bluuebunny/crossref_metadata_2025 huggingface dataset:
An International Retrospective Observational Study of Liver Functional Deterioration after Repeat Liver Resection for Patients with Hepatocellular Carcinoma
Authors: Morise Zenichi , Aldrighetti Luca , Belli Giulio , Ratti Francesca , Cheung Tan To , Lo Chung Mau , Tanaka Shogo , Kubo Shoji , Okamura Yukiyasu , Uesaka Katsuhiko , Monden Kazuteru , Sadamori Hiroshi , Hashida Kazuki , Kawamoto Kazuyuki , Gotohda Naoto , Chen KuoHsin , Kanazawa Akishige , Takeda Yutaka , Ohmura Yoshiaki , Ueno Masaki , Ogura Toshiro , Suh Kyung Suk , Kato Yutaro , Sugioka Atsushi , Belli Andrea , Nitta Hiroyuki , Yasunaga Masafumi , Cherqui Daniel , Halim Nasser Abdul , Laurent Alexis , Kaneko Hironori , Otsuka Yuichiro , Kim Ki Hun , Cho Hwui-Dong , Lin Charles Chung-Wei , Ome Yusuke , Seyama Yasuji , Troisi Roberto I. , Berardi Giammauro , Rotellar Fernando , Wilson Gregory C. , Geller David A. , Soubrane Olivier , Yoh Tomoaki , Kaizu Takashi , Kumamoto Yusuke , Han Ho-Seong , Ekmekcigil Ela , Dagher Ibrahim , Fuks David , Gayet Brice , Buell Joseph F. , Ciria Ruben , Briceno Javier , O’Rourke Nicholas , Lewin Joel , Edwin Bjorn , Shinoda Masahiro , Abe Yuta , Hilal Mohammed Abu , Alzoubi Mohammad , Tanabe Minoru , Wakabayashi Go
Published: May 2022

Whether albumin and bilirubin levels, platelet counts, ALBI, and ALPlat scores could be useful for the assessment of permanent liver functional deterioration after repeat liver resection was examined, and the deterioration after laparoscopic procedure was evaluated. For 657 patients with liver resection of segment or less in whom results of plasma albumin and bilirubin levels and platelet counts before and 3 months after surgery could be retrieved, liver functional indicators were compared before and after surgery. There were 268 patients who underwent open repeat after previous open liver resection, and 224 patients who underwent laparoscopic repeat after laparoscopic liver resection. The background factors, liver functional indicators before and after surgery and their changes were compared between both groups. Plasma levels of albumin (p = 0.006) and total bilirubin (p = 0.01) were decreased, and ALBI score (p = 0.001) indicated worse liver function after surgery. Laparoscopic group had poorer preoperative performance status and liver function. Changes of liver functional values before and after surgery and overall survivals were similar between laparoscopic and open groups. Plasma levels of albumin and bilirubin and ALBI score could be the indicators for permanent liver functional deterioration after liver resection. Laparoscopic group with poorer conditions showed the similar deterioration of liver function and overall survivals to open group.
Implementation of HPV Tests in Latin America: What We Learned; What Should We Have Learned, and What Can We Do Better?
Authors: Godoy Luani Rezende , Possati-Resende Júlio César , Guimarães Yasmin Medeiros , Pedrão Priscila Grecca , dos Reis Ricardo , Longatto-Filho Adhemar
Published: May 2022

Cervical cancer is caused by HPV. Although it is the fourth most common type of cancer diagnosed and the fourth cause of cancer death, cervical cancer is nearly completely preventable because of the vaccination and screening available. The present review aims to map the initiatives conducted to implement or evaluate the implementation of HPV testing in Latin American countries. We performed the review by searching on PubMed in the English language and on grey literature, as most of the information about the guidelines used was found in governmental websites in the Spanish language. We only found information in eight countries concerning HPV testing as primary screening. Only Mexico has established HPV-based screening in all territories. There are three countries with regional implementation. Two countries with pilot studies indicated results that supported implementation. Finally, there are another two countries with a national recommendation. We have learned that HPV implementation is feasible and a very promising tool for reducing cervical cancer morbidity and mortality. The costs associated with saving lives and reducing suffering due to morbidity of a preventable disease must be pragmatically evaluated by the Latin America governments, and improving outcomes must be a mandatory priority for those that are responsible for addressing an organized system of cervical cancer screening.
Near-Infrared Fluorescence Axillary Reverse Mapping (ARM) Procedure in Invasive Breast Cancer: Relationship between Fluorescence Signal in ARM Lymph Nodes and Clinical Outcomes
Authors: Abbaci Muriel , Conversano Angelica , Karimi Maryam , Mathieu Marie-Christine , Rouffiac Valérie , De Leeuw Frederic , Michiels Stefan , Laplace-Builhé Corinne , Mazouni Chafika
Published: May 2022

