bluuebunny/crossref_metadata_2025 huggingface dataset:
Biochar as a Soil Amendment: Reduction in Mercury Transport from Hydraulic Mine Debris
Authors: Brandt Madison , Page-Dumroese Deborah S. , Webster Jackson , Monohan Carrie
Published: October 2021

Mercury mining and its use in gold mine operations left a legacy of contamination in northern California. Contaminated sediments and water continue to affect local and downstream ecosystems. To assess the efficacy of biochar-amended soils on decreasing Hg transport, biochar was used to amend rock and sediment columns and mesocosms to decrease suspended sediment and associated mercury (Hg) in storm water runoff from Sierra Nevada hydraulic mines. Mercury-contaminated storm water runoff and hydraulic mine debris were collected from two hydraulic mine sites in the Yuba River, California watershed. Mercury concentrations and turbidity were analyzed from storm water samples and hydraulic mine debris in three simulated storm runoff experiments using decomposed granite columns, sediment columns, and sediment mesocosms amended at 0%, 2%, or 5% biochar by weight. Columns containing hydraulic mine debris and mixed with 5% biochar had a significant (p < 0.05) reduction in filter-passed mercury (FHg) in the outflow as compared to control columns. To simulate saturated hydraulic mine debris runoff, mesocosms were filled with mine sediment and saturated with deionized water to generate runoff. Five percent biochar in mesocosm trays decreased FHg significantly (p < 0.001), but, because of the angle of the tray, sediment also moved out of the trays. Biochar was effective at reducing FHg from hydraulic mine discharge. Biochar in laboratory columns with decomposed granite or mine sediments was more effective at removing Hg than mesocosms.
Intelligent Control System Architecture for Phosphorus Production from Apatite-Nepheline Ore Waste
Authors: Dli Maksim , Puchkov Andrey , Vasiliev Artem , Kirillova Elena , Selyavskiy Yuri , Kulyasov Nikolay
Published: October 2021

This paper proposes multilevel architecture for an intelligent control system for the complex chemical energy technological process of yellow phosphorus production from apatite-nepheline ore processing waste. The research revealed that, when controlling this process, one has to deal with large amounts of multiformat and polymodal information, and control goals differ at different levels not only in effectiveness criteria, but also in the structuredness of the level problems. On this basis, it is proposed that intelligent methods be used for the implementation of information processes and control goals at individual levels and the whole system. The artificial intelligence methods underlying the informational model of a control system offer solutions to problems of analyzing control processes at different hierarchy levels, namely the initial level of sensing devices, the levels of programmable logic controllers, dispatching of control and production processes, enterprise management and strategic planning. Besides, the intelligent control system architecture includes analytical and simulation models of processes occurring in the multistage procedure of ore waste processing by a plant consisting of a granulating machine, a conveyor-type multichambercalcining machine, and an ore thermal furnace. The architecture of information support for the control system comprises a knowledge-based inference block intended for implementing the self-refinement of neural network and simulation models. Fuzzy logic methods are proposed for constructing this block. The paper considers the deployment of control algorithms for a phosphorus production system using the Matlab software environment on the basis of a modern complex system development paradigm known as the model-oriented design concept.
Managing the Energy Transition through Discourse. The Case of Poland
Authors: Krzywda Joanna , Krzywda Dariusz , Androniceanu Armenia
Published: October 2021

Since energy transition has become a necessity, many countries are developing decarbonization plans and looking for ways to reduce CO2 emissions. The process takes different forms, most often being affected by local conditions, which means that it takes place in each country differently, due to the country’s social and economic specifics. One of the countries that has just started its energy transition process is Poland. The case of Poland is extremely interesting, as it is a country whose economy is still heavily dependent on coal and there are very strong traditions related to this particular source of energy. On the other hand, Poland has two very good reasons to move away from coal. The complexity and comprehensiveness of the energy transition results, among other things, from the diversity of actors involved in this issue and the multiplicity of their, often conflicting, interests. Using a critical discourse analysis, this paper attempts to show how those actors attempt to shape the transition through the discourses which they generate. The study covers the media discourse that took place in Poland between September 2020 and May 2021, i.e., a time when the Polish government negotiated with representatives of the miners’ trade unions the terms of Poland’s transition from coal. A critical analysis of the texts that appeared in the media during this time provides a picture of how different groups of social actors perceive the transition and how they try to manage that process.
Heating Performance and Ammonia Removal of a Single-Stage Bioscrubber Pilot Plant with Integrated Heat Exchanger under Field Conditions
Authors: Krommweh Manuel S. , Deeken Hauke F. , Licharz Hannah , Büscher Wolfgang
Published: October 2021

