bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostics of the structural risk level in the sphere of waste management at Ukrainian railways
Authors: Dvulit Zoriana , Melnyk Olga , Chyrkova Yuliia , Petryshyn Nataliia , Bortnikova Maryana
Published: October 2019

The article focuses on the problem of the structural risk level diagnostics in the sphere of waste management at the railway transport objects. The specifics of the railway enterprises activity are the multi-vector business processes executed, which determines a significant nomenclature and volumes of formation, accumulation of wastes of different danger classes. A retrospective analysis of this problem on Ukrainian railways for 2007 – 2018 showed significant structural fluctuations both in terms of volume formation and in the costs and ecological payments for environmental protection in sphere of waste management. The method of sensitivity analysis, the peculiarity of which is to calculate the elasticity coefficients for determining the degree of environmental costs interaction in the field of waste management with the change of their components (capital investment, current costs, environmental tax and environmental services), is implemented. The corresponding elasticities for 2008 – 2018 showed a considerable variation of the most significant risk factors that were atypical for JSC “Ukrzaliznytsia” and 6 railways. The existing structure needs to be better diagnosed with a purpose of ensuring stability and predictability of environmental costs in order to reduce structural risk, rational environmental management and to ensure the ecology of rolling stock and objects of railway transport infrastructure.
Concept of the railway safety, security and cybersecurity functional integrity levels
Authors: Pawlik Marek
Published: October 2019

Observed growing changes in the character and severity of the risks in rail traffic safety and rail transport security are associated with present development of utilized technical solutions. New hazards are coming out, besides known ones, including hazards associated with cyber-crime. As a result it is fully justified to undertake works dedicated to collect and settle all risks associated with technical solutions using modern technologies for acquisition, computing and transfer of the data, which are vital from the rail traffic safety and rail transport security point of view. Article defines rail transport systems safety, security and cybersecurity functional integrity levels thanks to knock-out and differentiating questions regarding identified key safety related functionalities. Proposed methodology was used for safety and security verification of a chosen homogenous rail transport system separated from the overall Polish railway system. Results have shown discrepancies in utilized protection measures. Proposed methodology can be used for assessment of existing systems as well as for specifying scopes of investments both for infrastructure and rolling stock modernizations. Applicability range covers railway transport, light rail services, metro, urban rail transport systems as well as rail based transport systems using autonomous vehicles.
Development of an algorithm for investigation of technical state of wagons’ running gears during their derailment
Authors: Batig Andriy , Hrytsyshyn Petro , Kuzyshyn Andriy , Milyanych Andriy , Voznyak Oleh , Tereshchak Yuriy
Published: October 2019

A freight wagon is a collection of a large number of parts and assemblies that form a single structure. During wagon operation, there are gradual changes in the characteristics and parameters of its structural elements. That is, the parameters of its constituent elements change – their numerical values increase or decrease that result in a change of the unit’s technical state, and, in turn, affects the totality of its performance. Gradually accumulating, the changes in the parameters of the structural elements of a wagon reach such a level that radical, sometimes abrupt qualitative change occurs. A malfunction that has not been repaired timely may lead to a failure of a wagon structural element, which, in turn, may result in rolling stock derailment. It has been established that the loss of stability of freight wagons during their movement is most often due to their unsatisfactory dynamic properties, which can be explained by design features and technical state of running gears. In this regard, the authors of the article have developed an algorithm for investigation technical state of running gears of freight wagons and determined the effect of their parameters’ deviation on rolling stock operation with possible further derailment.
Mathematical modelling of the communication channel between the rail circuit and the inputs devices of automatic locomotive signalization
Authors: Hololobova Oksana , Buriak Serhii , Havryliuk Volodymyr , Skovron Ihor , Nazarov Oleksii
Published: October 2019

In modern practice of operating under traffic safety conditions, the traffic light signal must be transmitted to the locomotive that moves to it, and duplicate in the driver’s cab. However, this communication channel is not protected from external interference. In order to prevent the occurrence of code failure, it is necessary to create conditions under which the automatic locomotive signalling system will distinguish between signals with useful information, from signals with false information. The best way to solve this problem at the first stage is to model the devices. Using the simulation tools of graphical environment of simulation modelling Simulink from Matlab software environment, the software model of the communication channel between the railroad and the input devices of automatic locomotive signalling system was constructed. The created mathematical model with the actual parameters allows us to obtain diagnostic signs of a proper condition, on the basis of which the research is aimed at the identification, recognition and definition of various types of malfunctions, failure, damages and defects in the work of the constituent elements of the system and the signal transmission channel of the automatic locomotive signalling system.
The intensity of rail failure flow
Authors: Patlasov Oleksandr , Fedorenko Yelyzaveta
Published: October 2019

