bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermo-Economic Performance Analysis of a Novel Organic Flash Rankine Cycle Using R600/R245fa Mixtures
Authors: Fu Guangbiao , Zhang Songyuan , Ge Zhong , Li Jian , Xu Jian , Xie Jianbin , Xie Zhiyong , Yao Dong , Zhao Tao , Wang Zhijie , Yue Shuaikun , Zhao Siyu , Liu Fanhan , Jiang Qiuping
Published: October 2022

The organic flash cycle (OFC) is a novel power cycle with small exergy loss in the endothermic process. However, the low-pressure throttle valve in the cycle has a large throttling loss. Aiming to reduce the cycle exergy loss and improve the system performance, this study constructs a new configuration named the organic flash Rankine cycle (OFRC). Using the R600/R245fa mixture as the circulating working fluid and 200 °C geothermal water as the heat source, the effects of the change in working fluid composition on the thermal properties of the OFRC were studied based on the first and second laws of thermodynamics. Then, the economic performance of the proposed OFRC was investigated and then compared with that of the conventional OFC. The results show that the OFRC system has a significant improvement in thermal performance and economy compared with the OFC system. When the mole composition of the R600/R245fa mixture is 0.5/0.5, the net output work, thermal efficiency, and exergy efficiency of the OFRC system can reach a maximum at 146.39 kW, 21.51%, and 80.94%, respectively, which are 98.2 kW, 14.43%, and 54.3% higher than those of the OFC system. The dual heaters in the OFRC system can effectively reduce loss in the endothermic process. When the R600 mole composition is 0.5 in the OFRC system, the exergy loss of the heater is only 7.42%, and the power generation cost (0.3267 $·kW−1·h−1 only) is lower than that in the OFC system.
Life-Cycle Assessment Study for Bio-Hydrogen Gas Production from Sewage Treatment Plants Using Solar PVs
Authors: Barghash Hind , AlRashdi Zuhoor , Okedu Kenneth , Desmond Peter
Published: October 2022

Currently, there is a global challenge of water scarcity due to climate change, rising temperatures, and other factors. One way to address this growing global challenge is by implementing technology to treat polluted water by reusing it in areas such as irrigation, cooling, and energy production, based on bio-hydrogen gas. Hydrogen gas can be produced by several methods, including dark fermentation. In this study, hydrogen gas was produced by 1L of sludge and Treated Effluent (TE) with several methods, using a reactor with a volume of 0.96 H2 L/L media. The Life-Cycle Impact Assessment (LCIA) process was used to study resource depletion, the ecosystem, and human impacts, and efforts were made to reduce the negative impacts by implementing several solutions. In this study, OpenLCA software was used as a tool for calculating the impacts, along with the ecoinvent database. Further analysis was carried out by comparing the LCIA with and without the use of solar energy. The results show that implementing hydrogen gas production with a solar energy system will help to obtain the best solution and reduce the carbon footprint, with 1.12 × 104 kg CO2 equivalent and a water depletion of 2.83 × 104 m3.
A Small Modular House as a Response to the Energy Crisis
Authors: Zukowski Miroslaw
Published: October 2022

Energy security is becoming one of the most important issues today. Continuous increases in the prices of fossil fuels, firewood and wood pellets have become commonplace in many countries. One positive effect of this situation is the greater focus on the development of renewable energy technologies and the search for solutions to reduce the heat demands of residential buildings. The purpose of this paper is to present a small modular building that can be a response to the energy crisis and Ukraine’s wave of refugees in Poland. The results of the energy simulations performed in DesignBuilder software showed that this type of house has a primary energy demand of 139.35 kWh/m2. The calculations were performed for the climatic conditions of north-eastern Poland, assuming natural gas as the fuel. The use of a geothermal heat pump reduced this value to 90.14 kWh/m2. In order to achieve a zero primary energy balance, 23.76 m2 of PV panels and 4 m2 of solar thermal collectors should be installed. In addition, the influence of the overhangs and the glazing area on the heat gain from the solar radiation was analyzed. A drop in temperature inside the house in the event of a continuous power failure was also investigated.
Enabling Technologies for Enhancing Power System Stability in the Presence of Converter-Interfaced Generators
Authors: Giannuzzi Giorgio M. , Mostova Viktoriya , Pisani Cosimo , Tessitore Salvatore , Vaccaro Alfredo
Published: October 2022

The growing attention to environmental issues is leading to an increasing integration of renewable energy sources into electrical grids. This integration process could contribute to power system decarbonization, supporting the diversification of primary energy sources and enhancing the security of energy supply, which is threatened by the uncertain costs of conventional energy sources. Despite these environmental and economical benefits, many technological and regulatory problems should be fixed in order to significantly increase the level of penetration of renewable power generators, which are connected to power transmission and distribution systems via power electronic interfaces. Indeed, these converter-interfaced generators (CIGs) perturb grid operation, especially those fueled by non-programmable energy sources (e.g., wind and solar generators), affecting the system stability and making power systems more vulnerable to dynamic perturbations. To face these issues, the conventional operating procedures based on pre-defined system conditions, which are currently adopted in power system operation tools, should be enhanced in order to allow the “online” solution of complex decision-making problems, providing power system operators with the necessary measures and alerts to promptly adjust the system. A comprehensive analysis of the most promising research directions and the main enabling technologies for addressing this complex issue is presented in this paper.
ESG Assessment from the Perspective of the Management Board and Trade Unions on the Example of the Opole Power Plant
Authors: Zieliński Mariusz , Adamska Małgorzata
Published: October 2022

