bluuebunny/crossref_metadata_2025 huggingface dataset:
Cinematographic Ethics Within the Autonomy of Art
Authors: Keşaplı Onur
Published: November 2020

Pedophilia, which at the same time is considered as a sickness, was mostly handled in cinema history as an element of crime. Apart from the examples where the evil is punished, there also exists movies where the subject is handled but not named. And in recent past, movies that aim to empathize started to appear. These movies places pedophilia in the center, study the justifications behind actions and tries to establish sympathy. There are movies such as The Woodsman and Kind in which the main character is a pedophile, ones like Little Children where pedophilia is handled as a whole and ones like Nympnomaniac Vol 2 wherein pedophilia is elaborately scrutinized. Common trait of all these movies is the acceptance of pedophilia, which is coded as a state of absolute evil, as a reality and engaging in an effort to understand it. These four movies which, within the frame of autonomy of art and within the context of cinematographic ethics, empathize with a state that is opposite to moral norms are of importance regarding confrontation with parts of human nature that is considered evil.
Political Economy of Land Policy Reform and Governance in Nigeria
Authors: Obayelu Abiodun Elijah , Bolarinwa Kamilu Kolade , Oyekunle Olalekan
Published: November 2020

Land is the most important asset of farmers that plays an indispensable role in agricultural production. Nigerian land system has strong social and cultural attraction making it difficult to separate from political, social, cultural, and economic effects. Politics and the process of politicking influence the course and outcome of government decision on land policy. This study examines the political economy of agricultural land policy reforms and governance in Nigeria. The study used a combination of methods, such as expository, comparative, and case analysis. Findings showed that land issues are delicate, demanding careful attention to avoid social or political conflicts. Politicization of land is a major cause of land dispute but with good land governance, land policy reform become easier to implement. Political will of government is crucial for land policy to succeed. Transparent, fair, and equitable land policy is necessary to continue on the path of peace, stability, and increase agricultural productivity.
Business Plan and Industrial Development
Authors: Lubawa Galinoma Gahele
Published: November 2020

Writing of business plans ensures performance of a business and contributes to enabling countries to achieve sustainable development goals (SDGs). The latter are intended, in part, to promote industrialization, and improved human living and working standards. This chapter identifies and analyses the importance of business plan for family-owned food processing small and medium enterprises (Fo-SMEs). It advocates for the establishment of an “integrated planning” strategy to link Fo-SMEs and government support system for business development. Business-planning forecasts industrial production based on consumers' demands. Integrated planning ensures sustainability of Fo-SMEs, farmers' economic growth, and consequent achievement of SDGs. Tanzania Fo-SMEs serve as a useful lesson for developing economies. Future studies should consider Fo-SMEs' succession planning framework.
When Teaching Composition Becomes an Art Through a Futuristic Book-Writing Pedagogy
Authors: Virgil Sharon M.
Published: November 2020

The author recognizes the importance of Freshman Composition students being equipped with the skills necessary to write effectively for college and beyond. In this chapter, the author shares her story of how a renowned Composition professor forces her to take a self-critical look at what she was doing in her Composition classroom, which compels her to change. For new teachers of Composition or for teachers looking to change, the author shares her newly adopted student-centered-book-writing pedagogy, which puts the focus on the student and creating an environment in which they can write, and write a lot. The author, forced to be honest and change herself, adopted a pedagogy that allows her students a voice and a chance to be honest in their writing through their expression of voice, an asset she recognizes as necessary in this 21st century, especially in our increasingly diversified world of academia. The author shares her student-centered-book-writing-pedagogy.
Identity Formation in Second Language Writing
Authors: Jomaa Nayef
Published: November 2020

Part of the researcher's duties towards his supervisees is to guide them in their postgraduate research journeys. Two important questions were raised by his supervisees. One of them is why the majority of studies follow Hyland's framework in analysing identity. The other question is why we do not follow Hyland's (framework in analysing the reporting verbs instead of Halliday's transitivity system. Is it because the latter is so difficult to understand? Therefore, this chapter aims at focusing on identity in second language (L2) writing, comparing between Halliday's modality, Vande Kopple's taxonomy, Crismore et al.'s taxonomy, and Hyland's model of metadiscourse. The findings showed a sort of similarity as well as variety, thus resulting in overlapping and lacking a solid model for analysing how writers reveal their identity. Therefore, a necessity arises to present a comprehensive model that can be used to identify all the categories and subcategories related to interpersonal meanings.
Advancements in Cancer Therapeutics
Authors: Kecel Gunduz Serda , Bicak Bilge , E. Ozel Aysen
Published: November 2020

In this chapter, computational approaches for the discovery of new drugs that are useful for diagnosis and treatment of disease will be described in three parts. MD technique uniquely supports protein design attempts by giving information about protein dynamics associated with atomic-level descriptions of the relationship between dynamics and function. The purpose of molecular docking is to provide an estimate of the ligand-receptor complex structure using computational methods. By this estimation, the mechanism of drug binding and action are described by determining the three-dimensional simulation of drug and drug-induced macrostructure. ADME characteristics are physicochemically significant descriptors and pharmacokinetically relevant properties used to design more effective drugs and new analogs. As a result, in-silico calculations can provide robust preliminary information as to drug activity and mechanism in the drug production process, as well as in vitro and in vivo studies.
Precision Medicine in Cancer
Authors: Ravichandiran Nerethika , Barman Muneesh Kumar , Lavuri Sai Tejaswi , Srivastava Manjita , Sakthivel Shalini , Singh Meenakshi , Chand Kailash , Sonkar Subash C. , Bhukya Prudhvilal
Published: November 2020

