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Статті в журналах з теми "Waste paper Grading"
1
Ray, Arpan, Radhikesh Prasad Nanda, and Pronab Roy. "Rutting Performance of Road Using Construction and Demolition Waste Materials." Key Engineering Materials 882 (April 2021): 221–27. http://dx.doi.org/10.4028/www.scientific.net/kem.882.221.
Повний текст джерелаАнотація:
Wastes arising from construction and demolition (C & D) constitute one of the major streams in many countries. In this paper experimental investigation was carried to see the feasibility of C& D waste as road aggregates. From the grading analysis it was observed that using C& D wastes, strength criteria is being satisfied and meet the specifications of MORTH which is then subjected to aggregate impact value (AIV) testing, CBR testing etc. The CBR value of C&D waste was found to be 43.46 which were well above the permissible value. A proposed three-layer system using soil layer, C & D waste layer and asphalt concrete layer is chosen to estimate rut depth using existing analytical model. From the analytical model rut depth is predicted to be 14.77 mm which is less then maximum allowable limits. Hence C& D waste materials can be used as alternate materials in road construction with economy and sustainability.
2
Saimanova, Olga, Svetlana Teplykh, and Vadim Alpatov. "Methods of organizing work on construction and demolition waste recycling." BIO Web of Conferences 43 (2022): 03018. http://dx.doi.org/10.1051/bioconf/20224303018.
Повний текст джерелаАнотація:
The research is aimed at finding new ways that contribute to environmental improvement. It is evident that there is a great need at the moment to find optimal methods of construction and demolition waste recycling while renovating urban areas. The researchers examine the recycling method which is characterized as one of the most effective ways to solve the problem of construction waste disposal. In this paper the authors resort to the method of comparison as well as to graphical, tabular, and abstract-logical methods. They analyze two main methods used to carry out recycling operations: the first method involves recycling waste at the site of construction using mobile crushing plants and the second involves recycling at stationary crushing and grading complexes. Then the authors point out advantages and disadvantages of these methods and examine the efficiency of a stationary complex. The researchers also calculate the prime cost of construction waste processing at a stationary crushing and grading complex and its payback period. It is concluded that the use of a stationary complex for construction and demolition waste recycling is technically and economically feasible.
3
Bolzonella, D., P. Pavan, P. Battistoni, and F. Cecchi. "Anaerobic co-digestion of sludge with other organic wastes and phosphorus reclamation in wastewater treatment plants for biological nutrients removal." Water Science and Technology 53, no. 12 (June 1, 2006): 177–86. http://dx.doi.org/10.2166/wst.2006.420.
Повний текст джерелаАнотація:
This paper deals with the performances obtained in full scale anaerobic digesters co-digesting waste activated sludge from biological nutrients removal wastewater treatment plants, together with different types of organic wastes (solid and liquid). Results showed that the biogas production can be increased from 4,000 to some 18,000 m3 per month when treating some 3–5 tons per day of organic municipal solid waste together with waste activated sludge. On the other hand, the specific biogas production was improved, passing from 0.3 to 0.5 m3 per kgVS fed the reactor, when treating liquid effluents from cheese factories. The addition of the co-substrates gave minimal increases in the organic loading rate while the hydraulic retention time remained constant. Further, the potentiality of the struvite crystallisation process for treating anaerobic supernatant rich in nitrogen and phosphorus was studied: 80% removal of phosphorus was observed in all the tested conditions. In conclusion, a possible layout is proposed for designing or up-grading wastewater treatment plants for biological nutrients removal process.
4
Mohd Pauzi, Nurul Noraziemah, Maslina Jamil, Roszilah Hamid, and Muhammad Fauzi Mohd Zain. "Influence of Morphology of Cathode-Ray Tube Glass as Coarse Aggregates on Compressive Strength and Water Absorption of Concrete." Solid State Phenomena 280 (August 2018): 399–409. http://dx.doi.org/10.4028/www.scientific.net/ssp.280.399.