In this study, biological exhaust air treatment was combined with a recuperative heat exchanger in one process stage. The aim of this plant development and testing is not only to reduce ammonia from the exhaust air of pig houses but also to recover thermal energy at the same time. This is intended to offset the high operating costs of exhaust air treatment with savings of heating costs in cold seasons and to use the plant more efficiently. This system was tested for the first time under practical conditions in a pig fattening house in southern Germany. Three different assembly situations of the heat exchanger were examined for 13 days each and then compared with each other. The heating performance of the plant is primarily dependent on the outside air temperature and secondarily on the scrubbing water temperature. Depending on the assembly situation of the heat exchanger, an average heating performance of between 6.0 and 10.0 kW was observed; the amount of recovered thermal energy was between 1860 and 3132 kWh. The coefficient of performance (COP) ranked between 7.1 and 11.5. Furthermore, ammonia removal up to 64% was demonstrated. A long-term investigation of the system under practical conditions is recommended to validate the data collected in this study.
Optical Methods for Measuring Icing of Wind Turbine Blades
Authors: Kabardin Ivan , Dvoynishnikov Sergey , Gordienko Maxim , Kakaulin Sergey , Ledovsky Vadim , Gusev Grigoriy , Zuev Vladislav , Okulov Valery
Published: October 2021

The development of wind-power engineering in the Arctic has led to increasing wind turbines in cold climatic zones. A problem operating wind turbines in cold conditions is the icing of blades. The icing of the blades leads to a change in rotor aerodynamics, a decrease in energy production, the additional weight of blades, and load on the rotor, which increase wear and reduce the lifetime of the turbines. The growth of icing on the blades threatens the uncontrollable separation of ice pieces from the blade edges, and the operation is unsafe. Non-contact methods for detecting icing on the blades need to prevent critical operating modes with ice formation on the blades. This review analyzes methods for detecting icing. The advantages and disadvantages of various optical methods are presented to give valuable insights on ice prevention for wind turbines operating in cold regions.
Pollution Flashover Characteristics of Composite Crossarm Insulator with a Large Diameter
Authors: Nan Jing , Li Hua , Wan Xiaodong , Huo Feng , Lin Fuchang
Published: October 2021

The composite crossarm insulator differs greatly from the suspension insulator in structure and arrangement. This study aims to determine the pollution flashover characteristics of composite crossarm insulators under different voltage grades. Four types of AC composite crossarm insulators with diameters ranging from 100 mm to 450 mm are subjected to artificial pollution test, and then the effects of the surface hydrophobicity state of silicone rubber, core diameter, umbrella structure, arrangement, and insulation distance on the pollution flashover voltage of the composite crossarm insulators are analyzed. Under the pollution grade 0.2/1.0 mg/cm2 and voltage grade from 66 kV to 1000 kV, if the silicone rubber surface changes from HC5 to HC6, the pollution flashover voltage of the composite crossarm insulator will increase by 13.5% to 21.0% compared with the hydrophilic surface. If the core diameter changes from 100 mm to 300 mm, the pollution flashover voltage gradient decreases with the increase in core diameter; if the core diameter changes from 300 mm to 450 mm, the pollution flashover voltage gradient increases with core diameter. Under the same insulation height and core diameter, the umbrella structure will have a certain impact on pollution flashover voltage by up to 1.7% to 5.4%. Under the horizontal arrangement, the pollution flashover voltage can increase by 10.5% to 12.1% compared with that under the vertical arrangement. Under the hydrophilic surface and weak hydrophobicity state, the pollution flashover voltage has a linear relationship with the insulation distance. The above results can provide a reference for the structural design and optimization of the composite crossarm insulator.
A Review of Multi-Objective Optimization in Organic Rankine Cycle (ORC) System Design
Authors: Hu Shuozhuo , Yang Zhen , Li Jian , Duan Yuanyuan
Published: October 2021

Organic Rankine cycle (ORC) is considered a promising heat-to-power technology to utilize waste heat and renewable energy, including solar, biomass and geothermal. However, since the thermodynamic, economic and environmental performance is usually conflict, the single objective design could no longer meet the requirements of the ORC system, putting forward urgent requirements for multi-objective optimization, which has attracted increasing attention with lots of papers published. However, due to these different decision variables, optimization objectives and approaches, existing research is significantly different from each other and is difficult to compare without a systematic summary. Therefore, this paper provides an overview of ORC multi-objective research from three perspectives: optimization objective, method and optimization parameters. Based on the classification of different objectives, this work summarizes the involved variables and provides a recommendation for selecting appropriate objectives in different scenarios. For the optimization method, this work compares different approaches and reveals their advantages and disadvantages. Finally, the decision variables are reviewed and classified into four levels. Then the integrated design approach considering “system-process-component-fluid” is proposed and recommended for further development.
Chiller Optimization Using Data Mining Based on Prediction Model, Clustering and Association Rule Mining
Authors: Nisa Elsa Chaerun , Kuan Yean-Der , Lai Chin-Chang
Published: October 2021

