bluuebunny/crossref_metadata_2025 huggingface dataset:
Failure’s Severity Affecting Railway Operation Based on Sensitivity Analysis: A Case Study of Addis Ababa Light Rail Transit (AALRT)
Authors: MİNWUYELET Ruhama , TILAHUN Daniel
Published: September 2022

Operation delays and trip cancelations affect the reliability of the operation and customer’s satisfaction. This review work adopts a case study of AALRTS operation system employing operation data and incident records of AALRTS. The purpose of this paper is assessing the failures frequency and the time it takes to get back to its operation aiming that how sensitive it is for the reliability of the operation. An extensive literature review has been used to approach the problem in which the sensitive failure`s analysis methods have been identified. The method that has been used to investigate the failure`s magnitude was sensitivity failure analysis by considering the case study of AALRTS. The method has been implemented to identify different failure modes through the analysis of the case how sensitive the failures are to the normal operation. The results that have been discovered from the analysis are: - the safety incidents and equipment failures are the major groups that affect the normal operation of AALRTS. When we go to the depth level-crossing incidents and power outages are the major sensitive failures (from safety incidents and equipment failures) that can reduce the reliability of the operation dramatically. Finally the researcher would like to recommend that giving a due attention for those sensitive failures might improve the reliability of the railway operation.
Reliability Assessment of Power System Network: A Detailed Review
Authors: AIROBOMAN Abel
Published: September 2022

Due to an increase in technological advancement and population, there is also a corresponding increase in the demand of electrical energy within Nigeria. Utility is presently characterized by suppressed demand due to the poor reliability inherent in the system. Utility, therefore, considers load shedding as a way out to ensure that the available power from each of the feeders from a network gets to its respective customers at any giving time they choose for the customer while the time the customers choose for themselves remains immaterial. However, in recent times, increased in downtime has been observed as a result of various faults and failures noticeable on the network and this has led to outrage by the customers who only considered protests as the only way out in expressing their dis-satisfaction with the system. This anomaly, therefore, arouses the interest for this study to carry out a detailed approach to carry out a review on the state of the reliability of the power system network in Nigeria and juxtaposing it with what is tenable outside the country with a view to determine the present state of the network and how it has fared with respect to time.
Analysis of jatropha oil-kerosene fuel mixtures on the performance of a variable-load direct injection CI engine
Authors: Ejilah Robinson , Ogbaneme Abiodun , Agboneni Osazoduwa , Adekunle Sikiru
Published: September 2022

Jatropha oil was blended with kerosene in ratios; JOK0, JOK20, JOK30, JOK40 and JOK50 and benchmarked against conventional diesel fuel. The blended fuel samples was test-run on a TD110-TD115 TQ small CI engine test rig, and emission levels for the fuel samples were examined using an SQV automobile exhaust gas analyzer. The JOK20 fuel sample offered a better performance in terms of higher BP, BTE, and EGT followed by; JOK30, JOK40 and JOK50 blends; and also exhibited lower SFC, BSEC and AFR, hence less fuel consuming than diesel fuel. A reduction in CO emission was recorded for JOK20, and a significant cut was also observed for JOK30, JOK40 blends with load increase.; while, JOK30, JOK40 and JOK50 samples exhibited higher CO2 and lower UHC emission levels than diesel. No traceable level of NOx emission was recorded for JOK20 fuel sample.
Análise de domínio de políticas institucionais de acesso aberto no Brasil
Authors: Café Luísa Chaves , Cavalcanti Vanessa Oliveira de Macêdo , Barros Camila Monteiro de , Vital Luciane Paula , Bisset Alvarez Edgar
Published: September 2022

Introdução: O Acesso Aberto à literatura científica é um movimento que se desenvolve há mais de duas décadas e se torna mais complexo como domínio de conhecimento. Com os avanços da área, algumas instituições criam políticas de acesso aberto que expressam normas, valores e paradigmas acerca do tema. Objetivo: Este estudo tem como objetivo a identificação dos aspectos fundamentais do acesso aberto em suas representações presentes nas políticas institucionais brasileiras. Metodologia: Utiliza como abordagem qualitativa a análise de domínio, e o percurso teórico-metodológico da análise de conteúdo por meio da aplicação da técnica categorial. Realiza o mapeamento dos documentos a partir do diretório de políticas de acesso aberto Melibea. Resultados: Aponta que há um reconhecimento da importância do acesso aberto como estratégia para democratização e universalização do conhecimento para a sociedade e indica aspectos importantes na visão das instituições brasileiras analisadas como direitos autorais, preservação e dados abertos. Conclusão: Conclui que há relações terminológicas a serem consideradas no domínio do acesso aberto e que as políticas são importantes para alinhar institucionalmente a compreensão sobre conceitos fundamentais e orientar as práticas de acesso aberto.
A ambientalização curricular nos cursos de agronomia em duas universidades paranaenses
Authors: Borges Ceyça Lia Palerosi , Silva Leticia da Costa e , Carniatto Irene
Published: September 2022

