bluuebunny/crossref_metadata_2025 huggingface dataset:
Stereotactic Radiosurgery Hypophysectomy for Palliative Treatment of Refractory Cancer Pain: A Historical Review and Update
Authors: Larkin M. Benjamin , Karas Patrick J. , McGinnis John P. , McCutcheon Ian E. , Viswanathan Ashwin
Published: December 2020

Medically refractory pain in those with advanced cancer significantly reduces one’s quality of life. Therefore, palliative interventions to mitigate cancer pain and reduce opioid requirements are necessary to reduce patient suffering and opioid-induced side effects. Hypophysectomy, a largely forgotten pain procedure with several technical variations, has been repeatedly studied in small series with encouraging results, though historically has been fraught with complications. As a result, the minimally invasive and more tolerable stereotactic radiosurgery (SRS) hypophysectomy has resurfaced as a possible treatment for cancer-related pain. While the mechanism of pain relief is not entirely understood, the hypothalamohypophyseal axis appears to play an essential role in pain perception and transmission and involves C fiber signal processing and downstream modulation of the brainstem and spinal cord via the hypothalamus. This review highlights the role of hypophysectomy in alleviating advanced cancer pain, both in hormonal and nonhormonal malignancy and the current mechanistic understanding of pain relief for the three primary hypophysectomy modalities used historically: surgical and chemical adenolysis, as well as the more recent, SRS hypophysectomy. Given the lack of high-quality evidence for stereotactic radiosurgery hypophysectomy, there is a need for further rigorous and prospective clinical studies despite its ideal and noninvasive approach.
A Novel Nomogram Model Based on Cone-Beam CT Radiomics Analysis Technology for Predicting Radiation Pneumonitis in Esophageal Cancer Patients Undergoing Radiotherapy
Authors: Du Feng , Tang Ning , Cui Yuzhong , Wang Wei , Zhang Yingjie , Li Zhenxiang , Li Jianbin
Published: December 2020

Purpose

We quantitatively analyzed the characteristics of cone-beam computed tomography (CBCT) radiomics in different periods during radiotherapy (RT) and then built a novel nomogram model integrating clinical features and dosimetric parameters for predicting radiation pneumonitis (RP) in patients with esophageal squamous cell carcinoma (ESCC).

Methods

At our institute, a retrospective study was conducted on 96 ESCC patients for whom we had complete clinical feature and dosimetric parameter data. CBCT images of each patient in three different periods of RT were obtained, the images were segmented using both lungs as the region of interest (ROI), and 851 image features were extracted. The least absolute shrinkage selection operator (LASSO) was applied to identify candidate radiomics features, and logistic regression analyses were applied to construct the rad-score. The optimal period for the rad-score, clinical features, and dosimetric parameters were selected to construct the nomogram model and then the receiver operating characteristic (ROC) curve was used to evaluate the prediction capacity of the model. Calibration curves and decision curves were used to demonstrate the discriminatory and clinical benefit ratios, respectively.

Results

The relative volume of total lung treated with ≥5 Gy (V5), mean lung dose (MLD), and tumor stage were independent predictors of RP and were finally incorporated into the nomogram. When the three time periods were modeled, the first period was better than the others. In the primary cohort, the area under the ROC curve (AUC) was 0.700 (95% confidence interval (CI) 0.568–0.832), and in the independent validation cohort, the AUC was 0.765 (95% CI 0.588–0.941). In the nomogram model that integrates clinical features and dosimetric parameters, the AUC in the primary cohort was 0.836 (95% CI 0.700–0.918), and the AUC in the validation cohort was 0.905 (95% CI 0.799–1.000). The nomogram model exhibits excellent performance. Calibration curves indicate a favorable consistency between the nomogram prediction and the actual outcomes. The decision curve exhibits satisfactory clinical utility.

Conclusion

The radiomics model based on early lung CBCT is a potentially valuable tool for predicting RP. V5, MLD, and tumor stage have certain predictive effects for RP. The developed nomogram model has a better prediction ability than any of the other predictors and can be used as a quantitative model to predict RP.
Understanding Independence: Board of Directors and CSR
Authors: Calderón Reyes , Piñero Ricardo , Redín Dulce M.
Published: December 2020

On August Business Roundtable (2019), the Business Roundtable redefined the purpose and social responsibility of the corporation. Yet, this statement must be followed by substantial changes in the business models of corporations for it to avoid becoming empty rhetoric. We believe that the figure of the independent director may be one of the catalysts needed for this change of paradigm for corporations. In spite of the positive correlation between Corporate Social Responsibility (CSR) and board independence, the development of the independence of boards during the last decade has not lead to the expected CSR results. Academics and regulators point to a weak definition and the non-standardized measurement of both independence and board independence (BI) as one possible explanation, and agree that a broader definition is needed. This paper aims to contribute to this debate. We develop a second-generation definition of independence based on a positive approximation to the concept by integrating an Aristotelian perspective of virtue ethics with the best practices of corporate governance. Thus, we define independence as a virtue guided by practical wisdom, that implies autonomy and autarky and which enables a person to act with integrity, fairness and truthfulness. In the context of corporate governance, independence is associated with an honest disposition to serve. Our proposal has political implications for supervisors that make decisions relating to the suitability of board members.
Effects of Probabilistic Risk Situation Awareness Tool (RSAT) on Aeronautical Weather-Hazard Decision Making
Authors: Parmar Sweta , Thomas Rickey P.
Published: December 2020

