bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Modification of Carbon Nanotubes in Silicone–Polyurethane for Improved Mechanical and Anticorrosion Properties
Authors: Hao Guoqiang , Li Xia , Wang Shuchuan , Wang Shirong , Ryu Moonhee , Yang Jingxia
Published: March 2023

Carbon nanotubes (CNT) were dispersed into homemade silicone–polyurethane (SPU) resin in order to enhance their mechanical and anticorrosion ability. Before mixing with SPU, CNT were modified by four different approaches to improve their dispersion in SPU, and the surface of CNT were covered by SiO2–TiO2 nanoparticles, -NH2 groups, epoxy groups or isocyanate groups, respectively. The structures of the modified CNTs were checked by XRD, FTIR, and SEM. After being dispersed in SPU to form a composite coating, the one with SiO2–TiO2 nanoparticles modified CNT exhibited the best mechanical properties and chemical resistance (low water absorption), and its corrosion current density (icorr) was only 9.246 × 10−9 A cm2, which is four orders of magnitude lower than the icorr value of the coating with unmodified CNT (1.599 × 10−5 A/cm2). This may be because the covered SiO2–TiO2 nanoparticle increased the roughness of the CNT surface, which can improve their dispersion in SPU resin.
Influence of Plasma Electrolytic Oxidation of Cast Al-Si Alloys on Their Phase Composition and Abrasive Wear Resistance
Authors: Student Mykhailo , Pohrelyuk Iryna , Padgurskas Juozas , Posuvailo Volodymyr , Hvozdets’kyi Volodymyr , Zadorozhna Khrystyna , Chumalo Halyna , Veselivska Halyna , Kovalchuk Ihor , Kychma Andrii
Published: March 2023

The microhardness and abrasive wear resistance of cast Al-Si alloys after plasma-electrolytic oxidation (PEO) in a weakly alkaline basic electrolyte (3 g/L KOH + 2 g/L Na2SiO3), as well as with the addition of H2O2, were determined. X-ray analysis showed that the PEO layer comprises two oxide phases, namely α-Al2O3 and γ-Al2O3, as well as sillimanite -Al2O3 · SiO2 and a small percentage of mullite -3 Al2O3 · 2SiO2. Silicon is present in the structure of the oxide layer, and its percentage is greater than that of the alloys in their initial state. It has been shown that the characteristics of PEO layers on AK9 and AK12 silumins synthesized in an electrolyte of basic composition increase (microhardness up to 900–1000 HV and abrasive wear resistance by 14–57 times). The formation of PEO layers in the base electrolyte with the addition of 3 g/L of hydrogen peroxide intensifies the synthesis process and promotes the formation of high-temperature oxide phases (in particular, corundum). The abrasive wear resistance of both silumins with PEO layers synthesized in such an electrolyte increases by 30–70%.
Water-Free SbOx ALD Process for Coating Bi2Te3 Particles
Authors: Lehmann Sebastian , Mitzscherling Fanny , He Shiyang , Yang Jun , Hantusch Martin , Nielsch Kornelius , Bahrami Amin
Published: March 2023

We developed a water-free atomic layer deposition (ALD) process to homogeneously deposit SbOx using SbCl5 and Sb-Ethoxide as precursors, and report it here for the first time. The coating is applied on Bi2Te3 particles synthesized via the solvothermal route to enhance the thermoelectric properties (i.e., Seebeck coefficient, thermal and electrical conductivity) via interface engineering. The amorphous character of the coating was shown by the missing reflexes on the X-ray diffractograms (XRD). A shift from the oxidation state +III to +V of the Sb species was observed using X-ray photoelectron spectroscopy (XPS), indicating increased thickness of the SbOx coating layer. Additionally, a peak shift of the Sb 3d5/2 + O 1s peak indicated increased n-type doping of the material. Electrical measurements of spark plasma-sintered bulk samples confirmed the doping effect on the basis of decreased specific resistivity with increasing SbOx layer thickness. The Seebeck coefficient was improved for the coated sample with 500 cycles of SbOx, while the total thermal conductivity was reduced, resulting in enhancement of the zT. The results distinctly show that surface engineering via powder ALD is an effective tool for improving key properties of thermoelectric materials like electrical conductivity and the Seebeck coefficient.
Study on Corrosion Resistance of LDH/Micro-Arc Oxidation Composite Superhydrophobic Coatings on AZ31 Magnesium Alloy
Authors: Liu Dongjie , Liu Jing , Liu Guangyu , Xie Yuntao , Duan Zongfan
Published: March 2023