The Opole Power Plant is part of the PGE group (Polish Energy Group), the largest power company in Poland. It produces electricity from coal combustion, which means that ESG (environmental, social and corporate governance) policy should be one of the power plant’s strategic priorities. The article focuses on evaluating the ESG activities implemented by the power plant and their relation to the standards set at the corporation. The article’s primary hypothesis is that ESG activities are a significant element of the power plant’s strategy, with most of them determined by policies undertaken at the level of the PGE Group as a whole. The secondary hypotheses assume that trade union representatives attach greater importance (than management) to the social elements of ESG (H2) and that individual management representatives rate higher regarding the importance of those ESG areas for which they are personally responsible (H3). The research method used in the article consists of interviews conducted with representatives of the power plant’s board of directors responsible for individual areas of ESG activities and representatives of trade unions. In addition to groups of questions relating to corporate governance, the empirical material was organized from the perspective of power plant stakeholders. The results obtained support the acceptance of the first two hypotheses posed and the rejection of the third one.
Fundamental Studies of Smart Distributed Energy Resources along with Energy Blockchain
Authors: Jin A. J. , Li C. , Su J. , Tan J.
Published: October 2022

This article studies the broad methodology and major application of smart distributed energy resources (DER) in terms of energy generation, consumption, transaction, and power scheduling. This article simplifies a general DER system into a generic type of integrated DER model. This model is used to investigate a smart DER system that transforms three input parameters, (3I parameters) into three critical output functions(3O functions); hence, the model is also called the 3I3O model. The power at a common connection joint can be enabled by a computer that makes computerized decisions to utilize smart DER. Therefore, the computer algorithm collects various data fed into a computer for deep learning and artificial intelligence (AI) decision making. The authors demonstrate important results and the best solutions to meet power demand, offer an economic advantage and have a low carbon footprint for consumers. Moreover, several network blockchain options are discussed. EBC and DER represent an ideal combination with advantages in managing exergy through so-called intelligent power technology. This technology is discussed in detail and includes special hardware, software, and a broad set of computerized intelligence. Finally, the exergy that can possibly be achieved for smart DER systems is discussed.
Gross Pathology in COVID-19
Authors: Zhang Bei
Published: October 2022

The global infectious disease COVID-19 is caused by SARS-CoV-2, a new member of the Coronaviridae family. Though presented as a novel disease that primarily affects the respiratory system, multi-organ involvement has been well-noticed and documented since the beginning of the pandemic. When performed properly with adequate safety measures, autopsy provides the most valuable information to decipher the pathogenesis of this novel disease, therefore providing a basis for clinical management. In addition to reviewing the macroscopic changes in organs and tissues involved in COVID-19, the relevant microscopic alterations and possible pathogenesis are also discussed.
Hybrid Method for Fitting Nonlinear Height–Diameter Functions
Authors: Monti Cassio Augusto Ussi , Oliveira Rafael Menali , Roise Joseph Peter , Scolforo Henrique Ferraço , Gomide Lucas Rezende
Published: October 2022

Regression analysis is widely applied in many fields of science to estimate important variables. In general, nonlinear regression is a complex optimization problem and presents intrinsic difficulties in estimating reliable parameters. Nonlinear optimization algorithms commonly require a precise initial estimate to return reasonable estimates. In this work, we introduce a new hybrid algorithm based on the association of a genetic algorithm with the Levenberg–Marquardt method (GALM) to adjust biological nonlinear models without knowledge of initial parameter estimates. The proposed hybrid algorithm was applied to 12 nonlinear models widely used in forest sciences and 12 databases under varying conditions considering classic hypsometric relationships to evaluate the robustness of this new approach. The hybrid method involves two stages; the curve approximation process begins with a genetic algorithm with a modified local search approach. The second stage involves the application of the Levenberg–Marquardt algorithm. The final performance of the hybrid method was evaluated using total fitting for all tested models and databases, confirming the reliability of the proposed algorithm in providing stable parameter estimates. The GA was able to predict the initial parameters, which assisted the LM in converging efficiently. The developed GALM method is effective, and its application is recommended for biological nonlinear analyses.
Forest Burned Area Detection Using a Novel Spectral Index Based on Multi-Objective Optimization
Authors: Wu Bo , Zheng He , Xu Zelong , Wu Zhiwei , Zhao Yindi
Published: October 2022