Neste estudo objetivou-se analisar as diferenças curriculares, no que tange à inserção da temática ambiental nos currículos do curso de agronomia em duas universidades paranaenses. Optou-se por uma pesquisa qualitativa caracterizada como um estudo de caso explicativo, cujas técnicas de coletas de dados foram: pesquisa documental e entrevista semiestruturada com 21 docentes das 48 disciplinas selecionadas, com 4 coordenadores de curso (primeiro e atual) de ambos os cursos investigados. Ao analisar as 10 características que devem estar presentes em um currículo ambientalizado, proposta pela Rede Ambientalização Curricular dos Estudos Superiores, reforça-se a importância do papel do docente no sucesso da ambientalização curricular no ensino superior. Dessa forma, mesmo em cursos com viés sustentável, como é o caso do curso de Agronomia da Universidade Federal da Fronteira Sul – UFFS, são as práticas dos docentes durante o processo de ensino e aprendizado o diferencial para o êxito da ambientalização curricular no processo formativo do discente. Por isso, torna-se compreensível a semelhança na presença das categorias da Rede ACES nos currículos dos cursos de agronomia com ênfase em agroecologia da UFFS e de agronomia convencional da Unioeste, mesmo que a Unioeste tenha menor número de disciplinas que discutam a temática ambiental do que o da UFFS.
Organizational Strategies to Creating a Culture of Well-Being Based on Human Caring Theory and a Self-Care ENERGY Model
Authors: Oehlert Julie Kennedy , Wei Holly , Bowen Christina , Hofler Linda , Hill Kevin N.
Published: September 2022

As the world continues to face pandemic challenges, healthcare professionals encounter another epidemic, psychological issues. This study aimed to describe the organizational strategies implemented to help team members during the pandemic and nurses’ and patients’ experiences through the health system’s employee pulse-check surveys and patients’ Hospital Consumer Assessment of Healthcare Providers and Systems survey. The guiding frameworks for the strategies were Watson’s human caring theory and a self-care ENERGY model. The organizations’ strategies included creating caring-healing environments, supporting work–life balance, and creating space for self-care. The health system is committed to exploring innovative approaches to support a culture of well-being.
Weight stigma mitigating approaches to gender-affirming genital surgery
Authors: Castle Elijah , Blasdel Gaines , Shakir Nabeel A. , Zhao Lee C. , Bluebond-Langner Rachel
Published: September 2022

The use of body mass index (BMI) to determine eligibility for gender-affirming surgery in transgender and nonbinary individuals has been contested. While BMI thresholds are often meant to be protective, restricting patients from access to surgery can also cause harm. There is a rationale for the continued use of BMI, but the inherent problems with it must also be recognized, including how weight stigma impacts patients’ access to gender-affirming surgery and influences clinical care. This article uses a narrative review of current literature to discuss how high BMI affects surgical outcomes in gender-affirming genital surgeries, as well as analogous procedures, existing de facto BMI thresholds, and how to both minimize the harms of proceeding with surgery in patients with a high BMI or the harms of delaying for weight loss. BMI factors into surgical decision-making based on the existing literature, which demonstrates that high BMI is associated with increased surgical risk, including higher incidences of surgical site infections and poor wound healing, as well as the possibility of free flap complications, which are a component of certain genital procedures. This patient population is at higher risk for eating disorders, and it is prudent to find alternatives to requiring patient self-monitored weight management. The impacts of weight stigma should be considered when treating gender-affirming surgery patients, and further data and research are needed to augment shared decision-making and lead to practice change.
Epidemiology of cholangiocarcinoma
Authors: Turati Federica , Bertuccio Paola , Negri Eva , La Vecchia Carlo
Published: September 2022

Aim: We aimed to analyze temporal trends in mortality from intrahepatic (ICC) and extrahepatic (ECC) cholangiocarcinoma in selected countries worldwide. Methods: Official death certification data for ICC and ECC and populations estimates for 29 countries worldwide (17 from Europe, 8 from the Americas, and 4 from Australasia) and for Hong Kong Special Administrative Region of the People’s Republic of China (SAR), from 1995 to 2018, were extracted from the World Health Organization and the Pan American Health Organization databases. Age-standardized mortality rates were computed. A joinpoint regression analysis was performed. Results: In both sexes, ICC mortality rates increased in most countries considered, including the USA, the UK, and Australia; in some countries, including Italy and France, the increasing trends leveled off over the most recent years. In men, around 2016, the highest rates (1.7-2.3/100,000) were observed in Hong Kong SAR, Portugal, France, Spain, Australia, Austria, the UK, and Canada; Latin American countries and some eastern European countries had the lowest rates (0.2-0.8/100,000). A similar pattern was observed in women, but with lower rates (from 1.7/100,000 in Hong Kong SAR to 0.14/100,000 in Argentina). ECC mortality declined in most European and Australasian countries, but it tended to increase in Americas. In both sexes, rates were below 1/100,000 around 2016, with the only exceptions being Japan (2.6/100,000 men and 1.2/100,000 women) and Hungary (1.5/100,000 men and 1.1/100,000 women). Conclusion: ICC mortality increased in most areas of the world, likely due to increased prevalence of risk factors and improved cancer recognition and classification. ECC mortality fell in most countries, largely due to the widespread use of cholecystectomy.
Oxidative stress and heart disease: the thyroid hormone mediation
Authors: Sabatino Laura , Ndreu Rudina , Vassalle Cristina
Published: September 2022

