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Records Added in November 2019
Records added in November 2019
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Showing records 51 to 75 of 115. [First] Page: 1 2 3 4 5 Last
Study of 4,4‘-Methylene Diisocyanate Phenyl Ester-Modified Cassava Residues/Polybutylene Succinate Biodegradable Composites: Preparation and Performance Research
Lijie Huang, Hanyu Zhao, Hao Xu, Shuxiang An, Chunying Li, Chongxing Huang, Shuangfei Wang, Yang Liu, Jie Chen
November 24, 2019 (v1)
Subject: Biosystems
Keywords: 4,4’-methylene diisocyanate phenyl ester, biodegradable, cassava residues, modification, polybutylene succinate
Biomass materials have become a research focus for humankind, due to the decreasing availability of fossil fuels and the increasing release of greenhouse gas. In this work, we prepared biodegradable composites with waste cassava residues and polybutylene succinate (PBS) by modifying cassava residues using 4,4’-methylene diisocyanate phenyl ester (MDI) and tested their properties. The effects of MDI modification on the structure, mechanical properties, water absorption, microstructure, and thermal stability of the composites were studied via Fourier transform infrared spectroscopy, contact angle measurement, mechanical property testing, water absorption analysis, scanning electron microscopy, and thermogravimetric analysis, respectively. The results showed that the tensile strength and flexural strength of the material increased by 72% and 20.89%, respectively, when the MDI-modified cassava residue content was 30%. When 10% MDI-modified cassava residues were added, the tensile strength... [more]
Lethality Calculation of Particulate Liquid Foods during Aseptic Processing
Mohd Tarmizan Ibrahim, Heiko Briesen, Petra Först, Jörg Zacharias
November 24, 2019 (v1)
Keywords: aseptic processing, heat transfer, model, non-spherical particles, particulate foods, sterility
In the past two decades, aseptic processing has been implemented in the food industry to sterilize particulate liquid food mixtures. To ensure that particulates in the liquid receive sufficient heating, mathematical modeling is employed to evaluate the temperature and lethality level in the particles. We developed a model for the thermal processing of liquid foods containing cubic particles in a continuous laminar pipe flow system, comprising a tubular heat exchanger. In our simplified approach, heat transfer equations for particulate liquid foods were solved analytically and numerically to evaluate the effect of certain process parameters on the time temperature profiles of particles and the lethality value in the products. A comparison of the particles’ lethality values was made between the experiment and simulation for two different particle residence times in a case study, and the model predictions were in good agreement with experimental data. Based on modeling studies, it was fou... [more]
Improvement of Catalytic Activity of Platinum Nanoparticles Decorated Carbon Graphene Composite on Oxygen Electroreduction for Fuel Cells
Halima Begum, Young-Bae Kim
November 24, 2019 (v1)
Keywords: composite, Fuel Cells, graphene, oxygen reduction reaction, platinum carbon
High-performance platinum (Pt)-based catalyst development is crucially important for reducing high overpotential of sluggish oxygen reduction reaction (ORR) at Pt-based electrocatalysts, although the high cost and scarcity in nature of Pt are profoundly hampering the practical use of it in fuel cells. Thus, the enhancing activity of Pt-based electrocatalysts with minimal Pt-loading through alloy, core−shell or composite making has been implemented. This article deals with enhancing electrocatalytic activity on ORR of commercially available platinum/carbon (Pt/C) with graphene sheets through a simple composite making. The Pt/C with graphene sheets composite materials (denoted as Pt/Cx:G10−x) have been characterized by several instrumental measurements. It shows that the Pt nanoparticles (NPs) from the Pt/C have been transferred towards the π-conjugated systems of the graphene sheets with better monolayer dispersion. The optimized Pt/C8:G2 composite has higher specific surface area and b... [more]
Pulsed Electric Field-Assisted Ethanolic Extraction of Date Palm Fruits: Bioactive Compounds, Antioxidant Activity and Physicochemical Properties
Azhari Siddeeg, Muhammad Faisal Manzoor, Muhammad Haseeb Ahmad, Nazir Ahmad, Zahoor Ahmed, Muhammad Kashif Iqbal Khan, Abid Aslam Maan, Mahr-Un-Nisa, Xin-An Zeng, Al-Farga Ammar
November 24, 2019 (v1)
Subject: Biosystems
Keywords: antioxidant activity, bioactive compounds, dates, ethanolic extraction, PEF