Повний текст джерелаАнотація:
The study on the substitution for natural coarse aggregates using waste CRT funnel glass in spherically shapes is still limited. In this paper, the waste CRT glass has been processed to form a spherical CRT glass (GS) and crushed CRT glass (GC), which were used as a coarse aggregate in concrete production. Results indicated that the inclusion of GS and GC has lower the compressive strength and decreased the rate of capillary water absorption of concrete. It was demonstrated that the morphology properties of GS and GC (shape, surface texture, size, grading) is significantly affected the concrete properties.
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Zhou, Yingwu, Yitao Weng, Limiao Li, Biao Hu, Xiaoxu Huang, and Zhongfeng Zhu. "Recycled GFRP Aggregate Concrete Considering Aggregate Grading: Compressive Behavior and Stress–Strain Modeling." Polymers 14, no. 3 (January 31, 2022): 581. http://dx.doi.org/10.3390/polym14030581.
Повний текст джерелаАнотація:
Fiber-reinforced polymer (FRP) composites have been used in various industries, thus a large amount of FRP wastes have been generated due to the out-of-service of FRP products. Recycling FRP wastes into coarse aggregates to replace natural coarse aggregates (NCA) to form the recycled FRP aggregate concrete (RFAC) is a potential approach to dispose of huge quantities of FRP wastes with low environmental impact. In this paper, waste glass FRP (GFRP) bars were cut into particles of 12 sizes to enable the grading of recycled FRP aggregate (RFA) as similar as possible to that of NAC. The influence of different RFA volume replacement ratios (0%, 30%, 50%, 70%, 100%) on the compressive performance of RFAC was investigated based on uniaxial compression tests of 15 standard cylinders. The results showed that the failure mode of RFAC was different from that of NAC. As the RFA replacement ratio increased, the compressive strength and elastic modulus of the RFAC gradually decreased, but its post-peak brittleness was significantly mitigated compared to NAC. The Poisson’s ratio of RFAC increased with the increase in the RGFA replacement ratio at the elastic stage and was smaller than that of NCA concrete. Both the existing stress–strain models developed for NAC and recycled aggregate concrete (RAC) were found not fit for the RFAC. Thus, a new stress–strain model that was applicable to RFAC was developed by modifying the classical existing model, and a good agreement between the model predictions and test data was reached.
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Mao, Peng Jun, Lu Liu, Jun Wang, and Chun Yan Hu. "A Study on Gray Relational Analysis of Many Factor Weights in Tobacco Leaves Classification." Advanced Materials Research 139-141 (October 2010): 1728–31. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.1728.
Повний текст джерелаАнотація:
For the nine characteristic factors of tobacco leaf grading standards have different degree of influence on final grading results and lack of objective evaluation method, in this paper, we applied the gray relational analysis method to determine the weight of tobacco leaf factors in every grade, which calculate the gray relational analysis of nine characteristic factors: such as hue, lightness value, chroma, length, leaf structure, waste, oil, maturity and body. The gray relation was normalized to get the weight of the nine factors in tobacco leaf classification. By contrasted with the subjective evaluation of five experts in tobacco field, the calculation results are basically consistent with the experts’ recommendation. It illustrates that the application of Grey relational method to calculate influence ability of flue-cured tobacco grading factors is feasible. This method eliminates the subjectivity of the weight of each factor and can make the results more realistic.
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Gerges, Najib Nicolas, Camille Amine Issa, Samer Ahmad Fawaz, Jacques Jabbour, Johnny Jreige, and Aiman Yacoub. "Recycled Glass Concrete: Coarse and Fine Aggregates." European Journal of Engineering Research and Science 3, no. 1 (January 19, 2018): 1. http://dx.doi.org/10.24018/ejers.2018.3.1.533.
