bluuebunny/crossref_metadata_2025 huggingface dataset:
Design, analysis, and fabrication of a direct drive permanent NdFeB magnet synchronous motor for precision position control
Authors: Hariri Ali M. , Damaki Aliabad Aliakbar , Ghafarzadeh Mahdi , Shamlou Sadegh
Published: April 2020

Direct drive motors have the excellent ability for precision position control due to their direct connection to load and elimination of the gearbox and pulley backlash. Among the direct drive motors, permanent NdFeB magnet synchronous motors (PMSMs) are the best choice for control systems due to their high efficiency, high power density, good dynamic behaviour, and excellent controllability. This study deals with the design, analysis, and fabrication of a direct drive PMSM for precision position control. To reach this aim, the designed motor should have very low cogging torque and torque ripple to avoid the motor deviation at the target point. To achieve these purposes, at first, a suitable combination of slot and pole has been selected for the motor and then the optimum shape of the magnets has been obtained by using the 2D finite element method. For the magnet shape, two important parameters of the magnet are optimised simultaneously. The designed motor has been fabricated and tested. Both simulation and experimental results show that the designed motor has a very good performance as the point of cogging torque and torque ripple views. Also, the experimental results validate the theoretical calculations.
Stability problems of PV inverter in weak grid: a review
Authors: Zhang Qianjin , Mao Mingxuan , Ke Guo , Zhou Lin , Xie Bao
Published: April 2020

Photovoltaic (PV) power generation, as one important part of renewable energy, has been greatly developed in recent years. The stability of PV inverters is very important for the normal operation of PV systems. However, most PV systems, especially the large PV plants, locate in rural areas. The corresponding equivalent grid impedance is rather large and easy to lead to stability problems of grid‐connected inverters and many researches have been done focusing on the stability problems. In this study, a survey of stability problems of PV inverters on weak grid condition is given. The stability problems are mainly divided into two parts, i.e. the control loops instability and inverter output voltage instability. The control loops cover the current loop and dc voltage loop. The output voltage instability refers to the voltage phasors relationship and the application of reactive power compensation. The non‐linear parts of inverter dead‐time, digital control delay, and phase‐locked loop are explored. Future trends and challenges are given.
Effect of heat treatments on the electronic properties of indium sulfide films
Authors: Gotoh Tamihiro
Published: April 2020

The optical and electrical properties of indium sulfide films with different heat treatments are investigated. Indium sulfide films are heat treated in Ar gas in a temperature range of 100–400 °C. Some annealed samples are heat treated at 300 °C with sulfur powder. The indium sulfide films show a band gap of 1.9–2.3 eV, an electrical resistivity in the range of 5.5 × 100–6.0 × 103 Ωm, and n-type electrical conduction. The resistivity decreases by three orders of magnitude by heat treatment at 300 °C in Ar gas and recovers almost to the initial state by heat treatment at 300 °C with sulfur powder. The Seebeck coefficient and subgap absorption at 1 eV show similar changes and recovery. The experimental results reveal the possible control of the density of states and of the Fermi level position by heat treatment and, hence, the feasibility of carrier control.
On forward and inverse uncertainty quantification for models involving hysteresis operators
Authors: Klein Olaf , Davino Daniele , Visone Ciro
Published: April 2020

Parameters within hysteresis operators modeling real world objects have to be identified from measurements and are therefore subject to corresponding errors. To investigate the influence of these errors, the methods of Uncertainty Quantification (UQ) are applied. Results of forward UQ for a play operator with a stochastic yield limit are presented. Moreover, inverse UQ is performed to identify the parameters in the weight function in a Prandtl-Ishlinskiĭ operator and the uncertainties of these parameters.
Enlarging the genetic diversity of winter oilseed rape (WOSR) by crossing with spring oilseed rape (SOSR)
Authors: Gourrion Alice , Simon Clara , Vallée Patrick , Delourme Régine , Chatre Sébastien , Dheu Jean-Éric
Published: April 2020

From 1970 to nowadays, breeders have improved oilseed rape (Brassica napus) in many ways: creation of double low varieties (free of erucic acid and with a low content in glucosinolates), increase of the seed yield and quality of seeds and improvement of resistance to diseases. All this work helped oilseed rape to become one of the most produced oilseed crop in the world. However, this intensive breeding on quality has reduced the genetic diversity of winter oilseed rape. In this study, a group of four breeding companies (RAGT, Limagrain, Syngenta, Euralis) called “GIE Colza” has been working with INRAE (National Research Institute for Agriculture, Food and Environment, France) on the FSRSO project “Printiver”. This project aimed at enlarging the genetic variability available in winter-type oilseed rape through crossing with spring-type materials to create lines with a winter-type behavior (need of vernalization) and a genetic background that has introgressed spring-type genetic diversity. Two pools have been created and selected for their need of vernalization, date of flowering, yield and other agronomic traits. The Group tested these two pools in multilocal trials. The results show interestingper sevalue and combining ability.
Homeopathy Deserves Its Own Scientific Identity
Authors: Rutten Lex
Published: April 2020