The current study was aimed to observe the influence of pulsed electric field (PEF) on the extraction of bioactive components; antioxidant activity and physicochemical properties of date palm fruit extract (DPFE) as compared to the extract untreated by PEF. The fruit was treated with PEF (frequency: 10 Hz, time: 100 µs, pulses number: 30, electric field strength (EFS): 1, 2, and 3 kV/cm. The results show that PEF has a positive impact on the total content of carotenoids, anthocyanins, flavonoids, and phenolics by increasing the EFS. DPFE treated with PEF exhibit a strong antioxidant activity as compared to untreated extract, while electrical conductivity, pH values, and titratable acidity were not affected by PEF. The results indicate a notable increase in the volatile components in DPFE treated with PEF at 3 kV/cm. Thus, PEF treatment can assist the ethanolic extraction of DPFE to improve the bioactivity and antioxidative activity. These findings suggest that PEF can be a more suitabl... [more]
Multiple Scenarios Forecast of Electric Power Substitution Potential in China: From Perspective of Green and Sustainable Development
Jing Wu, Zhongfu Tan, Gejirifu De, Lei Pu, Keke Wang, Qingkun Tan, Liwei Ju
November 24, 2019 (v1)
Subject: Energy Policy
Keywords: CSO-ELM, electric power substitution, green sustainable development, potential forecasting
To achieve sustainable social development, the Chinese government conducts electric power substitution strategy as a green move. Traditional fuels such as coal and oil could be replaced by electric power to achieve fundamental transformation of energy consumption structure. In order to forecast and analyze the developing potential of electric power substitution, a forecasting model based on a correlation test, the cuckoo search optimization (CSO) algorithm and extreme learning machine (ELM) method is constructed. Besides, China’s present situation of electric power substitution is analyzed as well and important influencing factors are selected and transmitted to the CSO-ELM model to carry out the fitting analysis. The results showed that the CSO-ELM model has great forecasting accuracy. Finally, combining with the cost, policy supports, subsidy mechanism and China’s power consumption data in the past 21 years, four forecasting scenarios are designed and the forecasting results of 2019−... [more]
Characterization of Natural Composites Fabricated from Abutilon-Fiber-Reinforced Poly (Lactic Acid)
Hua Wang, Elwathig. A. M. Hassan, Hafeezullah Memon, Tienah. H. H. Elagib, Fadlelmoula Abad AllaIdris
November 24, 2019 (v1)
Subject: Materials
Keywords: abutilon, characterization, green composite, poly (lactic acid) and reinforcement
In recent decades, natural-fiber-reinforced poly (lactic acid) (PLA) composites have received a great deal of attention. In this study, biocomposites of poly (lactic acid) and abutilon fibers are prepared by using melt blending and an extruder. The effects of fiber additions on rheological, thermomechanical, thermal, and morphological properties are investigated using a rheometer, dynamic mechanical analysis (DMA), differential scanning calorimeter (DSC), TGA, and SEM, respectively. The DSC results indicate that the fibers acted as a nucleating agent, which led to enhancing the crystallization of PLA. The results also reveal that the thermal stability of PLA was improved by abutilon fibers. Moreover, higher values of storage modulus are observed, which are attributed to strong interfacial adhesion. In addition, thetan delta isreduced upon the addition of fiber content into the PLA matrix, which restricts the mobility of PLA polymer molecules in the presence of the fibers. The improveme... [more]
Process Cost Management of Alzheimer’s Disease
Hana Tomaskova, Martin Kopecky, Petra Maresova
November 24, 2019 (v1)
Keywords: Alzheimer’s disease, BPMN, process cost management, Simulation, system dynamics
Summary: Determining the cost of healthcare and social care for patients is a crucial issue for many parties; therefore, both public and private payments play a decisive role in patient care. The article deals with the analysis of the possibilities of the simulation of costs related to Alzheimer’s disease. This disease is highly variable, and the cost items vary considerably. Therefore, it is necessary to use simulation methods. The results of simulation models can then be implemented in sophisticated methods working with activity costs. Findings: Models for health and social care are specific. No significant re-engineering is expected in this area, so the models must be unambiguous and easy to understand for all representatives involved. Modeling of business processes is thus a suitable means for analysis in this area. The process cost calculation is built on two simulation models. The first model is the Business Process Model and Notation (BPMN), the results of which are verified in... [more]