The near-infrared (NIR) fluorescence axillary reverse mapping (ARM) procedure is a promising tool to identify and preserve arm lymphatic drainage during axillary lymph node dissection (ALND). The ARMONIC clinical trial was conducted to validate the technique on a large cohort of patients and to analyze the predictive clinical factors for ARM lymph node metastasis. For the first time, the fluorescence signal intensity from the ARM lymph nodes was measured and correlated with clinical findings. A total of 109 patients with invasive breast cancer and indications of mastectomy and ALND underwent the NIR fluorescence ARM procedure. Indocyanine green was administered by intradermal injection followed by intraoperative identification and resection of the ARM lymph nodes with NIR fluorescence camera guidance. The fluorescence signal intensity and signal distribution were then measured ex vivo and compared with clinical outcomes. ARM lymph nodes were successfully identified by fluorescence in 94.5% of cases. The mean normalized fluorescence signal intensity value was 0.47 with no significant signal difference between metastatic and non-metastatic ARM lymph nodes (p = 0.3728). At the microscopic level, the fluorescence signal distribution was focally intense in lymphoid tissue areas. Only the preoperative diagnosis of metastasis in the axillary nodes of patients was significantly associated with a higher ARM node fluorescence signal intensity (p = 0.0253), though it was not significantly associated with the pathological nodal (pN) status (p = 0.8081). Based on an optimal cut-off fluorescence value, the final sensitivity and specificity of the NIR fluorescence ARM procedure for ARM lymph node metastatic involvement were 64.7% and 47.3%, respectively. Although our preliminary results did not show that fluorescence signal intensity is a reliable diagnostic tool, the NIR fluorescence ARM procedure may be useful for ARM lymph node identification. Clinical trial registration: NCT02994225.
Adaptive Proton Therapy of Pediatric Head and Neck Cases Using MRI-Based Synthetic CTs: Initial Experience of the Prospective KiAPT Study
Authors: Bäumer Christian , Frakulli Rezarta , Kohl Jessica , Nagaraja Sindhu , Steinmeier Theresa , Worawongsakul Rasin , Timmermann Beate
Published: May 2022

Background and Purpose: Interfractional anatomical changes might affect the outcome of proton therapy (PT). We aimed to prospectively evaluate the role of Magnetic Resonance Imaging (MRI) based adaptive PT for children with tumors of the head and neck and base of skull. Methods: MRI verification images were acquired at half of the treatment course. A synthetic computed tomography (CT) image was created using this MRI and a deformable image registration (DIR) to the reference MRI. The methodology was verified with in-silico phantoms and validated using a clinical case with a shrinking cystic hygroma on the basis of dosimetric quantities of contoured structures. The dose distributions on the verification X-ray CT and on the synthetic CT were compared with a gamma-index test using global 2 mm/2% criteria. Results: Regarding the clinical validation case, the gamma-index pass rate was 98.3%. Eleven patients were included in the clinical study. The most common diagnosis was rhabdomyosarcoma (73%). Craniofacial tumor site was predominant in 64% of patients, followed by base of skull (18%). For one individual case the synthetic CT showed an increase in the median D2 and Dmax dose on the spinal cord from 20.5 GyRBE to 24.8 GyRBE and 14.7 GyRBE to 25.1 GyRBE, respectively. Otherwise, doses received by OARs remained relatively stable. Similarly, the target volume coverage seen by D95% and V95% remained unchanged. Conclusions: The method of transferring anatomical changes from MRIs to a synthetic CTs was successfully implemented and validated with simple, commonly available tools. In the frame of our early results on a small cohort, no clinical relevant deterioration for neither PTV coverage nor an increased dose burden to OARs occurred. However, the study will be continued to identify a pediatric patient cohort, which benefits from adaptive treatment planning.
Coupled Biohydrogen Production and Bio-Nanocatalysis for Dual Energy from Cellulose: Towards Cellulosic Waste Up-Conversion into Biofuels
Authors: Gomez-Bolivar Jaime , Orozco Rafael L. , Stephen Alan J. , Mikheenko Iryna P. , Leeke Gary A. , Merroun Mohamed L. , Macaskie Lynne E.
Published: May 2022

Hydrogen, an emergent alternative energy vector to fossil fuels, can be produced sustainably by fermentation of cellulose following hydrolysis. Fermentation feedstock was produced hydrolytically using hot compressed water. The addition of CO2 enhanced hydrolysis by ~26% between 240 and 260 °C with comparable hydrolysis products as obtained under N2 but at a 10 °C lower temperature. Co-production of inhibitory 5-hydromethyl furfural was mitigated via activated carbon sorption, facilitating fermentative biohydrogen production from the hydrolysate by Escherichia coli. Post-fermentation E. coli cells were recycled to biomanufacture supported Pd/Ru nanocatalyst to up-convert liquid-extracted 5-HMF to 2,5-dimethyl furan, a precursor of ‘drop in’ liquid fuel, in a one-pot reaction. This side stream up-valorisation mitigates against the high ‘parasitic’ energy demand of cellulose bioenergy, potentially increasing process viability via the coupled generation of two biofuels. This is discussed with respect to example data obtained via a hydrogen biotechnology with catalytic side stream up-conversion from cellulose feedstock.
Artificial Intelligence and Circulating Cell-Free DNA Methylation Profiling: Mechanism and Detection of Alzheimer’s Disease
Authors: Bahado-Singh Ray O. , Radhakrishna Uppala , Gordevičius Juozas , Aydas Buket , Yilmaz Ali , Jafar Faryal , Imam Khaled , Maddens Michael , Challapalli Kshetra , Metpally Raghu P. , Berrettini Wade H. , Crist Richard C. , Graham Stewart F. , Vishweswaraiah Sangeetha
Published: May 2022

