bluuebunny/crossref_metadata_2025 huggingface dataset:
Collapse by Instability of Thin Cylindrical Shells Under External Pressure
Authors: Windenburg Dwight F. , Trilling Charles
Published: February 2023

This paper discusses the collapse by instability of thin-walled cylindrical vessels subjected to external pressure. The most important of the theoretical and empirical formulas that apply to this subject are presented in a common notation. A new and simple instability formula is developed.

Three classes of tubes are considered: Tubes of infinite length; tubes of finite length with uniform radial pressure only; and tubes of finite length with both uniform radial and axial pressure. Collapsing pressures calculated by the various formulas are presented in tabular form as a means of comparing the formulas.

The formulas are discussed briefly and checked against the results of tests conducted at the U. S. Experimental Model Basin for the Bureau of Construction and Repair, Navy Department.

This paper is a sequel to one previously published as a part of the work of the A.S.M.E. Special Research Committee on the Strength of Vessels Under External Pressure.
The Correlation of Spring-Wire Bending and Torsion Fatigue Tests
Authors: Weibel E. E.
Published: February 2023

The investigation reported in this paper was an attempt to correlate bending and torsion fatigue results for tempered Swedish valve-spring wire so that the torsion fatigue strength might be inferred within reasonable limits of accuracy from the fatigue values found in the simpler rotating-beam test. The original program called for (a) the development of suitable methods of gripping the wire for the torsion fatigue tests; (b) the determination of bending and torsion fatigue values for one size of wire in the as-received condition, and also after removal of the surface layer in a centerless grinder; (c) the determination of fatigue values for other sizes of wire between ⅛ in. and ¼ as permitted by time limitations; and (d) a survey of the literature for data bearing on the correlation of bending and torsion results. The results of these experiments on straight specimens of tempered Swedish wire in torsion and bending fatigue may be summarized as follows:

1 Methods of gripping were developed which are satisfactory for both bending and torsion fatigue tests with the exception of torsion tests on shot-blasted wire.

2 Zero to maximum torsion fatigue values for straight specimens in the as-received condition were about 70 per cent higher than values estimated from previous tests on carefully coiled springs.

3 The smaller of two sizes of wire tested in the as-received condition had the higher torsion fatigue limit and lower ultimate torsional strength.

4 Removal of the natural surface by grinding increased the bending fatigue strength about 20 per cent, but decreased the torsion fatigue strength about 4 per cent.

5 Shot-blasting increased the bending fatigue strength about 27 per cent and increased the torsion fatigue strength an undetermined amount.

6 The zero-to-maximum torsion fatigue limits of two sizes of wire tested in the as-received condition were 1.5 and 1.6 times their respective bending fatigue limits.

7 For two sizes of wire in the as-received condition the values of 0.84 and 0.90 were obtained for the ratio of reversed torsion fatigue strength to reversed bending fatigue strength.

8 Approximate measurements of surface residual stress were made on the wire in different conditions before and after fatigue testing and before and after coiling, which may have a bearing on the fatigue properties of springs.
The Contributions of the U. S. Bureau of Mines to Helium Production
Authors: Seibel C. W.
Published: February 2023

The production of helium for commercial use is of particular interest at this time since it had its inception in the State of Texas and has been carried on chiefly in that state ever since. The development of helium production is an excellent example of how American engineers attempt the seemingly impossible—and win. It also demonstrates the rapidity with which an almost hopeless undertaking can be completed when a determination really has been made to do so and the necessary funds are available. In this paper are outlined the early history of helium production, the steps in the necessary preliminary research, and how the data were applied. Early repurification plants are described, and facts given concerning the present Amarillo plant.
Abstract of Progress Report No. 3 on Heavy Helical Springs
Authors: Edgerton C. T.
Published: February 2023

This abstract gives the principal results of static tension and torsion tests, rotating-beam endurance tests in bending, and torsion endurance tests of straight pieces of plain carbon basic open-hearth, plain carbon electric-furnace and silicon-vanadium spring steel. These results are compared with those for other steels.
Complete Characteristics of Centrifugal Pumps and Their Use in the Prediction of Transient Behavior
Authors: Knapp R. T.
Published: February 2023

This paper describes the technique of determining the complete operating characteristics of a hydraulic machine such as a centrifugal pump or a turbine, together with a method of presenting these characteristics in a convenient manner on a single diagram. The characteristics of a modern, high-head, high-efficiency pump are analyzed and presented in the manner proposed. The use of these complete characteristics for the prediction of the behavior of the machine during operating transients is discussed and the analytical background is presented. The assumptions involved are investigated and experimental checks of their validity are offered. The interrelationships between the hydraulic characteristics of the machine and the pipe line are indicated.
Carbonaceous Zeolites—An Advance in Boiler-Feedwater Conditioning
Authors: Tiger Howard L.
Published: February 2023

The increased number of modern high-pressure steam boilers emphasizes the need for high-quality feedwater make-up of minimum scale-forming and minimum total-solids content consistent with the desired sulphate-carbonate ratio. The usual sodium zeolites hitherto known, which exchange their sodium base for calcium and magnesium (hardness), reduce this hardness to a minimum, but do not reduce total solids or alkalinity. The new hydrogen zeolites described in this paper retain the simplicity and complete hardness-removal characteristics of zeolite softeners and at the same time eliminate the alkalinity with (a) a corresponding reduction in total solids and CO2 content of steam, and (b) an increase in the sulphate-carbonate ratio. Furthermore, they remove alkalinity present in any form; thus, for the first time in history it is possible, by simple economical means, to remove sodium alkalinity often found in raw waters.