Forest fires cause environmental and economic damage, destroy large areas of land and displace entire communities. Accurate extraction of fire-affected areas is of vital importance to support post-fire management strategies and account for the environmental impact of fires. In this paper, an analytical burned area index, called ABAI, was proposed to map burned areas from the newly launched Sentinel-2 images. The innovation of this method is to separate the fire scars from other typical land covers by formulating different objective functions, which involved three main components: First, spectral differences between the burned land and other land covers were characterized by analyzing the spectral features of the existing burned area indices. Then, for each type of land cover, we formed an objective function by linear combination of bands with the values of band ratios. Second, all the objective functions and possible constraints were formulated as a multi-objective optimization problem, and then it was solved using a linear programming approach. Finally, the ABAI spectral index was achieved with the optimizing coefficients derived from the multi-objective problem. To validate the effectiveness of the proposed spectral index, three experimental datasets, clipped from Sentinel-2 images at different places, were tested and compared with baseline indices, such as normalized burned area (NBR) and burned area index (BAI) methods. Experimental results demonstrated that the injection of a green band to the spectral index has led to good applicability in burned area detection, where the ABAI can avoid most of the confusion presented by shadows or shallow water. Compared to other burned area indices, the proposed ABAI achieved the best classification accuracy, with the overall accuracy being over 90%. Visually, our approach significantly outperforms other spectral indexed methods, especially in confused areas covered by water bodies and shadows.
Working Time, Productivity, and Cost of Felling in a Tropical Forest: A Case Study from Wijaya Sentosa’s Forest Concession Area, West Papua, Indonesia
Authors: Soenarno  , Dulsalam  , Yuniawati  , Suhartana Sona , Gandaseca Seca , Rochmayanto Yanto , Supriadi Achmad , Andini Sarah
Published: October 2022

Felling of natural forest trees in West Papua Province is carried out mechanically using a chainsaw by applying a selective cutting silviculture system. This study aimed to determine the elements of working time, productivity, and cost of felling as well as factors influencing felling activities using the chainsaw in the tropical natural forests in West Papua, Indonesia. The felled trees are dominated by the meranti wood species group with a minimum diameter of 45 cm. The average volume of the felled tree is about 4.205 m3/tree. The result showed that total felling time ranged from 15.3 to 18.3 min/tree with an average of 16.7 min/tree. The effective felling time was 11.8 min/tree (70.86%) and the delay time was 4.9 min/tree (29.14%). Felling time in making undercuts was on average 1.7 min/tree (9.98%), longer than back cuts time of 1.10 min/tree (6.39%). Total felling time was influenced by various variables: tree diameter, buttress height, and slope. Felling productivity was accounted for between 14.901 m3/h and 17.067 m3/h (15.778 m3/h on average). Felling costs ranged from 3.366 USD/h to 3.473 USD/h with an average of 3.407 USD/h or equivalent to 0.209 USD/m3 to 0.238 USD/m3 with an average of 0.225 USD/m3. To improve the effectiveness of felling time and productivity, this study suggests (1) upgrading the skills of the chainsaw operators through formal or in-house training in felling techniques, and (2) ensuring chainsaw operators bring a tree distribution map completed by field conditions information.
Field Trials to Assess the Growth, Survival, and Stomatal Densities of Five Mexican Pine Species and Their Hybrids under Common Plantation Conditions
Authors: Sánchez-Hernández Ricardo Silas , Quiñones-Pérez Carmen Zulema , Hernández-Díaz José Ciro , Prieto-Ruíz José Ángel , Wehenkel Christian
Published: October 2022

Understanding hybridization is important for practical reasons, as the presence of hybrid trees in seed stands can influence the success of natural regeneration and reforestation. Hybridization creates new gene combinations, which can promote or enhance adaptation to new or changing environments. In the present research, we aimed, for the first time, to evaluate and compare the growth and survival of 541 putative hybrid seedlings and 455 seedlings of the pure parental trees of Pinus arizonica, P. durangensis, P. engelmannii, P. leiophylla, and P. teocote, in two reciprocal trials of duration 27 months in the Sierra Madre Occidental (SMO), Durango, Mexico. We also examined the possible correlation between needle stomatal density and seedling growth and survival. The overall analysis of the data showed that the mean height to the apical bud was significantly higher (p = 0.01) in the hybrids than in the pure trees. Considering both trials, the survival rate of P. arizonica (p = 0.002) and P. durangensis (p = 0.01) hybrids was significantly higher than that of the pure trees. The growth parameters were significantly correlated with the mean stomatal density (p < 0.01). Stomatal density and survival at the seed stand level were significantly and positively correlated in the hybrids, but not in the pure trees. In summary, Pinus hybrids generally exhibited the same ability as the pure species (or sometimes a greater ability) to withstand weather conditions, survive, and grow effectively in both growth trials. The systematic use of natural pine hybrids in Mexico could therefore be considered a possible option for sustainable management and as a component of adaptive silviculture.
Response of Tracheid Structure Characteristics and Lignin Distribution of Taxodium Hybrid Zhongshanshan to External Stress
Authors: Yong Lu , Bi Yujin , Shi Jiangtao , Wang Xinzhou , Pan Biao
Published: October 2022