Because of some defects such as holes and cracks, the corrosion resistance of micro-arc oxidation coating needs to be improved by surface modification. In this paper, LDH/MAO film with a micro-/nano-structure is constructed on the surface of AZ31 magnesium alloy by controlling the composition and concentration of the hydrothermal solution. The superhydrophobic surface is successfully constructed by coating an OTES modifier on the surface of LDH/MAO film by the spin-coating method. The surface morphologies, contact angles, and corrosion resistance of composite coatings are tested. The results show that the OTES-LDH/MAO composite coatings of magnesium alloy can seal the defects in the MAO film well to achieve a superhydrophobic effect and better corrosion resistance. Compared with a MgO ceramic film, the water contact angle of OTES-LDH/MAO composite coatings is increased from 38° to 155°; the corrosion potential increases by 0.7 V, the corrosion current density and polarization resistance decreases and increases by four orders of magnitude, respectively; and the corrosion resistance becomes much higher than that of MAO film.
Study on Fatigue Performance of 2200 MPa High-Strength Wire of Main Cables Based on FE-SAFE
Authors: Li Hongtao , Zhou Zhubing , Liu Sen , Wei Leyong , Zhao Jun , Su Han
Published: March 2023

In order to estimate the fatigue life of 2200 MPa high-strength steel wire for main cables at the outlet of the cable saddle, a fatigue loading test of a single steel wire was designed, and the value of the friction coefficient in finite element simulation and the scale factor in fatigue life analysis were determined. The fatigue life of the steel wire was analyzed by two-stage modelling. The results showed that the fatigue life of steel wire can be simulated effectively when the friction coefficient is 0.21 and the scale factor is 1.15. The fatigue life of 2200 MPa main cable wire at the saddle outlet is 4.78 million loading cycles. The research results laid a foundation for practical engineering application of high-strength steel wire for 2200 MPa main cables.
Analysis of the Dynamic Thermal Barrier in Building Envelopes
Authors: Mučková Veronika , Kalús Daniel , Koudelková Daniela , Kurčová Mária , Straková Zuzana , Sokol Martin , Ingeli Rastislav , Šťastný Patrik
Published: March 2023

This article focuses on the investigation of the dynamic thermal barrier (TB) and dynamic thermal resistance (DTR) of the building envelope. The aim is to analyze the DTR as a function of the temperature change of the heat transfer medium supplied to the dynamic TB layer and to determine the energy potential of several materially different fragments of the building envelope. The functions of TB and DTR depend on the uniform and continuous maintenance of temperature in a given layer of the building structure. The methodology is based on the analysis and synthesis of thermal resistance calculation, wall heating, and computer simulation. The research results show that the relatively low mean temperature of the heat transfer medium of approximately θm = 17 °C delivered to the TB layer represents RDTR = up to 30 ((m2·K)/W) for an equivalent dynamic thermal insulation thickness of 1000 mm for a required standard resistance of RSTANDARD = 6.50 ((m2·K)/W) of the individual fragments analyzed with static thermal insulation of 65 to 210 mm. The energy potential of a thermal barrier (TB) represents an increase of approximately 500% in the thermal resistance and up to 1500% in the thickness of the dynamic thermal insulation. Further research on the dynamic thermal barrier and verification of the results of the parametric study will continue with comprehensive computer simulations and experimental measurements on the test cell.
Effects of Surface Modification and Heat Treatment on the Storage and Application Properties of Waterborne Zinc-Based Paint
Authors: Liu Liran , Zhou Yangtao , Li Qingpeng , Yin Yuejun , Zhang Wei , Wang Na
Published: March 2023

The high activity of metallic zinc particles with water, and consequently the short pot lift of a mixed waterborne organic zinc-rich paint, are the most well-known problem for their application. In this study, zinc powders were modified by silane-crosslinked potassium silicate and the paint’s pot life was prolonged. Electron microscopy analysis showed that the zinc spheres in the waterborne paint were encapsulated by the shell consisted of silane-crosslinked potassium silicate and resin. The modification allowed the paint stay fluid after storage for 36 h. Nevertheless, the thickened shell was found to deteriorate the cathodic protection provided by the zinc particles. As a repair strategy, the post-heat treatment performing on the coating could awaken the protective effect of zinc powders. The anti-corrosion performance of the repaired coatings was confirmed by electrochemical tests and salt spray tests.
Modelling Qualitative Data from Repeated Surveys
Authors: Corduas Marcella , Piccolo Domenico
Published: March 2023

This article presents an innovative dynamic model that describes the probability distributions of ordered categorical variables observed over time. For this purpose, we extend the definition of the mixture distribution obtained from the combination of a uniform and a shifted binomial distribution (CUB model), introducing time-varying parameters. The model parameters identify the main components ruling the respondent evaluation process: the degree of attraction towards the object under assessment, the uncertainty related to the answer, and the weight of the refuge category that is selected when a respondent is unwilling to elaborate a thoughtful judgement. The method provides a tool to quantify the data from qualitative surveys. For illustrative purposes, the dynamic CUB model is applied to the consumers’ perceptions and expectations of inflation in Italy to investigate: (a) the effect of the COVID pandemic on inflation beliefs; (b) the impact of income level on respondents’ expectations.
Rehabilitation of Skin Bacterial Counts to Assess the Short-Term Impact of Ingredients in Topical Applications—Presenting a Culture-Based Viability Score
Authors: Robe Patrick , Jarrin Cyrille , Zanchetta Catherine , Dupont Joran , Chapuis Emilie , Scandolera Amandine , Auriol Daniel , Reynaud Romain
Published: March 2023