Cancer is the one of the deadliest diseases and takes the lives of millions of people every year across the world. Due to disease heterogeneity and multi-factorial reasons, traditional treatment such as radiation therapy, immunotherapy, or chemotherapy are effective only among a small population of the patients. Tumors can have different fundamental genetic causes and protein expressions that differ from one patient to another. This variability among individual lends itself to the field of precision and personalized medicine. Following the completion of human genome sequencing, significant progress has been observed in the characterization of human epigenome, proteome, and metabolome. Pharmacogenetics and pharmacogenomics use this sequence to study the genetic causes of individual variations in drug response and the simultaneous impact of change in genome that decide the patient's response to drug respectively. On summation, identify the subpopulation of patient and provide them tailored therapy thus increasing the effectiveness of treatment. All these evolved the field of precision or personalized medicine that plays a crucial role in cancer prevention, prognosis, diagnosis, and therapeutics. These tailored therapies are characterized by increased efficiency and reduced toxicity. Not all cancers have genetic variability; some are also influenced by polymorphism of gene encoding enzymes that play an important role in pharmacokinetics of drug. The discoveries of cancer predisposition genes allow diagnosis of a patient at risk of cancer development and let them make the decision on précised individual risk modification characteristic. The use of CYP2D6 genotyping for breast cancer, mutation in KRAS in colorectal cancer, genomic variation in EGFR in small lung cancer, melanoma are some of the examples of importance of cancer predisposition genes. In recent times, distinct molecular subtypes of cancers have been identified with requirement of different treatment for each subtype. Precision medicine shifts the trend from reaction to prevention and forestalls disease progression.
Functional Mechanisms of Green Tea Polyphenols and Their Molecular Targets in Prevention of Multiple Cancers
Authors: Hafeez Zubair Bin , Fakhri Khalid Umar , Zafaryab Md , Rizvi M. Moshahid Alam
Published: November 2020

Cancer is portrayed as a group of disease characterized by alteration in the normal regulation of cell growth by the successive acquisition of genetic, somatic, and epigenetic alteration. Synthetic drugs are single targets while natural products are multi-targeted to prevent cancer. NF-κB is persistently active in a number of disease states, including cancer, and therefore has a critical role in cancer development and progression. It also provides a mechanistic link between inflammation and cancer and is a major controlling factor resistant to apoptosis in both pre-neoplastic and malignant cells. Importantly, NF-kB and the signaling pathways that mediate its activation have become attractive targets for the development of new chemopreventive and chemotherapeutic approaches. Natural antioxidants have been shown to possess chemopreventive and chemotherapeutic potential via targeting NF-κB signaling, among which tea polyphenols have been studied extensively. In this chapter, the authors summarize the regulation of NF-κB pathway by green tea polyphenols in different cancer types.
Access and Use of Networked Electronic Devices for Educational Information Management by Undergraduates in South Africa
Authors: Salubi Oghenere Gabriel
Published: November 2020

Electronic networked devices have broken down fences of communication and information access from anywhere in the world, and its capacity to store, manage, as well as transmit vast amounts of information to anybody anywhere in the world often makes it to be referred to as the “Information Highway.” But digital divide has constraint access and use of these devices especially in developing countries like South Africa where economic-digital divide is very common. Four electronic devices (desktop, laptop computer, mobile phones, and tablets) that are mainly used for schoolwork and educational information management were sampled. The objectives of the study were to find out the electronic devices owned/accessible to undergraduate students for educational information management, identify the location where undergraduate students mainly access the internet, appraise the means and cost of accessing the internet by undergraduate student, and ascertain how undergraduate students utilise networked devices to manage educational information. Survey research design was adopted for the study and quantitative data was collected with the use of a questionnaire from 390 respondents. Results from the study indicated that mobile phone (362 or 92.8%) and laptop computers (305 or 78.2%) are the most owned electronic devices. Only 3 or 0.8% do not own any of the electronics listed in the survey while 2 (0.5%) do not have access to any electronic device listed for the survey. Most of the respondents (307 or 78.7%) access the internet from their mobile phones with access to the internet being free wi-fi on campus 349 (89.9%). Ninety percent of the respondents make use of their mobile phone in managing educational information while only 19% manage educational information on their laptops when outside the university campuses. Digital divide still plays a major role in the hindering undergraduate students in the management of educational information using networked devices.
Cyberspace Security Threats and Attacks on E-Records Management at Moi University, Eldoret, Kenya
Authors: Musembe Carolyne Nyaboke , Mutula Stephen M.
Published: November 2020