We argue that providing cumulative risk as an estimate of the uncertainty in dynamically changing risky environments can help decision-makers meet mission-critical goals. Specifically, we constructed a simplified aviation-like weather decision-making task incorporating Next-Generation Radar (NEXRAD) images of convective weather. NEXRAD radar images provide information about geographically referenced precipitation. NEXRAD radar images are used by both pilots and laypeople to support decision-making about the level of risk posed by future weather-hazard movements. Using NEXRAD, people and professionals have to infer the uncertainty in the meteorological information to understand current hazards and extrapolate future conditions. Recent advancements in meteorology modeling afford the possibility of providing uncertainty information concerning hazardous weather for the current flight. Although there are systematic biases that plague people’s use of uncertainty information, there is evidence that presenting forecast uncertainty can improve weather-related decision-making. The current study augments NEXRAD by providing flight-path risk, referred to as the Risk Situational Awareness Tool (RSAT). RSAT provides the probability that a route will come within 20 NMI radius (FAA recommended safety distance) of hazardous weather within the next 45 min of flight. The study evaluates four NEXRAD displays integrated with RSAT, providing varying levels of support. The “no” support condition has no RSAT (the NEXRAD only condition). The “baseline” support condition employs an RSAT whose accuracy is consistent with current capability in meteorological modeling. The “moderate” support condition applies an RSAT whose accuracy is likely at the top of what is achievable in meteorology in the near future. The “high” support condition provides a level of support that is likely unachievable in an aviation weather decision-making context without considerable technological innovation. The results indicate that the operators relied on the RSAT and improved their performance as a consequence. We discuss the implications of the findings for the safe introduction of probabilistic tools in future general aviation cockpits and other dynamic decision-making contexts. Moreover, we discuss how the results contribute to research in the fields of dynamic risk and uncertainty, risk situation awareness, cumulative risk, and risk communication.
Developing a Framework to Increase Access to Mental Health Services for Children With Special Needs in Ethiopia
Authors: Hughes Tammy L. , Quinn Cydney , Tiberi Amy , Zeleke Waganesh A.
Published: December 2020

The availability and accessibility of Westernized mental health diagnostic processes and evidence-based treatments are limited in developing countries, such as Ethiopia (Kakuma et al., 2011; Hohenshil et al., 2013; Wondie, 2014; Zeleke et al., 2017b). Similar to other developing nations, there is (a) a lack of health care services for mental practices to build on, (b) limited services that are well-suited to the culture (Wondie, 2014; Zeleke et al., 2019), (c) limited scientific literature useful for documenting the needs of the Ethiopian public, and (d) too few mental health professional preparation programs (Zeleke et al., 2019). Whereas Western cultures generally follow the biomedical model conceptualization and treatment of disease, non-Western cultures, such as Ethiopia tend to adhere to traditional and religious views to explain the origin of mental illness (Kortmann, 1987; Jacobsson and Merdassa, 1991). Mental health symptoms may be attributed to supernatural causes or other spiritual crises, rather than a combination of biopsychosocial influences. As such, individuals seeking help with mental health symptoms in Ethiopia are mostly limited to family, friends and local community healers (Zeleke et al., 2017a, 2019). When individuals are brought to the few places providing Westernized mental health care, it is often only after exhausting other traditional and religious alternatives (Bekele et al., 2000). Even when there is a desire to seek Westernized services, socioeconomic circumstance, cultural factors (e.g., a focus on collectivism practices), negative attitudes toward mental illness, along with unfamiliarity and fear of these new practices, are noted barriers to receiving treatments. Beliefs passed down through cultural taboos go on to effect multiple generations. Not only do barriers affect individuals, but they also negatively impact the range of services for children, families and communities. With the ultimate goal of improving mental health care access for children, a full appreciation of the context is essential.
Special Issue “Integrated Defense Responses in Crops against Soil-Borne Pathogens”
Authors: Witzel Katja , Berger Beatrice
Published: December 2020

Soil-borne pathogenic organisms can have severe detrimental effects on crop growth and yield production and represent a serious threat to food security [...]
Phenolic Profile and Bioactive Potential of Stems and Seed Kernels of Sweet Cherry Fruit
Authors: Afonso Sílvia , Oliveira Ivo Vaz , Meyer Anne S. , Aires Alfredo , Saavedra Maria José , Gonçalves Berta
Published: December 2020