The Taxodium hybrid Zhongshanshan fast-growing species is susceptible to environment and gravity to form reaction wood. In this study, individual growth rings of reaction wood are used as subjects, and an individual growth ring is divided into three zones: compression zone (CZ), lateral zone (LZ), and opposite zone (OZ). The microanatomical structure and chemical properties of the tracheids in CZ, LZ, and OZ forms by the inclined or bent growth of T. Zhongshanshan are comparatively analyzed by using optical microscopy, scanning electron microscope, laser confocal microscopy, and Raman imaging techniques. In CZ, the length and diameter of compression wood (CW) tracheids decreased, and the shape of cross-sections became rounded as compared to the OZ and LZ tracheids. More notably, threaded fissures appeared on the cell wall of tracheids, and the thickness of the cell wall increased in CW. The analysis of tracheids’ cell wall structure showed that CW tracheids had a complete outer secondary wall middle (S2L) layer, but had no secondary wall inner (S3) layer. In the transition zone (TA) between CW and normal early wood, tracheids were divided into compressed and normal tracheids. Despite the compressed tracheids having a similar cell morphology to normal tracheids, they had a thin secondary wall S2L layer. Tracheids in LZ had a thin S2L layer only at the angle of the cell. No S2L layer was seen in the cell wall of OZ and CZ late wood tracheids. It can be concluded that the response of lignin deposition location to external stress was faster than the change in cell morphology. The above results help provide the theoretical basis for the response mechanism of T. Zhongshanshan reaction wood anatomical structures to the external environment and has important theoretical value for understanding its characteristics and its rational and efficient usage.
Macronutrient Content in European Beech (Fagus sylvatica L.) Seedlings Grown in Differently Compacted Peat Substrates in a Container Nursery
Authors: Pająk Katarzyna , Małek Stanisław , Kormanek Mariusz , Jasik Michał , Banach Jacek
Published: October 2022

The macroelement (nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium) contents in individual parts of 1-year-old seedlings (leaves, shoots, root system) of the common beech (Fagus sylvatica L.) were investigated. The seedlings were grown in nine different densities of peat substrate (0.196–0.317 g cm−3) in 265 cm3 containers. It was found that substrate compaction influenced macroelement content in the seedlings. With an increase in substrate compaction, there was a decrease in macroelement content in the leaves (except for N). The macroelement contents derived from this study were compared to the optimal contents indicated in the literature. Studies have shown that the availability of Mg is of great importance for the growth of beech seedlings. The least-compacted substrate allowed for the best root growth in the seedlings, which translated into a higher Mg uptake, resulting in a better dry-mass shoot to root ratio. Our findings confirmed that the lowest compaction of a peat substrate (0.196 g cm−3 actual density) containing dolomite is the best for cultivating common beech under foliar fertilization in 265 cm3 containers.
Dendroclimatic Reconstruction of Mean Annual Temperatures over Treeline Regions of Northern Bhutan Himalayas
Authors: Khandu Yeshey , Polthanee Anan , Isarangkool Na Ayutthaya Supat
Published: October 2022

The Himalayan region is likely particularly exposed to climate change indicated by the high regional rate of change. The number of high-resolution, well-calibrated, and long-term paleoclimate reconstructions are however regrettably few, to set this change in a longer-term context. The dendroclimatic reconstructions over Himalaya that do exist have only reconstructed summer season temperatures, and rarely or never attempted to reconstruct mean annual temperatures. The paucity of long meteorological records is a matter of concern when developing chronologies of climate sensitive tree-ring data in Bhutan, but the chronologies would theoretically be of high potential for extending short meteorological records back in time using trees in high-elevation ecotones. The objectives of this study were to explore dendroclimatic signals in tree-ring width chronologies of Abies densa growing in these extreme ecotones and to reconstruct, if possible, annual temperatures over Northern Bhutan. A point-by-point regression analysis revealed that the regional composite chronology was significantly and positively correlated with temperatures of all months of the current year, i.e., January to December. The chronology was highly correlated with annual temperatures (calibration period R = 0.67 and validation period R = 0.50; p < 0.001) allowing a reconstruction of temperature over Northern Bhutan (NB-TEMR). The NB-TEMR reveals some common variations with summer temperature reconstructions of the Northern Hemisphere as well as the Himalayan region, particularly w.r.t to the recent warming trend. The reconstruction covers the period of 1765 to 2017. This reconstruction reveals a warming trend since 1850 with higher rates of warming 1935 to 2017, but with a pause around 1940–1970. The warming is consistent with reduced volcanic activity and increase of greenhouse gases. We anticipate that our new reconstruction of annual mean temperature could be an important contribution for future climate change studies and assessments of climate models.
Evaluating the Suitability and Overlap of Resting and Path Habitats of Giant Pandas in the Wanglang Nature Reserve
Authors: Chen Xiaoyu , Wang Xiaorong , Kang Dongwei , Li Junqing
Published: October 2022

