bluuebunny/crossref_metadata_2025 huggingface dataset:
Does the Choice of Anaesthesia Affect Cancer? A Molecular Crosstalk between Theory and Practice
Authors: Debel Wiebrecht , Ramadhan Ali , Vanpeteghem Caroline , Forsyth Ramses G.
Published: December 2022

In recent years, there has been an increasing scientific interest in the interaction between anaesthesia and cancer development. Retrospective studies show that the choice of anaesthetics may influence cancer outcome and cancer recurrence; however, these studies show contradictory results. Recently, some large randomized clinical trials have been completed, yet they show no significant effect of anaesthetics on cancer outcomes. In this scoping review, we compiled a body of in vivo and in vitro studies with the goal of evaluating the biological effects of anaesthetics on cancer cells in comparison to clinical effects as described in recent studies. It was found that sevoflurane, propofol, opioids and lidocaine are likely to display direct biological effects on cancer cells; however, significant effects are only found in studies with exposure to high concentrations of anaesthetics and/or during longer exposure times. When compared to clinical data, these differences in exposure and dose–effect relation, as well as tissue selectivity, population selection and unclear anaesthetic dosing protocols might explain the lack of outcome.
Intraoperative Assessment of Tumor Margins in Tissue Sections with Hyperspectral Imaging and Machine Learning
Authors: Pertzborn David , Nguyen Hoang-Ngan , Hüttmann Katharina , Prengel Jonas , Ernst Günther , Guntinas-Lichius Orlando , von Eggeling Ferdinand , Hoffmann Franziska
Published: December 2022

The intraoperative assessment of tumor margins of head and neck cancer is crucial for complete tumor resection and patient outcome. The current standard is to take tumor biopsies during surgery for frozen section analysis by a pathologist after H&E staining. This evaluation is time-consuming, subjective, methodologically limited and underlies a selection bias. Optical methods such as hyperspectral imaging (HSI) are therefore of high interest to overcome these limitations. We aimed to analyze the feasibility and accuracy of an intraoperative HSI assessment on unstained tissue sections taken from seven patients with oral squamous cell carcinoma. Afterwards, the tissue sections were subjected to standard histopathological processing and evaluation. We trained different machine learning models on the HSI data, including a supervised 3D convolutional neural network to perform tumor detection. The results were congruent with the histopathological annotations. Therefore, this approach enables the delineation of tumor margins with artificial HSI-based histopathological information during surgery with high speed and accuracy on par with traditional intraoperative tumor margin assessment (Accuracy: 0.76, Specificity: 0.89, Sensitivity: 0.48). With this, we introduce HSI in combination with ML hyperspectral imaging as a potential new tool for intraoperative tumor margin assessment.
Strategies to Optimize Treatment for Locally Advanced Rectal Cancer
Authors: Hu Xiaoyu , Xue Zhuang , He Kewen , Tian Yaru , Chen Yu , Zhao Mengyu , Yu Jinming , Yue Jinbo
Published: December 2022

Neoadjuvant long-course concurrent chemoradiation plus surgery, followed by optional adjuvant chemotherapy, is a standard of care for locally advanced rectal cancer (LARC). However, this traditional approach has several limitations, including low pathological complete response (pCR) (10–25%), high metastasis rate (30–35%), and highly inconsistent compliance with adjuvant chemotherapy (25–75%). Treatment modalities for LARC have dramatically evolved in recent years. Multiple clinical trials have focused on optimizing strategies to achieve a win-win situation for oncologic outcomes and functions. Here, we review the latest studies into optimizing neoadjuvant treatment for LARC.
Activation of cGAS-STING Pathway Is Associated with MSI-H Stage IV Colorectal Cancer
Authors: Kunac Nenad , Degoricija Marina , Viculin Jelena , Omerović Jasminka , Terzić Janoš , Vilović Katarina , Korac-Prlic Jelena
Published: December 2022

Colorectal cancer is the second most common cause of cancer-related mortality in adults. Understanding colorectal tumorigenesis at both the cellular and molecular levels is crucial for developing effective treatment options. Forty-one biopsy samples from patients with metastatic CRC (mCRC) were collected at Split University Hospital in Croatia. A total of 41 patients (21 with microsatellite unstable tumours and 20 with microsatellite stable tumours) were randomly included in the study. Immunolabelling of cGAS and STING in metastatic CRC was performed and further complemented by histological classification, tumour grade, and KRAS, NRAS, and BRAF mutational status of mCRC. In bivariate analysis, elevated expression of cGAS and STING was positively associated with MSI-H colon cancer (Fisher’s exact test, both p = 0.0203). Combined expression analysis of cGAS and STING showed a significantly higher percentage of patients with mCRC MSI-H with a fully or partially activated cGAS-STING signalling pathway (chi-square test, p = 0.0050). After adjusting for age, sex, and STING expression, increased cGAS expression remained significantly associated with MSI-H colon cancer in a multiple logistic regression model (β = 1.588, SE = ±0.799, p = 0.047). The cGAS-STING signalling axis represents a compelling new target for optimization of immune checkpoint inhibitor therapeutic approaches in patients with MSI-H stage IV CRC.
α-1,6-Fucosyltransferase Is Essential for Myogenesis in Zebrafish
Authors: Hayashiji Nozomi , Kawahara Genri , Xu Xing , Fukuda Tomohiko , Kerever Aurelien , Gu Jianguo , Hayashi Yukiko K. , Arikawa-Hirasawa Eri
Published: December 2022