Background: Despite extensive efforts, significant gaps remain in our understanding of Alzheimer’s disease (AD) pathophysiology. Novel approaches using circulating cell-free DNA (cfDNA) have the potential to revolutionize our understanding of neurodegenerative disorders. Methods: We performed DNA methylation profiling of cfDNA from AD patients and compared them to cognitively normal controls. Six Artificial Intelligence (AI) platforms were utilized for the diagnosis of AD while enrichment analysis was used to elucidate the pathogenesis of AD. Results: A total of 3684 CpGs were significantly (adj. p-value < 0.05) differentially methylated in AD versus controls. All six AI algorithms achieved high predictive accuracy (AUC = 0.949–0.998) in an independent test group. As an example, Deep Learning (DL) achieved an AUC (95% CI) = 0.99 (0.95–1.0), with 94.5% sensitivity and specificity. Conclusion: We describe numerous epigenetically altered genes which were previously reported to be differentially expressed in the brain of AD sufferers. Genes identified by AI to be the best predictors of AD were either known to be expressed in the brain or have been previously linked to AD. We highlight enrichment in the Calcium signaling pathway, Glutamatergic synapse, Hedgehog signaling pathway, Axon guidance and Olfactory transduction in AD sufferers. To the best of our knowledge, this is the first reported genome-wide DNA methylation study using cfDNA to detect AD.
Structural Diversity of Lithium Oligo-α-Pyridylamides
Authors: Raza Arsen , Mucci Adele , Nicolini Alessio , Cornia Andrea
Published: May 2022

Lithium oligo-α-pyridylamides are useful intermediates in coordination chemistry. Upon trans-metalation they have afforded a variety of extended metal atom chains (EMACs), which are currently investigated as molecular wires and single-molecule magnets. However, structural information on this class of compounds is scarce. Two trilithium salts of a new, sterically encumbered oligo-α-pyridylamido ligand were isolated in crystalline form and structurally characterized in the solid state and in solution. Lithiation of N2-(trimethylsilyl)-N6-{6-[(trimethylsilyl)amino]pyridin-2-yl}pyridine-2,6-diamine (H3L) with n-BuLi in thf yielded dimeric adduct [Li6L2(thf)6] (1), which was crystallized from n-hexane/thf as 1·C6H14. Crystals of a tetra-thf solvate with formula [Li6L2(thf)4] (2) were also obtained. The compounds feature two twisted L3− ligands exhibiting a cis-cis conformation and whose five nitrogen donors are all engaged in metal coordination. The six Li+ ions per molecule display coordination numbers ranging from 3 to 5. Compound 1·C6H14 was investigated by multinuclear 1D and 2D NMR spectroscopy, including 1H DOSY experiments, which indicated retention of the dimeric structure in benzene-d6 solution. To the best of our knowledge, 1 and 2 are the longest-chain lithium oligo-α-pyridylamides structurally authenticated so far, thereby qualifying as appealing intermediates to access high-nuclearity EMACs by trans-metalation.
Characterization of Gastric Tissue-Resident T Cells in Autoimmune and Helicobacter pylori-Associated Gastritis
Authors: Kametaka Daisuke , Iwamuro Masaya , Takahashi Takahide , Hirabata Araki , Hamada Kenta , Kono Yoshiyasu , Kanzaki Hiromitsu , Kawano Seiji , Tanaka Takehiro , Otsuka Fumio , Kawahara Yoshiro , Okada Hiroyuki
Published: May 2022

Data regarding the in-depth surface marker profiles of gastric tissue-resident lymphocytes in autoimmune and Helicobacter pylori-associated gastritis are lacking. In this study, we investigated potential differences in lymphocyte composition between these profiles. We enrolled patients with autoimmune (n = 14), active (current infection of H. pylori in the stomach; n = 10), and inactive gastritis (post-eradication of H. pylori; n = 20). Lymphocytes were isolated from the greater curvature of the stomach and lesser curvature of the body and analyzed using flow cytometry. The CD8+/CD3+ and CD4+/CD3+ ratios differed between the samples. Body CD4+/antrum CD4+, which is calculated by dividing the CD4+/CD3+ ratio in the body by that in the antrum, was significantly higher in autoimmune gastritis (3.54 ± 3.13) than in active (1.47 ± 0.41) and inactive gastritis (1.42 ± 0.77). Antrum CD8+/CD4+ in autoimmune gastritis (7.86 ± 7.23) was also higher than that in active (1.49 ± 0.58) and inactive gastritis (2.84 ± 2.17). The area under the receiver operating characteristic curve of antrum CD8+/CD4+ was 0.842, and the corresponding optimal cutoff point was 4.0, with a sensitivity of 71.4% and a specificity of 93.3%. We propose that an antrum CD8+/CD4+ ratio > 4.0 is a potential diagnostic marker for autoimmune gastritis.
Strengthening Saudi Arabia’s Primary Health Care through an e-Referral System: A Case Study
Authors: Alabbasi Khalid H. , Kruger Estie , Tennant Marc
Published: May 2022

