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Records Added in 2020
Records added in 2020
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39. LAPSE:2020.1246
Comparison of Two Different Designs of a Scraped Surface Crystallizer for Desalination Effect and Hydraulic and Thermodynamic Numbers
December 22, 2020 (v1)
Subject: Process Design
Keywords: desalination plant design, freeze desalination, scraped surface crystallizer, water purification, water treatment
The design of a desalination plant is most important if the desired product purity has to be as high as possible. This is also true for freeze crystallization plants. A correct solid-to-liquid ratio has to be ensured when pressing is used as a post-treatment. Thus, the dependence of the overall plant design on the achieved ice quality but also on different hydraulic and thermodynamic numbers is important. In this research, a scraped screw crystallizer plant is presented and examined for two different screw designs. Experiments with a low initial concentration, as for the usage to desalinate groundwater to gain it as process water, were conducted. Furthermore, solutions with high initial concentrations simulating seawater to produce potable water were used as another set of test solutions. The findings showed that neither of the screw designs is more favorable than the other, but it is important to have a plant design fitting the existing parameters on site.
40. LAPSE:2020.1245
Preparation of Curcumin Nanosuspension with Gum Arabic as a Natural Stabilizer: Process Optimization and Product Characterization
December 22, 2020 (v1)
Subject: Food & Agricultural Processes
Keywords: curcumin, gum arabic, high speed homogenization, nanosuspension, response surface methodology
Low aqueous solubility and poor bioavailability of curcumin have limited its application in various fields. One approach to address this issue is to formulate a nanosuspension that incorporates curcumin, which has been previously shown to exhibit remarkably improved solubility in comparison with that of a bare compound. In this study, the preparation process of curcumin nanosuspension was optimized with a median particle size as the outcome. Gum arabic was used as a natural polymeric surfactant and the suspension was formulated using high speed homogenization. Optimization results, realized via a response surface methodology, showed that a minimum median particle size (8.524 µm) could be attained under the following conditions: curcumin:gum arabic ratio of 1:6 g/g; homogenization speed of 8300 rpm and homogenization time of 40 min. Under these conditions, the particle size of obtained suspension was shown to be consistent for around seven days without major aggregation. The homogenizat... [more]
41. LAPSE:2020.1244
Whole-Cell Biotransformation of 1,12-Dodecanedioic Acid from Coconut Milk Factory Wastewater by Recombinant CYP52A17SS Expressing Saccharomyces cerevisiae
December 22, 2020 (v1)
Subject: Food & Agricultural Processes
Keywords: biotransformation, cytochrome P450, dodecanedioic acid, hydroxydodecanoic acid, Saccharomyces cerevisiae
Biotransformation of fatty acids from renewable wastewater as feedstock to value-added chemicals is a fascinating commercial opportunity. α,ω-Dicarboxylic acids (DCAs) are building blocks in many industries, such as polymers, cosmetic intermediates, and pharmaceuticals, and can be obtained by chemical synthesis under extreme conditions. However, biological synthesis can replace the traditional chemical synthesis using cytochrome P450 enzymes to oxidize fatty acids to DCAs. Saccharomyces cerevisiae BY(2R)/pYeDP60-CYP52A17SS (BCM), a transgenic strain expressing the galactose-inducible CYP52A17SS cytochrome P450 enzyme, was able to grow in a coconut milk factory wastewater (CCW) medium and produced 12-hydroxydodecanoic acid (HDDA) and 1,12-dodecanedioic acid (DDA). The supplementation of CCW with 10 g/L yeast extract and 20 g/L peptone (YPCCW) markedly increased the yeast growth rate and the yields of 12-HDDA and 1,12-DDA, with the highest levels of approximately 60 and 38 µg/L, respecti... [more]