Every year, large quantities of stems and pits are generated during sweet cherry processing, without any substantial use. Although stems are widely recognized by traditional medicine, detailed and feasible information about their bioactive composition or biological value is still scarce, as well as the characterization of kernels. Therefore, we conducted a study in which bioactivity potential of extracts from stems and kernels of four sweet cherry cultivars (Early Bigi (grown under net cover (C) and without net cover (NC)), Burlat, Lapins, and Van) were examined. The assays included antioxidant (by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene-linoleic acid bleaching assays), and antibacterial activities against important Gram negative and Gram positive bacterial human isolates. Profile and individual phenolic composition of each extract were determined by High-performance liquid chromatography (HPLC) analysis. Extracts from stems of cv. Lapins and kernels of Early Bigi NC presented high levels of total phenolics, flavonoids, ortho-diphenols and saponins. Excepting for cv. Early Bigi NC, major phenolic compounds identified in stems and kernels were sakuranetin and catechin, respectively. In cv. Early Bigi NC the most abundant compounds were ellagic acid for stems and protocatechuic acid for kernels. In all extracts, antioxidant activities showed a positive correlation with the increments in phenolic compounds. Antimicrobial activity assays showed that only stem’s extracts were capable of inhibiting the growth of Gram positive isolates. This new data is intended to provide new possibilities of valorization of these by-products and their valuable properties.
Spatial Distribution, Source Apportionment, Ozone Formation Potential, and Health Risks of Volatile Organic Compounds over a Typical Central Plain City in China
Authors: He Kun , Shen Zhenxing , Sun Jian , Lei Yali , Zhang Yue , Wang Xin
Published: December 2020

The profiles, contributions to ozone formation, and associated health risks of 56 volatile organic compounds (VOCs) species were investigated using high time resolution observations from photochemical assessment monitoring stations (PAMs) in Luoyang, China. The daily averaged concentration of total VOCs (TVOCs) was 21.66 ± 10.34 ppbv in urban areas, 14.45 ± 7.40 ppbv in suburbs, and 37.58 ± 13.99 ppbv in an industrial zone. Overall, the VOCs levels in these nine sites followed a decreasing sequence of alkanes > aromatics > alkenes > alkyne. Diurnal variations in VOCs exhibited two peaks at 8:00–9:00 and 19:00–20:00, with one valley at 23:00–24:00. Source apportionment indicated that vehicle and industrial emissions were the dominant sources of VOCs in urban and suburban sites. The industrial site displayed extreme levels, with contributions from petrochemical-related sources of up to 38.3%. Alkenes and aromatics displayed the highest ozone formation potentials because of their high photochemical reactivity. Cancer and noncancer risks in the industrial site were higher than those in the urban and suburban areas, and USEPA possible risk thresholds were reached in the industrial site, indicating PAMs VOC–related health problems cannot be ignored. Therefore, vehicle and industrial emissions should be prioritized when considering VOCs and O3 control strategies in Luoyang.
Biologically Inspired Surgical Needle Steering: Technology and Application of the Programmable Bevel-Tip Needle
Authors: Matheson Eloise , Rodriguez y Baena Ferdinando
Published: December 2020

Percutaneous interventions via minimally invasive surgical systems can provide patients with better outcomes and faster recovery times than open surgeries. Accurate needle insertions are vital for successful procedures, and actively steered needles can increase system precision. Here, we describe how biology inspired the design of a novel Programmable Bevel-Tip Needle (PBN), mimicking the mechanics and control methods of certain insects ovipositors. Following an overview of our unique research and development journey, this paper explores our latest, biomimetic control of PBNs and its application to neurosurgery, which we validate within a simulated environment. Three modalities are presented, namely a Direct Push Controller, a Cyclic Actuation Controller, and a newly developed Hybrid Controller, which have been integrated into a surgical visual interface. The results of open loop, expert human-in-the-loop and a non-expert user study show that the Hybrid Controller is the best choice when considering system performance and the ability to lesson strain on the surrounding tissue which we hypothesis will result in less damage along the insertion tract. Over representative trajectories for neurosurgery using a Hybrid Controller, an expert user could reach a target along a 3D path with an accuracy of 0.70±0.69 mm, and non-expert users 0.97±0.72 mm, both clinically viable results and equivalent or better than the state-of-the-art actively steered needles over 3D paths. This paper showcases a successful example of a biologically inspired, actively steered needle, which has been integrated within a clinical interface and designed for seamless integration into the neurosurgical workflow.
Toward a Computational Neuropsychology of Cognitive Flexibility
Authors: Steinke Alexander , Kopp Bruno
Published: December 2020

Cognitive inflexibility is a well-documented, yet non-specific corollary of many neurological diseases. Computational modeling of covert cognitive processes supporting cognitive flexibility may provide progress toward nosologically specific aspects of cognitive inflexibility. We review computational models of the Wisconsin Card Sorting Test (WCST), which represents a gold standard for the clinical assessment of cognitive flexibility. A parallel reinforcement-learning (RL) model provides the best conceptualization of individual trial-by-trial WCST responses among all models considered. Clinical applications of the parallel RL model suggest that patients with Parkinson’s disease (PD) and patients with amyotrophic lateral sclerosis (ALS) share a non-specific covert cognitive symptom: bradyphrenia. Impaired stimulus-response learning appears to occur specifically in patients with PD, whereas haphazard responding seems to occur specifically in patients with ALS. Computational modeling hence possesses the potential to reveal nosologically specific profiles of covert cognitive symptoms, which remain undetectable by traditionally applied behavioral methods. The present review exemplifies how computational neuropsychology may advance the assessment of cognitive flexibility. We discuss implications for neuropsychological assessment and directions for future research.
Dynamics of Fecal Microbiota with and without Invasive Cervical Cancer and Its Application in Early Diagnosis
Authors: Kang Gi-Ung , Jung Da-Ryung , Lee Yoon Hee , Jeon Se Young , Han Hyung Soo , Chong Gun Oh , Shin Jae-Ho
Published: December 2020

