bluuebunny/crossref_metadata_2025 huggingface dataset:
Low Cost Cooling Device for High Power LED Lamps
Authors: Martinez-Vega Pamela , Lopez-Badillo Araceli , Luviano-Ortiz J. Luis , Hernandez-Guerrero Abel , Cervantes Jaime G.
Published: February 2021

The modern world progressively demands more energy; according to forecasts energy consumption will grow at an average annual rate of 3 percent. Therefore, it is necessary to purchase products or devices that are efficient and environmentally friendly. Technology in LED (Light Emitting Diode) lighting is presented as an alternative to energy saving, since LEDs have proven to be extremely efficient, have a long service life and their cost-effective ratio is very good. However, the heat emitted by the LED chip must be dissipated effectively, since the overheating of the chip reduces the efficiency and lifetime of the lamp. Therefore, heat sinks that are reliable, efficient and inexpensive should be designed and built. The present work proposes new designs for heat sinks in LED lamps, some of the models in the design of the fins refer to the Fibonacci series. The models proposed in the present work that have a significant advantage are the Type 1E Model (5.2% mass savings and better thermal efficiency of 8.33%), GR Type 1 Model (3.12% lighter and 3.33% more efficient) and the GRL Type Model (4. 51% mass savings and 5.55% thermally more efficient) compared to the Type 2 Reference Model proposed by Jang et al. [12].
Load Distributions in Bolted Single Lap Joints Under Non-Central Tensile Shear Loading
Authors: Sinthusiri Chaiwat , Nassar Sayed A.
Published: February 2021

This study uses beam theory-based model to investigate a numerically calibrated bolt load distributions in a preloaded two-bolt single lap joint under non-central tensile shear loading. Linear spring-based modeling is used for the two preloaded bolts and substrates. In practice, due to geometric tolerance may not necessarily pass through the joint centerline causing an additional moment loading. Thus, the sharing load would not be equally distributed between all the bolt in the joint. The effect of various joint parameter, bolt preload and off-center location of the tensile shear loading is investigated and discussed. Proposed model would be useful in enhancing the reliability and safety of bolted joints.
Numerical Modeling and Analysis to Formulate Mechanical and Tactile Behavior of Skin
Authors: Yamamoto Tomohisa , Sakuma Atsushi
Published: February 2021

Tactile sensation by touching motion is one of the basic functions for human beings to recognize the characteristics and information of objects. It is known that information about touched objects is recognized through deformation of the skin, but it is difficult to physically clarify the mechanism of such sensations. In addition, there are several types of mechanoreceptors related to tactile sensation in human skin, and it is necessary to digitize the sensation in consideration of its response characteristics. The purpose of this study is to propose the product design method that recalls physical properties from mechanical information inside the skin in order to evaluate the relationship between human skin deformation and physical properties of touched objects. Humans can recognize the shape and softness of an object by pressing the skin against the surface of the object. The behavior inside the skin can be discussed by modeling the contact between human skin and rigid sphere and analyzing it mechanically by numerical simulation. Finite element method (FEM) was adopted as the numerical analysis method for this elucidation, and the three-layer laminated solid having the epidermis, dermis, and subcutaneous was developed as the numerical model, and mechanical information inside the skin was discussed.
The Effectiveness of Equipment Provisions on Rural Middle School Students’ Physical Activity During Lunch Recess
Authors: Yu Hyeonho , Kulinna Pamela H. , Mulhearn Shannon C.
Published: February 2021

Background: Environmental provisions can boost students’ discretionary participation in physical activity (PA) during lunchtime at school. This study investigated the effectiveness of providing PA equipment as an environmental intervention on middle school students’ PA levels and stakeholders’ perceptions of the effectiveness of equipment provisions during school lunch recess. Methods: A baseline–intervention research design was used in this study with a first baseline phase followed by an intervention phase (ie, equipment provision phase). A total of 514 students at 2 middle schools (school 1 and school 2) in a rural area of the western United States were observed directly using the System for Observing Play and Leisure Activity in Youth instrument. Interviews were conducted with stakeholders. Paired-sample t tests and visual analysis were conducted to explore differences in PA levels by gender, and common comparison (with trustworthiness measures) was used with the interview data. Results: The overall percentage of moderate to vigorous PA levels was increased in both schools (ranging from 8.0% to 24.0%). In school 2, there was a significant difference in seventh- and eighth-grade students’ moderate to vigorous PA levels from the baseline. Three major themes were identified: (1) unmotivated, (2) unequipped, and (3) unquestionable changes (with students becoming more active). Conclusions: Environmental supports (access, equipment, and supervision) significantly and positively influenced middle school students’ lunchtime PA levels.
Motor Skills and Participation in Middle Childhood: A Direct Path for Boys, a Mediated Path for Girls
Authors: Emadirad Elnaz , Temple Brad W.N. , Field Stephanie C. , Naylor Patti-Jean , Temple Viviene A.
Published: February 2021