Our understanding of the interplay between skin microbiota and the skin’s health status is growing. Consequently, the cosmetics industry is increasingly concerned with ensuring that beauty products do not adversely affect this microbiota and skin health. Prior to implementing demanding sequencing-based analyses of skin microbiota, an agile approach is needed to provide a first estimate of the short-term impact of cosmetic ingredients on the viability of skin microbiota. A standardized methodology, including topical applications, swabbing, and bacterial colony-counting, was set up and evaluated. The skin’s bacterial density was longitudinally monitored after repeated applications of two reference compounds: physiological saline, assumed to be neutral, and chlorhexidine, expected to have a perturbing effect. Healthy volunteers were enrolled in six clinical studies, involving application of physiological saline and chlorhexidine to both sides of the neck. Over 7 days, skin swabs were collected at defined time points, and bacterial density was assessed based on a classical colony-counting approach. The longitudinal assessment of skin bacterial density proved highly robust, with a very steady inter-seasonal impact of chlorhexidine on skin bacterial density. This consolidated methodology supported the development of an easy-to-understand viability score that quantifies the intrinsic short-term impact of an ingredient on skin bacterial populations.
New Composite Materials Based on Chitosan Films Reinforced with Chitin Nanofibrils for Cosmetic Application
Authors: Kodolova-Chukhontseva Vera V. , Rozova Elena Y. , Dresvyanina Elena N. , Nashchekina Yulia A. , Dobrovol’skaya Irina P. , Vlasova Elena N. , Bystrov Sergey G. , Popova Elena N. , Maslennikova Tatiana P. , Yudin Vladimir E. , Morganti Pierfrancesco
Published: March 2023

Bioactive biodegradable chitosan films containing chitin nanofibrils have been developed for use as face masks in cosmetology. It was found that thermal modification of chitosan films promotes the transformation of the polymer into insoluble form without the use of alkali or aldehydes. The structure and properties of the films were studied by IT spectroscopy, atomic force microscopy, thermogravimetric analysis, and X-ray structural analysis. Analysis of infrared (IR) spectra showed that the addition of nanofibrils accelerates the process of thermal transformation in the composite films. This is apparent from the observed increase in the intensity ratio of 1030 cm−1\1580 cm−1 peaks in the spectrum of the thermally treated film (as compared to the spectrum of the initial sample and the spectrum of a chitosan film without chitin nanofibrils). The prepared composite films containing chitin nanofibrils possess improved mechanical characteristics: tensile strength 99 MPa and tensile strain 14%. The tetrazolium bromide (MTT) test revealed good viability of human dermal fibroblasts cultivated in the presence of the conditioned medium obtained after incubation of all types of films in the nutrient medium. The used process of thermal modification of chitosan and composite films (which is efficient and environmentally safe) allows one to prepare bioactive materials for applications in medicine and cosmetology.
Computer-Assisted Reconstruction of an Orbital Trauma Case Treated with a Patient-Specific Titanium Prosthesis
Authors: Darwich Mhd Ayham , Darwich Khaldoun , Yousof Khalil , Szávai Szabolcs , Nazha Hasan Mhd , Juhre Daniel
Published: March 2023

Virtual planning is ideally suited for maxillofacial operations as it allows the surgeon to assess the bony and critical neurovascular structures and enables him to plan osteotomies and fracture reductions. This study aims to propose the use of titanium-based patient-specific implants (PSI), along with virtual surgical planning to assess the advantages and the complications in a case of orbital reconstruction. A three-dimensional model of the skull was generated using computed tomography (CT) data of a female patient using Mimics software (version 19, Materialize, Leuven, Belgium). Numerical PSI models were designed using 3-Matic software (version 13, Materialize, Leuven, Belgium) and the non-affected orbit as a template. Surgical virtual planning showed the suitability of the use of the numerical models in traumatic surgical rehabilitation. Moreover, the digital printing process enabled the trial of the designed PSIs on the patient’s face before the surgery. Reconstruction Biomechanical studies are an essential part of understanding the limits of maxillofacial traumas. The surgical results confirmed the virtual predictions, and the orbital reconstruction seems to be more enhanced and facilitated.
Investigation on Micro-Hardness, Surface Roughness and SEM of Nano TiO2/B4C/Graphene Reinforced AA 7075 Composites Fabricated by Frictional Stir Processing
Authors: Hotami Majed Mohammed , Yang Shengyuan
Published: March 2023

The current work seeks to discover and choose the proper friction stir processing (FSP) settings for aluminum alloy 7075 surface composites enhanced by adding three unique nanoparticles of titanium dioxide (TiO2), B4C, and graphene for superior performance. FSP is the only method that produces higher amounts of particle distribution and nanoscale reinforcing. For the sample fabrication, a special relatively high rotational speed of 2000 rpm and feed rate of 45 mm/min were tested with a suitable range of processing parameters (800–2000 rpm, 25–45 mm/min). To measure the micro-hardness and surface roughness of three different surface nano composites, they were studied under various FSP conditions. The findings showed that surface composites produced at high rotational speeds of 1400 rpm and 45 mm/min decreased surface roughness and granule distributions by 39% and 73%, respectively, and increased surface micro-hardness by 54%. According to the microstructure investigations, good bonding was produced between the AA7075 substrate generated at 1200 rpm and the base metal and friction stir processed specimens at 800 and 2000 rpm. The AA7075/B4C surface composite produced at 1200 rpm rotating speed had a higher micro-hardness than the other two surface composites.
Complex Vascular Resections for Retroperitoneal Soft Tissue Sarcoma
Authors: Devaud Nicolas A. , Butte Jean M. , De la Maza Juan C. , von Mühlenbrock Hugo Sebastian , Cardona Kenneth
Published: March 2023

