bluuebunny/crossref_metadata_2025 huggingface dataset:
Removal of Solid Impurities from Coal Gasification Wastewater by Sand Filtration
Authors: Dai Li , Wang Hualin
Published: March 2021

Coal gasification wastewater has complex pollutant components and high COD value, and contains a variety of toxic and harmful substances. The treatment of coal gasification wastewater has always been one of the important problems in the development of coal gasification industry in China. In this paper, aiming at the removal of fine particle pollution in coal gasification wastewater, the sand filtration method was used to explore the changes of parameters such as solid content removal, separation accuracy, grade efficiency under the conditions of separating different bed thicknesses. With this separation method, the fine particle pollutants in coal gasification wastewater can be effectively removed by more than 95%, the separation accuracy can reach 0.46 μm. The operation conditions are optimized for further industrial application.
Evaluating the Pollution of the Apies River in Pretoria South Africa
Authors: Tau P , Anyasi Ro , Mearns K
Published: March 2021

This study was done to assess the pollution of Apies River using both chemical and microbiological methods. The pollution index of the river revealed that the concentration of most pollutants downstream is more than 50% of the upstream concentration. The natural sources of the pollution in Apies River are the weathering of geological formations; whereas the anthropogenic sources are agriculture; Municipal WWTW and direct deposit of waste into the river. The natural sources of pollution contributed towards chemical pollution; whereas the anthropogenic sources contributed both chemical and microbiological pollution. The Apies River is hypertrophic downstream of the Rooiwal WWTW; however the current physiochemical state of the River warrants its ability to be used for safe irrigation in agricultural practices. The current microbiological state of the River does make it harmful for human consumption especially as drinking water; however, the water should be boiled prior to use to inactivate the bacteria present in the water. The study was able to provide in analysis the variation of the contaminants in the River.
Benchmarking Analysis of Carbon Emission in China and Foreign Countries from the Perspective of Urbanization
Authors: Wang Jun , Zhao Hua
Published: March 2021

With the further aggravation of global warming and the increasingly serious problems of ecological environment, the construction of low-carbon cities has become an inevitable choice for the global response to climate change and the sustainable development of economy and society. In order to understand the basic situation of China’s low-carbon cities more specifically, this paper selects countries with different urbanization rates to carry out benchmarking analysis with China, hoping to draw on the experience of other countries from the national level through multi-dimensional comparison, and guide the direction of China’s future urban development. Firstly, this paper selects the basic indicators such as the total amount of carbon dioxide emissions, per capita carbon emissions and carbon emissions per unit GDP of each country; Secondly, it compares the proportion of coal in energy and other indicators, and analyzes the energy structure of each country in depth; Thirdly, it compares the trend of carbon emissions in each country among 1990-2017. Finally, in order to reflect the carbon emission in the development of urbanization, this paper uses the “urbanization carbon emission index”, which is the ratio of per capita carbon emission and urbanization rate, to show the relationship between the degree of urbanization and carbon emission. Through benchmarking analysis, we can more clearly understand the overall trend of low-carbon city construction in different countries, recognize the gap between China and other countries, and better guide the development of low-carbon cities in China in the future.
Influence of Test Cycles on Energy Consumption Test of Electric Vehicles
Authors: Liu Yu , Ma Kunqi , Yu Hanzhengnan , Li Jingyuan , An Xiaopan
Published: March 2021

In order to verify the necessity of the application of China Automotive Test Cycle which is constructed through actual driving data in china of more than 55 million kilometers in the energy consumption test of electric vehicles in China, this paper compares the characteristics of New European Test Cycle (NEDC), World-wide harmonized Light duty Test Cycle (WLTC) and China light-duty vehicle test cycle for passenger car(CLTC-P), and analyzes the differences of vehicle energy demand under different test cycles from theoretical and simulation point, simulation results show that the endurance mileage is longest and the energy recovery strategy is more effective under CLTC-P cycle. Finally, four types of vehicles are selected to carry out the endurance mileage test under these three test cycles. The test results are consistent with the simulation results. Therefore, in order to make the test results of electric vehicle energy consumption closer to the actual use of our country, CLTC-P should be selected to replace NEDC and WLTC cycle.
Computational Modelling and Prediction of Consequences in Case of Accidental Releases of Hazardous Substances in an Industrial Plant
Authors: Pasculescu Vlad Mihai , Morar Marius Simion , Cioara Cristian Raul , Tuhut Ligia Ioana , Babut Andrada Denisa
Published: March 2021

Storing relatively large amounts of hazardous materials under certain conditions can lead to high-risk situations. In industrial units, the assessment of the amplitude and severity of the consequences of the identified major accidents is done in order to provide data on site intervention and emergency planning. This study aims to assess the consequences of untimely releases of hazardous explosive / toxic substances in an industrial unit by graphical modelling and analysis of such accident scenarios using specialized software tools. The main activity of the industrial unit under study consists in the manufacture, processing and marketing of essential oils and their derived products.
Analysis of the Correlation and Regional Distribution of Plastic Waste Pollution
Authors: Xu Jia , Wu Zixuan , Zhao Yazhi , Yang Jingsan
Published: March 2021