Scientific research, especially the randomised controlled trial, was once expected to provide recognition to homeopathy. However, the opposite happened: despite evidence that is not inferior to conventional evidence, the opposition has never been stronger. The philosopher Kuhn predicted this: scientific authorities cannot accept information that is contrary to their basic beliefs (paradigm) because their authority depends on that very paradigm. On the other hand, many patients discover that the conventional medical paradigm is incomplete and that homeopathy complements it. The problems with the present paradigm are expected to grow, especially with antimicrobial resistance1 with respect to respiratory tract infections. Homeopathy can be of great value in this respect. There is also growing awareness that there is no dichotomy between effective and not-effective medicines. The effect of a medicine is a probability depending or several variables. So far improving the homeopathic method with scientific research has been neglected. The increasing interest of conventional medicine in personalised medicine and prognostic factor research (PFR) is an excellent opportunity to redirect homeopathy research towards PFR.
Role of Silicea in Diabetic Foot Ulcer: A Retrospectively Analysed Case Series
Authors: Ponnam Hima Bindu , Gupta Jaya
Published: April 2020

Background and Objectives Diabetic foot is a condition especially vulnerable to amputation because of frequent complications of peripheral neuropathy, infection and peripheral arterial disease. Diabetic foot problems are a major cause of hospitalisation and prolonged hospital stays, constituting 20% of those entering hospitals. If treatment is delayed or improper treatment is given, it leads to infection, gangrene and amputation. Homoeopathic literature reveals that Silicea is a useful medicine for ulcers, but there is dearth of systematic research in this area. This article is an effort to provide detailed information of potentised Silicea in reference to diabetic foot ulcer (DFU).

Method A prospective observational study was conducted by Central Council for Research in Homoeopathy at its Extension Clinical Research Unit, Hyderabad, from 2005 to 2009. From the study, cases where Silicea (n = 22) was indicated and prescribed were taken for retrospective analysis.

Results The analysis showed usefulness of Silicea in treating DFU. The baseline symptom score of DFU and sugar values were statistically analysed before and after treatment. The mean symptom scores at the baseline (8.41 ± 3.03) and at the end of treatment (0.27 ± 0.70) were found to be statistically significant (p = 0.001).

Conclusion The result of the role of Silicea in ulcer healing was found to be positive and encouraging. Further, to validate the effect of Silicea, randomised controlled trials can be undertaken.
Optofluidic detection setup for multi-parametric analysis of microbiological samples in droplets
Authors: Hengoju S. , Wohlfeil S. , Munser A. S. , Boehme S. , Beckert E. , Shvydkiv O. , Tovar M. , Roth M. , Rosenbaum M. A.
Published: April 2020

High-throughput microbiological experimentation using droplet microfluidics is limited due to the complexity and restricted versatility of the available detection techniques. Current detection setups are bulky, complicated, expensive, and require tedious optical alignment procedures while still mostly limited to fluorescence. In this work, we demonstrate an optofluidic detection setup for multi-parametric analyses of droplet samples by easily integrating micro-lenses and embedding optical fibers for guiding light in and out of the microfluidic chip. The optofluidic setup was validated for detection of absorbance, fluorescence, and scattered light. The developed platform was used for simultaneous detection of multiple parameters in different microbiological applications like cell density determination, growth kinetics, and antibiotic inhibition assays. Combining the high-throughput potential of droplet microfluidics with the ease, flexibility, and simplicity of optical fibers results in a powerful platform for microbiological experiments.
Structural coupling and magnetic tuning in Mn2−xCoxP magnetocalorics for thermomagnetic power generation
Authors: Levin Emily E. , Bocarsly Joshua D. , Grebenkemper Jason H. , Issa Ramsey , Wilson Stephen D. , Pollock Tresa M. , Seshadri Ram
Published: April 2020

Promising materials for magnetic refrigeration and thermomagnetic power generation often display strong coupling between magnetism and structure. It has been previously proposed that MnCoP exhibits this strong coupling, contributing to its substantial magnetocaloric effect near TC = 578K. Here, we show from temperature-dependent synchrotron x-ray diffraction that MnCoP displays a discontinuity in the thermal expansion at TC, with spontaneous magnetostriction that is positive in the a direction and negative in the b direction, highlighting the anisotropic nature of the magnetostructural coupling. Varying the Mn:Co ratio of Mn2−xCoxP within the range of 0.6 ≤ x ≤ 1.4 allows the magnetic properties to be tuned. TC decreases as the composition deviates from stoichiometric MnCoP, as does the saturation magnetization. The magnitude of the magnetocaloric effect, |ΔSM|, decreases as well, due to broadening of the magnetic transition. The large reversible change in magnetization ΔM accessible over a small temperature range under moderate magnetic fields makes these materials promising for thermomagnetic power generation from waste heat.
Beta-phase gallium oxide and diamond fused through hydrophilic direct bonding
Authors: Frank Jodi Ackerman
Published: April 2020