Real-Scale Integral Valorization of Waste Orange Peel via Hydrodynamic Cavitation
Francesco Meneguzzo, Cecilia Brunetti, Alexandra Fidalgo, Rosaria Ciriminna, Riccardo Delisi, Lorenzo Albanese, Federica Zabini, Antonella Gori, Luana Beatriz dos Santos Nascimento, Anna De Carlo, Francesco Ferrini, Laura M. Ilharco, Mario Pagliaro
November 24, 2019 (v1)
Keywords: biomethane, d-limonene, flavanones, food waste, green extraction, hydrodynamic cavitation, orange waste, pectin, polyphenols
Waste orange peel represents a heavy burden for the orange juice industry, estimated in several million tons per year worldwide; nevertheless, this by-product is endowed with valuable bioactive compounds, such as pectin, polyphenols, and terpenes. The potential value of the waste orange peel has stimulated the search for extraction processes, alternative or complementary to landfilling or to the integral energy conversion. This study introduces controlled hydrodynamic cavitation as a new route to the integral valorization of this by-product, based on simple equipment, speed, effectiveness and efficiency, scalability, and compliance with green extraction principles. Waste orange peel, in batches of several kg, was processed in more than 100 L of water, without any other raw materials, in a device comprising a Venturi-shaped cavitation reactor. The extractions of pectin (with a remarkably low degree of esterification), polyphenols (flavanones and hydroxycinnamic acid derivatives), and te... [more]
Distinct and Quantitative Validation Method for Predictive Process Modelling in Preparative Chromatography of Synthetic and Bio-Based Feed Mixtures Following a Quality-by-Design (QbD) Approach
Steffen Zobel-Roos, Mourad Mouellef, Reinhard Ditz, Jochen Strube
November 24, 2019 (v1)
Keywords: biologics, continuous bioprocessing, manufacturing, Modelling, modular plants, Process Intensification, regulated industry
Process development, especially in regulated industries, where quality-by-design approaches have become a prerequisite, is cost intensive and time consuming. A main factor is the large number of experiments needed. Process modelling can reduce this number significantly by replacing experiments with simulations. However, this requires a validated model. In this paper, a process and model development workflow is presented, which focuses on implementing, parameterizing, and validating the model in four steps. The presented methods are laid out to gain, create, or generate the maximum information and process knowledge needed for successful process development. This includes design of experiments and statistical evaluations showing process robustness, sensitivity of target values to process parameters, and correlations between process and target values. Two case studies are presented. An ion exchange capture step for monoclonal antibodies focusing on high accuracy and low feed consumption;... [more]
Impact Analysis of Water Quality on the Development of Construction Materials
Hamad Farid, Muhammad Shoaib Mansoor, Syyed Adnan Raheel Shah, Nasir Mahmood Khan, Rana Muhammad Farooq Shabbir, Muhammad Adnan, Hunain Arshad, Inzmam-Ul Haq, Muhammad Waseem
November 24, 2019 (v1)
Subject: Materials
Keywords: materials, strength, Wastewater, water management, water quality
This research dealt with the impact of the quality of the water source on the mechanical properties of construction materials. The mechanical properties of construction materials include compressive, tensile, and flexural strength. Water samples were collected from different resources, these samples were then synthetically investigated to identify and compare their quality parameters. After a detailed chemical analysis of water samples from three sources—wastewater, surface or canal water, and ground water—construction concrete material samples were prepared. The construction materials were developed with the same water−cement ratio, i.e., 0.60 for each concrete mix sample at two mix ratios—M1 (1:2:4) and M2 (1:1.5:3). Slump cone and compacting factor tests were conducted on the fresh concrete to determine its workability prior to its hardening. Then, at 7, 14, 21, and 28 days for each mix, tests for mechanical properties were carried out to determine the compressive, tensile, and flex... [more]
Impact of Fractionation Process on the Technical and Economic Viability of Corn Dry Grind Ethanol Process
Chinmay Kurambhatti, Deepak Kumar, Vijay Singh
November 24, 2019 (v1)
Subject: Energy Policy
Keywords: corn fiber, corn processing, dry fractionation, dry grind, Ethanol, Technoeconomic Analysis, wet fractionation