Повний текст джерелаАнотація:
Conventional concrete aggregate consists of sand (fine aggregate) and various sizes and shapes of gravel or stones (coarse aggregate). However, there is a growing interest in substituting alternative aggregate materials, largely as a potential use for recycled materials. While there is significant research on many different materials for aggregate substitutes such as granulated coal ash, blast furnace slag or various solid wastes including fiberglass waste materials, granulated plastics, paper and wood products or wastes, sintered sludge pellets and others. Recycled waste glasses were used as coarse and fine aggregates replacement in concrete. Coarse aggregates were replaced with Green Bottles coarse aggregates at third, half, two thirds, and 100% replacement ratios. The replacement of a third coarse aggregate was established as being the most suitable for retaining the properties of the concrete mix design. As for fine aggregates, in order to account for the numbers of variables and clearly establish a bench mark, the sand grading, color of glass, source of waste glass (bottles and non-bottles), and design mix strength were used as parameters. Fine aggregates from green, brown, and transparent bottles in addition to clear window waste glass were used. Concrete properties were tested in fresh and hardened states. The incorporation of glass sand regardless of the ratios of replacement showed no significant influence on fresh or mechanical properties of concrete except for the case of transparent bottles. Transparent bottles due to the wide source of obtainability have introduced a non-uniform factor that caused discrepancy compared to the rest of the group.
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Gerges, Najib Nicolas, Camille Amine Issa, Samer Ahmad Fawaz, Jacques Jabbour, Johnny Jreige, and Aiman Yacoub. "Recycled Glass Concrete: Coarse and Fine Aggregates." European Journal of Engineering and Technology Research 3, no. 1 (January 19, 2018): 1–9. http://dx.doi.org/10.24018/ejeng.2018.3.1.533.
Повний текст джерелаАнотація:
Conventional concrete aggregate consists of sand (fine aggregate) and various sizes and shapes of gravel or stones (coarse aggregate). However, there is a growing interest in substituting alternative aggregate materials, largely as a potential use for recycled materials. While there is significant research on many different materials for aggregate substitutes such as granulated coal ash, blast furnace slag or various solid wastes including fiberglass waste materials, granulated plastics, paper and wood products or wastes, sintered sludge pellets and others. Recycled waste glasses were used as coarse and fine aggregates replacement in concrete. Coarse aggregates were replaced with Green Bottles coarse aggregates at third, half, two thirds, and 100% replacement ratios. The replacement of a third coarse aggregate was established as being the most suitable for retaining the properties of the concrete mix design. As for fine aggregates, in order to account for the numbers of variables and clearly establish a bench mark, the sand grading, color of glass, source of waste glass (bottles and non-bottles), and design mix strength were used as parameters. Fine aggregates from green, brown, and transparent bottles in addition to clear window waste glass were used. Concrete properties were tested in fresh and hardened states. The incorporation of glass sand regardless of the ratios of replacement showed no significant influence on fresh or mechanical properties of concrete except for the case of transparent bottles. Transparent bottles due to the wide source of obtainability have introduced a non-uniform factor that caused discrepancy compared to the rest of the group.
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Zhou, Wenfei, Huiling Du, Le Kang, Xian Du, Yupu Shi, Xiaojing Qiang, Haodong Li, and Jing Zhao. "Microstructure Evolution and Improved Permeability of Ceramic Waste-Based Bricks." Materials 15, no. 3 (January 31, 2022): 1130. http://dx.doi.org/10.3390/ma15031130.
Повний текст джерелаАнотація:
The resource and large-scale utilization of waste ceramic materials, magnesium slag, and coal gangue are one of the important ways for the sustainable development in metallurgy, coal, and other related enterprises. In this paper, waste ceramic materials were used as aggregates; coal gangue and magnesium slag were used as mixed binder; and the all solid-waste-based permeable bricks with excellent performance were prepared by forming pressure at 5 MPa. The mechanical properties and water permeability of the all-solid-waste-based permeable bricks were evaluated. The results proved that the porous channel of permeable brick is mainly composed of waste ceramic materials with a particle size of 2–3 mm. Pore structures below 200 μm were mainly composed of fine aggregate and mixed binder. Using 60% coarse aggregate, 20% fine aggregate, 10% coal gangue, and 10% magnesium slag as raw materials, the all-solid-waste-based permeable bricks were obtained by pressing at 6 MPa and sintering at 1200 °C, which exhibited the best performance, and its water permeability, compressive strength, and apparent porosity were 1.56 × 10−2 cm/s, 35.45 MPa, and 13.15%, respectively. Excellent water permeability, compressive strength, and apparent porosity of the all solid-waste-based permeable bricks were ascribed to the high content of connecting open pores, and closely adhesive force were ascribed to the porous microstructure constructed by the grading of waste ceramic materials and the tight conjoined points of the liquid phases in coal gangue and magnesium slag at a high sintering temperature.
