LAPSE

Records Added in May 2019
Records added in May 2019
Change year: 2018 | 2019
Change month: January | February | March | April | May | June
New Approaches in Modeling and Simulation of CO2 Absorption Reactor by Activated Potassium Carbonate Solution
Maria Harja, Gabriela Ciobanu, Tatjána Juzsakova, Igor Cretescu
May 16, 2019 (v1)
Keywords: activated carbonate–bicarbonate solution, CO2 absorption, gas purification, reactor modeling
The increase of CO₂ concentration in the atmosphere is in strong relation with the human-induced warming up due to industrial processes, transportation, etc. In order to reduce the CO₂ content, end of pipe post-combustion methods can be used in addition to other methods and techniques. The CO₂ capture by absorption in potassium carbonate⁻bicarbonate activated solutions remains a viable method. In this study, a mathematical model for a packed bed reactor has been developed and tested. The mathematical model is tested for an industrial reactor based on CO₂ absorption in Carsol solutions. The proposed model was validated by resolving for CO₂ and water content, carbonate⁻bicarbonate, concentrations etc. For each operational parameter the error was calculated. The error for CO₂ concentration is up to 4%. The height of the packed reactor is calculated as function of CO₂ concentration in the final gas phase. The validated model can also be used for absorbing other CO₂ streams taking into acco... [more]
Energy-Efficient Train Driving Strategy with Considering the Steep Downhill Segment
Wentao Liu, Tao Tang, Shuai Su, Jiateng Yin, Yuan Cao, Cheng Wang
May 16, 2019 (v1)
Keywords: energy-efficient driving strategy, local optimization, rail transit, steep downhill segment, train control
Implementation of energy-efficient train driving strategy is an effective method to save train traction energy consumption, which has attracted much attention from both researchers and practitioners in recent years. Reducing the unnecessary braking during the journey and increasing the coasting distance are efficient to save energy in urban rail transit systems. In the steep downhill segment, the train speed will continue to increase without applying traction due to the ramp force. A high initial speed before stepping into the steep downhill segment will bring partial braking to prevent trains from overspeeding. Optimization of the driving strategy of urban rail trains can avoid the partial braking such that the potential energy is efficiently used and the traction energy is reduced. This paper presents an energy-efficient driving strategy optimization model for the segment with the steep downhill slopes. A numerical method is proposed to calculate the corresponding energy-efficient dr... [more]
Increasing Salt Rejection of Polybenzimidazole Nanofiltration Membranes via the Addition of Immobilized and Aligned Aquaporins
Priyesh Wagh, Xinyi Zhang, Ryan Blood, Peter M. Kekenes-Huskey, Prasangi Rajapaksha, Yinan Wei, Isabel C. Escobar
May 16, 2019 (v1)
Subject: Materials
Keywords: aquaporins, biomimetic, immobilization, nanofiltration
Aquaporins are water channel proteins in cell membrane, highly specific for water molecules while restricting the passage of contaminants and small molecules, such as urea and boric acid. Cysteine functional groups were installed on aquaporin Z for covalent attachment to the polymer membrane matrix so that the proteins could be immobilized to the membranes and aligned in the direction of the flow. Depth profiling using x-ray photoelectron spectrometer (XPS) analysis showed the presence of functional groups corresponding to aquaporin Z modified with cysteine (Aqp-SH). Aqp-SH modified membranes showed a higher salt rejection as compared to unmodified membranes. For 2 M NaCl and CaCl₂ solutions, the rejection obtained from Aqp-SH membranes was 49.3 ± 7.5% and 59.1 ± 5.1%. On the other hand, the rejections obtained for 2 M NaCl and CaCl₂ solutions from unmodified membranes were 0.8 ± 0.4% and 1.3 ± 0.2% respectively. Furthermore, Aqp-SH membranes did not show a significant decrease in salt... [more]
Incremental Parameter Estimation under Rank-Deficient Measurement Conditions
Kris Villez, Julien Billeter, Dominique Bonvin
May 16, 2019 (v1)
Keywords: extents, graph theory, model identification, observability, optimal clustering, parameter estimation, state decoupling
