bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of the underground erosion of the soils adjoining the concrete constructions (on the example of Zagorsk pumped storage power plant, ZPSPP-2)
Authors: Lavrusevich Andrey , Lavrusevich Ivan
Published: May 2019

The matter of such a dangerous geological process as suffosion is briefly considered in the article. Some examples of destruction and removal of the suffusion unstable breeds on the contact with the concrete structure are given. Sone cases of vertical (downward and upward) and sloping streams in relation to a concrete construction are considered. It is proved that after the formation of the primary underground channel the suffosion process passes into the erosive one. This transition is smoothly and gradual, hidden from the immediate observation. However, the erosive process development leads to the repeated increase in the intensity of the incoherent soil destruction. In case of existence of soil removal zone, not only the large underground channel is formed, but also large cavities in the zone of contact of the concrete structure and the soil massif are formed. It quite often leads to the emergency situations. Studied the example of the Zagorsk PSPP-2 (ZPSPP-2). The development of the erosive process under the ZPSPP-2 building led to the formation of large cavities (up to 10 m) and to the general subsidence of the building of the plant and of the retaining wall 3 (RW3) on 1.17 m down.
Life prediction for spillway facility side wall
Authors: Yangiev Asror , Ashrabov Anvar , Muratov Oybek
Published: May 2019

This article includes the analytical assessment of the durability and remaining life of the I-st category reinforced concrete structures by the fracture mechanics approaches, the prediction is based on the consideration of temporal changes in the structural features of a particular type of concrete. The main purpose of this work is to determine the durability of reinforced concrete structures and the remaining life of the spillway and components in the implemented modes and operating conditions that ensure their safe operation and environmental protection. When predicting the durability of the spillway reinforced concrete structures, each structure is considered as a component of the structure behavior scheme. The result of the durability predictions is presented in years, which can eventually determine the remaining life of the structural component of spillway.
Calculation of the foundation settlement during compensation grouting
Authors: Luzin Ivan , Ermoshina Lyubov
Published: May 2019

The article presents the issue of correctly calculating the SSC of the foundation bases in the process of compensation grouting. It is shown that the numerical calculation should be performed in two versions: hydrostatic pressure and rear volume strain in a cluster of soil. Using the example of an object in Moscow, the use of the PLAXIS 3D design complex was shown to calculate additional precipitation of buildings during compensation grouting and the passage of a tunnel under it. A method is given for determining the required volume of suspension during compensation grouting using numerical methods for calculating the SSC.
Calculation of thermal stress-strain state of soil base under the building on permafrost soil
Authors: Rabinovich Mikhail
Published: May 2019

Article presents problem statement and solution for joint calculation of temperature regime and stress-strain state of permafrost soils under building footing, with consideration of thermal impact from on-surface and buried high-temperature utilities. Based on a series of optimization tasks, a design model for stress-strain state has been developed, solutions of test problems have been obtained and analyzed to determine the degree of influence of temperature stresses and relation of the deformation characteristics of frozen soil in the negative temperature spectrum on the stress distribution and settlement values of frozen soil base under the building.
Behavior of concrete beams reinforced with GFRP under transverse force
Authors: Gorbunov Igor , Kakusha Vladimir , Moshnikov Mikhail , Kudryavtsev Maksim , Dobrina Kristina
Published: May 2019

The article discusses the effect of transverse reinforcement spacing for the strength and deformation characteristics of beams with glass fibre reinforced polymer. The bending tests results of reinforced concrete specimens are presented (GFRP) with different concrete strength and reinforcement spacing. Force-deflection, force-GFRP bars deformation and force-concrete compressed zone deformation dependencies are given in the article. Based on ultimate force and beams destruction pattern it is established that increasing transverse reinforcement spacing reduces the beams strength and leads to destruction in oblique section. With narrow-mashed transverse reinforcement fracture occurs in the compressed zone of concrete. A computational analysis for different types of beams fracture is presented. It is established that transverse reinforcement spacing doesn’t affect the parameters determined by service limit state: crack formation load, crack width and beam deflection. A comparative analysis of maximum permissible deflection based on test results and theoretical calculations was carried out. The numerical values of bending stiffness parameter are obtained at the loading stages with linear deformation before and after first crack formation.
Stress-strain state of a soil array with a cylindrical cavity supported by a reinforcing ring
Authors: Andreev Vladimir , Nosyrin Vladislav
Published: May 2019

The article deals with the problem of calculating a stress-strain soil massif with a horizontal cylindrical cavity created by an explosion (for example, drilling and blasting method of penetration), in the presence of a reinforcing ring. The calculation takes into account the radial local inhomogeneity of the array near the cavity, due to the explosive effects. The problem is solved in a two-dimensional formulation (flat deformed state). The solution uses a numerical-analytical method that reduces the solution to a system of ordinary differential equations with variable coefficients.
Experience in designing and operating the buildings located on subsiding and heaving soils of the Minusinsk Hollows
Authors: Strelnikov Dmitry , Khalimov Oleg
Published: May 2019