The fecal microbiota is being increasingly implicated in the diagnosis of various diseases. However, evidence on changes in the fecal microbiota in invasive cervical cancer (ICC) remains scarce. Here, we aimed to investigate the fecal microbiota of our cohorts, develop a diagnostic model for predicting early ICC, and identify potential fecal microbiota-derived biomarkers using amplicon sequencing data. We obtained fecal samples from 29 healthy women (HC) and 17 women with clinically confirmed early ICC (CAN). Although Shannon’s diversity index was not reached at statistical significance, the Chao1 and Observed operational taxonomic units (OTUs) in fecal microbiota was significantly different between CAN and HC group. Furthermore, there were significant differences in the taxonomic profiles between HC and CAN; Prevotella was significantly more abundant in the CAN group and Clostridium in the HC group. Linear discriminant analysis effect size (LEfSe) analysis was applied to validate the taxonomic differences at the genus level. Furthermore, we identified a set of seven bacterial genera that were used to construct a machine learning (ML)-based classifier model to distinguish CAN from patients with HC. The model had high diagnostic utility (area under the curve [AUC] = 0.913) for predicting early ICC. Our study provides an initial step toward exploring the fecal microbiota and helps clinicians diagnose.
Insights into the Pt (111) Surface Aid in Predicting the Selective Hydrogenation Catalyst
Authors: Wang Tianzuo , Pan Lun , Zhang Xiangwen , Zou Ji-Jun
Published: December 2020

The d-band center position of the metal catalyst is one of the most important factors for catalytic selective hydrogenation, e.g., the conversion of nitrostyrene to aminostyrene. In this work, we modulate the d-band center position of the Pt surface via H coverage manipulation in order to assess the highly efficient selective hydrogenation catalyst using density functional theory (DFT) calculation, which is validated experimentally. The optimal transition metal catalysts are first screened by comparing the adsorption energy values of two ideal models, nitrobenzene and styrene, and by correlating the adsorption energy with the d-band center positions. Among the ten transition metals, Pt nanoparticles have a good balance between selectivity and the conversion rate. Then, the surface hydrogen covering strategy is applied to modulate the d-band center position on the Pt (111) surface, with the increase of H coverage leading to a decline of the d-band center position, which can selectively enhance the adsorption of nitro groups. However, excessively high H coverage (e.g., 75% or 100%) with an insufficiently low d-band center position can switch the chemisorption of nitro groups to physisorption, significantly reducing the catalytic activity. Therefore, a moderate d-band center shift (ca. −2.14 eV) resulted in both high selectivity and catalytic conversion. In addition, the PtSn experimental results met the theoretical expectations. This work provides a new strategy for the design of highly efficient metal catalysts for selective hydrogenation via the modulation of the d-band center position.
Poisoning of SCR Catalysts by Alkali and Alkaline Earth Metals
Authors: Lisi Luciana , Cimino Stefano
Published: December 2020

SCR still represents the most widely applied technique to remove nitrogen oxides from flue gas from both stationary and mobile sources. The catalyst lifetime is greatly affected by the presence of poisoning compounds in the exhaust gas that deactivate the catalysts over time on stream. The progressive and widespread transition towards bio-derived fuels is pushing research efforts to deeply understand and contrast the deactivating effects of some specific poisons among those commonly found in the emissions from combustion processes. In particular, exhaust gases from the combustion of bio-fuels, as well as from municipal waste incineration plants and marine engines, contain large amounts of alkali and alkaline earth metals that can severely affect the acid, redox, and physical properties of the SCR catalysts. This review analyzes recent studies on the effects of alkali and alkaline earth metals on different types of SCR catalysts divided into three main categories (conventional V2O5-WO3/TiO2, supported non-vanadium catalysts and zeolite-based catalysts) specifically focusing on the impact of poisons on the reaction mechanism while highlighting the different type of deactivation affecting each group of catalysts. An overview of the different regeneration techniques aimed at recovering as much as possible the original performance of the catalysts, highlighting the pros and cons, is given. Finally, current research trends aiming to improve the tolerance towards alkali-poisoning of SCR catalysts are reported.
Modelling the Sintering of Nickel Particles Supported on γ-Alumina under Hydrothermal Conditions
Authors: Champon Isabelle , Bengaouer Alain , Chaise Albin , Thomas Sébastien , Roger Anne-Cécile
Published: December 2020

