Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with ...Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with minimal noise and distortion that are generally acceptable to the human visual system, thereby reducing rendering costs. In this paper, we introduce a perception-entropy-driven temporal reusing method to accelerate real-time ray tracing. We first build a just noticeable difference(JND) model to represent the uncertainty of ray samples and image space masking effects. Then, we expand the shading gradient through gradient max-pooling and gradient filtering to enlarge the visual receipt field. Finally, we dynamically optimize reusable time segments to improve the accuracy of temporal reusing. Compared with Monte Carlo ray tracing, our algorithm enhances frames per second(fps) by 1.93× to 2.96× at 8 to 16 samples per pixel, significantly accelerating the Monte Carlo ray tracing process while maintaining visual quality.展开更多
The paper presents an innovative approach to studying the reuse of a decommissioned natural gas production platformfor the seasonal storage and extraction of a hydrogen-methane(H2-CH4)mixture froma depleted reservoir....The paper presents an innovative approach to studying the reuse of a decommissioned natural gas production platformfor the seasonal storage and extraction of a hydrogen-methane(H2-CH4)mixture froma depleted reservoir.The reuse plan involves removing outdated equipment from the platform’s decks while retaining essential components such as wellheads and separators.Exploiting a depleted reservoir for the injection of an H_(2)-CH_(4) mixture requires a thorough understanding of its specific characteristics.This paper focuses on the engineering approach adopted in the basic design phase for such a conversion,providing recommendations and HSE guidelines.Given the hazardous nature of substances like hydrogen in the gas mixture,the paper also examines potential risk scenarios,particularly those involving containment loss.A qualitative and quantitative assessment of these risks is conducted to evaluate their impact on the structure and equipment.The results of this assessment serve as a foundation for later studies on layout optimization and domino effect prevention.Additionally,some critical scenarios are simulated using an innovative approach known as the Source Box Accident Model(SBAM),which was proposed in previous works.SBAM leverages Computational Fluid Dynamics(CFD)but decouples the accidental phenomenon into a release phase and a dispersion phase.This method overcomes the challenges conventional CFD tools face in assessing congested plant configurations,providing more precise estimations of gas cloud behavior.The simulation results indicate that the released gas remains within the platform deck domain,and the flammable cloud is significantly smaller than what traditional,simplified tools predict.展开更多
Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand, "dry reusing and wet reclaiming of used sodium silicate sand" is considered as the most suitabl...Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand, "dry reusing and wet reclaiming of used sodium silicate sand" is considered as the most suitable technique for the used sand. When the recycled sand is used as support sand, the used sand is only reused by dry process including breaking, screening, dust-removal, etc., and it is not necessary that the used sand is reclaimed with strongly rubbing and scraping method, but when the recycled sand is used as facing sand (or single sand), the used sand must be reclaimed by wet method for higher removal rate of the residual binders. The characteristics and the properties of the dry reused sand are compared with the wet reclaimed sand after combining the different use requirements of support sand and facing sand (or single sand), and above the most adaptive scheme has also been validated.展开更多
To increase the convergence rate of the improved normalized subband adaptive filter,a simple but effective method is presented to change the reusing order of coefficient vectors of the adaptive filter. At the beginnin...To increase the convergence rate of the improved normalized subband adaptive filter,a simple but effective method is presented to change the reusing order of coefficient vectors of the adaptive filter. At the beginning of adaptation the algorithmjust uses its current coefficient vector to update the adaptive filter to maintain fast convergence rate,while in steady state it employs several most recent coefficient vectors to update the adaptive filter to reduce misalignment. Simulation results showthat the proposed algorithmcan obtain both fast convergence rate and small steady-state misalignment.展开更多
The demand for alternative cementitious materials is on the rise,as the cement causes huge energy consumption and produces greenhouse gas emission.Additionally,there is economic potential for the construction industry...The demand for alternative cementitious materials is on the rise,as the cement causes huge energy consumption and produces greenhouse gas emission.Additionally,there is economic potential for the construction industry to reuse wastes as supplementary building materials.The purpose of this study is to evaluate the potential of utilizing ferrochrome slag wastes in mortar as supplementary cementitious materials (SCMs),thereby achieving this double-sided goal.Thus,the mechanical and physical properties of ferrochrome slag wastes were investigated to be used as admixtures in concrete production.Three different cement mortar specimens were prepared by replacing cement with ferrochrome slag in ratios of 0,30%,and 60% by mass and flexural and compressive strengths of the specimens were determined at the ages of 7,28,56,90,and 180 days.Also,the effects of the ferrochrome slag replacement ratio on workability,setting time and volume expansion were revealed.Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were also investigated to study the microstructural properties of the specimens containing ferrochrome slag.Based on the results,it is concluded that ferrochrome slag wastes have pozzolanic activity,therefore reusing them as SCMs in the cement and concrete industry is convenient.展开更多
The current work seeks firstly the integration of a rainwater reuse system that will be of use in the watering of the green spaces, and secondly the re-use of purified water in the irrigation of agriculture spaces, wh...The current work seeks firstly the integration of a rainwater reuse system that will be of use in the watering of the green spaces, and secondly the re-use of purified water in the irrigation of agriculture spaces, which are in the nearby of wastewater treatment plant. The results show that 41% of the green spaces in the city of Fez require a renovation and installation of adequate watering systems taking into account the specificity of the city which is crossed by several rivers badly exploited for watering. The purified wastewater is of much better quality than the Moroccan reuse standards and is discharged with a flow that is large enough for the irrigation water requirements of the fields close to wastewater treatment plant.展开更多