The heart is one of the principal targets of thyroid hormones (TH) action, affecting cardiac contractility, heart rate, and diastolic function. Oxidative damage is pivotal for onset and development of cardiovascular disease (CVD) and heart failure. Specifically, free radical generation is associated to hyper-metabolic state in hyperthyroidism, whereas hypo-metabolic state induced by hypothyroidism leads to a decrease of oxidative stress. In the present review, the role of oxidative damage in CVD and failing heart-TH interplay will be considered. The main oxidative events leading to cardiac dysfunction and TH cardiac regulation at genomic and non-genomic levels will be discussed, as well as role of TH in cardioprotection and reversion of cardiac remodeling.
Chronic obstructive pulmonary disease (COPD) and metabolic fatty liver syndromes: a dangerous but neglected liaison
Authors: Lonardo Amedeo , Beghe Bianca , Fabbri Leonardo Michele
Published: September 2022

This perspective article aims at addressing the potential commonalities associated with chronic obstructive pulmonary disease (COPD) and the two metabolic fatty liver syndromes: nonalcoholic fatty liver disease (NAFLD) and metabolic (associated) fatty liver disease (MAFLD). To this end, we briefly review the definitions and burdens of COPD and NAFLD and highlight the differences in the diagnostic criteria of NAFLD and MAFLD. We also critically discuss the recent line of research trying to identify an association between COPD and NAFLD. Moreover, among the chief co-morbidities of COPD patients, we identify significant six that exert a major impact on the natural course of COPD: major cardiovascular events, cardiac arrhythmias, metabolic syndrome, obstructive sleep apnea, osteoporosis, and psychodepression. The potential role of NAFLD in each of these COPD co-morbidities is accurately examined based on published studies. We conclude that both COPD and NAFLD/MAFLD are heterogeneous systemic syndromes. While the complex mechanistic links underlying the association of NAFLD/MAFLD with COPD and its co-morbidities remain to be fully elucidated, we highlight that the diagnosis of metabolic fatty liver syndromes in patients with COPD might be clinically relevant, as it might allow identifying a subset of COPD individuals who, being at risk of severe clinical outcomes, would need more comprehensive treatment approaches.
Special Issue on Recent Progress in Manufacturing Technology
Authors: Narahara Hiroyuki , Gao Feng
Published: September 2022

The continued effects of the global spread of COVID-19 have reaffirmed that restrictions on the movement of people and products have geopolitical consequences. In addition, the impacts involved in the decarbonization of the global environment have further strengthened the growing demand for the building of a sustainable society. These factors have had no small impact on the global economy and on global manufacturing as well. In this context, the demand for the realization of new manufacturing technologies that can respond to changes in social and economic environments has been growing.

This special issue focuses on recent advances in manufacturing technologies that maximize product quality and reduce costs, with an emphasis on the machinery industry. This special issue of the IJAT contains 12 papers. These include works on cutting technology, machining metrology, advanced machine tools, gear manufacturing technology, additive manufacturing, and more. The first five papers are proposals for new cutting technologies and elucidations of cutting phenomena. The next three papers are new proposals for machining measurements. The next two papers are on precision positioning technologies and a rack gear compensation technology. The last two papers are theoretical investigations into the basic phenomenon of additive manufacturing and its applications.

These papers were originally presented at the 10th International Conference on Leading Edge Manufacturing in the 21st Century (LEM21), held in Kitakyushu, Japan in 2021. The papers have been revised and expanded at the request of the editors.

The editors would like to thank all authors for their comprehensive efforts in making this special issue possible, and would like to thank the anonymous reviewers for their hard work. We wish them all the best in their future research in this field of manufacturing technology.
High-Efficiency Machining of Titanium Alloy Using Combined Machining Method of Driven Rotary Tool and Hale Machining
Authors: Yamazaki Yuto , Takada Tetsuo , Kato Hideharu , Sakamoto Shigehiko ,   Kanazawa Institute of Technology 7-1 Ohgigaoka, Nonoichi, Ishikawa 921-8501, Japan,   Nakamura-Tome Precision Industry Co., Ltd., Hakusan, Japan
Published: September 2022

Titanium alloys are widely used as aerospace materials, especially for turbine blades, due to their excellent mechanical properties. In the high-efficiency machining of titanium alloy turbine blades, the feed rate for ball-end milling is limited to 1000 mm/min due to the low thermal conductivity and chemical reactivity of the titanium alloy. These characteristics result in tool damage and an increase in the cutting temperature, significantly reducing the machined surface accuracy. A new processing method is thus needed for achieving a high accuracy and high efficiency in titanium alloy machining. It has been reported that driven rotary machining of hardened steel improves the machined surface and increases the processing efficiency, suggesting that high-efficiency machining can be realized by employing hale machining with a rotary tool. In this study, hale machining was performed using a driven rotary tool and the effects of different cutting conditions and cutting environment on the machining characteristics were investigated. The results showed that the tool life was longest at a feed rate of 9000 mm/min among the three feed conditions because the number of times of adhesion and detachment decreased with the decreasing friction distance of the cutting edge. Furthermore, it was clarified that adhesion formation at the cutting edge was suppressed by lubrication with an oil mist in a minimum quantity lubrication environment. This lubrication effect reduced the tool damage and adherence at the cutting edge, significantly extending the tool life and improving the machined surface quality compared to the results obtained in a wet environment.
Effect of Cutting Fluid on Tool Wear in Finished Surface Formation Area of Rounded Nosed Tool When Turning Alloy 304
Authors: Hayashida Takahide ,   Graduate School of Advanced Science and Engineering, Hiroshima University 1-4-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8527, Japan, Tanaka Ryutaro , Sekiya Katsuhiko , Yamada Keiji
Published: September 2022

