these species and is considered undesirable by fishermen. To gain insights on the impact of bycatch on small-scale fishermen and put it in context with other financial and environmental challenges they face, we conducted questionnaire-based interviews on fishermen working on Crete, Greece. We investigated fishermen's perceptions of sea turtle and other protected species interactions, and the impacts of such interactions on their profession and livelihoods. Our results indicate a connection between declining fish stocks, related increased fishing effort, and reported increased frequency of interactions between fishermen and sea turtles. Respondents believed that their livelihoods were endangered by industrial fishing and environmental problems, but thought that combined interactions with turtles and other marine megafauna species were a larger problem. Responses suggested that extending compensation to fishermen may be a good conservation intervention. Small-scale fishermen hold a wealth of knowledge about the marine environment and its resources. This may be of help to researchers and policy makers as it could be used to achieve a better managed, sustainable fishery. Including small-scale fishermen in the process of developing regulations will both enhance those regulations and increase compliance with them.

  16. High-Performance Operating Systems

    Sharp, Robin

    1999-01-01

    Notes prepared for the DTU course 49421 "High Performance Operating Systems". The notes deal with quantitative and qualitative techniques for use in the design and evaluation of operating systems in computer systems for which performance is an important parameter, such as real-time applications......, communication systems and multimedia systems....

  17. Mercury Pollution Due to Small-Scale Gold Mining in the Philippines: An Economic Analysis

    Orbeta, Aniceto C.; Israel, Danilo C.; Asirot, Jasminda

    2000-01-01

    The study reviews small-scale gold mining in the Philippines and economically assesses mercury pollution and other development problems in the industry. The end purpose is to suggest measures to address the problems and promote better environmental and overall management of small-scale mining. The study has used secondary data from mining institutions and primary data from key informants and small-scale gold miners and processors in the two case study sites.

  18. Mercury Pollution Due to Small-Scale Gold Mining in the Philippines: An Economic Analysis

    Israel, Danilo C.; Asirot, Jasminda

    2002-01-01

    The study reviews small-scale gold mining in the Philippines and economically assesses mercury pollution and other development problems in the industry. The end purpose is to suggest measures to address the problems and promote better environmental and overall management of small-scale mining. The study has used secondary data from mining institutions and primary data from key informants and small-scale gold miners and processors in the two case study sites. brazzer

  19. Small-scale bioenergy projects in rural China: Lessons to be learnt

    Han Jingyi; Mol, Arthur P.J.; Lu Yonglong; Zhang Lei

    2008-01-01

    Large amounts of small-scale bioenergy projects were carried out in China's rural areas in light of its national renewable energy policies. These projects applied pyrolysis gasification as the main technology, which turns biomass waste at low costs into biogas. This paper selects seven bioenergy projects in Shandong Province as a case and assesses these projects in terms of economy, technological performance and effectiveness. Results show that these projects have not achieved a satisfying performance after 10 years experience. Many projects have been discontinued. This failure is attributed to a complex of shortcomings in institutional structure, technical level, financial support and social factors. For a more successful future development of bioenergy in rural areas, China should reform its institutional structure, establish a renewable energy market and enhance the technological level of bioenergy projects

  20. Validation of a power-law noise model for simulating small-scale breast tissue

    Reiser, I; Edwards, A; Nishikawa, R M

    2013-01-01

    We have validated a small-scale breast tissue model based on power-law noise. A set of 110 patient images served as truth. The statistical model parameters were determined by matching the radially averaged power-spectrum of the projected simulated tissue with that of the central tomosynthesis patient breast projections. Observer performance in a signal-known exactly detection task in simulated and actual breast backgrounds was compared. Observers included human readers, a pre-whitening observer model and a channelized Hotelling observer model. For all observers, good agreement between performance in the simulated and actual backgrounds was found, both in the tomosynthesis central projections and the reconstructed images. This tissue model can be used for breast x-ray imaging system optimization. The complete statistical description of the model is provided. (paper)

  1. Shortwave surface radiation network for observing small-scale cloud inhomogeneity fields

    Lakshmi Madhavan, Bomidi; Kalisch, John; Macke, Andreas

    2016-03-01

    As part of the High Definition Clouds and Precipitation for advancing Climate Prediction Observational Prototype Experiment (HOPE), a high-density network of 99 silicon photodiode pyranometers was set up around Jülich (10 km × 12 km area) from April to July 2013 to capture the small-scale variability of cloud-induced radiation fields at the surface. In this paper, we provide the details of this unique setup of the pyranometer network, data processing, quality control, and uncertainty assessment under variable conditions. Some exemplary days with clear, broken cloudy, and overcast skies were explored to assess the spatiotemporal observations from the network along with other collocated radiation and sky imager measurements available during the HOPE period.

  2. Evidence of small-scale magnetic concentrations dragged by vortex motion of solar photospheric plasma

    Balmaceda, L.; Vargas Domínguez, S.; Palacios, J.; Cabello, I.; Domingo, V.

    2010-04-01

    Vortex-type motions have been measured by tracking bright points in high-resolution observations of the solar photosphere. These small-scale motions are thought to be determinant in the evolution of magnetic footpoints and their interaction with plasma and therefore likely to play a role in heating the upper solar atmosphere by twisting magnetic flux tubes. We report the observation of magnetic concentrations being dragged towards the center of a convective vortex motion in the solar photosphere from high-resolution ground-based and space-borne data. We describe this event by analyzing a series of images at different solar atmospheric layers. By computing horizontal proper motions, we detect a vortex whose center appears to be the draining point for the magnetic concentrations detected in magnetograms and well-correlated with the locations of bright points seen in G-band and CN images.

  3. Limited usage of mechanical equipment in small-scale rice farming: a cause for concern

    Gaudiose Mujawamariya

    2017-06-01

    Full Text Available The role of mechanization in agriculture is well documented in terms of improving productivity of farm labour and land and sustaining income status and welfare of small-scale farmers. In rice production, there is a high cost associated with labour intensive production practices especially in land preparation, weeding and harvesting, the limited adoption of mechanical equipment in these operations remains an issue of concern. The current study investigates the usage of mechanical equipment in a setting where majority of farmers are exposed to technologies but cases of non-usage/adoption are observed. The choice of usage of mechanical equipment is analysed through probit and poisson models. Mechanization generally has a positive effect on production. However, the cost associated with its usage high. The equipment should be made available and affordable to farmers especially because demand for rent is not met. Awareness is essential for adoption and ease of use of mechanization.

  4. Feasibility of Producing Molybdenum-99 on a Small Scale Using Fission of Low Enriched Uranium or Neutron Activation of Natural Molybdenum

    2015-01-01

    This publication documents the work performed within the IAEA coordinated research project (CRP) on Developing Techniques for Small Scale Indigenous Molybdenum-99 Production Using LEU Fission or Neutron Activation. The project allowed participating institutions to receive training and information on aspects necessary for starting production of molybdenum-99 ( 99 Mo) on a small scale, that is, to become national level producers of this medical isotope. Stable production of 99Mo is one of the most pressing issues facing the nuclear community at present, because the medical isotope technetium-99m ( 99m Tc), which decays from 99 Mo, is one of the most widely used radionuclides in diagnostic imaging and treatment around the world. In the past five years, there have been widespread shortages of 99 Mo owing to the limited number of producers, many of which use ageing facilities. To assist in stabilizing the production of 99Mo, and to promote the use of production methods that do not rely on the use of highly enriched uranium (HEU), the IAEA initiated the abovementioned CRP on small scale 99Mo production using low enriched uranium (LEU) fission or neutron activation methods. The intention was to enable participating institutions to gain the knowledge necessary to become national level producers of 99Mo in the event of further global shortages. Some of the institutions that participated in the CRP have continued their work on 99 Mo production, and are enlisting the assistance of other CRP members and the IAEA’s technical cooperation programme to set up a small scale production capability. In total, the CRP was active for six years, and concluded in December 2011. During the CRP, fourteen IAEA Member States took part; four research coordination meetings were held, and four workshops were held on operational aspects of 99 Mo production, LEU target fabrication and waste management. Most participants carried out work related to the entire production process, from target

  5. Irradiation facilities for materials research: IFMIF and small scale installations

    Perlado, J. M.; Victoria, M.

    2007-01-01

    The research of advance materials in nuclear fields such as new fission reactors (Generation-IV), Accelerator Driven Systems for Transmutation of Radioactive Wastes and Nuclear Fusion, is becoming very much common in the types of low activation and radiation resistant Materials. Ferritic-Martensitic Steels (based in 9-12 Cr) with or without Oxide Dispersion Techniques (Ytria Nanoparticles), Composites materials are becoming the new generation to answer requirements of high temperature, high radiation resistance of structural materials. Special dedication is appearing in general research programmes to this area of Materials. The understanding of their final performance needs a wider knowledge of the mechanisms of radiation damage in these materials from the atomistic scale to the macroscopic responses. New extensive campaigns are being funded to irradiate from simple elements to model alloys and finally the complex materials themselves. That sequence and its state of art will be presented One clear technique for that understanding is the Multi scale Modelling which includes simulation techniques from quantum mechanics, molecular dynamics, defects diffusion, mesoscopic modelling and finally the macroscopic constitutive relations for macroscopic analysis. However, in each one of these steps is necessary a systematic and well established program of experiments that combines the irradiation and the very detailed analysis with techniques such as Transmission Electron Microscope, Positron Annihilation, SIMS, Atom Probe, Nanoindebntation. A key aspect that wants to be presented in this work is the state of art and discussion of Irradiation Facilities for Materials studies. Those facilities goes from ion implantation sources, small accelerator, Experimental Reactors such High Flux Reactor, sophisticated Triple Beams Sources as JANNUS in France to generate at the same time displacements-hydrogen-helium, and projected very large neutron installation such as IFMIF. The role to

  6. Identifying High Performance ERP Projects

    Stensrud, Erik; Myrtveit, Ingunn

    2002-01-01

    Learning from high performance projects is crucial for software process improvement. Therefore, we need to identify outstanding projects that may serve as role models. It is common to measure productivity as an indicator of performance. It is vital that productivity measurements deal correctly with variable returns to scale and multivariate data. Software projects generally exhibit variable returns to scale, and the output from ERP projects is multivariate. We propose to use Data Envelopment ...

  7. INL High Performance Building Strategy

    Jennifer D. Morton

    2010-02-01

    High performance buildings, also known as sustainable buildings and green buildings, are resource efficient structures that minimize the impact on the environment by using less energy and water, reduce solid waste and pollutants, and limit the depletion of natural resources while also providing a thermally and visually comfortable working environment that increases productivity for building occupants. As Idaho National Laboratory (INL) becomes the nation’s premier nuclear energy research laboratory, the physical infrastructure will be established to help accomplish this mission. This infrastructure, particularly the buildings, should incorporate high performance sustainable design features in order to be environmentally responsible and reflect an image of progressiveness and innovation to the public and prospective employees. Additionally, INL is a large consumer of energy that contributes to both carbon emissions and resource inefficiency. In the current climate of rising energy prices and political pressure for carbon reduction, this guide will help new construction project teams to design facilities that are sustainable and reduce energy costs, thereby reducing carbon emissions. With these concerns in mind, the recommendations described in the INL High Performance Building Strategy (previously called the INL Green Building Strategy) are intended to form the INL foundation for high performance building standards. This revised strategy incorporates the latest federal and DOE orders (Executive Order [EO] 13514, “Federal Leadership in Environmental, Energy, and Economic Performance” [2009], EO 13423, “Strengthening Federal Environmental, Energy, and Transportation Management” [2007], and DOE Order 430.2B, “Departmental Energy, Renewable Energy, and Transportation Management” [2008]), the latest guidelines, trends, and observations in high performance building construction, and the latest changes to the Leadership in Energy and Environmental Design

  8. Muscle Sensor Model Using Small Scale Optical Device for Pattern Recognitions

    Kreangsak Tamee

    2013-01-01

    Full Text Available A new sensor system for measuring contraction and relaxation of muscles by using a PANDA ring resonator is proposed. The small scale optical device is designed and configured to perform the coupling effects between the changes in optical device phase shift and human facial muscle movement, which can be used to form the relationship between optical phase shift and muscle movement. By using the Optiwave and MATLAB programs, the results obtained have shown that the measurement of the contraction and relaxation of muscles can be obtained after the muscle movements, in which the unique pattern of individual muscle movement from facial expression can be established. The obtained simulation results, that is, interference signal patterns, can be used to form the various pattern recognitions, which are useful for the human machine interface and the human computer interface application and discussed in detail.