The computation and modeling of extents has been proposed to handle the complexity of large-scale model identification tasks. Unfortunately, the existing extent-based framework only applies when certain conditions apply. Most typically, it is required that a unique value for each extent can be computed. This severely limits the applicability of this approach. In this work, we propose a novel procedure for parameter estimation inspired by the existing extent-based framework. A key difference with prior work is that the proposed procedure combines structural observability labeling, matrix factorization, and graph-based system partitioning to split the original model parameter estimation problem into parameter estimation problems with the least number of parameters. The value of the proposed method is demonstrated with an extensive simulation study and a study based on a historical data set collected to characterize the isomerization of α -pinene. Most importantly, the obtained resul... [more]
Effect of Temperature and Microwave Power Levels on Microwave Drying Kinetics of Zhaotong Lignite
Pengfei Zhao, Chenhui Liu, Wenwen Qu, Zhixiu He, Jiyun Gao, Lijuan Jia, Siping Ji, Roger Ruan
May 16, 2019 (v1)
Keywords: apparent activation energy, effective diffusion coefficient, hot-air drying kinetics, lignite, microwave drying kinetics
Microwave drying is a promising and effective way to drying and upgrading lignite. The influence of temperature (100⁻140 °C) and microwave power levels (500⁻800 W) on thin-layer drying characteristics of Zhaotong lignite under microwave irradiation were investigated. Fourteen thin-layer drying models were used to analyze the microwave drying process while six thin-layer drying models were used to analyze the hot-air drying process. The microwave drying processes at all temperature (100⁻140 °C) or low microwave power levels (500⁻700 W) exhibited four periods: a warm-up period, a short constant period, the first and second falling rate period, while one falling rate period was found during hot-air drying. The effective diffusion coefficient of lignite were calculated and it increases with increasing temperature and microwave power levels. During microwave drying, the two-term exponential model is the most suitable model for all applied conditions, while the Modified Page model is the mos... [more]
The Accident Path of Coal Mine Gas Explosion Based on 24Model: A Case Study of the Ruizhiyuan Gas Explosion Accident
Gui Fu, Ziqi Zhao, Chuanbo Hao, Qiang Wu
May 16, 2019 (v1)
Keywords: 24Model, accident prevention, action path, coal mine, gas explosion accident, safety management
In order to effectively prevent coal mine accidents, we selected the most serious type of accident in coal mines—gas explosions—as the research object. Based on the accident causation model (24Model), we propose an action path and analysis steps of accidents caused by different employees in the organization. A gas explosion coal mine accident was analyzed using the 24Model and the proposed action path, and 12 unsafe actions, 3 unsafe states, 4 habitual behaviors, 10 safety management systems, and 10 safety cultures were obtained. Case analysis results show that by using the 24Model and path analysis the proposed effect can help employees to clearly identify the cause of the accident, to better understand the logical relationship with the causes of the accident, improve the effectiveness of training, and effectively prevent similar accidents. The 24Model and the proposed path can be used to comprehensively analyze the reasons for and help to effectively prevent coal mine gas explosion a... [more]
Experimental Study on Electric Potential Response Characteristics of Gas-Bearing Coal During Deformation and Fracturing Process
Zhonghui Li, Yue Niu, Enyuan Wang, Lanbo Liu, Honghao Wang, Mingfu Wang, Muhammad Ali
May 16, 2019 (v1)
Subject: Other
Keywords: charge separation, damage evolution, electrical potential, gas adsorption, gas-bearing coal
Coal mass is deformed and fractured under stress to generate electrical potential (EP) signals. The mechanical properties of coal change with the adsorption of gas. To investigate the EP response characteristics of gas-bearing coal during deformation and fracture, a test system to monitor multi-parameters of gas-bearing coal under load was designed. The results showed that abundant EP signals were generated during the loading process and the EP response corresponded well with the stress change and crack expansion, and validated this with the results from acoustic emission (AE) and high-speed photography. The higher stress level and the greater the sudden stress change led to the greater EP abnormal response. With the increase of gas pressure, the confining action and erosion effect are promoted, causing the damage evolution impacted and failure characteristics changes. As a result, the EP response is similar while the characteristics were promoted. The EP response was generated due to... [more]