In this study, the effect of cutting fluid on tool wear in finished surface formation area was investigated when turning alloy 304 with a TiN coated carbide tool under different lubricant conditions and the transition of surface roughness caused by tool wear was investigated. In the case of water-soluble cutting fluid, the higher concentration emulsion caused a smaller wear width VB and larger VB’”. In the case of oily cutting fluid, the lower co-efficient of friction oil caused a smaller wear width VB and larger VB’”. In both cases of water soluble and oily cutting fluid, the cutting fluid of lower coefficient of friction caused a larger wear width VB in milling at the feed rate of around tool edge roundness. This tendency was consistent with the wear width VB” and VB’” in turning. In both cases of water soluble and oily cutting fluid, the cutting fluid of lower coefficient of friction caused a larger cutting force volatility. The feed marks were more irregular in lower coefficient cutting fluids.
Feasibility Study of EDM-Assisted Combined Turning for Unidirectional CFRP
Authors: Tanaka Hidetake , Fukada Yuta , Kuboshima Ryuta ,   Precision Engineering Research Group, Sophia University 7-1 Kioi-cho, Chiyoda-ku, Tokyo 102-8554, Japan,   Graduate School of Science and Technology, Sophia University, Tokyo, Japan
Published: September 2022

Carbon fiber-reinforced plastics (CFRP), which are classified as functional resins, are rapidly replacing conventional materials because of their excellent properties. Typically, they have been used to fabricate components of airplanes or cars. In the field of medicine, the demand for micro-machined products manufactured with lathes is also increasing. However, owing to the significant tool wear caused by the carbon fiber, CFRP machining can result in burrs and inaccuracies in the finished product. The tool wear caused by carbon fiber must be reduced to ensure high dimensional accuracy. In this study, the possibility of combining conventional turning with electric current or electrical discharge machining was explored.
High-Precision Small-Diameter Deep Hole Drilling Using Cooling and Step Feed in PEEK Resin
Authors: Nomura Mitsuyoshi ,   Department of Mechanical Engineering, Akita Prefectural University 84-4 Aza Ebinokuchi Tsuchiya, Yurihonjo City, Akita 015-0055, Japan, Ito Shogo , Fujii Tatsuya , Suzuki Tsunehisa
Published: September 2022

The objective of this study is to achieve a high-precision and high-efficiency machining process for industrial components of the polyether ether ketone (PEEK) resin, such as the inspection socket of a connector or semiconductor packages. However, the drilling of holes in PEEK resin is challenging. Because PEEK resin is a thermoplastic resin, it can soften or melt owing to the heat generated during processing, which causes burrs and degrades the accuracy of the machined hole, thereby resulting in quality deterioration and hindering post-processing. Since the thermal conductivity of plastic materials including PEEK resin is lower than those of metals, the heat generated during processing does not dissipate to the outside of the workpiece, and the effect of the processing temperature on the processing accuracy is significant, particularly during drilling. Hence, a workpiece is cooled via a cold gas supply in this study. The effect of cold gas cooling on the machined hole accuracy and cutting state in the small-hole machining of PEEK resin is investigated. Results show that cooling the workpiece effectively decreases the cutting temperature and improves the machined hole accuracy. Under the experimental conditions, the combination of nonstep drilling and cooling enables high-precision drilling at approximately the same accuracy as step drilling.
Elucidation of Drilling Behavior on Workpiece Superimposed with Ultrasonic Vibration
Authors: Tsuji Naofumi , Takashima Kota , Sakurada Akira , Miyawaki Kazuto , Isobe Hiromi ,   Nagaoka University of Technology 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan,   National Institute of Technology, Akita College, Akita, Japan
Published: September 2022

This study quantitatively and theoretically clarifies the machining characteristics of the chisel engagement and the cutting-edge wear behavior in drilling in a workpiece superimposed with ultrasonic vibration. The machining phenomenon of drilling by this method considers being the same as drilling by ultrasonic vibration spindle from the viewpoint of the relative motion of the cutting edge and workpiece. However, the details have not been clarified yet. The chisel engagement behavior experiment at the initial stage of the drilling and cutting-edge wear experiment were carried out in this study. The chisel engagement behavior experiment revealed lower axial relative velocity results in a minor effect. In the cutting-edge life experiment, when the cutting fluid and the supply method were changed, the minimal oil with mist supply showed the same result as water-soluble with jet supply without breaking the drill. However, considerable wear was generated at the cutting edge in the initial drilling stage. When suitable ultrasonic vibration-assisted drilling was applied, initial wear decreased by 40% but could not be suppressed entirely. As a result of theoretical elucidation on this initial wear, it was proven that the flank face of the cutting edge contacted the workpiece when critical amplitude was exceeded. In the experiment to prove the validity of this theory, the initial wear occurred when the critical amplitude was exceeded. The cutting-edge wears increased in proportion to the working relief angle.
Statistics-Based Measuring Point Selection for Monitoring the Thermal Deformation of a Workpiece in End-Milling
Authors: Yang Mengmeng , Zhang Feng , Teramoto Koji ,   Division of Engineering, Muroran Institute of Technology 27-1 Mizumoto, Muroran, Hokkaido 050-8585, Japan,   Shenyang Agricultural University, Shenyang, China
Published: September 2022

