bluuebunny/crossref_metadata_2025 huggingface dataset:
Editorial for the Special Issue on Physical Diagnosis and Rehabilitation Technologies
Authors: Liu Tao , Ferreira João Paulo Morais
Published: July 2022

Recently, physical diagnosis and human motion analysis have become active research topics in bioelectronics, and they have a broad range of applications, such as pathology detection, rehabilitation, prosthesis design, biometric identification, and humanoid robotic locomotion [...]
Real-Time CLAHE Algorithm Implementation in SoC FPGA Device for 4K UHD Video Stream
Authors: Kryjak Tomasz , Blachut Krzysztof , Szolc Hubert , Wasala Mateusz
Published: July 2022

One of the problems encountered in the field of computer vision and video data analysis is the extraction of information from low-contrast images. This problem can be addressed in several ways, including the use of histogram equalisation algorithms. In this work, a method designed for this purpose—the Contrast-Limited Adaptive Histogram Equalization (CLAHE) algorithm—is implemented in hardware. An FPGA platform is used for this purpose due to the ability to run parallel computations and very low power consumption. To enable the processing of a 4K resolution (UHD, 3840 × 2160 pixels) video stream at 60 fps (frames per second) by using the CLAHE method, it is necessary to use a vector data format and process multiple pixels simultaneously. The algorithm realised in this work can be a component of a larger vision system, such as in autonomous vehicles or drones, but it can also support the analysis of underwater, thermal, or medical images both by humans and in an automated system.
A Margin Design Method Based on the SPAN in Electricity Futures Market Considering the Risk of Power Factor
Authors: Lin Deqin , Deng Wenyang , Dai Siting
Published: July 2022

On-grid integration of renewable energy, also called “green power”, is attracting more and more attention nowadays. Green power futures can be effective in increasing returns to suppliers and increasing market liquidity. However, compared to traditional futures, green power feed-in tariffs may be subject to integrity problems due to lower power factors; therefore, existing margin calculation methods for the futures market are no longer applicable. A SPAN-based margin calculation method that considers the power factor risk is proposed in this paper. The method provides the classification policies of the green power futures, based on the historical power factors of green power suppliers, and allows the margin amount to be adjusted as per the classification. To verify the effectiveness of the proposed method, empirical validation is presented by applying actual transaction data. Results prove that the proposed method can reduce the margin amount while covering the risk effectively.
Research on Wave and Energy Reduction Performance of Floating Breakwater Based on S-Shaped Runner
Authors: Bao Lingjie , Wang Ying , Jiang Chuhua , Chen Junhua , Li Hao , Wang Shenghu
Published: July 2022

Aiming at the breeding environment where the construction of marine pastures requires low wind and waves, a floating breakwater (FB) with a Savonius type (referred to as S type) runner with wave absorption and energy reduction function is studied for wave absorption and energy reduction in aquaculture sea areas. The wave-absorbing and energy-reducing performance of the floating breakwater is studied by the method of combining numerical simulation and experiment. Using Star-CCM+ numerical simulation software, based on linear wave theory and energy conservation law, using overlapping grid technology, calling DFBI model, second-order time discretization, a three-dimensional flow field model of the floating breakwater was established and numerically simulated. At the same time, a floating breakwater physical test system was developed for experimental verification, the transmission wave and the conversion power consumption of the S-shaped runner under different wave heights and different periods were measured, and the results Please carefully check the accuracy of names and affiliations. of numerical simulation and physical experiments were comprehensively evaluated. The research results show that the floating breakwater based on the S-shaped runner has the functions of reducing the wave height and reducing the wave energy, which have guiding significance for practical engineering.
Characterization of the Lower Cretaceous Shale in Lishu Fault Depression, Southeastern Songliao Basin: Implications for Shale Gas Resources Potential
Authors: Xie Qilai , Xu Hao , Yu Shuang
Published: July 2022

Large thickness of shales over 180.0 m was developed in the source rocks of the Shahezi and Yingcheng formations in the Lishu Fault Depression. Moreover, the high amount of gas content and the total hydrocarbon value of gas logging in several boreholes illustrate that there is a great potential of shale gas resources in this region. Therefore, an integrated characterization of shales from the lower Cretaceous Shahezi and Yingcheng formations was provided to evaluate shale gas resources potential. The measurement results illustrated that the organic-rich shale samples with kerogen type Ⅱ during high to over thermal maturity had a higher content of brittle minerals (>50%) and clay mineral dominated by illite. The shales had a total porosity of 3.11–4.70%, a permeability of 1.24 × 10−3–1.52 × 10−3 μm2, and possessed pore types including dissolution pores, inter-layer pores of clay minerals, micro-fractures, intra-granular pores, and organic pores, which were dominated by micropores and mesopores (0.5–1.7 nm, 2.2–34.3 nm) with a significant contribution from OM and clay minerals. According to the N2 adsorption isotherms, the pore volume was comprised primarily of mesopores with mean widths of 4.314–6.989 nm, while the surface area was comprised primarily of micropores with widths in ranges of 0.5–0.8 nm and 1.0–1.7 nm. Thus, the shales have a suitable porosity and permeability, indicating that fine storage capacity and favorable gas flow capacity occur in the Shahezi and Yingcheng formations, which exhibit a good reservoir quality and excellent exploration potential since the considerable thickness of shales could form a closed reservoir and served as cap rocks for in situ gas generation and accumulation. Especially, according to the measured CH4 excess adsorption amount and the calculated maximum absolute adsorption capacities of CH4 based on the Langmuir adsorption model, the estimated GIP values (1.388–3.307 m3/t) of the shales happened to be in a sampling depth under geological hydrostatic pressure and temperature conditions. This means that the shale storage capacity and high gas content from well site desorption completely met the standard of industrial exploitation when synthetically considering the GIP model. As a consequence, shales in the Shahezi and Yingcheng formations in the Lishu Fault Depression could be potential targets for shale gas exploration.
Techno–Economic and Risk Evaluation of Combined Cycle Propulsion Systems in Large Container Ships
Authors: Alzayedi Abdulaziz M. T. , Sampath Suresh , Pilidis Pericles
Published: July 2022