The bonding process, achieved through typical surface cleaning, could set the stage for next-generation high-power electronics.
Temperature controlled microjets for liquid ammonia solutions
Authors: Mandel Savannah
Published: April 2020

Versatile apparatus allows researchers to study the release of liquid ammonia solutions in a vacuum using photoelectron spectroscopy.
Polar magnetic oxides from chemical ordering: A new class of multiferroics
Authors: P N Ravi Shankar , Mishra Swarnamayee , Athinarayanan Sundaresan
Published: April 2020

Combining ferroelectricity and magnetism in the same material remains a challenge because it involves complex crystal chemistry and stringent symmetry requirements. In conventional ferroelectrics, the polarization arises from the second-order Jahn–Teller effect associated with cations of d0 or s2 lone pair electronic configuration. In contrast, the magnetism arises from cations with partially filled d or f electrons. Materials that incorporate these two kinds of cations in different crystallographic sites exhibit multiferroic properties but with weak coupling between magnetism and ferroelectricity. On the other hand, a strong cross-coupling occurs in some materials, where specific spin structures induce weak ferroelectricity below the magnetic ordering temperature. In this article, we discuss a new class of multiferroics where the polar distortion results from chemical ordering. These polar oxides are mainly pyroelectric in the entire temperature range and exhibit magnetoelectric coupling below the magnetic ordering temperatures.
A RDA-Based Deep Reinforcement Learning Approach for Autonomous Motion Planning of UAV in Dynamic Unknown Environments
Authors: WAN Kaifang , GAO Xiaoguang , HU Zijian , ZHANG Wei
Published: April 2020

Autonomous motion planning (AMP) in dynamic unknown environments emerges as an urgent requirement with the prosperity of unmanned aerial vehicle (UAV). In this paper, we present a DRL-based planning framework to address the AMP problem, which is applicable in both military and civilian fields. To maintain learning efficiency, a novel reward difference amplifying (RDA) scheme is proposed to reshape the conventional reward functions and is introduced into state-of-the-art DRLs to constructs novel DRL algorithms for the planner’s learning. Different from conventional motion planning approaches, our DRL-based methods provide an end-to-end control for UAV, which directly maps the raw sensory measurements into high-level control signals. The training and testing experiments demonstrate that our RDA scheme makes great contributions to the performance improvement and provides the UAV good adaptability to dynamic environments.
Optimization of K-medoids Algorithm for Initial Clustering Center
Authors: E Wang Yan , Jian An , Yan Liang , HongGang Wang
Published: April 2020

This paper studies the k-medoids of the partitioning clustering algorithm. A variance-based density optimization algorithm is proposed to solve the problem of random selection of initial clustering centers, slow convergence speed and unstable clustering results in K-medoids algorithm. Based on the mean square deviation and distance mean of the sample set, the density radius of the sample set is calculated according to the size of the sample set. Under the same density radius, the samples in dense regions have high density. By dynamically selecting the samples are selected as initial clustering centers from different dense regions, in the clustering process local optimization is used to accelerate the convergence speed. These operations solve the shortcomings of K-medoids algorithm. In order to test the clustering effect, this algorithm is applied to data set of UCI machine learning. The experimental results show that the initial clustering centers selected by the algorithm are located in the dense area of the sample set, which is more in line with the original distribution of the data set. The algorithm has higher clustering accuracy, more stable clustering results and faster convergence speed on data sets.
An Intelligent Chatbot System Based on Entity Extraction Using RASA NLU and Neural Network
Authors: Jiao Anran
Published: April 2020

Intelligent chatbot systems are popular issues in the application fields of robot system and natural language processing. As the development of natural language processing and neural network algorithms, the application of artificial intelligence is increasing in Chatbot systems, which are typically used in dialog systems for various practical purposes including customer service or information acquisition. This paper designs the functional framework and introduces the principle of RASA NLU for the Chatbot system, then it integrates RASA NLU and neural network (NN) methods and implements the system based on entity extraction after intent recognition. With the experimental comparison and validation, our developed system can realize automatic learning and answering the collected questions about finance. The system analysis of two methods also validate that RASA NLU outperforms NN in accuracy for a single experiment, but NN has better integrity to classify entities from segmented words.
Representation Learning for Electronic Health Records: A Survey
Authors: Chen Peiying
Published: April 2020

With the wide application of Electronic Health Record (EHR) in hospitals in past few decades, researches that employ artificial intelligence (AI) and machine learning methods based on EHR data have been explosive. With such EHR data, one can engage in many tasks such as risk prediction, treatment recommendation, information imputation, etc. The performance of classification or prediction highly depends on the quality of data representation, i.e., representing original records into numerical vectors to facilitate further learning. However, there is little research that focuses on the representation learning techniques for EHR data at present, which makes it hard to understanding the development trend of EHR learning in a global map. In this paper, we bridge this gap by systematically investigating the related research efforts that apply the representation learning on EHR data. We analyze and conclude the techniques used in the typical representation learning approaches as well as the limitations and advantages of them. The survey would provide a comprehensive reference for further analysis and application in EHR research.
A Survey on Application of Knowledge Graph
Authors: Zou Xiaohan
Published: April 2020