Glycosylation is an important mechanism regulating various biological processes, including intercellular signaling and adhesion. α-1,6-fucosyltransferase (Fut8) belongs to a family of enzymes that determine the terminal structure of glycans. Fut8 is widely conserved from Caenorhabditis elegans to humans, and its mutants have been reported in humans, mice, and zebrafish. Although mutants show various symptoms, such as spinal deformity and growth retardation, its effects on skeletal muscles are unknown. We aimed to elucidate the function of Fut8 in skeletal muscle using zebrafish and C2C12 cells for evaluation. We observed that most fut8a morphants died at 2 days post-fertilization (dpf) or in earlier developmental stages even at low concentrations of morpholino oligonucleotides (MOs). Mutant juveniles also had small body sizes, and abnormal myocepta and sarcomere structures, suggesting that Fut8a plays important roles in myogenesis. Moreover, treatment of C2C12 cells with 2-fluorofucose (2FF), a fucosylation inhibitor, during cell differentiation dramatically reduced the expression of myogenic genes, such as Myomaker and other myogenic fusion genes, and inhibited myotube formation. These results indicate that Fut8 is an important factor in myogenesis, and myofusion in particular.
Long-Term Results of Pediatric Congenital Pulmonary Malformation: A Population-Based Matched Case–Control Study with a Mean 7-Year Follow-Up
Authors: Nuutinen Susanna , Ronkainen Eveliina , Perhomaa Marja , Harju Terttu , Sinikumpu Juha-Jaakko , Serlo Willy , Dunder Teija
Published: December 2022

Symptomatic congenital pulmonary malformations (CPMs) are a group of anomalies involving the lungs. The long-term outcomes of these patients are not well known. The present research aimed to study the pulmonary function, respiratory morbidity, and health-related quality of life (QoL) of patients treated for CPMs. All children (<16 years of age) treated for CPMs in 2002–2012 (in Oulu University Hospital) were invited to the follow-up visit. Altogether, there were 22 patients, out of which 17 (77%) participated. The mean follow-up time was 6.6 (ranged from 3 to 16) years. Pulmonary function tests, diffusing capacity, respiratory morbidity, and QoL were determined as the primary outcomes. Potential residual malformations and lung anatomy were investigated using computer tomography (CT) imaging. The outcomes were compared to the age- and sex-matched healthy controls. The forced expiratory volume at 1 s (FEV1, Z-score) remained lower in operated patients compared to the healthy controls (−1.57 ± SD 1.35 vs. −0.39 ± SD −0.86, p-value 0.005). There were no differences in respiratory morbidity or QoL between the patients and the controls. The surgical approach (lobectomy vs. partial resection) did not affect lung function. A younger age (<1 year of age) at the time of the surgery seemed to result in a higher lung capacity, but the finding was not statistically significant. Patients with CPMs treated with surgery were satisfied with their wellbeing in the long-term. A lower lung function did not have an impact on their wellbeing. However, there was a slight decrease in lung function compared to the healthy controls, and a clinical follow-up of the patients was recommended.
Growth Response of Red Oaks to Climatic Conditions in the Lower Mississippi Alluvial Valley: Implications for Bottomland Hardwood Restoration with a Changing Climate
Authors: Choi Junyeong , Tian Nana , Gan Jianbang , Pelkki Matthew , Mhotsha Ouname
Published: December 2022

Bottomland hardwood forests (BHFs) offer a wide range of ecosystem services that are of high environmental and socioeconomic value. Yet, nearly 70% of BHFs in the southern United States have been lost during the past 100 years primarily due to land use change including agricultural expansion, calling for restoration efforts. We estimated the statistical relationship of the annual radial growth rate of three red oak species with climatic conditions and tree age using the tree ring data collected from a BHF plantation in the Arkansas Delta region. These species were Cherry bark oak (Quercus pagoda), Shumard oak (Quercus shumardii), and Nuttall oak (Quercus texana). The destructive sampling method was employed to obtain tree growth data and the cross-dating method was used for tree age determination. A log-linear regression model was estimated to uncover the statistical relationship between annual tree ring growth rate and climatic conditions. We identified the most critical time windows of climate variables that affect the growth of these trees. We found that the average temperature in October of the previous year and the minimum temperature between December of the previous year and January of the current year were positively associated with the radial growth rate in the current year although the maximum temperature from January to August and total precipitation from April to July of the current year were negatively correlated with the growth rate. Compared to Cherry bark and Shumard oaks, Nuttall oak was less sensitive to a rise in the minimum temperature between December and January. The projected climate change is likely to create slightly more favorable overall climatic conditions for these oak species in the region. Our findings suggest that these three red oak species are well suited for the study region for restoring BHFs, especially with a changing climate.
Study on Microstructure and Oxidation Resistance Mechanism of Y-Modified NiCrAlY Coating Prepared by Pack Cementation
Authors: Zhang Shuting , Ouyang Peixuan , Yan Hongjuan , Si Lina
Published: December 2022