Owing to the stringent regulations on pollutant emissions that are imposed by the International Maritime Organization and increasing fuel prices, there has been significant research on developing cleaner fuels and novel propulsion systems. This study presents a techno-economical and risk assessment method for evaluating alternative propulsion technologies and cleaner fuels as substitutes for heavy fuel oil and two-stroke diesel engines in marine transportation. This analysis was carried out for two different journeys. Accordingly, we evaluated the economic benefits of using an enhanced intercooler/reheat combined gas and steam cycle or simple and intercooler/reheat combined gas and steam cycles that were fueled by marine diesel oil or liquified natural gas instead of a two-stroke diesel engine that was fueled by MDO as the propulsion system in a large container ship, considering different shipping routes. The results highlighted the advantages of implementing the simple, intercooler/reheat, and enhanced combined gas and steam cycles as propulsion systems. A sensitivity analysis was performed to investigate the effects of the fuel cost, capital cost, and hull fouling resistance on the economic analysis. For the routes that were considered herein, compared to a two-stroke diesel engine that was fueled by MDO, the simple, intercooler/reheat, and enhanced gas and steam combined cycles that were fueled by LNG increased the net present value by 78.3%, 78.5%, and 76.4%, respectively, and reduced the payback period by 38.8%, 38.9%, and 35%, respectively. Furthermore, the fuel and capital costs had a significant influence on the overall economic profit.
Online Failure Diagnostic in Full-Bridge Module for Optimum Setup of an IGBT-Based Multilevel Inverter
Authors: Iglesias-Rojas Juan Carlos , Velázquez-Lozada Erick , Baca-Arroyo Roberto
Published: July 2022

An online failure diagnostic test is essential to ensure the robustness and reliability of high-powered systems. Furthermore, the overall design must comprise diagnostic strategies to detect in-service and high-powered module defects. This paper describes the critical failure mechanisms––cross-conduction, inductive avalanche, second turn-on, VS-undershoot, inrush current, and thermal runaway––that directly affect insulated gate bipolar transistor (IGBT) operation. The constructed inverter contains 18 transformer-based taps (six per phase); however, this work studied a single tap (IGBT-based full-bridge module) to understand the reasons for failure and the routes to mitigate them. Moreover, a cost-effective solution using the IR2127STRPBF driver circuit was implemented to reduce the probability of thermal runaway in case of overcurrent, short-circuit, or avalanche events. For this reason, the electrical current state was adjusted using an FPGA digital resource to perform dynamic PWM control signals. The obtained correlation waveforms are valuable for verifying diagnostic data at the design stage to emphasize the significance of evading premature failure events. The comprehensive study on failure diagnosis enabled successful design strategies to construct a robust 45 kVA three-phase multilevel inverter for a 22 kW eolic-photovoltaic generation plant.
Power Quality Management Strategy for High-Speed Railway Traction Power Supply System Based on MMC-RPC
Authors: Li Teng , Shi Yongbin
Published: July 2022

This paper adopts the Modular Multilevel Converter Type Railway Power Conditioner (MMC-RPC) equipment to effectively manage the power quality of the high-speed railway traction power supply system including the reactive power and negative sequence component. Firstly, the single-phase model of the MMC was established to deduce the working characteristics of the MMC-RPC and its compensation principle for the traction power supply system with the v/v wiring transformer. Secondly, the adaptive VSG control strategy was adopted for the inverter of the MMC-RPC to provide dynamic inertial and damping support for the traction power supply system based on the virtual synchronous generator (VSG) control. Compared with the traditional double closed-loop (DCL) and VSG controls, it has better anti-disturbance and dynamic performance. The root locus analysis of control parameters based on a small signal model shows that VSG control can provide more stability margin. Furthermore, Differential Flatness Control (DFC) was used in the inner-loop controller to ensure the stable control of the inverter and the stability was verified by the Lyapunov stability analysis. For the rectifier of the MMC-RPC, a hierarchical three-level control strategy with system-level control, cluster-group voltage control, and inter-cluster voltage control for keeping the voltage balance was adopted. Finally, simulation results on the Matlab/Simulink platform verified the effectiveness and stability of the joint control applied in the MMC-RPC.
Socioeconomic Differences between Sexes in Surgically Treated Carpal Tunnel Syndrome and Ulnar Nerve Entrapment
Authors: Zimmerman Malin , Anker Ilka , Nyman Erika
Published: July 2022

