bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Thermal Water Physical Exercise in Patients with Lower Limb Chronic Venous Insufficiency Monitored by Bioimpedance Analysis
Authors: Menegatti Erica , Pagani Anselmo , Avruscio Giampiero , Mucignat Marianna , Gianesini Sergio
Published: November 2020

Background: Lower limb chronic venous diseases (CVD) lead to possible edema. The aim of the present investigation was to study the effect of thermal aquatic standardize exercise on lower limb edema control in CVD patients assessed by bioimpedance analysis (BIA). Methods: Seventeen patients (34 legs) affected by CVD clinical class CEAP C3, 4c, Ep, As, Pr were included. All the cohort performed a standardized exercise protocol in thermal water environment for a total of five sessions. BIA, leg volume, and heart rate at rest were measured. Results: After the five exercise sessions, BIA showed a significant percentage of extracellular water (ECW) reduction from 42.1 ± 5.8 to 41.24 ± 5.5%; p < 0.001. Moreover, an improvement of resistance (p < 0.0009) and reactance (p < 0.009) was assessed. At the same time, the leg volume reduction rate was 15.7%, p <0.0001. A moderate-strong correlation was found between % ECW and leg volume variation (R = 0.59, p < 0.01). Finally, a significant HR at rest reduction was recorded, p < 0.0001. Conclusion: The investigated exercise protocol significantly affects the lower limb volume, and BIA parameters related to the tissue drainage improvement. The correlation founded between the ECW rate and volume variations suggest the possible use of BIA as a biomarker for monitoring the treatments aimed to reduce edema in CVD.
Association of SARC-F Questionnaire and Mortality in Prevalent Hemodialysis Patients
Authors: Lin Yu-Li , Hou Jia-Sian , Lai Yu-Hsien , Wang Chih-Hsien , Kuo Chiu-Huang , Liou Hung-Hsiang , Hsu Bang-Gee
Published: November 2020

Sarcopenia is common in patients undergoing chronic hemodialysis, which leads to poor outcomes. SARC-F (sluggishness, assistance in walking, rising from a chair, climb stairs, falls), a self-report questionnaire, is recommended as an easily applied tool for screening sarcopenia in older people. However, there are limited data regarding its use in patients undergoing chronic hemodialysis. Therefore, we aimed to evaluate the association between SARC-F and mortality in these patients. SARC-F questionnaire was applied in 271 hemodialysis patients (mean age 64.4 ± 14.3 years) at baseline. The association between SARC-F and mortality during a 24-month follow-up was analyzed. During this follow-up period, 40 patients (14.8%) died. The discriminative power of SARC-F score for predicting mortality was 0.716 (95% confidence interval (CI) = 0.659–0.769; p < 0.001). The best cut-off was a score ≥1, which provided 85.0% sensitivity, 47.2% specificity, 21.8% positive predictive value, and 94.8% negative predictive value. Kaplan–Meier curves showed that patients with SARC-F ≥ 1 exhibited a higher risk of mortality than those with SARC-F < 1 (p < 0.001). Moreover, a stepwise decline in survival with higher SARC-F scores was also observed. After full adjustments, SARC-F ≥ 1 was independently associated with increased mortality (hazard ratio = 2.87, 95% CI = 1.11–7.38; p = 0.029). In conclusion, SARC-F applied for sarcopenia screening predicted mortality in patients undergoing chronic hemodialysis.
MicroRNA in Gastric Cancer Development: Mechanisms and Biomarkers
Authors: Kipkeeva Fatimat , Muzaffarova Tatyana , Korotaeva Alexandra , Nikulin Maxim , Grishina Kristina , Mansorunov Danzan , Apanovich Pavel , Karpukhin Alexander
Published: November 2020

Gastric cancer (GC) is one of the most common and difficult diseases to treat. The study of signaling pathway regulation by microRNA provides information on the mechanisms of GC development and is the basis for biomarker creation. In this study, a circuit of microRNA interactions with signaling pathways was constructed. The microRNAs, associated with metastasis and chemoresistance, are described. In most cases, microRNAs in GC regulate the Wnt/β-catenin, PI3K/AKT/mTOR, RAS/RAF/ERK/MAPK, NF-kB, TGF-β, and JAK/STAT pathways. Part of the microRNA acts on several target genes that function in different pathways. This often leads to an intensification of the induced processes. MicroRNAs have also been described that have the opposite effect on different pathways, causing different functional consequences. By acting on several target genes, or genes associated with several pathways, microRNAs can function in a signaling network. MicroRNAs associated with metastasis most often interact with the Wnt/β-catenin pathway. MicroRNAs affecting chemoresistance, in most cases, affect the regulators of apoptosis and are associated with the PI3K/AKT/mTOR pathway. The characteristics of microRNAs proposed as candidates for GC biomarkers were analyzed. The currently developed diagnostic and prognostic panels of microRNAs are also considered.
Comparison of Magnetic Resonance Angiography and Digital Subtraction Angiography for the Assessment of Infrapopliteal Arterial Occlusive Lesions, Based on the TASC II Classification Criteria
Authors: Baubeta Fridh Erik , Ludwigs Karin , Svalkvist Angelica , Andersson Manne , Nordanstig Joakim , Falkenberg Mårten , A. Johnsson Åse
Published: November 2020