Seepage Characteristics and Its Control Mechanism of Rock Mass in High-Steep Slopes
Hong Li, Hongyuan Tian, Ke Ma
May 16, 2019 (v1)
Keywords: fractured rock, high-steep slope, hydro-power, permeability, seepage control
In Southwest China large-scale hydropower projects, the hydraulic conductivity and fracture aperture within the rock mass of a reservoir bank slope has dramatically undergone a time series of evolution during dam abutment excavation, reservoir impounding and fluctuation operation, and discharge atomization. Accordingly, seepage control measures by hydro-structures such as drainage or water insulation curtains should be guided by scientific foundation with a dynamic process covering life-cycle performance. In this paper, the up-to-date status of studying the evolution mechanism of seepage characteristics relating to fractured rock hydraulics from experimental samples to the engineering scale of the rock mass is reviewed for the first time. Then, the experimental findings and improved practice method on nonlinear seepage flow under intensive pressure drives are introduced. Finally, the scientific progress made in fractured rock seepage control theory and optimization of the design techno... [more]
Experimental Study on Mixed Mode Fracture Behavior of Sandstone under Water⁻Rock Interactions
Wen Hua, Jianxiong Li, Shiming Dong, Xin Pan
May 16, 2019 (v1)
Subject: Other
Keywords: degradation mechanism, fracture criteria, mixed mode fracture resistance, T-stress, water–rock interaction
Water⁻rock interactions can significantly deteriorate the physical and mechanical properties of rocks, and it has been identified as one of the significant factors influencing the stability and safety of structures in rock⁻soil engineering. In this study, the fracture mechanical properties of sandstone under periodic water⁻rock interactions and long-term immersion have been studied with central cracked Brazilian disk specimens. The degradation mechanism of water⁻rock interactions was also studied using a scanning electron microscope (SEM). Finally, the generalized maximum tangential stress and generalized maximum tangential strain criteria were adopted to evaluate the experimental results. The results show that periodic water⁻rock interactions can remarkably affect the fracture resistance of sandstone. With the increase in the number of cycles, the pure mode I, pure mode II, and mixed mode fracture toughness decreases greatly, however, the values of KIf/KIC and KIIf/KIC decrease slight... [more]
A Hybrid Energy Feature Extraction Approach for Ship-Radiated Noise Based on CEEMDAN Combined with Energy Difference and Energy Entropy
Yuxing Li, Xiao Chen, Jing Yu
May 16, 2019 (v1)
Keywords: complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), energy difference (ED), energy entropy (EE), hybrid energy feature extraction, ship-radiated noise (S-RN)
Influenced by the complexity of ocean environmental noise and the time-varying of underwater acoustic channels, feature extraction of underwater acoustic signals has always been a difficult challenge. To solve this dilemma, this paper introduces a hybrid energy feature extraction approach for ship-radiated noise (S-RN) based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) combined with energy difference (ED) and energy entropy (EE). This approach, named CEEMDAN-ED-EE, has two main advantages: (i) compared with empirical mode decomposition (EMD) and ensemble EMD (EEMD), CEEMDAN has better decomposition performance by overcoming mode mixing, and the intrinsic mode function (IMF) obtained by CEEMDAN is beneficial to feature extraction; (ii) the classification performance of the single energy feature has some limitations, nevertheless, the proposed hybrid energy feature extraction approach has a better classification performance. In this paper, we first deco... [more]
Process Modeling and Evaluation of Plasma-Assisted Ethylene Production from Methane
Evangelos Delikonstantis, Marco Scapinello, Georgios D. Stefanidis
May 16, 2019 (v1)
Keywords: electrified process, Ethylene, non-oxidative methane coupling, non-thermal plasma, process modeling