Reusing test cases from existing test case library is quite common in the software testing field. Testing practice tells us that there is a strong relationship between the granularity of a function unit under testing ...Reusing test cases from existing test case library is quite common in the software testing field. Testing practice tells us that there is a strong relationship between the granularity of a function unit under testing and that of the test case. A function unit with small granularity usually results in the test cases with the same small granularity. Therefore a test case defined as the function point,i. e.,the smallest size function unit,was provided for the first time.Though test cases with smaller granularity usually have better reusability,the cost of accurately reusing and integrating such test cases is also higher. In order to balance the test case reusability and the cost of test case reuse,a novel test case reuse model based on the function point was proposed in this paper. In this model,a reusable test case for specification-based testing was defined and some reuse strategies and three formal reuse methods were given. Finally,the complete automatic software process was realized by a reusing generation tool. The new method has improved reuse accuracy,while greatly enhances the software productivity.展开更多
Footwear industries generate leather waste during the operation.Some of these wastes contain chromium,which may bring environmental concerns.This study aimed to reuse finished leather waste,the major part of these haz...Footwear industries generate leather waste during the operation.Some of these wastes contain chromium,which may bring environmental concerns.This study aimed to reuse finished leather waste,the major part of these hazard-ous wastes,via producing a composite with thermoplastic polyurethane(TPU)for shoe soles.Finished leather waste containing black dyes and pigments was used to color the TPU.The finished leather waste was fragmented,milled,micronized and blended with TPU in a ratio of 10%,15%,and 20%w/w to produce composite materials.The compos-ite materials were evaluated by morphological and thermal characterizations,physical-mechanical analysis,and envi-ronmental tests(leaching and solubilization),which presented that the physical-mechanical and thermal properties were within the standard of shoe soles,and the composites can be classified as non-hazardous.The composites enabled a new way of coloring polymeric matrices and reusing leather waste.展开更多
A low power fast settling multi-standard CMOS fractional-N frequency synthesizer is proposed. The current reusing and frequency presetting techniques are adopted to realize the low power fast settling multi-standard f...A low power fast settling multi-standard CMOS fractional-N frequency synthesizer is proposed. The current reusing and frequency presetting techniques are adopted to realize the low power fast settling multi-standard fractional-N frequency synthesizer. An auxiliary non-volatile memory （NVM） is embedded to avoid the repetitive calibration process and to save power in practical application. This PLL is implemented in a 0.18 #m technology. The frequency range is 0.3 to 2.54 GHz and the settling time is less than 5 #s over the entire frequency range. The LC-VCO with the stacked divide-by-2 has a good figure of merit of-193.5 dBc/Hz. The measured phase noise of frequency synthesizer is about -115 dBc/Hz at 1 MHz offset when the carrier frequency is 2.4 GHz and the reference spurs are less than -52 dBc. The whole frequency synthesizer consumes only 4.35 mA @ 1.8 V.展开更多
The protective remolding and reusing of industrial historic buildings and sites is regarded as a great scientific matter in today's urban development. Based on discussing its significance and value,this paper,taki...The protective remolding and reusing of industrial historic buildings and sites is regarded as a great scientific matter in today's urban development. Based on discussing its significance and value,this paper,taking a specific example,makes a systematic discussion on the design strategy and method from the aspects of overall planning,remolding the old buildings,designing the new buildings,etc.展开更多
Reconfigurable computing systems can be reconfigured at runtime and support partial reconfigurability which makes us able to execute tasks in a true multitasking manner. To manage such systems at runtime, a reconfigur...Reconfigurable computing systems can be reconfigured at runtime and support partial reconfigurability which makes us able to execute tasks in a true multitasking manner. To manage such systems at runtime, a reconfigurable operating system is needed. The main part of this operating system is resource management unit which performs on-line scheduling and placement of hardware tasks at runtime. Reconfiguration overhead is an important obstacle that limits the performance of on-line scheduling algorithms in reconfigurable computing systems and increases the overall execution time. Configuration reusing （task reusing） can decrease reconfiguration overhead considerably, particularly in periodic applications or the applications in which the probability of tasks recurrence is high. In this paper, we present a technique called reusing-based scheduling （RBS）, for on-line scheduling and placement in which configuration reusing is considered as a main characteristic in order to reduce reconfiguration overhead and decrease total execution time of the tasks. Several experiments have been conducted on the proposed algorithm. Obtained results show considerable improvement in overall execution time of the tasks.展开更多
Flotation is the most common method to recover valuable minerals by selective adsorption of collectors on target mineral surfaces.However,in subsequent hydrometallurgy of mineral flotation concentrates,the adsorbed co...Flotation is the most common method to recover valuable minerals by selective adsorption of collectors on target mineral surfaces.However,in subsequent hydrometallurgy of mineral flotation concentrates,the adsorbed collectors must be desorbed since it can adversely affect the efficiency of metallurgical process and produce wastewater.ZL,as a fatty acid mixture,is a typical industrially used collector for scheelite flotation in China.Sodium oleate(NaOL)has similar fatty acid group as ZL.In this study,the desorption behavior of NaOL/ZL from scheelite surface by a physical method of stirring at a low temperature was investigated.NaOL desorption tests of single mineral showed that a desorption rate of 77.75% for NaOL from scheelite surface into pulp was achieved in a stirring speed of2500 r/min at 5℃in a neutral environment.Under the above desorption condition,in the pulp containing desorbed collector by adding extra 30% normal NaOL dosage,the scheelite recovery reached about 95% in the single mineral flotation test.Desorption and reuse of ZL collector for the flotation of real scheelite ore showed only a 75%normal dosage of ZL could produce a qualified rough concentrate.The atomic force microscope(AFM)tests showed that after desorption treatment of low temperature and strong stirring,the dense strip-like structure of NaOL on the scheelite surface was destroyed to be speck-like.Molecular dynamics simulations(MDS)demonstrated that the adsorption energy between NaOL and scheelite surface was more negative at 25℃(-13.39 kcal/mol)than at 5℃(-11.50 kcal/mol)in a neutral pH,indicating that a low temperature was beneficial for the desorption of collector from mineral surface.Due to its simplicity and economy,the method we proposed of desorption of collector from mineral surface and its reuse for flotation has a great potential for industrial application.展开更多