This paper aimed to study the agreement and repeatability, both intra- and interobserver, of infrapopliteal lesion assessment with magnetic resonance angiography (MRA), using the TransAtlantic Inter-Society Consensus (TASC) II criteria, with perioperative digital subtraction angiography (DSA) as a reference. Sixty-eight patients with an MRA preceding an endovascular infrapopliteal revascularization were included. Preoperative MRAs and perioperative DSAs were evaluated in random order by three independent observers using the TASC II classification. The results were analyzed using visual grading characteristics (VGC) analysis and Krippendorff’s α. No systematic difference was found between modalities: area under the VGC curve (AUCVGC) = 0.48 (p = 0.58) or intraobserver; AUCVGC for Observer 1 and 2 respectively, 0.49 (p = 0.85) and 0.53 (p = 0.52) for MRA compared with 0.54 (p = 0.30) and 0.49 (p = 0.81) for DSA. Interobserver differences were seen: AUCVGC of 0.63 (p < 0.01) for DSA and 0.80 (p < 0.01) for MRA. These results were confirmed using Krippendorff’s α for the three observers showing 0.13 (95% confidence interval (CI) −0.07–0.31) for MRA and 0.39 (95% CI 0.23–0.53) for DSA. Poor interobserver agreement was also found in the choice of a target vessel on preoperative MRA: Krippendorff’s α = 0.19 (95% CI 0.01‒0.36). In conclusion, infrapopliteal lesions can be reliably determined on preoperative MRA, but interobserver variability regarding the choice of a target vessel is a major concern that appears to affect the overall TASC II grade.
Mediastinal Nodular Lesions Synchronous to Lung Carcinoma on Frozen Section: Trap and Lesson
Authors: Parente Paola , Taurchini Marco , Castelvetere Marina , Di Micco Concetta Martina , Greco Domenico , Graziano Paolo
Published: November 2020

Thymoma is the most frequent neoplasm arising in the anterior mediastum. It usually presents as an enlarged central mass. In the literature, multiple thymoma is described as an unusual finding; rare variants have also been described, like the signet ring-like cell variant. Evidence of co-existence of signet ring-like cells and lymphocytes in small biopsies from nodular mediastinal lesions can lead to a diagnosis of metastatic carcinoma, mostly at frozen sections. Thymoma and pulmonary carcinoma are very rarely associated neoplasms. We present a case of two mediastinal lesions discovered during pulmonary carcinoma staging. At frozen section, a diagnosis of ‘epithelioid proliferation associated to lymphoid tissue’ was advanced on a sample of nodular lesions and of ‘carcinoma’ on pulmonary biopsy. Double AB Type Thymoma with a signet ring cell-like component, synchronous to pulmonary adenocarcinoma, was the diagnosis made on formalin fixed-paraffin embedded samples. Reporting the coexistence of these two entities can help pathologists and surgeons to establish the best management of similar patients.
Species Classification in a Tropical Alpine Ecosystem Using UAV-Borne RGB and Hyperspectral Imagery
Authors: Garzon-Lopez Carol X. , Lasso Eloisa
Published: November 2020

Páramos host more than 3500 vascular plant species and are crucial water providers for millions of people in the northern Andes. Monitoring species distribution at large scales is an urgent conservation priority in the face of ongoing climatic changes and increasing anthropogenic pressure on this ecosystem. For the first time in this ecosystem, we explored the potential of unoccupied aerial vehicles (UAV)-borne red, green, and blue wavelengths (RGB) and hyperspectral imagery for páramo species classification by collecting both types of images in a 10-ha area, and ground vegetation cover data from 10 plots within this area. Five plots were used for calibration and the other five for validation. With the hyperspectral data, we tested our capacity to detect five representative páramo species with different growth forms using support vector machine (SVM) and random forest (RF) classifiers in combination with three feature selection methods and two class groups. Using RGB images, we could classify 21 species with an accuracy greater than 97%. From hyperspectral imaging, the highest accuracy (89%) was found using models built with RF or SVM classifiers combined with a binary grouping method and the sequential floating forward selection feature. Our results demonstrate that páramo species can be accurately mapped using both RGB and hyperspectral imagery.
On the Motion of Substance in a Channel of a Network: Extended Model and New Classes of Probability Distributions
Authors: Vitanov Nikolay K. , Vitanov Kaloyan N. , Kantz Holger
Published: November 2020

We discuss the motion of substance in a channel containing nodes of a network. Each node of the channel can exchange substance with: (i) neighboring nodes of the channel, (ii) network nodes which do not belong to the channel, and (iii) environment of the network. The new point in this study is that we assume possibility for exchange of substance among flows of substance between nodes of the channel and: (i) nodes that belong to the network but do not belong to the channel and (ii) environment of the network. This leads to an extension of the model of motion of substance and the extended model contains previous models as particular cases. We use a discrete-time model of motion of substance and consider a stationary regime of motion of substance in a channel containing a finite number of nodes. As results of the study, we obtain a class of probability distributions connected to the amount of substance in nodes of the channel. We prove that the obtained class of distributions contains all truncated discrete probability distributions of discrete random variable ω which can take values 0,1,⋯,N. Theory for the case of a channel containing infinite number of nodes is presented in Appendix A. The continuous version of the discussed discrete probability distributions is described in Appendix B. The discussed extended model and obtained results can be used for the study of phenomena that can be modeled by flows in networks: motion of resources, traffic flows, motion of migrants, etc.
Cooperative Learning in Swedish Classrooms: Engagement and Relationships as a Focus for Culturally Diverse Students
Authors: Ferguson-Patrick Kate
Published: November 2020