The article reveals the quantitative changes in the intensity of failure accumulations in areas with gradual introduction of high axial loads. To obtain the actual values, the authors received three-dimensional array of intensity of rail failure flow. According to the results of the research, it was discovered that the main cause of failure of the rails are the defects in the main contact-fatigue origin. The main factor that impacts the intensity of the rail failure flow is the number of transmitted tonnage. The size of the axial load and curvature of the line pours weight on this process. The proposed rail failure model is a model that can be used to optimize the track maintenance system. The authors conducted a study on the identification of quantitative changes in the intensity of accumulation of track failures in areas with high axial loads and evaluated their influence on the planning of repair and road works. On the basis of the obtained results it is possible to estimate the effect of the axial load on the intensity of changes in the state of the flow rail failure flows.
Algorithm of rescue units logistic support planning in the process of regional life safety systems development
Authors: Prydatko Oleksandr , Popovych Vasyl , Malets Igor , Prydatko Valentyn , Solotvinskyi Ivan
Published: October 2019

The problem of resource support planning in the process of reforming and developing rescue units of regional life safety systems is highlighted in this research. The absence of methods that allow optimizing the required amount of rescue equipment of the region in accordance with the optimal safety criterion is emphasized. Formulated the task of optimizing the safety criterion with the parameter of the number of rescue equipment and limitation in the form of logistical support capability. According to the results of previous studies, the algorithm and its software were developed for implementation in relation to planning of logistic support of rescue units (in the context of providing rescue equipment), which allows to determine the index of the optimal number of rescue units. The developed algorithm was tested on the example of administrative-territorial units of Lviv region, which showed its effectiveness.
Designing of transshipment terminals in the aspect of selected intermodal transport systems
Authors: Pyza Dariusz , Jachimowski Roland
Published: October 2019

The article deals with the problem of intermodal terminal designing for selected intermodal transport systems, determined by the type of intermodal transport unit. The purpose of the article is to present a comprehensive methodology for designing intermodal terminals, enabling the assessment of developed design solutions. Specificity of intermodal terminals due to the tasks carried out and their role in the integration of various modes of transport in freight transport was presented. In the following, the general principles and methodology of intermodal terminal design were characterized. Based on that, the conceptual project of the terminal was presented as a case study.
Innovative concept of loading bimodal trailers with the organization of a loading terminal
Authors: Strzemkowski Jan , Merkisz – Guranowska Agnieszka , Andrzejewski Maciej , Stawecka Hanna , Kamińska Michalina , Far Mariusz
Published: October 2019

The article presents an innovative concept of horizontal transverse loading of bimodal semitrailers by means of a transshipment terminal equipped with special the transshipment stands. An innovative switching station and a working principle improving the loading of bimodal trailers were described. The concept of the transshipment terminal equipped with several loading stands for bimodal semi-trailers is also presented. Various variants of organization of the terminal with horizontal transverse loading of bimodal semi-trailers are indicated. A preliminary computer simulation was carried out and the results are compared with the existing Polish system Tabor 1 and Tabor 2.
Multi-criteria method of selection the way of conducting railway traffic on the open line for modernized and revitalized railway lines
Authors: Gołębiowski Piotr , Jacyna Marianna , Żak Jolanta
Published: October 2019

Nowadays, thanks to funds coming from various sources -including the European Union, intensive modernization and revitalization works regarding railway transport infrastructure are carried out. These works include both the railway surface and the change in the way of conducting railway traffic on both open lines and operating control posts. During modernization and revitalization, efforts are being made to introduce more and more new solutions in both mentioned areas. However, there is no multi-criteria method that would allow to assess which method seems to be the most advantageous. The aim of this article is to present a multicriteria method of choosing the method of conducting railway traffic on the open line for modernized and revitalized railway lines. It should be noted that the basic group of criteria in the method applies to the organization of railway traffic. The article discusses the basic issues regarding the modernization and revitalization of railway lines, ways of conducting railway traffic on open lines and multi-criteria assessment methods. A multicriteria method for selecting the method of conducting trains was presented and it was verified for a selected railway line in Poland.
Selected aspects of proper integration between ERTMS/ETCS on-board and trackside devices.
Authors: Adamski Dominik , Białoń Andrzej , Łukasz Zwadka
Published: October 2019

Achieving the interoperability of the European rail system requires many measures to unify technical solutions as well as regulations in each Member State. However, there is a possibility of some incompatibilities between individual subsystems despite generating them in accordance with unified applicable requirements. It is possible that the interoperable rolling stock will not be able to move freely over the interoperable railway line due to some incompatibilities and differences in the versions of the installed firmware in the ERTMS/ETCS system devices. In connection with the above the correct integration of rail vehicles with track-side equipment should be examined by means of tests under operating conditions. The article presents compliance tests of the correct integration of the on-board subsystem with the track-side subsystem which are carried out by the Railway Research Institute.
The effect of ozone on wet atmospheric corrosion of aluminium of high-voltage lines
Authors: Tatarchenko Galina , Beloshitskaya Nataliia , Sychenko Viktor , Liashuk Vitalii
Published: October 2019