The digital revolution and internet connectivity are the power behind digital-based models in organizations. The broader reach and impact of cyberspace which is accelerating across Moi University seems to be generating complex challenge to address issues of e-records at Moi University. This chapter emanated from a thesis on e-records security management, and therefore investigates cyberspace security threats and attacks on e-records management at Moi University with a view to offering practical and policy interventions to address this challenge. Data was collected from Moi University staff using interviews and questionnaires and was analysed thematically and using Statistical Package for Social Sciences (SPSS) version 24. Findings revealed cyberspace as an e-records security challenge. Cybercriminals (hackers and crackers), when new technologies emerge, concurrently invent and discover new ways to tap in the new technologies with the intention to steal and corrupt e-records for their benefit, thus hurting the veracity of e-records and university's reputation. Cyber-attacks including an attempted attack on the network, viruses, and worms were widely mentioned in the findings as a threat to both the e-records, and the computer system that host them and storage devices. The chapter recommends that the university should set dynamic security strategy and vision, developing and implementing policies and adopting standards, threat analysis and assessment, integrated and intelligent cybersecurity management service, and investing in e-records security awareness campaigns and training for employees, among others.
Churn Prediction and Fraud Detection in Dairy Sector Using Machine Learning
Authors: Shah Hitarth Deepak , Bhatt Chintan M. , Patel Shubham Mitul , Khajanchi Jayshil Bhavin , Makwana Jaimin Narendrakumar
Published: November 2020

India has globally been the largest milk-producing country in the world for two decades. About 400 million litres of milk is produced every day. It is the responsibility of a dairy sector to look after the farmers by providing them with various services for their livelihood. The growing financial capital of the dairy industry has enticed various fraudulent behaviour. The majority of suspicious activities are seen during the collection at local collection centres, fake farmer entries, tempered quantity and fat entries manually, and adulteration are the profound malpractices exercised by farmers. So, in this research work, the authors present a profound study on the most popular machine learning methods applied to the problems of farmer churn prediction and fraud detection in the dairies. They applied a plethora of machine learning algorithms to get accurate results for churn and fraud detection. XGBoost Classifier was the best for churn prediction with 93% accuracy, while random forest classifier turns out to be effective for fraud detection with 94% accuracy.
Lands DSS
Authors: Fenu Gianni , Malloci Francesca Maridina
Published: November 2020

Decision support systems (DSSs) are used in precision farming to address climate and environmental changes due to human action. However, increments in the amount of data produced continuously by the latest sensor and satellite technologies have recently incentivized the integration of artificial intelligence (AI). A review of research dedicated to the application of DSSs and AI in forecasting crop disease is proposed. In this paper, the authors describe the DSS LANDS developed for monitoring the main crop productions in Sardinia and the case study conducted to forecast potato late blight. A feed-forward neural network was implemented to investigate if weather data provided by regional stations could be used to predict a disease risk index using an AI technique. The test performed by stratified k-fold cross validation achieved an accuracy of 96%.
Two Problem Formulations for Process Innovation Based on Operations Sophistication
Authors: Delias Pavlos , Grigori Daniela
Published: November 2020

Process innovation is assumed to require a more intrinsic rethinking of business processes, which is typically a creative process. Nevertheless, in this creative, prolific process, there can be artifacts derived from rational practices that are capable to provide insightful recommendations. In this work, the authors claim that an event log, a file that registers the execution of the relevant business processes, can be the source of such an artifact. They describe the fundamental elements of two problem formulations, namely the set of alternatives; the set of potential actions that the decision-maker may undertake; the set of points of view (dimensions) from which the potential actions are observed, analyzed, evaluated, compared, etc.; and the problem statement (what is expected to be done with the alternatives) for two cases.
SEF4CPSIoT Software Engineering Framework for Cyber-Physical and IoT Systems
Authors: Ramachandran Muthu
Published: November 2020

Cyber-physical systems (CPS) have emerged to address the need for more efficient integration of modern advancement in cyber and wireless communications technologies such as 5G with physical objects. In addition, CPSs systems also needed to efficient control of security and privacy when we compare them with internet of things (IoT). In recent years, we experienced lack of security concerns with smart home IoT applications such as home security camera, etc. Therefore, this paper proposes a systematic software engineering framework for CPS and IoT systems. This paper also proposed a comprehensive requirements engineering framework for CPS-IoT applications which can also be specified using BPMN modelling and simulation to verify and validate CPS-IoT requirements with smart contracts. In this context, one of the key contribution of this paper is the innovative and generic requirements classification model for CPS-IoT application services, and this can also be applied to other emerging technologies such as fog, edge, cloud, and blockchain computing.
A Novel Fuzzy Frequent Itemsets Mining Approach for the Detection of Breast Cancer
Authors: Ramesh Dhanaseelan F.  , Jeyasutha M.
Published: November 2020