The existence mode of Y is an important factor affecting the oxidation resistance of NiCrAlY coating. The traditional thermal sprayed NiCrAlY coating had some problems such as internal-stress-induced coating peeling, when it was used at high temperature for a long time. In this paper, Y-modified NiCrAlY coatings were prepared on the surface of thermal-sprayed NiCrAlY coatings by halide-activated pack-cementation technology. The microstructure and oxidation resistance of the coatings after thermal insulation at 1100 °C for 100 h were analyzed. The results show that the oxidation resistance of Y-modified NiCrAlY coatings was improved significantly. When the oxidation temperature and time were 1100 °C and 100 h, the oxidation weight gain of thermal sprayed NiCrAl0.5Y and NiCrAl1.0Y coatings was 3.8 and 2.2 times that of Y-modified coatings, respectively. In addition, the NiCrAlY coatings prepared by pack cementation had better oxidation resistance than thermal sprayed coatings when the content of Y was equal. The oxidation resistance of the pack-cemented NiCrAlY coatings were increased with the increase in Y content when it was in a range of 0~1 wt.%. When oxidized at 1100 °C for 100 h, the oxidation weight gain of the pack-cemented NiCrAl0.5Y and NiCrAl1.0Y coatings was about 1.8 and 0.9 mg/cm2, respectively. The formation of highly stable intermetallic compounds Ni5Y in the pack-cemented Y-modified coatings is concluded to be the reason for improving the oxidation resistance of the coatings. This work can provide a solution to improve the oxidation resistance of traditional MCrAlY coatings.
Application of the ARA Method in Solving Integro-Differential Equations in Two Dimensions
Authors: Saadeh Rania
Published: December 2022

The main purpose of this study is to investigate solutions of some integral equations of different classes using a new scheme. This research introduces and implements the new double ARA transform to solve integral and partial integro-differential equations. We introduce basic theorems and properties of the double ARA transform in two dimensions, and some results related to the double convolution theorem and partial derivatives are presented. In addition, to show the validity of the proposed technique, we introduce and solve some examples using the new approach.
The Effects of Annealing Temperatures and Dimethylformamide Doses on Porous TiO2 Films
Authors: Huang Pao-Hsun , Wu Cheng-Han , Wu Cheng-Kuan , Zhu Yu-Quan , Liu Jing , Lee Kuan-Wei , Huang Chien-Jung
Published: December 2022

In this study, we develop a facile and feasible synthetic technique for producing denser porous titanium dioxide (TiO2) films. The porous TiO2 films are effectively prepared using a sol–gel process with dimethylformamide (DMF). The TiO2 solution is synthesized by adjusting DMF doses ranging from 0 to 10 wt%, and the as-grown TiO2 films are further annealed at different temperatures from 300 to 500 °C. The TiO2 films exhibit an asymmetry anatase TiO2 phase as annealing temperatures increase, and a denser structure as DMF doses increase. The optical properties of all samples are studied, and the porous TiO2 obtained by 7.5 wt% DMF dose demonstrates a remarkable transmittance and reflectance of 51.87% and 27.55%, respectively, in the visible region from 350 to 850 nm when compared to the pure TiO2 films. The calculated band gap values range from 3.15 to 3.25 eV. Furthermore, the resistivity of 350 °C-annealed porous TiO2 thin film is determined by the Hall effect, revealing an increase from 4.46 to an of average 4.79 ohm · cm after injecting DMF solvent. These findings have the potential to assist a growing number of optoelectronic applications.
Structural and Functional Analysis of Dengue Virus Non-Structural Protein 5 (NS5) Using Molecular Dynamics
Authors: Fidel Darylle Ann , Macalino Stephani Joy Y. , Posadas George , Carrillo Maria Constancia O.
Published: December 2022

Dengue is an infection transmitted by the Aedes mosquito and is considered a major public health concern in many tropical and Asian countries, including the Philippines. It is caused by the dengue virus (DENV) which belongs to the Flaviviridae family and has four serotypes. The non-structural protein 5 (NS5), which consists of an MTase domain and an RdRp domain, is the largest and most conserved protein among flaviviruses and thus a potential target against DENV. However, there are very limited studies on the functional homodimer structure of NS5. Through molecular dynamics, it was found that residues 458–470, 583–586, 630–637, 743–744, and 890–900 of monomer A and residues 14–24, 311–315, and 462–464 of monomer B undergo essential motions for the conformational changes in the RdRp template tunnel and GTP binding in the MTase domain. Through the analysis of these motions, it was also proposed that in the dimeric structure of NS5 only one pair of domains contribute to the function of the protein. Other essential residues, specifically A-ASP533, A-LYS689, A-ARG620, A-ARG688, A-SER710, B-ARG620, B-LYS689, A-GLU40, A-ARG262, A-GLU267, A-ARG673, and B-ARG673, were also identified to play important roles in the information flow necessary for the function of the protein. In particular, shortest paths analysis led to the identification of ARG673 as an essential residue for the communication between RdRp and MTase catalytic sites. Mutation of this residue led to changes in the conformational flexibility of the RdRp finger subdomain, which may influence the RdRp catalytic function. These findings serve as a basis for future studies on the mechanism and inhibition of the NS5 dimer for dengue drug discovery.
Morbidity and Mortality after Surgery for Retroperitoneal Sarcoma
Authors: Ruff Samantha M. , Grignol Valerie P. , Contreras Carlo M. , Pollock Raphael E. , Beane Joal D.
Published: December 2022