Health systems are becoming more complex, regulatory bodies are increasing their vigilance, and reimbursement practices are shifting toward value, making closing the referral loop an imperative for patient safety, regulatory oversight, and financial viability. The aim of this study was to examine the referral pattern in PHC services and whether a significant variation exists among them based on geographic accessibility to a referred hospital. This was a cross-sectional retrospective study that included all sequentially referred patients between 1 January 2019 and 30 December 2021. A pre-initiative comparison could not be performed, as previous data on the traditional referral system could not be collected. The primary outcome measures considered in this study were the referral rate, and the proportion of the documented appointment date. The healthcare facilities’ geographic locations and data of the hospital departments to which the patients were referred were also available. Between 2019 and 2021, the hospital received 52,143 referrals from the 9 designated PHC centres covering 34 districts. In the PHC centres located within the ≤13 km zone, 1 in every 14 patients were referred to the hospital, whereas 1 in every 20 patients visited PHC centres outside this zone. Since the introduction of the Ehalati e-referral system, the number of documented appointment schedules of the referred patients has improved over time by 16.1% (from 79.6% to 95.7%, p < 0.001). Ophthalmologic (17.1%) and dental services (15.4%) received the most referrals among all other specialties, whereas the referral rate for cardiology services was the lowest (2.5%). The documented appointment scheduling record of referred patients has improved significantly since the introduction of the Ehalati e-referral system. However, the results of this study indicate that the proximity of PHC centres to specialised hospitals is more likely associated with higher referral and documented appointment scheduling rates. Strategies that improve scheduling, decrease variation among clinics, and improve patient access will likely improve the closing rates of the referral loop.
Performance of Insoluble IrO2 Anode for Sewage Sludge Cake Electrodehydration Application with Respect to Operation Conditions
Authors: Lee Nam-Young , You Mi-Young , Lee Jaemyung , Kim Seohan , Song Pung Keun
Published: May 2022

The efficient management of wastewater and sewage sludge treatment are becoming crucial with industrialization and increasing anthropological effects. Dehydration of sewage sludge cakes (SSCs) is typically carried out using mechanical and electrochemical processes. Using the mechanical dehydration process, only a limited amount of water can be removed, and the resultant SSCs have a water content of approximately 70–80 wt.%, which is significantly high for land dumping or recycling as solid fuel. Dumping high-moisture-content SSCs in land can lead to leakage of hazardous wastewater into the ground and cause economic loss. Therefore, dehydration of SSCs is crucial. Contemporary treatment methods focus on the development of anode materials for the electrochemical processes. IrO2 is an insoluble anode material that is eco-friendly, less expensive, and exhibits high chemical stability, and it has been widely used and investigated in wastewater treatment and electrodehydration (ED) industries. Herein, we evaluated the performance of the ED system developed using IrO2 anode material. The operating conditions of the anode such as reaction time, sludge thickness, and voltage on SSC were optimized. The performance of the ED system was evaluated based on the moisture content of SSCs after dehydration. The moisture content decreased proportionally with the reaction time, sludge thickness, and voltage. The moisture content of 40 wt.% was determined as the optimum quantity for land dumping or to be used as recycled solid fuel.
Mechanical Performance and Deformation Behavior of CoCrNi Medium-Entropy Alloy at the Atomic Scale
Authors: Liu ZF , Tian N , Tong YG , Hu YL , Deng DY , Zhang MJ , Cai ZH , Liu J
Published: May 2022

CoCrNi medium-entropy alloy has superior cryogenic properties with simultaneous growth of strength and plasticity at low temperatures. In order to observe the microstructure and deformation behavior of the alloy at the atomic scale, its mechanical properties and deformation mechanism at different temperatures and strain rates were investigated using molecular dynamics. It is indicated that the alloy’s strength was enhanced at low temperatures and high strain rates due to the production of high dislocation density. The introduction of grain boundaries significantly decreased the dislocation density during the alloy’s deformation and correspondingly reduced the crystal strength. However, the introduction of twin boundaries in polycrystalline grains obviously enhanced the strength of the polycrystal, especially at the twin boundary spacing of 3.08 nm. The strength’s enhancement was attributed to the increasing dislocation density produced by the interaction between twin boundaries and dislocations during deformation.
Modeling the Mechanical Properties of Heat-Treated Mg-Zn-RE-Zr-Ca-Sr Alloys with the Artificial Neural Network and the Regression Model
Authors: Fu Yu , Shao Zhiwen , Liu Chen , Wang Yinyang , Xu Yongdong , Zhu Xiurong
Published: May 2022

In this study, an artificial neural network approach and a regression model are adopted to predict the mechanical properties of heat-treated Mg-Zn-RE-Zr-Ca-Sr magnesium alloys. The dataset for artificial neural network (ANN) modeling is generated by investigating the microhardness of heat-treated Mg-Zn-RE-Zr-Ca-Sr alloys using Vickers hardness tests. A back-propagation (BP) neural network is established using experimental data that enable the prediction of mechanical properties as a function of the composition and heat treatment process. The input variables for the BP network model are Ca and Sr contents, ageing temperature and ageing time. The output variable corresponds to the microhardness. The optimal BP network model is acquired by optimizing the number of the hidden layer nodes. The results indicate that a reliable correlation coefficient is above 0.95 for architecture (4-8-1), which has a high level of accuracy for prediction. In addition, a second-order polynomial regression model is developed based on the least squares method. The results of determination coefficients and Fisher’s criterion indicate that the regression model is capable of modeling mechanical properties as a function of composition and the ageing process. Furthermore, supplemental experiments are conducted to check the accuracy of the BP model and the regression model, suggesting that the model predictions are well in accordance with experimental results. Therefore, both the BP network and regression models have high accuracy in modeling and predicting mechanical properties of heat-treated Mg-Zn-RE-Zr-Ca-Sr alloys.
Screening for Distress and Health Outcomes in Head and Neck Cancer
Authors: Gascon Bryan , Panjwani Aliza A. , Mazzurco Olivia , Li Madeline
Published: May 2022