Habitat fragmentation threatens the survival of giant panda (Ailuropoda melanoleuca); hence, it is vital to protect its habitat. However, a lack of detailed understanding of different functional habitats and their relationships restricts the protective effect. To reveal the relationship between different functional habitats, we distinguished and investigated giant pandas’ resting and path sites and evaluated the suitability patterns and overlap of resting and path habitats in the Wanglang Nature Reserve using MAXENT and overlay methods. A total of 28 resting sites and 30 path sites were used in this study. The results showed that the areas of suitable resting and path habitats were 42.03 km2 and 28.52 km2, respectively, and were fragmented due to the existence of roads. A total of 27.81 km2 of suitable habitat overlapped, indicating many areas have the dual attributes of suitable resting and path habitats for giant pandas. There were almost no suitable resting and path habitats within 200 m and 300 m from roads, respectively. Therefore, measures should be taken to restore the unsuitable habitats distributed in the roadside area and connect the fragmented habitat patches. The indicators and methods used in this study can be considered in studying different functional giant panda habitats and their relationships.
Effect of Moisture Content and Preservatives on the Discoloration of Oil Palm (Elaeis guineensis Jacq.) Lumber
Authors: Mensah Prosper , Danso Humphrey , Mitchual Stephen Jobson , Donkoh Mark Bright
Published: October 2022

Considering the current rate of expansion of the lumber processing industry in the world, the current annual allowable cut of one million cubic meters of round logs is considered to be insufficient to satisfy the increasing demand of timber industries. One major area that has been highlighted in the forest policy is the introduction of lesser-used species to widen the natural resource base of the forest and to address the imbalance between supply and demand for the resources. As a contribution to addressing this problem, oil palm lumber, a lesser-used species, was subjected to different moisture content variations to determine its behavior with respect to discoloration. Specimens of oil palm trunks were extracted at Norpalm Oil Mill in the Western Region of Ghana. Oil palm lumber specimens were conditioned in a kiln to a moisture content of 15%, 20%, 25%, 30%, 40%, and 50%. The results obtained covered discoloration and mold. The effect of the extractives on the discoloration of oil palm lumber was also investigated by means of immersing some samples of oil palm lumber into sea water and tap water for 48 h. Although Dursban 4E is a widely used preservative in the timber industry, oil palm lumber specimens of 40 mm thick immersed in Dursban 4E for 48 h and conditioned in a kiln to a moisture content of 30% were discolored from week 2. However, oil palm lumber specimens of 40 mm thick that were immersed in tap water for 48 h, and thereafter immersed in Dursban 4E for another 48 h, then kiln dried to a moisture content of 15%, 20%, 25%, and 30%, did not show any discoloration from week 2 to week 18. It was discovered that in the utilization of oil palm lumber, it should be immersed in tap water for 48 h before any chemical treatment is given, and thereafter kiln dried. From the general results, the species proved to be good substitute for some of the ‘noble’ species that are going extinct from the forests of Ghana.
Observation of External Wounding on Green Ash (Fraxinus pennsylvanica Marshall) Trees Associated with Tree Injection Systems
Authors: Hauer Richard J. , Ball John J. , North Eric
Published: October 2022

Field observations of external wounds associated with two common tree injection methods compared open (plug-less) and sealed (plug) systems in green ash (Fraxinus pennsylvanica Marshall) trees. A wound from any cause within 1.37 m above the ground was common with 28.8% of all trees. The open system had statistically fewer (p < 0.001) trees with at least one wound (11.6% of trees) than the sealed system (47.4% of trees). The open system had fewer (p < 0.001) wounds (0.17, 0.04 SE) per tree and a smaller (p < 0.001) total wound area (25.5 cm2, 8.7 SE) per tree, compared to the sealed system wounds (1.14, 0.13 SE) per tree and the total wound area (99.7 cm2, 16.2 SE) per tree. The incidence of a tree with a wound(s) within 1.37 m above the ground was 7.2 times more likely with trees treated though the sealed system. Wounds in the sealed system were observed to appear to have a high rate of improper application of plugs, which was associated in 77% of the cases to explain the wounds. Implications of study results are further provided to best protect ash trees, while at the same time reducing the incidence external wounding on ash trees.
Growth and Morphological Patterns of Norway Spruce (Picea abies (L.) Karst.) Juveniles in Response to Light Intensities
Authors: Bednář Pavel , Souček Jiří , Krejza Jan , Černý Jakub
Published: October 2022

(1) Background: The growth and morphology of Norway spruce (Picea abies (L.) Karst.) juveniles were observed under different light conditions due to overstory canopy openness. The aim was to investigate the photo-morphological responses of juveniles for the development of a desirable forest structure. The research was located in a higher altitude zone in central Europe. (2) Methods: Light was estimated using hemispherical photographs. Eight different parameters of natural regeneration were measured on individuals within 1 × 1 m around each point on a 3 × 3 m grid. A total of 1214 sapling measurements (from 10 to 431 cm in height) were taken. (3) Results: Light affected the growth and morphological development of juveniles, resulting in variation in the lateral crown growth and crown length. Acclimations manifested as trade-offs between height and lateral crown growth. Similar shifts were found within relative height growth (the terminal length to the total height) and apical dominance ratio (the terminal length to the branch length). The crown length was proven to be highly capable to acclimation. Light influenced the density weakly, however, when a regeneration index (density × median height) was considered, significant relations with light conditions were discovered.
Effects of Structural and Diversity Attributes on Biomass in Different Types of Urban Forests in Changchun, Northeast China, and Suggestions for Urban Forest Planning
Authors: Wu Junjie , Wang Zihan , Zhang Dan , Gong Chao , Zhai Chang , Wang Yuanyuan
Published: October 2022