The deformation of the thermal workpiece in the end-milling process has a significant effect on the accuracy of machining. In-process direct measurement of workpiece deformation is difficult because process disturbances occur during machining. On the other hand, local temperatures of the workpiece can be easily and accurately measured using common measuring methods. This study aims to develop a monitoring method for workpiece deformations. A sensor-configured thermal simulation is proposed by combining local temperature measurements with thermal simulations to estimate the thermal states of the workpiece in small-lot production. Furthermore, an empirical modeling method is introduced to estimate the workpiece deformation from measured temperatures, thereby accelerating process time. A reliable estimation requires the selection of appropriate measuring points. Using multiple linear regression (MLR), a statistics-based selection method is proposed to establish a relationship between thermal deformation and temperatures of measuring points in various machining situations. During the end-milling process, the predicted time-series of deformations at the machining point and temperatures of the measuring points are regarded as output variables and input variables, respectively, in the finite element method (FEM)-based thermal simulation. The number of measuring points is determined by evaluating Akaike information criterion (AIC), and effective measuring points are selected using the p-value index. The proposed systematic construction method is evaluated using simulation-based case studies. The constructed temperature-based model for measuring workpiece deformation corresponded well to the FEM simulation. Therefore, the constructed model can represent workpiece deformation with the minimum number of measuring points.
Design and Testing of a Compact Optical Angle Sensor for Pitch Deviation Measurement of a Scale Grating with a Small Angle of Diffraction
Authors: Quan Lue , Shimizu Yuki , Sato Ryo , Shin Dong Wook , Matsukuma Hiraku , Archenti Andreas , Gao Wei ,   Department of Finemechanics, Tohoku University 6-6-01 Aramaki Aza Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan,   Division of Mechanical and Space Engineering, Hokkaido University, Sapporo, Japan,   Department of Production Engineering, KTH Royal Institute of Technology, Stockholm, Sweden
Published: September 2022

The design and testing of different optical heads were performed to evaluate the pitch deviation of a diffraction scale grating with a small diffraction angle. Based on the proposed pitch deviation evaluation method employing optical angle sensors based on laser autocollimation, a modified optical head with position-sensitive detectors (PSDs) is first designed and constructed by following the conventional optical configuration. Owing to the small angle of diffraction of the first-order diffracted beams, the modified optical head has a large working distance, resulting in poor sensor stability. Therefore, a novel and compact optical head employing a pair of small prisms is designed and developed to shorten the working distance of the optical head. An additional modification was also made to the developed compact optical head in such a way that collimator objectives (COs) in the laser autocollimation units are removed to improve the sensor sensitivity. Experimental comparisons were conducted using the three types of optical heads to verify the feasibility of the developed optical angle sensor with PSDs.
A MEMS Device Integrating Multiple Cantilever Displacement Sensors to Evaluate Flat Machined Surfaces
Authors: Shimizu Hiroki ,   Graduate School of Engineering, Kyushu Institute of Technology 1-1 Sensui-cho, Tobata-ku, Kitakyushu-shi, Fukuoka 804-8550, Japan, Tamiya Koichi , Mizukami Shoichiro , Tamaru Yuuma
Published: September 2022

Multi-point scanning measurement, which is effective in eliminating motion errors of the stage in on-machine profile measurement, requires multiple displacement sensors of equal pitch to measure displacements simultaneously. However, it is not easy to arrange small sensors with high alignment accuracy when applying the multi-point method at a narrow pitch. In addition, if many sensors can be arranged in parallel, improvement in measurement accuracy can be expected. Therefore, a new micro electro mechanical system (MEMS) device for straightness measurement, one that integrates 10 cantilever displacement sensors, has been proposed. This device can be expected to solve the problem involved in the multi-point method because of the characteristics of MEMS, as the semiconductor processing method can make mechanical structures with high accuracy and it can easily make the device with many identical structures. The device is designed to measure waviness less than 100 μm in height. Ten cantilevers of 11 mm length are fabricated in parallel with 1.8 mm pitch on a side of a base substrate 20 mm square. The strain induced by a displacement of the probe placed near the front edge of the cantilever is detected as a change in the resistance of the piezo resistor at the foot of the cantilever. In the fabrication process of this device, crystal anisotropic etching is performed for 12 hours to form probes 250 μm high. A new fabrication process is also proposed in which a protective process is added to prevent damage to the circuits already formed during the etching. A prototype is investigated, and it is found that the resistance value increases about 0.45% in proportion to the displacement of 100 μm. It is therefore confirmed that this device has the basic ability to detect displacement.
Design and Prototyping of Biaxial Flexible Support Table for Fine Positioning Through Controlled Magnetic Attraction Forces
Authors: Tamaru Yuuma ,   Kyushu Institute of Technology  1-1 Sensui-cho, Tobata-ku, Kitakyushu-shi, Fukuoka 804-8550, Japan, Kawata Kensuke , Shimizu Hiroki
Published: September 2022

