Electroosmotically enhanced sludge dewatering-pilot-plant study

CSIR Research Space (South Africa)

Smollen, M

1994-01-01

Full Text Available role in determining the ease or difficulty of phase separation. It seems that the inefficiency of dewatering applied to gelatinous and fine-particle sludges can be overcome by mechanical dewatering enhanced by electroosmosis. A prototype pilot-plant...

Pressurised electro-osmotic dewatering of activated and anaerobically digested sludges: electrical variables analysis.

Science.gov (United States)

Citeau, M; Olivier, J; Mahmoud, A; Vaxelaire, J; Larue, O; Vorobiev, E

2012-09-15

Pressurised electro-osmotic dewatering (PEOD) of two sewage sludges (activated and anaerobically digested) was studied under constant electric current (C.C.) and constant voltage (C.V.) with a laboratory chamber simulating closely an industrial filter. The influence of sludge characteristics, process parameters, and electrode/filter cloth position was investigated. The next parameters were tested: 40 and 80 A/m², 20, 30, and 50 V-for digested sludge dewatering; and 20, 40 and 80 A/m², 20, 30, and 50 V-for activated sludge dewatering. Effects of filter cloth electric resistance and initial cake thickness were also investigated. The application of PEOD provides a gain of 12 points of dry solids content for the digested sludge (47.0% w/w) and for the activated sludge (31.7% w/w). In PEOD processed at C.C. or at C.V., the dewatering flow rate was similar for the same electric field intensity. In C.C. mode, both the electric resistance of cake and voltage increase, causing a temperature rise by ohmic effect. In C.V. mode, a current intensity peak was observed in the earlier dewatering period. Applying at first a constant current and later on a constant voltage, permitted to have better control of ohmic heating effect. The dewatering rate was not significantly affected by the presence of filter cloth on electrodes, but the use of a thin filter cloth reduced remarkably the energy consumption compared to a thicker one: 69% of reduction energy input at 45% w/w of dry solids content. The reduction of the initial cake thickness is advantageous to increase the final dry solids content. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of nanoparticles on the polymer-conditioned dewatering of wastewater sludges.

Science.gov (United States)

Boyle, N J; Evans, G M

2013-01-01

The effect of using small-scale, high surface area, nanoparticles to supplement polymer-conditioned wastewater sludge dewatering was investigated. Aerobically digested sludge and waste activated sludge sourced from the Hunter Valley, NSW, Australia, were tested with titanium dioxide nanoparticles. The sludge samples were dosed with the nanoparticles in an attempt to adsorb a component of the charged biopolymer surfactants present naturally in sludge. The sludge was conditioned with a cationic polymer. The dewatering characteristics were assessed by measuring the specific resistance to filtration through a modified time-to-filter testing apparatus. The solids content of the dosed samples was determined by a mass balance and compared to the original solids content in the activated sludge. Test results indicated that nanoparticle addition modified the structure of the sludge and provided benefits in terms of the dewatering rate. The samples dosed with nanoparticles exhibited faster water removal, indicating a more permeable filter cake and hence more permeable sludge. A concentration of 2-4% nanoparticles was required to achieve a noticeable benefit. As a comparison, the sludge samples were also tested with a larger particle size, powdered activated carbon (PAC). It was found that the PAC did provide some minor benefits to sludge dewatering but was outperformed by the nanoparticles. The solids content of the final sludge was increased by a maximum of up to 0.6%. The impact of the order sequence of particles and polymer was also investigated. It was found that nanoparticles added before polymer addition provided the best dewatering performance. This outcome was consistent with current theories and previous research through the literature. An economic analysis was undertaken to confirm the viability of the technology for implementation at a full-scale plant. It was found that, currently, this technology is unlikely to be favourable unless the nanoparticles can be

105-N Fuel Storage Basin dewatering conceptual plan

International Nuclear Information System (INIS)

Schilperoort, D.L.

1996-11-01

This conceptual plan discusses the processes that will be used for draining and disposing of water from the 105-N Fuel Storage Basin (N Basin), and includes a description of the activities to control surface contamination and potential high dose rates encountered during dewatering. The 105-N Fuel Storage Basin is located in the 100-N Area of the Hanford Site in Richland, Washington. The processes for water disposal include water filtration, water sampling and analysis, tanker loading and unloading, surface decontamination and sealing, and clean out and disposal of residual debris and sediments during final pumping to remove the N Basin water. Water disposal is critical for the deactivation of N Reactor. A Memorandum of Understanding (MOU) between the US Department of Energy (DOE) Environmental Restoration (ER) Program and DOE Waste Management (WM) Program establishes the 200 East Effluent Treatment Facility (ETF) as the final treatment and disposal site for N Basin water and identifies pre-treatment requirements. This MOU states that water delivery will be completed no later than October 31, 1996, and will require a revision due to the current de-watering schedule date. The current MOU requires four micron filtration prior to shipment to ETF. The MOU revision for delivery date extension seeks to have the filtration limit increased to five microns, which eliminates the need for a second filter system and simplifies dewatering. For the purposes of this plan, it will be assumed that five micron filtration will be used

Dewatering of ultrafine coal: Final report, August 1984-December 1986

Energy Technology Data Exchange (ETDEWEB)

Chiang, Shiao-Hung; Klinzing, G.E.; Morsi, B.I.; Tierney, J.W.; Badgujar, M.; Binkley, T.; Cheng, Yisun; Huang, Suxuan; Qamar, I.; Venkatadri, R.

1986-12-01

The surfactant, Aerosol-OT, was used to wash distilled water cakes. In previous studies, cakes were washed with Triton X-114. The dewatering performance and influence on cake structure of the two reagents are compared. Also, filter cakes were analyzed using an image analysis system and micrographic analysis of coal particles was initiated. In the area of theoretical modelling, the concept of bond-flow correlation greatly improved the network model predicting the experimental desaturation curves. Predicted results for treated cakes suggested that the effect of the presence of surface-active agents was adequately accounted for. The effects of the various operating conditions on the filtration/dewatering characteristics of the 10 ..mu..m coal particles were assessed and comparisons with the -32 mesh coal were made as to its trends in response to changes in the operating conditions. 20 refs., 75 figs., 17 tabs.

POC-scale testing of an advanced fine coal dewatering equipment/technique

Energy Technology Data Exchange (ETDEWEB)

Groppo, J.G.; Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States); Rawls, P. [Department of Energy, Pittsburgh, PA (United States)

1995-11-01

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. As the contract title suggests, the main focus of the program is on proof-of-concept testing of a dewatering technique for a fine clean coal product. The coal industry is reluctant to use the advanced fine coal recovery technology due to the non-availability of an economical dewatering process. in fact, in a recent survey conducted by U.S. DOE and Battelle, dewatering of fine clean coal was identified as the number one priority for the coal industry. This project will attempt to demonstrate an efficient and economic fine clean coal slurry dewatering process.

Maximizing the benefits of a dewatering system

International Nuclear Information System (INIS)

Matthews, P.; Iverson, T.S.

1999-01-01

The use of dewatering systems in the mining, industrial sludge and sewage waste treatment industries is discussed, also describing some of the problems that have been encountered while using drilling fluid dewatering technology. The technology is an acceptable drilling waste handling alternative but it has had problems associated with recycled fluid incompatibility, high chemical costs and system inefficiencies. This paper discussed the following five action areas that can maximize the benefits and help reduce costs of a dewatering project: (1) co-ordinate all services, (2) choose equipment that fits the drilling program, (3) match the chemical treatment with the drilling fluid types, (4) determine recycled fluid compatibility requirements, and (5) determine the disposal requirements before project start-up. 2 refs., 5 figs

A case study on stratified settlement and rebound characteristics due to dewatering in Shanghai subway station.

Science.gov (United States)

Wang, Jianxiu; Huang, Tianrong; Sui, Dongchang

2013-01-01

Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR) of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found in sandy clay, but both positive and negative rebound occurred in the silty clay, and the absolute value of rebound in sandy clay was larger than in silty clay, and the mechanism of SSR was discussed with mechanical sandwich model, and it was found that the load and cohesive force of different soils was the main source of different responses when decompressed.

Experimental assessment of factors influencing dewatering properties of thermophilically digested biosolids

Energy Technology Data Exchange (ETDEWEB)

Zhou, Jianpeng; Mavinic, Donald S.; Kelly, Harlan G.; Ramey, William D.

2003-07-01

Beneficial land application of processed wastewater sludges (biosolids) is a cost-effective, and environmentally sustainable option for the final disposal of sludges, because nutrients and organic matters in the sludge are recovered and reused as a resource. Thermophilic sludge digestion produces Class A biosolids, which can be reused without restrictions. Recent experience from full-scale thermophilic sludge digestion facilities in North America revealed that, dewatering thermophilically digested biosolids required more polymers to condition than mesophilically digested biosolids. This paper reports a laboratory study that investigated factors having significant impacts on dewatering properties of digested biosolids, and assessed the relationship among digestion, dewatering properties, and characteristics of thermophilically digested biosolids. The experimental work used batch-operated, bench-scale aerobic sludge digesters. Dewaterability was measured as Capillary Suction Time (CST). The study found that feed sludge composition significantly affected dewaterability of digested sludge. Higher percentage of the secondary sludge in the feed sludge corresponded to more significant deterioration in dewaterability. The effect of thermophilic digestion temperatures on dewaterabilty was rapid, occurred within 3-hour of digestion, indicting a heat shock effect, rather than a microbiological effect. When a high shear was applied to the sludge in digesters, it resulted In a significant deterioration in dewaterability in the digested sludge. It appears there was a strong correlation between dewaterability and extracellular biopolymers. Enzymes (protease) treatment confirmed that role of extracellular proteins in affecting the dewatering properties of thermophilic biosolids, also revealed the complex nature of biopolymers' effect on dewaterability. Such effects might be due to protein-polysaccharides interactions, hydrogen bonding, or hydrophilic and hydrophobic

The utilization of forward osmosis for coal tailings dewatering

Science.gov (United States)

The feasibility of dewatering coal tailings slurry by forward osmosis (FO) membrane process was investigated in this research. A prototype cell was designed and used for the dewatering tests. A cellulosic FO membrane (Hydration Technology Innovations, LLC, Albany, OR) was used fo...

Synergetic pretreatment of waste activated sludge by hydrodynamic cavitation combined with Fenton reaction for enhanced dewatering.

Science.gov (United States)

Cai, Meiqiang; Hu, Jianqiang; Lian, Guanghu; Xiao, Ruiyang; Song, Zhijun; Jin, Micong; Dong, Chunying; Wang, Quanyuan; Luo, Dewen; Wei, Zongsu

2018-04-01

The dewatering of waste activated sludge by integrated hydrodynamic cavitation (HC) and Fenton reaction was explored in this study. We first investigated the effects of initial pH, sludge concentration, flow rate, and H 2 O 2 concentration on the sludge dewaterability represented by water content, capillary suction time and specific resistance to filtration. The results of dewatering tests showed that acidic pH and low sludge concentration were favorable to improve dewatering performance in the HC/Fenton system, whereas optimal flow rate and H 2 O 2 concentration applied depended on the system operation. To reveal the synergism of HC/Fenton treatment, a suite of analysis were implemented: three-dimensional excitation emission matrix (3-DEEM) spectra of extracellular polymeric substances (EPS) such as proteins and polysaccharides, zeta potential and particle size of sludge flocs, and SEM/TEM imaging of sludge morphology. The characterization results indicate a three-step mechanism, namely HC fracture of different EPS in sludge flocs, Fenton oxidation of the released EPS, and Fe(III) re-flocculation, that is responsible for the synergistically enhanced sludge dewatering. Results of current study provide a basis to improve our understanding on the sludge dewatering performance by HC/Fenton treatment and possible scale-up of the technology for use in wastewater treatment plants. Copyright © 2017 Elsevier B.V. All rights reserved.

Techno-economic evaluation of microalgae harvesting and dewatering systems

NARCIS (Netherlands)

Fasaei, F.; Bitter, J.H.; Slegers, P.M.; Boxtel, van A.J.B.

2018-01-01

Microalgal biomass is processed into products by two main process steps: 1) harvesting and dewatering; and 2) extraction, fractionation and conversion. The performance of unit operations for harvesting and dewatering is often expressed in qualitative terms, like “high energy consumption” and “low in

A Case Study on Stratified Settlement and Rebound Characteristics due to Dewatering in Shanghai Subway Station

Directory of Open Access Journals (Sweden)

Jianxiu Wang

2013-01-01

Full Text Available Based on the Yishan Metro Station Project of Shanghai Metro Line number 9, a centrifugal model test was conducted to investigate the behavior of stratified settlement and rebound (SSR of Shanghai soft clay caused by dewatering in deep subway station pit. The soil model was composed of three layers, and the dewatering process was simulated by self-invention of decompressing devise. The results indicate that SSR occurs when the decompression was carried out, and only negative rebound was found in sandy clay, but both positive and negative rebound occurred in the silty clay, and the absolute value of rebound in sandy clay was larger than in silty clay, and the mechanism of SSR was discussed with mechanical sandwich model, and it was found that the load and cohesive force of different soils was the main source of different responses when decompressed.

Dewatering blastholes cuts explosives costs

Energy Technology Data Exchange (ETDEWEB)

Pilshaw, S.R.

1987-11-01

Large mining operations often require a combination of presplitting and dewatering with blasthole pumps. Increasing the percentage of bulk ANFO in any blast will reduce cost and should increase profitability.

Characteristics of water obtained by dewatering cyanobacteria-containing sludge formed during drinking water treatment, including C-, N-disinfection byproduct formation.

Science.gov (United States)

Xu, Hangzhou; Pei, Haiyan; Jin, Yan; Xiao, Hongdi; Ma, Chunxia; Sun, Jiongming; Li, Hongmin

2017-03-15

This is the first study to systematically investigate the characteristics of the water obtained by dewatering cyanobacteria-containing sludge generated in the drinking water treatment plant, including formation of C- and N-disinfection by-products (DBPs). Results showed that this 'dewatering water' (DW) had different properties when the sludge was stored at different times. The content of dissolved organic matter (DOM) and microcystins (MCs) in the DW were low when the sludge was treated or disposed of within 4 days; correspondingly, the C-, N-DBP production was also low. However, due to the damage of algal cells to some extent, the DOM and MC levels increased significantly for storage time longer than 4 days; the production of C-, N-DBPs also increased. There were also obvious differences in the characteristics of the DW from sludges generated with different coagulant species. Due to the better protective effect of FeCl 3 and polymeric aluminium ferric chloride (PAFC) flocs, the DOM and MC levels and the production of C-, N-DBPs in the DW with FeCl 3 and PAFC coagulation were lower than those with AlCl 3 coagulation, even though the sludges were stored for the same amount of time. Furthermore, because of the formation of Al and Fe hydroxides, precipitated onto the surface of flocs, the soluble Al and Fe in the DW decreased with increased storage time, especially in the first four days. Overall, this study revealed the trends in variation of DW quality for cyanobacteria-containing sludges formed with different coagulants, then FeCl 3 and PAFC coagulants are recommended and sludge should be treated or disposed of within 4 days. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tectonic controlled submarine slidings and dewatering structures

Science.gov (United States)

Yamamoto, Y.; Hirono, T.; Takahashi, M.

2003-04-01

Geologic structures associated with mass movements processes such as slumping, sliding, and creeping can be the key to understanding the tectonic or geologic constraints in the time they were formed. Because they are sensitively reflected by the paleo-topography which must be associated with active tectonics. It must be very useful if the direction of paleo-slope instability is known easily in a wide area. We paid attentions to convolute lamination and flame structure which might be associated with dewatering and loading, respectively. Some recent researches report the possibility that well regulated flame structures might be formed in relation to paleo-slope instability. However, there is an alternative idea that they were reflection of heterogeneous loading associated with ripple marks on the sandy layers. This controversy has not been settled. Accordingly, to evaluate the reliability of the relationship between formation of such structures with well regulated arrays and paleo-slope instability, the Pliocene Chikura Group in the southern part of the Boso Peninsula, central Japan, was studied. The Chikura Group overlying the Miura Group, Miocene accretionary prism, is composed of trench-fill sediments in the lowermost and of trench-slope basin sediments in the upper. The Chikura Group was deposited on an east-west extended sedimentary basin during east-west trending folds and faults development. These indicate the direction of paleo-slope in the Chikura Group due north or south. Flame structures and convolute laminations were recognized over 60 sites in the Chikura Group. They have well-regulated planar arrays which extend almost east west, perpendicular to the direction of paleo-slope instability. Some examples of such structures and slump deposit were observed in the same outcrop. Vergence of these slump deposits were toward north or south, and ridges of flame structures and convolute laminations extend east-west. Experimental study of direct imaging of

Dewatering and Treatment of Septage Using Vertical Flow Constructed Wetlands

Directory of Open Access Journals (Sweden)

Yee Yong Tan

2017-10-01

Full Text Available The vertical flow constructed wetland (VFCW has become an attractive decentralised technology for septage treatment. One of the main purposes of the septage treatment is to reduce the volume of raw septage through dewatering, where the solids content is retained in the wetland bed and the water content is released. The retention of solids forms a layer of sludge deposit at the wetland surface, and the drained water, the so-called leachate, typically contains a lower solids content. This article reports the performance of dewatering and filtration of a pilot-scale VFCW designed for septage treatment. A comparison between two feeding strategies, hydraulic loading rate (HLR and solids loading rate (SLR, is presented. The dewatering efficiency through drainage was found to be dependent on the solids load. The removal of total solids (TS and chemical oxygen demand (COD were excellent as the quality of leachate showed that more than 90% of TS and COD were retained in the system. This study reveals that the feeding based on SLR delivered a more sustainable performance for dewatering and solids removal. The build-up of sludge deposit significantly deteriorated the dewatering efficiency through drainage, but it tended to improve the filtration capacity.

Microalgae dewatering based on forward osmosis employing proton exchange membrane.

Science.gov (United States)

Son, Jieun; Sung, Mina; Ryu, Hoyoung; Oh, You-Kwan; Han, Jong-In

2017-11-01

In this study, electrically-facilitated forward osmosis (FO) employing proton exchange membrane (PEM) was established for the purpose of microalgae dewatering. An increase in water flux was observed when an external voltage was applied to the FO equipped with the PEM; as expected, the trend became more dramatic with both concentration of draw solution and applied voltage raised. With this FO used for microalgae dewatering, 247% of increase in flux and 86% in final biomass concentration were observed. In addition to the effect on flux improvement, the electrically-facilitated FO exhibited the ability to remove chlorophyll from the dewatered biomass, down to 0.021±0015mg/g cell. All these suggest that the newly suggested electrically-facilitated FO, one particularly employed PEM, can indeed offer a workable way of dewatering of microalgae; it appeared to be so because it can also remove the ever-problematic chlorophyll from extracted lipids in a simultaneous fashion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fundamental study for improvement of dewatering of fine coal/refuse. Final report, August 1981-December 1984

Energy Technology Data Exchange (ETDEWEB)

Chiang, S.H.; Klinzing, G.E.; Morsi, B.I.; Tierney, J.W.; Binkley, T.; Chi, S.M.; Huang, S.; Qamar, I.; Venkatadri, R.

1984-12-01

Fine coal in slurry form must be dewatered to minimize handling and transportation problems and be reduced to a desirable level for subsequent preparation of coal/water mixtures as a substitute utility fuel. The current practice is inadequate for the dewatering of fine coal, particularly for coal particles with sizes smaller than 400 mesh. Therefore, it is most desirable to develop improved mechanical methods for reducing the moisture content of fine coal. In the light of this, a fundamental study of the dewatering of fine coal/refuse was initiated in June 1979 and continued through 1984. The overall objective of the study is to seek improved methods of dewatering through a better understanding of the filtration and post-filtration processes. As a first step, efforts have been focused on the mechanism of dewatering in terms of the basic properties of coal (and refuse) particles and the microstructures of filter cakes, and their relations to filtration rate and final moisture content. Pittsburgh seam-Bruceton Mine coal was used as a base coal. During the past year, filter cakes from coals with widely varying size ranges were micrographically characterized. The effects of a number of surface active agents and of entrapped air bubbles on the filter cake properties were also studied. Modules of the network model for calculating single phase and two phase permeabilities were formulated and tested. The report is divided into four parts: summary and deliverables; work forecast for 1984-1985; detailed description of technical progress; and appendices. 21 refs., 55 figs., 17 tabs.

Prediction and verification of centrifugal dewatering of P. pastoris fermentation cultures using an ultra scale-down approach.

Science.gov (United States)

Lopes, A G; Keshavarz-Moore, E

2012-08-01

Recent years have seen a dramatic rise in fermentation broth cell densities and a shift to extracellular product expression in microbial cells. As a result, dewatering characteristics during cell separation is of importance, as any liquor trapped in the sediment results in loss of product, and thus a decrease in product recovery. In this study, an ultra scale-down (USD) approach was developed to enable the rapid assessment of dewatering performance of pilot-scale centrifuges with intermittent solids discharge. The results were then verified at scale for two types of pilot-scale centrifuges: a tubular bowl equipment and a disk-stack centrifuge. Initial experiments showed that employing a laboratory-scale centrifugal mimic based on using a comparable feed concentration to that of the pilot-scale centrifuge, does not successfully predict the dewatering performance at scale (P-value centrifuge. Initial experiments used Baker's yeast feed suspensions followed by fresh Pichia pastoris fermentation cultures. This work presents a simple and novel USD approach to predict dewatering levels in two types of pilot-scale centrifuges using small quantities of feedstock (centrifuge needs to be operated, reducing the need for repeated pilot-scale runs during early stages of process development. Copyright © 2012 Wiley Periodicals, Inc.

Microbiological and physico-chemical studies on irradiated dewatered sludge

International Nuclear Information System (INIS)

Hilmy, N.; Suwirma, S.; Harsoyo; Suhadi, F.

1987-01-01

Microbiological and physico-chemical studies on irradiated dewatered sludge. Microbiological and physico-chemical dewatered have been carried out and non-irradiated dewatered sludge of Jakarta city, collected during the rainy and dry season. Total bacterial counts of non-irradiated dewatered sludge with water content of around 20%, were found to be about 7x10 8 per g during the rainy season and 7x10 6 up to 1.3x10 8 per g during the dry season, while coliform fecal Streptococcus and Pseudomonas were found to be 1.6x10 4 to 1.0x10 7 , 3x10 5 , and 5x10 3 per g, respectively. No Salmonella, Shigella and Vibrio were detected in all of the samples observed. About 10% of the total number of coliforms were found to be Escherichia coli. A dose of 6 kGy could eliminate the coliform, E. Coli, fecal Streptococcus and Pseudomonas from all of the dewatered sludge observed. The nutrient value of the sludge was sufficient, i.e. total nitrogen content ranged between 1 and 4,42%, phosphorus between 1.55 and 2.36%, and potassium between 0,1 and 0,2% of dry matter. Heavy metal contents were found a little bit high to be applied as animal feed, but it is still acceptable for soil conditioner. Combining 3 months storage at ambient environment and irradiation dose of 2.5 kGy were found to work synergistically to eliminate coliforms and E. Coli from sludge. (author). 8 figs, 17 refs

Determination of Juice Removal Difficulty from Mash Cake in Cassava Mash Dewatering Operation

Directory of Open Access Journals (Sweden)

Oladele Peter KOLAWOLE

2012-08-01

Full Text Available Cassava processing equipment operators have limited knowledge; this militates against the success recorded in the research so far in cassava mash dewatering. New dewatering schemes to make food processing economical to handle are in progress. Common dewatering processes use a variety of mechanical means such as screw presses and belt presses. Experiments were conducted using three samples of TMS 4(2 1425 variety while evaluating the difficulty of separating juice from mash cake. Average specific cake resistance (a of 5×1011 m/kg was obtained confirming that it is moderately easy to dewatering.

Enhanced Brine Dewatering System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The purpose of the Enhanced Brine Dewatering System (EBDS) is to provide an easily scalable means of completely recovering usable water from byproducts created by...

Enhanced Brine Dewatering System, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The purpose of the Enhanced Brine Dewatering System (EBDS) is to provide a scalable means of completely recovering usable water from byproducts created by reverse...

Electric dewatering and drying of fine-grained products; Elektrisk afvanding og toerring af finkornede produkter

Energy Technology Data Exchange (ETDEWEB)

Hansen, H.K.; Villumsen, A.

2001-07-01

The aim of the project was to elucidate four aspects related to using electric direct current to find an energy saving alternative to existing methods within dewatering of fine-grained products. The four aspects were a) electrophoresis forced sedimentation of chalk slurry, b) electro osmotic dewatering of chalk slurry, c) electro osmotic dewatering of agricultural chalk and d) electro osmotic dewatering of liquid organic wastes. (EHS)

Electro-dewatering of wastewater sludge: influence of the operating conditions and their interactions effects.

Science.gov (United States)

Mahmoud, Akrama; Olivier, Jérémy; Vaxelaire, Jean; Hoadley, Andrew F A

2011-04-01

Electric field-assisted dewatering, also called electro-dewatering (EDW), is a technology in which a conventional dewatering mechanism such a pressure dewatering is combined with electrokinetic effects to realize an improved liquid/solids separation, to increase the final dry solids content and to accelerate the dewatering process with low energy consumption compared to thermal drying. The application of these additional fields can be applied to either or both dewatering stages (filtration and/or compression), or as a pre-or post-treatment of the dewatering process. In this study, the performance of the EDW on wastewater sludge was investigated. Experiments were carried out on a laboratory filtration/compression cell, provided with electrodes, in order to apply an electrical field. The chosen operating conditions pressure (200-1200 kPa) and voltage (10-50 V) are sufficient to remove a significant proportion of the water that cannot be removed using mechanical dewatering technologies alone. A response surface methodology (RSM) was used to evaluate the effects of the processing parameters of EDW on (i) the final dry solids content, which is a fundamental dewatering parameter and an excellent indicator of the extent of EDW and (ii) the energy consumption calculated for each additional mass of water removed. A two-factor central composite design was used to establish the optimum conditions for the EDW of wastewater sludge. Experiments showed that the use of an electric field combined with mechanical compression requires less than 10 and 25% of the theoretical thermal drying energy for the low and moderate voltages cases, respectively. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Fundamental study for improvement of dewatering of fine coal/refuse. Annual report, August 1982-August 1983

Energy Technology Data Exchange (ETDEWEB)

Chiang, S.H.; Klinzing, G.E.; Morsi, B.J.; Tierney, J.W.; Adams, J.; Bhat, N.; Binkley, T.; Chi, S.M.; Kakwani, R.; Qamar, I.

1983-09-01

The overall objective of the study is to seek improved methods of dewatering through a better understanding of the filtration and post-filtration processes. As a first step, efforts have been focused on the mechanism of dewatering in terms of basic properties of coal (and refuse) particles and microstructures of filter cakes, and their relations to filtration rate and final moisture content. Pittsburgh seam-Bruceton Mine coal was used as a base coal with experiments also being conducted with Upper Freeport and Illinois No. 6 coals. During the past year, filter cakes from the above coals with widely varied size ranges were micrographically characterized. The effects of a number of surface active agents and of entrapped air bubbles on the filter cake properties were also studied. A module of the network model for calculating single phase permeabilities was completed and tested. The report is divided into four parts: summary and deliverables; work forecast for the 1983-84; detailed descriptions of technical progress for particle/filter cake characterization; theoretical modeling, and enhanced dewatering methods; and appendices. 11 references, 35 figures, 11 tables.

Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

Science.gov (United States)

Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

2016-03-01

Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanical dewatering of silage; Mechanische Entwaesserung von Silage

Energy Technology Data Exchange (ETDEWEB)

Scholz, Volkhard; Daries, Werner [Leibniz-Institut fuer Agrartechnik Potsdam-Bornim e.V. (ATB), Potsdam (Germany). Abteilung Technik der Aufbereitung, Lagerung und Konservierung; Rinder, Ralf [Anhydro GmbH, Kassel (Germany)

2009-07-01

The use of screw presses for dewatering of silage is energetically more efficient than thermal drying. Tests with two types of screw presses show that on dry matter flow rates of more than 1.0 tDM/h the specific energy consumption is less than 30 kWh/tDM. The water content of the silage is decreased by 5 to 20 % and the share of undesired ingredients by 2 to 30 %. Besides press design and plant species, in particular moisture content, chip size and density of silage are essentially for the dewatering success. (orig.)

Pervaporation applied for dewatering of reaction mixture during esterification

OpenAIRE

Krasiński Andrzej; Wierzba Patrycja; Grudzień Agata; Hajmowicz Halina; Zawada Krzysztof; Synoradzki Ludwik

2016-01-01

In this work the esterification of diethyl tartrate was studied. The research was focused on the enhancement of reversible reaction yield, which is accomplished by dewatering of the reaction mixture. The removal of water shifts the equilibrium towards the main product. Pervaporation was applied for this purpose, and results were compared to distillation. The advantages and limitations of both processes are discussed. The experimental part consists of dewatering of mixture after the reaction h...

Laboratory and field experience with rim ditch dewatering of MFT

Energy Technology Data Exchange (ETDEWEB)

Demoz, A.; Mikula, R. [Natural Resources Canada, Devon, AB (Canada). CANMET Western Research Centre; Lahaie, R. [Syncrude Canada Ltd., Edmonton, AB (Canada)

2010-07-01

This PowerPoint presentation described a rim ditch method of dewatering mature fine tailings (MFT). Polymer additions were used to strengthen the MFT and to decrease the capillary suction time (CST). Laboratory and field-scale studies were conducted to demonstrate the dewatering method. The flocculants were added in a Komax inline mixer. Polymers were then injected into the tailings. The mixing processes were optimized in a series of laboratory studies and then demonstrated in the field tests. The tests showed that CST and high dewatering rates were consistently maintained using the method. MFT feeds were also consistent. Release water quality was improved using the method. The large-scale test site is now being monitored for compliance with Directive 74. tabs., figs.

Osmotic Effects in Sludge Dewatering

DEFF Research Database (Denmark)

Keiding, Kristian; Rasmussen, Michael R.

2003-01-01

A model of filtration dewatering is presented. The model is based on the d’Arcy flow equation in which the resistance to filtration is described by the Corzeny–Carman equation and the driving force is the difference between the external pressure and the osmotic pressure of the filter cake. It has...

Co-conditioning and dewatering of chemical sludge and waste activated sludge.

Science.gov (United States)

Chang, G R; Liu, J C; Lee, D J

2001-03-01

The conditioning and dewatering behaviors of chemical and waste activated sludges from a tannery were studied. Capillary suction time (CST), specific resistance to filtration (SRF), and bound water content were used to evaluate the sludge dewatering behaviors. Zeta potentials were also measured. Experiments were conducted on each sludge conditioned and dewatered separately, and on the sludge mixed at various ratios. Results indicate that the chemical sludge was relatively difficult to be dewatered, even in the presence of polyelectrolyte. When the waste activated sludge was mixed with the chemical sludge at ratios of 1:1 and 2:1, respectively, the dewaterability of chemical sludge improved remarkably while the relatively better dewaterability of the waste activated sludge deteriorated only to a limited extent. As the mixing ratios became 4:1 and 8:1, the dewaterability of the mixed sludge was equal to that of the waste activated sludge. The optimal polyelectrolyte dosage for the mixed sludge was equal to or less than that of the waste activated sludge. It is proposed that the chemical sludges act as skeleton builders that reduce the compressibility of the mixed sludge whose dewaterability is enhanced. Bound water contents of sludge decreased at low polyelectrolyte dosage and were not significantly affected as polyelectrolyte dosage increased. Advantages and disadvantages of co-conditioning and dewatering chemical sludge and waste activated sludge were discussed.

A comparison of the economic benefits of centralized and distributed model predictive control strategies for optimal and sub-optimal mine dewatering system designs

International Nuclear Information System (INIS)

Romero, Alberto; Millar, Dean; Carvalho, Monica; Maestre, José M.; Camacho, Eduardo F.

2015-01-01

Mine dewatering can represent up to 5% of the total energy demand of a mine, and is one of the mine systems that aim to guarantee safe operating conditions. As mines go deeper, dewatering pumping heads become bigger, potentially involving several lift stages. Greater depth does not only mean greater dewatering cost, but more complex systems that require more sophisticated control systems, especially if mine operators wish to gain benefits from demand response incentives that are becoming a routine part of electricity tariffs. This work explores a two stage economic optimization procedure of an underground mine dewatering system, comprising two lifting stages, each one including a pump station and a water reservoir. First, the system design is optimized considering hourly characteristic dewatering demands for twelve days, one day representing each month of the year to account for seasonal dewatering demand variations. This design optimization minimizes the annualized cost of the system, and therefore includes the investment costs in underground reservoirs. Reservoir size, as well as an hourly pumping operation plan are calculated for specific operating environments, defined by characteristic hourly electricity prices and water inflows (seepage and water use from production activities), at best known through historical observations for the previous year. There is no guarantee that the system design will remain optimal when it faces the water inflows and market determined electricity prices of the year ahead, or subsequent years ahead, because these remain unknown at design time. Consequently, the dewatering optimized system design is adopted subsequently as part of a Model Predictive Control (MPC) strategy that adaptively maintains optimality during the operations phase. Centralized, distributed and non-centralized MPC strategies are explored. Results show that the system can be reliably controlled using any of these control strategies proposed. Under the operating

46 CFR 28.255 - Bilge pumps, bilge piping, and dewatering systems.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Bilge pumps, bilge piping, and dewatering systems. 28... the Aleutian Trade § 28.255 Bilge pumps, bilge piping, and dewatering systems. (a) Each vessel must be equipped with a bilge pump and bilge piping capable of draining any watertight compartment, other than...

Synthesis, characterization, and secondary sludge dewatering performance of a novel combined silicon–aluminum–iron–starch flocculant

Energy Technology Data Exchange (ETDEWEB)

Lin, Qintie, E-mail: qintlin@163.com; Peng, Huanlong; Zhong, Songxiong; Xiang, Jiangxin

2015-03-21

Highlights: • Silicon, aluminum, and iron were grafted onto starch chains to synthesize CSiAFS. • The sludge dewatering performance of CSiAFS was superior to PAC, PAM, and FeCl{sub 3}. • CSiAFS exhibited a good dewatering efficiency over a wide range of pH (3.0–11.0). • CSiAFS had a discontinuous surface with channels which helped to sludge dewatering. - Abstract: Flocculation is one of the most widely used cost-effective pretreatment method for sludge dewatering, and a novel environmentally friendly and efficient flocculant is highly desired in the sludge dewatering field. In this study, a novel combined silicon–aluminum–ferric–starch was synthesized by grafting silicon, aluminum, and iron onto a starch backbone. The synthesized starch flocculant was characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy, X-ray powder diffraction, and thermogravimetric analysis. The dewatering performance of secondary sludge was evaluated according to the capillary suction time, settling volume percentage, and specific resistance to filtration. The results indicated that the copolymer exhibited: (1) a good dewatering efficiency over a wide pH range of 3.0–11.0, (2) superior sludge dewatering performance compared to those of polyaluminum chloride (PACl), polyacrylamide (PAM), ferric chloride, and (3) a discontinuous surface with many channels or voids that helps to mobilize the impermeable thin layer of secondary sludge during filter pressing. Such a novel copolymer is a promising green flocculant for secondary sludge dewatering applications.

Atomistic Structure of Mineral Nano-aggregates from Simulated Compaction and Dewatering.

Science.gov (United States)

Ho, Tuan Anh; Greathouse, Jeffery A; Wang, Yifeng; Criscenti, Louise J

2017-11-10

The porosity of clay aggregates is an important property governing chemical reactions and fluid flow in low-permeability geologic formations and clay-based engineered barrier systems. Pore spaces in clays include interlayer and interparticle pores. Under compaction and dewatering, the size and geometry of such pore spaces may vary significantly (sub-nanometer to microns) depending on ambient physical and chemical conditions. Here we report a molecular dynamics simulation method to construct a complex and realistic clay-like nanoparticle aggregate with interparticle pores and grain boundaries. The model structure is then used to investigate the effect of dewatering and water content on micro-porosity of the aggregates. The results suggest that slow dewatering would create more compact aggregates compared to fast dewatering. Furthermore, the amount of water present in the aggregates strongly affects the particle-particle interactions and hence the aggregate structure. Detailed analyses of particle-particle and water-particle interactions provide a molecular-scale view of porosity and texture development of the aggregates. The simulation method developed here may also aid in modeling the synthesis of nanostructured materials through self-assembly of nanoparticles.

Effect of hydrothermal dewatering on the slurryability of brown coals

International Nuclear Information System (INIS)

Yu Yujie; Liu Jianzhong; Wang Ruikun; Zhou Junhu; Cen Kefa

2012-01-01

Highlights: ► Brown coals are upgraded by hydrothermal dewatering. ► The moisture content and oxygen functional groups decrease during the process. ► The point of zero charge and the contact angle rise as the temperature increases. ► The products were highly hydrophobic. ► The improvement on slurryability of solid products were examined. - Abstract: Two brown coals from China were dewatered under hydrothermal dewatering (HTD) conditions at 250–320 °C for 1 h in a 2 L autoclave. The hydrothermally dewatered products were used to prepare coal water slurry (CWS) with a lower viscosity than brown raw coal slurry. Moreover, the coal rank and heat value of the brown coal increased as the inherent moisture and oxygen content decreased during the HTD process. The maximum solid concentration of CWS prepared from XiMeng coal increased from 45.7% to 59.3%, whereas that of CWS prepared from BaoTou coal increased from 53.7% to 62.1%, after being dewatered at 320 °C. The improvement in the slurryability of brown coal significantly depended on the final temperature of the HTD process, the mechanism of which can be explained by the chemical analysis of oxygen functional groups, zeta potential, and the contact angle of the surface between coal and water. The oxygen functional groups, the oxygen/carbon ratio and hydrogen/carbon ratio in brown coal decreased, indicating that the coal rank was upgraded during the HTD process. As a result, both the point of zero charge and the contact angle increased, implying that the HTD products were highly hydrophobic.

Dewatering of planned Key Lake open pits in northern Saskatchewan

International Nuclear Information System (INIS)

Unland, W.; Holl, N.

1980-01-01

The engineering design and experience gained so far with a dewatering system for an open-pit uranium mine planned at Key Lake in Northern Saskatchewan are presented. An extensive unconfined overburden aquifer is hydraulically connected with the underlying Athabasca Formation and basement rocks, both of relatively low hydraulic conductivity. The overburden aquifer is embedded in a bedrock trough, with the deepest depression between the planned pits. Hydrogeological data were used in a numerical dewatering model simulating groundwater flow at different stages of the pit development. Based on the model results, the enginering design had to provide for different pumping rates, varying between 1.0 and 0.21 m 3 /sec. This problem was solved by using a double line pressure system. The design concept for the complete peripheral discharge system and the well design used for 26 dewatering wells are discussed. (auth)

Centrifuge - dewatering of oil sand fluid tailings: phase 2 field-scale test

Energy Technology Data Exchange (ETDEWEB)

Seto, Jack T.C. [BGC Engineering Inc (Canada); O' Kane, Mike [O' Kane Consultants Inc (Canada); Donahue, Robert [Applied Geochemical Solutions Engineering (Canada); Lahaie, Rick [Syncrude Canada Ltd (Canada)

2011-07-01

In order to reduce the accumulation of oil sand fluid fine tailings (FFT) and to create trafficable surfaces for reclamation, Syncrude Canada Ltd. has been studying several tailings technologies. Centrifuge-dewatering is one such technology. This paper discusses the phase 2 field-scale tests for centrifuge-dewatering of oil sand FFT. In centrifuge-dewatering, FFT is diluted and treated with flocculant, then processed through a centrifuge plant and the high-density underflow is transported to a tailings deposit. This technology has evolved since 2005 from laboratory bench scale tests. More than 10,000 cubic meters of centrifuge cake was treated, produced and transported to ten different deposits over a 12-week period from August to October 2010. The amount of solids in FFT was increased from 30% to 50% by centrifuging. Sampled deposits were tested and instrumented for in situ strength. It can be concluded that the deposits can be strengthened and densified by natural dewatering processes like freeze-thaw action and evaporative drying.

Field performance of de-watered fluid fine tailings for oil sands reclamation

Energy Technology Data Exchange (ETDEWEB)

Ward Wilson, G.; Kabwe, Louis [University of Alberta (Canada); Donahue, Robert [Applied Geochemical Engineering Inc. (Canada); Lahaie, Rick [Syncrude Canada Ltd (Canada)

2011-07-01

This document presents research carried out by Syncrude Canada Ltd and its partners to evaluate several methods of de-watering fluid fine tailings to increase the solids content and at the same time produce a tailings profile which will permit final reclamation. Several de-watering methods are discussed in this paper, particularly in-line flocculation and centrifuged fluid fine tailings. First, in-line flocculation with organic polymers is discussed followed by thin left deposition, then the flocculation and centrifugation process to produce a paste- like material that is deposited in a thicker layer is presented. This document details the preliminary performance of both discussed methods; extensive instrumentation was used to measure de-watering rates due to consolidation, atmospheric drying, downward drainage to the foundation materials, and freeze/thaw consolidation. Finally, a summary of the measured results of de-watering rates and numerical model results obtained from the SoilCover model are presented and discussed.

METODE PELAKSANAAN DEWATERING YANG RAMAH LINGKUNGAN PADA PROYEK THE NEST CONDOTEL

Directory of Open Access Journals (Sweden)

I Wayan Intara

2016-03-01

Full Text Available Proyek Pembangunan The Nest Condotel merupakan salah satu upaya untuk memenuhi sarana dan prasarana pariwisata khusunya daerah Nusa Dua-Bali. Proyek ini dibangun di tengah-tengah pemukiman penduduk dan berdekatan dengan Pengolahan Limbah BTDC. Setelah dilaksanakan survei lapangan ada permasalahan yang dihadapi pada pembangunan proyek ini yaitu pada pengerjaan struktur basement. Kondisi muka air tanah lebih tinggi daripada rencana pemukaan galian lantai basement yang akan dibuat. Di samping itu, kondisi tanah yang kurang baik dengan kondisi tanah yang berpasir. Berdasarkan permasalahan di atas perlu adanya pemilihan perencanaan metode penanganan muka air tanah yang paling tepat dalam pekerjaan  galian basement. Dewatering adalah proses penurunan muka air tanah pada suatu area tertentu dengan cara pemompaan dari sebuah sumur ataupun saluran. Tujuannya adalah untuk menjaga area galian tetap kering dalam proses konstruksi dan menjaga kestabilan lereng galian. Pemompaan dilakukan melalui sumur-sumur dewatering (dewatering well atau well point atau saluran-saluran (sump dengan menggunakan pompa submersible (submersible pump. Dengan demikian penggalian basement bisa dikerjakan dengan baik. Penelitian ini adalah menentukan metode pelaksanaan pekerjaan dewatering yang paling tepat dari metode-metode pelaksanaan yang mungkin untuk dilaksankan berdasarkan biaya, waktu, dan dampak terhadap lingkungan. Metodelogi yang digunakan untuk analisis data adalah menganalisis metode-metode pelaksanaan yang ada dan dari hasil analisis akan ditetapkan metode pelaksanaan terbaik. Hasil analisis dari beberapa metode pelaksanaan yang ada untuk pekerjaan dewatering digunakan adalah predrainage dan open pumping, metode yang terpilih yaitu open pumping adalah metode terbaik untuk dilaksanakan pada proyek tersebut dengan biaya yang terendah, waktu pelaksanaan yang lebih cepat, dan dampak lingkungan yang dapat diminimalisir

Permanganate/bisulfite (PM/BS) conditioning-horizontal electro-dewatering (HED) of activated sludge: Effect of reactive Mn(III) species.

Science.gov (United States)

Guo, Xinxin; Wang, Yili; Wang, Dongsheng

2017-11-01

A novel activated sludge (AS) conditioning method through permanganate/bisulfate (PM/BS) process was proposed. The method involved a new conditioner of reactive Mn(III) intermediate. Moreover, a Mn(III) conditioning-horizontal electro-dewatering (Mn(III) C-HED) process was established to improve AS dewatering performance. Underlying mechanisms were unraveled by investigating changes in physicochemical characteristics, scanning electron microscope (SEM) morphology, and transformation of water and organic matters. The optimum dewatering conditions for Mn(III) C-HED process with the final water content of 86.94% were determined as the combination of KMnO 4 0.01 mol/L AS and NaHSO 3 0.05 mol/L AS at 20 V for 120 min. Results showed that Mn(III) C-HED process effectively reduced free water and bound water with the corresponding removal ratios of 51.68% and 87.62% at the anode-side as well as 36.55% and 85.08% at the cathode-side, respectively. During the PM/BS process, the produced Mn(III), Mn 2+ , and MnO 2 exerted chemical and physical effects on AS conditioning and dewatering. Mn(III) disintegrated extracellular polymeric substances (EPS) fractions and cells in AS, as well as induced partial bound water release. Additionally, flocculation effect induced by Mn 2+ and MnO 2 skeleton building also benefited AS dewatering. AS cells were further disrupted under the effect of a horizontal electric field. Accordingly, EPS within the AS matrix was solubilized, tightly bound (TB)-EPS or loosely bound (LB)-EPS was converted to their corresponding outer EPS fractions, and AS dewaterability improved. Additionally, changes in pH and temperature at HED stage damaged the AS cells and changed the floc properties, thereby leading to easy separation of liquid and AS particles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dewatering of Yoghurt Using Permeable Membrane and Acrylic Superabsorbent Hydrogel

Directory of Open Access Journals (Sweden)

A. Ahmadpour

2008-02-01

Full Text Available Conventional processes of food dewatering, such as thermal, have undesirable and destruction effects on vitamins, aromatic compounds and pigments. In addition, they are accompanied with some technological complications and energy consumption. Thus, food concentration processes are directed to non-thermal techniques or methods with reduced heat effects. Superabsorbents are highly hydrophilic polymer networks which can absorb water and aqueous solutions some hundred times of their weights and retain them. These materials are subgroups of hydrogel family that are transformed into gels after absorbing water. In the present research, the possibilities of yoghurt dewatering using superabsorbents have been investigated for the first time in Iran and some remarkable results are obtained for this vital product. In the experiments carried out to investigate the effect of these absorbents on normal method of yoghurt concentration (use of permeable membrane, type of bed (wide and vertical and time are also studied. The percentage of total soluble solids and dry solids of dewatered samples were measured in different time intervals up to 180 min. The results showed that superabsorbent on a wide bed would reduce the concentration time to one third. In other words, in a certain time interval, more than 70% increase in yoghurt dry solids was observed compared to normal method. These results show that acrylic superabsorbent hydrogel can be applied as highly hydrophilic material in non-thermal food dewatering methods.

Network model for fine coal dewatering. Part I. The model

Energy Technology Data Exchange (ETDEWEB)

Qamar, I.; Tierney, J.W.; Chiang, S.H.

1985-08-01

There is a body of well established research in filtration and related subjects, but much of it has been empirical - based on correlations from experimental data. This approach has the disadvantage that it lacks generality, and it is difficult to predict the behavior of new or different systems. A more general method for studying dewatering is needed-one which will include the microscopic characteristics of the filter cake, which, like other porous media, contains a complicated network of interconnected pores through which the fluid must flow. These pores play an important role in dewatering because they give rise to capillary forces when one fluid is displacing another. In this report, we describe a network model which we believe satisfies these requirements. In the main body of this report, the model is described in detail. Background information is given where appropriate, and a brief description is given of the experimental work being done in our laboratories to verify the model. A detailed description of the experimental procedures and results is given in other DOE reports. The computer programs which are needed to solve the model are described in detail in the Appendices and are accompanied by flow charts, sample problems, and sample outputs. Sufficient detail is given in order to use the model programs on other computer systems. 32 refs., 7 figs., 5 tabs.

Insight into effects of electro-dewatering pretreatment on nitrous oxide emission involved in related functional genes in sewage sludge composting.

Science.gov (United States)

Wang, Ke; Wu, Yiqi; Wang, Zhe; Wang, Wei; Ren, Nanqi

2018-05-26

Electro-dewatering (ED) pretreatment could improve sludge dewatering performance and remove heavy metal, but the effect of ED pretreatment on nitrous oxide (N 2 O) emission and related functional genes in sludge composting process is still unknown, which was firstly investigated in this study. The results revealed that ED pretreatment changed the physicochemical characteristics of sludge and impacted N 2 O related functional genes, resulting in the reduction of cumulative N 2 O emission by 77.04% during 60 days composting. The higher pH and NH 4 + -N, but lower moisture, ORP and NO 2 - -N emerged in the composting of ED sludge compared to mechanical dewatering (MD) sludge. Furthermore, ED pretreatment reduced amoA, hao, narG, nirK and nosZ in ED sludge on Day-10 and Day-60 of composting. It was found that nirK reduction was the major factor impacting N 2 O generation in the initial composting of ED sludge, and the decline of amoA restricted N 2 O production in the curing period. Copyright © 2018 Elsevier Ltd. All rights reserved.

Characterization and dewatering of flotation technological tailings

Directory of Open Access Journals (Sweden)

Grigorova I.

2014-01-01

Full Text Available The treatment of flotation tailings is today a subject of interest in mineral processing because of the potential of wasted materials as an actual mineral resource and because of environmental reasons. Decantation ponds are found at almost every mine in the world. They are large earth fill dams containing the residue of the milling process to extract metals from mined ores. Traditional wet tailings disposal has been problematic due to the risk of ground water contamination and the difficulty in rehabilitating storage sites. Tailings dams are at risk of failure due to leakage, instability, liquefaction, and poor design. In the last few years the use of paste technology in the disposal of mine tailings is increasingly studied as an option to conventional tailings dams. The Lucky Invest Concentrator is located in the Eastern Rhodopes Mountain of Bulgaria. Since 1959 lead-zinc ores are dressed. Finally, during the flotation cycle lead and zinc concentrates are produced. The final technological processing waste precipitates in tailing pond. Research and development program has started to established opportunities to obtain dry deposit of the ore processing residue and analyses the feature of new tailing disposal method. The tailings particle size distributions and chemical compositions were determined. The data from laboratory and pilot scale tests clearly illustrate that there are the possibilities to obtaine lead-zinc dewatered tailings. The experimental results show that new cyclone modifications have a potential in dewatering technology of flotation tailings. It appears that dewatering cyclones can be an approach on new tailings pond elimination technology.

Application of a thermally assisted mechanical dewatering process to biomass

Energy Technology Data Exchange (ETDEWEB)

Mahmoud, A.; Arlabosse, P. [Universite de Toulouse, Mines Albi, CNRS, Campus Jarlard, F-81013 Albi cedex 09 (France); Ecole des Mines Albi, Centre RAPSODEE, Campus Jarlard, F-81013 Albi (France); Fernandez, A. [Universite de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31400 Toulouse (France); INRA, UMR792 Ingenierie des Systemes Biologiques et des Procedes, CNRS, UMR5504, F-31400 Toulouse (France)

2011-01-15

Thermally assisted mechanical dewatering (TAMD) is a new process for energy-efficient liquid/solids separation which enhances conventional-device efficiency. The main idea of this process is to supply a flow of heat in mechanical dewatering processes to favour the reduction of the liquid content. This is not a new idea but the proposed combination, especially the chosen operating conditions (T < 100 C and P < 3000 kPa) constitutes an original approach and a significant energy saving since the liquid is kept in liquid state. Response surface methodology was used to evaluate the effects of the processing parameters of TAMD on the final dry solids content, which is a fundamental dewatering parameter and an excellent indicator of the extent of TAMD. In this study, a two-factor central composite design was used to establish the optimum conditions for the TAMD of alfalfa biomass. Experiments were carried out on a laboratory compression cell. Experiments showed that the dewatering enhancement results only from thermal effects. With a moderate heat supply (T{sub piston} = 80 C), the dry solid content of the press cake can reach 66%, compared to 36% at ambient temperature. A significant regression model, describing changes on final dry solids content with respect to independent variables, was established with determination coefficient, R{sup 2}, greater than 88%. With an energy consumption of less than 150 kWh/m{sup 3}, the use of the TAMD process before a thermal drying process leads to an energy saving of at least 30% on the overall separation chain. (author)

Electroosmotically enhanced dewatering/deliquoring of fine-particle coal: Final report, January 1--December 31, 1988

Energy Technology Data Exchange (ETDEWEB)

Sami, Sedat [Department of Civil Engineering and Mechanics, Southern Illinois Univ., Carbondale, IL (United States); Davis, Philip K. [Department of Civil Engineering and Mechanics, Southern Illinois Univ., Carbondale, IL (United States); Smith, James G. [Department of Electrical Engineering, Southern Illinois Univ., Carbondale, IL (United States)

1989-03-01

This research is an investigation of the use of electroosmosis to dewater/deliquor ultrafine coal. Post-beneficiation dewatering/deliquoring methods for ultrafine coal are inadequate and generally require subsequent thermal drying. Thermal drying is not only expensive and time consuming, it also does not recover liquids for reuse in beneficiation processes. The degree of difficulty associated with dewatering increases as surface forces become more important than gravimetric forces. Electroosmotic flow has advantages for dewatering because it is much less sensitive to pore size than hydraulic gradient flow for the 1 to 75 ..mu..m ultrafine size range. The first year of this project focused upon preparation of ultrafine coal samples, development of test equipment and test cells, identification of variables affecting electroosmosis, and trial runs. Techniques and procedures not previously used by researchers of electroosmotic dewatering have revealed important information about the dynamics of the electroosmosis process. The identification of the first few millimeters of the cathode region of the cell as the sink for most of the energy input into the process provides the potential for improving efficiency by concentrating the second year effort on intervention in that region. Information gathered about differences in FTIR spectra as a function of location in the dewatering cell will be investigated. Changes in pH with temperature and by the application of electroosmotic current flow will receive attention, as well. 178 refs., 16 figs.

Ultra scale-down device to predict dewatering levels of solids recovered in a continuous scroll decanter centrifuge.

Science.gov (United States)

Lopes, A G; Keshavarz-Moore, E

2013-01-01

During centrifugation operation, the major challenge in the recovery of extracellular proteins is the removal of the maximum liquid entrapped within the spaces between the settled solids-dewatering level. The ability of the scroll decanter centrifuge (SDC) to process continuously large amounts of feed material with high concentration of solids without the need for resuspension of feeds, and also to achieve relatively high dewatering, could be of great benefit for future use in the biopharmaceutical industry. However, for reliable prediction of dewatering in such a centrifuge, tests using the same kind of equipment at pilot-scale are required, which are time consuming and costly. To alleviate the need of pilot-scale trials, a novel USD device, with reduced amounts of feed (2 mL) and to be used in the laboratory, was developed to predict the dewatering levels of a SDC. To verify USD device, dewatering levels achieved were plotted against equivalent compression (Gtcomp ) and decanting (Gtdec ) times, obtained from scroll rates and feed flow rates operated at pilot-scale, respectively. The USD device was able to successfully match dewatering trends of the pilot-scale as a function of both Gtcomp and Gtdec , particularly for high cell density feeds, hence accounting for all key variables that influenced dewatering in a SDC. In addition, it accurately mimicked the maximum dewatering performance of the pilot-scale equipment. Therefore the USD device has the potential to be a useful tool at early stages of process development to gather performance data in the laboratory thus minimizing lengthy and costly runs with pilot-scale SDC. © 2013 American Institute of Chemical Engineers.

A new dewatering technique for stingless bees honey

Directory of Open Access Journals (Sweden)

Ramli Ahmad Syazwan

2017-01-01

Full Text Available One of the problems faced in stingless bee honey storage is spoilage by the fermentation process occurs in honey due to its high water content. There are a few techniques available currently, but they are time consuming and there is excessive heat involved in the process. The temperature of the process must be kept low because excessive heat can deteriorate nutrition value and biochemical content in honey. Hence, a new method of honey dewatering was developed using a Low Temperature Vacuum Drying (LTVD with induced nucleation technique.The objective of this research is to investigate the performance of a LTVD with induced nucleation to reduce the water content in honey. First, the honey was placed in a pressure vessel, and then air was removed. Then, the honey was slightly heated at 30°C and the water content before and after the experiment was measured by a refractometer. The steps were repeated until the water content reached below 20%. It was found that the LTVD method improved the water removal rate significantly with an average of 0.15% of water content per minute. That is 3 times much faster than the conventional method of low temperature heating by Tabouret. Higher temperature during dewatering process improved the dewatering rate significantly. It can be concluded that LTVD is a promising option in tackling the high water content in stingless bee honey issue.

Influence of process operating parameters on dryness level and energy saving during wastewater sludge electro-dewatering.

Science.gov (United States)

Mahmoud, Akrama; Hoadley, Andrew F A; Conrardy, Jean-Baptiste; Olivier, Jérémy; Vaxelaire, Jean

2016-10-15

Electrically assisted mechanical dewatering, known as electro-dewatering (EDW), is an alternative emerging technology for energy-efficient liquid/solids separation in the dewatering of wastewater sludge. In this study, the performance of the electro-dewatering (EDW) process for activated wastewater sludge was investigated. The influence of the operating modes; being the timing of voltage (U-EDW) or current (I-EDW) application to either or both the filtration and compression stages, and the influence of the applied pressure (in successive 30 min pressure steps) were studied. The results showed that by delaying the application of the electric field to the filter cake compression stage, there was a potential saving in power consumption of around 10-12% in the case of U-EDW and about 30-46% in the case of I-EDW. The increase of the applied pressure from 0.5 to 12 bar during the filter cake compression stage leads to an increase in electro-dewatering kinetics. The results also reveal that at a low electric field level the increase of the processing pressure has a relatively pronounced effect on the dewatering process. At high levels of the electric field, a minimum processing pressure (4-6 bar) is required to improve the electrical contact between the electrode and the sludge and thus lower the energy consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reconstitution of dewatered food processing residuals with manure to increase energy production from anaerobic digestion

International Nuclear Information System (INIS)

Wall, David M.; Wu-Haan, Wei; Safferman, Steven I.

2012-01-01

Solid residuals generated from dewatering food processing wastewater contain organic carbon that can potentially be reclaimed for energy through anaerobic digestion. This results in the diversion of waste from a landfill and uses it for a beneficial purpose. Dewatering the waste concentrates the carbon, reducing transportation costs to a farm digester where it can be blended with manure to increase biogas yield. Polymers are often used in the dewatering of the food waste but little is known regarding their impact on biogas production. Four 2 dm 3 working volume, semi-continuous reactors, were used at a mesophilic temperature and a solids retention time (SRT) of 15 days. Reactors were fed daily with a blended feedstock containing a food processing sludge waste (FPSW)/manure ratio of 2.2:1 (by weight) as this produced the optimized carbon to nitrogen ratio. Results demonstrated that reconstitution of dewatered FPSW with dairy manure produced approximately 2 times more methane than animal manure alone for the same volume. However, only approximately 30% of volatile solids (VS) were consumed indicating energy potential still remained. Further, the efficiency of the conversion of VS to methane for the blended FPSW/manure was substantially less than for manure only. However, the overall result is an increase in energy production for a given tank volume, which can decrease life cycle costs. Because all FPSW is unique and the determination of dewatering additives is customized based on laboratory testing and field adjustment, generalizations are difficult and specific testing is required. -- Highlights: ► Energy production in anaerobic digestion can increase by co-blending food waste. ► Energy for transporting food waste to blend with manure is less when dewatered. ► Dewatered food waste in manure produced twice as much methane than manure. ► Efficiency of carbon to methane was low because of ammonium bicarbonate production. ► Carbon destruction was 30%, more

An experimental investigation of microalgal dewatering efficiency of belt filter system

Directory of Open Access Journals (Sweden)

Anjali Sandip

2015-11-01

Full Text Available The objective of this study was to investigate the microalgal dewatering efficiency of a belt filter system for feed concentrations below 10 g dry wt./L. A prototype belt filtration system designed for 50 g dry wt./L microalgal feed concentration was used for this investigation. The highest concentration of microalgal suspension available for testing on the prototype belt filtration system was 6 g dry wt./L obtained from biomass settling tanks at the Lawrence, Kansas domestic wastewater treatment plant. For preparation of feed suspension with concentrations below 10 g dry wt./L, microalgal cultivation was followed by flocculation. A mixed laboratory culture of freshwater species dominated by three eukaryotic green microalgae (Chlorella vulgaris, Scenedesmus sp., and Kirchneriella sp. was cultivated in wastewater effluent. This was followed by flocculation which resulted in a microalgal feed suspension concentration of 4 g dry wt./L. Belt dewatering tests were conducted on microalgal suspensions with feed concentrations of 4 g dry wt./L and 6 g dry wt./L. The maximum microalgal recovery with the belt dewatering system was 46% from the 4 g dry wt./L, and 84% from the 6 g dry wt./L suspensions respectively. The results of this study indicate that microalgal suspension concentrations as low as 6 g dry wt./L can be recovered with a belt filter system improving the overall dewatering efficiency of the system.

Modelagem do processo de desidratação de lodo anaeróbio em leitos de secagem simulados Anaerobic sludge dewatering process modeling in simulated drying beds

Directory of Open Access Journals (Sweden)

Sérgio R. A. Soares

2001-05-01

Full Text Available O emprego de leitos de secagem para a desidratação de lodo de descarte de reatores UASB, constitui excelente alternativa, face a sua simplicidade operacional e aos reduzidos custos de implantação. Este trabalho apresenta uma análise dos fenômenos que influenciam o processo de desidratação de lodo anaeróbio, a partir de simulação de leitos de secagem. Neste sentido, são feitas considerações sobre as características e o comportamento do lodo durante cada fase da secagem. Sugere-se também, um modelo matemático para representar o processo de secagem, obtido a partir dos dados experimentais.The employment of drying beds is an excellent option for dewatering of UASB reactor discarded sludge, because of their simple operation and low construction costs. This paper presents an anaerobic sludge dewatering process analysis of the most influential phenomenon based on drying beds simulation. Therefore, some considerations were made about sludge characteristics and behavior during each dewatering stage. A mathematical model for dewatering process representation obtained from experimental data is also suggested.

Effects of gamma-radiation at pilot plant level as compared to effects of pasteurization on the dewatering of sewage sludges

International Nuclear Information System (INIS)

Groneman, A.F.