Understanding of the relationship between structural and diversity attributes and biomass is important for plant biodiversity conservation, ecosystem service function enhancement and sustainable development of urban forest ecosystems. In this study, road forest (RF), attached forest (AF) and landscape and relaxation forest (LF) were selected as research objects. We systematically evaluated the diversity attributes and above ground biomass (AGB) at two dimensions of different diameter at breast height (DBH) grades and different tree height grades of urban forests in Changchun, Northeast China. Structural equation modeling (SEM) analyses of the correlation between structure attributes, diversity attributes and biomass among different types of urban forests were carried out. The results showed that species richness (SR) and Shannon–Wiener index (H′) of shrubs were lower than those of trees. Under the DBH grades, H′ in each forest type was highest in the 0–10 m grades and SR was highest in the 10–20 m grades. Under tree height grades, both H′ and SR of each type were at the top of the list. AGB was highest in each forest type under 5–10 m height grades. The relationship between AGB and H′ was better in LF, but with no significant relationships in the other forest types. SEM highlighted that in the overall aspect, the effect of forest type on biomass was mediated by structure and diversity attributes. Particularly in LF, there were direct and indirect effects between structure attributes and biomass mediated by diversity attributes. The improvement of the H′, evenness index (J′) and SR could enhance urban forest services, especially for the biomass and diversity of LF.
Influence of Four Spacings between Trees and Four Samplings Heights on Selected Wood Quality Attributes of White Spruce (Picea glauca (Moench) Voss)
Authors: Mvolo Cyriac S. , Goudiaby Venceslas , Koubaa Ahmed , Stewart James D.
Published: October 2022

Four Picea glauca (Moench) Voss trees grown at each of four square spacing intensities between trees: 1.2 m, 1.8 m, 4.3 m, and 6.1 m in a plantation established in 1967 in the Petawawa Research Forest, Ontario, Canada (lat. 45.59° N, long. 77.25° W, elev. 168 m) and sampled at four different heights (1.3 m, 4.3 m, 7.3 m, 10.3 m) were used to study the impact of spacing between trees and sampling height on nine wood quality attributes (ring width, ring density, tracheid length, tracheid diameter, latewood proportion, intra-ring density variation, ring area, earlywood width, and latewood width). In the juvenile wood, ring width was wider and ring density higher than in the mature wood. Tracheid length was longer and tracheid diameter wider in the mature wood compared to the juvenile wood. The variation of ring density between the two wood zones was limited, and latewood proportion did not show any difference with wood zone. Sampling height induced variation in more wood quality attributes than did spacing. Except for growth rate, spacing between trees did not significantly impact wood quality attributes. Most of these variations were registered between widely different spacings.
G×E Analysis of Early Growth Traits of Populus deltoides in East China by Using BLUP-GGE
Authors: Yuan Zhengsai , Dong Yufeng , Liu Ning , Li Shanwen , Zhang Weixi , Wang Yanping , Han Youji , Zhuang Ruonan , Zhang Xiaoyan , Su Xiaohua , Ding Changjun , Liu Guanjun
Published: October 2022

In temperate and subtropical climates, Populus deltoides is an important poplar species. To analyze the stability, adaptability, and high yield of P. deltoides hybrid genotypes in East China, 38 P. deltoides genotypes were screened at three experimental sites in Shandong Province, and the coefficients of variation and genetic characteristics of 5-year growth were examined using BLUP-GGE. Results showed that all coefficients of variance were higher for diameter at breast height (DBH) than for tree height at all sites; the repeatability and heritability of tree height were greater than those of DBH at all sites. The fitting degree of tree height and DBH was 93.72% and 92.22%, respectively. The optimum genotype varied by location and grouping, of which Shanxian County divisions are the most powerful and representative of the three sites. The growth of 5-year-old P. deltoides was highly varied because of hereditary factors. Shanxian County is the more appropriate site for growth of P. deltoides in the tested sites in East China. In East China, genotypes 16, 5, 21, and 7 are regarded as superior. The genotypes 8, 26, and 36 are better for the site Rizhao; 16, 5, and 21 for site Shanxian; and 22, 21, and 5 for site Boxing.
Carbon Sequestration in Harvested Wood Products in Hungary an Estimation Based on the IPCC 2019 Refinement
Authors: Király Éva , Börcsök Zoltán , Kocsis Zoltán , Németh Gábor , Polgár András , Borovics Attila
Published: October 2022

As wood products in use store carbon and can contribute to reducing the concentration of atmospheric CO2, the improved and enhanced use of wood products can be a successful measure in climate change mitigation. This study estimates the amount of carbon stored in the Hungarian harvested wood product (HWP) pool and the CO2 emissions and removals of the pool. According to our results, the total carbon stock of the Hungarian HWP pool is continuously increasing. We estimated the total carbon stock of the HWP pool to be 17,306 kt C in the year 2020. Our results show that the HWP pool in Hungary is a carbon sink in most parts of the time series, with some years where it turns to a source of emissions. We carried out a simple projection up to 2070, assuming a constant inflow for the projected years that is equal to the average inflow of the last five historic years. This resulted in a decreasing trend in CO2 removals, with removals already very close to zero in 2070. We concluded that in order to achieve significant future carbon sinks in the HWP pool technological improvements are needed, such as increasing the lifetime of the wood products and expanding the carbon storage capacity of wood products by reusing and recycling wood in a cascade system.
Impact of Calcium and Nitrogen Addition on Bioethanol Production by S. cerevisiae Fermentation from Date By-Products: Physicochemical Characterization and Technical Design
Authors: Alminderej Fahad M. , Hamden Zeineb , El-Ghoul Yassine , Hammami Bechir , Saleh Sayed M. , Majdoub Hatem
Published: October 2022