Breast cancer, a type of malignant tumor, affects women more than men. About one-third of women with breast cancer die of this disease. Hence, it is imperative to find a tool for the proper identification and early treatment of breast cancer. Unlike the conventional data mining algorithms, fuzzy logic-based approaches help in the mining of association rules from quantitative transactions. In this study, a novel fuzzy methodology, IFFP (improved fuzzy frequent pattern mining), based on a fuzzy association rule mining for biological knowledge extraction, is introduced to analyze the dataset in order to find the core factors that cause breast cancer. It is determined that the factor, mitoses, has low range of values on both malignant and benign, and hence it does not contribute to the detection of breast cancer. On the other hand, the high range of bare nuclei shows more chances for the presence of breast cancer. Experimental evaluations on real datasets show that the proposed method outperforms recently proposed state-of-the-art algorithms in terms of runtime and memory usage.
Converging Semantic Knowledge and Deep Learning for Medical Coding
Authors: Garcia-Santa Nuria , San Miguel Beatriz , Ugai Takanori
Published: November 2020

The field of medical coding enables to assign codes of medical classifications such as the international classification of diseases (ICD) to clinical notes, which are medical reports about patients' conditions written by healthcare professionals in natural language. These texts potentially include medical terms that define diagnosis, symptoms, drugs, treatments, etc., and the use of spontaneous language is challenging for automatic processing. Medical coding is usually performed manually by human medical coders becoming time-consuming and prone to errors. This research aims at developing new approaches that combine deep learning elements together with traditional technologies. A semantic-based proposal supported by a proprietary knowledge graph (KG), neural network implementations, and an ensemble model to resolve the medical coding are presented. A comparative discussion between the proposals where the advantages and disadvantages of each one is analysed. To evaluate approaches, two main corpus have been used: MIMIC-III and private de-identified clinical notes.
Texture Evolution during Cold Drawing of Steel Tube with Respect to the Stress - Strain State
Authors: Parilák Ľudovít , Burik Peter , Bella Peter , Kejzlar Pavel
Published: November 2020

Cold tube drawing is a metal forming process that enable to manufacturers to produce high precision tubes. The dimensions of the tube are reduced by drawing it through a conical converging die with or without inner tool. There are four types of tube cold drawing process. Their difference relies on the technique used for inner diameter calibration. Therefore, the main objective was determining the difference in development of crystallographic texture and stress-strain state between drawing with the fixed plug and hollow sinking process. The input feedstock (with E235 steel grade) after the recrystallizing anneal was cold drawn (drawing with the fixed plug, hollow sinking) by one drawing passes. Electron BackScatter Diffraction (EBSD) analysis was used to evaluate the changes of grain structure and texture connected with tubes manufacturing. The stress-strain state in the tube material during drawing was calculated using DEFORM-3D software and the crystallographic orientation with respect to the cylindrical reference frame (Z-direction = drawing direction). A significant difference in stress-strain state between drawing with the fixed plug and hollow sinking process was recorded in radial direction.
Microstructure Influenced by Controlled Rolling, Cooling and Thermal Processing of Seamless Tubes Made of Steel 25CrMo4
Authors: Kawulok Petr , Schindler Ivo , Rusz Stanislav , Kawulok Rostislav , Opěla Petr , Navrátil Horymír , Turoň Rostislav , Jurča Radek
Published: November 2020

By use of physical simulations, it was studied the influence of finish rolling temperature (from 820 °C to 970 °C) on the microstructural and mechanical properties of seamless tubes with a different wall thickness (from 6.3 to 40 mm) – in the state after rolling as well as after quenching and tempering. In laboratory conditions, by use of the Simulator HDS-20, the bloom piercing and rolling of the seamless tubes from 25CrMo4 low-alloy steel in a pilger mill were in a simplified way simulated. The wall thickness of the tube influenced the total deformation of specimens at anisothermal multi-pass plain-strain compression tests as well as the final cooling rate. The quenching and tempering of the deformed specimens was subsequently performed with use of the electric resistance furnaces. The finish rolling temperature had only insignificant effect on the resulting properties. Markedly lower hardness was obtained only after the simulation of tube production with the wall thickness of 40 mm contrary to the wall thickness of 6.3 and 20 mm. Structural variations of the specimens after rolling simulations were more or less overlapped by the subsequent quenching from the temperature of 850 °C and tempering at the temperature of 680 °C.
Influence of Boric Acid Solution and Gamma Irradiation on Selective Sorbents
Authors: Marušáková Daniela , Kůs Pavel , Szatmary Lorant , Prokůpková Iveta Adéla
Published: November 2020

We tested stability of 43 selective sorbents, covering the widest range of functional groups, efficiency of sorption, method of production, and which are theoretically useful for sorption of cesium, strontium, cobalt, arsenic and actinoids. We present 3 of them: A = TiO2, B = Al2O3 and C = MxH(TiO)4(SiO4)3 . z H2O. In first testing, sorbents were exposed to the model solution of boric acid for 168 hours, in which they were mixed in a closed container with a rotator. After the exposure, sorbent solutions were filtered and analysed by spectroscopic techniques (Infrared Spectroscopy (IR), Raman Spectroscopy (RS) and newly by Scanning Electron Microscopy (SEM), combined with Energy Dispersive Spectroscopy (EDS)). Exposed spectra were compared with spectra of new, non-exposed sorbents. In second testing, sorbents were exposed to gamma radiation for 12 days with total dose 666 ± 43 kGy, produced by cobalt bomb and analysed by same techniques. The aim of our testing was to find out how sorbents behave in model boric acid solution and what effect has the gamma radiation on sorbent spectra and to analyse sorbents by SEM with EDX.
The Failure of Carbon Fiber Reinforced Composite Analyzed by Acoustic Emission
Authors: Mára Vladimír , Krčil Jan , Michalcová Lenka , Čižmárová Elena
Published: November 2020