The electrification of the petrochemical industry, imposed by the urgent need for decarbonization and driven by the incessant growth of renewable electricity share, necessitates electricity-driven technologies for efficient conversion of fossil fuels to chemicals. Non-thermal plasma reactor systems that successfully perform in lab scale are investigated for this purpose. However, the feasibility of such electrified processes at industrial scale is still questionable. In this context, two process alternatives for ethylene production via plasma-assisted non-oxidative methane coupling have conceptually been designed based on previous work of our group namely, a direct plasma-assisted methane-to-ethylene process (one-step process) and a hybrid plasma-catalytic methane-to-ethylene process (two-step process). Both processes are simulated in the Aspen Plus V10 process simulator and also consider the technical limitations of a real industrial environment. The economically favorable operating w... [more]
Advances in Mathematical Modeling of Gas-Phase Olefin Polymerization
Mohd Farid Atan, Mohd Azlan Hussain, Mohammad Reza Abbasi, Mohammad Jakir Hossain Khan, Muhamad Fazly Abdul Patah
May 16, 2019 (v1)
Keywords: gas phase, kinetics, Modelling, olefin
Mathematical modeling of olefin polymerization processes has advanced significantly, driven by factors such as the need for higher-quality end products and more environmentally-friendly processes. The modeling studies have had a wide scope, from reactant and catalyst characterization and polymer synthesis to model validation with plant data. This article reviews mathematical models developed for olefin polymerization processes. Coordination and free-radical mechanisms occurring in different types of reactors, such as fluidized bed reactor (FBR), horizontal-stirred-bed reactor (HSBR), vertical-stirred-bed reactor (VSBR), and tubular reactor are reviewed. A guideline for the development of mathematical models of gas-phase olefin polymerization processes is presented.
The Effects of Backfill Mining on Strata Movement Rule and Water Inrush: A Case Study
Jian Hao, Yongkui Shi, Jiahui Lin, Xin Wang, Hongchun Xia
May 16, 2019 (v1)
Subject: Other
Keywords: backfill mining, floor failure depth, ground pressure, strata movement, water inrush prevention
Backfill mining is widely used to control strata movement and improve the stress environment in China’s coal mines. In the present study, the effects of backfill mining on strata movement and water inrush were studied based on a case study conducted in Caozhuang Coal Mine. The in-situ investigation measured abutment pressure distribution (APD), roof floor displacement (RFD), and vertical stress in the backfill area. Results are as follows: (i) The range and peak of APD, RFD, and vertical stress in the backfill area are smaller than in traditional longwall mining with the caving method. (ii) Backfill mining could change the movement form and amplitude of overburden and improve the ground pressure environment. (iii) Floor failure depth (FFD) is much smaller in backfill mining. Backfill mining can be an effective method for floor water inrush prevention.
Comparison of Three Deoxidation Agents for Ozonated Broths Used in Anaerobic Biotechnological Processes
Ewelina Pawlikowska, Jaroslaw Domanski, Piotr Dziugan, Joanna Berlowska, Weronika Cieciura-Wloch, Krzysztof Smigielski, Dorota Kregiel
May 16, 2019 (v1)
Subject: Biosystems
Keywords: deoxidation, iron sulfate, Metschnikowia sp., ozonation, ultrasound
Anaerobic fermentation of organic compounds is used in many biotechnological processes and has been the subject of much research. A variety of process conditions and different growth media can be used to obtain microbial metabolites. The media must be free from contamination before fermentation. Sterilization is most often achieved by applying heat or other treatments, such as ozonation. Sterilization of liquid media using ozone can be very beneficial, but this method introduces high concentrations of residual oxygen, which inhibit anaerobic processes. Deoxidation is therefore necessary to remove the oxygen from ozonated broths. This study evaluates the effectiveness of three deoxidation agents for two kinds of fermentation media based on malt or molasses: ultrasound, iron(II) sulfate, and Metschnikowia sp. yeast. The time needed for deoxidation varied, depending on the kind of broth and the deoxidation agent. In general, the dynamics of oxygen removal were faster in malt broth. A comp... [more]