Plastic has brought great convenience to people’s lives, but it has also brought severe environmental pollution to the world. It is almost impossible to break down entirely in nature, and plastic waste, whether in rivers, oceans, or on land, can persist in the environment for centuries. The problem of plastic waste disposal has caused worldwide concern. It is necessary to reduce the production of plastic products through global cooperation effectively. However, achieving this goal will also involve some unexpected issues, such as controlling the adverse economic impact of plastics, and the rationality and fairness of the distribution of responsibilities between different countries. This paper collects massive data and takes China as an example to study the impact of plastic output reduction on China’s Express industry and the plastics manufacturing industry using multivariate regression. This paper summarizes the positive and negative effects of plastic waste reduction. Given the distribution and management of national and regional plastic waste responsibilities, the global carbon emission rights distribution method is used for reference. The comprehensive index allocation method is used to deal with the problem of both fairness and efficiency relatively. What is more, based on the conclusions, this paper also provides suggestions for a global joint response to plastic waste.
Risk Assessment for Illegal Waste Open Burning
Authors: Buzzo Gianpiero , Gigante Gabriella , Nebula Francesco , Palumbo Roberto , Pascarella Domenico , Vozella Angela
Published: March 2021

The area of Naples and Campania region, in Italy, has been experiencing the dramatic consequences of diffuse open burning of illegal waste, resulting in possible threats to human health. The need of evaluating a risk index of open burning rises from this emergency where it is important quantify the risk to support local stakeholder to intervene timely and effectively order and to prioritize the interventions. Nevertheless, open burning phenomenon is still uncontrolled all over the world, and implies not only impacts on health at local level but emission of pollutants in the atmosphere. A deep understanding can support policy makers in order to prevent risky behaviours and to mitigate the severity of their occurrences. The risk model related to open burning is still an open issue, and the attempt to model the probability of its occurrence is completely new. This paper proposes a model for the evaluation of risk of illegal waste open burning in Campania enabling the identification of the priority of intervention in order to optimize the available resources. In detail, it defines a layered and seamless approach to evaluate the related impact at different levels of accuracy leveraging on reference guidelines.
Environmental Regulations (its Identification and Downstream Implementation in Bangka Belitung)
Authors: Haryadi Dwi , Ibrahim Ibrahim , Darwance Darwance
Published: March 2021

Article 28H and section (4) of Article 33 in the Indonesian Constitution guarantee every citizen the right to a good and healthy environment with green economy. In order to implement it, the government issued Law No. 32 of 2009 on Environmental Protection and Management. The environmental regulations that became the umbrella act are facing challenges both in substance and implementation. Substantially, questions remain whether the green constitution has been incarnated in this regulation, and how it positions itself as the umbrella act for a number of regulations. In implementation, the challenges include the availability of legislations, from government regulations to technical policy, and its implementation in regional level, both at the provincial and regency levels in Bangka Belitung Islands. In each regime, the environmental issues have always been a part of strategic issues. This research focused on identifying environmental regulations from upstream to downstream, and how they are implemented in the context of environmental issues due to tin mining in Bangka Belitung. Data were obtained through literature review using statute and conceptual approaches.
Thermo-economic optimization of supercritical CO2 Brayton cycle on the design point for application in solar power tower system
Authors: Liu Tianye , Yang Jingze , Yang Zhen , Duan Yuanyuan
Published: March 2021

The supercritical CO2 Brayton cycle integrated with a solar power tower system has the advantages of high efficiency, compact cycle structure, strong scalability, and great power generation potential, which can positively deal with the energy crisis and global warming. The selection and optimization of design points are very important for actual operating situations. In this paper, the thermodynamic and economic models of the 10 MWe supercritical CO2 Brayton cycle for application in solar power tower system are established. Multi-objective optimizations of the simple recuperative cycle, reheating cycle, and recompression cycle at different compressor inlet temperature are completed. The thermal efficiency and the levelized energy cost are selected as the fitness functions. The ranges of the optimal compressor inlet pressure and reheating pressure on the Pareto frontier are analyzed. Finally, multiobjective optimizations and analysis of the supercritical CO2 Brayton cycle at different ambient temperature are carried out. This paper investigates the influence of the compressor inlet temperature and ambient temperature on the thermal efficiency and economic performance of the supercritical CO2 Brayton cycle.
Solar Field Optimization and its Impact on Overall Design and Performance of Solar Tower Thermal Power Plant in Bangladesh
Authors: Hossain Md. Sakib , Shajid Soad
Published: March 2021