Retroperitoneal sarcomas (RPSs) are locally aggressive tumors that can compromise major vessels of the retroperitoneum including the inferior vena cava, aorta, or main tributary vessels. Vascular involvement can be secondary to the tumor’s infiltrating growth pattern or primary vascular origin. Surgery is still the mainstay for curing this disease, and resection of RPSs may include major vascular resections to secure adequate oncologic results. Our improved knowledge in the tumor biology of RPSs, in conjunction with the growing surgical expertise in both sarcoma and vascular surgical techniques, has allowed for major vascular reconstructions within multi-visceral resections for RPSs with good perioperative results. This complex surgical approach may include the combined work of various surgical subspecialties.
On the Occurrence of Arbuscular Mycorrhizal Fungi in a Bryophyte Community of Punta Lara Natural Reserve, Buenos Aires, Argentina
Authors: Valdés Fabricio Emanuel , Peralta Denilson Fernandes , Velázquez María Silvana , Covacevich Fernanda , Becerra Alejandra Gabriela , Cabello Marta Noemí
Published: March 2023

The evolutionary history of the symbiotic association between arbuscular mycorrhizal fungi (AMF) and embryophytes dates back to the Devonian period. Previous ecological and physiological studies have described the presence of arbuscules, inter- and intracellular hyphae, vesicles, coils and spores, in liverworts and hornworts, which are considered absent in mosses. This study aimed to report the presence of AMF in a community of bryophytes (mosses and liverworts) from Punta Lara Natural Reserve, Argentina. Senescent and green sections of gametophytes were stained and, following microscopic observation, revealed AMF structures. We found intracellular hyphae, vesicles, spores and sporocarps associated with thallus and rhizoids of mosses and liverworts and senescent moss caulidia. The morphological characterization of spores resulted in the determination of Rhizophagus intraradices and Dominikia aurea. The species D. aurea is reported for the first time for Argentina. Sequencing of the D1 variable domain of the LSUrDNA from AMF spores mixes plus hyphae resulted in high similitude to the Dominikia sequences available from NCBI. This study reported the presence of AMF associated with declining and senescent gametophytes of bryophytes (mosses and liverworts) in a Natural Reserve in Argentina. These findings open up new lines of study, which should further investigate these associations and their diversity, physiology and significance.
Natal Philopatry in a Long-Lived Species: The Return of Reproductive River Turtles Marked and Released as Hatchlings
Authors: Nagle Roy D. , Russell Travis J. , Grant Christopher J. , Innerst Melissa , Strawser Seth J.
Published: March 2023

Natal philopatry—the return of an animal to its place of birth to reproduce—can shape population genetics and link essential habitats across generations, yet examples from long-term mark-recapture studies are rare. In this study, we observed 136 nests of Northern Map Turtles at Mount Union, Pennsylvania, between 2000 and 2008 and then individually marked and released 691 hatchling turtles into the Juniata River. During a recent six-year period (from 2017 to 2022), 46 of the hatchling-marked turtles (6.7%) returned to Mount Union as adult females to nest. The ages of these turtles ranged from 11–22 years at first recapture, and their mean age was 17 years. Forty-one hatchling-marked females came from observed nests with known mothers, and remarkably, just four (of 52) mothers produced over half of the returning females. The minimum ages of the oldest female turtles were estimated at 39 years, with reproductive lifetimes of at least 23 years. Our results indicate that a few long-lived Super Moms have made extraordinary contributions to hatchling recruitment and population viability of Northern Map Turtles of the Juniata River. The timing of release also had a significant influence on the probability of a turtle returning, with hatchlings released in May returning at a higher rate than those released earlier in the spring. In addition, morphological characteristics of hatchling-marked females suggest that factors causing shell shape abnormalities in adult turtles have not abated over the past two decades as previously theorized and likely involve exposure of juveniles to contaminants in the Juniata River rather than any maternal influence.
Elephants Not in the Room: Systematic Review Shows Major Geographic Publication Bias in African Elephant Ecological Research
Authors: Gross Rachael B. , Heinsohn Robert
Published: March 2023