Background: Beyond the often examined perceptions of competence and motor skill proficiency, perceived value and children’s expectations for success are thought to affect engagement in physical activities. We used parallel mediation models to examine the direct effect of motor skill proficiency on participation in physical activities, as well as whether children’s beliefs and value for physical activities mediated this relationship. Methods: The participants in this cross-sectional study were a total of 398 grade 3 children (201 girls) from 8 schools. Motor skills were assessed using the Test of Gross Motor Development-2, the Value Expectancy Questionnaire measured the psychological variables, and the Children’s Assessment of Participation and Enjoyment measured physical activities. Results: Motor skill proficiency predicted all 3 psychological constructs for the boys and the girls, and boys’ participation in physical activities. However, the psychological variables did not mediate the relationship between motor skills and participation among the boys. For the girls, task value mediated the relationship between motor skills and physical activity participation. Conclusion: It is possible that the girls are further along in their ability to reflect on their competence, successes, and failures; it is also possible that the lower motor skill levels of girls had a deleterious effect on their feelings about participating.
Drugging mutant p53
Authors: Ferrarelli Leslie K.
Published: February 2021

Arsenic trioxide may be effective against tumors with structural p53 mutations.
Radicicol, a Novel Lead Compound against the Migratory-Stage Schistosomula of
Schistosoma japonicum
Authors: Xu Liangxiong , Liu Qiuli , Zeng Qingren , Wu Ping , Yu Quan , Gu Kongzhen , Xue Jinghua , Wei Xiaoyi
Published: February 2021

Schistosomiasis poses a serious threat to human health and remains a major tropical and parasitic disease in more than 70 countries. Praziquantel (PZQ) has been the primary treatment for schistosomiasis for nearly 4 decades.
Atypical Molecular Basis for Drug Resistance to Mitochondrial Function Inhibitors in Plasmodium falciparum
Authors: Painter Heather J. , Morrisey Joanne M. , Mather Michael W. , Orchard Lindsey M. , Luck Cuyler , Smilkstein Martin J. , Riscoe Michael K. , Vaidya Akhil B. , Llinás Manuel
Published: February 2021

The continued emergence of drug-resistant
Plasmodium falciparum
parasites hinders global attempts to eradicate malaria, emphasizing the need to identify new antimalarial drugs. Attractive targets for chemotherapeutic intervention are the cytochrome (cyt)
bc
1
complex, which is an essential component of the mitochondrial electron transport chain (mtETC) required for ubiquinone recycling and mitochondrially localized dihydroorotate dehydrogenase (DHODH) critical for
de novo
pyrimidine synthesis.
Pharmacokinetics and Efficacy of a Potential Smallpox Therapeutic, Brincidofovir, in a Lethal Monkeypox Virus Animal Model
Authors: Hutson Christina L. , Kondas Ashley V. , Mauldin Mathew R. , Doty Jeffrey B. , Grossi Irma M. , Morgan Clint N. , Ostergaard Sharon Dietz , Hughes Christine M. , Nakazawa Yoshinori , Kling Chantal , Martin Brock E. , Ellison James A. , Carroll Darin D. , Gallardo-Romero Nadia F. , Olson Victoria A.
Published: February 2021

Preparedness activities against highly transmissible viruses with high mortality rates have been highlighted during the ongoing coronavirus disease 2019 (COVID-19) pandemic. Smallpox, caused by variola virus (VARV) infection, is highly transmissible, with an estimated 30% mortality.
Perceived hazardous physical work environments and job-related affective well-being of navy officers aboard the Republic of Korea Navy ships and submarines in South Korea
Authors: Jo Doseon , Koh C K
Published: February 2021

Introduction

Navy ships and submarines are important military measures that protect the Republic of Korea. They also comprise naval officers’ workplace. However, few studies have examined naval officers’ working environment and their job-related well-being. This study aimed to explore exposure to hazardous work environments among navy officers aboard ships and submarines and their association with job-related affective well-being.

Methods

This was a cross-sectional descriptive study. The sample comprised 146 officers from 4 navy ships and 98 officers from 5 submarines. Items of exposure to the eight types of hazardous work environments and the Job-related Affective Well-being Scale (JAWS) were included in the self-report survey questionnaires.

Results

The most common hazards reported by officers aboard navy ships were vibration (63.7%) and air pollution (56.2%). For submarine officers, these hazards were lack of personal space (72.4%) and air pollution (67.3%). The average JAWS score for ship officers and submarine officers was 69.81 (SD=10.89) and 70.50 (SD=10.83), respectively. For ship officers, exposure to air pollution, noise, vibration, thermal discomfort during summer or winter and lack of personal space were significantly correlated with lower JAWS scores. For submarine officers, exposure to fire, burning or electrical shock, air pollution, noise, thermal discomfort during summer or winter and lack of personal space were significantly correlated with lower JAWS scores.

Conclusions

This study revealed that some naval officers aboard ships or submarines are exposed to hazardous work environments. Moreover, certain types of hazardous work environments were associated with naval officers’ job-related affective well-being.
Suicide capacity within the ideation-to-action framework: a scoping review protocol
Authors: Bayliss Luke T , Lamont-Mills Andrea , du Plessis Carol , Morgan Talia
Published: February 2021

Introduction

A core facilitator of the transition from suicidal thoughts to suicide attempt is the individual’s capacity for suicide. Suicide capacity is a theoretically universal concept adaptable for specific groups that is hypothesised to comprise three contributing factors: acquired capability, for example, previous self-harm; dispositional, such as genetic influences and practical, knowledge of and access to lethal means. Given that suicide capacity as a concept is continuing to develop, a review and synthesis of the current literature is timely to ensure future research and development of suicide prevention strategies are based on evidential knowledge. The aim of this review is to map the available evidence to provide an overview of factors that contribute to an adult’s capacity for suicide.