Sintering of nickel particles is a well-known path of deactivation for Ni/Al2O3 catalysts. Considering the CO2 methanation in the context of Power-to-Gas, a sintering study for up to 300 h was performed in a controlled atmosphere between 450 and 600 °C. Since water is a product of the methanation reaction and is known to favor the particle sintering, the H2O:H2 molar ratio was varied in the range 0–3.2. Characterization of the post mortem samples showed sintering of both nickel and support particles. The absence of carbon oxides in the gas feed allows us to rule out other causes of deactivation such as carbon deposits. A sintering law is derived from the loss of metallic surface area with time-on-stream according to local temperature and H2O:H2 molar ratio. An excellent fit of the experimental data was obtained allowing the prediction of the metallic surface area within 15%.
Polyoxometalate Template-Based Synthetic Strategy to Prepare Ni, Mo Co-Doped CdS for Efficient Photocatalytic Hydrogen Evolution from Water Splitting
Authors: Yan Jiawei , Wei Zhidong , Xu Meiqi , Jiang Zhi , Shangguan Wenfeng
Published: December 2020

In this work, a novel polyoxometalate template-based strategy was applied to construct the bi-metal-doped CdS photocatalysts. NiMo6 polyoxometalate template precursor was applied for the preparation of Ni, Mo co-doped CdS photocatalysts (NiMo-CdS). The structures of the materials were explored by XRD, SEM, HRTEM, HAADF, element mapping, XPS, Raman spectrum and UV-vis DRS. Moreover, the results of the UV-vis spectrum showed that NiMo-CdS exhibited an enhanced performance on light absorption. The results of photocatalytic hydrogen evolution from water splitting demonstrated that the NiMo-CdS showed higher efficiency on hydrogen evolution than noble-metal Pt-doped CdS. The reason could be ascribed to the enhanced light absorption ability and charge separation after Ni and Mo were introduced, which could also act as co-catalysts. The apparent quantum yield (AQY) efficiency could reach 42% at 365 nm. This work proposed a novel and inexpensive method to synthesize the bi-metal (Ni, Mo) decorated CdS photocatalysts for efficient hydrogen evolution from water splitting.
An Accurate Growth Mechanism and Photocatalytic Degradation Rhodamine B of Crystalline Nb2O5 Nanotube Arrays
Authors: Guo Wei , Yang Libin , Lu Jinghao , Gao Peng , Li Wenjing , Feng Zhiying
Published: December 2020

To effectively improve photocatalytic activity, the morphology and crystallinity of semiconductor photocatalysts must be precisely controlled during the formation process. Self-aligned Nb2O5 nanotube arrays have been successfully fabricated using the electrochemical anodization method. A novel growth mechanism of Nb2O5 nanotubes has been proposed. Starting from the initial oxidation process, the “multi-point” corrosion of fluoride ions is a key factor in the formation of nanotube arrays. The inner diameter and wall thickness of the nanotubes present a gradually increasing trend with increased dissociative fluorine ion concentration and water content in the electrolyte. With dehydroxylation and lattice recombination, the increased crystallinity of Nb2O5 represents a reduction of lattice defects, which effectively facilitates the separation and suppresses the recombination of photo-generated carriers to enhance their catalytic degradation activity.
Process Evaluation of a School-Based High-Intensity Interval Training Program for Older Adolescents: The Burn 2 Learn Cluster Randomised Controlled Trial
Authors: Kennedy Sarah G. , Leahy Angus A. , Smith Jordan J. , Eather Narelle , Hillman Charles H. , Morgan Philip J. , Plotnikoff Ronald C. , Boyer James , Lubans David R.
Published: December 2020

Process evaluations can help to optimise the implementation of school-based physical activity interventions. The purpose of this paper is to describe the process evaluation of a school-based high-intensity interval training (HIIT) program for older adolescent students, known as Burn 2 Learn (B2L). B2L was evaluated via a cluster randomised controlled trial in 20 secondary schools (10 intervention, 10 control) in New South Wales, Australia. Teachers (n = 22 (55% female)) from the 10 intervention schools, delivered the program over three phases (Phases 1 and 2, 6 months; Phase 3, 6 months) to older adolescent students (n = 337 (50% female); mean ± standard deviation (SD) age = 16.0 ± 0.4 years). Process evaluation data were collected across the 12-month study period. Teachers delivered 2.0 ± 0.8 and 1.7 ± 0.6 sessions/week in Phases 1 and 2 respectively (mean total 25.9 ± 5.2), but only 0.6 ± 0.7 sessions/week in Phase 3. Observational data showed that session quality was high, however heart rate (HR) data indicated that only half of the students reached the prescribed threshold of ≥85% predicted HRmax during sessions. Over 80% of teachers reported they intended to deliver the B2L program to future student cohorts. Almost 70% of students indicated they intended to participate in HIIT in the future. Teachers considered the program to be adaptable, and both students and teachers were satisfied with the intervention. B2L was implemented with moderate-to-high fidelity in Phases 1 and 2, but low in Phase 3. Our findings add to the relatively scant process evaluation literature focused on the delivery of school-based physical activity programs.
Influence of Phenylmethylsilicone Oil on Anti-Fouling and Drag-Reduction Performance of Silicone Composite Coatings
Authors: Yang Qiang , Zhang Zhanping , Qi Yuhong , Zhang Hongyang
Published: December 2020