Electricity generation using solar thermal power systems can be made more efficient and both technically and economically feasible in countries receiving moderate solar radiation like Bangladesh through thorough optimization of different parts of the power plant. In this paper a theoretical and mathematical framework for optimization of a 150 MW solar tower thermal power plant in Bangladesh which uses molten salt as HTF has been developed by applying different methods of selecting crucial design aspects, such as design point DNI, solar multiple, design point temperature etc. after selecting the most appropriate location based on GHI and DNI data. The effect of these design aspects on the overall design of the power plant including the number of heliostats, solar field land area, tower height, receiver dimensions etc. have also been studied and finally the performance analysis of the power plant has been conducted. Analysis of performance reveals that the optimized power plant would be able to deliver 528.66 GW-h electricity annually to the national grid while operating at a capacity factor of 40.2% and gross-net conversion efficiency of 88.635%. The promising performance of the power plant would encourage further research and innovation regarding large scale electricity generation from solar energy in Bangladesh.
Roll-to-Roll Compatible Methods and Outlook for Perovskite Solar Cells
Authors: Li Chenglin
Published: March 2021

Perovskite Solar Cells (PSCs) are regarded as a highly effective low-cost solar energy collector, which is promised to sustain considerable energy supplies for modern society. Roll-to-Roll (R2R) compatible PSCs fabrication method is promised to realized industrialized PSCs production. This paper presents an overview of recent R2R compatible methods for PSC fabrication, which covers five R2R compatible strategies towards industrialized R2R production. To further tackle technical obstacles towards the PSC industrialization, improving perovskite morphology, adopting ambient production conditions and enhancing moisture resistance, as three aspects towards a high-effective, low-cost and highly stable PSCs, are discussed and concluded. This paper also discussed the possibility of hybrid wind-solar energy collector and raises a wind-flutter-PSCs composed conceptional structure.
Modeling, prediction and multi-objective optimization of the coal gasification system
Authors: Li Ran , Yang Zhen , Duan Yuanyuan
Published: March 2021

As global energy demand continues to increase, coal as basic energy still accounts for a significant proportion. Under the pressure of environmental protection, clean and efficient coal utilization technologies are in great demand. Coal gasification technology has the potential to realize near-zero-emissions for coal utilization. This paper establishes the coal gasification system model and analyzes the effect of oxygen/coal ratio and water/coal ratio on the system performance index of cold syngas efficiency, effective component ratio, carbon conversion ratio, and production ratio of hydrogen. The results show that when the oxygen/coal ratio increases, the efficiency of cold syngas and effective components ratio increase first and then decrease, carbon conversion ratio first increases and then remains unchanged, hydrogen production ratio gradually decreases; When the steam/coal ratio increases, the cold syngas efficiency, and carbon conversion ratio first increase and then decrease, effective component ratio ingredients gradually decreases, and the hydrogen production ratio increases. Using BP neural network to realize the prediction of the gasification system, and the mean square error reaches the magnitude of 10e-7. Multi-objective optimization results show that the oxygen/coal ratio and steam/coal ratio corresponding to the highest production ratio of hydrogen is 0.52 and 0.05. The highest carbon conversion ratio corresponds to the oxygen/coal ratio of 0.95 and the steam/coal ratio of 0.05.
Power Coefficient Analysis of Double-blade Half-rotating Impeller Tidal Turbine Operating at Yaw
Authors: Liu Cong , Wang Xiaoyi , Yu Xiaofeng , Zhang Yuhua , Qiu Zhizhen , Xu Xiangrong
Published: March 2021

The double-blade half-rotating impeller tidal turbine (DHITT) is a new type of vertical shaft tidal current turbine with lift and resistance performance. The power coefficient of the DHITT is affected by the flow direction. In order to research the power coefficient (CP) of the DHITT under different flow direction, the optimal attack flow angle of a half-impeller turbine was explored, and the fluctuation of power coefficient of the DHITT operating at yaw was analyzed based on the optimal attack flow angle. The unsteady flow of the turbine was simulated by overlapping grid technique, and the fluctuation of the turbine’s power coefficient under different flow directions was analyzed, which was verified by experiments. The results have demonstrated that the power coefficient at the optimal angle of attack is 0.53. As the yaw angle greater than 30º, the power reduction is nearly 40%, but the average efficiency loss is only 3.7% in the range of -3º to 3º.
Patientenverlegungen: Ausgeflogen
Authors: Kohrs Jens
Published: March 2021

Ob Kliniken überlastet sind oder Patienten eine speziellere Versorgung brauchen – bei Verlegungen spielt der Luftweg eine entscheidende Rolle. Auch das Kleeblattkonzept setzt darauf. Für die Häuser und die Notärzte an Bord ist das nicht nur medizinisch ein Härtetest.
Planbare Eingriffe: „Der Begriff elektiv führt ins Dilemma“
Authors: Rößing Sabine
Published: March 2021