When the capacity of these hydrogen zeolites is exhausted, they are regenerated by dilute acid solutions in the same manner as a salt solution is used to regenerate sodium-zeolite softeners. By combining the hydrogen- and sodium-zeolite effluents in correct proportions, or by alkali neutralization, it is a simple matter to obtain a feedwater completely free from hardness and of any predetermined desired alkalinity.

These hydrogen zeolites are made of carbonaceous substances and are therefore practically free from silica. They can also be regenerated with common salt, and with such regeneration they can function in the usual sodium-zeolite cycle. Being extremely resistant to low pH waters and practically free from silica, and of relatively high capacity, they also possess great advantages when used in the usual sodium-zeolite cycle, especially where it is desired to avoid any increase in silica content, a condition that is gaining favor rapidly in the high-pressure-boiler feedwater field.
Quantitative Analysis of Single-Capacity Processes
Authors: Spitzglass Albert F.
Published: February 2023

The paper compares methods of quantitative analysis of continuous-process regulation. It complements the paper by C. E. Mason (17) by comparing the quantitative approach proposed by him with that of other writers, both American and foreign.

The fundamental considerations underlying process analysis and the simplifying assumptions necessary to facilitate mathematical approach are investigated. The equations of the regulator are defined and then combined with those for the process. The results are presented in tabulated form to permit making a critical analysis.

Only single-capacity processes are considered in this paper, and the consideration of multiple-capacity processes as well as the critical analysis is reserved for a later time.
Online cognitive behavioural therapy for post-traumatic stress disorder is as effective as face-to-face therapy
Authors: Saul Helen , Cassidy Samantha , Deeney Brendan , Kwint Jemma , Bisson Jonathan
Published: February 2023

The study

Bisson JI, Ariti C, Cullen K, et al. Guided, internet based, cognitive behavioural therapy for post-traumatic stress disorder: pragmatic, multicentre, randomised controlled non-inferiority trial (RAPID).
BMJ
2022;377:e069405.

To read the full NIHR Alert, go to:
https://evidence.nihr.ac.uk/alert/online-cbt-for-ptsd-is-as-effective-as-face-to-face-therapy/
BSG 2024 IBD guidelines protocol (standard operating procedures)
Authors: Gordon Morris , Darie Ana-Maria , Sinopoulou Vasiliki , Verma Ajay , Bel Kok Klaartje , Patel Kamal V , Limdi Jimmy , Arebi Naila , Smith Philip , Din Shahida , Din Said , Shale Matthew , Subramanian Sreedhar , Pavlidis Polychronis , Cooney Rachel , McGonagle Dennis , A C S Wong Newton , Moran Gordon W
Published: February 2023

Introduction

In the past 5 years, there have been several advances in the management of inflammatory bowel disease (IBD). We aim for a new guideline to update the most recent guideline published in 2019. We present the prospective operating procedure and technical summary protocol in the manuscript.

Methods

‘Grading of Recommendations Assessment, Development and Evaluation’ (GRADE) will be followed in the development of the guideline, approach as laid out in the GRADE handbook, supported by the WHO. The guideline development group is formed by a variety of disciplines, across both primary and secondary care that took part in an online Delphi process and split into key areas. A final consensus list of thematic questions within a ‘patient, intervention, comparison, outcome’ format has been produced and agreed in the final phase of the Delphi process.

There will be a detailed technical evidence review with source data including systematic reviews appraised with AMSATAR 2 tool (Assessment of multiple systematic reviews), randomised controlled trial data that will be judged for risk of bias with the Cochrane tool and observational studies for safety concerns assessed through the Robins-I tool. Based on the available evidence, some of the recommendations will be based on GRADE while others will be best practice statements.

A full Delphi process will be used to make recommendations using online response systems.

This set of procedures has been approved by the Clinical Services and Standards Committee, the British Society of Gastroenterology executive board and aligned with IBD UK standards.
How has the COVID-19 pandemic affected the utilisation of online consultation and face-to-face medical treatment? An interrupted time-series study in Beijing, China
Authors: Zhang Shan , Ma Chengyu
Published: February 2023

Objective

The COVID-19 pandemic has had a major impact on healthcare utilisation. This study aimed to quantify how the online and face-to-face utilisation of healthcare services changed during this time and thus gain insights into the planning of future healthcare resources during the outbreak of infectious diseases.

Design

This work is an interrupted time-series study.

Setting

Monthly hospital-grade healthcare-service data from 22 tertiary first-class public hospitals managed by the Beijing Hospital Authority and online-consultation data from GoodDoctor were used in this study.

Methods

This is an interrupted time-series study about the change in face-to-face and online healthcare utilisation before and after the COVID-19 outbreak. We compared the impact of COVID-19 on the primary outcomes of both face-to-face healthcare utilisation (outpatient and emergency visits, discharge volume) and online healthcare utilisation (online consultation volume). And we also analysed the impact of COVID-19 on the healthcare utilisation of different types of diseases.