We aimed to investigate socioeconomic differences between sexes and the influence on outcome following surgery for carpal tunnel syndrome (CTS) or ulnar nerve entrapment (UNE) at the elbow. Patients with CTS (n = 9000) or UNE (n = 1266) registered in the Swedish National Register for Hand Surgery (HAKIR) 2010–2016 were included and evaluated using QuickDASH 12 months postoperatively. Statistics Sweden (SCB) provided socioeconomic data. In women with CTS, being born outside Sweden, having received social assistance, and more sick leave days predicted worse outcomes. Higher earnings and the highest level of education predicted better outcomes. In men with CTS, more sick leave days and having received social assistance predicted worse outcomes. Higher earnings predicted better outcomes. For women with UNE, higher earnings predicted better outcomes. In men with UNE, only sick leave days predicted worse outcomes. In long-term follow up, socioeconomic status affects outcomes differently in women and men with CTS or UNE.
Livestock Grazing Impact on Species Composition and Richness Understory of the Pinus cembroides Zucc. Forest in Northeastern Mexico
Authors: Encina-Domínguez Juan A. , Estrada-Castillón Eduardo , Mellado Miguel , González-Montelongo Cristina , Arévalo José Ramón
Published: July 2022

In the pine forests of Mexico, disturbances are primarily due to cattle, horses, goat, and sheep grazing, particularly in communal grazing lands. The most evident disturbances are low tree recruitment, invasive shrubs establishment, species composition changes, and invasion of weeds dispersed mainly by livestock. The Sierra de Zapalinamé is a mountain range and natural protected area of northeast Mexico. We conducted the current study in this area in a forest stand of Pinus cembroides excluded from grazing in the last 25 years (1200 ha with pine forest vegetation and mountain chaparral) and another area nearby subjected to livestock grazing. Forest structure (basal area and density), tree species richness, total understory species richness, and understory species composition were analyzed at the control and grazed sites. Our results revealed that grazing has modified the understory species composition and reduced the evenness in the control plots. Therefore, to maintain species diversity and forest structure, we concluded that extensive grazing should be restricted for some areas or the number of animals reduced in zones of high ecological value.
Fire Damage to the Soil Bacterial Structure and Function Depends on Burn Severity: Experimental Burnings at a Lysimetric Facility (MedForECOtron)
Authors: Moya Daniel , Fonturbel Teresa , Peña Esther , Alfaro-Sanchez Raquel , Plaza-Álvarez Pedro Antonio , González-Romero Javier , Lucas-Borja Manuel Esteban , de Las Heras Jorge
Published: July 2022

The soil microbiota is vulnerable to burning; however, it shows some resilience. No indices have yet been developed to assess fire damage related to soil biota. We evaluated the biological soil indices recorded by a Biolog EcoPlate System in a Mediterranean ecosystem. The experiment was carried out in an outdoor forest lysimeter facility (MedForECOtron), where we simulated burns with different burn severities. Burning increased the metabolic diversity of bacteria and most C-substrate utilization groups. Soil organic matter, phosphorus, electric conductivity, and calcium increased with increasing burn severity. Microbial richness and activity, as well as the integrated capacity of soil microbes to use a C source, lowered by burning, but recovered 6 months later. The functional diversity and amount of the C source used by microbes immediately increased after fire, and values remained higher than for unburned soils. We evaluated the changes in the vulnerability and resilience of fire-adapted ecosystems to improve their adaptive forest management. We found that the high burn severity reduced microbial richness, functional diversity, and the C source utilization of soil microbes (marked vulnerability to high temperatures), which recovered in the short term (high resilience). These results help to understand the main mechanisms of the effects of wildfire on semi-arid Mediterranean ecosystems, whose field validation will be helpful for fire prevention planning and restoration of burned areas.
Protocol for In Vitro Propagation of Salix acmophylla (Boiss.). Studies on Three Ecotypes
Authors: Capuana Maurizio , Nissim Werther Guidi , Klein Joshua D.
Published: July 2022

Salix acmophylla Boiss. has a traditional role in several regions of the Middle East and the Indian subcontinent. As with many other woody species, the development of methods for fast propagation and ex situ conservation of this species is needed. We describe for the first time a micropropagation protocol of three S. acmophylla ecotypes. The best results for shoot proliferation were obtained by culturing the shoot explants on Woody Plant Medium (WPM) containing benzyladenine (BA) 5 μM, but it was also observed that proliferation can be further enhanced by the separation of the shoot tip from the underlying internodes, followed by their respective culture on BA- or activated-charcoal-containing medium. Thidiazuron or zeatin did not enhance shoot proliferation. The rooting of shoots occurred spontaneously, but for the ecotype with a lower propensity for rooting, treatment with 5 μM indolebutyric acid (IBA) increased rooting percentage. Genetic differences were evident in rooting success, but not in shoot development of the tested ecotypes in response to in vitro cultural conditions.
Motivations and Trade-Offs for Sustainability in Family Forestry and Tourism Firms: A Cross-National Survey
Authors: Nikolakis William , Olaru Doina , Roco Lisandro , Reyes René
Published: July 2022