Knowledge graphs, representation of information as a semantic graph, have caused wide concern in both industrial and academic world. Their property of providing semantically structured information has brought important possible solutions for many tasks including question answering, recommendation and information retrieval, and is considered to offer great promise for building more intelligent machines by many researchers. Although knowledge graphs have already supported multiple “Big Data” applications in all sorts of commercial and scientific domains since Google coined this term in 2012, there was no previous study give a systemically review of the application of knowledge graphs. Therefore, unlike other related work which focuses on the construction techniques of knowledge graphs, this present paper aims at providing a first survey on these applications stemming from different domains. This paper also points out that while important advancements of applying knowledge graphs’ great ability of providing semantically structured information into specific domains have been made in recent years, several aspects still remain to be explored.
A Systematic Study for Learning-Based Software Defect Prediction
Authors: Cao Han
Published: April 2020

Software defect refers to the code error in the process of software development, which could cause execution fault under specific conditions, resulting in failure, collapse, and high cost of the target software. Traditional detection techniques for software defect contain static and dynamic analysis, both of which require a great deal of workforce and time. With the development of machine learning and deep learning, software defect prediction has opened a new avenue to circumvent the drawbacks of traditional analysis approaches. Although various learning-based techniques in the prediction field have been developed, there is a lack of systematic summary and classification from the technical point of view. This paper studies the problem from the three aspects: traditional machine learning, deep learning, and hybrid learning. Moreover, the predicted performance is discussed in detail, especially in cross-project and just-in-time, to understand current research status thoroughly. This paper also provides a useful guide for further research, particularly for the potential usage of deep learning in semantic defect prediction.
Application and Development Trend of Smart Home in Residential Interior Design
Authors: Yang Ziqi , Cho JoungHyung
Published: April 2020

Smart home is the product of artificial intelligence, which can provide people with a safe, comfortable and environmentally friendly home environment, as well asmeets people’s living needs in residences in an all-round and personalized way and has a good development prospect. This paper expounded the development, classification and application of smart home in residential interior design. Taking Bill Gates’ “Future Home” as an example, it analyzed that the introduction of smart home can organically combine residences, users, environment and plants to provide a better living environment for human beings.
Massive Learning Behaviours Influence Educational Sustainability: A Machine Learning Approach
Authors: Muhammad Raza Abidi Syed , Hussain Mushtaq , Ge Sen , Ding Hu , Zhu Wenhao , Zhang Wu
Published: April 2020

Discovering learning behavior patterns while using Massive Open Online Courses (MOOCs) or e-learning platform education is being one of the substantial aspects in the plethora of past studies. In this study, we predict the taxonomy of learner behaviors by using the data of Junyi Academy, an e-learning platform similar to Khan Academy. We evaluate the dataset of first 2,000 unique learners and applying machine learning algorithms, i.e., Logistic Regression, and Neural Network (NNET) to predict the status of learners’ behavior. Our result shows that NNET autotuned is high accuracy champion predictive model as compared to Logistic Regression and NNET manually tuned hyperparameters models. The accuracy we measured based on Kolmogorov-Smirnov (KS) statistic for VALIDATION partition dataset. Furthermore, our model allows teachers to track or predict behavioral changes of the individual student and reveal insights into the content of the course material. It will also assist teachers in getting an early prediction of behaviors before finishing the course or skill, which is constructive and valuable for sustainable education or educational sustainability.
Improvement of Performance of Navigation System for Supporting Independence Rehabilitation of Wheelchair - Bed Transfer
Authors: Kato Jin , Deguchi Genbu , Inoue Jun , Iwase Masami
Published: April 2020

The purpose of this research is to improve the position and angle estimation accuracy of the wheelchair guide system for Hemiplegic patients. The wheelchair guide system aims to assist the patients to transfer between their wheelchair and bed. This system prompts properly to user depending on the situation as same as care worker. Therefore, the system is developed to prompt the measured position and angle of wheelchair. The position estimator uses an AR marker to detect the wheelchair position. However, its estimation is contaminated by measurement noises and sometimes fails because the marker is out of the camera’s field of view. To improve the estimation of position and moving direction, we introduce the kinematic model of the wheelchair and utilize the Extended Kalman Filter with the model. In this paper, we describe the self-position estimation method of the navigation system and AR marker, with the estimation method using Kalman Filter.
Design and Implementation of an EOG-based Mouse Cursor Control for Application in Human-Computer Interaction
Authors: Kabir Ahsan-ul , Bin Shahin Faisal , Kafiul Islam Md.
Published: April 2020