  9. Small scale thermal-hydraulic experiment for stable operation of a pius-type reactor

    Tasaka, K.; Tamaki, M.; Imai, S.; Irianto, I.D.; Tsuji, Y.; Kukita, Y.

    1994-01-01

    Thermal-hydraulic experiments using a small-scale atmospheric pressure test loop have been performed for the Process Inherent Ultimate Safety (PIUS)-type reactor to develop the new pump speed feedback control system. Three feedback control systems based on the measurement of flow rate, differential pressure, and fluid temperature distribution in the lower density lock have been proposed and confirmed by a series of experiments. Each of the feedback control systems had been verified in the simulation experiment such as a start-up simulation test. The automatic pump speed control based on the fluid temperature at the lower density lock was quite effective to maintain the stratified interface between primary water and borated pool water for stable operation of the reactor. (author)

  10. Design and operation of small-scale glass melters for immobilizing radioactive waste

    Plodinec, M.J.; Chismar, P.H.

    1980-01-01

    A small-scale (3-kg), joule-heated, continuous melter has been designed to study vitrification of Savannah River Plant radioactive waste. The first melter built has been in nonradioactive service for nearly three years. This melter had Inconel 690 electrodes and uses Monofrax K-3 for the contact refractory. Several problems seem in this melter have had an impact on the design of a full-scale system. Problems include uncontrolled electric currents passing through the throat, and formation of a slag layer at the bottom of the melter. The performance of a similar melter in a low-maintenance, radioactive environment is also described. Problems such as halide refluxing, and hot streaking, first observed in this melter, are also discussed

  11. Resonant Wave Energy Converters: Small-scale field experiments and first full-scale prototype

    Arena, Felice; Fiamma, Vincenzo; Iannolo, Roberto; Laface, Valentina; Malara, Giovanni; Romolo, Alessandra; Strati Federica Maria

    2015-01-01

    The Resonant Wave Energy Converter 3 (REWEC3) is a device belonging to the family of Oscillating Water Columns (OWCs), that can convert the energy of incident waves into electrical energy via turbines. In contrast to classical OWCs, it incorporates a small vertical U-shaped duct to connect the water column to the open wave field. This article shows the results of a small-scale field experiment involving a REWEC3 designed for working with a 2 kW turbine. Then, the next experimental activity on a REWEC3 installed in the NOEL laboratory with the collaboration of ENEA, is presented. Finally, the first prototype of ReWEC3 under construction in Civitavecchia (Rome, Italy) is shown. The crucial features of the construction stage are discussed and some initial performances are provided. [it

  12. A versatile, steam reforming based small-scale hydrogen production process

    P C Hulteberg; F A Silversand; B Porter; R Woods

    2006-01-01

    In this paper, a new design methodology and process is proposed for small scale pure hydrogen production capable of serving energy markets ranging from distributed generation to vehicular refuelling. The system was designed for producing 7 Nm 3 /hr pure hydrogen (purity of ≤ 1 ppm CO dry), yielding 10 kWe net power from a fuel cell system with an overall parasitic power loss ≤ 10 %. The discussion of this process includes a detailed description of the design methodology and operational results of the catalytic converter, the hydrogen purification system and the fuel cell system. This paper will discuss the design methodology of the overall system, as well as the specific design of the catalytic converter, the catalysts used within, and the hydrogen purification system. It will also report the system performance including gas purity, recovery rate, overall hydrogen production efficiencies, and electrical efficiencies during fuel cell operation. (authors)

  13. Efficiency Comparison between Conventional and Modern Port Operation System for Small-Scale Dry Bulk Cargo

    Tiara Aulia

    2018-01-01

    Full Text Available Since the launching of Sea Toll Road Program in 2015, the improvement in ports’ operation systems has become Indonesia’s foremost necessity. This improvement commonly leads to equipment modernization, while realistically, modern equipment does not always amount to a productive performance, especially in the context of small-scale ports. Instead, it is prone to creating wasteful capital and maintenance cost as well as making the planning time ineffective. This study compares two options of port operation systems in a small port, which is conventional and technologically-advanced method for dry bulk cargo. It results in thin gaps between each option’s financial assessment variables, which are Internal Rate of Return, Benefit/Cost Ratio and Payback Period, regardless of a stark difference between each option’s equipment cost. This study concludes that with the right approach, the conventional operation system is still the most efficient option compared to its contemporary opposite.

  14. Small-scale cosmic microwave background anisotropies as probe of the geometry of the universe

    Kamionkowski, Marc; Spergel, David N.; Sugiyama, Naoshi

    1994-01-01

    We perform detailed calculations of cosmic microwave background (CMB) anisotropies in a cold dark matter (CDM)-dominated open universe with primordial adiabatic density perturbations for a variety of reionization histories. The CMB anisotropies depend primarily on the geometry of the universe, which in a matter-dominated universe is determined by Omega and the optical depth to the surface of last scattering. In particular, the location on the primary Doppler peak depends primarily on Omega and is fairly insensitive to the other unknown parameters, such as Omega(sub b), h, Lambda, and the shape of the power spectrum. Therefore, if the primordial density perturbations are adiabatic, measurements of CMB anisotropies on small scales may be used to determine Omega.

  15. Development, modelling and evaluation of a small-scale gas liquefaction plant

    Nguyen, Tuong-Van; Rothuizen, Erasmus Damgaard; Markussen, Wiebke Brix

    2017-01-01

    A small-scale gas liquefaction plant was developed and analysed based on process simulation tools and pilot tests. It will be installed in harbours, easing the penetration of liquefied natural gas (LNG) as a maritime fuel, in a sector facing more stringent environmental regulations. The proposed...... plant uses a multi-component refrigerant together with a propane precooling cycle and plate heat exchangers, to achieve a higher performance. This LNG production concept was modelled based on the Danish natural gas composition. Firstly, the total power consumption and heat transfer conductance were...... minimised by optimising the operating conditions and the refrigerant composition. The effects of varying feed and refrigerant compositions were analysed. Secondly, the system layouts were evaluated by conducting an exergetic assessment. Finally, the most promising layouts were validated by pilot plant...

  16. Chaotic Artificial Bee Colony Algorithm for System Identification of a Small-Scale Unmanned Helicopter

    Li Ding

    2015-01-01

    Full Text Available The purpose of this paper is devoted to developing a chaotic artificial bee colony algorithm (CABC for the system identification of a small-scale unmanned helicopter state-space model in hover condition. In order to avoid the premature of traditional artificial bee colony algorithm (ABC, which is stuck in local optimum and can not reach the global optimum, a novel chaotic operator with the characteristics of ergodicity and irregularity was introduced to enhance its performance. With input-output data collected from actual flight experiments, the identification results showed the superiority of CABC over the ABC and the genetic algorithm (GA. Simulations are presented to demonstrate the effectiveness of our proposed algorithm and the accuracy of the identified helicopter model.

  17. Modelling and Analysis of Radial Flux Surface Mounted Direct-Driven PMSG in Small Scale Wind Turbine

    Theint Zar Htet

    2017-11-01

    Full Text Available This paper presents the modelling and analysis of permanent magnet synchronous generator (PMSG which are used in direct driven small scale wind turbines. The 3 kW PM generator which is driven directly without gear system is analyzed by Ansoft Maxwell 2D RMxprt. The performance analysis of generator includes the cogging torque in two teeth, induced coil voltages under load, winding current under load, airgap flux density distribution and so on. The modelling analysis is based on the 2D finite element techniques. In an electrical machine, an accurate determination of the geometry parameters is a vital role. The proper performance results of 3kW PMSG in small scale wind turbine can be seen in this paper.

  18. Solar Thermoelectricity via Advanced Latent Heat Storage: A Cost-Effective Small-Scale CSP Application

    Glatzmaier, Greg C.; Rea, J.; Olsen, Michele L.; Oshman, C.; Hardin, C.; Alleman, Jeff; Sharp, J.; Weigand, R.; Campo, D.; Hoeschele, G.; Parilla, Philip A.; Siegel, N. P.; Toberer, Eric S.; Ginley, David S.

    2017-06-27

    We are developing a novel concentrating solar electricity-generating technology that is both modular and dispatchable. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) uses concentrated solar flux to generate high-temperature thermal energy, which directly converts to electricity via thermoelectric generators (TEGs), stored within a phase-change material (PCM) for electricity generation at a later time, or both allowing for simultaneous charging of the PCM and electricity generation. STEALS has inherent features that drive its cost-competitive scale to be much smaller than current commercial concentrating solar power (CSP) plants. Most obvious is modularity of the solid-state TEG, which favors smaller scales in the kilowatt range as compared to CSP steam turbines, which are minimally 50 MWe for commercial power plants. Here, we present techno-economic and market analyses that show STEALS can be a cost-effective electricity-generating technology with particular appeal to small-scale microgrid applications. We evaluated levelized cost of energy (LCOE) for STEALS and for a comparable photovoltaic (PV) system with battery storage. For STEALS, we estimated capital costs and the LCOE as functions of the type of PCM including the use of recycled aluminum alloys, and evaluated the cost tradeoffs between plasma spray coatings and solution-based boron coatings that are applied to the wetted surfaces of the PCM subsystem. We developed a probabilistic cost model that accounts for uncertainties in the cost and performance inputs to the LCOE estimation. Our probabilistic model estimated LCOE for a 100-kWe STEALS system that had 5 hours of thermal storage and 8-10 hours of total daily power generation. For these cases, the solar multiple for the heliostat field varied between 1.12 and 1.5. We identified microgrids as a likely market for the STEALS system. We characterized microgrid markets in terms of nominal power, dispatchability, geographic location, and