Family firms are the foundation of economies across the world. Yet, little is understood about what motivates sustainability in these firms, particularly in developing economies. In this study, we examine family forestry and tourism firms in Chile and India and use a novel stated-choice method to understand preferences for sustainability and the trade-offs with profit maximization, law and regulation, and family relations (among others). There were heterogeneous preferences across the sample, with respondents favoring financial outcomes and viewing regulation negatively. Respondents preferred positive environmental impacts, and this was significantly favored by tourism firms. Forestry firms were particularly focused on maintaining satisfactory family relationships, where there was stronger family involvement in the firm’s management decisions. Indian respondents were more likely to prefer the expansion option in the choice study (financial outcomes), while Chileans preferred the eco-labeling choice (sustainability), suggesting more supportive sustainability norms in Chile. Chileans were more likely to exceed legal compliance in their choice selection and favored positive environmental impacts more. Overall, tourism firms were larger in terms of revenues and favored the eco-labeling choice with positive environmental impacts but with minimal regulations, while forestry favored expansion. These differences may be driven by the resources available to tourism firms for supporting sustainability measures and the importance of sustainability to their business models. Policies to support sustainability among family firms must account for their heterogeneity and must provide supports and incentives rather than regulations to facilitate sustainability.
Influences of Shading on Ascorbic Acid Biosynthesis of Blackcurrant (Ribes nigrum L.)
Authors: Gang Huixin , Zhang Danni , Sun Xiaojuan , Huo Junwei , Qin Dong
Published: July 2022

Cultivation conditions may greatly affect fruit quality, especially in the accumulation of functional metabolites. Blackcurrant fruits (Ribes nigrum L.) have high ascorbic acid (AsA) concentrations. The purpose of the current study was to investigate the influence of different shading treatments (full sunlight, and 40% and 60% sunlight) on the fruits’ maturity, and on the levels of fruit firmness, soluble solid, AsA, and enzyme activity involved in AsA biosynthesis and recycling in two blackcurrant (Ribes nigrum) cultivars, ‘Heifeng’ and ‘Adelinia’. Shading conditions of 40% and 60% sunlight delayed fruit ripening and increased fruit firmness in both ‘Adelinia’ and ‘Heifeng’. Soluble solids in ‘Adelinia’ were markedly reduced by shading compared with ‘Heifeng’. Compared with full sunlight, the AsA content was significantly decreased in the ripe fruits under the 40% and 60% shading treatments. Additionally, the AsA content was decreased during the fruit development process under the 60% shading treatment, which was associated with the reduced activity of the enzymes monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), glutathione oxidoreductase (GR), ascorbate peroxidase (APX), and L-galactose dehydrogenase (GalDH) involved in the biosynthesis and recycling pathway of AsA. The correlation analysis results showed that the activity of MDHAR, DHAR, GR, APX, and GalDH was significantly positively correlated with AsA concentrations during the 60% shading treatment in ‘Adelinia’ and ‘Heifeng’ fruits, suggesting that AsA biosynthesis and recycling were affected and the two cultivars have similar mechanisms to deal with shading. Our results not only provide a better understanding of the regulation mechanism of AsA accumulation under shading, but also provide a theoretical basis for taking effective cultivation measures aimed at the improvement of AsA levels in blackcurrant fruits.
Heritage Trees as an Important Sanctuary for Saproxylic Beetles in the Central European Landscape: A Case Study from Litovelské Pomoraví, Czech Republic
Authors: Nakládal Oto , Zumr Václav , Remeš Jiří , Macháčová Markéta , Pešková Vítězslava
Published: July 2022

Intensive forest and agroforestry management has greatly reduced the biodiversity of saproxylic organisms. Large trees are one of the most important refuges of saproxylic beetles. These large trees that grow outside and inside the forest are declining in the wider landscape. Heritage trees are one of the essential groups of beneficial trees in the landscape. We investigated saproxylic beetles associated with 35 selected oak heritage trees in Litovelské Pomoraví in the eastern Czech Republic. The study aimed to investigate the distribution of saproxylic beetles on trees growing inside or at the edge of forest stands, or on free-growing heritage trees. The other studied variables were the height, DBH, and light condition (sunny or shady) of heritage trees. The results showed that sunny habitats were the only significant factor found for all saproxylic species. However, the significance of increasing tree trunk dimension was found for the endangered species. Diversity indices q = 0 (species richness) and q = 1 (exponential of Shannon entropy index) were also higher for sunny trees, while solitary trees showed a high Shannon index value despite the low number of samples. Redundancy analysis of saproxylic species showed that the preferred habitats of most species were sunny massive solitary oaks. The results indicated that strictly protected heritage trees scattered in the landscape are crucial sanctuaries for many species—especially in landscapes where there are not enough suitable habitats for saproxylic beetles. Finding, conserving, and protecting these rare types of massive trees in the landscape has a significant impact on the conservation of saproxylic beetle biodiversity.
Forest Fire Prediction with Imbalanced Data Using a Deep Neural Network Method
Authors: Lai Can , Zeng Shucai , Guo Wei , Liu Xiaodong , Li Yongquan , Liao Boyong
Published: July 2022

Forests suffer from heavy losses due to the occurrence of fires. A prediction model based on environmental condition, such as meteorological and vegetation indexes, is considered a promising tool to control forest fires. The construction of prediction models can be challenging due to (i) the requirement of selection of features most relevant to the prediction task, and (ii) heavily imbalanced data distribution where the number of large-scale forest fires is much less than that of small-scale ones. In this paper, we propose a forest fire prediction method that employs a sparse autoencoder-based deep neural network and a novel data balancing procedure. The method was tested on a forest fire dataset collected from the Montesinho Natural Park of Portugal. Compared to the best prediction results of other state-of-the-art methods, the proposed method could predict large-scale forest fires more accurately, and reduces the mean absolute error by 3–19.3 and root mean squared error by 0.95–19.3. The proposed method can better benefit the management of wildland fires in advance and the prevention of serious fire accidents. It is expected that the prediction performance could be further improved if additional information and more data are available.
Income and Insurability as Factors in Wildfire Risk
Authors: Auer Matthew Robert , Hexamer Benjamin Evan
Published: July 2022