One of the factors influencing traffic safety is the uninterrupted power supply of interlocking devices. As a rule transmission of electric energy is carried out using aluminum wires. In order to assess the reliability of power lines in the work, research was carried out on the influence of ozone on corrosion of aluminum in a humid atmosphere and acidic medium. It was found that the presence of oxygen dissolved in acetic acid leads to anode currents increase, while at crossover ozone, cathode currents increase by an order of magnitude and 2-3 times the anode decreases; the corrosion potential of an Ecor shifts to the positive side at 0.15V. The decrease in the density of anode currents in the presence of ozone proceeds due to the growth of the thickness of the aluminum oxide film. According to the Auger-spectra, the film is increased by 3-4 times compared with the nonzonized medium, due to which the corrosion resistance of aluminum Кm increases from 0.066 to 0.025 g/(m2·h). The rate of formation of oxides depends on the concentration of oxidants in the solution, and on their oxidative activity. According to calculations of thermodynamic factors that determine the preferred route of oxidation, the probability of formation of oxides in the presence of ozone is significantly higher. Local destruction of the protective layer occurs mainly in defective places and places of local increase in pH of the electrode layer. Investigation of the cyclic polarization of a sample of aluminum, pre-cathode activated by a current of 1 mA/cm2 density, showed the presence of hysteresis, which decreases in the next 2-3 cycles. In this case, the exterior of the aluminum shifts to (0.10 ÷ 0.15) V is more positive and the corrosion rate is reduced, which indicates the formation of an oxide film in which irreversible changes occur. The change in the inclination of the polarization curves indicates that the cathodic reaction is delayed and is associated with the change in the structure of the surface layer of the electrode and the diffusion restrictions of ozone recovery.
Estimation of Private Locomotives Usage Efficiency for Freight Transportation in Ukraine
Authors: Kozachenko Dmytro , Gera Bogdan , Sannytskyy Nazar , Hermaniuk Yuliia , Shargun Tetyana
Published: October 2019

Ukraine has undertaken the implementation of European Union Directives, which provide non-discriminatory admission to the railway infrastructure of independent carriers. A significant number of factors considerably affect working conditions of the carriers which are independent of Ukrzaliznytsia. One of the goals while performing transportation by independent carriers is the organization of private locomotives operation and their service by engine crews. The purpose of the article is to assess technical and economic indices of private locomotives use for goods transportation. The schemes of infrastructure objects arrangement for locomotives operation and engine crews work are presented. Performed calculations show the potential possibility of independent railway carriers to fulfil transportation to seaports with the use of its private locomotive infrastructure exclusively. The estimation of economically expedient volumes of cargo transportation by private locomotives in comparison with existing pricing of Ukrzaliznytsia is carried out. The nonlinear dependence of transportation volume depending on the distance is determined, at which the total cost of cargo transportation by Ukrzaliznytsia locomotives is equal to the cost of cargo transportation by private locomotives. The results of the study allow concerned companies to evaluate the investment efficiency into the development of locomotive fleet for rail transportation.
Improvement of the technique of calculating operational parameters using an automated system
Authors: Statyvka Yurii , Kyrychenko Hanna , Strelko Oleh , Berdnychenko Yuliia , Gaba Vasyl , Hrushevska Tetiana
Published: October 2019

Impact of the existing operating conditions on terms of cargo delivery and compliance with the rolling stock circulation norms is studied. Planned and actual rolling stock circulation characteristics are analyzed. Deviations from the norms have been detected, which is indicative of non-compliance with technological processes. Nowadays the rolling stock circulation problem becomes more complex; for the service recipients, i.e. customers of the railway, it means delays in cargo deliveries, non-fulfillment of financial obligations before other participants in the railway transport process. A new approach to the methodology and principle of calculating anticipated key performance characteristics are proposed. The existing information technologies for railway management make it possible to monitor compliance with the rolling stock circulation norms and the terms of cargo deliveries and to further improve methods and techniques of performance parameters. This will enable establishing realistic rolling stock circulation norms and cargo delivery terms, thus ensuring compliance with technological requirements of the railway transport processes in order to provide good customer service.
Die körperdysmorphe Störung in der Plastischen Chirurgie – Eine systematische Übersicht der Screening-Methoden
Authors: Houschyar K. S. , Philipps H. M. , Duscher D. , Rein S. , Weissenberg K. , Nietzschmann I. , Maan Z. N. , Pyles M.N. , Siemers F.
Published: October 2019

Hintergrund Die körperdysmorphe Störung, englisch „body dysmorphic disorder“ (BDD), gilt als Unterform der somatoformen Störungen. BDD kann sich in wahnhaftem Erleben, einer übermäßigen Bewertung und Beschäftigung des äußeren Erscheinungsbildes, insbesondere dem Gesicht äußern. Vorläufige Ergebnisse legen nahe, dass Personen mit BDD nicht von plastisch-chirurgischen Behandlungen profitieren, so dass durch ästhetische operative Eingriffe häufig sogar eine Aggravation ihrer Symptome resultiert. Somit ist die Identifikation von Anzeichen für ein BDD entscheidend, ob ein Patient plastisch- ästhetisch operiert werden sollte. Diese Übersichtsarbeit erläutert die oft schwierige Diagnostik der BDD, indem sie die aktuelle Literatur zu dessen Screening zusammenfasst.

Studiendesign Systematische Übersichtsarbeit

Methoden Es wurde eine elektronische Suche in der deutschund englischsprachigen Literatur durchgeführt, um alle Screening-Instrumente für die BDD zu identifizieren. Es werden die spezifischen Entwicklungs- und Validierungsprozesse beurteilt, ob die Screening-Instrumente einen positiven prädiktiven Wert für die BDD haben.