  19. Human mercury exposure associated with small-scale gold mining in Burkina Faso.

    Tomicic, Catherine; Vernez, David; Belem, Tounaba; Berode, Michèle

    2011-06-01

    In Burkina Faso, gold ore is one of the main sources of income for an important part of the active population. Artisan gold miners use mercury in the extraction, a toxic metal whose human health risks are well known. The aim of the present study was to assess mercury exposure as well as to understand the exposure determinants of gold miners in Burkinabe small-scale mines. The examined gold miners' population on the different selected gold mining sites was composed by persons who were directly and indirectly related to gold mining activities. But measurement of urinary mercury was performed on workers most susceptible to be exposed to mercury. Thus, occupational exposure to mercury was evaluated among ninety-three workers belonging to eight different gold mining sites spread in six regions of Burkina Faso. Among others, work-related exposure determinants were taken into account for each person during urine sampling as for example amalgamating or heating mercury. All participants were medically examined by a local medical team in order to identify possible symptoms related to the toxic effect of mercury. Mercury levels were high, showing that 69% of the measurements exceeded the ACGIH (American Conference of Industrial Hygienists) biological exposure indice (BEI) of 35 μg per g of creatinine (μg/g-Cr) (prior to shift) while 16% even exceeded 350 μg/g-Cr. Basically, unspecific but also specific symptoms related to mercury toxicity could be underlined among the persons who were directly related to gold mining activities. Only one-third among the studied subpopulation reported about less than three symptoms possibly associated to mercury exposure and nearly half of them suffered from at least five of these symptoms. Ore washers were more involved in the direct handling of mercury while gold dealers in the final gold recovery activities. These differences may explain the overexposure observed in gold dealers and indicate that the refining process is the major source

  20. Atomistic modeling of nanowires, small-scale fatigue damage in cast magnesium, and materials for MEMS

    Dunn, Martin L. [Univ. of Colorado, Boulder, CO (United States); Talmage, Mellisa J. [Univ. of Colorado, Boulder, CO (United States); McDowell, David L. [Georgia Inst. of Technology, Atlanta, GA (United States); West, Neil [Univ. of Colorado, Boulder, CO (United States); Gullett, Philip Michael [Mississippi State Univ., Mississippi State, MS (United States); Miller, David C. [Univ. of Colorado, Boulder, CO (United States); Spark, Kevin [Univ. of Colorado, Boulder, CO (United States); Diao, Jiankuai [Univ. of Colorado, Boulder, CO (United States); Horstemeyer, Mark F. [Mississippi State Univ., Mississippi State, MS (United States); Zimmerman, Jonathan A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gall, K. [Georgia Inst. of Technology, Atlanta, GA (United States)

    2006-10-01

    Lightweight and miniaturized weapon systems are driving the use of new materials in design such as microscale materials and ultra low-density metallic materials. Reliable design of future weapon components and systems demands a thorough understanding of the deformation modes in these materials that comprise the components and a robust methodology to predict their performance during service or storage. Traditional continuum models of material deformation and failure are not easily extended to these new materials unless microstructural characteristics are included in the formulation. For example, in LIGA Ni and Al-Si thin films, the physical size is on the order of microns, a scale approaching key microstructural features. For a new potential structural material, cast Mg offers a high stiffness-to-weight ratio, but the microstructural heterogeneity at various scales requires a structure-property continuum model. Processes occurring at the nanoscale and microscale develop certain structures that drive material behavior. The objective of the work presented in this report was to understand material characteristics in relation to mechanical properties at the nanoscale and microscale in these promising new material systems. Research was conducted primarily at the University of Colorado at Boulder to employ tightly coupled experimentation and simulation to study damage at various material size scales under monotonic and cyclic loading conditions. Experimental characterization of nano/micro damage will be accomplished by novel techniques such as in-situ environmental scanning electron microscopy (ESEM), 1 MeV transmission electron microscopy (TEM), and atomic force microscopy (AFM). New simulations to support experimental efforts will include modified embedded atom method (MEAM) atomistic simulations at the nanoscale and single crystal micromechanical finite element simulations. This report summarizes the major research and development accomplishments for the LDRD project

  1. Solar thermoelectricity via advanced latent heat storage: A cost-effective small-scale CSP application

    Glatzmaier, G. C.; Rea, J.; Olsen, M. L.; Oshman, C.; Hardin, C.; Alleman, J.; Sharp, J.; Weigand, R.; Campo, D.; Hoeschele, G.; Parilla, P. A.; Siegel, N. P.; Toberer, E. S.; Ginley, D. S.

    2017-06-01

    We are developing a novel concentrating solar electricity-generating technology that is both modular and dispatchable. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) uses concentrated solar flux to generate high-temperature thermal energy, which directly converts to electricity via thermoelectric generators (TEGs), stored within a phase-change material (PCM) for electricity generation at a later time, or both allowing for simultaneous charging of the PCM and electricity generation. STEALS has inherent features that drive its cost-competitive scale to be much smaller than current commercial concentrating solar power (CSP) plants. Most obvious is modularity of the solid-state TEG, which favors smaller scales in the kilowatt range as compared to CSP steam turbines, which are minimally 50 MWe for commercial power plants. Here, we present techno-economic and market analyses that show STEALS can be a cost-effective electricity-generating technology with particular appeal to small-scale microgrid applications. We evaluated levelized cost of energy (LCOE) for STEALS and for a comparable photovoltaic (PV) system with battery storage. For STEALS, we estimated capital costs and the LCOE as functions of the type of PCM including the use of recycled aluminum alloys, and evaluated the cost tradeoffs between plasma spray coatings and solution-based boron coatings that are applied to the wetted surfaces of the PCM subsystem. We developed a probabilistic cost model that accounts for uncertainties in the cost and performance inputs to the LCOE estimation. Our probabilistic model estimated LCOE for a 100-kWe STEALS system that had 5 hours of thermal storage and 8-10 hours of total daily power generation. For these cases, the solar multiple for the heliostat field varied between 1.12 and 1.5. We identified microgrids as a likely market for the STEALS system. We characterized microgrid markets in terms of nominal power, dispatchability, geographic location, and

  2. The efficiency of an open-cavity tubular solar receiver for a small-scale solar thermal Brayton cycle

    Le Roux, W.G.; Bello-Ochende, T.; Meyer, J.P.

    2014-01-01

    Highlights: • Results show efficiencies of a low-cost stainless steel tubular cavity receiver. • Optimum ratio of 0.0035 is found for receiver aperture area to concentrator area. • Smaller receiver tube and higher mass flow rate increase receiver efficiency. • Larger tube and smaller mass flow rate increase second law efficiency. • Large-tube receiver performs better in the small-scale solar thermal Brayton cycle. - Abstract: The first law and second law efficiencies are determined for a stainless steel closed-tube open rectangular cavity solar receiver. It is to be used in a small-scale solar thermal Brayton cycle using a micro-turbine with low compressor pressure ratios. There are many different variables at play to model the air temperature increase of the air running through such a receiver. These variables include concentrator shape, concentrator diameter, concentrator rim angle, concentrator reflectivity, concentrator optical error, solar tracking error, receiver aperture area, receiver material, effect of wind, receiver tube diameter, inlet temperature and mass flow rate through the receiver. All these variables are considered in this paper. The Brayton cycle requires very high receiver surface temperatures in order to be successful. These high temperatures, however, have many disadvantages in terms of heat loss from the receiver, especially radiation heat loss. With the help of ray-tracing software, SolTrace, and receiver modelling techniques, an optimum receiver-to-concentrator-area ratio of A′ ≈ 0.0035 was found for a concentrator with 45° rim angle, 10 mrad optical error and 1° tracking error. A method to determine the temperature profile and net heat transfer rate along the length of the receiver tube is presented. Receiver efficiencies are shown in terms of mass flow rate, receiver tube diameter, pressure drop, maximum receiver surface temperature and inlet temperature of the working fluid. For a 4.8 m diameter parabolic dish, the

  3. The Impact of Small Scale Mining on Irrigation Water Quality in ...

    Small scale mining is a major threat to water resources and agricultural activities in most mining communities across Ghana. This study investigated the effect of small scale mining on the quality of water for irrigation from some selected sites along a river and a reservoir which was used as a control. The physical and ...

  4. Mercury use in small scale gold mining in Ghana: an assessment of its impact on miners

    Biagya, Robert Yakubu

    2002-12-01

    Small scale gold mining is responsible for about 5% of Ghana’s annual gold production. It is estimated that between 80,000 and 100,000 people are engaged in small scale gold mining either on part-time or permanent basis. Amalgamation is the preferred method used by small scale gold miners for extracting free gold from its ores. The rate at which mercury, an important input in this method, is discharged into the atmosphere and water bodies is alarming. This research describes the various mining and processing methods in small scale gold mining and the extent of mercury use and releases to the environment. It discusses mercury and its human and environmental effects. It defines the various forms of mercury, routes of exposure, toxic effects. The levels of exposure to mercury by all groups of small scale gold miners are determined, and the impacts on the miners and the environment are assessed. It concludes that: • Mercury is mainly released into the environment as a result of small scale gold mining through spillage of elemental mercury and evaporation of mercury from the amalgam and sponge gold when they are heated on open fire. • Mercury in environmental samples from small scale gold mining areas is well above standard limit values. • Mercury released into the environment through small scale gold mining impacts negatively on the miners themselves and the general environment. Finally, it recommends the need for the adoption of mercury emission reduction strategies for dealing with the mercury problem. (au)

  5. Methodological foundations of evaluation of effectiveness indicators of small-scale business activities

    Ivanova T.

    2013-01-01

    Full Text Available The methodological approach to the measurement of financial indicators of small-scale enterprises has been developed. It enables to secure the comparability of financial condition indicators and the results of small-scale enterprise activities, and also to develop the methods of vertical integral estimate calculation at separate aspects of financial condition and the results of smallscale enterprise activities.

  6. Enhancing stewardship in Latin America and Caribbean small-scale fisheries : challenges and opportunities

    Gasalla, M.A.; de Castro, F.

    2016-01-01

    This thematic series, entitled “Enhancing Stewardship in Latin America and Caribbean Small-Scale Fisheries”, emerged as part of a joint effort to bridge Latin-American scholars interested in networking on small-scale fisheries in the region. Built on results presented at two meetings (‘Too Big to

  7. Socio-technical study of small-scale gold mining in Suriname

    Seccatore, J; de Theije, M.E.M.

    2017-01-01

    Small-scale gold mining is Suriname’s main economic sector, producing about two thirds of the nation’s gold. Despite this, the sector is only very loosely regulated and most small-scale mining activities are informal. Surinamese miners are only a minority: the majority are Brazilian migrants, who

  8. Category, narrative and value in the governance of small-scale fisheries

    Johnson, D.S.

    2006-01-01

    Since the 1970s, small-scale fisheries have had an important place in fisheries social science and in fisheries management. While there has been substantial discussion of what constitutes the category of small-scale fisheries, its considerable ambiguity is nevertheless often passed over. This paper

  9. A small-scale dynamo in feedback-dominated galaxies - III. Cosmological simulations

    Rieder, Michael; Teyssier, Romain

    2017-12-01

    Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific genesis has long been debated. Due to the development of more realistic models of galaxy formation, viable scenarios are emerging to explain cosmic magnetism, thanks to both deeper observations and more efficient and accurate computer simulations. We present here a new cosmological high-resolution zoom-in magnetohydrodynamic (MHD) simulation, using the adaptive mesh refinement technique, of a dwarf galaxy with an initially weak and uniform magnetic seed field that is amplified by a small-scale dynamo (SSD) driven by supernova-induced turbulence. As first structures form from the gravitational collapse of small density fluctuations, the frozen-in magnetic field separates from the cosmic expansion and grows through compression. In a second step, star formation sets in and establishes a strong galactic fountain, self-regulated by supernova explosions. Inside the galaxy, the interstellar medium becomes highly turbulent, dominated by strong supersonic shocks, as demonstrated by the spectral analysis of the gas kinetic energy. In this turbulent environment, the magnetic field is quickly amplified via a SSD process and is finally carried out into the circumgalactic medium by a galactic wind. This realistic cosmological simulation explains how initially weak magnetic seed fields can be amplified quickly in early, feedback-dominated galaxies, and predicts, as a consequence of the SSD process, that high-redshift magnetic fields are likely to be dominated by their small-scale components.