Retroperitoneal sarcoma (RPS) is a rare disease with over 100 histologic types and accounts for 10–15% of all soft tissue sarcomas. Due to the rarity of RPS, sarcoma centers in Europe and North America have created the Transatlantic RPS Working Group (TARPSWG) to study this disease and establish best practices for its management. Current guidelines dictate complete resection of all macro and microscopic disease as the gold standard for patients with RPS. Complete extirpation often requires a multi-visceral resection. In addition, recent evidence suggests that en bloc compartmental resections are associated with reduced rates of local recurrence. However, this approach must be balanced by the potential for added morbidity. Strategies to mitigate postoperative complications include optimization of the patient through improved preoperative nutrition and pre-habilitation therapy, referral to a high-volume sarcoma center, and implementation of enhanced recovery protocols. This review will focus on the factors associated with perioperative complications following surgery for RPS and outline approaches to mitigate poor surgical outcomes in this patient population.
A Unified Approach to Analysis of Body Condition in Green Toads
Authors: Landler Lukas , Burgstaller Stephan , Spießberger Magdalena , Horvath Andras , Zhelev Zhivko , Mollov Ivelin , Sinsch Ulrich , Nepita Johannes , Schwabel Florian , Kuhn Wolfgang , Köbele Christian , Sedlmeier Heinz , Amon Cornelia , Mazgajska Joanna , Mazgajski Tomasz D. , Sistani Amir , Schluckebier Rieke , Andrä Eberhard , Ott Moritz , Gollmann Günter
Published: December 2022

Body condition is increasingly used to assess the status of populations and as a proxy for individual fitness. A common, quick and non-invasive approach is to estimate condition from the relation between body length and mass. Among the methods developed for this purpose, the Scaled Mass Index (SMI) appears best suited for comparisons among populations. We assembled data from 17 populations of European green toads (Bufotes viridis) with the aim of devising a standard formula applicable for monitoring this species. The mean value of the exponents describing length–mass allometry in these samples was 3.0047. Hence, we propose using 3 as a scaling coefficient for calculating the SMI in green toads. From the contrast of SMI values for both sexes within populations, estimated with either the population-specific or the standard coefficient, we conclude that applying the standard formula not only facilitates comparisons among populations but may also help to avoid misinterpretation of variation within populations.
Fossil History of Ambrosia Beetles (Coleoptera; Platypodidae) with Description of a New Genus from Dominican Amber
Authors: Legalov Andrei A. , Poinar George O.
Published: December 2022

The fossil record of ambrosia beetles is summarized and a new genus and species in the subfamily Mecopelminae, Gongyloceria dominicana gen. et sp. nov. is described. The new genus differs from the extant genus Mecopelmus Blackman, 1944, possessing weakly elongated tarsi, finely faceted eyes, a scape not reaching the posterior margin of the eye, coarsely sculptured pronotum and elytra, and a larger body size. It is the first Miocene record of the Mecopelminae. The genus Xyleborites Wickham, 1913, placem. n. is transferred from the Scolytidae to the Platypodidae. A list of the fossil Platypodidae, including a key to the subfamilies and tribes of ambrosia beetles, is presented. Xyleborites longipennis Wickham, 1913 and Gongyloceria dominicana sp. nov. may have been related to Paullinieae recorded from the late Eocene and the early Miocene of North and Central America. Distribution maps with fossil records for ambrosia beetles are included.
Adaptive IoU Thresholding for Improving Small Object Detection: A Proof-of-Concept Study of Hand Erosions Classification of Patients with Rheumatic Arthritis on X-ray Images
Authors: Radke Karl Ludger , Kors Matthias , Müller-Lutz Anja , Frenken Miriam , Wilms Lena Marie , Baraliakos Xenofon , Wittsack Hans-Jörg , Distler Jörg H. W. , Abrar Daniel B. , Antoch Gerald , Sewerin Philipp
Published: December 2022

In recent years, much research evaluating the radiographic destruction of finger joints in patients with rheumatoid arthritis (RA) using deep learning models was conducted. Unfortunately, most previous models were not clinically applicable due to the small object regions as well as the close spatial relationship. In recent years, a new network structure called RetinaNets, in combination with the focal loss function, proved reliable for detecting even small objects. Therefore, the study aimed to increase the recognition performance to a clinically valuable level by proposing an innovative approach with adaptive changes in intersection over union (IoU) values during training of Retina Networks using the focal loss error function. To this end, the erosion score was determined using the Sharp van der Heijde (SvH) metric on 300 conventional radiographs from 119 patients with RA. Subsequently, a standard RetinaNet with different IoU values as well as adaptively modified IoU values were trained and compared in terms of accuracy, mean average accuracy (mAP), and IoU. With the proposed approach of adaptive IoU values during training, erosion detection accuracy could be improved to 94% and an mAP of 0.81 ± 0.18. In contrast Retina networks with static IoU values achieved only an accuracy of 80% and an mAP of 0.43 ± 0.24. Thus, adaptive adjustment of IoU values during training is a simple and effective method to increase the recognition accuracy of small objects such as finger and wrist joints.
SHOX Deletion and Idiopathic Short Stature: What Does the Clinician Need to Know? Case Series Report
Authors: Ungureanu Maria-Christina , Hrisca Anamaria , Caba Lavinia , Teodoriu Laura , Bilha Stefana , Preda Cristina , Leustean Letitia
Published: December 2022