African savanna elephants (Loxodonta africana) are a keystone species in African ecosystems. As a result of increasing anthropogenic pressure, elephant populations have declined significantly in the last two centuries. Research on a broad sample of these populations is necessary to inform management strategies over a range of environmental and socio-political conditions. In order to evaluate the current state of literature that is informing evidence-based management and conservation of elephants, we systematically reviewed all research published on the ecology of African elephants from the last 20 years (492 publications). We contrasted the geographic distribution of published research against the 2016 IUCN elephant census. We found several statistically significant biases in the geographic distribution of elephant research. South Africa has 4.54% of the total elephant population and accounted for 28.28% of all research publications. Kenya has 5.49% the total elephant population but accounts for 20.6% of the research. Conversely, Botswana has 31.68% of the total elephant population but accounts for only 9.29% of the research and Zimbabwe has 19.89% of the total elephant population with only 10.50% of research. We also found that 41.85% of areas with ~60,100 elephants have not had any research published on their populations in the last 20 years. This publication imbalance may encourage management strategies that are overly dependent on misrepresentative information from a small subset of the elephant population. We recommend that (1) marginalised areas with large elephant populations (e.g., Botswana and Zimbabwe) should receive higher priority for future research, (2) new research and proposals should design theoretical frameworks to account for and overcome the present biases, and (3) local community-based management approaches should be prioritised and amplified in order to overcome the barriers to conducting research in priority areas.
Microeukaryotic Communities of the Long-Term Ice-Covered Freshwater Lakes in the Subarctic Region of Yakutia, Russia
Authors: Galachyants Yuri , Zakharova Yulia , Bashenkhaeva Maria , Petrova Darya , Kopyrina Liubov , Likhoshway Yelena
Published: March 2023

Currently, microeukaryotic communities of the freshwater arctic and subarctic ecosystems are poorly studied. Still, these are of considerable interest due to the species biogeography and autecology as well as global climate change. Here, we used high-throughput 18S rRNA amplicon sequencing to study the microeukaryotic communities of the large subarctic freshwater lakes Labynkyr and Vorota in Yakutia, Russia, during the end of the ice cover period, from April to June. By applying the statistical methods, we coupled the microeukaryotic community structure profiles with available discrete factor variables and hydrophysical, hydrochemical, and environmental parameters. The sub-ice layer and the water column communities were differentiated due to the temporal change in environmental conditions, particularly temperature regime and electric conductivity. Additionally, the community composition of unicellular eukaryotes in lakes Labynkyr and Vorota was changing due to seasonal environmental factors, with these alterations having similar patterns in both sites. We suggest the community developed in the sub-ice layer in April serves as a primer for summer freshwater microeukaryotes. Our results extend the current knowledge on the community composition and seasonal succession of unicellular eukaryotes within subarctic freshwater ecosystems.
Reproductive Biology of the Golden Cuttlefish Sepia esculenta (Cephalopoda, Sepiida)
Authors: Vlasova Elizaveta V. , Sabirov Rushan M. , Golikov Alexey V.
Published: March 2023

The golden cuttlefish Sepia esculenta is the one of most abundant cuttlefish species around south-east Asia and has a high commercial value. Despite its wide distribution and high commercial value, its reproductive biology is still poorly understood. This study was based on 25 males and 6 females. The potential fecundity (PF) of females was 1701–3719 oocytes, which was an increase, as compared to the previously known values. The oocyte resorption reached up to 13.2% of fecundity. The ovulation pattern was group-synchronous, with a predominance of previtellogenic oocytes. The pre-meiotic and primary growth oocyte phases were absent in mature females. The number of spermatophores carried by an individual male was 146–1698 (length 9–20 mm). The spermatophores were characterised by a cement body consisting of conical oral and cylindrical aboral parts. The ontogenetic changes in the spermatophores and their parts were recorded for the first time in the order of Sepiida. Their sperm content and their adhesive abilities also increased during ontogenesis. The data obtained in the present study significantly increased and corrected the existing knowledge of S. esculenta biology. Moreover, these data help to explain the general patterns of reproductive biology in cuttlefish, as well as in Cephalopoda as a whole.
Drone-Based Identification and Monitoring of Two Invasive Alien Plant Species in Open Sand Grasslands by Six RGB Vegetation Indices
Authors: Bakacsy László , Tobak Zalán , van Leeuwen Boudewijn , Szilassi Péter , Biró Csaba , Szatmári József
Published: March 2023

Today, invasive alien species cause serious trouble for biodiversity and ecosystem services, which are essential for human survival. In order to effectively manage invasive species, it is important to know their current distribution and the dynamics of their spread. Unmanned aerial vehicle (UAV) monitoring is one of the best tools for gathering this information from large areas. Vegetation indices for multispectral camera images are often used for this, but RGB colour-based vegetation indices can provide a simpler and less expensive solution. The goal was to examine whether six RGB indices are suitable for identifying invasive plant species in the QGIS environment on UAV images. To examine this, we determined the shoot area and number of common milkweed (Asclepias syriaca) and the inflorescence area and number of blanket flowers (Gaillardia pulchella) as two typical invasive species in open sandy grasslands. According to the results, the cover area of common milkweed was best identified with the TGI and SSI indices. The producers’ accuracy was 76.38% (TGI) and 67.02% (SSI), while the user’s accuracy was 75.42% (TGI) and 75.12% (SSI), respectively. For the cover area of blanket flower, the IF index proved to be the most suitable index. In spite of this, it gave a low producer’s accuracy of 43.74% and user’s accuracy of 51.4%. The used methods were not suitable for the determination of milkweed shoot and the blanket flower inflorescence number, due to significant overestimation. With the methods presented here, the data of large populations of invasive species can be processed in a simple, fast, and cost-effective manner, which can ensure the precise planning of treatments for nature conservation practitioners.
A Robust Real-Time Ellipse Detection Method for Robot Applications
Authors: He Wenshan , Wu Gongping , Fan Fei , Liu Zhongyun , Zhou Shujie
Published: March 2023