The chiller is the major energy consuming HVAC component in a building. Currently, huge chiller data is easy to obtain due to Internet of Things (IoT) technology development. In order to optimize the chiller system, this study presents a data mining technique that utilizes the available chiller data. The data mining techniques used are prediction model, clustering analysis, and association rules mining (ARM) analysis. The dataset was collected every minute for a year from a water-cooled chiller at an institutional building in Taiwan and from meteorological data. The power consumption prediction model was built using deep neural networks with 0.955 of R2, 4.470 of MAE, and 6.716 of RMSE. Clustering analysis was performed using the k-means algorithm and ARM analysis was performed using Apriori algorithm. Each cluster identifies those operational parameters that have strong association rules with high performance. The operational parameters from ARM were simulated using the prediction model. The simulation result shows that the ARM operational parameters can successfully save the energy consumption by 22.36 MWh or 18.17% in a year.
COVID-19 and the Energy Price Volatility
Authors: Christopoulos Apostolos G. , Kalantonis Petros , Katsampoxakis Ioannis , Vergos Konstantinos
Published: October 2021

The challenges of the world economy and their societies, after the outbreak of the COVID-19 pandemic have led policy-makers to seek for effective solutions. This paper examines the oil price volatility response to the COVID-19 pandemic and stock market volatility using daily data. A general econometric panel model is applied to investigate the relationship between COVID-19 infection and death announcements with oil price volatility. The paper uses data from six geographical zones, Europe, Africa, Asia, North America, South America, and Oceania for the period 21 January 2020 until 13 May 2021 and the empirical findings show that COVID-19 deaths affected oil volatility significantly. This conclusion is confirmed by a second stage analysis applied separately for each geographical area. The only geographical area where the existence of correlation is not confirmed between the rate of increase in deaths and the volatility of the price of crude oil is Asia. The conclusions of this study clearly suggest that COVID-19 is a new risk component on top of economic and market uncertainty that affects oil prices and volatility. Overall, our results are useful for policy-makers, especially in the case of a new wave of infection and deaths in the future.
Research on Hydraulic Conversion Technology of Small Ocean Current Turbines for Low-Flow Current Energy Generation
Authors: Su Wenbin , Wei Hongbo , Guo Penghua , Hu Qiao , Guo Mengyuan , Zhou Yuanjie , Zhang Dayu , Lei Zhufeng , Wang Chaohui
Published: October 2021

Ocean energy is a kind of renewable energy contained in seawater, which has the characteristics of large total reserves, sustainable use, and its being green and clean. Influenced by rising oil prices and global climate change, an increasing number of countries are attaching great importance to the strategic position of ocean energy in the future energy sector, and are formulating national ocean energy development roadmaps and conducting research and development on ocean energy technologies. Ocean current energy is a widely existing kind of ocean energy with abundant reserves. However, due to the low current velocity in most of the deep sea, low current energy has not been effectively exploited. In this paper, the Blade element momentum (BEM) theory based on Vortex column theory is used to design a special airfoil for low current energy applications, and a prototype turbine with rotor diameter of 4.46 m and tip speed ratio (TSR) of 6 is fabricated. In order to achieve stable electric power output, this paper designs a hydraulic conversion power generation control system with flexible control, and the hydraulic system working pressure designed to 21 MPa. In this paper, we conducted towing experiments on the prototype of an ocean current energy turbine, with hydraulic transmission and a control power generation system applied to the low flow rate, and achieved the target of hydraulic motor speed in the range of 14.7~15.9 r/min and steady-state speed accuracy in the range of ±1%. The research conducted in this paper can provide a research basis for the efficient exploitation of low-flow ocean current energy.
Energy Management Scheduling for Microgrids in the Virtual Power Plant System Using Artificial Neural Networks
Authors: G. M. Abdolrasol Maher , Hannan Mahammad Abdul , Hussain S. M. Suhail , Ustun Taha Selim , Sarker Mahidur R. , Ker Pin Jern
Published: October 2021

This study uses an artificial neural network (ANN) as an intelligent controller for the management and scheduling of a number of microgrids (MGs) in virtual power plants (VPP). Two ANN-based scheduling control approaches are presented: the ANN-based backtracking search algorithm (ANN-BBSA) and ANN-based binary practical swarm optimization (ANN-BPSO) algorithm. Both algorithms provide the optimal schedule for every distribution generation (DG) to limit fuel consumption, reduce CO2 emission, and increase the system efficiency towards smart and economic VPP operation as well as grid decarbonization. Different test scenarios are executed to evaluate the controllers’ robustness and performance under changing system conditions. The test cases are different load curves to evaluate the ANN’s performance on untrained data. The untrained and trained load models used are real-load parameter data recorders in northern parts of Malaysia. The test results are analyzed to investigate the performance of these controllers under varying power system conditions. Additionally, a comparative study is performed to compare their performances with other solutions available in the literature based on several parameters. Results show the superiority of the ANN-based controllers in terms of cost reduction and efficiency.
Controls of Radiogenic Heat and Moho Geometry on the Thermal Setting of the Marche Region (Central Italy): An Analytical 3D Geothermal Model
Authors: Santini Stefano , Basilici Matteo , Invernizzi Chiara , Jablonska Danica , Mazzoli Stefano , Megna Antonella , Pierantoni Pietro Paolo
Published: October 2021

