Compact electrothermal model of laboratory made GaN Schottky diodes

2020 ◽  
Vol 37 (2) ◽  
pp. 95-102 ◽  
Author(s):  
Krzysztof Górecki ◽  
Paweł Górecki
Keyword(s):  
Integrated Circuit ◽  
Design Methodology ◽  
Schottky Diodes ◽  
Parameters Estimation ◽  
Model Parameters ◽  
Content Type ◽  
Self Heating ◽  
Dc Characteristics ◽  
Wide Range ◽  
Electrothermal Simulation

Purpose The purpose of this paper is to propose a simple electrothermal model of GaN Schottky diodes, and its usefulness for circuit-level electrothermal simulation of laboratory-made devices is proved. Design/methodology/approach The compact electrothermal model of this device has the form of a subcircuit for simulation program with integrated circuit emphasis. This model takes into account influence of a change in ambient temperature in a wide range as well as influence of self-heating phenomena on dc characteristics of laboratory-made GaN Schottky diodes. The method of model parameters estimation is described. Findings It is shown that temperature influences fewer characteristics of GaN Schottky diodes than classical silicon diodes. The discussed model accurately describes properties of laboratory made GaN Schottky diodes. Additionally, the measured and computed characteristics of these diodes are shown and discussed. Research limitations/implications The presented model together with the results of measurements and computations is dedicated only to laboratory-made GaN Schottky diodes. Originality/value The presented investigations show that characteristics of laboratory-made GaN Schottky diodes visibly change with temperature. These changes can be correctly estimated using the compact electrothermal model proposed in this paper. The correctness of this model is proved for four structures of such diodes characterised by different values of structure area and a different assembly process.

Investigations of mutual thermal coupling between SiC Schottky diodes situated in the common case

Circuit World ◽  
2017 ◽  
Vol 43 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Krzysztof Górecki ◽  
Damian Bisewski ◽  
Janusz Zarębski ◽  
Ryszard Kisiel ◽  
Marcin Myśliwiec
Keyword(s):  
Silicon Carbide ◽  
Design Methodology ◽  
Schottky Diodes ◽  
Semiconductor Materials ◽  
Thermal Coupling ◽  
Internal Temperature ◽  
Content Type ◽  
Self Heating ◽  
The Common ◽  
Transient Thermal

Purpose This paper aims to present the results of measurements and calculations illustrating mutual thermal coupling between power Schottky diodes made of silicon carbide situated in the common case. Design/methodology/approach The idea of measurements of mutual transient thermal impedances of the investigated device is described. Findings The results of measurements of mutual transient thermal impedances between the considered diodes are shown. The experimentally verified results of calculations of the internal temperature waveforms of the considered diodes obtained with mutual thermal coupling taken into account are presented and discussed. The influence of mutual thermal coupling and a self-heating phenomenon on the internal temperature of the considered diodes is pointed out. Research limitations/implications The presented methods of measurements and calculations can be used for constructing the investigated diodes made of other semiconductor materials. Originality/value The presented results prove that mutual thermal coupling between diodes mounted in the common case must be taken into account to calculate correctly the waveforms of the device internal temperature.

scholarly journals New experiences in nature areas: architecture as a tool to stimulate transformative experiences among visitors in nature areas?

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ben Wielenga
Keyword(s):  
Design Methodology ◽  
Content Type ◽  
Transformative Experiences ◽  
Wide Range

Purpose The purpose of this paper is to share architecture as a tool that is increasingly implemented in nature areas and its potential for stimulating transformative experiences among visitors in nature-based tourism. Design/methodology/approach Based on three examples of architecture in nature, the value of architecture to nature-based tourism is presented. Findings It was found that architecture in nature has a wide range of benefits for nature-based tourism and may form a catalyst for gaining transformative experiences in the examples presented. Originality/value The findings presented in this paper touch upon a new way of stimulating transformative experiences among visitors in nature-based tourism by implementing architecture.