  10. High performance fuel technology development

    Koon, Yang Hyun; Kim, Keon Sik; Park, Jeong Yong; Yang, Yong Sik; In, Wang Kee; Kim, Hyung Kyu [KAERI, Daejeon (Korea, Republic of)

    2012-01-15

    {omicron} Development of High Plasticity and Annular Pellet - Development of strong candidates of ultra high burn-up fuel pellets for a PCI remedy - Development of fabrication technology of annular fuel pellet {omicron} Development of High Performance Cladding Materials - Irradiation test of HANA claddings in Halden research reactor and the evaluation of the in-pile performance - Development of the final candidates for the next generation cladding materials. - Development of the manufacturing technology for the dual-cooled fuel cladding tubes. {omicron} Irradiated Fuel Performance Evaluation Technology Development - Development of performance analysis code system for the dual-cooled fuel - Development of fuel performance-proving technology {omicron} Feasibility Studies on Dual-Cooled Annular Fuel Core - Analysis on the property of a reactor core with dual-cooled fuel - Feasibility evaluation on the dual-cooled fuel core {omicron} Development of Design Technology for Dual-Cooled Fuel Structure - Definition of technical issues and invention of concept for dual-cooled fuel structure - Basic design and development of main structure components for dual- cooled fuel - Basic design of a dual-cooled fuel rod.

  11. High Performance Bulk Thermoelectric Materials

    Ren, Zhifeng [Boston College, Chestnut Hill, MA (United States)

    2013-03-31

    Over 13 plus years, we have carried out research on electron pairing symmetry of superconductors, growth and their field emission property studies on carbon nanotubes and semiconducting nanowires, high performance thermoelectric materials and other interesting materials. As a result of the research, we have published 104 papers, have educated six undergraduate students, twenty graduate students, nine postdocs, nine visitors, and one technician.

  12. A New Precision Measurement of the Small-scale Line-of-sight Power Spectrum of the Lyα Forest

    Walther, Michael; Hennawi, Joseph F.; Hiss, Hector; Oñorbe, Jose; Lee, Khee-Gan; Rorai, Alberto; O’Meara, John

    2018-01-01

    We present a new measurement of the Lyα forest power spectrum at 1.8 masking missing data, damped Lyα absorption systems, and metal absorption lines. Our measurement results in unprecedented precision on the small-scale modes k> 0.02 {{s}} {{km}}-1, inaccessible to previous SDSS/BOSS analyses. It is well known that these high-k modes are highly sensitive to the thermal state of the intergalactic medium, but contamination by narrow metal lines is a significant concern. We quantify the effect of metals on the small-scale power and find a modest effect on modes with kmasking metals and restricting to kmasking as our data are generated from Lyα forest simulations. These mock spectra are used to build a custom emulator, enabling us to interpolate between a sparse grid of models and perform Markov chain Monte Carlo fits. Our results agree well with BOSS on scales kdata set for precisely constraining the thermal history of the intergalactic medium, cosmological parameters, and the nature of dark matter. The power spectra and their covariance matrices are provided as electronic tables.

  13. High performance in software development

    CERN. Geneva; Haapio, Petri; Liukkonen, Juha-Matti

    2015-01-01

    What are the ingredients of high-performing software? Software development, especially for large high-performance systems, is one the most complex tasks mankind has ever tried. Technological change leads to huge opportunities but challenges our old ways of working. Processing large data sets, possibly in real time or with other tight computational constraints, requires an efficient solution architecture. Efficiency requirements span from the distributed storage and large-scale organization of computation and data onto the lowest level of processor and data bus behavior. Integrating performance behavior over these levels is especially important when the computation is resource-bounded, as it is in numerics: physical simulation, machine learning, estimation of statistical models, etc. For example, memory locality and utilization of vector processing are essential for harnessing the computing power of modern processor architectures due to the deep memory hierarchies of modern general-purpose computers. As a r...

  14. Studies of small-scale plasma inhomogeneities in the cusp ionosphere using sounding rocket data

    Chernyshov, Alexander A.; Spicher, Andres; Ilyasov, Askar A.; Miloch, Wojciech J.; Clausen, Lasse B. N.; Saito, Yoshifumi; Jin, Yaqi; Moen, Jøran I.

    2018-04-01

    Microprocesses associated with plasma inhomogeneities are studied on the basis of data from the Investigation of Cusp Irregularities (ICI-3) sounding rocket. The ICI-3 rocket is devoted to investigating a reverse flow event in the cusp F region ionosphere. By numerical stability analysis, it is demonstrated that inhomogeneous-energy-density-driven (IEDD) instability can be a mechanism for the excitation of small-scale plasma inhomogeneities. The Local Intermittency Measure (LIM) method also applied the rocket data to analyze irregular structures of the electric field during rocket flight in the cusp. A qualitative agreement between high values of the growth rates of the IEDD instability and the regions with enhanced LIM is observed. This suggests that IEDD instability is connected to turbulent non-Gaussian processes.

  15. [Acidity and microbial flora contaminating Senegalese reconstituted curdled milk produced on small scale].

    Seydi, M; Ndiaye, M

    1993-01-01

    The present study is carried out to appreciate the acidity, and survey the microbiological quality of reconstituted curdled milk (R.C.M.) obtained on small scale. For his, a total of 100 samples collected from Dakar's sellers were examined. The results show that: pH of R.C.M. is low and very variable: 4.17 +/- 0.30, titrable acidity is high: 152.6 +/- 26.5 degrees D, 5% of samples are contaminated by fecal coliforms and yielded counts of 20 germs/g, 19% of samples are polluted by Staphylococcus aureus to level equal to 10(2) germs/g or higher, yeasts and moulds are present in all samples, salmonella were absent. Saphylococcus aureus survival in curdled milk despite a dysgenesic acidity may be the result of very unhygienic conditions of preparation. Sellers and consumers must be encouraged to respect hygienic rules of preparation. It is the only way to prevent food poisoning.

  16. A small scale accelerator driven subcritical assembly development and demonstration experiment at LAMPF

    Wender, S.A.; Venneri, F.; Bowman, C.D.; Arthur, E.D.; Heighway, E.A.; Beard, C.A.; Bracht, R.R.; Buksa, J.J.; Chavez, W.; DeVolder, B.G.

    1994-01-01

    A small scale experiment is described that will demonstrate many of the aspects of accelerator-driven transmutation technology. This experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator and will be located in the Area-A experimental hall. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by a molten salt and graphite moderator blanket. Fissionable material can be added to the molten salt to demonstrate plutonium burning or transmutation of commercial spent fuel or energy production from thorium. The experiment will be operated at power levels up to 5 MW t

  17. Fast magnetic reconnection supported by sporadic small-scale Petschek-type shocks

    Shibayama, Takuya; Nakabou, Takashi; Kusano, Kanya; Miyoshi, Takahiro; Vekstein, Grigory

    2015-01-01

    Standard magnetohydrodynamic (MHD) theory predicts reconnection rate that is far too slow to account for a wide variety of reconnection events observed in space and laboratory plasmas. Therefore, it was commonly accepted that some non-MHD (kinetic) effects play a crucial role in fast reconnection. A recently renewed interest in simple MHD models is associated with the so-called plasmoid instability of reconnecting current sheets. Although it is now evident that this effect can significantly enhance the rate of reconnection, many details of the underlying multiple-plasmoid process still remain controversial. Here, we report results of a high-resolution computer simulation which demonstrate that fast albeit intermittent magnetic reconnection is sustained by numerous small-scale Petschek-type shocks spontaneously formed in the current sheet due to its plasmoid instability

  18. Fast magnetic reconnection supported by sporadic small-scale Petschek-type shocks

    Shibayama, Takuya, E-mail: shibayama@stelab.nagoya-u.ac.jp; Nakabou, Takashi [Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan); Kusano, Kanya [Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan); Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kanazawa-ku, Yokohama, Kanagawa 236-0001 (Japan); Miyoshi, Takahiro [Department of Physical Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Vekstein, Grigory [Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester M13 9PL (United Kingdom)

    2015-10-15

    Standard magnetohydrodynamic (MHD) theory predicts reconnection rate that is far too slow to account for a wide variety of reconnection events observed in space and laboratory plasmas. Therefore, it was commonly accepted that some non-MHD (kinetic) effects play a crucial role in fast reconnection. A recently renewed interest in simple MHD models is associated with the so-called plasmoid instability of reconnecting current sheets. Although it is now evident that this effect can significantly enhance the rate of reconnection, many details of the underlying multiple-plasmoid process still remain controversial. Here, we report results of a high-resolution computer simulation which demonstrate that fast albeit intermittent magnetic reconnection is sustained by numerous small-scale Petschek-type shocks spontaneously formed in the current sheet due to its plasmoid instability.

  19. Small-scale structure and 21cm fluctuations by primordial black holes

    Gong, Jinn-Ouk; Kitajima, Naoya, E-mail: jinn-ouk.gong@apctp.org, E-mail: kitajima.naoya@f.mbox.nagoya-u.ac.jp [Asia Pacific Center for Theoretical Physics, Pohang 37673 (Korea, Republic of)

    2017-08-01

    We discuss early structure formation of small scales sourced by primordial black holes (PBHs) which constitute a small part of present cold dark matter component. We calculate the mass function and power spectrum of haloes originated from the Poisson fluctuations of PBH number and show that the number of small haloes is significantly modified in the presence of PBHs even if their fraction accounts for only 10{sup −4}–10{sup −3} of total dark matter abundance. We then compute the subsequent 21cm signature from those haloes. We find that PBHs can provide major contributions at high redshifts within the detectability of future experiments such as Square Kilometer Array, and provide a forecast constraint on the PBH fraction.

  20. Recycling of NiCd batteries by hydrometallurgical process on small scale

    Kim, Y.J.; Kim, J.H.; Thi, L.D.; Qureshi, T.I.

    2011-01-01

    High recovery of cadmium metal from household spent nickel cadmium batteries through hydrometallurgical process on small scale was conducted. Recovery of metal through separation of leached metal ions using ion exchange resin was examined. Hydrochloric acid (4.0 M) solution showed relatively better leaching potential than other acids, however, considering overall efficiency of the process, sulphuric acid was suggested to be employed as leaching and regeneration reagent in this study. Variations in solid/liquid ratio did not show a significant difference in the amount of heavy metal ions leached out; however, leaching temperature greatly affected the leaching efficiency. Changes in bed volume of the resin greatly influenced the sorption of cadmium metal ions while concentration and flow rate of the regeneration reagent were found important parameters affecting regeneration capacity of the resin. (author)

  1. Simulation Study Of Small Scale Jobshop | Ubani | Journal of ...

    This paper examines the impact of strategic change management on the performances of public transport in Osun State, Nigeria. It aimed at determining the role of leadership style in strategic change management; identify in factors that are influencing change process and actual performance of an organization. The study ...