Using published cross-sections and a series of geological constraints, a 3D geological model of an important area of the Adriatic sector of peninsular Italy—i.e., the Marche region—was developed. Then, an analytical procedure, taking into account the heat rising from the mantle and the radiogenic heat produced by the crust, was applied on the pre-built structural model, in order to obtain the 3D geothermal setting of the entire region. The results highlighted the key role played by the Moho geometry, particularly as a step of ~10 km occurs between the Adriatic Moho of the subducting plate to the west and the new Tyrrhenian Moho characterizing the back-arc area to the west. The comparison between our results and available borehole data suggests a good fit between the applied analytical methodology and published datasets. A visible anomaly is located at a specific site (i.e., the coastal town of Senigallia), where it may be envisaged that fluid circulation produced a local surface heat flow increase; this makes the Senigallia area a promising feature for the possible exploitation of geothermal systems.
Inward FDI: Characterizations and Evaluation
Authors: Hintošová Aneta Bobenič
Published: October 2021

Foreign direct investment can be defined as an investment made by an entity (usually a company) incorporated in a home country in the business interests of a host country, in the form of either establishing new business operations or acquiring controlling interest in existing business assets. Foreign direct investment is expected to meet the following characteristics: (1) the capital movement is typically accompanied by further technological, material, information, financial or personnel flows; (2) the foreign direct investor effectively controls facilities abroad; and (3) the investor has a long-term interest in the host country.
Genetic Diversity and Population Structure Revealed by SSR Markers on Endemic Species Osmanthusserrulatus Rehder from Southwestern Sichuan Basin, China
Authors: Chen Lin , Pan Tingting , Qian Huirong , Zhang Min , Yang Guodong , Wang Xianrong
Published: October 2021

Osmanthus serrulatus Rehder (Oleaceae) is an endemic spring-flowering species in China. It is narrowly distributed in the southwestern Sichuan Basin, and is facing the unprecedented threat of extinction due to problems associated with natural regeneration, habitat fragmentation and persistent and serious human interference. Here, the genetic diversity and population structure of 262 individuals from ten natural populations were analyzed using 18 microsatellites (SSR) markers. In total, 465 alleles were detected across 262 individuals, with a high polymorphic information content (PIC = 0.893). A high level of genetic diversity was inferred from the genetic diversity parameters (He = 0.694, I = 1.492 and PPL = 98.33%). AMOVA showed that a 21.55% genetic variation existed among populations and the mean pairwise Fst (0.215) indicated moderate genetic population differentiation. The ten populations were basically divided into three groups, including two obviously independent groups. Our results indicate that multiple factors were responsible for the complicated genetic relationship and endangered status of O. serrulatus. The concentrated distribution seems to be the key factor causing endangerment, and poor regeneration, human-induced habitat loss and fragmentation seem to be the primary factors in the population decline and further genetic diversity loss. These findings will assist in future conservation management and the scientific breeding of O. serrulatus.
Present and Future Climate-Related Distribution of Narrow- versus Wide-Ranged Ostrya Species in China
Authors: Tang Shuang-Li , Song Yao-Bin , Zeng Bo , Dong Ming
Published: October 2021

The niche breadth–range size hypothesis states that geographic range size of a species is positively correlated with its environmental niche breadth. We test this hypothesis and examine whether the correlation varies with climate change and among taxa through modeling (processing Maximum entropy (Maxent)) potential distributions in present and future climate scenario of four sympatric Ostrya species in China and with different geographic range sizes, including extremely rare O. rehderiana. Potential geographical distributions of narrow- versus wide-ranged Ostrya species were predicted based on their niche breadths. Niche equivalency and similarity tests were performed to examine niche overlap between species pairs. Potential distribution areas of wide niche breadth species (O. japonica and O. trichocarpa) were significantly wider than those of narrow niche breadth species (O. multinervis and O. rehderiana) although niche divergence was hardly observed among them. In the future scenarios of global climate change, wide-ranged O. japonica would have wider potential distribution than in the current scenario, even expanding their geographic range. Conversely, suitable habitats of narrow-ranged O. multinervis and O. rehderiana would be reduced strikingly in future scenarios compared to in the current scenario, and they might be subjected to a high risk of extinction. Potential distribution range sizes of the Ostrya species would positively correlate with their niche breadths in future scenarios, and their niche breadths would determine their distribution variation with climate change. The Ostrya species having broader niche currently would be further widespread in future scenarios while narrowly distributed Ostrya species having narrower niche currently would further reduce their distribution range under changed climate and might be subjected to a high risk of extinction in future scenarios. Our results support the range size–niche breadth hypothesis both at present and future climate scenarios, and they provide useful reference for conservation of rare species like O. rehderiana.
Stakeholder Perceptions on the Need for Updated Tree Species Distribution Maps
Authors: Bettinger Pete , Merry Krista , Garzon Alba Rocio Gutierrez , Lee Taeyoon , Siry Jacek , McNulty Steve , Gavazzi Michael
Published: October 2021