This paper focus on evaluation of behavior, damage and failure processes occurring during the loading cycles in the carbon fiber reinforced composite by acoustic emission method. Since acoustic emission is physical phenomenon that detects the released energy in form of waves spreading through the material due to stimulation of material by external or internal stress, it is possible to evaluate complex damage and failure processes. For that purpose, the standard and open holes tensile testing specimens with different number of plies were manufactured. Selected acoustic emission parameters were correlated with data obtained from mechanical test. Linear localization method together with signal analysis using Fast Fourier transform algorithm were used as another tool for detection and evaluation of spreading damage processes inside the composite during the load. Basic damage types inside the composite material were identified by metallographic analysis using light microscopy. More complex damage processes were observed on the fracture surface using stereomicroscopy and scanning electron microscopy.
Rarely Occurring Defects on Tinplates
Authors: Vranec Peter , Hockicková Slavka , Mašlejová Alicia , Demčáková Mária , Hrabčáková Lucia , Zubko Pavol , Kalmár Peter , Drotár Atila
Published: November 2020

This paper deals with rarely occurring defect on the surface of the tinplates produced in the conditions of U. S. Steel Košice, s.r.o. at the cleaning section of the continuous annealing line (CAL), which was caused by burnt. Random occurrence of such surface imperfections was observed within the short period of time (two months) for various continuous annealed tinplate grades, i.e. TH415, TH435 or TH550 with the thickness of the materials in the interval of 0.172 – 0.240 mm. Surface defects caused by burnt (thermal attack) manifested in different ways. Their appearance on the sheet surface was spot with regular or irregular circle shape, as well as line with the length of up to 2 mm oriented not directly in the rolling direction. By observing of the imperfections in scanning electron microscope (SEM) it was found that the surface of the steel substrate was always compact in the defective areas with clearly visible rolling lines. Foreign material, EDS analysis of which revealed that its chemical composition was on the basis of Fe and Cr, was deposited on the surface of the base material. The appearance of the foreign material shape indicated that it was in the liquid state at the time of incidence on the steel substrate surface. Metallographic analysis from the longitudinal metallographic sections through the defective areas revealed that the substrate under the spot defect with regular circle shape had thermally influenced microstructure. Similar manifestations of the microstructure influence were observed for the line defects. In the case of the spot defect with irregular shape, the microstructure of the material was not influenced, what indicated that the particle of liquid metal was solidified at the time of incidence on the plate surface. After revising technical conditions of the cleaning section of CAL, this type of imperfection was suppressed.
3D Textural Analysis of Fatigue Fracture Surfaces
Authors: Lauschmann Hynek , Tesař Karel , Vronková Tereza
Published: November 2020

Three CT specimens from stainless steel AISI 304L were subjected to constant amplitude cyclic loadings with various asymmetries. Crack growth was recorded in detail. Fracture surfaces were documented by 3D maps in about 110 locations in the crack growth direction. 3D maps and their local gradients were represented by 2D wavelet decompositions in 10 levels resulting in 60 textural features. Statistical models expressing crack growth rate as a function of textural features were optimized. Training and testing approach, a high ratio of overfitting, and testing of significance of components ensured model's robustness. Quality of results is documented by graphs confronting model outputs with real data known from experiment. Results are acceptable in all cases.
The Effect of Prior Surface Roughness on Fatigue Life of Nitrided Specimens
Authors: Kianicova Marta , Šandera Pavel , Horníková Jana , Kottfer Daniel , Pokluda Jaroslav
Published: November 2020

The effect of surface roughness of virgin specimens (prior roughness) made of low-alloyed high strength steel on their fatigue life after the case-hardening treatment was studied by rotating bending tests of virgin and nitrided samples. In a whole range of S-N curves, the fatigue strength of virgin samples after lathe-turning machining (high roughness) was naturally much higher than that of samples after grinding (low roughness). As expected, the fatigue strength of nitrided specimens was higher than that of virgin samples when averaged through the whole fatigue life range. When distinguishing the rough and smooth nitrided samples, the low-cycle fatigue strength of rough samples revealed to be lower than that of the smooth ones and vice a versa in the high-cycle region. This could be explained by the fact that, in the low cycle region, the cracks in the rough samples nucleated from deep surface defects while, in the smooth specimens, they nucleated from shallow defects (or as fish eyes) which prolonged their initiation stage. Almost all cracks in the high cycle region initiated as fish-eyes but the extent of nitrided layers in the rough specimens was slightly higher than that in the smooth specimens. Therefore, the fish-eye centers were shifted further to the interior of the rough specimens which increased their fatigue life.
Near-Surface Structure and Fatigue Crack Initiation Mechanisms of As-Built SLM Inconel 718
Authors: Konečná Radomila , Nicoletto Gianni
Published: November 2020