The increasing frequency of destructive wildfire incidents in the United States, particularly in the West, is well-documented, and the key causal variables are increasingly well understood. Among stakeholders with heightened concerns about risks from destructive wildfire are insurance companies and the homeowners they insure. The cancellation and nonrenewal of insurance due to wildfire risk has received media attention in the wake of major wildfire seasons, particularly in California. However, less attention has been directed to wildfire-related risks borne by lower-income policy holders, specifically. For example, the probability of maintaining or replacing an at-risk policy increases when a homeowner invests in fire protection measures. However, these investments are comparatively costly for lower-income homeowners. The present research aims to identify regions in the lower 48 states where moderate and high wildfire risk, lower income, and insurability are coterminous risks. The concentration of at-risk homes in counties with comparatively high wildfire hazard potential and comparatively higher poverty rates are considered. This paper also considers how the concentrated market share of insurance underwriting may pose a risk to lower income homeowners, considering the overlap between highly concentrated insurance markets and states with high wildfire risk and higher poverty rates.
Nematicidal Properties and Chemical Composition of Pinus rigida Mill. Resin against Pinewood Nematodes
Authors: Hwang Hwan-Su , Kim Yi-Re , Han Jung-Yeon , Choi Yong-Eui
Published: July 2022

Pitch pine (Pinus rigida Mill.) is native to North America and has a strong resistance to pine wood nematodes (PWNs). The PWN resistance mechanism of this tree species has yet to be discovered. In this work, we found that the spreading of inoculated PWNs in the branch of P. rigida was significantly suppressed compared to those in the branches of Pinus densiflora (Sieb. et Zucc.) and Pinus koraiensis (Sieb. et Zucc.). Dipping of PWNs in the resins isolated from P. rigida significantly suppressed the PWN mobility and conferred significantly higher PWN mortality compared to those in the resins from P. densiflora and P. koraiensis. All PWNs dipped in P. rigida resin were killed after six days, but more than 50% of the PWNs dipped in the resin from P. densiflora, and P. koraiensis were still alive after six days. The phytochemical analysis of resins revealed that P. rigida resin contained little or no amount of sesquiterpenes compared to those from P. densiflora and P. koraiensis. However, P. rigida resin contained rich amounts of diterpenes, among which dehydroabietic aldehyde, methyl dehydroabietate, and methyl abietate were uniquely detected. Particularly, two pinosylvin stilbenes (trans and cis-3,5-dimethoxystilbene) were accumulated in P. rigida resin, which were not detected in the resins from P. densiflora and P. koraiensis. cis-3,5-Dimethoxystilbene showed high nematicidal activity but not in trans-3,5-dimethoxystilbene. Conclusively, PWN resistance of P. rigida may be due to the toxic chemicals in the resin, in which cis-3,5-dimethoxystilbene may contribute to PWN toxicity. This work is the first demonstration that resin from PWN-resistant P. rigida directly affected PWN mobility and mortality, probably due to toxic phytochemicals in the resin.
Shaping an Open Microbiome for Butanol Production through Process Control
Authors: Pinto Tiago , Grimalt-Alemany Antonio , Flores-Alsina Xavier , Gavala Hariklia N. , Gernaey Krist V. , Junicke Helena
Published: July 2022

The growing awareness of limited resource availability has driven production systems towards greater efficiencies, and motivated the transition of wastewater treatment plants to water resource recovery facilities. Open microbiome fermentation offers a robust platform for resource recovery, due to its higher metabolic versatility, which is capable of dealing with even dilute residual liquid streams. Organic matter, e.g., fatty acids, lost in these streams can potentially be recovered into higher value chemicals such as alcohols. This study aims to shape an open microbiome towards butanol production from butyrate and hydrogen through pH control and continuous hydrogen supply. Two sets of experiments were conducted in Scott bottles (1 L) and a lab-fermenter (3 L). The open microbiome produced up to 4.4 mM butanol in 1 L bottles. More promising conversions were obtained when up-scaling to a lab-fermenter with pH control and an increased hydrogen partial pressure of 2 bar; results included a butanol concentration of 10.9 mM and an average volumetric productivity of 0.68 mmol L−1 d−1 after 16 days. This corresponds to 2.98- and 4.65-fold increases, respectively, over previously reported values. Thermodynamic calculations revealed that product formation from butyrate was unfeasible, but energetically favorable from bicarbonate present in the inoculum. For the first time, this study provides insights regarding the community structure of an open microbiome producing butanol from butyrate and hydrogen. DNA sequencing combined with 16S rRNA gene amplicon analysis showed high correlation between Mesotoga spp. and butanol formation. Microbial diversity can also explain the formation of by-products from non-butyrate carbon sources.
Comparative Genome Analysis of Two Heterotrophic Nitrifying Pseudomonas putida Strains Isolated from Freshwater Shrimp Ponds in Soc Trang Province
Authors: Tran Thanh Trung , Bott Nathan J. , Gelderen Rebecca van , Nguyen Nam Trung , Chu Phuong Minh Thi , Chu Ha Hoang
Published: July 2022