  2. Adoption of Small-Scale Irrigation Farming as a Climate-Smart Agriculture Practice and Its Influence on Household Income in the Chinyanja Triangle, Southern Africa

    Nelson Mango

    2018-04-01

    Full Text Available This article is concerned with the adoption of small-scale irrigation farming as a climate-smart agriculture practice and its influence on household income in the Chinyanja Triangle. Chinyanja Triangle is a region that is increasingly experiencing mid-season dry spells and an increase in occurrence of drought, which is attributed largely to climate variability and change. This poses high agricultural production risks, which aggravate poverty and food insecurity. For this region, adoption of small-scale irrigation farming as a climate-smart agriculture practice is very important. Through a binary logistic and ordinary least squares regression, this article determines factors that influence the adoption of small-scale irrigation farming as a climate-smart agriculture practice and its influence on income among smallholder farmers. The results show that off-farm employment, access to irrigation equipment, access to reliable water sources and awareness of water conservation practices, such as rainwater harvesting, have a significant influence on the adoption of small-scale irrigation farming. On the other hand, the farmer’s age, distance travelled to the nearest market and nature of employment negatively influence the adoption of small-scale irrigation farming decisions. Ordinary least squares regression results showed that the adoption of small-scale irrigation farming as a climate-smart agriculture practice has a significant positive influence on agricultural income. We therefore conclude that to empower smallholder farmers to respond quickly to climate variability and change, practices that will enhance the adoption of small-scale irrigation farming in the Chinyanja Triangle are critical, as this will significantly affect agricultural income. In terms of policy, we recommend that the governments of Zambia, Malawi and Mozambique, which cover the Chinyanja Triangle, formulate policies that will enhance the adoption of sustainable small scale

  3. Designing a Frost Forecasting Service for Small Scale Tea Farmers in East Africa

    Adams, E. C.; Nyaga, J. W.; Ellenburg, W. L.; Limaye, A. S.; Mugo, R. M.; Flores Cordova, A. I.; Irwin, D.; Case, J.; Malaso, S.; Sedah, A.

    2017-12-01

    Kenya is the third largest tea exporter in the world, producing 10% of the world's black tea. Sixty percent of this production occurs largely by small scale tea holders, with an average farm size of 1.04 acres, and an annual net income of 1,075. According to a recent evaluation, a typical frost event in the tea growing region causes about 200 dollars in losses which can be catastrophic for a small holder farm. A 72-hour frost forecast would provide these small-scale tea farmers with enough notice to reduce losses by approximately $80 annually. With this knowledge, SERVIR, a joint NASA-USAID initiative that brings Earth observations for improved decision making in developing countries, sought to design a frost monitoring and forecasting service that would provide farmers with enough lead time to react to and protect against a forecasted frost occurrence on their farm. SERVIR Eastern and Southern Africa, through its implementing partner, the Regional Centre for Mapping of Resources for Development (RCMRD), designed a service that included multiple stakeholder engagement events whereby stakeholders from the tea industry value chain were invited to share their experiences so that the exact needs and flow of information could be identified. This unique event allowed enabled the design of a service that fit the specifications of the stakeholders. The monitoring service component uses the MODIS Land Surface Temperature product to identify frost occurrences in near-real time. The prediction component, currently under testing, uses the 2-m air temperature, relative humidity, and 10-m wind speed from a series of high-resolution Weather Research and Forecasting (WRF) numerical weather prediction model runs over eastern Kenya as inputs into a frost prediction algorithm. Accuracy and sensitivity of the algorithm is being assessed with observations collected from the farmers using a smart phone app developed specifically to report frost occurrences, and from data shared through

  4. Small-scale density variations in the lunar crust revealed by GRAIL

    Jansen, J. C.; Andrews-Hanna, J. C.; Li, Y.; Lucey, P. G.; Taylor, G. J.; Goossens, S.; Lemoine, F. G.; Mazarico, E.; Head, J. W.; Milbury, C.; Kiefer, W. S.; Soderblom, J. M.; Zuber, M. T.

    2017-07-01

    Data from the Gravity Recovery and Interior Laboratory (GRAIL) mission have revealed that ∼98% of the power of the gravity signal of the Moon at high spherical harmonic degrees correlates with the topography. The remaining 2% of the signal, which cannot be explained by topography, contains information about density variations within the crust. These high-degree Bouguer gravity anomalies are likely caused by small-scale (10‧s of km) shallow density variations. Here we use gravity inversions to model the small-scale three-dimensional variations in the density of the lunar crust. Inversion results from three non-descript areas yield shallow density variations in the range of 100-200 kg/m3. Three end-member scenarios of variations in porosity, intrusions into the crust, and variations in bulk crustal composition were tested as possible sources of the density variations. We find that the density anomalies can be caused entirely by changes in porosity. Characteristics of density anomalies in the South Pole-Aitken basin also support porosity as a primary source of these variations. Mafic intrusions into the crust could explain many, but not all of the anomalies. Additionally, variations in crustal composition revealed by spectral data could only explain a small fraction of the density anomalies. Nevertheless, all three sources of density variations likely contribute. Collectively, results from this study of GRAIL gravity data, combined with other studies of remote sensing data and lunar samples, show that the lunar crust exhibits variations in density by ± 10% over scales ranging from centimeters to 100‧s of kilometers.

  5. Small-Scale Density Variations in the Lunar Crust Revealed by GRAIL

    Jansen, J. C.; Andrews-Hanna, J. C.; Li, Y.; Lucey, P. G.; Taylor, G. J.; Goossens, S.; Lemoine, F. G.; Mazarico, E.; Head, J. W., III; Milbury, C.; hide

    2017-01-01

    Data from the Gravity Recovery and Interior Laboratory (GRAIL) mission have revealed that approximately 98 percent of the power of the gravity signal of the Moon at high spherical harmonic degrees correlates with the topography. The remaining 2 percent of the signal, which cannot be explained by topography, contains information about density variations within the crust. These high-degree Bouguer gravity anomalies are likely caused by small-scale (10's of km) shallow density variations. Here we use gravity inversions to model the small-scale three-dimensional variations in the density of the lunar crust. Inversion results from three non-descript areas yield shallow density variations in the range of 100-200 kg/m3. Three end-member scenarios of variations in porosity, intrusions into the crust, and variations in bulk crustal composition were tested as possible sources of the density variations. We find that the density anomalies can be caused entirely by changes in porosity. Characteristics of density anomalies in the South Pole-Aitken basin also support porosity as a primary source of these variations. Mafic intrusions into the crust could explain many, but not all of the anomalies. Additionally, variations in crustal composition revealed by spectral data could only explain a small fraction of the density anomalies. Nevertheless, all three sources of density variations likely contribute. Collectively, results from this study of GRAIL gravity data, combined with other studies of remote sensing data and lunar samples, show that the lunar crust exhibits variations in density by plus or minus 10 percent over scales ranging from centimeters to 100’s of kilometers.

  6. Multi-GNSS PPP-RTK: From Large- to Small-Scale Networks

    Nandakumaran Nadarajah

    2018-04-01

    Full Text Available Precise point positioning (PPP and its integer ambiguity resolution-enabled variant, PPP-RTK (real-time kinematic, can benefit enormously from the integration of multiple global navigation satellite systems (GNSS. In such a multi-GNSS landscape, the positioning convergence time is expected to be reduced considerably as compared to the one obtained by a single-GNSS setup. It is therefore the goal of the present contribution to provide numerical insights into the role taken by the multi-GNSS integration in delivering fast and high-precision positioning solutions (sub-decimeter and centimeter levels using PPP-RTK. To that end, we employ the Curtin PPP-RTK platform and process data-sets of GPS, BeiDou Navigation Satellite System (BDS and Galileo in stand-alone and combined forms. The data-sets are collected by various receiver types, ranging from high-end multi-frequency geodetic receivers to low-cost single-frequency mass-market receivers. The corresponding stations form a large-scale (Australia-wide network as well as a small-scale network with inter-station distances less than 30 km. In case of the Australia-wide GPS-only ambiguity-float setup, 90% of the horizontal positioning errors (kinematic mode are shown to become less than five centimeters after 103 min. The stated required time is reduced to 66 min for the corresponding GPS + BDS + Galieo setup. The time is further reduced to 15 min by applying single-receiver ambiguity resolution. The outcomes are supported by the positioning results of the small-scale network.

  7. Comparison of Waste Feed Delivery Small Scale Mixing Demonstration Simulant to Hanford Waste

    Wells, Beric E.; Gauglitz, Phillip A.; Rector, David R.

    2012-07-10

    The Hanford double-shell tank (DST) system provides the staging location for waste that will be transferred to the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Specific WTP acceptance criteria for waste feed delivery describe the physical and chemical characteristics of the waste that must be met before the waste is transferred from the DSTs to the WTP. One of the more challenging requirements relates to the sampling and characterization of the undissolved solids (UDS) in a waste feed DST because the waste contains solid particles that settle and their concentration and relative proportion can change during the transfer of the waste in individual batches. A key uncertainty in the waste feed delivery system is the potential variation in UDS transferred in individual batches in comparison to an initial sample used for evaluating the acceptance criteria. To address this uncertainty, a number of small-scale mixing tests have been conducted as part of Washington River Protection Solutions' Small Scale Mixing Demonstration (SSMD) project to determine the performance of the DST mixing and sampling systems. A series of these tests have used a five-part simulant composed of particles of different size and density and designed to be equal or more challenging than AY-102 waste. This five-part simulant, however, has not been compared with the broad range of Hanford waste, and thus there is an additional uncertainty that this simulant may not be as challenging as the most difficult Hanford waste. The purpose of this study is to quantify how the current five-part simulant compares to all of the Hanford sludge waste, and to suggest alternate simulants that could be tested to reduce the uncertainty in applying the current testing results to potentially more challenging wastes.

  8. Theoretical simulation of small scale psychometric solar water desalination system in semi-arid region

    Shatat, Mahmoud; Omer, Siddig; Gillott, Mark; Riffat, Saffa

    2013-01-01

    Many countries around the world suffer from water scarcity. This is especially true in remote and semi-arid regions in the Middle East and North Africa (MENA) where per capita water supplies decline as populations increase. This paper presents the results of a theoretical simulation of an affordable small scale solar water desalination plant using the psychometric humidification and dehumidification process coupled with an evacuated tube solar collector with an area of about 2 m 2 . A mathematical model was developed to describe the system's operation. Then a computer program using Simulink Matlab software was developed to provide the governing equations for the theoretical calculations of the humidification and dehumidification processes. The experimental and theoretical values for the total daily distillate output were found to be closely correlated. After the experimental calibration of the mathematical model, a model simulating solar radiation under the climatic conditions in the Middle East region proved that the performance of the system could be improved to produce a considerably higher amount of fresh water, namely up to 17.5 kg/m 2 day. This work suggests that utilizing the concept of humidification and dehumidification, a compact water desalination unit coupled with solar collectors would significantly increase the potable water supply in remote area. It could be a unique solution of water shortages in such areas. -- Highlights: • An affordable small scale desalination system is proposed. • A mathematical model of the desalination system is developed and programmed using Matlab Simulink. • The model describes the psychometric process based on humidification and dehumidification. • The model is used in optimal selection of elements and operating conditions for solar desalination system. • The use of solar water desalination contributes significantly to reducing global warming

  9. The epidemiology and small-scale spatial heterogeneity of urinary schistosomiasis in Lusaka province, Zambia

    Christopher Simoonga

    2008-11-01

    Full Text Available In line with the aims of the “National Bilharzia Control Programme” and the “School Health and Nutrition Programme” in Zambia, a study on urinary schistosomiasis was conducted in 20 primary schools of Lusaka province to further our understanding of the epidemiology of the infection, and to enhance spatial targeting of control. We investigated risk factors associated with urinary schistosomiasis, and examined small-scale spatial heterogeneity in prevalence, using data collected from 1,912 schoolchildren, 6 to 15-year-old, recruited from 20 schools in Kafue and Luangwa districts. The risk factors identified included geographical location, altitude, normalized difference vegetation index (NDVI, maximum temperature, age, sex of the child and intermediate host snail abundance. Three logistic regression models were fitted assuming different random effects to allow for spatial structuring. The mean prevalence rate was 9.6%, with significance difference between young and older children (odds ratio (OR = 0.71; 95% confidence interval (CI = 0.51-0.96. The risk of infection was related to intermediate host snail abundance (OR = 1.03; 95% CI = 1.00-1.05 and vegetation cover (OR = 1.04; 95% CI = 1.00-1.07. Schools located either on the plateau and the valley also differed in prevalence and intensity of infection for moderate infection to none (OR = 1.64; 95% CI = 1.36- 1.96. The overall predictive performance of the spatial random effects model was higher than the ordinary logistic regression. In addition, evidence of heterogeneity of the infection risk was found at the micro-geographical level. A sound understanding of small-scale heterogeneity, caused by spatial aggregation of schoolchildren, is important to inform health planners for implementing control schistosomiasis interventions.