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Wang, Yong Yi, and Lin Li. "Environment Pollution and Control Strategy for Exploitation of Asbestos Mine." Advanced Materials Research 726-731 (August 2013): 1845–49. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.1845.
Повний текст джерелаАнотація:
To control environment pollution by exploitation of asbestos mine and forming of tailing pond effectively and provide decision-making basis to competent authorities, the paper analyzed the causes for asbestos powder pollution in course of exploitation of asbestos mine and tailing pond of asbestos through field investigation and research. Slow exploitation and grading process of asbestos mine and shortage of management were the root causes for environment pollution by asbestos, and the tailing pond of asbestos resulted in resources waste and pollution of the atmosphere, water and land. The government should regulate in terms policy, industrial planning etc. offer economic support, change the backward exploitation process, perform comprehensive resources utilization and utilize asbestos properly.
Тези доповідей конференцій з теми "Waste paper Grading"
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Joshy, Hanna C., Mansoor Ali K, Rameez Z, Sarath S, and Ramaswamy K. P. "A Suitability Study of Using Crushed Fluorescent Lamp Waste as Fine Aggregates." In International Web Conference in Civil Engineering for a Sustainable Planet. AIJR Publisher, 2021. http://dx.doi.org/10.21467/proceedings.112.42.
Повний текст джерелаАнотація:
Fluorescent lamp wastes are one of the discarded electrical devices. These lamp wastes pose serious health concerns, and require extreme care in its disposal to avoid any adverse impacts. Also, with the widespread use of energy efficient LED lamps for lighting purposes, environmental concerns related to disposal of used mercury containing fluorescent lamps have become progressively important. This paper explores the possibility of replacement of fine aggregates in mortar with different proportions of fluorescent lamp wastes in order to find the optimum percentage of replacement to get better properties. Fluorescent lamp wastes were collected and crushed to the grading of fine aggregates. Compressive strength and bulk density of mortar cubes with 0%, 25%, 50%, 75% and 100% replacement of fine aggregates with fluorescent lamp wastes were evaluated after 7 days of initial curing. The compressive strength and bulk density of mortar was found to be decreasing with increasing percentage of lamp waste added. The replacement of fine aggregate by 25% lamp waste has greater strength compared to other proportions. Bulk density was found to be lesser at higher replacement levels and can be tried in producing light weight mortar. The utilization of lamp waste in mortar/concrete is a noble attempt in reducing the negative impact of lamp wastes on the environment
2
Bond, Alex, George Towler, Alan Paulley, and Simon Norris. "Implementation of a Geological Disposal Facility (GDF) in the UK by the NDA Radioactive Waste Management Directorate (RWMD): Coupled Modelling of Gas Generation and Multiphase Flow Between the Co-Located ILW/LLW and HLW/SF Components of a GDF." In ASME 2009 12th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2009. http://dx.doi.org/10.1115/icem2009-16307.