Nitrogen compounds, especially ammonia, are widely produced in aquaculture systems during cultivation. Ammonia has been investigated as a model compound for use by heterotrophic nitrifying bacteria. Pseudomonas TT321 and Pseudomonas TT322, isolated from shrimp pond water in Soc Trang province, Vietnam, are identified by comparing them with 31 of the closest genomes sequences from the NCBI nucleotide database. The genome sizes of strains TT321 and TT322 were 5,566,241 bp and 5,563,644 bp, respectively. No plasmids were evident in these strains. Genome analysis revealed that TT321 and TT322 belonged to Pseudomonas putida and shared a common ancestor with 33 genomes. Analysis based on the comparison of genomes showed that three genes, carbamate kinase (arcC), glutamine synthetase (Glul), and aminomethyltransferase (amt), are involved in three metabolic pathways. These pathways are: (i) arginine and proline metabolism, (ii) alanine, aspartate and glutamate metabolism, and (iii) glycine, serine and threonine metabolism. These genes may play important roles in ammonia reduction and support bacterial growth via ammonia assimilation.
Numerical Simulation on the Effect of Fire Shutter Descending Height on Smoke Extraction Efficiency in a Large Atrium
Authors: Liu Qiyu , Xiao Jianren , Cai Bihe , Guo Xiaoying , Wang Hui , Chen Jian , Zhang Meihong , Qiu Huasheng , Zheng Chunlin , Zhou Yang
Published: July 2022

In this study, a series of numerical simulations were carried out to investigate the effect of fire shutter descending height on the smoke extraction efficiency in a large space atrium. Based on the full-scale fire experiments, this paper carried out more numerical simulations to explore factors affecting the smoke extraction efficiency in the atrium. The smoke flow characteristics, temperature distribution law and smoke extraction efficiency of natural and mechanical smoke exhaust systems were discussed under different heat release rates and fire shutter descending heights. The results show that the smoke spread rate and the average temperature of the smoke are higher with a greater heat release rate. After the mechanical smoke exhaust system is activated, the smoke layer thickness and smoke temperature decrease, and the stable period of heat release rate is shorter. In the condition of natural smoke exhaust, the smoke extraction efficiency increases exponentially with the increase of heat release rate and the descending height of the fire shutter, and the maximum smoke extraction efficiency is 48.8%. In the condition of mechanical smoke exhaust, the smoke extraction efficiency increases with the increase of mechanical exhaust velocity. When the velocity increases to the critical value (8 m/s), the smoke extraction efficiency is essentially stable. The smoke extraction efficiency is increased first with the increase of fire shutter descending height and then has a downward trend when the descending height drops to half, and the maximum smoke extraction efficiency is 70.3% in the condition of mechanical smoke exhaust. Empirical correlations between the smoke extraction efficiency and the dimensionless fire shutter descending height, the dimensionless heat release rate and the dimensionless smoke exhaust velocity have been established. The results of this study can provide a reference for the design of smoke prevention and exhaust systems in the atrium.
Feasibility Analysis of Cross Passage Ventilation and Smoke Control in Extra-Long Submarine Tunnel
Authors: You Wenjiao , Kong Jie
Published: July 2022

Longitudinal ventilation fans in extra-long submarine tunnels are usually arranged at both ends of the tunnel limited by the tunnel cross section, which is usually hindered by insufficient power caused by extra-long ventilation distances. In this paper, the conception of a ventilation mode is proposed that services the tunnel and cross passages, to provide auxiliary air supply to the main tunnel. Two critical factors have been analyzed on the premise of evacuation safety, which combine to affect the ventilation efficiency in the case of an accident inside the tunnel, these are: air volume within the service tunnel, and cross passage open numbers. FDS simulation software is used to simulate the tunnel model; consider the number of cross passages from one to four; and simulate the service tunnel airflow velocity of 0.7 m/s, 0.75 m/s, 0.85 m/s, 1.0 m/s and 1.3 m/s. The results show that when 1.3 m/s wind speed is applied at both ends of the service tunnel, and three cross passages are operated, 20 MW of fire smoke within the accident tunnel can be effectively controlled; additionally, the wind speed in the cross passage will not hinder the evacuation. The simulation results are verified by ventilation network calculation.
Influence of Sill on the Hydraulic Regime in Sluice Gates: An Experimental and Numerical Analysis
Authors: Daneshfaraz Rasoul , Norouzi Reza , Abbaszadeh Hamidreza , Kuriqi Alban , Di Francesco Silvia
Published: July 2022

This study investigates experimentally and numerically the effects of sills with different geometric specifications at various positions on the hydraulic characteristics of flow through sluice gates. The simulation results showed that the RNG turbulence model’s statistical indicators yield high accuracy compared to the k-ε, k-ω, and LES turbulence models. The discharge coefficient (Cd) has an inverse relationship with gate opening. Regarding sill state, the discharge coefficient is higher than no-sill state. In the case of non-suppressed sills, the Cd decreases compared to the smaller openings as the opening of the gate changes. The results showed that the Cd with a sill in the tangent position upstream of the gate is higher than the downstream tangent and below situations. Increasing the sill length leads to an increase in flow shear stress and consequently a decrease in Cd. The Cd of gates with different sill thicknesses is always higher than the no-sill state, but due to the constant ratio of the fluid depth above the sill to the gate opening, the Cd increases to a certain extent and then decreases with increasing sill thickness.
Advances in CFD Modeling of Urban Wind Applied to Aerial Mobility
Authors: García-Gutiérrez Adrián , Gonzalo Jesús , López Deibi , Delgado Adrián
Published: July 2022