Ergebnisse Sechs verschiedene Screening-Instrumente wurden für die BDD identifiziert. Davon wurden nur zwei in einem kosmetischen Rahmen evaluiert: der „Body Dysmorphic Disorder Questionnaire–Dermatology Version“ (BDDQ-DV) und der „Dysmorphic Concern Questionnaire“ (DCQ). Der Einfluss auf die subjektiven Ergebnisse nach einem plastisch-ästhetischen Eingriff wurde nur für den DCQ gemessen.

Schlussfolgerung Die begrenzte Verfügbarkeit von validierten Screening-Instrumenten für die BDD in der plastischen Chirurgie steht in bemerkenswerten Gegensatz zu der vermeintlich hohen Prävalenz der Erkrankung von 2,4 %. Unter den derzeit verwendeten Screening-Tools scheinen die BDDQ-DV und der DCQ am besten geeignet zu sein. Weitere Forschungsbemühungen zur Etablierung besserer Screeningmethoden für die BDD in der plastischen chirurgischen Patientenpopulation und zur Untersuchung der Auswirkungen von BDD auf Behandlungsergebnisse sind notwendig.
Match Running Performance on Three Different Competitive Standards in Norwegian Soccer
Authors: Sæterbakken Atle , Haug Vebjorn , Fransson Dan , Grendstad Halvard Nikolai , Gundersen Hilde Stokvold , Moe Vegard Fusche , Ylvisaker Einar , Shaw Matthew , Riiser Amund , Andersen Vidar
Published: October 2019

The aim of the study was to compare running performance of three competitive standards and to examine the effects of being promoted to a higher league in Norwegian football. One clubʼs first and second team were included. The first team consisted of professional soccer players playing at Level 2 (2015 season) and Level 1 (2016 season). The second team consisted of amateurs playing at Level 4. A fully automatic tracking system was used to examine running performance, divided into different running-speed categories and playing position. Forty-one matches were included containing 278 observations. Level 1 performed 61 and 51% sprinting compared to Level 2 and Level 4 but similar high-speed running. Similar high-speed running distances were observed only for the different playing positions at Level 1 compared to Level 2 and 4. The sprinting distance was greater for the central defender and attacker, and the number of accelerations was greater for central midfielders and wide midfielders’ playing at Level 1 compared to lower competitive standards. In conclusion, better competitive standards resulted in greater high-intensity actions than lower leagues in Norwegian soccer. Furthermore, only central defenders and attackers increased their high-intensity locomotions when the team was promoted.
A feasibility trial of Acetic acid-targeted Biopsies versus nontargeted quadrantic biopsies during BArrett’s surveillance: the ABBA trial
Authors: Longcroft-Wheaton Gaius , Fogg Carole , Chedgy Fergus , Kandiah Kesavan , Murray Lisa , Dewey Ann , Barr Hugh , Higgins Bernie , Poller David , Jankowski Janusz , DeCaestecker John , Bhandari Pradeep ,   on behalf of the ABBA Study Group
Published: October 2019

Background The aims of this study were to compare neoplasia detection rates for nontargeted biopsies (Seattle protocol) versus acetic acid-targeted biopsies (Portsmouth protocol) during Barrett’s surveillance and to explore feasibility, patient/clinician experience, acceptance, and barriers/enablers to study participation and implementation of the acetic acid technique.

Methods This was a mixed-methods feasibility study including a pilot multicenter, randomized, crossover trial with qualitative interviews. Patients under Barrett’s surveillance with no history of neoplasia were included. Patients underwent two endoscopies, one with each protocol, 8 weeks apart. Outcomes included recruitment and retention rates, neoplasia yield, and number of biopsies.

Results 200 patients were recruited from 6 centers, and 174 (87.0 %) underwent both procedures. Neoplasia prevalence was 4.7 % (9/192). High grade dysplasia and cancer were detected with both protocols. Five low grade dysplasias were detected (two with acetic acid, four with nontargeted biopsies; one lesion was detected with both techniques). A total of 2139 biopsies were taken in the nontargeted arm and 226 in the acetic acid arm. Both patients and clinicians found the acetic acid technique acceptable. Based on these data, a noninferiority, tandem, crossover trial would require an estimated 2828 patients.