Condition monitoring based on modified CUSUM and EWMA control charts

2018 ◽  
Vol 24 (1) ◽  
pp. 119-132 ◽  
Author(s):  
Suzana Paula Gomes Fernando da Silva Lampreia ◽  
José Fernando Gomes Requeijo ◽  
José António Mendonça Dias ◽  
Valter Martins Vairinhos ◽  
Patrícia Isabel Soares Barbosa
Keyword(s):  
Control Charts ◽  
Moving Average ◽  
Failure Detection ◽  
Parameters Estimation ◽  
False Alarms ◽  
Model Parameters ◽  
Content Type ◽  
Catastrophic Failures ◽  
The Right ◽  
Weighted Moving Average

Purpose The application of condition-based maintenance on selected equipment can allow online monitoring using fixed, half-fixed or portable sensors. The collected data not always allow a straightforward interpretation and many false alarms can happen. The paper aims to discuss these issues. Design/methodology/approach Statistical techniques can be used to perform early failure detection. With the application of Cumulative Sum (CUSUM) Modified Charts and the Exponentially Weighted Moving Average (EWMA) Charts, special causes of variation can be detected online and during the equipment functioning. Before applying these methods, it is important to check data for independence. When the independence condition is not verified, data should be modeled with an ARIMA (p, d, q) model. Parameters estimation is obtained using the Shewhart Traditional Charts. Findings With data monitoring and statistical methods, it is possible to detect any system or equipment failure trend, so that we can act at the right time to avoid catastrophic failures. Originality/value In this work, an electro pump condition is monitored. Through this process, an anomaly and four stages of aggravation are forced, and the CUSUM and EWMA modified control charts are applied to test an online equipment monitoring. When the detection occurs, the methodology will have rules to define the degree of intervention.

Woodworking marking tool structuration based on craft traditions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ilze Gūtmane ◽  
Silvija Kukle ◽  
Inga Zotova ◽  
Artūrs Ķīsis
Keyword(s):  
Design Methodology ◽  
Wood Product ◽  
Baltic Region ◽  
Content Type ◽  
Data Object ◽  
Hand Tool ◽  
Wide Range ◽  
Product Creation ◽  
Information Materials ◽  
The Baltic

PurposeBased on profound information lacking in compiled information materials, the risks of losing knowledge related to the values of traditional woodworking processes are increasing. The purpose of this article is to collect and structure diverse marking tool data into a comprehensive, understandable and clear design schematic view, which serves as a basis for the accumulation and preservation of diverse marking objects and shows woodworking marking tool relation in the group and subgroup levels.Design/methodology/approachA method for marking tools structuring and analysis are described, including breaking down a set of objects into groups of marking objects, and assigning one or more attributes to the parcelled objects by arranging them into hierarchic levels. Research is based on marking tools used by carpenters, joiners and woodcarvers mainly in the Baltic region.FindingsCollected data, object analyses and comparison within-group and subgroup levels are based on written and visual sources, museum and museum funds visits, and participation in the local craftsmen events. The created structure is expandable in group and subgroup levels. The most comprehensive way for object structuring is chosen as a base to reveal a diversity of the objects.Originality/valueStructure schemes of woodworking marking tools are important in scientific, educative and cultural levels based on their wide range and use. Aggregated information of the woodworking tools serves as a base for existing tool studies and improvement, new tool and wood product creation as well as complements the structure of the upcoming woodworking hand tool database and book.

Multi-jet ice 3D printing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Pushkar Prakash Kamble ◽  
Subodh Chavan ◽  
Rajendra Hodgir ◽  
Gopal Gote ◽  
K.P. Karunakaran
Keyword(s):  
Design Methodology ◽  
Good Accuracy ◽  
Microfluidic Channel ◽  
Content Type ◽  
Water Ice ◽  
Volumetric Expansion ◽  
Low Viscosity ◽  
Wide Range ◽  
Water Layers ◽  
Potential Applications