In this study, we explore the effect of phenylmethylsilicone oil (PSO) addition amount and viscosity in a fouling release coating based on polydimethylsiloxane (PDMS). The surface properties, mechanical properties, anti-fouling and drag-reduction performance of the coating were studied. Meanwhile the influence of the basic properties of the coating on the anti-fouling and drag-reduction performance was also studied. Subsequently, the antifouling performance of the coating was investigated by the Navicula Tenera and bacteria adhesion test. As a result, the high content of PSO paint has a high foul removal rate. The incorporation of PSO into paint can reduce the elastic modulus and surface energy of the coating to reduce its relative adhesion factor (RAF). The lower the RAF, the better the antifouling effect of the coating. The drag-reduction performance of the coating was verified by the torque selection experiment, and the results showed that incorporation of PSO into paint can enhance the elongation and hydrophobicity of the coating, thereby increasing the drag reduction rate of the coating.
Effect of Substrate Strain, Aluminum Thickness and Corona Pretreatment on the Electrical Resistance of Physical Vapor Deposited Aluminum Coatings
Authors: Lindner Martina
Published: December 2020

Aluminum coatings applied to polymer films by physical vapor deposition should be defect-free for applications such as packaging and electronic devices. However, cracks can appear in the aluminum coating as the polymer film stretches, becoming manifest as an increase in resistance. We evaluated the effect of different aluminum thicknesses (10–85 nm), polymer films (polyethylene terephthalate or polypropylene), and corona doses (0–280 W∙min/m2) on the relative increase in resistance during stretching (strain = 0–100%). We found that the thickness of the aluminum coating was inversely related to the increase in resistance. Corona pretreatment led to an increase in surface energy (≤40 mN/m for polypropylene; ≤50 mN/m for polyethylene terephthalate) although high corona doses resulted in overtreatment, which limited the adhesion of aluminum to the substrate and led to a greater increase in resistance. Varying the coating thickness had a much greater effect than the corona pretreatment, suggesting that thicker aluminum coatings are more effective than corona pretreatment as a strategy to increase coating stability. The effect of aluminum thickness and strain on resistance was described using a fit function containing three fit factors.
Understanding of Various Type of Unambiguous Discrimination in View of Coherence Distribution
Authors: Namkung Min , Kwon Younghun
Published: December 2020

Unambiguous quantum state discrimination is a strategy where the conclusive result can always be trusted. This strategy is very important, since it can be used for various quantum information protocols, including quantum key distribution. However, in the view of quantumness, it is not clear what is going on in performing unambiguous quantum state discrimination. To answer the question, we investigate coherence distribution when unambiguous discrimination is performed by generalized measurement. Specially, we study coherence distribution in three cases, which consist of unambiguous quantum state discrimination, sequential quantum state discrimination, and assisted optimal discrimination, which are considered to be a family of unambiguous quantum state discrimination. In this investigation, we show that the structure of generalized measurements performing various types of unambiguous quantum state discrimination can be understood in terms of coherence distribution. Our result is not limited to the discrimination of two pure quantum states, but it is extended to the discrimination of two mixed states.
Foundations of the Quaternion Quantum Mechanics
Authors: Danielewski Marek , Sapa Lucjan
Published: December 2020

We show that quaternion quantum mechanics has well-founded mathematical roots and can be derived from the model of the elastic continuum by French mathematician Augustin Cauchy, i.e., it can be regarded as representing the physical reality of elastic continuum. Starting from the Cauchy theory (classical balance equations for isotropic Cauchy-elastic material) and using the Hamilton quaternion algebra, we present a rigorous derivation of the quaternion form of the non- and relativistic wave equations. The family of the wave equations and the Poisson equation are a straightforward consequence of the quaternion representation of the Cauchy model of the elastic continuum. This is the most general kind of quantum mechanics possessing the same kind of calculus of assertions as conventional quantum mechanics. The problem of the Schrödinger equation, where imaginary ‘i’ should emerge, is solved. This interpretation is a serious attempt to describe the ontology of quantum mechanics, and demonstrates that, besides Bohmian mechanics, the complete ontological interpretations of quantum theory exists. The model can be generalized and falsified. To ensure this theory to be true, we specified problems, allowing exposing its falsity.
Novel Multi-AP Coordinated Transmission Scheme for 7th Generation WLAN 802.11be
Authors: Ahn Woojin
Published: December 2020

The demand for high-data-rate and time-sensitive applications, such as 4k/8k video streaming and real-time augmented reality (AR), virtual reality (VR), and gaming, has increased significantly. Addressing the inefficiency of distributed channel access and the fairness problem between uplink and downlink flows is crucial for the development of wireless local area network (WLAN) technologies. In this study, we propose a novel transmission scheme for IEEE 802.11be networks that addresses the fairness problem and improves the system throughput. Utilizing the concept of multi-AP coordinated OFDMA introduced in the 7th-generation WLAN IEEE 802.11be, the proposed transmission scheme allows an AP to share a granted transmission opportunity (TXOP) with nearby APs. A mathematically analysis of the throughput performance of the proposed schemes was performed using a Markov chain model. The simulation results verify that the scheme effectively improves the downlink fairness and the system throughput. Combined with the advanced multiuser (MU) features of IEEE 802.11ax, such as TUA, MU cascading sequence, and MU EDCA, the proposed scheme not only enhances downlink AP transmission, but also guarantees improved control over the medium. The scheme is carefully designed to be fully compatible with conventional IEEE 802.11 protocols, and is thus potentially universal.
Performance Enhancement of a Sludge Continuous Feed Heat Pump Drying System by Air Deflectors and Auxiliary Cooling Subsystems
Authors: Luo Win-Jet , Lin Cheng-Yan , Wu Nai-Feng , Xu Zhi-Qun
Published: December 2020