The ongoing refugee crisis makes intercultural competence and culturally responsive education crucial issues in schools. At the same time, increased migration poses new challenges for social cohesion in countries around the world. How schools and classrooms can be fair and inclusive in terms of experiences and outcomes for migrant and refugee students is therefore a key question. This paper will explore the increase in migration of newly arrived students in Sweden, and how teachers in this country are catering for diverse students through cooperative learning. I explore cooperative learning as an inclusive and culturally responsive pedagogy that can be effectively used in schools to support all students and especially ‘refugee’ or newly arrived students. Using theory from cooperative learning and Stembridge (2020) as a theoretical framework, I particularly focus on analysis using two of Stembridge’s themes of Culturally Responsive Education: Engagement and Relationships to analyze Swedish primary school classroom observations and teacher interviews and find commonalities between these two themes and the key ideas in cooperative learning. This research is built on the premise that there is more need in education research for up to date observations into the classroom factors that support or hinder learning and the way that within-class groupings can support diversity and inclusivity. Cooperative learning allows participants to develop a commitment to fairness, social responsibility and a concern for others and this particularly caters for our diverse student populations.
Optimal Transient Search Algorithm-Based PI Controllers for Enhancing Low Voltage Ride-Through Ability of Grid-Linked PMSG-Based Wind Turbine
Authors: Qais Mohammed H. , Hasanien Hany M. , Alghuwainem Saad
Published: November 2020

This paper depicts a new attempt to apply a novel transient search optimization (TSO) algorithm to optimally design the proportional-integral (PI) controllers. Optimal PI controllers are utilized in all converters of a grid-linked permanent magnet synchronous generator (PMSG) powered by a variable-speed wind turbine. The converters of such wind energy systems contain a generator-side converter (GSC) and a grid-side inverter (GSI). Both of these converters are optimally controlled by the proposed TSO-based PI controllers using a vector control scheme. The GSC is responsible for regulating the maximum power point, the reactive generator power, and the generator currents. In addition, the GSI is essentially controlled to control the point of common coupling (PCC) voltage, DC link voltage, and the grid currents. The TSO is applied to minimize the fitness function, which has the sum of these variables’ squared error. The optimization problem’s constraints include the range of the proportional and integral gains of the PI controllers. All the simulation studies, including the TSO code, are implemented using PSCAD software. This represents a salient and new contribution of this study, where the TSO is coded using Fortran language within PSCAD software. The TSO-PI control scheme’s effectiveness is compared with that achieved by using a recent grey wolf optimization (GWO) algorithm–PI control scheme. The validity of the proposed TSO–PI controllers is tested under several network disturbances, such as subjecting the system to balanced and unbalanced faults. With the optimal TSO–PI controller, the low voltage ride-through ability of the grid-linked PMSG can be further improved.
Improving Municipal Solid Waste Management Strategies of Montréal (Canada) Using Life Cycle Assessment and Optimization of Technology Options
Authors: Malmir Tahereh , Ranjbar Saeed , Eicker Ursula
Published: November 2020

Landfilling of organic waste is still the predominant waste management method in Canada. Data collection and analysis of the waste were done for the case study city of Montréal in Canada. A life cycle assessment was carried out for the current and proposed waste management system using the IWM-2 software. Using life cycle assessment results, a non-dominated sorting genetic algorithm was used to optimize the waste flows. The optimization showed that the current recovery ratio of organic waste of 23% in 2017 could be increased to 100% recovery of food waste. Also, recycling could be doubled, and landfilling halved. The objective functions were minimizing the total energy consumption and CO2eq emissions as well as the total cost in the waste management system. By using a three-objective optimization algorithm, the optimized waste flow for Montréal results in 2% of waste (14.7 kt) to anaerobic digestion (AD), 7% (66.3 kt) to compost, 32% (295 kt) to recycling, 1% (8.5 kt) to incineration, and 58% (543 kt) to landfill.
Effect on the Thermal Properties of Mortar Blocks by Using Recycled Glass and Its Application for Social Dwellings
Authors: Flores-Alés Vicente , Pérez-Fargallo Alexis , Pulido Arcas Jesús A. , Rubio-Bellido Carlos
Published: November 2020