42. LAPSE:2020.1243
Effect of Bed Particle Size on Thermal Performance of a Directly-Irradiated Fluidized Bed Gas Heater
December 22, 2020 (v1)
Subject: Other
Keywords: fluidized bed, gas heater, particle size, silicon carbide, solar thermal energy
There is a growing interest in a fluidized bed particle receiver that directly irradiates sunlight to particles in the fluidized bed as a solar thermal collector for heating. Thermal performance of directly-irradiated fluidized bed gas heater is strongly affected by the physical properties of the particles. The effect of SiC particle size on heat transfer characteristics in the solar fluidized bed gas heater (50 mm-ID × 100 mm high) has been determined. The outlet gas temperatures showed a maximum value with increasing gas velocity due to the particles motion by bubble behavior in the bed, and the maximum values were found at 3.6 times of Umf for fine SiC and less than 2.0 times of Umf for coarse SiC. Heat absorption from the receiver increased with increasing gas velocity, showing with maximum 18 W for the fine SiC and 23 W for the coarse SiC at 4.5 times of Umf. The thermal efficiency of the receiver increased with increasing gas velocity, but was affected by the content of finer par... [more]
43. LAPSE:2020.1242
Characterization of HCN-Derived Thermal Polymer: Implications for Chemical Evolution
December 22, 2020 (v1)
Subject: Materials
Keywords: alkaline hydrothermal systems, chemical evolution, HCN-derived thermal polymer, thermolysis
Hydrogen cyanide (HCN)-derived polymers have been recognized as sources of relevant organic molecules in prebiotic chemistry and material sciences. However, there are considerable gaps in the knowledge regarding the polymeric nature, the physicochemical properties, and the chemical pathways along polymer synthesis. HCN might have played an important role in prebiotic hydrothermal environments; however, only few experiments use cyanide species considering hydrothermal conditions. In this work, we synthesized an HCN-derived thermal polymer simulating an alkaline hydrothermal environment (i.e., HCN (l) 0.15 M, 50 h, 100 °C, pH approximately 10) and characterized its chemical structure, thermal behavior, and the hydrolysis effect. Elemental analysis and infrared spectroscopy suggest an important oxidation degree. The thermal behavior indicates that the polymer is more stable compared to other HCN-derived polymers. The mass spectrometric thermal analysis showed the gradual release of severa... [more]
44. LAPSE:2020.1241
MicroRNAs: Biogenesis, Functions and Potential Biomarkers for Early Screening, Prognosis and Therapeutic Molecular Monitoring of Nasopharyngeal Carcinoma
December 22, 2020 (v1)
Subject: Biosystems
Keywords: biomarker, circulating microRNA, microRNA, nasopharyngeal carcinoma
According to reports published, the aberrant expression of microRNAs (miRNAs), a class of 19−25 nucleotide-long small non-coding RNAs, is responsible for human cancers, including nasopharyngeal cancer (NPC). The dysregulation of miRNAs that act either as a tumor suppressor or oncogene, leading to a wide range of NPC pathogenesis pathways, includes the proliferation, invasion, migration as well as the metastasis of NPC cells. This article reviews and highlights recent advances in the studies of miRNAs in NPC, with a specific demonstration of the functions of miRNA, especially circulating miRNAs, in the pathway of NPC pathogenesis. Additionally, the possible use of miRNAs as early screening and prognostic biomarkers and for therapeutic molecular monitoring has been extensively studied.