High-precision positioning can be obtained by reducing sliding friction and securing support rigidity. A prototype of a biaxial positioning table with non-contact drive by magnetic force and flexible mechanism support was developed to meet these requirements. The magnetic poles of a permanent magnet and an electromagnet were placed opposite to each other with an appropriate gap between them, and the attraction force between the two poles was used as the actuator for fine feed. The table was supported with a flexible mechanism composed of metal (A2017) beams with notches and elastic hinges assembled into a square frame shape. The permanent magnets were commercial neodymium magnets, and the electromagnets were self-made of S45C core bars. Two types of attraction force, maximum and minimum, were set depending on the number of neodymium magnets and the magnetic pole gap. The relationship between the applied current and attraction force for each type was calibrated using an electronic balance. Upon increasing and decreasing the applied current to the electromagnets, a linear relationship was shown between them. The relationship between the attraction force and the X- and Y-axes displacements was simulated by finite element analysis. Based on both results, the relationship between the applied current and displacement was estimated. The fine-feed experiment was conducted in both directions of the X- and Y-axes by applying current to electromagnets in a stepwise sequence. The displacements of total strokes in the long-stroke feed on applying the maximum attraction force were 340 μm and 315 μm for the X-axis and 160 μm and 133 μm for the Y-axis. These values are 2.0–2.8 times larger than the estimated displacement. Additionally, 3%–12% of the other axes interference occurred between the X- and Y-axes. In the high resolution feed applying the minimum attraction force, the displacement per step was 75 nm and 78 nm for the X-axis and 35 nm and 39 nm for the Y-axis. Cooperative feed with a combination of long stroke and high resolution was verified to be feasible.
Process of Straightening by Three-Point and Four-Point Bending for Curved Brass Rack
Authors: Aono Yuuta , Sato Nobukatsu , Inoue Shinji , Koga Daichi ,   National Institute of Technology, Kurume College 1-1-1 Komorino, Kurume, Fukuoka 830-8555, Japan,   Koga Gear Product Company, Kurume, Japan
Published: September 2022

Racks are typically curved after cutting their gear teeth, and a straightening process is required to correct the distortion due to machining. In this study, key factors in the straightening of curved racks by three-point and four-point bending are examined with to automate the correction. The relationship between load and deformation is plotted in real time to determine the unloading point to correct the target deflection for straightening. The parameters constituting the above-mentioned relationship are important for achieving precise correction. The load and deflection at the central loading point are known to be suitable parameters for three-point bending. The smaller the deflection required for correction, the higher is the precision of the displacement sensor required for three-point bending. In the case of four-point bending, the bending moment and bending angle should be selected. In addition, a four-point bending jig is required to load the uniform bending moment during the correction. A modified four-point bending jig is made and the effectiveness was examined.
Simplified Prediction of Melt Pool Shape in Metal Additive Manufacturing Using Maraging Steel
Authors: Fukunaga Taiichiro ,   Kyushu Institute of Technology 680-4 Kawazu, Iizuka-shi, Fukuoka 820-8502, Japan, Narahara Hiroyuki
Published: September 2022

This paper describes a method to represent and predict the melting and solidifying shape of metal powder materials in the selective laser melting (SLM) method of metal addition manufacturing using a small number of physical properties. This is a processing method to complete a three-dimensional modeling object by layer-by-layer stacking. A laser beam is used to create objects with minimal voids and distortion by appropriately setting the scanning speed, output intensity, spot diameter, hatch spacing, and other conditions. Repeating actual experiments to determine the optimal build conditions increases the cost of operating the machine, such as electricity and labor, and the cost of materials when a modeling failure occurs. In recent years, attempts have been made to determine the optimal build conditions by analyzing the melting and solidification phenomena of metallic materials through precise simulations. However, it is necessary to set many physical property values as the parameters. Many physical property values are difficult to measure, and if these values are incorrect, the analysis results can differ significantly. In this study, a theoretical model for predicting the cross-sectional area and cross-sectional thickness of the melt pool using a single-track laser was developed using a small number of physical properties, such as melting point, thermal conductivity, and latent heat. To further examine the validity of the theoretical model, experiments were conducted for comparison purposes. In this experiment, 5 × 1 × 1 mm rectangular specimens were stacked and fabricated by a metal additive manufacturing machine using different laser beam irradiation conditions. The fabricated samples were cut, polished, and etched with nital, and the melt pool shapes were measured. Finally, experimental and theoretical values were compared to confirm the validity of the constructed theoretical model. This indicates that the proposed model can predict the melt pool shape.
Mechanical Joining with Aluminum Part by 3D Printing of Polylactic Acid and Acrylonitrile-Butadiene-Styrene Parts for Fabrication of Multi-Material Parts
Authors: Nakagawa Yuki , Abe Ayumu , Yoshino Masahiko ,   Department of Systems, Control and Information Engineering, National Institute of Technology, Asahikawa College 2-2-1-6 Shunkodai, Asahikawa, Hokkaido 071-8142, Japan,   School of Engineering, Tokyo Institute of Technology, Tokyo, Japan
Published: September 2022