Head and neck cancers (HNC) have higher rates of emotional distress than other cancer types and the general population. This paper compares the prevalence of emotional distress in HNC across various distress screening measures and examines whether significant distress or distress screening are associated with cancer-related survival. A retrospective observational cohort design was employed, with data collected from the Distress Assessment and Response Tool (DART) and linkages to administrative databases from 2010 to 2016. Descriptive and prevalence data were reported using multiple concurrently administered distress tools, including the Patient Health Questionaire-9 (PHQ-9), Generalized Anxiety Disorders-7 (GAD-7), Edmonton Symptom Assessment Scale-revised (ESAS-r), and MD Anderson Symptom Index-Head and Neck module (MDASI-HN). Across measures, 7.8 to 28.1% of the sample reported clinically significant emotional distress, with PHQ-9 and GAD-7 identifying lowest prevalence of moderate/severe distress, and the ultrashort distress screens within ESAS-r and MDASI-HN performing equivalently. Cox hazards models were used in univariate and multivariate survival analyses. ESAS depression (≥4), but not anxiety, was associated with increased risk of cancer-related mortality and patient completion of DART was associated with greater cancer-related survival. The findings underscore the importance of implementing routine distress screening for HNC populations and the utility of ultra-brief screening measures.
Ethnobotanical Knowledge on Herbs and Spices in Bulgarian Traditional Dry-Cured Meat Products
Authors: Ivanova Teodora , Chervenkov Mihail , Kozuharova Ekaterina , Dimitrova Dessislava
Published: May 2022

Artisan food production, with its unique flavors, is a source of knowledge about sustainable use of natural resources. This is because it reflects the skills of local communities in utilizing these resources (e.g., wild and cultivated plants and autochthonous breeds) under specific environmental conditions for a long period of time. Therefore, the use of local ingredients and the reduction in food miles make traditional food a safer, healthier and more ecofriendly choice for consumers. In the present research, we examined the herbal ingredients in Bulgarian dry-cured meats and discuss their contribution to the flavor and durability of the products. A combination of field data, collected through semi-structured interviews in local communities, and an analysis of the available literature was used to reveal the typicity of 24 artisanal/homemade meat products available mostly in their place of origin. We compared the obtained data to 16 industrial products branded as “traditional”, with 6 of them registered under the European Union quality schemes. The recorded ingredients of plant origin (dry and fresh) belonged to 16 taxa. Most diverse spice mixtures were used in products made of pork meat and in products originating from the southern, and hence warmer, regions of the country. The herbs and spices were combined freely except for Alliums, which were not mixed, and only one species was used per product. Most of the spices used in the artisanal dry meats were sourced from home gardens (some specifically cultivated for that purpose). Those collected from the wild, e.g., Origanum vulgare subp. hirtum (Link) Ietsw., were gathered sustainably in small quantities. The number of spices used in industrial dry meat products was limited to two–three, and was provided by cultivated sources, without exploiting natural populations. Manufacturing of all artisanal products was seasonal to avoid the cold winter weather, a measure which was necessary for the natural air-drying of the meat. The long-lasting effects of the abolishment of artisanal production under Communism, the adaptation of traditional products for industry, and the current challenges and perspectives surrounding artisanal production of meat products were discussed.
Can Humans and Elephants Coexist? A Review of the Conflict on Sumatra Island, Indonesia
Authors: Kuswanda Wanda , Garsetiasih Raden , Gunawan Hendra , Situmorang Rospita Odorlina Pilianna , Hutapea Freddy Jontara , Kwatrina Rozza Tri , Karlina Endang , Atmoko Tri , Zahrah Ma’rifatin , Takandjandji Mariana , Gunaryadi Donny
Published: May 2022

The high rate of deforestation and fragmentation of elephant habitat on Sumatra Island has triggered human-elephant conflict (HEC) in Sumatra Island, Indonesia. This conflict brings negative impacts on humans and elephants. Despite numerous efforts having been made to solve this problem, the HEC continues to occur in the remaining elephant enclave every year. The harmonious coexistence between humans and elephants could be improved through HEC mitigation programs. The aim of this paper was to review information on HEC in Sumatra Island, investigate the causes and implications of HEC, review existing HEC mitigation methods, and formulate strategies to improve the harmonious coexistence between humans and elephants. The best strategies to create successful human and elephant coexistence are strengthening the institutions and policies, restoring the habitat, developing wildlife corridors, establishing Essential Ecosystem Areas (EEA), community empowerment through ecotourism, providing legal access to forests through Social Forestry (SF), and providing compensation schemes for conflict victims.
Electron Kinetic Entropy across Quasi-Perpendicular Shocks
Authors: Lindberg Martin , Vaivads Andris , Raptis Savvas , Lindqvist Per-Arne , Giles Barbara L. , Gershman Daniel Jonathan
Published: May 2022