Children diagnosticated with idiopathic short stature (ISS) are probably, in most cases, underdiagnosticated. The genetic causes of ISS may be mutations of genes involved in local regulation of the growth plate or genes involved in the GH-IGF1 axis physiology. We present a kindred of five children evaluated for short stature or low normal stature, initially diagnosticated as idiopathic short stature, familial short stature, or being small for gestational age. Clinical signs suggestive of SHOX deletion screening in a child with short stature are low arm span/height ratio, increased sitting height/height ratio, BMI > 50% percentile, Madelung deformity, cubitus valgus, bowing and shortening of the forearm, dislocation of the ulna (at the elbow), and the appearance of muscular hypertrophy. Radiological characteristics suggestive of SHOX deficiency are triangularisation of the distal radial epiphysis, an enlarged diaphysis of the radius plus bowing of the radius, the convexity of the distal radial metaphysis, short fourth and fifth metacarpals, pyramidalization of the carpal row. Treatment with rGH is approved for children with SHOX gene deficiency and short stature. This kindred is an example that familial short stature, idiopathic short stature, and short stature due to a small gestational age are not final diagnoses. Complex investigations are necessary to identify the precise cause, leading to optimal clinical management. Treatment with rGH is an option for some of them; for others, it has no therapeutic response and, in some cases, is even harmful.
Assessment of Hearing and Vestibular Functions in a Post-COVID-19 Patient: A Clinical Case Study
Authors: Andreeva Irina Germanovna , Gvozdeva Alisa , Pimenova Vera , Ryabkova Varvara , Lukashenko Maria , Kamaeva Evelina , Shapkina Valeria , Soprun Lidia , Gavrilova Natalia , Fedotkina Tamara Viktorovna , Churilov Leonid Pavlovich , Shoenfeld Yehuda
Published: December 2022

SARS-CoV-2 infection may cause such complications as post-COVID-19 syndrome, which includes chronic fatigue, myalgia, arthralgia, as well as a variety of neurological manifestations, e.g., neuropathy of small fibers, hearing and vestibular dysfunction, and cognitive impairment. This clinical case describes a 41-year-old patient suffering from post-COVID-19 syndrome and chronic fatigue syndrome. A detailed examination was performed, including an in-depth study of peripheral and central hearing and vestibular functions, as well as small nerve fibers length and density in the skin and cornea of the eye. Contrary to expectations, no peripheral nervous system dysfunction was detected, despite the presence of dizziness and gait instability in the patient. Hearing tests (gap detection test and dichotic test) showed central auditory processing disorders. The evaluated lesion in the processing of temporal and verbal auditory information can be a significant factor contributing to additional overload of the neural activity and leading to chronic fatigue when performing daily activities in patients with CFS and post-COVID-19 complications.
The Strongly Asynchronous Massive Access Channel
Authors: Shahi Sara , Tuninetti Daniela , Devroye Natasha
Published: December 2022

This paper considers the Strongly Asynchronous, Slotted, Discrete Memoryless, Massive Access Channel (SAS-DM-MAC) in which the number of users, the number of messages, and the asynchronous window length grow exponentially with the coding blocklength with their respective exponents. A joint probability of error is enforced, ensuring that all the users’ identities and messages are correctly identified and decoded. Achievability bounds are derived for the case that different users have similar channels, the case that users’ channels can be chosen from a set which has polynomially many elements in the blocklength, and the case with no restriction on the users’ channels. A general converse bound on the capacity region and a converse bound on the maximum growth rate of the number of users are derived. It is shown that reliable transmission with an exponential number of users with an exponential asynchronous exponent with joint error probability is possible at strictly positive rates.
The Application of Biochar from Waste Biomass to Improve Soil Fertility and Soil Enzyme Activity and Increase Carbon Sequestration
Authors: Wojewódzki Piotr , Lemanowicz Joanna , Debska Bozena , Haddad Samir A. , Tobiasova Erika
Published: December 2022

Biochar (BC) is a material that has many applications in agricultural and environmental activities. The aim of the study was to define the influence of BC produced in low-temperature pyrolysis from various organic waste materials, including one-month-old compost (OMOC), pine bark (PB), pine needle mulch (NM), pine cones (PC) and maple leaves (ML), on soil enzyme activity as well as its relation with organic matter properties. A 60-day incubation pot experiment was set up to investigate the influence of BC amendment on soil (S) characteristics. After incubation, we investigated the activity of soil enzymes, the content of available phosphorus (AP), potassium (AK) and magnesium (AMg), total organic carbon (TOC), total nitrogen (TN), dissolved organic matter (DOM) and its fractional composition (content and share of carbon and nitrogen of humic (CHAs, NHAs) and fulvic (CFAs, NFAs) acids and humin fractions). The effect of the amended biochars differed depending on the feedstock material. In general, the use of biochar enriched the soil with AP, AK and AMg increased the soil carbon stock, increased the intensity of nitrogen transformation and influenced the soil enzyme activity. OMOC and ML biochars significantly increased soil fertility, which was expressed by the high value of the CHA/CFA ratio.
Aerodynamic Performance and Wake Characteristics Analysis of Archimedes Spiral Wind Turbine Rotors with Different Blade Angle
Authors: Song Ke , Huan Huiting , Kang Yuchi
Published: December 2022