Fipronil is an insecticide with low residual activity and high efficacy at low concentrations.Due to its widespread use and long half-life,fipronil can persist during wastewater treatment and is found even in surface ...Fipronil is an insecticide with low residual activity and high efficacy at low concentrations.Due to its widespread use and long half-life,fipronil can persist during wastewater treatment and is found even in surface waters.When released into the environment,it can accumulate over time and can lead to concentrations in soil and plant tissues that are harmful to both target and non-target organisms.As the reuse of treated wastewater and sewage sludge presents challenges and opportunities for farmers,this study investigates the effects of irrigation with environmentally relevant doses of fipronil on zucchini plants and their main insect pest,Aphis gossypii.Traces of fipronil were found in the zucchini leaves,but not in the flowers,after 35-days of cumulative exposure.A decrease in nymph-to-adult survival and a dose-dependent reduction in the fecundity of A.gossypii feeding on contaminated host plants was observed.Also,aphids feeding on contaminated host plants exhibited the same mortality rate as the control group when exposed to an acute dose of fipronil.However,when natural pyrethrins were used,there was a significant increase in resistance to this insecticide.Our results demonstrate the potential for fipronil to accumulate in plant tissues and highlight the risk of changes in insecticide susceptibility in insect pests.This suggests a need for a holistic approach to the complex dynamics of wastewater reuse in agriculture.展开更多
Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficult...Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficulties associated with managing SSW sludge.This study comprehensively evaluated the water quality of SSW by comparing it to a well-documented wastewater(filter backwash water(FBW)).Furthermore,it investigated the pollutant variations in the SSW during pre-sedimentation process,probed the underlying reaction mechanism,and explored the feasibility of employing a pilot-scale coagulation-sedimentation process for SSW treatment.The levels of most water quality parameters were generally comparable between SSW and FBW.During the pre-sedimentation of SSW,significant removal of turbidity,bacterial counts,and dissolved organic matter(DOM)was observed.The characterization of DOM components,molecular weight distributions,and optical properties revealed that the macromolecular proteinaceous biopolymers and humic acids were preferentially removed.The characterization of particulates indicated that high surface energy,zeta potential,and bridging/adsorption/sedimentation/coagulation capacities in aluminum residuals of SSW,underscoring its potential as a coagulant and promoting the generation and sedimentation of inorganic-organic complexes.The coagulation-sedimentation process could effectively remove pollutants from low-turbidity SSW([turbidity]0<15 NTU).These findings provide valuable insights into the water quality dynamics of SSW during the pre-sedimentation process,facilitating the development of SSW quality management and enhancing its reuse rate.展开更多
Photonuclear data are increasingly used in fundamental nuclear research and technological applications.These data are generated using advanced γ-ray sources.The Shanghai laser electron gamma source(SLEGS)is a new las...Photonuclear data are increasingly used in fundamental nuclear research and technological applications.These data are generated using advanced γ-ray sources.The Shanghai laser electron gamma source(SLEGS)is a new laser Compton scattering γ-ray source at the Shanghai Synchrotron Radiation Facility.It delivers energy-tunable,quasi-monoenergetic gamma beams for high-precision photonuclear measurements.This paper presents the flat-efficiency detector(FED)array at SLEGS and its application in photoneutron cross-section measurements.Systematic uncertainties of the FED array were determined to be 3.02%through calibration with a ^(252)Cf neutron source.Using ^(197)Au and ^(159)Tb as representative nuclei,we demonstrate the format and processing methodology for raw photoneutron data.The results validate SLEGS’capability for high-precision photoneutron measurements.展开更多
This study presents a holistic framework for sustainable urban design,using the proposed redevelopment design of Berlin’s Tegel Airport as a case study.The research addresses the need for comprehensive,real-world app...This study presents a holistic framework for sustainable urban design,using the proposed redevelopment design of Berlin’s Tegel Airport as a case study.The research addresses the need for comprehensive,real-world applications of sustainable urban design principles in the context of climate change and urban challenges.The proposed framework integrates multiple sustainability elements,including adaptive reuse,innovative energy systems,and a’resource community’concept.Key features include mixed-use development,a phased approach,and innovative mobility solutions.The study demonstrates the practical application of urban resilience theory,adaptive reuse concepts,circular economy principles,and compact city theory.Findings reveal the potential for significant environmental benefits,including reduced energy consumption and improved resource efficiency.The framework shows promise in fostering social cohesion through mixed-use spaces and community-centered design.Economic implications include creating local job opportunities and the potential for long-term cost savings through efficient resource management.However,challenges such as initial implementation costs and the need for stakeholder coordination are identified.The study contributes to sustainable urban planning by bridging the theoretical concepts and practical implementation gap.It offers a model for transforming urban brownfields into sustainable communities,providing valuable insights for urban planners,policymakers,and developers.Future research directions include longitudinal studies of implemented projects and comparative analyses across diverse urban contexts.展开更多
Memory-unsafe programming languages,such as C/C++,are often used to develop system programs,rendering the programs susceptible to a variety of memory corruption attacks.Among these threats,just-in-time return-oriented...Memory-unsafe programming languages,such as C/C++,are often used to develop system programs,rendering the programs susceptible to a variety of memory corruption attacks.Among these threats,just-in-time return-oriented programming(JIT-ROP)stands out as an advanced method for conducting code-reuse attacks,effectively circumventing code randomization safeguards.JIT-ROP leverages memory disclosure vulnerabilities to obtain reusable code fragments dynamically and assemble malicious payloads dynamically.In response to JIT-ROP attacks,several re-randomization implementations have been developed to prevent the use of disclosed code.However,existing re-randomization methods require recurrent re-randomization during program runtime according to fixed time windows or specific events such as system calls,incurring significant runtime overhead.In this paper,we present the design and implementation of PtrProxy,an efficient re-randomization approach on the AArch64 platform.Unlike previous methods that necessitate frequent runtime rerandomization or reply on unreliable triggering conditions,this approach triggers the re-randomization process by detecting the code page harvest operation,which is a fundamental operation of the JIT-ROP at-tacks,making our method more efficient and reliable than previous approaches.We evaluate PtrProxy on benchmarks and real-world applications.The evaluation results show that our approach can effectively protect programs from JIT-ROP attacks while introducing marginal runtime overhead.展开更多