1975-01-01

Dewatering and disposal of sludge are costly and time consuming processes. At a pilot plant near Munich efforts were made to estimate the effects of ionizing radiation on dewatering characteristics of different sludges, used for recycling in agriculture. The ease with which sludge drains on drying beds and in mechanical devices is reflected in the value of the specific resistance to filtration. A dose of 300 krad, delivered at an average dose rate of 62 krad per hour in the irradiation plant, was effective for disinfection and reduced the specific resistance to filtration in sludges from the waste water works at Geiselbullach and Starnberg from 24.2 x 10 9 sec 2 /g and 18.0 x 10 9 sec 2 /g to 9.7 x 10 9 sec 2 /g and 5.6 x 10 9 sec 2 /g, respectively. These improved dewatering properties were associated with a clear increase of the compressibility of the anaerobically digested sludges. Pasteurization at 70 0 C during 30 minutes drastically deteriorated the dewatering properties, raising the specific resistance to values approximately 4 times as high as the specific resistance in irradiated sludges. Information obtained from filterability tests was confirmed by plant operators who noticed that irradiated sludges dewatered much better than untreated sludges in drying beds. Experimental evidence indicated that the conditioning effect of gamma irradiation persisted for more than 20 days suggesting that permanent changes were induced in the physical-chemical properties of the domestic, anaerobically digested sludges. Measurements of electrophoretic mobilities showed that the negative electrostatic charges of colloidal particles in sludges were reduced by gamma irradiation whereas pasteurization increased this negative electrostatic charge. Evidence indicated that the specific resistance was considerably increased by effects of the recirculating pumping. This pumping is done to obtain a homogeneous irradiation dose for disinfection. Alternative designs for irradiation

Field Evaluation/Demonstration of a Multisegmented Dewatering System for Accreting Beach Sand in a High-Wave-Energy Environment

National Research Council Canada - National Science Library

Curtis, William

1998-01-01

This study documents the use of beach dewatering systems to accrete beach sand and minimize erosion, and to develop quantitative guidance for constructing and operating beach dewatering installations...

Dewatering cuts drilling mud and disposal costs

International Nuclear Information System (INIS)

West, G.; Pharis, B.

1991-01-01

This paper reports on rig site dewatering of drilling fluids with recycling of processed water that can help an operator to comply with environmental rules by reducing volumes of waste and reducing long term liabilities. It can also reduce disposal costs and provide a cleaner drill site overall. Rig site dewatering is the process of injecting coagulants or flocculating chemicals into the mud entering a large clarifying centrifuge. This coagulates the fine, drilled particles allowing them to be separated from the fluid which can then be handled separately. Most of the environmental concerns during the 1980s involved hazardous materials and toxic wastes. Drilling fluids, many of which are chemically benign, have escaped many of the difficult-to-comply-with rules and regulations. During the 1990s, however, operators may be required to submit a written plan for liquid waste reduction for even nonhazardous materials. Many states and local agencies may institute total bans on oil field wastes. Drilling rigs typically produce about 1 bbl of liquid waste for every 1 ft of hole drilled. Thus, a typical drilling operation can produce a large quantity of waste

Waste water from dewatering of peat

International Nuclear Information System (INIS)

Ringqvist, L.; Bergner, K.; Olsson, Tommy; Bystroem, P.

1991-01-01

The influence of waste water from mechanical dewatering of peat was tested on two species of stream invertebrates. We compared the effects of waste water from peat without any chemical treatment, and waste water from peat where one of the following treatments of the peat had preceded dewatering; a: acidification combined with addition of the cationic polymer Zetag 78 FS40, b: addition of aluminium in combination with the anionic polymer Magnafloc E10, c: polymerisation of the peat by acidification and addition of ferrous chloride and hydrogen peroxide. Waste water from Al/Magnafloc and from the polymerisation treatments had a higher content of suspended matter and a higher oxygen demand than those of other treatments. Total metal content of the water from all treatments was higher than in water from non-treated peat. Survival and growth of nymphs of the mayfly Heptagenia fuscogrisa and the stonefly Nemoura cinerea were compared in waste water from the different treatments. In all tests, the waste water was diluted to 5% (volume) with unchlorinated tapwater and pH was between 7.0-8.0 in all treatments during the experiment. The nymphs were fed with birch leaves that had been incubated in natural stream water for one month. Under these conditions, we did not find any significant effect of waste water on either survival or growth of these two species

Ecotoxicological assessment of dewatered drinking water treatment residue for environmental recycling.

Science.gov (United States)

Yuan, Nannan; Wang, Changhui; Wendling, Laura A; Pei, Yuansheng

2017-09-01

The beneficial recycle of drinking water treatment residue (DWTR) in environmental remediation has been demonstrated in many reports. However, the lack of information concerning the potential toxicity of dewatered DWTR hinders its widespread use. The present study examined the ecotoxicity of dewatered aluminum (Al) and iron (Fe) DWTR leachates to a green alga, Chlorella vulgaris. Data from the variations of cell density and chlorophyll a content suggested that algal growth in DWTR leachates was inhibited. The algal cellular oxidation stress was initially induced but completely eliminated within 72 h by antioxidant enzymes. The expression of three photosynthesis-related algae genes (psaB, psbC, and rbcL) also temporarily decreased (within 72 h). Moreover, the algal cells showed intact cytomembranes after exposure to DWTR leachates. Further investigation confirmed that inhibition of algal growth was due to DWTR-induced phosphorus (P) deficiency in growth medium, rather than potentially toxic contaminants (e.g. copper and Al) contained in DWTR. Interestingly, the leachates could potentially promote algal growth via increasing the supply of new components (e.g. calcium, kalium, magnesium, and ammonia nitrogen) from DWTR. In summary, based on the algae toxicity test, the dewatered Fe/Al DWTR was nontoxic and its environment recycling does not represent an ecotoxicological risk to algae.

Pervaporation applied for dewatering of reaction mixture during esterification

Directory of Open Access Journals (Sweden)

Krasiński Andrzej

2016-03-01

Full Text Available In this work the esterification of diethyl tartrate was studied. The research was focused on the enhancement of reversible reaction yield, which is accomplished by dewatering of the reaction mixture. The removal of water shifts the equilibrium towards the main product. Pervaporation was applied for this purpose, and results were compared to distillation. The advantages and limitations of both processes are discussed. The experimental part consists of dewatering of mixture after the reaction had reached the equilibrium, and was subsequently fed to the test rig equipped with a single zeolite membrane purchased from Pervatech B.V. Results show a significant conversion increase as a result of water removal by pervaporation. Compared to distillation no addition of organics is necessary to efficiently remove water above the azeotrope. Nevertheless, some limitations and issues which call for optimisation are pointed out. A simple numerical model is proposed to support design and sizing of the pervaporation system. Various modes of integrated system operation are also briefly discussed.

Centrifugal dewatering of acid casein curd: effect of casein manufacturing and centrifugation variables on curd compression in a laboratory centrifuge.

Science.gov (United States)

Munro, P A; Van Til, H J

1988-10-20

Data relevant to curd compression in a horizontal, solid bowl decanter centrifuge have been obtained by studying the dewatering of acid casein curd in a batch laboratory centrifuge. Analysis of curd compression under centrifugal force predicts a moisture content gradient in the dewatered curd from a maximum at the curd-liquid interface to a minimum at the centrifuge bowl wall. This moisture content gradient was also measured experimentally, and its practical implications are discussed. Increases in centrifugal force, centrifugation time, and centrifugation temperature all caused a marked de crease in dewatered curd moisture content, whereas in creases in precipitation pH and maximum washing temperature caused a smaller decrease in dewatered curd moisture content.

Dewatering tailings impoundments : interior drains

International Nuclear Information System (INIS)

Charlie, W.A.; Doehring, D.O.; Durnford, D.S.

1984-01-01

For the design of a new uranium tailings impoundment in the western United States, it was proposed that an interior drainage system be considered to economically and reliably minimize potential short- and long-term environmental impacts. The objectives were to decrease the effective hydraulic head on the clay liner, to dewater and stabilize the tailings, and to increase the amount of water recycled to the mill. In addition, desaturation of the impoundment would induce capillary pressure (negative porewater pressure), further reducing the potential movement of dissolved pollutants. This paper presents saturated and unsaturated seepage principles and reviews the concept, criteria and design of the various interior drainage systems considered

Locally produced natural conditioners for dewatering of faecal sludge.

Science.gov (United States)

Gold, Moritz; Dayer, Pauline; Faye, Marie Christine Amie Sene; Clair, Guillaume; Seck, Alsane; Niang, Seydou; Morgenroth, Eberhard; Strande, Linda

2016-11-01

In urban areas of low-income countries, treatment of faecal sludge (FS) is insufficient or non-existent. This results in large amounts of FS being dumped into the environment. Existing treatment technologies for FS, such as settling-thickening tanks and drying beds, are land intensive which is limiting in urban areas. Enhanced settling and dewatering by conditioning was evaluated in order to reduce the treatment footprint (or increase treatment capacity). Conventional wastewater conditioners, such as commercially available lime and polymers, are expensive, and commonly rely on complex supply chains for use in low-income countries. Therefore, the treatment performance of five conditioners which could be produced locally was evaluated: Moringa oleifera seeds and press cake, Jatropha curcas seeds, Jatropha Calotropis leaves and chitosan. M. oleifera seeds and press cake, and chitosan improved settling and dewatering and had a similar performance compared to lime and polymers. Optimal dosages were 400-500 kg M. oleifera/t TS, 300-800 kg lime/t TS and 25-50 kg polymer solution/t TS. In comparison, chitosan required 1.5-3.75 kg/t TS. These dosages are comparable to those recommended for wastewater (sludge). The results indicate that conditioning of FS can reduce total suspended solids (TSS) in the effluent of settling-thickening tanks by 22-81% and reduce dewatering time with drying beds by 59-97%. This means that the area of drying beds could be reduced by 59-97% with end-use as soil conditioner, or 9-26% as solid fuel. Least expensive options and availability will depend on the local context. In Dakar, Senegal, chitosan produced from shrimp waste appears to be most promising.

Effects of different sludge disintegration methods on sludge moisture distribution and dewatering performance.

Science.gov (United States)

Jin, Lingyun; Zhang, Guangming; Zheng, Xiang

2015-02-01

A key step in sludge treatment is sludge dewatering. However, activated sludge is generally very difficult to be dewatered. Sludge dewatering performance is largely affected by the sludge moisture distribution. Sludge disintegration can destroy the sludge structure and cell wall, so as change the sludge floc structure and moisture distribution, thus affecting the dewatering performance of sludge. In this article, the disintegration methods were ultrasound treatment, K2FeO4 oxidation and KMnO4 oxidation. The degree of disintegration (DDCOD), sludge moisture distribution and the final water content of sludge cake after centrifuging were measured. Results showed that three disintegration methods were all effective, and K2FeO4 oxidation was more efficient than KMnO4 oxidation. The content of free water increased obviously with K2FeO4 and KMnO4 oxidations, while it decreased with ultrasound treatment. The changes of free water and interstitial water were in the opposite trend. The content of bounding water decreased with K2FeO4 oxidation, and increased slightly with KMnO4 oxidation, while it increased obviously with ultrasound treatment. The water content of sludge cake after centrifuging decreased with K2FeO4 oxidation, and did not changed with KMnO4 oxidation, but increased obviously with ultrasound treatment. In summary, ultrasound treatment deteriorated the sludge dewaterability, while K2FeO4 and KMnO4 oxidation improved the sludge dewaterability. Copyright © 2014. Published by Elsevier B.V.

[Magnetic Fe₃O₄Microparticles Conditioning-Pressure Electro-osmotic Dewatering (MPEOD) of Sewage Sludge].

Science.gov (United States)

Qian, Xu; Wang, Yi-li; Zhao, Li

2016-05-15

For magnetic Fe₃O₄ microparticles conditioning--pressure electro-osmotic dewatering (MPEOD) process of activated sludge (AS), the effects of operating parameters (optimal dosage of Fe₃O₄, electric field duration, mechanical pressure and voltage) on the dewatering efficiency and energy consumption were investigated, and the optimal conditions were determined. Moreover, the properties of supernatant and sludge along MPEOD process were studied as well as the interaction force between the sludge biosolids. Taking the energy consumption into consideration, the results showed that the optimal dewatering effect for AS could be achieved with a magnetic Fe₃O₄ microparticles dosage of 0.15 g · g⁻¹, an electric field duration of 2 h, a mechanical pressure of 400-600 kPa and a voltage of 30-50 V. When MPEOD was conducted at 400 kPa and 50 V for 2 h, the sludge reduction rate reached 98.30%, the percentage of water removal was 99.34% and the moisture content of AS decreased from 99.18% to 44.46%. The corresponding consumption of energy was 0.013 3 kW · h · kg⁻¹. The coagulation mechanism played a slight role in the AS conditioning with magnetic Fe₃O₄ micro-particles. In fact, magnetic Fe₃O₄micro-particles could greatly decrease the acid-base interaction (WA) between AS biosolids, cause floc growth and enlarge pores in AS aggregates, which will be beneficial to AS dewatering. Compared to DLVO theory, the extended DLVO theory could accurately describe the aggregation and dispersion behavior of sludge particles.

Full-scale performance of selected starch-based biodegradable polymers in sludge dewatering and recommendation for applications.

Science.gov (United States)

Zhou, Kuangxin; Stüber, Johan; Schubert, Rabea-Luisa; Kabbe, Christian; Barjenbruch, Matthias

2018-01-01

Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the use of starch-based polymers for full-scale dewatering of municipal sewage sludge. The laboratory-scale and pilot-scale trials paved the way for full-scale trials at three WWTPs in Germany. The general feasibility of applying starch-based 'green' polymers in full-scale centrifugation was demonstrated. Depending on the sludge type and the process used, the substitution potential was up to 70%. Substitution of 20-30% of the polyacrylamide (PAM)-based polymer was shown to achieve similar total solids (TS) of the dewatered sludge. Optimization of operational parameters as well as machinery set up in WWTPs is recommended in order to improve the shear stability force of sludge flocs and to achieve higher substitution potential. This study suggests that starch-based biodegradable polymers have great potential as alternatives to synthetic polymers in sludge dewatering.

Electroosmotic dewatering of chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge

DEFF Research Database (Denmark)

Hansen, H.K.; Christensen, Iben Vernegren; Ottosen, Lisbeth M.

2003-01-01

. Casagrande's coefficients were determined for the four materials at different water contents. The experiments in this work showed that chalk could be dewatered from 40% to 79% DM (dry matter), fly ash from 75 to 82% DM, iron hydroxide sludge from 2.7 to 19% DM and biomass from 3 to 33% DM by electroosmosis....... The process was not optimised indicating that higher dry matter contents could be achieved by electroosmosis. It was possible to relate Casagrande's coefficient directly to the electroosmotic coefficient obtained by dewatering experiments....

Model test on partial expansion in stratified subsidence during foundation pit dewatering

Science.gov (United States)

Wang, Jianxiu; Deng, Yansheng; Ma, Ruiqiang; Liu, Xiaotian; Guo, Qingfeng; Liu, Shaoli; Shao, Yule; Wu, Linbo; Zhou, Jie; Yang, Tianliang; Wang, Hanmei; Huang, Xinlei

2018-02-01

Partial expansion was observed in stratified subsidence during foundation pit dewatering. However, the phenomenon was suspected to be an error because the compression of layers is known to occur when subsidence occurs. A slice of the subsidence cone induced by drawdown was selected as the prototype. Model tests were performed to investigate the phenomenon. The underlying confined aquifer was generated as a movable rigid plate with a hinge at one end. The overlying layers were simulated with remolded materials collected from a construction site. Model tests performed under the conceptual model indicated that partial expansion occurred in stratified settlements under coordination deformation and consolidation conditions. During foundation pit dewatering, rapid drawdown resulted in rapid subsidence in the dewatered confined aquifer. The rapidly subsiding confined aquifer top was the bottom deformation boundary of the overlying layers. Non-coordination deformation was observed at the top and bottom of the subsiding overlying layers. The subsidence of overlying layers was larger at the bottom than at the top. The layers expanded and became thicker. The phenomenon was verified using numerical simulation method based on finite difference method. Compared with numerical simulation results, the boundary effect of the physical tests was obvious in the observation point close to the movable endpoint. The tensile stress of the overlying soil layers induced by the underlying settlement of dewatered confined aquifer contributed to the expansion phenomenon. The partial expansion of overlying soil layers was defined as inversed rebound. The inversed rebound was induced by inversed coordination deformation. Compression was induced by the consolidation in the overlying soil layers because of drainage. Partial expansion occurred when the expansion exceeded the compression. Considering the inversed rebound, traditional layer-wise summation method for calculating subsidence should be

Cleaning and dewatering fine coal

Science.gov (United States)

Yoon, Roe-Hoan; Eraydin, Mert K.; Freeland, Chad

2017-10-17

Fine coal is cleaned of its mineral matter impurities and dewatered by mixing the aqueous slurry containing both with a hydrophobic liquid, subjecting the mixture to a phase separation. The resulting hydrophobic liquid phase contains coal particles free of surface moisture and droplets of water stabilized by coal particles, while the aqueous phase contains the mineral matter. By separating the entrained water droplets from the coal particles mechanically, a clean coal product of substantially reduced mineral matter and moisture contents is obtained. The spent hydrophobic liquid is separated from the clean coal product and recycled. The process can also be used to separate one type of hydrophilic particles from another by selectively hydrophobizing one.

Acceleration of organic removal and electricity generation from dewatered oily sludge in a bioelectrochemical system by rhamnolipid addition.

Science.gov (United States)

Zhang, Yunshu; Zhao, Qingliang; Jiang, Junqiu; Wang, Kun; Wei, Liangliang; Ding, Jing; Yu, Hang

2017-11-01

Conversion of biomass energy of dewatered oily sludge to electricity is the rate-limiting process in bioelectrochemical system (BES). In this study, 2mgg -1 rhamnolipids were added to dewatered oily sludge, resulting in a significant enhancement in maximum power density from 3.84±0.37 to 8.63±0.81Wm -3 , together with an increase in total organic carbon (TOC) and total petroleum hydrocarbon (TPH) removal from 24.52±4.30 to 36.15±2.79mgg -1 and 29.51±3.30 to 39.80±2.47mgg -1 , respectively. Rhamnolipids can also enhance the solubilization and promote the hydrolysis of dewatered oily sludge with increases in SOCD from 14.93±2.44 to 18.40±0.08mgg -1 and VFAs from 1.02±0.07 to 1.39±0.12mgg -1 . Furthermore, bacteria related to substrate degradation were predominant in dewatered oily sludge, and bacteria related to the sulfate/sulfide cycle were significantly enriched by rhamnolipid addition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficient Calculation of Dewatered and Entrapped Areas Using Hydrodynamic Modeling and GIS

International Nuclear Information System (INIS)

Richmond, Marshall C.; Perkins, William A.

2009-01-01

River waters downstream of a hydroelectric project are often subject to rapidly changing discharge. Abrupt decreases in discharge can quickly dewater and expose some areas and isolate other areas from the main river channel, potentially stranding or entrapping fish, which often results in mortality. A methodology is described to estimate the areas dewatered or entrapped by a specific reduction in upstream discharge. A one-dimensional hydrodynamic model was used to simulate steady flows. Using flow simulation results from the model and a geographic information system (GIS), estimates of dewatered and entrapped areas were made for a wide discharge range. The methodology was applied to the Hanford Reach of the Columbia River in central Washington State. Results showed that a 280 m 3 /s discharge reduction affected the most area at discharges less than 3400 m 3 /s. At flows above 3400 m 3 /s, the affected area by a 280 m 3 /s discharge reduction (about 25 ha) was relatively constant. A 280 m 3 /s discharge reduction at lower flows affected about twice as much area. The methodology and resulting area estimates were, at the time of writing, being used to identify discharge regimes, and associated water surface elevations, that might be expected to minimize adverse impacts on juvenile fall chinook salmon (Oncorhynchus tshawytscha) that rear in the shallow near-shore areas in the Hanford Reach

Monitoring and troubleshooting of non-filamentous settling and dewatering problems in an industrial activated sludge treatment plant

DEFF Research Database (Denmark)

Kjellerup, B. V.; Keiding, Kristian; Nielsen, Per Halkjær

2001-01-01

dewaterability. The monitoring program revealed that a deterioration of the floc strength and the settling properties in the process tanks was closely connected to downstream dewatering problems and poor effluent quality. Particularly severe problems were observed a few weeks after the production at the factory......A large industrial activated sludge wastewater treatment plant had temporary problems with settling and dewatering of the sludge. Microscopical investigations revealed that the poor settling properties were not due to presence of filamentous bacteria, but poor floc properties. In order...... to characterise the changes in floc properties that led to settling and dewatering problems and to find reasons for this taking place, a comprehensive monitoring program was conducted during more than one year. The monitoring program included various measurements of floc settleability, floc strength and sludge...

Electroosmotic dewatering of chalk sludge, iron hydroxide sludge, wet fly ash and biomass

Energy Technology Data Exchange (ETDEWEB)

Hansen, H.K.; Kristensen, I.V.; Ottosen, L.M.; Villumsen, A. [Dept. of Geology and Geotechnical Engineering, The Technical Univ. of Denmark, Lyngby (Denmark)

2001-07-01

Electroosmotic dewatering has been tested in laboratory cells for 4 different porous materials: chalk sludge, iron hydroxide sludge, wet fly ash and biomass sludge from enzyme production. In all cases it was possible to remove water when passing electric DC current through the material. Casagrande's coefficients for the three materials where determined at different water contents. In the electroosmotic experiments shown in this work chalk can be dewatered from 40% to 79% DM (dry matter), fly ash from 75 to 82% DM, iron hydroxide sludge from 2.7 to 19% DM and biomass from 3 to 33% DM. The process was not optimised indicating that higher dry matter contents could be achieved. (orig.)

Monitoring and optimizing the co-composting of dewatered sludge: a mixture experimental design approach.

Science.gov (United States)

Komilis, Dimitrios; Evangelou, Alexandros; Voudrias, Evangelos

2011-09-01

The management of dewatered wastewater sludge is a major issue worldwide. Sludge disposal to landfills is not sustainable and thus alternative treatment techniques are being sought. The objective of this work was to determine optimal mixing ratios of dewatered sludge with other organic amendments in order to maximize the degradability of the mixtures during composting. This objective was achieved using mixture experimental design principles. An additional objective was to study the impact of the initial C/N ratio and moisture contents on the co-composting process of dewatered sludge. The composting process was monitored through measurements of O(2) uptake rates, CO(2) evolution, temperature profile and solids reduction. Eight (8) runs were performed in 100 L insulated air-tight bioreactors under a dynamic air flow regime. The initial mixtures were prepared using dewatered wastewater sludge, mixed paper wastes, food wastes, tree branches and sawdust at various initial C/N ratios and moisture contents. According to empirical modeling, mixtures of sludge and food waste mixtures at 1:1 ratio (ww, wet weight) maximize degradability. Structural amendments should be maintained below 30% to reach thermophilic temperatures. The initial C/N ratio and initial moisture content of the mixture were not found to influence the decomposition process. The bio C/bio N ratio started from around 10, for all runs, decreased during the middle of the process and increased to up to 20 at the end of the process. The solid carbon reduction of the mixtures without the branches ranged from 28% to 62%, whilst solid N reductions ranged from 30% to 63%. Respiratory quotients had a decreasing trend throughout the composting process. Copyright © 2011 Elsevier Ltd. All rights reserved.

Sludge dewatering on filters aiming the utilization as fuel; Desaguamento de lodos em filtro visando aproveitamento como combustivel

Energy Technology Data Exchange (ETDEWEB)

Paschoalim, Luis Gustavo; Neves, Jose Mangolini

1993-12-31

This work presents modern methodologies for sludge dewatering and alternatives for environmental disposal of the so obtained cakes. Among the possible alternatives, special emphasis is given to the characterization and study of the variables which determine the behaviour of dewatering operation of sludges form pulp and paper industries. Results are presents for bench scale tests and pilot plant tests 28 refs., 9 figs., 7 tabs.

Sludge dewatering on filters aiming the utilization as fuel; Desaguamento de lodos em filtro visando aproveitamento como combustivel

Energy Technology Data Exchange (ETDEWEB)

Paschoalim, Luis Gustavo; Neves, Jose Mangolini

1992-12-31

This work presents modern methodologies for sludge dewatering and alternatives for environmental disposal of the so obtained cakes. Among the possible alternatives, special emphasis is given to the characterization and study of the variables which determine the behaviour of dewatering operation of sludges form pulp and paper industries. Results are presents for bench scale tests and pilot plant tests 28 refs., 9 figs., 7 tabs.

Feasibility study of green wastes composting with digested and dewatering sludge from municipal wastewater treatment plant in Iran

Directory of Open Access Journals (Sweden)

Neamat Jaafarzadeh Haghighi Fard

2015-09-01

Full Text Available Background: Composting as a waste management technology is becoming more widespread. The purpose of this study was to assess the feasibility and to find the most effective composting process for the ratio of green waste, digested and dewatered sludge from Chonibieh wastewater treatment plant in the west region of Ahvaz. Methods: The composting time was 23 days and the evaluated parameters in this period of the study were organic carbon, total nitrogen, phosphorus, carbon to nitrogen ratio (C/N, moisture content and pH. The C/N ratio was maintained at 30 with weight:weight ratio of 1:1, 1:2, 1:3 (digested and dewatered sludge to green waste. Results: It was observed that vessel R3 produced higher quality of compost with final total nitrogen (1.28%, final total phosphorus (0.71%, final total organic carbon (TOC (25.78% and C/N (20.65% within the 23 days of composting. While vessel R1 produced higher final total nitrogen and total phosphorus with lower amount of total coliform indicating suitable quality of composting. Therefore, the results showed that the characteristics of dewatered sludge mixed with green waste proportion of green waste significantly influenced the compost quality and process dynamics. The results also showed that the quality of final products in all the conditions was in agreement with Global Organic Textile Standard (GOTS and World Health Organization (WHO guidelines. However, the moisture content ratios were lower than the mentioned guidelines. With regards to microbial quality, all three ratios were in agreement with US Environmental Protection Agency (EPA and Iranian guidelines. Conclusion: It is suggested that the final product of composting can be safely used in farmland and green space.

Dewatering and low-temperature pyrolysis of oily sludge in the presence of various agricultural biomasses.

Science.gov (United States)

Zhao, Song; Zhou, Xiehong; Wang, Chuanyi; Jia, Hanzhong

2017-08-24

Pyrolysis is potentially an effective treatment of waste oil residues for recovery of petroleum hydrocarbons, and the addition of biomass is expected to improve its dewatering and pyrolysis behavior. In this study, the dewatering and low-temperature co-pyrolysis of oil-containing sludge in the presence of various agricultural biomasses, such as rice husk, walnut shell, sawdust, and apricot shell, were explored. As a result, the water content gradually decreases with the increase of biomass addition within 0-1.0 wt % in original oily sludge. Comparatively, the dewatering efficiency of sludge in the presence of four types of biomasses follows the order of apricot shell > walnut shell > rice husk > sawdust. On the other hand, rice husk and sawdust are relatively more efficient in the recovery of petroleum hydrocarbons compared with walnut shell and apricot shell. The recovery efficiency generally increased with the increase in the biomass content in the range of 0-0.2 wt %, then exhibited a gradually decreasing trend with the increase in the biomass content from 0.2 to 1.0 wt %. The results suggest that optimum amount of biomass plays an important role in the recovery efficiency. In addition, the addition of biomass (such as rice husk) also promotes the formation of C x H y and CO, increasing the calorific value of pyrolysis residue, and controlled the pollution components of the exhaust gas discharged from residue incineration. The present work implies that biomass as addictive holds great potential in the industrial dewatering and pyrolysis of oil-containing sludge.

Process Design and Economics for the Production of Algal Biomass: Algal Biomass Production in Open Pond Systems and Processing Through Dewatering for Downstream Conversion

Energy Technology Data Exchange (ETDEWEB)

Davis, Ryan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Markham, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kinchin, Christopher [National Renewable Energy Lab. (NREL), Golden, CO (United States); Grundl, Nicholas [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tan, Eric C.D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Humbird, David [DWH Process Consulting, Denver, CO (United States)

2016-02-17

This report describes in detail a set of aspirational design and process targets to better understand the realistic economic potential for the production of algal biomass for subsequent conversion to biofuels and/or coproducts, based on the use of open pond cultivation systems and a series of dewatering operations to concentrate the biomass up to 20 wt% solids (ash-free dry weight basis).

Optimal dewatering schemes in the foundation design of an electronuclear plant

International Nuclear Information System (INIS)

Galeati, G.; Gambolati, G.

1988-01-01

A three-dimensional finite element model combined with an optimization approach based on linear mixed integer programming is developed and applied to assist in the design of the dewatering system for the electronuclear plant to be built by the Italian Electric Agency (ENEL) in Trino Vercellese, northwestern Italy. The foundations site is encompassed by a 25- to 35-m deep plastic wall with the purpose of protecting the unconfined aquifer from the significant water table lowering required by the construction project. To reduce further the propagation of the depression cone a large amount of the water pumped out is reinjected through ad hoc recharge ditches. The finite element optimization model includes both the natural and the artificial constraints and provides several optimal withdrawal strategies for the dewatering system design concerning the distribution of the abstraction wells and the corresponding pumping rates. Physical and economical objective functions are explored and the related solutions are discussed

Vibrating membrane filtration as improved technology for microalgae dewatering

OpenAIRE

Nurra, C.; Clavero, E.; Salvadó, J.; Torras, C.

2014-01-01

10.1016/j.biortech.2014.01.115 The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean ...

Artistic Understanding and Motivational Characteristics

Science.gov (United States)

Lekue, Pablo

2015-01-01

This study aims to analyse artistic understanding in primary and secondary education and the relationship between this understanding and motivational characteristics such as goal orientation, engagement in art activities and attitude to art education at school, which determine (according to prior research) learners' academic achievement, in…

46 CFR 28.815 - Bilge pumps, bilge piping, and dewatering systems.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Bilge pumps, bilge piping, and dewatering systems. 28... REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.815 Bilge pumps, bilge... fixed, self priming, powered, bilge pump, having a minimum capacity rating of 50 gallons per minute...

Demonstration of FBRM as process analytical technology tool for dewatering processes via CST correlation.

Science.gov (United States)

Cobbledick, Jeffrey; Nguyen, Alexander; Latulippe, David R

2014-07-01

The current challenges associated with the design and operation of net-energy positive wastewater treatment plants demand sophisticated approaches for the monitoring of polymer-induced flocculation. In anaerobic digestion (AD) processes, the dewaterability of the sludge is typically assessed from off-line lab-bench tests - the capillary suction time (CST) test is one of the most common. Focused beam reflectance measurement (FBRM) is a promising technique for real-time monitoring of critical performance attributes in large scale processes and is ideally suited for dewatering applications. The flocculation performance of twenty-four cationic polymers, that spanned a range of polymer size and charge properties, was measured using both the FBRM and CST tests. Analysis of the data revealed a decreasing monotonic trend; the samples that had the highest percent removal of particles less than 50 microns in size as determined by FBRM had the lowest CST values. A subset of the best performing polymers was used to evaluate the effects of dosage amount and digestate sources on dewatering performance. The results from this work show that FBRM is a powerful tool that can be used for optimization and on-line monitoring of dewatering processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dewatering behavior of fine oil sands tailings : A summary of laboratory results

NARCIS (Netherlands)

Yao, Y.; van Tol, A.F.; van Paassen, L.A.; Vardon, P.J.; Sego, D.C.; Wilson, G.W.; Beier, N.A.

2016-01-01

To evaluate the disposal technology for fine oil sands tailings, the appropriate engineering properties of the tailings should be ascertained. A laboratory study was conducted by Delft University of Technology (the Netherlands) on the geotechnical properties and dewatering behavior of the fine oil

Isolation and Characterization of Polyacrylamide-Degrading Bacteria from Dewatered Sludge

Directory of Open Access Journals (Sweden)

Feng Yu

2015-04-01

Full Text Available Polyacrylamide (PAM is a water-soluble polymer that is widely used as a flocculant in sewage treatment. The accumulation of PAM affects the formation of dewatered sludge and potentially produces hazardous monomers. In the present study, the bacterial strain HI47 was isolated from dewatered sludge. This strain could metabolize PAM as its sole nutrient source and was subsequently identified as Pseudomonas putida. The efficiency of PAM degradation was 31.1% in 7 days and exceeded 45% under optimum culture condition (pH 7.2, 39 °C and 100 rpm. The addition of yeast extract and glucose improved the bacterial growth and PAM degradation. The degraded PAM samples were analyzed by gel-filtration chromatography, Fourier transform infrared and high-performance liquid chromatography. The results showed that high-molecular-weight PAM was partly cleaved to small molecular oligomer derivatives and part of the amide groups of PAM had been converted to carboxyl groups. The biodegradation did not accumulate acrylamide monomers. Based on the SDS-PAGE and N-terminal sequencing results, the PAM amide groups were converted into carboxyl groups by a PAM-induced extracellular enzyme from the aliphatic amidase family.

A novel acrylamide-free flocculant and its application for sludge dewatering.

Science.gov (United States)

Lu, Lianghua; Pan, Zhida; Hao, Nan; Peng, Wenqing

2014-06-15

In the present research, copolymers of methyl acrylate (MA) with anionic or cationic monomers were synthesized via emulsion polymerization, and used as sludge dewatering aids in wastewater treatment. The copolymerization of different stoichiometry of two monomers afforded a variety of water soluble copolymers with charge densities ranging from 40% to 80%, which align with the charge density of current flocculant products. These copolymers resemble current commercial products, but provide a greener solution by eliminating acrylamide monomer, which is a suspected carcinogen. High molecular weight copolymers were achieved by applying powder-like synthesis process with intrinsic viscosity of final products as high as 12.98 dl/g for anionic flocculant and 10.74 dl/g for cationic flocculant. The copolymers of methyl acrylate and [2-(Acryloyloxy)ethyl]trimethylammonium chloride (AETAC) with 55% charge density exhibited comparable performance in clay settling test, real water jar test, and sludge dewatering, when compared to AM-based commercial product in the real wastewater treatment application. Copyright © 2014 Elsevier Ltd. All rights reserved.

Dewatering properties of differently treated sewage sludge

International Nuclear Information System (INIS)

Zehnder, H.J.

1977-01-01

A study on dewatering properties of radiosterilized sewage sludge of different type and origin was carried out. For comparison, also heat-treated (pasteurized) sludge was investigated. The specific filtration resistance of irradiated sewage sludge was lowered in all types of sludge examined. In general, pasteurization increased this parameter. The settling properties of irradiated digested sewage sludge was slightly improved, mainly in the first hours after treatment. Microbial effects may mask the real sedimentation relations especcially in aerobically stabilized sludges. A pasteurization treatment of sewage sludge caused an increased content of soluble substances and suspended particles in the supernatant water. The supernatant water from irradiated sludge showed a smaller increase

An environmental isotope study of a major dewatering operation at Sishen mine, northern Cape Province

International Nuclear Information System (INIS)

Verhagen, B.T.; Smith, P.E.; Dziembowski, Z.; Oosthuizen, J.H.

1978-01-01

Geohydrological studies using environmental isotopes of the Sishen iron ore mine were started after major rainfalls in 1973/74 produced flooding of the open cast workings. The mine is underlain by dolomite which has been extensively karstified and geohydrologically compartmentalized by several dykes. Major dewatering takes place in a pit called Hill 2 by pumping an array of large diameter boreholes at a combined rate of 2000 m 3 h -1 . The probable recharge areas (dolomites, superficial Kalahari Beds) were isotopically surveyed to assess their relative importance to the dewatering problem. Several major pumping outlets at the mine were regularly sampled for isotopic and chemical analysis and from the data a preliminary mixing model is proposed. The data also show that with the total pumped volume up to March 1978, no very recent (i.e. post bomb) water has reached the dewatering points. On this basis a minimum storage of 0.75 x 10 8 m 3 is derived compared to a classical calculation of 10 8 m 3 for the compartment. Isotopic composition and response differ for waters on either side of a dyke crossing the mining area, corroborating classical evidence suggesting that the dyke acts as an aquiclude. (orig.) [de

An environmental isotope study of a major dewatering operation at Sishen mine, northern Cape Province

International Nuclear Information System (INIS)

Verhagen, B.Th.; Smith, P.E.; Oosthuizen, J.H.

1979-01-01

Geohydrological studies using environmental isotopes of the Sishen iron ore mine were started after major rainfalls in 1973/74 produced flooding of the open cast workings. The mine is underlain by dolomite which has been extensively karstified and geohydrologically compartmentalized by several dykes. Major dewatering takes place in a pit called Hill 2 by pumping an array of large-diameter boreholes at a combined rate of 2000m 3 h -1 . The probable recharge areas (dolomites, superficial Kalahari Beds) were isotopically surveyed to assess their relative importance to the dewatering problem. Several major pumping outlets at the mine were regularly sampled for isotopic and chemical analysis and from the data a preliminary mixing model is proposed. The data also show that, with the total pumped volume up to March 1978, no very recent (i.e. post-bomb) water has reached the dewatering points. On this basis a minimum storage of 0.75x10 8 m 3 is derived compared with a classical calculation of 10 8 m 3 for the compartment. Isotopic composition and response differ for waters on either side of a dyke crossing the mining area, corroborating classical evidence suggesting that the dyke acts as an aquiclude. (author)

Design of the Nonlinear Pin Rubber Forming Equipment Integrating the Functions of Extruding, Dewatering, Drying & Expanding

Directory of Open Access Journals (Sweden)

Yuefeng Yuan

2014-12-01

Full Text Available The top priority of car-tire suppliers is to improve wetland grip force of the using tires, reduce the rolling resistance and the rolling noise of tires. It is urgent for the tire industry to research and develop high-performance tires to solve the above problems. They must use the high- performance synthetic rubber and auxiliary rubber to develop the most advanced manufacturing technologies and equipment. Silica, a kind of important tire auxiliary rubber, can significantly reduce the rolling resistance of tires, improve the grip force and properties resistant to ice, wetness or slippery of tires. In this paper, based on the conventional tire rubber forming technologies of extrusion, dewatering, drying and expanding, a study is made on the conical screw, the dewatering barrel, the drying barrel, the pin layout scheme, the expanding die head, cutter and the control system. The nonlinear pin rubber forming equipment integrating the functions of extrusion, dewatering, drying and expanding is designed and applied to tire auxiliary rubber forming. The experiment shows that the forming device can realize the one-step forming, with high forming efficiency, low cost and less labor.

Device for dewatering of raw biomass. Anordning foer avvattning och uppluckring av raa biomassa

Energy Technology Data Exchange (ETDEWEB)

Kubat, J; Aabom, J J.V.; Klason, T C.F.; Bultzingsloewen, F von

1993-09-27

This invention concerns a device for loosening of raw biomass through roll dewatering. It is primarily applicable for comminuted and milled raw wood. The invention is of special interest for the production of pulverized wood fuel

Effect of TiO2 nanoparticles on UASB biomass activity and dewatered sludge.

Science.gov (United States)

Yadav, Tushar; Mungray, Alka A; Mungray, Arvind K

2017-02-01

The accumulation of the nanowastes in the wastewater treatment plants has raised several concerns; therefore, it is an utmost priority to study the nanoparticle (NP) toxicity in such systems. In this work, the effect of TiO 2 NPs on up-flow anaerobic sludge blanket (UASB) microflora and their photocatalytic effect on dewatered sludge were studied. We observed 99.98% removal of TiO 2 NPs by sludge biomass within 24 h, though negligible toxicity was found up to 100 mg/L TiO 2 concentration on extracellular polymeric substances (EPS), volatile fatty acid and biogas generation. The low toxicity corresponds to the agglomeration of TiO 2 NPs in UASB sludge. Alterations in dewatered sludge biochemical composition and increase in cell damage were observed upon exposure to sunlight as evidenced by FTIR and fluorescent microscopy, respectively. Results suggest the negligible toxicity of TiO 2 NPs on UASB biomass activity; however, once exposed to open environment and sunlight, they may exert detrimental effects.

Environmental control of drilling mud discharge through dewatering in cold weather climates: effect of ambient temperature

Energy Technology Data Exchange (ETDEWEB)

Wojtanowicz, A. K. [Louisiana State Univ., Baton Rouge, LA (United States); Ye, Y. [Jianghan Petroleum Institute, Beijing, (China)

1998-05-01

Results of an experimental study of the effects of drilling mud temperature upon dewatering performance at various temperatures were presented. Three temperature ranges (from flowline temperature to room temperature, from room temperature to freezing point, and freeze/thaw, i.e. from -20 degrees C to 12 degrees C) were considered. Both unweighted and weighted fresh water muds and weighted salt water mud were tested using a sealed laboratory batch reactor, to prevent rapid vaporization of separated water at temperatures above 60 degrees C. Deep freezing was achieved by using ice or ice-salt baths. Net water removal was measured with a bench-top plate press under constant expression pressure of 270 kPa. Results showed that the freeze/thaw treatment process proved to be very effective, enhancing water removal by 34 to 39 per cent, and reducing waste mud volume by 64 to 72 per cent. No advantage to dewatering hot drilling mud from active systems was observed at temperatures above 21 degrees C. It was suggested that at temperatures under 21 degrees C, the waste drilling mud diverted from an active system should be dewatered when its temperature is still over 40 degrees C. to reduce the amount of chemicals needed for separation enhancement. 14 refs., 4 tabs., 4 figs.

Chitosan use in chemical conditioning for dewatering municipal-activated sludge.

Science.gov (United States)

Zemmouri, H; Mameri, N; Lounici, H

2015-01-01

This work aims to evaluate the potential use of chitosan as an eco-friendly flocculant in chemical conditioning of municipal-activated sludge. Chitosan effectiveness was compared with synthetic cationic polyelectrolyte Sedipur CF802 (Sed CF802) and ferric chloride (FeCl₃). In this context, raw sludge samples from Beni-Messous wastewater treatment plant (WWTP) were tested. The classic jar test method was used to condition sludge samples. Capillary suction time (CST), specific resistance to filtration (SRF), cakes dry solid content and filtrate turbidity were analyzed to determine filterability, dewatering capacity of conditioned sludge and the optimum dose of each conditioner. Data exhibit that chitosan, FeCl₃and Sed CF802 improve sludge dewatering. Optimum dosages of chitosan, Sed CF802 and FeCl₃allowing CST values of 6, 5 and 9 s, were found, respectively, between 2-3, 1.5-3 and 6 kg/t ds. Both polymers have shown faster water removal with more permeable sludge. SRF values were 0.634 × 10¹², 0.932 × 10¹² and 2 × 10¹² m/kg for Sed CF802, chitosan and FeCl₃respectively. A reduction of 94.68 and 87.85% of the filtrate turbidity was obtained with optimal dosage of chitosan and Sed CF802, respectively. In contrast, 54.18% of turbidity abatement has been obtained using optimal dosage of FeCl₃.

Procedure of dewatering by pressing of biomass pulp, especially a peat cake. Saett att genom pressning avvattna en kaka av biomassa, foeretraedesvis en torvkaka

Energy Technology Data Exchange (ETDEWEB)

Eriksson, S

1988-05-24

The pulp is dewatered by pressing above 90 degrees C, the pulp water being displaced by warmer water under successively increased pressure. A device designed like a closed washing press is used. The pulp is subjected to dewatering, washing or displacement by warmer water and thus heating, and calendering. (O.S.).

Development of the electroacoustic dewatering (EAD) process for fine/ultrafine coal: Second quarterly progress report period ending 31 March 1989

Energy Technology Data Exchange (ETDEWEB)

None

1989-04-18

Battelle, in cooperation with the Electric Power Research Institute (EPRI), Ashbrook-Simon-Hartley (ASH), Kaiser Engineers (KE), Lewis Corporation, and Prof. S.H. Chiang of the University of Pittsburgh, is developing an advanced process for the dewatering of fine and ultrafine coals. The advanced process, called Electroacoustic Dewatering (EAD), capitalizes on the adaptation of synergistic effects of electric and acoustic fields to a commercial belt filter press design that is used in many other applications. The EAD equipment is described. 2 figs.

Ground movement and deformation due to dewatering and open pit excavation

International Nuclear Information System (INIS)

Liu, B.; Yang, J.; Zhang, J.

1996-01-01

In the application of stochastic medium theory, it is assumed that ground movement process has the property of Markov Process. Based on superposition principle and rock consolidation principle, the ground movement and deformation due to dewatering and open pit excavation can be calculated. The comparison between the field measurements in Morwell Open Pit, Latrobe Valley (Victoria, Australia) and the calculated results shows the validity of the method in this paper. 5 refs

Effect of dewatering on seismic performance of multi-anchor wall due to high ground water level

Science.gov (United States)

Kobayashi, Makoto; Miura, Kinya; Konami, Takeharu; Hayashi, Taketo; Sato, Hiroki

2017-10-01

Previous research reported that the ground water in the backfill of reinforced soil wall made it deteriorate. According to the damage investigation of Great East Earthquake 2011, the reinforced soil structure due to high ground water level by seismic wave were deformed remarkably. Some of them classified ultimate limit state or restorability limit state. However, more than 90% of reinforced soil structure, which suffered from this earthquake, were classified into no damage condition. Therefore, it is necessary that the seismic behaviors of multi-anchor wall due to seepage flow should be clarified in order to adopt the performance-based design in such reinforced soil structure. In this study, a series of centrifugal shaking table tests were conducted to investigate the seismic behavior of multi-anchor wall due to high ground water level. The reinforced drainage pipes were installed into the backfill in order to verify the dewatering effect and additional reinforcement. Furthermore, to check only the dewatering effect, the model tests was carried out with several ground water table that was modeled the case reinforced drainage pipes installed. The test results show unique behavior of reinforced region that moved integrally. This implies that the reinforced region has been behaved as if it became one mass, and this behavior make this structure increase seismic performance. Thus, the effectiveness of dewatering was observed remarkably because of decreasing the inertial force during earthquake.

Improvements in or relating to dewatering of materials

International Nuclear Information System (INIS)

Lane, E.S.; Lyon, C.E.; Simpson, M.P.; Wace, P.F.

1980-01-01

A process is described for the dewatering of a gel precipitated gel body having an open porous network comprising contacting the gel body containing water with an organic liquid capable of extracting water from the gel body thereby to extract water from the gel body, the organic liquid and conditions under which the contacting is effected being chosen such that organic liquid permeates the gel body so as to maintain an open porous network as water is extracted and such that an open porous network remains after removal of organic liquid. Examples are given of the use of the process in the preparation of spherical particles of (U,Th)O 2 and (U,Pu)O 2 . (author)

Understanding Team Communication Characteristics using Social Network Analysis

International Nuclear Information System (INIS)

Kim, Ar Ryum; Lee, Seung Woo; Seong, Poong Hyun; Park, Jin Kyun

2011-01-01

An important aspect of human behavior in nuclear power plants (NPPs) is team interaction since operating NPPs involves the coordination of several team members among and within workplaces. Since operators in main control room (MCR) get a great deal of information through communication to perform a task, communication is one of the important characteristics for team characteristics. Many researchers have been studying how to understand the characteristics of communication. Social network analysis (SNA) which is considered as an objective and easily applicable method has been already applied in many fields to investigate characteristics of team communication. Henttonen (2010) has struggled to perform the research on the impact of social networks in a team and he found some team communication characteristics could be obtained using some properties of SNA. In this paper, SNA is used to understand communication characteristics within operators in NPPs

Textural evidence for jamming and dewatering of a sub-surface, fluid-saturated granular flow

Science.gov (United States)

Sherry, T. J.; Rowe, C. D.; Kirkpatrick, J. D.; Brodsky, E. E.

2011-12-01

Sand injectites are spectacular examples of large-scale granular flows involving migration of hundreds of cubic meters of sand slurry over hundreds of meters to kilometers in the sub-surface. By studying the macro- and microstructural textures of a kilometer-scale sand injectite, we interpret the fluid flow regimes during emplacement and define the timing of formation of specific textures in the injected material. Fluidized sand sourced from the Santa Margarita Fm., was injected upward into the Santa Cruz Mudstone, Santa Cruz County, California. The sand injectite exposed at Yellow Bank Beach records emplacement of both hydrocarbon and aqueous sand slurries. Elongate, angular mudstone clasts were ripped from the wall rock during sand migration, providing evidence for high velocity, turbid flow. However, clast long axis orientations are consistently sub-horizontal suggesting the slurry transitioned to a laminar flow as the flow velocity decreased in the sill-like intrusion. Millimeter to centimeter scale laminations are ubiquitous throughout the sand body and are locally parallel to the mudstone clast long axes. The laminations are distinct in exposure because alternating layers are preferentially cemented with limonite sourced from later groundwater infiltration. Quantitative microstructural analyses show that the laminations are defined by subtle oscillations in grain alignment between limonite and non-limonite stained layers. Grain packing, size and shape distributions do not vary. The presence of limonite in alternating layers results from differential infiltration of groundwater, indicating permeability changes between the layers despite minimal grain scale differences. Convolute dewatering structures deform the laminations. Dolomite-cemented sand, a signature of hydrocarbon saturation, forms irregular bodies that cross-cut the laminations and dewatering structures. Laminations are not formed in the dolomite-cemented sand. The relative viscosity difference

Decide, design, and dewater de waste: A blueprint from Fitzpatrick

International Nuclear Information System (INIS)

Robert, D.E.

1994-01-01

Using a different process to clean concentrated waste tanks at the James A. FitzPatrick nuclear power plant in New York saved nearly half million dollars. The plan essentially allowed processing concentrator bottoms as waste sludge (solidification versus dewatering) that could still meet burial ground requirements. The process reduced the volume from 802.2 to 55 cubic feet. This resin throwaway system eliminated chemicals in the radwaste systems and was designed to ease pressure on the pradwaste processing system, reduce waste and improve plant chemistry. This article discusses general aspects of the process

Dewatering of sludge using the hydrosoft high-pressure process; Entwaessern von Schlaemmen mit dem Hydrosoft-Hochdruckverfahren

Energy Technology Data Exchange (ETDEWEB)

Eder, C.; Eder, G. [Christian Eder Technology GbR, Neunkirchen (Germany)

1999-07-01

The hydrosoft process permits to dewater sludge, especially also sludge from municipal sewage treatment plant, until it contains a high proportion of dry substance. For existing dewatering systems equipped with the long-lived chamber filter presses, too, the dry matter content of the filter cake can be substantially increased using the hydrosoft process; only the pump system must be retrofitted. As a preliminary measure, tests with mobile pilot plants should be carried out. (orig.) [German] Mit dem Hydrosoft-Verfahren besteht die Moeglichkeit Schlaemme, insbesondere auch Schlaemme aus kommunalen Klaeranlagen, auf hohe Trockensubstanz-Gehalte zu entwaessern. Auch bei bestehenden Entwaesserungsanlagen, die mit den langlebigen Kammerfilterpressen ausgeruestet sind, koennen die Trockensubstanzgehalte der Filterkuchen mit dem Hydrosoft-Verfahren, fuer das dann nur noch das Pumpsystem nachgeruestet werden muss, wesentlich angehoben werden. Vorausgehen sollten jeweils Vorversuche mit mobilen Versuchsanlagen. (orig.)

A high-fidelity model for coupling flow and mechanical deformation of the porous paper web - a key to improved understanding of dewatering and rewet at the press section in paper making

Energy Technology Data Exchange (ETDEWEB)

Hao, Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Trebotich, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wang, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Xu, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Turpin, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-04-05

The U.S. pulp and paper industry is the third-largest manufacturing user of energy, with an energy demand of 2,540 trillion Btu in 2010. Within the papermaking process, drying consumes over 400 trillion Btu annually which makes it one of the largest energy saving opportunities. In the 2014 Forest Products Industry Technology Roadmap, it is concluded that increasing the paper web solid content entering the dryer section from the current 45- 55 percent to approaching 65 percent, which would save 1.0 MMBtu per ton or 20 percent of the energy used in drying, is one of the most needed technology breakthroughs to achieve a more sustainable approach for manufacturing pulp and paper products. Achieving such significant energy savings highly depends on understanding the fundamental dynamics of the wet press process and then developing optimized solutions for design of more energy-efficient press processes and equipment. The objective of this project is to develop reliable computational capabilities to accurately simulate the flow of water from/to the porous pulp medium (dewatering/rewetting) during the pressing process in paper making.

Possibility of sludge conditioning and dewatering with rice husk biochar modified by ferric chloride.

Science.gov (United States)

Wu, Yan; Zhang, Panyue; Zhang, Haibo; Zeng, Guangming; Liu, Jianbo; Ye, Jie; Fang, Wei; Gou, Xiying

2016-04-01

Rice husk biochar modified by FeCl3 (MRB-Fe) was used to enhance sludge dewaterability in this study. MRB-Fe preparation conditions and dosage were optimized. Mechanisms of MRB-Fe improving sludge dewaterability were investigated. The optimal modification conditions were: FeCl3 concentration, 3mol/L; ultrasound time, 1h. The optimal MRB-Fe dosage was 60% DS. Compared with raw sludge, the sludge specific resistance to filtration (SRF) decreased by 97.9%, the moisture content of sludge cake decreased from 96.7% to 77.9% for 6min dewatering through vacuum filtration under 0.03MPa, the SV30% decreased from 96% to 60%, and the net sludge solids yield (YN) increased by 28 times. Positive charge from iron species on MRB-Fe surface counteracted negative charge of sludge flocs to promote sludge settleability and dewaterability. Meanwhile, MRB-Fe kept a certain skeleton structure in sludge cake, making the moisture pass through easily. Using MRB-Fe, therefore, for sludge conditioning and dewatering is promising. Copyright © 2016. Published by Elsevier Ltd.

Combined treatment of solar energy and gamma irradiation to eliminate pathogenic bacteria in dewatered sludge

International Nuclear Information System (INIS)

Hilmy, N.; Harsoyo, S.; Suwirma, S.

1987-01-01

Combined treatment of solar energy and gamma irradiation to eliminate pathogenic bacteria in dewatered sludge. A combined treatment of solar energy and gamma irradiation has been done to eliminate the pathogenic microbes contaminating dewatered sludge. Samples were collected during dry season, i.e. from June to September 1985. To reduce the water content from 70% to 20%, solar energy from sun rays was used, i.e. from 9 a.m. to 2 p.m. for 4 days. Total bacterial count coliform bacteria Escherichia coli, Fecal Streptococcus, Enterobacteriaceae, and Pseudomonas sp were found to be 7.4x10 8 per g, 4.1x10 3 per g, 4.5x10 2 per g, 3.1x10 5 per g, 3.6x10 4 per g, and 5.4x10 3 per g of samples respectively. The combined treatment could reduce the irradiation dose needed to eliminate the pathogenic microbes of samples investigated from 6 to 2 kGy. (author). 5 figs, 11 refs

Bioelectrochemically-assisted anaerobic composting process enhancing compost maturity of dewatered sludge with synchronous electricity generation.

Science.gov (United States)

Yu, Hang; Jiang, Junqiu; Zhao, Qingliang; Wang, Kun; Zhang, Yunshu; Zheng, Zhen; Hao, Xiaodi

2015-10-01

Bioelectrochemically-assisted anaerobic composting process (AnCBE) with dewatered sludge as the anode fuel was constructed to accelerate composting of dewatered sludge, which could increase the quality of the compost and harvest electric energy in comparison with the traditional anaerobic composting (AnC). Results revealed that the AnCBE yielded a voltage of 0.60 ± 0.02 V, and total COD (TCOD) removal reached 19.8 ± 0.2% at the end of 35 d. The maximum power density was 5.6 W/m(3). At the end of composting, organic matter content (OM) reduction rate increased to 19.5 ± 0.2% in AnCBE and to 12.9 ± 0.1% in AnC. The fuzzy comprehensive assessment (FCA) result indicated that the membership degree of class I of AnCBE compost (0.64) was higher than that of AnC compost (0.44). It was demonstrated that electrogenesis in the AnCBE could improve the sludge stabilization degree, accelerate anaerobic composting process and enhance composting maturity with bioelectricity generation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preconcentration of a low grade uranium ore in CPDU and laboratory investigation to optimize the dewatering conditions of the preconcentration products

International Nuclear Information System (INIS)

Cristovici, M.A.; Berry, T.F.; Raicevic, M.M.; Brady, E.L.; Bredin, E.L.; Leigh, G.W.; Rouleau, J.P.

1982-04-01

A process consisting of pyrite flotation and magnetic concentration of radionuclides was developed by CANMET over several years, to preconcentrate low grade uranium ores prior to leaching. When the economics of the preconcentration-leaching technology was compared with the leaching of the entire ore after pyrite flotation (Base Case variant), the preconcentration method appeared to be economically less advantageous than expected, due to the high cost of dewatering the preconcentration products. Further investigations examined in-depth the metallurgy and dewatering of the two variants: preconcentration and base case. A typical low grade uranium ore from Elliot Lake area was used. The metallurgy was compared based on data from continuous operation (CPDU). In the preconcentration variant the amount of ore directed to leaching was reduced to more than one third of that processed in the base case, while the radionuclide concentration became more than three times higher. However, by preconcentration 7% of the uranium was lost before leaching. Systematic laboratory-scale settling and filter tests optimized the dewatering conditions of the preconcentration technology to the extent that rates similar to those of the base case were obtained

Application of Fuzzy Synthetic Evaluation in Selection of Best Sludge Dewatering Option in Ghods Town WWTP in Tehran

Directory of Open Access Journals (Sweden)

Masoud Taheriyoun

2015-03-01

Full Text Available The design and upgrade of sludge treatment systems generally depend on the decision made regarding the appropriate system from among the options available. The selection process has become increasingly important and complex due to recent technological developments that have led to increased diversity in the available options which offer a wide variety of capabilities. The multi-criteria decision making method is one of the techniques recently developed which takes into account all the criteria involved in the decision making process. The Ghods Town WWTP in the west of Tehran located in the vicinity of residential areas has given rise to claims by citizens due to the odors emitted by the sludge sand drying bed, which justifies the replacement of the present sludge dewatering system. For this purpose, the multi-criteria decision making method based on the fuzzy synthetic evaluation method was used to identify the optimal sludge dewatering system appropriate for the WWTP under consideration. Furthermore, weighting of the subjective (social, environmental, and administrative criteria was accomplished using the analytical hierarchy process and the objective (i.e., economic criteria were weighted using the entropy concept. In this method, the triangular fuzzy membership function was also used to take into account the uncertainty associated with each of the decision making parameters. Based on the results obtained, the belt filter press dewatering system and the filter press were identified as the preferred solutions.

Dewatering e bonifica dell’ area ˝ex Whitehead Motofides˝ (Pisa, Italia

Directory of Open Access Journals (Sweden)

Nicola Conti

2014-12-01

Full Text Available In 2007 the activities for the remediation of the “ex-Whitehead Motofides area” (in Marina di Pisa, Italy started. In order to allow the contaminated soil excavation in dry conditions a dewatering system was necessary. The water pumped through this system was then treated in an adequate plant. Acque Industriali realized and managed the whole system. The dewatering system was made of suction pins fixed to a depth of 5.5 m, connected by a junction manifold to the suction and booster vacuum assisted pump, which allowed the groundwater release toward the plant. The treatment plant, entirely designed by Acque Industriali and called ITAM (Impianto di Trattamento Acque di Falda Mobile, which means movable groundwater treatment, was realized and set up at the end of 2008. It consisted of a pre-treatment section, made of reinforced concrete, prefabricated nitrogen sweep elements, and a physical chemical treatment plant, in a continuous loop, completely made on skid. The plant, with 25 m3/h of maximum potential, was able to remove possible sedimentable or in suspension material particles from water, iron, manganese, residual organic substances such as hydrocarbons, solvents (chlorinated and not, PCBs, and partly heavy metals. Totally, 98,167 m3 of groundwater were managed in about 25 months of activity. The analytic input and output results confirmed extremely high and satisfactory pollutant removal efficiency. The concentration values of the pollutants, in fact, were always lower than the limits imposed by law.

Hot dewatering and resin encapsulation of intermediate level radioactive waste

International Nuclear Information System (INIS)

Rickman, J.; Birch, D.

1985-01-01

The chemistry of the processes involved in the hot dewatering and encapsulation of alumino-ferric hydroxide floc in epoxide resin have been studied. Pretreatment of the floc to reduce resin attack and hydrolysis and to increase the dimensional stability of the solidified wasteform has been evaluated. It has been demonstrated that removal of ammonium nitrate from the floc and control of the residual water in the resin are important factors in ensuring dimensional stability of the solidified resin. Resin systems have been identified which, together with the appropriate waste pretreatment have successfully encapsulated a simulated magnox sludge producing a stable wasteform having mechanical and physical properties comparable with the basic resin. (author)

An assessment of filter aids and filter cloths in the dewatering of intermediate level wastes

International Nuclear Information System (INIS)

Knibbs, R.H.; Hudson, B.C.; Blackwell, J.C.W.

1984-12-01

This report considers a range of filter cloths and precoat materials intended for use in dewatering intermediate level radioactive wastes, and their interaction when used on a rotary drum vacuum filter. The report outlines the advantages and disadvantages of various grades and types of precoat and shows that grades with permeabilities in the intermediate range, 3 to 4 x 10 -12 m 2 , give satisfactory filtrate quality together with ease of operation. The work on filter cloths shows that: radiation damage is not a limiting factor as regards operational life for any of the cloths examined; polyester-based cloths are unsuitable due to their poor resistance to alkali attack; polyamide cloths are satisfactory; and stainless steel Dutch weave cloths are satisfactory and have the added advantage of high strength. The report also briefly considers the radiation resistance of two elastomeric membranes used on the 'epidermal' filter and shows that the natural latex rubber membrane is considerably more resistant to radiation than the silicone rubber membrane and has an estimated operational life of at least 1200 hours when dewatering Magnox silo sludge or α-contaminated alumino ferric flocs. (author)

Efficient dewatering of bark in heated presses. Survey and pilot-scale trials; Effektivare avvattning av bark i vaermda pressar. Problemkartering samt foersoek i pilotskala

Energy Technology Data Exchange (ETDEWEB)

Haakansson, Martin; Stenstroem, Stig (Lund Inst. of Technology, Lund (SE))

2007-12-15

Dewatering and drying of biofuels such as bark and GROT have received increased importance due to an increased interest to use these products as energy sources. In Sweden there are about 30 bark presses installed, however the amount of available information is very limited about dewatering of bark. The goal with this work is to increase the knowledge about dewatering of bark. Two separate goals have been defined in the project: A. Survey about problems related to dewatering of bark and compilation of operating experiences at Swedish mills. B. Study how different parameters affect bark dewatering at pilot scale experiments. Study different techniques for heating bark and the bark pressing process. The results will mainly be of interest for mills which are handling bark, for municipal power plants who buy wet forest residues (bark, GROT etc.) and for manufacturers of industrial bark pressing equipment. The results show that the dry matter content for birch- and pine bark normally are so high that pressing does not result in dewatering of the barks. Both dry and wet debarking is used and these bark fractions should be pressed separately. On line measurement of the dry matter content for the bark should be used as a standard tool on the bark press. This will facilitate improved control of the bark press during the year. Other conclusions are that smaller bark particles result in an increased dry matter content, large bark- and wood pieces decrease the dewatering in the bark press and that the total residence time in the press nip should be at least 30 seconds. The most common method to take care of bark water is to send it to the evaporators or to the water purification plant. Maintenance of the bark press appears not to be a big problem. Hot pressing can be accomplished in different ways, either the bark press can be heated or the bark can be heated in different ways. The alternatives that have been studied in this project are steaming the bark, heating the bark using

Dewatering treatments to increase dry matter content of the brown seaweed, kelp (Laminaria digitata ((Hudson) JV Lamouroux)).