Integrated Hydrolysis of Mixed Agro-Waste for a Second Generation Biorefinery Using Nepenthes mirabilis Pod Digestive Fluids
Nkosikho Dlangamandla, Seteno Karabo Obed Ntwampe, Justine Oma Angadam, Elie Fereche Itoba-Tombo, Boredi Silas Chidi, Lukhanyo Mekuto
May 16, 2019 (v1)
Subject: Biosystems
Keywords: agro-waste, biorefinery, carboxylesterases, cellulases, Nepenthes mirabilis, total reducing sugars, xylanase, β-glucosidase
To sustainably operate a biorefinery with a low cost input in a commercial setting, the hydrolysis of lignocellulosic biomass must be undertaken in a manner which will impart environmental tolerance while reducing fermenter inhibitors from the delignification process. The challenge lies with the highly recalcitrant lignin structure, which limits the conversion of the holocelluloses to fermentable total reducing sugars (TRS). Due to these challenges, sustainable and innovative methods to pre-treat biomass must be developed for delignocellulolytic operations. Herein, Nepenthes mirabilis digestive fluids shown to have ligninolytic, cellulolytic and xylanolytic activities were used as an enzyme cocktail to hydrolyse mixed agro-waste constituted by Citrus sinensis (orange), Malus domestica (apple) peels, cobs from Zea mays (maize) and Quercus robur (oak) yard waste. The digestive fluids contained carboxylesterases (529.41 ± 30.50 U/L), β-glucosidases (251.94 ± 11.48 U/L) and xylanases (36.0... [more]
Smart Community Energy Cost Optimization Taking User Comfort Level and Renewable Energy Consumption Rate into Consideration
Kun Shi, Dezhi Li, Taorong Gong, Mingyu Dong, Feixiang Gong, Yajie Sun
May 16, 2019 (v1)
Keywords: renewable energy consumption rate, smart communities, user comfort levels
With the rapid development of smart community technologies, how to improve user comfort levels and make full use of renewable energy have become urgent problems. This paper proposes an optimization algorithm to minimize daily energy costs while considering user comfort level and renewable energy consumption rate. In this paper, the structure of a typical smart community and the output models of all components installed in the community are introduced first. Then, the characteristics of different types of loads are analyzed, followed by defining the coefficients of user comfort level. In this step, the influence of load-scheduling on user comfort level and the renewable energy consumption rate is emphasized. Finally, based on the time-of-use gas price, this paper optimizes the daily energy costs for an off-grid community under the constraints of the comfort level and renewable energy consumption rate. Results show that scheduling transferable loads and interruptible loads are not indepe... [more]
Investigation of Pore-Formers to Modify Extrusion-Spheronized CaO-Based Pellets for CO₂ Capture
Zonghao Zhang, Shuai Pi, Donglin He, Changlei Qin, Jingyu Ran
May 16, 2019 (v1)
Subject: Materials
Keywords: anti-attrition, calcium looping, Carbon Dioxide Capture, chemical sorption, pore-former particle size
The application of circulating fluidized bed technology in calcium looping (CaL) requires that CaO-based sorbents should be manufactured in the form of spherical pellets. However, the pelletization of powdered sorbents is always hampered by the problem that the mechanical strength of sorbents is improved at the cost of loss in CO₂ sorption performance. To promote both the CO₂ sorption and anti-attrition performance, in this work, four kinds of pore-forming materials were screened and utilized to prepare sorbent pellets via the extrusion-spheronization process. In addition, impacts of the additional content of pore-forming material and their particle sizes were also investigated comprehensively. It was found that the addition of 5 wt.% polyethylene possesses the highest CO₂ capture capacity (0.155 g-CO₂/g-sorbent in the 25th cycle) and mechanical performance of 4.0 N after high-temperature calcination, which were about 14% higher and 25% improved, compared to pure calcium hydrate pellet... [more]
Multiscale and Multi-Granularity Process Analytics: A Review
Marco S. Reis
May 16, 2019 (v1)
Keywords: data aggregation, industrial big data, multi-granularity methods, multiscale methods