Die Pandemie und die mit ihr einhergehende Knappheit an Intensivkapazitäten zwingen Krankenhäuser dazu, bei der Planung von Eingriffen Prioritäten zu setzen. Doch gibt es kaum verbindliche Parameter.
Patientenzimmer: Intelligenter Schutz vor Keimen
Authors: Lang Michael
Published: March 2021

Um das Infektionsrisiko für Patienten zu senken, hat ein interdisziplinäres Forscherteam ein Patientenzimmer völlig neu gestaltet und mit besonders leicht zu reinigenden Oberflächen ausgestattet.
Community Health Nursing: Pioniere für die Pflege
Authors: Orth Anne
Published: March 2021

In Ländern wie Finnland und Kanada sind sie schon länger im Einsatz: Community Health Nurses. Das sind speziell ausgebildete Pflegefachpersonen, die in der primären Gesundheitsversorgung unterstützen. Pflegefachkräfte können sich dafür in neu konzipierten Masterstudiengängen qualifizieren.
Infrared spectroscopy of neutral clusters based on a vacuum ultraviolet free electron laser
Authors: Li Gang , Wang Chong , Zheng Hui-jun , Wang Tian-tong , Xie Hua , Yang Xue-ming , Jiang Ling
Published: March 2021

Spectroscopic characterization of clusters is crucial to understanding the structures and reaction mechanisms at the microscopic level, but it has been proven to be a grand challenge for neutral clusters because the absence of a charge makes it difficult for the size selection and detection. Infrared (IR) spectroscopy based on threshold photoionization using a tunable vacuum ultraviolet free electron laser (VUV-FEL) has recently been developed in the lab. The IR-VUV depletion and IR+VUV enhancement spectroscopic techniques open new avenues for size-selected IR spectroscopies of a large variety of neutral clusters without confinement (i.e., an ultraviolet chromophore, a messenger tag, or a host matrix). The spectroscopic principles have been demonstrated by investigations of some neutral water clusters and some metal carbonyls. Here, the spectroscopic principles and their applications for neutral clusters are reviewed.
Ferroelectric/multiferroic self-assembled vertically aligned nanocomposites: Current and future status
Authors: Lee Oon Jew , Misra Shikhar , Wang Haiyan , MacManus-Driscoll J. L.
Published: March 2021

Even a century after the discovery of ferroelectricity, the quest for the novel multifunctionalities in ferroelectric and multiferroics continues unbounded. Vertically aligned nanocomposites (VANs) offer a new avenue toward improved (multi)functionality, both for fundamental understanding and for real-world applications. In these systems, vertical strain effects, interfaces, and defects serve as key driving forces to tune properties in very positive ways. In this Perspective, the twists and turns in the development of ferroelectric/multiferroics oxide–oxide and unconventional metal–oxide VANs are highlighted. In addition, the future trends and challenges to improve classic ferroelectric/multiferroic VANs are presented, with emphasis on the enhanced functionalities offered by existing VANs, as well as those in emerging systems.
Drag coefficient identification of high-spinning projectile using cubature Kalman filter
Authors: Zheng Yucheng , Guan Jun , Yi Wenjun
Published: March 2021

In order to obtain the aerodynamic parameters of a high-spinning projectile, a new parameter identification method is proposed based on the Cubature Kalman Filter (CKF). First of all, the motion equation of the spinning stabilized projectile is established by the 4D trajectory model. Second, unknown parameters are added to the state vector to obtain the augmented state vector. Next, a new filter is designed for the identification of the unknown parameters based on the basic theory of the CKF. Finally, the simulation results of the CKF are compared with those of the Extended Kalman Filter (EKF) and the Unscented Kalman Filter (UKF). The results of comparison show that the CKF method can effectively identify the aerodynamic parameters and the identification error is less than 1.2%. The CKF method has greater accuracy than the EKF and the UKF.
The substitution effect of grass-fed livestock products on grain-fed livestock products from the perspective of supply-side reform in China
Authors: Lin Huilong , Xiong Xiaoyu , Liu Yifan , Zhao Yuting , Tang Rong , Nyandwi Charles
Published: March 2021

Clarification of the direction of China’s future agricultural structural transformation is important, particularly by analysing the dynamic characteristics of upgrading the food consumption structure, especially the relationship between grain and grass-fed livestock products, and by predicting future food consumption patterns. Based on the food equivalent unit (FEU) and the arable land equivalent unit (ALEU), characteristics of meat consumption elasticity across China and between regions were analysed using the extend linear expenditure system for national meat consumption elasticity and regional changes. Similarly, in addition to the substitution effect of grass-fed livestock products on grain-fed livestock products, the prediction of the future gap in demand for grass-fed livestock products was explored. Results indicated that: (1) from 2005 to 2012, the per-capita food consumption on average has stabilised at 460 kg FEU per year. The consumption of grain-fed livestock products is stable, and that for grass-fed livestock products has increased dramatically since 2000; (2) there is a substitution effect of consumption of grass-fed on consumption of grain-fed livestock products on individual and regional scales; (3) By 2035, the overall demand gap for future grass-fed livestock products in China will be 1.14 × 1010 kg, and the main demand will be in grain farming areas. Based on the aggregated advantage index of each region, the seven grassland ecological-economic regions are divided into three priority groups for grassland agricultural development.
Two subjunctives or three?
Authors: Guajardo Gustavo
Published: March 2021