In this study, the manufacturing process of multi-material parts by simultaneous mechanical joining and three-dimensional (3D) printing of plastic parts was developed. In this process, a metal part with a hole sets on a lower 3D printed plastic part having a projection, and an upper plastic part is deposited on the metal part, while caulking is formed by a 3D printer. The effect of 3D printing conditions and a dimension of caulking on the joint strength was evaluated through the tensile shear and three-point bending tests. It was observed that squashing the projection while printing the upper part effectively improved the strength. The strength decreased as the clearance increased, whereas the shape of the projection was changed to a cylinder and a cone to ease positioning while preventing a decrease in the strength.
Motion Analysis of Lathe Machining Work Using a Digital Position Display Device
Authors: Taki Seiko ,   Chiba Institute of Technology 2-17-1 Tsudanuma, Narashino, Chiba 275-0016, Japan, Yonezawa Shohei
Published: September 2022

The ocular movements of skilled and unskilled engine lathe operators were analyzed as a preliminary step in developing a method for supporting the transfer of skills in engine lathe machining. An attempt was made to elucidate the difference in skilled and unskilled workers operating a lathe with a digital position display device (digital readout display meter) that can display the machining status of the workpieces. The impact of the digital position display device was investigated by evaluating and comparing the quality of each production from the operations. In addition, because skillful estimation is necessary for most manufacturing tasks, the differences between the ranges of visual examination of workers were analyzed while a workpiece was being measured.
A Compound Control Algorithm for Height Following of Laser Cutting Head
Authors: Da Wu , Chunnian Zeng , Jie Luo , Shu Yan , Lei Chen , Hu Jinmin ,   Wuhan University of Technology 122 Luoshi Road, Hongshan District, Wuhan 430070, China,   Shenzhen Road Rover Technology Co., Ltd., Shenzhen, China
Published: September 2022

A composite algorithm combined with fuzzy proportional-integral-derivative (PID) control and acceleration closed-loop control is proposed to address the defects of slow response speed, strong oscillation, and long adjustment time of the current height following control system for a laser cutting head. The fuzzy PID control can satisfy the different requirements for the control parameters in each stage of the height follow-up adjustment process for the laser cutting head via the adaptive adjustment of the PID parameters. Accordingly, the height following error can be attenuated to the set positioning accuracy range. The acceleration closed-loop control can improve the acceleration and deceleration performance of the system through the positive and negative feedback regulation of the motion acceleration of the laser cutting head to achieve high-speed servo. An experimental bench of height follow-up control system for laser fabrication is developed to verify the effectiveness of the algorithm. Through experimental verification, compared with the conventional digital PID incremental algorithm, this composite control algorithm can accelerate the response speed of height follow-up control system for the laser cutting head, improve the dynamic performance of the system, and realize fast and precise servo control of laser cutting head height under the premise of ensuring positioning accuracy. The proposed algorithm is expected to lay a foundation for the development of the new intelligent laser processing system.
Enhancing the Shape Complexity in Direct Energy Deposition with Phased Deformation
Authors: Gudur Srinath ,   Department of Mechanical and Aerospace Engineering, Indian Institute of Technology Hyderabad (IITH) Kandi, Sangareddy, Telangana 502285, India, Simhambhatla Suryakumar , Reddy N. Venkata
Published: September 2022

Wire-based direct energy deposition (W-DED) techniques in metal additive manufacturing allow part-fabrication at higher deposition rates and lower costs. Given the lack of any support mechanism, these processes face challenges in fabricating overhanging features. The inherent overhang capability of weld-beads and higher-order kinematics can help realize certain complex geometries. However, significant challenges like non-uniform slicing, constrained deposition-torch accessibility, etc., limit the efficacy of these approaches. The present work describes a deformation-aided deposition process designed to overcome some of these limitations and to manufacture complex metallic components. It is based on a sequential combination of deposition and bending processes: a shape fabricated through W-DED deposition is bent to form the required shape. The cycle of deposition and bending is repeated until the final desired geometry is realized. The anisotropic and deterministic behaviors of the deposited components are analyzed in terms of springback and the punch force. Finally, the benefit of current hybrid process is demonstrated through a few illustrative geometries.
Investigation of Air Filter Properties of Flash-Spinning Nanofiber Non-Woven Fabric
Authors: Tsai Shih-Pang , Wu Wei , Sota Hiroyoshi , Hirogaki Toshiki , Aoyama Eiichi ,   R&D Center, M-TechX Inc. 104 D-egg, 1 Jizodani, Kodo, Kyotanabe-city, Kyoto 610-0332, Japan,   M-TechX Inc., Tokyo, Japan,   Faculty of Science and Engineering, Doshisha University, Kyotanabe, Japan
Published: September 2022

Using computational fluid dynamics (CFD) technology, a stable manufacturing method for polymeric nanofiber non-woven fabrics based on an improved melt-blowing method and flash spinning is realized to achieve mass productivity. Subsequently, a method to predict filter efficiency using two production methods based on the effects of thickness, filling rate, and fiber diameter on filtration performance is developed to establish a filter design via CFD technology. CFD models featuring uniform fiber diameters are proposed. Next, the pressure loss and flow resistivity are calculated using CFD flow analysis software, as in a filter experiment. The proposed fiber diameter distribution model yields results similar to the experimental value, and the relationship among filling rate, fiber diameter, and flow resistivity is verified. The non-woven filter fabricated in this study demonstrates superior filtration properties, based on the results. Additionally, a method to satisfy both low pressure loss (low flow resistivity) and high filtration efficiency is discussed. Although the pressure loss increases, the filter yields a value below the standard for high-performance face masks, since the fiber diameter is on the nano-order.
Analysis of Gender Roles in the Context of Space: Feminist Approaches and Ethics of Care Perspective
Authors: ÖNER Yasemin , ATSIZ Hasan
Published: September 2022