45. LAPSE:2020.1240
As-Synthesized Oleic Amido Propyl Betaine Surfactant Mixture and the Effect on the Crude Oil−Seawater Interfacial Tension
December 22, 2020 (v1)
Subject: Materials
Keywords: characterization, surfactant, ultra-low IFT
As-synthesized oleic amido propyl betaine surfactant mixture was developed through a slight modification of a conventional two-step betaine synthesis process of amidation and quaternization reactions. This method is a “direct formulating through synthesis” to achieve a targeted interfacial property (interfacial tension or IFT) of the as-synthesized surfactant. Oil−water IFT was measured in the crude oil−seawater system at 96 °C. The result showed that the as-synthesized surfactant was able to reduce crude oil−seawater IFT to the ultra-low level (<0.01 mN/m). As the finding emerged, the investigation was conducted to identify the elements that would bring the characteristic of ultra-low IFT. The characterization of the surfactant using FTIR, TG-IR, and HPLC suggested that unreacted materials associated with the surfactant remained, such as the carryover of a fatty amide from the intermediate process, residues of N, N trimethylene dimethylamine and sodium chloride as a by-product, and... [more]
46. LAPSE:2020.1239
Radial Movement Optimization Based Optimal Operating Parameters of a Capacitive Deionization Desalination System
December 22, 2020 (v1)
Subject: Process Design
Keywords: capacitive deionization, desalination, modern optimization, performance improvement
The productivity of the capacitive deionization (CDI) system is enhanced by determining the optimum operational and structural parameters using radial movement optimization (RMO) algorithm. Six different parameters, i.e., pool water concentration, freshwater recovery, salt ion adsorption, lowest concentration point, volumetric (based on the volume of deionized water), and gravimetric (based on salt removed) energy consumptions are used to evaluate the performance of the CDI process. During the optimization process, the decision variables are represented by the applied voltage, capacitance, flow rate, spacer volume, and cell volume. Two different optimization techniques are considered: single-objective and multi-objective functions. The obtained results by RMO optimizer are compared with those obtained using a genetic algorithm (GA). The results demonstrated that the RMO optimization technique is useful in exploring all possibilities and finding the optimum conditions for operating the... [more]
47. LAPSE:2020.1238
An Enhanced Segment Particle Swarm Optimization Algorithm for Kinetic Parameters Estimation of the Main Metabolic Model of Escherichia Coli
December 22, 2020 (v1)
Subject: System Identification
Keywords: kinetic model, kinetic parameters estimation, metabolic engineering, PSO algorithm, Se-PSO algorithm
Building a biologic model that describes the behavior of a cell in biologic systems is aimed at understanding the physiology of the cell, predicting the production of enzymes and metabolites, and providing a suitable data that is valid for bio-products. In addition, building a kinetic model requires the estimation of the kinetic parameters, but kinetic parameters estimation in kinetic modeling is a difficult task due to the nonlinearity of the model. As a result, kinetic parameters are mostly reported or estimated from different laboratories in different conditions and time consumption. Hence, based on the aforementioned problems, the optimization algorithm methods played an important role in addressing these problems. In this study, an Enhanced Segment Particle Swarm Optimization algorithm (ESe-PSO) was proposed for kinetic parameters estimation. This method was proposed to increase the exploration and the exploitation of the Segment Particle Swarm Optimization algorithm (Se-PSO). The... [more]
48. LAPSE:2020.1237
Rapid TLC with Densitometry for Evaluation of Naproxen Stability
December 22, 2020 (v1)
Subject: Process Design
Keywords: naproxen, stability testing, stress degradation, TLC-densitometry
The purpose of the work was to develop such chromatographic conditions that allowed to separate as many naproxen degradation products as possible. In order to follow this process, thin-layer chromatography (TLC) coupled with densitometry and spectrodensitometry was used. A forced degradation study was performed using an ethanolic solution of naproxen spotted on silica gel plates, existing in the form of an aqueous solution at various pH values, and as solution prepared in saline and in hydrogen peroxide. Degradative effect of UV light on naproxen was watched in the context of naproxen spotted on plates precoated with silica gel and exposed to UV light, and also for its solution treated with UV light. However, the solution of naproxen prepared in water at pH ≈ 2.60 undergoes the largest changes as the results of its exposure to UV light during 10 h. Stressed samples of naproxen were analyzed by using a new and well validated TLC procedure including toluene (TOL)—acetone (ACE)—chloroform... [more]