Methods and analysis

This review will encompass five stages. Studies will be identified through broad search strings applied to 11 academic databases: Academic Search Ultimate, APA PsycArticles, APA PsycINFO, CINAHL, Psychology & Behavioural Sciences, & Sociology Source Ultimate via EBSCOHost Megafile Ultimate; PubMed; Science Direct; Wiley Online; Taylor & Francis and ProQuest dissertations and theses. Grey literature databases and key suicide organisations will also be searched for relevant literature. Two reviewers will independently screen titles and abstracts then review full texts to identify articles meeting inclusion criteria. Articles will be assessed for eligibility based on suicide attempt history, primary research study design, language and publication date. Data from eligible full texts will be extracted using a predesigned template for analysis. The synthesisation method will be textual narrative synthesis with an incorporated quality appraisal checklist tool.

Ethics and dissemination

Ethics approval is not required for this scoping review as no human participants are involved. Study findings will be shared with key suicide organisations, through peer-reviewed publications, and conference presentations.
Recreational substance use among patients with premature atherosclerotic cardiovascular disease
Authors: Mahtta Dhruv , Ramsey David , Krittanawong Chayakrit , Al Rifai Mahmoud , Khurram Nasir , Samad Zainab , Jneid Hani , Ballantyne Christie , Petersen Laura A , Virani Salim S
Published: February 2021

Objective

Despite an upsurge in the incidence of atherosclerotic cardiovascular diseases (ASCVD) among young adults, the attributable risk of recreational substance use among young patients has been incompletely evaluated. We evaluated the association of all recreational substances with premature and extremely premature ASCVD.

Methods

In a cross-sectional analysis using the 2014–2015 nationwide Veterans Affairs Healthcare database and the Veterans wIth premaTure AtheroscLerosis (VITAL) registry, patients were categorised as having premature, extremely premature or non-premature ASCVD. Premature ASCVD was defined as having first ASCVD event at age <55 years for men and <65 years for women. Extremely premature was defined as having first ASCVD event at age <40 years while non-premature ASCVD was defined as having first ASCVD event at age ≥55 years for men and ≥65 years for women. Patients with premature ASCVD (n=135 703) and those with extremely premature ASCVD (n=7716) were compared against patients with non-premature ASCVD (n=1 112 455). Multivariable logistic regression models were used to study the independent association of all recreational substances with premature and extremely premature ASCVD.

Results

Compared with patients with non-premature ASCVD, patients with premature ASCVD had a higher use of tobacco (62.9% vs 40.6%), alcohol (31.8% vs 14.8%), cocaine (12.9% vs 2.5%), amphetamine (2.9% vs 0.5%) and cannabis (12.5% vs 2.7%) (p<0.01 for all comparisons). In adjusted models, the use of tobacco (OR 1.97, 95% CI 1.94 to 2.00), alcohol (OR 1.50, 95% CI 1.47 to 1.52), cocaine (OR 2.44, 95% CI 2.38 to 2.50), amphetamine (OR 2.74, 95% CI 2.62 to 2.87), cannabis (OR 2.65, 95% CI 2.59 to 2.71) and other drugs (OR 2.53, 95% CI 2.47 to 2.59) was independently associated with premature ASCVD. Patients with polysubstance use had a graded response with the highest risk (~9-fold) of premature ASCVD among patients with use of ≥4 recreational substances. Similar trends were observed among patients with extremely premature ASCVD. Gender interactions with substance use were significant (p-interaction <0.05), with recreational substance use and premature ASCVD showing stronger associations among women than in men with premature ASCVD.

Conclusions

All subgroups of recreational substances were independently associated with a higher likelihood of premature and extremely premature ASCVD. Recreational substance use confers a greater magnitude of risk for premature ASCVD among women. A graded response relationship exists between increasing number of recreational substances used and higher likelihood of early-onset ASCVD.
Effects of warming and oxalic acid addition on plant–microbial competition in Picea brachytyla
Authors: Liu Weilong , Xu Gang , Bai Jingwei , Duan Baoli
Published: February 2021

The importance of oxalic acid for tree seedling growth and the competition for inorganic nitrogen (N) by plants and soil microorganisms under warming was investigated using 15N tracer techniques in Picea brachytyla (Franch.) E. Pritz. Results showed that warming combined with oxalic acid application induced growth enhancements in seedlings primarily through increases in fine root length and fine root surface area. Moreover, soil NH4 +, NO3 –, PO4 3–, N mineralization, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) were significantly higher or tended to be higher with oxalic acid application. However, warming with oxalic acid application altered the partitioning of N between plants and soil microorganisms by increasing microbial 15N recovery to a lesser extent than it increased plant 15N recovery. While plants showed no specific preferences between N forms under normal conditions or warming alone, under warming and oxalic acid, plants showed a preference for 15NO3. Microorganisms showed a stronger preference for 15NH4 especially under warming and oxalic acid treatments. These findings suggest that plasticity in resource use could be an important mechanism in alleviating competition for soil N between plants and microbes under warming and oxalic acid addition.
Optimizing Convolutional Neural Network Accelerator on Low-Cost FPGA
Authors: Vinh Truong Quang , Hai Dinh Viet
Published: February 2021