Tree species distributions presented as range maps are powerful tools for forest-based decision-making processes. In the United States, Silvics of North America is a well-known reference for over 200 tree species. However, the current range maps are likely outdated due to changes in land use, advancements in technology, shifts in plant hardiness zones due to climate change, and shifting societal values that influence the development of these resources. Therefore, a survey was distributed to two stakeholder groups, registered foresters in four states and members of several professional organizations, to gain insight into whether Silvics of North America range maps should be updated. Although the survey delivery method varied between the two survey sampling frames, the opinions on updating species range maps between the two stakeholder groups were similar. Both groups indicated that updating the current range maps would be valuable and would best be informed by remote sensing, national field inventories, and expert insight, and by adding color and perhaps importance classes.
Effect of Environmental Factors on Soil Nutrient Loss under Conditions of Mining Disturbance in a Coalfield
Authors: Wang Ziguan , Wang Guangcai , Wang Chengshu , Wang Xiaohui , Li Meiling , Ren Tingyu
Published: October 2021

Underground coal mining can result in land deformation (e.g., land subsidence and ground fissures), and may consequently change the soil nutrients. Soil organic matter (SOM), total nitrogen (TN), and available phosphorus (AP) are critical indicators of soil fertility and eco-restoration in mining areas. In this study, soil samples (depth: 0–20 cm) were collected twice from 20 sampling points in pre-mining and post-mining in the No.12 panel of Caojiatan coalfield, in the Loess Plateau of China. SOM, TN, and AP in soil samples were measured, and the nutrient loss was evaluated. Ten environmental factors affecting soil nutrient loss were identified from a 5-m resolution digital elevation map (DEM). The paired t-test was utilized to evaluate the differences between SOM, TN, and AP in pre-mining and post-mining soil. The mechanisms of the effects of environmental factors on soil nutrient loss were revealed based on multiple linear regression, redundancy analysis (RDA), and the random forest algorithm (RF). Ordinary kriging and RF were utilized to predict and optimize the spatial distribution of the soil nutrient loss. The results showed that significant differences existed between the SOM, TN, and AP in the pre-mining and post-mining soil. The model established by RF provided a higher accuracy in terms of fitting the correlation between soil nutrient loss and environmental factors compared to the model established by multiple linear regression, and the feature importance obtained by RF showed that profile curvature, distance to working panel margin, and surface roughness were the most significant factors affecting the loss of SOM, TN, and AP, respectively. This study provides a theoretical reference for eco-restoration, as well as soil and water conservation, in subsided lands in coalfields.
Metabolic and Transcriptional Profiling of Fraxinus chinensis var. rhynchophylla Unravels Possible Constitutive Resistance against Agrilus planipennis
Authors: Qu Liangjian , Li Jifu , Wang Ruizhen , Wang Xiaoyi , Zhao Tonghai , Chen Yuequ , Wang Lijuan
Published: October 2021

The emerald ash borer (EAB, Agrilus planipennis), an ash-tree wood-boring beetle, has caused widespread mortality of ash. Asian ash, which coevolved with EAB, is considered more resistant than its North American and European congeners. Although some compounds and proteins related to resistance to EAB have been identified, the underlying ash resistance mechanism to EAB still needs further study. The Asian ash species, Fraxinus chinensis var. rhynchophylla, is highly resistant to EAB. In this study, metabolic and transcriptional profiling of the phloem of this species was investigated, and differentially expressed metabolites and genes were analyzed by comparing them with those of the susceptible F. pennsylvanica. Four hundred and twenty-eight metabolites were detected in both species, and several coumarins and lignans, which were exclusive to F. chinensis var. rhynchophylla, were identified. Compared with susceptible F. pennsylvanica, genes related to phenylpropanoid biosynthesis, ethylene (ET), and jasmonic acid (JA) biosynthesis and signaling in F. chinensis var. rhynchophylla were found to be up-regulated. It was hypothesized that coumarins, lignans, and ET and JA signaling might contribute to greater resistance to EAB in F. chinensis var. rhynchophylla. This study suggests candidate metabolites and genes for biomarker development in future ash-breeding programs.
Seedling Growth and Biomass Production under Different Light Availability Levels and Competition Types
Authors: Bebre Ieva , Riebl Hannes , Annighöfer Peter
Published: October 2021