  10. "Non-cold" dark matter at small scales: a general approach

    Murgia, R.; Merle, A.; Viel, M.; Totzauer, M.; Schneider, A.

    2017-11-01

    Structure formation at small cosmological scales provides an important frontier for dark matter (DM) research. Scenarios with small DM particle masses, large momenta or hidden interactions tend to suppress the gravitational clustering at small scales. The details of this suppression depend on the DM particle nature, allowing for a direct link between DM models and astrophysical observations. However, most of the astrophysical constraints obtained so far refer to a very specific shape of the power suppression, corresponding to thermal warm dark matter (WDM), i.e., candidates with a Fermi-Dirac or Bose-Einstein momentum distribution. In this work we introduce a new analytical fitting formula for the power spectrum, which is simple yet flexible enough to reproduce the clustering signal of large classes of non-thermal DM models, which are not at all adequately described by the oversimplified notion of WDM . We show that the formula is able to fully cover the parameter space of sterile neutrinos (whether resonantly produced or from particle decay), mixed cold and warm models, fuzzy dark matter, as well as other models suggested by effective theory of structure formation (ETHOS). Based on this fitting formula, we perform a large suite of N-body simulations and we extract important nonlinear statistics, such as the matter power spectrum and the halo mass function. Finally, we present first preliminary astrophysical constraints, based on linear theory, from both the number of Milky Way satellites and the Lyman-α forest. This paper is a first step towards a general and comprehensive modeling of small-scale departures from the standard cold DM model.

  11. Fishing Farmers or Farming Fishers? Fishing Typology of Inland Small-Scale Fishing Households and Fisheries Management in Singkarak Lake, West Sumatra, Indonesia

    Yuerlita; Perret, Sylvain Roger; Shivakoti, Ganesh P.

    2013-07-01

    Technical and socio-economic characteristics are known to determine different types of fishers and their livelihood strategies. Faced with declining fish and water resources, small-scale fisheries engage into transformations in livelihood and fishing practices. The paper is an attempt to understand these changes and their socio-economic patterns, in the case of Singkarak Lake in West Sumatra, Indonesia. Based upon the hypothesis that riparian communities have diverse, complex yet structured and dynamic livelihood systems, the paper's main objective is to study, document and model the actual diversity in livelihood, practices and performance of inland small-scale fisheries along the Singkarak Lake, to picture how households are adapted to the situation, and propose an updated, workable model (typology) of those for policy. Principal component analysis and cluster analysis were used to develop a typology of fishing households. The results show that small-scale fishers can be classified into different types characterized by distinct livelihood strategies. Three household types are identified, namely "farming fishers" households (type I, 30 %), "fishing farmers" households (type II, 30 %), and "mainly fishers" households (type III, 40 %). There are significant differences among these groups in the number of boats owned, annual fishing income, agriculture income and farming experience. Type I consists of farming fishers, well equipped, with high fishing costs and income, yet with the lowest return on fishing assets. They are also landowners with farming income, showing the lowest return on land capital. Type II includes poor fishing farmers, landowners with higher farming income; they show the highest return on land asset. They have less fishing equipment, costs and income. Type III (mainly fishers) consists of poorer, younger fishers, with highest return on fishing assets and on fishing costs. They have little land, low farming income, and diversified livelihood

  12. Small scale industrial application of rubber seed oil in soap ...

    The oil, which was extracted from the rubber seed using the mechanical pressing method, was of high acid value, that is, the free fatty acid content is high and the oil is not edible, with an average saponification value. Its pH was slightly basic which makes it suitable for use in soap manufacture. It was, therefore, used as a ...

  13. An Empirical Model for Build-Up of Sodium and Calcium Ions in Small Scale Reverse Osmosis

    Subriyer Nasir

    2011-05-01

    Full Text Available A simple models for predicting build-up of solute on membrane surface were formulated in this paper. The experiments were conducted with secondary effluent, groundwater and simulated feed water in small-scale of RO with capacity of 2000 L/d. Feed water used in the experiments contained varying concentrations of sodium, calcium, combined sodium and calcium. In order to study the effect of sodium and calcium ions on membrane performance, experiments with ground water and secondary effluent wastewater were also performed. Build-up of salts on the membrane surface was calculated by measuring concentrations of sodium and calcium ions in feed water permeate and reject streams using Atomic Absorption Spectrophotometer (AAS. Multiple linear regression of natural logarithmic transformation was used to develop the model based on four main parameters that affect the build-up of solute in a small scale of RO namely applied pressure, permeate flux, membrane resistance, and feed concentration. Experimental data obtained in a small scale RO unit were used to develop the empirical model. The predicted values of theoretical build-up of sodium and calcium on membrane surface were found in agreement with experimental data. The deviation in the prediction of build-up of sodium and calcium were found to be 1.4 to 10.47 % and 1.12 to 4.46%, respectively.

  14. Agricultural Incentives: Implications for Small-Scale and Subsistence Farming in the US Caribbean Islands

    Alvarez-Berrios, N.; Parés-Ramos, I.; Gould, W. A.

    2017-12-01

    The effects of climate change threaten the world's most sensitive agroecosystems and our potential to reach agricultural productivity levels needed to feed a projected global population of 9.7 billion people by 2050. The US Caribbean agriculture is especially vulnerable to the effects of climate change, due to the region's frequent exposure to extreme weather events, its geographic and economic scale, shortage of labor force, and rapid urban expansion. Currently, agriculture contributes less than 1% of the island's GDP, and over 80% of the food consumed in the region is imported. Despite low production levels, there is widespread interest in reinvigorating the agricultural sector's contribution to the economy. Local and federal institutions play a major role strengthening the agricultural sector by providing access to incentives, loans, and education for best management practices. However, many of these efforts conform to agricultural systems of larger scale of production and temperate environments. In this study, we explore agricultural incentives programs and their implication for highly diverse, small-scale, and subsistence operations that characterize agricultural systems in Puerto Rico and the US Virgin Islands. We analyze records and maps from the USDA Farm Service Agency, to typify participating farms, and to track changes in land cover, farm size, crop diversity, practices, and production levels resulting from their enrollment in such programs. Preliminary results indicate that many incentives programs are not tailored to agricultural tropical systems and prescribe alternatives that exclude traditional farming methods employed in small-scale and subsistence farms (e.g. crop insurance that benefit monoculture over intercropped systems). Moreover, many of the incentives are contradictory in their recommendations (e.g., crop insurance benefit sun-grown coffee production, while best agricultural practices recommend agroforestry with shade-grown coffee

  15. Intensive land use drives small-scale homogenization of plant- and leafhopper communities and promotes generalists.

    Chisté, Melanie N; Mody, Karsten; Kunz, Gernot; Gunczy, Johanna; Blüthgen, Nico

    2018-02-01

    The current biodiversity decline through anthropogenic land-use not only involves local species losses, but also homogenization of communities, with a few generalist species benefitting most from human activities. Most studies assessed community heterogeneity (β-diversity) on larger scales by comparing different sites, but little is known about impacts on β-diversity within each site, which is relevant for understanding variation in the level of α-diversity, the small-scale distribution of species and associated habitat heterogeneity. To obtain our dataset with 36,899 individuals out of 117 different plant- and leafhopper (Auchenorrhyncha) species, we sampled communities of 140 managed grassland sites across Germany by quantitative vacuum suction of five 1 m 2 plots on each site. Sites differed in land-use intensity as characterized by intensity of fertilization, mowing and grazing. Our results demonstrate a significant within-site homogenization of plant- and leafhopper communities with increasing land-use intensity. Correspondingly, density (- 78%) and γ-diversity (- 35%) declined, particularly with fertilization and mowing intensity. More than 34% of plant- and leafhopper species were significant losers and only 6% were winners of high land-use intensity, with abundant and widespread species being less affected. Increasing land-use intensity adversely affected dietary specialists and promoted generalist species. Our study emphasizes considerable, multifaceted effects of land-use intensification on species loss, with a few dominant generalists winning, and an emerging trend towards more homogenized assemblages. By demonstrating homogenization for the first time within sites, our study highlights that anthropogenic influences on biodiversity even occur on small scales.

  16. Properties of a Small-scale Short-duration Solar Eruption with a Driven Shock

    Ying, Beili; Feng, Li; Lu, Lei; Zhang, Jie; Magdalenic, Jasmina; Su, Yingna; Su, Yang; Gan, Weiqun

    2018-03-01

    Large-scale solar eruptions have been extensively explored over many years. However, the properties of small-scale events with associated shocks have rarely been investigated. We present analyses of a small-scale, short-duration event originating from a small region. The impulsive phase of the M1.9-class flare lasted only four minutes. The kinematic evolution of the CME hot channel reveals some exceptional characteristics, including a very short duration of the main acceleration phase (fast and impulsive kinematics subsequently results in a piston-driven shock related to a metric type II radio burst with a high starting frequency of ∼320 MHz of the fundamental band. The type II source is formed at a low height of below 1.1 R ⊙ less than ∼2 minutes after the onset of the main acceleration phase. Through the band-split of the type II burst, the shock compression ratio decreases from 2.2 to 1.3, and the magnetic field strength of the shock upstream region decreases from 13 to 0.5 Gauss at heights of 1.1–2.3 R ⊙. We find that the CME (∼4 × 1030 erg) and flare (∼1.6 × 1030 erg) consume similar amounts of magnetic energy. The same conclusion for large-scale eruptions implies that small- and large-scale events possibly share a similar relationship between CMEs and flares. The kinematic particularities of this event are possibly related to the small footpoint-separation distance of the associated magnetic flux rope, as predicted by the Erupting Flux Rope model.

  17. Small-scale, hydrogen-oxidizing-denitrifying bioreactor for treatment of nitrate-contaminated drinking water.

    Smith, Richard L; Buckwalter, Seanne P; Repert, Deborah A; Miller, Daniel N

    2005-05-01

    Nitrate removal by hydrogen-coupled denitrification was examined using flow-through, packed-bed bioreactors to develop a small-scale, cost effective system for treating nitrate-contaminated drinking-water supplies. Nitrate removal was accomplished using a Rhodocyclus sp., strain HOD 5, isolated from a sole-source drinking-water aquifer. The autotrophic capacity of the purple non-sulfur photosynthetic bacterium made it particularly adept for this purpose. Initial tests used a commercial bioreactor filled with glass beads and countercurrent, non-sterile flow of an autotrophic, air-saturated, growth medium and hydrogen gas. Complete removal of 2 mM nitrate was achieved for more than 300 days of operation at a 2-h retention time. A low-cost hydrogen generator/bioreactor system was then constructed from readily available materials as a water treatment approach using the Rhodocyclus strain. After initial tests with the growth medium, the constructed system was tested using nitrate-amended drinking water obtained from fractured granite and sandstone aquifers, with moderate and low TDS loads, respectively. Incomplete nitrate removal was evident in both water types, with high-nitrite concentrations in the bioreactor output, due to a pH increase, which inhibited nitrite reduction. This was rectified by including carbon dioxide in the hydrogen stream. Additionally, complete nitrate removal was accomplished with wastewater-impacted surface water, with a concurrent decrease in dissolved organic carbon. The results of this study using three chemically distinct water supplies demonstrate that hydrogen-coupled denitrification can serve as the basis for small-scale remediation and that pilot-scale testing might be the next logical step.