Over the years, many ellipse detection algorithms have been studied broadly, while the critical problem of accurately and effectively detecting ellipses in the real-world using robots remains a challenge. In this paper, we proposed a valuable real-time robot-oriented detector and simple tracking algorithm for ellipses. This method uses low-cost RGB cameras for conversion into HSV space to obtain reddish regions of interest (RROIs) contours, effective arc selection and grouping strategies, and the candidate ellipses selection procedures that eliminate invalid edges and clustering functions. Extensive experiments are conducted to adjust and verify the method’s parameters for achieving the best performance. The method combined with a simple tracking algorithm executes only approximately 30 ms on a video frame in most cases. The results show that the proposed method had high-quality performance (precision, recall, F-Measure scores) and the least execution time compared with the existing nine most advanced methods on three public actual application datasets. Our method could detect elliptical markers in real-time in practical applications, detect ellipses adaptively under natural light, well detect severely blocked and specular reflection ellipses when the elliptical object was far from or close to the robot. The average detection frequency can meet the real-time requirements (>10 Hz).
Real-Time Positioning Method for UAVs in Complex Structural Health Monitoring Scenarios
Authors: Zhou Jianguo , He Linshu , Luo Haitao
Published: March 2023

UAVs are becoming increasingly used in the field of structural health monitoring, and the position information of them during the tasks is crucial. However, in complex scenarios such as bridges and high-rise buildings, the GNSS positioning method cannot obtain the positions of the UAV all the time due to the blockage of satellite signals and multi-path effects. This paper proposes a real-time positioning method to address the issue combining GNSS and total station. The GNSS is first used to locate the UAV when it is not in the line of sight of the total station, and the coordinates of the UAV are transmitted to the total station for blind tracking through coordinates conversion. The total station is then used to directly track the UAV when it flies to the GNSS-denied area and appears in the field view of the total station. Experiments show that the shift from blind tracking to direct tracking can be guaranteed as the coordinates conversion error is always less than the field of view range of the total station, even if only two common points are used for coordinates conversion. In addition, high positioning accuracy can be achieved in complex structural health monitoring scenarios.
Advances in Solar-Derived Chemical Fuel Systems
Authors: Twi-Yeboah Nigel , Osei Dacosta , Danquah Michael K.
Published: March 2023

Fuel cells are essential components of a large portfolio for developing a competitive, secure, and sustainable clean energy economy as they possess the ability to efficiently convert a variety of fuels into electricity. They convert chemical energy from fuels into electricity through chemical reactions with an oxidizing agent. Fuel cells are highly efficient and can produce electricity with very little pollution. They are used in a variety of applications, including powering buildings and vehicles, and as a backup power source. However, the infrastructure for fuel cells is still not fully developed and the cost of fuel cells is currently high, hindering their widespread adoption. This article discusses various advanced fuel cell types with descriptions of their working principles and applications. It provides some insights on the requirements of solar-derived chemical fuel cells as well as some novel materials for the fabrication of solar-derived chemical fuel cells. Discussions on the limitations of solar-derived fuel cells were provided in relation to environmental hazards involved in the use of these cells.
A Methodology for Air Temperature Extrema Characterization Pertinent to Improving the Accuracy of Climatological Analyses
Authors: Žaknić-Ćatović Ana , Gough William A.
Published: March 2023

The suggested methodology for the characterization of temperature extrema presents a multistep preprocessing procedure intended to derive extrema time series of correctly identified and thermally defined daily air temperature extrema pairs. The underlying conceptual framework for this approach was developed in response to the existing gaps in the current state of daily extrema identification and the development of extrema-based synthetic air temperature time series. A code consisting of a series of algorithms was developed to establish four-parameter criteria for a more accurate representation of daily variability that allows easy replication of temperature distribution based on the correct characterization of daily temperature patterns. The first preprocessing step consists of subjecting the high-frequency temperature time series to a theoretical diurnal observing window that imposes latitudinally and seasonally crafted limits for the individual identification of daily minima and maxima. The following pre-processing step involves the supplementation of air temperature extrema with the information on the occurrence of extrema timing deemed as vital information for the reconstruction of the temperature time series. The subsequent step involves the application of an innovative temperature pattern recognition algorithm that identifies physically homogeneous air temperature populations based on the information obtained in previous steps. The last step involves the use of a metric for the assessment of extrema temperature and timing parameters’ susceptibility to climate change. The application of the presented procedure to high-frequency temperature data yields two strains of physically homogeneous extrema time series with the preserved characteristics of the overall temperature variability. In the present form, individual elements of this methodology are applicable for correcting historical sampling and air temperature averaging biases, improving the reproducibility of daily air temperature variation, and enhancing the performance of temperature index formulae based on daily temperature extrema. The objective of this analysis is the eventual implementation of the presented methodology into the practice of systematic temperature extrema identification and preprocessing of temperature time series for the configuration of physically homogeneous air temperature subpopulations.
Effects of Board Independence on Greenhouse Gas Emissions and Financial Consequences: Evidence from South Korea
Authors: Kim Sang Joon , Kim Hohyun , Atukeren Erdal
Published: March 2023