Science.gov (United States)

Gallagher, Joe A; Turner, Lesley B; Adams, Jessica M M; Dyer, Philip W; Theodorou, Michael K

2017-01-01

Macroalgal water content is an on-going problem for the use of readily accessible seaweeds in sustainable biorefining, including fuel production. Silage is a reduced-water, compactable, easily stored, transportable material. Ensiling could establish a non-seasonal supply of preserved algal biomass, but requires high initial dry matter content to mitigate environmental pollution risks from effluent. This study investigated potential dewatering methods for kelp harvested throughout the year. Treatments included air-drying, osmotic media and acids. Significant interactions between treatment and harvest-time were observed for traits of interest. Fresh weight loss during treatment was composed of changes in water and dry matter content. Air-drying gave reliable increase in final dry matter content; in summer and autumn 30% dry matter content was reached after 24h. Dilute hydrochloric acid reduced stickiness and rendered material suitable for dewatering by screw-pressing; it may be possible to use the consequent pH reduction to promote efficient preservation. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Field experiment and numerical simulation of coupling non-Darcy flow caused by curtain and pumping well in foundation pit dewatering

Science.gov (United States)

Wang, Jianxiu; Liu, Xiaotian; Wu, Yuanbin; Liu, Shaoli; Wu, Lingao; Lou, Rongxiang; Lu, Jiansheng; Yin, Yao

2017-06-01

High-velocity non-Darcy flow produced larger drawdown than Darcy flow under the same pumping rate. When the non-Darcy flow caused by curtain met non-Darcy flow caused by pumping wells, superposition and amplification effect occurred in the coupling area, the non-Darcy flow was defined as coupling non-Darcy flow. The coupling non-Darcy flow can be produced and controlled using different combination of curtain and pumping wells in foundation pit dewatering to obtain the maximum drawdown using the minimum pumping rate. The Qianjiang Century City Station foundation pit of Hangzhou subway, China, was selected as background. Field experiments were performed to observe the coupling non-Darcy flow in round gravel. A generalized conceptual model was established to study the coupling effect under different combination of curtain and pumping wells. Numerical simulations of the coupling non-Darcy flow in foundation pit dewatering were carried out based on the Forchheimer equation. The non-Darcy flow area and flow velocity were influenced by the coupling effect. Short filter tube, large pumping rate, small horizontal distance between filter tube and diaphragm wall, and small vertical distance between the filter tube and confined aquifer roof effectively strengthened the coupling effect and obtained a large drawdown. The pumping wells installed close to a curtain was an intentional choice designed to create coupling non-Darcy flow and obtain the maximize drawdown. It can be used in the dewatering of a long and narrow foundation pit, such as a subway foundation pit.

Bacterial pathogen indicators regrowth and reduced sulphur compounds' emissions during storage of electro-dewatered biosolids.

Science.gov (United States)

Navab-Daneshmand, Tala; Enayet, Samia; Gehr, Ronald; Frigon, Dominic

2014-10-01

Electro-dewatering (ED) increases biosolids dryness from 10-15 to 30-50%, which helps wastewater treatment facilities control disposal costs. Previous work showed that high temperatures due to Joule heating during ED inactivate total coliforms to meet USEPA Class A biosolids requirements. This allows biosolids land application if the requirements are still met after the storage period between production and application. In this study, we examined bacterial regrowth and odour emissions during the storage of ED biosolids. No regrowth of total coliforms was observed in ED biosolids over 7d under aerobic or anaerobic incubations. To mimic on-site contamination during storage or transport, ED samples were seeded with untreated sludge. Total coliform counts decreased to detection limits after 4d in inoculated samples. Olfactometric analysis of ED biosolids odours showed that odour concentrations were lower compared to the untreated and heat-treated control biosolids. Furthermore, under anaerobic conditions, odorous reduced sulphur compounds (methanethiol, dimethyl sulphide and dimethyl disulphide) were produced by untreated and heat-treated biosolids, but were not detected in the headspaces above ED samples. The data demonstrate that ED provides advantages not only as a dewatering technique, but also for producing biosolids with lower microbial counts and odour levels. Copyright © 2014 Elsevier Ltd. All rights reserved.

The exploitation of swamp plants for dewatering liquid sewage sludge

Directory of Open Access Journals (Sweden)

Jiří Šálek

2006-01-01

Full Text Available The operators of little rural wastewater treatment plants have been interested in economic exploitation of sewage sludge in local conditions. The chance is searching simply and natural ways of processing and exploitation stabilized sewage sludge in agriculture. Manure substrate have been obtained by composting waterless sewage sludge including rest plant biomass after closing 6–8 years period of filling liquid sewage sludge to the basin. Main attention was focused on exploitation of swamp plants for dewatering liquid sewage sludge and determination of influence sewage sludge on plants, intensity and course of evapotranspiration and design and setting of drying beds. On the base of determined ability of swamp plants evapotranspiration were edited suggestion solutions of design and operation sludge bed facilities in the conditions of small rural wastewater treatment plant.

Performance of Sandy Dry Beds for sludge dewatering

International Nuclear Information System (INIS)

Al-Muzaini, S.

2003-01-01

Sludge produced by the Jahra treatment plant was assessed. The assessment was directed at determining the performance of sand drying beds. The assessment of quality of the sludge produced was based on the standards for land application of sewage sludge. Analyses were carried out for trace heavy metals and bacteria. The results of analyses showed that the sludge produced was high in organic matter and sand content but low in heavy metals. The collected data indicated that the sand drying beds at the Jahra treatment plant are at present inadequate to handle the projected sludge production. The investigation showed that the sand drying beds are fully used and the plant will require 3-4 times the capacity of the existing drying beds when the plant becomes fully operational. In addition, these sand drying beds are subjected to uncontrollable conditions such as temperature, rainfall and sludge drainage rate. Thus, sand drying beds have become less popular as a dewatering system. This paper evaluates the performance of the existing sand drying beds and suggests the most appropriate technology to alleviate the above mentioned problems. (author)

The use of geotextile tube containers for dewatering the Restigouche open pit zinc mine and settling pond basin in New Brunswick, Canada

Energy Technology Data Exchange (ETDEWEB)

Douheret [Terratube, Saint-Romuald, PQ (Canada)

2010-07-01

This PowerPoint presentation discussed the use of geotextile tube containers for the dewatering of an open pit zinc mine and settling pond in New Brunswick (NB). The zinc and lead mine closed in 1996 and will be re-opened in 2007. Remediation of the site has been challenged by severe discharge criteria for treated water, as well as by the different types of wastewater produced at the site, which is located in a mountainous area with no impermeable soil. The remediation projects include an open pit cleaning procedure where water is removed and the mine is then desludged. A wastewater treatment plant will then be installed. More than 32,000 m{sup 3} of sludge has accumulated at the bottom of the pit. The zinc content of the sludge was estimated at 2.5 ppm. The water management phase of the project will include batch treatments and the addition of 140 metric tonnes of lime to raise the pH and to precipitate metal ions. The sludge management program included the use of mechanical dewatering, the construction of a storage area, and the use of geocontainers for dewatering and temporary containment. Seventeen geotextile containers were used to reduce the zinc content of the water to less than the 250 ppb authorized by environmental agencies. The containers were changed once every 2 months. tabs., figs.

Predicting spread of invasive exotic plants into de-watered reservoirs following dam removal on the Elwha River, Olympic National Park, Washington

Science.gov (United States)

Woodward, Andrea; Torgersen, Christian E.; Chenoweth, Joshua; Beirne, Katherine; Acker, Steve

2011-01-01

The National Park Service is planning to start the restoration of the Elwha River ecosystem in Olympic National Park by removing two high head dams beginning in 2011. The potential for dispersal of exotic plants into dewatered reservoirs following dam removal, which would inhibit restoration of native vegetation, is of great concern. We focused on predicting long-distance dispersal of invasive exotic plants rather than diffusive spread because local sources of invasive species have been surveyed. We included the long-distance dispersal vectors: wind, water, birds, beavers, ungulates, and users of roads and trails. Using information about the current distribution of invasive species from two surveys, various geographic information system techniques and models, and statistical methods, we identified high-priority areas for Park staff to treat prior to dam removal, and areas of the dewatered reservoirs at risk after dam removal.

Environmental control of drilling mud discharge through dewatering in cold weather climates

International Nuclear Information System (INIS)

Wojtanowicz, A.K.

1991-01-01

The paper presents results of an experimental study into the effect of drilling mud temperature upon the dewatering performance. Three temperature ranges were considered: from flowline temperature to room temperature, from room temperature to freezing point, and the freeze (4 degrees F)/thaw (54 degrees F) cycle. The tested drilling fluids included unweighted and weighted fresh water muds and a weighted salt water mud. a sealed laboratory batch reactor was used in the experiments to prevent rapid vaporization of separated water at temperatures above 140 degrees F. Also, ice or ice-salt baths were utilized for deep freezing. The dewaterability (net water removal) was measured with a bench-top plate press under constant expression pressure 30 psi

Detecting Dewatering of Peatland Pastures Using Sentinel-1 Satellite Radar Interferometry.

Science.gov (United States)

Heuff, F.; Samiei-Esfahany, S.; van Leijen, F. J.; Hanssen, R. F.

2017-12-01

The Netherlands are famous for their polders and the draining of soils to be used as pastures. Around 30% of the pastures are situated on peat soils, mostly in the western part of the Netherlands. Peat is composed of organic materials that oxidize and emit greenhouse gases when exposed to air. Oxidation of peat soils results in volume reduction and subsequent subsidence. As a result, the groundwater level rises relative to the surface. Consequently, the soil needs to be dewatered to keep it sufficiently dry for farming, resulting in more oxidation, and therefore more subsidence. This process is bound to continue until the peat soils have disappeared completely. The societal cost of land subsidence due to peat soils are estimated to be 5200 million euro for urban areas and 200 million euro for peatland pastures, for a period until 2050. Measuring the subsidence is not straightforward, if not impossible, with conventional geodetic means as soft soils make it impossible to install fixed benchmarks for repeated surveying. Also, due to the very fast temporal decorrelation over pastures, conventional InSAR approaches cannot measure a signal due to loss of coherence. Here we deploy a complete set of available SAR data from Sentinel-1, Radarsat-2 and TerraSAR-X to estimate the spatio-temporally varying subsidence signal due to the dewatering of peatland pastures over the western part of the Netherlands. We compute the InSAR coherence matrix for all possible interferometric combination, and compute an equivalent single-master stack to estimate the subsidence. Using terrain and land-use defined coherence estimation areas we optimize the phase estimation over areas severely affected by temporal decorrelation. This leads to a first estimate of deformation signals correlated with ancient shallow soil structures due to fluviatile structures. We use the methodology to investigate the effect of advanced local drainage schemes to slow down the subsidence phenomena.

Dewatering of contaminated river sediments

Science.gov (United States)

Church, Ronald H.; Smith, Carl W.; Scheiner, Bernard J.

1994-01-01

Dewatering of slurries has been successfully accomplished by the proper use of polymers in flocculating the fine particulate matter suspended in mineral processing streams. The U.S. Bureau of Mines (USBM) entered into a cooperative research effort with the U.S. Army Corps of Engineers (Corps) for the purpose of testing and demonstrating the applicability of mining flocculation technology to dredging activities associated with the removal of sediments from navigable waterways. The Corps has the responsibility for maintaining the navigable waterways in the United States. Current technology relies primarily on dredging operations which excavate the material from the bottom of waterways. The Corps is testing new dredging technology which may reduce resuspension of sediments by the dredging operation. Pilot plant dredging equipment was tested by the Corps which generated larger quantities of water when compared to conventional equipment, such as the clam shell. The transportation of this 'excess' water adds to the cost of sediment removal. The process developed by the USBM consists of feed material from the barge being pumped through a 4-in line by a centrifugal pump and exiting through a 4-in PVC delivery system. A 1,000-gal fiberglass tank was used to mix the polymer concentrate. The polymer was pumped through a 1-in line using a variable speed progressive cavity pump and introduced to the 4-in feed line prior to passing through a 6-in by 2-ft static mixer. The polymer/feed slurry travels to the clarifying tank where the flocculated material settled to the bottom and allowed 'clean' water to exit the overflow. A pilot scale flocculation unit was operated on-site at the Corps' 'Confined Disposal Facility' in Buffalo, NY.

Effect of biodegradation on the consolidation properties of a dewatered municipal sewage sludge.

Science.gov (United States)

O'Kelly, Brendan C

2008-01-01

The effect of biodegradation on the consolidation characteristics of an anaerobically digested, dewatered municipal sewage sludge was studied. Maintained-load oedometer consolidation tests that included measurement of the pore fluid pressure response were conducted on moderately degraded sludge material and saturated bulk samples that had been stored under static conditions and allowed to anaerobically biodegrade further (simulating what would happen in an actual sewage sludge monofill or lagoon condition). Strongly degraded sludge material was produced after a storage period of 13 years at ambient temperatures of 5-15 degrees C, with the total volatile solids reducing from initially 70% to 55%. The sludge materials were highly compressible, although impermeable for practical purposes. Primary consolidation generally occurred very slowly, which was attributed to the microstructure of the solid phase, the composition and viscosity of the pore fluid, ongoing biodegradation and the high organic contents. The coefficient of primary consolidation values decreased from initially about 0.35m2/yr to 0.003-0.03m2/yr with increasing effective stress (sigmav'=3-100kPa). Initially, the strongly degraded sludge material was slightly more permeable, although both the moderately and strongly degraded materials became impermeable for practical purposes (k=10(-9)-10(-12)m/s) below about 650% and 450% water contents, respectively. Secondary compression became more dominant with increasing effective stress with a mean secondary compression index (Calphae) value of 0.9 measured for both the moderately and strongly degraded materials.

Development of producing equipment of mixed butane-air with low dew point. Energy saving dewatering apparatus and 6A-Gas producing apparatus utilizing vaporization latent heat of butane and potential heat of air

Energy Technology Data Exchange (ETDEWEB)

Komine, Jin; Okada, Hiroto; Taniue, Nobuo; Tanoue, Keiju; Yamada, Tatsuhiko; Maekawa, Hisami; Murakami, Keiji

1988-02-10

A producing equipment of mixed butane-air with low dew point was developed. The dewatering was made during the period from the middle of May to the middle of October with high atmospheric humidity. The production capacity of the mixed gas is 3000 Nm/sup 3/ of 22% of butane and 78% of air per hour. The designed dew point is 18/sup 0/C or less under the pressure of 0.7 kg/cm/sup 2/G. The saturation temperature is 7.5/sup 0/C after the liquid butane is evacuated by a regulating valve. The air introduced into the dehumidifier through finned tubes is cooled to dewater based on those data. The partially vaporized butane is completely gasified by hot water in a vaporizer and mixed with the dewatered air by a venture mixer to produce the mixed butane-air. When the dewatering is incomplete, the spray nozzle must be just exchanged. The dew point of the produced gas was sufficiently below the designed value. The investment cost is low. The total operating cost is reduced by the remarkably decreased fuel cost though the power cost is increased. The noise level is low and the heat control is easy. (11 figs, 4 tabs, 1 photo)

Vibrating membrane filtration as improved technology for microalgae dewatering.

Science.gov (United States)

Nurra, Claudia; Clavero, Ester; Salvadó, Joan; Torras, Carles

2014-04-01

The effect of shear-enhanced filtration by vibratory process in microalgae dewatering is presented in this paper. The aim of this research was to investigate the technical performance and improvement of vibrating membrane filtration compared with conventional tangential cross-flow filtration in microalgae concentration. An industrial-scale available commercial set-up was used. Several membrane materials as polyethersulfone, polyacrylonitrile, etc., and mean pore sizes (from 7000Da to 0.2μm) were tested and compared in both filtration set-ups. Experiments were carried-out with Nannochloropsis gaditana and Phaeodactylum tricornutum microalgae. It has been demonstrated that, even if the choice of the membrane depends on its cut-off, its material and the type of microalgae filtrated, dynamic filtration is always the best technology over a conventional one. If with conventional filtration permeability values were in the vicinity of 10L/h/m(2)/bar in steady state phase, with dynamic filtration these values increased to 30L/h/m(2)/bar or more. Copyright © 2014 Elsevier Ltd. All rights reserved.

Learner Characteristics and Understanding Nature of Science: Is There an Association?

Science.gov (United States)

Çetinkaya-Aydin, Gamze; Çakiroglu, Jale

2017-01-01

The purpose of this study was to investigate the possible associations between preservice science teachers' understanding of nature of science and their learner characteristics; understanding of nature of scientific inquiry, science teaching self-efficacy beliefs, metacognitive awareness level, and faith/worldview schemas. The sample of the…

Consolidation theory and its applicability to the dewatering and covering of uranium-mill tailings

International Nuclear Information System (INIS)

Gates, T.E.

1982-11-01

This report is a review and evaluation of soil consolidation theories applicable for evaluating settlement during dewatering and subsequent covering of uranium-mill tailings. Such theories may be used to predict both consolidation and water flow related effects in uranium-mill tailings during drainage, following sluicing into burial pits. A consolidation theory to be useful must consider the effect of time-dependent loads, nonhomogeneous soil mass, nonlinear variation of soil properties with the stress-state parameters, large strain, and saturated and unsaturated flow. Constitutive relations linking the stress-deformation-state variables with void ratio should be adopted for predicting both consolidation and fluid-flow interaction in unsaturated uranium-mill tailings

Upgrading of brown coal by slurry-dewatering; Kattan no yuchu dassui ni yoru clean kotai nenryo no seizo

Energy Technology Data Exchange (ETDEWEB)

Okuma, O.; Shimizu, T.; Inoue, T.; Shigehisa, T.; Deguchi, T.; Katsushima, S. [Kobe Steel, Ltd., Kobe (Japan)

1996-10-28

This paper describes an outline of solid fuel production process from brown coal and the investigation results of its elemental techniques. Dried coal is produced by this process which consists of a dewatering of crushed brown coal in oil-based solvent, a solid and liquid separation of slurry, and a remained oil recovery by heating. This process is characterized by the higher thermal efficiency compared with usual drying and the restraint of spontaneous combustion of product coal. It was revealed that solid fuel with low moisture, low ash, low sulfur, and suppressed spontaneous combustion property can be produced from Australian brown coal through this process. From the comparison between kerosene and fuel oil A, it was confirmed that the oil content during dewatering was smaller and the oil recovery by heating was easier by using a solvent with lower boiling point. It was also confirmed that the spontaneous combustion property can be suppressed using small amount of asphalt by solving asphalt in the solvent and adsorbing asphalt on the surface of brown coal. From these results, low rank coals including brown coal, which are difficult to use, are expected to be used as clean coal with low ash and low sulfur through this process. 2 refs., 7 figs., 2 tabs.

Heating value characteristics of sewage sludge: a comparative study of different sludge types

International Nuclear Information System (INIS)

Kim, Young-JU.; Kang, Hae-Ok.; Qureshi, T.I.

2005-01-01

Heating value characteristics of three different types of sludge, i.e. domestic sewage sludge, industrial sludge, and industrial + domestic sewage sludge were investigated. Industrial + domestic sewage sludge (thickened) showed the highest heating value (5040 kcal/kg) than other sludge types. This may be due to increased amount of organic matter presents in thickened sludge than de-watered sludge. A gradual increase in organic matter of the sludge was observed with the increase of the moisture contents. Heating value of the sludge having 60% moisture contents was found in the range between 924-1656 kcal/kg and this amount was higher than the minimum heating value (800 kcal/kg) required sustaining auto thermal combustion in sludge incineration process. Energy consumption requirement for pre drying sludge operations revealed that industrial sludge (de-watered) required the minimum cost (13 $/ton of sludge) to make it a sludge of fuel grade (60% W), while mixed sludge cost the highest amount for its pre-drying operations. (author)

Hydrothermal and alkaline hydrothermal pretreatments plus anaerobic digestion of sewage sludge for dewatering and biogas production: Bench-scale research and pilot-scale verification.

Science.gov (United States)

Li, Chunxing; Wang, Xingdong; Zhang, Guangyi; Yu, Guangwei; Lin, Jingjiang; Wang, Yin

2017-06-15

To test the feasibility and practicability of the process combing hydrothermal pretreatment for dewatering with biogas production for full utilization of sewage sludge, hydrothermal/alkaline hydrothermal pretreatments and in turn anaerobic digestion of the filtrates obtained after dewatering the pretreated sludge were performed at bench- and pilot-scales. The hydrothermal temperature fell within the range of 140 °C-220 °C and the pretreatment time varied from 30 min to 120 min. For the alkaline hydrothermal pretreatment the pH value of the sludge was adjusted to 9.0-11.0 by adding Ca(OH) 2 . The results showed that the dewaterability of the sewage sludge was improved with increasing pretreatment temperature but the impact of the pretreatment time was not significant. The addition of Ca(OH) 2 gave better performance on the subsequent mechanical dewatering of the pretreated sludge compared to pure hydrothermal pretreatment, and the higher the pH value was, the better the dewaterability of the pretreated sludge was. The conditions of 180 °C/30 min and 160 °C/60 min/pH = 10.0 (for hydrothermal and alkaline hydrothermal pretreatments, respectively) resulted in relatively good results in the theoretical energy balance, which were verified in the pilot-scale tests. Based on the data from the pilot tests, the alkaline hydrothermal process realized self-sufficiency in energy at the cost of a proper amount of CaO. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of drought characteristics for improved understanding of a water resource system

Directory of Open Access Journals (Sweden)

A. T. Lennard

2014-09-01

Full Text Available Droughts are a reoccurring feature of the UK climate; recent drought events (2004–2006 and 2010–2012 have highlighted the UK’s continued vulnerability to this hazard. There is a need for further understanding of extreme events, particularly from a water resource perspective. A number of drought indices are available, which can help to improve our understanding of drought characteristics such as frequency, severity and duration. However, at present little of this is applied to water resource management in the water supply sector. Improved understanding of drought characteristics using indices can inform water resource management plans and enhance future drought resilience. This study applies the standardised precipitation index (SPI to a series of rainfall records (1962–2012 across the water supply region of a single utility provider. Key droughts within this period are analysed to develop an understanding of the meteorological characteristics that lead to, exist during and terminate drought events. The results of this analysis highlight how drought severity and duration can vary across a small-scale water supply region, indicating that the spatial coherence of drought events cannot be assumed.

An Experimental Study on Axial Temperature Distribution of Combustion of Dewatered Poultry Sludge in Fluidized bed combustor

Directory of Open Access Journals (Sweden)

Abbas A.H.

2016-01-01

Full Text Available A laboratory scale bubbling fluidized bed combustor was designed and fabricated to study the combustion of dewatered poultry sludge at different operational parameters. This paper present a study on the influence of equivalent ratio, secondary to primary air ratio and the fuel feed rate on the temperature distribution along the combustor. The equivalent ratio has been changed between 0.8 to 1.4% under poultry sludge feed rate of 10 kg/h and from 0.8 to 1 under poultry sludge feed rate of 15 kg/h. The secondary to primary air ratio was varied from 0.1 to 0.5 at 0.65 m injection height and 1.25 equivalent ratio. The results showed that these factors had a significant influence on the combustion characteristics of poultry sludge. The temperature distribution along the combustor was found to be strongly dependent on the fuel feed rate and the equivalent ratio and it increased when these two factors increased. However, the secondary air ratio increased the temperature in the lower region of the combustor while no significant effect was observed at the upper region of the combustor. The results suggested that the poultry sludge can be used as a fuel with high thermal combustor efficiency.

The understanding of art students toward characteristic of Negeri Sembilan Minangkabau Traditional House

Directory of Open Access Journals (Sweden)

Taharuddin Nurul Shima

2016-01-01

Full Text Available In Negeri Sembilan, they are still practicing Minangkabau culture and custom. Element of uniqueness in Negeri. Sembilan has been shown on its architectural where the houses have dramatic curved roof structures with multitier. The art and architecture features a unique regional style. This house fills with cultural values, customs and reflects the people’s understanding about designing art and architecture that is in harmony with nature. The house serves as a residence, a hall for family meetings, and for ceremonial activities. This research, studies the understanding of art students towards the characteristic that are found in the Negeri Sembilan Minangkabau Traditional House (NSMTH in Negeri Sembilan, Malaysia. The objectives are to identify the element of characteristic that shows the identity of Negeri Sembilan Minangkabau Traditional House and to determine the level of understanding on characteristic of a Minangkabau house by art students. Scope of this research is on understanding of Faculty Art & Design student that has syllabus on Malay art. The research methodology that been use in this research is quantitative where surveys are made among the art students

Assessment of technical-scale dewatering results in decanters on the basis of measurements of water types in sewage sludge; Bestimmung grosstechnischer Entwaesserungsergebnisse in Dekantern basierend auf der Messung der Wasserarten von Klaerschlaemmen

Energy Technology Data Exchange (ETDEWEB)

Kopp, J.; Dichtl, N. [Technische Univ. Braunschweig (Germany). Inst. fuer Siedlungswasserwirtschaft

1999-07-01

In a sewage sludge suspension, three water portions can be measured and distinguished from each other. The free water portion is not bound to sludge particles and can be separated by mechanical dewatering. The interstitial water portion bound by capillary forces and bound water (on surfaces and in cells) remain in the sludge cake after dewatering. The described measuring system for thermo-gravimetric determination of the water portions of sewage sludge was adjusted and calibrated at Braunschweig Technical University and permits prognosticating the maximum attainable content of solids through mechanical dewatering in high-performance decanters. (orig.) [German] In einer Klaerschlammsuspension koennen drei Wasseranteile messtechnisch unterschieden werden. Der freie Wasseranteil ist nicht an die Schlammpartikel gebunden und ist bei einer maschinellen Entwaesserung abtrennbar. Der kapillar gehaltene Zwischenraumwasseranteil und das gebundene Wasser (auf Oberflaechen und in Zellen) verbleibt nach der Entwaesserung im Schlammkuchen. Die an der TU Braunschweig angepasste und kalibrierte Messanlage zur thermo-gravimetrischen Bestimmung der Wasseranteile eines Klaerschlammes ermoeglicht es, den maximal bei der maschinellen Entwaesserung in Hochleistungsdekantern erreichbaren Feststoffgehalt zu prognostizieren. (orig.)

Use of a water treatment sludge in a sewage sludge dewatering process

Science.gov (United States)

Górka, Justyna; Cimochowicz-Rybicka, Małgorzata; Kryłów, Małgorzata

2018-02-01

The objective of the research study was to determine whether a sewage sludge conditioning had any impact on sludge dewaterability. As a conditioning agent a water treatment sludge was used, which was mixed with a sewage sludge before a digestion process. The capillary suction time (CST) and the specific filtration resistance (SRF) were the measures used to determine the effects of a water sludge addition on a dewatering process. Based on the CST curves the water sludge dose of 0.3 g total volatile solids (TVS) per 1.0 g TVS of a sewage sludge was selected. Once the water treatment sludge dose was accepted, disintegration of the water treatment sludge was performed and its dewaterability was determined. The studies have shown that sludge dewaterability was much better after its conditioning with a water sludge as well as after disintegration and conditioning, if comparing to sludge with no conditioning. Nevertheless, these findings are of preliminary nature and future studies will be needed to investigate this topic.

STABILIZATION OF DEWATERED SEWAGE SLUDGE BY AEROBIC COMPOSTING METHOD: USING SAWDUST AS BULKING AGENTS

Directory of Open Access Journals (Sweden)

A PARVARESH

2002-12-01

Full Text Available Introduction. Sludge production from municipal wastewater treatment plants should have quality standards before disposal in to the environment. Environmental specialists classified sewage sludge as a hazardous waste because of high organic compounds and pathogenic microorganisms. They belive that sewage should be stabilized before disposal and so composting of sewage sludge is an effective and economical method to stabilize. Sewage sludge compost could be used to improve soil structure and enrich the soil with nutrients. Methods. To evaluate the optimum conditions of aerobic compost, the mixture of dewatered sewage sludge from Isfahan municipal waste water treatment plant and sawdust as bulking agent were used. Pilot scale study were performed in Isfahan municipal waste water treatment plant. To perform this research project, the dewatered sewage sludge with humidity between 78 to 82 percent were mixed with sawdust. Turning over method of the piles with one week interval were applied to aerate the mixture. Temperature of the piles were monitored at different depths daily. Other parameters such as N, G, organic matters and pH were determined weekly. Total and fecal coli form, and salmonella were determined at the beginning and end of the composting process, also heavy metals were measured at the same time. Results. The results of this study showed that after days, temperature of the mixture reached up to 55 G, and were stabled for 15 days. Humidity, organic matter, organic carbon and GIN ratio of the mixture decreased over the period of the study, due to increasing the temperature. Also organic matter and humidity mainly decreased in thermofilic phase. The number of total and fecal coliform and also salmonella decreased to A class standards of US.EPA at the end of the operation. Discussion. The results of the study also showed that, this type of composting method is reliable, and simple to schedule, with high flexibility and low odor

Learner Characteristics and Understanding Nature of Science. Is There an Association?

Science.gov (United States)

Çetinkaya-Aydın, Gamze; Çakıroğlu, Jale

2017-11-01

The purpose of this study was to investigate the possible associations between preservice science teachers' understanding of nature of science and their learner characteristics; understanding of nature of scientific inquiry, science teaching self-efficacy beliefs, metacognitive awareness level, and faith/worldview schemas. The sample of the current study was 60 3rd-year preservice science teachers enrolled in the Nature of Science and History of Science course. Using a descriptive and associational case study design, data were collected by means of different qualitative and quantitative questionnaires. Analysis of the data revealed that preservice science teachers' understanding of nature of science and nature of scientific inquiry were highly associated. Similarly, science teaching self-efficacy beliefs, metacognitive awareness levels, and faith/worldviews of the preservice science teachers were found to be significantly associated with their understanding of nature of science. Thus, it can be concluded that there might be other factors interfering with the learning processes of nature of science.

Reuse of liquid, dewatered, and composted sewage sludge on agricultural land: effects of long-term application on soil and crop.

Science.gov (United States)

Mantovi, Paolo; Baldoni, Guido; Toderi, Giovanni

2005-01-01

To evaluate the effects of repeated sewage sludge applications in comparison to mineral fertilisers on a winter wheat-maize-sugar beet rotation, a field experiment on a silty-loam soil, in the eastern Po Valley (Italy), was carried out since 1988. Municipal-industrial wastewater sludge as anaerobically digested, belt filtered (dewatered), and composted with wheat straw, has been applied at 5 and 10 Mg DM ha(-1)yr(-1). Biosolids gave crop yields similar to the highest mineral fertiliser dressing. However, with the higher rate of liquid and dewatered sludge, excessive N supply was harmful, leading to wheat lodging and poor quality of sugar beet and wheat crops. From this standpoint compost use was safer. Biosolids increased organic matter (OM), total N, and available P in the soil and reduced soil alkalinity, with more evident effects at the highest rate. Compost caused the most pronounced OM top soil accumulation. Significant accumulations of total Zn and Cu were detected in amended top soil, but no other heavy metals (Cd, Cr, Ni, Pb), whose total concentration remained well below the hazard limits. Biosolid applications significantly increased the content of N, P, Zn, and Cu in wheat grain, N and Cu in sugar beet roots, and only Cu in maize grain. The application of biosolids brought about notable benefits to soil fertility but it was associated with possible negative effects on water quality due to increased P availability and on soil ecology due to Zn accumulation.

Dewatering and RCRA partial closure action on solar evaporation ponds, Rocky Flats Plant, Golden, Colorado

International Nuclear Information System (INIS)

1991-06-01

The Department of Energy (DOE) has prepared an Environmental Assessment (DOE/EA-0487) on its proposal to partially close five solar evaporation ponds at the Rocky Flats Plant (RFP) pursuant to the requirements of the Resource Conservation and Recovery Act (RCRA). This proposal would be known as a RCRA partial closure and would be accomplished by dewatering the ponds, where necessary, and converting any remaining sludge or evaporator concentrate to a solid wasteform (pondcrete and saltcrete). The pond sites would be stabilized to prevent erosion or other disturbance to the soil and to prevent infiltration of rain or snowmelt. The solid wasteform would be transported offsite for disposal. The five solar ponds (designated 207-A, 207-B (north, center, and south), and 207-C), are the only solar evaporation ponds that exist at the RFP. A finding of no significant impact is included

Do doctors understand the test characteristics of lung cancer screening?

Science.gov (United States)

Schmidt, Richard; Breyer, Marie; Breyer-Kohansal, Robab; Urban, Matthias; Funk, Georg-Christian

2018-04-01

Screening for lung cancer with a low-dose computed tomography (CT) scan is estimated to prevent 3 deaths per 1000 individuals at high risk; however, false positive results and radiation exposure are relevant harms and deserve careful consideration. Screening candidates can only make an autonomous decision if doctors correctly inform them of the pros and cons of the method; therefore, this study aimed to evaluate whether doctors understand the test characteristics of lung cancer screening. In a randomized trial 556 doctors (members of the Austrian Respiratory Society) were invited to answer questions regarding lung cancer screening based on online case vignettes. Half of the participants were randomized to the group 'solutions provided' and received the correct solutions in advance. The group 'solutions withheld' had to rely on prior knowledge or estimates. The primary endpoint was the between-group difference in the estimated number of deaths preventable by screening. Secondary endpoints were the between-group differences in the prevalence of lung cancer, prevalence of a positive screening results, sensitivity, specificity, positive predictive value, and false negative rate. Estimations were also compared with current data from the literature. The response rate was 29% in both groups. The reduction in the number of deaths due to screening was overestimated six-fold (95% confidence interval CI: 4-8) compared with the actual data, and there was no effect of group allocation. Providing the correct solutions to doctors had no systematic effect on their answers. Doctors poorly understand the test characteristics of lung cancer screening. Providing the correct solutions in advance did not improve the answers. Continuing education regarding lung cancer screening and the interpretation of test characteristics may be a simple remedy. Clinical trial registered with www.clinicaltrials.gov (NCT02542332).

Investigation of Parameters Affecting Gypsum Dewatering Properties in a Wet Flue Gas Desulphurization Pilot Plant

DEFF Research Database (Denmark)

Hansen, Brian Brun; Kiil, Søren

2012-01-01

of impurities (0.002 M Al2F6; 50 g quartz/L; 0.02 M Al3+, and 0.040 M Mg2+) were investigated. In addition, slurry from a full-scale wet FGD plant, experiencing formation of flat shaped crystals and poor gypsum dewatering properties, was transferred to the pilot plant to test if the plant would now start...... to time. In this work, the particle size distribution, morphology, and filtration rate of wet FGD gypsum formed in a pilot-scale experimental setup, operated in forced oxidation mode, have been studied. The influence of holding tank residence time (10–408 h), solids content (30–169 g/L), and the presence...... to produce low quality gypsum. The crystals formed in the pilot plant, on the basis of the full-scale slurry did, however, show acceptable filtration rates and crystal morphologies closer to the prismatic crystals from after pilot plant experiments with demineralized water. The gypsum slurry filtration rates...

Applicability of industrial wastewater as carbon source for denitrification of a sludge dewatering liquor.

Science.gov (United States)

Chen, Jiazhong; Lee, Yoomin; Oleszkiewicz, Jan A

2013-01-01

The applicability of four industrial waste streams from potato processing, canola processing and oil refining, biodiesel production (glycerol), and glycol as substitutes to methanol and ethanol in denitrification of anaerobically digested sludge dewatering liquor (centrate) was evaluated in bench-scale sequencing batch reactors. It was found that glycerol was the best substitute with the specific denitrification rate (SDNR) of 13 mg NO3-N/(g VSS x h) followed by potato processing wastewater at 12mg NO3-N/(g VSS x h). Both substrates produced faster SDNR than methanol's 10mg NO3-N/(g VSS x h); however, they were inferior to ethanol's 17 mg NO3-N/(g VSS x h). Glycol had SDNR of 8 mg NO3-N/(g VSS x h) and demonstrated a very fast acclimation rate, i.e. the response in increased denitrification rate was visible in three days following glycol addition. Canola processing and oil refining wastewater was considered an inappropriate carbon source due to a low SDNR of 5 mg NO3-N/(g VSS x h) and apparent inhibitory effect on nitrification.

Brown Coal Dewatering Using Poly (Acrylamide-Co-Potassium Acrylic Based Super Absorbent Polymers

Directory of Open Access Journals (Sweden)

Sheila Devasahayam

2015-09-01

Full Text Available With the rising cost of energy and fuel oils, clean coal technologies will continue to play an important role during the transition to a clean energy future. Victorian brown coals have high oxygen and moisture contents and hence low calorific value. This paper presents an alternative non evaporative drying technology for high moisture brown coals based on osmotic dewatering. This involves contacting and mixing brown coal with anionic super absorbent polymers (SAP which are highly crossed linked synthetic co-polymers based on a cross-linked copolymer of acryl amide and potassium acrylate. The paper focuses on evaluating the water absorption potential of SAP in contact with 61% moisture Loy Yang brown coal, under varying SAP dosages for different contact times and conditions. The amount of water present in Loy Yang coal was reduced by approximately 57% during four hours of SAP contact. The extent of SAP brown coal drying is directly proportional to the SAP/coal weight ratio. It is observed that moisture content of fine brown coal can readily be reduced from about 59% to 38% in four hours at a 20% SAP/coal ratio.

Application of a three-dimensional network model to coal dewatering

Energy Technology Data Exchange (ETDEWEB)

Qamar, I.

1986-01-01

A bond-flow correlated network model has been successfully used to calculate equilibrium desaturation curves, single phase permeabilities and two phase flow properties (dewatering curves) for coal filter cakes. A new method of pore volume assignment is presented in which the pore volume occupied by the large pores (which give a capillary pressure less than 0.5 psia) is assigned to the nodes and the rest is distributed to the bonds according to the pore size distribution. The micrographic pore size distribution, used as an input, is determined experimentally. Equilibrium desaturation curves for -32 mesh, -200 mesh and -100 + 200 mesh coal cakes (Pittsburgh Seam Coal), formed with distilled water, have been calculated. The results for six -32 mesh coal cakes formed with surfactants show that the effect of surfactants can be accounted for by modifying one of the model parameters - the entry diameter constant. A correlation is presented to estimate the modified entry diameter constant using experimentally determined surface tension and contact angle values. The size distribution of particles in dispersed state has been correlated with that in the cake which in turn has been correlated with the pore size distribution. An equilibrium desaturation curve has been successfully calculated for -32 mesh Pittsburgh Seam coal using the pore size distribution estimated from the dispersed particle size distribution. Calculated single phase permeabilities, using a bond-flow correlated network and a simple cubic lattice, agree with the experimental values better than a bond-correlated network using a face-centered cubic lattice.

Earthworms facilitate the stabilization of pelletized dewatered sludge through shaping microbial biomass and activity and community.

Science.gov (United States)

Fu, Xiaoyong; Cui, Guangyu; Huang, Kui; Chen, Xuemin; Li, Fusheng; Zhang, Xiaoyu; Li, Fei

2016-03-01

In this study, the effect of earthworms on microbial features during vermicomposting of pelletized dewatered sludge (PDS) was investigated through comparing two degradation systems with and without earthworm E isenia fetida involvement. After 60 days of experimentation, a relatively stable product with low organic matter and high nitrate and phosphorous was harvested when the earthworms were involved. During the process, earthworms could enhance microbial activity and biomass at the initial stage and thus accelerating the rapid decomposition of PDS. The end products of vermicomposting allowed the lower values of bacterial and eukaryotic densities comparison with those of no earthworm addition. In addition, the presence of earthworms modified the bacterial and fungal diversity, making the disappearances of some pathogens and specific decomposing bacteria of recalcitrant substrates in the vermicomposting process. This study evidences that earthworms can facilitate the stabilization of PDS through modifying microbial activity and number and community during vermicomposting.

Comparative evaluation of microbial and chemical leaching processes for heavy metal removal from dewatered metal plating sludge

International Nuclear Information System (INIS)

Bayat, Belgin; Sari, Bulent

2010-01-01

The purpose of the study described in this paper was to evaluate the application of bioleaching technique involving Acidithiobacillus ferrooxidans to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge (with no sulfide or sulfate compounds). The effect of some conditional parameters (i.e. pH, oxidation-reduction potential (ORP), sulfate production) and operational parameters (i.e. pulp density of the sludge and agitation time) were investigated in a 3 l completely mixed batch (CMB) reactor. The metal recovery yields in bioleaching were also compared with chemical leaching of the sludge waste using commercial inorganic acids (sulfuric acids and ferric chloride). The leaching of heavy metals increased with decreasing of pH and increasing of ORP and sulfate production during the bioleaching experiment. Optimum pulp density for bioleaching was observed at 2% (w/v), and leaching efficiency decreased with increasing pulp density in bioleaching experiments. Maximum metal solubilization (97% of Zn, 96% of Cu, 93% of Ni, 84% of Pb, 67% of Cd and 34% of Cr) was achieved at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 ± 2 deg. C during the bioleaching process. The maximum removal efficiencies of 72% and 79% Zn, 70% and 75% Cu, 69% and 73% Ni, 57% and 70% Pb, 55% and 65% Cd, and 11% and 22% Cr were also attained with the chemical leaching using sulfuric acids and ferric chloride, respectively, at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 ± 2 deg. C during the acid leaching processes. The rates of metal leaching for bioleaching and chemical leaching are well described by a kinetic equation related to time. Although bioleaching generally requires a longer period of operation compared to chemical leaching, it achieves higher removal efficiency for heavy metals. The efficiency of leaching processes can be arranged in descending order as follows: bioleaching > ferric chloride leaching > sulfuric acid

Comparative evaluation of microbial and chemical leaching processes for heavy metal removal from dewatered metal plating sludge

Energy Technology Data Exchange (ETDEWEB)

Bayat, Belgin, E-mail: bbayat@cu.edu.tr [Department of Environmental Engineering, Faculty of Engineering and Architecture, Cukurova University, Balcali, Adana 01330 (Turkey); Sari, Bulent [Department of Environmental Engineering, Faculty of Engineering and Architecture, Cukurova University, Balcali, Adana 01330 (Turkey)

2010-02-15

The purpose of the study described in this paper was to evaluate the application of bioleaching technique involving Acidithiobacillus ferrooxidans to recover heavy metals (Zn, Cu, Ni, Pb, Cd and Cr) in dewatered metal plating sludge (with no sulfide or sulfate compounds). The effect of some conditional parameters (i.e. pH, oxidation-reduction potential (ORP), sulfate production) and operational parameters (i.e. pulp density of the sludge and agitation time) were investigated in a 3 l completely mixed batch (CMB) reactor. The metal recovery yields in bioleaching were also compared with chemical leaching of the sludge waste using commercial inorganic acids (sulfuric acids and ferric chloride). The leaching of heavy metals increased with decreasing of pH and increasing of ORP and sulfate production during the bioleaching experiment. Optimum pulp density for bioleaching was observed at 2% (w/v), and leaching efficiency decreased with increasing pulp density in bioleaching experiments. Maximum metal solubilization (97% of Zn, 96% of Cu, 93% of Ni, 84% of Pb, 67% of Cd and 34% of Cr) was achieved at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 {+-} 2 deg. C during the bioleaching process. The maximum removal efficiencies of 72% and 79% Zn, 70% and 75% Cu, 69% and 73% Ni, 57% and 70% Pb, 55% and 65% Cd, and 11% and 22% Cr were also attained with the chemical leaching using sulfuric acids and ferric chloride, respectively, at pH 2, solids contents of 2% (w/v), and a reaction temperature of 25 {+-} 2 deg. C during the acid leaching processes. The rates of metal leaching for bioleaching and chemical leaching are well described by a kinetic equation related to time. Although bioleaching generally requires a longer period of operation compared to chemical leaching, it achieves higher removal efficiency for heavy metals. The efficiency of leaching processes can be arranged in descending order as follows: bioleaching > ferric chloride leaching > sulfuric

Effect of Long-Term Freezing and Freeze–Thaw Cycles on Indigenous and Inoculated Microorganisms in Dewatered Blackwater

DEFF Research Database (Denmark)

Gunnarsdottir, Ragnhildur; Müller, Karoline; Jensen, Pernille Erland

2012-01-01

Wastewater treatment in many Arctic regions is inadequate, even nonexisting. Natural freezing of wastewater in those areas may be beneficial for reduction of microorganisms. The aim of this study was to investigate the effect of long-term freezing, and repeated freezing and thawing, on indigenous...... coliforms, fecal streptococci, and antibiotic-resistant (AR) bacteria, and inoculated Salmonella Enteriditis and E. coli bacteriophage ΦX174 in dewatered blackwater. At the end of the long-term freezing experiment (10 months), an MPN recovery study was done, including the microbial groups that had shown...... the largest reduction, using tryptone soy broth at incubation temperatures of 10 and 20 °C overnight for the coliforms and AR bacteria, and buffered peptone water at incubation temperature of 37 °C for 18–20 h for Salmonella. Fecal streptococci were more resistant to long-term freezing than the coliform group...

Understanding the electrical characteristics of micromotors

Science.gov (United States)

Emadi, Ali; Irudayaraj, Sujay S.

2005-06-01

This paper presents a comprehensive list of issues related to the electrical characteristics of both electrostatic and electromagnetic micromotors and aims at understanding the behavior of the micromotor from the electrical standpoint. The paper takes the step-by-step approach by first presenting an overview of the laws of electrostatics and electromagnetism for micromachines, their applicability, features and limitations, and then progresses to independently analyze some of the important machine related quantities like electromotive torque, force-output, angular frequencies, supply conditions and requirements, for different types of electrostatic and electromagnetic micromotor constructions. A thorough study on the electric machine parameters that affect the performance of the micromotor need to be performed, since it would serve as a useful link in integrating the micromachine output performance with the fabrication process and challenges associated with it. Achieving such integration would then determine the optimized working condition for the micromotor. The main reason for this study is that although significant advancements have fostered the growth of micromotors in the recent past which has led to the establishment of the micromotor as quite a remarkable machine for powering micromechanical devices, and also as an industrial requirement for various applications, there has always been a concern about the optimal performance of the micromotor, since there is more than just one technology that is being incorporated to realize the micromotor. With fields ranging from surface engineering and chemistry to material science engineering exerting influence on the micromotor design, it becomes very important to completely comprehend the electrophysics of the micromachine that would in turn interact with the science of fabrication to result in the development of better micromotors with considerably less functional complexity.

Influence of the microwave irradiation dewatering on the combustion characteristics of Chinese brown coals

Science.gov (United States)

Ge, Lichao; Feng, Hongcui; Xu, Chang; Zhang, Yanwei; Wang, Zhihua

2018-02-01

This study investigates the influence of microwave irradiation on coal composition, pore structure, coal rank, and combustion characteristics of typical brown coals in China. Results show that the upgrading process significantly decreased the inherent moisture, and increased calorific value and fixed carbon content. After upgrading, pore distribution extended to micropore region, oxygen functional groups were reduced and destroyed, and the apparent aromaticity increased suggesting an improvement in the coal rank. Based on thermogravimetric analysis, the combustion processes of upgraded coals were delayed toward the high temperature region, and the temperatures of ignition, peak and burnout increased. Based on the average combustion rate and comprehensive combustion parameter, the upgraded coals performed better compared with raw brown coals and a high rank coal. In ignition and burnout segments, the activation energy increased but exhibited a decrease in the combustion stage.

Development of Graft Copolymer Flocculant Based on Acrylamide and Acrylic Acid for the dewatering of coal

International Nuclear Information System (INIS)

Mahmoud, G.A.; Abdel Khalek, M.A

2012-01-01

Most coal preparation processes were carried out in water medium. The water content of coal product has a negative impact on handling and specific energy value. The moisture content may be attributed to the proportion of fine coal, which presents the greatest dewatering problem. A novel polymeric flocculant has been developed by graft copolymerization of acrylamide (AAm) with acrylic acid (AAc) using gamma irradiation technique. The grafted copol621621ymer P(AAm/AAc) was characterized by Fourier-transform infrared spectroscopy (FTIR), and thermo-gravimetric analysis (TGA). The effects of reaction parameters, such as total absorbed dose, and monomer concentration on grafting yield were investigated. The flocculation performance of the graft copolymer P(AAm/AAc) was investigated in coal suspension. It was observed that the grafting ratio was one of the key factors for the flocculating effects. The copolymers with various grafting ratios showed different flocculating properties. It was found that as the grafting ratio increased, the flocculating effect also increased. The flocculation performance of the grafted copolymer was better than that of the commercial flocculant, poly-acrylamide (Magnafloc 1011).

Mine dewatering and impact assessment in an arid area: Case of Gulf region.

Science.gov (United States)

Yihdego, Yohannes; Drury, Len

2016-11-01

Analytical and empirical solution coupled with water balance method were used to predict the ground water inflow to a mine pit excavated below the water table, final pit lake level/recovery and radius of influence, through long-term and time variant simulations. The solution considers the effect of decreased saturated thickness near the pit walls, distributed recharge to the water table and upward flow through the pit bottom. The approach is flexible to accommodate the anisotropy/heterogeneity of the real world. Final pit void water level was assessed through scenarios to know whether it will be consumed by evaporation and a shallow lake will form or not. The optimised radius of influence was estimated which is considered as crucial information in relation to the engineering aspects of mine planning and sustainable development of the mine area. Time-transient inflow over a period of time was estimated using solutions, including analytical element method (AEM). Their primary value is in providing estimates of pit inflow rates to be used in the mine dewatering. Inflow estimation and recovery helps whether there is water to supplement the demand and if there is any recovery issue to be dealt with in relation to surface and groundwater quality/eco-system, environmental evaluations and mitigation. Therefore, this method is good at informing decision makers in assessing the effects of mining operations and developing an appropriate water management strategy.

Design and construction of solidification and dewatering facility at Alabama Power Company's Farley Nuclear Plant

International Nuclear Information System (INIS)

Farnsworth, P.

1988-01-01

The approximate total cost of the structure and supporting piping systems is estimated to be 4.1 million dollars. Total dose savings per year could be as high as 70 man Rem for resin processing alone. The ability to store refueling equipment, process contaminated oils, load and unload trucks and containers regardless of weather conditions and support repair work on equipment greatly enhances the cost effectiveness of the project. It will take at least one year of operation of the facility to accurately assess the true cost savings to Alabama Power Company. The morale factor for the Waste and Decon Group has escalated measurably due to the dose reduction to our personnel. Plant and company management are well pleased due to the possibility of a spill or release to the environment has been eliminated which was on intangible cost. Facility construction has been completed as of this date and resin transfer anticipated within the next few days. Some of the problems encountered in planning and constructing this solidification and dewatering facility are presented. A safety evaluation for the facility is included in the appendix

Dewatering of Chlorella pyrenoidosa using diatomite dynamic membrane: filtration performance, membrane fouling and cake behavior.

Science.gov (United States)

Zhang, Yalei; Zhao, Yangying; Chu, Huaqiang; Zhou, Xuefei; Dong, Bingzhi

2014-01-01

The diatomite dynamic membrane (DDM) was utilized to dewater Chlorella pyrenoidosa of 2 g dry weight/L under continuous-flow mode, whose ultimate algae concentration ranged from 43 g to 22 g dry weight/L of different culture time. The stable flux of DDM could reach 30 L/m(2) h over a 24 h operation time without backwash. Influences of extracellular organic matters (EOM) on filtration behavior and membrane fouling were studied. The DDM was divided into three sub-layers, the slime layer, the algae layer and the diatomite layer from the outside to the inside of the cake layer based on components and morphologies. It was found that EOM caused membrane fouling by accumulating in the slime and algae layers. The DDM intercepted polysaccharides, protein-like substances, humic-like substances and some low-MW organics. Proteins were indicated the major membrane foulants with increased protein/polysaccharide ratio from the slime layer to the diatomite layer as culture time increased. This method could be applied to subsequent treatment of microalgae coupling technology of wastewater treatment or microalgae harvesting for producing biofuel. Copyright © 2013 Elsevier B.V. All rights reserved.

Optimization of volatile fatty acid production with co-substrate of food wastes and dewatered excess sludge using response surface methodology.

Science.gov (United States)

Hong, Chen; Haiyun, Wu

2010-07-01

Central-composite design (CCD) and response surface methodology (RSM) were used to optimize the parameters of volatile fatty acid (VFA) production from food wastes and dewatered excess sludge in a semi-continuous process. The effects of four variables (food wastes composition in the co-substrate of food wastes and excess sludge, hydraulic retention time (HRT), organic loading rate (OLR), and pH) on acidogenesis were evaluated individually and interactively. The optimum condition derived via RSM was food wastes composition, 88.03%; HRT, 8.92 days; OLR, 8.31 g VSS/ld; and pH 6.99. The experimental VFA concentration was 29,099 mg/l under this optimum condition, which was well in agreement with the predicted value of 28,000 mg/l. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Feasibility of vermicomposting dewatered sludge from paper mills using Perionyx excavatus

Directory of Open Access Journals (Sweden)

Puspanjali Sonowal

2013-06-01

Full Text Available India has a large network of pulp and paper mills of varying capacity. On an industrial scale the sludge from paper and pulp mills is disposed of either as landfill or incinerated. Both methods result in the loss of a valuable resource and have obvious environmental and economic disadvantages. The solid waste from pulp and paper mills is a source of organic matter and its proper disposal and management is the responsibility of the industry. As composting/vermicomposting could be used to transform this waste trials were carried out to determine the feasibility of converting dewatered sludge (DS into a value added end product using an earthworm, Perionyx excavatus. The vermicomposting of the waste resulted in an increase in its electrical conductivity (EC, ash content, total nitrogen (TN, total phosphorous (TP and available phosphorous (AP, respectively, and a decrease in total organic carbon (TOC, biochemical oxygen demand (BOD, chemical oxygen demand (COD, oxygen uptake rate (OUR and evolution of carbon dioxide (CO2. Overall, the best treatment was T5 in which there was a 76.1% increase in TP, 58.7% in TN, 74.5% decrease in TOC , and a reduction of 6.7 fold in the production of CO2 and 10.7 fold in BOD, respectively. Our trials demonstrate that vermicomposting using an epigeic earthworm, Perionyx excavatus, is an alternate and environmentally safe way of recycling paper mill sludge if it is mixed with an appropriate amount of cow dung and food processing waste. Overall T5 was the best combination of paper mill sludge and waste for vermicomposting followed by T3, T2, T4 and T1, respectively.

Extracellular polymeric substances (EPS) producing bacterial strains of municipal wastewater sludge: isolation, molecular identification, EPS characterization and performance for sludge settling and dewatering.

Science.gov (United States)

Bala Subramanian, S; Yan, S; Tyagi, R D; Surampalli, R Y

2010-04-01

Wastewater treatment plants often face the problems of sludge settling mainly due to sludge bulking. Generally, synthetic organic polymer and/or inorganic coagulants (ferric chloride, alum and quick lime) are used for sludge settling. These chemicals are very expensive and further pollute the environment. Whereas, the bioflocculants are environment friendly and may be used to flocculate the sludge. Extracellular polymeric substances (EPS) produced by sludge microorganisms play a definite role in sludge flocculation. In this study, 25 EPS producing strains were isolated from municipal wastewater treatment plant. Microorganisms were selected based on EPS production properties on solid agar medium. Three types of EPS (slime, capsular and bacterial broth mixture of both slime and capsular) were harvested and their characteristics were studied. EPS concentration (dry weight), viscosity and their charge (using a Zetaphoremeter) were also measured. Bioflocculability of obtained EPS was evaluated by measuring the kaolin clay flocculation activity. Six bacterial strains (BS2, BS8, BS9, BS11, BS15 and BS25) were selected based on the kaolin clay flocculation. The slime EPS was better for bioflocculation than capsular EPS and bacterial broth. Therefore, extracted slime EPS (partially purified) from six bacterial strains was studied in terms of sludge settling [sludge volume index (SVI)] and dewatering [capillary suction time (CST)]. Biopolymers produced by individual strains substantially improved dewaterability. The extracted slime EPS from six different strains were partially characterized. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

[Effects of ultrasonic pretreatment on drying characteristics of sewage sludge].

Science.gov (United States)

Li, Run-Dong; Yang, Yu-Ting; Li, Yan-Long; Niu, Hui-Chang; Wei, Li-Hong; Sun, Yang; Ke, Xin

2009-11-01

The high water content of sewage sludge has engendered many inconveniences to its treatment and disposal. While ultrasonic takes on unique advantages on the sludge drying because of its high ultrasonic power, mighty penetrating capability and the ability of causing cavitations. Thus this research studies the characteristics influences of ultrasonic bring to the sludge drying and effects of the exposure time, ultrasonic generator power, temperatures of ultrasonic and drying temperature on the drying characteristics of dewatered sludge. Results indicate that ultrasonic pretreatment could speed up evaporation of the free water in sludge surface and help to end the drying stage with constant speed. In addition, ultrasonic treatment can effectively improve the sludge drying efficiency which could be more evident with the rise of the ultrasonic power (100-250 W), ultrasonic temperature and drying temperature. If dried under low temperature such as 105 degrees C, sludge will have premium drying characteristics when radiated under ultrasound for a shorter time such as 3 min. In the end, the ultrasonic treatment is expected to be an effective way to the low-cost sludge drying and also be an important reference to the optimization of the sludge drying process because of its effects on the increase of sludge drying efficiency.

Technical report on treatment of radioactive slurry liquid waste

International Nuclear Information System (INIS)

Jeong, Gyeong Hwan; Jo, Eun Sung; Park, Seung Kook; Jung, Ki Jung

1999-06-01

By literature survey, this report deals with the technology on typical pre-treatment and filtration of radioactive slurry liquid waste, produced during the operation of TRIGA Mark-II, III research reactor, and produced during the decommission/decontamination of TRIGA Mark-II, III research reactor. It is reviewed pre-treatment procedure, both physical and chemical that optimise the dewatering characteristics, and also surveyed types of dewatering devices based on centrifuges, vacuum and pressure filters with particular reference to various combined field approaches using two or more complementary driving forces to achieve better performance. Dewatering operations and devises on filtration of radioactive slurry liquid waste are also analysed. (author)

Speeding by young novice drivers: What can personal characteristics and psychosocial theory add to our understanding?

Science.gov (United States)

Scott-Parker, Bridie; Hyde, Melissa K; Watson, Barry; King, Mark J

2013-01-01

Young novice drivers continue to be overrepresented in fatalities and injuries arising from crashes even with the introduction of countermeasures such as graduated driver licensing (GDL). Enhancing countermeasures requires a better understanding of the variables influencing risky driving. One of the most common risky behaviours performed by drivers of all ages is speeding, which is particularly risky for young novice drivers who, due to their driving inexperience, have difficulty in identifying and responding appropriately to road hazards. Psychosocial theory can improve our understanding of contributors to speeding, thereby informing countermeasure development and evaluation. This paper reports an application of Akers' social learning theory (SLT), augmented by Gerrard and Gibbons' prototype/willingness model (PWM), in addition to personal characteristics of age, gender, car ownership, and psychological traits/states of anxiety, depression, sensation seeking propensity and reward sensitivity, to examine the influences on self-reported speeding of young novice drivers with a Provisional (intermediate) licence in Queensland, Australia. Young drivers (n=378) recruited in 2010 for longitudinal research completed two surveys containing the Behaviour of Young Novice Drivers Scale, and reported their attitudes and behaviours as pre-Licence/Learner (Survey 1) and Provisional (Survey 2) drivers and their sociodemographic characteristics. An Akers' measurement model was created. Hierarchical multiple regressions revealed that (1) personal characteristics (PC) explained 20.3%; (2) the combination of PC and SLT explained 41.1%; (3) the combination of PC, SLT and PWM explained 53.7% of variance in self-reported speeding. Whilst there appeared to be considerable shared variance, the significant predictors in the final model included gender, car ownership, reward sensitivity, depression, personal attitudes, and Learner speeding. These results highlight the capacity for

Paste pumping and deposition field trials and concepts on Syncrude's dewatered mature fine tailings MFT centrifuge cake

Energy Technology Data Exchange (ETDEWEB)

Lahaie, R. [Syncrude Canada Ltd., Edmonton, AB (Canada); Ahmed, I.; Labelle, M.; Brown, R. [Golder Paste Technology, Sudbury, ON (Canada)

2009-07-01

This presentation discussed a paste pumping and deposition field study conducted on dewatered mature fine tailings (MFT) located at Syncrude's Mildred Lake operation. Bench scale rheological examinations of centrifuge cakes and design field testing are used to determine the pumpability of MFT centrifuge cakes. The study included a transportation assessment for the conveyor and positive displacement pumps and pipelines, as well as geotechnical and environmental analyses of bulk materials. Flocculant optimization and centrifuge operational parameter assessments were conducted. Pressure differential and flow rate data were captured in the field studies in order to determine pipeline friction loss. The study showed that pipe friction factors can be obtained using the Bingham plastic model. A natural deposition angle was determined for the MFT centrifuged cake. The study showed that the cake must be sheared in order to reduce yield stress before pumping. It was concluded that displacement pumps can be used to reduced pipeline friction factors. tabs., figs.

