bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Modeling of the Wave Soldering Process and Experimental Validation
Authors: Carvalho Violeta , Arcipreste Bruno , Soares Delfim , Ribas Luís , Rodrigues Nelson , Teixeira Senhorinha F. C. F. , Teixeira José Carlos
Published: April 2021

One of the most important procedures in the electronics industry is the assembly of electronic components onto printed circuit boards (PCBs) through the soldering process. Among the various soldering methods available, wave soldering is a very effective technique. In this process, the components are placed onto the PCB, which, subsequently, is coated with a flux and then passed across a preheat zone. In the end, the assembly is moved by the conveyor and passed over the surface of the molten solder wave in order to create a reliable connection both mechanically and electrically. Although this process has been frequently used, there are soldering defects that remain unsolved and continue to emerge, such as the missing of surface-mount components in the PCB after the soldering process. Aiming to understand if such defects are related to the force exerted by the solder wave in the PCB, a numerical and experimental study was performed in this article. For this purpose, a computational fluid dynamic model was developed by using the fluent software to describe the interaction between the solder jet and the PCB with the integrated circuits, and the multiphase method, volume of fluid, was also applied to track the solder–air interface boundary. The results obtained were numerically validated by using an experimental setup designed and built to this end. In general, the data obtained showed to be in good agreement and it was concluded that the force exerted by the solder wave is approximately 0.02 N.
Analytical Determination of the Optimal Clearance for the Fatigue Life of Ball Bearing Under Different Load Conditions
Authors: Fang Bin , Zhang Jinhua
Published: April 2021

In this paper, a comprehensive analytical model for the fatigue life prediction of ball bearing in various operating conditions is presented. Not only the internal clearance variations induced by the centrifugal expansion and assembly interference but also ball inertia forces and ball–raceway separations are fully considered in theoretical modeling to achieve accurate life prediction of the ball bearing. The model has been validated by comparison with the static results in previous literature. Based on this, the results of the load distribution and fatigue life versus the internal clearance of ball bearing under various operating conditions are studied. The results show that there is always an optimal clearance to maximize bearing fatigue life for the radial load or the combined load conditions, and the size of the optimal clearance for bearing life is determined by both the load conditions and rotating speeds to ensure the uniformity of the internal load distribution of the ball bearing. Therefore, the above-mentioned theoretical and conclusions can be used in structural design optimization and assembly parameters selection of ball bearing to maximize the life characteristic.
The Effects of Gravity on the Response of Centrifugal Pendulum Vibration Absorbers
Authors: Tchokogoué Darryl , Mu Ming , Feeny Brian F. , Geist Bruce K. , Shaw Steven W.
Published: April 2021

This article describes the effects of gravity on the response of systems of identical, cyclically arranged, centrifugal pendulum vibration absorbers (CPVAs) fitted to a rotor spinning about a vertical axis. CPVAs are passive devices composed of movable masses suspended on a rotor, suspended such that they reduce torsional vibrations at a given engine order. Gravitational effects acting on the absorbers can be important for systems spinning at relatively low rotation speeds, for example, during engine idle conditions. The main goal of this study is to predict the response of a CPVA/rotor system in the presence of gravity. A linearized model that includes the effects of gravity and an order n torque acting on the rotor is analyzed by exploiting the cyclic symmetry of the system. The results show that a system of N absorbers responds in one or more groups, where the absorbers in each group have identical waveforms but shifted phases. The nature of the waveforms can have a limiting effect on the absorber operating envelope. The number of groups is shown to depend on the engine order n and the ratio N/n. It is also shown that there are special resonant effects if the engine order is n = 1 or n = 2, the latter of which is particularly important in applications. In these cases, the response of the absorbers has a complicated dependence on the relative levels of the applied torque and gravity. In addition, it is shown that for N > 1, the rotor response is not affected by gravity, at least to leading order, due to the cyclic symmetry of the gravity effects. The linear model and the attendant analytical predictions are verified by numerical simulations of the full nonlinear equations of motion.
Effects of 8-Week FIFA 11+ for Kids Intervention on Physical Fitness and Attention in Elementary School Children
Authors: Tseng Wen-Yen , Rekik Ghazi , Chen Chia-Hui , Clemente Filipe M. , Bezerra Pedro , Crowley-McHattan Zachary J. , Chen Yung-Sheng
Published: April 2021

Background: The psychological and physiological adaptations in response to the FIFA 11+ for kids (FIFA11+kid) program has not been examined in school children. This study aimed to investigate the effects of 8-week FIFA11+kid intervention on physical fitness and attentional capacity in elementary school children. Methods: A total of 55 elementary school students voluntarily participated in the study. Participants were assigned to either the FIFA11+kid (n = 28, 5 times per week) or the control (n = 27) group. At baseline and after 8 weeks, all participants were asked to perform a battery of physical fitness tests (sit-and-reach, broad jump, sit-up test, and 800-m run) and the Attention Scale for Elementary School Children, including 5 subscales: focused, sustained, selective, alternating, and divided attentions. Results: The FIFA11+kid group demonstrated larger pre–post change in sit-and-reach (P < .001) and sit-up test (P < .001) than that of control group. Moreover, the FIFA11+kid group demonstrated large improvements pre–post change in Attention Scale for Elementary School Children scores of total score (P < .001), focused (P < .001), sustained (P < .001), and selective attentions (P < .001) compared with the control group. Conclusion: A total of 8 weeks of FIFA11+kid exercise intervention can improve general physical fitness and attentional capacities in elementary school children.
Trait Perfectionism and Dance Goals Among Young Female Dancers: An Application of the 2 × 2 Model of Perfectionism
Authors: Molnar Danielle S. , Blackburn Melissa , Zinga Dawn , Spadafora Natalie , Methot-Jones Tabitha , Connolly Maureen
Published: April 2021