Including recycled waste material in cement mixes, as substitutes for natural aggregates, has resulted in diverse research projects, normally focused on mechanical capacities. In the case of recycled glass as an aggregate, this provides a noticeable improvement in thermal properties, depending on its dosage. This idea raises possible construction solutions that reduce the environmental impact and improves thermal behavior. For this research, an extended building typology that is susceptible to experiencing the risk of energy poverty has been chosen. The typology is typical for social housing, built using mortar blocks with crushed glass. First, the basic thermophysical properties of the mortars were determined by laboratory tests; after that, the dynamic thermal properties of representative constructive solutions using these mortars were simulated in seven representative climate zones in Chile. An analysis methodology based on periodic thermal transmittance, adaptive comfort levels and energy demand was run for the 21 proposed models. In addition, the results show that thermal comfort hours increases significantly in thermal zones 1, 2, 3 and 6; from 23 h up to 199 h during a year. It is in these zones where the distance with respect to the neutral temperature of the m50 solution reduces that of the m25 solution by half; i.e., in zone 1, from −429 °C with the m25 solution to −864 °C with the m50. This research intends to be a starting point to generate an analysis methodology for construction solutions in the built environment, from the point of view of thermal comfort.
Multi-Objective Optimization of the Halbach Array Permanent Magnet Spherical Motor Based on Support Vector Machine
Authors: Li Hongfeng , Cui Lifeng , Ma Zigang , Li Bin
Published: November 2020

The fundamental harmonic amplitude and waveform distortion rate of the air-gap flux density directly affect the performance of a permanent magnet spherical motor (PMSM). Therefore, in the paper, the axial air-gap magnetic field including the end leakage of the Halbach array PMSM is analyzed and optimized. In order to reduce the calculation time of the objective function, the air gap magnetic field model adopts a non-linear regression model based on support vector machine (SVM). At the same time, the improved grid search (GS) algorithm is used to optimize the parameters of SVM model, which improves the efficiency and accuracy of parameter optimization. Considering the influence of moment of inertia on the dynamic response of the motor, the moment of inertia of the PMSM is calculated. This paper takes the air gap magnetic density fundamental wave amplitude, waveform distortion rate and rotor moment of inertia as the optimization objectives. The particle swarm optimization (PSO) algorithm is used to optimize the motor structure with multiple objectives. The optimal structure design of the PMSM is selected from all of non-dominated solutions by the technique for order preference by similarity to an ideal solution (TOPSIS). The performance of the motor before and after the optimization is analyzed by the method of finite element (FEM) and experimental verification. The results verify the effectiveness and efficiency of the optimization method for the optimal structure designing of the complex PMSM.
Utilization of Boiler Slag from Pulverized-Coal-Combustion Power Plants in China for Manufacturing Acoustic Materials
Authors: Li Jing , Zhuang Xinguo , Leiva Carlos , Arenas Celia , Cornejo Ana , Querol Xavier , Moreno Natalia , Font Oriol , Fernández Pereira Constantino
Published: November 2020

The potential utilization of boiler slag generated in large amounts from pulverized-coal-combustion (PCC) power plants has recently drawn much attention due to the serious problems caused to ecosystems. In order to make maximal use of the boiler slag and reduce the environmental risk it poses, this study focused on manufacturing acoustic materials using boiler slag from Chinese PCC power plants. Three promising acoustic materials were successfully manufactured from up to 80% boiler slag with different grain sizes, with the addition of 20% Portland cement. The density and compressive strength of the products were inversely proportional and the sound absorption coefficient was positively proportional to the grain size of the boiler slag. The best sound absorption coefficient was obtained in products made from the coarsest fraction of the boiler slag (MS-C). Nonetheless, all the boiler-slag-based acoustic products still demonstrated compressive strength and densities comparable to those of other acoustic materials made of Spanish bottom ash or other conventional/recycled materials. The acoustic products made from the coarsest fraction (MS-C) and medium fraction (MS-M) of the boiler slag presented good noise absorption characteristics, like those of the commercial coarse porous cement that is traditionally used as an acoustic product. Furthermore, the acoustic products were characterized by very low leach ability of potentially hazardous elements. Consequently, the manufacture of acoustic materials is a very promising application for boiler slag. On the one hand, it consumes huge amounts of boiler slag that is generated in large amounts in China. On the other hand, the acoustic products can be used extensively to produce road acoustic barriers with a high sound absorption efficiency, no significant physical or mechanical limitations and no environmental implication.
Time and Cost Efficient Cloud Resource Allocation for Real-Time Data-Intensive Smart Systems
Authors: Qureshi Muhammad Shuaib , Qureshi Muhammad Bilal , Fayaz Muhammad , Zakarya Muhammad , Aslam Sheraz , Shah Asadullah
Published: November 2020

Cloud computing is the de facto platform for deploying resource- and data-intensive real-time applications due to the collaboration of large scale resources operating in cross-administrative domains. For example, real-time systems are generated by smart devices (e.g., sensors in smart homes that monitor surroundings in real-time, security cameras that produce video streams in real-time, cloud gaming, social media streams, etc.). Such low-end devices form a microgrid which has low computational and storage capacity and hence offload data unto the cloud for processing. Cloud computing still lacks mature time-oriented scheduling and resource allocation strategies which thoroughly deliberate stringent QoS. Traditional approaches are sufficient only when applications have real-time and data constraints, and cloud storage resources are located with computational resources where the data are locally available for task execution. Such approaches mainly focus on resource provision and latency, and are prone to missing deadlines during tasks execution due to the urgency of the tasks and limited user budget constraints. The timing and data requirements exacerbate the efficient task scheduling and resource allocation problems. To cope with the aforementioned gaps, we propose a time- and cost-efficient resource allocation strategy for smart systems that periodically offload computational and data-intensive load to the cloud. The proposed strategy minimizes the data files transfer overhead to computing resources by selecting appropriate pairs of computing and storage resources. The celebrated results show the effectiveness of the proposed technique in terms of resource selection and tasks processing within time and budget constraints when compared with the other counterparts.
Resource and Load Compatibility Assessment of Wind Energy Offshore of Humboldt County, California
Authors: Ortega Christina , Younes Amin , Severy Mark , Chamberlin Charles , Jacobson Arne
Published: November 2020