Human Computer Interaction (HCI) has turned into an emerging technology due to the advancement in the field artificial intelligence and biomedical engineering. Acquiring different bio-signals such as Electro-oculography (EOG), Electromyography (EMG) and Electroencephalography (EEG) to control external machine or computer is the essence of HCI technology. In this research, we attempt to extract the EOG signal from different ways of eye movements and process it for HCI application. By utilizing Arduino, EOG data can be transmitted to computer and those signal characteristics is analysed through MATLAB. We have designed and implemented hardware and interfaced it with software to control a computer mouse cursor only by eye movement. Certain classification module like Support Vector machine (SVM) and Multilayer Perceptron (MLP) are used to classify different EOG data generated from different eye movement. According to the eye position, cursor automatically moves in that specific direction and PyAutoGUI module is used for this task. Results after experimentations with different subjects to control mouse cursor in real-time show that the average classification accuracy can reach up to 93% across all directions.
Robot Positioning Error Compensation Method Based on Deep Neural Network
Authors: Hu Junshan , Hua Fangfang , Tian Wei
Published: April 2020

Industrial robots are widely used in intelligent manufacturing industry because of their high efficiency and low cost, but the low absolute positioning accuracy limits their application in the field of high-precision manufacturing. To improve the absolute positioning accuracy of robot and solve the traditional complex error modeling problems, a robot positioning error compensation method based on deep neural network is proposed. The Latin hypercube sampling is carried out in Cartesian space, and the influence rule of target attitude on error is obtained. A positioning error prediction model based on genetic particle swarm optimization and deep neural network (GPSO-DNN) is established to realize the prediction and compensation of the positioning errors. The experimental results show that the positioning error compensation method based on GPSO-DNN presents good compensation accuracy. The positioning error is reduced from 1.529mm before compensation to 0.343mm, and the accuracy is increased by 77.57%. This method can effectively compensate the positioning error of the robot and greatly improve the positioning accuracy of the robot.
Flexible Adaptive Control of Snake-Like Robot Based on LSTM and Gait
Authors: Ouyang Sheng , Wei Wu
Published: April 2020

This paper presents a flexible control method for snake-like robots to adapt to the environment autonomously. This method enables the snake-like robot to sense the environment and adjust autonomously according to the changes of the environment. For example, snake-like robots climb pipes with varying diameters. In order to achieve efficient and flexible motion, we adopt closed-loop gait control. This control method uses a parameterized sine wave (gait function) and long short-term memory network (LSTM) model. Because of the structure of LSTM is suitable for prediction of time series data, we use LSTM to predict the changes of joint angles that can best represent the shape change of snake-like robot, and integrate the predicted joint angle values with the gait values to realize the control of robot. Because this control method will eventually allow the snake-like robot to move autonomously in the changing environment, we can achieve the flexible adaptive behavior of the robot.
Wind, sun, and wildlife: do wind and solar energy development ‘short-circuit’ conservation in the western United States?
Authors: Agha Mickey , Lovich Jeffrey E , Ennen Joshua R , Todd Brian D
Published: April 2020

Despite the trade-offs between renewable energy development, land use, humans, and wildlife, wind and solar development continues to transform the western US into a green energy landscape. While renewable energy reduces carbon emissions and reliance on fossil fuels, many studies have emerged on the associated ecological and social impacts of this technology. Here, we review the current state of knowledge on the nexus between wildlife conservation and energy development in the western US since 2010. We revisit pertinent ecological concepts presented in earlier reviews to assess how far the field has progressed in mitigating negative effects. Specifically, we examine: (i) recent trends in the literature on how wind and solar energy development impact wildlife in the US, (ii) how siting and design of development may maximize energy benefits while minimizing negative effects on wildlife, (iii) the availability and benefits of before-after control-impact studies, and ultimately (iv) how impacts of renewable energy development on wildlife may be mitigated. We also provide case studies on the desert tortoise and greater sage-grouse, two conservation-reliant umbrella species in the western US, to highlight efforts to mitigate the effects of solar and wind energy development, respectively. We recognize that many other species are affected by renewable energy development, but desert tortoises and sage-grouse are representative of the conflicts that need to be addressed. Our review concludes that mitigation can be improved via use of spatial decision support tools, applying novel wildlife deterrence and detection systems developed for existing installed facilities, and incorporating impact studies that provide managers with conservation metrics for evaluating different future development land-use scenarios.
Promoting agroforestry model in increasing land cover to sustain community livelihood in Paru Village Forest
Authors: Octavia D , Rachmat H H
Published: April 2020