This paper examines the use of the three non-periphrastic subjunctives in Spanish in embedded clauses under obligatory subjunctive predicates in the past tense in three Spanish varieties: Argentinean, Mexican and Peninsular Spanish. By means of random forest and logistic regression analyses, I demonstrate that a grammar where the two “past” subjunctives make up one group, such that the variation can be modeled on a binary opposition between (morphologically) past vs. (morphologically) present, achieves better prediction accuracy and goodness-of-fit parameters than a grammar with a three-way split. The results suggest that, at least in complement clauses of obligatory subjunctive predicates, there appear to be no semantic differences between the two past subjunctives but there are still relatively large differences in how the three subjunctive forms are used across the three Spanish varieties studied.1
Antibacterial activities of polyphenols from olive leaves against Klebsiella pneumoniae
Authors: Yuan Jiao-Jiao , Yan Han-Jun , He Jing , Liu Yang-Yang
Published: March 2021

In this paper, the polyphenols existed in olive leaf were evaluated for its antibacterial activities against Klebsiella pneumoniae. 11 phenols all presented certain antibacterial effect against above-mentioned bacteria, and hydroxytyrosol (HT), oleuropein, 3,4-dihydroxybenzoic acid and caffeic acid, could have excellent inhibition results. The results indicated that several phenols could be a valuable source of natural agents with functional properties for the food and pharmacology industries.
The BIM-based Integrated Design of the SHiP Project Decay Volume
Authors: Salzano A , Miano A , Porfidia G , Fiorillo A , Prota A , Jacobsson R
Published: March 2021

The Search for Hidden Particles (SHiP) experiment is a new general-purpose fixed target facility proposed at the CERN Super Proton Synchrotron accelerator to search for long- lived exotic particles associated with Hidden Sectors and Dark Matter. This paper reports on the BIM integrated design of SHiP’s decay volume, a conical steel vessel under vacuum that should host several large particle physics detector systems. The use of BIM characterized the design of the decay volume, both in the modeling and structural design phase, and in the process definition phase for the realization and implementation in the facility of the device. This procedure helps to minimize the risks of incorrect design and construction of the device during the whole process. With the automation of the virtual model and the use of interoperable software, in addition to speeding up the exchange of information, it is possible also to export the detailed information of the structural design directly to the numerical control machines for the prefabrication of the various steel modules. Then, the BIM approach to support the integrated design of the SHiP project decay volume from the conceptual planning to the construction phase is shown in this work.
Building Renovation Process Map in Private and Public Works to Improve Communication and Data Exchange
Authors: Signorini Martina , Spagnolo Sonia Lupica
Published: March 2021

Along the building process the cooperation among several stakeholders and the integration of information during the whole project life cycle, whether it is a new project or a renovation intervention, are two key essential factors. In fact, in AEC sector the loss of information, the lack of data and the improper or repetitive exchange of information are common issues that may cause delays and cost increase. To enhance communication and data transfer, an appropriate rationalization of information flows is necessary. Starting from the outcomes of BIM4EEB, an ongoing Horizon2020 project, the paper analyses the workflow processes to understand how to optimise information workflows among different actors and along different stages by the use of ICT and BIM-based tools. Particular attention was payed to individualise the differences between public and private works in order to provide methods and apply the BIM4EEB approach to renovation process in both cases.
Road Peculiarities Detection using Deep Learning for Vehicle Vision System
Authors: Rani M.R. , Mustafar M.Z.C. , Ismail N.H.F. , Mansor M.S.F. , Zainuddin Z.
Published: March 2021

Recent development of Advance Driver Assistance System (ADAS) has seen various advancement in object detection for vehicle vision system, particularly on the detection of other vehicles, pedestrians, road lane and signage. While these detections can provide assistant to avoid road accidents, they still lack to include road condition factors that also contributed to road accidents in Malaysia. This paper proposes a detection of the road peculiarities such as pothole and road bumps to act as additional safety feature in ADAS. With the breakthrough of deep learning in solving image recognition problems, this work takes advantage of Single Shot Detector (SSD)-MobileNetV2 as the detection algorithm, implemented on the real-time. The training images for potholes and road bumps taken from the Malaysia roads are fed into the detection model, and then the pre-trained weights are fine-tuned over the training process. The results show that the detection algorithm can predicts the potholes and road bumps, while exhibit the detection accuracy and confidence limitation due to the variety of shape and pattern of potholes and road bumps. Testing the detection algorithm with NVIDIA Jetson Nano yielded about 20 frames per second (fps), suitable for real-time applications.
Composites of Polymer Blends and Their Applications Using Natural Fibres: A Review
Authors: Mohd A. , Bahiyah Baba N. , Umor M. Z. , Mohamed R. M.
Published: March 2021