Improving the support characteristics of hydraulic fill

Energy Technology Data Exchange (ETDEWEB)

Corson, D. R.; Dorman, K. R.; Sprute, R. H.

1980-05-15

Extensive laboratory and field testing has defined the physical properties of hydraulic fill. Effect of void ratio on percolation rate has been quantified, and tests were developed to estimate waterflow through fill material in a given state underground. Beneficial effect on fill's support capability through addition of cement alone or in conjunction with vibratory compaction has been investigated. Two separate field studies in operating cut-and-fill mines measured vein-wall deformation and loads imposed on backfilled stopes. Technology has been developed that will effectively and efficiently dewater and densify ultra-fine-grained slurries typical of metal mine hydraulic backfill. At least two operators are using this electrokinetic technique to dewater slimes collected in underground sumps or impoundments. This technique opens up the possibility of using the total unclassified tailings product as a hydraulic backfill. Theoretical enhancement of ground support and rock-burst control through improved support capability will be tested in a full-scale mine stope installation. Both a horizontal layer and a vertical column of high modulus fill will be placed in an attempt to reduce stope wall closure, support more ground pressure, and lessen rock-burst occurrence.

Groundwater Sustainability through a Novel Dewatering Technology

Science.gov (United States)

Jin, Y.; Holzbecher, E.; Ebneth, S.

2012-12-01

Groundwater plays a key role in the hydrologic cycle and ecosystem balances. Over the past decades, groundwater is intensively extracted in order to keep construction or mining sites dry. For the latter purpose the pumped water is usually discharged into a nearby surface water body or injected into an aquifer distant from the abstraction sites. As a result, aquifers are depleted and the local eco-system is disrupted as a consequence of falling groundwater tables. Given ongoing pressure on aquifer from abstraction sites, it is vital to bring up adequate attention on groundwater conservation. We demonstrate a novel technique, Düsensauginfiltration (DSI, translated as 'nozzel-suction-infiltration'), which avoids water conveyance but still lowers the groundwater table locally. The method combines abstraction of groundwater at the upper part of the aquifer with injection in the same borehole, but at a greater depth. Hence no water is withdrawn from the system. The method is already used practically in Germany, Netherlands, and China, however, it is not yet fully scientifically understood and evaluated. Currently, two tests sites in Germany, for single and multi well respectively, are selected, at which the DSI technology is currently examined. The project is cooperated with a leading dewatering company (Hoelscher Wasserbau GmbH) and funded by Deutsche Bundesstiftung Umwelt (DBU). To provide the basic principle of the method, we present numerical models solving the differential equation, which is derived from Darcy's Law and mass conservation, describing groundwater flow. We set up stationary numerical models in 2D (vertical cross section for single well case) and 3D (multi well case and/or when ambient groundwater flow is considered) using COMSOL Multiphysics. Since our model region only involves the saturated part of the unconfined aquifer, the numerical model solves a free boundary problem using hydraulic pressure as unknown variable. Two physical modes are included

Understanding Changes in Modeled Land Surface Characteristics Prior to Lightning-Initiated Holdover Fire Breakout

Science.gov (United States)

Schultz, Christopher J.; Case, Jonathan L.; Hain, Christopher R.; White, Kristopher; Wachter, J. Brent; Nauslar, Nicholas; MacNamara, Brittany

2018-01-01

Lightning initiated wildfires are only 16% of the total number of wildfires within the United States, but account for 56% of the acreage burned. One of the challenges with lightning-initiated wildfires is their ability to "holdover" which means smolder for up to 2+ weeks before breaking out into a full fledged fire. This work helps characterize the percentage of holdover events due to lightning, and helps quantify changes in the land surface characteristics to help understand trends in soil moisture and vegetation stress that potentially contribute to the fire breaking out into a full wildfire.

The impact of pumped water from a de-watered Magnesian limestone quarry on an adjacent wetland: Thrislington, County Durham, UK

International Nuclear Information System (INIS)

Mayes, W.M.; Large, A.R.G.; Younger, P.L.

2005-01-01

Although quarrying is often cited as a potential threat to wetland systems, there is a lack of relevant, quantitative case studies in the literature. The impact of pumped groundwater discharged from a quarry into a wetland area was assessed relative to reference conditions in an adjacent fen wetland that receives only natural runoff. Analysis of vegetation patterns at the quarry wetland site, using Detrended Correspondence Analysis and the species indicator values of Ellenberg, revealed a clear disparity between community transitions in the quarry wetland and the reference site. Limited establishment of moisture-sensitive taxa, the preferential proliferation of robust wetland species and an overall shift towards lower species diversity in the quarry wetland were explicable primarily by the physico-chemical environment created by quarry dewatering. This encompassed high pH (up to 12.8), sediment-rich effluent creating a nutrient-poor substrate with poor moisture retention in the quarry wetland, and large fluctuations in water levels. - High pH, sediment-rich runoff from a quarry constrains floristic diversity in an adjacent wetland

The impact of pumped water from a de-watered Magnesian limestone quarry on an adjacent wetland: Thrislington, County Durham, UK

Energy Technology Data Exchange (ETDEWEB)

Mayes, W.M. [Institute for Research on Environment and Sustainability, University of Newcastle, Newcastle upon Tyne NE1 7RU (United Kingdom)]. E-mail: w.m.mayes@ncl.ac.uk; Large, A.R.G. [School of Geography, Politics and Sociology, University of Newcastle, Newcastle upon Tyne NE1 7RU (United Kingdom); Younger, P.L. [Institute for Research on Environment and Sustainability, University of Newcastle, Newcastle upon Tyne NE1 7RU (United Kingdom)

2005-12-15

Although quarrying is often cited as a potential threat to wetland systems, there is a lack of relevant, quantitative case studies in the literature. The impact of pumped groundwater discharged from a quarry into a wetland area was assessed relative to reference conditions in an adjacent fen wetland that receives only natural runoff. Analysis of vegetation patterns at the quarry wetland site, using Detrended Correspondence Analysis and the species indicator values of Ellenberg, revealed a clear disparity between community transitions in the quarry wetland and the reference site. Limited establishment of moisture-sensitive taxa, the preferential proliferation of robust wetland species and an overall shift towards lower species diversity in the quarry wetland were explicable primarily by the physico-chemical environment created by quarry dewatering. This encompassed high pH (up to 12.8), sediment-rich effluent creating a nutrient-poor substrate with poor moisture retention in the quarry wetland, and large fluctuations in water levels. - High pH, sediment-rich runoff from a quarry constrains floristic diversity in an adjacent wetland.

WtF‐Nano: One‐Pot Dewatering and Water‐Free Topochemical Modification of Nanocellulose in Ionic Liquids or γ‐Valerolactone

Science.gov (United States)

Laaksonen, Tiina; Helminen, Jussi K. J.; Lemetti, Laura; Långbacka, Jesper; Rico del Cerro, Daniel; Hummel, Michael; Rantamäki, Antti H.; Kakko, Tia; Kemell, Marianna L.; Wiedmer, Susanne K.; Heikkinen, Sami; Kilpeläinen, Ilkka

2017-01-01

Abstract Ionic liquids are used to dewater a suspension of birch Kraft pulp cellulose nanofibrils (CNF) and as a medium for water‐free topochemical modification of the nanocellulose (a process denoted as “WtF‐Nano”). Acetylation was applied as a model reaction to investigate the degree of modification and scope of effective ionic liquid structures. Little difference in reactivity was observed when water was removed, after introduction of an ionic liquid or molecular co‐solvent. However, the viscoelastic properties of the CNF suspended in two ionic liquids show that the more basic, but non‐dissolving ionic liquid, allows for better solvation of the CNF. Vibrio fischeri bacterial tests show that all ionic liquids in this study were harmless. Scanning electron microscopy and wide‐angle X‐ray scattering on regenerated samples show that the acetylated CNF is still in a fibrillar form. 1 D and 2 D NMR analyses, after direct dissolution in a novel ionic liquid electrolyte solution, indicate that both cellulose and residual xylan on the surface of the nanofibrils reacts to give acetate esters. PMID:29112334

Understanding the Characteristics of the Sexual Harasser.

Science.gov (United States)

Sundt, Melora

1996-01-01

Information on characteristics of harassers can help policymakers and educators develop more effective prevention programs. Results of a survey of 336 men and 333 women are presented in terms of institutional size, satisfaction with institutional response, views on the acceptability of harassment, beliefs related to harassment, and types of…

Observations of ebb flows on tidal flats: Evidence of dewatering?

Science.gov (United States)

Rinehimer, J. P.; Thomson, J. M.; Chickadel, C.

2010-12-01

Incised channels are a common morphological feature of tidal flats. When the flats are inundated, flows are generally forced by the tidally varying sea surface height. During low tide, however, these channels continue to drain throughout flat exposure even without an upstream source of water. While the role of porewater is generally overlooked due to the low permeability of marine muds, it remains the only potential source of flows through the channels during low tide. In situ and remotely sensed observations (Figure 1) at an incised channel on a tidal flat in Willapa Bay from Spring 2010 indicate that dewatering of the flats may be driving these low tide flows. High resolution Aquadopp ADCP velocity profiles are combined with observations from tower-based infrared (IR) video to produce a complete time series of surface velocity measurements throughout low tide. The IR video observations provide a measurement of surface currents even when the channel depth is below the blanking distance of the ADCP (10 cm). As the depth within the channel drops from 50 cm to 10 cm surface velocities increase from 10 cm/s to 60 cm/s even as the tide level drops below the channel flanks and the flats are dry. As the drainage continues, the temperature of the flow rises throughout low tide, mirroring temperatures within the sediment bed on the tidal flat. Drainage salinity falls despite the lack of any freshwater input to the flat indicating that less saline porewater may be the source. The likely source of the drainage water is from the channel flanks where time-lapse video shows slumping and compaction of channel sediments. Velocity profiles, in situ temperatures, and IR observations also are consistent with the presence of fluid muds and a hyperpycnal, density driven outflow at the channel mouth highlighting a possible pathway for sediment delivery from the flats to the main distributary channels of the bay. Figure 1: Time series of tidal flat channel velocities and temperatures

Understanding Consumer Interaction on Instagram: The Role of Satisfaction, Hedonism, and Content Characteristics.

Science.gov (United States)

Casaló, Luis V; Flavián, Carlos; Ibáñez-Sánchez, Sergio

2017-06-01

The increasing relevance of Instagram and its growing adoption among top brands suggest an effort to better understand consumers' behaviors within this context. The purpose of this study is to examine the role of perceived hedonism and satisfaction in determining consumers' intentions to interact and their actual interaction behaviors (the number of likes, by tapping a heart icon, and comments) in a brand's official Instagram account. Also, we investigate the effect of consumer perceptions about the characteristics of the content generated in the account (perceived originality, quantity, and quality) on their perceived hedonism and satisfaction. Data were collected in two stages from 808 members of a fashion brand's official Instagram account. First, participants answered an online questionnaire to evaluate their perceptions, satisfaction, and interaction intentions. Second, 1 month later, we measure the number of likes and comments done by each participant in the brand's official Instagram account during that month. Using partial least squares to analyze the data, perceived hedonism is found to affect both satisfaction and the intention to interact in Instagram, which in turn influences actual behavior. Besides, perceived originality is the most relevant content characteristic to develop perceived hedonism. These findings offer managers a general vision of consumers' behaviors on Instagram, highlighting the importance of hedonism to create a satisfactory experience.

Understanding I/O workload characteristics of a Peta-scale storage system

Energy Technology Data Exchange (ETDEWEB)

Kim, Youngjae [ORNL; Gunasekaran, Raghul [ORNL

2015-01-01

Understanding workload characteristics is critical for optimizing and improving the performance of current systems and software, and architecting new storage systems based on observed workload patterns. In this paper, we characterize the I/O workloads of scientific applications of one of the world s fastest high performance computing (HPC) storage cluster, Spider, at the Oak Ridge Leadership Computing Facility (OLCF). OLCF flagship petascale simulation platform, Titan, and other large HPC clusters, in total over 250 thousands compute cores, depend on Spider for their I/O needs. We characterize the system utilization, the demands of reads and writes, idle time, storage space utilization, and the distribution of read requests to write requests for the Peta-scale Storage Systems. From this study, we develop synthesized workloads, and we show that the read and write I/O bandwidth usage as well as the inter-arrival time of requests can be modeled as a Pareto distribution. We also study the I/O load imbalance problems using I/O performance data collected from the Spider storage system.

Characteristics of residues from thermally treated anaerobic sludges

International Nuclear Information System (INIS)

Friedman, A.A.; Smith, J.E.; De Santis, J.; Ptak, T.; Ganley, R.C.

1988-01-01

Sludge management and disposal are probably the most difficult and expensive operations involved in wastewater treatment today. To minimize final disposal costs many waste treatment facilities practice some form of anaerobic digestion and dewatering to reduce the volume and offensiveness of their by-product sludges. One potential alternative for reducing sludge volumes consists of high temperature, partial oxidation of these previously digested sludges (PDS) and subsequent anaerobic biological conversion of resulting soluble organics to methane. This paper describes solids destruction, residue characteristics and biodegradability factors that should be considered in the design of liquid thermal treatment processes for the management of anaerobic sludges. To date only very limited information is available concerning the suitability of thermally treated PDS to serve as a substrate for the generation of methane. The primary objective of this research was to determine the feasibility of producing methane efficiently from the residual VSS in anaerobically digested sludges. Secondary goals were to establish the ''best'' conditions for thermal treatment for solubilizing PDS, to observe the effect of the soluble products on methanogenesis and to evaluate process sidestreams for dewaterability and anaerobic biodegradability

Nitrogen dynamics model for a pilot field-scale novel dewatered alum sludge cake-based constructed wetland system.

Science.gov (United States)

Kumar, J L G; Zhao, Y Q; Hu, Y S; Babatunde, A O; Zhao, X H

2015-01-01

A model simulating the effluent nitrogen (N) concentration of treated animal farm wastewater in a pilot on-site constructed wetland (CW) system, using dewatered alum sludge cake (DASC) as wetland substrate, is presented. The N-model was developed based on the Structural Thinking Experiential Learning Laboratory with Animation software and is considering organic nitrogen, ammonia nitrogen (NH3) and nitrate nitrogen (NO3-N) as the major forms of nitrogen involved in the transformation chains. Ammonification (AMM), ammonia volatilization, nitrification (NIT), denitrification, plant uptake, plant decaying and uptake of inorganic nitrogen by algae and bacteria were considered in this model. pH, dissolved oxygen, temperature, precipitation, solar radiation and nitrogen concentrations were considered as forcing functions in the model. The model was calibrated by observed data with a reasonable agreement prior to its applications. The simulated effluent detritus nitrogen, NH4-N, NO3-N and TN had a considerably good agreement with the observed results. The mass balance analysis shows that NIT accounts for 65.60%, adsorption (ad) (11.90%), AMM (8.90%) followed by NH4-N (Plants) (5.90%) and NO3-N (Plants) (4.40%). The TN removal was found 52% of the total influent TN in the CW. This study suggested an improved overall performance of a DASC-based CW and efficient N removal from wastewater.

The value of a combined word recognition and knowledge measure to understand characteristics of our patients' oral health literacy.

Science.gov (United States)

Atchison, Kathryn A; Macek, Mark D; Markovic, Daniela

2017-08-01

The objective of the analysis was to examine the association between sociodemographic and dental understanding and utilization characteristics and lower oral health literacy (HL) and knowledge. The cross-sectional Multicenter Oral Health Literacy Research Study (MOHLRS) recruited and interviewed 923 English-speaking, initial care-seeking adults. The questionnaire included participant sociodemographic characteristics, measures of the participant's understanding and utilization of dentistry, and two oral HL measures, the Rapid Estimate of Adult Literacy in Medicine and Dentistry (REALM-D) and the Comprehensive Measure of Oral Health Knowledge (CMOHK), which were combined into a new composite HL and knowledge measure, the MOHLR-K. In adjusted multivariable analysis, persons who reported more understanding of dentist instructions had higher mean scores for all HL measures. Subjects reporting the highest level of understanding had greater scores by an average of 1.6 points for the MOHLR-K (95% CI: 0.85-2.40, Pdental understanding and utilization factors. Persons who reported history of tooth decay had higher MOHLR-K scores by an average of about 0.77 points (95% CI: 0.49-1.04, Ptooth decay history after controlling for the other factors. Persons who had support all of the time for travel to the dentist had higher scores by an average of about 0.5 points for the MOHLR-K (95% CI: 0.04-0.96, P=.03) and about 0.89 points for the REALMD-20 (95% CI: 0-1.79, P=.05) as compared to subjects with no support after controlling for other factors. Report of periodontal history, financial challenges to delay a dental visit and dental utilization were not significantly associated with any of the HL measures once the other factors were adjusted for in the model. The analysis confirmed that pronunciation of medical and dental terms may not fully reflect comprehension and revealed that understanding both patients' sociodemographic and dental understanding and utilization factors, such as

Characteristics of biosolids from sludge treatment wetlands for agricultural reuse

DEFF Research Database (Denmark)

Uggetti, Enrica; Ferrer, Ivet; Nielsen, Steen

2012-01-01

Sludge treatment wetlands (STW) consist of constructed wetlands systems specifically developed for sludge treatment over the last decades. Sludge dewatering and stabilisation are the main features of this technology, leading to a final product which may be recycled as an organic fertiliser or soi...... legal limits for land application of the sludge. Our results suggest that biosolids from the studied STW can be valorised in agriculture, especially as soil conditioner....

Ongoing child welfare services: Understanding the relationship of worker and organizational characteristics to service provision.

Science.gov (United States)

Lwin, Kristen; Fluke, John; Trocmé, Nico; Fallon, Barbara; Mishna, Faye

2018-06-01

Ongoing child welfare services are put in place after completion of the initial maltreatment investigation when there is a perceived need to mitigate the risk of future harm. The knowledge of how clinical, worker, and organizational characteristics interact with this decision to provide ongoing child welfare services is not well integrated in the research literature. Using secondary data from the Canadian Incidence Study of Reported Child Abuse and Neglect-2008, this study's primary objective is to understand the relationship of clinical, worker, and organizational characteristics to the decision to transfer a case to ongoing child welfare services and their relative contribution to the transfer decision in Canada. Findings indicate that several clinical level variables are associated with families receiving ongoing services. Additionally, organizational factors, such as type of services offered by the organization and the number of employee support programs available to workers, significantly predicted the decision to transfer a case to ongoing services. While no worker factors, such as education, amount of training, experience, or caseload, were associated with ongoing service receipt, the intraclass correlation coefficient of the final three-level parsimonious model indicated substantial clustering at the worker level. Results indicate that Canadian child welfare workers make decisions differently based on factors not available in the current study and that what would be deemed as important worker characteristics do not necessarily predict this outcome. Findings and implications for future research are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

The disc method. A new method for selecting facilitations in flocculating sludge to be dewatered in centrifuges; Metodo de disco. Un nuevo metodo para la seleccion de floculantes en la floculacion de lodos a deshidratar en centrifugas

Energy Technology Data Exchange (ETDEWEB)

Canga Rodriguez, J.; Gutierrez Lavin, A.

2002-07-01

An experimental protocol was designed at a laboratory scale, in view of achieving the selection with different poly electrolytes related to the chemical conditioning (flocculation) of sewage sludge before dewatering it in a drying centrifuge. The method is based on a new parameter of quality of the formed floc, which measures its compaction when is submitted to a fix external strength. Some experimental tests have been introduced, whose results are numbers, avoiding all subjective aspects related to direct observation of flocs. (Author) 8 refs.

Further understanding of PbWO4 Scintillator characteristics and their optimisation. LUMEN activity in 1998

CERN Document Server

Baccaro, Stefania; Borgia, Bruno; Cecilia, Angelica; Dafinei, Ioan; Diemoz, Marcella; Fabeni, P; Festinesi, Armando; Longo, Egidio; Martini, M; Meinardi, F; Mihoková, E; Montecchi, Marco; Nikl, M; Pazzi, G P; Rosa, J; Sulc, Miroslav

2000-01-01

The aim of LUMEN collaboration was the investigation on single crystals of PbWO4 ( PWO): the results performed up to now provide the evidence of the possibility to optimise the optical properties of an intrinsic scintillator such as PWO. The control of essential requirements in the crystal preparation ( raw material purity, growing methods and post-growth annealing) as well as the introduction of selected dopants at suitable concentrations ( particularly trivalent and pentavalent ions) were found to be very successful in lowering the concentration of point defects in the lattice which strongly affect scintillation properties and radiation hardness. The systematic investigation effort to better understand the scintillation characteristics and to improve the quality of PWO crystals is due to their use for the CMS electromagnetic calorimeter.

Understanding the visual resource

Science.gov (United States)

Floyd L. Newby

1971-01-01

Understanding our visual resources involves a complex interweaving of motivation and cognitive recesses; but, more important, it requires that we understand and can identify those characteristics of a landscape that influence the image formation process. From research conducted in Florida, three major variables were identified that appear to have significant effect...

Towards understanding the impact of assimilating along-track SLA data on simulated eddy characteristics in the Agulhas System

CSIR Research Space (South Africa)

De Vos, M

2016-10-01

Full Text Available understanding the impact of assimilating along-track SLA data on simulated eddy characteristics in the Agulhas System Marc de Vos1, 3, Björn Backeberg2, 3, 4 and François Counillon4 Marine Research Unit, South African Weather Service, South Africa1 Coastal... and 1 Tel: +27 21 935 5764; Email: marc.devos@weathersa.co.za dipoles reach the Agulhas Current frequently and on occasion propagate all the way to the retroflection, influencing its position and modulating ring shedding events there (Schouten et al...

Quantifying physical characteristics of wildland fuels using the fuel characteristic classification system.

Science.gov (United States)

Cynthia L. Riccardi; Susan J. Prichard; David V. Sandberg; Roger D. Ottmar

2007-01-01

Wildland fuel characteristics are used in many applications of operational fire predictions and to understand fire effects and behaviour. Even so, there is a shortage of information on basic fuel properties and the physical characteristics of wildland fuels. The Fuel Characteristic Classification System (FCCS) builds and catalogues fuelbed descriptions based on...

A feasibility study of in-line rheological characterisation of a ...

African Journals Online (AJOL)

The rheological characteristics of sludge affect transportation, treatment and the disposal processes involved in sludge system design and management operations such as dewatering, including flocculation and filtration. The concentration of solid matter in the sludge has an effect on rheological parameters such as yield ...

Effects of microwave irradiation treatment on physicochemical characteristics of Chinese low-rank coals

International Nuclear Information System (INIS)

Ge, Lichao; Zhang, Yanwei; Wang, Zhihua; Zhou, Junhu; Cen, Kefa

2013-01-01

Highlights: • Typical Chinese lignites with various ranks are upgraded through microwave. • The pore distribution extends to micropore region, BET area and volume increase. • FTIR show the change of microstructure and improvement in coal rank after upgrading. • Upgraded coals exhibit weak combustion similar to Da Tong bituminous coal. • More evident effects are obtained for raw brown coal with relative lower rank. - Abstract: This study investigates the effects of microwave irradiation treatment on coal composition, pore structure, coal rank, function groups, and combustion characteristics of typical Chinese low-rank coals. Results showed that the upgrading process (microwave irradiation treatment) significantly reduced the coals’ inherent moisture, and increased their calorific value and fixed carbon content. It was also found that the upgrading process generated micropores and increased pore volume and surface area of the coals. Results on the oxygen/carbon ratio parameter indicated that the low-rank coals were upgraded to high-rank coals after the upgrading process, which is in agreement with the findings from Fourier transform infrared spectroscopy. Unstable components in the coal were converted into stable components during the upgrading process. Thermo-gravimetric analysis showed that the combustion processes of upgraded coals were delayed toward the high-temperature region, the ignition and burnout temperatures increased, and the comprehensive combustion parameter decreased. Compared with raw brown coals, the upgraded coals exhibited weak combustion characteristics similar to bituminous coal. The changes in physicochemical characteristics became more notable when processing temperature increased from 130 °C to 160 °C or the rank of raw brown coal was lower. Microwave irradiation treatment could be considered as an effective dewatering and upgrading process

Characteristics of reading and understanding of hearing impaired students in classes VI-VIII

Directory of Open Access Journals (Sweden)

Mustaf Morina

2015-03-01

impairment have stagnated compared with their peers in 8/1. Significant differences exist even within the group of deaf students in the three aspects of the study based on three dimensions of text, the terms of the speed of reading, significant differences exist also in the manifestation of errors and understanding of the text. Differences are also evident in terms of the degree of the hearing impairment, in terms of age and gender within the group of the deaf; this means that individual characteristics of students represent important facts.

Beyond OCR : Multi-faceted understanding of handwritten document characteristics

NARCIS (Netherlands)

He, Sheng; Schomaker, Lambert

Handwritten document understanding is a fundamental research problem in pattern recognition and it relies on the effective features. In this paper, we propose a joint feature distribution (JFD) principle to design novel discriminative features which could be the joint distribution of features on

Profiling of Intracellular Metabolites: An Approach to Understanding the Characteristic Physiology of Mycobacterium leprae.

Science.gov (United States)

Miyamoto, Yuji; Mukai, Tetsu; Matsuoka, Masanori; Kai, Masanori; Maeda, Yumi; Makino, Masahiko

2016-08-01

Mycobacterium leprae is the causative agent of leprosy and also known to possess unique features such as inability to proliferate in vitro. Among the cellular components of M. leprae, various glycolipids present on the cell envelope are well characterized and some of them are identified to be pathogenic factors responsible for intracellular survival in host cells, while other intracellular metabolites, assumed to be associated with basic physiological feature, remain largely unknown. In the present study, to elucidate the comprehensive profile of intracellular metabolites, we performed the capillary electrophoresis-mass spectrometry (CE-MS) analysis on M. leprae and compared to that of M. bovis BCG. Interestingly, comparison of these two profiles showed that, in M. leprae, amino acids and their derivatives are significantly accumulated, but most of intermediates related to central carbon metabolism markedly decreased, implying that M. leprae possess unique metabolic features. The present study is the first report demonstrating the unique profiles of M. leprae metabolites and these insights might contribute to understanding undefined metabolism of M. leprae as well as pathogenic characteristics related to the manifestation of the disease.

PENERAPAN ELEKTROOSMOSIS UNTUK PENGERINGAN SLUDGE DARI PENGOLAHAN LIMBAH CAIR

Directory of Open Access Journals (Sweden)

Darmawan Darmawan

2013-11-01

Full Text Available APPLICATION OF ELECTROOSMOSIS FOR DEWATERING OF SLUDGE FROM WASTE WATER TREATMENT. Wastewater treatment produces semi-solid residue (sludge that must be handled carefully during dumping and discharge to avoid polluting the environment. A low cost and easy treatment of dewatering is needed. This research aimed to apply electroosmosis technique for dewatering sludge in order to seek for parameters that can efficiently reduce water content of sludge, including range of voltage, type of electrodes, and distance between electrodes; and to determine the effect of electroosmosis processes on changes of chemical characteristics of sludge. The results showed that: (1 electroosmosis dewatering occurred on the sludge taken from waste water treatment of landfill but not on sludge from water purification plant (PDAM, (2 direct current voltage of 30 volts was the optimum voltage, (3 copper rod cathode provided electroosmosis process as good as stainless steel cathode and both were better than the woven stainless steel cathode, (4 the dewatering time to reduce 1200% (w/w water content to about 400% was about 40 hours for sludge of 2500 cm3 in volume (laboratory bench scale, (5 the anode need to reinserted gradually approaching the cathode due to current lost when the water content at the anode point reached 400% and sludge at the point shrink, and (6 some chemical elements in the sludge decreased significantly after treatment. Pengolahan limbah cair menghasilkan residu berupa bahan semi padat yang dikenal sebagai sludge. Sludge tersebut juga perlu dikelola penyimpanan dan pembuangannya agar tidak mencemari lingkungan. Salah satu pengelolaan sludge yang perlu dilakukan adalah pengeringan (dewatering. Salahsatu teknik dewatering yang mungkin diterapkan ialah teknik elektroosmosis, yaitu teknik yang memanfaatkan adanya pergerakan air pada media poros di dalam medan istrik searah. Penelitian ini bertujuan untuk mencari parameter sistem dewatering secara

Unified Modeling of Filtration and Expression of Biological Sludge

DEFF Research Database (Denmark)

Sørensen, Peter Borgen

Dewatering is a costly operation in both industry, e.g . when dewatering drilling mud, harbor sludge or biomass, and at municipal wastewater treatment plants when dewatering biological sludges. In practice, design and operation of dewatering equipment are mostly based on empirical knowledge, and ......, and normally results are not satisfactory, e.g. in terms of cake solids or capacity of equipment. Thus, there is a need for theoretical and technical developments to improve dewatering performance, based on better scientific knowledge and well defined principles and rules....

Understanding the undelaying mechanism of HA-subtyping in the level of physic-chemical characteristics of protein.

Science.gov (United States)

Ebrahimi, Mansour; Aghagolzadeh, Parisa; Shamabadi, Narges; Tahmasebi, Ahmad; Alsharifi, Mohammed; Adelson, David L; Hemmatzadeh, Farhid; Ebrahimie, Esmaeil

2014-01-01

The evolution of the influenza A virus to increase its host range is a major concern worldwide. Molecular mechanisms of increasing host range are largely unknown. Influenza surface proteins play determining roles in reorganization of host-sialic acid receptors and host range. In an attempt to uncover the physic-chemical attributes which govern HA subtyping, we performed a large scale functional analysis of over 7000 sequences of 16 different HA subtypes. Large number (896) of physic-chemical protein characteristics were calculated for each HA sequence. Then, 10 different attribute weighting algorithms were used to find the key characteristics distinguishing HA subtypes. Furthermore, to discover machine leaning models which can predict HA subtypes, various Decision Tree, Support Vector Machine, Naïve Bayes, and Neural Network models were trained on calculated protein characteristics dataset as well as 10 trimmed datasets generated by attribute weighting algorithms. The prediction accuracies of the machine learning methods were evaluated by 10-fold cross validation. The results highlighted the frequency of Gln (selected by 80% of attribute weighting algorithms), percentage/frequency of Tyr, percentage of Cys, and frequencies of Try and Glu (selected by 70% of attribute weighting algorithms) as the key features that are associated with HA subtyping. Random Forest tree induction algorithm and RBF kernel function of SVM (scaled by grid search) showed high accuracy of 98% in clustering and predicting HA subtypes based on protein attributes. Decision tree models were successful in monitoring the short mutation/reassortment paths by which influenza virus can gain the key protein structure of another HA subtype and increase its host range in a short period of time with less energy consumption. Extracting and mining a large number of amino acid attributes of HA subtypes of influenza A virus through supervised algorithms represent a new avenue for understanding and

Understanding the undelaying mechanism of HA-subtyping in the level of physic-chemical characteristics of protein.

Directory of Open Access Journals (Sweden)

Mansour Ebrahimi

Full Text Available The evolution of the influenza A virus to increase its host range is a major concern worldwide. Molecular mechanisms of increasing host range are largely unknown. Influenza surface proteins play determining roles in reorganization of host-sialic acid receptors and host range. In an attempt to uncover the physic-chemical attributes which govern HA subtyping, we performed a large scale functional analysis of over 7000 sequences of 16 different HA subtypes. Large number (896 of physic-chemical protein characteristics were calculated for each HA sequence. Then, 10 different attribute weighting algorithms were used to find the key characteristics distinguishing HA subtypes. Furthermore, to discover machine leaning models which can predict HA subtypes, various Decision Tree, Support Vector Machine, Naïve Bayes, and Neural Network models were trained on calculated protein characteristics dataset as well as 10 trimmed datasets generated by attribute weighting algorithms. The prediction accuracies of the machine learning methods were evaluated by 10-fold cross validation. The results highlighted the frequency of Gln (selected by 80% of attribute weighting algorithms, percentage/frequency of Tyr, percentage of Cys, and frequencies of Try and Glu (selected by 70% of attribute weighting algorithms as the key features that are associated with HA subtyping. Random Forest tree induction algorithm and RBF kernel function of SVM (scaled by grid search showed high accuracy of 98% in clustering and predicting HA subtypes based on protein attributes. Decision tree models were successful in monitoring the short mutation/reassortment paths by which influenza virus can gain the key protein structure of another HA subtype and increase its host range in a short period of time with less energy consumption. Extracting and mining a large number of amino acid attributes of HA subtypes of influenza A virus through supervised algorithms represent a new avenue for

Slab dehydration in Cascadia and its relationship to volcanism, seismicity, and non-volcanic tremor

Science.gov (United States)

Delph, J. R.; Levander, A.; Niu, F.

2017-12-01

The characteristics of subduction beneath the Pacific Northwest (Cascadia) are variable along strike, leading to the segmentation of Cascadia into 3 general zones: Klamath, Siletzia, and Wrangelia. These zones show marked differences in tremor density, earthquake density, seismicity rates, and the locus and amount of volcanism in the subduction-related volcanic arc. To better understand what controls these variations, we have constructed a 3D shear-wave velocity model of the upper 80 km along the Cascadia margin from the joint inversion of CCP-derived receiver functions and ambient noise surface wave data using 900 temporary and permanent broadband seismic stations. With this model, we can investigate variations in the seismic structure of the downgoing oceanic lithosphere and overlying mantle wedge, the character of the crust-mantle transition beneath the volcanic arc, and local to regional variations in crustal structure. From these results, we infer the presence and distribution of fluids released from the subducting slab and how they affect the seismic structure of the overriding lithosphere. In the Klamath and Wrangelia zones, high seismicity rates in the subducting plate and high tremor density correlate with low shear velocities in the overriding plate's forearc and relatively little arc volcanism. While the cause of tremor is debated, intermediate depth earthquakes are generally thought to be due to metamorphic dehydration reactions resulting from the dewatering of the downgoing slab. Thus, the seismic characteristics of these zones combined with rather sparse arc volcanism may indicate that the slab has largely dewatered by the time it reaches sub-arc depths. Some of the water released during earthquakes (and possibly tremor) may percolate into the overriding plate, leading to slow seismic velocities in the forearc. In contrast, Siletzia shows relatively low seismicity rates and tremor density, with relatively higher shear velocities in the forearc

The influence of zeta potential and yield stress on the filtration characteristics of a magnesium hydroxide simulant

International Nuclear Information System (INIS)

Biggs, Simon; Nabi, Rafiq; Poole, Colin; Patel, Ashok

2007-01-01

In the UK, irradiated fuels from Magnox reactors are often stored in water-filled ponds under alkaline conditions, so as to minimise corrosion of fuel cladding. This is important to prevent or reduce leakage of soluble fission products and actinides to the pond water. A variety of intermediate level wastes derived from Magnox materials are stored at power stations. Under these alkaline conditions, various species of magnesium are formed, of which magnesium hydroxide is the dominant material. The particle-fluid interactions are significant for the design and operation of facilities for hydraulic retrieval, filtration, dewatering and ion exchange treatment of fuel storage pond water and stored wet Magnox wastes. Here we describe a study of particulate properties and filtration characteristics of oxide particle simulants under laboratory conditions. Cake and medium resistance data were correlated across a range of pH conditions with electro-acoustic zeta potential and shear yield stress measurements, as a function of particle volume fractions. The influence of zeta potential on filtration properties arises directly from the interaction of particles within the sediment cake. (authors)

The constructive and physical characteristics of the Linacs built at the Institute of atomic physics- Bucharest

International Nuclear Information System (INIS)

Martin, D.; Oproiu, C.; Radu, S.; Marghitu, S.; Cojocaru, G.; Indreias, I.; Margaritesc, A.

1997-01-01

Our research proved that by developing proper electron technologies it is expected to bring new and efficient applications in the near future with linacs of low output power (up to 1000 W) and high energy (up to 10 MeV). With the ALID-7 linac it could be possible to satisfy the required production of flocculants for municipal sludge dewatering in our country.(author)

Payment Instrument Characteristics

DEFF Research Database (Denmark)

Holst, Jacques; Kjeldsen, Martin; Hedman, Jonas

2015-01-01

Over the last decade, we have witnessed payment innovations that fundamentally have changed the ways we pay. Payment innovations, such as mobile payments and on-line banking, include characteristics or features that are essential to understand if we want to know how and why payers choose among...... payment innovations. Using the Repertory Grid technique to explore 15 payers’ perception of six payment instruments, including coins, banknotes, debit cards, credit cards, mobile payments, and on-line banking, we identify 16 payment characteristics. The characteristics aggregate seventy-six unique...

Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

Energy Technology Data Exchange (ETDEWEB)

Al-Rajab, Abdul Jabbar; Sabourin, Lyne [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Lapen, David R. [Agriculture and Agri-Food Canada, Ottawa, ON K1A 0C6 (Canada); Topp, Edward, E-mail: ed.topp@agr.gc.ca [Agriculture and Agri-Food Canada, London, ON N5V 4T3 (Canada); Department of Biology, Western University, London, ON N6A 5B7 (Canada)

2015-04-15

In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with {sup 14}C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules. - Highlights: • We characterized the soil fate of four organic contaminants carried in biosolids. • Biosolids were placed on the soil surface or incorporated within the soil profile. • Naproxen, triclosan and triclocarban were dissipated more rapidly when incorporated. • Depth of placement did not influence the rate of carbamazepine dissipation. • Soil incorporation of biosolids will result in more rapid dissipation of contaminants.

Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

International Nuclear Information System (INIS)

Al-Rajab, Abdul Jabbar; Sabourin, Lyne; Lapen, David R.; Topp, Edward

2015-01-01

In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with 14 C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules. - Highlights: • We characterized the soil fate of four organic contaminants carried in biosolids. • Biosolids were placed on the soil surface or incorporated within the soil profile. • Naproxen, triclosan and triclocarban were dissipated more rapidly when incorporated. • Depth of placement did not influence the rate of carbamazepine dissipation. • Soil incorporation of biosolids will result in more rapid dissipation of contaminants

Work Practice Characteristics

DEFF Research Database (Denmark)

Pors, Jens Kaaber; Simonsen, Jesper

2003-01-01

and work practice. To understand these issues a framework of characteristics is identified and termed work practice characteristics to describe important aspects of the hybrid configuration of groupware and situated work practices. Drawing on concepts and work practice studies in the field of computer...... investigation of how groupware is employed to support new ways of working in a large European financial organisation are analysed to illustrate situations with high and low integration of groupware. The framework of work practice characteristics is discussed in the light of these findings and implications...

Understanding Liking in Relation to Sensory Characteristics, Consumer Concept Associations, Arousal Potential and "Appropriateness for Use" Using Apple Juice as an Application

DEFF Research Database (Denmark)

Stolzenbach, Sandra; Bredie, Wender L P; Christensen, Rune Haubo Bojesen

2016-01-01

potential and appropriateness for use using apple juices as an application. First, a laboratory panel (n=15: F=10, M=5) determined the sensory profile of the apple juices using the methods Partial Napping and Ultra Flash Profiling based on taste and flavor. Next, consumers (n=196: F=136, M=60) evaluated key......It is crucial to understand influential parameters for acquisition of consumer liking to ensure succesful product introduction and competativeness in the marketplace. This article aims to study and understand liking in relation to sensory characteristics, consumer concept associations, arousal...... apple juice parameters. The basic tastes sweet and sour were key properties and played a central role in liking acquisition. Apple juices having a sweet/sour balance were most liked. The importance of balance in sensory properties was underlined by the fact that consumer liking was related...

77 FR 67777 - National Oil and Hazardous Substance Pollution Contingency Plan; National Priorities List...

Science.gov (United States)

2012-11-14

... vegetable pickling waste, apple pulp, digester sludge, barrels of spent extracts, brine, the dewatering of... Michigan in Ottawa County. The Site consists of a site entrance, former lagoon area, dewatering lagoons... Company as a municipal garbage dump, liquid waste dewatering facility, and headquarters for its hauling...

Readability, suitability, and characteristics of asthma action plans: examination of factors that may impair understanding.

Science.gov (United States)

Yin, H Shonna; Gupta, Ruchi S; Tomopoulos, Suzy; Wolf, Michael S; Mendelsohn, Alan L; Antler, Lauren; Sanchez, Dayana C; Lau, Claudia Hillam; Dreyer, Benard P

2013-01-01

Recognition of the complexity of asthma management has led to the development of asthma treatment guidelines that include the recommendation that all pediatric asthma patients receive a written asthma action plan. We assessed the readability, suitability, and characteristics of asthma action plans, elements that contribute to the effectiveness of action plan use, particularly for those with limited literacy. This was a descriptive study of 30 asthma action plans (27 state Department of Health (DOH)-endorsed, 3 national action plans endorsed by 6 states). (1) readability (as assessed by Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, Simple Measure of Gobbledygook, Forcast), (2) suitability (Suitability Assessment of Materials [SAM], adequate: ≥ 0.4; unsuitable: typography (30.0%), learning stimulation/motivation (26.7%), and graphics (13.3%). There were no statistically significant differences between the average grade level or SAM score of state DOH developed action plans and those from or adapted from national organizations. Plans varied with respect to terms used, symptoms included, and recommended actions. Specific improvements in asthma action plans could maximize patient and parent understanding of appropriate asthma management and could particularly benefit individuals with limited literacy skills.

Bugs, butterflies, and spiders: children's understandings about insects

Science.gov (United States)

Shepardson, Daniel P.

2002-06-01

This article explores elementary children's ideas about insects. The study involved 20 children from each grade level, kindergarten through fifth-grade, for a total of 120 children. The data collection procedure was designed to investigate what an insect means to children, through the use of three different tasks: draw and explain, interview about instances, and the formulation of a general rule. Considering children's responses to the three tasks, I found that their ideas about insects reflect understandings based on physical characteristics of size and shape, arthropod characteristics, insect characteristics, human-insect interactions, life habits of insects, feeding habits of insects, and means of locomotion. Children's understandings are juxtaposed to that of a scientific perspective, elucidating implications for curriculum development and instructional practice.

Towards a better understanding of unethical consumer behavior : the influence of individual characteristics, situational circumstances and emotional experiences in consumers' ethical decision-making processes

OpenAIRE

Steenhaut, Sarah

2006-01-01

In sum, we may conclude that – although many questions are still to be resolved – the present dissertation contributes to a better understanding of unethical consumer behavior by further enhancing the theory development of consumers’ ethical decision-making processes by conceiving and testing (1) additional individual characteristics, (2) situational circumstances, and (3) emotional experiences (along with other issue-related influences), and considering the potential mediating and moderating...

Texas Science Teacher Characteristics and Conceptual Understanding of Newton's Laws of Motion

Science.gov (United States)

Busby, Karin Burk

extrapolated to determine any correlations. The sample size for this study was small (n=24), requiring a second study investigate potential correlations to teacher characteristics. The second study was conducted using the 2013-2014 school year participants in the Texas Regional Collaboratives for Excellence in Science and Mathematics Teaching [TRC] (Texas Regional Collaborative for Excellence in Science and Mathematics Teaching, 2013), a statewide program led by The University of Texas at Austin Center for STEM Education (Texas Regional Collaborative for Excellence in Science and Mathematics Teaching, 2013). Participants completed a demographic survey and took the TRC Physics Assessment instrument developed for the TRC to determine current conceptual understanding of Newtonian mechanics as defined by the Texas Essential Knowledge and Skills. The TRC also collected demographic data including Texas Educational Agency region, participant's sex, years of service in teaching, current teaching position, level of highest degree earned, whether or not the participant had a STEM degree, and certification type. Correlations were determined between overall average and conceptual force questions only. The sample size was substantial (n=368) but due to time constraints in its development, the TRC Physics Assessment was unable to undergo reliability or validity testing before implementation. Test question pertaining to each of Newton's three laws of motion were extrapolated to determine any correlations. A significance value of p= 0.05 was used for all tests. Both content assessments indicated that, on average, teacher-participants had a considerable misunderstanding of Newtonian mechanics with Newton's third law questions especially difficult for the populations. Teachers' current teaching assignment was statistically significant for most tests, suggesting that high school physics teachers have more conceptual understanding of Newtonian mechanics than middle school teachers but have not

Sewage sludge drying process integration with a waste-to-energy power plant.

Science.gov (United States)

Bianchini, A; Bonfiglioli, L; Pellegrini, M; Saccani, C

2015-08-01

Dewatered sewage sludge from Waste Water Treatment Plants (WWTPs) is encountering increasing problems associated with its disposal. Several solutions have been proposed in the last years regarding energy and materials recovery from sewage sludge. Current technological solutions have relevant limits as dewatered sewage sludge is characterized by a high water content (70-75% by weight), even if mechanically treated. A Refuse Derived Fuel (RDF) with good thermal characteristics in terms of Lower Heating Value (LHV) can be obtained if dewatered sludge is further processed, for example by a thermal drying stage. Sewage sludge thermal drying is not sustainable if the power is fed by primary energy sources, but can be appealing if waste heat, recovered from other processes, is used. A suitable integration can be realized between a WWTP and a waste-to-energy (WTE) power plant through the recovery of WTE waste heat as energy source for sewage sludge drying. In this paper, the properties of sewage sludge from three different WWTPs are studied. On the basis of the results obtained, a facility for the integration of sewage sludge drying within a WTE power plant is developed. Furthermore, energy and mass balances are set up in order to evaluate the benefits brought by the described integration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Understanding the Characteristics of Dispute Settlement in Sharia Economic System

OpenAIRE

M. Arfin Hamid

2017-01-01

One of the most developed areas of Islamic law (sharia) today is “Fiqh Muamalah Iqtishadiyyah” or known as term “Sharia Economics.” The outcomes of the research indicate that the characteristics of sharia dispute are important to be understood by sharia businessmen and law enforcers. As it turns out in practice, however, it has certain weaknesses, particularly in view of the accountability and legitimacy aspects of its establishment. The sharia economic disputes, whether through litigation or...

Thermophilic anaerobic co-digestion of sewage sludge with grease waste: Effect of long chain fatty acids in the methane yield and its dewatering properties

International Nuclear Information System (INIS)

Silvestre, G.; Illa, J.; Fernández, B.; Bonmatí, A.

2014-01-01

Highlights: • Thermophilic anaerobic codigestion of sewage sludge and grease waste (GW) doubles methane yield. • High GW doses in the influent leads to instability and LCFA accumulation in the effluent. • GW addition promotes acetoclastic activity whilst worsening the hydrogenothrophic activity. • The mesophilic codigestion with GW performs better than the thermophilic one. - Abstract: Thermophilic co-digestion of sewage sludge with three different doses of trapped grease waste (GW) from the pre-treatment of a WWTP has been assessed in a CSTR bench-scale reactor. After adding 12% and 27% of grease waste (on COD basis), the organic loading rate increased from 2.2 to 2.3 and 2.8 kg COD m −3 d −1 respectively, and the methane yield increased 1.2 and 2.2 times. Further GW increase (37% on COD basis) resulted in an unstable methane yield and in long chain fatty acids (LCFA) accumulation. Although this inestability, the presence of volatile fatty acids in the effluent was negligible, showing good adaptation to fats of the thermophilic biomass. Nevertheless, the presence of LCFA in the effluent worsens its dewatering properties. Specific methanogenic activity tests showed that the addition of grease waste ameliorates the acetoclastic activity in detriment of the hydrogenotrophic activity, and suggests that the tolerance to LCFA can be further enhanced by slowly increasing the addition of lipid-rich materials

Some new understanding on the characteristics of geological structure and uranium metallogenetic prospect on both sides of the Shandianhe down-faulted zone

International Nuclear Information System (INIS)

Zhang Xuequan

1992-01-01

On the basis of the systematic work in the field and at the laboratory, the metallogenetic prognosis map (1:100000) of geological structures and uranium metallogenetic prospect on both sides of the Shandianhe down-faulted zone is compiled. According to this, the regional setting of metallogenesis is emphatically expounded and some new understanding is presented. After the detailed study on the characteristics of geological structures on both sides of the Shangdianhe down-faulted zone, the metallogenetic prospective area are selected and the further prospecting targets in the area are suggested

Effect of hydrothermal treatment temperature on the properties of sewage sludge derived solid fuel

Directory of Open Access Journals (Sweden)

Mi Yan

2015-10-01

Full Text Available High moisture content along with poor dewaterability are the main challenges for sewage sludge treatment and utilization. In this study, the effect of hydrothermal treatment at various temperature (120-200 ˚C on the properties of sewage sludge derived solid fuel was investigated in the terms of mechanical dewatering character, drying character, calorific value and heavy metal distribution. Hydrothermal treatment (HT followed by dewatering process significantly reduced moisture content and improved calorific value of sewage sludge with the optimum condition obtained at 140˚C. No significant alteration of drying characteristic was produced by HT. Heavy metal enrichment in solid particle was found after HT that highlighted the importance of further study regarding heavy metal behavior during combustion. However, it also implied the potential application of HT on sewage sludge for heavy metal removal from wastewater.

Progress report Waste Resources Utilization Program period ending March 31, 1976

International Nuclear Information System (INIS)

1976-06-01

This report describes the work on the Waste Resources Utilization Program for the quarter ending March 31, 1976. The purpose of this program is to develop technologies to utilize a 137 Cs γ source to modify sewage sludge for safe application as a fertilizer or an animal feed supplement. Results are reported from studies in microbiology, virology, and physical-chemical studies. Determinations were made of inactivation rates for Salmonella species, coliforms, and fecal strep in sewage sludge when radiation and thermoradiation were applied while bubbling oxygen through the sludge. Virology studies were continued investigating virucidal characteristics of anaerobically digested sludge. Another area of study was the dewatering of sewage sludge to reduce the drying time of the sewage sludge in the drying beds. A centrifuge was also installed to dewater treated sludge to approximately 30 percent solids

Understanding Water Storage Practices of Urban Residents of an Endemic Dengue Area in Colombia: Perceptions, Rationale and Socio-Demographic Characteristics.

Directory of Open Access Journals (Sweden)

Tatiana García-Betancourt

Full Text Available The main preventive measure against dengue virus transmission is often based on actions to control Ae. Aegypti reproduction by targeting water containers of clean and stagnant water. Household water storage has received special attention in prevention strategies but the evidence about the rationale of this human practice is limited. The objective was to identify and describe water storage practices among residents of an urban area in Colombia (Girardot and its association with reported perceptions, rationales and socio-demographic characteristics with a mixed methods approach.Knowledge, attitudes and practices and entomological surveys from 1,721 households and 26 semi-structured interviews were conducted among residents of Girardot and technicians of the local vector borne disease program. A multivariate analysis was performed to identify associations between a water storage practice and socio-demographic characteristics, and knowledge, attitudes and practices about dengue and immature forms of the vector, which were then triangulated with qualitative information.Water storage is a cultural practice in Girardot. There are two main reasons for storage: The scarcity concern based on a long history of shortages of water in the region and the perception of high prices in water rates, contrary to what was reported by the local water company. The practice of water storage was associated with being a housewife (Inverse OR: 2.6, 95% CI 1.5 -4.3. The use of stored water depends on the type of container used, while water stored in alberca (Intra household cement basins is mainly used for domestic cleaning chores, water in plastic containers is used for cooking.It is essential to understand social practices that can increase or reduce the number of breeding sites of Ae. Aegypti. Identification of individuals who store water and the rationale of such storage allow a better understanding of the social dynamics that lead to water accumulation.

Filtros plantados com macrófitas de fluxo vertical aplicados na mineralização e desaguamento de lodo de tanque séptico Vertical flow constructed wetlands for septic sludge mineralization and dewatering

Directory of Open Access Journals (Sweden)

Carla Suntti

2011-03-01

Full Text Available O lodo acumulado no interior de tanques sépticos deve passar por um tratamento antes de sua adequada disposição final, pois apresenta uma fração da matéria orgânica não estabilizada, elevado teor de umidade e organismos patogênicos. Como alternativa para o tratamento do lodo, os filtros plantados com macrófitas são uma tecnologia promissora. Para se avaliar o potencial dos filtros no desaguamento e mineralização do lodo de tanque séptico, foram construídos dois filtros pilotos (F1 e F2 aplicando-se duas taxas de sólidos totais (ST - F1: 250 kgST.m-2.ano-1; F2: 125 kgST.m-2.ano-1. Os resultados revelaram que o F2 apresentou melhor desempenho em relação ao F1 em termos de remoção de sólidos totais (96%, demanda química de oxigênio (99% e nitrogênio amoniacal (72%. O F2 proporcionou melhor desaguamento, com 67% de umidade no lodo acumulado no leito e 33% de sólidos totais.The accumulated sludge in septic tanks has to be treated before the adequate final disposal, because of its high concentration of non-established organic matter, elevated content of moisture and pathogenic organisms. As an alternative to the treatment of sludge, the vertical flow constructed wetlands are a promising technology. To evaluate the potential of the filters in dewatering and mineralization of septic tank sludge, two pilot-scale constructed wetlands (CW1 and CW2 were implanted according with two total solids loads (TS - CW1: 250 kgTS.m-2.year-1; CW2: 125kgTS.m-2.year-1. The results demonstrated that the CW2 had better efficiencies compared with CW1, in terms of total solids (96%, chemical oxygen demand (99% and ammonia (72% removal. CW2 also provided a better dewatering, with moisture of 67% in accumulated sludge and 33% of total solids.

An Insight towards Conceptual Understanding: Looking into the Molecular Structures of Compounds

Science.gov (United States)

Uyulgan, Melis Arzu; Akkuzu, Nalan

2016-01-01

The subject of molecular structures is one of the most important and complex subject in chemistry which a majority of the undergraduate students have difficulties to understand its concepts and characteristics correctly. To comprehend the molecular structures and their characteristics the students need to understand related subjects such as Lewis…

Nuclear dewatering

International Nuclear Information System (INIS)

Anon.

1989-01-01

The Sizewell 'B' Nuclear Power Station, the first in a new family of PWR (Pressurised Water Reactor) stations in the UK, is currently under construction on the Suffolk coast. One of the first civil engineering tasks associated with the power station construction was the necessity to lower the water table by 17-18 m over an area of approximately 8 hectares to allow the excavation for the foundations to be carried out in the dry. The way chosen to do this was to construct a diaphragm wall around the site area. This had the least effect on surrounding sites -the Sizewell-A station and various nature reserves and wetlands. The reasons for the choice of method are discussed. Following the construction of the wall the water was pumped out from within the diaphragm wall in January 1988. (author)

Characteristics of transitional and turbulent jet diffusion flames in microgravity

Science.gov (United States)

Bahadori, Yousef M.; Small, James F., Jr.; Hegde, Uday G.; Zhou, Liming; Stocker, Dennis P.

1995-01-01

This paper presents the ground-based results obtained to date in preparation of a proposed space experiment to study the role of large-scale structures in microgravity transitional and turbulent gas-jet diffusion flames by investigating the dynamics of vortex/flame interactions and their influence on flame characteristics. The overall objective is to gain an understanding of the fundamental characteristics of transitional and turbulent gas-jet diffusion flames. Understanding of the role of large-scale structures on the characteristics of microgravity transitional and turbulent flames will ultimately lead to improved understanding of normal-gravity turbulent combustion.

Recovery, restoration, and development of an enhancement plan for the Leading Creek watershed after dewatering of the Meigs number-sign 31 coal mine in Ohio

International Nuclear Information System (INIS)

Cherry, D.S.; Hassel, J.H. Van; Yeager, M.M.; Babendreier, J.E.; Currie, R.J.; Astin, L.E.; Lynde, S.R.

1995-01-01

Following the flooding of the Meigs number-sign 31 deep coal mine in Meigs County, Ohio, a proactive plan was developed to evaluate effects of initial dewatering, recovery, and development of a watershed enhancement plan. Approximately half of the 31-mile Leading Creek mainstem received coal mine discharge of high conductivity, low pH, high metals and total suspended solids loading. Most forms of aquatic life were depleted in the impacted areas of the creek. After three years since the incident, many forms of benthic macroinvertebrates and fish have returned to the creek, and sediments have been purged of metal loading by storm water events. The enhancement plan involves a reconnaissance of the creek and tributaries pinpointing areas of agricultural sedimentation and abandoned mined land (AML) influences in the lower half. Research activities involved sampling water and sediment in 10 stations of the creek and 17 major tributaries. The tributaries were addressed as point source discharges with water/sediment toxicity testing conducted. In-situ testing included growth impairment evaluation of Asian clams at 27 stations in the watershed. Several tributaries were intermittently toxic depending upon rainfall and the degree of AML input. Benthic macroinvertebrate assembles in most tributaries were stressed and comprised 0--3 taxa. Erosion/sedimentation loading was being addressed by hydrological modeling of the creek, land use management/habitat assessment, and data management by geographic information systems

Spectroscopy, Understanding the Atom Series.

Science.gov (United States)

Hellman, Hal

This booklet is one of the "Understanding the Atom" Series. The science of spectroscopy is presented by a number of topics dealing with (1) the uses of spectroscopy, (2) its origin and background, (3) the basic optical systems of spectroscopes, spectrometers, and spectrophotometers, (4) the characteristics of wave motion, (5) the…

Characteristics of the Understanding and Expression of Emotional Prosody among Children with Autism Spectrum Disorder

DEFF Research Database (Denmark)

Yoshimatsu, Yasufumi; Umino, Ayumi; Dammeyer, Jesper

2016-01-01

In verbal communication with others, children with Autism Spectrum Disorders (ASD) experience difficulties with understanding jokes, irony, and other pragmatic aspects of communication. Difficulties with the understanding and expression of prosody may be one reason. In this study an understanding...

Understanding China’s Economic Success

DEFF Research Database (Denmark)

Li, Xing

2016-01-01

This study attempts to provide a framework for understanding the role of the “embeddedness” in China’s economic success reflected by a unique embedded integration of state-market-society relations. “Embeddedness with Chinese characteristics” is the central concept of this study for analyzing how...... cultural and political uniqueness influences economic activities and shapes distinctive institutional forms. In order to grasp the factors behind the Chinese economic success, it is important to understand how the disembedded forces of marketization and commodification were balanced by the embedded forces...... context to explain and analyze the “embedded” hegemony in transitional China. The first part of the this paper provides a conceptual framework for understanding socio-cultural and political embeddedness in China and the second part analyzes some characteristics of the state-market-society embedded process...

Understanding the Exhibitionary Characteristics of Popular Music Museums

Directory of Open Access Journals (Sweden)

Charles Fairchild

2017-03-01

Full Text Available The literature on the popular music museum has primarily focused on the study of heritage and cultural memory with a secondary focus on tourism. Given the unprecedented expansion of the museum sector worldwide in recent decades, which has produced an increasing number of major museums dedicated to popular music, it is an opportune time to expand this range of analytical concerns. Specifically, the development of popular music museums has not yet been closely examined within the broader historical trajectory of the so-called ‘new museum.’ This article seeks to outline the range of exhibitionary types commonly used in a range of high-profile popular music museums in pursuit of this line of inquiry. The goal is not simply to produce a generic survey or typology of displays, but to place the use of different forms of museum display within the specific historical trajectory that has produced steadily larger numbers of these kinds of museums in recent years. I organize these exhibitionary types into two broad streams of museum exhibition practice implied in the historical survey presented here: a populist-vernacular stream of museum display and an institutional-educational one. I seek to place the exhibitionary practices of contemporary popular music museums in a broader and longer trajectory of similar practices in order to get a more grounded sense of the more important characteristics of these kinds of museums.

Understanding Children's Reading Activities: Reading Motivation, Skill and Child Characteristics as Predictors

Science.gov (United States)

McGeown, Sarah P.; Osborne, Cara; Warhurst, Amy; Norgate, Roger; Duncan, Lynne G.

2016-01-01

This study examined the extent to which a range of child characteristics (sex, age, socioeconomic status, reading skill and intrinsic and extrinsic reading motivation) predicted engagement (i.e., time spent) in different reading activities (fiction books, factual books, school textbooks, comics, magazines and digital texts). In total, 791 children…

The characteristics of successful entrepreneurs

OpenAIRE

Pokrajčić Dragana M.

2004-01-01

This paper examines the economic, psychological and social-behavioral theories of the entrepreneur in order to determine the characteristics of a successful entrepreneur. The major contribution of economic theories of the entrepreneur is better understanding of the entrepreneur and his/her role in economic development. The psychological characteristic theory of entrepreneur argues that successful entrepreneurs possess certain personality traits that mark them out as special, and tries to dete...

Dewaterability of five sewage sludges in Guangzhou conditioned with Fenton's reagent/lime and pilot-scale experiments using ultrahigh pressure filtration system.

Science.gov (United States)

Liang, Jialin; Huang, Shaosong; Dai, Yongkang; Li, Lei; Sun, Shuiyu

2015-11-01

Sludge conditioning with Fenton's reagent and lime is a valid method for sludge dewatering. This study investigated the influence of different organic matter content sludge on sludge dewatering and discussed the main mechanism of sludge conditioning by combined Fenton's reagent and lime. The results indicated that the specific resistance to filterability (SRF) of sludge was reduced efficiently by approximately 90%, when conditioned with Fenton's reagent and lime. Through single factor experiments, the optimal conditioning combinations were found. In addition, the relationship between VSS% and consumption of the reagents was detected. Furthermore, it was also demonstrated that the SRF and filtrate TOC values had a significant correlation with VSS% of sludge (including raw and conditioned). The main mechanism of sludge dewatering was also investigated. Firstly, it revealed that the dewaterability of sludge was closely correlated to extracellular polymeric substances (EPS) and bound water contents. Secondly, the results of scanning electron microscopy (SEM) stated that sludge particles were to be smaller and thinner after conditioning. And this structure could easily form outflow channels for releasing free water. Additionally, with the ultrahigh pressure filtration system, the water content of sludge cake conditioned with Fenton's reagent and lime could be reduced to below 50%. Moreover, the economic assessment shows that Fenton's reagent and lime combined with ultrahigh pressure filtration system can be an economical and viable technology for sewage sludge dewatering. Finally, three types of sludge were classified: (1) Fast to dewater; (2) Moderately fast to dewater; (3) Slow to dewater sludge. Copyright © 2015 Elsevier Ltd. All rights reserved.

A review on paint sludge from automotive industries: Generation, characteristics and management.