As Industry 4.0 makes its course into the Chemical Processing Industry (CPI), new challenges emerge that require an adaptation of the Process Analytics toolkit. In particular, two recurring classes of problems arise, motivated by the growing complexity of systems on one hand, and increasing data throughput (i.e., the product of two well-known “V’s„ from Big Data: Volume × Velocity) on the other. More specifically, as enabling IT technologies (IoT, smart sensors, etc.) enlarge the focus of analysis from the unit level to the entire plant or even to the supply chain level, the existence of relevant dynamics at multiple scales becomes a common pattern; therefore, multiscale methods are called for and must be applied in order to avoid biased analysis towards a certain scale, compromising the benefits from the balanced exploitation of the information content at all scales. Also, these same enabling technologies currently collect large volumes of data at high-sampling rates, creating a flood... [more]
Effect of Supercritical Fluid Extraction Process on Chemical Composition of Polianthes tuberosa Flower Extracts
Javier C. Fragoso-Jiménez, Ernesto Tapia-Campos, Mirna Estarron-Espinosa, Rodrigo Barba-Gonzalez, Ma. Claudia Castañeda-Saucedo, Gustavo A. Castillo-Herrera
May 16, 2019 (v1)
Subject: Biosystems
Keywords: chemical composition, Polianthes tuberosa, supercritical fluid extraction
Supercritical fluid extracts from flowers of Polianthes tuberosa var. double were ob tained using carbon dioxide as a solvent. Yield extract obtained was 2.5%. The effects of the pressure process (18 MPa, 28 MPa, and 38 MPa) and temperature process (313 K, 323 K, and 333 K) on the volatile composition of tuberose flowers extracts were evaluated, and a significant variation in chemical composition was found. Characteristic compounds of tuberose as methyl isoeugenol, benzyl benzoate, methyl anthranilate, pentacosene, and heptacosene were obtained mainly at 18 MPa and 333 K process conditions, and could be used in the perfume or fragrance industry. Components such as geraniol, farnesol, and methyl eugenol were also obtained, these extracts could be used in the development of cosmeceutical products. This work allowed to identification of the chemical composition profile and evaluation of the changes in tuberose extracts due to the extraction process.
A Systems Engineering Approach to Performance-Based Maintenance Services Design
Maria Holgado
May 16, 2019 (v1)
Subject: Energy Policy
Keywords: IDEF0, industrial services, maintenance services, outcome-based services, performance-based services, systems engineering
Traditionally, industrial services have been mainly transaction-based, i.e., the equipment user pays the service provider for getting a job done or providing assistance and support for equipment operations. Recently, a trend has emerged of increasing the relational perspective of these services, which are becoming more oriented towards customer value and service performance levels. Among these emergent industrial services, performance-based services represent an opportunity for equipment manufacturers to transform their service offerings towards more relational and customer-oriented services. The purpose of this work is to study the design of a generic performance-based maintenance service under a novel perspective given by systems engineering. This paper is intended to serve as a starting point to fully understand this type of services and to develop a method that can support equipment manufacturers who wish to advance their service offerings.
Simulation Study on the Influence of Gas Mole Fraction and Aqueous Activity under Phase Equilibrium
Weilong Zhao, Hao Wu, Jing Wen, Xin Guo, Yongsheng Zhang, Ruirui Wang
May 16, 2019 (v1)
Keywords: activity, gas mole fraction, phase equilibrium, threshold value, UNIFAC
This work explored the influence of gas mole fraction and activity in aqueous phase while predicting phase equilibrium conditions. In pure gas systems, such as CH₄, CO₂, N₂ and O₂, the gas mole fraction in aqueous phase as one of phase equilibrium conditions was proposed, and a simplified correlation of the gas mole fraction was established. The gas mole fraction threshold maintaining three-phase equilibrium was obtained by phase equilibrium data regression. The UNIFAC model, the predictive Soave-Redlich-Kwong equation and the Chen-Guo model were used to calculate aqueous phase activity, the fugacity of gas and hydrate phase, respectively. It showed that the predicted phase equilibrium pressures are in good agreement with published phase equilibrium experiment data, and the percentage of Absolute Average Deviation Pressures are given. The water activity, gas mole fraction in aqueous phase and the fugacity coefficient in vapor phase are discussed.