Study on new composite materials in engineering products with promising physical and mechanical properties has been considered as one of the fields of concern in recent decades. Strength, hardness and fatigue properties make engineering structural more flexible. They are extensively used in the aerospace industry, mechanical engineering applications and parts, electronic packaging, vehicle and aircraft structures, process industry equipment, as well as in biomedical equipment. Disposing of composite wastes however, are very difficult because of its structure and compositions. Hence, composite materials recycling has become one of the major measures of the future. This study seeks to analyse the present state of engineering plastics using natural fibers in their properties and manufacturing techniques. The effects of various chemical treatments on natural fibres’ mechanical and thermal properties have been studied in strengthening thermosetting and thermoplastics composites. The mix ratio of polymer waste used from the industry sector with natural fiber is expected to rise in the future, thus issues regarding recycling need to be tackled. It concluded that chemically treated natural fibre improved the adhesion between fibre surface and polymer matrix, which gradually increased the properties of natural fibres incorporated composites.
Palm Oil Mill Effluent Treatment by Using Copperas as Physicochemical Treatment Agent
Authors: Razak Noor Aiman , Yahya Nor Aisyah Mat , Abdullah Nabihah
Published: March 2021

The palm oil mill industry in Malaysia are a huge agriculture industry which generates significant amount Palm Oil Mill Effluent (POME). POME is an oily wastewater which consist of various suspended components, the liquid are a combination of steriliser condensate and cooling water. The wastewater is very pollutant to human and environment, the coagulants applied to reduce the suspended materials in POME as following the stringent requirements of biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solid (TDS), total solid (TS) and turbidity as stated by the Department of environment. This paper analyses the use of ferrous sulphate heptahydrate as a coagulant as it was applied on the primary treatment and the results improvement upon physicochemical treatment parameters. Series of batch treatment for coagulation and flocculation with ferrous sulphate heptahydrate were conducted. Dosage and pH were conducted to determine the optimum conditions to apply the coagulants. The result of coagulants showed that ferrous sulphate heptahydrate have a good effect on BOD reduction at dosage 1500 mg/l pH of 3.4 before pH adjustment. There were eight different samples used for different concentration of coagulant, the sample of 250 ppm copperas feed till 1000 ppm feed has the COD result difference of 171 ppm. When the copperas feed increased the COD value will decreased gradually. For the second parameter, biological oxygen demands the BOD value are reduced successfully, the first sample with feed concentration 500 ppm of copperas has BOD value of 288 ppm. As we increase the feed of copperas to 2000 ppm the BOD value reduced to 13 ppm. Next the highest value of TSS reduction is at 2000 ppm of copperas feed, at the specific dosage the TSS reading was 7502 ppm
Investigation of magnetic field effect on MRR, EWR and surface roughness during EDM of AISI420 tool Steel
Authors: Efendee A M , Azhari A , Hasnain A R , Zainal Ariffin S , Mukhtar M
Published: March 2021

Electrical discharge machine (EDM) is a machining process that is not affected by the toughness or hardness of the sample material but the electrical and thermal conductivity. In EDM process, good surface quality can only be produced if low peak current is used but the machining process will take a long time causing material removal rate (MRR) to be too low. While the accumulated machine debris in the machining zone can cause abnormal discharge and disrupt the material removal process. The present research aims to study the magnetic field effect on MRR, EWR and SR for EDM process improvement. In addition to MRR, electrode wear rate (EWR) and surface roughness illustrate the effectiveness of the EDM process. The installation of magnetic devices in the EDM machining area were implemented and the experiments were conducted using graphite electrode and AISI420 as the workpiece. Permanent magnets having 0.54 Tesla were applied to produce magnetic fields during EDM operations. The presence of this magnetic field also contributes to the effectiveness of the flushing process because the evaporated debris will be attracted and attached to the magnet, then purify the spark gap medium for the next discharge process. Dielectric that stays clean and sparks under magnetic field influence increases the effectiveness of the material removal process. Surface roughness from Ra measurement has recorded 12.6% to 28.1% improvement when magnetic devices were applied on EDM. The spark ignition delays and the refinement of EDM spark enhanced the surface quality compared to conventional EDM. Comparison of images through optical microscopy and SEM also proves that the Magnetic Field Assisted EDM (MFAEDM) method is capable of producing better surface quality. This MFAEDM shows that action to hybridize EDM is necessary to increase EDM competency by attaining both of machining efficiency and high quality of surface integrity.
Performance and Emission Measurement of a Single Cylinder Diesel Engine Fueled with Palm Oil Biodiesel Fuel Blends
Authors: Rusli M Q , Muhamad Said M F , Sulaiman A M , Roslan M F , Veza I , Mohd Perang M R , Lau H L N , Abd Wafti N S
Published: March 2021