Light availability is a crucial resource determining seedling survival, establishment, and growth. Competition for light is asymmetric, giving the taller individuals a competitive advantage for obtaining light resources. Species-specific traits, e.g., shade tolerance, rooting depth, and leaf morphology, determine their strategical growth response under limited resource availability and different competitive interactions. We established a controlled pot experiment using European beech, Norway spruce, and Douglas fir seedlings and applying three different light availability levels—10%, 20%, and 50%. The experiment’s main aim was to better understand the effects of light availability and competition type on the growth, growth allocation, and biomass production of recently planted seedlings. We planted four seedlings per pot in either monocultures or mixtures of two species. Relative height and diameter growth and aboveground woody biomass of seedlings increased with increasing light availability. All seedlings allocated more growth to height than diameter with decreasing light availability. Seedlings that reached on average greater height in the previous year allocated less growth to height in the following year. Additionally, there were general differences in growth allocation to the height between gymnosperms and angiosperms, but we did not find an effect of the competitor’s identity. Our mixture effect analysis trends suggested that mixtures of functionally dissimilar species are more likely to produce higher biomass than mixtures of more similar species such as the two studied conifers. This finding points towards increased productivity through complementarity.
Perceptions by Smallholder Farmers of Forest Plantations in Malaysia
Authors: Ratnasingam Jegatheswaran , Ioras Florin , Farrokhpayam Saeid Reza , Mariapan Manohar , Latib Hazirah Ab , Liew Kang Chiang
Published: October 2021

Plantation forests are perceived to be the supplementary source of wood material for the large wood products industry in Malaysia, amidst the steadily reducing supply from her natural forests. Despite the government’s initiated plantation forests scheme, the participation of smallholder farmers has been limited. Smallholder farmers constitute the largest proportion of private farmers involved in all sectors of agricultural and plantation tree crop cultivation, including commodities such as rubber and palm oil. Therefore, this study examines the lack of interest among smallholder farmers to participate in establishing forest plantations, although they have a strong presence in the palm oil and rubber sectors. A structured questionnaire survey was conducted among 12,895 smallholder farmers currently involved in palm oil, rubber and other tree-crop cultivation. The study found that this group has little knowledge and awareness of the forest plantation scheme available, and there is a prevailing perception that the establishment of forest plantations is not environment-friendly and leads to biodiversity loss. The poor economic return, small land holding, and poorly structured market and supply chain are perceived as the significant constraints faced that limit the interest among the target groups to participate in this sector. Any effort to reverse this trend and garner higher interest from the target group will necessarily require a new policy framework that boosts the economic outlook of forest plantations among smallholder farmers.
Stochastic Economic Analysis of Investment Projects in Forest Restoration Involving Containerized Tree Seedlings in Brazil
Authors: Simões Danilo , Gil Jean Fernando Silva , da Silva Richardson Barbosa Gomes , Munis Rafaele Almeida , da Silva Magali Ribeiro
Published: October 2021

Background: Experts in ecological restoration have discussed the cost reduction to make forest restoration financially feasible. This is very important in developing countries, such as Brazil, and for smallholder farmers; however, economic studies do not usually consider the uncertainties in their analysis. Therefore, this study aimed to analyze, under conditions of uncertainty, how tropical tree seedlings produced in polyethylene bags, polyethylene tubes, and biodegradable containers (Ellepot®) interfere with the costs of implementation and post-planting maintenance investment projects in a deforested tropical seasonal forest area in southern Brazil. Methods: We evaluated total costs, production costs, and equivalent annual uniform costs, and the probability distributions and estimated ranges of stochastic values were adjusted through Monte Carlo method simulation. Furthermore, the seedling survival rate was recorded over 12 months post-planting. Results: The costs with tree seedling acquisition and direct labor were the components that most impacted total costs in the three investment projects. The forest restoration investment project with tree seedlings produced in polyethylene bags was economically unfeasible in relation to other projects. Conclusions: The best economic alternative was observed in the investment project with tree seedlings produced in Ellepot®, which showed a survival rate >80% after one year and the lowest total cost, production cost, and equivalent uniform annual cost.
Radial Growth Response of Picea crassifolia to Climatic Conditions in a Dryland Forest Ecosystem in Northwest China
Authors: Liang Hanxue , Jiang Shaowei , Muhammad Ali , Kang Jian , Zhu Huoxing , Li Xuebin , Chen Lin , Zhu Liangjun , Huang Jian-Guo
Published: October 2021