Experimental Study on the Shear-Flow Coupled Behavior of Tension Fractures Under Constant Normal Stiffness Boundary Conditions
Changsheng Wang, Yujing Jiang, Hengjie Luan, Jiankang Liu, Satoshi Sugimoto
May 16, 2019 (v1)
Subject: Other
Keywords: constant normal stiffness conditions, hydraulic aperture, rock fracture, shear-flow coupled test, transmissivity
This study experimentally investigated the effects of fracture surface roughness, normal stiffness, and initial normal stress on the shear-flow behavior of rough-walled rock fractures. A series of shear-flow tests were performed on two rough fractures, under various constant normal stiffness (CNS) boundary conditions. The results showed that the CNS boundary conditions have a significant influence on the mechanical and hydraulic behaviors of fractures, during shearing. The peak shear stress shows an increasing trend with the increases in the initial normal stress and fracture roughness. The residual shear stress increases with increasing the surface roughness, normal stiffness, and initial normal stress. The dilation of fracture is restrained more significantly under high normal stiffness and initial normal stress conditions. The hydraulic tests show that the evolutions of transmissivity and hydraulic aperture exhibit a three-stage behavior, during the shear process—a slight decrease s... [more]
The Study on Extraction Process and Analysis of Components in Essential Oils of Black Pepper (Piper nigrum L.) Seeds Harvested in Gia Lai Province, Vietnam
Thien Hien Tran, Le Ke Ha, Duy Chinh Nguyen, Tan Phat Dao, Le Thi Hong Nhan, Dai Hai Nguyen, Trinh Duy Nguyen, Dai-Viet N. Vo, Quoc Toan Tran, Long Giang Bach
May 16, 2019 (v1)
Subject: Biosystems
Keywords: black pepper (Piper nigrum L.), essential oils, chemical composition analysis, GC-MS, hydrodistillation
Black pepper (Piper nigrum L.) is a tropical crop with extensive medicinal potential in ethnomedicine and nutraceutical applications. The essential oil of black pepper finds wide applications in inhabitation of respiratory infections and soothing of muscular pains due to its warming and energizing property. The pungent bioactive piperine is responsible for this function, and therefore, efficient technology is required for an optimal extraction process of this compound. In the present article, we have developed a procedure for extracting black pepper essential oil from Vietnam, optimizing conditions that affect the extraction process. The effect of process parameters, namely material size, preservation method, the concentration of sodium chloride, the concentration of soak time, the ratio of material to water, temperature extraction, time extraction on the extraction yield, and relative efficiency were investigated. Results demonstrated that 20 g of black pepper milled with a mesh size... [more]
Application of Data Mining in an Intelligent Early Warning System for Rock Bursts
Xuejun Zhu, Xiaona Jin, Dongdong Jia, Naiwei Sun, Pu Wang
May 16, 2019 (v1)
Keywords: clustering analysis, data mining, data warehouse, intelligent early warning, rock burst
In view of rock burst accidents frequently occurring, a basic framework for an intelligent early warning system for rock bursts (IEWSRB) is constructed based on several big data technologies in the computer industry, including data mining, databases and data warehouses. Then, a data warehouse is modeled with regard to monitoring the data of rock bursts, and the effective application of data mining technology in this system is discussed in detail. Furthermore, we focus on the K-means clustering algorithm, and a data visualization interface based on the Browser/Server (B/S) mode is developed, which is mainly based on the Java language, supplemented by Cascading Style Sheets (CSS), JavaScript and HyperText Markup Language (HTML), with Tomcat, as the server and Mysql as the JavaWeb project of the rock burst monitoring data warehouse. The application of data mining technology in IEWSRB can improve the existing rock burst monitoring system and enhance the prediction. It can also realize real... [more]
Change year: 2018 | 2019
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