This study provided the first test of the 2 × 2 model of perfectionism with respect to dancers’ goals for dancing in competitive dance. Four hundred twenty-five young female North American competitive dancers (M = 11.33 years;SD = 2.14) completed questionnaires assessing multidimensional perfectionism and goals for participation in dance. The latent moderated structural equations approach along with procedures outlined by Gaudreau indicated partial support for the 2 × 2 model of perfectionism. Pure Evaluative Concerns Perfectionism was associated with fewer intrinsic goals for dance and greater extrinsic goals for dance relative to nonperfectionism. Pure Personal Standards Perfectionism was related to less endorsement of extrinsic goals relative to nonperfectionism. Findings were complex with respect to mixed perfectionism, with this form of perfectionism being related to greater endorsement of both intrinsic and extrinsic goals for dance. Results provide partial support for the 2 × 2 model in youth dance.
ZTCG: Viruses expand the genetic alphabet
Authors: Grome Michael W. , Isaacs Farren J.
Published: April 2021

Viruses build nucleotide Z, identified in meteorites, replacing adenine in DNA genomes
Mycobacterium abscessus
in cystic fibrosis
Authors: Brugha Rossa , Spencer Helen
Published: April 2021

Environmental Mycobacteria share genes and evolve to become pathogens
COVID-19 Pandemic in Lebanon: One Year Later, What Have We Learnt?
Authors: Koweyes Jad , Salloum Tamara , Haidar Siwar , Merhi Georgi , Tokajian Sima
Published: April 2021

Lebanon is witnessing an unprecedented crisis with the rapid spread of coronavirus disease 2019 (COVID-19), financial meltdown, economic collapse, and the Beirut Port explosion. The first wave began in February 2020, following which the country experienced several episodes and peaks while alternating between lockdowns and phased liftings. One year of the pandemic revealed that effective mitigation could not be separated from the collapse of the ongoing economic, political, and health sectors.
Viability and thresholds for treatment of extremely preterm infants: survey of UK neonatal professionals
Authors: Di Stefano Lydia Mietta , Wood Katherine , Mactier Helen , Bates Sarah Elizabeth , Wilkinson Dominic
Published: April 2021

Background

Decisions about treatments for extremely preterm infants (EPIs) born in the ‘grey zone’ of viability can be ethically complex. This 2020 survey aimed to determine views of UK neonatal staff about thresholds for treatment of EPIs given a recently revised national Framework for Practice from the British Association of Perinatal Medicine.

Methods

The online survey requested participants indicate the lowest gestation at which they would be willing to offer active treatment and the highest gestation at which they would withhold active treatment of an EPI at parental request (their lower and upper thresholds). Relative risks were used to compare respondents’ views based on profession and neonatal unit designation. Further questions explored respondents’ conceptual understanding of viability.

Results

336 respondents included 167 consultants, 127 registrars/fellows and 42 advanced neonatal nurse practitioners (ANNPs). Respondents reported a median grey zone for neonatal resuscitation between 22+1 and 24+0 weeks’ gestation. Registrars/fellows were more likely to select a lower threshold at 22+0 weeks compared with consultants (Relative Risk (RR)=1.37 (95% CI 1.07 to 1.74)) and ANNPs (RR=2.68 (95% CI 1.42 to 5.06)). Those working in neonatal intensive care units compared with other units were also more likely to offer active treatment at 22+0 weeks (RR=1.86 (95% CI 1.18 to 2.94)). Most participants understood a fetus/newborn to be ‘viable’ if it was possible to survive, regardless of disability, with medical interventions accessible to the treating team.

Conclusion

Compared with previous studies, we found a shift in the reported lower threshold for resuscitation in the UK, with greater acceptance of active treatment for infants <23 weeks’ gestation.
‘The nurse did not even greet me’: how informed versus non-informed
patients evaluate health systems responsiveness in South Africa
Authors: Hompashe Dumisani MacDonald , Gerdtham Ulf-G , Christian Carmen S , Smith Anja , Burger Ronelle
Published: April 2021

Introduction

Universal Health Coverage is not only about access to health
services but also about access to high-quality care, since poor
experiences may deter patients from accessing care. Evidence shows that
quality of care drives health outcomes, yet little is known about
non-clinical dimensions of care, and patients’ experience thereof
relative to satisfaction with visits. This paper investigates the role
of non-clinical dimensions of care in patient satisfaction.

Methods

Our study describes the interactions of informed and non-informed
patients with primary healthcare workers at 39 public healthcare
facilities in two metropolitan centres in two South African provinces.
Our analysis included 1357 interactions using standardised patients (for
informed patients) and patients’ exit interviews (for non-informed
patients). The data were combined for three types of visits:
contraception, hypertension and tuberculosis. We describe how
satisfaction with care was related to patients’ experiences of
non-clinical dimensions.

Results

We show that when real patients (RPs) reported being satisfied (vs
dissatisfied) with a visit, it was associated with a 30% increase in the
probability that a patient is greeted at the facilities. Likewise, when
the RPs reported being satisfied (vs dissatisfied) with the visit, it
was correlated with a 15% increase in the prospect that patients are
pleased with healthcare workers’ explanations of health
conditions.