Conclusions We demonstrated the feasibility of performing a crossover endoscopy trial in Barrett’s surveillance. Low neoplasia yield makes this design necessary and qualitative results demonstrated patient and clinician acceptance. The reduced numbers of biopsies suggest that the acetic acid technique could result in cost savings, providing the lack of missed pathology can be proven in a fully powered definitive trial.
Natural Compounds with Anti-BACE1 Activity as Promising Therapeutic Drugs for Treating Alzheimerʼs Disease
Authors: Naushad Mehjabeen , Durairajan Siva Sundara Kumar , Bera Amal Kanti , Senapati Sanjib , Li Min
Published: October 2019

Alzheimerʼs disease is a neurodegenerative disease that leads to irreversible neuronal damage. Senile plaques, composed of amyloid beta peptide, is the principal abnormal characteristic of the disease. Among the factors involved, the secretase enzymes, namely, α secretase, beta-site amyloid precursor protein-cleaving enzyme, β secretase, and γ secretase, hold consequential importance. Beta-site amyloid precursor protein-cleaving enzyme 1 is considered to be the rate-limiting factor in the production of amyloid beta peptide. Research supporting the concept of inhibition of beta-site amyloid precursor protein-cleaving enzyme activity as one of the effective therapeutic targets in the mitigation of Alzheimerʼs disease is well accepted. The identification of natural compounds, such as β-amyloid precursor protein-selective beta-site amyloid precursor protein-cleaving enzyme inhibitors, and the idea of compartmentalisation of the beta-site amyloid precursor protein-cleaving enzyme 1 action have caused a dire need to closely examine the natural compounds and their effectiveness in the disease mitigation. Many natural compounds have been reported to effectively modulate beta-site amyloid precursor protein-cleaving enzyme 1. At lower doses, compounds like 2,2′,4′-trihydroxychalcone acid, quercetin, and myricetin have been shown to effectively reduce beta-site amyloid precursor protein-cleaving enzyme 1 activity. The currently used five drugs that are marketed and used for the management of Alzheimerʼs disease have an increased risk of toxicity and restricted therapeutic efficiency, hence, the search for new anti-Alzheimerʼs disease drugs is of primary concern. A variety of natural compounds having pure pharmacological moieties showing multitargeting activity and others exhibiting specific beta-site amyloid precursor protein-cleaving enzyme 1 inhibition as discussed below have superior biosafety. Many of these compounds, which are isolated from medicinal herbs and marine flora, have been long used for the treatment of various ailments since ancient times in the Chinese and Ayurvedic medical systems. The aim of this article is to review the available data on the selected natural compounds, giving emphasis to the inhibition of beta-site amyloid precursor protein-cleaving enzyme 1 activity as a mode of Alzheimerʼs disease treatment.
A Newly Described, Highly Prevalent Arterial Pedicle Perfuses Both Gracilis and Profunda Artery Perforator Flap Tissues: An Angiographic Study of the Medial Thigh
Authors: Hammond Jacob B. , Flug Jonathan A. , Foley Brittany M. , Bryant Lyndsey A. , Casey William J. , Velazco Cristine S. , Rebecca Alanna M.
Published: October 2019

Background Novel secondary flap options are paramount for patients who are not candidates for common reconstructive methods. The purpose of this study is to identify the prevalence of single arterial pedicle supplying both the gracilis muscle and medial thigh tissue carried in a profunda artery perforator (PAP) flap. Such a pedicle could allow the creation of a chimeric gracilis and PAP flap with a single-arterial anastomosis.

Methods We conducted a retrospective review of 157 lower extremity computed tomography (CT) angiograms to assess the vasculature of the thigh soft tissues. Imaging evaluation was supervised by a board-certified musculoskeletal radiologist.

Results Prevalence of a single-arterial pedicle to a gracilis and PAP flap in each patient was 59% (31% within the right leg and 28% in the left leg). Furthermore, 16% of patients had a common arterial pedicle in both lower extremities.

Conclusion Existence of a single-arterial pedicle to both the gracilis muscle and PAP flap tissues is frequently present in most patients in at least one lower extremity. This chimeric flap configuration could serve as a reconstructive avenue for patients, particularly those who have exhausted other more common flap options. Screening angiography is warranted in patients looking for this anatomic variation to establish its presence.
Nascent Malunion of an Isolated Intraarticular Fracture of the Ulnar Head
Authors: Nienstedt Frank , Mariacher Markus , Stuflesser Günther , Berger Wilhelm
Published: October 2019

Background Isolated fractures of the ulnar head are rare. Only few cases have been reported in literature.

Case Description We report a case of a 16-year-old student who was treated for an ulnar styloid fracture conservatively. An associated displaced intraarticular fracture of the ulnar head has been overlooked. He presented late in our clinic with a symptomatic nascent malunion of the ulnar head fracture. A corrective osteotomy by a palmar approach was performed. Fixation by screws was used with an excellent result at 7-year follow-up.

Literature Review The rare cases of isolated ulnar head fractures reported in literature were treated by open reduction and internal fixation only in case of fracture dislocation.

Clinical Relevance The authors highlight the fact that even a nascent malunion of an isolated intraarticular fracture of the ulnar head may be treated successfully by open reduction and internal fixation.
Microsurgery Fellows' Impression of Clinical and Educational Offerings during Fellowship Year
Authors: Sullivan Brianne J. , Maliha Samantha , Henderson Peter W.
Published: October 2019

Background Acquisition of microsurgical skill and clinical knowledge is the primary goal of a microsurgery fellowship. There has yet to be any comprehensive reporting in the literature of how American microsurgery fellows viewed their curricula and training at the conclusion of their fellowship year.

Methods An anonymous, electronic survey was developed and distributed to all 2016 to 2017 microsurgery fellows (n = 37) at the U.S.-based microsurgery fellowship programs (n = 23). Qualitative questions were assessed using either a Likert-type scale of 1 (not at all) to 5 (very), multiple choice, or free response.