Science.gov (United States)

Salihoglu, Guray; Salihoglu, Nezih Kamil

2016-03-15

The automotive manufacturing process results in the consumption of several natural sources and the generation of various types of wastes. The primary source of hazardous wastes at an automotive manufacturing plant is the painting process, and the major waste fraction is paint sludge, which is classified with EU waste code of 080113* implying hazardous characteristics. The amount of the paint sludge generated increases every year with the worldwide increase in the car production. The characteristics of the paint sludge, which mainly designate the management route, are mainly determined by the type of the paint used, application technique employed, and the chemicals applied such as flocculants, detackifiers, pH boosters, antifoam agents, and biocides as well as the dewatering techniques preferred. Major routes for the disposal of the paint sludges are incineration as hazardous waste or combustion at cement kilns. Because of high dissolved organic carbon content of the paint, the paint sludge cannot be accepted by landfills according to European Union Legislations. More investigations are needed in the field of paint sludge recycling such as recycling it as a new paint or as other formulations, or making use of the sludge for the production of construction materials. Research on the applicability of the paint sludge in composting and biogasification can also be useful. Ongoing research is currently being conducted on new application techniques to increase the effectiveness of paint transfer, which helps to prevent the generation of paint sludge. Advancements in paint and coating chemistry such as the reduction in the coating layers with its thickness also help to decrease the level of paint sludge generation. Investigations on the effects of the chemicals on the recycling potential of paint sludges and consideration of these effects by the chemical manufacturer companies would be extremely important. This review presents the formation of paint sludge, the factors

Energy from refuse by bioconversion, fermentation and residue disposal processes

Energy Technology Data Exchange (ETDEWEB)

Pfeffer, J T; Liebman, J C

1976-01-01

Bioconversion of organic refuse to CH/sub 4/ by anaerobic fermentation is 1 mechanism by which the energy in urban waste can be reclaimed. Laboratory studies were made to determine the rate and amount of gas production at various operating temperatures. The dewatering characteristics of the spent fermentation slurry were evaluated. The spent solids can be dewatered to a sufficiently low moisture content such that incineration is self-sustaining. The incineration system was evaluated to determine the possible energy recovery from the spent cake. A process for treating the liquid blowdown from the system was developed. A mathematical simulation of the total system was constructed to evaluate performance under various operating conditions. A plant processing 908 tons of refuse/day will produce 3905 m/sup 3/ CH/sub 4//hr. Recovery of just CH/sub 4/ provides a 32.6% efficiency of energy recovery. This efficiency can be increased to 63.4% if steam from the incinerator can be sold.

Understanding technology adoption through individual and context characteristics: the case of HDTV

NARCIS (Netherlands)

Baaren, Eva; van de Wijngaert, Lidwien; Huizer, E.

2011-01-01

Technology adoption research has a tradition of using and improving Davis' (1989) “Technology Acceptance Model” (TAM) and extended versions of it. This article suggests a break with this tradition by showing that the TAM is limited in its understanding of technology adoption. Two alternative

The importance of understanding military culture.

Science.gov (United States)

Hall, Lynn K

2011-01-01

Social workers can make a significant contribution to military service members and their families, but first it is essential that the worldview, the mindset, and the historical perspective of life in the military are understood. Unless we understand how the unique characteristics of the military impact the service members and their families, we cannot work effectively with them. In addition, unless we understand their language, their structure, why they join, their commitment to the mission, and the role of honor and sacrifice in military service, we will not be able to adequately intervene and offer care to these families.

Characteristics of manipulative in mathematics laboratory

Science.gov (United States)

Istiandaru, A.; Istihapsari, V.; Prahmana, R. C. I.; Setyawan, F.; Hendroanto, A.

2017-12-01

A manipulative is a teaching aid designed such that students could understand mathematical concepts by manipulating it. This article aims to provide an insight to the characteristics of manipulatives produced in the mathematics laboratory of Universitas Ahmad Dahlan, Indonesia. A case study was conducted to observe the existing manipulatives produced during the latest three years and classified the manipulatives based on the characteristics found. There are four kinds of manipulatives: constructivism manipulative, virtual manipulative, informative manipulative, and game-based manipulative. Each kinds of manipulative has different characteristics and impact towards the mathematics learning.

Volume reduction of filter media at Susquehanna steam and electric station

International Nuclear Information System (INIS)

Boris, G.F.; Hettinger, J.

1990-01-01

This paper describes the joint efforts between Pennsylvania Power ampersand Light (PPQL) and Scientific Ecology Group, Inc. (SEG) to reduce the volume of waste shipped to the burial site by the Susquehanna Steam and Electric Station (SSES) and the resulting savings realized as a result. The filter media used at SSES for its radwaste filters is composed of a mix of anion and cation powered resins, powered carbon, diatomaceous earth and a fibrous overlay. Due to the nature of this waste stream, dewatering was difficult using systems previously available in the industry. Thus, processing was accomplished by decanting (to concentrate the waste) and solidification. In the continuing effort to dewater wastes of this nature, SEG developed a new fabric filter dewatering system (RDU). To investigate its potential use in large containers, this dewatering system was installed in drum-size high integrity containers and used to test its dewatering capabilities on actual SSES waste. Promising results from these tests warranted a full-scale test. This proved successful and implementation of this processing scheme was immediate. Cost savings were substantial in transportation, burial and processing costs as well as personnel exposure. Also, additional waste volume reduction was found due to the volume reduction capability of the dewatering system (equivalent volume of new filter media approximately 1.2 times that of dewatered product volume). Additional savings resulted from SSES's continuing effort to minimize radwaste generation. Combined, these have reduced the number of shipments of filter media in 1989 to sixty percent of the number made in 1988 and have reduced costs by approximately fifty percent. 4 figs., 1 tab

The importance of understanding during the teaching process

Directory of Open Access Journals (Sweden)

Dubljanin Saša

2015-01-01

Full Text Available Learning in the teaching process often goes on without proper understanding which is one of important problems that modern didactics tries to solve. In order to direct the totality of teaching towards understanding it is necessary to answer the question what understanding is, which is why we analysed different philosophical views on the concept of understanding and stressed their semblance to pedagogic explanations. Different kinds of understanding were analyzed as well as their role and contribution in different teaching situations, especially in the context of problem solving. As an alternative to the teaching based on accumulation of knowledge the characteristics and some principles of teaching focused on understanding are described, and the need for stimulating and developing understanding as an important goal of education. The results of our research unequivocally show that learning with understanding enables students to memorize the teaching material better, as well as to understand the whole teaching subject and efficiently apply the acquired knowledge out of school, and leads to more flexible behaviour and better coping in everyday life.

The use of Functional Resonance Analysis Method (FRAM) in a mid-air collision to understand some characteristics of the air traffic management system resilience

Energy Technology Data Exchange (ETDEWEB)

Rodrigues de Carvalho, Paulo Victor, E-mail: paulov@ien.gov.br [National Nuclear Energy Commission/Nuclear Engineering Institute, Cidade Universitaria-Ilha do Fundao, Rio de Janeiro, RJ 21945-970 (Brazil)

2011-11-15

The Functional Resonance Analysis Model (FRAM) defines a systemic framework to model complex systems for accident analysis purposes. We use FRAM in the mid-air collision between flight GLO1907, a commercial aircraft Boeing 737-800, and flight N600XL, an executive jet EMBRAER E-145, to investigate key resilience characteristics of the Air Traffic Management System (ATM). This ATM system related accident occurred at 16:56 Brazilian time on September 29, 2006 in the Amazonian sky. FRAM analysis of flight monitoring functions showed system constraints (equipment, training, time, and supervision) that produce variability in system behavior, creating demand resources mismatches in an attempt to perceive and control the developing situation. This variability also included control and coordination breakdowns and automation surprises (TCAS functioning). The analysis showed that under normal variability conditions (without catastrophic failures) the ATM system (pilots, controllers, supervisors, and equipment) was not able to close the control loops of the flight monitoring functions using feedback or feedforward strategies to achieve an adequate control of an aircraft flying in the controlled air space. Our findings shed some light on the resilience of Brazilian ATM system operation and indicated that there is a need of a deeper understanding on how the system is actually functioning. - Highlights: > The Functional Resonance Analysis Model (FRAM) was used in a mid-air collision over Amazon. > The aim was to understand key resilience characteristics of the Air Traffic Management System (ATM). > The analysis showed how, under normal conditions, the system was not able to control flight functions. > The findings shed some light about the resilience of Brazilian ATM system operation.

The use of Functional Resonance Analysis Method (FRAM) in a mid-air collision to understand some characteristics of the air traffic management system resilience

International Nuclear Information System (INIS)

Rodrigues de Carvalho, Paulo Victor

2011-01-01

The Functional Resonance Analysis Model (FRAM) defines a systemic framework to model complex systems for accident analysis purposes. We use FRAM in the mid-air collision between flight GLO1907, a commercial aircraft Boeing 737-800, and flight N600XL, an executive jet EMBRAER E-145, to investigate key resilience characteristics of the Air Traffic Management System (ATM). This ATM system related accident occurred at 16:56 Brazilian time on September 29, 2006 in the Amazonian sky. FRAM analysis of flight monitoring functions showed system constraints (equipment, training, time, and supervision) that produce variability in system behavior, creating demand resources mismatches in an attempt to perceive and control the developing situation. This variability also included control and coordination breakdowns and automation surprises (TCAS functioning). The analysis showed that under normal variability conditions (without catastrophic failures) the ATM system (pilots, controllers, supervisors, and equipment) was not able to close the control loops of the flight monitoring functions using feedback or feedforward strategies to achieve an adequate control of an aircraft flying in the controlled air space. Our findings shed some light on the resilience of Brazilian ATM system operation and indicated that there is a need of a deeper understanding on how the system is actually functioning. - Highlights: → The Functional Resonance Analysis Model (FRAM) was used in a mid-air collision over Amazon. → The aim was to understand key resilience characteristics of the Air Traffic Management System (ATM). → The analysis showed how, under normal conditions, the system was not able to control flight functions. → The findings shed some light about the resilience of Brazilian ATM system operation.

Oscillatory shear response of moisture barrier coatings containing clay of different shape factor.

Science.gov (United States)

Kugge, C; Vanderhoek, N; Bousfield, D W

2011-06-01

Oscillatory shear rheology of barrier coatings based on dispersed styrene-butadiene latex and clay of various shape factors or aspect ratio has been explored. Barrier performance of these coatings when applied to paperboard has been assessed in terms of water vapour transmission rates and the results related to shape factor, dewatering and critical strain. It has been shown that a system based on clay with high shape factor gives a lower critical strain, dewatering and water vapour transmission rate compared with clays of lower shape factor. The dissipated energy, as calculated from an amplitude sweep, indicated no attractive interaction between clay and latex implying a critical strain that appears to be solely dependent on the shape factor at a constant volume fraction. Particle size distribution was shown to have no effect on the critical strain while coatings of high elasticity exhibited high yield strains as expected. The loss modulus demonstrated strain hardening before the elastic to viscous transition. The loss modulus peak was identified by a maximum strain which was significantly lower for a coating based on clay with a high shape factor. The characteristic elastic time was found to vary between 0.6 and 1.3s. The zero shear viscosity of barrier dispersion coatings were estimated from the characteristic elastic time and the characteristic modulus to be of the order of 25-100 Pa s. Copyright © 2011 Elsevier Inc. All rights reserved.

Understanding the petrochemical cycle: Part 1

International Nuclear Information System (INIS)

Sedriks, W.

1994-01-01

Fitness in the hydrocarbon processing industry (HPI) arena involves understanding and coping with business cycles: supply and demand. This becomes increasingly more important as the industry globalizes and matures. Competitive-edge thinking needs to look hard at the forces that influence business cycles. Recognition of potential pitfalls is very important when considering: future capacity expansion, mergers and acquisitions, market departure, plant closure, potential product substitution, etc. Understanding pricing mechanisms and the workings of hockey-stick profitability profiles help HPI operators endure cycle downturns and prepare plants to maximize profits for the next upswing. The paper discusses characteristic trends, cycles in the hydrocarbon processing industry, current conditions, and mitigating cycle effects

Quantitative Understanding on the Amplitude Decay Characteristic of the Evanescent Electromagnetic Waves Generated by Seismoelectric Conversion

Science.gov (United States)

Ren, Hengxin; Huang, Qinghua; Chen, Xiaofei

2018-03-01

We conduct numerical simulations and theoretical analyses to quantitatively study the amplitude decay characteristic of the evanescent electromagnetic (EM) waves, which has been neglected in previous studies on the seismoelectric conversion occurring at a porous-porous interface. Time slice snapshots of seismic and EM wave-fields generated by a vertical single force point source in a two-layer porous model show that evanescent EM waves can be induced at a porous-porous interface. The seismic and EM wave-fields computed for a receiver array located in a vertical line nearby the interface are investigated in detail. In addition to the direct and interface-response radiation EM waves, we identify three groups of coseismic EM fields and evanescent EM waves associated with the direct P, refracted SV-P and direct SV waves, respectively. Thereafter, we derive the mathematical expression of the amplitude decay factor of the evanescent EM waves. This mathematical expression is further validated by our numerical simulations. It turns out the amplitude decay of the evanescent EM waves generated by seismoelectric conversion is greatly dependent on the horizontal wavenumber of seismic waves. It is also found the evanescent EM waves have a higher detectability at a lower frequency range. This work provides a better understanding on the EM wave-fields generated by seismoelectric conversion, which probably will help improve the interpretation of the seismoelectric coupling phenomena associated with natural earthquakes or possibly will inspire some new ideas on the application of the seismoelectric coupling effect.

Socio-Demographic Characteristics Of Dog Meat Consumers In ...

African Journals Online (AJOL)

The need to understand consumer spread prompted this study, which had the general objective of understanding the socio-demographic characteristics of dog meat consumers Calabar area of Cross River State, Nigeria. Thirty two (32) dog meat joints, 16 in Calabar Municipality, and 16 in Calabar South Local Government ...

Dewatering of sludges

International Nuclear Information System (INIS)

Bode, P.

1984-01-01

A filter rig has been designed and built. Simulated magnox and alumino ferric hydroxide sludges have been successfully filtered on this equipment and both types of sludge produced a clear filtrate and a cake. The flow rates were low. The cake often partially remained adhered to the filter membrane instead of dropping clear during the filter cleaning cycle. This filtration technique can only be used on sludges which form a non-binding cake. Permeability of the membrane can be altered by stretching. Irradiation of the membrane showed that it should withstand 20 to 50 M.rads. (author)

Radioactive waste processing device

International Nuclear Information System (INIS)

Inaguma, Masahiko; Takahara, Nobuaki; Hara, Satomi.

1996-01-01

In a processing device for filtering laundry liquid wastes and shower drains incorporated with radioactive materials, a fiber filtration device is disposed and an activated carbon filtration device is also disposed subsequent to the fiber filtration device. In addition, a centrifugal dewatering device is disposed for dewatering spent granular activated carbon in the activated carbon filtration device, and a minute filtering device is disposed for filtering the separated dewatering liquid. Filtrates filtered by the minute filtration device are recovered in a collecting tank. Namely, at first, suspended solid materials in laundry liquid wastes and shower drains are captured, and then, ingredients concerning COD are adsorbed in the activated carbon filtration device. The radioactive liquid wastes of spent granular activated carbon in the activated carbon filtration device are reduced by dewatering them by the centrifugal dewatering device, and then the granular activated carbon is subjected to an additional processing. Further, it is separated by filtration using the minute filtration device and removed as cakes. Since the filtrates are recovered to the collecting tank and filtered again, the water quality of the drains is not degraded. (N.H.)

Pharmaceutical and personal care products in tile drainage following surface spreading and injection of dewatered municipal biosolids to an agricultural field.

Science.gov (United States)

Edwards, M; Topp, E; Metcalfe, C D; Li, H; Gottschall, N; Bolton, P; Curnoe, W; Payne, M; Beck, A; Kleywegt, S; Lapen, D R

2009-07-01

Land application of municipal biosolids can be a source of environmental contamination by pharmaceutical and personal care products (PPCPs). This study examined PPCP concentrations/temporally discrete mass loads in agricultural tile drainage systems where two applications of biosolids had previously taken place. The field plots received liquid municipal biosolids (LMB) in the fall of 2005 at an application rate of approximately 93,500 L ha (-1), and a second land application was conducted using dewatered municipal biosolids (DMB) applied at a rate of approximately 8Mg dw ha (-1) in the summer of 2006 [corrected].The DMB land application treatments consisted of direct injection (DI) of the DMB beneath the soil surface at a nominal depth of approximately 0.11 m, and surface spreading (SS) plus subsequent tillage incorporation of DMB in the topsoil (approximately 0.10 m depth). The PPCPs examined included eight pharmaceuticals (acetaminophen, fluoxetine, ibuprofen, gemfibrozil, naproxen, carbamazepine, atenolol, sulfamethoxazole), the nicotine metabolite cotinine, and two antibacterial personal care products triclosan and triclocarban. Residues of naproxen, cotinine, atenolol and triclosan originating from the fall 2005 LMB application were detected in tile water nearly nine months after application (triclocarban was not measured in 2005). There were no significant differences (p>0.05) in PPCP mass loads among the two DMB land application treatments (i.e., SS vs. DI); although, average PPCP mass loads late in the study season (>100 days after application) were consistently higher for the DI treatment relative to the SS treatment. While the concentration of triclosan (approximately 14,000 ng g(-1) dw) in DMB was about twice that of triclocarban (approximately 8000 ng g(-1) dw), the average tile water concentrations for triclosan were much higher (43+/-5 ng L(-1)) than they were for triclocarban (0.73+/-0.14 ng L(-1)). Triclosan concentrations (maximum observed in 2006

Understanding Application Behaviours for Android Security: A Systematic Characterization

OpenAIRE

Cai, Haipeng; Ryder, Barbara

2016-01-01

In contrast to most existing research on Android focusing on specific security issues, there is little broad understanding of Android application run-time characteristics and their security implications. To mitigate this gap, we present the first dynamic characterization study of Android applications that targets such a broad understanding for Android security. Through lightweight method-level profiling, we have collected 33GB traces of method calls and inter-component communication (ICC) fro...

Characteristics of the General Physics student population.

Science.gov (United States)

Hunt, Gary L.

2006-12-01

Are pre-medical students different than the other students in a General physics class? They often appear to be different, based on how often they seek help from the instructor or how nervous they are about 2 points on a lab report. But are these students different in a measurable characteristic? The purpose of this study is to better understand the characteristics of the students in the introductory physics classes. This is the first step toward improving the instruction. By better understanding the students the classroom, the organization and pedagogy can be adjusted to optimize student learning. The characteristics to be investigated during this study are: · student epistemological structure, · student attitudes, · science course preparation prior to this course, · study techniques used, · physics concepts gained during the class · performance in the class. The data will be analyzed to investigate differences between groups. The groups investigated will be major, gender, and traditional/nontraditional students.

Understanding the Entrepreneurial Process: a Dynamic Approach

Directory of Open Access Journals (Sweden)

Vânia Maria Jorge Nassif

2010-04-01

Full Text Available There is considerable predominance in the adoption of perspectives based on characteristics in research into entrepreneurship. However, most studies describe the entrepreneur from a static or snapshot approach; very few adopt a dynamic perspective. The aim of this study is to contribute to the enhancement of knowledge concerning entrepreneurial process dynamics through an understanding of the values, characteristics and actions of the entrepreneur over time. By focusing on personal attributes, we have developed a framework that shows the importance of affective and cognitive aspects of entrepreneurs and the way that they evolve during the development of their business.

77 FR 10809 - Endangered and Threatened Wildlife and Plants; Endangered Status and Designations of Critical...

Science.gov (United States)

2012-02-23

... streams into intermittent streams, large reservoirs, or dewatered channels, thus eliminating suitable... either dewater channels or reduce flows to low levels or pools within an active channel therefore... River has undergone sedimentation, riparian habitat degradation, and extensive water diversion and at...

Hydrochemical characteristic of surface and groundwater Lisichansk and Almazno-Marevske geological and industrial districts Nnorth-Eastern Donbas

Directory of Open Access Journals (Sweden)

Udalov Y.V.

2014-12-01

Full Text Available Incorporates a complex of problems accompanying the operation of coal deposits of Donbass. See hydrochemical characteristics of surface and groundwater Lisichansk and Almazno-Maryevskogo geological and industrial areas of the North-Eastern Donbass. Identified the main hydrochemical features of the waste mine waters of the enterprises of the coal industry on the territory of the studies. It is established that the surface waters of the study area exposed to intensive anthropogenic influence. Set content of basic elements-pollutants in surface waters. It is revealed that this pollution is of a complex nature. Identifies key elements contained in the effluent of industrial enterprises. Analyzed that a change of the chemical composition of groundwater has led to increased hardness and mineralization of water in the main water intakes of the research area. Identifies key elements-contaminants in groundwater. It was found that as a result of mine dewatering groundwater level fell over an area of 200km2, far exceeding the area of coal mining. This operational reserves fresh underground waters in the groundwater runoff module 1.2 dm3 / sec. km2 decreased by 200 - 300 m3 / day. Within funnel depression hydraulic connection is created not only a few confined aquifers, but also located near the mine fields. For example, in the area of Stakhanov the Luhansk region in general depression funnel width of about 25 km and a depth of 600-800m were 8 mine ("Central Irmino", "Maximovska" Ilyich, named after I.V. Chesnokov, "Krivoy Rog", 11-RAD "Brjankovsky" and "Dzerzhinsk". The purpose of research is general hydrochemical characteristics and identification of key elements polluting surface and groundwater Lisichanskiy and diamond-Marevskogo geological and industrial areas of the North-East Donbas.

Internal cavity characteristics of northern long-eared bat (Myotis septentrionalis) maternity day-roosts

Science.gov (United States)

Alexander Silvis; R. Edward Thomas; W. Mark Ford; Eric R. Britzke; Meryl J. Friedrich

2015-01-01

This report discusses characteristics of seven tree cavities used as day-roosts by female northern long-eared bats (Myotis septentrionalis) during the maternity season in a deciduous forest in north-central Kentucky. Understanding the characteristics of cavities selected by bats will help us better understand the ecology of cavity roosting bats and...

Modeling of Activated Sludge Floc Characteristics

OpenAIRE

Ibrahim H. Mustafa; G. Ibrahim; Ali Elkamel; A. H. Elahwany

2009-01-01

Problem Statement: The activated sludge system needs to improve the operational performance and to achieve more effective control. To realize this, a better quantitative understanding of the biofloc characteristics is required. The objectives of this study were to: (i) Study the biofloc characteristics from kinetics-mass transfer interaction point of view by quantification of the weight of the aerobic portion of the activated sludge floc to the total floc weight. (ii) Study the effect of bulk...

Shape understanding system machine understanding and human understanding

CERN Document Server

Les, Zbigniew

2015-01-01

This is the third book presenting selected results of research on the further development of the shape understanding system (SUS) carried out by authors in the newly founded Queen Jadwiga Research Institute of Understanding. In this book the new term Machine Understanding is introduced referring to a new area of research aiming to investigate the possibility of building machines with the ability to understand. It is presented that SUS needs to some extent mimic human understanding and for this reason machines are evaluated according to the rules applied for the evaluation of human understanding. The book shows how to formulate problems and how it can be tested if the machine is able to solve these problems.    

Solidification/Stabilization of High Nitrate and Biodenitrified Heavy Metal Sludges with a Portland Cement/Flyash System

International Nuclear Information System (INIS)

Canonico, J.S.

1995-01-01

Pond 207C at Rocky Flats Environmental Technology Site (RFETS) contains process wastewaters characterized by high levels of nitrates and other salts, heavy metal contamination, and low level alpha activity. The purpose of this research was to investigate the feasibility of treating a high-nitrate waste, contaminated with heavy metals, with a coupled dewateriug and S/S process, as well as to investigate the effects of biodenitrification pretreatment on the S/S process. Pond 207C residuals served as the target waste. A bench-scale treatability study was conducted to demonstrate an S/S process that would minimize final product volume without a significant decrease in contaminant stabilization or loss of desirable physical characteristics. The process formulation recommended as a result a previous S/S treatability study conducted on Pond 207C residuals was used as the baseline formulation for this research. Because the actual waste was unavailable due to difficulties associated with radioactive waste handling and storage, a surrogate waste, of known composition and representative of Pond 207C residuals, was used throughout this research. The contaminants of regulatory concern added to the surrogate were cadmium, chromium, nickel, and silver. Product volume reduction was achieved by dewatering the waste prior to S/S treatment. The surrogate was dewatered by evaporation at 60 to 80 C to total solids contents from 43% to 78% by weight, and treated with Portland cement and fly ash. Two cement to flyash ratios were tested, 2:1 and 1:2, by weight. Contaminant leachability testing was conducted with a 0.5 water to pozzolan (the cement/flyash mixture) ratio and both cement to flyash ratios. Each product was tested for unconfined compressive strength (UCS) and for contaminant leachability by the Toxicity Characteristics Leaching Procedure (TCLP). At the highest solids content achieved by dewatering, 78% solids by weight, the predicted final waste form volume f or Pond 207C

The Ecology and Environmental Impacts of Hydrilla

Science.gov (United States)

1992-10-15

in the dewatered areas. The drawdown also encouraged the germination of waterhyacinth seeds in the dewatered areas. Plant Analysis The productivity of...controls hydrilla in most situations. Sonar is the DowElanco registered trademark for products containing the active ingredient fluridone . Sonar aquatic

APPLICATION OF ESSENTIAL OILS EXTRACTED FROM PEELS OF ORANGES AS A PARTIAL SUBSTITUTE OF FLOCCULANT

Directory of Open Access Journals (Sweden)

Anna Kowalczyk

2016-05-01

Full Text Available The study attempts to determine the optimum conditions of the process of mechanical dewatering of municipal sewage sludge and reduction of odours emitted during this process. The process of dewatering of municipal sewage sludge was carried out using laboratory sedimentation centrifuge of MPW-350 type. Municipal sewage sludge stabilized during anaerobic digestion, taken from Wastewater Treatment Plant Jamno. The dewatering process was aided by cationic flocculant Praestol 855BS of real solution concentration 0.3% and essential oil from orange, which was extracted from orange peels in the process of steam distillation. Constant parameters of dewatering process were: pH, temperature, colour, texture, smell, water content and dry matter content. Independent variables of dewatering process were: centrifugation time (in the range 1–10 min, centrifugation speed (in the range 1000–3000 rotations/min and dose of mixture of flocculant Praestol 855BS (79% + essential oil of orange (21% in the range 0–48 ml/dm3. Water content in the sludge after the process, dry matter content in the effluent and the duration of the smell of oil in the sediment were determined. Studies showed that the essential oil from orange may be used as a partial substitute of flocculant Praestol 855BS in the process of centrifugal sedimentation. Essential oil of orange significantly reduces unpleasant odours which are emitted from sludge during mechanical dewatering. Simultaneous application of both reagents, ie. flocculant Praestol 855BS 79%, and essential oil of orange 21% of volume is recommended.

Environmental and economic life cycle assessment for sewage sludge treatment processes in Japan.

Science.gov (United States)

Hong, Jinglan; Hong, Jingmin; Otaki, Masahiro; Jolliet, Olivier

2009-02-01

Life cycle assessment for sewage sludge treatment was carried out by estimating the environmental and economic impacts of the six alternative scenarios most often used in Japan: dewatering, composting, drying, incineration, incinerated ash melting and dewatered sludge melting, each with or without digestion. Three end-of-life treatments were also studied: landfilling, agricultural application and building material application. The results demonstrate that sewage sludge digestion can reduce the environmental load and cost through reduced dry matter volume. The global warming potential (GWP) generated from incineration and melting processes can be significantly reduced through the reuse of waste heat for electricity and/or heat generation. Equipment production in scenarios except dewatering has an important effect on GWP, whereas the contribution of construction is negligible. In addition, the results show that the dewatering scenario has the highest impact on land use and cost, the drying scenario has the highest impact on GWP and acidification, and the incinerated ash melting scenario has the highest impact on human toxicity due to re-emissions of heavy metals from incinerated ash in the melting unit process. On the contrary, the dewatering, composting and incineration scenarios generate the lowest impact on human toxicity, land use and acidification, respectively, and the incinerated ash melting scenario has the lowest impact on GWP and cost. Heavy metals released from atmospheric effluents generated the highest human toxicity impact, with the effect of dioxin emissions being significantly lower. This study proved that the dewatered sludge melting scenario is an environmentally optimal and economically affordable method.

Understanding Masculinity Ideology in Convicted Rapists

OpenAIRE

Pandey, Madhumita

2016-01-01

While violence against women has gained prominence in India, there is still a dearth of literature addressing these issues in the society. Amongst available research, the focus has primarily been on victims; judiciary and policing systems while, there are minimum efforts in understanding the alleged offenders. Masculinity originally emerged as concept opposite to femininity (Constantinople, 1973), was later developed into an independent personality characteristic (Bem, 1974) and is now being ...

Understanding the anaerobic biodegradability of food waste: Relationship between the typological, biochemical and microbial characteristics.

Science.gov (United States)

Fisgativa, Henry; Tremier, Anne; Le Roux, Sophie; Bureau, Chrystelle; Dabert, Patrick

2017-03-01

In this study, an extensive characterisation of food waste (FW) was performed with the aim of studying the relation between FW characteristics and FW treatability through an anaerobic digestion process. In addition to the typological composition (paper, meat, fruits, vegetables contents, etc) and the physicochemical characteristics, this study provides an original characterisation of microbial populations present in FW. These intrinsic populations can actively participate to aerobic and anaerobic degradation with the presence of Proteobacteria and Firmicutes species for the bacteria and of Ascomycota phylum for the fungi. However, the characterisation of FW bacterial and fungi community shows to be a challenge because of the biases generated by the non-microbial DNA coming from plant and by the presence of mushrooms in the food. In terms of relations, it was demonstrated that some FW characteristics as the density, the volatile solids and the fibres content vary as a function of the typological composition. No direct relationship was demonstrated between the typological composition and the anaerobic biodegradability. However, the Pearson's matrix results reveal that the anaerobic biodegradation potential of FW was highly related to the total chemical oxygen demand (tCOD), the total solid content (TS), the high weight organic matter molecules soluble in water (SOL W >1.5 kDa) and the C/N ratio content. These relations may help predicting FW behaviour through anaerobic digestion process. Finally, this study also showed that the storage of FW before collection, that could induce pre-biodegradation, seems to impact several biochemical characteristics and could improve the biodegradability of FW. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of energy consumption during aerobic sewage sludge treatment in dairy wastewater treatment plant.

Science.gov (United States)

Dąbrowski, Wojciech; Żyłka, Radosław; Malinowski, Paweł

2017-02-01

The subject of the research conducted in an operating dairy wastewater treatment plant (WWTP) was to examine electric energy consumption during sewage sludge treatment. The excess sewage sludge was aerobically stabilized and dewatered with a screw press. Organic matter varied from 48% to 56% in sludge after stabilization and dewatering. It proves that sludge was properly stabilized and it was possible to apply it as a fertilizer. Measurement factors for electric energy consumption for mechanically dewatered sewage sludge were determined, which ranged between 0.94 and 1.5 kWhm -3 with the average value at 1.17 kWhm -3 . The shares of devices used for sludge dewatering and aerobic stabilization in the total energy consumption of the plant were also established, which were 3% and 25% respectively. A model of energy consumption during sewage sludge treatment was estimated according to experimental data. Two models were applied: linear regression for dewatering process and segmented linear regression for aerobic stabilization. The segmented linear regression model was also applied to total energy consumption during sewage sludge treatment in the examined dairy WWTP. The research constitutes an introduction for further studies on defining a mathematical model used to optimize electric energy consumption by dairy WWTPs. Copyright © 2016 Elsevier Inc. All rights reserved.

Science Communication for the Public Understanding of Nuclear Issues

Energy Technology Data Exchange (ETDEWEB)

Cho, Seongkyung [Myungji Univ., Yongin (Korea, Republic of)

2006-04-15

Uncertainty, stigma, risk perception, and value judgment represent characteristics of nuclear issues in the public arena. Nuclear issue, in the public arena, is a kind of risk rather than technology that we are willing to use for good purpose. There are uncertainty, stigma, risk perception, and value judgment as characteristics of nuclear. The notion of the public, here is of active, sensitive, and sensible citizens, with power and influence. The public understands nuclear issues less through direct experience or education than through the filter of mass media. Trust has been a key issue on public understanding of nuclear issues. Trust belongs to human. The public understanding process includes perception, interpretation, and evaluation. Therefore, science communication is needed for public understanding. Unfortunately, science communication is rarely performed well, nowadays, There are three important actors-the public, experts, and media. Effective science communication means finding comprehensible ways of presenting opaque and complex nuclear issues. It makes new and strong demands on experts. In order to meet that requirement, experts should fulfill their duty about developing nuclear technology for good purpose, understand the public before expecting the public to understand nuclear issues, accept the unique culture of the media process, take the responsibility for any consequence which nuclear technologies give rise to, communicate with an access route based on sensibility and rationality, have a flexible angle in the science communication process, get creative leadership for the communication process with deliberation and disagreement, make efficient use of various science technologies for science communication. We should try to proceed with patience, because science communication makes for a more credible society.

Science Communication for the Public Understanding of Nuclear Issues

International Nuclear Information System (INIS)

Cho, Seongkyung

2006-01-01

Uncertainty, stigma, risk perception, and value judgment represent characteristics of nuclear issues in the public arena. Nuclear issue, in the public arena, is a kind of risk rather than technology that we are willing to use for good purpose. There are uncertainty, stigma, risk perception, and value judgment as characteristics of nuclear. The notion of the public, here is of active, sensitive, and sensible citizens, with power and influence. The public understands nuclear issues less through direct experience or education than through the filter of mass media. Trust has been a key issue on public understanding of nuclear issues. Trust belongs to human. The public understanding process includes perception, interpretation, and evaluation. Therefore, science communication is needed for public understanding. Unfortunately, science communication is rarely performed well, nowadays, There are three important actors-the public, experts, and media. Effective science communication means finding comprehensible ways of presenting opaque and complex nuclear issues. It makes new and strong demands on experts. In order to meet that requirement, experts should fulfill their duty about developing nuclear technology for good purpose, understand the public before expecting the public to understand nuclear issues, accept the unique culture of the media process, take the responsibility for any consequence which nuclear technologies give rise to, communicate with an access route based on sensibility and rationality, have a flexible angle in the science communication process, get creative leadership for the communication process with deliberation and disagreement, make efficient use of various science technologies for science communication. We should try to proceed with patience, because science communication makes for a more credible society

Power System Oscillatory Behaviors: Sources, Characteristics, & Analyses

Energy Technology Data Exchange (ETDEWEB)

Follum, James D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tuffner, Francis K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dosiek, Luke A. [Union College, Schenectady, NY (United States); Pierre, John W. [Univ. of Wyoming, Laramie, WY (United States)

2017-05-17

This document is intended to provide a broad overview of the sources, characteristics, and analyses of natural and forced oscillatory behaviors in power systems. These aspects are necessarily linked. Oscillations appear in measurements with distinguishing characteristics derived from the oscillation’s source. These characteristics determine which analysis methods can be appropriately applied, and the results from these analyses can only be interpreted correctly with an understanding of the oscillation’s origin. To describe oscillations both at their source within a physical power system and within measurements, a perspective from the boundary between power system and signal processing theory has been adopted.

Teaching Teaching & Understanding Understanding

DEFF Research Database (Denmark)

2006-01-01

"Teaching Teaching & Understanding Understanding" is a 19-minute award-winning short-film about teaching at university and higher-level educational institutions. It is based on the "Constructive Alignment" theory developed by Prof. John Biggs. The film delivers a foundation for understanding what...

Calculation analysis on steady state natural circulation characteristics

International Nuclear Information System (INIS)

Wang Fei; Nie Changhua; Huang Yanping

2005-01-01

The calculation results of single-phase steady state natural circulation characteristics by using Retran02 code have been presented, good agreement is achieved between the verified calculation result and the experimental data which were conducted at a test facility. Based on the calculation model, some sensibility analyses were made and much deeper understanding for single-phase steady state natural circulation characteristics was obtained. (author)

Fractal Characteristics Analysis of Blackouts in Interconnected Power Grid

DEFF Research Database (Denmark)

Wang, Feng; Li, Lijuan; Li, Canbing

2018-01-01

The power failure models are a key to understand the mechanism of large scale blackouts. In this letter, the similarity of blackouts in interconnected power grids (IPGs) and their sub-grids is discovered by the fractal characteristics analysis to simplify the failure models of the IPG. The distri......The power failure models are a key to understand the mechanism of large scale blackouts. In this letter, the similarity of blackouts in interconnected power grids (IPGs) and their sub-grids is discovered by the fractal characteristics analysis to simplify the failure models of the IPG....... The distribution characteristics of blackouts in various sub-grids are demonstrated based on the Kolmogorov-Smirnov (KS) test. The fractal dimensions (FDs) of the IPG and its sub-grids are then obtained by using the KS test and the maximum likelihood estimation (MLE). The blackouts data in China were used...

Applying a social network analysis (SNA) approach to understanding radiologists' performance in reading mammograms

Science.gov (United States)

Tavakoli Taba, Seyedamir; Hossain, Liaquat; Heard, Robert; Brennan, Patrick; Lee, Warwick; Lewis, Sarah

2017-03-01

Rationale and objectives: Observer performance has been widely studied through examining the characteristics of individuals. Applying a systems perspective, while understanding of the system's output, requires a study of the interactions between observers. This research explains a mixed methods approach to applying a social network analysis (SNA), together with a more traditional approach of examining personal/ individual characteristics in understanding observer performance in mammography. Materials and Methods: Using social networks theories and measures in order to understand observer performance, we designed a social networks survey instrument for collecting personal and network data about observers involved in mammography performance studies. We present the results of a study by our group where 31 Australian breast radiologists originally reviewed 60 mammographic cases (comprising of 20 abnormal and 40 normal cases) and then completed an online questionnaire about their social networks and personal characteristics. A jackknife free response operating characteristic (JAFROC) method was used to measure performance of radiologists. JAFROC was tested against various personal and network measures to verify the theoretical model. Results: The results from this study suggest a strong association between social networks and observer performance for Australian radiologists. Network factors accounted for 48% of variance in observer performance, in comparison to 15.5% for the personal characteristics for this study group. Conclusion: This study suggest a strong new direction for research into improving observer performance. Future studies in observer performance should consider social networks' influence as part of their research paradigm, with equal or greater vigour than traditional constructs of personal characteristics.

Externalizing Behaviors in Toddlerhood: A Longitudinal Study on the Role of Child and Parental Characteristics

NARCIS (Netherlands)

van Aken, A.A.A.M.

2008-01-01

According to recent theories, both person characteristics and environmental characteristics have to be taken into account in order to understand individual development. In line with these theories, the present thesis focused on the ways in which child characteristics and parental characteristics

Regional characteristics, opportunity perception and entrepreneurial activities

DEFF Research Database (Denmark)

Stuetzer, Michael; Obschonka, Martin; Brixy, Udo

2014-01-01

This article seeks to better understand the link between regional characteristics and individual entrepreneurship. We combine individual-level Global Entrepreneurship Monitor data for Western Germany with regional-level data, using multilevel analysis to test our hypotheses. We find no direct link...

Is it Oscar-worthy? Children's metarepresentational understanding of acting.

Directory of Open Access Journals (Sweden)

Thalia R Goldstein

Full Text Available Although it is an essential aspect of one of the most common forms of entertainment, psychologists know almost nothing about how children understand the act of portraying a character in a realistic manner-realistic acting. Do children possess the sort of meta-theory of acting that adults possess? In two studies we find that, unlike adults, children between the ages of 3-5 do not think that a realistic actor is better at portraying a characteristic than a nonrealistic actor, nor do they prefer one to the other. As they develop, they come to understand that realistic acting is different from nonrealistic acting, but unlike adults, children think that a nonrealistic, pretense-like portrayal is more difficult to achieve than a realistic representation of an emotional or physical state. These findings show that children's metarepresentational understanding of acting is relatively immature at age 5, and that their understanding of this specific domain of pretense lags behind their understanding of pretense in general.

Understanding postoperative fatigue.

Science.gov (United States)

Rose, E A; King, T C

1978-07-01

Performance characteristics of the central nervous, cardiovascular, respiratory and muscular systems in man postoperatively have received little investigative attention, despite the well known syndrome of postoperative fatigue. The impairmen in perception and psychomotor skills that has been shown to result from caloric restriction, bedrest, sedation and sleep deprivation suggests that a similar deficit may occur after surgical procedures. After a simple elective surgical procedure, maximal oxygen uptake decreases and the adaptability of heart rate to submaximal workloads is impaired. Similar deleterious effects on cardiorespiratory performance have been documented with starvation and bedrest; an understanding of cardiorespiratory performance postoperatively awaits further investigation. Maximal muscular force of contraction is also impaired by caloric restriction and bedrest, suggesting that similar effects may be seen in the postoperative state, although this has not been studied. A better understanding of the syndrome of postoperative fatigue could be achieved by a descriptive analysis of physiologic performance postoperatively. Such descriptive data could form the basis for objective evaluation of therapeutic measures intended to improve performance, such as nutritional supplementation and pharmacologic intervention. The observation that exercise with the patient in the supine position may decrease the impairment in maximal aerobic power otherwise expected in immobilized patients suggests that controlled exercise therapy may be of value in reducing physiologic impairment postoperatively.

Volume reduction and encapsulation process for water containing low-level radioactive waste

International Nuclear Information System (INIS)

Fox, D.W.; Miller, G.P.; Weech, M.E.

1984-01-01

Solutions or slurries of waste material in water are dewatered and encapsulated within a polymer for disposal, comprising the operations of removing water therefrom with azeotropic mixture evaporation and encasing the dewatered waste residue in an organic polymer. The method and system disclosed are especially useful for the safe disposal of radioactive waste

Investigation of friction and wear characteristics of cast iron material under various conditions

Energy Technology Data Exchange (ETDEWEB)

Joo, Ji Hoon; Kim, Chang Lae; Oh, Jeong Taek; Kim, Dae Eun [Yonsei University, Seoul (Korea, Republic of); Nemati, Narguess [School of Materials and Metallurgy, University of Tehran, Tehran (Iran, Islamic Republic of)

2015-08-15

Cast iron is widely used in fields such as the transport and heavy industries. For parts where contact damage is expected to occur, it is necessary to understand the friction and wear characteristics of cast iron. In this study, we use cast iron plates as the specimens to investigate their friction and wear characteristics. We perform various experiments using a reciprocating type tribotester. We assess the frictional characteristics by analyzing the friction coefficient values that were obtained during the sliding tests. We observe the wear surfaces of cast iron and steel balls using a scanning electron microscope, confocal microscope, and 3D profiler. We investigate the friction and wear characteristics of cast iron by injecting sand and alumina particles having various sizes. Furthermore, we estimate the effect of temperature on the friction and wear characteristics. The results obtained are expected to aid in the understanding of the tribological characteristics of cast iron in industry.

An Ecological Understanding of Youth Suicide in South Korea

Science.gov (United States)

Lee, Seung-yeon; Hong, Jun Sung; Espelage, Dorothy L.

2010-01-01

This article reviews risk factors for youth suicide in South Korea (hereafter referred to as Korea), based on the ecological systems theory. Although youth suicide is a major concern for Korean society, understanding of this phenomenon has been limited since most of the empirical studies address personal characteristics without much consideration…

Issue of ecological impacts due to hydro-peaking management. Characterization of hydro-peaks - Operating experience on Maronne River; Impacts ecologiques des eclusees hydroelectriques. Caracterisaton des regimes d'eclusees et Retour d'experience sur la Maronne

Energy Technology Data Exchange (ETDEWEB)

Courret, Dominique; Larinier, Michel [Office National de l' Eau et des Milieux Aquatiques - ONEMA, Pole Ecohydraulique, IMFT, Cemagref, Avenue du Professeur Camille Soula, 31400 Toulouse (France); Chanseau, Matthieu [MIGADO, 18ter rue de la Garonne - 47520 Le Passage (France); Office National de l' Eau et des Milieux Aquatiques - ONEMA, Direction Interregionale de Toulouse, Avenue du Professeur Camille Soula, 31400 Toulouse (France); Lascaux, Jean-Marc [Etudes et COnseils en Gestion de l' Environnement Aquatique - ECOGEA, 10 avenue de Toulouse, 31860 Pins-Justaret (France)

2012-01-15

Hydro-peaking management can consistently alter fish populations, and particularly recruitment of diadromous species, like salmon. To progress in understanding the impacts and defining mitigation measures, it appears essential to combine long-term biological survey, hydrological analysis including hydro-peaks characterization, and hydro-morphologic approach. In a first time, a methodology for hydrological characterization of hydro-peaks is presented. Their diversity and high variability are illustrated. Then, we present operating experience on Maronne River, a tributary of the Dordogne River downstream Argentat affected by hydro-peaks of Hautefage scheme. Biological surveys and hydrologic and hydro-morphologic studies allowed a better understanding and a quantification of some biological impacts (redds dewatering, stranding-trapping of alevins), to support mitigation measures and to assess its effectiveness. The relevance of work on morphology, in addition to measures on flow management, is also illustrated. Some positive results have already been obtained. Studies on the Maronne River are pursued to achieve a really satisfactory situation. This example shows that the current knowledge does not allow, on a given stream, to pre-define mitigation measures and ensure their efficiency. This leads to advocate the setting up of similar approach on other river, to identify biological communities' responses depending on the characteristics of hydro-peaks and hydro-systems. (authors)

Intracranial Infections: Clinical and Imaging Characteristics

Energy Technology Data Exchange (ETDEWEB)

Foerster, B.R.; Thurnher, M.M.; Malani, P.N.; Petrou, M.; Carets-Zumelzu, F.; Sundgren, P.C. [Dept. of Radiology, and Divisions of Infectious Diseases and G eriatric Medicine, Dept. of Internal Medicine, Univ. of Michigan Medical Center, Ann Arbor, MI (United States)

2007-10-15

The radiologist plays a crucial role in identifying and narrowing the differential diagnosis of intracranial infections. A thorough understanding of the intracranial compartment anatomy and characteristic imaging findings of specific pathogens, as well incorporation of the clinical information, is essential to establish correct diagnosis. Specific types of infections have certain propensities for different anatomical regions within the brain. In addition, the imaging findings must be placed in the context of the clinical setting, particularly in immunocompromised and human immunodeficiency virus (HIV)-positive patients. This paper describes and depicts infections within the different compartments of the brain. Pathology-proven infectious cases are presented in both immunocompetent and immunocompromised patients, with a discussion of the characteristic findings of each pathogen. Magnetic resonance spectroscopy (MRS) characteristics for several infections are also discussed.

Bifunctional polymer hydrogel layers as forward osmosis draw agents for continuous production of fresh water using solar energy.

Science.gov (United States)

Razmjou, Amir; Liu, Qi; Simon, George P; Wang, Huanting

2013-11-19

The feasibility of bilayer polymer hydrogels as draw agent in forward osmosis process has been investigated. The dual-functionality hydrogels consist of a water-absorptive layer (particles of a copolymer of sodium acrylate and N-isopropylacrylamide) to provide osmotic pressure, and a dewatering layer (particles of N-isopropylacrylamide) to allow the ready release of the water absorbed during the FO drawing process at lower critical solution temperature (32 °C). The use of solar concentrated energy as the source of heat resulted in a significant increase in the dewatering rate as the temperature of dewatering layer increased to its LSCT more rapidly. Dewatering flux rose from 10 to 25 LMH when the solar concentrator increased the input energy from 0.5 to 2 kW/m(2). Thermodynamic analysis was also performed to find out the minimum energy requirement of such a bilayer hydrogel-driven FO process. This study represents a significant step forward toward the commercial implementation of hydrogel-driven FO system for continuous production of fresh water from saline water or wastewaters.

Understand B-type stars

Science.gov (United States)

1982-01-01

When observations of B stars made from space are added to observations made from the ground and the total body of observational information is confronted with theoretical expectations about B stars, it is clear that nonthermal phenomena occur in the atmospheres of B stars. The nature of these phenomena and what they imply about the physical state of a B star and how a B star evolves are examined using knowledge of the spectrum of a B star as a key to obtaining an understanding of what a B star is like. Three approaches to modeling stellar structure (atmospheres) are considered, the characteristic properties of a mantle, and B stars and evolution are discussed.

Predicting the risk of extinction from shared ecological characteristics

OpenAIRE

Kotiaho, Janne S.; Kaitala, Veijo; Komonen, Atte; Päivinen, Jussi

2005-01-01

Understanding the ultimate causes of population declines and extinction is vital in our quest to stop the currently rampant biodiversity loss. Comparison of ecological characteristics between threatened and nonthreatened species may reveal these ultimate causes. Here, we report an analysis of ecological characteristics of 23 threatened and 72 nonthreatened butterfly species. Our analysis reveals that threatened butterflies are characterized by narrow niche breadth, restricted resource distrib...

Understanding the biology of urothelial cancer metastasis

Directory of Open Access Journals (Sweden)

Takashi Kobayashi

2016-10-01

Full Text Available Management of unresectable urothelial cancer (UC has been a clinical challenge for decades. While drug resistance is a key issue, precise understanding of biology of UC metastasis is another challenge for the improvement of treatment outcome of UC patients. Introduction of the cell biology concepts including epithelial-mesenchymal transition (EMT and cancer stemness seems to explain UC metastasis. Molecular genetics based on gene expression profiling, next generation sequencing, and explosion of non-coding RNA world has opened the door to intrinsic molecular subtyping of UC. Next steps include, based on the recently accumulated understanding, the establishment of novel disease models representing UC metastasis in various experimental platforms, particularly in vivo animal systems. Indeed, novel knowledge molecular genetics has not been fully linked to the modeling of UC metastasis. Further understanding of bladder carcinogenesis is needed particularly with regard to cell of origin related to tumor characteristics including driver gene alterations, pathological differentiations, and metastatic ability. Then we will be able to establish better disease models, which will consequently lead us to further understanding of biology and eventually the development of novel therapeutic strategies for UC metastasis.

Understanding the thermal, mechanical and electrical properties of epoxy nanocomposites

International Nuclear Information System (INIS)

Sarathi, R.; Sahu, R.K.; Rajeshkumar, P.

2007-01-01

In the present work, the electrical, mechanical and thermal properties of epoxy nanocomposite materials were studied. The electrical insulation characteristics were analyzed through short time breakdown voltage test, accelerated electrical ageing test, and by tracking test. The breakdown voltage increases with increase in nano-clay content up to 5 wt%, under AC and DC voltages. The volume resistivity, permittivity and tan(δ) of the epoxy nanocomposites were measured. The Weibull studies indicate that addition of nanoclay upto 5 wt% enhances the characteristic life of epoxy nanocomposite insulation material. The tracking test results indicate that the tracking time is high with epoxy nanocomposites as compared to pure epoxy. Ageing studies were carried out to understand the surface characteristic variation through contact angle measurement. The hydrophobicity of the insulating material was analysed through contact angle measurement. The diffusion coefficients of the material with different percentage of clay in epoxy nanocomposites were calculated. The exfoliation characteristics in epoxy nanocomposites were analyzed through wide angle X-ray diffraction (WAXD) studies. The thermal behaviour of the epoxy nanocomposites was analyzed by carrying out thermo gravimetric-differential thermal analysis (TG-DTA) studies. Heat deflection temperature of the material was measured to understand the stability of the material for intermittent temperature variation. The dynamic mechanical analysis (DMA) results indicated that storage modulus of the material increases with small amount of clay in epoxy resin. The activation energy of the material was calculated from the DMA results

Static Characteristics of the Ferroelectric Transistor Inverter

Science.gov (United States)

Mitchell, Cody; Laws, crystal; MacLeond, Todd C.; Ho, Fat D.

2010-01-01

The inverter is one of the most fundamental building blocks of digital logic, and it can be used as the foundation for understanding more complex logic gates and circuits. This paper presents the characteristics of an inverter circuit using a ferroelectric field-effect transistor. The voltage transfer characteristics are analyzed with respect to varying parameters such as supply voltage, input voltage, and load resistance. The effects of the ferroelectric layer between the gate and semiconductor are examined, and comparisons are made between the inverters using ferroelectric transistors and those using traditional MOSFETs.

The Use of Biochemical Processes in Sludge Treatment

Directory of Open Access Journals (Sweden)

Mohammed S. Shahaab

2012-03-01

Full Text Available The feasibility of using combination of effective microorganism (EM1 and conventional chemical conditioner was evaluated in this study to assess and discern the dewatering properties of the secondary sludge that produced from wastewater treatment plant of the medical assembly in Mosul city. Conventional coagulants such as lime, Alum, and ferrous sulfate, six doses for each coagulant type i.e5- 30(10 - 60 (and (25 -150mg/l(  respectively, were used in the sludge conditioning processes for enhancement of the sludge dewatering capacity. The characteristics of conditioned sludge, such as specific resistance of filtration (SRF (were determined at each dose.Experimental results indicated that effective microorganism seeds have a passive effect on SRF value which was about   % 71.4(and (%75(in lime and ferrous sulfate respectively.While in Alum conditioning process a significant effect on SRF reduction was accomplished which was about %-47.9( and (- %32.8( for effective microorganism and Alum dose increments respectively. The best Alum dosage, for minimum SRF 0.98348×10 12 m /kg, was 60 mg/l at 1 % of effective microorganism.

The Importance of Motivation Theories for Understanding Washback to the Learner

OpenAIRE

WATANABE, Yoshinori

2006-01-01

The present paper portrays three theories of motivation in the expectation that it will help to understand the washback effect of language tests on learning English as a Foreign Language (EFL). The three theories that are identified involve attribution theories of motivation, flow, and functional theories of motivation. The characteristics of these theories are described in a way in which they may help understand the meaning of the recent attempt by the Japanese Ministry of Education to innov...

Using a Malcolm Baldrige framework to understand high-performing clinical microsystems.

Science.gov (United States)

Foster, Tina C; Johnson, Julie K; Nelson, Eugene C; Batalden, Paul B

2007-10-01

BACKGROUND, OBJECTIVES AND METHOD: The Malcolm Baldrige National Quality Award (MBNQA) provides a set of criteria for organisational quality assessment and improvement that has been used by thousands of business, healthcare and educational organisations for more than a decade. The criteria can be used as a tool for self-evaluation, and are widely recognised as a robust framework for design and evaluation of healthcare systems. The clinical microsystem, as an organisational construct, is a systems approach for providing clinical care based on theories from organisational development, leadership and improvement. This study compared the MBNQA criteria for healthcare and the success factors of high-performing clinical microsystems to (1) determine whether microsystem success characteristics cover the same range of issues addressed by the Baldrige criteria and (2) examine whether this comparison might better inform our understanding of either framework. Both Baldrige criteria and microsystem success characteristics cover a wide range of areas crucial to high performance. Those particularly called out by this analysis are organisational leadership, work systems and service processes from a Baldrige standpoint, and leadership, performance results, process improvement, and information and information technology from the microsystem success characteristics view. Although in many cases the relationship between Baldrige criteria and microsystem success characteristics are obvious, in others the analysis points to ways in which the Baldrige criteria might be better understood and worked with by a microsystem through the design of work systems and a deep understanding of processes. Several tools are available for those who wish to engage in self-assessment based on MBNQA criteria and microsystem characteristics.

Fire Regime Characteristics along Environmental Gradients in Spain

Directory of Open Access Journals (Sweden)

María Vanesa Moreno

2016-11-01

Full Text Available Concern regarding global change has increased the need to understand the relationship between fire regime characteristics and the environment. Pyrogeographical theory suggests that fire regimes are constrained by climate, vegetation and fire ignition processes, but it is not obvious how fire regime characteristics are related to those factors. We used a three-matrix approach with a multivariate statistical methodology that combined an ordination method and fourth-corner analysis for hypothesis testing to investigate the relationship between fire regime characteristics and environmental gradients across Spain. Our results suggest that fire regime characteristics (i.e., density and seasonality of fire activity are constrained primarily by direct gradients based on climate, population, and resource gradients based on forest potential productivity. Our results can be used to establish a predictive model for how fire regimes emerge in order to support fire management, particularly as global environmental changes impact fire regime characteristics.

Understanding the Role of Online Reviews on Customers' Risk Perception

Science.gov (United States)

Yang, Jing

2013-01-01

Customer reviews play an important role in today's online shopping environment. Research into customer reviews has largely focused on the predictive effect of review characteristics on variables such as product sales. However, relatively little attention has been directed towards understanding how reviews impact a customer's decision to purchase a…

Analysis of potential saltwater intrusion at NEP I and II power station

Energy Technology Data Exchange (ETDEWEB)

Lee, D.W.

1980-06-01

The potential of adverse environmental impacts to groundwater availability and groundwater quality from construction dewatering of the coastal aquifer at a proposed New England Power site was examined with an analytical model. The drawdown zone and the extent of saltwater intrusion were predicted with and without the use of a slurry-wall barrier. The use of a slurry wall to mitigate any adverse impacts is feasible but the limited understanding of the coastal aquifer demands that monitoring requirements be included in the construction plan.

Analysis of potential saltwater intrusion at NEP I and II power station

International Nuclear Information System (INIS)

Lee, D.W.

1980-06-01

The potential of adverse environmental impacts to groundwater availability and groundwater quality from construction dewatering of the coastal aquifer at a proposed New England Power site was examined with an analytical model. The drawdown zone and the extent of saltwater intrusion were predicted with and without the use of a slurry-wall barrier. The use of a slurry wall to mitigate any adverse impacts is feasible but the limited understanding of the coastal aquifer demands that monitoring requirements be included in the construction plan

Comparison of macrostickies measurement methods

Science.gov (United States)

Mahendra R. Doshi; William J. Moore; R.A. Venditti; K. Copeland; H.-M. Chang; Hans-Joachim Putz; Thierry Delagoutte; Carl Houtman; Freya Tan; Lisa Davie; Gregg Sauve; Tim Dahl; Dave Robinson

2003-01-01

Pulp containing PSA was prepared in the laboratory and blended with sticky-free pulp in four different proportions. The four pulps were then dewatered and shipped to four laboratories for the evaluation of macro stickies in terms of mm2/kg. Also, five pulp samples from specific locations in a deinking mill were dewatered and shipped to the same four laboratories....

Cutting down operating costs at sewage treatment plant through aimed application of new characterization methods; Betriebskostenreduzierung auf Klaeranlagen durch gezielte Anwendung neuer Charakterisierungsmethoden

Energy Technology Data Exchange (ETDEWEB)

Friedrich, H.; Potthoff, A. [Fraunhofer-Institut fuer Keramische Technologien und Sinterwerkstoffe (IKTS), Dresden (Germany); Friedrich, E. [Ingenieurgesellschaft fuer Wasser und Entsorgung mbH, Radebeul (Germany)

1999-07-01

Mechanical dewatering of sewage sludge is state of the art. Because of increasing cost, more stringent regulations (act on waste recycling 'Kreislaufwirtschaftsgesetz' and the technical code on municipal waste), and the lack of landfill space, expensive thermal processing techniques are gaining ever greater weight. To assure that disposal costs remain reasonable, mechanical dewatering must be more and more enhanced. The following need to be optimized and enhanced: sludge properties, conditioning, and dewatering. (orig.) [German] Klaerschlaemme maschinell zu entwaessern ist Stand der Technik. Steigende Kosten, verschaerfte Bestimmungen (Kreislaufwirtschaftsgesetz, TA Siedlungsabfall) und fehlende Deponien geben den teuren thermischen Behandlungsverfahren ein immer groesseres Gewicht. Damit die Entsorgung bezahlbar bleibt, muss immer staerker mechanisch entwaessert werden. Optimiert und verbessert werden muessen die Schlammeigenschaften, die Konditionierung und die Entwaesserung. (orig.)

Evolution Characteristics of the Network Core in the Facebook

OpenAIRE

Liu, Jian-Guo; Ren, Zhuo-Ming; Guo, Qiang; Chen, Duan-Bing

2014-01-01

Statistical properties of the static networks have been extensively studied. However, online social networks are evolving dynamically, understanding the evolving characteristics of the core is one of major concerns in online social networks. In this paper, we empirically investigate the evolving characteristics of the Facebook core. Firstly, we separate the Facebook-link(FL) and Facebook-wall(FW) datasets into 28 snapshots in terms of timestamps. By employing the k-core decomposition method t...

Understanding the workplace culture of a special care nursery.

Science.gov (United States)

Wilson, Valerie J; McCormack, Brendan G; Ives, Glenice

2005-04-01

This paper presents findings from the first phase of a research study focusing on implementation and evaluation of emancipatory practice development strategies. Understanding the culture of practice is essential to undertaking effective developments in practice. Culture is a dominant feature of discussions about modernizing health care, yet few studies have been undertaken that systematically evaluate the development of effective practice cultures. The study intervention is that of emancipatory practice development with an integrated evaluation approach based on Realistic Evaluation. The aim of Realistic Evaluation is to evaluate relationships between Context (setting), Mechanism (process characteristics) and Outcome (arising from the context-mechanism configuration). This first phase of the study focuses on uncovering the context (in particular the culture) of the Special Care Nursery in order to evaluate the emancipatory practice development processes and outcomes. Data collection methods included survey, participant observation and interview. Cognitive mapping, constant comparative method and coding were used to analyse the data. Findings. Four key categories were identified: Teamwork, Learning in Practice, Inevitability of Change and Family-Centred Care and collectively these formed a central category of Core Values and Beliefs. A number of themes were identified in each category, and reflected tensions that existed between differing values and beliefs within the culture of the unit. Understanding values and beliefs is an important part of understanding a workplace culture. Whilst survey methods are capable of outlining espoused workplace characteristics, observation of staff interactions and perceptions gives an understanding of culture as a living entity manifested through interpersonal relationships. Attempts at changing workplace cultures should start from the clarification of values held among staff in that culture.

Understanding nurses' and physicians' fear of repercussions for reporting errors: clinician characteristics, organization demographics, or leadership factors?