Purpose Multi-jet deposition of the materials is a matured technology used for graphic printing and 3 D printing for a wide range of materials. The multi-jet technology is fine-tuned for liquids with a specific range of viscosity and surface tension. However, the use of multi-jet for low viscosity fluids like water is not very popular. This paper aims to demonstrate the technique, particularly for the water-ice 3 D printing. 3 D printed ice parts can be used as patterns for investment casting, templates for microfluidic channel fabrication, support material for polymer 3 D printing, etc. Design/methodology/approach Multi-jet ice 3 D printing is a novel technique for producing ice parts by selective deposition and freezing water layers. The paper confers the design, embodiment and integration of various subsystems of multi-jet ice 3 D printer. The outcomes of the machine trials are reported as case studies with elaborate details. Findings The prismatic geometries are realized by ice 3 D printing. The accuracy of 0.1 mm is found in the build direction. The part height tends to increase due to volumetric expansion during the phase change. Originality/value The present paper gives a novel architecture of the ice 3 D printer that produces the ice parts with good accuracy. The potential applications of the process are deliberated in this paper.

Managing COVID-19 in workplaces – a theoretical framework for integral employees’ health

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sandra Gauer ◽  
Barbara Germann
Keyword(s):  
Literature Review ◽  
Psychological Stress ◽  
Design Methodology ◽  
Job Demands ◽  
Theoretical Framework ◽  
Theoretical Base ◽  
Content Type ◽  
Stress Theory ◽  
Wide Range ◽  
Strategic Measures

Purpose The purpose of this paper is to develop a framework on how to deal with stressors emerging from the COVID-19 outbreak. The theoretical framework aims to explain pandemic-related stressors and potential ways to prevent them, considering a wide range of interacting factors at individual, team and organizational levels to ensure their employees’ health. Design/methodology/approach The authors drew on an integrative literature review to identify pandemic-related stressors influenceable by the organization and gathered solution approaches to counteract them. Popular psychological stress theories served as a theoretical base for the framework. Findings The authors based the framework on an integration of the transactional stress theory (Lazarus and Folkman, 1984) and the job demands resources model (Schaufeli and Bakker, 2004), focusing on their respective theoretical strengths. The final framework offers a solid orientation for scholars regarding the introduction of holistic and strategic measures in coping with pandemic-related stressors. A section describing possibilities for practitioners’ use of the framework has been integrated. Originality/value To the best of the authors’ knowledge, this study is the first to offer a framework on how to handle COVID-19-related stressors in the workplace by implementing teamwide and companywide measures.

scholarly journals Mapping post-diagnostic dementia care in England: an e-survey

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rachael Frost ◽  
Kate Walters ◽  
Jane Wilcock ◽  
Louise Robinson ◽  
Karen Harrison Dening ◽  
...  
Keyword(s):  
Design Methodology ◽  
Dementia Care ◽  
Community Based ◽  
Content Type ◽  
The United Kingdom ◽  
Mailing Lists ◽  
Wide Range ◽  
Survey Responses ◽  
Practical Implications ◽  
Pathways Of Care

PurposePost-diagnostic dementia care is often fragmented in the United Kingdom, with great variation in provision. Recent policies suggest moving towards better community-based care for dementia; however, little is known on how this care is delivered. This study aimed to map the post-diagnostic dementia support provided in England a decade after the introduction of a National Dementia Strategy.Design/methodology/approachA mixed-methods e-survey (open Nov 2018–Mar 2019) of dementia commissioners in England recruited through mailing lists of relevant organisations was conducted. The authors descriptively summarised quantitative data and carried out thematic analysis of open-ended survey responses.Findings52 completed responses were received, which covered 82 commissioning bodies, with representation from each region in England. Respondents reported great variation in the types of services provided. Information, caregiver assessments and dementia navigation were commonly reported and usually delivered by the voluntary sector or local authorities. Integrated pathways of care were seen as important to avoid overlap or gaps in service coverage. Despite an increasingly diverse population, few areas reported providing dementia health services specifically for BME populations. Over half of providers planned to change services further within five years.Practical implicationsThere is a need for greater availability of and consistency in services in post-diagnostic dementia care across England.Originality/valuePost-diagnostic dementia care remains fragmented and provided by a wide range of providers in England.