Floating offshore wind is being considered in northern California as indicated by the Bureau of Ocean Energy Management’s issuance of a lease consideration in the Humboldt Call Area. Humboldt County offers access to this enormous resource, but local electric load and transmission are limited. The potential impacts of offshore wind generators at three different scales were studied using a regional grid model of Humboldt County. Offshore wind generation was calculated using modeled wind speed data and 12-MW turbine specifications and integrated with projected load and historical generation. Offshore wind farms deployed in the Humboldt Call Area achieve annual capacity factors between 45% and 54% after losses and maintenance. Power output is variable between and within seasons, with full power output 30% of the time and no output approximately 20% of the time. Electricity from a 48-MW wind farm provides 22% of regional load with limited exports. A 144-MW wind farm serves 38% of local load, exporting 40% of its electricity with the extant 70-MW transmission capacity. A full build-out of 1836 MW would result in 88% curtailment with existing transmission. Across scenarios, offshore wind variability necessitates reliance on existing power plants to meet local demand in periods of low wind.
Diesel Engine Performance, Emissions and Combustion Characteristics of Biodiesel and Its Blends Derived from Catalytic Pyrolysis of Waste Cooking Oil
Authors: Mohamed Mohamed , Tan Chee-Keong , Fouda Ali , Gad Mohammed Saber , Abu-Elyazeed Osayed , Hashem Abdel-Fatah
Published: November 2020

This paper first describes a slow catalytic pyrolysis process used for synthesizing biodiesel from waste cooking oil (WCO) as a feedstock. The influence of variations in the catalyst type (sodium hydroxide and potassium hydroxide), and catalyst concentration (0.5, 1.0, 3.0, 5.0, 7.0 and 10.0% by weight) on both the pyrolysis temperature range and biodiesel yield were investigated. The results suggested that sodium hydroxide (NaOH) was more effective than potassium hydroxide (KOH) as catalysts and that the highest yield (around 70 wt.%) was observed for a NaOH concentration of about 1 wt.% The resultant pyrolysis temperature range was also significantly lower for NaOH catalyst, thus suggesting overall lower energy consumption. Compared to conventional diesel, the synthesized biodiesel exhibited relatively similar physical properties and calorific value. The biodiesel was subsequently blended with diesel fuel in different blend ratios of 0, 20, 40, 60, 80 and 100% by volume of biodiesel and were later tested in a compression ignition engine. Brake thermal efficiency and specific fuel consumption were observed to be worse with biodiesel fuel blends particularly at higher engine load above 50%. However, NOx emission generally decreased with increasing blend ratio across all engine load, with greater reduction observed at higher engine load. Similar observation can also be concluded for CO emission. In contrast, lower hydrocarbon (HC) emission from the biodiesel fuel blends was only observed for blend ratios no higher than 40%. Particulate emission from the biodiesel fuel blends did not pose an issue given its comparable smoke opacity to diesel observed during the engine test. The in-cylinder peak pressures, temperature and heat release rate of biodiesel fuel blends were lower than diesel. Overall, biodiesel fuel blends exhibited shorter ignition delays when compared to diesel fuel.
Hydrodynamics of Two-Phase Gas-Very Viscous Liquid Flow in Heat Exchange Conditions
Authors: Czernek Krystian , Witczak Stanisław
Published: November 2020

This paper presents the results of analyses of the impact of heat transfer conditions on the hydrodynamics of downward co-current annular flow in vertical tubes of very viscous liquid and gas. The research was conducted within the range of gas velocities of 0–30.0 m/s and liquid velocities of 0.001–0.254 m/s, while the viscosity was in the unprecedented range of 0.046–3.5 Pas. The research demonstrates that the volume and nature of the liquid waves with various amplitudes and frequencies arising on the surface of the film are relative to the flow rate and viscosity of the gas phase. At the same time, we found that, under the condition of liquid cooling, an increase in viscosity resulted in the formation of a smooth interface whereas, under the conditions where the liquid is heated at the end of the channel section, a greater number of capillary waves were formed. This research resulted in the development of new dependencies which take into account the influence of selected thermal and flow parameters (including mass fraction) on the values of volumes specific to very viscous liquid film flows. These dependencies improve the accuracy of calculation by 8–10% and are fully applicable to the description of the performance of an apparatus with a hydraulically generated liquid film.
Can High-Entropy Interlayers Develop Intermetallic-Free Welded Joints of Dissimilar Metals?
Authors: Waseem Owais Ahmed
Published: November 2020