Conclusion

Informed patients are better equipped to assess health-systems
responsiveness in healthcare provision. Insights into responsiveness
could guide broader efforts aimed at targeted education and empowerment
of primary healthcare users to strengthen health systems and shape
expectations for appropriate care and conduct.
High-flow nasal cannula oxygen therapy for outpatients undergoing flexible bronchoscopy: a randomised controlled trial
Authors: Longhini Federico , Pelaia Corrado , Garofalo Eugenio , Bruni Andrea , Placida Roberta , Iaquinta Caterina , Arrighi Eugenio , Perri Graziella , Procopio Giada , Cancelliere Anna , Rovida Serena , Marrazzo Giuseppina , Pelaia Girolamo , Navalesi Paolo
Published: April 2021

Introduction

High-flow nasal cannula (HFNC) provides benefits to patients undergoing flexible bronchoscopy (FOB). We compared the effects of HFNC versus standard therapy (ST) on gas exchange, lung volume and diaphragm function in patients undergoing FOB for bronchoalveolar lavage (BAL).

Methods

36 outpatients were randomised to ST or HFNC. Arterial blood gases, episodes of severe desaturation, changes of end-expiratory lung impedance (ΔEELI), diaphragm ultrasound were recorded. Measurements were done at baseline (T0), after bronchoscope insertion (T1), at the end of the procedure (T2) and 10 min afterwards (T3).

Results

Arterial partial oxygen pressure (PaO2) was not different between T0 (10.8 (95% CI 8.7 to 12.0) kPa and T2 (11.1 (95% CI 10.4 to 12.0) kPa) with HFNC, while decreased from 11.1 (95% CI 10.5 to 12.1) to 9.1 (95% CI 8.4 to 9.8) kPa with ST. At T2, PaO2 was significantly higher with HFNC than with ST (p<0.001). Also, with HFNC, compared with ST, fewer desaturations occurred (11% vs 56%; p<0.01). ΔEELI was no different at the different time points with HFNC, while with ST there was a significant decrease at T1 (−170 (95% CI −382 to −32) mL, p=0.003), T2 (−211 (95% CI −425 to −148) mL, p<0.001) and T3 (−213 (95% CI −398 to −81) mL, p<0.001), as opposed to T0. EELI was lower with ST than HFNC at T1 (p=0.006), T2 (p=0.001) and T3 (p=0.002). Diaphragm displacement was no different between groups (p=0.748), while the thickening fraction significantly increased at T1 and T2 with ST only (p<0.01).

Conclusions

During FOB for BAL, HFNC improves gas exchange, avoiding loss of end-expiratory lung volume and preventing increase of diaphragm activation.

Trial registration number

NCT04016480.
Assessment of moisture content in sandy beach environments from multispectral satellite imagery
Authors: Paprocki Julie , Stark Nina , Graber Hans C. , Wadman Heidi , McNinch Jesse E.
Published: April 2021

A framework for estimating moisture content from satellite-based multispectral imagery of sandy beaches was tested under various site conditions and sensors. It utilizes the reflectance of dry soil and an empirical factor c relating reflectance and moisture content for a specific sediment. Here, c was derived two ways: first, from in situ measurements of moisture content and average NIR image reflectance; and second, from laboratory-based measurements of moisture content and spectrometer reflectance. The proposed method was tested at four sandy beaches: Duck, North Carolina; and Cannon Beach, Ocean Cape, and Point Carrew, Yakutat, Alaska. Both measured and estimated moisture content profiles were impacted by site geomorphology. For profiles with uniform slopes, moisture contents ranged from 3.0% to 8.0% (zone 1) and from 8.0% to 23.0% (zone 2). Compared to field measurements, the moisture contents estimated using c calibrated from in situ and laboratory data resulted in percent error of 3.6%–44.7% and 2.7%–58.6%, respectively. The highest percent error occurred at the transition from zone 1 to zone 2. Generally, moisture contents were overestimated in zone 1 and underestimated in zone 2, but followed the expected trends based on field measurements. When estimated moisture contents in zone 1 exceeded 10%, surface roughness, debris, geomorphology, and weather conditions were considered.
Vitexin regulates Epac and NLRP3 and ameliorates chronic cerebral hypoperfusion injury
Authors: Zhang Qilong , Fan Zhijia , Xue Wei , Sun Fanfan , Zhu Huaqing , Huang Dake , Wang Zhicheng , Dong Liuyi
Published: April 2021

Chronic cerebral hypoperfusion (CCH), as a critical factor of chronic cerebrovascular diseases, has greatly influenced the health of patients with vascular dementia. Vitexin, a flavone C-glycoside (apigenin-8-C-β-D-glucopyranoside) that belongs to the flavone subclass of flavonoids, has been shown to possess antioxidant and anti-ischemic properties; however, the putative protective effects of vitexin on the CCH need further investigation. In the current study, the role of vitexin and its underlying mechanism were investigated with permanent bilateral common carotid artery occlusion (2VO) in rats as well as mouse hippocampal neuronal (HT22) cells with oxygen and glucose deprivation/reoxygenation (OGD/R) injury model. The results demonstrated that vitexin improved cognitive dysfunction as well as alleviated pathological neuronal damage in hematoxylin plus eosin (HE) and TUNEL results. The decreased levels of exchange protein directly activated by cAMP 1 (Epac1), Epac2, Ras-associated protein 1 (Rap1), and phospho-extracellular signal-regulated kinase (p-ERK) were reversed by vitexin in rats with CCH. Furthermore, this study indicated that vitexin alleviated CCH-induced inflammation injuries by reducing the expression of NOD-like receptor 3 (NLRP3), caspase-1, interleukin 1β (IL-1β), IL-6, and cleaved caspase-3. In vitro, vitexin increased the expression of Epac1 and Epac2, decreased the activation of the NLRP3-mediated inflammation, and improved cell viability. Taken together, our findings suggest that vitexin can reduce the degree of the progressing pathological damage in the cortex and hippocampus and inhibit further deterioration of cognitive function in rats with CCH. Epac and NLRP3 can be regulated by vitexin in vivo and in vitro, which provides enlightenment for the protection of CCH injury.
Design of a digital control system of gyroscope
Authors: Xu Xiaodong , Liu Xiaowei , Zhang Yufeng
Published: April 2021