Results

The monthly average outpatient visits and discharges decreased by 36.33% and 35.75%, respectively, compared with those in 2019 in 22 public hospitals in Beijing. Moreover, the monthly average online consultations increased by 90.06%. A highly significant reduction occurred in the mean outpatients and inpatients, which dropped by 1 755 930 cases (p<0.01) and 5 920 000 cases (p<0.01), respectively. Online consultations rose by 3650 cases (p<0.05). We identified an immediate and significant drop in healthcare services for four major diseases, that is, acute myocardial infarction (−174, p<0.1), lung cancer (−2502, p<0.01), disk disease (−3756, p<0.01) and Parkinson’s disease (−205, p<0.01). Otherwise, online consultations for disk disease (63, p<0.01) and Parkinson’s disease (25, p<0.05) significantly increased. More than 1300 unique physicians provided online-consultation services per month in 2020, which was 35.3% higher than in 2019.

Conclusions

Obvious complementary trends in online and face-to-face healthcare services existed during the COVID-19 pandemic. Different changes in healthcare utilisation were shown for different diseases. Non-critically ill patients chose online consultation immediately after the COVID-19 lockdown, but critically ill patients chose hospital healthcare services first. Additionally, the volume of online physician services significantly rose as a result of COVID-19.
Mechanisms of chiropractic spinal manipulative therapy for patients with chronic primary low back pain: protocol for a mechanistic randomised placebo-controlled trial
Authors: Gevers-Montoro Carlos , Ortega-De Mues Arantxa , Piché Mathieu
Published: February 2023

Introduction

Chronic low back pain (CLBP) is a highly prevalent and disabling condition. Identifying subgroups of patients afflicted with CLBP is a current research priority, for which a classification system based on pain mechanisms was proposed. Spinal manipulative therapy (SMT) is recommended for the management of CLBP. Yet, little data are available regarding its mechanisms of action, making it difficult to match this intervention to the patients who may benefit the most. It was suggested that SMT may influence mechanisms associated with central sensitisation. Therefore, classifying patients with CLBP according to central sensitisation mechanisms may help predict their response to SMT.

Methods and analysis

This protocol describes a randomised placebo-controlled trial aiming to examine which variables linked to central sensitisation may help predict the clinical response to SMT in a cohort of patients with CLBP. One hundred patients with chronic primary low back pain will be randomised to receive 12 sessions of SMT or placebo SMT over a 4-week period. Pain intensity and disability will be assessed as primary outcomes after completing the 4-week treatment (primary endpoint), and at 4-week and 12-week follow-ups. Baseline values of two pain questionnaires, lumbar pressure pain thresholds, concentrations of an inflammatory cytokine and expectations of pain relief will be entered as predictors of the response to SMT in a multiple regression model. Changes in these variables after treatment will be used in a second multiple regression model. The reference values of these predictors will be measured from 50 age and sex-matched healthy controls to allow interpretation of values in patients. Mixed analyses of variance will also be conducted to compare the primary outcomes and the predictors between groups (SMT vs placebo) over time (baseline vs post-treatment).

Ethics and dissemination

Ethical approval was granted by the Fundación Jiménez Díaz Clinical Research Ethics Committee.

Trial registration number

NCT05162924.
Influence of the COVID-19 pandemic and social media on the behaviour of pregnant and lactating women towards vaccination: a scoping review
Authors: De Brabandere Larissa , Hendrickx Greet , Poels Karolien , Daelemans Walter , Van Damme Pierre , Maertens Kirsten
Published: February 2023

Background

Pregnant women, foetuses and infants are at risk of infectious disease-related complications. Maternal vaccination is a strategy developed to better protect pregnant women and their offspring against infectious disease-related morbidity and mortality. Vaccines against influenza, pertussis and recently also COVID-19 are widely recommended for pregnant women. Yet, there is still a significant amount of hesitation towards maternal vaccination policies. Furthermore, contradictory messages circulating social media impact vaccine confidence.

Objectives

This scoping review aims to reveal how COVID-19 and COVID-19 vaccination impacted vaccine confidence in pregnant and lactating women. Additionally, this review studied the role social media plays in creating opinions towards vaccination in these target groups.

Eligibility criteria

Articles published between 23 November 2018 and 18 July 2022 that are linked to the objectives of this review were included. Reviews, articles not focusing on the target group, abstracts, articles describing outcomes of COVID-19 infection/COVID-19 vaccination were excluded.

Sources of evidence

The PubMed database was searched to select articles. Search terms used were linked to pregnancy, lactation, vaccination, vaccine hesitancy, COVID-19 and social media.

Charting methods

Included articles were abstracted and synthesised by one reviewer. Verification was done by a second reviewer. Disagreements were addressed through discussion between reviewers and other researchers.

Results

Pregnant and lactating women are generally less likely to accept a COVID-19 vaccine compared with non-pregnant and non-nursing women. The main reason to refuse maternal vaccination is safety concerns. A positive link was detected between COVID-19 vaccine willingness and acceptance of other vaccines during pregnancy. The internet and social media are identified as important information sources for maternal vaccination.