Use of corn fractionation techniques in dry grind process increases the number of coproducts, enhances their quality and value, generates feedstock for cellulosic ethanol production and potentially increases profitability of the dry grind process. The aim of this study is to develop process simulation models for eight different wet and dry corn fractionation techniques recovering germ, pericarp fiber and/or endosperm fiber, and evaluate their techno-economic feasibility at the commercial scale. Ethanol yields for plants processing 1113.11 MT corn/day were 37.2 to 40 million gal for wet fractionation and 37.3 to 31.3 million gal for dry fractionation, compared to 40.2 million gal for conventional dry grind process. Capital costs were higher for wet fractionation processes ($92.85 to $97.38 million) in comparison to conventional ($83.95 million) and dry fractionation ($83.35 to $84.91 million) processes. Due to high value of coproducts, ethanol production costs in most fractionation proc... [more]
A Thermodynamic Approach for the Prediction of Oiling Out Boundaries from Solubility Data
Venkateswarlu Bhamidi, Brendan P. Abolins
November 24, 2019 (v1)
Keywords: binodal, gel boundary, liquid–liquid phase separation, LLPS, oiling out, phase diagram prediction, phase diagrams, prediction of oiling out, spinodal
Many pharmaceutical molecules, fine chemicals, and proteins exhibit liquid−liquid phase separation (LLPS, also known as oiling out) during solution crystallization. LLPS is of significant concern in crystallization process development, as oiling out can compromise the effectiveness of a crystallization and can lead to operational problems. A comprehensive methodology that allows a process scientist/engineer to characterize the various phase boundaries relevant to oiling out is currently lacking. In this work, we present a modeling framework useful in predicting the binodal, spinodal, and gelation boundaries starting from the solubility data of a solute that is prone to oiling out. We collate the necessary theoretical concepts from the literature and describe a unified approach to model the phase equilibria of solute−solvent systems from first principles. The modeling effort is validated using experimental data reported in the literature for various solute−solvent systems. The predictiv... [more]
Effect of Hydrothermal Pretreatment on Volatile Fatty Acids Production from Source-Separated Organics
Farokh laqa Kakar, Ehssan Hosseini Koupaie, Hisham Hafez, Elsayed Elbeshbishy
November 24, 2019 (v1)
Subject: Biosystems
Keywords: acidification, dark fermentation, hydrothermal pretreatment, source-separated organics, volatile fatty acids
The current study investigates the effect of hydrothermal pretreatment (HTP) on acidification of source-separated organics (SSO) in terms of volatile fatty acids (VFAs) production and solubilization. Temperature and retention time for HTP of SSO ranged from 150 to 240 °C and 5 to 30 min, respectively. The soluble substance after hydrothermal pretreatment initially increased, reaching its peak at 210 °C and then declined gradually. The highest overall chemical oxygen demand (COD) solubilization of 63% was observed at “210 °C-20 min” compared to 17% for raw SSO. The highest VFAs yield of 1536 mg VFAs/g VSS added was observed at “210 °C-20 min” compared to 768 mg VFAs/g VSS for raw SSO. Intensification of hydrothermal pretreatment temperature beyond 210 °C resulted in the mineralization of the organics and adversely affected the process.
Performance and Economic Analysis of Concentrated Solar Power Generation for Pakistan
Mujeeb Iqbal Soomro, Abdullah Mengal, Yasir Aftab Memon, Muhammad Waris Ali Khan, Qadir Nawaz Shafiq, Nayyar Hussain Mirjat
November 24, 2019 (v1)
Subject: Energy Policy
Keywords: concentrated solar power, CSP plants, economic analyses, Pakistan, performance analyses, site assessment, system advisor model
In Pakistan, the utilization of renewable energy sources is increasing in order to reduce the electricity supply and demand gap. However, concentrated solar power (CSP) generation has not been considered in the country even though it has gained considerable attention worldwide. This study, as such, investigates the potential, performance, and economic analyses of four CSP technologies for different locations in Pakistan. Initially, an assessment of CSP sites, including solar resource, land, and water availability, was undertaken. Then, performance simulations of CSP technologies for four different locations of Pakistan, namely Quetta, Hyderabad, Multan, and Peshawar, were examined. For all cases, highest energy production was achieved in summers and lowest in winters, and CSP plants with evaporative cooling were found to be efficient compared to air cooling. The results also revealed that the Quetta and Hyderabad regions were promising for CSP development while parabolic tough (PT) and... [more]
Comparison of Growth Characteristics and Properties of CVD TiN and TiO2 Anti-Coking Coatings