Given crude oil prices and their environmental impacts, the use of sustainable renewable alternative energies such as biofuels is rapidly progressing in numerous countries. Among biofuels, bioethanol is a renewable and clean fuel that can be obtained from the fermentation of several raw agricultural materials, including date fruit. However, the low product yield, mainly due to the low-grade nutrient content, limits its use as a promising alternative biofuel. This current study investigated bioethanol production from date by-products in Saudi Arabia and examined the impact of calcium and nitrogen sources added at different concentrations (0 to 1 g/L) on the productivity and ethanol concentration using Saccharomyces cerevisiae. Yeast extracts and ammonium chloride (NH4Cl) were tested as nitrogen sources for bioethanol fermentation from date juice. Calcium chloride (CaCl2) and calcium carbonate (CaCO3) were evaluated as calcium sources for the same purpose mentioned above. The results showed that both calcium and nitrogen sources improved ethanol production efficiencies. The addition of calcium sources such as CaCl2 at 0.4 g/L resulted in maximum ethanol concentration (41.5 ± 0.85 g/L) and the highest productivity of 0.511 g/L/h. Thus, an increase of 31.3% compared to the control sample was acquired. Ammonium chloride was found to be the best nitrogen supplement among them. Indeed, supplementing the fermentation medium with 1 g/L NH4Cl gave an optimal ethanol concentration and productivity, reaching more than 65 g/L and 0.83 g/L/h, respectively. This is an increase of 106.6%. The functional group of ethanol (C2H5OH) for all the elaborated samples was confirmed by Fourier-transform infrared spectroscopy (FTIR) and NMR analyses. Moreover, the results confirmed the high quality and purity of the bioethanol products. Thus, the “Khodhari” date variety of low market value is a privileged substrate for industrial bioethanol production. For this reason, a proposed flow diagram of a designed plant for bioethanol industrialization is provided and detailed.
Enabling Ethanologenesis in Moorella thermoacetica through Construction of a Replicating Shuttle Vector
Authors: Bourgade Barbara , Millard James , Humphreys Christopher M. , Minton Nigel P. , Islam M. Ahsanul
Published: October 2022

Replicating plasmid shuttle vectors are key tools for efficient genetic and metabolic engineering applications, allowing the development of sustainable bioprocesses using non-model organisms with unique metabolic capabilities. To date, very limited genetic manipulation has been achieved in the thermophilic acetogen, Moorella thermoacetica, partly due to the lack of suitable shuttle vectors. However, M. thermoacetica has considerable potential as an industrial chassis organism, which can only be unlocked if reliable and effective genetic tools are in place. This study reports the construction of a replicating shuttle vector for M. thermoacetica through the identification and implementation of a compatible Gram-positive replicon to allow plasmid maintenance within the host. Although characterisation of plasmid behaviour proved difficult, the designed shuttle vector was subsequently applied for ethanologenesis, i.e., ethanol production in this organism. The non-native ethanologenesis in M. thermoacetica was achieved via plasmid-borne overexpression of the native aldh gene and heterologous expression of Clostridium autoethanogenum adhE1 gene. This result demonstrates the importance of the developed replicating plasmid vector for genetic and metabolic engineering efforts in industrially important M. thermoacetica.
The Effect of E. coli Uridine-Cytidine Kinase Gene Deletion on Cytidine Synthesis and Transcriptome Analysis
Authors: Liu Fengmin , Ye Tong , Zhang Xiangjun , Ma Cong , Liu Huiyan , Fang Haitian
Published: October 2022

Cytidine is an antiviral and anticancer drug intermediate, its primary method of manufacture being fermentation. Uridine-cytidine kinase (UCK) catalyzes the reverse process of phosphorylation of cytidine to produce cytidylic acid, which influences cytidine accumulation in the Escherichia coli cytidine biosynthesis pathway. The cytidine-producing strain E. coli NXBG-11 was used as the starting strain in this work; the udk gene coding UCK was knocked out of the chromosomal genome using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology. The mutant strain E. coli NXBG-12 was obtained; its transcriptomics were studied to see how udk gene deletion affected cytidine synthesis and cell-wide transcription. The mutant strain E. coli NXBG-12 generated 1.28 times more cytidine than the original strain E. coli NXBG-11 after 40 h of shake-flask fermentation at 37 °C. The udk gene was knocked out, and transcriptome analysis showed that there were 1168 differentially expressed genes between the mutant and original strains, 559 upregulated genes and 609 downregulated genes. It was primarily shown that udk gene knockout has a positive impact on the cytidine synthesis network because genes involved in cytidine synthesis were significantly upregulated (p < 0.05) and genes related to the cytidine precursor PRPP and cofactor NADPH were upregulated in the PPP and TCA pathways. These results principally demonstrate that udk gene deletion has a favorable impact on the cytidine synthesis network. The continual improvement of cytidine synthesis and metasynthesis is made possible by this information, which is also useful for further converting microorganisms that produce cytidine.
Real-Time Flood Monitoring with Computer Vision through Edge Computing-Based Internet of Things
Authors: Jan Obaid Rafiq , Jo Hudyjaya Siswoyo , Jo Riady Siswoyo , Kua Jonathan
Published: October 2022