In forestry sector, social forestry gained more concern nowadays and subjected to create new economic growth. Agroforestry is a silviculture practice that is suitable to be applied in areas with social forestry schemes. In this condition, Agroforestry is one of solution to restore degraded forest and other form of landscapes which can cover ecological, economical, and social aspect. This paper aim to gain information of plant survival rate in the establishment of agroforestry plot for a total 8 hectares in Paru Village Forest under Sijunjung Forest Management Unit, West Sumatra by planting 9 tree species (both of forest tree and fruit tree/multipurpose tree species) and 3 seasonal crops species. We applied different planting technique for two types of land status. For protection forest was applied by gap planting technique while for other land status area was applied Intensive Artificial Regeneration (IAR) with planting distance of 8 m x 8 m. Data collection covered for survival rate and initial height measurement. Growth percentage was observed at ages 1, 6 and 12 months after planting, respectively 95.2%; 94.5% and 93.5%. Survival rate is good enough for 12 months after planting, supported by community participation which looks high in maintaining their crops.
Business Model Development of Oil Palm Empty Fruit Bunch and Trunk Carbon Nanofibers – Based Water Purifier
Authors: Fadillah A , Hartoyo A P P , Solikhin A
Published: April 2020

Indonesia have confronted the decrease in water quality due to mining, industry, agricultural practices, and waste disposal. Carbon nanofibers derived from oil palm empty fruit bunch (OPEFB) and oil palm trunk (OPT) have the economic potential to be commercialized as water purifier. This paper aims to analyze the potential economic value by means of a business model from OPEFB and OPT carbon nanofibers. The methods used in this paper were the qualitative method and the business model development. The result showed that the carbon nanofibers based–water purifier has high economic value. The economic value of this innovation is predicted to increase from $1.6 billion in 2007 to $6.6 billion in 2015 in the market. Furthermore, the suitable business model for water purifier from OPEFB and OPT carbon nanofibers was the fabless business model (FLBM). That model is more focused on the core competencies (research, design, development) and marketing of the nanotechnology products. This FLBM was suitable for the new startup business with innovative technology to enter the market by collaborating with key partners (manufacture, government, academic, research center, and community).
Effect of chopping on yield, physico-chemical properties, and chemical composition of Clove (Syzygium aromaticum L.) leaf essential from three varieties
Authors: Pujiarti R , Humairoh A , Wibisono M G , Hardiyanto E B
Published: April 2020

Clove oil is one of the highest potential essential oil to be developed and traded in Indonesia. Several factors that can affect the yield and quality of the clove oils such as material pretreatment and plant variety. The purpose of this study was to assess the yield and quality of clove leaf oil between three plant varieties (var. A, var. B and var. C) without leaf chopping and with leaf chopping (chopped with a size of diameter ± 0.5-1cm). Chemical compositions of the oil were analyzed using GC-MS and the physico-chemical properties and measured based on SNI 06-2387-2006. The results showed var. C with chopping treatment produced the highest yield (2,67%). GC-MS analysis showed that the main compound of clove oil was eugenol (66.10 – 72.29%), which the highest content obtained at whole leaves var. A. Varieties of clove plants and leaves chopping have effects on yield, amount and percent of chemical compounds, but no significant effect on physicochemical properties. Var. A has best clove leaf oil quality, whereas var. C with chopped treatment produced the highest yield.
Selection of adaptive teak provenance in Gunungkidul
Authors: Kurniasari E , Indrioko S , Ratnaningrum Y W N
Published: April 2020

The teak planting program for rehabilitation and research, as well as for social forestry purposes, requires a constant supply of planting materials with good phenotype and genetic qualities. Most of teak seeds in Indonesia are collected from seed production areas, and even from unidentified stands when the improved stands are unavailable. Vegetative material production from hedge orchards has also been used in a lesser number due to the more complex production techniques and the more expensive cost. Therefore, it is a need to look for any other alternatives for teak planting material supplies. The success of Wanagama on rehabilitation of critical land area suggested an idea to increase the value of Wanagama plantations as a seed source. A 31 years old provenance trial plantation PPGM-T73-88 consists of 21 provenances, located in Compartment 17 Wanagama, made in 5 blocks, 4 tree plots, and 4 m x 4 m spacing, was selected to be an alternative seed source. This study was aimed to evaluate the possibility of the plantation to be a seed source, by selecting the adaptive provenances based on survival rate, height, and diameter. This study concluded that Malabar and Central Province provenances have the highest survival rate. Kouai and Deling provenances are the highest rank of height and diameter characteristics. Respectively, the heights of both provenances are 14.58 m and 13.86 m; the diameters are 31.95 cm and 34.73 cm. Key words: teak, provenance trial, seed source, Wanagama
Biodiversity exploration of host trees (phorophyte) of epiphyte orchids in the natural habitat
Authors: Soetopo L , Utami A P
Published: April 2020