With digital coding technology,reconfigurable intelligent surfaces(RISs)become powerful real-time sys-tems for manipulating electromagnetic(EM)waves.However,most automatic RIS designs involve exten-sive numerical simu...With digital coding technology,reconfigurable intelligent surfaces(RISs)become powerful real-time sys-tems for manipulating electromagnetic(EM)waves.However,most automatic RIS designs involve exten-sive numerical simulations of the unit,including the passive pattern and active devices,requiring high data acquisition and training costs.In addition,for passive patterns,the widely employed random pixe-lated method presents design efficiency and effectiveness challenges due to the massive pixel combina-tions and blocked excitation current flow in discrete patterns.To overcome these two critical problems,we propose a versatile RIS design paradigm with efficient topology representation and a separate design architecture.First,a non-uniform rational B-spline(NURBS)is introduced to represent continuous pat-terns and solve excitation current flow issues.This representation makes it possible to finely tune con-tinuous patterns with several control points,greatly reducing the pattern solution space by 20-fold and facilitating RIS optimization.Then,employing multiport network theory to separate the passive pat-tern and active device from the unit,the separate design architecture significantly reduces the dataset acquisition cost by 62.5%.Through multistep multiport calculation,the multistate EM responses of the RIS under different structural combinations can be quickly obtained with only one prediction of pattern response,thereby achieving dataset and model reuse for different RIS designs.With a hybrid continuous-discrete optimization algorithm,three examples—including two typical high-performance RISs and an ultra-wideband multilayer RIS—are provided to validate the superiority of our paradigm.Our work offers an efficient solution for RIS automatic design,and the resulting structure is expected to boost RIS appli-cations in the fields of wireless communication and sensing.展开更多
Renewable paper reusing plays a significant role in the sustainable environment under the background of the shortage in forest resources and the pollution from the paper industry.The conventional reusing stream of was...Renewable paper reusing plays a significant role in the sustainable environment under the background of the shortage in forest resources and the pollution from the paper industry.The conventional reusing stream of waste office paper appears to have low reusing rates while consuming massive amounts of energy in intermediate steps.In this study,we developed a novel portable renewable desktop paper reusing system based on font area detection and greyscale sensor.The proposed system consists of two main parts,namely,a greyscale sensor and font area detection model and a polishing mechanism.Acting as an ink mark detector for waste desktop paper,the greyscale sensor and font area detection model can detect the font in the waste desktop paper using an adaptive dynamic compensation schematic.The polishing mechanism will grind the font area of the wasted desktop paper,and this paper reusing processing is non-chemical,energy saving and environmentally friendly.The proposed system is demonstrated through simulations and experimental results,which show that the proposed renewable desktop paper reusing system is portable and is effective for reusing waste office paper in the office.An accuracy of 99.78%is demonstrated in the greyscale sensor and font area detection model,and the average reuse rate of one piece of paper is 2.52 times,verifying that the proposed portable system is effective and practical in renewable desktop paper reusing applications.展开更多
In the context of transforming traditional labour-intensive industries into the service economy in China,the reuse of industrial heritage as museums has become a trend,for example,along Shanghai waterfronts,gradually ...In the context of transforming traditional labour-intensive industries into the service economy in China,the reuse of industrial heritage as museums has become a trend,for example,along Shanghai waterfronts,gradually fuelling the continuation of urban memory,reshaping urban cultural identity and promoting the development of the waterfront economy.Additionally,the connotation of a museum is continually being expanded from an institution to a method,and the major function is gradually shifting from collection to display.Previous studies on Shanghai waterfront industrial heritage have mostly referred to cultural factors,but these factors are still mainly included in macroscale large waterfront projects or microscale single practical project analyses.Mesoscale typology discussions between the two are rare.Therefore,this paper examines eleven industrial heritage sites that have been repurposed as museums along Shanghai waterfronts to analyse the urban memory elements of industrial heritage and summarise three classes of memory interpretation strategies:translating memory information,renovating memory carriers,and relating memory clues.Finally,the advantages and disadvantages of the study cases are discussed separately,and the following corresponding recommendations are made:1)further enrich and balance memory interpretation strategies;2)enhance the rationality,service,and tolerance of the“exhibition+”mode;and 3)improve local laws and regulations related to the protection and utilisation of industrial heritage to provide references for similar reuse designs.展开更多
基金supported by the National Natural Science Foundation of China (No.U19A2063)the Jilin Provincial Science&Technology Development Program of China (No.20230201080GX)。
文摘Although ray tracing produces high-fidelity, realistic images, it is considered computationally burdensome when implemented on a high rendering rate system. Perception-driven rendering techniques generate images with minimal noise and distortion that are generally acceptable to the human visual system, thereby reducing rendering costs. In this paper, we introduce a perception-entropy-driven temporal reusing method to accelerate real-time ray tracing. We first build a just noticeable difference(JND) model to represent the uncertainty of ray samples and image space masking effects. Then, we expand the shading gradient through gradient max-pooling and gradient filtering to enlarge the visual receipt field. Finally, we dynamically optimize reusable time segments to improve the accuracy of temporal reusing. Compared with Monte Carlo ray tracing, our algorithm enhances frames per second(fps) by 1.93× to 2.96× at 8 to 16 samples per pixel, significantly accelerating the Monte Carlo ray tracing process while maintaining visual quality.