Natural disasters such as severe flooding can cause catastrophic losses to properties and human lives. Constant real-time water level monitoring prior to a flooding event can minimise damages and casualties. Many of the currently deployed water level monitoring systems typically use a combination of float-type or ultrasonic sensing, image processing and computer vision techniques. However, these systems incur high computing and hardware requirements, which hinder the deployment of such systems in resource-constrained and low-cost environments. The recent development of technologies empowered by the Internet of things (IoT) and edge computing have enabled real-time systems to be deployed at a significantly lower cost and a far more distributed manner. In this paper, we propose an architecture for flood monitoring using RGB-D cameras with stereoscopic capabilities to measure the water level in an open environment. Our system uses image preprocessing techniques to account for chromatic aberration due to overexposure, followed by postprocessing before the depth readings are extracted. Data processing and water level information extraction are entirely performed on an edge computing device, therefore greatly reducing the amount of data transmitted to the cloud server. We practically implemented and experimentally validated this system in the real world, under a wide range of weather and lighting conditions. Our results showed promising outcomes and demonstrated the applicability of our proposed system in a wider context.
A Spectrum Management Platform Architecture to Enable a Sharing Economy in 6G
Authors: Bouhafs Faycal , Raschellà Alessandro , Mackay Michael , den Hartog Frank
Published: October 2022

We propose a novel vision to trade and allocate wireless spectrum in 6G communication networks inspired by the concept of the sharing economy. We argue that such an approach will help ease the surge in demands for wireless spectrum that will characterise the 6G world. We also introduce HODNET (Heterogeneous on Demand NETwork resource negotiation), an open platform that is able to realise this new spectrum-sharing model. To demonstrate the benefits of spectrum trading and allocation in this new paradigm, we considered the use-case of massive Internet of Things (IoT) on a local scale. We simulated a large IoT deployment and evaluated the spectral efficiency of the system when managed using HODNET compared with a standard 5G deployment. Our experiments show that HODNET can indeed offer better allocation, based on our spectrum sharing model, of spectrum resources compared with standard allocation approaches.
EduTVA: Metadata Schema for Educational Audiovisual Contents in Digital Television Environments
Authors: Vargas-Arcila Angela M. , Caicedo-Muñoz Julian A. , Estrada-Solano Felipe , González-Amarillo Carlos , Ordonez Armando , Arciniegas Jose L.
Published: October 2022

The educational model faced unprecedented changes during the COVID-19 pandemic. In particular, the remote communication between teachers and learners was affected due to either the lack of or a poor Internet connection at home. Hence, television facilitates a more widespread communication technology with easier access than the Internet by playing an educational role for the mass audience through the broadcast of several learning resources (e.g., films, news, documentaries). However, there exists an increase in the educational audiovisual content, which needs to be organized and represented through description structures to be recovered. This paper proposes Educational TV-Anytime (EduTvA), a metadata schema for marking up educational audiovisual content and segments of the content in digital television. EduTVA emerges from an extensive revision of different metadata schemas for digital television and E-learning. Implementations of an EduTVA metadata authoring tool and an educational content search service support the evaluation of the user acceptance and functionality of the EduTVA metadata schema. Results show that EduTVA allows detailed descriptions of educational content and enables an accurate search of educational content.
Numerical Study of the Performance of Existing Prestressed Cylindrical Concrete Pipes Strengthened with Reinforced Concrete or Carbon-Reinforced Fiber Polymer Jackets—Part B
Authors: Katakalos Konstantinos , Melidis Lazaros , Manos George , Soulis Vassilios
Published: October 2022

A popular water pipe system, used in many countries, is one formed by prestressed cylindrical concrete pipes (PCCP). This study used the results of an experimental investigation on ten (10) PCCP samples taken from an existing water pipeline. The objective was to investigate their bearing capacity under three-edge bending or internal hydraulic pressure loads to check the capability of specific retrofitting/strengthening schemes to upgrade this bearing capacity and thus enhance the operational period (Part A). In this part B study, the measured response of the PCCP pipes was made to validate a numerical approach aimed at numerically simulating the behavior of the original and retrofitted PCCP pipes under hydraulic internal pressure. From the obtained numerical results, it was seen that the assumed nonlinear mechanisms for the concrete volume and steel membrane were verified by comparing numerical predictions with measurements in terms of strain response of the steel membrane, damage patterns of the concrete volume, and the overall internal pressure versus radial expansion response. The numerical predictions of the bearing capacity contribution of the fully active prestress as well as the three specific jacketing schemes, including carbon fiber reinforced polymer (CFRP) or reinforced concrete (RC) jackets, were also verified from comparisons with the corresponding measured response.