Challenging structural applications such as customized jet engine parts are increasingly fabricated by Selective Laser Melting (SLM) of Inconel 718 powder. The as-built surface quality of SLM parts is however inferior of the machined version and the fatigue behavior is negatively affected. The as-built fatigue response of SLM Inconel 718 was quantified here using three sets of directional specimens. Since the surface quality is influenced by powder characteristics, process parameters and layer-wise fabrication, fatigue results showed a directional contribution that was interpreted using metallography and fractography.
Microstructure, Stiffness and Corrosion of Bare and Phosphated Specimens Made by Sintering of Structured Iron-Iron Oxide Spheres
Authors: Kupková Miriam , Kupka Martin , Oriňáková Renáta , Gorejová Radka
Published: November 2020

Granulated iron oxide particles were incompletely reduced to structured particles comprised metallic iron and residual iron oxides. Structured particles were pressed into prismatic compacts and sintered. Some of sintered specimens were subsequently phosphatized and calcined. Specimens with an iron phosphate coating were found stiffer than specimens without coating. In Hanks' solution, a galvanic corrosion was induced by more noble iron oxides coupled to a less noble metallic iron. This could explain higher corrosion potentials and higher rates of iron dissolution in comparison with a pure iron. The coating of specimens with iron phosphates shifted corrosion potentials towards more negative values and slowed down the dissolution of iron. This was most likely caused by a reduction in oxygen flow through the coating to iron-oxide cathodes, which has enhanced the influence of diffusion control on the kinetics of reduction reaction.
A Thermomechanical Model of Retention of a Diamond Particle in Matrices Based on Fe
Authors: Borowiecka-Jamrozek Joanna , Lachowski Jan
Published: November 2020

The aim of this paper was to determine the influence of the mechanical and thermal parameters of the matrix materials on their retentive properties. The term ‘matrix retention’ denotes the capacity of a metallic matrix material to retain diamond particles at the surface of a diamond tool during working. The bonding is obtained during cooling after the hot pressing process. Proper mechanical bonding depends on elastic and plastic properties of the matrix. The model of a diamond particle embedded in a metallic matrix was created using Abaqus software. The analysis has indicated the mechanical parameters that are responsible for the retention of diamond particles in a matrix.
SEM Imaging of In Situ Tensile Testing of 27CrNiMoV Steel
Authors: Bystrianský Martin , Kučerová Ludmila , Bunda Zbyněk
Published: November 2020

In-situ tensile testing of a 27CrNiMoV alloy which is used for steam turbine rotors was carried out using scanning electron microscope (SEM). Deformation and crack formation and propagation were examined with this test. Small (45 × 10 × 1.5 mm, with gauge length of 20 mm), flat samples based on dog-bone shape were prepared from the steel. The material in its initial state contained high number of defects in form of microcracks. A comparison of behaviour at tensile tests of samples without visible defect and with crack in the gauge section was performed. Apparently, the presence of defect in the initial state showed direct influence on properties like lower tensile strength. The sample, its necking and propagated crack is displayed at different stages of the tensile load. In-situ testing reveals differences in the sample deformation. The defect-free sample is affected in its whole body and regular necking can be observed, whereas the presence of the crack in the defect samples concentrates stress to a smaller area and also changed the shape of the stress-strain curve.
A Study of the High-K Enhanced Depletion-JTE for Ultra-High Voltage SiC Power Device with Improved JTE-Dose Window
Authors: Wen Yi , Xu Xiao Jie , Tao Meng Ling , Deng Xiao Chuan , Li Xuan , Li Zhi Qiang , Zhang Bo
Published: November 2020

In this paper, a High-K dielectric permittivity Enhanced Depletion-JTE(HKED-JTE) for 10 kV ultra-high voltage is studied. The HKED-JTE improves the terminal protection efficiency by the self-charge balance of High-K dielectric polarization charges. The tolerance of the implantation dose window of HKED-JTE reaches 9 times as large as that of normal TZ-JTE with the same terminal area, and the corresponding BV holding theoretical breakdown voltage is over 80%. The thicker High-K layer accomplishes the modulation of the surface electric flux and decreases the electric field up to 51% and 47% at the abrupt junction J2 and J3 along the device interface between the SiC and High-K materials.
Design, Fabrication and Characterization of 10kV/100A 4H-SiC PiN Power Rectifier
Authors: Tao Meng Ling , Deng Xiao Chuan , Wu Hao , Wen Yi
Published: November 2020

A 10kV/100A SiC PiN rectifier with MRM-JTE (multiple-ring modulated junction termination extension) is designed, fabricated and characterized. The optimized MRM-JTE achieves high breakdown capability and extends the optimal JTE dose window. A 100μm thick epitaxial SiC PiN rectifier with a doping concentration of 5×1014cm−3 has been fabricated using a standard TZ-JTE process. A 5.4V forward voltage drop is obtained at 100A forward current. Moreover, a measured breakdown voltage is up to 13.5kV corresponding to about 96% of the ideal parallel plane junction. The fabricated device exhibits a low RON,SP of 3.76mΩ·cm2 at 200A/cm2 , and a high BFOM of 48.5GW/cm2. In addition, the C-V characteristic and reverse recovery switch characteristic are also analyzed. In this paper, the successfully fabrication of high-voltage SiC PiN rectifier provides a further development for high-voltage high-power SiC power modules.
Design and Fabrication of Non-Uniform Spacing Multiple Floating Field Limiting Rings for 6500V 4H-SiC JBS Diodes
Authors: Sang Ling , Tian Li Xin , Yang Fei , Xia Jing Hua , Jin Rui , Zha Yi Ying , Tian Liang , Niu Xi Ping , Wu Jun Min
Published: November 2020