基金funded by the Italian Ministry of Environment and Energy Security(MASE)-Direzione Generale per le Fonti energetiche e Titoli Abilitativi(DGFTA).
文摘The paper presents an innovative approach to studying the reuse of a decommissioned natural gas production platformfor the seasonal storage and extraction of a hydrogen-methane(H2-CH4)mixture froma depleted reservoir.The reuse plan involves removing outdated equipment from the platform’s decks while retaining essential components such as wellheads and separators.Exploiting a depleted reservoir for the injection of an H_(2)-CH_(4) mixture requires a thorough understanding of its specific characteristics.This paper focuses on the engineering approach adopted in the basic design phase for such a conversion,providing recommendations and HSE guidelines.Given the hazardous nature of substances like hydrogen in the gas mixture,the paper also examines potential risk scenarios,particularly those involving containment loss.A qualitative and quantitative assessment of these risks is conducted to evaluate their impact on the structure and equipment.The results of this assessment serve as a foundation for later studies on layout optimization and domino effect prevention.Additionally,some critical scenarios are simulated using an innovative approach known as the Source Box Accident Model(SBAM),which was proposed in previous works.SBAM leverages Computational Fluid Dynamics(CFD)but decouples the accidental phenomenon into a release phase and a dispersion phase.This method overcomes the challenges conventional CFD tools face in assessing congested plant configurations,providing more precise estimations of gas cloud behavior.The simulation results indicate that the released gas remains within the platform deck domain,and the flammable cloud is significantly smaller than what traditional,simplified tools predict.
文摘Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand, "dry reusing and wet reclaiming of used sodium silicate sand" is considered as the most suitable technique for the used sand. When the recycled sand is used as support sand, the used sand is only reused by dry process including breaking, screening, dust-removal, etc., and it is not necessary that the used sand is reclaimed with strongly rubbing and scraping method, but when the recycled sand is used as facing sand (or single sand), the used sand must be reclaimed by wet method for higher removal rate of the residual binders. The characteristics and the properties of the dry reused sand are compared with the wet reclaimed sand after combining the different use requirements of support sand and facing sand (or single sand), and above the most adaptive scheme has also been validated.
基金Supported by the National Natural Science Foundation of China( 61471251 61101217)the Natural Science Foundation of Jiangsu Province of China (BK20131164)
文摘To increase the convergence rate of the improved normalized subband adaptive filter,a simple but effective method is presented to change the reusing order of coefficient vectors of the adaptive filter. At the beginning of adaptation the algorithmjust uses its current coefficient vector to update the adaptive filter to maintain fast convergence rate,while in steady state it employs several most recent coefficient vectors to update the adaptive filter to reduce misalignment. Simulation results showthat the proposed algorithmcan obtain both fast convergence rate and small steady-state misalignment.
文摘The demand for alternative cementitious materials is on the rise,as the cement causes huge energy consumption and produces greenhouse gas emission.Additionally,there is economic potential for the construction industry to reuse wastes as supplementary building materials.The purpose of this study is to evaluate the potential of utilizing ferrochrome slag wastes in mortar as supplementary cementitious materials (SCMs),thereby achieving this double-sided goal.Thus,the mechanical and physical properties of ferrochrome slag wastes were investigated to be used as admixtures in concrete production.Three different cement mortar specimens were prepared by replacing cement with ferrochrome slag in ratios of 0,30%,and 60% by mass and flexural and compressive strengths of the specimens were determined at the ages of 7,28,56,90,and 180 days.Also,the effects of the ferrochrome slag replacement ratio on workability,setting time and volume expansion were revealed.Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were also investigated to study the microstructural properties of the specimens containing ferrochrome slag.Based on the results,it is concluded that ferrochrome slag wastes have pozzolanic activity,therefore reusing them as SCMs in the cement and concrete industry is convenient.
文摘The current work seeks firstly the integration of a rainwater reuse system that will be of use in the watering of the green spaces, and secondly the re-use of purified water in the irrigation of agriculture spaces, which are in the nearby of wastewater treatment plant. The results show that 41% of the green spaces in the city of Fez require a renovation and installation of adequate watering systems taking into account the specificity of the city which is crossed by several rivers badly exploited for watering. The purified wastewater is of much better quality than the Moroccan reuse standards and is discharged with a flow that is large enough for the irrigation water requirements of the fields close to wastewater treatment plant.
基金National Natural Science Foundation of China(No.61262010)
文摘Reusing test cases from existing test case library is quite common in the software testing field. Testing practice tells us that there is a strong relationship between the granularity of a function unit under testing and that of the test case. A function unit with small granularity usually results in the test cases with the same small granularity. Therefore a test case defined as the function point,i. e.,the smallest size function unit,was provided for the first time.Though test cases with smaller granularity usually have better reusability,the cost of accurately reusing and integrating such test cases is also higher. In order to balance the test case reusability and the cost of test case reuse,a novel test case reuse model based on the function point was proposed in this paper. In this model,a reusable test case for specification-based testing was defined and some reuse strategies and three formal reuse methods were given. Finally,the complete automatic software process was realized by a reusing generation tool. The new method has improved reuse accuracy,while greatly enhances the software productivity.