Continuous improvement of wind turbines represent an effective way of achieving green energy and reducing dependence on fossil fuel. Conventional lift-type horizontal axis wind turbines, which are widely used, are designed to run under high wind speed to obtain a high efficiency. Aiming to use the low-speed wind in urban areas, a novel turbine, which is called the Archimedes Spiral Wind Turbine (abbreviated as ASWT), was recently proposed for low-speed wind applications. In the current work, a numerical simulation on the five ASWT rotors with different blade angles was carried out, which were performed to predict the detailed aerodynamic performance and wake characteristics. The results show that the ASWT rotor with a large blade angle has a wider operating tip speed ratio range and a higher tip speed ratio point of maximum power coefficient within a certain range, and yet the ASWT rotor with the larger blade angle has a higher thrust coefficient. Additionally, the ASWT rotor with a large blade angle usually has a large power coefficient and thrust coefficient fluctuation amplitude. On the other hand, the ASWT rotor with a small blade angle permits the undisturbed free stream to pass through the rotor blades more easily than that with a large blade angle. This causes a stronger blockage effect for the ASWT rotor with a large blade angle. Moreover, the blade angle also has a great effect on the shape of the vortex structure. The blade tip vortex of the fixed-angle ASWT rotors is more stable than those of the variable-angle ASWT rotors. The hub vortex of the ASWT rotors with a large blade angle is stronger than those with a small blade angle. Meanwhile, the wake recovery for ASWT rotors with a small blade angle is evidently lower than those with a large blade angle.
Numerical Modeling of Laser Heating and Evaporation of a Single Droplet
Authors: Pokharel Sagar , Tropina Albina , Shneider Mikhail
Published: December 2022

Laser technology is being widely studied for controlled energy deposition for a range of applications, including flow control, ignition, combustion, and diagnostics. The absorption and scattering of laser radiation by liquid droplets in aerosols affects propagation of the laser beam in the atmosphere, while the ignition and combustion characteristics in combustion chambers are influenced by the evaporation rate of the sprayed fuel. In this work, we present a mathematical model built on OpenFOAM for laser heating and evaporation of a single droplet in the diffusion-dominated regime taking into account absorption of the laser radiation, evaporation process, and vapor flow dynamics. The developed solver is validated against available experimental and numerical data for heating and evaporation of ethanol and water droplets. The two main regimes—continuous and pulsed laser heating—are explored. For continuous laser heating, the peak temperature is higher for larger droplets. For pulsed laser heating, when the peak irradiance is close to transition to the boiling regime, the temporal dynamics of the droplet temperature does not depend on the droplet size. With the empirical normalization of time, the dynamics of the droplet shrinkage and cooling are found to be independent of droplet sizes and peak laser intensities.
Insuring a Small Retail Electric Provider’s Procurement Cost Risk in Texas
Authors: Woo Chi-Keung , Zarnikau Jay , Tishler Asher , Cao Kang Hua
Published: December 2022

Motivated by the relatively infrequent but very large price spikes in the day-ahead and real-time energy markets operated by the Electric Reliability Council of Texas, this paper proposes an insurance that a small and risk-averse retailer in Texas (i.e., a retail electric provider (REP)) may buy to prevent financial insolvency caused by inadequate risk management. It also demonstrates the insurance’s practical design, pricing, and implementation. As participation in the REP’s procurement auction is voluntary, the insurance is mutually beneficial for the REP and the insurance seller. Hence, the proposed insurance is a newly developed wholesale market product that deserves consideration by REPs in Texas and competitive retailers elsewhere.
Design and Implementation of a Driving Strategy for Star-Connected Active Magnetic Bearings with Application to Sensorless Driving
Authors: Brasse Romain , Vennemann Jonah , König Niklas , Nienhaus Matthias , Grasso Emanuele
Published: December 2022

For decades, sensorless position estimation methods gained lots of interest from the research community, especially in the field of electric drives and active magnetic bearings (AMBs). In particular, the direct flux control (DFC) technique promises unique advantages over other sensorless techniques, such as a higher bandwidth, but on the other hand, it requires the coils to be connected in a star topology. Until now, star-point connections are rarely found on active magnetic bearings. In consequence, there is no known publication about the application of the DFC to an AMB to this date. In order to apply the DFC to an AMB, a star-point driving approach for AMBs must be developed beforehand. A star-connected driving approach, capable of driving a four-phase AMB, is proposed and validated against traditional H-bridges in a simulation. Further, the strategy is tested in a physical application and generalised for 4∗n phases. In terms of current dynamics, the simulation results can be compared to the well-known full H-bridge driving. The experiments on the physical application show that the actual current in the coils follows a reference with satisfactory accuracy. Moreover, the inductance measurements of the coils show a strong dependency on the rotor’s position, which is crucial for sensorless operation. A star-point connection delivers a satisfying response behaviour in an AMB application, which makes sensorless techniques that require a star point, such as the DFC, applicable to active magnetic bearings.
Design, Technical and Economic Optimization of Renewable Energy-Based Electric Vehicle Charging Stations in Africa: The Case of Nigeria
Authors: Oladigbolu Jamiu O. , Mujeeb Asad , Imam Amir A. , Rushdi Ali Muhammad
Published: December 2022