Convolutional neural network (CNN) is one of the most promising algorithms that outweighs other traditional methods in terms of accuracy in classification tasks. However, several CNNs, such as VGG, demand a huge computation in convolutional layers. Many accelerators implemented on powerful FPGAs have been introduced to address the problems. In this paper, we present a VGG-based accelerator which is optimized for a low-cost FPGA. In order to optimize the FPGA resource of logic element and memory, we propose a dedicated input buffer that maximizes the data reuse. In addition, we design a low resource processing engine with the optimal number of Multiply Accumulate (MAC) units. In the experiments, we use VGG16 model for inference to evaluate the performance of our accelerator and achieve a throughput of 38.8[Formula: see text]GOPS at a clock speed of 150[Formula: see text]MHz on Intel Cyclone V SX SoC. The experimental results show that our design is better than previous works in terms of resource efficiency.
New Resistorless Third-Order Quadrature Sinusoidal Oscillators
Authors: Bhaskar D. R. , Raj Ajishek , Kumar Pragati
Published: February 2021

This paper introduces four new resistorless, third-order, electronically tunable, quadrature sinusoidal oscillators using three operational transconductance amplifiers (OTAs) and three capacitors. The proposed third-order quadrature sinusoidal oscillators (TOQSOs) provide noninteracting control of the oscillation condition (OC) and oscillation frequency (OF) by changing the transconductance of different OTAs, to produce sustained oscillations and offer quadrature output voltages and currents. Two of the proposed quadrature oscillator circuits have capacitor control of OF, a feature, useful in capacitive transducers. The presented TOQSO structures have good frequency stability and exhibit low active and passive sensitivities. PSPICE simulations using CMOS OTAs along with hardware results (using off-the-shelf available OTA IC LM13700) have also been provided to confirm the workability of the presented circuits.
A Novel Darlington-Based 8T CNTFET SRAM Cell for Low Power Applications
Authors: Elangovan M.
Published: February 2021

The design of low power memory cells is the dream of engineers in memory design. A Darlington-based 8T CNTFET SRAM cell is suggested in this paper. It is called the proposed P_CNTFET Darlington 8T SRAM Cell. Compared with that of the traditional 6T and 8T CNTFET SRAM cells, the power and noise performances of the proposed SRAM cell are comparable. Compared to the traditional SRAM cells, the write, hold, read and dynamic power consumption of the proposed cell is much lower. The CNTFET parameters are optimized to boost the noise margin performance of the suggested bit cell. For optimized parameters, the power consumption and SNM of the proposed cell are compared with conventional cells. In contrast to the conventional cells, the HSNM and WSNM of the proposed cell are improved by 6.25% and 66.6%. The proposed cell’s RSNM is 38% greater than the traditional 6T SRAM cell. The proposed cell’s RSNM is 3.33% less than the traditional 8T SRAM cell. MOSFET is also used to implement the proposed SRAM cell and its noise margin and power performance are compared with traditional MOSFET-based SRAM cells. As with the conventional cells, the MOSFET-based implementation of the proposed cell power and SNM performance is also very good. The simulation is done with the HSPICE simulation tool using the Stanford University 32[Formula: see text]nm CNTFET model.
Semiclassical analysis of the tensor power spectrum in the Starobinsky inflationary model
Authors: Tapia Truman , Rojas Clara
Published: February 2021

In this work, we calculate the tensor power spectrum and the tensor-to-scalar ratio [Formula: see text] within the frame of the Starobinsky inflationary model using the improved uniform approximation method and the third-order phase-integral method. We compare our results with those obtained with numerical integration and the slow-roll approximation to second-order. We have obtained consistent values of [Formula: see text] using the different approximations, and [Formula: see text] is inside the interval reported by observations.
COMPETITION AND COOPERATION ON PREDATION: BIFURCATION THEORY OF MUTUALISM
Authors: GHIMIRE SRIJANA , WANG XIANG-SHENG
Published: February 2021

In this paper, we investigate two predator–prey models which take into consideration hunting cooperation (i.e., mutualism) between two different predators and within one predator species, respectively. Local and global dynamics are obtained for the model systems. By a detailed bifurcation analysis, we investigate the dependence of predation dynamics on mutualism (cooperative predation). From our study, we prove that mutualism may enhance the survival of mutualist predators in a severe condition and break the competitive exclusion principle. We further provide quantitative information about how the cooperative predation (mutualism) may (i) establish multiple stability switches on the positive equilibrium; (ii) generate backward bifurcation on equilibria; (iii) induce supercritical or subcritical Hopf bifurcations; and (iv) establish bi-stability phenomenon between the predator-free equilibrium and a positive equilibrium (or a limit cycle).
CLINICAL AND ULTRASONOGRAPHIC CORRELATION OF PES ANSERINUS BURSITIS
Authors: Deepak Joshi Ameya , Gupta Shefali , Shukla Aradhana , Gaur Anil K.
Published: February 2021

Purpose: Pes anserinus bursitis is a commonly overlooked cause of medial knee pain. It is diagnosed clinically and involves tendons/bursa or both. Majority of studies fail to provide imaging evidence of tendon/bursal pathology in clinically diagnosed patients. This study documents the ultrasonographic findings associated with clinically diagnosed pes anserinus bursitis and correlates between clinical and positive ultrasonographic findings.