A high concentration of palm oil biodiesel fuel blend is a strong candidate to substitute conventional diesel fuel (B10) due to its prospect to release fewer emissions. This paper shall present findings when testing palm oil biodiesel fuel blends (B10, B20, and B30) at medium speed (2500 rpm) in a single-cylinder Yanmar L70N diesel engine coupled to an eddy current dynamometer. In this study, a timed burette and an airbox determined the engine’s fuel and air consumption, respectively. In contrast, a flue gas analyzer measured the emission released by the fuel blend. The result indicates that as the concentration of palm oil biodiesel increases in the blends (from B10 to B30), there is no significant difference (average less than 5%) between the fuel blends in terms of brake thermal efficiency, brake specific fuel consumption, and air-fuel ratio. On the other hand, the emission results showed a reduction in CO, CO2, and NOx when the concentration of palm oil biodiesel increases in the blends. Considering the fuel blend would have no significant difference in the engine performance and its ability to reduce most emission, it is safe to conclude that B30 would be a good alternative for current diesel fuel (B10).
Tendencies of non-assur mechanisms use in the structure of technological machines
Authors: Isakov V S , Deriglazov V S , Isakova O V , Yereyskiy A V
Published: March 2021

The article gives the scientific research analysis results in the field of non-assured mechanisms on the basis of which the conclusion is made about the need for further development of mechanisms and methodological approaches to the synthesis of machines with special properties of the kinematic structure. This makes it possible to reduce energy consumption and improve technical performance, in particular, grinding machines and presses with gear and jagged actuating devices. The developed general scheme for the formation of the adaptable parameters of the technological machine establishes the dependence of these parameters on the conditions determined by the external environment, the properties of the initial and final product, and also implements the design of a materials grinder with different physical and mechanical properties, a press for molding fuel granules based on gear and jagged actuating devices with tense closed kinematic contours. The results of experimental studies have confirmed the existence of a relationship between the magnitude of the closed kinematic loop prestressing and the energy of the grinding and pressing process. The revealed regularities make it possible to minimize energy consumption in accordance with the strength of the mill charge or the size of the deformed sample by choosing rational parameters of the circuit stress, i.e. to adapt the technological machine to the properties of the processed material. Experimental studies of a gear mill on a sample of sandstone, quartz, marble have confirmed that, with the same energy consumption, the maximum grinding efficiency (an increase in the proportion of fine particles) is achieved only in a certain range of closed kinematic circuit loading corresponding to the strength of the mill charge. The data obtained make it possible to use the effect of a tense closed kinematic contour of gear and jagged actuating devices in technological machines for various purposes.
Comparative analysis of experimental methods to assess the resistance of milling road asphalt concrete
Authors: Furmanov D V
Published: March 2021

The paper is devoted to the comparative analysis of experimental evaluation of cutting resistance of road asphalt concrete to cutting elements with cylindrical carbide tips, which are widely used in rotors of road milling machines. The paper shows the comparison of the results obtained from the study of cutting of typical asphalt concrete with a single cutter on a pendulum stand and on a stand with a mechanical low-speed drive of the cutting element. The advantages and disadvantages of both methods are determined and provided in the paper. The conclusions obtained allow us to recommend reasonably the methods of research of strength indicators of asphalt concrete from the point of view of cutting resistance to cutting with working bodies of road machinery.
Monitoring of water quality in ponds using a miniature unmanned underwater vehicle
Authors: Safarov D I , Efimov S V , Knyazev S I , Jatsun S F
Published: March 2021

The proposed article is based on mathematical models of study and development setting up computational experiments of a miniature unmanned underwater vehicles (MUUV) The development and study of systems for automated monitoring of water quality in reservoirs (SAWM) allows the prompt real-time assessment of the environmental situation at various points in the monitoring area. The research objectives are the development of mathematical models describing the process of MUUV control, as well as the development of a mathematical model of the MUUV system. The development of a motion control strategy in the study of water quality is carried out to organize the sampling process. A mathematical model which describes perturbed motion is proposed and a method for the synthesis of the parameters of regulator of the control system based on the decomposition of the equations of motion of the MUUV and transient process is developed. Mathematical models of the force factors acting on the MUUV were developed in view of external pulse disturbances. Mathematical models of control factors were developed which ensured the motion of the MUUV with a variable thrust vector.
Investigation of return movement process of vibrocleaver blade
Authors: Kligunov E S , Voskresenskiy G G
Published: March 2021