The feasibility, safety, and efficiency of a drone mission in an urban environment are heavily influenced by atmospheric conditions. However, numerical meteorological models cannot cope with fine-grained grids capturing urban geometries; they are typically tuned for best resolutions ranging from 1 to 10 km. To enable urban air mobility, new now-casting techniques are being developed based on different techniques, such as data assimilation, variational analysis, machine-learning algorithms, and time series analysis. Most of these methods require generating an urban wind field database using CFD codes coupled with the mesoscale models. The quality and accuracy of that database determines the accuracy of the now-casting techniques. This review describes the latest advances in CFD simulations applied to urban wind and the alternatives that exist for the coupling with the mesoscale model. First, the distinct turbulence models are introduced, analyzing their advantages and limitations. Secondly, a study of the meshing is introduced, exploring how it has to be adapted to the characteristics of the urban environment. Then, the several alternatives for the definition of the boundary conditions and the interpolation methods for the initial conditions are described. As a key step, the available order reduction methods applicable to the models are presented, so the size and operability of the wind database can be reduced as much as possible. Finally, the data assimilation techniques and the model validation are presented.
Electrohydrodynamic Liquid Sheet Instability of Moving Viscoelastic Couple-Stress Dielectric Fluid Surrounded by an Inviscid Gas through Porous Medium
Authors: El-Sayed Mohamed Fahmy , Alanzi Agaeb Mahal
Published: July 2022

Viscoelastic liquid sheet of couple-stress type streaming with relative motion into an inviscid gas through porous molium is studied theoretically and quantitatively in this project. To derive the differential equations that describe liquids, gases, and the electric field, we linearized the governing equations of motion and continuity, Maxwell’s equations in quasi-static approximation, and the appropriate boundary conditions at the two interfaces. Then we used the normal mode method. It was demonstrated analytically that the solutions to these differential equations can be found for both symmetric and antisymmetric disturbances, respectively. We could not obtain an explicit form of the growth rates since we could not solve the dispersion relations for both situations because they were obtained in highly complex forms. The Mathematica program is used to solve the dimensionless forms of the dispersion relations numerically using Gaster’s theorem. Various influences on the stability analysis of the considered system have been studied in detail, and it is determined that the system in the presence of a porous material is more unstable than it would be otherwise. In a two-dimensional system, the antisymmetric disturbance case is found to be more unstable than the corresponding symmetric disturbance situation. Some characteristics, such as Wabe number, Ohnesorge number, and electric field, have destabilizing effects, whereas others, such as porosity, medium permeability, viscoelasticity parameter, gas-to-liquid viscosity ratio, and dielachic constants, have stabilizing effects. Finally, it is discovered that the gas-to-liquid velocity ratio plays a dual role in the stability condition depending on whether the gas-to-liquid velocity ratio U ≶ 1. In the past, we have only found evidence of very few previous studies.
Microencapsulation of Erythrocytes Extracted from Cavia porcellus Blood in Matrices of Tara Gum and Native Potato Starch
Authors: Ligarda-Samanez Carlos A. , Moscoso-Moscoso Elibet , Choque-Quispe David , Palomino-Rincón Henry , Martínez-Huamán Edgar L. , Huamán-Carrión Mary L. , Peralta-Guevara Diego E. , Aroni-Huamán Jimmy , Arévalo-Quijano José C. , Palomino-Rincón Wilbert , Cruz Germán De la , Ramos-Pacheco Betsy S. , Muñoz-Saenz Jenny C. , Muñoz-Melgarejo Mauricio
Published: July 2022

Ferropenic anemy is the leading iron deficiency disease in the world. The aim was to encapsulate erythrocytes extracted from the blood of Cavia porcellus, in matrices of tara gum and native potato starch. For microencapsulation, solutions were prepared with 20% erythrocytes; and encapsulants at 5, 10, and 20%. The mixtures were spray-dried at 120 and 140 °C. The iron content in the erythrocytes was 3.30 mg/g and between 2.32 and 2.05 mg/g for the encapsulates (p < 0.05). The yield of the treatments varied between 47.84 and 58.73%. The moisture, water activity, and bulk density were influenced by the temperature and proportion of encapsulants. The total organic carbon in the atomized samples was around 14%. The particles had diverse reddish tonalities, which were heterogeneous in their form and size; openings on their surface were also observed by SEM. The particle size was at the nanometer level, and the zeta potential (ζ) indicated a tendency to agglomerate and precipitation the solutions. The presence of iron was observed on the surface of the atomized by SEM-EDX, and FTIR confirmed the encapsulation due to the presence of the chemical groups OH, C-O, C-H, and N-H in the atomized. On the other hand, high percentages of iron release in vitro were obtained between 88.45 and 94.71%. The treatment with the lowest proportion of encapsulants performed at 140 °C obtained the best results and could potentially be used to fortify different functional foods.
Systematic Review and Meta-Analysis of the Efficacy of Interventions Applied during Primary Processing to Reduce Microbial Contamination on Pig Carcasses
Authors: Zdolec Nevijo , Kotsiri Aurelia , Houf Kurt , Alvarez-Ordóñez Avelino , Blagojevic Bojan , Karabasil Nedjeljko , Salines Morgane , Antic Dragan
Published: July 2022