This paper introduces a digital control system of gyroscope. The control circuit includes amplitude control loop, phase control loop and detection circuit. The amplitude control loop realizes the stability of driving mode vibration signal amplitude. The phase control loop consists of coarse phase locking loop and precise phase locking loop. At the initial stage, coarse phase locking is used to realize the rapid start-up of the gyroscope. Then after resonance frequency settles into the lock-in range of PLL, precise phase locking is used to realize the precise phase locking. The detection circuit realizes the output of gyro angular velocity signal. The design is implemented on PCB. The test results show that the scheme can realize the stable operation of gyroscope.
INFORMATION AND MEMORY-BASED ANALYSIS FOR DECODING OF THE HUMAN LEARNING BETWEEN NORMAL AND VIRTUAL REALITY (VR) CONDITIONS
Authors: NAMAZI HAMIDREZA , BABINI MOHAMMAD HOSSEIN , KUCA KAMIL , KREJCAR ONDREJ
Published: April 2021

In this paper, we investigated the learning ability of students in normal versus virtual reality (VR) watching of videos by mathematical analysis of electroencephalogram (EEG) signals. We played six videos in the 2D and 3D modes for nine subjects and calculated the Shannon entropy of recorded EEG signals to investigate how much their embedded information changes between these modes. We also calculated the Hurst exponent of EEG signals to compare the changes in the memory of signals. The analysis results showed that watching the videos in a VR condition causes greater information and memory in EEG signals. A strong correlation was obtained between the increment of information and memory of EEG signals. These increments also have been verified based on the answers that subjects gave to the questions about the content of videos. Therefore, we can say that when subjects watch a video in a VR condition, more information is transferred to their brains that cause increments in their memory.
Pulse Potential Confined Electrochemical Polishing on Gallium Arsenide Wafer
Authors: Han Lianhuan , Xu Hantao , Sartin Matthew M. , Hu Zhenjiang , Zhao Xuesen , Cao Yongzhi , Yan Yongda , Su Jian-Jia , Zhan Dongping , Tian Zhong-Qun
Published: April 2021

Free of tool wear, residual stress, and surface damage, electrochemistry plays a significant role in precision machining. We report here a semiconductor polishing technique based on electrochemically induced chemical etching, in which the concentration distribution of electrogenerated etchant between the tool electrode and the semiconductor workpiece can be precisely controlled by the pulse frequency of the potential applied to the tool electrode. A theoretical model is established, and the finite element analysis shows that the concentration difference of the electrogenerated etchant at the peak and valley of the rough surface of the semiconductor workpiece is dependent on the frequency of the potential pulse. Consequently, the diffusion distance and concentration distribution of electrogenerated etchant at the tool electrode/electrolyte interface can be controlled effectively by tuning the frequency of pulse potential. Under a mechanical motion mode, the roughness of a raw GaAs workpiece can be reduced efficiently from 700 nm to 5.1 nm. This technique is ideal for the electrochemical polishing of semiconductor wafers.
Analytical System for Simultaneous Operando Measurements of Electrochemical Reaction Rate and Hard X-ray Photoemission Spectroscopy
Authors: Suda Kohei , Kawamoto Teppei , Yasuno Satoshi , Watanabe Takeshi , Koganezawa Tomoyuki , Matsumoto Masashi , Imai Hideto , Hirosawa Ichiro , Inukai Junji
Published: April 2021

We have developed an operando analytical system designed for the simultaneous measurements of the electrochemical reaction rate and the hard X-ray photoemission spectrum. In this system, a solution containing reactants was continuously supplied in a Hagen-Poiseuille flow to a specimen, such as catalyst, under the control of temperature, pressure, concentration, and solution flow rate, so that the electrochemical reaction rate is able to be accurately measured or controlled by electrochemical current generated by the reaction. Two different environments, solution and ultra-high vacuum, were connected with an ultra-thin Au/SixNy window with a thickness of 20 nm to make the operando hard X-ray photoemission spectroscopy possible during the steady-state electrochemical reaction. In this paper, we report this analytical system in detail.
Discharge Performance of Mg-6 wt%Al Alloy Anodes Containing Ca and Zn for Magnesium-Air Batteries
Authors: Nakatsugawa Isao , Chino Yasumasa
Published: April 2021