Повний текст джерелаАнотація:
In June 2008 the UK government published a ‘White Paper’ as part of the “Managing Radioactive Waste Safety” (MRWS) programme to provide a framework for managing higher activity radioactive wastes in the long-term through geological disposal. The White Paper identifies that there are benefits to disposing all of the UK’s higher activity wastes (Low and Intermediate Level Waste (LLW and ILW), High Level Waste (HLW), Spent Fuel (SF), Uranium (U) and Plutonium (Pu)) at the same site, and this is currently the preferred option. It also notes that research will be required to support the detailed design and safety assessment in relation to any potentially detrimental interactions between the different modules. Different disposal system designs and associated Engineered Barrier Systems (EBS) will be required for these different waste types, i.e. ILW/LLW and HLW/SF. If declared as waste U would be disposed as ILW and Pu as HLW/SF. The Geological Disposal Facility (GDF) would therefore comprise two co-located modules (respectively for ILW/LLW and HLW/SF). A study has recently been undertaken by NDA RWMD to identify the key Thermo-Hydro-Mechanical-Chemical (THMC) interactions which might occur during both the operational and post-closure phases in order to assess the potential implications of co-location in a range of host rocks. This paper presents supporting modelling work used to help understand the potential interactions between the modules. A multi-phase flow and coupled gas generation model was used to help investigate the potential groundwater and gas fluxes between the modules, in particular considering the operational phase and resaturation behaviour of the different modules. These early phases are important because gas generation rates and hydraulic gradients will be at their maximum, and the pressure gradients associated with GDF operations will, at least initially, dominate over the background hydraulic gradient. The gas generation and multi-phase flow study considered a mudstone host rock in which gas pressurisation might significantly influence resaturation behaviour, or drive water from one module to the other. The results of the multiphase flow modelling show that although gas generation affects pressure recovery in the ILW/LLW module, the smaller size of the HLW/SF excavations compared with the ILW/LLW excavations, and the operational timings, mean that in general the groundwater pressure gradient in the GDF is from the HLW/SF module (higher pressure) to the ILW module (lower pressure). Transport of solutes from the HLW/SF module towards the ILW module is not expected to result in any deleterious interactions, indicating that hydraulic interactions during the resaturation period are unlikely to pose a fundamental barrier to co-location.
3
Lee, Shang-Hsiu, and Marco J. Castaldi. "High Temperature Corrosion Resistance of Different Commercial Alloys Under Various Corrosive Environments." In 15th Annual North American Waste-to-Energy Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/nawtec15-3220.
Повний текст джерелаАнотація:
High temperature corrosion is a major operating problem because it results in unscheduled shutdowns in Waste-to-Energy (WTE) plants and accounts for a significant fraction of the total operating cost of WTE plants. Due to the heterogeneous nature of municipal solid waste (MSW) fuel and the presence of aggressive elements such as sulfur and chlorine, WTE plants have higher corrosion rates than coal-fired power plants which operate at higher temperature. To reduce corrosion rates while maximizing the heat recovery efficiency has long been a critical task for WTE operators. Past researchers focused on high temperature corrosion mechanisms and have identified important factors which affect the corrosion rate [1–4]. Also, there have been many laboratory tests seeking to classify the effects of these corrosion factors. However, many tests were performed under isothermal conditions where temperatures of flue gas and metal surface were the same and did not incorporate the synergistic effect of the thermal gradient between environment (flue gas) and metal surface. This paper presents a corrosion resistance test using an apparatus that can maintain a well controlled thermal gradient between the environment and the surface of the metals tested for corrosion resistance. Two commercial substrates (steels SA213-T11 and NSSER-4) were tested under different corrosive environments. The post-test investigation consisted of mass loss measurement of tested coupons, observation of cross-sectional morphology by scanning electron microscopy (SEM), and elemental analysis of corrosion products by energy dispersive spectrometry (EDS). The stainless steel NSSER-4 showed good corrosion resistance within the metal temperature range of 500 °C to 630 °C. The alloy steel SA213-T11 had an acceptable corrosion resistance at metal temperatures up to 540 °C, and the performance decreased dramatically at higher temperatures.
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Lee, Soochan, Nishant Singh, Patrick E. Phelan, and Carole-Jean Wu. "Harvesting CPU Waste Heat Through Pyroelectric Materials." In ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ipack2015-48421.