Discussion and conclusion

Vaccine hesitancy in pregnant and lactating women remains an important issue, expressing the need for effective interventions to increase vaccine confidence and coverage. The role social media plays in vaccine uptake remains unclear.
Protocol for Multi-modality MEdical imaging sTudy bAsed on KaiLuan Study (META-KLS): rationale, design and database building
Authors: Sun Jing , Hui Ying , Li Jing , Zhao Xinyu , Chen Qian , Li Xiaoshuai , Wu Ning , Xu Mingze , Liu Wenjuan , Li Rui , Zhao Pengfei , Wu YunTao , Xing Aijun , Shi Huijing , Zhang Shun , Liang Xiaoliang , Wang Yongxin , Lv Han , Wu Shouling , Wang Zhenchang
Published: February 2023

Introduction

Multi-modality medical imaging study, especially brain MRI, greatly facilitates the research on subclinical brain disease. However, there is still a lack of such studies with a wider age span of participants. The Multi-modality MEdical imaging sTudy bAsed on KaiLuan Study (META-KLS) was designed to address this issue with a large sample size population.

Methods and analysis

We aim to enrol at least 1000 subjects in META-KLS. All the participants without contraindications will perform multi-modality medical imaging, including brain MRI, retinal fundus photograph, fundus optical coherence tomography (OCT) and ultrasonography of the internal carotid artery (ICA) every 2–4 years. The acquired medical imaging will be further processed with a standardised and validated workflow. The clinical data at baseline and follow-up will be collected from the KaiLuan Study. The associations between multiple risk factors and subclinical brain disease are able to be fully investigated. Researches based on META-KLS will provide a series of state-of-the-art evidence for the prevention of neurological diseases and common chronic diseases.

Ethics and dissemination

The Kailuan Study and META-KLS have been approved by the Medical Ethics Committee of Kailuan General Hospital (IRB number: 2008 No. 1 and 2021002, respectively). Written informed consent will be acquired from each participant. Results are expected to be published in professional peer-reviewed journals beginning in 2023.

Trial registration number

NCT05453877.
Healthcare waste management practice and its predictors among health workers in private health facilities in Ilu Aba Bor Zone, Oromia region, South West Ethiopia: a community-based cross-sectional study
Authors: Tilahun Degemegn , Donacho Dereje Oljira , Zewdie Asrat , Kera Abeza Mitiku , Haile Degefa Gutama
Published: February 2023

Objectives

A lack of safe healthcare waste management (HCWM) practice poses a risk to healthcare staff, patients and communities. In low-income countries like Ethiopia, studies on the level of safe HCWM practices in private healthcare facilities are limited. This study was designed to assess the level of good HCWM practice and associated factors among health workers in private health facilities.

Methods

An institution-based cross-sectional study was conducted in the Ilu Aba Bor zone, South West Ethiopia. A random sample of 282 health workers from 143 private health facilities was included in the study. Data were collected using a pretested structured questionnaire that included sociodemographic characteristics, healthcare factors, knowledge assessment and an observation checklist adapted from WHO guidelines. The collected data were entered into EpiData V.3.1 and analysed with SPSS V.25.0. Multivariable logistic regression analysis was used to identify factors associated with HCWM practice. Variables with a p value of <0.05 at 95% CI were declared significant.

Results

More than half (58.7%) of private-sector health workers had good HCWM practice. The presence of the HCWM committee (adjusted OR (AOR)=9.6, 95% CI 4.5 to 20.6), designated healthcare waste storage site (AOR=3.0, 95% CI 1.5 to 6.5), reading the HCWM manual (AOR=4.4, 95% CI 2.2 to 9.0) and having good knowledge of HCWM (AOR=2.6, 95% CI 1.06 to 6.15) were factors associated with good HCWM practice.

Conclusion

About three out of five health workers in private healthcare facilities were practising good HCWM. The presence of an HCWM committee, waste management utilities, reading HCWM guidelines and knowledge of health workers were the identified factors. Health workers should read guidelines to improve their knowledge, and the presence of committees and waste management utilities in private clinics should be followed to ensure compliance with safe HCWM practice.
Subcutaneous fast-acting insulin analogues, alone or in combination with long-acting insulin, versus intravenous regular insulin infusion in patients with diabetic ketoacidosis: protocol for an updated systematic review and meta-analysis of randomised trials
Authors: Lim Beng Leong , Lee Wei Feng , Lee Berlin , Chung Yan Ee Lynette , Loo Kee Vooi
Published: February 2023

Introduction

Diabetic ketoacidosis (DKA) is traditionally managed using intravenous regular insulin infusion (RII) in intensive care unit (ICU)/high dependency unit (HDU). Subcutaneous fast-acting insulin analogues (FAIAs) may help to manage DKA outside ICU/HDU. Furthermore, combining subcutaneous long-acting insulin (LAI) with subcutaneous FAIAs may accelerate ketoacidosis resolution. The latest (2016) Cochrane review was inconclusive regarding subcutaneous FAIAs versus intravenous RII in DKA. It was limited by small sample sizes, unclear risk of bias (RoB) in primary trials and did not examine subcutaneous FAIAs with subcutaneous LAI versus intravenous RII in DKA. We report the protocol for an updated meta-analysis on the safety and benefits of subcutaneous FAIAs with/without subcutaneous LAI versus intravenous RII in DKA.