Shiyun Tang, Tao Liu, Shuiping Duan, Junjiang Guo, Anjiang Tang
November 24, 2019 (v1)
Subject: Materials
Keywords: anti-coking coating, coke, growth characteristics, hydrocarbon fuel
Coating metals with anti-coking materials inhibit their catalytic coking and are especially beneficial in the pyrolysis of hydrocarbon fuels. It is believed that growth characteristics and properties may play a pivotal role in the anti-coking performance of chemical vapor deposition (CVD) coatings. In this study, TiN and TiO2 coatings were obtained by CVD using TiCl4−N2−H2 and TiCl4−H2−CO2 systems, respectively. The effects of deposition time, residence time, and partial pressure were examined, and the coating microstructure was characterized by scanning electron microscopy (SEM). The results reveal that the effect of deposition parameters on the growth characteristics of TiN and TiO2 coatings is very different. The growth of the TiN coating shows characteristics of the island growth model, while the TiO2 coating follows the layer model. In general, the growth rate of the star-shaped TiN crystals is higher than that of crystals of other shapes. For the TiO2 coating, the layer mode grow... [more]
Large-Scale Green Supplier Selection Approach under a Q-Rung Interval-Valued Orthopair Fuzzy Environment
Limei Liu, Wenzhi Cao, Biao Shi, Ming Tang
November 24, 2019 (v1)
Subject: Energy Policy
Keywords: clustering method, large-scale green supplier selection, q-RIVOF-MULTIMOORA method, q-rung interval-valued orthopair fuzzy set
As enterprises pay more and more attention to environmental issues, the green supply chain management (GSCM) mode has been extensively utilized to guarantee profit and sustainable development. Green supplier selection (GSS), which is a key segment of GSCM, has been investigated to put forward plenty of GSS approaches. At present, enterprises prefer to construct the large-scale teams of decision makers to obtain the more reasonable ranking results during GSS process. However, the existing methods pay little attention to the large-scale GSS procedure. To investigate the GSS issue with a large-scale group of decision makers, a new GSS approach under a q-rung interval-valued orthopair fuzzy environment is developed. The q-rung interval-valued orthopair fuzzy numbers are introduced to describe the evaluation information of green suppliers. Combined with a clustering approach and several clustering principles, the large-scale decision makers are divided into several subgroups. Next, the simi... [more]
A Sugarcane-Bagasse-Based Adsorbent Employed for Mitigating Eutrophication Threats and Producing Biodiesel Simultaneously
Wan Nurain Farahah Wan Basri, Hanita Daud, Man Kee Lam, Chin Kui Cheng, Wen Da Oh, Wen Nee Tan, Maizatul Shima Shaharun, Yin Fong Yeong, Ujang Paman, Katsuki Kusakabe, Evizal Abdul Kadir, Pau Loke Show, Jun Wei Lim
November 24, 2019 (v1)
Subject: Biosystems
Keywords: Adsorption, biodiesel, eutrophication, harvest, reusability, sugarcane bagasse
Eutrophication is an inevitable phenomenon, and it has recently become an unabated threat. As a positive, the thriving microalgal biomass in eutrophic water is conventionally perceived to be loaded with myriad valuable biochemical compounds. Therefore, a sugarcane-bagasse-based adsorbent was proposed in this study to harvest the microalgal biomass for producing biodiesel. By activating the sugarcane-bagasse-based adsorbent with 1.5 M of H2SO4, a highest adsorption capacity of 108.9 ± 0.3 mg/g was attained. This was fundamentally due to the surface potential of the 1.5 M H2SO4 acid-modified sugarcane-bagasse-based adsorbent possessing the lowest surface positivity value as calculated from its point of zero charge. The adsorption capacity was then improved to 192.9 ± 0.1 mg/g by stepwise optimizing the adsorbent size to 6.7−8.0 mm, adsorption medium pH to 2−4, and adsorbent dosage to 0.4 g per 100 mL of adsorption medium. This resulted in 91.5% microalgae removal efficiency. Excellent-qu... [more]
The Impact of Equilibrium Gas Pressure and Coal Particle Size on Gas Dynamic Diffusion in Coal
Chengwu Li, Yao Nie, Jianwei Tian, Yuechao Zhao, Xiaoqian Zhang
November 24, 2019 (v1)
Keywords: coal matrix, gas diffusion, gas pressure, particle size, unsteady dynamic diffusion model (UDD model)