Methods: A cross-sectional study was done in outpatient department settings of physical medicine and rehabilitation department in participants with clinically diagnosed pes anserinus bursitis. Clinically evaluation was done by Physiatrist and ultrasonographic evaluation by a radiologist. Patient characteristics, clinical findings and ultrasonographic features were documented and studied.

Results: In the evaluated 67 knees, Pes anserinus tendonitis (53.73%) with statistical significance ([Formula: see text].0001) was found on ultrasonography over bursitis (2.99%). Abnormal findings involving medial collateral ligament (38.81%), medial meniscus (26.87%), suprapatellar recess (47.76%), and other structures (17.91%) were also documented. Age, gender, body mass index, and duration had no effect on presence of positive ultrasonographic findings.

Conclusion: Ultrasonographic changes of tendonitis involving pes anserinus tendons correlate with clinically diagnosed pes anserinus bursitis. The ultrasonography also helps in identifying potential sources of pain other than pes anserinus tendon or bursa in such cases.
Nonlinear Traveling-Wave Vibration of a Ring-Stringer Stiffened Cylindrical Shell
Authors: Liu Lun , Sun Shupeng , Han Jiajie
Published: February 2021

The nonlinear traveling-wave vibration of a ring-stringer stiffened cylindrical shell is analyzed. Using Donnell’s nonlinear shell theory and Lagrange equations, the nonlinear dynamic model of the ring-stringer stiffened cylindrical shell is derived. Galerkin’s method based on multi-mode instead of single-mode approximation is used to discretize the shell’s displacements. Two types of orthogonal circumferential modes with same frequency are used and the interaction between them is considered in the analysis of the shell’s nonlinear traveling-wave vibration. The harmonic balance (HB) method, along with the pseudo-arc length continuation algorithm, is adopted to solve the forced vibration responses of the shell. The stability of the solution is determined by the Floquet theory. Through comparison with the results available in the literature, the correctness of the present nonlinear dynamic model and its solution process are validated first. Next, the mode selection rules are determined through a convergence study. Finally, the nonlinear traveling-wave vibration of the ring-stringer stiffened cylindrical shell is studied. Also, the paper investigates, in detail, the effects of stiffener parameters on the nonlinear dynamic characteristics of the stiffened shell.
A Computational Study on Buckling Behavior of Cold-Formed Steel Built-Up Columns Using Compound Spline Finite Strip Method
Authors: Mahar Akshay Mangal , Jayachandran S. Arul
Published: February 2021

This paper presents a computational methodology to compute the critical buckling stress of built-up cold-formed steel columns joined with discrete fasteners. The fasteners are modeled as three-dimensional beam elements, and their effect is integrated into the spline finite strip framework, evolving the compound strip methodology. Although this technique has been presented in the literature, this paper presents yet another robust framework for the buckling load evaluation of compound cold-formed steel columns with arbitrarily located fasteners. The proposed framework is applied to study the effect of fasteners on the formation of local, distortional, and global buckling modes of built-up section and a comparison is drawn with the buckling behavior of a single section. In this study, the proposed formulations are also used to get insights into the stability behavior of single-span and multi-span compound cold-formed steel columns in the presence of (i) fasteners with varied spacings with respect to span and (ii) the presence of the additional restraining system such as wall panels. For different buckling modes, a significant increment in buckling stress for a built-up section from a single section is observed when the fastener spacing is kept less than the critical buckling half-wavelength of the respective buckling modes. The study on the effect of wall panels shows that in comparison to unsheathed wall studs, the sheathed wall studs that produce additional constraints lead to the elimination of the global buckling deformations. The proposed formulations are simple, yet rigorous and have been validated using finite element-based numerical results.
On (m,n)-hyperideals in ordered semihyperrings: Applications to ordered semirings
Authors: Al Tahan M. , Davvaz B.
Published: February 2021

In this paper, we deal with [Formula: see text]-hyperideals of ordered semihyperrings. First, we provide some properties about these [Formula: see text]-hyperideals. Next, we provide nontrivial examples of [Formula: see text]-hyperideals that are not left/right hyperideals. Finally, we apply our results to ordered semirings and provide nontrivial examples on [Formula: see text]-ideals that are not left/right ideals.
Strategy to Reduce Floor Area and Flow Distance of Products in Multi-Row Parallel Machine Layout Design Using Cuckoo Search Algorithm
Authors: Mahalingam Siva Kumar , Nagarajan Lenin
Published: February 2021