Повний текст джерелаАнотація:
Modern CPUs generate considerable wasted heat due to increased power dissipation from high-performance computation. Lots of research effort has extensively focused on using thermoelectric generators (TEGs) to harvest CPU waste heat to increase overall system energy efficiency. To harvest waste heat using TEGs requires a significant temperature differential between the processor as a heat source and the heat spreader/heat sink, as well as a high heat flow. However, the heat-to-electricity conversion efficiency is typically limited to 15 to 20 percent, due to large heat conductivity, low Seebeck coefficient, and low figure of merit of TEGs. In addition, TEGs on a CPU could significantly increase CPU junction temperature compared to the baseline CPU temperature due to its high thermal resistance. Contrary to using TEGs to harvest waste heat from a fixed, spatial temperature differential, this paper presents an approach to harvest CPU waste heat using pyroelectric (PE) materials from the time-varying, temporal temperature differential that is common in current processors. PE materials can generate electricity when subjected to a temporal temperature gradient. The operation of PE materials is distinctly different from TEGs and they have the following advantages. First, the theoretical efficiency is up to 50% using thin films. Second, the overall optimization of PE material is easier than thermoelectric material, since the conversion ratio, the ratio of net harvested energy divided by the heat taken from the hot reservoir, of PE material is independent of the material properties, whereas that of TEG is highly dependent on material properties. Although PE material is also a long-researched energy harvesting material, it is less explored by researchers compared to TEG in the application domain of processor waste heat management. In this paper, we review current PE materials in terms of pyroelectric coefficient and thermal conductivity, and also investigate the harvested power generation from CPU waste heat in a modern computing system.
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Brossard, Jean-Michel, Florimonde Lebel, Christophe Rapin, Jean-Franc¸ois Mareˆche´, Xavier Chaucherie, Franc¸ois Nicol, and Michel Vilasi. "Lab-Scale Study on Fireside Superheaters Corrosion in MSWI Plants." In 17th Annual North American Waste-to-Energy Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/nawtec17-2339.
Повний текст джерелаАнотація:
Combustion of the municipal waste generates highly corrosive gases (HCl, SO2, NaCl, KCl and heavy metals chlorides) and ashes containing alkaline chlorides and sulphates. Currently, corrosion phenomena are particularly observed on superheater’s tubes. Corrosion rates depend mainly on installation design, operating conditions i.e. gas and steam temperature and velocity of the flue gas containing ashes. This paper presents the results obtained using an innovative laboratory-scale corrosion pilot, which simulates MSWI boilers conditions characterized by a temperature gradient at metal tube on the presence of corrosive gases and ashes. The presented corrosion tests were realized on carbon steel at fixed metal temperature (400°C). The influence of the flue gas temperature, synthetic ashes composition and flue gas flow pattern were investigated. After corrosion test, cross section of tube samples were characterised to evaluate thickness loss and estimate corrosion rate while the elements present in corrosion layers were analysed. Corrosion tests were carried out twice in order to validate the accuracy and reproducibility of results. First results highlight the key role of molten phase related to the ash composition and flue gas temperature as well as the deposit morphology, related to the flue gas flow pattern, on the mechanisms and corrosion rates.
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Hamdan, Lubna K., John C. Walton, and Arturo Woocay. "Effect of the Residual Heat Release of the Nuclear Waste Stored in an Unsaturated Zone on Radionuclide Release." In ASME 2010 13th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2010. http://dx.doi.org/10.1115/icem2010-40196.
Повний текст джерелаАнотація:
Over time, nuclear waste packages disposed in geological repositories are expected to fail gradually due to localized and general corrosion. As a result, water will have access to the nuclear waste and radionuclides will be transported to the accessible environment by ground water. In this paper we consider a serious failure case in which penetrations at the top and bottom of the waste package will allow water to flow through it (flow-through model). We introduce a new conceptual model that examines the effect of the residual heat release of the nuclear waste stored in an unsaturated environment on radionuclide release. This model predicts that the evaporation of water at the hotter sheltered areas (from condensate and seepage) inside the failed waste package will create a capillary pressure gradient that drives water to wick with its dissolved and suspended contents toward these relict areas, effectively preventing radionuclides release. We drive a dimensionless group to estimate the minimum length of the sheltered areas required to sequester radionuclides and prevent their release. The implications of this model on the performance of the proposed repository at Yucca Mountain or unsaturated zone geological repositories in general are explored.
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Woerner, Joerg, Sonja Margraf, and Walter Hackel. "Remediation of a Uranium-Contamination in Ground Water." In The 11th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2007. http://dx.doi.org/10.1115/icem2007-7270.