文摘Footwear industries generate leather waste during the operation.Some of these wastes contain chromium,which may bring environmental concerns.This study aimed to reuse finished leather waste,the major part of these hazard-ous wastes,via producing a composite with thermoplastic polyurethane(TPU)for shoe soles.Finished leather waste containing black dyes and pigments was used to color the TPU.The finished leather waste was fragmented,milled,micronized and blended with TPU in a ratio of 10%,15%,and 20%w/w to produce composite materials.The compos-ite materials were evaluated by morphological and thermal characterizations,physical-mechanical analysis,and envi-ronmental tests(leaching and solubilization),which presented that the physical-mechanical and thermal properties were within the standard of shoe soles,and the composites can be classified as non-hazardous.The composites enabled a new way of coloring polymeric matrices and reusing leather waste.
基金Project supported by the National Natural Science Foundation of China(No.60976023)the National Science and Technology Major Project of China(Nos.2009ZX03007-001,2012ZX03004007-002)
文摘A low power fast settling multi-standard CMOS fractional-N frequency synthesizer is proposed. The current reusing and frequency presetting techniques are adopted to realize the low power fast settling multi-standard fractional-N frequency synthesizer. An auxiliary non-volatile memory （NVM） is embedded to avoid the repetitive calibration process and to save power in practical application. This PLL is implemented in a 0.18 #m technology. The frequency range is 0.3 to 2.54 GHz and the settling time is less than 5 #s over the entire frequency range. The LC-VCO with the stacked divide-by-2 has a good figure of merit of-193.5 dBc/Hz. The measured phase noise of frequency synthesizer is about -115 dBc/Hz at 1 MHz offset when the carrier frequency is 2.4 GHz and the reference spurs are less than -52 dBc. The whole frequency synthesizer consumes only 4.35 mA @ 1.8 V.
基金Supported by the Key Program of the National Natural Science Foundation of China (Grant No. 50878042)
文摘The protective remolding and reusing of industrial historic buildings and sites is regarded as a great scientific matter in today's urban development. Based on discussing its significance and value,this paper,taking a specific example,makes a systematic discussion on the design strategy and method from the aspects of overall planning,remolding the old buildings,designing the new buildings,etc.
基金Supported by a grant from Iran Telecommunication Research Center
文摘Reconfigurable computing systems can be reconfigured at runtime and support partial reconfigurability which makes us able to execute tasks in a true multitasking manner. To manage such systems at runtime, a reconfigurable operating system is needed. The main part of this operating system is resource management unit which performs on-line scheduling and placement of hardware tasks at runtime. Reconfiguration overhead is an important obstacle that limits the performance of on-line scheduling algorithms in reconfigurable computing systems and increases the overall execution time. Configuration reusing （task reusing） can decrease reconfiguration overhead considerably, particularly in periodic applications or the applications in which the probability of tasks recurrence is high. In this paper, we present a technique called reusing-based scheduling （RBS）, for on-line scheduling and placement in which configuration reusing is considered as a main characteristic in order to reduce reconfiguration overhead and decrease total execution time of the tasks. Several experiments have been conducted on the proposed algorithm. Obtained results show considerable improvement in overall execution time of the tasks.
基金financially supported by the National Natural Science Foundation of China(Nos.52304314 and U23A20602)the Open Fund of the Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control,Ministry of Ecology and Environment+3 种基金China(No.HB202406)the Fundamental Research Funds for the Central Universities of Central South University,China(Nos.CX20240021 and 2024ZZTS0008)the Innovation and Entrepreneurship Funding Project for College Students of Central South UniversityChina(No.S202410533166)。
文摘Flotation is the most common method to recover valuable minerals by selective adsorption of collectors on target mineral surfaces.However,in subsequent hydrometallurgy of mineral flotation concentrates,the adsorbed collectors must be desorbed since it can adversely affect the efficiency of metallurgical process and produce wastewater.ZL,as a fatty acid mixture,is a typical industrially used collector for scheelite flotation in China.Sodium oleate(NaOL)has similar fatty acid group as ZL.In this study,the desorption behavior of NaOL/ZL from scheelite surface by a physical method of stirring at a low temperature was investigated.NaOL desorption tests of single mineral showed that a desorption rate of 77.75% for NaOL from scheelite surface into pulp was achieved in a stirring speed of2500 r/min at 5℃in a neutral environment.Under the above desorption condition,in the pulp containing desorbed collector by adding extra 30% normal NaOL dosage,the scheelite recovery reached about 95% in the single mineral flotation test.Desorption and reuse of ZL collector for the flotation of real scheelite ore showed only a 75%normal dosage of ZL could produce a qualified rough concentrate.The atomic force microscope(AFM)tests showed that after desorption treatment of low temperature and strong stirring,the dense strip-like structure of NaOL on the scheelite surface was destroyed to be speck-like.Molecular dynamics simulations(MDS)demonstrated that the adsorption energy between NaOL and scheelite surface was more negative at 25℃(-13.39 kcal/mol)than at 5℃(-11.50 kcal/mol)in a neutral pH,indicating that a low temperature was beneficial for the desorption of collector from mineral surface.Due to its simplicity and economy,the method we proposed of desorption of collector from mineral surface and its reuse for flotation has a great potential for industrial application.