Epiphyte orcids host trees grow naturally in tropical rainforests. Nowadays tropical rainforest destruction could decreased these specific host trees alongside with the various epiphyte orchids. Little information could be found on epiphyte host trees in Indonesia. The aim of this research was to explore the biodiversity of epiphyte orchid host trees (phorophytes) at Highway Forest Park Raden Soeryo and supported by exploration data in 2003, 2005, 2018 at Bromo Tengger Semeru National Park, and in 2006, 2007 at Highway Forest Park R. Soeryo. Exploration of epiphyte orchid host trees at Jogging Track site and Coban Watu Ondo site, Highway Forest Park R. Soeryo, East Java was conducted in May-July 2019. The research methode was carried out using a purposive sampling methode at Jogging Track and line transect at Coban Watu Ondo. From the main transect 30 plots were made with the area of each plot 20 m x 20 m with a distance between plots of 60 m at Jogging Track site and 100 m at Coban Watu Ondo. From the exploration we found at Jogging Track site 15 species of 173 hosts trees with diversity index 1.57 (medium). While at Coban Watu Ondo 10 species of 171 host trees with diversity index 1.52 (medium). Host trees bark characterizes by rough. grooved, hard skin no latex, tree diameter 20.00-85.00 cm. canopy medium-sparse. The biodiversity of porophyte trees exist in the area of National Park Bromo Tengger Semeru and Highway Forest Raden Soeryo south of Mt Arjuno Lalijiwo and east of Mt Anjasmoro regions is quite diverse.
The use of mycorrhizae in production of clonal seedlings of superior teak, a prospective tree species for increasing agroforestry system productivity
Authors: Rosyidah U , Nurjanto H H , Widiyatno
Published: April 2020

Agroforestry system which consisted of Teak as the main tree component has been widely established in Java. Teak is selected because it produces luxurious wood. The demand of Teak wood increases continuously, therefore Superior Teak becomes fascinating. Seedlings of selected Superior Teaks can be obtained through clonal propagation. The growth of Teak Clonal seedlings can be improved further by application of mycorrhizal fungi which help roots to obtain essential nutrition and water. This study aimed to determine the relationship between root biomass and mycorrhizal fungal colonization with growth of the seedlings. This study used four selected Teak clones (WG1, WG2, F71, and D15). Shoot plantlets were planted on cocopeat: rice husk charcoal mixture (1:1 v/v) in polybags and inoculated with soil containing mycorrhizal spores. Growth parameters were measured fortnightly. Four months after mycorrhizal inoculum application, the plants were harvested and assessed for lateral root number and length and biomass dry weight. Sample of roots were stained with 0.05 % tryphan blue lactoglycerol and assessed for mycorrhizal infection. The results showed that survival and rooting rates varied among clones, ranging from 45-83% and 23-63%, respectively. In the nursery condition, growth of all clonal seedlings was strongly correlated with mycorrhizal colonization varied between positive and negative correlation. The correlation varied among clones, being the greatest at clone WG1, D15, F71 and the least at clone WG 2. The growth and productivity of the selected superior teak in the agroforestry system may be enhanced by application of suitable mycorrhizal inoculum.
Studies on the anti-oxidative ability of quinones in natural ester based insulating liquids for transformers
Authors: Zeng Miao , Cai Shengwei , Chen Cheng , Guo Huihao , Shao Minfeng , Li Hui , Yin Jing , Chen Jiangbo , Yin Guochuan
Published: April 2020

Due to the unsaturated olefinic structure of natural esters, their antioxidation ability is generally poorer than that of the mineral oils, thus certain antioxidants were commonly added as the additives to improve the oxidative stability of natural ester for their service as transformer oils. The present study reported the influences of adding quinones as additives on the oxidative stability of versatile natural esters. It was found that, under the accelerated oxidation conditions, added quinones could improve the oxidative stability of these tested natural esters through decreasing their acidic values, viscosity increase and dielectric losses to certain extent, thus providing a new category of antioxidants to improve the oxidative stability of natural ester based transformer oils.
Rare-earth elements and isotopic geochemistry of thermal waters of the Okhotsk sea shore, Far East of Russia
Authors: Bragin I.V. , Chelnokov G.A. , Kharitonova N.A. , Veldemar A.A. , Pavlov A.A.
Published: April 2020

New data on hydrogeochemistry of thermal waters of the Okhotsk sea-shore (Ulskiy, Annensky Tumnin, Talaya, Paratunka, Dagi and Lesogorsky) is presented in the paper. Sikhote-Alin ridge thermal waters with crystalline host rocks refer to sulfate-hydrocarbonate or hydrocarbonate sodium fresh waters with elevated silicon content (up to 41 ppm), lowest TDS (<0.3 g/L), alkaline (9.1<pH<9.3). Thermal waters of Talaya and Paratunka refer to sedimentary basins, resulting in presence of sulfate and chlorine in main ions, higher TDS (1-1.2 g/L), lower pH (∼8.6) values and reducing conditions (-82>Eh>-157 mV). Geological conditions were proved by shapes of REE patterns (positive Eu-anomaly for sedimentary basins). Stable water isotopes led us to divide roughly studied waters into two groups, using peculiarities of moisture source for water recharge areas. First group: Tumin, Annensky and Talaya with more “continental” climate as for mainland thermal waters, forming isotopically lighter water and second group: Ulskiy, Paratunka, Dagi and Lesogorsky, with “marine” climate of Sakhalin and Kamchatka, forming isotopically heavier water.
A study of the effect of air temperature on the possibility and rate of formation of nitrogen oxides in boiler flue gases
Authors: Balandina O A , Puring S M , Vatuzov D N , Filatova E B
Published: April 2020