In this study, the discharge performance of Mg-6 wt% Al alloy anodes with varying Ca and Zn contents was evaluated by electrochemical studies and surface analyses. The results indicated that the cell voltage and anode efficiencies changed according to the alloy compositions and discharge currents. The 6 wt%Al-1wt%Zn-1wt%Ca (AZX611) alloy was discovered to exhibit the highest cell voltage of 0.678 V and anode efficiency of 64% at the discharge current of 10 mA cm−2. Although the calculated charge corresponding to the mass loss of AZX611 was equal to the sum of the calculated charge stemming from the captured H2 and the discharge current, the other alloys yielded smaller values. The discharge products of these alloys were analyzed by X-ray diffraction to locate the peaks related to metallic Mg species. The electrochemical impedance spectroscopy analysis of the AZX611 alloy, conducted under the discharged state using a proposed equivalent circuit, revealed a close relationship between the resistance in the high frequency loop and the anode efficiency.
Review—Progress in Electrolytes for Rechargeable Aluminium Batteries
Authors: Leung Oi Man , Schoetz Theresa , Prodromakis Themis , Ponce de Leon Carlos
Published: April 2021

The growing demand for safe, sustainable and energy-dense energy storage devices has spurred intensive investigations into post-lithium battery technologies. Rechargeable aluminium batteries are promising candidates for future electrochemical energy storage systems due to the high theoretical volumetric capacity of aluminium and its natural abundance in the Earth’s crust, but their practical application is currently hindered by the limitations of presently available electrolytes. In this review, we highlight the key considerations needed to optimise the electrolyte design in relation to the aluminium battery system and critically assess the current state of knowledge and new concepts in liquid and quasi-solid polymer electrolytes, focusing primarily on non-aqueous systems. We then discuss the challenges and approaches in developing polymer electrolytes and finally provide an overview of the opportunities in quasi-solid electrolytes which could pave the way to achieving further improvements in aluminium batteries.
Formulating a Non-Flammable Highly Concentrated Dual-Salt Electrolyte for Wide Temperature High-Nickel Lithium Ion Batteries
Authors: Zhao Min , Xu Gaojie , Lu Di , Xie Bin , Huang Lang , Wang Wei , Cui Guanglei
Published: April 2021

With the ever-increasing energy density of lithium ion batteries (LIBs), the safety concerns have aroused great interests. It is well known that electrolytes play a crucial role in determining the safety of LIBs. Here, a non-flammable highly concentrated dual-salt electrolyte is formulated by dissolving 2 M lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 2 M lithium difluoro(oxalate)borate (LiDFOB) in trimethyl phosphate (TMP) and gamma-butyrolactone (GBL). Encouragingly, this delicately tailored concentrated dual-salt electrolyte possesses high compatibility with high-nickel LIB systems of LiNi0.6Co0.2Mn0.2O2 (NCM622)/mesocarbon microbeads (MCMB), LiNi0.8Co0.1Mn0.1O2 (NCM811)/MCMB, LiNi0.8Co0.15Al0.05O2 (NCA)/MCMB. Especially, NCM622/MCMB full cell using this electrolyte delivers excellent electrochemical performances over a wide temperature range (−30 °C ∼ 90 °C). It is revealed that thermally stable dual-salt of LiTFSI and LiDFOB will form favorable synergistic effects on electrode interfaces. This paper will guide the formulation of highly safe electrolytes for next generation high energy high nickel LIBs.
Review—Nanopillar Structure in the Direction of Optical Biosensor On-Chip Integration
Authors: Pradana Arfat , Septiani Ni Luh Wulan , Dipojono Hermawan Kresno , Suyatman  , Yuliarto Brian
Published: April 2021

Biosensors based on nanomaterial have attracted so much interest due to their high-performance potential. Its structure allows the biosensor to have high sensitivity and selectivity. Nanopillar (NPLA) is one class of material with unique properties, especially optical properties. Its unique properties cause it to be the structure that has drawn so much attention recently. The advantages owned by NPLA, including high surface area and its unique optical properties, provide the possibility to build a sensitive layer for a biosensor that is very promising for health and medical applications. This structure also offers low-cost fabrication and can be produced on a mass scale due to its compactness and reliability. Furthermore, NPLA has a high capability to be used as optical biosensors. This article reviews diverse fabrication routes of NPLA structures. Their applications in biomolecular detection, mainly by optical approach, are highlighted. The comparison of the limit of detection of the different kinds of optical biosensors is also presented. The focus of this article lies on the possibilities of NPLA structure integrating into biosensors on-chip.
Communication—A Rotating Ring Disk Study to Monitor the Concentration of 2M5S in Copper Low TEC Electrolytes
Authors: Van Nhat Tran Anh , Hirato Tetsuji , Kondo Kazuo
Published: April 2021

A leveller additive, 2-mercapto-5-benzimidazolesulfonic acid (2M5S), is characterized and monitored by cyclic voltammetry stripping (CVS) measurements using a rotating ring disk electrode (RRDE). The ring current gradually decreases with the increase of 2M5S concentration from 1 to 8 ppm. The relationship between the ring current and 2M5S concentration is used for determining the deterioration of the low thermal expansion coefficient (TEC) copper electrodeposition solution. The amount of 2M5S in the 20-hour-electrolyzed solution has been monitored then supplied. The copper pipe electrodeposited with the refreshed solution achieved low TEC, approximately the same as the copper pipe electrodeposited with the fresh solution.
Different Transfer Functions for Binary Particle Swarm Optimization with a New Encoding Scheme for Discounted {0-1} Knapsack Problem
Authors: Truong Tung Khac
Published: April 2021