The diffusion coefficient of gases in coal varies with time. This study aims to develop an unsteady dynamic diffusion (UDD) model based on the decay of diffusion coefficient with time and the change of integral. This study conducted a series of gas desorption and diffusion experiments with three different combinations of particle sizes and gas pressures and compared the diffusion coefficients of the three models. The UDD model exhibited good fitting results, and both the UDD and bidisperse models fitted the experimental data better than the unipore model. In addition, the dynamic diffusion coefficient (DDe) decreased rapidly in the initial stage but gradually decreased to a stable level in the later stage. All the effective diffusion coefficients of the three models negatively correlated with the particle size. In the unipore model, the diffusion coefficient of coal samples with three particle sizes increased with gas pressure. In the bidisperse and UDD models, the diffusion coefficien... [more]
Economic Dispatch of Multi-Energy System Considering Load Replaceability
Tao Zheng, Zemei Dai, Jiahao Yao, Yufeng Yang, Jing Cao
November 24, 2019 (v1)
Keywords: economic dispatch, load replaceability, multi-energy conversion, multi-energy system
By integrating gas, electricity, and cooling and heat networks, multi-energy system (MES) breaks the bondage of isolated planning and operation of independent energy systems. Appropriate scheduling of MES is critical to the operational economy, and it is essential to design scheduling strategies to achieve maximum economic benefits. In addition to the emergence of energy conversion systems, the other main novelty of MES is the multivariate of load, which offers a great optimization potential by changing load replaceability (flexibly adjusting the composition of loads). In this paper, by designing load replaceability index (LRI) of composite load in MES, its interaction mechanism with scheduling optimum is systematically analyzed. Through case studies, it is proven that the optimum can be improved by elevating load replaceability.
Monitoring and Analysis of Wave Characteristics during Pipeline End Termination Installation
Duanfeng Han, Ting Cui, Lihao Yuan, Yingfei Zan, Zhaohui Wu
November 24, 2019 (v1)
Keywords: direction spectra, monitoring system, pipeline end termination, spectral regression, wave probability distribution
Pipeline end termination (PLET) installation is an essential part of offshore pipe-laying operation. Pipe-laying operations are sensitive to pipe-laying barge motion and marine environmental conditions. Monitoring the field environment can provide a reasonable basis for planning pipe-laying. Therefore, the measurement and analysis of sea wave motion is helpful for the control and operational safety of the pipeline and vessels. In this study, an environmental monitoring system was established to measure wave motion during PLET operation. Fourier transforms were used to process images that were acquired by ultra-high-frequency X-band marine radar to extract wave parameters. The resulting wave spectra, as measured each minute, were used to simulate real-time wave data and calculate wave characteristics and regressed wave frequency and direction spectrum throughout the PLET operation. The regressed frequency, spectral density, and direction spectra were compared with the theoretical spectr... [more]
Raw Material Variability and Its Impact on the Online Adaptive Control of Cohesive Powder Blend Homogeneity Using NIR Spectroscopy
Guolin Shi, Bing Xu, Zhiqiang Zhang, Chan Yang, Shengyun Dai, Zhaozhou Lin, Xinyuan Shi, Jing Fu, Yanjiang Qiao
November 24, 2019 (v1)
Keywords: adaptive modeling algorithm, blend homogeneity, cohesive powder, near-infrared sensor, quality by design, raw material variability
It is significant to analyze the blend homogeneity of cohesive powders during pharmaceutical manufacturing in order to provide the exact content of the active pharmaceutical ingredient (API) for each individual dose unit. In this paper, an online monitoring platform using an MEMS near infrared (NIR) sensor was designed to control the bin blending process of cohesive powders. The state of blend homogeneity was detected by an adaptive algorithm, which was calibration free. The online control procedures and algorithm’s parameters were fine-tuned through six pilot experiments and were successfully transferred to the industrial production. The reliability of homogeneity detection results was validated by 16 commercial scale experiments using 16 kinds of natural product powders (NPPs), respectively. Furthermore, 19 physical quality attributes of all NPPs and the excipient were fully characterized. The blending end time was used to denote the degree of difficulty of blending. The empirical re... [more]
Research on Ecological Efficiency for the Remanufacturing Process Considering Optimization and Evaluation
Hong Peng, Zhigang Jiang, Han Wang
November 24, 2019 (v1)
Subject: Energy Policy
Keywords: ecological efficiency, evaluation, process optimization, remanufacturing