The transportation sector accounts for more than 70% of Nigeria’s energy consumption. This sector has been the major consumer of fossil fuels in the past 20 years. In this study, the technical and economic feasibility of an electrical vehicle (EV) charging scheme is investigated based on the availability of renewable energy (RE) sources in six sites representing diverse geographic and climatic conditions in Nigeria. The HOMER Pro® microgrid software with the grid-search and proprietary derivative-free optimization techniques is used to assess the viability of the proposed EV charging scheme. The PV/WT/battery charging station with a quantity of two WT, 174 kW of PV panels, a quantity of 380 batteries storage, and a converter of 109 kW located in Sokoto provide the best economic metrics with the lowest NPC, electricity cost, and initial costs of USD547,717, USD0.211/kWh, and USD449,134, respectively. The optimal charging scheme is able to reliably satisfy most of the EV charging demand as it presents a small percentage of the unmet load, which is the lowest when compared with the corresponding values of the other charging stations. Moreover, the optimal charging system in all six locations is able to sufficiently meet the EV charge requirement with maximum uptime. A sensitivity analysis was conducted to check the robustness of the optimum charging scheme. This sensitivity analysis reveals that the technical and economic performance indicators of the optimum charging station are sensitive to the changes in the sensitivity variables. Furthermore, the outcomes ensure that the hybrid system of RE sources and EVs can minimize carbon and other pollutant emissions. The results and findings in this study can be implemented by all relevant parties involved to accelerate the development of EVs not only in Nigeria but also in other parts of the African continent and the rest of the world.
Experimental Investigation on Heat Transfer Characteristics of Liquid Nitrogen Spray Cooling for Large Area
Authors: Gong Yu , Zhao Jinhong , Li Wei , Ai Qing , Gong Jiaming , Shuai Yong , Sun Chuang
Published: December 2022

Spray cooling has demonstrated advantages in the thermal control of avionic devices. In this study, a spray cooling system is established using liquid nitrogen (LN2) as a working fluid to investigate the effect of heat transfer characteristics on a large heating surface. The temperature response measurement and experimental analysis of the heating surface of a large-area shell structure under the boundary conditions of different heat flux and temperature regions were carried out. The temperature response curves for the outer surface of the shell structure from the initial temperature to the set temperature were obtained under different heat flows and temperature zones. The results show that the thermal response time of the surface spray phase cooling is less than 2 s, the stability time for the cooling temperature of the covering layer is longer than 60 s, and the cooling state can be maintained for 30 min under different working conditions. This study can provide a technical reference for the application of spray systems in the field of aircraft cooling.
Biochar Acts as an Emerging Soil Amendment and Its Potential Ecological Risks: A Review
Authors: Zhao Yue , Li Xin , Li Yunyang , Bao Huanyu , Xing Jia , Zhu Yongzhao , Nan Jun , Xu Guoren
Published: December 2022

Biochar, known as “Black Gold”, has become a novel approach with potential benefits for soil amendment, such as improving soil physicochemical properties, reducing greenhouse gas emissions, and enhancing soil fertility. The previous research studies mainly focus on exploring different methods for the improvement of biochar enriched nutrients as fertilizers; however, the migration and transformation mechanisms of these nutrients induced by biochar are yet to be extensively investigated. This paper provides an overview of recent advances in the application and mechanisms of biochar for soil amendment focusing on soil properties and nutrients improvement. Biochar positively alters microbial-mediated reactions in the soil C and N cycles, i.e., mineralization of C and N, and N2 fixation, thus enhancing maximizing C and N use efficiency and reducing the potential losses. Moreover, biochar provides reactive surfaces where P and K ions are retained in soil microbial biomass and in exchange sites, leading to increasing the availability of P and K to plants uptake. In addition, the toxic substances and potential ecological risks of biochar were also reviewed and discussed, thereby providing a baseline reference and guiding significance for future biochar applications as promising soil amendments.
Design of Stator Winding Turn Number of Tap-Change PMSM for EVs According to Driving Cycles
Authors: Lim Jong-Kyong , Gu Bon-Gwan , Im Seong-Hwan , Kim Rae-Young
Published: December 2022

Driving cycles are commonly used to evaluate the fuel efficiency and mileage of internal combustion engine vehicles and electric vehicles (EVs). To improve the mileage of EVs, efficient propulsion motors and inverters must be employed, particularly at frequently used speed and torque points of driving cycles. In this study, the number of the stator winding turns of a tap-change permanent magnet synchronous motor (PMSM) used for EV propulsion was investigated to increase the motor and inverter energy efficiencies under an urban dynamometer driving schedule (UDDS), a highway fuel economy test (HWFET), and combined UDDS/HWFET driving cycles. The motor core loss due to the carrier harmonics, copper loss, and inverter loss were analyzed for various winding turn number combinations, and the most efficient combination was selected. Based on the analysis results, the tap-change motor winding turns that exhibited the least loss were rewound on a PMSM of a mass-produced EV. The demand energy of the proposed tap-change PMSM and that of a mass-produced PMSM in the UDDS, HWFET, and combined UDDS/HWFET driving cycles were compared through experimentation. The proposed PMSM exhibited energy improvements of 1.50%, 1.84%, and 1.65%, respectively.
Accurate Peer-to-Peer Hierarchical Control Method for Hybrid DC Microgrid Clusters
Authors: Zhao Ensheng , Han Yang , Zeng Hao , Li Luqiao , Yang Ping , Wang Congling , Zalhaf Amr S.
Published: December 2022