Повний текст джерелаАнотація:
The former production site of NUKEM where nuclear fuel-elements were developed and handled from 1958 to 1988 was situated in the centre of an industrial park for various activities of the chemical and metallurgical industry. The size of the industrially used part is about 300.000m2. Regulatory routine controls showed elevated CHC (Chlorinated Hydro-Carbons) values of the ground water at the beginning of the 1990’s in an area which represented about 80.000 m2 down-gradient of locations where CHC compounds were stored and handled. Further investigations until 1998 proved that former activities on the NUKEM site, like the UF6 conversion process, were of certain relevance. The fact that several measured values were above the threshold values made the remediation of the ground water mandatory. This was addressed in the permission given by the Ministry for Nuclear Installations and Environment of Hesse according to §7 of the German atomic law in October 2000 [1]. Ground water samples taken in an area of about 5.000 m2 showed elevated values of total Uranium activity up to between 50 and 75 Bq/l in 2002. Furthermore in an area of another 20.000m2 the samples were above threshold value. In this paper results of the remediation are presented. The actual alpha-activities of the ground waters of the remediation wells show values of 3 to 9Bq/l which are dominated by 80 to 90% U-234 activity. The mass-share of total Uranium for this nuclide amounts to 0,05% on average. The authority responsible for conventional water utilisation defined target values for remediation: 20μg/l for dissolved Uranium and 10μg/l for CHC [2]. Both values have not yet been reached for an area of about 10.000 m2. The remediation process by extracting water from four remediation wells has proved its efficiency by reduction of the starting concentrations by a factor of 3 to 6. Further pumping will be necessary especially in that area of the site where the contaminations were found later during soil remediation activities. Only two wells have been in operation since July 2002 when the remediation technique was installed and an apparatus for direct gamma-spectroscopic measurement of the accumulated activities on the adsorbers was qualified. Two further remediation wells have been in operation since August 2006, when the installed remediation technique was about to be doubled from a throughput of 5 m3/h to 10 m3/h. About 20.000 m3 of ground water have been extracted since from these two wells and the decrease of their Uranium-concentrations behaves similar to that of the two other wells being extracted since the beginning of remediation. Both, total Uranium-concentrations and the weight-share of the nuclides U-234, U-235 and U-238 are measured by ICP-MS (Inductively Coupled Plasma – Mass Spectrometry) besides measurements of Uranium-Alpha-Activities in addition to the measurement of CHC components of which PCE (Perchlor-Ethene) is dominant in the contaminated area. CHC compounds are measured by GC (Gas Chromatography). Down-gradient naturally attenuated products are detected in various compositions. Overall 183.000m3 of ground water have been extracted. Using a pump & treat method 11 kg Uranium have been collected on an ion-exchange material based on cellulose, containing almost 100 MBq U-235 activity, and almost 15 kg of CHC, essentially PCE, were collected on GAC (Granules of Activated Carbon). Less than 3% of the extracted Uranium have passed the adsorber-system of the remediation plant and were adsorbed by the sewage sludge of the industrial site’s waste water treatment. The monthly monitoring of 19 monitoring wells shows that an efficient artificial barrier was built up by the water extraction. The Uranium contamination of two ground water plumes has drastically been reduced by the used technique dependent on the amounts of extracted water. The concentration of the CHC contamination has changed depending on the location of temporal pumping. Thereby maximum availability of this contaminant for the remediation process is ensured. If locations with unchanged water quality are detected electrochemical parameters of the water or hydro-geologic data of the aquifer have to be taken into further consideration to improve the process of remediation.
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Ozeh, Michael, and A. G. Agwu Nnanna. "Waste Heat Recovery for Powering Mobile Devices Using Thermoelectric Generators and Evaporatively-Cooled Heat Sink." In ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/ipack2018-8354.
Повний текст джерелаАнотація:
Powering small electronics like mobile devices off-grid has remained a challenge; hence, there exists a need for an alternate source of powering these devices. This paper examines the efficacy of a novel nanoparticle-immobilized polyethylene wick in maintaining sufficient thermal gradient across a thermoelectric generator to power these devices with energy from waste heat. The work examines several other heat exchangers including heat pipes and loop heat pipe setups. The experimental evidence reveals that the nanoparticle-immobilized polyethylene wick is capable of generating sufficient thermal potential resulting in 5V, which is the minimum voltage required to power small mobile devices. In the opinion of the authors, this is the first ever recorded account of utilizing waste heat to generate enough voltage to power a mobile device. Experiment demonstrated that the nanoparticle-immobilized polyethylene wick showed over 40% thermoelectric voltage generation increment over a plain polyethylene wick and a metal wick in a loop heat pipe setup.