The discounted {0-1} knapsack problem (DKP01) is a kind of knapsack problem with group structure and discount relationships among items. It is more challenging than the classical 0-1 knapsack problem. In this paper, we study binary particle swarm optimization (PSO) algorithms with different transfer functions and a new encoding scheme for DKP01. An effective binary vector with shorter length is used to represent a solution for new binary PSO algorithms. Eight transfer functions are used to design binary PSO algorithms for DKP01. A new repair operator is developed to handle isolation solution while improving its quality. Finally, we conducted extensive experiments on four groups of 40 instances using our proposed approaches. The experience results show that the proposed algorithms outperform the previous algorithms named FirEGA and SecEGA . Overall, the proposed algorithms with a new encoding scheme represent a potential approach for solving the DKP01.
Research on Market Stock Index Prediction Based on Network Security and Deep Learning
Authors: Li Jiake
Published: April 2021

As one of the most popular financial management methods, stocks have attracted more and more investors to participate. The risks of stock investment are relatively high. How to reduce risks and increase profits has become the most concerned issue for investors. Traditional stock forecasting models use forecasting models based on stock time series analysis, but time series models cannot consider the influence of investor sentiment on stock market changes. In order to use investor sentiment information to make more accurate stock market forecasts, this paper establishes a stock index forecast and network security model based on time series and deep learning. Based on the time series model, it is proposed to use CNN to extract in-depth emotional information to replace the basic emotional features of the emotional extraction level. At the data source level, other information sources, such as basic features, are introduced to further improve the predictive performance of the model. The results show that the algorithm is feasible and effective and can better predict the changes in the market stock index. This also proves that multiple information sources can improve the accuracy of model prediction more effectively than a single information source.
Soil Chemical Properties under Various Land-Use Types in the Karst Area with a Case Study in Shibing County of China
Authors: Xiao Shizhen , He Jianghu , Zeng Cheng , Wang Jialu
Published: April 2021

The effects of different land-use types on the pH, organic carbon, total nutrient, and available nutrients of soil in the 0–30 cm and 30–60 cm layers were studied using the gray relational analysis method. The research area is located in Baiduo village in the dolomite karst region and Shiqiao village in the limestone karst region of Shibing County, Guizhou Province, China. The land-use types investigated included shrubland, forest, grass slope, dryland, paddy field, pear orchard, and flue-cured tobacco field. The contents of organic carbon, total nitrogen, alkaline hydrolysable nitrogen, and available potassium, as well as the pH of the soil in the dolomite shrubland, were higher than those in the limestone shrubland. The total potassium, total phosphorus, and available phosphorus contents of soil in the limestone shrubland were higher than those in the dolomite shrubland. Among the four types of land-use most strongly affected by human activities (paddy field, dryland, flue-cured tobacco field, and pear orchard), the nutrient contents (except potassium in the upper soil layer) were higher than those in the lower layer. The differences in nutrient contents between upper and lower layers were relatively small in the dryland and the pear orchard, whereas they were large for the paddy field and flue-cured tobacco field. The gray relational degree of various land-use types decreased in the following order: dolomite shrubland > forest > grass slope > pear orchard > limestone shrubland > paddy field > dryland > flue-cured tobacco field. The dolomite shrubland had the best soil quality, while the flue-cured tobacco field had the worst. Of the four types of land use most strongly affected by human activities, pear orchard had the best soil quality. This study can provide reference for soil nutrient management and sustainable management in karst areas.
Unified Analytical Solutions of Circular Tunnel Excavated in an Elastic‐Brittle‐Plastic Rock Mass considering Blast‐Induced Damage and Dead Weight Loading
Authors: Cao Yue , Chen Liang , Xu Jinhai , Li Chong , Zhang Wei
Published: April 2021

Stress and deformation around circular tunnel are crucial for optimizing the support system and evaluating the tunnel stability. The damage zone induced by blasting or mechanical excavation can dramatically influence the support design and methods because the self‐weight of broken rock mass at the roof of the tunnel can exert a high pressure on the support system, leading to the support system instability due to the overload. This paper presents a new closed‐form solution for analyzing the stress and deformation of deep circular tunnel excavated in elastic‐brittle rock mass with the consideration of the rock gravity and damage zone by using the unified strength criterion. A new modified equilibrium equation in the fracture zone is used to determine the stress and the radius of fracture zone. The correctness of the solution is also verified by comparison with the numerical simulation results. The results illustrate that the rock gravity, damage zone radius, and intermediate principal stress have an extremely important influence on the ground response. The tunnel surface convergence and damage zone radius with the consideration of the gravity are obviously larger than those without consideration of the gravity. The rock gravity effect under the high intermediate principal stress gradually weakens, illustrating that the intermediate principal stress is beneficial to tunnel stability. Large deformation instability of the tunnel is dependent on the extension of damage zone. The larger the radius of damage zone, the larger both fracture range and tunnel surface deformation. The proposed solution in this study is novel and can be used to assess the ground convergence for different scenarios and to optimize the support system during the early design stage of the tunnel.
The Influence of Calcitonin Gene‐Related Peptide on Cerebral Hemodynamics in Nonmigraine Subjects with Calcitonin Gene‐Related Peptide‐Induced Headaches
Authors: Zupan Matija , Zaletel Marjan , Visočnik Darja , Žvan Bojana
Published: April 2021