Results Twenty-six of 37 fellows (70%) responded to the survey. Respondents reported a mean of 14.4 lectures offered, with a range of 0 to 100. Dry laboratory simulation training was formally incorporated into 32% of microsurgery fellowships and live animal simulation training was formally incorporated into 12%. The median number of free deep inferior epigastric perforator flap cases performed was 112.5, ranging from 60 to 230. A majority felt that an organized microsurgical educational curriculum would be “beneficial,” with 42% reporting that an organized microsurgery curriculum would be “very beneficial.” Twenty-six of the respondents (100%) said that they would choose to do a microsurgery fellowship again if given the choice.

Conclusion Respondent data show that microsurgery fellows are satisfied with training, clinical experience is variable but adequate, educational experiences and opportunities vary from program to program, simulation skills training are perceived to be underutilized, and a program-organized microsurgery curriculum is believed to be advantageous to optimize development of technical and clinical skills.
Correction: Twin deficit hypothesis and reverse causality: a case study of China
Authors: Banday Umer Jeelanie , Aneja Ranjan
Published: October 2019

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Calculation and analysis of the thermophysical properties of C5F10O-N2 mixtures
Authors: Deng Yunkun , Chen Li , Ma Yi , Wang Dada , Zhao Su , Xiao Dengming
Published: October 2019

C5-PFK (C5F10O), with high dielectric strength and low global warming potential, is the new environmental-friendly potential alternative gases to SF6. In order to reduce its excessively high liquefaction temperature while retaining its excellent properties, a certain amount of buffer gases, such as N2 can be added to it. Therefore, to understand the plasma behavior of under C5F10O-N2 mixtures, the composition, thermodynamic properties and transport properties of the C5F10O-N2 mixtures in a temperature range of 300K to 30000K and a pressure range of 0.1 MPa to 0.8 MPa is calculated under the assumption of local thermodynamic equilibrium. Then, the influence of mixing ratios and pressures are analyzed. The results can be used to determine the optimal proportion of C5F10O-N2 mixtures. Several peaks of the specific heat can be observed below 5000K, which could be a favorable factor for arc quenching.
Inertial focusing of a neutrally buoyant particle in stratified flows
Authors: Jyothi S. Kiran , Renganathan T. , Pushpavanam S.
Published: October 2019

Particles in microfluidic channels experience two dominant lift forces in the direction transverse to the flow—the shear gradient lift force and the wall lift force. These forces contribute to the lift experienced by the particle and cause their cross stream migration until they attain an equilibrium position where the net lift force in the transverse direction is zero. Stratified coflow of two liquids with different viscosities is a stable flow-regime observed under some operating conditions. The presence of the second fluid alters the shear gradient induced lift force and the wall force acting on the particle at each point, changing the final equilibrium position. These positions can be tuned and controlled by altering the viscosity or the flow rates of the two fluids so that the particles focus in one fluid. A numerical method based on the combined Immersed Boundary-Lattice Boltzmann Method is used to study inertial focusing of neutrally buoyant particles in stratified Couette flows and pressure driven flows. We analyze how different factors such as the Reynolds number, flow rate ratio, viscosity ratio of the fluids, and particle size affect the particle migration in two-dimensional (2D) and three-dimensional (3D) geometries. Our study shows that in Couette flows, the particle focuses in the low viscosity fluid when the interface is at the center. We also found that a critical viscosity ratio exists beyond which particle focusing in low viscous fluid is guaranteed, for a given flow rate ratio in pressure driven flows.
Surface patterning of high density polyethylene by oblique argon ion irradiation
Authors: Kumari Rimpi , Gupta Divya , Singhal Rahul , Sharma Annu , Aggarwal Sanjeev
Published: October 2019

Oblique ion beam induced spontaneous patterning opens up a simple and inexpensive route to fabricate useful nanoscale textured materials that have important implications in biosensors, optoelectronic devices, templates for liquid crystal orientation, etc. In this regard, the evolution of patterns over high density polyethylene surfaces induced by 100 keV Ar+ irradiation at off normal incidences of 30°, 40°, and 50° with a fluence of 5 × 1016 Ar+ cm−2 has been investigated. Structural modifications have been analyzed using high resolution X-ray diffraction. An increase in crystallite size and a decrease in parameters such as dislocation density (δ), microstrain (ϵ), and distortion (g) have been observed after oblique Ar+ irradiation with an increase in the angle of incidence from 30° to 40°. Atomic force microscopy analysis revealed that the wavelength of ripplelike patterns decreases from 3.19 μm to 2.51 μm, while its amplitude increases from 77.4 nm to 101 nm with an increase in the angle of incidence from 30° to 40°. Similarly, with an increase of oblique incidence to 40°, the root mean square (Rq) and average surface roughness (Rav) have been found to increase. These results are accredited to the curvature dependent sputtering and smoothing processes at oblique incidences. The possible correlation between ion beam sputtering induced patterning and the structural modification in the matrix has been established and discussed.
Influence of convection regimes of two-layer thermal convection with large viscosity contrast on the thermal and mechanical states at the interface of the two layers: Implications for dynamics in the present-day and past Earth
Authors: Yoshida Masaki
Published: October 2019