Interventions from lairage to the chilling stage of the pig slaughter process are important to reduce microbial contamination of carcasses. The aim of this systematic review and meta-analysis was to assess the effectiveness of abattoir interventions in reducing aerobic colony count (ACC), Enterobacteriaceae, generic Escherichia coli, and Yersinia spp. on pig carcasses. The database searches spanned a 30 year period from 1990 to 2021. Following a structured, predefined protocol, 22 articles, which were judged as having a low risk of bias, were used for detailed data extraction and meta-analysis. The meta-analysis included data on lairage interventions for live pigs, standard processing procedures for pig carcasses, prechilling interventions, multiple carcass interventions, and carcass chilling. Risk ratios (RRs) for prevalence studies and mean log differences (MDs) for concentration outcomes were calculated using random effects models. The meta-analysis found that scalding under commercial abattoir conditions effectively reduced the prevalence of Enterobacteriaceae (RR: 0.05, 95% CI: 0.02 to 0.12, I2 = 87%) and ACC (MD: −2.84, 95% CI: −3.50 to −2.18, I2 = 99%) on pig carcasses. Similarly, significant reductions of these two groups of bacteria on carcasses were also found after singeing (RR: 0.25, 95% CI: 0.14 to 0.44, I2 = 90% and MD: −1.95, 95% CI: −2.40 to −1.50, I2 = 96%, respectively). Rectum sealing effectively reduces the prevalence of Y. enterocolitica on pig carcasses (RR: 0.60, 95% CI: 0.41 to 0.89, I2 = 0%). Under commercial abattoir conditions, hot water washing significantly reduced ACC (MD: −1.32, 95% CI: −1.93 to −0.71, I2 = 93%) and generic E. coli counts (MD: −1.23, 95% CI: −1.89 to −0.57, I2 = 61%) on pig carcasses. Conventional dry chilling reduced Enterobacteriaceae prevalence on pig carcasses (RR: 0.32, 95% CI: 0.21 to 0.48, I2 = 81%). Multiple carcass interventions significantly reduced Enterobacteriaceae prevalence (RR: 0.11, 95% CI: 0.05 to 0.23, I2 = 94%) and ACC on carcasses (MD: −2.85, 95% CI: −3.33 to −2.37, I2 = 97%). The results clearly show that standard processing procedures of scalding and singeing and the hazard-based intervention of hot water washing are effective in reducing indicator bacteria on pig carcasses. The prevalence of Y. enterocolitica on pig carcasses was effectively reduced by the standard procedure of rectum sealing; nevertheless, this was the only intervention for Yersinia investigated under commercial conditions. High heterogeneity among studies and trials investigating interventions and overall lack of large, controlled trials conducted under commercial conditions suggest that more in-depth research is needed.
Pasting, Rheological, and Tribological Properties of Rice Starch and Oat Flour Mixtures at Different Proportions
Authors: Chen Cunshe , Liu Ping , Cao Jinnuo , Ouyang Zhixuan , Pang Zhihua
Published: July 2022

Rice starch (RS) and oat flour (OF) were mixed in different proportions, and the pasting properties, particle size, rheology, and tribological properties of the mixed system were analyzed. According to the RVA results, OF inhibited the starch pasting, and the pasting temperature and peak viscosity of the mixed system increased. The particle size shifted toward the small particle size after the mixing of RS and OF components, and the RS/OF 9/1 particle size is the smallest. All samples exhibited shear dilution behavior and the viscosity of the system could be significantly increased at a 10 wt% RS content. At sliding speeds of >1 mm/s, the friction of the mixture is usually between the two individual components, which also confirmed the association or interaction between the two polymers.
Production of Indigo by Recombinant Escherichia coli with Expression of Monooxygenase, Tryptophanase, and Molecular Chaperone
Authors: Du Lingyan , Yue Jianming , Zhu Yiying , Yin Sheng
Published: July 2022

Indigo is an important pigment widely used in industries of food, cosmetics, and textile. In this work, the styrene monooxygenase StyAB from Pseudomonas putida was co-expressed with the tryptophanase TnaA and the chaperone groES-groEL in Escherichia coli for indigo production. Over-expression of the gene styAB endowed the recombinant E. coli AB with the capacity of indigo biosynthesis from indole and tryptophan. Tryptophan fermentation in E. coli AB generated about five times more indigo than that from indole, and the maximum 530 mg/L of indigo was obtained from 1.2 mg/mL of tryptophan. The gene TnaA was then co-expressed with styAB, and the tryptophanase activity significantly increased in the recombinant E. coli ABT. However, TnaA expression led to a decrease in the activity of StyAB and indigo yield in E. coli ABT. Furthermore, the plasmid pGro7 harboring groES-groEL was introduced into E. coli AB, which obviously promoted the activity of StyAB and accelerated indigo biosynthesis in the recombinant E. coli ABP. In addition, the maximum yield of indigo was further increased to 550 mg/L from 1.2 mg/mL of tryptophan in E. coli ABP. The genetic manipulation strategy proposed in this work could provide new insights into construction of indigo biosynthesis cell factory for industrial production.