The joining of two chemically dissimilar metals is a challenge due to the formation of hard and brittle intermetallic compounds (IMCs) in the diffusion layer. The joining of steel/Fe with aluminum (Al) and zirconium (Zr) alloy is particularly important for the automobile and nuclear industries, respectively. The Al–steel and Zr–steel joints produced by conventional fusion welding exhibit IMCs. The IMCs can enhance brittleness and cause catastrophic failure. This concept paper presents a novel idea of suppressing IMCs in welded joints using a high-entropy interlayer (HEI). It also discusses the potential candidates for HEIs and inspires research to exploit this new and promising research area.
Reducing Bridge Pier Scour Using Gabion Mattresses Filled with Recycled and Alternative Materials
Authors: Craswell Tom , Akib Shatirah
Published: November 2020

Scour is caused by the erosive action of flowing water, which causes materials from the bed and the banks of a river to be moved or unsettled. Hydraulic structures can be drastically impacted as a result of scour, which is why it is one of the most common causes of bridge failure around the world. With a predicted increase in climate conditions, the subsequent failure of hydraulic structures due to scour is likely to proliferate as the flooding of waterways is projected to rise. This study aims to determine the viability of introducing alternative materials to a scour countermeasure used in construction—gabion models—in a bid to improve the sustainability of a project whilst providing suitable scour mitigation measures. Existing literature was examined to comprehend the different scour countermeasures used, as well as the use of alternative materials that can be used as a scour countermeasure. A laboratory experiment was then carried out using a bridge pier embedded in a flume channel protected by gabion mattresses filled with alternative materials—stone, clothing and plastic—to analyse their effectiveness. The results demonstrate that stone filled gabions are most effective at reducing bridge pier scour. However, recycled clothing as a gabion fill could prove to be a viable alternative in construction projects, potentially leading to reduced construction costs and greater sustainability. However, more research on a greater scale is required to test this thesis.
The Liriodendron chinense MKK2 Gene Enhances Arabidopsis thaliana Salt Resistance
Authors: Chen Xinying , Wang Pengkai , Zhao Fangfang , Lu Lu , Long Xiaofei , Hao Zhaodong , Shi Jisen , Chen Jinhui
Published: November 2020

To adapt and sense environmental perturbations, including a variety of biotic and abiotic stress conditions, plants have developed disparate regulatory pathways. Mitogen-activated protein kinase (MAPK or MPK) signaling cascades are found widespread across the eukaryotic kingdoms of life. In plants, they may regulate signaling pathways aimed at resisting the stressful effects of low temperature, salt damage, drought, touch, and mechanical damage. To date, no conclusive studies into Liriodendron chinense (Hemsl.) Sarg MPK-related stress resistance signaling have been performed. In our study, we cloned three homologous L. chinense MAP kinase kinase family genes: LcMKK2, LcMKK4, and LcMKK6. LcMKK2 and LcMKK6 have their highest expression level in the root, while LcMKK4 is highly expressed in the stem. LcMKK2 showed upregulation in response to salt and cold stress conditions in L. chinense. To further analyze its gene function, we overexpressed LcMKK2 in wild-type Arabidopsis thaliana (L.) Heynh. and obtained transgenic plants. Overexpression of LcMKK2 caused a significant reduction in plant mortality (from 96% to 70%) in response to a 7-day 200 mM NaCl treatment. Therefore, we conclude that LcMKK2 is involved in a signaling response to salt stress, and it could thus prove an effective target gene for breeding strategies to improve Liriodendron salt tolerance.
Why Do Beavers Leave Home? Lodge Abandonment in an Invasive Population in Patagonia
Authors: Feldman Mariano J. , Girona Miguel Montoro , Grosbois Guillaume , Pietrek Alejandro G.
Published: November 2020

Research Highlights: Lodge abandonment by beavers is apparently a common phenomenon in Patagonia, but it is still poorly understood and we ignore what drives it. In relatively slow growth Nothofagus forests, resource depletion can impact abandonment while water availability may be a major driver in the semiarid steppe. Background and Objectives: North American beaver (Castor canadensis) was introduced in 1946 on the island of Tierra del Fuego (TDF) in southern Argentina. Since then, beavers have become a major disturbance affecting not only forest but also treeless steppe landscapes. Our goal was to determine the factors affecting lodge abandonment by beavers in two habitats of TDF: forest and steppe. Materials and Methods: A total of 47 lodges were surveyed between February and March from 2012 to 2014 in both habitat types, 22 in the forest and 25 in the steppe. To explain factors involved in lodge abandonment by beavers, we measured the following variables: water level variation, stream gradient, vegetation cover adjacent to shore and forest structure. Results: We recorded 24 abandonments events, with a similar proportion of lodges abandoned in both habitats. Our results revealed that lodge abandonment was mostly linked to water level fluctuations irrespective of habitat type. The water level at the entrances of the lodge generally decreased in abandoned lodges. Variables that characterize understory cover had some influence on lodge abandonment in the forest, and no effect in the steppe. Conclusions: Water level variation was associated with lodge abandonment in both habitats, and we found some evidence of resource depletion in the forest. However, we caution that changes in water level may be not only due to extrinsic factors but rather to beaver’s own activities or to a decay in pond maintenance following abandonment.
Livelihood Impacts of Plantation Forests on Farmers in the Greater Mekong Subregion: A Systematic Review of Plantation Forest Models
Authors: van der Meer Simo Alexander
Published: November 2020