Methods and analysis

We will search Medline, Embase, CINAHL and Cochrane Library, from inception until December 2022, without language restrictions, for randomised trials on subcutaneous FAIAs with/without subcutaneous LAI versus intravenous RII in DKA. We also search ClinicalTrials.gov, ClinicalTrialsRegister.eu and reference lists of included trials. Primary outcomes include all-cause in-hospital mortality, time to DKA resolution, in-hospital DKA recurrence and hospital readmission for DKA post-discharge. Secondary outcomes include resource utilisation and patient satisfaction. Safety outcomes include important complications of DKA and insulin. Reviewers will extract data, assess overall RoB and quality of evidence using Grading of Recommendations, Assessment, Development and Evaluation. We will assess statistical heterogeneity by visually inspecting forest plots and the I2statistic. We will synthesise data using the random-effects model. Predefined subgroup analyses are: mild versus moderate versus severe DKA; age <20 vs ≥20 years; pregnant versus non-pregnant; infective versus non-infective DKA precipitating cause; subcutaneous FAIAs alone versus subcutaneous FAIAs and subcutaneous LAI; and high versus low overall RoB. We will also perform trial sequential analysis for primary outcomes.

Ethics and dissemination

Ethics board approval is not required. Results will be disseminated through publication in a peer-reviewed journal.

PROSPERO registration number

CRD42022369518.
Hybridised production of technetium-99m and technetium-101 with fluorine-18 on a low-energy biomedical cyclotron
Authors: Johnstone Erik V. , Mayordomo Natalia , Mausolf Edward J.
Published: February 2023

New modes of production and supply of short-lived radioisotopes using accelerators are becoming attractive alternatives to the use of nuclear reactors. In this study, the use of a compact accelerator neutron source (CANS) was implemented to explore the production of 99mTc and 101Tc. Irradiations were performed with neutrons generated from a 16.5 MeV cyclotron utilising the 18O(p, n)18F reaction during routine 18F-fluorodeoxyglucose (FDG) production in a commercial radiopharmacy. Natural molybdenum targets in metal form were employed for the production of several Tc isotopes interest via (n, γ) reactions on 98Mo and 100Mo. The production of 99mTc and 101Tc under these conditions is considered and discussed.
Magneto-Aero-Elastic Superharmonic and Subharmonic Resonances, Bifurcations and Chaos of Conductive Spinning Circular Plates
Authors: Li Wenqiang , Hu Yuda , Li Zhe
Published: February 2023

This paper focuses on the magneto-aero-elastic nonlinear resonances, bifurcations and chaos for superharmonic and subharmonic responses of conductive circular plates spinning in air and magnetic fields. The electromagnetic forces acting on in-plane are presented by using electromagnetic field theory, and a rotational dissipative damping aerodynamic model is employed to characterize the aerodynamic forces acting on the plates. Considering the effects of the geometric nonlinearity and centrifugal tensioning, the magneto-aero-elastic governing equations of spinning conductive circular plates are derived by the Hamiltonian principle. Based on the mode shapes with Bessel functions, the transverse nonlinear vibration differential equations of spinning plates with clamped-edge are derived by the Galerkin method. Amplitude-frequency equations for subharmonic and superharmonic responses are obtained by using the approach of multiple scales, respectively. Numerical calculations indicate the influences of important parameters (e.g. magnetic field intensity, excitation amplitude and rotational speed) on amplitude frequency characteristics. Moreover, it is demonstrated by the numerical results that system responses are sensitive to the variation of these important parameters, where the complex intermittency, period-doubling and chaotic dynamical behaviors exist.
Dynamical Analysis of Hybrid-Scale Bifurcation in One-Cycle Controlled Single-Inductor Dual-Output Buck DC–DC Converters
Authors: Liu Wei , Zhang Hao , Zhang Xinfeng , Liu Wei
Published: February 2023

In this paper, the hybrid-scale bifurcation evolutionary phenomena in one-cycle controlled (OCC) single-inductor dual-output (SIDO) Buck DC–DC converter are investigated thoroughly. First, the single-cycle and crossing-cycle iterative mapping models of the OCC SIDO converter in four operation modes are derived to describe the dynamical information under different topology switching sequences. Second, the evolutionary trend of hybrid-scale bifurcation behaviors is identified by numerical simulation. Third, bifurcation analysis based on the proposed models is performed by the trajectories of the eigenvalues, and significantly, the occurrence mechanism of hybrid-scale bifurcations in the evolutionary phenomena is explained in detail. And then, the participation factor is used to analyze the relationship between the variables and the eigenvalues. Especially, the relative parameter sensitivity of the iterative mapping model is proposed to evaluate the influence of such key parameters as load resistors on the eigenvalues so that plenty of design-oriented information will be provided to avoid the hybrid-scale bifurcation behaviors. Finally, PSpice circuit simulation and hardware experiments are carried out to verify the analysis results.
Exact Solution of Four-Coupled Nonidentical Kuramoto Oscillators at a Full Phase Locked State
Authors: Mahmoud M. S. , Medhat M. , Cerdeira Hilda A. , El-Nashar Hassan F.
Published: February 2023