Background. Calcitonin gene‐related peptide (CGRP) is regarded as an important molecule in trigeminovascular sensitization (TVS). CGRP‐induced headaches (CGRP‐IH) are evoked by intravascular administration of CGRP in nonmigraine and migraine subjects. CGRP might be associated with vasodilatation of the middle cerebral artery (MCA). It is unclear whether CGRP‐induced hemodynamic changes relate to CGRP‐IH in nonmigraine subjects. Methods. Twenty healthy subjects participated in our study. Polymodal recording of mean arterial velocity in MCA (vm MCA), end‐tidal carbon dioxide partial pressure (Et‐CO2), mean arterial pressure (MAP), and heart rate (HR) was employed using transcranial Doppler (TCD) sonography. During the experiment, we administered intravenous infusion of CGRP at a rate of 1.5 mcg/min. The vm MCA, Et‐CO2, HR, and MAP were determined at time points T0, T1, T2, and T3. We calculated the responses at different time points and combined them into a single response vm MCAtot, Et‐CO2tot, HRtot, and MAPtot. Results. We found significant differences along the time points in vm MCA (p = <0.001), Et‐CO2 (p = 0.003), MAP (p < 0.001), and HR (p < 0.001). The relationship between vm MCAtot and Et‐CO2tot was significant and positive (p = 0.005). The t‐test showed significant differences between CGRP‐IH and non‐CGRP‐IH subjects in vm MCAtot (p = 0.021) but not in Et‐CO2tot (p = 0.838), MAPtot (p = 0.839), and HRtot (p = 0.198). Only vm MCAtot showed a significant relationship with CGRP‐IH (p = 0.028). Conclusions. Our study provides evidence for vasodilatation of MCA in relation to CGRP‐IH due to intravascular CGRP detected by multimodal TCD. In the context of TVS induced by CGRP, MCA vasodilatation seems to represent an epiphenomenon of the underlying TVS.
Contrast-Enhanced Computed Tomography Does Not Provide More Information about Sarcopenia than Unenhanced Computed Tomography in Patients with Pancreatic Cancer
Authors: Zhang Yan , Liu Jiabin , Li Fei , Cao Feng , Li Ang
Published: April 2021

Objective. The aim of this study was to understand whether enhanced CT can provide more information than unenhanced CT on diagnosis of sarcopenia. Materials and Methods. We reviewed the enhanced CT data of 45 patients of pancreatic cancer. Manual tracing of the psoas muscles was used for measuring the cross-sectional muscle areas and attenuation at umbilicus level; afterwards, PMI, PMD, and Δ PMD were calculated. Results. In the unenhanced scanning, arterial, venous, and parenchymal phases of enhanced CT, PMI values were 6.905 ± 2.170, 6.886 ± 2.195, 6.923 ± 2.239, and 6.866 ± 2.218, respectively, and the difference was not statistically significant. The PMD values at different phases were 34.311 ± 7.535, 37.487 ± 7.118, 40.689 ± 7.116, and 42.989 ± 7.745, respectively, which were gradually increased, and the difference was statistically significant. Meanwhile, the PMD of arterial phase, venous phase, and parenchyma phase showed a linear correlation with PMD of unenhanced scanning phase. 31 patients had low PMD and 14 had normal PMD during the unenhanced scanning phase. With the addition of contrast agent, ΔPMD values increased faster in the low PMD group than in the normal PMD group during the venous and parenchymal phases (7.048 ± 3.067 vs 4.893 ± 2.558; 9.581 ± 3.033 vs 6.679 ± 2.621;

p
<
0.05

), which made the gap between PMD after contrast-enhancement vs. unenhanced scanning smaller. Conclusion. The use of contrast agent has no effect on the manually measured PMI values but can change the results of PMD. This change makes the difference of PMD in different enhancement phases smaller than that in plain scan phase and furthermore increases the examination cost; therefore, it is not recommended to use enhanced CT routinely with fixed dose administration of contrast agent for patients’ assessment of PMI and PMD.
Effects of Cyclic Loading on the Pore Structure of Anthracite Coal
Authors: Wang Dong , Li Tie , Cheng Zhiheng , Wang Weihua
Published: April 2021

In the process of improving coalbed permeability through pulse hydraulic fracturing, the cyclic loading effect influences the characteristics of micropores in coal matrix, thus affecting the process of gas migration. Therefore, it is essential to investigate the effect of cyclic loading on the pore structure of coal. Seven groups of loading tests at different frequencies and amplitudes were conducted on anthracite coal obtained from Shanxi Province, China, using a fatigue‐testing machine. Subsequently, using a PoreMaster GT‐60 Mercury‐intrusion apparatus, the influence of the frequency and amplitude on the structural characteristics (including mercury‐injection and mercury‐ejection curves, pore size distribution, porosity, and specific surface area) of pores in coal samples was analyzed. Finally, the law and mechanism of action of the loading frequency and amplitude on pores in coal samples were comprehensively analyzed. The test results showed that, in the case of maintaining the sine‐wave amplitude unchanged during loading while altering the loading frequency, the overall porosity and pore volume rise at different degrees. The growth of the loading frequency presents a more significant promotive effect on the initiation and development of pores and fractures. Moreover, it drives the transformation of micropores and transition pores into mesopores and macropores, thus increasing the proportion of seepage pores. Under the condition of large sine‐wave amplitude during loading, macropores and mesopores are subjected to the repeated action of the external force, thereby reducing the overall porosity. In addition, the volume of the seepage pores declines, and the number of the coalesced pores decreases. Finally, in light of these results, the implications of frequency and amplitude selection in the process of pulse hydraulic fracturing are discussed. Therefore, the results of this research will provide an important theoretical basis for the field application of pulse hydraulic fracturing technology in coal mines.
Potential of Soft-Shelled Rugby Headgear to Reduce Linear Impact Accelerations
Authors: Draper Nick , Kabaliuk Natalia , Stitt Danyon , Alexander Keith
Published: April 2021