As an important barrier against desert invasion in Northwest China, Helan Mountains (HL), Luoshan Mountains (LS) and their natural forests have an extremely important ecological status. It is of great significance to study the relationship between forest growth and climate in this region under the background of global change. At present, relevant research mostly focuses on the Chinese pine (Pinus tabulaeformis Carr.), and little is known about how Qinghai spruce (Picea crassifolia Kom.) responds to climate change. To investigate the potential relationships between radial growth of P. crassifolia and climatic conditions in Ningxia, China, we collected tree-ring samples from P. crassifolia growing in the HL and LS and then established the standard tree-ring width chronologies for the two sites. Correlation analysis together with multivariate linear regression and relative contribution analyses were used, and results showed that radial growth in the HL was determined by the precipitation in the previous September, by the standardized evapotranspiration index (SPEI) in the current March and June, and by the maximum air temperature in the current September. The maximum air temperature in the current September contributed the most (0.348) to the radial growth in the HL. In the LS, radial growth was determined by the precipitation in the previous September and in the current March and by the minimum air temperature in the current July. The factor that made the most contribution was the precipitation in the current March (0.489). Our results suggested that in the wetting and warming future, growth of P. crassifolia in the HL will increase while that in the LS needs further investigation. Our results also provide a basis for predicting how P. crassifolia in northwest China will grow under the background of future climate change and provide a reference for formulating relevant management measures to achieve ecological protection and sustainable development policies.
Impacts of Payment for Forest Ecosystem Services in Protecting Forests in Dak Lak Province, Vietnam
Authors: Pham Thu Thuy , Le Thi Thanh Thuy , Tuyet Hoa Nie Kdam , Pham Van Trương , Tran Phuong Hanh Nie Kdam , Tran Trung Dung , Tran Ngoc My Hoa , Nguyen Thi Thuy Anh , Nguyen Thi Van Anh
Published: October 2021

Vietnam’s Payment for Forest Ecosystem Services (PFES) scheme has the goal of protecting remaining natural forests by providing financial support to people involved in forest protection. However, studying the case of Dak Lak province in the Central Highlands region of Vietnam shows that even after eight years of PFES implementation, achieving this goal remains a challenge. Although PFES does provide a stable income source and higher payments than state forest protection programs, enables the mobilization of more personnel resources for patrolling forest and relieves a great burden on the state budget in terms of investment in forest protection and development, forest cover in Dak Lak province is still decreasing, mainly due to conversion for other land uses, especially commercial agricultural and industrial crops. These drivers are rooted in national socio-economic planning aimed at boosting economic growth and in local people’s need to sustain their livelihoods. In addition, our paper shows that illegal logging is still widespread in Dak Lak. Weak law enforcement in areas of forest managed by state forest authorities and state companies also contributes to deforestation. However, these drivers are neither fully recognized nor addressed, and instead, the blame for deforestation is laid on local communities. PFES alone cannot protect forests in Dak Lak province. It needs to be backed up by political commitment to address underlying drivers of deforestation, improved social programs to help local people diversify their income sources and clarity over land use.
Proteomic Analysis: Explosive Salt Accumulation in Leaves of Morus alba L. under Salt Stress
Authors: Yang Jiajun , Wu Yongbo
Published: October 2021

The salt tolerance of glycophytes is thought to be related to their ability to restrict sodium access to their aboveground parts. A previous study on the mulberry (Morus alba L.) revealed a phenomenon of explosive salt accumulation in the leaves after exceeding a certain treatment concentration. Here, we aim to observe the internal state of mulberry seedlings under salt stress by the proteomic method and to identify the possible inducements associated with salt bursts. In this study, the target treatments for TMT-label free quantitative analyses were determined by measuring the sodium content in the roots and leaves. The results showed that the expressions of proteins classified as “plant hormones”, “ion channels”, “REDOX homeostasis”, “cytoskeleton” and “cell wall” changed significantly after salt bursts. This phenotype is associated with the destruction of the apoplast, in which the assembly of the Casparian strip may be affected by the inhibition of some key proteins, indirectly increasing the rate of ion migration through the endodermis into the shoots.
Authentication and Billing for Dynamic Wireless EV Charging in an Internet of Electric Vehicles
Authors: ElGhanam Eiman , Ahmed Ibtihal , Hassan Mohamed , Osman Ahmed
Published: October 2021

Dynamic wireless charging (DWC) is a promising technology to charge Electric Vehicles (EV) using on-road charging segments (CS), also known as DWC pads. In order to ensure effective utilization of this on-the-road charging service, communication and coordination need to be established between the EVs and the different network entities, thereby forming an Internet of Electric Vehicles (IoEV). In an IoEV, EVs can utilize different V2X communication modes to enable charging scheduling, load management, and reliable authentication and billing services. Yet, designing an authentication scheme for dynamic EV charging presents significant challenges given the mobility of the EVs and the short contact time between the EVs and the charging segments. Accordingly, this work proposes a fast, secure and lightweight authentication scheme that allows only authentic EVs with valid credentials to charge their batteries while ensuring secure and fair payments. The presented scheme starts with a key pre-distribution phase between the charging service company (CSC) and the charging pad owner (PO), followed by a hash chain and digital signature-based registration and authentication phase between the EV and the CSC, before the EV reaches the beginning of the charging lane. These preliminary authentication phases allow the authentication between the EVs and the charging segments to be performed using simple hash key verification operations prior to charging activation, which reduces the computational cost of the EVs and the CS. Symmetric and asymmetric key cryptography are utilized to secure the communication between the different network entities. Analysis of the computational and transmission time requirements of the proposed authentication scheme shows that, for an EV traveling at 60 km/h to start charging at the beginning of the charging lane, the authentication process must be initiated at least 1.35 m ahead of the starting point of the lane as it requires ≃81 ms to be completed.
An SDN-Enabled Architecture for IT/OT Converged Networks: A Proposal and Qualitative Analysis under DDoS Attacks
Authors: Foschini Luca , Mignardi Valentina , Montanari Rebecca , Scotece Domenico
Published: October 2021