Background and Objectives: Plantation forests remain a highly contested element of rural development. Successive reviews of large-scale plantations established under land concessions identify predominantly negative impacts on local farmers’ livelihoods. Although concession models of plantation development have been common in the global South, other models characterised by different forms of land tenure, labour arrangements, and plantation design have also emerged. The impacts of these models on the livelihoods of local farmers are likely to be more varied. This paper presents the results of a systematic review on the impacts of different models of plantation forests on the livelihoods of local farmers in the Greater Mekong Sub-region. Materials and Methods: Seventy-two of more than 1000 publications were identified as meeting review criteria and were assessed systematically to identify how plantation forests impacted on the natural, financial, human, physical, and social assets of proximate rural communities. Plantation models included: state forest plantations; land and land-sharing concessions; land purchase programs; and “enrolled”, contracted, and independent smallholders. Results: The results confirm those of earlier studies that land concessions delivered lasting livelihoods benefits only to few communities. A small number of positive examples among these cases demonstrate, however, that these plantation models are not necessarily detrimental to local livelihoods. Other plantation forest models, based on contract farming, land purchase, and independent smallholders have generally brought economic benefits to local people, although differentially. Research Highlights and Conclusions: Overall, this review suggests that plantation forests are not inherently positive or negative for local livelihoods, and all plantation models have the potential to contribute positively to local livelihoods. Future research on this topic needs to adopt more holistic livelihoods perspectives.
The Nutrient Status of Plant Roots Reveals Competition Intensities in Rubber Agroforestry Systems
Authors: Wu Junen , Zeng Huanhuan , Zhao Fan , Chen Chunfeng , Jiang Xiaojin , Zhu Xiai , Wang Pingyuan , Wu Zhixiang , Liu Wenjie
Published: November 2020

Controversial competition theories may confuse the current understanding of belowground plant competition and thus result in incorrect diagnoses and mitigation strategies for nutrient competition. As such, the management of nutrient competition is a major challenge in the application and development of rubber agroforestry systems (AFSs). To explore the effects of plant competition on the nutrient status of rubber AFSs, this study measured the carbon, nitrogen, and phosphorus concentrations of the litter and soil and in plant leaves, stems, and roots from five rubber plantations (i.e., rubber monocultures and rubber mixed with cocoa, coffee, tea, and Flemingia macrophylla (Willd.) Merr., 1910)). The relative competition intensity indexes were calculated to evaluate the competition intensity of each mixed-species system, and Bayesian networks were established to investigate the linkage effects of interspecific competition for nutrients. This study demonstrated that rubber trees had weak competition with cocoa trees, moderate competition with F. macrophylla and tea trees, and intense competition with coffee trees. With the increase in competition intensity, the negative effects of interspecific competition on soil gradually offset the improvement in soil nutrients achieved with intercropping. Nitrogen and phosphorous translocation from the stems to the roots was enhanced by competition. However, enhanced nutrient allocation to roots may have led to insufficient nitrogen and phosphorous supplies in plant leaves. The quality of the litter therefore decreased because the nutrient status of fallen leaves determines the initial litter conditions. Such consequences may reduce the release of nutrients from the litter to the soil and thus increase soil nutrient depletion. This study revealed that competition effects were most obvious for the root nutrient status, followed by the stem and leaf nutrient statuses. Moreover, this study further demonstrated that the nutrient concentration of plant roots can better indicate the intensity of nutrient competition than the nutrient concentration of other plant organs.
A Multi-Layer Model for Transpiration of Urban Trees Considering Vertical Structure
Authors: Yun Seok Hwan , Park Chae Yeon , Kim Eun Sub , Lee Dong Kun
Published: November 2020

As the intensity of the urban heat island effect increases, the cooling effect of urban trees has become important. Urban trees cool surfaces during the day via shading, increasing albedo and transpiration. Many studies are being conducted to calculate the transpiration rate; however, most approaches are not suitable for urban trees and oversimplify plant physiological processes. We propose a multi-layer model for the transpiration of urban trees, accounting for plant physiological processes and considering the vertical structure of trees and buildings. It has been expanded from an urban canopy model to accurately simulate the photosynthetically active radiation and leaf surface temperature. To evaluate how tree and surrounding building conditions affect transpiration, we simulated the transpiration of trees in different scenarios such as building height (i.e., 1H, 2H and 3H, H = 12 m), tree location (i.e., south tree and north tree in a E-W street), and vertical leaf area density (LAD) (i.e., constant density, high density with few layers, high density in middle layers, and high density in lower layers). The transpiration rate was estimated to be more sensitive to the building height and tree location than the LAD distribution. Transpiration-efficient trees differed depending on the surrounding condition and plant location. This model is a useful tool that provides guidelines on the planting of thermo-efficient trees depending on the structure or environment of the city.
A Topographic Wetness Index for Forest Road Quality Assessment: An Application in the Lakeland Region of Finland
Authors: Waga Katalin , Malinen Jukka , Tokola Timo
Published: November 2020