We use Magnetospheric Multiscale (MMS) data to study electron kinetic entropy per particle Se across Earth’s quasi-perpendicular bow shock. We have selected 22 shock crossings covering a wide range of shock conditions. Measured distribution functions are calibrated and corrected for spacecraft potential, secondary electron contamination, lack of measurements at the lowest energies and electron density measurements based on plasma frequency measurements. All crossings display an increase in electron kinetic entropy across the shock ΔSe being positive or zero within their error margin. There is a strong dependence of ΔSe on the change in electron temperature, ΔTe, and the upstream electron plasma beta, βe. Shocks with large ΔTe have large ΔSe. Shocks with smaller βe are associated with larger ΔSe. We use the values of ΔSe, ΔTe and density change Δne to determine the effective adiabatic index of electrons for each shock crossing. The average effective adiabatic index is ⟨γe⟩=1.64±0.07.
The Use of Organic Rankine Cycles for Recovering the Heat Lost in the Compression Area of a Cryogenic Air Separation Unit
Authors: Ionita Claudia , Bucsa Sorin , Serban Alexandru , Dobre Catalina , Dobrovicescu Alexandru
Published: May 2022

The use of organic Rankine cycles (ORCs) is a viable solution for the recovery of waste heat. For an air separation unit (ASU) with a production of V˙O2=58300mN3/h operating in Romania, the value of utilization of the heat transferred to the cooling system of the compression area represents 21% of the global system electrical energy input. To recover this thermal energy and transform it into mechanical energy, an ORC system was proposed. To maximize the production of mechanical power, an exergy analysis was performed. Exergy analysis was used to choose the most suitable organic fluid and find the optimum constructive structure of the Rankine cycle. The calculation of the exergy destruction in the key apparatuses of the system allowed investigation into the optimization search procedure. The large exergy destruction in the liquid preheater suggested the decrease in the temperature difference in this part of the evaporator by increasing the inlet temperature of the liquid; and an internal recuperative heat exchanger was used for this purpose. When permitted, the overheating of the vapors also reduced the temperature difference between the heat source and the organic fluid during the heat transfer process. The analysis was comparatively performed for several organic fluids such as R-245fa, R123, n-pentane and R717. The use of ammonia, that offered the possibility of superheating the vapors at the turbine inlet, brought a gain of mechanical power corresponding to 6% economy in the electrical energy input of the global plant.
Application of Two Novel Acoustic Emission Parameters on Identifying the Instability of Granite
Authors: Ji Zhenxing , Jiang Peihua , Yi Haiyang , Zhuo Zhuang , Li Chunyuan , Wu Zhide
Published: May 2022

The issue of monitoring and early warning of rock instability has received increasing critical attention in the study of rock engineering. To investigate the damage evolution process of granite under triaxial compression tests, acoustic emission (AE) tests were performed simultaneously. This study firstly introduced two novel parameters, i.e., the coefficient of variation (CoV) of the information entropy and correlation dimension of the amplitude data from the AE tests, to identify the precursor of the failure of granite. Then the relationship between the changes in these parameters and the stress-time curve was compared and analyzed. The results of this study show that: (1) There is a strong correlation between the CoV of the information entropy and the failure process of granite. The granite failed when the CoV curve raised to a plateau, which could be used as an indicator of rock instability. (2) The fluctuation of the correlation dimension indicates the different stages during the loading process, i.e., the initial compaction stage, the linear elastic stage, the yield stage, and the failure stage. Each stage contains a descending and a rising process in the correlation dimension curve, and the exhibited starting point or the bottom point at the correlation dimension curve could be selected as the indicator point for the rock instability. (3) The combined analysis of the Information entropy and Correlation dimension can improve the accuracy of rock instability prediction. This study provides new insights into the prediction of rock instability, which has theoretical implications for the stability of subsurface engineering rock masses.
Enhancing Student Employability in Collaboration with the Industry: Case Study of a Partnership with Amazon Web Services Academy
Authors: Goteng Gokop L. , Shohel M. Mahruf C. , Tariq Faisal
Published: May 2022

The continuous increase in tuition fees in high education in many countries requires justification by the university authorities of what students receive from them in return. One of the key factors of student recruitment is values for money and quality learning experiences including hands-on industry training that can guarantee immediate employment for the graduates. This article describes redesigning the curriculum of a cloud computing undergraduate module in collaboration with Amazon Web Services (AWS) Academy. Industry-based practical hands-on labs were incorporated into this module for engineering students to improve their practical knowledge and skills related to the Internet of Things. Through an innovative approach, this practitioner research introduces industry best practices and hands-on labs in cloud computing. In this approach, academic theories were incorporated in cloud computing with their applications through industry attachment. It enables students to have both the theoretical and practical knowledge and skills for ensuring their careers in the field of cloud computing. The study finds that students tend to be more engaged and learn better when theoretical knowledge and understanding are combined with real-world applications through the attachment with the industry.
Performance Degradation Investigation for a GaAs PHEMT High Gain MMIC PA Taking into Account the Temperature
Authors: Jia Lining , Lin Qian , Wu Haifeng , Wang Xiaozheng
Published: May 2022

In order to comprehensively grasp the performance changes for the monolithic microwave integrated circuit (MMIC), this paper proposes that the complete temperature reliability tests for a 2.4–4.4 GHz gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) high gain power amplifier (PA) should be investigated. The performance for this MMIC PA at different temperatures has been presented effectively. The results show that the direct current (DC) characteristics, small-signal gain (S21), and radio frequency (RF) output characteristics for this MMIC PA decrease and the output third-order intersection point (OIP3) increases with the rising temperature. The main factor influencing the performance is analyzed in detail. For further applications of this MMIC PA, several measures can be utilized to remedy the performance degradation. This paper can provide significant engineer guidance for the reliability design of RF microwave circuits.
Empirical Characterization of ReRAM Devices Using Memory Maps and a Dynamic Route Map
Authors: Picos Rodrigo , Stavrinides Stavros G. , Al Chawa Mohamad Moner , de Benito Carola , Dueñas Salvador , Castan Helena , Hatzikraniotis Euripides , Chua Leon O.
Published: May 2022