Because of climate change issues, greenhouse gas (GHG) emissions have been emerging as an important research topic in recent years. This study examines the role of corporate governance in reducing GHG emissions by focusing on board independence. We use the industry fixed effect panel regression model to analyze data from 156 listed South Korean firms during the period from 2011 to 2019. Our results suggest that board independence is related positively with the reduction in GHG emissions. In addition, our evidence shows that firms with higher levels of GHG emissions have better financial performance, but board independence weakens the relation. Our findings imply that an independent board tends to focus on balancing the firm’s financial versus environmental performance. This quantitative study contributes to our understanding of the effects of corporate effects on firms’ GHG emissions and their financial consequences. The findings have implications for corporate managers and policymakers with respect to choosing corporate governance structures that reduce GHG emissions effectively.
The Effect of Forest Certification on Log Sale Prices: A Case Study in Northwestern Turkey
Authors: Deniz Tuğba
Published: March 2023

Forest certification is a tool contributing to the achievement of sustainable and responsible forest management. It also presents consumers with a market to purchase products coming from responsibly managed forests and provides forest managers with improved market access for their products. Even if forest certification incurs higher costs that affect the sale price, consumers generally have a greater willingness to pay more for certified products than for uncertified products. The objective of this study is to analyze the changes in the sales prices of oak and beech log in auction sales occurring during certified and uncertified periods at Demirköy Forest Enterprise, which received an FSC Certificate in 2014. For this aim, the Chow test was used and linear regression models were developed. It was found that the log sales prices of certified and uncertified periods are statistically different from each other at p = 0.05 significance level. As a consequence, it was determined that there was an increase in price of approximately 12% for oak and 19% for beech at log sales after certification. This study deals with only part of the economic impact of certification. The results can contribute to the forest certification database in order to support the decision-makers (managers and wood manufacturers) in their strategic decisions. The study will enable the forestry sector to see the possible reflections of certification practices in the country and the world markets. The effect of certification should be further investigated by including other factors (supply-demand situation of the forest industry, sales of neighboring enterprises, market conditions, etc.) affecting log sales prices.
Carbon Sink Limitation Determines the Formation of the Altitudinal Upper Limit of an Evergreen Oak in Eastern China
Authors: Zhang Xijin , Song Kun , Cieraad Ellen
Published: March 2023

Temperature is a critical environmental factor determining the upper limits of evergreen broadleaved tree taxa. However, whether carbon source or carbon sink limitation shapes this limit is not yet fully understood. We studied a subtropical evergreen oak (Cyclobalanopsis gracilis) at the northern limit of its distributional range. Along an elevational/temperature gradient towards its upper limit, we surveyed the variations in non-structural carbohydrate (NSC) concentrations of C. gracilis adults for 3 years. Additionally, a carbon balance manipulation experiment of debudding and defoliation was done to C. gracilis seedlings close to the upper distributional limit, aiming at investigating the changes in NSC concentrations and growth rates in different treatment groups. Our results showed that increasing elevation or decreasing temperature did not affect the trends of NSC concentration in twigs, old branches, or trunks of adults, nor did carbon balance manipulations (debudding or defoliation) of seedlings have a significant effect on the growth, while defoliation decreased NSC concentration in twigs. These results suggest that carbon sink limitation is the key physiological mechanism underlying low temperature in the shaping of this dominant evergreen broadleaved tree species in eastern China. Therefore, the formation of upper limits in evergreen oaks is most likely the result of a direct low-temperature restriction on meristematic activity and tissue formation instead of the result of insufficient carbon supply. More studies with expanded sample sizes are needed on other evergreen broadleaved tree species growing at their upper limits to confirm the carbon sink limitation hypothesis and reveal the detailed mechanisms.
Influence of Earlier Snowmelt on the Seedling Growth of Six Subboreal Tree Species in the Spring
Authors: Marumo Erica , Ueda Miki U. , Seki Osamu , Takagi Kentaro , Makoto Kobayashi
Published: March 2023