Science.gov (United States)

Castel, Evan S; Ginsburg, Liane R; Zaheer, Shahram; Tamim, Hala

2015-08-14

Identifying and understanding factors influencing fear of repercussions for reporting and discussing medical errors in nurses and physicians remains an important area of inquiry. Work is needed to disentangle the role of clinician characteristics from those of the organization-level and unit-level safety environments in which these clinicians work and learn, as well as probing the differing reporting behaviours of nurses and physicians. This study examines the influence of clinician demographics (age, gender, and tenure), organization demographics (teaching status, location of care, and province) and leadership factors (organization and unit leadership support for safety) on fear of repercussions, and does so for nurses and physicians separately. A cross-sectional analysis of 2319 nurse and 386 physician responders from three Canadian provinces to the Modified Stanford patient safety climate survey (MSI-06). Data were analyzed using exploratory factor analysis, multiple linear regression, and hierarchical linear regression. Age, gender, tenure, teaching status, and province were not significantly associated with fear of repercussions for nurses or physicians. Mental health nurses had poorer fear responses than their peers outside of these areas, as did community physicians. Strong organization and unit leadership support for safety explained the most variance in fear for both nurses and physicians. The absence of associations between several plausible factors including age, tenure and teaching status suggests that fear is a complex construct requiring more study. Substantially differing fear responses across locations of care indicate areas where interventions may be needed. In addition, since factors affecting fear of repercussions appear to be different for nurses and physicians, tailoring patient safety initiatives to each group may, in some instances, be fruitful. Although further investigation is needed to examine these and other factors in detail, supportive

FINANCIAL ACCOUNTING QUALITY AND ITS DEFINING CHARACTERISTICS

Directory of Open Access Journals (Sweden)

Andra M. ACHIM

2014-11-01

Full Text Available The importance ofhigh-quality financial statements is highlighted by the main standard-setting institutions activating in the field of accounting and reporting. These have issued Conceptual Frameworks which state and describe the qualitative characteristics of accounting information. In this qualitative study, the research methodology consists of reviewing the literature related to the definition of accounting quality and striving for understanding how it can be explained. The main objective of the study is to identify the characteristics information should possess in order to be of high quality. These characteristics also contribute to the way of defining financial accounting quality. The main conclusions that arise from this research are represented by the facts that indeed financial accounting quality cannot be uniquely defined and that financial information is of good quality when it enhances the characteristics incorporated in the conceptual frameworks issued by both International Accounting Standards Board and Financial Accounting Standards Board.

Consolidation of tailings

International Nuclear Information System (INIS)

Nelson, J.D.; Wardwell, R.E.; Abt, S.R.; Staub, W.P.

1983-09-01

The integrity of cover systems placed on tailings impoundments will be affected by the potential for differential settlement of the tailings surface. Settlement of the sand fraction will occur relatively rapidly. The slimes will take longer time for consolidation and will produce greater settlement. This report reviews the phenomenon of consolidation for saturated and unsaturated tailings. The effect of load application by cover placement and the extent to which dewatering of tailings will cause consolidation are considered. In addition, the feasibility of inducing consolidation by alternative means and the potential applicability of these methods to tailings impoundments reclamation are discussed. Differential settlement of the tailings will cause tensile strain to be developed in covers. This strain could be large enough to cause cracking within a relatively brittle compacted clay. Dewatering of tailings by drainage can cause settlement even greater than that by placement of a cover material. Dewatering of the tailings would also increase the stability of the tailings surface, thereby enhancing reclamation operations. Consequently, in view of the enhanced surface stability and the fact that a portion of the differential settlement can be accomplished prior to cover placement, dewatering of tailings impoundments during operations may have benefical effects

Seasonal changes in bacterial counts and radiation-disinfection of sewage sludge

International Nuclear Information System (INIS)

Watanabe, Hiroshi; Ito, Hitoshi; Takehisa, Masaaki; Iizuka, Hiroshi.

1981-01-01

The effect of radiation on sewage sludge was investigated to disinfect it. The results obtained were as follows: 1. In either activated sludge or digested sludge dewatered by centrifugation, total bacteria and coliforms were up to 3.0 x 10 9 /g and 3.5 x 10 8 /g, respectively. In the activated sludge which was dewatered by a filter-press with calcium oxide and iron chloride, total bacteria were up to 3.0 x 10 5 /g, while coliforms were hardly detected. 2. The fraction of coliforms was somewhat more in centrifuged sludge than in raw sludge. 3. The radiosensitivity of coliforms in raw sludge differed between samples. Namely, some sludge was sterilized with 0.5 Mrad while others were not sterilized even with 1.0 Mrad. On the other hand, coliforms in dewatered sludge were sterilized with 0.5 Mrad without seasonal change, but total bacteria were more radioresistant and more than 13 Mrad was required to reduce it to an undetectable level. From these results it is concluded that the dewatered sludge should be irradiated at 0.5 Mrad to eliminate the coliforms in it. (author)

Flexural testing of weld site and HVOF coating characteristics

CERN Document Server

Yilbas, Bekir Sami; Sahin, Ahmet

2014-01-01

This book provides fundamental understanding and practical application of characteristics of flexural motion in the assessment of the weld size and coating thickness. Some formulations of heat transfer and flexural motion are introduced while displacement and load correlation are used to estimate elastic modules and the size of the heat affected zone as well as the coating thickness. The case studies presented give a practical understanding of weld size and coating thickness characterizations.

First Time: Characteristics of Teens' First Sexual Relationships. Child Trends Research Brief.

Science.gov (United States)

Ryan, Suzanne; Manlove, Jennifer; Franzetta, Kerry

Understanding characteristics of teens' sexual relationships may help us to better understand how to reduce teens' risk of early unintended pregnancy and sexually transmitted diseases (STDs), as well as the psychological and emotional problems that may be associated with teenage romantic relationships and sexual activity. Using data from the…

The relative contribution of near-bed vs. intragravel horizontal transport to fine sediment accumulation processes in river gravel beds

Science.gov (United States)

Casas-Mulet, Roser; Lakhanpal, Garima; Stewardson, Michael J.

2018-02-01

Understanding flow-sediment interactions is important for comprehending river functioning. Fine sediment accumulation processes, in particular, have key implications for ecosystem health. However, the amount of fines generated by intragravel flows and later accumulated in gravel streambeds may have been underestimated, as the hydraulic-related driving transport mechanisms in play are not clearly identified. Specifically, the relative contribution of fines from upper vs. lower sediment layers in gravel beds is not well understood. By recreating flooded and dewatered conditions in an experimental flume filled with natural sediment, we estimated such contributions by observing and collecting intragravel transported fines that were later accumulated into a void in the middle of the sediment matrix. Near-bed transport in the upper sediment layers (named Brinkman load) during flooded conditions accounted for most (90%) of the accumulated fines. Intragravel transport in the lower sediment layers (named Interstitial load) was the sole source of transport and accumulation during dewatered conditions with steeper hydraulic gradients. Interstitial load accounted for 10% of the total transport during flooded conditions. Although small, such estimations demonstrate that hydraulic-gradient transport in the lower sediment layers occurs in spite of the contradicting analytical assessments. We provide a case study to challenge the traditional approaches of assessing intragravel transport, and a useful framework to understand the origin and relative contribution of fine sediment accumulation in gravel beds. Such knowledge will be highly useful for the design of monitoring programs aiding river management, particularly in regulated rivers.

Enhancing sewage sludge dewaterability by bioleaching approach with comparison to other physical and chemical conditioning methods.

Science.gov (United States)

Liu, Fenwu; Zhou, Jun; Wang, Dianzhan; Zhou, Lixiang

2012-01-01

The sewage sludge conditioning process is critical to improve the sludge dewaterability prior to mechanical dewatering. Traditionally, sludge is conditioned by physical or chemical approaches, mostly with the addition of inorganic or organic chemicals. Here we report that bioleaching, an efficient and economical microbial method for the removal of sludge-borne heavy metals, also plays a significant role in enhancing sludge dewaterability. The effects of bioleaching and physical or chemical approaches on sludge dewaterability were compared. The conditioning result of bioleaching by Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans on sludge dewatering was investigated and compared with the effects of hydrothermal (121 degrees C for 2 hr), microwave (1050 W for 50 sec), ultrasonic (250 W for 2 min), and chemical conditioning (24% ferric chloride and 68% calcium oxide; dry basis). The results show that the specific resistance to filtration (SRF) or capillary suction time (CST) of sludge is decreased by 93.1% or 74.1%, respectively, after fresh sludge is conditioned by bioleaching, which is similar to chemical conditioning treatment with ferric chloride and calcium oxide but much more effective than other conditioning approaches including hydrothermal, microwave, and ultrasonic conditioning. Furthermore, after sludge dewatering, bioleached sludge filtrate contains the lowest concentrations of chroma (18 times), COD (542 mg/L), total N (TN, 300 mg/L), NH4(+)-N (208 mg/L), and total P (TP, 2 mg/L) while the hydrothermal process resulted in the highest concentration of chroma (660 times), COD (18,155 mg/L), TN (472 mg/L), NH4(+)-N (381 mg/L), and TP (191 mg/L) among these selected conditioning methods. Moreover, unlike chemical conditioning, sludge bioleaching does not result in a significant reduction of organic matter, TN, and TP in the resulting dewatered sludge cake. Therefore, considering sludge dewaterability and the chemical properties of sludge

Characteristics of students in comparative problem solving

Science.gov (United States)

Irfan, M.; Sudirman; Rahardi, R.

2018-01-01

Often teachers provided examples and exercised to students with regard to comparative problems consisting of one quantity. In this study, the researchers gave the problem of comparison with the two quantities mixed. It was necessary to have a good understanding to solve this problem. This study aimed to determine whether students understand the comparison in depth and be able to solve the problem of non-routine comparison. This study used qualitative explorative methods, with researchers conducting in-depth interviews on subjects to explore the thinking process when solving comparative problems. The subject of this study was three students selected by purposive sampling of 120 students. From this research, researchers found there were three subjects with different characteristics, namely: subject 1, he did the first and second questions with methods of elimination and substitution (non-comparison); subject 2, he did the first question with the concept of comparison although the answer was wrong, and did the second question with the method of elimination and substitution (non-comparison); and subject 3, he did both questions with the concept of comparison. In the first question, he did wrong because he was unable to understand the problem, while on the second he did correctly. From the characteristics of the answers, the researchers divided into 3 groups based on thinking process, namely: blind-proportion, partial-proportion, and proportion thinking.

Enhancing the dewatering properties of sludge through aimed building-up of floc structures on the basis of detailed morphological analyses; Verbesserung der Entwaesserungseigenschaften von Schlaemmen durch den gezielten Aufbau von Flockenstrukturen auf der Basis detaillierter morphologischer Analysen

Energy Technology Data Exchange (ETDEWEB)

Nagel, M.; Ay, P. [Brandenburgische Technische Univ. Cottbus (Germany). Lehrstuhl Aufbereitungstechnik

1999-07-01

Aimed building-up of aggregates as they originate in flocculation processes, for instance in sewage and sludge treatment, have especially lately been meeting with increasing resonance: they permit to influence, inter alia, important properties (e.g., the dewatering properties) of such systems. As conventional mathematical methods for the characterization of flocs - as a basis for process optimization - are inadequate or flawed, a concept for the effective characterization of the inner getup of such structures needs to be sought. One approach is cluster analysis, which is demonstrated and discussed in the present paper by means of the evaluation of sectional views of floc structures. (orig.) [German] Der gezielte Aufbau von Aggregaten, wie sie bei Flockungsprozessen z.B. in der Abwasser- und Schlammbehandlung entstehen, findet besonders in juengerer Zeit zunehmend Beachtung, da sich damit unter anderem wichtige Eigenschaften (z.B. die Entwaesserungseigenschaften) dieser Systeme beeinflussen lassen. Da herkoemmliche mathematische Methoden zur Charakterisierung von Flocken - als Basis fuer eine Prozessoptimierung - nur unzureichend bzw. fehlerbehaftet sind, ergibt sich daraus die Notwendigkeit, nach einem Konzept zur effektiven Charakterisierung des inneren Aufbaus solcher Strukturen zu suchen. Ein Ansatz ist die Clusteranalyse, die im Beitrag durch die Auswertung von Schnittbildern von Flockenstrukturen vorgestellt und diskutiert wird. (orig.)

Students' Energy Understanding Across Biology, Chemistry, and Physics Contexts

Science.gov (United States)

Opitz, S. T.; Neumann, K.; Bernholt, S.; Harms, U.

2017-07-01

Energy is considered both as a disciplinary core idea and as a concept cutting across science disciplines. Most previous approaches studied progressing energy understanding in specific disciplinary contexts, while disregarding the relation of understanding across them. Hence, this study provides a systematic analysis of cross-disciplinary energy learning. On the basis of a cross-sectional study with n = 742 students from grades 6, 8, and 10, we analyze students' progression in understanding energy across biology, chemistry, and physics contexts. The study is guided by three hypothetical scenarios that describe how the connection between energy understanding in the three disciplinary contexts changes across grade levels. These scenarios are compared using confirmatory factor analysis (CFA). The results suggest that, from grade 6 to grade 10, energy understanding in the three disciplinary contexts is highly interrelated, thus indicating a parallel progression of energy understanding in the three disciplinary contexts. In our study, students from grade 6 onwards appeared to have few problems to apply one energy understanding across the three disciplinary contexts. These findings were unexpected, as previous research concluded that students likely face difficulties in connecting energy learning across disciplinary boundaries. Potential reasons for these results and the characteristics of the observed cross-disciplinary energy understanding are discussed in the light of earlier findings and implications for future research, and the teaching of energy as a core idea and a crosscutting concept are addressed.

Understanding the Changing Planet: Strategic Directions for the Geographical Sciences

Science.gov (United States)

National Academies Press, 2010

2010-01-01

From the oceans to continental heartlands, human activities have altered the physical characteristics of Earth's surface. With Earth's population projected to peak at 8 to 12 billion people by 2050 and the additional stress of climate change, it is more important than ever to understand how and where these changes are happening. Innovation in the…

Understanding S-shaped current-voltage characteristics of organic solar cells: Direct measurement of potential distributions by scanning Kelvin probe

Science.gov (United States)

Saive, Rebecca; Mueller, Christian; Schinke, Janusz; Lovrincic, Robert; Kowalsky, Wolfgang

2013-12-01

We present a comparison of the potential distribution along the cross section of bilayer poly(3-hexylthiophene)/1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C61 (P3HT/PCBM) solar cells, which show normal and anomalous, S-shaped current-voltage (IV) characteristics. We expose the cross sections of the devices with a focussed ion beam and measure them with scanning Kelvin probe microscopy. We find that in the case of S-shaped IV-characteristics, there is a huge potential drop at the PCBM/Al top contact, which does not occur in solar cells with normal IV-characteristics. This behavior confirms the assumption that S-shaped curves are caused by hindered charge transport at interfaces.

Understanding S-shaped current-voltage characteristics of organic solar cells: Direct measurement of potential distributions by scanning Kelvin probe

International Nuclear Information System (INIS)

Saive, Rebecca; Kowalsky, Wolfgang; Mueller, Christian; Schinke, Janusz; Lovrincic, Robert

2013-01-01

We present a comparison of the potential distribution along the cross section of bilayer poly(3-hexylthiophene)/1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]C61 (P3HT/PCBM) solar cells, which show normal and anomalous, S-shaped current-voltage (IV) characteristics. We expose the cross sections of the devices with a focussed ion beam and measure them with scanning Kelvin probe microscopy. We find that in the case of S-shaped IV-characteristics, there is a huge potential drop at the PCBM/Al top contact, which does not occur in solar cells with normal IV-characteristics. This behavior confirms the assumption that S-shaped curves are caused by hindered charge transport at interfaces

Water use characteristics of a bambara groundnut ( Vigna ...

African Journals Online (AJOL)

Bambara groundnut is slow to establish and this has negative implications for total water use. Consideration of bambara groundnut as a water-efficient crop for dry areas will benefit from an understanding of water use efficiency and water use characteristics during establishment. We investigated whether there is an ...

The Psychology of Isolated and Confined Environments: Understanding Human Behavior in Antarctica.

Science.gov (United States)

Palinkas, Lawrence A.

2003-01-01

Reviews lessons learned from research in Antarctica with relevance to understanding human behavior in other isolated and confined environments. Outlines four distinct characteristics of psychosocial adaptation to such environments and discusses some of the benefits for individuals seeking challenging experiences. (Contains references.) (SLD)

A Numerical Study on Characteristics of Flow and Reactive Pollutant Dispersion in Step‒up Street Canyons

Science.gov (United States)

Kim, E. R.; Kim, J.

2014-12-01

For decades, many metro‒ and/or mega‒cities have grown and densities of population and building have increased. Because pollutants released from sources near ground surface such as vehicles are not easy to escape from street canyons which are spaces between buildings standing along streets pedestrians, drivers and residents are likely to be exposed to high concentrations of hazardous pollutants. Therefore, it is important to understand characteristics of flow and pollutant dispersion in street canyons. In this study, step‒up street canyons with higher downwind buildings are considered for understanding flow and reactive pollutants' dispersion characteristics there as a basic step to understand the characteristics in wider urban areas. This study used a CFD model coupled to a chemistry module. Detailed flow and air pollutant concentration are analyzed in step‒up street canyons with different upwind building heights.

Understanding the Entrepreneur: An Index of Entrepreneurial Success

OpenAIRE

Fried, Harold O.; Tauer, Loren W.

2009-01-01

A measure of entrepreneur success is important to identify current and future successful ventures, to further our understanding of the entrepreneurial process and to guide public policies to improve the success rate of start-ups. In this paper we propose an index of entrepreneur success that accommodates multiple inputs and outputs, that is predicated on inputs and that mitigates the impact of outliers. We relate the index to characteristics of the entrepreneur and the venture: age, experienc...

Understanding characteristics in multivariate traffic flow time series from complex network structure

Science.gov (United States)

Yan, Ying; Zhang, Shen; Tang, Jinjun; Wang, Xiaofei

2017-07-01

Discovering dynamic characteristics in traffic flow is the significant step to design effective traffic managing and controlling strategy for relieving traffic congestion in urban cities. A new method based on complex network theory is proposed to study multivariate traffic flow time series. The data were collected from loop detectors on freeway during a year. In order to construct complex network from original traffic flow, a weighted Froenius norm is adopt to estimate similarity between multivariate time series, and Principal Component Analysis is implemented to determine the weights. We discuss how to select optimal critical threshold for networks at different hour in term of cumulative probability distribution of degree. Furthermore, two statistical properties of networks: normalized network structure entropy and cumulative probability of degree, are utilized to explore hourly variation in traffic flow. The results demonstrate these two statistical quantities express similar pattern to traffic flow parameters with morning and evening peak hours. Accordingly, we detect three traffic states: trough, peak and transitional hours, according to the correlation between two aforementioned properties. The classifying results of states can actually represent hourly fluctuation in traffic flow by analyzing annual average hourly values of traffic volume, occupancy and speed in corresponding hours.

Performance characteristics of the Mayo/IBM PACS

Science.gov (United States)

Persons, Kenneth R.; Gehring, Dale G.; Pavicic, Mark J.; Ding, Yingjai

1991-07-01

The Mayo Clinic and IBM (at Rochester, Minnesota) have jointly developed a picture archiving system for use with Mayo's MRI and Neuro CT imaging modalities. The communications backbone of the PACS is a portion of the Mayo institutional network: a series of 4-Mbps token rings interconnected by bridges and fiber optic extensions. The performance characteristics of this system are important to understand because they affect the response time a PACS user can expect, and the response time for non-PACS users competing for resources on the institutional network. The performance characteristics of each component and the average load levels of the network were measured for various load distributions. These data were used to quantify the response characteristics of the existing system and to tune a model developed by North Dakota State University Department of Computer Science for predicting response times of more complex topologies.

Operational strategy, economic and environmental performance of sludge treatment reed bed systems - based on 28 years of experience

DEFF Research Database (Denmark)

Nielsen, S.; Larsen, Julie Dam

2016-01-01

Sludge treatment reed bed (STRB) systems have been used for dewatering and mineralisation of sludge in Europe since 1988. STRB systems provide substantial environmental, economic, and operational benefits compared to mechanical sludge dewatering solutions such as belt presses and centrifuges....... They require less energy, no chemicals, reduce the sludge volume and produce bio solids with dry solid contents up to 20-40% under Danish climate conditions, depending on the sludge quality. Experience has shown that sludge treated in STRBs represents a high quality product with a low content of pathogens...... compared to conventional mechanical dewatering devices, delivering an economic break-even of about 3-5 years. This paper provides an overview of the operation and maintenance costs and environmental benefits of a typical STRB based on the experiences gained from the operation of a large number of STRBs...

Sewage sludge conditioning with the application of ash from biomass-fired power plant

Science.gov (United States)

Wójcik, Marta; Stachowicz, Feliks; Masłoń, Adam

2018-02-01

During biomass combustion, there are formed combustion products. Available data indicates that only 29.1 % of biomass ashes were recycled in Poland in 2013. Chemical composition and sorptive properties of ashes enable their application in the sewage sludge treatment. This paper analyses the impact of ashes from biomass-combustion power plant on sewage sludge dewatering and higienisation. The results obtained in laboratory tests proved the possitive impact of biomass ashes on sewage sludge hydration reduction after dewatering and the increase of filtrate volume. After sludge conditioning with the use of biomass combustion by-products, the final moisture content decreased by approximatelly 10÷25 % in comparison with raw sewage sludge depending on the method of dewatering. The application of biomass combustion products in sewage sludge management could provide an alternative method of their utilization according to law and environmental requirements.

Winery waste recycling through anaerobic co-digestion with waste activated sludge.

Science.gov (United States)

Da Ros, C; Cavinato, C; Pavan, P; Bolzonella, D

2014-11-01

In this study biogas and high quality digestate were recovered from winery waste (wine lees) through anaerobic co-digestion with waste activated sludge both in mesophilic and thermophilic conditions. The two conditions studied showed similar yields (0.40 m(3)/kgCODfed) but different biological process stability: in fact the mesophilic process was clearly more stable than the thermophilic one in terms of bioprocess parameters. The resulting digestates showed good characteristics for both the tested conditions: heavy metals, dioxins (PCDD/F), and dioxin like bi-phenyls (PCBs) were concentred in the effluent if compared with the influent because of the important reduction of the solid dry matter, but remained at levels acceptable for agricultural reuse. Pathogens in digestate decreased. Best reductions were observed in thermophilic condition, while at 37°C the concentration of Escherichia coli was at concentrations level as high as 1000 UFC/g. Dewatering properties of digestates were evaluated by means of the capillary suction time (CST) and specific resistance to filtration (SRF) tests and it was found that a good dewatering level was achievable only when high doses of polymer (more than 25 g per kg dry solids) were added to sludge. Copyright © 2014 Elsevier Ltd. All rights reserved.

A study on the treatment of radioactive slurry liquid waste

International Nuclear Information System (INIS)

Jeong, Gyeong Hwan; Chung, U. S.; Baik, S. T.; Park, S. K.; Moon, J.S.; Jung, K.J.

1998-12-01

The influence of anionic flocculants on the dewatering of radioactive slurries has been investigated in a laboratory-scale vacuum filtration unit. Simultaneously the influence of certain surfactants on the dewatering of radioactive slurries with anionic flocculants has also been investigated. Test results show that the flocculated filter cake generally contains higher residual water than the unflocculated cake. The non-ionic surfactant Triton X-100 was effective in reducing the moisture content of the cake

Development of harvesting and up concentration technologies for microalgae as an ingredient in fish feed

DEFF Research Database (Denmark)

Safafar, Hamed; Jacobsen, Charlotte; Møller, Per

2014-01-01

andfish oil. In applications of algae in fish feed, it is essential to produce a product comparable to fish proteinand fish oil both in terms of quality and costs.Downstream processing of microalgae includes harvest, dewatering, cell rupture, fractionation and drying.The dewatering and drying which...... ingredients forfish feed. Further we evaluate the chemical composition of six different microalgae species including;Nanochloropsis limnethica, Chlorella sorokiniana, Phaeodactylum tinctorium, Dunaliella salina,Nannochloropsis salina and Nannochloropsis occulata ....

A study on the treatment of radioactive slurry liquid waste

Energy Technology Data Exchange (ETDEWEB)

Jeong, Gyeong Hwan; Chung, U. S.; Baik, S. T.; Park, S. K.; Moon, J.S.; Jung, K.J

1998-12-01

The influence of anionic flocculants on the dewatering of radioactive slurries has been investigated in a laboratory-scale vacuum filtration unit. Simultaneously the influence of certain surfactants on the dewatering of radioactive slurries with anionic flocculants has also been investigated. Test results show that the flocculated filter cake generally contains higher residual water than the unflocculated cake. The non-ionic surfactant Triton X-100 was effective in reducing the moisture content of the cake.

Recycling of nutrients through struvite precipitation from digestions residues; Aatervinning av naering genom struvitfaellninggsaemnen fraan roetrest

Energy Technology Data Exchange (ETDEWEB)

Fransson, Liisa; Loewgren, Sofia; Thelin, Gunnar (Ekobalans Fenix AB, Lund (Sweden))

2010-05-15

The aim of the project which is described in this report was to gather information about struvite precipitation and studies that have been performed within this area, and also to investigate struvite precipitation in four different digestates through laboratory experiments. Digestates from biogas plants with household waste, beet, manure and distillery residues as raw materials were used in this study. Struvite, MgNH{sub 4}PO{sub 4}-6H{sub 2}O, is a white crystal powder which is soluble at low pH and precipitates at pH 7-11. For struvite to precipitate the solution also has to be over saturated and the influence of other competitive ions has to be low. Many studies in struvite precipitation have been done as laboratory trials and in pilot plants. The experiments were performed on for example digestates from sewage treatment plants. The reactors were stirred or aerated and the solutions were either dewatered or non dewatered. The experiments were performed both with and without the addition of phosphate. A few full scale plants are also described in this report. Most of them consist of a fluidized bed and are connected to sewage treatment plants. Dewatered sewage sludge is most commonly used but there are also examples of non dewatered sludge. Some of the products from the full scale plants are sold as fertilizers. MgCl{sub 2}-6H{sub 2}O is the most common magnesium additive in the studies that have been summarized in this report, but for example Mg(OH){sub 2} has also been used in a few cases. The laboratory experiments in this report were performed on non dewatered and dewatered digestates. The dewatering was performed by filtration in three steps, except for the digestate from distillery residues which was centrifuged. The experiments were performed with and without phosphate addition. First, a few trials on synthetic solutions were performed to verify the chosen experimental conditions. All of the trials, with the synthetic and digestate solutions, were

Empowering Teachers: Characteristics, Strategies, and Practices of Successful Principals

Science.gov (United States)

Ellis, Cailin Patrice

2012-01-01

This study implemented an exploratory mixed-methods design to better understand how the characteristics of a principal, specifically the strategies, behaviors, and actions, lead to the perception of empowerment as perceived by the teachers themselves. An expert panel identified three "highly successful" principals assigned to elementary…

North European Understanding of Zero Energy/Emission Buildings

DEFF Research Database (Denmark)

Marszal, Anna Joanna; Bourrelle, J. S.; Nieminen, J.

2010-01-01

countries are still to adopt a national definition for these types of buildings. This results often in more than one understanding of ZEBs in each country. This study provides a concise source of information on the north European understanding of zero energy/emission buildings. It puts forward a number......The worldwide CO2 emission mitigation efforts, the growing energy resource shortage and the fact that buildings are responsible for a large share of the world’s primary energy use drives research towards new building concepts, in particular Zero Energy/Emission Buildings (ZEBs). Unfortunately...... may observe a correlation between the zero energy/emission building approach adopted by a country and this particular country’s utility grid characteristics. Moreover, it is to be noted that the ZEB concept is not well defined at the national level in northern Europe and that all of the participating...

77 FR 55795 - Request for Information: Research on the Causes, Characteristics, and Consequences of Childhood...

Science.gov (United States)

2012-09-11

... Causes, Characteristics, and Consequences of Childhood Hunger and Food Insecurity AGENCY: Food and... the causes, characteristics, and consequences of childhood hunger and food insecurity. The funding... understanding of the causes and consequences of child hunger and food insecurity? In addition, commenters are...

Understanding Informal Learning in Small- and Medium-Sized Enterprises in South Korea

Science.gov (United States)

Jeong, Shinhee; McLean, Gary N.; Park, Soyoun

2018-01-01

Purpose: This paper aims to explore informal learning experiences among employees working in South Korean small- and medium-sized enterprises (SMEs) with fewer than 100 employees. This study specifically seeks to understand the characteristics of informal learning in Korean SMEs and culturally sensitive contextual factors that shape informal…

Spatial Characteristics of Twitter Users—Toward the Understanding of Geosocial Media Production

Directory of Open Access Journals (Sweden)

Michal Rzeszewski

2017-08-01

Full Text Available Social media is a rich source of spatial data but it has also many flaws and well-known limitations, especially in regard to representation and representativeness, since very little is known about the demographics of the user population. At the same time, the use of locational services, is in fact, dependent on those characteristics. We address this gap in knowledge by exploring divides between Twitter users, based on the spatial and temporal distribution of the content they produce. We chose five cities and data from 2015 to represent different socio-spatial contexts. Users were classified according to spatial and non-spatial measures: home range estimation; standard distance; nearest neighbor index, and; proposed localness index. There are distinct groups of geosocial media producers, which suggests that such datasets cannot be treated as uniform representations. We found a positive correlation between spatial behavior and posting activity. It is suggested that there are universal patterns of behavior that are conditioned by software services—the example of Foucauldian “technologies of self”. They can also represent the dominance of the most prolific users over the whole data stream. Results are discussed in the context of the importance and role of user location in social media.

Evaluation of Management of Water Release for Painted Rocks Reservoir, Bitterroot River, Montana, 1984 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Lere, Mark E. (Montana Department of Fish, Wildlife and Parks, Missoula, MT)

1984-11-01

Baseline fisheries and habitat data were gathered during 1983 and 1984 to evaluate the effectiveness of supplemental water releases from Painted Rocks Reservoir in improving the fisheries resource in the Bitterroot River. Discharge relationships among main stem gaging stations varied annually and seasonally. Flow relationships in the river were dependent upon rainfall events and the timing and duration of the irrigation season. Daily discharge monitored during the summers of 1983 and 1984 was greater than median values derived at the U.S.G.S. station near Darby. Supplemental water released from Painted Rocks Reservoir totaled 14,476 acre feet in 1983 and 13,958 acre feet in 1984. Approximately 63% of a 5.66 m{sup 3}/sec test release of supplemental water conducted during April, 1984 was lost to irrigation withdrawals and natural phenomena before passing Bell Crossing. A similar loss occurred during a 5.66 m{sup 3}/sec test release conducted in August, 1984. Daily maximum temperature monitored during 1984 in the Bitterroot River averaged 11.0, 12.5, 13.9 and 13.6 C at the Darby, Hamilton, Bell and McClay stations, respectively. Chemical parameters measured in the Bitterroot River were favorable to aquatic life. Population estimates conducted in the Fall, 1983 indicated densities of I+ and older rainbow trout (Salmo gairdneri) were significantly greater in a control section than in a dewatered section (p < 0.20). Numbers of I+ and older brown trout (Salmo trutta) were not significantly different between the control and dewatered sections (p > 0.20). Population and biomass estimates for trout in the control section were 631/km and 154.4 kg/km. In the dewatered section, population and biomass estimates for trout were 253/km and 122.8 kg/km. The growth increments of back-calculated length for rainbow trout averaged 75.6 mm in the control section and 66.9mm in the dewatered section. The growth increments of back-calculated length for brown trout averaged 79.5 mm in the

A Conceptual Framework for Understanding Unintended Prolonged Opioid Use.

Science.gov (United States)

Hooten, W Michael; Brummett, Chad M; Sullivan, Mark D; Goesling, Jenna; Tilburt, Jon C; Merlin, Jessica S; St Sauver, Jennifer L; Wasan, Ajay D; Clauw, Daniel J; Warner, David O

2017-12-01

An urgent need exists to better understand the transition from short-term opioid use to unintended prolonged opioid use (UPOU). The purpose of this work is to propose a conceptual framework for understanding UPOU that posits the influence of 3 principal domains that include the characteristics of (1) individual patients, (2) the practice environment, and (3) opioid prescribers. Although no standardized method exists for developing a conceptual framework, the process often involves identifying corroborative evidence, leveraging expert opinion to identify factors for inclusion in the framework, and developing a graphic depiction of the relationships between the various factors and the clinical problem of interest. Key patient characteristics potentially associated with UPOU include (1) medical and mental health conditions; (2) pain etiology; (3) individual affective, behavioral, and neurophysiologic reactions to pain and opioids; and (4) sociodemographic factors. Also, UPOU could be influenced by structural and health care policy factors: (1) the practice environment, including the roles of prescribing clinicians, adoption of relevant practice guidelines, and clinician incentives or disincentives, and (2) the regulatory environment. Finally, characteristics inherent to clinicians that could influence prescribing practices include (1) training in pain management and opioid use; (2) personal attitudes, knowledge, and beliefs regarding the risks and benefits of opioids; and (3) professionalism. As the gatekeeper to opioid access, the behavior of prescribing clinicians directly mediates UPOU, with the 3 domains interacting to determine this behavior. This proposed conceptual framework could guide future research on the topic and allow plausible hypothesis-based interventions to reduce UPOU. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Understanding of the color in composite resin

Directory of Open Access Journals (Sweden)

Jeong-Won Park

2011-07-01

Full Text Available In clinic, esthetic restoration of a defective natural tooth with composite resin is challenging procedure and needs complete understanding of the color of tooth itself and materials used. The optical characteristics of the composites are different because the chemical compositions and microstructures are not same. This review provided basic knowledge of the color and the color measurement devices, and analyze the color of the natural tooth. Further, the accuracy of the shade tab, color of the composite resins before and after curing, effect of the water, food and bleaching agent, and translucency, opalescence, and fluorescence effects were evaluated.

Application of acid dissolution and natural evaporation to wet cake containing uranium

International Nuclear Information System (INIS)

Kim, Kil J.; Kang, Il Sik; Shon, Jong S.; Hong, Kwon P.

2005-01-01

Chemical wastes containing small amounts of uranium cause environmental problems, if those wastes exceed the concentration of the EPA standard, 20 μg.. /L, and the concentrated sludge should be additionally dried and packaged into a drum, and categorized as a radioactive waste. Diphosil resin is developed to specifically remove actinides or multivalent metals. The immobilization technique is adopted to make a bead form of Diphosil by embedding into sodium alginate, and adsorption characteristics for uranium are reported for a simulated waste solution. In this study, acid dissolution is applied to dissolve uranium from the precipitates of sludge or the dewatered cake in the reduced volume of wastes solution, and removal characteristics of uranium is experimented. From the results, the most effective treatment method for the dissolved solution is suggested

Leveraging social networks for understanding the evolution of epidemics

Science.gov (United States)

2011-01-01

Background To understand how infectious agents disseminate throughout a population it is essential to capture the social model in a realistic manner. This paper presents a novel approach to modeling the propagation of the influenza virus throughout a realistic interconnection network based on actual individual interactions which we extract from online social networks. The advantage is that these networks can be extracted from existing sources which faithfully record interactions between people in their natural environment. We additionally allow modeling the characteristics of each individual as well as customizing his daily interaction patterns by making them time-dependent. Our purpose is to understand how the infection spreads depending on the structure of the contact network and the individuals who introduce the infection in the population. This would help public health authorities to respond more efficiently to epidemics. Results We implement a scalable, fully distributed simulator and validate the epidemic model by comparing the simulation results against the data in the 2004-2005 New York State Department of Health Report (NYSDOH), with similar temporal distribution results for the number of infected individuals. We analyze the impact of different types of connection models on the virus propagation. Lastly, we analyze and compare the effects of adopting several different vaccination policies, some of them based on individual characteristics -such as age- while others targeting the super-connectors in the social model. Conclusions This paper presents an approach to modeling the propagation of the influenza virus via a realistic social model based on actual individual interactions extracted from online social networks. We implemented a scalable, fully distributed simulator and we analyzed both the dissemination of the infection and the effect of different vaccination policies on the progress of the epidemics. The epidemic values predicted by our simulator match

Leveraging social networks for understanding the evolution of epidemics

Directory of Open Access Journals (Sweden)

Martín Gonzalo

2011-12-01

Full Text Available Abstract Background To understand how infectious agents disseminate throughout a population it is essential to capture the social model in a realistic manner. This paper presents a novel approach to modeling the propagation of the influenza virus throughout a realistic interconnection network based on actual individual interactions which we extract from online social networks. The advantage is that these networks can be extracted from existing sources which faithfully record interactions between people in their natural environment. We additionally allow modeling the characteristics of each individual as well as customizing his daily interaction patterns by making them time-dependent. Our purpose is to understand how the infection spreads depending on the structure of the contact network and the individuals who introduce the infection in the population. This would help public health authorities to respond more efficiently to epidemics. Results We implement a scalable, fully distributed simulator and validate the epidemic model by comparing the simulation results against the data in the 2004-2005 New York State Department of Health Report (NYSDOH, with similar temporal distribution results for the number of infected individuals. We analyze the impact of different types of connection models on the virus propagation. Lastly, we analyze and compare the effects of adopting several different vaccination policies, some of them based on individual characteristics -such as age- while others targeting the super-connectors in the social model. Conclusions This paper presents an approach to modeling the propagation of the influenza virus via a realistic social model based on actual individual interactions extracted from online social networks. We implemented a scalable, fully distributed simulator and we analyzed both the dissemination of the infection and the effect of different vaccination policies on the progress of the epidemics. The epidemic values

An Investigation on In-Vessel Composting of Pistachio Residuals with Different Additions

OpenAIRE

M Jalili; M Mokhtari; AA Ebrahimi; F Boghri

2016-01-01

Background and Objective: About 1.35×105 tons of pistachio waste are produced in annually Iran that can result in environmental problems if managed improperly. . The purpose of this study was to investigate in-vessel composting of pistachio residuals with addition of cow manure and dewatered sludge as a recycling alternative. Materials and Methods: Pistachios wastes were combined with weight ratio of 5.5:10 (dewatered sludge: pistachio waste) and weight ratio of 1:10 (Cow manure: pi...

Performance Validation and Scaling of a Capillary Membrane Solid-Liquid Separation System

Energy Technology Data Exchange (ETDEWEB)

Rogers, S; Cook, J; Juratovac, J; Goodwillie, J; Burke, T

2011-10-25

Algaeventure Systems (AVS) has previously demonstrated an innovative technology for dewatering algae slurries that dramatically reduces energy consumption by utilizing surface physics and capillary action. Funded by a $6M ARPA-E award, transforming the original Harvesting, Dewatering and Drying (HDD) prototype machine into a commercially viable technology has required significant attention to material performance, integration of sensors and control systems, and especially addressing scaling issues that would allow processing extreme volumes of algal cultivation media/slurry. Decoupling the harvesting, dewatering and drying processes, and addressing the rate limiting steps for each of the individual steps has allowed for the development individual technologies that may be tailored to the specific needs of various cultivation systems. The primary performance metric used by AVS to assess the economic viability of its Solid-Liquid Separation (SLS) dewatering technology is algae mass production rate as a function of power consumption (cost), cake solids/moisture content, and solids capture efficiency. An associated secondary performance metric is algae mass loading rate which is dependent on hydraulic loading rate, area-specific hydraulic processing capacity (gpm/in2), filter:capillary belt contact area, and influent algae concentration. The system is capable of dewatering 4 g/L (0.4%) algae streams to solids concentrations up to 30% with capture efficiencies of 80+%, however mass production is highly dependent on average cell size (which determines filter mesh size and percent open area). This paper will present data detailing the scaling efforts to date. Characterization and performance data for novel membranes, as well as optimization of off-the-shelf filter materials will be examined. Third party validation from Ohio University on performance and operating cost, as well as design modification suggestions will be discussed. Extrapolation of current productivities

uFLIP: Understanding the Energy Consumption of Flash Devices

DEFF Research Database (Denmark)

Bjørling, Matias; Bonnet, Philippe; Bouganim, Luc

2010-01-01

Understanding the energy consumption of flash devices is important for two reasons. First, energy is emerging as a key metric for data management systems. It is thus important to understand how we can reason about the energy consumption of flash devices beyond their approximate aggregate...... consumption (low power consumption in idle mode, average Watt consumption from the data sheets). Second, when measured at a sufficiently fine granularity, the energy consumption of a given device might complement the performance characteristics derived from its response time profile. Indeed, background work...... which is not directly observable with a response time profile appears clearly when energy is used as a metric. In this paper, we discuss the results from the {uFLIP} benchmark applied to four different {SSD} devices using both response time and energy as metric....

The characteristics and application of sludge-fly ash ceramic particles (SFCP) as novel filter media

International Nuclear Information System (INIS)

Han Shuxin; Yue Qinyan; Yue Min; Gao Baoyu; Li Qian; Yu Hui; Zhao Yaqin; Qi Yuanfeng

2009-01-01

Novel filter media-sludge-fly ash ceramic particles (SFCP) were prepared using dewatered sludge, fly ash and clay with a mass ratio of 1:1:1. Compared with commercial ceramic particles (CCP), SFCP had higher total porosity, larger total surface area and lower bulk and apparent density. Tests of heavy metal elements in lixivium proved that SFCP were safe for wastewater treatment. A lab-scale upflow anaerobic bioreactor was employed to ascertain the application of SFCP in denitrification process using acetate as carbon source. The results showed that SFCP reactor brought a relative superiority to CCP reactor in terms of total nitrogen (TN) removal at the optimum C/N ratio of 4.03 when volumetric loading rates (VLR) ranged from 0.33 to 3.69 kg TN (m 3 d) -1 . Therefore, SFCP application, as a novel process of treating wastes with wastes, provided a promising way in sludge and fly ash utilization.

Examining Preservice Science Teacher Understanding of Nature of Science: Discriminating Variables on the Aspects of Nature of Science

Science.gov (United States)

Jones, William I.

This study examined the understanding of nature of science among participants in their final year of a 4-year undergraduate teacher education program at a Midwest liberal arts university. The Logic Model Process was used as an integrative framework to focus the collection, organization, analysis, and interpretation of the data for the purpose of (1) describing participant understanding of NOS and (2) to identify participant characteristics and teacher education program features related to those understandings. The Views of Nature of Science Questionnaire form C (VNOS-C) was used to survey participant understanding of 7 target aspects of Nature of Science (NOS). A rubric was developed from a review of the literature to categorize and score participant understanding of the target aspects of NOS. Participants' high school and college transcripts, planning guides for their respective teacher education program majors, and science content and science teaching methods course syllabi were examined to identify and categorize participant characteristics and teacher education program features. The R software (R Project for Statistical Computing, 2010) was used to conduct an exploratory analysis to determine correlations of the antecedent and transaction predictor variables with participants' scores on the 7 target aspects of NOS. Fourteen participant characteristics and teacher education program features were moderately and significantly ( p Middle Childhood with a science concentration program major or in the Adolescent/Young Adult Science Education program major were more likely to have an informed understanding on each of the 7 target aspects of NOS. Analyses of the planning guides and the course syllabi in each teacher education program major revealed differences between the program majors that may account for the results.

The characteristics of successful entrepreneurs

Directory of Open Access Journals (Sweden)

Pokrajčić Dragana M.

2004-01-01

Full Text Available This paper examines the economic, psychological and social-behavioral theories of the entrepreneur in order to determine the characteristics of a successful entrepreneur. The major contribution of economic theories of the entrepreneur is better understanding of the entrepreneur and his/her role in economic development. The psychological characteristic theory of entrepreneur argues that successful entrepreneurs possess certain personality traits that mark them out as special, and tries to determine and to evaluate these special traits. The social-behavioral theories stress the influence of experience, knowledge, social environment and ability to learn on the entrepreneur’s success as well as his/her personality traits. Neither of the examined theories of entrepreneur gives a satisfactory explanation of the entrepreneur’s success, but taken as a whole, they can explain key factors of entrepreneur’s success. The entrepreneur’s success comes about as a result of his/her personality traits, ability to learn from experience and ability to adjust to his/her environment.

FINANCIAL ACCOUNTING QUALITY AND ITS DEFINING CHARACTERISTICS

OpenAIRE

Andra M. ACHIM; Anca O. CHIŞ

2014-01-01

The importance ofhigh-quality financial statements is highlighted by the main standard-setting institutions activating in the field of accounting and reporting. These have issued Conceptual Frameworks which state and describe the qualitative characteristics of accounting information. In this qualitative study, the research methodology consists of reviewing the literature related to the definition of accounting quality and striving for understanding how it can be explained. The main objective ...

Propagating Characteristics of Pulsed Laser in Rain

Directory of Open Access Journals (Sweden)

Jing Guo

2015-01-01

Full Text Available To understand the performance of laser ranging system under the rain weather condition, we need to know the propagating characteristics of laser pulse in rain. In this paper, the absorption and attenuation coefficients were calculated based on the scattering theories in discrete stochastic media, and the propagating characteristics of laser pulse in rain were simulated and analyzed using Monte-Carlo method. Some simulation results were verified by experiments, and the simulation results are well matched with the experimental data, with the maximal deviation not less than 7.5%. The results indicated that the propagating laser beam would be attenuated and distorted due to the scattering and absorption of raindrops, and the energy attenuation and pulse shape distortion strongly depended on the laser pulse widths.

Analysing Personal Characteristics of Lone-Actor Terrorists: Research Findings and Recommendations

OpenAIRE

Roy, de, van Zuijdewijn J.; Bakker, E.

2016-01-01

This Research Note presents the outcome of a project that looked at the personal characteristics of lone-actor terrorists. It is part of the larger Countering Lone-Actor Terrorism (CLAT) project. The project described here aimed to improve understanding of, and responses to, the phenomenon of (potentially) violent lone-actors based on an analysis of 120 cases from across Europe. The Research Note focuses on the personal characteristics of lone-actor terrorists.[1] First of all, it presents th...

Key Competencies and Characteristics for Innovative Teaching among Secondary School Teachers: A Mixed-Methods Research

Science.gov (United States)

Zhu, Chang; Wang, Di

2014-01-01

This research aims to understand the key competencies and characteristics for innovative teaching as perceived by Chinese secondary teachers. A mixed-methods research was used to investigate secondary teachers' views. First, a qualitative study was conducted with interviews of teachers to understand the perceived key competencies and…

The effect of hospital organizational characteristics on postoperative complications.

Science.gov (United States)

Knight, Margaret

2013-12-01

To determine if there is a relationship between the risk of postoperative complications and the nonclinical hospital characteristics of bed size, ownership structure, relative urbanicity, regional location, teaching status, and area income status. This study involved a secondary analysis of 2006 administrative hospital data from a number of U.S. states. This data, gathered annually by the Agency for Healthcare Research and Quality (AHRQ) via the National Inpatient Sample (NIS) Healthcare Utilization Project (HCUP), was analyzed using probit regressions to measure the effects of several nonclinical hospital categories on seven diagnostic groupings. The study model included postoperative complications as well as additional potentially confounding variables. The results showed mixed outcomes for each of the hospital characteristic groupings. Subdividing these groupings to correspond with the HCUP data analysis allowed a greater understanding of how hospital characteristics' may affect postoperative outcomes. Nonclinical hospital characteristics do affect the various postoperative complications, but they do so inconsistently.

Solar drying in sludge management in Turkey

Energy Technology Data Exchange (ETDEWEB)

Kamil Salihoglu, Nezih; Pinarli, Vedat; Salihoglu, Guray [Faculty of Engineering and Architecture, Environmental Engineering Department, Uludag University, 16059, Bursa (Turkey)

2007-08-15

Two main wastewater treatment plants in Bursa city in Turkey will start to operate and produce at least 27,000 tons of dry solids per year by the end of 2006. The purpose of this study was to investigate an economical solution to the sludge management problem that Bursa city would encounter. The general trend in Turkey is mechanical dewatering to obtain a dry solid (DS) content of 20%, and liming the mechanically dewatered sludge to reach the legal land filling requirement, 35% DS content. This study recommends limited liming and solar drying as an alternative to only-liming the mechanically dewatered sludge. Open and covered solar sludge drying plants were constructed in pilot scale for experimental purposes. Dry solids and climatic conditions were constantly measured. Faecal coliform reduction was also monitored. The specially designed covered solar drying plant proved to be more efficient than the open plant in terms of drying and faecal coliform reduction. It was found that, if the limited liming and solar drying method was applied after mechanical dewatering instead of only-liming method, the total amount of the sludge to be disposed would be reduced by approximately 40%. This would lead to a reduction in the transportation, handling, and land filling costs. The covered drying system would amortize itself in 4 years. (author)

Reliability Characteristics of Power Plants

Directory of Open Access Journals (Sweden)

Zbynek Martinek

2017-01-01

Full Text Available This paper describes the phenomenon of reliability of power plants. It gives an explanation of the terms connected with this topic as their proper understanding is important for understanding the relations and equations which model the possible real situations. The reliability phenomenon is analysed using both the exponential distribution and the Weibull distribution. The results of our analysis are specific equations giving information about the characteristics of the power plants, the mean time of operations and the probability of failure-free operation. Equations solved for the Weibull distribution respect the failures as well as the actual operating hours. Thanks to our results, we are able to create a model of dynamic reliability for prediction of future states. It can be useful for improving the current situation of the unit as well as for creating the optimal plan of maintenance and thus have an impact on the overall economics of the operation of these power plants.

Visual observation of a heat pipe working characteristics

International Nuclear Information System (INIS)

Tsuyuzaki, Noriyoshi; Saito, Takashi; Ishigami, Shinya; Kawada, Michitaka; Konno, Masanobu; Kaminaga, Fumito; Okamoto, Yoshizo.

1988-10-01

When the heat pipe is used in a nuclear engineering field, it is indispensable to understand transient characteristics of an accident condition as well as in a steady state at a normal operation. However there have been few informations about the transient characteristics of a heat pipe in case of rapid temperature or heat load change in an evaporator section. The purpose of this study is to examine transient and steady state characteristics of a gravity assisted heat pipe and variable conductance heat pipe(VCHP) which will be used in a neutron irradiation capsule. This report presents results of visual observation of boiling and condensation patterns on steady state or transient condition in a visible heat pipe made of a glass. The response time of the heat pipe is on the order of a few seconds when the temperature of the evaporator part is kept above the operating temperature. (author)

Atmospheric River Characteristics under Decadal Climate Variability

Science.gov (United States)

Done, J.; Ge, M.

2017-12-01

How does decadal climate variability change the nature and predictability of atmospheric river events? Decadal swings in atmospheric river frequency, or shifts in the proportion of precipitation falling as rain, could challenge current water resource and flood risk management practice. Physical multi-scale processes operating between Pacific sea surface temperatures (SSTs) and atmospheric rivers over the Western U.S. are explored using the global Model for Prediction Across Scales (MPAS). A 45km global mesh is refined over the Western U.S. to 12km to capture the major terrain effects on precipitation. The performance of the MPAS is first evaluated for a case study atmospheric river event over California. Atmospheric river characteristics are then compared in a pair of idealized simulations, each driven by Pacific SST patterns characteristic of opposite phases of the Interdecadal Pacific Oscillation (IPO). Given recent evidence that we have entered a positive phase of the IPO, implications for current reservoir management practice over the next decade will be discussed. This work contributes to the NSF-funded project UDECIDE (Understanding Decision-Climate Interactions on Decadal Scales). UDECIDE brings together practitioners, engineers, statisticians, and climate scientists to understand the role of decadal climate information for water management and decisions.

Sociodemographic Characteristics of Croatian MPs and Croatian Government Offi cials 2000-2003

Directory of Open Access Journals (Sweden)

Davorka Budimir

2006-01-01

Full Text Available The article analyses sociodemographic characteristics of the Croatian MPs in the fourth term (2000-2003 and Croatian government offi cials (2000-2003, based on a conducted survey. The lack of empirical research of the Croatian political élite since 1990 is the main reason why it is not possible to establish with certainty measurable indicators of changes in their social structure and comings and goings. The analysis of sociodemographic characteristics of MPs and government offi cials is a method for better understanding of structural changes, and the data on sex, age, and type and level of education ensure better understanding of some specifi c qualities of the Croatian political élite. Sociodemographic characteristics of the parents of the interviewed MPs and government offi cials show that members of the political élite have found a successful channel of social promotion through their engagement in politics. The results have shown that high politics is a privilege of mostly highly educated men older than 40, who have graduated in social sciences, with an evident lack of women and the young in politics.

Current-voltage characteristics of dendrimer light-emitting diodes

International Nuclear Information System (INIS)

Stevenson, S G; Samuel, I D W; Staton, S V; Knights, K A; Burn, P L; Williams, J H T; Walker, Alison B

2010-01-01

We have investigated current-voltage (I-V) characteristics of unipolar and bipolar organic diodes that use phosphorescent dendrimers as the emissive organic layer. Through simulation of the measured I-V characteristics we were able to determine the device parameters for each device structure studied, leading to a better understanding of injection and transport behaviour in these devices. It was found that the common practice of assuming injection barriers are equal to the difference between bare electrode work functions and molecular orbital levels is unsuitable for the devices considered here, particularly for gold contacts. The studies confirm that different aromatic units in the dendrons can give significant differences in the charge transporting properties of the dendrimers.

Current-voltage characteristics of dendrimer light-emitting diodes

Science.gov (United States)

Stevenson, S. G.; Samuel, I. D. W.; Staton, S. V.; Knights, K. A.; Burn, P. L.; Williams, J. H. T.; Walker, Alison B.

2010-09-01

We have investigated current-voltage (I-V) characteristics of unipolar and bipolar organic diodes that use phosphorescent dendrimers as the emissive organic layer. Through simulation of the measured I-V characteristics we were able to determine the device parameters for each device structure studied, leading to a better understanding of injection and transport behaviour in these devices. It was found that the common practice of assuming injection barriers are equal to the difference between bare electrode work functions and molecular orbital levels is unsuitable for the devices considered here, particularly for gold contacts. The studies confirm that different aromatic units in the dendrons can give significant differences in the charge transporting properties of the dendrimers.

Current-voltage characteristics of dendrimer light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Stevenson, S G; Samuel, I D W [Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9SS (United Kingdom); Staton, S V; Knights, K A; Burn, P L [Department of Chemistry, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA (United Kingdom); Williams, J H T; Walker, Alison B, E-mail: a.b.walker@bath.ac.u [Department of Physics, University of Bath, Bath, BA2 7AY (United Kingdom)

2010-09-29

We have investigated current-voltage (I-V) characteristics of unipolar and bipolar organic diodes that use phosphorescent dendrimers as the emissive organic layer. Through simulation of the measured I-V characteristics we were able to determine the device parameters for each device structure studied, leading to a better understanding of injection and transport behaviour in these devices. It was found that the common practice of assuming injection barriers are equal to the difference between bare electrode work functions and molecular orbital levels is unsuitable for the devices considered here, particularly for gold contacts. The studies confirm that different aromatic units in the dendrons can give significant differences in the charge transporting properties of the dendrimers.

Motion characteristic of a free piston linear engine

Energy Technology Data Exchange (ETDEWEB)

Xiao, Jin; Li, Qingfeng; Huang, Zhen [Key Laboratory for Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai, 200240 (China)

2010-04-15

A mathematical model of a free piston linear engine is established. The motion characteristics as well as the natural frequency map of the free piston are established. Then, its motion characteristics are successfully explained from the oscillation point. The full simulation model is built up in Matlab/Simulink for a better understanding of its motion features. The results show that the free piston system is a forced vibration system with variable damping coefficient and stiffness. Its steady-state response of periodical excitation is convergent which means that the system is stable under the periodical combustion. Furthermore, it has some unique features which are different from those of traditional Internal Combustion (IC) engines. (author)

Understanding the mechanical and acoustical characteristics of sand aggregates compacting under triaxial conditions

Science.gov (United States)

Hangx, Suzanne; Brantut, Nicolas

2016-04-01

failure being present but occurring to a relatively limited extent. Acoustic emission localization showed that failure was focussed along a broad shear plane. At higher confining pressure pervasive grain failure clearly accommodated compaction, though no strain localization was observed and failure appeared to be through cataclastic flow. Chemical environment, i.e. chemically inert decane vs. water as a pore fluid, had no significant effect on compaction in the strain rate range tested. Grain size distribution or grain shape also appeared to not affect the observed mechanical behaviour. Our results can be used to better understand the compaction behaviour of poorly consolidated sandstones. Future research will focus on understanding the effect of cementation on strain localization in deforming artificial Ottawa sandstone.

The Fundamentals of Waste Water Sludge Characterization and Filtration

Energy Technology Data Exchange (ETDEWEB)

Scales, Peter J.; Dixon, David R.; Harbour, Peter J.; Stickland, Anthony D.

2003-07-01

The move to greater emphasis on the disposal of waste water sludges through routes such as incineration and the added cost of landfill emplacement puts high demands on dewatering technology for these sludges. A dear problem in this area is that waste water sludges are slow and difficult to dewater and traditional methods of laboratory measurement for prediction of filtration performance are inadequate. This is highly problematic for the design and operational optimisation of centrifuges, filters and settling devices in the waste water industry. The behaviour is assessed as being due to non-linear behaviour of these sludges which negates the use of classical approaches. These approaches utilise the linear portion of a t versus V{sup 2} plot (where t is the time to filtration and V is the specific filtrate volume) to extract a simple Darcian permeability. Without this parameter, a predictive capacity for dewatering using current theory is negated. (author)

A review of methods developed to solve the issue of weak mature fine tailings

Energy Technology Data Exchange (ETDEWEB)

Long, M.; Ulrich, A.; Sego, D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

2010-07-01

This PowerPoint presentation discussed new techniques for managing weak mature fine tailings (MFT) produced during the oil sands refining process. The techniques included non-segregating tailings, freeze-thaw dewatering, atmospheric drying, and dewatering by vegetation. MFT are produced after water from oil sands slurries is decanted. MFT contain a complex chemical interaction of clays and hydrocarbons. A large proportion of the solids in MFTs are clay minerals and clay-sized. MFTs have low rates of sedimentation and consolidation, and a low bearing capacity and shear strength with high compressibility. MFTs cannot physically support remediation activities, and must be stored in an impounded area. More aggressive dewatering and stabilization processes are required for MFTs. Atmospheric drying involves the deposition of tailings in order to evaporate water. Thin- and thick-lift deposition schemes are used. Atmospheric drying is often complicated by the formation of a bitumen skin over the tailings. Various case studies were presented. Space requirements and issues related to clay content were reviewed. tabs., figs.

Comparisons and Analyses of Gifted Students' Characteristics and Learning Methods

Science.gov (United States)

Lu, Jiamei; Li, Daqi; Stevens, Carla; Ye, Renmin

2017-01-01

Using PISA 2009, an international education database, this study compares gifted and talented (GT) students in three groups with normal (non-GT) students by examining student characteristics, reading, schooling, learning methods, and use of strategies for understanding and memorizing. Results indicate that the GT and non-GT gender distributions…

Understanding Complex Construction Systems Through Modularity

DEFF Research Database (Denmark)

Jensen, Tor Clarke; Bekdik, Baris; Thuesen, Christian

2014-01-01

This paper develops a framework for understanding complexity in construction projects by combining theories of complexity management and modularization. The framework incorporates three dimensions of product, process, and organizational modularity with the case of gypsum wall elements. The analysis...... system, rather than a modular, although the industry forces modular organizational structures. This creates a high complexity degree caused by the non-alignment of building parts and organizations and the frequent swapping of modules....... finds that the main driver of complexity is the fragmentation of the design and production, which causes the production modules to construct and install new product types and variants for each project as the designers are swapped for every project. The many interfaces are characteristics of an integral...

Fractographic observations of the microstructural characteristics of flax fibre composites

DEFF Research Database (Denmark)

Madsen, Bo; Asian, Mustafa; Lilholt, Hans

2016-01-01

Natural fibre composites possess a number of special microstructural characteristics, which need to be documented to aid in the further development of these materials. Using field emission scanning electron microscopy, fractographic observations of the microstructural characteristics of aligned f...... novel observations, measurements and interpretations to be used in the further analysis and understanding of the properties of natural fibre composites. (C) 2015 Elsevier Ltd. All rights reserved.......Natural fibre composites possess a number of special microstructural characteristics, which need to be documented to aid in the further development of these materials. Using field emission scanning electron microscopy, fractographic observations of the microstructural characteristics of aligned...... flax fibre/thermoplastic composites are presented. The findings are presented in relation to the three operational parts in composites: fibres, matrix and fibre/matrix interface. For the flax fibres, the striated structure on the fibre surface is shown to consist of cellulose macrofibrils oriented...

The Development of Mature Capabilities for Understanding and Valuing Technology through School Project Work.

Science.gov (United States)

Schallies, Michael; Wellensiek, Anneliese; Lembens, Anja

This paper describes a German project that developed students' capabilities for understanding and valuing biotechnology and genetic engineering, focusing on practical fieldwork with schools by an interdisciplinary team. The paper identifies the characteristics of individual and structural preconditions and their development during active project…

Characteristics of hyperacusis in the general population

Directory of Open Access Journals (Sweden)

Johan Paulin

2016-01-01

Full Text Available There is a need for better understanding of various characteristics in hyperacusis in the general population. The objectives of the present study were to investigate individuals in the general population with hyperacusis regarding demographics, lifestyle, perceived general health and hearing ability, hyperacusis-specific characteristics and behavior, and comorbidity. Using data from a large-scale population-based questionnaire study, we investigated individuals with physician-diagnosed (n = 66 and self-reported (n = 313 hyperacusis in comparison to individuals without hyperacusis (n = 2995. High age, female sex, and high education were associated with hyperacusis, and that trying to avoid sound sources, being able to affect the sound environment, and having sough medical attention were common reactions and behaviors. Posttraumatic stress disorder, chronic fatigue syndrome, generalized anxiety disorder, depression, exhaustion, fibromyalgia, irritable bowel syndrome, migraine, hearing impairment, tinnitus, and back/joint/muscle disorders were comorbid with hyperacusis. The results provide ground for future study of these characteristic features being risk factors for development of hyperacusis and/or consequences of hyperacusis.

Understanding the Relationships between mHealth Apps' Characteristics, Trialability, and mHealth Literacy.