Research Highlights: A Topographic Wetness Index calculated using LiDAR-derived elevation models can help in identifying unpaved forest roads that need maintenance. Materials and Methods: Low-pulse LiDAR data were used to calculate a Topographic Wetness Index to predict unpaved forest roads’ quality. Results: The results of this analysis and comparison of road-quality features derived from LiDAR data at resolutions of 1, 10 and 25 m for assessing road quality in the boreal forests of Finnish Lakeland show that the wetness index can predict road quality correctly in up to 70% of cases and up to 86% when combined with other auxiliary GIS-based variables. Conclusions: Road-quality assessments, using airborne LiDAR data, can greatly help forest managers to decide which sections of the ageing road network will benefit the most from maintenance, while reducing the need of field visits.
Low-Cost Methods to Assess Beer Quality Using Artificial Intelligence Involving Robotics, an Electronic Nose, and Machine Learning
Authors: Gonzalez Viejo Claudia , Fuentes Sigfredo
Published: November 2020

Beer quality is a difficult concept to describe and assess by physicochemical and sensory analysis due to the complexity of beer appreciation and acceptability by consumers, which can be dynamic and related to changes in climate affecting raw materials, consumer preference, and rising quality requirements. Artificial intelligence (AI) may offer unique capabilities based on the integration of sensor technology, robotics, and data analysis using machine learning (ML) to identify specific quality traits and process modifications to produce quality beers. This research presented the integration and implementation of AI technology based on low-cost sensor networks in the form of an electronic nose (e-nose), robotics, and ML. Results of ML showed high accuracy (97%) in the identification of fermentation type (Model 1) based on e-nose data; prediction of consumer acceptability from near-infrared (Model 2; R = 0.90) and e-nose data (Model 3; R = 0.95), and physicochemical and colorimetry of beers from e-nose data. The use of the RoboBEER coupled with the e-nose and AI could be used by brewers to assess the fermentation process, quality of beers, detection of faults, traceability, and authentication purposes in an affordable, user-friendly, and accurate manner.
Fog Computing for Smart Cities’ Big Data Management and Analytics: A Review
Authors: Badidi Elarbi , Mahrez Zineb , Sabir Essaid
Published: November 2020

Demographic growth in urban areas means that modern cities face challenges in ensuring a steady supply of water and electricity, smart transport, livable space, better health services, and citizens’ safety. Advances in sensing, communication, and digital technologies promise to mitigate these challenges. Hence, many smart cities have taken a new step in moving away from internal information technology (IT) infrastructure to utility-supplied IT delivered over the Internet. The benefit of this move is to manage the vast amounts of data generated by the various city systems, including water and electricity systems, the waste management system, transportation system, public space management systems, health and education systems, and many more. Furthermore, many smart city applications are time-sensitive and need to quickly analyze data to react promptly to the various events occurring in a city. The new and emerging paradigms of edge and fog computing promise to address big data storage and analysis in the field of smart cities. Here, we review existing service delivery models in smart cities and present our perspective on adopting these two emerging paradigms. We specifically describe the design of a fog-based data pipeline to address the issues of latency and network bandwidth required by time-sensitive smart city applications.
An Elementary Model for a Self-Accelerating Outward Propagating Flame Subject to the Rayleigh–Taylor Instability: Transition to Detonation
Authors: Kagan Leonid , Sivashinsky Gregory
Published: November 2020

Within the Boussinesq approximation, an elementary model for the deflagration-to-detonation transition triggered by self-acceleration of an expanding flame is formulated and explored. The self-acceleration is sustained by the intrinsic Rayleigh–Taylor instability until the Deshaies–Joulin deflagrability threshold is reached, followed by an abrupt transition to detonation. Emergence of the threshold is caused by positive feedback between the accelerating flame and the flame-driven pressure shock that results in the thermal runaway when the flame speed reaches a critical level. The model offers a simple mechanism that may be responsible for the transition to detonation in thermonuclear supernovae.
An Exploratory Study on the Diverse Uses and Benefits of Locally-Sourced Fruit Species in Three Villages of Mpumalanga Province, South Africa
Authors: Shai Kutullo Nick , Ncama Khayelihle , Ndhlovu Peter Tshepiso , Struwig Madeleen , Aremu Adeyemi Oladapo
Published: November 2020

Globally, the potential of indigenous and neglected fruit species is continuously being recognized. In the current study, we explored the uses and benefits of locally available fruit species among the Mapulana people in Bushbuckridge Local Municipality. An ethno-botanical survey was conducted using in-depth interviews to record the names of the fruit species, their uses, seasonal availability, and occurrence in three villages, namely, Mokhololine, Motlamogatsane, and Rooiboklaagte B. Forty-one (41) participants aged 23 to 89 years old, identified by community members as knowledgeable on the utilization of fruit species, were interviewed. The frequency of citation (FC), use value (UV), and use report (UR) of the locally sourced fruit species were determined. The study revealed thirty-one (31) indigenous/naturalized plants belonging to 17 families with Anacardiaceae (four species) and Rubiaceae (three species) as the dominant ones. Approximately 48% of the 31 plants had FC of 100%, suggesting their high popularity in the study area. The identified plants had diverse uses that were categorized into six (6) groups and mainly dominated by food (59%) and medicine (34%). Strychnos madagascariensis had the highest (0.56) UV while Berchemia discolor, Parinari capensis, Parinari curatellifolia, and Sclerocarya birrea had the highest (6) URs. Overall, these locally sourced fruit species still play a significant role in the daily lives of the Mapulana people. The identified fruit species have the potential to be considered as alternative sources to meet the dietary requirements and health needs, especially in rural communities.