This paper reports on results for the thermal and mechanical states at the interface of two-layer thermal convection in two-dimensional (2-D) spherical geometry solved by numerical calculations. The two-layer system was composed of a highly viscous layer (HVL) and a low-viscosity layer (LVL) underneath. The two end-member convection regimes were studied by varying two free model parameters, which control the degree of layering in HVL convection and separate the HVL into the upper and lower parts. One of the regimes was a nearly whole-layer convection regime in which the upwelling and downwelling plumes easily penetrated into another layer in the HVL, while the other was a so-called hybrid convection regime, which represented a transitional regime between the whole-layer convection and the double-layer convection. The spatiotemporal analyses of convection behavior showed that the lateral scale of HVL convection and the resultant lateral scale of thermal heterogeneity beneath the HVL–LVL interface tended to be larger in the hybrid convection regime than those in the whole-layer convection regime. On the other hand, the fluctuation of shear-stress at the HVL–LVL interface was more time-dependent in the hybrid convection regime, whereas the mechanical heterogeneity near the HVL–LVL interface was larger in the whole-layer convection regime. The present results on the differences in the scale of dynamically determined thermal and mechanical states beneath the HVL–LVL interface between the two end-member convection regimes may apply to issues on the relationship between thermal and mechanical conditions at the Earth’s core–mantle boundary and the strength of the geomagnetic field.
An iterative Q-learning based global consensus of discrete-time saturated multi-agent systems
Authors: Long Mingkang , Su Housheng , Wang Xiaoling , Jiang Guo-Ping , Wang Xiaofan
Published: October 2019

This paper addresses the consensus problem of discrete-time multiagent systems (DTMASs), which are subject to input saturation and lack of the information of agent dynamics. In the previous works, the DTMASs with input saturation can achieve semiglobal consensus by utilizing the low gain feedback (LGF) method, but computing the LGF matrices by solving the modified algebraic Riccati equation requires the knowledge of agent dynamics. In this paper, motivated by the reinforcement learning method, we propose a model-free Q-learning algorithm to obtain the LGF matrices for the DTMASs achieving global consensus. Firstly, we define a Q-learning function and deduce a Q-learning Bellman equation, whose solution can work out the LGF matrix. Then, we develop an iterative Q-learning algorithm to obtain the LGF matrix without the requirement of the knowledge about agent dynamics. Moreover, the DTMASs can achieve global consensus. Lastly, some simulation results are proposed to validate the effectiveness of the Q-learning algorithm and show the effect on the rate of convergence from the initial states of agents and the input saturation limit.
Spatially resolved thermoreflectance techniques for thermal conductivity measurements from the nanoscale to the mesoscale
Authors: Olson David H. , Braun Jeffrey L. , Hopkins Patrick E.
Published: October 2019

Thermoreflectance techniques, namely, time- and frequency-domain thermoreflectance (TDTR and FDTR, respectively), are ubiquitously used for the thermophysical characterization of thin films and bulk materials. In this perspective, we discuss several recent advancements in thermoreflectance techniques to measure the thermal conductivity of solids, with emphasis on the governing length scales and future directions in expanding these advances to different length scales and material structures. Specifically, the lateral resolution of these techniques, typically on the order of several micrometers, allows for an understanding of the spatially varying properties for various materials. Similarly, limitations of TDTR and FDTR with respect to their volumetric probing regions are discussed. With a recently developed steady-state thermoreflectance technique, these limitations are overcome as probing volumes approach spot sizes. Finally, recent pushes toward the implementation of these techniques without the use of a thin metal transducer are presented, with guidelines for future avenues in the implementation under these specimen configurations.
Creating oscillons and oscillating kinks in two scalar field theories
Authors: Correa R. A. C. , de Souza Dutra A. , Frederico T. , Malomed Boris A. , Oliveira O. , Sawado N.
Published: October 2019

Oscillons are time-dependent, localized in space, extremely long-lived states in nonlinear scalar-field models, while kinks are topological solitons in one spatial dimension. In the present work, we show new classes of oscillons and oscillating kinks in a system of two nonlinearly coupled scalar fields in 1+1 spatiotemporal dimensions. The solutions contain a control parameter, the variation of which produces oscillons and kinks with a flat-top shape. The model finds applications in condensed matter, cosmology, and high-energy physics.
Dynamics at the non-ionic micelle/water interface: Impact of linkage substitution
Authors: Tarif Ejaj , Mukherjee Kallol , Kumbhakar Kajal , Barman Anjan , Biswas Ranjit
Published: October 2019