基金funding from MUR under the umbrella of the PRIMA-Partnership for Research&Innovation in the Mediterranean Area through the research project SAFE"Sustainable water reuse practices improving safety in agriculture,food and environment"support from the CERCA Institute through the CERCAGINYS programme,funded by the Spanish Ministry of Science and Innovationsupport from the Economy and Knowledge Department of the Catalan Government through a Consolidated Research Groups(ICRA-ENV-2021 SGR 01282 and ICRA-TECH 2021 SGR 01283)。
文摘Fipronil is an insecticide with low residual activity and high efficacy at low concentrations.Due to its widespread use and long half-life,fipronil can persist during wastewater treatment and is found even in surface waters.When released into the environment,it can accumulate over time and can lead to concentrations in soil and plant tissues that are harmful to both target and non-target organisms.As the reuse of treated wastewater and sewage sludge presents challenges and opportunities for farmers,this study investigates the effects of irrigation with environmentally relevant doses of fipronil on zucchini plants and their main insect pest,Aphis gossypii.Traces of fipronil were found in the zucchini leaves,but not in the flowers,after 35-days of cumulative exposure.A decrease in nymph-to-adult survival and a dose-dependent reduction in the fecundity of A.gossypii feeding on contaminated host plants was observed.Also,aphids feeding on contaminated host plants exhibited the same mortality rate as the control group when exposed to an acute dose of fipronil.However,when natural pyrethrins were used,there was a significant increase in resistance to this insecticide.Our results demonstrate the potential for fipronil to accumulate in plant tissues and highlight the risk of changes in insecticide susceptibility in insect pests.This suggests a need for a holistic approach to the complex dynamics of wastewater reuse in agriculture.
基金supported by the Ministry of Science and Technology of China (Nos.2021YFC3200904,and 2022YFC3203705)the National Natural Science Foundation of China (Nos.52070184,and 52270012)the Nanning Scientific Research and Technology Development Project (No.ZC20223238).
文摘Sedimentation sludge water(SSW),a prominent constituent of wastewater from drinking water treatment plants,has received limited attention in terms of its treatment and utilization likely due to the perceived difficulties associated with managing SSW sludge.This study comprehensively evaluated the water quality of SSW by comparing it to a well-documented wastewater(filter backwash water(FBW)).Furthermore,it investigated the pollutant variations in the SSW during pre-sedimentation process,probed the underlying reaction mechanism,and explored the feasibility of employing a pilot-scale coagulation-sedimentation process for SSW treatment.The levels of most water quality parameters were generally comparable between SSW and FBW.During the pre-sedimentation of SSW,significant removal of turbidity,bacterial counts,and dissolved organic matter(DOM)was observed.The characterization of DOM components,molecular weight distributions,and optical properties revealed that the macromolecular proteinaceous biopolymers and humic acids were preferentially removed.The characterization of particulates indicated that high surface energy,zeta potential,and bridging/adsorption/sedimentation/coagulation capacities in aluminum residuals of SSW,underscoring its potential as a coagulant and promoting the generation and sedimentation of inorganic-organic complexes.The coagulation-sedimentation process could effectively remove pollutants from low-turbidity SSW([turbidity]0<15 NTU).These findings provide valuable insights into the water quality dynamics of SSW during the pre-sedimentation process,facilitating the development of SSW quality management and enhancing its reuse rate.
基金supported by National Key Research and Development Program of China(Nos.2022YFA1602404 and 2023YFA1606901)the National Natural Science Foundation of China(Nos.12275338,12388102,and U2441221)the Key Laboratory of Nuclear Data Foundation(JCKY2022201C152).
文摘Photonuclear data are increasingly used in fundamental nuclear research and technological applications.These data are generated using advanced γ-ray sources.The Shanghai laser electron gamma source(SLEGS)is a new laser Compton scattering γ-ray source at the Shanghai Synchrotron Radiation Facility.It delivers energy-tunable,quasi-monoenergetic gamma beams for high-precision photonuclear measurements.This paper presents the flat-efficiency detector(FED)array at SLEGS and its application in photoneutron cross-section measurements.Systematic uncertainties of the FED array were determined to be 3.02%through calibration with a ^(252)Cf neutron source.Using ^(197)Au and ^(159)Tb as representative nuclei,we demonstrate the format and processing methodology for raw photoneutron data.The results validate SLEGS’capability for high-precision photoneutron measurements.
文摘This study presents a holistic framework for sustainable urban design,using the proposed redevelopment design of Berlin’s Tegel Airport as a case study.The research addresses the need for comprehensive,real-world applications of sustainable urban design principles in the context of climate change and urban challenges.The proposed framework integrates multiple sustainability elements,including adaptive reuse,innovative energy systems,and a’resource community’concept.Key features include mixed-use development,a phased approach,and innovative mobility solutions.The study demonstrates the practical application of urban resilience theory,adaptive reuse concepts,circular economy principles,and compact city theory.Findings reveal the potential for significant environmental benefits,including reduced energy consumption and improved resource efficiency.The framework shows promise in fostering social cohesion through mixed-use spaces and community-centered design.Economic implications include creating local job opportunities and the potential for long-term cost savings through efficient resource management.However,challenges such as initial implementation costs and the need for stakeholder coordination are identified.The study contributes to sustainable urban planning by bridging the theoretical concepts and practical implementation gap.It offers a model for transforming urban brownfields into sustainable communities,providing valuable insights for urban planners,policymakers,and developers.Future research directions include longitudinal studies of implemented projects and comparative analyses across diverse urban contexts.
基金supported in part by the National Natural Science Foundation of China(62272351,61972297,62172308).