The purpose of this study was to examine the potential of soft-shelled rugby headgear to reduce linear impact accelerations. A hybrid III head form instrumented with a 3-axis accelerometer was used to assess headgear performance on a drop test rig. Six headgear units were examined in this study: Canterbury Clothing Company (CCC) Ventilator, Kukri, 2nd Skull, N-Pro, and two Gamebreaker headgear units of different sizes (headgears 1–6, respectively). Drop heights were 238, 300, 610, and 912 mm with 5 orientations at each height (forehead, front boss, rear, rear boss, and side). Impact severity was quantified using peak linear acceleration (PLA) and head injury criterion (HIC). All headgear was tested in comparison to a no headgear condition (for all heights). Compared to the no headgear condition, all headgear significantly reduced PLA and HIC at 238 mm (16.2–45.3% PLA and 29.2–62.7% HIC reduction;

P
<
0.0005

, ηp2 = 0.987–0.991). Headgear impact attenuation lowered significantly as the drop height increased (32.4–5.6% PLA and 50.9–11.7% HIC reduction at 912 mm). There were no significant differences in PLA or HIC reduction between headgear units 1–3. Post hoc testing indicated that headgear units 4–6 significantly outperformed headgear units 1–3 and additionally headgear units 5 and 6 significantly outperformed headgear 4 (

P
<
0.05

). The lowest reduction PLA and HIC was for impacts rear orientation for headgear units 1–4 (3.3 ± 3.6%–11 ± 5.8%). In contrast, headgear units 5 and 6 significantly outperformed all other headgear in this orientation (

P
<
0.0005

, ηp2 = 0.982–0.990). Side impacts showed the greatest reduction in PLA and HIC for all headgear. All headgear units tested demonstrated some degree of reduction in PLA and HIC from a linear impact; however, units 4–6 performed significantly better than headgear units 1–3.
Impact of Progression of Parkinson’s Disease on Swallowing Ability and Oral Environment
Authors: Umemoto George , Fujioka Shinsuke , Iwasa Yasuyuki , Ozaki Yoshie , Koga Kayoko , Nishimura Kazumi , Tsuboi Yoshio
Published: April 2021

This study investigated the impact of the severity and treatment of Parkinson’s disease (PD) on the swallowing ability and oral environment of patients. Swallowing dysfunction increases the aspiration risk and may lead to poor oral health among patients with PD. We investigated the influences of PD progression and drug treatment on the swallowing ability and oral environment using simple noninvasive screening measurements. We recruited 87 patients with PD (mean age, 71.9 ± 8.0 years; mean Hoehn and Yahr score, 2.9 ± 0.9). The PD condition was assessed in each patient using the unified Parkinson’s disease rating scale (UPDRS) part III, diet type and oropharyngeal function using the swallowing disturbances questionnaire (SDQ), maximum bite force (MBF), tongue pressure (TP), and oral bacterial count (OBC). Levodopa equivalent daily dose (LEDD) was also calculated for 56 participants. Based on an SDQ score of ≥11, 29.5% of patients were dysphagic, but almost all were still on a regular diet. The SDQ score was positively correlated with disease duration (rho = 0.228,

p
=
0.047

) and UPDRS part III score (rho = 0.307,

p
=
0.007

) but was negatively correlated with OBC (rho = −0.289,

p
=
0.012

). OBC was significantly higher among patients with an SDQ score of <11 (nondysphagic) (

p
=
0.01

), and the SDQ score was lower in patients with higher OBC requiring professional oral care (

p
=
0.03

). However, OBC was also negatively correlated with LEDD (rho = −0.411,

p
=
0.004

). These results indicated low self-awareness of dysphagia among the participants and an association between dysphagia and PD progression. Moreover, the oral environment could have deteriorated with swallowing dysfunction. Patients and clinicians should be aware that higher LEDD can increase xerostomia and associated deficits in oral health.
Comparison of BIM Adoption Models between Public and Private Sectors through Empirical Investigation
Authors: Belay Solomon , Goedert James , Woldesenbet Asregedew , Rokooei Saeed
Published: April 2021

In recent years, the integration of new technology‐aided processes and methods, such as BIM in complex infrastructure projects, is becoming popular in the construction sector. Despite the growing popularity of BIM in the built environment, there is still a dearth of studies that focus on the intersectorial comparison of BIM adoption drivers in construction projects. Thus, the study aims to examine the project‐specific BIM adoption drivers across the public and private construction sectors. Initially, a hypothetical BIM adoption model was developed based on a systematic literature review and desk study. Then, a structured questionnaire survey was employed to collect data from experts working across the Ethiopian construction industry. The empirical data were analyzed using a structural equation modeling and validated through confirmatory factor analysis. The result reveals that Relative Advantage, Financial Competency, Top Management Support, and Customer Pressure are common BIM adoption drivers amongst the public and private construction sectors. Similarly, a few distinct drivers were identified within both sectors. These include Government Pressure and Social/Cultural Factors in public, whereas Competitor Pressure and Communication Behavior in the private construction sector. The paper provides key intersectorial BIM adoption drivers within different adoption stages to reinforce the effort across the public and private construction projects. In addition, practical implications and key recommendations were forwarded to enhance the current BIM uptake in the Ethiopian construction sector.