A multi-row parallel machine layout (MRPML) design is the best alternative solution to overcome the downside associated with a single-row machine layout design. Especially, the reduction in the investment cost on machines by eliminating its duplicates is the greatest advantage of a MRPML over the single-row machine layout. This paper addresses the MRPML design strategy to reduce the floor area of the layout along with a reduction in demand-based flow distance of products. The cuckoo search algorithm is used for this purpose. The efficacy of the proposed method is assessed and proved by comparing the solutions to the problems associated with single-row layout design dealt by [Lenin et al. Eur. J. Ind. Eng. 12(2) (2018) 252–275] and multi-row layout design dealt by [Vitayasak and Pongcharoen Exp. Syst. Appl. 98 (2018) 129–152] along with few randomly generated problems. This work provides a better tool to identify the optimal MRPML design to satisfy the objectives of mass production industries.
Statistical and Intelligent Techniques for Modeling and Optimization of Duplex Turning for Aerospace Material
Authors: Yadav Ravindra Nath
Published: February 2021

Duplex turning becomes an important metal cutting process due to unique features like higher productivity with better surface finish at lower specific energy and vibration. Such process requires two-cutting tools which are mounted parallelly and fed inward to cut the material from rotating surfaces. Such complex process needs modeling and optimization to analyze the effect of factors and identify the optimal cutting condition. This paper focuses to develop two models related to statistical and intelligent techniques especially responses surface methodology (RSM) and artificial neural network (ANN) for prediction analysis of duplex turning. Based on prediction potential, the ANN model is utilized to analyze the effect of various parameters (cutting speed, feed rate, primary depth-of-cut (DOC) and secondary-DOC on the responses as surface roughness and cutting forces (primary and secondary). Further, the parameters are optimized using Taguchi Methodology (TM) and experimentally validated. The results show that ANN model predicts the data with more precision than RSM model. Further, the optimal data are experimentally validated and significantly agreed with predicted data of ANN model with percentage error as 2.24%, 1.40% and 0.75% for surface roughness, cutting forces (primary and secondary), respectively.
Microstructure Analysis of 17-4 Precipitation Hardened Stainless Steel at Welded Spots in Resistance Spot Welding
Authors: Mallaradhya H. M. , Vijay Kumar M.
Published: February 2021

Many researchers have developed models which are capable of analyzing the effects of process parameters on the responses of different welding operations carried out on 17-4 PH steel which bears extensive properties and have wide range of applications. The weld quality of any material plays a major role in determining the strength of the joint. Hence a proper and procedural analysis has to be made in order to assess the quality of the weld. This could happen only when the analysis of the weld quality is reviewed. Here in this work, RSW of special kind of stainless steel is welded considering the very important parameters which alter the response characteristics to a greater extent. From literature it is evident that no full proof plan is available to conduct welding process of any kind. Hence, an attempt is made to design experiments of welding on the material with the help of Taguchi method and the same is analyzed using ANOVA for the superiority of the parameters on basis of which the optimization of responses can be done. The weld quality can be assessed using one of the responses known as tensile test which determines the breaking load required for the failure of the welded specimen. The micro structural analysis is then carried out using Scanning Electron Microscope which yields the results of failure analysis. It can be clearly seen from the results that the electrode force is the most effecting factor which behaves linearly and then the weld current which drastically or nonlinearly change the characteristics of the response (tensile strength). The micro structural analysis shows that the dimple and ridges are present at the break point which is the evidence for the ductile property of the material. From the pictures of the SEM results, the even distribution of the secondary phase particles is clearly visible, this is again the evidence for the ductile property or the increase in the yield strength. Also pores and cracks are visible but up to a very smaller extent, hence more resistance of the joint for breaking when the load is applied can be seen.
Cost Comparison of Selective Laser Sintering with Injection Molding in the Presence of Uncertainties
Authors: Sharma Faladrum , Dixit Uday Shanker
Published: February 2021

The application of additive manufacturing (AM) has increased exponentially in recent years. Industries are keen to explore this innovative technology but are apprehensive about the high processing cost of the process. Hence, it is crucial to carry out a cost analysis of the process. This paper presents an approach to compare the costs of an AM process (selective laser sintering (SLS)) and a traditional manufacturing process (injection molding (IM)) in the presence of uncertainties. Initially, the deterministic cost models comprising necessary cost variables for SLS and IM are described. The deterministic models are converted to fuzzy set-based models for tackling uncertainties. For this purpose, important uncertain variables are treated as fuzzy members and fuzzy arithmetic is employed. Only linear triangular fuzzy numbers are used in this work. Fuzzy cost estimates produce three values (low, most likely and high estimates) of cost corresponding to membership grades. A methodology to compare two fuzzy costs of the processes is proposed for a variable demand scenario. Concept of fuzzy reliability is suitably utilized and variability in demand is tackled from probability theory. Variable demand is assumed to follow uniform as well as normal probability distributions. The methodology is illustrated with the help of two examples.
Use of digital photography to identify neoplastic skin lesions after labelling by ALA-derived protoporphyrin
Authors: Yu Hyunseon , Ho Tien Son , Kang Heesung , Bae Youngwoo , Choi Eung Ho , Choi Seung Ho , Jung Byungjo
Published: February 2021