  18. Upgrading of reformate gas for different applications with focus on small-scale hydrogen production

    Jannasch, Anna-Karin; Silversand, Fredrik [CATATOR AB, Lund (Sweden)

    2004-12-01

    Hydrogen gas or hydrogen rich gas is today used in many different applications, i.e. as fuel in fuel cells or additive in vehicle fuel (i.e. hythane) and as reagent or reducing agent in different industrial product lines. The majority of the hydrogen is produced either via electrolysis or reformation, where this work has entirely been focused on the latter alternative. The overarching aims of this project have been to demonstrate the need for reformate purification for different applications, and then, to investigate different available methods that can be used in order to enable the requested gas clean-up. The different purification methods have been examined with respect to parameters such as operating conditions (temperature, pressure), impurity tolerance, size, weight and cost. Another goal of the project has been to investigate how the reformer fuel type used influences the reformate gas quality and hence, the need for gas purification before the reformate can be fed to e.g. a low temperature polymer membrane fuel cell (PEMFC). For this reason, some experimental work has been performed. First, analysis of the reformate gas composition when natural gas, LPG, gasoline, diesel, kerosene (low and high S-concentration (i.e. JP8)) and ethanol have been processed. The reformation tests were carried out in a small scale reformer unit ({approx} 1 kW H{sub 2}) including Catator's catalyst formulations developed for the steam reforming, the water gas shift and the preferential oxidation reaction, respectively. Verification tests, with synthetic gas blends, including different potential reformate impurities, and with real reformate gas were thereafter performed with a commercial 4-cell PEMFC stack (3-5 W). Finally, some examination and also to some extent further development of Catator's existing gas purification units were made, i.e. chemical (WGS, PROX) and physical (regenerative adsorption). The Pd-alloy membrane seems to be the obvious choice of purification

  19. Neo4j high performance

    Raj, Sonal

    2015-01-01

    If you are a professional or enthusiast who has a basic understanding of graphs or has basic knowledge of Neo4j operations, this is the book for you. Although it is targeted at an advanced user base, this book can be used by beginners as it touches upon the basics. So, if you are passionate about taming complex data with the help of graphs and building high performance applications, you will be able to get valuable insights from this book.

  20. Magnetic energy storage devices for small scale applications

    Kumar, B.

    1992-01-01

    This paper covers basic principles of magnetic energy storage, structure requirements and limitations, configurations of inductors, attributes of high-T c superconducting materials including thermal instabilities, a relative comparison with the state-of-the-art high energy density power sources, and refrigeration requirements. Based on these fundamental considerations, the design parameters of a micro superconducting magnetic energy unit for Air Force applications is presented and discussed

  1. Evaluation of High-Performance Network Technologies for ITER

    Zagar, K.; Kolaric, P.; Sabjan, R.; Zagar, A. [Cosylab d.d., Ljubljana (Slovenia); Hunt, S. [Alceli Hunt Beratung, Meisterschwanden (Switzerland)

    2009-07-01

    To facilitate fast feedback control of plasma, ITER's Control, Data Access and Communication system (CODAC) will need to provide a mechanism for hard real-time communication between its distributed nodes. In particular, four types of high-performance communication have been identified. Synchronous Databus Network (SDN) is to provide an ability to distribute parameters of plasma (estimated to about 5000 double-valued signals) across the system to allow for 1 ms control cycles. Event Distribution Network (EDN) and Time Communication Network (TCN) are to allow synchronization of node I/O operations to 10 ns. Finally, the Audio Video Network (AVN) is to provide sufficient bandwidth for streaming of surveillance and diagnostics video at a high resolution (1024*1024) and frame rate (30 Hz). In this article, we present some combinations of common off-the-shelf (COTS) technologies that allow the above requirements to be met. Also, we present the performances achieved in a practical (though small scale) technology demonstrator, which involved a real-time LINUS operating running on National Instruments' PXI platform, UDP communication implemented directly atop the Ethernet network adapter, CISCO switches, Micro Research Finland's timing and event solution, and GigE audio-video streaming. This document is composed of an abstract followed by the presentation transparencies. (authors)

  2. Evaluation of high-performance network technologies for ITER

    Zagar, K., E-mail: klemen.zagar@cosylab.co [Cosylab d.d., 1000 Ljubljana (Slovenia); Hunt, S. [Alceli Hunt Beratung, 5616 Meisterschwanden (Switzerland); Kolaric, P.; Sabjan, R.; Zagar, A.; Dedic, J. [Cosylab d.d., 1000 Ljubljana (Slovenia)

    2010-07-15

    For the fast feedback plasma controllers, ITER's Control, Data Access and Communication system (CODAC) will need to provide a mechanism for hard real-time communication between its distributed nodes. In particular, the ITER CODAC team identified four types of high-performance communication applications. Synchronous Databus Network (SDN) is to provide an ability to distribute parameters of plasma (estimated to about 5000 double-valued signals) across the system to allow for 1 ms control cycles. Event Distribution Network (EDN) and Time Communication Network (TCN) are to allow synchronization of node I/O operations to 10 ns. Finally, the Audio-Video Network (AVN) is to provide sufficient bandwidth for streaming of surveillance and diagnostics video at a high resolution (1024 x 1024) and frame rate (30 Hz). In this article, we present some combinations of common-off-the-shelf (COTS) technologies that allow the above requirements to be met. Also, we present the performances achieved in a practical (though small scale) technology demonstrator, which involved a real-time Linux operating running on National Instruments' PXI platform, UDP communication implemented directly atop the Ethernet network adapter, CISCO switches, Micro Research Finland's timing and event solution, and GigE audio-video streaming.

  3. Evaluation of high-performance network technologies for ITER

    Zagar, K.; Hunt, S.; Kolaric, P.; Sabjan, R.; Zagar, A.; Dedic, J.

    2010-01-01

    For the fast feedback plasma controllers, ITER's Control, Data Access and Communication system (CODAC) will need to provide a mechanism for hard real-time communication between its distributed nodes. In particular, the ITER CODAC team identified four types of high-performance communication applications. Synchronous Databus Network (SDN) is to provide an ability to distribute parameters of plasma (estimated to about 5000 double-valued signals) across the system to allow for 1 ms control cycles. Event Distribution Network (EDN) and Time Communication Network (TCN) are to allow synchronization of node I/O operations to 10 ns. Finally, the Audio-Video Network (AVN) is to provide sufficient bandwidth for streaming of surveillance and diagnostics video at a high resolution (1024 x 1024) and frame rate (30 Hz). In this article, we present some combinations of common-off-the-shelf (COTS) technologies that allow the above requirements to be met. Also, we present the performances achieved in a practical (though small scale) technology demonstrator, which involved a real-time Linux operating running on National Instruments' PXI platform, UDP communication implemented directly atop the Ethernet network adapter, CISCO switches, Micro Research Finland's timing and event solution, and GigE audio-video streaming.

  4. THE DEVELOPMENT OF SMALL-SCALE BUSINESS IN RUSSIA, TYPES OF FUNDING

    Kirill O. Voronin

    2015-01-01

    Full Text Available In Russia small-scale business originated in the end of 1980s duringRestructuring. It has been developing as fast as Russian economics.Unlike large industrial companies, which just continued to run businessas they used to, small-scale businessmen had to start from scratch ordisaffiliate with large organizations. Basically, in 1990-s small-scale business as a financial institute was self-regulated due to its highcriminalization and nonpayment of tax.For a period of only 25 years small-scale business has improved muchand now provides well-being to the country. The improvement happeneddue to the following factors:- propitious economic and political climate of the country against thebackground of global economy and the years of restricting- important and useful measures for economic development were taken - important and useful measures for development of small-scale enterprises were takenThe development of this new financial institute is quite fast, but historyhas other examples of such phenomenon. In the 21st century RussianFederation adopted experience of advanced countries and imposed it onits historic experience. However, we can’t say that small-scale business is on its top of development in our country. Nowadays development of small-scale business is one of the priorities of the Russian government.

  5. Is small-scale irrigation an efficient pro-poor strategy in the upper Limpopo Basin in Mozambique?

    Ducrot, Raphaelle

    2017-08-01

    In Sub-Saharan Africa, there is evidence that households with access to small-scale irrigation are significantly less poor than households that do not have access to irrigation. However, private motopumps tend to be distributed inequitably. This paper investigates the success of explicit pro-poor interventions with emphasis on small-scale irrigation in the semi-arid Limpopo Basin in Mozambique. It reveals that high irrigation costs are progressively excluding the poor, who are unable to generate a cash income from other activities they need to fund irrigation. In addition, the operation of collective schemes involving the poor is being jeopardized by the development of private irrigation schemes, which benefit from hidden subsidies appropriated by local elites. This results in unequal access to irrigation, which can cause resentment at community level. This weakens community cohesiveness, as well as communities' capacities for collective action and coordination, which are crucial for collective irrigation.

  6. A review of advanced small-scale parallel bioreactor technology for accelerated process development: current state and future need.

    Bareither, Rachel; Pollard, David

    2011-01-01

    The pharmaceutical and biotech industries face continued pressure to reduce development costs and accelerate process development. This challenge occurs alongside the need for increased upstream experimentation to support quality by design initiatives and the pursuit of predictive models from systems biology. A small scale system enabling multiple reactions in parallel (n ≥ 20), with automated sampling and integrated to purification, would provide significant improvement (four to fivefold) to development timelines. State of the art attempts to pursue high throughput process development include shake flasks, microfluidic reactors, microtiter plates and small-scale stirred reactors. The limitations of these systems are compared to desired criteria to mimic large scale commercial processes. The comparison shows that significant technological improvement is still required to provide automated solutions that can speed upstream process development. Copyright © 2010 American Institute of Chemical Engineers (AIChE).