Designed for 6500V 4H-SiC JBS diodes, a highly-efficient termination structure of a non-uniform multiple floating field limiting rings (MFFLR) featuring with a non-uniform ring spacing and a multiple region division is studied and purposed. For each region, ring spacing is modulated independently by a multiplication factor and a linear increment factor. The non-uniform MFFLR structure is simulated and optimized for a better electric field distribution and a higher breakdown voltage. Based on the simulation results, 4H-SiC JBS diodes with the optimized non-uniform termination designs are fabricated. Experimental results show that the SiC JBS diode with optimized non-uniform MFFLR termination structure can achieve a breakdown voltage of up to 7800 V, and its termination efficiency is about 94% of an ideal parallel-plane junction’s. Our results demonstrate that the optimized non-uniform MFFLR termination structure is capable for SiC JBS diodes with breakdown voltage of 6500V and above. Our results can provide a valuable design methodology of edge termination structures for other high-voltage SiC devices.
Effect of the Field Oxidation Process on the Electrical Characteristics of 6500V 4H-SiC JBS Diodes
Authors: Sang Ling , Xia Jing Hua , Tian Liang , Yang Fei , Jin Rui , Wu Jun Min
Published: November 2020

The effect of the field oxidation process on the electrical characteristics of 6500V 4H-SiC JBS diodes is studied. The oxide thickness and field plate length have an effect on the reverse breakdown voltage of the SiC JBS diode. According the simulation results, we choose the optimal thickness of the oxide layer and field plate length of the SiC JBS diode. Two different field oxide deposition processes, which are plasma enhanced chemical vapor deposition (PECVD) and low pressure chemical vapor deposition (LPCVD), are compared in our paper. When the reverse voltage is 6600V, the reverse leakage current of SiC JBS diodes with the field oxide layer obtained by LPCVD process is 0.7 μA, which is 60% lower than that of PECVD process. When the forward current is 25 A, the forward voltage of SiC JBS diodes with the field oxide layer obtained by LPCVD process is 3.75 V, which is 10% higher than that of PECVD process. There should be a trade-off between the forward and reverse characteristics in the actual high power and high temperature applications.
Optimal Design of Large Signal and Noise Performance of GaN/SiC Hetero-Structural IMPATT Diodes Based on QCDD Model
Authors: Zheng Jun Ding , Wei Wen Sheng , Yang Wei Bo , Li Chang
Published: November 2020

Successes of GaN and SiC electronics in high frequency, large power realm indicate that, the GaN/SiC hetero-structures can be used to design the impact avalanche transit time (IMPATT) diodes operating at Terahertz range, of which holds advantages over homo-structural counterparts in lower noise and reduced tunnel current. Here, the (n)GaN/(p)SiC and (p)GaN/(n)SiC double drift region (DDR) IMPATT diodes operating at 0.85 THz are proposed based on the quantum corrected drift-diffusion (QCDD) model, the performance parameters of static state, large signal and noise properties of the studied devices such as peak electric field intensity, breakdown voltage, optimal negative conductance, output power, conversion efficiency, admittance-frequency relation, quality factor, noise electric field, mean-square noise voltage per band-width and noise measure were numerically calculated and analyzed, which can guide to optimize the GaN/SiC IMPATT diodes.
Advances for Enhanced GaN-Based HEMT Devices with p-GaN Gate
Authors: Zhong Min , Niu Ying Xi , Cheng Hai Ying , Yan Chen Xi , Liu Zhi Yuan , Song Dong Bo
Published: November 2020

With the development of high-voltage switches and high-speed RF circuits, the enhancement mode(E-mode) AlGaN/GaN HEMTs have become a hot topic in those fields. The E-mode GaN-based HEMTs have channel current at the positive gate voltage, greatly expanding the device in low power digital circuit applications. The main methods to realize E-mode AlGaN/GaN HEMT power devices are p-GaN gate technology, recessed gate structure, fluoride ion implantation technology and Cascode structure (Cascode). In this paper, the advantage and main realizable methods of E-mode AlGaN/GaN HEMT are briefly described. The research status and problems of E-mode AlGaN/GaN HEMT devices fabricated by p-GaN gate technology are summarized. The advances of p-GaN gate technology, and focuses on how these research results can improve the power characteristics and reliability of E-mode AlGaN/GaN HEMT by optimizing device structure and improving process technology, are discussed.
Normally-Off GaN Power Device Based on Stack AlGaN Barrier Structure and P-Type NiO Gate Electrode
Authors: Zhang Tong , Pu Tao Fei , Li Xiao Bo , Li Liu An , Cheng Shao Heng
Published: November 2020