This study proposes an improved design for a typical sludge continuous feeding drying system connected with three air-source heat pumps. The system’s performance was further improved using air-deflectors on the drying chamber’s internal sidewalls, enhancing the heat and mass transfer between the conveyor sludge and circulating airflow. In this study, numerical analysis was performed to elucidate the deflector designs on the airflow field and thermal temperature field distributions in the drying chamber. The specific moisture extraction rate (SMER) value was quantified to evaluate the system’s overall improvement during experiments. With a suitable deflector design, the average percent water content in sludge could be further reduced to 22.2% with drying time of 18.3 h, and the SMER value could be enhanced from 1.38 kg/kWh to as high as 1.83 kg/kWh with an increment of 32.44%. Moreover, to prevent overloading and frequent shutdown of the compressors, an auxiliary cooling subsystem was designed to attain stable operational conditions. By the auxiliary cooling subsystem design, the compressors’ shutdown can be avoided, the temperature difference between airflow inlets and outlet of the drying chamber can be increased, and SMER value can be further increased to a value of 1.94 kg/kWh.
Cross-Border Electricity Trading in Southeast Europe Towards an Internal European Market
Authors: Makrygiorgou Despoina I. , Andriopoulos Nikos , Georgantas Ioannis , Dikaiakos Christos , Papaioannou George P.
Published: December 2020

The European Commission’s Target Model’s main objective is to integrate European electricity markets, leading to a single internal energy market and guaranteeing the instantaneous balance between electricity generation and demand. According to the target model for electricity trading, proposed by the European Network Transmission System Operators for Electricity (ENTSO-E), within each zone, electricity can be traded freely without taking into consideration network limitations. In contrast, for cross-border trading, the exchanges with other market areas are taken into account. Cross-border trade poses a further burden on the interconnection lines, resulting in increasing network congestion, which in turn restricts electricity trading. Thus, calculating the available capacity for trade has a significant ramification on the market. Today, the Available Transfer Capacity (ATC) mechanism dominates cross-border trading, but this methodology may be replaced by the Flow-Based (FB) approach across Europe. This paper investigates both approaches regarding the cross-border congestion management under the market coupling procedure. In our case study, the Southeast Europe (SEE) region is taken into consideration; it consists of both the FB and ATC approach in a five country (Greece, North Macedonia, Bulgaria, Serbia, and Romania) scenario. The purpose of our tests is to perform, compare, and evaluate the effectiveness of each method for the SEE region, while the main findings are the maximization of social welfare, better cross-border trading opportunities, and price convergence via the FB method.
The Data-Driven Multi-Step Approach for Dynamic Estimation of Buildings’ Interior Temperature
Authors: Villa Stefano , Sassanelli Claudio
Published: December 2020

Buildings are among the main protagonists of the world’s growing energy consumption, employing up to 45%. Wide efforts have been directed to improve energy saving and reduce environmental impacts to attempt to address the objectives fixed by policymakers in the past years. Meanwhile, new approaches using Machine Learning regression models surged in the modeling and simulation research context. This research develops and proposes an innovative data-driven black box predictive model for estimating in a dynamic way the interior temperature of a building. Therefore, the rationale behind the approach has been chosen based on two steps. First, an investigation of the extant literature on the methods to be considered for tests has been conducted, shrinking the field of investigation to non-recursive multi-step approaches. Second, the results obtained on a pilot case using various Machine Learning regression models in the multi-step approach have been assessed, leading to the choice of the Support Vector Regression model. The prediction mean absolute error on the pilot case is 0.1 ± 0.2 °C when the offset from the prediction instant is 15 min and grows slowly for further future instants, up to 0.3 ± 0.8 °C for a prediction horizon of 8 h. In the end, the advantages and limitations of the new data-driven multi-step approach based on the Support Vector Regression model are provided. Relying only on data related to external weather, interior temperature and calendar, the proposed approach is promising to be applicable to any type of building without needing as input specific geometrical/physical characteristics.
Enrichment of Li–Ga–Zr–Hf and Se–Mo–Cr–V–As–Pb Assemblages in the No. 11 Superhigh Organic Sulfur Coal from the Sangshuping Coal Mine, Weibei Coalfield, Shaanxi, North China
Authors: Li Jing , Wu Peng , Yang Guanghua , Pan Lei , Zhuang Xinguo , Querol Xavier , Moreno Natalia , Li Baoqing , Shangguan Yunfei
Published: December 2020