Memristors were proposed in the early 1970s by Leon Chua as a new electrical element linking charge to flux. Since that first introduction, these devices have positioned themselves to be considered as possible fundamental ones for the generations of electronic devices to come. In this paper, we propose a new way to investigate the effects of the electrical variables on the memristance of a device, and we successfully apply this technique to model the behavior of a TiN/Ti/HfO2/W ReRAM structure. To do so, we initially apply the Dynamic Route Map technique in the general case to obtain an approximation to the differential equation that determines the behaviour of the device. This is performed by choosing a variable of interest and observing the evolution of its own temporal derivative versus both its value and the applied voltage. Then, according to this technique, it is possible to obtain an approach to the governing equations with no need to make any assumption about the underlying physical mechanisms, by fitting a function to this. We have used a polynomial function, which allows accurate reproduction of the observed electrical behavior of the measured devices, by integrating the resulting differential equation system.
Accelerating Microbial Activity of Soil Aquifer Treatment by Hydrogen Peroxide
Authors: Friedman Liron , Chandran Kartik , Avisar Dror , Taher Edris , Kirchmaier-Hurpia Amanda , Mamane Hadas
Published: May 2022

Soil aquifer treatment (SAT), as a gravity-based wastewater reuse process, is limited by oxygen availability to the microbial community in the soil. Using oxygen from enzymatic degradation of H2O2 to generate hyper-oxygen conditions can exceed solubility limitations associated with aeration, but little is known about the effect of hyper-oxygen conditions on the microbial community and the dominant bio-reactions. This study examined the impact of H2O2 addition on the community structure and process performance, along with SAT depth. Overall, two soil columns were incrementally fed synthetic secondary effluents to simulate infiltration through SAT. The experimental column received 14 mg/L hydrogen peroxide to double the level of natural oxygen available. The microbial kinetics of nitrifiers and heterotrophs were evaluated. We found that all of the H2O2 was degraded within the top 10 cm of the column, accompanied by a higher removal of COD (23 ± 0.25%) and ammonia (31 ± 3%) in comparison to the reference column. Higher nitrogen removal (23 ± 0.04%) was obtained for the whole process using H2O2. Analysis of nitrifiers indicated that ammonia-oxidizing bacteria were most influenced, obtaining higher concentration and abundance when exposed to H2O2. DNA sequencing analysis of samples exposed to H2O2 revealed significant community structure and diversity differences among heterotrophs. This study shows that not only aerobic, but also anoxic, microbial activity and process performance in a SAT system could be accelerated in existing infrastructure with H2O2, which could significantly decrease the associated environmental footprint.
High-Performance Fractional Order PIMR-Type Repetitive Control for a Grid-Tied Inverter
Authors: Yu Jun , Zhao Qiangsong , Li Hengyi , Yue Xuebin , Wen Shengjun
Published: May 2022

Low switching frequency is usually used in high-power wind grid-tied inverter systems to reduce power loss caused by on–off switching activity. Proportional integral multi-resonant type repetitive control (PIMR-type RC) can track reference grid current signals and suppress harmonic signals of grid-tied inverter system. A low switching frequency will result in a low sampling rate of control system. However, integer-order phase-lead compensation will lead to a poor compensation accuracy of PIMR-type RC with a low sampling rate, leading to poor tracking and suppressing performance of PIMR-type RC, and even result in system instability. To solve these problems, a high-performance fractional-order phase-lead compensation PIMR-type RC (FO-PIMR-RC) scheme is proposed in this paper. Fractional-order phase-lead compensation is adopted to compensate accurately the phase lag caused by controlled plant and PIMR-type RC and approximately realized by a finite impulse response (FIR) filter. Stability analysis and harmonic suppression performance are provided, and the parameter optimization design is implemented. Simulation and experimental results prove the desirable performance of the proposed control scheme.
Research on Reactive Power Optimization Control of a Series-Resonant Dual-Active-Bridge Converter
Authors: Wu Junjuan , Zhang Wei , Sun Xiaofeng , Su Xinyu
Published: May 2022

In order to meet the demands of the bidirectional transmission of electric vehicle charger power, a series-resonant dual-active-bridge (DAB) converter is investigated in this paper. Firstly, the active and reactive power and zero voltage switching (ZVS) conditions of the full-bridge arm under extended phase-shift modulation, dual phase-shift modulation and triple phase-shift modulation are analyzed. Secondly, with the minimum reactive power as the optimization objective, the extended phase shift (EPS) is finally selected as the modulation method after comparing the minimum reactive power under various modulation methods when the normalized value of active power is varied in the range of 0–1. By constructing the objective function and determining the constraints, an off-line reactive power–minimization control strategy is proposed to achieve the ZVS of the full-bridge arm and, finally, the feasibility of the proposed control strategy is verified by simulation and experiment.
Assessment of the Reliability of Wind Farm Devices in the Operation Process
Authors: Duer Stanisław , Paś Jacek , Hapka Aneta , Duer Radosław , Ostrowski Arkadiusz , Woźniak Marek
Published: May 2022