scholarly journals A biopsychosocial framework for recovery from COVID-19

2020 ◽  
Vol 40 (9/10) ◽  
pp. 1021-1039
Author(s):  
Kaz Stuart ◽  
Mark A. Faghy ◽  
Elaine Bidmead ◽  
Ruth Browning ◽  
Catriona Roberts ◽  
...  
Keyword(s):  
Living Arrangements ◽  
Design Methodology ◽  
Online Survey ◽  
Narrow Range ◽  
Analytical Framework ◽  
Content Type ◽  
Wide Range ◽  
Social Media Platforms ◽  
Practical Implications

PurposeThis paper proposes a biopsychosocial (BPS) analysis of COVID-19 experiences which enhances understanding of complex and interrelated factors and leads to the proposition of a BPS recovery framework.Design/methodology/approachOnline narrative research was used to explore people's experiences of COVID-19 and was conducted over a four-month period. The call was distributed via a short open-ended qualitative online survey advertised on social media platforms and 305 responses came from across England.FindingsThe findings illustrate people with a narrow range of BPS characteristics experienced over a wide range of BPS impacts which are nuanced, complex and dynamic. Left unaddressed these may create future adverse BPS characteristics. An integrated BPS framework for recovery is proposed to avoid such further negative outcomes from the pandemic.Research limitations/implicationsThe sample contained a bias in age, gender and living arrangements.Practical implicationsThe paper offers a clear framework to enable integrated holistic recovery/regrowth planning.Social implicationsUsing the framework would reduce social and health inequities which have been recently deepened by COVID-19 in the long-term.Originality/valueThe paper is original in its use of a BPS analytical framework.

Lasers sensors very accurately measure both speed and length in real time

Sensor Review ◽  
2014 ◽  
Vol 34 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Richard Bloss
Keyword(s):  
Real Time ◽  
Design Methodology ◽  
Laser Measurement ◽  
Quality Cost ◽  
Content Type ◽  
Laser Sensors ◽  
Wide Range ◽  
Length Measurements ◽  
Practical Implications ◽  
Insight Into

Purpose – Review of the advancements in non-contact laser sensors for much more accurate real time speed as well as length measurements. The paper aims to discuss these issues. Design/methodology/approach – In-depth review of a number of applications of laser sensors. Findings – A wide range of manufacturers in the converting industries have solved measurement problems and realized major improvements in product quality, cost of production and productivity by applying laser measurement as well as reduction in scrap. Practical implications – Others with the need to make very accurate measurements of speed and length in real time may find that laser sensors may provide the answer. Originality/value – An expert insight into how to solve real time speed and length measurement problems.

Synthesis and characterisation of heatproof polyester polyols used in polyurethane adhesive

2016 ◽  
Vol 45 (6) ◽  
pp. 439-443 ◽  
Author(s):  
Tingting Xu ◽  
Cuifeng Zhang ◽  
Lijun Chen
Keyword(s):  
Heat Resistance ◽  
Benzene Ring ◽  
Design Methodology ◽  
Raw Materials ◽  
Sebacic Acid ◽  
Vacuum Melting ◽  
Polyurethane Adhesive ◽  
Content Type ◽  
Wide Range ◽  
Polyurethane Adhesives

Purpose Presently, a wide range of polyurethane adhesives can be obtained using different kinds of polyols and isocyanates. However, the applied temperature of the polyurethane adhesive is not more than 80°C. The film of polyurethane adhesive will be softened and deformed when its applied temperature is more than 100°C. Thus, the mechanical property of the polyurethane adhesive is decreased clearly, which limits its further application. The purpose of the study is to improve the heat resistance of polyols, especially polyester polyols and its resultant polyurethane adhesives. Design/methodology/approach The more rigid benzene ring is introduced into the polyester polyols to improve the heat resistance of its resultant polyurethane adhesive. Findings The more rigid benzene ring has ben introduced into the polyester polyols and the heat resistance of its resultant polyurethane adhesive is improved. Originality/value The polyester polyols with more rigid benzene ring have been prepared successfully by the vacuum melting method when diethylene glycol, neopentyl glycol, 1,6-hexanediol, ethanediol, isophthalic acid, terephthalic acid, sebacic acid and adipic acid are used as raw materials and tetra-isopropyl titanate is adopted as the catalyst.

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