Superhigh organic sulfur(SHOS) coals have currently attracted great attention due to their typical depositional environments and formation history as well as their great negative impact on the ecosystem. This study investigated the geochemistry of the No. 11coalof the Late Carboniferous Taiyuan Formation from the Sangshuping coalmine, Hancheng miningarea, Weibei coalfield, Shaanxi, North China. The No. 11 coal is a high-sulfur coal with a large proportion of organic sulfur content (3.7 to 5.5%, avg. 4.4%) and belongs to typical SHOS coal. The high sulfur content in the Sangshuping coal mine has been mainly caused by the combined influences of seawater and hydrothermal fluids. The SHOS in No. 11 coal was formed in the Fe-poor and S-rich high-marine influenced occlusive environment. During the late coalification stage, a high proportion of pyritic sulfur was formed due to sufficient Fe supply from the Fe–S-rich epigenetic hydrothermal fluids. The No. 11 SHOS coal is enriched in Li–Ga–Zr–Hf and Se–Mo–Cr–V–As–Pb element assemblages. The sediment provenance of the Sangshuping coal mine is predominantly felsic–intermediate rocks from both the Yinshan and Qinling Oldland. However, the elevated concentrations of critical elements (Li, Ga, Zr, and Hf) in the No. 11 coal are primarily inherited from the Yinshan Oldland. The enrichment of the Se–Mo–Cr–V–As–Pb assemblage in No. 11 coal can be ascribed to the influence of both seawater and epigenetic hydrothermal activity.
Review of Control Techniques for Wind Energy Systems
Authors: Ghaffarzadeh Hooman , Mehrizi-Sani Ali
Published: December 2020

In recent years, penetration of renewable energy resources into the power grid has increased significantly. Wind, as a renewable, clean, and abundantly available source of energy, has an important share in the energy mix. However, increasing the penetration of wind power in the power grid can adversely affect the power quality and introduce new operational challenges. This paper discusses issues related to the integration of wind farms in the power system, such as maximum power point tracking, fault ride-through capabilities, interarea and subsynchronous oscillations, and voltage flicker, and provides a review of the existing control strategies to address these issues in Types I, II, III, and IV wind turbines. This paper also identifies challenges and opportunities ahead.
A Computational Workflow for Flow and Transport in Fractured Porous Media Based on a Hierarchical Nonlinear Discrete Fracture Modeling Approach
Authors: Zhang Wenjuan , Diab Waleed , Hajibeygi Hadi , Al Kobaisi Mohammed
Published: December 2020

Modeling flow and transport in fractured porous media has been a topic of intensive research for a number of energy- and environment-related industries. The presence of multiscale fractures makes it an extremely challenging task to resolve accurately and efficiently the flow dynamics at both the local and global scales. To tackle this challenge, we developed a computational workflow that adopts a two-level hierarchical strategy based on fracture length partitioning. This was achieved by specifying a partition length to split the discrete fracture network (DFN) into small-scale fractures and large-scale fractures. Flow-based numerical upscaling was then employed to homogenize the small-scale fractures and the porous matrix into an equivalent/effective single medium, whereas the large-scale fractures were modeled explicitly. As the effective medium properties can be fully tensorial, the developed hierarchical framework constructed the discrete systems for the explicit fracture–matrix sub-domains using the nonlinear two-point flux approximation (NTPFA) scheme. This led to a significant reduction of grid orientation effects, thus developing a robust, applicable, and field-relevant framework. To assess the efficacy of the proposed hierarchical workflow, several numerical simulations were carried out to systematically analyze the effects of the homogenized explicit cutoff length scale, as well as the fracture length and orientation distributions. The effect of different boundary conditions, namely, the constant pressure drop boundary condition and the linear pressure boundary condition, for the numerical upscaling on the accuracy of the workflow was investigated. The results show that when the partition length is much larger than the characteristic length of the grid block, and when the DFN has a predominant orientation that is often the case in practical simulations, the workflow employing linear pressure boundary conditions for numerical upscaling give closer results to the full-model reference solutions. Our findings shed new light on the development of meaningful computational frameworks for highly fractured, heterogeneous geological media where fractures are present at multiple scales.
Decoupling Economic Growth from Fossil Fuel Use—Evidence from 141 Countries in the 25-Year Perspective
Authors: Frodyma Katarzyna , Papież Monika , Śmiech Sławomir
Published: December 2020

This study offers an in-depth analysis of the decoupling of economic growth from fossil fuel use in 141 countries over the last 25 years. The study is based on the Tapio decoupling approach, and two methods of measuring fossil fuel use, i.e., domestic material consumption (DMC) and material footprint (MF), are applied. Groups of countries with similar decoupling patterns are identified through the k-medoids method. Next, the relationship between these patterns and the level of countries’ development is examined. The results reveal that using different measures of fossil fuel use yields different processes of decoupling economic growth from fossil fuel use. In particular, when the DMC indicator is considered, relative decoupling is observed in most analysed cases. When the MF indicator is applied, the decoupling states of individual countries change more frequently. Finally, in highly developed countries, absolute decoupling is frequently observed, although only when the DMC indicator is used.