Hybrid DC microgrid clusters contain various types of converters such as BOOST, BUCK, and bidirectional DC/DC converters, making the control strategy complex and difficult to achieve plug-and-play. The common master–slave hierarchical control strategy makes it difficult to achieve accurate and stable system control. This paper proposes an accurate peer-to-peer hierarchical control method for the hybrid DC microgrid cluster, and the working principle of this hierarchical control method is analyzed in detail. The microgrid cluster consists of three sub-microgrids, where sub-microgrid A consists of three BUCK converters, sub-microgrid B consists of three BOOST converters, and sub-microgrid C consists of two bidirectional DC/DC converters. According to all possible operations of various sub-microgrids in the microgrid cluster, the top-, mid-, and bottom-level controls are designed to solve the coordination control problem among different types of sub-microgrids. In this paper, a hybrid microgrid cluster simulation model is built in the PLECS simulation environment, and an experimental hardware platform is designed. The simulation and experiment results verified the accuracy of the proposed control strategy and its fast plug-and-play regulation ability for the system.
Novel Materials and Processes for Photovoltaic Technology
Authors: Vesce Luigi
Published: December 2022

Photovoltaic (PV) technology is the symbol of a sustainable future in many countries around the globe [...]
Leaf Traits and Resource Use Efficiencies of 19 Woody Plant Species in a Plantation in Fangshan, Beijing, China
Authors: Zhong Guowei , Tian Yun , Liu Peng , Jia Xin , Zha Tianshan
Published: December 2022

Plantations are typically monocultures, which limits their sustainability. Therefore, understanding acclimatization strategies and resource use efficiencies in plant species and life forms aids the improvement of vegetation diversity and ecological functions. Here, 19 species from forest plantations in Fangshan, Beijing, China were studied. We determined their net photosynthetic (Pn), and transpiration rates (E), light response curve, stomatal conductance (gs), and leaf nitrogen (N) content. We analyzed the leaf N content (Nmass), specific leaf area (SLA), maximum net photosynthetic rate (Pnmax), water use (WUE), nitrogen use (NUE), and carbon use (CUE) efficiencies and connected them with both species and life forms. Pnmax, SLA, Nmass, WUE, NUE, and CUE significantly differed among species. Evergreen conifers had the lowest SLA and Nmass but the highest WUE and CUE. Evergreen coniferous trees had lower SLA, Nmass, Pnmax, and NUE but higher WUE than deciduous trees and shrubs. The SLA, Nmass, and Pnmax of nitrogen-fixing plants were the highest. A correlation analysis revealed that WUE was positively correlated with CUE and negatively correlated with NUE. Moreover, WUE was negatively correlated with Nmass and SLA. These insights into the adaptability differences of woody plant species and life forms provide a scientific basis for the selection of appropriate species for sustainable forest plantations.
Using the Error-in-Variable Simultaneous Equations Approach to Construct Compatible Estimation Models of Forest Inventory Attributes Based on Airborne LiDAR
Authors: Li Chungan , Yu Zhu , Zhou Xiangbei , Zhou Mei , Li Zhen
Published: December 2022

Airborne LiDAR has been extensively used for estimating and mapping forest attributes at various scales. However, most models have been developed separately and independently without considering the intrinsic mathematical relationships and correlations among the estimates, which results in the mathematical and biophysical incompatibility of the estimates. In this paper, using the measurement error model approach, the error-in-variable simultaneous equation (SEq) for airborne LiDAR-assisted estimations of four forest attributes (stand volume, V; basal area, G; mean stand height, H; and diameter at breast height, D) for four forest types (Chinese fir, pine, eucalyptus, and broad-leaved forest) is developed and compared to the independence models (IMs). The results indicated that both the SEqs and IMs performed well, and the rRMSEs of the SEqs were slightly larger than those of the IMs, while the increases in rRMSE were less than 2% for the SEqs. There were statistically significant differences (α = 0.05) in the means of the estimates between SEqs and IMs, even though their average differences were less than ±1.0% for most attributes. There were no statistically significant differences in the mean estimates between SEqs, except for the estimates of the D and G of the eucalyptus forest. The SEqs with H and G as the endogenous variables (EVs) to estimate V performed slightly better than other SEqs in the fir, pine, and broad-leaved forests. The SEq that used D, H, and V as the EVs for estimating G was best in the eucalyptus forests. The SEq ensures the definite mathematical relationship among the estimates of forest attributes is maintained, which is consistent with forest measurement principles and therefore facilitates forest resource management applications, which is an issue that needs to be addressed for airborne LIDAR forest parameter estimation.