Science.gov (United States)

Lin, Trisha T C; Bautista, John Robert

2017-04-01

The widespread adoption of mobile phones has increased the potential of mHealth to improve health communication and health outcomes because these devices could serve as a ubiquitous and affordable means to disseminate health information to large populations. Given that mHealth apps offer free or limited trials as part of promotional strategies, potential users' trialability is a critical step of the preadoption process. Drawing from Rogers' diffusion of innovation theory, this study examines the relationships of adopters' perceived characteristics of mHealth apps (i.e., relative advantage, complexity, compatibility, and observability) with their trialability. It further investigates how the perceived control of mobile devices and trialability of mHealth apps influence two dimensions of mHealth literacy, namely seeking and appraisal of health information. This web survey recruited 295 young mHealth app users from a Singaporean university. Results of partial least squares regression show that the observability of mHealth apps is the only factor positively related to mHealth trialability. Perceived control of mobile devices and trialability of mHealth apps are positively associated with seeking and appraisal of health information. Practical and theoretical implications to mHealth are discussed.

Characteristics of reversible-pump turbines

Energy Technology Data Exchange (ETDEWEB)

Olimstad, Grunde

2012-07-01

The primary goal for this PhD project has been to investigate instability of reversible-pump turbines (RPTs) as a phenomenon and to find remedies to solve it. The instability occurs for turbines with s-shaped characteristics, unfavourable waterway and limited rotating inertia. It is only observed for certain operation pints at either high speed or low load. These correspond to ether high values of Ned or low values of Qed. The work done in this PhD thesis can be divided in to the three following categories. Investigate and understand the behaviour of a pump turbine: A model was designed in order to investigate the pump turbine behaviour related to its characteristics. This model was manufactured and measurements were performed in the laboratory. By using throttling valves or torque as input the full s-shaped characteristics was measured. When neither of these techniques is used, the laboratory system has unstable operation points which result in hysteresis behaviour. Global behaviour of the RPT in power plant system was investigated through analytical stability analysis and dynamic system simulations. The latter included both rigid and elastic representation of the water column. Turbine internal flow: The flow inside the runner was investigated by computer simulations (CFD). Two-dimensional analysis was used to study the inlet part of the runner. This showed that a vortex forming at the inlet is one of the causes for the unstable operation range. Measurements at different pressure levels showed that the characteristics were dependent on the Reynolds number at high Ned values in turbine mode. This means that the similarity of flows is not sufficiently described by constant Qed and Ned values at this part of the characteristics. Design modifications: The root of the stability problem was considered to be the runners geometric design at the inlet in turbine mode. Therefore different design parameters were investigated to find relations to the characteristics. Methods

An investigation on the effect of surface characteristics on adhesion between polymer melts and replication tools

DEFF Research Database (Denmark)

Delaney, Kevin D.; Kennedy, Jonathan David; Bissacco, Giuliano

2012-01-01

Understanding interfacial characteristics between a polymer and its associated tool surface is critical to successful optimization of processes such as injection moulding, embossing and extrusion used to produce polymer parts. One of the factors characterizing the strength of the polymer-tool int......Understanding interfacial characteristics between a polymer and its associated tool surface is critical to successful optimization of processes such as injection moulding, embossing and extrusion used to produce polymer parts. One of the factors characterizing the strength of the polymer...... the results of an experimental study aimed at determining the effect of selected tool surface characteristics on the work of adhesion, by measuring contact angles of polymer droplets on the surfaces. The experimental set-up, selection of test parameters and main challenges faced to date are described...

The psychosocial and behavioral characteristics related to energy misreporting.

Science.gov (United States)

Maurer, Jaclyn; Taren, Douglas L; Teixeira, Pedro J; Thomson, Cynthia A; Lohman, Timothy G; Going, Scott B; Houtkooper, Linda B

2006-02-01

Energy underreporting occurs in 2% to 85% and overreporting in 1% to 39% of various populations. Efforts are needed to understand the psychosocial and behavioral characteristics associated with misreporting to help improve the accuracy of dietary self-reporting. Past research suggests that higher social desirability and greater eating restraint are key factors influencing misreporting, while a history of dieting and being overweight are more moderately associated. Eating disinhibition, body image, depression, anxiety, and fear of negative evaluation may be related to energy misreporting, but evidence is insufficient. This review will provide a detailed discussion of the published associations among psychosocial and behavioral characteristics and energy misreporting.

Modelling associations between public understanding, engagement and forest conditions in the Inland Northwest, USA.

Directory of Open Access Journals (Sweden)

Joel Hartter

Full Text Available Opinions about public lands and the actions of private non-industrial forest owners in the western United States play important roles in forested landscape management as both public and private forests face increasing risks from large wildfires, pests and disease. This work presents the responses from two surveys, a random-sample telephone survey of more than 1500 residents and a mail survey targeting owners of parcels with 10 or more acres of forest. These surveys were conducted in three counties (Wallowa, Union, and Baker in northeast Oregon, USA. We analyze these survey data using structural equation models in order to assess how individual characteristics and understanding of forest management issues affect perceptions about forest conditions and risks associated with declining forest health on public lands. We test whether forest understanding is informed by background, beliefs, and experiences, and whether as an intervening variable it is associated with views about forest conditions on publicly managed forests. Individual background characteristics such as age, gender and county of residence have significant direct or indirect effects on our measurement of understanding. Controlling for background factors, we found that forest owners with higher self-assessed understanding, and more education about forest management, tend to hold more pessimistic views about forest conditions. Based on our results we argue that self-assessed understanding, interest in learning, and willingness to engage in extension activities together have leverage to affect perceptions about the risks posed by declining forest conditions on public lands, influence land owner actions, and affect support for public policies. These results also have broader implications for management of forested landscapes on public and private lands amidst changing demographics in rural communities across the Inland Northwest where migration may significantly alter the composition of

Modelling Associations between Public Understanding, Engagement and Forest Conditions in the Inland Northwest, USA

Science.gov (United States)

Hartter, Joel; Stevens, Forrest R.; Hamilton, Lawrence C.; Congalton, Russell G.; Ducey, Mark J.; Oester, Paul T.

2015-01-01

Opinions about public lands and the actions of private non-industrial forest owners in the western United States play important roles in forested landscape management as both public and private forests face increasing risks from large wildfires, pests and disease. This work presents the responses from two surveys, a random-sample telephone survey of more than 1500 residents and a mail survey targeting owners of parcels with 10 or more acres of forest. These surveys were conducted in three counties (Wallowa, Union, and Baker) in northeast Oregon, USA. We analyze these survey data using structural equation models in order to assess how individual characteristics and understanding of forest management issues affect perceptions about forest conditions and risks associated with declining forest health on public lands. We test whether forest understanding is informed by background, beliefs, and experiences, and whether as an intervening variable it is associated with views about forest conditions on publicly managed forests. Individual background characteristics such as age, gender and county of residence have significant direct or indirect effects on our measurement of understanding. Controlling for background factors, we found that forest owners with higher self-assessed understanding, and more education about forest management, tend to hold more pessimistic views about forest conditions. Based on our results we argue that self-assessed understanding, interest in learning, and willingness to engage in extension activities together have leverage to affect perceptions about the risks posed by declining forest conditions on public lands, influence land owner actions, and affect support for public policies. These results also have broader implications for management of forested landscapes on public and private lands amidst changing demographics in rural communities across the Inland Northwest where migration may significantly alter the composition of forest owner goals

Geohydrological and environmental isotope observation of Sishen ground waters

International Nuclear Information System (INIS)

Verhagen, B.Th.; Dziembowski, Z.M.

1985-01-01

The dewatering of Sishen Mine in the northern Cape Province supplies good quality water for the mine and surrounding areas. Using various approaches, attempts are made to quantify the remaining storage of ground water. Geohydrological observations provide an estimate based on extrapolating the thickness of dewatered rock. Environmental isotope observations on various borehole outputs show contrasts between different ground-water bodies and their mixtures and allows for some extrapolations of observed trends. Indications are that previous estimates of storage, based on ground-water level changes, are conservative

Performance characteristics of long-track speed skaters: a literature review.

Science.gov (United States)

Konings, Marco J; Elferink-Gemser, Marije T; Stoter, Inge K; van der Meer, Dirk; Otten, Egbert; Hettinga, Florentina J

2015-04-01

Speed skating is an intriguing sport to study from different perspectives due to the peculiar way of motion and the multiple determinants for performance. This review aimed to identify what is known on (long-track) speed skating, and which individual characteristics determine speed skating performance. A total of 49 studies were included. Based on a multidimensional performance model, person-related performance characteristics were categorized in anthropometrical, technical, physiological, tactical, and psychological characteristics. Literature was found on anthropometry, technique, physiology, and tactics. However, psychological studies were clearly under-represented. In particular, the role of self-regulation might deserve more attention to further understand mechanisms relevant for optimal performance and for instance pacing. Another remarkable finding was that the technically/biomechanically favourable crouched skating technique (i.e. small knee and trunk angle) leads to a physiological disadvantage: a smaller knee angle may increase the deoxygenation of the working muscles. This is an important underlying aspect for the pacing tactics in speed skating. Elite speed skaters need to find the optimal balance between obtaining a fast start and preventing negative technical adaptations later on in the race by distributing their available energy over the race in an optimal way. More research is required to gain more insight into how this impacts on the processes of fatigue and coordination during speed skating races. This can lead to a better understanding on how elite speed skaters can maintain the optimal technical characteristics throughout the entire race, and how they can adapt their pacing to optimize all identified aspects that determine performance.

"Stew without Bread or Bread without Stew": Children's Understandings of Poverty in Ethiopia

Science.gov (United States)

Camfield, Laura

2010-01-01

This paper explores children's understandings of poverty, ill-being and well-being in Ethiopia using data collected through group exercises with children aged 5-6 and 11-13 participating in Young Lives, an international study of childhood poverty. In some respects the characteristics of poverty reported by children resemble those reported by…

Analysis of Indonesia Confucians Understanding Towards Religious Doctrines and Ordinances in Confucianism

Directory of Open Access Journals (Sweden)

Sugiato Lim

2013-10-01

Full Text Available To a great extent, daily life of Indonesia Chinese community is filled with religious overtones. This paper basically analyzes the understanding of Indonesia Confucians towards their religion. The first part of this paper will be discussing about the general definition of religion and its religious elements. The second part will analyze the understanding of Indonesia Confucians towards their religious doctrines and ordinances respectively. In conclusion, overview regarding Indonesia Confucians and a special historical background of Indonesia Confucianism, which consists of its formation and development as a legal religion in line with Indonesia national conditions, social conditions and characteristic, will be presented.   

A study on the dewatering of industrial waste sludge by fry-drying technology

International Nuclear Information System (INIS)

Ohm, Tae-In; Chae, Jong-Seong; Kim, Jeong-Eun; Kim, Hee-kyum; Moon, Seung-Hyun

2009-01-01

In sludge treatment, drying sludge using typical technology with high water content to a water content of approximately 10% is always difficult because of adhesive characteristics of sludge. Many methods have been applied, including direct and indirect heat drying, but these approaches of reducing water content to below 40% after drying is very inefficient in energy utilization of drying sludge. In this study, fry-drying technology with a high heat transfer coefficient of approximately 500 W/m 2 deg. C was used to dry industrial wastewater sludge. Also waste oil was used in the fry-drying process, and because the oil's boiling point is between 240 and 340 deg. C and the specific heat is approximately 60% of that of water. In the fry-drying system, the sludge is input by molding it into a designated form after heating the waste oil at temperatures between 120 and 170 deg. C. At these temperatures, the heated oil rapidly evaporates the water contained in the sludge, leaving the oil itself. After approximately 10 min, the water content of the sludge was less than 10%, and its heating value surpassed 5300 kcal/kg. Indeed, this makes the organic sludge appropriate for use as a solid fuel. The wastewater sludge used in this study was the designated waste discharged from chemical, leather and plating plants. These samples varied in characteristics, especially with regard to heavy metal concentration. After drying the three kinds of wastewater sludge at oil temperatures 160 deg. C for 10 min, it was found that the water content in the sludge from the chemical, leather, and plating plants reduced from 80.0 to 5.5%, 81.6 to 1.0%, and 65.4 to 0.8%, respectively. Furthermore, the heat values of the sludge from the chemical, leather, and plating plants prior to fry-drying were 217, 264, and 428 kcal/kg, respectively. After drying, these values of sludge increased to 5317, 5983 and 6031 kcal/kg, respectively. The heavy metals detected in the sludge after drying were aluminum

Developing an In-depth Understanding of Elderly Adult's Vulnerability to Climate Change.

Science.gov (United States)

Rhoades, Jason L; Gruber, James S; Horton, Bill

2018-05-08

Recent reports highlight the vulnerability of elderly adults to climate change, yet limited research has focused on this topic. To address this, the purpose of this study was to develop an in-depth understanding of elderly adult's vulnerability to climate change within the context of a specific community. A case study methodology utilizing a community-based action research approach was employed to engage elderly participants living in Bridgeport, CT, in exploring their vulnerability to current and predicted climate stressors with a focus on extreme heat, flooding and storms, and air pollution. This research identifies personal characteristics that interact with contextual factors to influence elderly adult's vulnerability to climate change. Personal characteristics include health, economic, and social considerations. Contextual factors include the adequacy of emergency preparedness measures, transportation resources, and coping and recovery resources. As a result of the interplay of these characteristics and factors, predicted climate changes could have serious consequences for Bridgeport's elderly adults. This research provides a contextualized and detailed illustration of how climate change could overwhelm elderly adult's adaptive capacity and highlights the need for support services to provide safeguards. The issues and concerns raised may bear similarities to other locations, especially urban settings facing similar climate stressors with similar socioeconomic conditions. The findings suggest a need for further research to improve our understanding and serve as the basis for collaborative adaptation planning that engages elderly communities with local governments and a broad coalition of partners to keep elders safe.

POC-scale testing of a dry triboelectrostatic separator for fine coal cleaning

Energy Technology Data Exchange (ETDEWEB)

Yoon, R.H.; Luttrell, G.H.; Adel, G.T. [Virginia Polytechnic Institute and State Univ., Blacksburg, VA (United States)

1995-11-01

Numerous advanced coal cleaning processes have been developed in recent years that are capable of substantially reducing both the ash and sulfur contents of run-of-mine coals. The extent of cleaning depends on the liberation characteristics of the coal, which generally improve with reducing particle size. however, since most of the advanced technologies are wet processes, the clean coal product must be dewatered before it can be transported and burned in conventional boilers. This additional treatment step significantly increases the processing cost and makes the industrial applicability of these advanced technologies much less attractive. In order to avoid problems associated with fine coal dewatering, researchers at the Pittsburgh Energy Technology Center (PETC) developed a novel triboelectrostatic separation (TES) process that can remove mineral matter from dry coal. In this technique, finely pulverized coal is brought into contact with a material (such as copper) having a work function intermediate to that of the carbonaceous material and associated mineral matter. Carbonaceous particles having a relatively low work function become positively charged, while particles of mineral matter having significantly higher work functions become negatively charged. once the particles become selectively charged, a separation can be achieved by passing the particle stream through an electrically charged field. Details related to the triboelectrostatic charging phenomenon have been discussed elsewhere (Inculet, 1984).

When Injury Clouds Understanding of Others: Theory of Mind after Mild TBI in Preschool Children.

Science.gov (United States)

Bellerose, Jenny; Bernier, Annie; Beaudoin, Cindy; Gravel, Jocelyn; Beauchamp, Miriam H

2015-08-01

There is evidence to suggest that social skills, such as the ability to understand the perspective of others (theory of mind), may be affected by childhood traumatic brain injuries; however, studies to date have only considered moderate and severe traumatic brain injury (TBI). This study aimed to assess theory of mind after early, mild TBI (mTBI). Fifty-one children who sustained mTBI between 18 and 60 months were evaluated 6 months post-injury on emotion and desires reasoning and false-belief understanding tasks. Their results were compared to that of 50 typically developing children. The two groups did not differ on baseline characteristics, except for pre- and post-injury externalizing behavior. The mTBI group obtained poorer scores relative to controls on both the emotion and desires task and the false-belief understanding task, even after controlling for pre-injury externalizing behavior. No correlations were found between TBI injury characteristics and theory of mind. This is the first evidence that mTBI in preschool children is associated with theory of mind difficulties. Reduced perspective taking abilities could be linked with the social impairments that have been shown to arise following TBI.

Compression Characteristics of Solid Wastes as Backfill Materials

OpenAIRE

Meng Li; Jixiong Zhang; Rui Gao

2016-01-01

A self-made large-diameter compression steel chamber and a SANS material testing machine were chosen to perform a series of compression tests in order to fully understand the compression characteristics of differently graded filling gangue samples. The relationship between the stress-deformation modulus and stress-compression degree was analyzed comparatively. The results showed that, during compression, the deformation modulus of gangue grew linearly with stress, the overall relationship bet...

Numerical Analysis on Combustion Characteristic of Leaf Spring Rotary Engine

Directory of Open Access Journals (Sweden)

Yan Zhang

2015-08-01

Full Text Available The purpose of this paper is to investigate combustion characteristics for rotary engine via numerical studies. A 3D numerical model was developed to study the influence of several operative parameters on combustion characteristics. A novel rotary engine called, “Leaf Spring Rotary Engine”, was used to illustrate the structure and principle of the engine. The aims are to (1 improve the understanding of combustion process, and (2 quantify the influence of rotational speed, excess air ratio, initial pressure and temperature on combustion characteristics. The chamber space changed with crankshaft rotation. Due to the complexity of chamber volume, an equivalent modeling method was presented to simulate the chamber space variation. The numerical simulations were performed by solving the incompressible, multiphase Unsteady Reynolds-Averaged Navier–Stokes Equations via the commercial code FLUENT using a transport equation-based combustion model; a realizable  turbulence model and finite-rate/eddy-dissipation model were used to account for the effect of local factors on the combustion characteristics.

Geohydrological simulation of a deep coastal repository

International Nuclear Information System (INIS)

Follin, S.

1995-12-01

This conceptual-numerical study treats the dewatering and resaturation phases associated with the construction, use and closure of a coastal nuclear waste repository located at depth in sparsely fractured Baltic Shield rocks. The main objective is to simulate the extent and duration of saline intrusion for a reasonable set of geohydrological assumptions. Long-term changes in the chemical environment associated with saline intrusion may affect the properties of the buffer zone material (bentonite). The first part of the study deals with history matching of a simple model geometry and the second part treats the dewatering and resaturation phases of the simulated repository. The history matching supports the standpoint that the occurrence of saline ground water reflects an ongoing but incomplete Holocene flushing of the Baltic Shield. The drawdown after fifty years of dewatering is highly dependent on the permeability of the excavated damaged zone. If the permeability close the repository is unaltered the entire region between the top side of the model and the repository is more or less partially saturated at the end of the simulation period. The simulations of a fifty year long recovery period suggest that the distribution between fresh and saline ground waters may be quite close to the conditions prior to the dewatering phase already after fifty years of closure despite an incomplete pressure recovery, which is an interesting result considering the objective of the study. 12 refs

Characteristics and Motivational Factors of Effective Extension Advisory Leaders: Implications for Building Strong Extension Advisory Councils

Directory of Open Access Journals (Sweden)

Joy Kish

2014-10-01

Full Text Available The purpose of this study was to determine the characteristics and motivational factors of effective Extension advisory leaders. This Delphi study was conducted with a selected group of County Extension Directors and a group of Extension State Advisory Leaders. The study identified 10 characteristics that distinguish an effective Extension advisory leader. Some of these characteristics are explicit and easy to observe, while others are implicit and difficult to directly observe. Therefore, it is practical to use directly observable characteristics of effective advisory leaders when selecting volunteers. Once potential volunteers are spotted in the community, implicit characteristics of effective advisory leaders should be used to further screen them before they are selected. The study also identified the eight most important factors motivating individuals to volunteer as effective advisory leaders. Understanding these motivational factors is helpful for creating an environment for attracting and retaining effective volunteers. Understanding their motivation for volunteer work and creating an environment for them to meet the motivating factors for volunteering will lead to volunteer satisfaction and retention. The findings of this study can be used to build strong Extension advisory councils.

Analysing Personal Characteristics of Lone-Actor Terrorists : Research Findings and Recommendations

NARCIS (Netherlands)

Roy, de van Zuijdewijn J.; Bakker, E.

2016-01-01

This Research Note presents the outcome of a project that looked at the personal characteristics of lone-actor terrorists. It is part of the larger Countering Lone-Actor Terrorism (CLAT) project. The project described here aimed to improve understanding of, and responses to, the phenomenon of

Characteristics of Marijuana Acquisition among a National Sample of Adolescent Users

Science.gov (United States)

King, Keith A.; Merianos, Ashley L.; Vidourek, Rebecca A.

2016-01-01

Background: Because marijuana is becoming more accessible and perceived norms of use are becoming increasingly more favorable, research is needed to understand characteristics of marijuana acquisition among adolescents. Purpose: The study purpose was to examine whether sources and locations where adolescent users obtain and use marijuana differed…

Neighborhood Variation of Sustainable Urban Morphological Characteristics

Science.gov (United States)

Chen, Si; Stimson, Robert

2018-01-01

Compact cities and their urban forms have implications on sustainable city development because of high density urban settlement, increased accessibility, and a balanced land use mix. This paper uses quantitative means of understanding urban morphological characteristics with reference to the differing qualities of the urban form (i.e., street patterns, building volumes, land uses and greenery). The results, based on 89 neighborhood communities of Hong Kong, show varying degrees of regional differences in the urban built form supported by numerical statistics and graphical illustrations. This paper offers empirical evidence on some morphological characteristics that can be estimated objectively using modern geospatial technologies and applied universally to inform urban planning. However, more studies linking these quantifiable measures of the physical form with sustainable urban living are needed to account for human comfort in the totality of environmental, social, and economic responsibilities. PMID:29518956

A characteristic of angiographic cone-beam CT

International Nuclear Information System (INIS)

Takase, Tadashi; Take, Toshio; Nakazawa, Yasuo; Kinouchi, Katsunori

2009-01-01

Angiographic cone-beam CT, called DynaCT by SIEMENS, is a 3D imaging tool reconstructed from projection data by a rotational C-arm with a flat panel detector. It can visualize low-contrast objects such as soft tissue or small vessels as well as high-contrast structures such as enhanced vessels or bone. We need to understand its image characteristics and dose distribution during 200 degree rotation around a patient. In this research, we evaluated fundamental characteristics and dose effectiveness for optimized clinical images. DynaCT, including soft tissue information and isochronal voxel data along the z-axis, could provide enough CT-like image quality for interventional radiology (IVR) use. In addition, evaluation of accumulated dose distribution helped us to predict and avoid the occurrence of radiodermatitis. Thus, DynaCT is useful as a support and navigation tool for IVR. (author)

Neighborhood Variation of Sustainable Urban Morphological Characteristics

Directory of Open Access Journals (Sweden)

Poh-Chin Lai

2018-03-01

Full Text Available Compact cities and their urban forms have implications on sustainable city development because of high density urban settlement, increased accessibility, and a balanced land use mix. This paper uses quantitative means of understanding urban morphological characteristics with reference to the differing qualities of the urban form (i.e., street patterns, building volumes, land uses and greenery. The results, based on 89 neighborhood communities of Hong Kong, show varying degrees of regional differences in the urban built form supported by numerical statistics and graphical illustrations. This paper offers empirical evidence on some morphological characteristics that can be estimated objectively using modern geospatial technologies and applied universally to inform urban planning. However, more studies linking these quantifiable measures of the physical form with sustainable urban living are needed to account for human comfort in the totality of environmental, social, and economic responsibilities.

Voltage current characteristics of type III superconductors

International Nuclear Information System (INIS)

Dorofejev, G.L.; Imenitov, A.B.; Klimenko, E.Y.

1980-01-01

An adequate description of voltage-current characteristics is important in order to understand the nature of high critical current for the electrodynamic construction of type-III superconductors and for commercial superconductor specification. Homogeneous monofilament and multifilament Nb-Ti, Nb-Zr,Nb 3 Sn wires were investigated in different ranges of magnetic field, temperature and current. The shape of the voltage-current characteristics of multifilament wires, and the parameter's dependence on temperature and magnetic field may be explained qualitatively by the longitudinal heterogeneous nature of the filaments. A method of attaining the complete specification of the wire's electro-physical properties is proposed. It includes the traditional description of a critical surface (i.e. the surface corresponding to a certain conventional effective resistivity in T,B,J-space) and a description of any increasing parameter that depends on B and T. (author)

Voltage current characteristics of type III superconductors

Energy Technology Data Exchange (ETDEWEB)

Dorofeiev, G L; Imenitov, A B; Klimenko, E Y [Gosudarstvennyi Komitet po Ispol' zovaniyu Atomnoi Ehnergii SSSR, Moscow. Inst. Atomnoi Ehnergii

1980-06-01

An adequate description of voltage-current characteristics is important in order to understand the nature of high critical current for the electrodynamic construction of type-III superconductors and for commercial superconductor specification. Homogeneous monofilament and multifilament Nb-Ti, Nb-Zr,Nb/sub 3/Sn wires were investigated in different ranges of magnetic field, temperature and current. The shape of the voltage-current characteristics of multifilament wires, and the parameter's dependence on temperature and magnetic field may be explained qualitatively by the longitudinal heterogeneous nature of the filaments. A method of attaining the complete specification of the wire's electro-physical properties is proposed. It includes the traditional description of a critical surface (i.e. the surface corresponding to a certain conventional effective resistivity in T,B,J-space) and a description of any increasing parameter that depends on B and T.

Neighborhood Variation of Sustainable Urban Morphological Characteristics.

Science.gov (United States)

Lai, Poh-Chin; Chen, Si; Low, Chien-Tat; Cerin, Ester; Stimson, Robert; Wong, Pui Yun Paulina

2018-03-07

Compact cities and their urban forms have implications on sustainable city development because of high density urban settlement, increased accessibility, and a balanced land use mix. This paper uses quantitative means of understanding urban morphological characteristics with reference to the differing qualities of the urban form (i.e., street patterns, building volumes, land uses and greenery). The results, based on 89 neighborhood communities of Hong Kong, show varying degrees of regional differences in the urban built form supported by numerical statistics and graphical illustrations. This paper offers empirical evidence on some morphological characteristics that can be estimated objectively using modern geospatial technologies and applied universally to inform urban planning. However, more studies linking these quantifiable measures of the physical form with sustainable urban living are needed to account for human comfort in the totality of environmental, social, and economic responsibilities.

Analytical Raman spectroscopic study for discriminant analysis of different animal-derived feedstuff: Understanding the high correlation between Raman spectroscopy and lipid characteristics.

Science.gov (United States)

Gao, Fei; Xu, Lingzhi; Zhang, Yuejing; Yang, Zengling; Han, Lujia; Liu, Xian

2018-02-01

The objectives of the current study were to explore the correlation between Raman spectroscopy and lipid characteristics and to assess the potential of Raman spectroscopic methods for distinguishing the different sources of animal-originated feed based on lipid characteristics. A total of 105 lipid samples derived from five animal species have been analyzed by gas chromatography (GC) and FT-Raman spectroscopy. High correlations (r 2 >0.94) were found between the characteristic peak ratio of the Raman spectra (1654/1748 and 1654/1445) and the degree of unsaturation of the animal lipids. The results of FT-Raman data combined with chemometrics showed that the fishmeal, poultry, porcine and ruminant (bovine and ovine) MBMs could be well separated based on their lipid spectral characteristics. This study demonstrated that FT-Raman spectroscopy can mostly exhibit the lipid structure specificity of different species of animal-originated feed and can be used to discriminate different animal-originated feed samples. Copyright © 2017. Published by Elsevier Ltd.

Visualizing team characteristics from the HRA perspective-its feasibility

Energy Technology Data Exchange (ETDEWEB)

Park, Jinkyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

In this study, as a method to visualize the nature of the team characteristics, the applicability of Hofstede's culture model is investigated. In this study, as a promising solution for visualizing the team characteristics, the applicability of Hofstede's culture model is briefly investigated. As a result, it is expected that the use of Hofstede's culture model allows us to have another viewpoint that is helpful for understanding the relationship between the team characteristics and the associated team performance. Actually, the following excerpts advocate the importance of a cultural aspect in understanding the responses of operating personnel working in NPPs: 'However, the Fukushima Daiichi NPP accident identified significant and new human, organisational and cultural challenges that also need to be addressed. The accident revealed the importance of applying existing concepts and technical knowledge throughout the decision-making processes for design, operation and accident management.' (p. 54) 'Nuclear industry culture has been described as culture of control where organisations and workers emphasise that risks are in control and they do not appreciate the inherent uncertainties. This has also been recognised by some of the Fukushima accident investigations. In reality many activities in the nuclear industry, for example maintenance, design work, construction of new plants and emergency management involve dealing with unforeseen situations and performing underspecified work tasks. In order to smoothly cope with these the culture of the organisation need to support flexibility and adaptability to some degree.' (p. 19) Therefore, although this study is still premature, it is reasonable to say that this study is a good starting point to scrutinize the nature of the team characteristics in a systematic manner, at least to some extent.

Application of Electro-Technologies in Processing of Flax Fiber

Directory of Open Access Journals (Sweden)

G. S. Vijaya Raghavan

2013-08-01

Full Text Available Flax fibers used for various applications are obtained from flax stems. Retting followed by drying and mechanical separation leads to the production of fibers. This review article discusses the application of electro-technologies in the production of bast fibers from the flax stem. In these technologies, flax stems harvested from the field are subjected to microwave assisted retting, followed by electro–osmotic dewatering which reduces the water content of the stems. Dewatered stems are transferred to a microwave chamber for further drying, thus retted stems are obtained for further processing.

Cost effective treatment for wet FGD scrubber bleedoff

Energy Technology Data Exchange (ETDEWEB)

Janecek, K.F. [EIMCO Process Equipment Company, Salt Lake City, UT (United States); Kim, J.Y. [Samkook Corporation, Seoul (Korea, Democratic People`s Republic of)

1994-12-31

The dewatering of scrubber bleedoff gypsum is a thoroughly proven technology, whether for production of wallboard grade gypsum or environmentally responsible land fill. Careful review of the technology options will show which one is the most effective for the specific plant site. Likewise, a recipe for wastewater treatment for heavy metals removal can be found that will meet local regulatory limits. EIMCO has worldwide experience in FGD gypsum sludge dewatering and wastewater treatment. Contacting EIMCO can be the most important step toward a practical cost effective system for handling FGD scrubber bleed slurries.

Assessment of Fluctuating Reservoir Elevations Using Hydraulic Models and Impacts to Larval Pacific Lamprey Rearing Habitat in the Bonneville Pool

Energy Technology Data Exchange (ETDEWEB)

Mueller, Robert P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rakowski, Cynthia L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Perkins, William A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Richmond, Marshall C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-02-24

This report presents the results of a modeling assessment of likely lamprey larval habitat that may be impacted by dewatering of the major tributary delta regions in the Bonneville Pool of the Columbia River. This assessment was conducted by the Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers Portland District (CENWP). The goal of the study was to provide baseline data about how the regions of interest would potentially be impacted at three river flows (10, 50, and 90 percent exceedance flow) for four different forebay elevations at Bonneville Dam. Impacts of unsteady flows at The Dalles Dam and changing forebay elevation at Bonneville Dam for a 2-week period were also assessed. The area of dewatered regions was calculated by importing modeled data outputs into a GIS and then calculating the change in inundated area near tributary deltas for the four Bonneville forebay surface elevations. From the modeled output we determined that the overall change in area is less sensitive to elevations changes during higher river discharges. Changing the forebay elevation at Bonneville and the resulting impact to total dewatered regions was greater at the lowest modeled river flow (97 kcfs) and showed the greatest variation at the White Salmon/Hood River delta regions followed by the Wind, Klickitat and the Little White Salmon rivers. To understand how inundation might change on a daily and hourly basis. Unsteady flow models were run for a 2-week period in 2002 and compared to 2014. The water surface elevation in the upstream pool closely follows that of the Bonneville Dam forebay with rapid changes of 1 to 2-ft possible. The data shows that 2.5-ft variation in water surface elevation occurred during this period in 2002 and a 3.7-ft change occurred in 2014. The duration of these changes were highly variable and generally did not stay constant for more than a 5-hr period.

Laboratory investigations into fracture propagation characteristics of rock material

Science.gov (United States)

Prasad, B. N. V. Siva; Murthy, V. M. S. R.

2018-04-01

After Industrial Revolution, demand of materials for building up structures have increased enormously. Unfortunately, failures of such structures resulted in loss of life and property. Rock is anisotropic and discontinuous in nature with inherent flaws or so-called discontinuities in it. Rock is apparently used for construction in mining, civil, tunnelling, hydropower, geothermal and nuclear sectors [1]. Therefore, the strength of the structure built up considering rockmass as the construction material needs proper technical evaluation during designing stage itself to prevent and predict the scenarios of catastrophic failures due to these inherent fractures [2]. In this study, samples collected from nine different drilling sites have been investigated in laboratory for understanding the fracture propagation characteristics in rock. Rock material properties, ultrasonic velocities through pulse transmission technique and Mode I Fracture Toughness Testing of different variants of Dolomites and Graywackes are determined in laboratory and the resistance of the rock material to catastrophic crack extension or propagation has been determined. Based on the Fracture Toughness values and the rock properties, critical Energy Release Rates have been estimated. However further studies in this direction is to be carried out to understand the fracture propagation characteristics in three-dimensional space.

Understanding vaccines: a public imperative.

Science.gov (United States)

Federman, Ross S

2014-12-01

Though once a discovery greatly celebrated by the nation, the vaccine has come under fire in recent decades from skeptics, critics, and a movement set into motion by fraudulent scientists and fueled by frustrated parents looking for answers to the autism conundrum. There is enough denialist resistance to vaccination to bring upon renewed fear of young children and infants becoming infected with diseases, the threats of which had been functionally eradicated from the United States. In more recent years, the surge in independent online journalism and blogging has invited many to rapidly share their opinions with millions of readers and, importantly, has appeared to open the door for opinion to be portrayed as fact. As a result, many parents are inundated with horror stories of vaccine dangers, all designed to eat away at them emotionally while the medical and scientific communities have mounted their characteristic response by sharing the facts, the data, and all of the reliable peer-reviewed and well-cited research to show that vaccines are safe and effective. It has become clear to me that facts are no match for emotion, but perhaps an understanding behind vaccine methodology will help parents overcome these fears of vaccinating. By helping those who doubt vaccines better understand what vaccines really are and how they work in such an incredibly engineered fashion, we may have a stronger weapon than we realize in battling the emotional arsenal that comes from the fear and skepticism of vaccinating.

Fundamental Studies on the Mechanical Behavior and Fracture Characteristics of Metal-Ceramic Interfaces

National Research Council Canada - National Science Library

Mukai, K

1995-01-01

.... There is need for a fundamental level of understanding of the strength characteristics and the origin of failure of the interface since it is the means by which load is transferred from the matrix to reinforcement...

Acoustic Resonance Characteristics of Rock and Concrete Containing Fractures

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Seiji [Univ. of California, Berkeley, CA (United States)

1998-08-01

In recent years, acoustic resonance has drawn great attention as a quantitative tool for characterizing properties of materials and detecting defects in both engineering and geological materials. In quasi-brittle materials such as rock and concrete, inherent fractures have a significant influence on their mechanical and hydraulic properties. Most of these fractures are partially open, providing internal boundaries that are visible to propagating seismic waves. Acoustic resonance occurs as a result of constructive and destructive interferences of propagating waves. Therefore the geometrical and mechanical properties of the fracture are also interrogated by the acoustic resonance characteristics of materials. The objective of this dissertation is to understand the acoustic resonance characteristics of fractured rock and concrete.

FashionBrain Project: A Vision for Understanding Europe's Fashion Data Universe

OpenAIRE

Checco, Alessandro; Demartini, Gianluca; Loeser, Alexander; Arous, Ines; Khayati, Mourad; Dantone, Matthias; Koopmanschap, Richard; Stalinov, Svetlin; Kersten, Martin; Zhang, Ying

2017-01-01

A core business in the fashion industry is the understanding and prediction of customer needs and trends. Search engines and social networks are at the same time a fundamental bridge and a costly middleman between the customer's purchase intention and the retailer. To better exploit Europe's distinctive characteristics e.g., multiple languages, fashion and cultural differences, it is pivotal to reduce retailers' dependence to search engines. This goal can be achieved by harnessing various dat...

Florida long-distance travel characteristics and their potential impacts on the transportation system.

Science.gov (United States)

2013-03-01

The overall goal of this project is to enhance the fundamental understanding of Florida long-distance travel characteristics, and to provide policy implications for long-distance transportation planning in the future. To achieve the research goal, th...

Recent Progress on Understanding SEP Acceleration and Transport

Science.gov (United States)

Cohen, C.

2017-12-01

Joint observations between near-Earth spacecraft and the twin STEREO spacecraft have allowed new examinations of the longitudinal extent of solar energetic particles (SEPs). Although the radial dependence will not be measured in detail until Parker Solar Probe and Solar Orbiter have launched, recent developments in modeling SEP acceleration and transport have revealed interesting dependences on magnetic field configurations and the characteristics of seed particle populations. This talk will review recent SEP in-situ observations along with theoretical studies and their implications for our understanding of SEP acceleration and transport in the inner heliosphere and our expectations for upcoming Solar Orbiter and Parker Solar Probe observations.

Understanding understanding in secondary school science: An interpretive study

Science.gov (United States)

O'Neill, Maureen Gail

This study investigated the teaching of secondary school science with an emphasis on promoting student understanding. In particular, I focused on two research questions: What are the possible meanings of teaching for understanding? And, how might one teach secondary school science for understanding? After semi-structured interviews were conducted with 13 secondary school science teachers, grounded theory methodology was used to interpret the data. As a result of the selective coding process, I was able to identify 14 connected components of teaching for understanding (TfU). The process of TfU involves: puzzle-solving, a specific pedagogy and a conscious decision. The teacher must be a reflective practitioner who has some knowledge of the facets of understanding. The teacher comes to a critical incident or crisis in his or her pedagogy and adopts a mindset which highlights TfU as a personal problematic. Teachers operate with student-centred rather than teacher-centred metaphors. TfU requires a firm belief in and passion for the process, a positive attitude and excellent pedagogical content knowledge. It hinges on a performance view of understanding and demands risk-taking in the science classroom. Abstracting these ideas to a theory led me to the notion of Purposive Teaching . In their purposive-driven role as pedagogues, these teachers have placed TfU at the core of their daily practice. Constraints and challenges facing TfU as well as implications of the findings are discussed. Keywords. science teaching, teaching for understanding, purposive teaching, constructivism, understanding, pedagogy, pedagogical content knowledge, memorization, meaningful learning, reflective practice.

Effect of magnetic resonance imaging characteristics on uterine fibroid treatment

Directory of Open Access Journals (Sweden)

Duc NM

2018-04-01

Full Text Available Nguyen Minh Duc, Huynh Quang HuyDepartment of Radiology, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, VietnamAbstract: Uterine fibroids are the most common gynecological benign tumors adversely affecting the quality of life of women of a reproductive age. Magnetic resonance imaging (MRI is efficient at localizing the site of lesions and characterizing uterine fibroids before treatment. Understanding the different characteristics of uterine fibroids on MRI is essential, because it not only enables prompt diagnosis, but also guides the development of suitable therapeutic methods. This pictorial review demonstrates the effect of MRI features on uterine fibroid treatment. Keywords: uterine fibroids, characteristics, magnetic resonance imaging, treatments

Understanding InP Nanowire Array Solar Cell Performance by Nanoprobe-Enabled Single Nanowire Measurements.

Science.gov (United States)

Otnes, Gaute; Barrigón, Enrique; Sundvall, Christian; Svensson, K Erik; Heurlin, Magnus; Siefer, Gerald; Samuelson, Lars; Åberg, Ingvar; Borgström, Magnus T

2018-05-09

III-V solar cells in the nanowire geometry might hold significant synthesis-cost and device-design advantages as compared to thin films and have shown impressive performance improvements in recent years. To continue this development there is a need for characterization techniques giving quick and reliable feedback for growth development. Further, characterization techniques which can improve understanding of the link between nanowire growth conditions, subsequent processing, and solar cell performance are desired. Here, we present the use of a nanoprobe system inside a scanning electron microscope to efficiently contact single nanowires and characterize them in terms of key parameters for solar cell performance. Specifically, we study single as-grown InP nanowires and use electron beam induced current characterization to understand the charge carrier collection properties, and dark current-voltage characteristics to understand the diode recombination characteristics. By correlating the single nanowire measurements to performance of fully processed nanowire array solar cells, we identify how the performance limiting parameters are related to growth and/or processing conditions. We use this understanding to achieve a more than 7-fold improvement in efficiency of our InP nanowire solar cells, grown from a different seed particle pattern than previously reported from our group. The best cell shows a certified efficiency of 15.0%; the highest reported value for a bottom-up synthesized InP nanowire solar cell. We believe the presented approach have significant potential to speed-up the development of nanowire solar cells, as well as other nanowire-based electronic/optoelectronic devices.

Characteristics of healthcare wastes

International Nuclear Information System (INIS)

Diaz, L.F.; Eggerth, L.L.; Enkhtsetseg, Sh.; Savage, G.M.

2008-01-01

A comprehensive understanding of the quantities and characteristics of the material that needs to be managed is one of the most basic steps in the development of a plan for solid waste management. In this case, the material under consideration is the solid waste generated in healthcare facilities, also known as healthcare waste. Unfortunately, limited reliable information is available in the open literature on the quantities and characteristics of the various types of wastes that are generated in healthcare facilities. Thus, sound management of these wastes, particularly in developing countries, often is problematic. This article provides information on the quantities and properties of healthcare wastes in various types of facilities located in developing countries, as well as in some industrialized countries. Most of the information has been obtained from the open literature, although some information has been collected by the authors and from reports available to the authors. Only data collected within approximately the last 15 years and using prescribed methodologies are presented. The range of hospital waste generation (both infectious and mixed solid waste fractions) varies from 0.016 to 3.23 kg/bed-day. The relatively wide variation is due to the fact that some of the facilities surveyed in Ulaanbaatar include out-patient services and district health clinics; these facilities essentially provide very basic services and thus the quantities of waste generated are relatively small. On the other hand, the reported amount of infectious (clinical, yellow bag) waste varied from 0.01 to 0.65 kg/bed-day. The characteristics of the components of healthcare wastes, such as the bulk density and the calorific value, have substantial variability. This literature review and the associated attempt at a comparative analysis point to the need for worldwide consensus on the terms and characteristics that describe wastes from healthcare facilities. Such a consensus would greatly

Embodied Understanding

Directory of Open Access Journals (Sweden)

Mark Leonard Johnson

2015-06-01

Full Text Available Western culture has inherited a view of understanding as an intellectual cognitive operation of grasping of concepts and their relations. However, cognitive science research has shown that this received intellectualist conception is substantially out of touch with how humans actually make and experience meaning. The view emerging from the mind sciences recognizes that understanding is profoundly embodied, insofar as our conceptualization and reasoning recruit sensory, motor, and affective patterns and processes to structure our understanding of, and engagement with, our world. A psychologically realistic account of understanding must begin with the patterns of ongoing interaction between an organism and its physical and cultural environments and must include both our emotional responses to changes in our body and environment, and also the actions by which we continuously transform our experience. Consequently, embodied understanding is not merely a conceptual/propositional activity of thought, but rather constitutes our most basic way of being in, and engaging with, our surroundings in a deep visceral manner.

Automatic Detection and Visualization of Qualitative Hemodynamic Characteristics in Cerebral Aneurysms.

Science.gov (United States)

Gasteiger, R; Lehmann, D J; van Pelt, R; Janiga, G; Beuing, O; Vilanova, A; Theisel, H; Preim, B

2012-12-01

Cerebral aneurysms are a pathological vessel dilatation that bear a high risk of rupture. For the understanding and evaluation of the risk of rupture, the analysis of hemodynamic information plays an important role. Besides quantitative hemodynamic information, also qualitative flow characteristics, e.g., the inflow jet and impingement zone are correlated with the risk of rupture. However, the assessment of these two characteristics is currently based on an interactive visual investigation of the flow field, obtained by computational fluid dynamics (CFD) or blood flow measurements. We present an automatic and robust detection as well as an expressive visualization of these characteristics. The detection can be used to support a comparison, e.g., of simulation results reflecting different treatment options. Our approach utilizes local streamline properties to formalize the inflow jet and impingement zone. We extract a characteristic seeding curve on the ostium, on which an inflow jet boundary contour is constructed. Based on this boundary contour we identify the impingement zone. Furthermore, we present several visualization techniques to depict both characteristics expressively. Thereby, we consider accuracy and robustness of the extracted characteristics, minimal visual clutter and occlusions. An evaluation with six domain experts confirms that our approach detects both hemodynamic characteristics reasonably.

Understanding nursing units with data and theory.

Science.gov (United States)

Diers, Donna; Hendrickson, Karrie; Rimar, Joan; Donovan, Donna

2013-01-01

Nursing units are social systems whose function depends on many variables. Available nursing data, combined with a theory of organizational diagnosis, can be used to understand nursing unit performance. One troubled unit served as a case study in organizational diagnosis and treatment using modern methods of data mining and performance improvement. Systems theory did not prescribe how to fix an underbounded system. The theory did suggest, however, that addressing the characteristics of overbounded and underbounded systems can provide some order and structure and identify helpful resources. In this instance, the data analysis served to help define the unit's problems in conjunction with information gained from talking with the nurses and touring the unit, but it was the theory that gave hints for direction for change.

Application of electro-osmosis to radioactive waste processing

International Nuclear Information System (INIS)

Turner, A.D.

1989-01-01

Electro-osmotic dewatering (EOD) is a remotely controllable process for the final stage of slurry concentration after gravity settling or filtration prior to immobilization in cement. It operates by using an electric field instead of pressure as the driving force across a microporous non-conducting membrane - partitioning the solid and liquid components by charge separation. The high solids retention factor (> 99.99%) yields decontamination factors > 1000. Dewatering of a wide range of suspensions can be accomplished at a variety of membranes - including fabrics (eg cotton) for LLW, and ceramics or glass for MLW. Volume reduction factors of 10 can be achieved for low conductivity streams. Planar and tubular membrane designs have been considered for compact full-scale plants. Cost-benefit analyses indicate that, in common with other techniques, large savings on immobilization and disposal costs (> 87%) can be made by this further dewatering stage after gravity settling prior to cementing. Estimates for EOD of capital and running costs amount to 2% and 1.3% respectively of the savings made over 10 years, with electrical power contributing only 0.15%. (author)

Didactic tools for understanding respiratory physiology

International Nuclear Information System (INIS)

Kehoe, P Donnelly; Bratovich, C; Perrone, Ms; Castells, L Mendez

2007-01-01

The challenges in Bioengineering are not only the application of engineering knowledge to the measurement of physiological variables, but also the simulation of biological systems. Experience has shown that the physiology of the respiratory system involves a set of concepts that cannot be effectively taught without the help of a group of didactic tools that contribute to the measurement of characteristic specific variables and to the simulation of the system itself. This article describes a series of tools designed to optimize the teaching of the respiratory system, including the use of spirometers and software developed entirely by undergraduate Bioengineering students from Universidad Nacional de Entre Rios (UNER). The impact these resources have caused on the understanding of the topic and how each of them has facilitated the interpretation of the concepts by the students is also discussed

Leito de drenagem: sistema natural para redução de volume de lodo de estação de tratamento de água Draining beds: natural system for sludge volume reduction in the water treatment plant

Directory of Open Access Journals (Sweden)

Cali Laguna Achon

2008-03-01

Full Text Available As Estações de Tratamento de Água (ETAs tem funcionamento semelhante a uma indústria e podem em diversas etapas gerar resíduos que, na maioria das ETAs, são lançados nos corpos d’água sem tratamento. Neste trabalho avaliou-se o desempenho de Leitos de Drenagem, para o desaguamento de lodo, provenientes de ETAs de ciclo completo que empregam sulfato de alumínio e cloreto de polialumínio (PACl, como coagulantes. Analisou-se as características, a drenagem e secagem dos amostras de lodo e característica do drenado. Os Leitos de Drenagem mostraram-se eficientes para desaguamento e redução de volume de lodo de ETA, de forma natural, sem consumo de energia ou adição de produtos químicos. Obteve-se, aos sete dias, reduções da ordem de 87 % em volume para os lodos de PACl e 83 % para o lodo de Sulfato de Alumínio e teor de sólidos totais 28% e 31% respectivamente.In this work the performance of Draining Beds for sludge dewatering was assessed. The sludge was provided from full cycle Water Treatment Plants (WTPs that employ aluminum sulfate and polyaluminium chloride (PACl as coagulants. The characteristics, drainage and drying of samples of sludge and characteristic of drained were analysed. The Draining Beds were shown to be efficient for dewatering and sludge volume reduction in the WTP, in a natural way, without energy consumption or adding of chemical products. On the seventh day, it was possible to obtain reduction around 87% in volume for PACl sludge and 83% for the aluminum sulfate sludge and total solids content of 28 and 31% respectively.

Understanding the edge effect in wetting: a thermodynamic approach.

Science.gov (United States)

Fang, Guoping; Amirfazli, A

2012-06-26

Edge effect is known to hinder spreading of a sessile drop. However, the underlying thermodynamic mechanisms responsible for the edge effect still is not well-understood. In this study, a free energy model has been developed to investigate the energetic state of drops on a single pillar (from upright frustum to inverted frustum geometries). An analysis of drop free energy levels before and after crossing the edge allows us to understand the thermodynamic origin of the edge effect. In particular, four wetting cases for a drop on a single pillar with different edge angles have been determined by understanding the characteristics of FE plots. A wetting map describing the four wetting cases is given in terms of edge angle and intrinsic contact angle. The results show that the free energy barrier observed near the edge plays an important role in determining the drop states, i.e., (1) stable or metastable drop states at the pillar's edge, and (2) drop collapse by liquid spilling over the edge completely or staying at an intermediate sidewall position of the pillar. This thermodynamic model presents an energetic framework to describe the functioning of the so-called "re-entrant" structures. Results show good consistency with the literature and expand the current understanding of Gibbs' inequality condition.

Characteristics of the polar cap at ionospheric levels and present understanding of the physical processes that give rise to these characteristics

International Nuclear Information System (INIS)

Brekke, A.

1983-01-01

This chapter discusses the relationship between the interplanetary magnetic field (IMF) and various polar cap current systems, such as the DP2-system and the S /SUB q/ P-system. The disagreements concerning these systems are examined. Topics considered include the polar cap (a result of an open magnetosphere); studies of the polar cap magnetic field variations; the DP2-current system and its relation to the IMF; the polar cap current system during a northward IMF; the azimuthal component of IMF and its influence on the polar cap magnetic field variations; the electric potential distribution on the polar cap; rocket observations of the polar cap electric field; the auroral arcs as a visible trace of the ionospheric convection; neutral wind measurements in the polar cap F-region; and further studies of polar cap dynamics. The focus is on the polar region inside the auroral oval. It is suggested that more research is needed of the polar cap current system in order to understand the magnetosphereionosphere coupling, with the polar cap ionospheric conductivity distribution being the most crucial parameter

[Students' perceptions of team-based learning by individual characteristics in a medical school].

Science.gov (United States)

Park, Kwi Hwa; Choi, Chang-Hyu; Jeon, Yang-Bin; Park, Kook-Yang; Park, Chul-Hyun

2013-06-01

The purpose of this study was to examine medical students' perceptions of team-based learning (TBL) according to their individual characteristics: gender, team efficacy, interpersonal understanding, proactivity in problem solving, and academic ability. Thirty-eight second-year medical students who took an integrated cardiology course participated in this study; 28 were male and 10 were female. A questionnaire on individual characteristics and a questionnaire on the perception of TBL were administered, and the scores of individual characteristics were grouped into three: high, middle, and low. The data were analyzed by t-test, analysis of variance, and multiple regression analysis. The TBL efficacy perception scale consisted of 3 factors: team skill, learning ability, and team learning. The group of male students and the group of students with high academic ability recognized the effect of TBL on improvements in learning ability more than females and those with low academic ability. The group of students with high team efficacy reported that TBL was effective with regard to team skill improvement. The group of students with high scores on interpersonal understanding and high proactive problem solving tended to perceive the TBL's effect on team skill improvement. Team efficacy and proactivity in problem solving had a positive effect on the perception of TBL. Medical students' perceptions of the effectiveness of TBL differ according to individual characteristics. The results of this study suggest that these individual characteristics should be considered in planning of team learning, such as TBL, to have a positive impact and stronger effects.

Pharmaceuticals, hormones, anthropogenic waste indicators, and total estrogenicity in liquid and solid samples from municipal sludge stabilization and dewatering

Science.gov (United States)

Furlong, Edward T.; Gray, James L.; Quanrud, David M.; Teske, Sondra S.; Werner, Stephen L.; Esposito, Kathleen; Marine, Jeremy; Ela, Wendell P.; Zaugg, Steven D.; Phillips, Patrick J.; Stinson, Beverley

2012-01-01

The ubiquitous presence of pharmaceuticals and other emerging contaminants, or trace organic compounds, in surface water has resulted in research and monitoring efforts to identify contaminant sources to surface waters and to better understand loadings from these sources. Wastewater treatment plant discharges have been identified as an important point source of trace organic compounds to surface water and understanding the transport and transformation of these contaminants through wastewater treatment process is essential to controlling their introduction to receiving waters.

Sensory characteristics and consumer acceptability of fermented soybean paste (Doenjang).

Science.gov (United States)

Kim, H G; Hong, J H; Song, C K; Shin, H W; Kim, K O

2010-09-01

This study was conducted to examine the sensory profiles of fermented soybean paste (Doenjang), to understand consumers' acceptability of different types of Doenjang samples and to identify the sensory characteristics that drive consumer acceptability of Doenjang products. Descriptive analysis and consumer acceptability test were conducted for 7 different types of Doenjang samples. The samples included 2 types of Doenjang made by either traditional or commercially modified methods. For the descriptive analysis, 8 trained panelists developed and evaluated 31 descriptors. There were significant differences in all 31 attributes among the samples. Principal component analysis was also performed to summarize the sensory characteristics of the samples. In consumer testing, 200 consumers evaluated the acceptability of Doenjang samples. Significant differences in consumer acceptability were observed among the samples. The consumers preferred the Doenjang samples manufactured using a commercially modified method. In overall point of view, most consumers liked the Doenjang samples that had strong "sweet" and "MSG (monosodium glutamate)" tastes. It appears that "sweet" and "MSG" tastes are the drivers of liking for Doenjang. "Salty" taste, "meju,"traditional Korean soy sauce," and "fermented fish" odor/flavors seem to be the drivers of disliking for Doenjang. Cluster analysis identified 3 subconsumer segments sharing a common preference pattern for the 7 samples within a cluster. The results showed that each consumer cluster preferred different Doenjang samples. External preference mapping was performed to establish the relationships between the sensory attributes and consumer acceptability in each cluster. Consumption of the fermented soybean products is gradually expanding around the world, due to their various health benefits. Therefore, understanding sensory characteristics and consumer acceptability of Doenjang are becoming increasingly important. The intense and complex

Characterization of clinical-imaging characteristics of the binswanger's disease

International Nuclear Information System (INIS)

Rodriguez Mutuberria, Livan; Serra Valdes, Yusimi

2002-01-01

A review was made to go deep into the understanding of vascular dementias that behave as the second cause of dementia in practice. Binswanger's disease is one of the most important among them. Its detection has progressively increased with the continual improvement of the radiological diagnostic tools that allow to identify the ischemic damage of the hemispherical cerebral white matter and the presence of lacunar infarctions. It is a disease of chronic course and inexorably progressive that is characterized by the association of subcortical cognitive dysfunction, evidence of cerebrovascular disease, Parkinsonian rigidity and vesicle dysfunction with a characteristic imaging picture. The clinical picture and the main imaging characteristics are explained in this paper and the pathogens of the disease is briefly described

The Impact of Personal Characteristics and Intrinsic Motivation on Creative Behavior among Indonesian Radio Station Managers

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Nugroho J. Setiadi

2013-07-01

Full Text Available The main purpose of the article is to increase understanding in some personal characteristics affecting creative performance among Indonesian radio station managers’ leadership context. Using creativity-relevant personal characteristics and motivation as input model, the authors identified that both of these two variables are positively related to creative performance. The study hypothesized that Leader-member exchange (LMX moderate the relationship between personal characteristics and creative performance. Among a sample of 283 Indonesian radio station managers, results found that creativity-relevant personal characteristics and intrinsic motivation were positively related to creative performance when managers’ perception of followers’ work contribution toward them (as the second dimension of LMX was high.Keywords: Creativity; Personal characteristics; Motivation; Leader-member exchange.

Current understanding of SEP acceleration and propagation

International Nuclear Information System (INIS)

Klecker, B

2013-01-01

The solar energetic particle (SEP) populations of electrons and ions are highly variable in space and time, in intensity, energy, and composition. Over the last ∼20 years advanced instrumentation onboard many spacecraft (e.g. ACE, Coronas, GOES, Hinode, RHESSI, SAMPEX, SDO, SOHO, STEREO, TRACE, Ulysses, Yokoh, to name a few) extended our ability to explore the characteristics of solar energetic particles by in-situ measurements in interplanetary space and by observing their source characteristics near the Sun by remote-sensing observation of electromagnetic emission over a wide frequency range. These measurements provide crucial information for understanding the sources of the particle populations and the acceleration and propagation processes involved. We are now able to measure intensity-time profiles and anisotropies, energy spectra, elemental and isotopic abundances, and the ionic charge of particles over an extended energy range of 0.01 to several 100 MeV/nuc and for a large dynamic range of particle intensities. Furthermore, multi-spacecraft in-situ observations at different solar longitudes and latitudes provide new insight into the acceleration and propagation processes of SEPs near the Sun and in interplanetary space. In this paper we present an overview of SEP observations, their implications for SEP acceleration and propagation processes, and discuss open questions.

Effects of drying methods on the low temperature reactivity of Victorian brown coal to oxygen

Energy Technology Data Exchange (ETDEWEB)

Unal, S.; Wood, D.G.; Harris, I.J. (University of Marmara, Istanbul (Turkey). Ataturk Faculty of Education, Division of Science Education)

1992-02-01

The effects of air drying and thermal dewatering on the low temperature oxygen reactivity of Victorian brown coal have been investigated in the temperature range 35-55{degree}C and at 100 kPa oxygen pressure using coal samples ground to {lt} 100 mesh. An attempt has also been made to relate the low temperature oxygen reactivity of the coal to its free radical concentration as measured prior to oxidation. Two rate models, the Schmidt and Winmill models, have been adapted to include the initial free radical concentration of the coal samples as the drying method sensitivity parameter in lieu of the concentration of oxygen-reactive sites in the coal material. The experimental results show that air drying, which reduces the free radical concentration of the coal, causes a decline in its oxygen reactivity whereas thermal dewatering, which causes an increase in the free radical concentration of the coal, enhances its oxygen reactivity. Air drying does not affect the distribution of the consumed oxygen in the oxidation products. A difference is observed in the case of the thermally dewatered coal samples. The correlation of the two rate models adopted is considered equally satisfactory. However, only the values obtained for the two activation energies in the Winmill model reflect the changes caused by thermal dewatering in the oxidation pattern of the coal. The activation energy values obtained from the two models are within the range of those quoted in the literature for the abstraction of hydrogen from various arene structures by free radicals. 35 refs., 10 figs., 8 tabs.

Characteristics of coal mine ventilation air flows.

Science.gov (United States)

Su, Shi; Chen, Hongwei; Teakle, Philip; Xue, Sheng

2008-01-01

Coal mine methane (CMM) is not only a greenhouse gas but also a wasted energy resource if not utilised. Underground coal mining is by far the most important source of fugitive methane emissions, and approximately 70% of all coal mining related methane is emitted to the atmosphere through mine ventilation air. Therefore, research and development on mine methane mitigation and utilisation now focuses on methane emitted from underground coal mines, in particular ventilation air methane (VAM) capture and utilisation. To date, most work has focused on the oxidation of very low concentration methane. These processes may be classified based on their combustion kinetic mechanisms into thermal oxidation and catalytic oxidation. VAM mitigation/utilisation technologies are generally divided into two basic categories: ancillary uses and principal uses. However, it is possible that the characteristics of ventilation air flows, for example the variations in methane concentration and the presence of certain compounds, which have not been reported so far, could make some potential VAM mitigation and utilisation technologies unfeasible if they cannot cope with the characteristics of mine site ventilation air flows. Therefore, it is important to understand the characteristics of mine ventilation air flows. Moreover, dust, hydrogen sulphide, sulphur dioxide, and other possible compounds emitted through mine ventilation air into the atmosphere are also pollutants. Therefore, this paper presents mine-site experimental results on the characteristics of mine ventilation air flows, including methane concentration and its variations, dust loadings, particle size, mineral matter of the dust, and other compounds in the ventilation air flows. The paper also discusses possible correlations between ventilation air characteristics and underground mining activities.

Examining the Characteristics of Digital Learning Games Designed by In-Service Teachers

Science.gov (United States)

An, Yun-Jo; Cao, Li

2017-01-01

In order to better understand teachers' perspectives on the design and development of digital game-based learning environments, this study examined the characteristics of digital learning games designed by teachers. In addition, this study explored how game design and peer critique activities influenced their perceptions of digital game-based…

Afrocentric cultural values and beliefs: movement beyond the race and ethnicity proxy to understand views of diabetes.

Science.gov (United States)

Scollan-Koliopoulos, Melissa; Rapp, Kenneth J; Bleich, David

2012-01-01

The purpose of this study was to estimate the benefit of using a cultural characteristics scale to help diabetes educators understand how African Americans cope with diabetes. Illness representations are influenced by culture. Race and ethnicity as a proxy for culture provides an incomplete understanding of the mechanism by which cultural values influence representations of diabetes. A descriptive correlational design was employed by recruiting hospitalized adults with type 2 diabetes at 3 metropolitan northeast coast sites. The TRIOS Afrocentric cultural characteristics measure and the Illness perception Questionnaire were administered by paper-and-pencil to a diverse sample. Black race and African American ethnicity was used as a proxy for culture and compared to levels of agreement on an Afrocentric cultural scale to determine the relative ability to explain variance in illness representations of diabetes. The TRIOS measure adapted to diabetes care explained variance in illness representations of diabetes, while African American ethnicity/black race was not able to explain variance in illness representations. Clinicians would benefit from considering the degree to which a patient identifies with particular cultural characteristics when tailoring interventions to manipulate illness representations that are not concordant with biomedical representations.