49. LAPSE:2020.1236
Stretchable and Flexible Thin Films Based on Expanded Graphite Particles
December 22, 2020 (v1)
Subject: Materials
Keywords: expanded graphite, flexible, polydimethylsiloxane, stretchable, thin films
Stretchable and flexible graphite films can be effectively applied as functional layers in the progressively increasing field of stretchable and flexible electronics. In this paper, we focus on the feasibility of making stretchable and flexible films based on expanded graphite particles on a polymeric substrate material, polydimethylsiloxane (PDMS). The expanded graphite particles used in this work are prepared by utilizing bath sonication processes at the ultrasonic frequency of either the commercially available graphite flakes or graphite particles obtained through electrolysis under the interstitial substitution of silver and sulfate, respectively. The X-ray diffraction (XRD) patterns confirm that, due to the action of the bath sonication intercalation of graphite taking place, the resistances of the as-fabricated thin films is ultimately lowered. Mechanical characterizations, such as stretchability, flexibility and reliability tests were performed using home-made tools. The films w... [more]
50. LAPSE:2020.1235
Optimization of CCUS Supply Chains for Some European Countries under the Uncertainty
December 17, 2020 (v1)
Subject: Process Operations
Keywords: CCUS supply chain, mathematical model, Optimization, stochastic model
This paper develops a two-stage stochastic mixed integer linear programming model to optimize Carbon Capture, Utilization and Storage (CCUS) supply chains in Italy, Germany and the UK. Few works are present in the literature about this topic, thus this paper overcomes this limitation considering carbon supply chains producing different products. The objective of the numerical models is to minimize expected total costs, under the uncertainties of the production costs of carbon-dioxide-based compounds. Once carbon dioxide emissions that should be avoided are fixed, according to environmental protection requirements for each country, the optimal design of these supply chains is obtained finding the distribution of carbon dioxide captured between utilization and storage sections, the amount of different carbon-based products and the best connection between each element inside the system. The expected total costs for the CCUS supply chain of Italy, Germany and the UK are, respectively, 77.3... [more]
51. LAPSE:2020.1234
Heat and Mass Transfer during Lignocellulosic Biomass Torrefaction: Contributions from the Major Components—Cellulose, Hemicellulose, and Lignin
December 17, 2020 (v1)
Subject: Modelling and Simulations
Keywords: biomass major components, biomass torrefaction, numerical simulation, packed bed reactor, reaction enthalpy
The torrefaction of three representative types of biomass—bamboo, and Douglas fir and its bark—was carried out in a cylindrical-shaped packed bed reactor under nitrogen flow at 573 K of the reactor wall temperature. As the thermal energy for the torrefaction was supplied from the top and the side of the bed, the propagation of the temperature profile of the bed is a crucial factor for discussing and improving the torrefaction reactor performance. Therefore, the temperature and gas flow rate (vector) profiles throughout the bed were calculated by model simulation so as to scrutinize this point. The measured temperature at a certain representative location (z = 30 mm and r = 38 mm) of the bed was well reproduced by the simulation. The volume faction of the bed at temperatures higher than 500 K at 75 min was 0.89, 0.85, and 0.99 for bamboo, and Douglas fir and its bark, respectively. It was found that the effective thermal conductivity is the determining factor for this difference. The he... [more]
52. LAPSE:2020.1233
Investigation on Unsteady Flow Characteristics in an Axial-Flow Fan under Stall Conditions
December 17, 2020 (v1)
Subject: Modelling and Simulations
Keywords: axial-flow fan, incidence angle, modal and spike disturbance, rotating stall, unsteady flow characteristics, wavelet analysis