We consider a Kuramoto model of four-coupled oscillators of nonidentical initial frequencies. Under the influence of coupling, the oscillators fall into a full phase locked state of a common frequency when the coupling strength surpasses a threshold value. We find numerically the parameters that control this distinguishable coupling constant at the moment the oscillators transit into an entire frequency synchronization when a complete phase lock state takes place. We are able to set apart a recognizable phase condition at the fully locked state. This phase condition helps to derive an analytic formula to calculate the coupling factor as soon as the oscillators depart to a full phase locking state. The explicit expression of the edge coupling factor is given in terms of the initial frequencies of the four oscillators. The formula valid for calculating the distinct coupling allows to find mathematical expressions to calculate the phase differences when the four-coupled phase oscillators are strictly at the full phase locked state and have a common frequency synchronization.
Fully Dynamic No-Back-Edge-Traversal Forest via 2D-Range Queries
Authors: Lee Kuo-Kai , Hon Wing-Kai , Liao Chung-Shou , Sadakane Kunihiko , Tsai Meng-Tsung
Published: February 2023

Orthogonal range search is ubiquitous nowadays, with natural applications in databases, data mining, and text indexing. Very recently, yet another application was discovered, which is to maintain a DFS forest in a dynamic graph. In this paper, we want to extend the above recent study, by applying orthogonal range search to efficient maintenance of a BFS-like forest, called no-back-edge-traversal (NBET) forest, which refers to a spanning forest obtained from a traversal that does not create any back edge. The study of such a problem is motivated by the fact that NBET forest can be used as a strong certificate of 2-connectivity of an undirected graph, which is more general than a spanning forest obtained from a scan-first search traversal.
BISTABILITY AND TRISTABILITY IN A PREDATOR–PREY MODEL WITH STRONG ALLEE EFFECT IN PREY
Authors: KUMBHAKAR RUMA , PAL SAHEB , PAL NIKHIL , TIWARI PANKAJ KUMAR
Published: February 2023

Understanding the Allee effect on endangered species is crucial for ecological conservation and management as it highly affects the extinction of a population. Due to several ecological mechanisms accounting for the Allee effect, it is necessary to study the dynamics of a predator–prey model incorporating this phenomenon. In 1999, Cosner et al. [Effects of spatial grouping on the functional response of predators, Theor Popul Biol 56:65–75, 1999] derived a new kind of functional response by considering spatially grouped predators. This paper deals with the dynamical behavior of a predator–prey system with functional response proposed by Cosner et al., and the growth of the prey population suffers a strong Allee effect. We find that the system undergoes various types of bifurcations such as Hopf bifurcation, saddle-node bifurcation, and Bogdanov–Takens bifurcation. We also observe that the model exhibits bistability and two different types of tristability phenomena. Our findings reveal that for such a kind of multistability in ecological systems, the initial population size plays a crucial role and also impacts the system’s state in the long term.
Dynamic Analysis of Mindlin Plate Subjected to a Moving Mass-Spring-Damper System Using the Moving Element Method
Authors: Tran Minh Thi , Truong Trong Can , Do Ngoc Thuan , Luong Van Hai
Published: February 2023

The moving element method (MEM) is applied in this paper to study the dynamic behavior of the Mindlin plate subjected to a moving mass-spring-damper system. Reissner- Mindlin plate theory is utilized to study the plate structure. The plate is modeled by the Isoparametric quadrilateral nine-node element. The governing equation of motion is built into a coordinate system which moves with the moving mass-spring-damper system and is based on the principle of virtual work. The MEM is proposed to solve the governing equation of motion of the plate resting on a Pasternak foundation under the moving mass-spring-damper system including roughness of plate surface which is a dynamic source. Numerical results are investigated and verified by comparing with the published results. The effects of different parameters, such as spring stiffness, damping coefficient and velocity of the moving load system, plate thickness, foundation parameters and roughness of the plate surface on the dynamic response of the Mindlin plate are investigated.
Sublattice Magnetizations of Ultrathin Ferrimagnetic Lamellar Nanostructures between Cobalt Leads
Authors: Ashokan Vinod , Khater A. , Ghantous M. Abou
Published: February 2023

In this work, we model the salient magnetic properties of the alloy lamellar ferrimagnetic nanostructures [Formula: see text] between [Formula: see text] semiinfinite leads. We have employed the Ising spin effective field theory (EFT) to compute the reliable magnetic exchange constants for the pure cobalt [Formula: see text] and gadolinium [Formula: see text] materials in complete agreement with their experimental data. The sublattice magnetizations of the [Formula: see text] and [Formula: see text] sites on the individual hcp atomic (0001) planes of the Co–Gd layered nanostructures are computed for each plane and corresponding sites by using the combined EFT and mean field theory (MFT) spin methods. The sublattice magnetizations, effective site magnetic moments, and ferrimagnetic compensation characteristics for the individual hcp atomic planes of the embedded nanostructures, are computed as a function of temperature, and for various stable eutectic concentrations in the range [Formula: see text]. The theoretical results for the sublattice magnetizations and the local magnetic variables of these ultrathin ferrimagnetic lamellar nanostructured systems, between cobalt leads, are necessary for the study of their magnonic transport properties, and eventually their spintronic dynamic computations. The method developed in this work is general and can be applied to comparable magnetic systems nanostructured with other materials.
The Impact of Artificial Intelligence (AI) on the Low-Carbon Economy: A Prospective Study on the Long-Term Rental Housing Market in Guangxi, China
Authors: LI Dandan , AZMAN Nik Hadiyan Nik
Published: February 2023