Real-time business practices require huge amounts of data directly from the production assets. This new thirst for accurate and timely data has forced the convergence of the traditionally business-focused information technology (IT) environment with the production-focused operational technology (OT). Recently, software-defined network (SDN) methodologies have benefitted OT networks with enhanced situational awareness, centralized configuration, deny-by-default forwarding rules, and increased performance. What makes SDNs so innovative is the separation between the control plane and the data plane, centralizing the command in the controllers. However, due to their young age, the use of SDNs in the industry context has not yet matured comprehensive SDN-based architectures for IT/OT networks, which are also resistant to security attacks such as denial-of-service ones, which may occur in SDN-based industrial IoT (IIoT) networks. One main motivation is that the lack of comprehensive SDN-based architectures for IT/OT networks making it difficult to effectively simulate, analyze, and identify proper detection and mitigation strategies for DoS attacks in IT/OT networks. No consolidated security solutions are available that provide DoS detection and mitigation strategies in IT/OT networks. Along this direction, this paper’s contributions are twofold. On the one hand, this paper proposes a convergent IT/OT SDN-based architecture applied in a real implementation of an IT/OT support infrastructure called SIRDAM4.0 within the context of the SBDIOI40 project. On the other hand, this paper proposes a qualitative analysis on how this architecture works under DoS attacks, focusing on what the specific problems and vulnerabilities are. In particular, we simulated several distributed denial-of-service (DDoS) attack scenarios within the context of the proposed architecture to show the minimum effort needed by the attacker to hack the network, and our obtained experimental results show how it is possible to compromise the network, thus considerably worsening the performance and, in general, the functioning of the network. Finally, we conclude our analysis with a brief description on the importance of employing machine learning approaches for attack detection and for mitigation techniques.
An Intelligent TCP Congestion Control Method Based on Deep Q Network
Authors: Wang Yinfeng , Wang Longxiang , Dong Xiaoshe
Published: October 2021

To optimize the data migration performance between different supercomputing centers in China, we present TCP-DQN, which is an intelligent TCP congestion control method based on DQN (Deep Q network). The TCP congestion control process is abstracted as a partially observed Markov decision process. In this process, an agent is constructed to interact with the network environment. The agent adjusts the size of the congestion window by observing the characteristics of the network state. The network environment feeds back the reward to the agent, and the agent tries to maximize the expected reward in an episode. We designed a weighted reward function to balance the throughput and delay. Compared with traditional Q-learning, DQN uses double-layer neural networks and experience replay to reduce the oscillation problem that may occur in gradient descent. We implemented the TCP-DQN method and compared it with mainstream congestion control algorithms such as cubic, Highspeed and NewReno. The results show that the throughput of TCP-DQN can reach more than 2 times of the comparison method while the latency is close to the three compared methods.
Numerical and Analytical Studies of Soret-Driven Convection Flow Inside an Annular Horizontal Porous Cavity
Authors: Mojtabi Abdelkader , Sioud Khairi , Bergeon Alain , Charrier-Mojtabi Marie Catherine
Published: October 2021

This paper studies the species separation of a binary fluid in a porous cavity between two horizontal concentric cylinders, submitted to a temperature gradient. The thickness of the cavity is e=Ro−Ri, where Ri and Ro are the internal and external radius, respectively. The numerous previous experiments performed in thermogravitational vertical columns (TGCs) showed that in order to obtain a significant separation, the thickness of the cell must be very small, compared with its height. Therefore, in our configuration, we considered e≪Ri. The solution is assumed to be axisymmetric. Under the assumptions of parallel flow and forgotten effect, an analytical solution is obtained using Maple software, and the results are compared with those found numerically using Comsol Multiphysics. In natural convection, our results are in very good agreement with those evaluated with a regular perturbation method in powers of the dimensionless gap width ε=eRi  of order 15, and with the Galerkin method. The species separation calculated for our configuration is very close to the one obtained in a TGC column of height: H=πRi. One of the main interests of the analytical solution presented here is that it can be used as a basic solution for a stability study analysis.