Based on Shear Stress Transport (SST) turbulence model for unsteady simulation of an axial-flow fan, this paper studies the time-frequency information in the hump region, and investigates the disturbance information of spike and modal wave under different flow coefficients based on continuous wavelet transform (CWT). The results show that before the hump point, the low-frequency modal wave occupies the main disturbance form and circularly propagates at 1/10 of the rotor speed, and the axial-flow fan does not enter the stall stage; while after the flow coefficient reduces to the hump point, the spike wave with higher frequency replaces the modal wave as the main disturbance mode while the axial-flow fan enters the stall stage. Through in-depth investigation of unsteady flow characteristics under the hump point, it is found that after experiencing the emerging spike, with the sharp increase of incidence angle, some flow distortions appear on the intake surface, and further induce some fl... [more]
53. LAPSE:2020.1232
Evaluation of Postharvest Processing of Hazelnut Kernel Oil Extraction Using Uniaxial Pressure and Organic Solvent
December 17, 2020 (v1)
Subject: Food & Agricultural Processes
Keywords: bulk hazelnut kernels, heating temperature, mechanical properties, oil efficiency, relaxation process
Uniaxial loading and organic solvent are small-scale oil expression methods used to evaluate the mechanical behavior, oil content, and oil efficiency of oil-bearing materials aimed at designing a low-cost mechanical pressing system. Bulk kernels of pressing height 40 mm were heated from 40 to 60 °C and compressed at maximum force of 60 kN and speeds from 4 to 8 mm/min. Relaxation times between 3 and 12 min were applied to assess the kernel oil efficiency. The kernel oil point was identified at deformation levels between 15 and 25 mm at a speed of 4 mm/min using a litmus test. The kernel oil was analyzed for peroxide value and free fatty acid. Kernel oil content was determined by Soxhlet extraction. Increased speed caused a serration effect on the force−deformation curve leading to lower oil yield. Lower and upper oil point forces at 6.21 ± 0.58 and 10.61 ± 0.71 kN were observed to be useful for predicting the pressure for maximum output oil. The peroxide value and free fatty acid conte... [more]
54. LAPSE:2020.1231
Application of Theoretical and Experimental Findings for Optimization of Mixing Processes and Equipment
December 17, 2020 (v1)
Subject: Process Design
Keywords: agitator, blending, hydrofoil impeller, impeller efficiency, Mixing, particle suspension, pumping capacity
The homogenization of the agitated batch and ensuring the suspension of particles are the most frequently encountered requirements in terms of mixing applications. These operations are affected by the flow of the agitated batch. The geometrical parameters of the mixing system, especially the shape of the agitator blade, affect flow and circulation in the agitated batch. The present work provides a general description of the most common processes in the agitated batch (blending and particle suspension), hydrodynamic parameters (flow in agitated batches, pumping and circulation capacity of impellers) and the geometrical configurations of the mixing equipment (shape of vessel, baffle and impeller, and their mutual arrangement) that influence the process. The dimensionless process characteristics of the agitator were derived by theoretical analysis. These characteristics were applied to evaluate an extensive set of experimental data with various geometric configurations of the mixing equip... [more]
55. LAPSE:2020.1230
An Overview of Natural Extracts with Antioxidant Activity for the Improvement of the Oxidative Stability and Shelf Life of Edible Oils
December 17, 2020 (v1)
Subject: Food & Agricultural Processes
Keywords: edible oils, natural antioxidants, oxidative stability, shelf life, vegetable extracts, waste
Many plant materials, such as fruits and vegetables as well as herbs and spices, represent valuable sources of antioxidants. In recent years, wastes from agriculture and food industrial processes have been shown to be interesting sources for bioactive compound recovery, strongly contributing to the circular economy. Nowadays, because of their possible adverse effects on human health, there is a tendency to replace synthetic antioxidants with natural compounds. This review attempts to critically summarize the current evidence on plant bioactives, extracted from food or waste, added to unsaturated vegetable oils, in order to obtain high added-value products and to ameliorate their oxidative stability and shelf life. The goal of this review is to demonstrate the current status of the research on edible oils added with natural plant bioactives, highlighting new approaches in the field of health-promoting foods.