In recent years, the tourism economy of Guangxi Zhuang Autonomous Region (hereinafter referred to as “Guangxi”), China, has been caught in the contradiction between infrastructure construction and natural environmental protection. By combing Guangxi’s tourism economy with its development path of smart long-term rental housing, this paper finds that the long-term rental market in Guangxi based on artificial intelligence (AI) technology can solve the development contradiction through accurate construction planning to improve efficiency. The long-term rental housing market in Guangxi has entered a low-carbon economy period since pilot programs were launched for the policy of managing public rental housing with AI and information technologies. From the perspective of AI, facts have proved that AI has the ability to re-adjust the competition order of an industry, which not only realizes the low-carbon development of the rental market, but also promotes the industrial upgrading of the tourist industry.
A Survey on Automated Driving System Testing: Landscapes and Trends
Authors: Tang Shuncheng , Zhang Zhenya , Zhang Yi , Zhou Jixiang , Guo Yan , Liu Shuang , Guo Shengjian , Li Yan-Fu , Ma Lei , Xue Yinxing , Liu Yang
Published: February 2023

Automated Driving Systems
(
ADS
) have made great achievements in recent years thanks to the efforts from both academia and industry. A typical ADS is composed of multiple modules, including sensing, perception, planning, and control, which brings together the latest advances in different domains. Despite these achievements, safety assurance of ADS is of great significance, since unsafe behavior of ADS can bring catastrophic consequences. Testing has been recognized as an important system validation approach that aims to expose unsafe system behavior; however, in the context of ADS, it is extremely challenging to devise effective testing techniques, due to the high complexity and multidisciplinarity of the systems. There has been great much literature that focuses on the testing of ADS, and a number of surveys have also emerged to summarize the technical advances. Most of the surveys focus on the system-level testing performed within software simulators, and they thereby ignore the distinct features of different modules. In this article, we provide a comprehensive survey on the existing ADS testing literature, which takes into account both module-level and system-level testing. Specifically, we make the following contributions: (1) We survey the module-level testing techniques for ADS and highlight the technical differences affected by the features of different modules; (2) we also survey the system-level testing techniques, with focuses on the empirical studies that summarize the issues occurring in system development or deployment, the problems due to the collaborations between different modules, and the gap between ADS testing in simulators and the real world; and (3) we identify the challenges and opportunities in ADS testing, which pave the path to the future research in this field.
A Review on Tools, Mechanics, Benefits, and Challenges of Gamified Software Testing
Authors: Fulcini Tommaso , Coppola Riccardo , Ardito Luca , Torchiano Marco
Published: February 2023

Gamification is an established practice in Software Engineering to increase effectiveness and engagement in many practices. This manuscript provides a characterization of the application of gamification to the Software Testing area. Such practice in fact reportedly suffers from low engagement by both personnel in industrial contexts and learners in educational contexts. Our goal is to identify the application areas and utilized gamified techniques and mechanics, the provided benefits and drawbacks, as well as the open challenges in the field. To this purpose, we conducted a Multivocal Literature Review to identify white and grey literature sources addressing gamified software testing.

We analyzed 73 contributions and summarized the most common gamified mechanics, concepts, tools, and domains where they are mostly applied. We conclude that gamification in software testing is mostly applied to the test creation phase with simple white-box unit or mutation testing tools and is mostly used to foster good behaviors by promoting the testers’ accomplishment. Key research areas and main challenges in the field are: careful design of tailored gamified mechanics for specific testing techniques; the need for technological improvements to enable crowdsourcing, cooperation, and concurrency; the necessity for empirical and large-scale evaluation of the benefits delivered by gamification mechanics.
Parallel Peeling of Bipartite Networks for Hierarchical Dense Subgraph Discovery
Authors: Lakhotia Kartik , Kannan Rajgopal , Prasanna Viktor
Published: February 2023

Wing
and
Tip
decomposition are motif-based analytics for bipartite graphs that construct a hierarchy of butterfly (2,2-biclique) dense edge and vertex induced subgraphs, respectively. They have applications in several domains, including e-commerce, recommendation systems, document analysis, and others.

Existing decomposition algorithms use a bottom-up approach that constructs the hierarchy in an increasing order of the subgraph density. They iteratively select the edges or vertices with minimum butterfly count
peel
, i.e., remove them along with their butterflies. The amount of butterflies in real-world bipartite graphs makes bottom-up peeling computationally demanding. Furthermore, the strict order of peeling entities results in a large number of sequentially dependent iterations. Consequently, parallel algorithms based on bottom up peeling incur heavy synchronization and poor scalability.