Actinic keratosis is a premalignant skin lesion that develops into non-melanoma skin cancer. Various imaging techniques have been developed to find the actinic keratosis lesion. In this clinical study, the feasibility of a nonspectroscopic fluorescence imaging system is investigated for spatial assessment of the actinic keratosis lesion. Six patients between the ages of 70 and 80 years old are diagnosed with actinic keratosis by a board-certified dermatologist to obtain biopsy-proven clinical images. The patients were treated with 5-aminolevulinic acid, which is transformed into the protoporphyrin IX. After illuminating ultraviolet-A light on facial lesions, the protoporphyrin IX produces the exogenous fluorescence. The fluorescence is measured using both a hyperspectral camera and an RGB color camera to obtain spectroscopic and nonspectroscopic fluorescence images, respectively. It is found that fluorescence intensity of the actinic keratosis lesion is higher than that of normal skin. Based on combined fluorescence and physiological characteristics, the actinic keratosis lesion is distinguished from the adjacent normal skin area. For delineation of the actinic keratosis lesion, a linear unmixing algorithm is applied to spectroscopic image data and an erythema index is calculated from nonspectroscopic image data. Then, two extracted actinic keratosis lesions are compared for cross-validation. As a result, both spectroscopic and nonspectroscopic fluorescence images demarcate an identical lesion of actinic keratosis. Given the affordability and simplicity, an RGB camera and a 5-ALA photosensitizer can be used as a cost-effective nonspectroscopic imaging modality for accurate assessment of actinic keratosis margins.
Efficient oxidation of cumene to cumene hydroperoxide with ambient O2 catalyzed by metalloporphyrins
Authors: Shen Hai M. , Ye Hong L. , Wang Qin , Hu Meng Y. , Liu Lei , She Yuan B.
Published: February 2021

A novel and efficient protocol for oxidation of cumene to cumene hydroperoxide was presented using ambient O2 catalyzed by very simple metalloporphyrins. The selectivity toward cumene hydroperoxide reached 98.3% in the cumene conversion of 28.1% with T(4-COOH)PPCu as a catalyst at 80[Formula: see text]C. The origin of the higher performance of T(4-COOH)PPCu was mainly ascribed to the low catalytic performance of copper(II) in the cumene hydroperoxide decomposition, and the ability of T(4-COOH)PP in stabilizing cumene hydroperoxide through hydrogen-bond interactions between them. Compared with current industrial processes and academic research in oxidation of cumene to cumene hydroperoxide with O2, the main superiorities of this protocol were the high selectivity, high conversion, simple catalysts, solvent-free, additive-free and mild conditions which made this work an appealing reference for the industrial oxidation of cumene to cumene hydroperoxide, as well as the oxidative functionalization of other C-H bonds in various hydrocarbons.
Hexathianonaphyrin(1.0.0.1.0.0.1.0.0): Synthesis, optical, redox and protonation induced antiaromaticity
Authors: Ajay Jayaprakash , Sulfikarali Thondikkal , Chakravarthy Kakarlamudi Akhil , Reddy Vennapusa Sivaranjana , Gokulnath Sabapathi
Published: February 2021

A simple non-rigid precursor termed as a “triheterole” comprising of 2,2[Formula: see text]-bithiophene linked to [Formula: see text]-pyrrole was prepared using a four-step synthetic strategy. This functionalized triheterole was allowed to undergo acid catalyzed condensation in the presence of Lewis acid (BF3 [Formula: see text] Et2O) to produce the [3 + 3 + 3] cyclotrimer 1 as a major product with trace formation of its higher homologues. Electronic absorption spectrum of 1exhibited a characteristic band (520 nm) and broad band in the visible region. Upon protonation, significant bathochromic shift of the band (608 nm) and the broad band towards near-IR region (ca.1250 nm) indicates its antiaromatic (4[Formula: see text] conjugated circuit. Detailed structural analyses using temperature-dependent 1D and 2D NMR along with DFT level theoretical investigations indicate that the molecule exhibits weak antiaromaticity due to its large fluxional nature.
Study of the Composite Modified Positive Electrode between NCM811 and V2O5 Materials in Li-Ion Cells
Authors: Wang Yunke , Zha Guozheng , Zhang Yenan , Liang Feng , Dai Yongnian , Yao Yaochun , Kong Lingxin
Published: February 2021

The possibility of combining the promising cathode material LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]O2 (NCM811) with V2O5 material with excellent conductivity as a composite cathode material for lithium-ion batteries was discussed. The fact that the mechanical and physical mixing process did not change the original structure of both NCM811 and V2O5 was confirmed by XRD. SEM and TEM show that the V2O5 particles were attached to the surface of NCM811 and filled the gaps between NCM811 particles. Furthermore, TEM image after cycling reveals that the gathering of Nano-plates V2O5 on the surface of spherical-like NCM811 particles transformed to coating layers ([Formula: see text][Formula: see text]nm) after reacting with lithium, which leads to the increase of impedance, while the stable coating layer would protect the active material from being corroded by the decomposition products of the electrolyte and prevent the collapse of the microstructure to maintain the stability of Li[Formula: see text] mobility channels. The sample exhibited an attractive first discharge capacity of 214[Formula: see text]mAh[Formula: see text]g[Formula: see text] with the 94.7% initial columbic efficiency and a higher capacity retention when the mass ratio of V2O5 is 15[Formula: see text]wt.%. Thus, the reversibility of reaction at low voltage 2.0[Formula: see text]V and high temperature have been enhanced after the modification. This is undoubtedly the necessary condition to improve the security of electrolyte thermal decomposition. Our work will provide some guidance for the future development of high temperature Li-ion batteries.
Learning Japanese-English Bilingual Word Embeddings by Using Language Specificity
Authors: Song Yuting , Batjargal Biligsaikhan , Maeda Akira
Published: February 2021