56. LAPSE:2020.1229
A Study to Investigate the Mechanical Properties of Recycled Carbon Fibre/Glass Fibre-Reinforced Epoxy Composites Using a Novel Thermal Recycling Process
December 17, 2020 (v1)
Subject: Materials
Keywords: carbon fibre, compression moulding, glass fibre, manufacturing waste, mechanical properties, thermal recycling
Manufacturing-based carbon fibre-reinforced polymer (CFRP) and glass fibre-reinforced polymer (GFRP) wastes (pre-consumer waste) were recycled to recover valuable carbon fibres (CFs) and glass fibres (GFs), utilising a novel thermal recycling process with a cone calorimeter setup. The ideal conditions to recycle both the fibres occurred at 550 °C in atmospheric pressure. The processing time in the batch reactor to recycle CFs was 20−25 min, and to recycle GFs it was 25−30 min. The recovery rate of the recycled CFs was 95−98 wt%, and for GFs it was 80−82 wt%. Both the recycled fibres possessed a 100−110 mm average length. The resin phase elimination was verified by employing scanning electron microscopy (SEM). Furthermore, the fibres were manually realigned, compression moulded at room temperature, and cured for 24 h by a laminating epoxy resin system. The newly manufactured CFRP and GFRP composites were continuous (uniform length from end to end), unidirectionally oriented (0°), and no... [more]
57. LAPSE:2020.1228
Online High Performance Genetic Algorithm Based Sliding Mode Control for Controllable Pitch Propeller
December 17, 2020 (v1)
Subject: Process Control
Keywords: chattering-free, controllable pitch propeller, high-performance genetic algorithm, real-time, sliding mode control
During the voyage of a ship, the performance of a controllable pitch propeller (CPP) is severely affected by the changing load demand and ever-present disturbance from ocean waves, which will also result in model uncertainty. In order to improve the performance of the CPP system, an online high-performance genetic algorithm (HPGA)-based sliding mode control (SMC) strategy is proposed. Firstly, the model of the CPP system is obtained according to the manufacturer’s instructions. Then, a chattering-free sliding mode controller (CF-SMC) is designed for the CPP system, after which the parameters in the CF-SMC are optimized with the HPGA method. Finally, the optimized CF-SMC is applied to an experimental setup of a prototype CPP system. In order to validate the effectiveness of the proposed method, it is compared with a proportional-integral-derivative (PID) controller, which is typically applied on real CPP-systems, with results indicating the superiority of the proposed method.
58. LAPSE:2020.1227
Integrated Control Policy for a Multiple Machines and Multiple Product Types Manufacturing System Production Process with Uncertain Fault
December 17, 2020 (v1)
Subject: Process Control
Keywords: manufacturing system, multiple machines and multiple product types, optimal production control, prioritized hedging point policy, process diagnostics, production capacity planning, uncertain fault
The optimization of production cost has always been a key issue in manufacturing systems; for the single product type manufacturing systems, lots of research studies have proved the validity of the hedging point control policy in production cost control. However, due to the complexity of the multiple machines and multiple product types manufacturing systems with uncertain fault, it is difficult to achieve a good control effect only by using the hedging point control policy. To optimize the total production cost under constantly changing demands, an integrated control policy that combines the prioritized hedging point (PHP) control policy with the production capacity planning during production is proposed, and the decision variables are obtained by a particle swarm optimization (PSO) algorithm. The simulation experiments show the effectiveness of the proposed integrated control policy in production cost control for the multiple machines and multiple product types manufacturing system.
59. LAPSE:2020.1226
Application of Systems Engineering Principles and Techniques in Biological Big Data Analytics: A Review
December 17, 2020 (v1)
Subject: Intelligent Systems
Keywords: biological big data, dynamic analysis, feature engineering, Machine Learning, overfitting, systems engineering
In the past few decades, we have witnessed tremendous advancements in biology, life sciences and healthcare. These advancements are due in no small part to the big data made available by various high-throughput technologies, the ever-advancing computing power, and the algorithmic advancements in machine learning. Specifically, big data analytics such as statistical and machine learning has become an essential tool in these rapidly developing fields. As a result, the subject has drawn increased attention and many review papers have been published in just the past few years on the subject. Different from all existing reviews, this work focuses on the application of systems, engineering principles and techniques in addressing some of the common challenges in big data analytics for biological, biomedical and healthcare applications. Specifically, this review focuses on the following three key areas in biological big data analytics where systems engineering principles and techniques have be... [more]