Bu makale, kadınların toplumsal cinsiyet normlarının tarihsel koşullarıyla sınırlandırılmasına karşı ciddi bir literatüre sahip feminist çalışmalarda, kadın ve ev mekânı arasında kurulan bağı incelemeyi amaçlamıştır. Çalışmanın sınırları çerçevesinde, kadınların özel alan pratiklerinin ayrı bir değer ve kültür oluşturduğu iddiasına sahip feminist özen etiği perspektifi ve onun bir kritiğine yer verilmiştir. Öncelikle feminist perspektifin ev ve ev işlerine bakışına değinilmiştir. Özel alanın, kadınları ikincil kılan bir cinsel farklılığının kurulmasında ön plana çıkarıldığı görülmüştür. İkinci olarak özen etiği yaklaşımın kadınların toplumsal cinsiyet rollerine atfettiği bakım (care) kavramına ilişkin görüşlerine yer verilmiştir. Son olarak Carol Gilligan’ın özen etiği yaklaşımını, homojen bir kadınlık ve erkeklik varsayma riski açısından sorunsallaştıran Joan Tronto’nun açtığı bazı sorular incelenmiştir. Kadın ve erkek psişelerinin farklı işleyişini, kadınların bilme yapıları ve ahlaki muhakemelerinin farklılığını annelik ve ev deneyimi ile ilişkilendiren özen etiği yaklaşımı; kadınları, “ilişkisellik” temelinde anlamaya/anlamlandırmaya çalışmaktadır. Buna göre, kadın-erkek farklılığının kabul edilerek bazı problemlerin aşılabileceğine dair umut taşıyan; ilişkisellik, bağlantılılık, görecelik ve çok anlamlılığın önemini hatırlatan feminist özen etiğinin alternatif bakış açısı hem etik hem de feminist çerçeveyi yeniden yorumlamaya imkân tanımaktadır. Yine de bu yaklaşım, ön planda tuttuğu ve değer verdiği bakım kavramı hakkında, kadınların bireysel özerkliğinin gerçekleşmesine engel olabileceği eleştirisiyle başa çıkmak durumundadır. Ayrıca özenin bir cinsel farklılık teması olarak sunulmasındaki ısrar, güçlü bir etik teori kurma ve politik eylemi yönlendirmede yetersizlikle eleştirilmektedir.
Hypocortisolism in attention deficit hyperactivity disorder – roles of sex, comorbidity, and symptom presentation
Authors: Pauli-Pott Ursula , Skoluda Nadine , Nater Urs M. , Becker Katja , Derz Friederike , Kaspar Elena , Kasperzack Daria , Kehm Kira , Kött Marie , Mann Christopher , Schurek Pia , Pott Wilfried , Schloß Susan
Published: September 2022

Objective: Low activity of the hypothalamic-pituitary-adrenal axis (HPAA) has been found in children with ADHD. The condition may be related to the reduced attention regulation capacity and/or to comorbid oppositional defiant or conduct disorder (ODD/CD). Sex differences are probable but not sufficiently studied. We analyzed hypocortisolism and the reactivity of the sympathetic nervous system (SR) in boys and girls with ADHD and healthy controls. Methods: The sample comprised 205 children (98 with ADHD and 107 healthy controls). DSM-5 phenotypic symptom presentation and comorbid ODD/CD were assessed using clinical interviews. Hair cortisol concentration (HCC) was used to assess the long-term, cumulative activity of the HPAA. SR was assessed via skin conductance response (SCR). For control purposes, comorbid internalizing symptoms and indicators of adverse childhood experiences were assessed. Children were medication naive.Results: Boys presenting with predominantly inattentive symptoms (ADHD-I) showed lower HCC than did healthy boys. Girls presenting with combined symptoms (ADHD-C) showed higher HCC than did healthy girls (p’s<.05, sex-by-group interaction, F(2,194)=4.09, p=.018). Boys with ADHD plus ODD/CD showed a blunted SR (p<.001, sex-by-group interaction, F(2,172)=3.08, p=.048). Conclusion: HCC constitutes an easily assessable, reliable, and valid marker of phenotypic ADHD-related features. It indicates more homogenous subgroups of ADHD and might point to specifically involved pathophysiological processes.
The effect of exogenously induced magnetic fields on neurotransmitter dynamics
Authors: Rivas Manuel , Martinez-Garcia Marina
Published: September 2022

Over the past decades, there has been significant controversy regarding the role of exogenous electromagnetic (EM) fields on the dynamics of molecules in living cells. Here we present a model of electromagnetic forces in the synaptic cleft using the bidomain theory as a framework and the averaged field theory as the theoretical basis, suggesting that the exogenously induced magnetic field may modify the neurotransmitter dynamics. Our model is based on a voltage cell membrane amplification due to the Hall effect principle and the hypothesis that synaptic cleft electric conductivity is represented by tensors with non-zero off-diagonal terms. The physical interpretation of the off-diagonal components is explained, and analytical expressions for the induced magnetic field and conductivity tensor are derived.