Valuation of Understanding

DEFF Research Database (Denmark)

Wiberg, Merete

An important aim for the teacher in Higher Education is that students, in order to learn, achieve understanding in terms of being able to handle knowledge in a certain way. In this paper focus will be on understanding as a phenomenon which is permeated with values of what good understanding might...... be. Understanding is to be discussed as a phenomenon which in its definition is relative to the paradigm of educational thinking in which it is embedded. Paradigms of valuation of understanding in higher education will be viewed from two perspectives: An anglosaxon curriculum studies tradition...

Understanding Understanding Mathematics. Artificial Intelligence Memo No. 488.

Science.gov (United States)

Michener, Edwina Rissland

This document is concerned with the important extra-logical knowledge that is often outside of traditional discussions in mathematics, and looks at some of the ingredients and processes involved in the understanding of mathematics. The goal is to develop a conceptual framework in which to talk about mathematical knowledge and to understand the…

The relationship of individual characteristics, perceived worksite support and perceived creativity to clinical nurses' innovative outcome.

Science.gov (United States)

Tsai, Hsiu-Min; Liou, Shwu-Ru; Hsiao, Ya-Chu; Cheng, Ching-Yu

2013-09-01

To understand the relationship of individual characteristics, perceived worksite support and perceived personal creativity to clinical nurses' innovative outcome (receiving the Nursing Innovation Award). Since the idea of applying creativity and innovation to clinical nursing practice and management was first advocated in the Nursing Administration Quarterly in 1982, the topic of nursing innovation has gained worldwide attention. To increase the prevalence of nursing innovation, it is important to identify and understand the related factors that influence nurses' innovative outcome. This study used a cross-sectional descriptive survey design. A self-administered questionnaire was completed by 32 award winners and 506 nonawarded clinical nurses in Taiwan. The level of creativity perceived by all participants was moderate-to-high. Individual characteristics (r = 0·61) and worksite support (r = 0·27) were both correlated with perceived creativity. Individual characteristics and worksite support showed some correlation as well (r = 0·21). Individual characteristics and worksite support could predict perceived creativity after controlling for demographic variables, but only individual characteristics had an effect on innovative outcome. Perceived creativity did not have mediation effects either between individual characteristics and innovative outcome or between worksite support and innovative outcome. Clinical nurses' individual characteristics had a direct relationship to innovative outcome, whereas neither worksite support nor creativity was correlated with innovative outcome. Although worksite support did not show effects on innovative outcome, it was related to both perceived creativity and individual characteristics. As suggested by other scholars, there might be other related factors between creativity and innovative outcome. Although worksite support did not have effect on clinical nurses' innovative outcome, it was related to individual characteristics

Characteristics of Tornado-Like Vortices Simulated in a Large-Scale Ward-Type Simulator

Science.gov (United States)

Tang, Zhuo; Feng, Changda; Wu, Liang; Zuo, Delong; James, Darryl L.

2018-02-01

Tornado-like vortices are simulated in a large-scale Ward-type simulator to further advance the understanding of such flows, and to facilitate future studies of tornado wind loading on structures. Measurements of the velocity fields near the simulator floor and the resulting floor surface pressures are interpreted to reveal the mean and fluctuating characteristics of the flow as well as the characteristics of the static-pressure deficit. We focus on the manner in which the swirl ratio and the radial Reynolds number affect these characteristics. The transition of the tornado-like flow from a single-celled vortex to a dual-celled vortex with increasing swirl ratio and the impact of this transition on the flow field and the surface-pressure deficit are closely examined. The mean characteristics of the surface-pressure deficit caused by tornado-like vortices simulated at a number of swirl ratios compare well with the corresponding characteristics recorded during full-scale tornadoes.

Impact Of Real-World Driving Characteristics On Vehicular Emissions

OpenAIRE

Nesamani, K S; Subramanian, K. P.

2005-01-01

With increase in traffic volume and change in travel related characteristics, vehicular emissions and energy consumption have increased significantly since two decades in India. Current models are not capable of estimating vehicular emissions accurately due to inadequate representation of real-world driving. The focus of this paper is to understand the level of Indian Driving cycle (IDC) in representing the real-world driving and to assess the impact of real-world driving on vehicular emissio...

Characteristics of Placebo Responders in Pediatric Clinical Trials of Attention-Deficit/Hyperactivity Disorder

Science.gov (United States)

Newcorn, Jeffrey H.; Sutton, Virginia K.; Zhang, Shuyu; Wilens, Timothy; Kratochvil, Christopher; Emslie, Graham J.; D'Souza, Deborah N.; Schuh, Leslie M.; Allen, Albert J.

2009-01-01

Objective: Understanding placebo response is a prerequisite to improving clinical trial methodology. Data from placebo-controlled trials of atomoxetine in the treatment of children and adolescents with attention-deficit/hyperactivity disorder (ADHD) were analyzed to identify demographic and clinical characteristics that might predict placebo…

Understanding quantum physics

International Nuclear Information System (INIS)

Spillner, Vera

2011-01-01

This thesis presents a bundle definition for 'scientific understanding' through which the empirically equivalent interpretations of quantum mechanics can be evaluated with respect to the understanding they generate. The definition of understanding is based on a sufficient and necessary criterion, as well as a bundle of conditions - where a theory can be called most understandable whenever it fulfills the highest number of bundle criteria. Thereby the definition of understanding is based on the one hand on the objective number of criteria a theory fulfills, as well as, on the other hand, on the individual's preference of bundle criteria. Applying the definition onto three interpretations of quantum mechanics, the interpretation of David Bohm appears as most understandable, followed by the interpretation of Tim Maudlin and the Kopenhagen interpretation. These three interpretations are discussed in length in my thesis. (orig.)

Social networks as the context for understanding employment services utilization among homeless youth.

Science.gov (United States)

Barman-Adhikari, Anamika; Rice, Eric

2014-08-01

Little is known about the factors associated with use of employment services among homeless youth. Social network characteristics have been known to be influential in motivating people's decision to seek services. Traditional theoretical frameworks applied to studies of service use emphasize individual factors over social contexts and interactions. Using key social network, social capital, and social influence theories, this paper developed an integrated theoretical framework that capture the social network processes that act as barriers or facilitators of use of employment services by homeless youth, and understand empirically, the salience of each of these constructs in influencing the use of employment services among homeless youth. We used the "Event based-approach" strategy to recruit a sample of 136 homeless youth at one drop-in agency serving homeless youth in Los Angeles, California in 2008. The participants were queried regarding their individual and network characteristics. Data were entered into NetDraw 2.090 and the spring embedder routine was used to generate the network visualizations. Logistic regression was used to assess the influence of the network characteristics on use of employment services. The study findings suggest that social capital is more significant in understanding why homeless youth use employment services, relative to network structure and network influence. In particular, bonding and bridging social capital were found to have differential effects on use of employment services among this population. The results from this study provide specific directions for interventions aimed to increase use of employment services among homeless youth. Copyright © 2014 Elsevier Ltd. All rights reserved.

Differential geometry connections, curvature, and characteristic classes

CERN Document Server

Tu, Loring W

2017-01-01

This text presents a graduate-level introduction to differential geometry for mathematics and physics students. The exposition follows the historical development of the concepts of connection and curvature with the goal of explaining the Chern–Weil theory of characteristic classes on a principal bundle. Along the way we encounter some of the high points in the history of differential geometry, for example, Gauss' Theorema Egregium and the Gauss–Bonnet theorem. Exercises throughout the book test the reader’s understanding of the material and sometimes illustrate extensions of the theory. Initially, the prerequisites for the reader include a passing familiarity with manifolds. After the first chapter, it becomes necessary to understand and manipulate differential forms. A knowledge of de Rham cohomology is required for the last third of the text. Prerequisite material is contained in author's text An Introduction to Manifolds, and can be learned in one semester. For the benefit of the reader and to establ...

The Phenomenological, Sociological, and Psychological Understanding of Music

Directory of Open Access Journals (Sweden)

Gregor Pompe

2016-03-01

Full Text Available When trying to investigate the understanding of music, there are a number of epistemologically and methodologically diverse perspectives, and this is associated with the fairly vague definition of music. Firstly, music exists in the form of a waving motion as a physical-acoustic dimension that reaches the listener’s/receiver’s ear. At the time of the »reception« of music, the human neuropsychological mechanism is triggered, which causes the process of semiosis – when we imbue music with meaning strongly exceeding the basic, physical characteristics of music as a sound. In the history of music studies, one can discern the periodical shifting of scientific methodologies that have placed now this and later the other perspective in the center of their research. Meanwhile the author of the article claims that for a holistic understanding of music one needs to employ all the different methodological starting points. Music must be understood as a “two-sided” process: it is possible to investigate the “path” that leads from the creation of music to the emergence of listener’s meaning or to begin with the latter and try to connect it with the intentionality of the author.

Understanding the ice nucleation characteristics of feldspars suspended in solution

Science.gov (United States)

Kumar, Anand; Marcolli, Claudia; Kaufmann, Lukas; Krieger, Ulrich; Peter, Thomas

2017-04-01

Freezing of liquid droplets and subsequent ice crystal growth affects optical properties of clouds and precipitation. Field measurements show that ice formation in cumulus and stratiform clouds begins at temperatures much warmer than those associated with homogeneous ice nucleation in pure water, which is ascribed to heterogeneous ice nucleation occurring on the foreign surfaces of ice nuclei (IN). Various insoluble particles such as mineral dust, soot, metallic particles, volcanic ash, or primary biological particles have been suggested as IN. Among these the suitability of mineral dusts is best established. The ice nucleation ability of mineral dust particles may be modified when secondary organic or inorganic substances are accumulating on the dust during atmospheric transport. If the coating is completely wetting the mineral dust particles, heterogeneous ice nucleation occurs in immersion mode also below 100 % RH. A previous study by Zobrist et al. (2008) Arizona test dust, silver iodide, nonadecanol and silicon dioxide suspensions in various solutes showed reduced ice nucleation efficiency (in immersion mode) of the particles. Though it is still quite unclear how surface modifications and coatings influence the ice nucleation activity of the components present in natural dust particles at a microphysical scale. To improve our understanding how solute and mineral dust particle surface interaction, we run freezing experiments using a differential scanning calorimeter (DSC) with microcline, sanidine, plagioclase, kaolinite and quartz particles suspended in pure water and solutions containing ammonia, ammonium bisulfate, ammonium sulfate, ammonium chloride, ammonium nitrate, potassium chloride, potassium sulfate, sodium sulfate and sulfuric acid. Methodology Suspensions of mineral dust samples (2 - 5 wt%) are prepared in water with varying solute concentrations (0 - 15 wt%). 20 vol% of this suspension plus 80 vol% of a mixture of 95 wt% mineral oil (Aldrich

THE UNDERSTANDING OF THE TOURISTIC VALUE OF PORTUGUESE OVERSEAS MONUMENTS: THE CASE OF ANGOLA (1959-1974

Directory of Open Access Journals (Sweden)

Vera Mariz

2016-06-01

Full Text Available The present study aimed to evaluate the understanding of the touristic value of Portuguese overseas monuments during Estado Novo, having as case-study the then colony of Angola between 1959 and 1974, years marked by the creation of the Information and Tourism Centre and the fall of the regime. Thus, considering the reality of the metropolis, we aimed to identify and analyse the evolution of tourism in this territory, as well the understanding and use of historic monuments by a nationalist regime as points of touristic interest and legitimisers of the national colonialism. We argue that during two different but totally complementary moments devoted to the relation between tourism and historic monuments of Angola, there was a real understanding of their touristic value. Besides that we claim that the believers of the touristic value of those monuments were very often advocates of the preservation or restoration of their pristine characteristics, an idea that we can affiliate to the thought of António Ferro to whom the success of tourism was extremely dependent on preserving and emphasizing the picturesque and idiosyncratic characteristics of those tourist destinations. To achieve our goals we have identified and analysed some tourism-related periodicals, thematic studies and legislation.

Internet-based mental health services in Norway and Sweden: characteristics and consequences.

Science.gov (United States)

Andersen, Anders Johan W; Svensson, Tommy

2013-03-01

Internet-based mental health services increase rapidly. However, national surveys are incomplete and the consequences for such services are poorly discussed. This study describes characteristics of 60 Internet-based mental health services in Norway and Sweden and discusses their social consequences. More than half of the services were offered by voluntary organisations and targeted towards young people. Professionals answered service users' questions in 60% of the services. Eight major themes were identified. These characteristics may indicate a shift in the delivery of mental health services in both countries, and imply changes in the understanding of mental health.

Teamwork in perioperative nursing. Understanding team development, effectiveness, evaluation.

Science.gov (United States)

Farley, M J

1991-03-01

Teams are an essential part of perioperative nursing practice. Nurses who have a knowledge of teamwork and experience in working on teams have a greater understanding of the processes and problems involved as teams develop from new, immature teams to those that are mature and effective. This understanding will assist nurses in helping their teams achieve a higher level of productivity, and members will be more satisfied with team efforts. Team development progresses through several stages. Each stage has certain characteristics and desired outcomes. At each stage, team members and leaders have certain responsibilities. Team growth does not take place automatically and inevitably, but as a consequence of conscious and unconscious efforts of its leader and members to solve problems and satisfy needs. Building and maintaining a team is certainly work, but work that brings a great deal of satisfaction and feelings of pride in accomplishment. According to I Tenzer, RN, MS, teamwork "is not a panacea; it is a viable approach to developing a hospital's most valuable resource--people."

Understanding the biological underpinnings of ecohydrological processes

Science.gov (United States)

Huxman, T. E.; Scott, R. L.; Barron-Gafford, G. A.; Hamerlynck, E. P.; Jenerette, D.; Tissue, D. T.; Breshears, D. D.; Saleska, S. R.

2012-12-01

Climate change presents a challenge for predicting ecosystem response, as multiple factors drive both the physical and life processes happening on the land surface and their interactions result in a complex, evolving coupled system. For example, changes in surface temperature and precipitation influence near-surface hydrology through impacts on system energy balance, affecting a range of physical processes. These changes in the salient features of the environment affect biological processes and elicit responses along the hierarchy of life (biochemistry to community composition). Many of these structural or process changes can alter patterns of soil water-use and influence land surface characteristics that affect local climate. Of the many features that affect our ability to predict the future dynamics of ecosystems, it is this hierarchical response of life that creates substantial complexity. Advances in the ability to predict or understand aspects of demography help describe thresholds in coupled ecohydrological system. Disentangling the physical and biological features that underlie land surface dynamics following disturbance are allowing a better understanding of the partitioning of water in the time-course of recovery. Better predicting the timing of phenology and key seasonal events allow for a more accurate description of the full functional response of the land surface to climate. In addition, explicitly considering the hierarchical structural features of life are helping to describe complex time-dependent behavior in ecosystems. However, despite this progress, we have yet to build an ability to fully account for the generalization of the main features of living systems into models that can describe ecohydrological processes, especially acclimation, assembly and adaptation. This is unfortunate, given that many key ecosystem services are functions of these coupled co-evolutionary processes. To date, both the lack of controlled measurements and experimentation

Specifying the Graphic Characteristics of Words That Influence Children's Handwriting

Science.gov (United States)

Gosse, Claire; Carbonnelle, Simon; de Vleeschouwer, Christophe; Van Reybroeck, Marie

2018-01-01

Research about the development of the graphomotor side of writing is very scarce. The goal of this study was to gain a better understanding of what constitutes graphic complexity of written material by determining the impact of graphic characteristics on handwriting production. In this end, the pen stroke of cursive handwriting was precisely…

The characteristics of energy-efficiency measures – a neglected dimension

International Nuclear Information System (INIS)

Fleiter, Tobias; Hirzel, Simon; Worrell, Ernst

2012-01-01

The diffusion of cost-effective energy-efficiency measures (EEMs) in firms is often surprisingly slow. This phenomenon is usually attributed to a variety of barriers which have been the focus of numerous studies over the last two decades. However, many studies treat EEMs homogenously and assume they have few inherent differences apart from their profitability. We argue that complementing such analyses by considering the characteristics of EEMs in a structured manner can enhance the understanding of EEM adoption. For this purpose, we suggest a classification scheme for EEMs in industry which aims to provide a better understanding of their adoption by industrial firms and to assist in selecting and designing energy-efficiency policies. The suggested classification scheme is derived from the literature on the adoption of EEMs and the related fields including the diffusion of innovations, eco-innovations and advanced manufacturing technology. Our proposed scheme includes 12 characteristics based on the relative advantage, the technical and the information context of the EEM. Applying this classification scheme to six example EEMs demonstrates that it can help to systematically explain why certain EEMs diffuse faster than others. Furthermore, it provides a basis for identifying policies able to increase the rate of adoption. - Highlights: ► The characteristics of energy-efficiency measures critically affect their adoption. ► We propose a classification for energy-efficiency measures in industry. ► It allows to draw conclusions on the adoption likelihood and intensity of barriers. ► As such it provides a basis for policy design and technology analysis.

An Overview of Structural Characteristics in Problematic Video Game Playing.

Science.gov (United States)

Griffiths, Mark D; Nuyens, Filip

2017-01-01

There are many different factors involved in how and why people develop problems with video game playing. One such set of factors concerns the structural characteristics of video games (i.e., the structure, elements, and components of the video games themselves). Much of the research examining the structural characteristics of video games was initially based on research and theorizing from the gambling studies field. The present review briefly overviews the key papers in the field to date. The paper examines a number of areas including (i) similarities in structural characteristics of gambling and video gaming, (ii) structural characteristics in video games, (iii) narrative and flow in video games, (iv) structural characteristic taxonomies for video games, and (v) video game structural characteristics and game design ethics. Many of the studies carried out to date are small-scale, and comprise self-selected convenience samples (typically using self-report surveys or non-ecologically valid laboratory experiments). Based on the small amount of empirical data, it appears that structural features that take a long time to achieve in-game are the ones most associated with problematic video game play (e.g., earning experience points, managing in-game resources, mastering the video game, getting 100% in-game). The study of video games from a structural characteristic perspective is of benefit to many different stakeholders including academic researchers, video game players, and video game designers, as well as those interested in prevention and policymaking by making the games more socially responsible. It is important that researchers understand and recognize the psycho-social effects and impacts that the structural characteristics of video games can have on players, both positive and negative.

Workplace characteristics and work disability onset for men and women.

Science.gov (United States)

Crimmins, Eileen M; Hayward, Mark D

2004-01-01

This paper investigates the association between job characteristics and work disability among men and women in older working ages in the United States. We examine whether the association persists when controlling for major chronic disease experience. We also address whether job characteristics are ultimately associated with the receipt of disability benefits. Data are from the Health and Retirement Survey and are nationally representative of noninstitutionalized persons 51-61 in 1992. Disability onset is estimated using a hazard modeling approach for those working at wave 1 (N = 5,999). A logistic regression analysis of disability benefits is based on a risk set of 525 persons who become work-disabled before the second interview. Women's disability onset and health problems appear less related to job characteristics than men's. For men, work disability is associated with stressful jobs, lack of job control, and environmentally hazardous conditions but is not associated with physical demands. Participation in disability benefit programs among those with work disability is unrelated to most job characteristics or health conditions. Understanding of the differing process to work disability for men and women and the relationship between work and health by gender is important for current policy development.

CHARACTERISTICS OF CORN STALK HEMICELLULOSE PYROLYSIS IN A TUBULAR REACTOR

OpenAIRE

Gao-Jin Lv; Shu-Bin Wu; Rui Lou

2010-01-01

Pyrolysis characteristics of corn stalk hemicellulose were investigated in a tubular reactor at different temperatures, with focus mainly on the releasing profiles and forming behaviors of pyrolysis products (gas, char, and tar). The products obtained were further identified using various approaches (including GC, SEM, and GC-MS) to understand the influence of temperature on product properties and compositions. It was found that the devolatilization of hemicellulose mainly occurred at low tem...

Physical properties, evaporation and combustion characteristics of nanofluid-type fuels

OpenAIRE

Tanvir, Saad

2016-01-01

Nanofluids are liquids with stable suspension of nanoparticles. Limited studies in the past have shown that both energetic and catalytic nanoparticles once mixed with traditional liquid fuels can be advantageous in combustion applications, e.g., increased energy density and shortened ignition delay. Contradictions in existing literature, scarcity of experimental data and lack of understanding on how the added nanoparticles affect the physical properties as well as combustion characteristics o...

The radiographer-patient relationship: Enhancing understanding using a transactional analysis approach

International Nuclear Information System (INIS)

Booth, Lisa

2008-01-01

Purpose: Government initiatives such as the NHS Plan, the NHS Key Skills Framework and the NHS Career framework place communication at the centre of effective patient care, and role/career development. All advocate a patient-centred approach to dealing with patients, through open communication styles that encourage patients to become active participants in their care. Previous research, that has investigated communication in diagnostic radiography, demonstrated a preference for practitioner-centred, rather than patient-centred approaches to communication, however, there is little evidence to suggest why this should be the case or how a more patient-centred approach might be encouraged. The present study therefore sought to explore factors that influence communication in diagnostic radiography, with the view to understanding the barriers to patient-centred care. Method: Semi-structured group interviews took place with 12 radiographers, across two NHS trusts, with the aim of understanding their communication with patients and the factors that influence it. An open coding approach was used to analyse the data. Results: Four attitude categories were identified as influencing the communication used by diagnostic radiographers. 1. Characteristics of the radiographer. 2. Characteristics of the patient. 3. The need to produce a diagnostic image. 4. The need to keep the department running. Conclusion: Radiographer-patient communication is evidently influenced by these four attitude categories. If patient-centred styles of communication are to be encouraged, these factors need to be recognised and taken account of in the selection, education/training and workforce planning of diagnostic radiographers

[Improvement of municipal sewage sludge dewaterability by bioleaching: a pilot-scale study with sequence batch reaction model].

Science.gov (United States)

Liu, Fen-Wu; Zhou, Li-Xiang; Zhou, Jun; Jiang, Feng; Wang, Dian-Zhan

2011-07-01

To observe the bioleaching effect on sewage sludge dewaterability, three consecutive batch bioleaching experiments were conducted through a bioleaching bio-reactor with 700 L of working volume. Subsequently, the bioleached sludge was dewatered by using chamber filter press. The results show that the 1st batch bioleaching process can be finished within 90 hours if the aeration amount was 1.2 m3/h with the 1: 15 mixing ratio of bioleached sludge to raw sludge. The pH of sludge declines from initial 6.11 to 2.33 while ORP increased from initial -134 mV to finial 507 mV. The specific resistance to filtration (SRF) of the tested sludge was decreased from original 1.00 x 10(13) m/kg to final 0.09 x 10(13) m/kg after bioleaching. For the subsequent two batch trials, the bioleaching process can be finished in 40 hours and 46 hours, respectively. Likewise, sludge SRF is also significantly decreased to 0.19 x 10(13) m/kg and 0.36 x 10(13) m/kg if the mixing ratio of bioleached sludge to fresh sludge is 1:1 although the microbial nutrient substance dosage is reduced by 25% and 50% for 2nd, and 3rd batch experiments, respectively. The harvested bioleached sludge from three batch trails is dewatered by chamber filter press with 0.3-0.4 MPa working pressure for 2 hours. It is found that the moisture of dewatered sludge cake can be reduced to 58%, and that the dewatered sludge cake is of khaki appearance and didn't emit any offensive odor. In addition, it is also observes that sludge organic matter only changed a bit from 52.9% to 48.0%, but 58% of sludge-borne Cu and 88% of sludge-borne Zn can be removed from sludge by bioleaching process. Therefore, dual goals for sludge-borne heavy metal removal and sludge dewatering of high efficiency can be achieved simultaneously through the approach mentioned above. Therefore, bioleaching technique is of great engineering application for the treatment of sewage sludge.

Revised Sunspot Numbers and the Effects on Understanding the Sunspot Cycle

Science.gov (United States)

Hathaway, D. H.

2014-12-01

While sunspot numbers provide only limited information about the sunspot cycle, they provide that information for at least twice as many sunspot cycles as any other direct solar observation. In particular, sunspot numbers are available before, during, and immediately after the Maunder Minimum (1645-1715). The instruments and methods used to count sunspots have changed over the last 400+ years. This leads to systematic changes in the sunspot number that can mask, or artificially introduce, characteristics of the sunspot cycle. The most widely used sunspot number is the International (Wolf/Zurich) sunspot number which is now calculated at the Solar Influences Data Center in Brussels, Belgium. These numbers extend back to 1749. The Group sunspot number extends back to the first telescopic observations of the Sun in 1610. There are well-known and significant differences between these two numbers where they overlap. Recent work has helped us to understand the sources of these differences and has led to proposed revisions in the sunspot numbers. Independent studies now support many of these revisions. These revised sunspot numbers suggest changes to our understanding of the sunspot cycle itself and to our understanding of its connection to climate change.

Post-anaerobic digestion thermal hydrolysis of sewage sludge and food waste: Effect on methane yields, dewaterability and solids reduction.

Science.gov (United States)

Svensson, Kine; Kjørlaug, Oda; Higgins, Matthew J; Linjordet, Roar; Horn, Svein J

2018-04-01

Post-anaerobic digestion (PAD) treatment technologies have been suggested for anaerobic digestion (AD) to improve process efficiency and assure hygenization of organic waste. Because AD reduces the amount of organic waste, PAD can be applied to a much smaller volume of waste compared to pre-digestion treatment, thereby improving efficiency. In this study, dewatered digestate cakes from two different AD plants were thermally hydrolyzed and dewatered, and the liquid fraction was recirculated to a semi-continuous AD reactor. The thermal hydrolysis was more efficient in relation to methane yields and extent of dewaterability for the cake from a plant treating waste activated sludge, than the cake from a plant treating source separated food waste (SSFW). Temperatures above 165 °C yielded the best results. Post-treatment improved volumetric methane yields by 7% and the COD-reduction increased from 68% to 74% in a mesophilic (37 °C) semi-continuous system despite lowering the solid retention time (from 17 to 14 days) compared to a conventional system with pre-treatment of feed substrates at 70 °C. Results from thermogravimetric analysis showed an expected increase in maximum TS content of dewatered digestate cake from 34% up to 46% for the SSFW digestate cake, and from 17% up to 43% in the sludge digestate cake, after the PAD thermal hydrolysis process (PAD-THP). The increased dewatering alone accounts for a reduction in wet mass of cake leaving the plant of 60% in the case of sludge digestate cake. Additionaly, the increased VS-reduction will contribute to further reduce the mass of wet cake. Copyright © 2018 Elsevier Ltd. All rights reserved.

Uncertainty characteristics of EPA's ground-water transport model for low-level waste performance assessment

International Nuclear Information System (INIS)

Yim, Man-Sung

1995-01-01

Performance assessment is an essential step either in design or in licensing processes to ensure the safety of any proposed radioactive waste disposal facilities. Since performance assessment requires the use of computer codes, understanding the characteristics of computer models used and the uncertainties of the estimated results is important. The PRESTO-EPA code, which was the basis of the Environmental Protection Agency's analysis for low-level-waste rulemaking, is widely used for various performance assessment activities in the country with no adequate information available for the uncertainty characteristics of the results. In this study, the groundwater transport model PRESTO-EPA was examined based on the analysis of 14 C transport along with the investigation of uncertainty characteristics

Understanding Magnitudes to Understand Fractions

Science.gov (United States)

Gabriel, Florence

2016-01-01

Fractions are known to be difficult to learn and difficult to teach, yet they are vital for students to have access to further mathematical concepts. This article uses evidence to support teachers employing teaching methods that focus on the conceptual understanding of the magnitude of fractions.

Ecological Understanding 2: Transformation--A Key to Ecological Understanding.

Science.gov (United States)

Carlsson, Britta

2002-01-01

Describes the structure and general features of the phenomenon of ecological understanding. Presents qualitatively different ways of experiencing cycling of matter and the flow of energy in the context of ecosystems. The idea of transformation is key to the development of ecological understanding. (Contains 17 references.) (Author/YDS)

Understanding how individuals perceive carbon dioxide. Implications for acceptance of carbon dioxide capture and storage

Energy Technology Data Exchange (ETDEWEB)

Itaoka, K.; Saito, A. [Mizuho Information and Research Institute, Tokyo (Japan); Paukovic, M.; De Best-Waldhober, M. [ECN Policy Studies, Petten (Netherlands); Dowd, A.M.; Jeanneret, T.; Ashworth, P.; James, M. [The Global CCS Institute, Canberra (Australia)

2012-06-15

Carbon dioxide capture and storage (CCS) presents one potential technological solution for mitigating the atmospheric emission of carbon dioxide sources. However, CCS is a relatively new technology with associated uncertainties and perceived risks. For this reason, a growing body of research now focuses on public perceptions and potential for societal acceptance of CCS technology. Almost all explanations of CCS technology make reference to carbon dioxide, with an assumption that the general public understands CO2. It has become apparent that the general public’s knowledge and understanding of CO2’s properties influences how they engage with CO2 emitting industries and CCS technologies. However, surprisingly little research has investigated public perceptions, knowledge, and understanding of CO2. This investigation attempts to fill that gap. This report describes an investigation of how citizens of three countries (Japan, Australia, and the Netherlands) perceive CO2. Furthermore, it attempts to relate individual perceptions of CO2 to perceptions of CCS, and to determine how information provision about the underlying properties and characteristics of CO2 influences individual attitudes towards low carbon energy options, particularly CCS. In brief, the research had four ultimate aims. It aimed to: Explore the public’s knowledge and understanding of the properties of CO2; Examine the influence of that knowledge on their perceptions of CO2 and CCS; Investigate how information provision about the underlying properties and characteristics of CO2 influences individual attitudes towards CCS; and Identify if any differences between countries exist in relation to values and beliefs, knowledge of CO2’s properties, and CCS perceptions.

Accurate diagnosis of prenatal cleft lip/palate by understanding the embryology

Science.gov (United States)

Smarius, Bram; Loozen, Charlotte; Manten, Wendy; Bekker, Mireille; Pistorius, Lou; Breugem, Corstiaan

2017-01-01

Cleft lip with or without cleft palate (CP) is one of the most common congenital malformations. Ultrasonographers involved in the routine 20-wk ultrasound screening could encounter these malformations. The face and palate develop in a very characteristic way. For ultrasonographers involved in screening these patients it is crucial to have a thorough understanding of the embryology of the face. This could help them to make a more accurate diagnosis and save time during the ultrasound. Subsequently, the current postnatal classification will be discussed to facilitate the communication with the CP teams. PMID:29026689

The measurement of water transport in porous materials using impedance spectroscopy

International Nuclear Information System (INIS)

Ball, R J; Allen, G C

2010-01-01

This paper describes the application of electrical measurements to monitor the extraction (movement of water from the mortar) of water from calcium lime, natural hydraulic lime and Portland cement mortars placed on an adsorbent brick substrate. Impedance measurements were used to identify the changes in bulk resistance of the mortar. A model has been developed combining sharp front theory and Boltzmann's distribution law of statistical thermodynamics to identify the point at which no further absorption of water into the brick occurs. A linear relationship was found between the exponential of bulk resistance and the square root of time during dewatering. A change in gradient was attributed to the end of dewatering.

Job Satisfaction of People with Intellectual Disability: Associations with Job Characteristics and Personality

Science.gov (United States)

Akkerman, Alma; Kef, Sabina; Meininger, Herman P.

2018-01-01

To obtain an understanding of factors associated with job satisfaction of people with intellectual disability (ID), this study investigates the associations of job satisfaction with job characteristics (i.e., job demands, job resources) and personality, using the job demands-resources model. Data were gathered from 117 people and their employment…

Parental and Child Characteristics Related to Early-Onset Disordered Eating: A Systematic Review.

Science.gov (United States)

Larsen, Pernille Stemann; Strandberg-Larsen, Katrine; Micali, Nadia; Andersen, Anne-Marie Nybo

2015-01-01

After participating in this activity, learners should be better able to: Evaluate the evidence regarding parental and child characteristics related to early-onset disordered eating. Eating disorders are rare in children, but disordered eating is common. Understanding the phenomenology of disordered eating in childhood can aid prevention of full-blown eating disorders. The purpose of this review is to systematically extract and synthesize the evidence on parental and child characteristics related to early-onset disordered eating. Systematic searches were conducted in PubMED/MEDLINE, EMBASE, and PsycInfo using the following search terms: eating disorder, disordered eating, problem eating, anorexia nervosa, bulimia nervosa, binge eating, child, preadolescent, and early onset. Studies published from 1990 to 2013 addressing parental and child characteristics of disordered eating in children aged 6 to 12 years were eligible for inclusion. The search was restricted to studies with cross-sectional, case-control, or longitudinal designs, studies in English, and with abstracts available. Forty-four studies fit these criteria. Most studies were based on community samples with a cross-sectional design. The included studies varied considerably in size, instruments used to assess early-onset disordered eating, and parental and child characteristics investigated. Important determinants included the following: higher body weight, previously reported disordered eating, body dissatisfaction, depression, parental disordered eating, and parental comments/concerns about child's weight and eating. The findings were inconsistent for sex, age, socioeconomic status, ethnicity, self-esteem/worth, and parental body weight. In conclusion, characteristics related to early-onset disordered eating have mainly been explored with a cross-sectional design. Full understanding of causal pathways will require good-quality longitudinal studies designed to address the influence of parental eating

TCRP H-37 Characteristics of Premium Transit Services That Affect Mode Choice: Summary of Phase 1

Science.gov (United States)

2010-11-15

This research seeks to improve the understanding of the full range of determinants for mode choice behavior and to offer practical solutions to practitioners on representing and distinguishing these characteristics in travel demand forecasting models...

A study of understanding: Alchemy, abstraction, and circulating reference in tertiary science education

Science.gov (United States)

Merritt, Brett W.

Understanding is widely touted to be of paramount importance for education. This is especially true in science education research and development where understanding is heralded as one of the cornerstones of reform. Teachers are expected to teach for understanding and students are expected to learn with understanding. This dissertation is an empirical study of the concept of understanding. After analyzing various constructions of understanding in current U.S. education literature, I suggest that understanding is defined by five distinct features---they are knowledge (or knowledge base), coherence, transfer, extrapolation, and cognition--- and that these features are heavily informed and shaped by the psychological sciences. This relationship is neither good nor bad, I argue, but it means that teaching for and learning with understanding are not heavily informed and shaped by, for example, the natural sciences. Drawing from historical, philosophical, and anthropological perspectives of science, but especially from the work of Bruno Latour, I enact a radical revision(ing) of psychological notions such as "abstraction" and "transfer." The two main purposes of this re-visioning are (1) to draw critical attention to particular characteristics of a cognitive learning theory that emphasizes abstract concepts, and (2) to align many of the principles and tools used in science education more closely with those used in empirical scientific research. Finally, by bringing some examples of teaching and learning from an undergraduate biology classroom into conversation with both psychological and empirical practices and perspectives, I suggest that problematizing the current construction of understanding creates much needed room in mainstream science education for more empirical forms of learning and styles of teaching. A shift to such forms and styles, I conclude, should prove to be more inclusive and less constraining for both students and teachers.

Snap-lock bags with red band: A study of manufacturing characteristics, thermal and chemical properties.

Science.gov (United States)

Sim, Yvonne Hui Ying; Koh, Alaric C W; Lim, Shing Min; Yew, Sok Yee

2015-10-01

Drug packaging is commonly submitted to the Forensic Chemistry and Physics Laboratory of the Health Sciences Authority, Singapore, for examination. The drugs seized are often packaged in plastic bags. These bags are examined for linkages to provide law enforcement with useful associations between the traffickers and drug abusers. The plastic bags submitted may include snap-lock bags, some with a red band located above the snap-lock closure and some without. Current techniques for examination involve looking at the physical characteristics (dimensions, thickness and polarising patterns) and manufacturing marks of these bags. In cases where manufacturing marks on the main body of the bags are poor or absent, the manufacturing characteristics present on the red band can be examined. A study involving approximately 1000 bags was conducted to better understand the variations in the manufacturing characteristics of the red band. This understanding is crucial in helping to determine associations/eliminations between bags. Two instrumental techniques, namely differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) were explored to evaluate the effectiveness of examining the chemical composition to discriminate the bags. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Interaction of Working Memory, Compressor Speed and Background Noise Characteristics

OpenAIRE

Ohlenforst, Barbara; MacDonald, Ewen; Souza, Pamela

2014-01-01

Previous studies have shown that individuals with poor working memory perform worse in speech recognition tests when fast compression release time is applied. However, it is not clear why this effect occurs only when modulations are present in the background noise. This study explored the relationship between working memory capacity, compression release time and characteristics of the background noise. This relationship is important to understand because the majority of everyday listening sit...

Who Tweets with Their Location? Understanding the Relationship between Demographic Characteristics and the Use of Geoservices and Geotagging on Twitter.

Directory of Open Access Journals (Sweden)

Luke Sloan

Full Text Available In this paper we take advantage of recent developments in identifying the demographic characteristics of Twitter users to explore the demographic differences between those who do and do not enable location services and those who do and do not geotag their tweets. We discuss the collation and processing of two datasets-one focusing on enabling geoservices and the other on tweet geotagging. We then investigate how opting in to either of these behaviours is associated with gender, age, class, the language in which tweets are written and the language in which users interact with the Twitter user interface. We find statistically significant differences for both behaviours for all demographic characteristics, although the magnitude of association differs substantially by factor. We conclude that there are significant demographic variations between those who opt in to geoservices and those who geotag their tweets. Not withstanding the limitations of the data, we suggest that Twitter users who publish geographical information are not representative of the wider Twitter population.

Acoustic characteristics of bubble bursting at the surface of a high-viscosity liquid

International Nuclear Information System (INIS)

Liu Xiao-Bo; Zhang Jian-Run; Li Pu

2012-01-01

An acoustic pressure model of bubble bursting is proposed. An experiment studying the acoustic characteristics of the bursting bubble at the surface of a high-viscosity liquid is reported. It is found that the sudden bursting of a bubble at the high-viscosity liquid surface generates N-shape wave at first, then it transforms into a jet wave. The fundamental frequency of the acoustic signal caused by the bursting bubble decreases linearly as the bubble size increases. The results of the investigation can be used to understand the acoustic characteristics of bubble bursting. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Added ingredients affect the microbiota and biochemical characteristics of durum wheat type-I sourdough.

Science.gov (United States)

Minervini, Fabio; Celano, Giuseppe; Lattanzi, Anna; De Angelis, Maria; Gobbetti, Marco

2016-12-01

This study aimed at understanding the effect of additional ingredients (baker's yeast, macerated pears, grape must, honey, or water from macerated pears) on the microbiota and biochemical characteristics of durum wheat-based sourdough. One dough prepared using only flour was used as the control (control-dough). Compared to the control-dough, doughs containing additional ingredients showed higher (P  0.7, P < 0.05) with several biochemical characteristics of the sourdoughs (e.g., free amino acids and their derivatives). Copyright © 2016 Elsevier Ltd. All rights reserved.

Testing Understanding and Understanding Testing.

Science.gov (United States)

Pedersen, Jean; Ross, Peter

1985-01-01

Provides examples in which graphs are used in the statements of problems or in their solutions as a means of testing understanding of mathematical concepts. Examples (appropriate for a beginning course in calculus and analytic geometry) include slopes of lines and curves, quadratic formula, properties of the definite integral, and others. (JN)

SPATIO-TEMPORAL CHARACTERISTICS OF RESIDENT TRIP BASED ON POI AND OD DATA OF FLOAT CAR IN BEIJING

OpenAIRE

N. Mou; N. Mou; J. Li; L. Zhang; W. Liu; Y. Xu

2017-01-01

Due to the influence of the urban inherent regional functional distribution, the daily activities of the residents presented some spatio-temporal patterns (periodic patterns, gathering patterns, etc.). In order to further understand the spatial and temporal characteristics of urban residents, this paper research takes the taxi trajectory data of Beijing as a sample data and studies the spatio-temporal characteristics of the residents' activities on the weekdays. At first, according t...

The disposition to understand for oneself at university: integrating learning processes with motivation and metacognition.

Science.gov (United States)

Entwistle, Noel; McCune, Velda

2013-06-01

A re-analysis of several university-level interview studies has suggested that some students show evidence of a deep and stable approach to learning, along with other characteristics that support the approach. This combination, it was argued, could be seen to indicate a disposition to understand for oneself. To identify a group of students who showed high and consistent scores on deep approach, combined with equivalently high scores on effort and monitoring studying, and to explore these students' experiences of the teaching-learning environments they had experienced. Re-analysis of data from 1,896 students from 25 undergraduate courses taking four contrasting subject areas in eleven British universities. Inventories measuring approaches to studying were given at the beginning and the end of a semester, with the second inventory also exploring students' experiences of teaching. K-means cluster analysis was used to identify groups of students with differing patterns of response on the inventory scales, with a particular focus on students showing high, stable scores. One cluster clearly showed the characteristics expected of the disposition to understand and was also fairly stable over time. Other clusters also had deep approaches, but also showed either surface elements or lower scores on organized effort or monitoring their studying. Combining these findings with interview studies previously reported reinforces the idea of there being a disposition to understand for oneself that could be identified from an inventory scale or through further interviews. © 2013 The British Psychological Society.

Quantifying space, understanding minds: A visual summary approach

Directory of Open Access Journals (Sweden)

Mark Simpson

2017-06-01

Full Text Available This paper presents an illustrated, validated taxonomy of research that compares spatial measures to human behavior. Spatial measures quantify the spatial characteristics of environments, such as the centrality of intersections in a street network or the accessibility of a room in a building from all the other rooms. While spatial measures have been of interest to spatial sciences, they are also of importance in the behavioral sciences for use in modeling human behavior. A high correlation between values for spatial measures and specific behaviors can provide insights into an environment's legibility, and contribute to a deeper understanding of human spatial cognition. Research in this area takes place in several domains, which makes a full understanding of existing literature difficult. To address this challenge, we adopt a visual summary approach. Literature is analyzed, and recurring topics are identified and validated with independent inter-rater agreement tasks in order to create a robust taxonomy for spatial measures and human behavior. The taxonomy is then illustrated with a visual representation that allows for at-a-glance visual access to the content of individual research papers in a corpus. A public web interface has been created that allows interested researchers to add to the database and create visual summaries for their research papers using our taxonomy.

An experimental study on the characteristics of electromagnetic filter

International Nuclear Information System (INIS)

Lee, Geum Yong; Lim, Seung Cheol; Lee, Kun Jai

1993-01-01

The electromagnetic filter has been recognized as a technological replacement for the conventional filtration systems of the nuclear power plant coolant. But, as of now there are neither clear understandings of the phenomena occurring in the electromagnetic filter nor the general theoretical analyses. These facts make the application of the electromagnetic filter to the real systems a little risky, and therfore it has not been commercialized although it shows excellent performances in such situations as the plant abnormality, where the conventional filters usually fail. This experimental study of the low power electromagnetic filter aims at the clarification of the general characteristics under varying operational parameters. Since the detailed characteristics may differ from one electromagnetic filter to another, they are considered secondary. The impurities applied are the highly magnetic magnetite (Fe 3 O 4 ) and the diamagnetic cuprous oxide (Cu 2 O). The empirical equations are derived from the experimental data by the regressional analyses. They are classified of three types : Efficiencies vs. Time, Efficiencies vs. Load, and Load vs. Time. The characteristics of the electromagnetic filter observed in this experiment agreed well with other related works in many aspects. Especially in this study, some assumptions and discussions including the physical deposition are combined for the explanations of the filter characteristics found in our and other experimental works. (Author)

Evaluation of secondary environmental impacts of urban runoff pollution control

International Nuclear Information System (INIS)

Huibregtse, K.R.; Geinopolos, A.

1982-03-01

A generalized evaluation of the impacts associated with different urban stormwater runoff (UR) treatment techniques is presented. It addresses the definition of the problem, estimates the volume and characteristics of the UR and the sludges expected, evaluates six methods of UR sludge treatment, and examines alternatives and impacts for UR treatment sludge handling such as bleed/pump back to the dry weather plant, and land disposal. Regarding bleed/pump back of UR sludges, solids deposition in sewers and overload to the dry weather facilities are anticipated to cause problems. The most cost effective sludge treatment alternative appeared to be lime stabilization followed by thickening, pressure filter dewatering, and landfill disposal. Secondary impacts included costs, water quality, noise, energy consumption, air pollution, and land area requirements

Experiments as to the influence of heat recovery from a bioreactor on sewage sludge disinfecting

Energy Technology Data Exchange (ETDEWEB)

Tarjanyi, J.; Strauch, D.; Philipp, W.

The influence of heat recovery on the disinfecting effect of composting of sewage sludge in a bio-reactor (in-vessel-composting) was investigated in a reactor type Weiss-system Kneer. As test agents 3 different serovars of salmonella, Parvo- and Poliovirus and eggs of Ascaris suum were used. The experiments were done in a reactor which was fed with dewatered municipal sewage sludge mixed with waste-paper as C-carrier for better composting. Even under winter conditions the test agents were inactivated within the time which is characteristic for the passage of the composting material through the plug-flow reactor. These results cannot simply be applied without further investigation to other reactors of the same type but with different ways of operation. (orig.)

Biological characteristics of crucian by quantitative inspection method

Science.gov (United States)

Chu, Mengqi

2015-04-01

Biological characteristics of crucian by quantitative inspection method Through quantitative inspection method , the biological characteristics of crucian was preliminary researched. Crucian , Belongs to Cypriniformes, Cyprinidae, Carassius auratus, is a kind of main plant-eating omnivorous fish,like Gregarious, selection and ranking. Crucian are widely distributed, perennial water all over the country all have production. Determine the indicators of crucian in the experiment, to understand the growth, reproduction situation of crucian in this area . Using the measured data (such as the scale length ,scale size and wheel diameter and so on) and related functional to calculate growth of crucian in any one year.According to the egg shape, color, weight ,etc to determine its maturity, with the mean egg diameter per 20 eggs and the number of eggs per 0.5 grams, to calculate the relative and absolute fecundity of the fish .Measured crucian were female puberty. Based on the relation between the scale diameter and length and the information, linear relationship between crucian scale diameter and length: y=1.530+3.0649. From the data, the fertility and is closely relative to the increase of age. The older, the more mature gonad development. The more amount of eggs. In addition, absolute fecundity increases with the pituitary gland.Through quantitative check crucian bait food intake by the object, reveals the main food, secondary foods, and chance food of crucian ,and understand that crucian degree of be fond of of all kinds of bait organisms.Fish fertility with weight gain, it has the characteristics of species and populations, and at the same tmes influenced by the age of the individual, body length, body weight, environmental conditions (especially the nutrition conditions), and breeding habits, spawning times factors and the size of the egg. After a series of studies of crucian biological character, provide the ecological basis for local crucian's feeding, breeding

Estimation of Anonymous Email Network Characteristics through Statistical Disclosure Attacks

Directory of Open Access Journals (Sweden)

Javier Portela

2016-11-01

Full Text Available Social network analysis aims to obtain relational data from social systems to identify leaders, roles, and communities in order to model profiles or predict a specific behavior in users’ network. Preserving anonymity in social networks is a subject of major concern. Anonymity can be compromised by disclosing senders’ or receivers’ identity, message content, or sender-receiver relationships. Under strongly incomplete information, a statistical disclosure attack is used to estimate the network and node characteristics such as centrality and clustering measures, degree distribution, and small-world-ness. A database of email networks in 29 university faculties is used to study the method. A research on the small-world-ness and Power law characteristics of these email networks is also developed, helping to understand the behavior of small email networks.

Estimation of Anonymous Email Network Characteristics through Statistical Disclosure Attacks

Science.gov (United States)

Portela, Javier; García Villalba, Luis Javier; Silva Trujillo, Alejandra Guadalupe; Sandoval Orozco, Ana Lucila; Kim, Tai-Hoon

2016-01-01

Social network analysis aims to obtain relational data from social systems to identify leaders, roles, and communities in order to model profiles or predict a specific behavior in users’ network. Preserving anonymity in social networks is a subject of major concern. Anonymity can be compromised by disclosing senders’ or receivers’ identity, message content, or sender-receiver relationships. Under strongly incomplete information, a statistical disclosure attack is used to estimate the network and node characteristics such as centrality and clustering measures, degree distribution, and small-world-ness. A database of email networks in 29 university faculties is used to study the method. A research on the small-world-ness and Power law characteristics of these email networks is also developed, helping to understand the behavior of small email networks. PMID:27809275

Understanding sudden environmental and societal change through coupled geochronological and artefact shape analyses

DEFF Research Database (Denmark)

Hoggard, Christian Steven; Sauer, Florian Rudolf; Zernack, Anke Verena

Over the last twenty years, advances in geometric morphometric methodologies have revolutionised how archaeologists understand changes in artefact shape and form (size plus shape) throughout the Quaternary period. Such methodologies provide a high resolution of artefact coverage, and allow...... a critical analysis of previous taxonomic classificatory schemas and human tool-use in the past. Despite this, methodologies into artefact shape through geometric morphometrics have not been integrated within extensive geochronological data to better understand periods of high environmental stress and......, with respect to archaeology, how past societies reacted to such stress. The Laacher See volcanic eruption (c. 13,000 BP) in western Germany is believed, given its hypothesised characteristics, to have had profound impact on the lifeways of hunter-gatherers towards the end of the Final Palaeolithic (Riede, 2017...

Effects of Rainfall Characteristics on the Stability of Tropical Residual Soil Slope

Directory of Open Access Journals (Sweden)

Rahardjo Harianto

2016-01-01

Full Text Available Global climate change has a significant impact on rainfall characteristics, sea water level and groundwater table. Changes in rainfall characteristics may affect stability of slopes and have severe impacts on sustainable urban living. Information on the intensity, frequency and duration of rainfall is often required by geotechnical engineers for performing slope stability analyses. Many seepage analyses are commonly performed using the most extreme rainfall possible which is uneconomical in designing a slope repair or slope failure preventive measure. In this study, the historical rainfall data were analyzed and investigated to understand the characteristics of rainfall in Singapore. The frequency distribution method was used to estimate future rainfall characteristics in Singapore. New intensity-duration-frequency (IDF curves for rainfall in Singapore were developed for six different durations (10, 20, 30 min and 1, 2 and 24 h and six frequencies (2, 5, 10, 25, 50 and 100 years. The new IDF curves were used in the seepage and slope stability analyses to determine the variation of factor of safety of residual soil slopes under different rainfall intensities in Singapore.

Analysis of farm performance in Europe under different climate and management conditions to improve understanding of adaptive capacity

NARCIS (Netherlands)

Reidsma, P.; Ewert, F.; Oude Lansink, A.

2007-01-01

The aim of this paper is to improve understanding of the adaptive capacity of European agriculture to climate change. Extensive data on farm characteristics of individual farms from the Farm Accountancy Data Network (FADN) have been combined with climatic and socio-economic data to analyze the

Planting the SEED : Towards a Spatial Economic Ecological Database for a shared understanding of the Dutch Wadden area

NARCIS (Netherlands)

Daams, Michiel N.; Sijtsma, Frans J.

In this paper we address the characteristics of a publicly accessible Spatial Economic Ecological Database (SEED) and its ability to support a shared understanding among planners and experts of the economy and ecology of the Dutch Wadden area. Theoretical building blocks for a Wadden SEED are

Understanding Cancer Prognosis

Medline Plus

Full Text Available ... Understanding Cancer What Is Cancer? Cancer Statistics Cancer Disparities Understanding Cancer What Is Cancer Cancer Statistics Cancer Disparities Causes & Prevention Risk Factors Genetics Cancer Prevention Overview ...

Enhancing Student’s Understanding in Entrepreneurship Through Business Plan Simulation

Directory of Open Access Journals (Sweden)

Guzairy M.

2018-01-01

Full Text Available Business Plan is an important document for entrepreneurs to guide them managing their business. Business Plan also assist the entrepreneur to strategies their business and manage future growth. That is why Malaysian government has foster all Higher Education Provider to set entrepreneurship education as compulsory course. One of the entrepreneurship education learning outcome is the student can write effective business plan. This study focused on enhancing student’s understanding in entrepreneurship through business plan simulation. This study also considers which of the factor that most facilitate the business simulation that help the student to prepare effective business plan. The methodology of this study using quantitative approach with pre-and post-research design. 114 students take part as respondent in the business simulation and answer quantitative survey pre-question and post question. The crucial findings of this study are student characteristic factor after playing the simulation contribute much on facilitate business plan learning. The result has shown that the business plan simulation can enhance undergraduate student in understanding entrepreneurship by preparing effective business plan before opening new startup.

Role of Pre-Course Student Characteristics on Student Learning in Interactive Teaching Environments

Science.gov (United States)

Miller, Kelly Anne

The goal of this dissertation is to broaden our understanding of interactive teaching strategies, in the context of the introductory physics classroom at the undergraduate level. The dissertation is divided into four main projects, each of which investigates a specific aspect of teaching physics interactively. All four projects look towards improving the effectiveness of interactive teaching by understanding how pre-course student characteristics affect the way students learn interactively. We first discuss lecture demonstrations in the context of an interactive classroom using Peer Instruction. We study the role of predictions in conceptual learning. We examine how students' predictions affect what they report having seen during a demonstration. We also examine how student predictions affect what they recall as the outcome of the demonstration at the end of the semester. We then analyze student response patterns to conceptual questions posed during Peer Instruction. We look at the relationship between a student's tendency to switch their answer and pre-course student characteristics like science self-efficacy. Next we elucidate response timing to conceptual questions posed over the course of the semester, in two introductory physics classes taught using Peer Instruction. We look at the relationship between student response times and student characteristics like pre-course physics knowledge, science self-efficacy and gender. We study response times as a way of gaining insight into students thinking in Peer Instruction environments as well as to improve the implementation of Peer Instruction. Finally, we present work on the role of NB, an online collaborative textbook annotation tool, in a flipped, project based, physics class. We analyze the relationship between students' level of online engagement and traditional learning metrics to understand the effectiveness of NB in the context of flipped classrooms. We also report the results of experiments conducted to

Understanding rational non-adherence to medications. A discrete choice experiment in a community sample in Australia

Directory of Open Access Journals (Sweden)

Laba Tracey-Lea

2012-06-01

Full Text Available Abstract Background In spite of the potential impact upon population health and expenditure, interventions promoting medication adherence have been found to be of moderate effectiveness and cost effectiveness. Understanding the relative influence of factors affecting patient medication adherence decisions and the characteristics of individuals associated with variation in adherence will lead to a better understanding of how future interventions should be designed and targeted. This study aims to explore medication-taking decisions that may underpin intentional medication non-adherence behaviour amongst a community sample and the relative importance of medication specific factors and patient background characteristics contributing to those decisions. Methods A discrete choice experiment conducted through a web-enabled online survey was used to estimate the relative importance of eight medication factors (immediate and long-term medication harms and benefits, cost, regimen, symptom severity, alcohol restrictions on the preference to continue taking a medication. To reflect more closely what usually occurs in practice, non-disease specific medication and health terms were used to mimic decisions across multiple medications and conditions.161 general community participants, matching the national Australian census data (age, gender were recruited through an online panel provider (participation rate: 10% in 2010. Results Six of the eight factors (i.e. immediate and long-term medication harms and benefits, cost, and regimen had a significant influence on medication choice. Patient background characteristics did not improve the model. Respondents with private health insurance appeared less sensitive to cost then those without private health insurance. In general, health outcomes, framed as a side-effect, were found to have a greater influence over adherence than outcomes framed as therapeutic benefits. Conclusions Medication-taking decisions are the

Understanding rational non-adherence to medications. A discrete choice experiment in a community sample in Australia.

Science.gov (United States)

Laba, Tracey-Lea; Brien, Jo-Anne; Jan, Stephen

2012-06-20

In spite of the potential impact upon population health and expenditure, interventions promoting medication adherence have been found to be of moderate effectiveness and cost effectiveness. Understanding the relative influence of factors affecting patient medication adherence decisions and the characteristics of individuals associated with variation in adherence will lead to a better understanding of how future interventions should be designed and targeted. This study aims to explore medication-taking decisions that may underpin intentional medication non-adherence behaviour amongst a community sample and the relative importance of medication specific factors and patient background characteristics contributing to those decisions. A discrete choice experiment conducted through a web-enabled online survey was used to estimate the relative importance of eight medication factors (immediate and long-term medication harms and benefits, cost, regimen, symptom severity, alcohol restrictions) on the preference to continue taking a medication. To reflect more closely what usually occurs in practice, non-disease specific medication and health terms were used to mimic decisions across multiple medications and conditions.161 general community participants, matching the national Australian census data (age, gender) were recruited through an online panel provider (participation rate: 10%) in 2010. Six of the eight factors (i.e. immediate and long-term medication harms and benefits, cost, and regimen) had a significant influence on medication choice. Patient background characteristics did not improve the model. Respondents with private health insurance appeared less sensitive to cost then those without private health insurance. In general, health outcomes, framed as a side-effect, were found to have a greater influence over adherence than outcomes framed as therapeutic benefits. Medication-taking decisions are the subject of rational choices, influenced by the attributes of

The contribution of research on expertise to understanding of expert thinking

Directory of Open Access Journals (Sweden)

Krnjaić Zora

2013-01-01

Full Text Available Expertise is determined based on the high level of mastery of knowledge and skills in different areas of human activities (science, art, sports and other less formal domains. This paper explores the contribution of empirical research on expertise to understanding of the nature of expert thinking. For that purpose we have compiled an overview and performed an analysis of the findings of relevant research on expertise based on different approaches and paradigms. We have included the studies that researched experts singled out based on their exceptional performances in different domains (absolute expertise and the studies based on comparing experts with novices (relative expertise. We have analyzed the studies using different paradigms: psychometric and cognitive paradigms, as well as the new offshoot, the paradigm based on viewing giftedness as developing expertise. Research results provide empirically grounded findings on the characteristics of expert thinking and consistently point to the fact that knowledge is the core of expertise. The characteristics of expert knowledge are operationalized via the quantity and organization of knowledge and the mastery of deep contents and knowledge systems, which enables the recognition of rules, models and information sets, as well as the use of knowledge in further studying, detecting and solving different problems. It can be concluded that research findings on expertise are one of the foundations in the conceptualization of expert thinking. They significantly contribute to obtaining an insight into the way in which knowledge shapes thought and into understanding the mechanisms of demonstrating knowledge in the mental processes of experts.

The Means-End Approach to Understanding Customer Values of a On-Line Newspaper

Directory of Open Access Journals (Sweden)

André Luiz Maranhão de Souza Leão

2007-01-01

Full Text Available Customer value is understood as one of the constructs that best explains consumer decision making. Its proposal is to understand how consumers translate product or service characteristics and consequences of use into personal self-relevant values. The means-end theory is a way of systematically thinking in this hierarchicalrepresentation. The most commonly used method to achieve means-end chains is laddering. This theory and method were used to understand customer values of an important on-line Brazilian newspaper, which is an innovative approach, since on-line laddering is uncommon. The findings indicate that values related to goals of a personal nature are the most important ones. However, other values indicate the increase of the public man pointing to an alternative vision of what is commonly thought of as the contemporary isolated and selfish human. Academic research could benefit from a broader understanding and use of the means-end theory and laddering on the Web. Future research for managerial practices is warranted in areas such as segmentation, satisfaction measuring and customer value reevaluation, in addition to copy tests.

Investigation Characteristics Of Pulp Fibers AS Green Potential Polymer Reinforcing Agents

OpenAIRE

Masruchin, Nanang; Subyakto

2012-01-01

Three kinds of pulp fiber (i.e. kenaf, pineapple and coconut fiber)were characterized as reinforcing agents in compositematerials to be applied at automotive interior industry.Abetter understanding on characteristics of fiber will lead to enhance interface adhesion between fiber and matrices. Furthermore, it will improve the properties of polymer significantly. Chemical, surface compositions as well as morphology of pulp fiber were investigated using TAPPI standard test method, Fourier Transf...

The Correlation Characteristics of Polarization Backscattering Matrix of Dense Chaff Clouds

Directory of Open Access Journals (Sweden)

B. Tang

2018-04-01

Full Text Available This paper studied the correlation characteristics of the polarization backscattering matrix of the dense chaff cloud with uniform orientation and location distributions in circular symmetry region. Based on the theoretical analysis and numerical experiments, the correlation coefficients of the four elements in the polarization backscattering matrix are obtained, and the results indicate that the cross to co-polar correlation coefficient is still zero; and that the sum of the co-polar cross-correlation coefficient and the two times of linear depolarization ratio equals one. The results are beneficial for better understanding of the backscattering characteristics of dense chaff clouds, and are useful in the application of jamming recognition in radar electronic warfare. Numerical experiments are performed by using the method of moments.

The Effect of Personal Characteristics, Perceived Threat, Efficacy and Breast Cancer Anxiety on Breast Cancer Screening Activation

OpenAIRE

De Pelsmacker, Patrick; Lewi, Martine; Cauberghe, Veroline

2017-01-01

Abstract: In order to activate women to participate in breast cancer screening programs, a good understanding is needed of the personal characteristics that influence how women can be activated to search for more information, consult friends and doctors, and participate in breast cancer screening programs. In the current study, we investigate the effect of six personal characteristics that have in previous research been identified as important triggers of health behavior on breast cancer scre...

Understanding childbirth practices as an organizational cultural phenomenon: a conceptual framework.

Science.gov (United States)

Behruzi, Roxana; Hatem, Marie; Goulet, Lise; Fraser, William; Misago, Chizuru

2013-11-11

Understanding the main values and beliefs that might promote humanized birth practices in the specialized hospitals requires articulating the theoretical knowledge of the social and cultural characteristics of the childbirth field and the relations between these and the institution. This paper aims to provide a conceptual framework allowing examination of childbirth practices through the lens of an organizational culture theory. A literature review performed to extrapolate the social and cultural factors contribute to birth practices and the factors likely overlap and mutually reinforce one another, instead of complying with the organizational culture of the birth place. The proposed conceptual framework in this paper examined childbirth patterns as an organizational cultural phenomenon in a highly specialized hospital, in Montreal, Canada. Allaire and Firsirotu's organizational culture theory served as a guide in the development of the framework. We discussed the application of our conceptual model in understanding the influences of organizational culture components in the humanization of birth practices in the highly specialized hospitals and explained how these components configure both the birth practice and women's choice in highly specialized hospitals. The proposed framework can be used as a tool for understanding the barriers and facilitating factors encountered birth practices in specialized hospitals.