Cross-lingual word embeddings have been gaining attention because they can capture the semantic meaning of words across languages, which can be applied to cross-lingual tasks. Most methods learn a single mapping (e.g., a linear mapping) to transform a word embedding space from one language to another. To improve bilingual word embeddings, we propose an advanced method that adds a language-specific mapping. We focus on learning Japanese-English bilingual word embedding mapping by considering the specificity of the Japanese language. We evaluated our method by comparing it with single mapping-based-models on bilingual lexicon induction between Japanese and English. We determined that our method was more effective, with significant improvements on words of Japanese origin.
Effect of Applying a Carbon Coating on the Crystal Structure and De-/Lithiation Mechanism of Mn-Doped ZnO Lithium-Ion Anodes
Authors: Eisenmann Tobias , Birrozzi Adele , Mullaliu Angelo , Giuli Gabriele , Trapananti Angela , Passerini Stefano , Bresser Dominic
Published: February 2021

The introduction of transition metal dopants such as Fe and Co in zinc oxide enables substantially enhanced reversible capacities and greater reversibility of the de-/lithiation reactions occurring. Herein, we report a comprehensive analysis of the electrochemical processes taking place in Mn-doped ZnO (Zn0.9Mn0.1O) and carbon-coated Zn0.9Mn0.1O upon de-/lithiation. The results shed light on the impact of the dopant chemistry and, especially, its coordination in the crystal structure. When manganese does not replace zinc in the wurtzite structure, only a moderate improvement in electrochemical performance is observed. However, when applying the carbonaceous coating, a partial reduction of manganese and its reallocation in the crystal structure occur, leading to a substantial improvement in the material’s specific capacity. These results provide important insights into the impact of the lattice position of transition metal dopants—a field that has received very little, essentially no attention, so far.
Review—Status and Challenges in Hetero-epitaxial Growth Approach for Large Diameter AlN Single Crystalline Substrates
Authors: Sumathi Rajappan Radhakrishnan
Published: February 2021

Aluminium nitride (AlN) crystalline substrate has emerged as a striking material and received tremendous attention for applications in high power electronics (HPE), deep-ultraviolet (DUV) light sources due to its exceptional properties. Single crystal growth of AlN by physical vapour transport (PVT) technique, and the necessity of large diameter AlN native substrates for the fabrication of HPE and DUV devices are described here. Two competing growth approaches in PVT are utilised to produce initial AlN single crystalline seeds namely, starting with self-nucleation followed by iterative homo-epitaxial growth for enlarging the crystal diameter in steps, and directly seeding on a closely lattice-matched foreign substrate of desired diameter by hetero-epitaxial growth. Both of these approaches are intended to grow bulk single crystals from which wafers might be prepared for further fabrication of devices. The hetero-epitaxial growth approach is specifically and comprehensively reviewed in this present work. A specific attention is given in using 6H- and 4H- polytype silicon carbide (SiC) substrates. The issues in hetero-epitaxially grown crystals such as presence of misfit dislocations, control of low-angle grain boundaries, incorporation of unintentional impurities, are highlighted together with the recent progress made in the achievement of about 2.5-inch dia. free-standing AlN wafer by this approach.
Multiple Sulfatase Deficiency (MSD): Review of the Literature and Case Reports of Two Siblings with Dental Caries and Trauma
Authors: Hirst Lorna , Abou-Ameira Gehan , Uudelepp Mari-Liis
Published: February 2021

Multiple sulfatase deficiency (MSD) (MIM # 272200) is an extraordinarily rare inborn error of metabolism (IEM). The phenotypic spectrum is largely heterogeneous and attributed to the combined effects of deficiencies in the nine sulfatases currently known to be related to human diseases. Systemic sequelae of MSD are vast and multisystemic, primarily encompassing developmental delay and neurological, cardiopulmonary, dermatological, gastroenterological, and skeletal manifestations. The dental phenotype is scarcely described in the literature due to a paucity of cases. Dental treatment under local and general anaesthesia mandates an integrated multidisciplinary approach to safeguard systemic health and optimise outcomes. This paper presents two siblings with multiple sulfatase deficiency who presented to the Paediatric Dental Department at Great Ormond Street Hospital, requiring comprehensive care under general anaesthesia for dental caries and trauma.
Long-Time Behaviours of a Stochastic Predator-Prey System with Holling-Type II Functional Response and Regime Switching
Authors: Kong Weili , Shao Yuanfu
Published: February 2021

Considering the impacts of white noise, Holling-type II functional response, and regime switching, we formulate a stochastic predator-prey model in this paper. By constructing some suitable functionals, we establish the sufficient criteria of the stationary distribution and stochastic permanence. By numerical simulations, we illustrate the results and analyze the influence of regime switching on the dynamics.