We consider the mechanisms of formation of nitrogen oxides in boiler flue gases. Thermodynamic calculations are used to determine the possibility and rate of formation of nitrogen oxides in the temperature range from 25 to 2000°C. We apply the methods of geometric thermodynamics to demonstrate the changes in the Gibbs free energy of nitrogen oxides formation reactions and determine the conditions of achieving the chemical equilibrium for these reactions. An analysis of concentrations of formed nitrogen oxides and temperatures of the jet flame under different conditions of mixture formation was performed. We produced and analyzed a number of diagrams of distribution of the flame temperatures and nitrogen oxide concentrations in the calculation area for the temperatures of the oxidant of 20, 60, 100, 150 and 200°C. Mathematical simulation of the process of gaseous fuel combustion was performed using FlowVision software package. The analysis of the results showed that the decrease in the temperature of the air supplied as an oxidant results in a considerable drop in the concentration of nitrogen oxides in flue gases without any significant impact on the changes of the flame temperature. The results of the study can be used in addressing the problems of optimization of boiler plants in order to reduce harmful flue gas emissions.
The study of the heat transfer process in bodies with internal heat sources of variable power
Authors: Eremin A V , Gubareva K V , Ilyasov A A , Trubitsyn K V , Iglin P V
Published: April 2020

An analytical solution to an unsteady heat conductivity problem based on the method of using a new function for a plate under first-order boundary conditions with time-varying internal heat sources was obtained. Obtaining an exact analytical solution for such problems has encountered serious mathematical difficulties. However, analytical solutions have significant advantages compared to numerical ones. For example, solutions obtained in an analytical form make it possible to perform the parametric analysis of the system under study, parametric identification, programming of measuring devices; controlling the production process, etc. Therefore, approximate analytical methods have been widely used. So, this paper is devoted to the development of such a method. The solutions obtained have a simple form of algebraic polynomials without special functions. This allows doing the research in the fields of isotherms and determining their velocities.
Method for determining the characteristics of a gas-steam chp with a steam turbo drive of a compressor
Authors: Tian V K , Gulina S A , Sheludko L P , Biryuk V V , Goryunova I Y
Published: April 2020

A new type of maneuverable combined-cycle plant with a steam-turbine drive of a low-pressure compressor is considered. The analysis of its technological processes in the generation of electric and thermal energy in heating and non-heating periods of the year is carried out. It is shown that in heating conditions, the burning of additional fuel in the afterburner between the stages of the evaporator of the utilizer boiler provides an increase in its steam production, maneuverability, thermal and electric power of the CCGT-CHP plant. The influence of the chemical composition and thermophysical properties of natural gas on obtaining the required excess air in the combustion chamber of a combined cycle gas turbine is considered. A mathematical model of technological processes is developed. The influence of deep utilization of the heat of the flue gases of the utilizer boiler on increasing the efficiency and improving the environmental characteristics of the gas-steam plant of a thermal power plant was recorded.
Application of phase portraits for estimation of reactive power of electric circuits
Authors: Andrianov D P , Badalyan N P , Kolesnik G P
Published: April 2020

In this paper we consider the principal possibility of using the estimation of the reactive power of electric circuits by phase portraits of electric current oscillations. The shift of the phase angle of current and AC voltage oscillations relative to each other is displayed on the phase portrait of oscillations by bifurcation of the phase trajectory. The region described by the phase trajectory corresponds to the reactive power. Reactive power must be kept to a minimum to produce an energy efficient power supply. As an optimization criterion it is proposed to use the size of the phase portrait area of stationary oscillations of alternating current. Simulation of the optimization process was carried out on the basis of numerical solution of the system of differential equations using dynamic programming methods. Typical functions of numerical solution of systems of differential equations and optimization of the target function, available in mathematical packages, were used.
Analysis of applicability of conventional units in power grid companies in the Russian Federation
Authors: Dronova Y V , Chernenko N A , Tikhonova D A , Shinkaryuk D I
Published: April 2020

Value formation for energy transmission services in the Russian Federation is carried out under strict state control, basing on the widespread practice of benchmarking or “best practice” methods. The basis for calculating some of the best indicators is the concept of “unit credit”. (c.u.). Over the past few years, the issue of the “unjustified” application of the CU and the need to review it has been raised several times. The analysis of the current normative documentation has shown that use of different documents allows changing the results of calculation of the basic items of the expenses using c.u. as the basic indicator, for example, the expenses for maintenance service and repair (MRO) regarding a labor payment. This situation arises in the process of transferring the actual labor intensity of maintenance and repair works in c.u. The value of deviation of labor inputs determined by the difference in periodicity and labor intensity leads to significant distortion of result when forming costing and defining the optimum or the most effective values. Thus, these differences can become a tool for manipulation by energy companies when costing making use of benchmarking.