In this study, we propose a novel normally-off AlGaN/GaN HFET based on stack AlGaN barrier structure and p-type NiO gate. The residual thin AlGaN barrier (with low Al content) is adopted to alleviate mobility degradation. Besides, p-type conductive NiO formed by thermal oxidation at 500 °C was used as gate electrode, which contribute to the positive shift of threshold voltage. Combining NiO gate and thin barrier structure, normally-off device with a threshold voltage of +1.1 V is realized. Temperature dependent transfer characteristics show that the normally-off device presents good thermally stability within the temperature range from 25 to 150 °C.
Design and Fabrication of 4H-Sic Mosfets with Optimized JFET and p-Body Design
Authors: Ni Wei Jiang , Wang Xiao Liang , Feng Chun , Xiao Hong Ling , Jiang Li Juan , li wei , Wang Quan , Li Ming Shan , Schlichting Holger , Erlbacher Tobias
Published: November 2020

In this paper, 4H-SiC planar MOSFETs were designed and fabricated. By using TCAD tool, the trade-off between on-resistance and maximum gate oxide electric field was optimized. With optimized gate oxide growth process, the gate oxide’s critical electric field of 9.8 MV/cm and the effective barrier height of 2.57 eV between SiO2 and 4H-SiC were obtained. The field effective mobility with different p-body doping was compared and studied. The MOS interface state density of 1.12E12 cm-2eV-1 at EC - EIT = 0.21 eV and channel mobility of 19.3 cm2/Vs at VGS = 20 V were obtained. The fabricated MOSFET’s on-resistance of 6.4 mΩcm2 was obtained with hexagonal cell structure which is very consistent with the simulation results.
Targeted Geoscience Initiative 5: integrated multidisciplinary studies of unconformity-related uranium deposits from the Patterson Lake corridor, northern Saskatchewan
Authors: Potter E G , Tschirhart V , Powell J
W , Kelly C J , Rabiei M , Johnstone D , Craven J A , Davis W J , Pehrsson S , Mount S
M , Chi G , Bethune K M
Published: November 2020

Basement-hosted uranium deposits of the Patterson Lake corridor are located on the southwestern margin of the Athabasca Basin in atypical hosts: altered and metamorphosed granite, granodiorite, and ultramafic to mafic rocks. Fluid inclusions record incursion of
two fluids, NaCl- and CaCl2-dominant, at temperatures up to 250°C and approximately 1 km into the basement during episodic brittle reactivation of high-strain-ductile to brittle-ductile structures, in particular late west- and north-northwest-striking brittle conjugate faults that crosscut the
Athabasca sandstone. Isotopic data from pyrite and tourmaline record basinal fluid-rock interactions under fluctuating pressure and oxidizing to reducing conditions. New 3-D geophysical modelling illustrates linkages between the surface architecture and lower crust to mantle and influence of the
Clearwater Domain granitic intrusions on the ore systems. High radiogenic heat production from these intrusions and other ca. 1.8 Ga felsic intrusions contributed to a prolonged, elevated geothermal gradient under the Proterozoic basins that permitted shallow (less than 3 km) depths of
mineralization.
Ядерные операторы Тeплица с сингулярными символами
Authors: Rozenblum Grigorii Vladimirovich , Vasilevski Nikolai Leonidovich
Published: November 2020

Приведены достаточные условия ядерности операторов Тeплица с символом-распределением, действующих в пространстве Бергмана на единичном круге. Дано определение преобразования Березина распределений, позволившее вывести формулу для следа оператора. Приведены примеры, поясняющие общую конструкцию.
Фильтрация под ступенчатой плотиной и римановы тета-функции
Authors: Bogatyrev Andrei Borisovich , Grigor'ev Oleg Alexandrovich
Published: November 2020

Предлагается новый полуаналитический метод вычисления характеристик течения в пористой среде, ограниченной водонепроницаемой преградой в виде прямоугольной ломаной. Основой метода является применение римановых тета-функций. Метод позволяет с машинной точностью находить решения задач фильтрации, а также некоторые характеристики решений, не решая задачу в целом.
Formulation and development of a topical combination cream for arthritis management
Authors: Hossain Shafayat , Shamim Abdullah , Saifuzzaman Md , Attiquzzaman Md , Hossain Golam , Raihan Obayed
Published: November 2020

Purpose: To design and prepare a non-prescription cream for cost-effective, potent, rapid and longlasting relief from arthritic pain.Method: The cream was prepared by formulating the aqueous phase using glucosamine sulphate, potassium chloride and chondroitin sulphate sodium, and then pouring it into the oil phase under suitable conditions. The physicochemical and antimicrobial properties, in vitro and ex vivo drug release, and overall physical and chemical stability of the formulations were characterized.Results: Sodium metabisulfite (0.5 %) and butylated hydroxyanisole (BHA) (0.01 %) showed a very strong synergistic effect on overall stability of the cream.Conclusion: This study confirms that the formulated cream is potentially suitable for the management of arthritis pain in patients.

Keywords: Arthritis, Ex vivo drug release, Sodium metabisulfite, Butylated hydroxyanisole, Product stability