The lack of the necessary amount of equipment for winter maintenance, significant precipitation leads to a decrease in the efficiency of roads. Inside, courtyards and sidewalks are also covered with a layer of compacted snow due to untimely snow removal. The mechanical method of breaking compacted snow is currently insufficiently studied and so far there is no effective equipment to combat snow and ice formations. A peculiarity of the process of compacted snow destruction in the mode of “vibration cutting” is intermittent contact of the blade with the destroyed medium. Condition of steady mode of vibration cutting is criterion of vibration scraper blade release from contact with medium to be destroyed. The purpose of the study is to establish the time at which the contact of the blade with compacted snow is interrupted. Obtained results of calculations make it possible to set values at which vibration cutting mode is possible and to select parameters of hydraulic accumulator, which provides movement of the vibrocleaver blade of compacted snow.
Studying the dynamics of the automatic control system for the elevation position of a motor grader blade with an alternative position sensor
Authors: Galitskov K S , Nazarov M A , Lukyanov A S
Published: March 2021

The existing problems of controlling the elevation position of a motor grader blade when leveling a roadbed, caused by arising measurement errors associated with both the operation of the control systems themselves and disturbing influences, are considered. It is shown that the optimally tuned regulators in the existing control system do not provide the required quality indicators for the operation of a construction machine. It is proposed to equip the automatic control system for the elevation position of the grader blade with an alternative position sensor, the signal from which is compared with the reference action and the difference is introduced as a correction to the control system. The developed system allows us to increase the accuracy of automatic elevation positioning of the motor grader blade up to the quality required by regulatory documents.
Modeling the warm-up process for hydraulic actuator components
Authors: Polovnikov E V , Konev V V , Merdanov Sh M
Published: March 2021

This paper discusses warm-up processes for the hydraulic system components of road construction machinery using mathematical and physical simulations. The efficiency of these processes is governed by warm-up and cool-down rates of the hydraulic actuator components. It studies how various hydraulic system components interface as they warm up. The general task is to estimate the dynamic behavior of the components and loops comprising such components and the entire warm-upsystem. The models of the transient heat flow process of the warm-up system are based on the heat balance equation of the flowing medium (of the heat transfer fluid – a hydraulic fluid) within the control volume. For experimental verification, the hydraulic actuator components warm-up modes using the warmed-up hydraulic fluid from the hydraulic tank have been tested on the hydraulic test bench that we developed. The example of consecutive warm-up of the hydraulic system components is given. Based on this, after the experimental findings were processed, correlation coefficients for different warm-up modes and types of relationships between the hydraulic actuator component temperatures and their warm-up times were determined.
One way to reduce the dynamic loads in the gearing engagement of construction machinery mechanisms
Authors: Skel V I
Published: March 2021

In the gear mechanisms of the machine drive, vibrations occur mainly due to the difference in the circular pitches of a gear and a pinion, errors in the profile of the teeth, variable gearing stiffness and friction in the mesh. For involute gear transmissions of construction machinery, the difference between circular pitches of a gear and a pinion contributes significantly to the dynamic component of the load. The influence of the difference between the gear and pinion pitches on a change in the gear ratio of a gear pair with a gear frequency as a source of vibration is considered. It is known that the dynamic load is usually greater if the main pitch of the gear is greater than the main pitch of the pinion. The authors show that it is possible to choose such a gear displacement coefficient, with which the gear ratio error will not depend on the sign of the difference between the main gear and pinion pitches and will have the smallest possible value. Then, at low cost, it is possible to obtain the least probable dynamic effect of the difference in the main pitches of the meshing gears in the construction mechanisms.
Approaches to reduction of dynamic loads arising in truck-mounted hydraulic lifts
Authors: Stepanov M A , Kaitukov B A
Published: March 2021

The article addresses approaches to reduction of dynamic loads arising in truck-mounted hydraulic lifts. Lifts are widely used to perform assembly and painting work in the course of construction. Dynamic loads, arising in the process of their operation, reduce performance and operational safety of lifts. The co-authors focused their research efforts on hinge mechanisms installed in truck-mounted hydraulic lifts. Hydraulic lift booms have hydraulic drives that ensure a uniformly continuous pace of hydraulic cylinder rod extension, but rotation speeds of the booms do not coincide, thus, causing them to move up by fits. This phenomenon triggers dynamic loads that arise in booms and make workers feel uncomfortable when on the platform. The co-authors provide motion equations for upper and lower booms of a lift. Having solved these equations, the co-authors obtained rational values of loads applied to the booms. Dependencies between varying values of the force in a hydraulic cylinder rod and the boom swing angle, as well as between the boom swing angle and the boom lifting angle are to be identified to reduce dynamic loads. These dependencies enable the co-authors to tailor the pump output. The co-authors suggest a rational system of proportional hydraulic cylinder control over acceleration or the force. Dependencies, obtained by the co-authors, can be applied to fine-tune the proportional distributor to make booms move smoothly, to reduce dynamic loads and to ensure a comfortable working environment for workers on the platform.