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Watson, J. H. P., D. C. Ellwood, and R. G. Lidzey. "Removal of Actinides and Other Radioactive Metal Ions From Water Systems." In ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4909.
Повний текст джерелаАнотація:
In previous work the adsorption of a number of radioactive ions from solution by a strongly-magnetic iron sulfide material has been studied. The material was produced by sulfate-reducing bacteria in a novel bioreactor. The uptake is rapid and the loading on the adsorbent is high due to the high surface area of the adsorbent and because many of the ions are chemisorbed. Following the success of the biologically-generated material, Lidzey at Bio Separation Ltd was able to produce an iron sulfide material; studies at the University of Southampton reveal that it has the tochilinite structure which has similar adsorption properties for cations, but not anions, as the biologically-generated material but the Lidzey material is considerably cheaper to produce. Tochilinite is a layered metal hydroxide/sulfide composite. The composition of tochilinite ranges around 2Fe1-xS. {1.7Fe(OH)2}. In nature, these materials also have Mg0.7Al 0.3 replacing Fe in the hydroxide layer. By also precipitating magnetite, Fe3O4, together with the tochilinite Lidzey has made the adsorbent strongly magnetic. This paper presents individual results on the adsorption of 137Cs, 59Fe, 60Co, 106Ru, 110mAg, 51Cr, 54Mn, 203Hg, 109Cd, 90Sr, 239Pu and 241Am. Using 0.5g.l−l of the adsorbent the reduced the activity in solutions from 1190 Bq.ml−1 to <530 Bq.ml−1 after 1 h and to 340 Bq.ml−1 after 24 h. with 51Cr and 203Hg being responsible for 270 Bq.ml−1 of the total. For the decontamination of water streams containing dissolved radioactive isotopes the method proposed is to add the adsorbent and after a suitable residence time to extract the contaminated adsorbent using high gradient magnetic separation. In this method a slurry containing the particles to be separated are passed through a matrix of fine ferromagnetic wires magnetised to magnetic saturation by an externally applied magnetic field usually 5 Tesla. The particles to be separated are captured on the matrix, the decontaminated liquid passing through. The matrix is removed from the field and at the same time a clean matrix is inserted. The captured material recovered outside the magnetic field as a thick slurry and he cycle is repeated. These magnetic separation systems are in use throughout the world and will process up to 500m3.h−1.
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Sauret, Emilie, Kamel Hooman, and Suvash C. Saha. "CFD Simulations of Flow and Heat Transfer Through the Porous Interface of a Metal Foam Heat Exchanger." In ASME 2014 Power Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/power2014-32157.
Повний текст джерелаАнотація:
This paper offers numerical modelling of a waste heat recovery system. A thin layer of metal foam is attached to a cold plate to absorb heat from hot gases leaving the system. The heat transferred from the exhaust gas is then transferred to a cold liquid flowing in a secondary loop. Two different foam PPI (Pores Per Inch) values are examined over a range of fluid velocities. Numerical results are then compared to both experimental data and theoretical results available in the literature. Challenges in getting the simulation results to match those of the experiments are addressed and discussed in detail. In particular, interface boundary conditions specified between a porous layer and a fluid layer are investigated. While physically one expects much lower fluid velocity in the pores compared to that of free flow, capturing this sharp gradient at the interface can add to the difficulties of numerical simulation. The existing models in the literature are modified by considering the pressure gradient inside and outside the foam. Comparisons against the numerical modelling are presented. Finally, based on experimentally-validated numerical results, thermo-hydraulic performance of foam heat exchangers as waste heat recovery units is discussed with the main goal of reducing the excess pressure drop and maximising the amount of heat that can be recovered from the hot gas stream.