Climate warming is advancing snowmelt timing in the spring at high latitudes. To predict tree growth in subboreal forests under warmer climates based on mechanistic understanding, it is important to assess how advancing snowmelt influences tree growth in the spring via ecophysiological changes in subboreal forests. In this study, we conducted a field manipulation experiment of snowmelt timing and investigated the response of tree growth, leaf functional traits, and bud-burst phenology in the spring for the seedlings of six dominant tree species in subboreal forests. We found that the spring growth of only one species (Kalopanax septemlobus) out of six species responded positively to advancing snowmelt. Among the leaf functional traits (leaf mass per area, leaf nitrogen content, leaf δ13C value, leaf dry matter content, and leaf area) and bud-burst phenology, only the increase in leaf area was linked to the enhanced shoot growth of K. septemlobus. The significant change in K. septemlobus might be associated with its ecological characteristics to prefer regeneration in canopy gaps. These results indicate that advancing snowmelt under warmer winters can be beneficial for tree species that can plastically develop leaf area in Japanese subboreal forests.
Automatic Detection and Classification of Dead Nematode-Infested Pine Wood in Stages Based on YOLO v4 and GoogLeNet
Authors: Zhu Xianhao , Wang Ruirui , Shi Wei , Yu Qiang , Li Xiuting , Chen Xingwang
Published: March 2023

Pine wood nematode disease has harmed forests in several countries, and can be reduced by locating and clearing infested pine trees from forests. The target detection model of deep learning was utilized to monitor a pine nematode-infested wood. The detecting effect was good, but limited by low-resolution photos with poor accuracy and speed. Our work presents a staged detection and classification approach for a dead nematode-infested pine wood based using You Only Look Once version 4 (YOLO v4) and Google Inception version 1 Net (GoogLeNet), employing high-resolution images acquired by helicopter. Experiments showed that the detection accuracy of the staged detection and classification method and the method using only the YOLO v4 model were comparable for a dead nematode-infested pine wood when the amount of data was sufficient, but when the amount of data was limited the detection accuracy of the former was higher than that of the latter. The staged detection and classification method retained the fast training and detection speed of the one-stage target detection model, further improving the detection accuracy with limited data volume, and was more flexible in achieving accurate classification, meeting the needs of forest areas for pine nematode disease epidemic prevention and control.
Effect of Different Vegetation Restoration on Recovery of Compaction-Induced Soil Degradation in Hyrcanian Mixed Forests: Influence on Soil C and N Pools and Enzyme Activities
Authors: Ramineh Alireza , Jourgholami Meghdad , Etemad Vahid , Jafari Mohammad , Picchio Rodolfo
Published: March 2023

Reforestation with native and non-native tree species is one of the most effective strategies to cope with climate change, and is also the most effective management method for solving soil erosion problems in degraded forests around the world. The current research investigates three skid trails, which were planted with three species in the clearcutting areas, in comparison with a natural forest of hornbeam (CB; Carpinus betulus L.) and velvet maple (AV; Acer velutinum Boiss.) and degraded land without trees (DL), as well as evaluates the recovery of soil characteristics in the skid trails in response to the planting of native species, including black alder (Alnus glutinosa (L.) Gaertn.), and non-native species, including eastern cottonwood (Populus deltoides L.) and Italian cypress (Cupressus sempervirens L. var. horizontalis (Mill.) Gord.) in a mid-term period of 25 years, in the Hyrcanian forests in northern Iran. Significantly higher litter nitrogen (N), phosphorus (P), and potassium (K) were detected in the plantation of black alder (AG), whereas the lowest values were measured under the DL treatment. Soil physio-chemical properties significantly differed among treatments, except silt content. Among the soil chemical properties, N storage and available nutrients of P and K under the black alder plantation were fully restored as compared to the value observed at the hornbeam and velvet maple (CB-AV) stand over a 25-year period after soil disturbance and planting. Over a 25-year period after logging operations, soil biological and microbial properties of carbon and nitrogen, and enzyme activity in the black alder plantation were partially recovered, but these values have not returned to pre-harvest level at the CB-AV treatment as control. Overall, these results suggested that black alder had greater positive effects on the recovery of soil properties than other trees due to the faster litter decomposition as a N-fixing species, and its labile substrate with low organic C and high N concentration. Therefore, black alder reforestation should be increase in future ecosystem restoration in the area influenced by logging operations.
Validation of Forest Vegetation Simulator Model Finds Overprediction of Carbon Growth in California
Authors: Herbert Claudia , Fried Jeremy S. , Butsic Van
Published: March 2023

Using regression-based, bootstrapped equivalence tests, and remeasured inventory plot data from thousands of plots across California, we found that the Forest Vegetation Simulator (FVS), as typically used out-of-the-box, overpredicts carbon sequestration in live trees that remain alive ten years later by 27%, on average. We found FVS growth prediction sensitive to forest type and FVS variant, with the largest overpredictions occurring in stands within the North Coast variant, growing on the lowest site class, having ages that are unknown or between 50 and 100 years, and that are within governmentally designated reserved areas or on national forests. Direction and magnitude of errors are related to the stand attributes; these relationships point the way towards opportunities to improve the underlying growth models or calibrate the system to improve prediction accuracy. Our findings suggest that forest managers relying on out-of-the-box FVS growth models to forecast carbon sequestration implications of their management of California forests will obtain estimates that overstate the carbon that can be sequestered under light-touch or caretaker management, potentially leading to management decisions that fail to deliver the expected carbon sequestration benefits—a failure that could take a long time to recognize.