文摘Memory-unsafe programming languages,such as C/C++,are often used to develop system programs,rendering the programs susceptible to a variety of memory corruption attacks.Among these threats,just-in-time return-oriented programming(JIT-ROP)stands out as an advanced method for conducting code-reuse attacks,effectively circumventing code randomization safeguards.JIT-ROP leverages memory disclosure vulnerabilities to obtain reusable code fragments dynamically and assemble malicious payloads dynamically.In response to JIT-ROP attacks,several re-randomization implementations have been developed to prevent the use of disclosed code.However,existing re-randomization methods require recurrent re-randomization during program runtime according to fixed time windows or specific events such as system calls,incurring significant runtime overhead.In this paper,we present the design and implementation of PtrProxy,an efficient re-randomization approach on the AArch64 platform.Unlike previous methods that necessitate frequent runtime rerandomization or reply on unreliable triggering conditions,this approach triggers the re-randomization process by detecting the code page harvest operation,which is a fundamental operation of the JIT-ROP at-tacks,making our method more efficient and reliable than previous approaches.We evaluate PtrProxy on benchmarks and real-world applications.The evaluation results show that our approach can effectively protect programs from JIT-ROP attacks while introducing marginal runtime overhead.
基金supported by the National Key Research and Development Program of China(2023YFB3811502)the National Science Foundation of China(62225108)+5 种基金the Fundamental Research Funds for the Central Universities(2242022k60003)the National Natural Science Foundation of China(62288101 and 62201139)the Jiangsu Province Frontier Leading Technology Basic Research Project(BK20212002)the Jiangsu Provincial Scientific Research Center of Applied Mathematics(BK20233002)the Fundamental Research Funds for the Central Universities(2242024RCB0005 and 2242024K30009)the 111 Project(111-2-05).
文摘With digital coding technology,reconfigurable intelligent surfaces(RISs)become powerful real-time sys-tems for manipulating electromagnetic(EM)waves.However,most automatic RIS designs involve exten-sive numerical simulations of the unit,including the passive pattern and active devices,requiring high data acquisition and training costs.In addition,for passive patterns,the widely employed random pixe-lated method presents design efficiency and effectiveness challenges due to the massive pixel combina-tions and blocked excitation current flow in discrete patterns.To overcome these two critical problems,we propose a versatile RIS design paradigm with efficient topology representation and a separate design architecture.First,a non-uniform rational B-spline(NURBS)is introduced to represent continuous pat-terns and solve excitation current flow issues.This representation makes it possible to finely tune con-tinuous patterns with several control points,greatly reducing the pattern solution space by 20-fold and facilitating RIS optimization.Then,employing multiport network theory to separate the passive pat-tern and active device from the unit,the separate design architecture significantly reduces the dataset acquisition cost by 62.5%.Through multistep multiport calculation,the multistate EM responses of the RIS under different structural combinations can be quickly obtained with only one prediction of pattern response,thereby achieving dataset and model reuse for different RIS designs.With a hybrid continuous-discrete optimization algorithm,three examples—including two typical high-performance RISs and an ultra-wideband multilayer RIS—are provided to validate the superiority of our paradigm.Our work offers an efficient solution for RIS automatic design,and the resulting structure is expected to boost RIS appli-cations in the fields of wireless communication and sensing.
基金This work was supported by the National Natural Science Founda-tion of China under Grant Nos.51675451 and 51975490by the Science and Technology Projects of Sichuan under Grant Nos.19MZGC0116,19MZGC0117 and 19MZGC0110.
文摘Renewable paper reusing plays a significant role in the sustainable environment under the background of the shortage in forest resources and the pollution from the paper industry.The conventional reusing stream of waste office paper appears to have low reusing rates while consuming massive amounts of energy in intermediate steps.In this study,we developed a novel portable renewable desktop paper reusing system based on font area detection and greyscale sensor.The proposed system consists of two main parts,namely,a greyscale sensor and font area detection model and a polishing mechanism.Acting as an ink mark detector for waste desktop paper,the greyscale sensor and font area detection model can detect the font in the waste desktop paper using an adaptive dynamic compensation schematic.The polishing mechanism will grind the font area of the wasted desktop paper,and this paper reusing processing is non-chemical,energy saving and environmentally friendly.The proposed system is demonstrated through simulations and experimental results,which show that the proposed renewable desktop paper reusing system is portable and is effective for reusing waste office paper in the office.An accuracy of 99.78%is demonstrated in the greyscale sensor and font area detection model,and the average reuse rate of one piece of paper is 2.52 times,verifying that the proposed portable system is effective and practical in renewable desktop paper reusing applications.
文摘In the context of transforming traditional labour-intensive industries into the service economy in China,the reuse of industrial heritage as museums has become a trend,for example,along Shanghai waterfronts,gradually fuelling the continuation of urban memory,reshaping urban cultural identity and promoting the development of the waterfront economy.Additionally,the connotation of a museum is continually being expanded from an institution to a method,and the major function is gradually shifting from collection to display.Previous studies on Shanghai waterfront industrial heritage have mostly referred to cultural factors,but these factors are still mainly included in macroscale large waterfront projects or microscale single practical project analyses.Mesoscale typology discussions between the two are rare.Therefore,this paper examines eleven industrial heritage sites that have been repurposed as museums along Shanghai waterfronts to analyse the urban memory elements of industrial heritage and summarise three classes of memory interpretation strategies:translating memory information,renovating memory carriers,and relating memory clues.Finally,the advantages and disadvantages of the study cases are discussed separately,and the following corresponding recommendations are made:1)further enrich and balance memory interpretation strategies;2)enhance the rationality,service,and tolerance of the“exhibition+”mode;and 3)improve local laws and regulations related to the protection and utilisation of industrial heritage to provide references for similar reuse designs.