The impact of atom substitution on the glycoside linkage bridging the head and the tail parts in a nonionic surfactant molecule on aqueous dynamics of the resultant micellar solutions has been explored, employing time-resolved fluorescence and dielectric relaxation (DR) measurements. We have utilized n-octyl-β-D-glucopyranoside (OG) and n-octyl-β-D-thioglucopyranoside (OTG) as nonionic surfactants where the oxygen atom in the glucopyranoside unit is substituted by a sulfur atom. The substitution impact is immediately reflected in the dynamic light scattering measurements of aqueous solutions where the estimated size of the OTG micelles is found to be approximately four times larger than the OG micelles. Steady state spectral features obtained by using a fluorescent probe solute, coumarin 153 (C153), in these micellar solutions are quite similar and indicate locations of the solute at the micelle/water interface for both the surfactants. Interestingly, significant differences in the rotational and solvation dynamics of C153 in these two micellar solutions have been registered. The corresponding DR measurements do not indicate any signature of relaxation typical of bound water. The absence of bound water is further supported by the differential scanning calorimetric measurements. However, the typical slow solvation time scale for aqueous micellar solutions has been observed for these surfactants. Fluctuations in the solute-interface interaction energy due to the solute motion has been argued to be the origin for this slow solvation component as DR measurements do not indicate the presence of qualitatively similar relaxation time scale in the medium.
Small-angle light scattering in large-amplitude oscillatory shear
Authors: Gilbert P. H. , Giacomin A. J.
Published: October 2019

We explore wormlike micellar orientation during oscillatory shear using small-angle light scattering. Previous oscillatory-shear light scattering measurements focused on phase separation in polymeric solutions undergoing shear and none on wormlike micelles. We correlate light scattering videos of wormlike micelles undergoing oscillatory shear with molecular orientation. Specifically, we compare our orientation measurements with the predictions of rigid dumbbell theory. We find that “tulip” shaped scattering patterns caused by micellar orientation are only partially captured by the predicted scattering generated by rigid dumbbell theory. Additionally, we confirm that rigid dumbbell theory cannot describe the “butterfly” shaped scattering patterns arising from concentration fluctuations during micelle breakup. We successfully create a theory to describe both orientation and concentration fluctuation scattering by combining rigid rod Rayleigh-Debye scattering theory with flow induced Helfand-Fredrickson scattering theory.
Leaky mode transition and enhanced resonance in tilted fiber Bragg grating
Authors: Li Zhihong , Shen Xin’ge , Hua Yiqi , Ruan Xiukai , Dai Yuxing
Published: October 2019

Leaky mode resonance in tilted fiber Bragg grating (TFBG) has been widely underestimated and ignored. Herein, we theoretically demonstrate that the leaky mode resonance can be greatly enhanced, and it presents a highly sensitive property by virtue of its mode transition. The leaky mode transition consists of five stages from the cladding guided mode to radiationlike and guidedlike leaky modes for both p- and s-polarized modes of bare TFBG. However, the graphene induces only one transition for the s-polarized guidedlike leaky mode, which, in turn, leads to an insensitive wavelength shift. The resonance amplitude depends on the imaginary part of the effective refractive index. Consequently, the enhanced leaky mode resonance (eLMR) in the s-polarized state is obtained and presents higher sensitivity than the widespread surface plasmon resonance (SPR). Furthermore, a general empirical rule associated with the refractive index of nanometer materials for exciting the eLMR in TFBG is obtained (the SPR is also discussed for comparison). The results obtained in this work have shed contemporary light on the undervalued leaky mode resonance, which is of great interest and importance to the development of novel multimodal and multifunctional eLMR-based TFBG devices, such as tunable lasers, optical modulators, and sensors.
Force balance approach for advanced approximations in density functional theories
Authors: Tchenkoue Mary-Leena M. , Penz Markus , Theophilou Iris , Ruggenthaler Michael , Rubio Angel
Published: October 2019

We propose a systematic and constructive way to determine the exchange-correlation potentials of density-functional theories including vector potentials. The approach does not rely on energy or action functionals. Instead, it is based on equations of motion of current quantities (force balance equations) and is feasible both in the ground-state and the time-dependent settings. This avoids, besides differentiability and causality issues, the optimized-effective-potential procedure of orbital-dependent functionals. We provide straightforward exchange-type approximations for different density functional theories that for a homogeneous system and no external vector potential reduce to the exchange-only local-density and Slater Xα approximations.
Fano resonance in the CsPbBr3 nanocrystal/Ag nanostructure through the exciton-plasmon coupling
Authors: Cai Chunfeng , Bi Gang , Xu Tianning
Published: October 2019

Fano resonance (FR) has attracted more attention recently due to its outstanding properties, such as coherent interference at the resonant energy and intense changes in the spectral lines. Here, we studied the FR effects in the CsPbBr3 nanocrystal (NC)/Ag nanostructure coupling structure. The FR effects cause asymmetric line shapes in both the reflection and transmission spectra. A sharp variation was observed in the spectral line at the exciton energy of CsPbBr3 NC. The FR in this coupling structure is attributed to the configuration interaction between the exciton state and the surface plasmon (SP) states. From the coupling theory, we suggest that it is necessary to consider multiSP states in the interaction Hamiltonian, instead of a single SP state, which will induce more interesting effects. Moreover, we demonstrate that the FR effects are sensitively dependent on the spacing in the coupling structure. The sharp variation of the spectral line shape at the resonant energy and its sensitivity on the spacing in the coupling structure make the FR effects an important candidate as the optical monitoring methods in the application of real time artificial tunable optoelectronic device at the nanoscale.