In this article, we propose a novel Parallel Bipartite Network peelinG (PBNG) framework that adopts a two-phased peeling approach to relax the order of peeling, and in turn, dramatically reduce synchronization. The first phase divides the decomposition hierarchy into few partitions and requires little synchronization. The second phase concurrently processes all partitions to generate individual levels of the hierarchy and requires no global synchronization. The two-phased peeling further enables batching optimizations that dramatically improve the computational efficiency of PBNG.

We empirically evaluate PBNG using several real-world bipartite graphs and demonstrate radical improvements over the existing approaches. On a shared-memory 36 core server, PBNG achieves up to 19.7× self-relative parallel speedup. Compared to the state-of-the-art parallel framework P
ar
B
utterfly
, PBNG reduces synchronization by up to 15,260× and execution time by up to 295×. Furthermore, it achieves up to 38.5× speedup over state-of-the-art algorithms specifically tuned for wing decomposition. Our source code is made available at
https://github.com/kartiklakhotia/RECEIPT
.
Synthesis of Cs+-Tuned (PEA)2PbI4 Perovskite Thin Films by One-Step Spin Coating
Authors: Ren Enliang , Zhang Canyun , Wang Fengchao , Kong Jinfang , Li Lan , Chen Jin , Xu Jiayue , zhang Yan
Published: February 2023

As a candidate material for the next generation photovoltaic and light-emitting devices, organic-inorganic hybrid perovskite materials have attracted extensive attention. In this study, a (PEA)2PbI4 hybrid perovskite film was prepared by a one-step spin-coating method at room temperature. Based on the synthesis of (PEA)2PbI4, the inorganic Cs+ ions were doped in the film to investigate the influence of Cs+ doping on the structure and properties of two-dimensional (2D) perovskite film. The results show that both as-grown (PEA)2PbI4 film and Cs+-doped (PEA)2PbI4 film exhibit the instinct of the layered structure, though excess Cs+ ions doping would make the structure weakened. Through analyzing the optical properties, it is found that, besides the 2D (PEA)2PbI4 phase, a quasi-2D structure with two layers of [PbI6]4−-octahedron forms in Cs+-doped (PEA)2PbI4 perovskite films, which is ascribed to the phase rearrangement of the (PEA)2PbI4 crystal structure under the induction of Cs+ ions.
Establishing consensus for the core concepts of physiology in the Australian higher education context using the Delphi method
Authors: Tangalakis Kathy , Lexis Louise , Hryciw Deanne H. , Towstoless Michelle , Bakker Anthony J. , Beckett Elizabeth , Brown Daniel , Cameron Melissa , Choate Julia , Chopin Lisa , Cooke Matthew B. , Douglas Tracy , Estaphan Suzanne , Etherington Sarah , Gaganis Voula , Moorhouse Andrew , Moro Christian , Paravicini Tamara , Perry Ben , Phillips Ruben , Scott Christopher , Todd Gabrielle , Uebergang Tanya , Wadley Glenn , Watt Matthew , Hayes Alan
Published: February 2023

This is the first time Australia-wide agreement has been reached on the core concepts of physiology with the Delphi method. Embedding of the core concepts will result in consistency in physiology curricula, improvements to teaching and learning, and benchmarking across Australian universities.
LecturePlus: a learner-centered teaching method to promote deep learning
Authors: Hashim Muhammad Jawad , Govender Romona , Ghenimi Nadirah , Kieu Alexander , Khan Moien A. B.
Published: February 2023

We developed a new structured teaching format, the LecturePlus, to promote deep learning. A LecturePlus session consists of a brief lecture, followed by small-group problem-solving exercises, ending with a closing discussion moderated by the teacher. During the small-group exercises, students were divided into groups of three (triads) and given case-based problems. One faculty tutor supervised the entire session. LecturePlus resulted in improved learning outcomes and was rated highly by medical students.
Increased adiposity is associated with altered skeletal muscle energetics
Authors: Reiter David A. , Bellissimo Moriah P. , Zhou Lei , Boebinger Scott , Wells Greg D. , Jones Dean P. , Ziegler Thomas R. , Alvarez Jessica A. , Fleischer Candace C.
Published: February 2023

Skeletal muscle energy production is influenced by both lean body mass and adipose tissue but the effect of their distribution on energy metabolism is unclear. This study examined variations in quadriceps muscle energy metabolism in healthy adults with varied relative amounts of lean and adipose tissue. Results suggest increased adiposity is associated with reduced muscle energetic efficiency with more reliance on glycolysis, and when accompanied with reduced lean mass, is associated with reduced maximum oxidative capacity.
Force potentiation during eccentric contractions in rat skeletal muscle
Authors: Andersen Ole Emil , Kristensen Anders M. , Nielsen Ole B. , Overgaard Kristian
Published: February 2023

Force during eccentric contractions can increase to a magnitude that may have profound consequences for our understanding of skeletal muscle locomotion. This increase in eccentric force occurs over consecutive, shortly interspaced, tetanic contractions in rat extensor digitorum longus muscles—not in rat soleus muscles—and coincides with well-known traits of postactivation potentiation. Eccentric force potentiation may significantly enhance muscle performance in activities involving stretch-shortening cycles.