The article deals with simulation tests on the reliability of the equipment of the wind farm WF in the operation process. The improvement, modernization, and introduction of new solutions that change the reliability, as well as the quality and conditions of use and operation of wind farm equipment, require testing. Based on these tests, it is possible to continuously evaluate the reliability of the equipment of WF. The issue of reliability assessment of wind farm equipment, for which intelligent systems, diagnostic systems DIAG, and Wind Power Plant Expert System (WPPES) are used to modernize the operation process, can only be tested in a simulative way. The topic of testing the reliability of complex technical objects is constantly developing in the literature. In this paper, it is assumed that the operation of wind farm equipment is described and modeled based on Markov processes. The adoption of this assumption justified the use of the Kolmogorov–Chapman equations to describe the developed model. Based on this equation, an analytically developed model of the wind farm operation process was described. The simulation analysis determines the reliability of the wind farm in terms of the availability factor Kg(t). The simulation tests are performed in two phases using the computer program LabView. In the first stage, the reliability value in the form of the readiness factor Kg(t) as a function of changes in the mean repair time value ranging {from 0.3 to 1.0} was investigated. In the second stage, the reliability value of WF devices was examined as a function of changes in the value of the average time between successive failures, ranging from 1000 to 3000 (h)}.
Regression-Analysis-Based Empirical Correlations to Design Regenerative Flow Machines
Authors: M. Feroskhan , M. Sreekanth , K. Karunamurthy , R. Sivakumar , Sinaga Nazaruddin , Khan T. M. Yunus
Published: May 2022

Regenerative flow machines are known to be simple in construction but complex in flow characteristics. Due to this reason, the design of these machines has been primarily esoteric, and hence its performance heavily relies on the experience and expertise of the designer. Since there are no established rules of thumb for designing them, this paper attempts to provide simple design correlations for systematically designing regenerative flow machines viz. pumps, blowers, and compressors. Three different impeller designs have been considered, namely the (i) single-side vane impeller, (ii) double-side vane impeller, and (iii) peripheral vane impeller, for the three types of machines. More than ten design parameters have been considered for sizing the machines. Experimental and computational data available in open literature have been used to obtain physically meaningful correlations in simple form, and require minimal and practically available inputs. Fluid properties and practical constraints were taken into consideration while deriving the correlations. Constants in the correlations were obtained using least square regression analysis. The accuracy of the obtained correlation is determined by the correlation coefficient. The deviation obtained using the derived correlations varied from 10 to 25%. A consolidated set of correlations has been presented, which will be helpful in making a preliminary design before CFD simulation, design optimization, and prototype building. Finally, the obtained correlations have been used to demonstrate the design of a regenerative flow pump.
Electric Vehicle Efficient Power and Propulsion Systems
Authors: Trovão João Pedro F. , Ta Minh Cao
Published: May 2022

Vehicle electrification is one of the main growing trends with an identified growth capacity of 15% until 2030 [...]
Analysis of the Influence of Parameter Condition on Whole Load Power Factor and Efficiency of Line Start Permanent Magnet Assisted Synchronous Reluctance Motor
Authors: Wang Jin , Li Yan , Wu Shengnan , Yu Zhanyang , Chen Lihui
Published: May 2022

Line start permanent magnet assisted synchronous reluctance motor (LSPMaSynRM) is an important high-efficiency and high-quality motor. Its parameter matching and operating characteristics are complex, with an increase in salient ratio resulting in a valley in the power factor curve. In this study, the formation principle of power factor curve valley was first deduced by the mathematical model of LSPMaSynRM. Then, the parameter matching principle of power factor curve valley was analyzed in detail. On this basis, the characteristics of load rate corresponding to the critical state of the power factor curve valley were obtained, and its influence on whole load efficiency was analyzed. The design principles for optimal efficiency in wide high-efficiency region and specific load point were obtained. Finally, a 5.5 kW LSPMaSynRM was designed and manufactured to verify the validity of the principle.
Optimal Reactive Power Dispatch under Transmission and Distribution Coordination Based on an Accelerated Augmented Lagrangian Algorithm
Authors: Zhou Bin , Shen Xiaodong , Pan Caimei , Bai Yuanbao , Wu Tian
Published: May 2022

As many distributed power sources flood into the distribution network, the relationship between transmission and distribution grids in reactive power and voltage is becoming closer and closer. The traditional way of independent reactive power optimization in transmission and distribution grids is no longer appropriate. In this study, a collaborative and distributed reactive power optimization method for transmission and distribution grids based on the accelerated augmented Lagrangian (AAL) algorithm is proposed to adapt to the independence of the transmission and distribution grids in operation and management. The global reactive power optimization problem is decomposed into the transmission network subproblem and several distribution network subproblems. According to AAL, subproblems are solved in a distributed manner until the optimal global solution is finally reached after several iterations, and coordination between transmission and distribution grids is achieved only through the interaction of information on coordinating variables. For better convergence, a linearized and convergence-guaranteed optimal power flow model (OPF) with reactive power and voltage magnitude was applied to model the transmission grid optimization subproblem, while the second-order cone programming (SOCP) technique is used in the distribution network subproblems. The simulation results confirm that the method in this paper can effectively reduce network losses and achieve better economic performance, and converges better when compared to other algorithms.