The ecological efficiency (EE) of the remanufacturing process occupies an important position in the whole index system of remanufacturing because it will directly affect the economic and environmental benefits of remanufacturing. Therefore, in order to study the EE of the remanufacturing process, a method is proposed to optimize and evaluate the EE of the remanufacturing process. In this method, firstly, the original remanufacturing sub-schemes of used components are designed according to the extracted fault characteristics; secondly, a set of optional process schemes are integrated by using directed graph (DG) to reduce the process schemes; thirdly, the objective function of EE is established, and then an ant colony algorithm with elite strategy (ES-ACO) is proposed to optimize the process schemes. After obtaining the optimal value of EE, the quality coefficient of used components can be calculated, and then numerical simulations (NS) are used to analyze the correlation between the qu... [more]
Grouping Method of Semiconductor Bonding Equipment Based on Clustering by Fast Search and Find of Density Peaks for Dynamic Matching According to Processing Tasks
Zhijun Gao, Wen Si, Zhonghua Han, Jiayu Peng, Feng Qiao
November 24, 2019 (v1)
Keywords: association matrix, CFSFDP algorithm, graph theory, semiconductor bonding equipment-grouping method
Given that the equipment for the semiconductor packaging line adopts the fixed grouping production method, thus failing to dynamically match the processing task demand capacity, in the present study, we proposed a semiconductor bonding equipment-grouping method based on processing task matching. This method sets the device group closed position constraint and the matching constraint between the device type and the processing type and uses the graph theory method to establish the device grouping model. The dynamic grouping of equipment under the capacity demand of different processing tasks was achieved by changing the relationship matrix between devices. The drawback of this grouping method is rather large grouping deviation, which we tried to solve with the clustering by fast search and find of density peaks (CFSFDP) that was added to cluster the sets of attribute information of the devices so as to obtain the maximum number of grouping groups obtained to reduce the grouping deviation... [more]
Adsorption Process and Properties Analyses of a Pure Magadiite and a Modified Magadiite on Rhodamine-B from an Aqueous Solution
Mingliang Ge, Zhuangzhuang Xi, Caiping Zhu, Guodong Liang, Yinye Yang, Guoqing Hu, Lafifa Jamal, Jahangir Alam S.M.
November 24, 2019 (v1)
Subject: Materials
Keywords: adsorption process, CTAB-Magadiite, magadiite, rhodamine-B
The result of an adsorption experiment indicated that the pure magadiite (MAG) and the modified MAG via cetyltrimethylammonium-bromide (CTAB-MAG) possessed pronounced affinity to the Rhodamine-B (Rh-B) dye molecules. CTAB-MAG was synthesized with an ion-exchange method between MAG and cetyltrimethylammonium-bromide (CTAB) in an aqueous solution. The adsorption capacities of CTAB-MAG and MAG on Rh-B were 67.19 mg/g and 48.13 mg/g, respectively; while the pH and the time were 7 and 60 min, respectively; however, the initial concentration of Rh-B was 100 mg/L, and adsorbent dosage was 1 g/L. Whereas, the adsorption capacity of CTAB-MAG was increased by 40% over MAG which indicated that CTAB-MAG can be used as an efficient low-cost adsorbent. Adsorption kinetics were consistent with the pseudo-second-order kinetic equation; the adsorption processes were dominated by film diffusion process which belonged to monomolecular layer adsorption.
Numerical Study of the Effects of Injection Fluctuations on Liquid Nitrogen Spray Cooling
Rong Xue, Yixiao Ruan, Xiufang Liu, Liang Chen, Liqiang Liu, Yu Hou
November 24, 2019 (v1)
Keywords: droplet distribution, evaporation rate, liquid nitrogen spray, mass flow rate fluctuation, temperature distribution
Spray cooling with liquid nitrogen is increasingly utilized as an efficient approach to achieve cryogenic cooling. Effects of injection mass flow rate fluctuations on the evaporation, temperature distribution, and droplet distribution of a spray field were examined by employing a validated Computational Fluid Dynamics (CFD) numerical model. The numerical results indicated that injection fluctuations enhanced the volume-averaging turbulent kinetic energy and promoted the evaporation of the whole spray field. The strengthened mass and heat transfer between the liquid nitrogen droplets and the surrounding vapor created by the fluctuating injection led to a lower temperature of the whole volume. A relatively smaller droplet size and a more inhomogeneous droplet distribution were obtained under the unsteady inlet. The changes of the frequency and the amplitude of the fluctuations had little effects on the overall spray development. The results could enrich the knowledge of the relation betw... [more]
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