60. LAPSE:2020.1225
A Novel Approach for Predicting the Height of Water-Conducting Fracture Zone under the High Overburden Caving Strength Based on Optimized Processes
December 17, 2020 (v1)
Subject: Other
Keywords: approach based on optimized processes, Brillouin optical time-domain reflectometry (BOTDR), high overburden caving strength, optical fiber strain, overburden, water-conducting fracture zone (WCFZ)
The height of water-conducting fracture zones (WCFZs) is vital for the prevention of water, gas, and roof accidents in coal mines. However, its dynamic evolution law and maximum height are difficult to be obtained by traditional prediction methods, especially for conditions in which there is high overburden caving strength and a thick coal seam. Therefore, taking the 150,313 fully mechanized caving working face in Yingying Coal Mine as a background, according to the principle of optimized processes, a new predicting approach based on the Brillouin optical time-domain reflectometry (BOTDR) is proposed. Firstly, we estimated the height through empirical formula calculation, theoretical analysis, and similar model simulation tests. Secondly, we studied the optimized layout of optical cables in the overburden in detail for predicting the maximum height of the WCFZ and keeping the cables in good performance during field prediction. Thirdly, we researched and optimized the borehole parameter... [more]
61. LAPSE:2020.1224
Analysis of Chemical and Biochemical Parameters of Petrol-Contaminated Soil after Biostimulation with an Enzyme Reagent
December 17, 2020 (v1)
Subject: Food & Agricultural Processes
Keywords: dehydrogenases, Fyre-Zyme, hydrocarbons, nitrogen total, organic carbon, phosphatases, soil remediation
This study aimed to assess the effect of petrol and the Fyre Zyme reagent on selected chemical and biochemical properties of loamy sand. The experiment was conducted under laboratory conditions. First, petrol was introduced into the soil at doses of 0 and 50 g k−1dry matter (DM). Next, 6% Fyre-Zyme enzyme reagent solution was added to the samples contaminated and uncontaminated with petrol, in the following combinations: 0 (control), once at 40 cm3 kg−1 DM, twice at 20 cm3 kg−1 DM at two-week intervals, and four times at 10 cm3 kg−1 DM at weekly intervals. Contamination of loamy sand with petrol caused slight changes in the determined chemical parameters and stimulated dehydrogenase activities, but inhibited the activity of phosphatases. The introduction of the enzyme reagent into the soil increased the Corg and Ntot content. The greatest changes were observed in the activity of phosphatases. The receiver operating characteristic (ROC) curves revealed that the application of the enzyme... [more]
62. LAPSE:2020.1223
The Evolution of Biodiesel Policies in China over the Period 2000−2019
December 17, 2020 (v1)
Subject: Energy Policy
Keywords: biodiesel, China, content analysis, policy, policy transitions
The Chinese government launched policies supporting biodiesel production and innovation to meet sustainable energy demands under rapid economic and social development. This study systematically investigates the dynamic transitions of biodiesel policies in China regarding policy contents and policy networks. We performed a content analysis in this study and used NVivo12 software to support the analysis process. The results highlighted some issues. First, the Chinese government supported the development of biodiesel from multiple policy objectives and adopted various policy instruments, eventually transforming biodiesel in China from the first- to second-generation. Second, the State Council was the main institution to promote biodiesel policies, and the National Development and Reform Commission under the State Council burdened most of the responsibilities of policy implementation. Most of the policies were issued at a lower level of administration rather than a higher level of decision... [more]
63. LAPSE:2020.1222
A Comparison of “Bottom-Up” and “Top-Down” Approaches to the Synthesis of Pt/C Electrocatalysts
December 17, 2020 (v1)
Subject: Materials
Keywords: alternating current, electrocatalysis, electrochemical dispersion, ethanol electrooxidation, fuel cell, nanoparticles, platinum catalyst, polyol process, synthesis method
Three 40 wt % Pt/C electrocatalysts prepared using two different approaches—the polyol process and electrochemical dispersion of platinum under pulse alternating current—and a commercial Pt/C catalyst (Johnson Matthey prod.) were examined via X-ray diffraction (XRD) and transmission electron microscopy (TEM). The stability characteristics of the Pt/C catalysts were studied via long-term cycling, revealing that, for all cycling modes, the best stability was achieved for the Pt/C catalyst with the largest platinum nanoparticle sizes, which was synthesized via electrochemical dispersion of platinum under pulse alternating current. Our results show that the mass and specific electrocatalytic activities of Pt/C catalysts toward ethanol electrooxidation are determined by the value of the electrochemically active Pt surface area in the catalysts.
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