  7. Investigations of surface-tension effects due to small-scale complex boundaries

    Feng, Jiansheng

    these two different types of surfaces differed by about 50° ˜ 60°, with the low-adhesion surfaces at about 120° ˜ 130° and the high-adhesion surfaces at about 70° ˜ 80°. Characterizations of both the microscopic structures and macroscopic wetting properties of these product surfaces allowed us to pinpoint the structural features responsible for specific wetting properties. It is found that the advancing contact angle was mainly determined by the primary structures while the receding contact angle is largely affected by the side-wall slope of the secondary features. This study established a platform for further exploration of the structure aspects of surface wettability. In the third and final project (Chapter 4), we demonstrated a new type of microfluidic channel that enable asymmetric wicking of wetting fluids based on structure-induced direction-dependent surface-tension effect. By decorating the side-walls of open microfluidic channels with tilted fins, we were able to experimentally demonstrate preferential wicking behaviors of various IPA-water mixtures with a range of contact angles in these channels. A simplified 2D model was established to explain the wicking asymmetry, and a complete 3D model was developed to provide more accurate quantitative predictions. The design principles developed in this study provide an additional scheme for controlling the spreading of fluids. The research presented in this dissertation spreads out across a wide range of physical phenomena (wicking, wetting, and capillarity), and involves a number of computational and experimental techniques, yet all of these projects are intrinsically united under a common theme: we want to better understand how simple fluids respond to small-scale complex surface structures as manifestations of surface-tension effects. We hope our findings can serve as building blocks for a larger scale endeavor of scientific research and engineering development. After all, the pursue of knowledge is most

  8. Small-scale lacustrine drifts in Lake Champlain, Vermont

    Manley, Patricia L.; Manley, T.O.; Hayo, Kathryn; Cronin, Thomas

    2012-01-01

    High resolution CHIRP (Compressed High Intensity Radar Pulse) seismic profiles reveal the presence of two lacustrine sediment drifts located in Lake Champlain's Juniper Deep. Both drifts are positive features composed of highly laminated sediments. Drift B sits on a basement high while Drift A is built on a trough-filling acoustically-transparent sediment unit inferred to be a mass-transport event. These drifts are oriented approximately north–south and are parallel to a steep ridge along the eastern shore of the basin. Drift A, located at the bottom of a structural trough, is classified as a confined, elongate drift that transitions northward to become a system of upslope asymmetric mudwaves. Drift B is perched atop a structural high to the west of Drift A and is classified as a detached elongate drift. Bottom current depositional control was investigated using Acoustic Doppler Current Profilers (ADCPs) located across Drift A. Sediment cores were taken at the crest and at the edges of the Drift A and were dated. Drift source, deposition, and evolution show that these drifts are formed by a water column shear with the highest deposition occurring along its crest and western flank and began developing circa 8700–8800 year BP.

  9. Small-Scale vertical axis wind turbine design

    Castillo Tudela, Javier

    2011-01-01

    The thesis focuses on the design of a small vertical axis wind turbine rotor with solid wood as a construction material. The aerodynamic analysis is performed implementing a momentum based model on a mathematical computer program. A three bladed wind turbine is proposed as candidate for further prototype testing after evaluating the effect of several parameters in turbine efficiency, torque and acceleration. The results obtained indicate that wood is a suitable material for rotor cons...

  10. Exposure of Small-Scale Gold Miners in Prestea to Mercury, Ghana, 2012.

    Mensah, Ebenezer Kofi; Afari, Edwin; Wurapa, Frederick; Sackey, Samuel; Quainoo, Albert; Kenu, Ernest; Nyarko, Kofi Mensah

    2016-01-01

    Small-scale gold miners in Ghana have been using mercury to amalgamate gold for many years. Mercury is toxic even at low concentration. We assessed occupational exposure of small-scale gold miners to mercury in Prestea, a gold mining town in Ghana . We conducted a cross-sectional study in which we collected morning urine samples from 343 small-scale gold miners and tested for elemental mercury. Data on small-scale gold miner's socio-demographics, adverse health effects and occupational factors for mercury exposure were obtained and analyzed using SPSS Version 16 to determine frequency and percentage. Bivariate analysis was used to determine occupational factors associated with mercury exposure at 95% confidence level. The mean age of the small-scale gold miners was 29.5 ±9.6 years, and 323(94.20%) were males. One hundred and sixty (46.65%) of the small-scale gold miners had urine mercury above the recommended exposure limit (mercury exposure among those who have previously worked at other small-scale gold mines (χ 2 =4.96, p=0.03). The use of personal protective equipment among the small-scale gold miners was low. Retorts, which are globally recommended for burning amalgam, were not found at mining sites. A large proportion of small-scale gold miners in Prestea were having mercury exposure in excess of occupational exposure limits, and are at risk of experiencing adverse health related complications. Ghana Environmental Protection Agency should organize training for the miners.

  11. Evaluation of high-definition television for remote task performance

    Draper, J.V.; Fujita, Y.; Herndon, J.N.

    1987-04-01

    High-definition television (HDTV) transmits a video image with more than twice the number (1125 for HDTV to 525 for standard-resolution TV) of horizontal scan lines that standard-resolution TV provides. The improvement in picture quality (compared to standard-resolution TV) that the extra scan lines provide is impressive. Objects in the HDTV picture have more sharply defined edges, better contrast, and more accurate reproduction of shading and color patterns than do those in the standard-resolution TV picture. Because the TV viewing system is a key component for teleoperator performance, an improvement in TV picture quality could mean an improvement in the speed and accuracy with which teleoperators perform tasks. This report describes three experiments designed to evaluate the impact of HDTV on the performance of typical remote tasks. The performance of HDTV was compared to that of standard-resolution, monochromatic TV and standard-resolution, stereoscopic, monochromatic TV in the context of judgment of depth in a televised scene, visual inspection of an object, and performance of a typical remote handling task. The results of the three experiments show that in some areas HDTV can lead to improvement in teleoperator performance. Observers inspecting a small object for a flaw were more accurate with HDTV than with either of the standard-resolution systems. High resolution is critical for detection of small-scale flaws of the type in the experiment (a scratch on a glass bottle). These experiments provided an evaluation of HDTV television for use in tasks that must be routinely performed to remotely maintain a nuclear fuel reprocessing facility. 5 refs., 7 figs., 9 tabs

  12. Wave processes. Small-scale inhomogeneities in the ionosphere

    Uspenskij, M.V.

    1993-01-01

    The problem of existence of intensive electron density fluctuations in the high latitude E region is discussed. It is pointed out that the size of fluctuations changes from several decimeters to several decameters in the direction across the geomagnetic field. The indicated size along the geomagnetic field is more than 1-2 order of magnitude

  13. Resource-Use Efficiency in Rice Production Under Small Scale ...

    This was attested by the high ratios (greater than unity) of MVP/MFC of all the variables. For optimum resource allocation to fertilizer, labour and land about 85.7%, 83.3% and 69% increase in MVP is required respectively. The estimated elasticity of production summed up to 0.815 meaning decreasing return to scale.

  14. The sustainability of small scale cane growers through youth ...

    Cane farming makes an important contribution to the socio-economic development of the rural areas where it takes place. These cane growing areas are characterised by high levels of poverty and youth unemployment. The current crop of cane growers is ageing and there is a need to prepare to handover the baton to the ...

  15. Work Related Injuries and Associated Factors among Small Scale ...

    user

    smoking, alcohol consumption, working for more than 8 hours and working at night had high odds of occupational injuries. Use of ... equivalent to 4 % of the world's gross national product. The impact ... required them to miss a week of work (9).

  16. Cut and carry vs. grazing of cultivated pastures in small-scale dairy systems in the central highlands of Mexico

    Paola Estefania Pincay-Figueroa

    2016-12-01

    Full Text Available Small-scale dairy systems are an option to alleviate poverty and contribute up to 37% of milk production in Mexico; however high costs affect their economic sustainability. Since grazing may reduce feeding costs, a participatory on farm experiment was undertaken to compare animal performance and feeding costs of the traditional cut-and-carry strategy or grazing cultivated pastures, during the dry season in the highlands of Mexico. Pastures of perennial and annual ryegrasses with white clover were utilised, complemented with maize silage and commercial concentrate. Five dairy cows were assigned to each strategy. The experiment ran for 12 weeks, recording weekly milk yields and fat and milk protein content; live-weight and body condition score every 14 days. Analysis was as a split-plot design. The adjusted (covariance mean milk yield was 18.78 kg/cow/day with no significant differences (P>0.05 between treatments, and no significant differences for live-weight or body condition score. There were no significant differences for milk fat (P>0.05, but there were for protein in milk (P

  17. Assessing the Economic Situation of Small-Scale Farm Forestry in Mountain Regions: A Case Study in Austria

    Philipp Toscani

    2017-08-01

    Full Text Available Austria is one of the few countries with a long tradition of monitoring the economic performance of forest holdings. The national Farm Accountancy Data Network also addresses some forestry-specific issues, given the high significance of farm forestry in this country. However, it is not possible to assess the profitability of small-scale farm forestry in mountainous regions based on a representative sample. In this paper, we demonstrate how information gaps can be overcome by means of economic modeling and present results of this approach for mountain forestry for the first time. In spite of the unfavorable conditions of an alpine setting, forestry tends to be of special significance for the viability and resilience of family farms in these regions. Sustainable forest management that safeguards the ecosystem services provided by forests relies mostly on the profitability of timber production. Thus, the economic development of farm forestry is a key factor in achieving targets 15.1 and 15.4 of the United Nations Sustainable Development Goals in mountain regions.

  18. Evaluation of pharmaceuticals removal by sewage sludge-derived adsorbents with rapid small-scale column tests

    Zhang, P.; Ding, R.; Wallace, R.; Bandosz, T.

    2015-12-01

    New composite adsorbents were developed by pyrolyzing sewage sludge and fish waste (75:25 or 90:10 dry mass ratio) at 650 oC and 950 oC. Batch adsorption experiments demonstrated that the composite adsorbents were able to adsorb a wide range of organic contaminants (volatile organic compounds, pharmaceuticals and endocrine disrupting compounds (EDCs), and nitrosamine disinfection byproducts) with high capacities. Here we further examine the performance of the adsorbents for the simultaneous removal of 8 pharmaceuticals and EDCs with rapid small-scale column tests (RSSCT). Results show that the order of breakthrough in RSSCT is in general consistent with the affinity determined via batch tests. As expected, the maximum amount of adsorption for each compound obtained from RSSCT is identical to or less than that obtained from batch tests (with only one exception), due to adsorption kinetics. However, despite the very different input concentration (1 mg/L vs. 100 mg/L) and contact time (2 min empty bed contact time vs. 16 hour equilibrium time) used in RSSCT and batch tests, the maximum amount of pharmaceuticals and EDCs adsorbed under RSSCT is still about one half of that under equilibrium batch tests, validating the approach of using batch tests with much higher input concentrations to determine adsorption capacities. Results of a pilot-scale column test in a drinking water treatment plant for pharmaceuticals removal will also be presented.

  19. Small-scale upgrading and refinement of biogas; Smaaskalig uppgradering och foeraedling av biogas

    Blom, Helena; Mccann, Michael; Westman, Johan (Poeyry SwedPower AB, Stockholm (Sweden))

    2012-02-15

    Small-scale upgrading and refinement of biogas is a report which aims to compile the state of knowledge in small-scale biogas upgrading. The project have been a collaboration with Agrovaest and Energy Farm and was funded by the Foundation for Agricultural Research, Western Goetaland and the Agriculture Department. The technology available for small scale upgrade has been examined from the technical and economic standpoint. An economic comparison has been made and the production of upgraded biogas has been estimated for different raw gas flows. The work also contains information related to biogas production, upgrading and a comparison of liquid biogas, DME and Ecopar-diesel

  20. Comparison between full- and small-scale sensory assessments of air quality

    Wargocki, Pawel; Sabikova, J.; Lagercrantz, Love Per

    2002-01-01

    Thirty-nine untrained subjects made small- and full-scale evaluations of the acceptability of the quality of air at 22 deg.C and 40% RH, polluted by either carpet, felt floor covering, painted gypsum board, linoleum or chipboard. Small-scale evaluations were made on the air extracted from 200-L......-scale sensory ratings of acceptability of air polluted by carpet and by linoleum were systematically better than small-scale assessments, but not for the other three materials. Calculated sensory emission rates from carpet and linoleum were significantly lower in full scale than in small scale. When modelling...