The article presents the experience of design, expert research within the period of construction and operation of the buildings located on subsiding soils. It describes the experiment in conducting the organized soaking of a mounted house made of reinforced-concrete slabs and claydite-concrete panels. It shows the absence of danger of frost heaving while soaking the subsiding soils. There are tables demonstrating the expert studies during the inspections of deformable buildings and long-term observations over their behavior in freezing and thawing depending on the groundwater level and pressures under the bottom of the foundations. As a result of the analysis of long-term studies it has been established that the building load contributes to the reduction of frost heaving for sandy soils (fine and dust sands). In case of clayey soils, in contrast to the views on this problem emerged at the end of the 20th century, it is impossible to extinguish the migration process using pressure. If the migration flow slows down under the foundation bottom, it occurs due to the higher rate of soil freezing arising from the high thermal conductivity of the foundation body and the formation of vertical ice lenses on the borders of tension zones. The most important thing showed herein is that the thawing process in these lenses provokes the process of stability loss, where the soil protrudes from the foundation bottom. The long-term studies of frost heaving in a severe continental climate of the Minusinsk hollows enabled the development of the most effective direction of the anti-heave stabilization.
Calculation of beams with corrugated wall on the stability of a flat bending shape
Authors: Lapina Anastasia , Zotov Ivan , Chepurnenko Anton , Yazyev Batyr
Published: May 2019

The article presents the method of calculating beams with a corrugated wall on the stability of a flat bending shape. The problem reduces to a differential equation of fourth order with respect to the twist angle. The solution is performed numerically by the finite difference method. A comparison of the results with the software package LIRA is presented.
The interaction of long and compressible piles with the surrounding and underlying subgrade soils
Authors: Ter-Martirosyan Zaven , Luzin Ivan , Yakubov Mukim
Published: May 2019

The article specifies the formulation and solution of problems on the interaction of a long incompressible and compressible pile with the surrounding and underlying subgrade firm soil by an analytical method. It is indicated, that there is the significant effect of the compressibility of the pile shaft on the patterns of force distribution applied to the long pile top between the side surface of the pile and its lower end. The force that comes on the pile toe bulb substantially depends on the ratio of the stiffness of the surrounding and underlying soils (G1 / G2). With the decrease of this ratio, all things being equal, the force on the pile toe bulb increases. It grows with a decrease in the ratio of the radii of the pile and the surrounding thick-wall soil cylinder (G / a). The analysis of the problem solution showed that it is possible to find the optimal ratios between the parameters G1 / G2,b / a,l / a, at which the force on the pile toe bulb reaches the optimum value wherein the bearing capacity of the underlying soil is at the most used at a given degree of approximation to the limit value.
Risk management of water distribution system in Armenia
Authors: Khachatryan Artur , Khachatryan Emil
Published: May 2019

Risks in the water distribution system in the Armenian village of Noratus, have been assessed and treated following a risk management study based on the ISO 31 000:2009 standards, but extended for a strategic and long term level of analysis. The main goal is to ensure the safety of the whole water supply system. The brief description of the region as well as the current condition of the water supply system is given in order to clarify system features. The risk management here presented approach is now implemented in the Noratus network. Simulation have been performed using the AWARE-P software platform with the purpose of identifying critical components in the network and the asset probability of structural failure, as inputs for risk quantification. Then the risk magnitude is evaluated with the introduction of risk matrix. The phases of risk estimation and treatment are also carried out to propose the solutions for risk level reduction.
Computer Modeling of Aerosol Emissions Spread in the Atmosphere
Authors: Sharipov Daler , Aynakulov Sharofiddin , Khafizov Otabek
Published: May 2019

The paper deals with the development of mathematical model and numerical algorithms for solving the problem of transfer and diffusion of aerosol emissions in the atmospheric boundary layer. The model takes into account several significant parameters such as terrain relief, characteristics of underlying surface and weather-climatic factors. A series of numerical experiments were conducted based on the given model. The obtained results presented here show how these factors affect aerosol emissions spread in the atmosphere.
Theoretical and empirical methods of estimating energy and force characteristics of impact wrenches
Authors: Drozdov Anatoliy
Published: May 2019

The Article represents theoretical and empirical methods of estimating the characteristics of impact wrenches when torquing specific threaded connections and in fixed anvil mode. They allow addressing the following issues: indirect determination of single impact energy in production conditions based on the proposed technique of estimating specific characteristics of stiffness and impact threshold of the wrenches, which are used to obtain base of the initial design values of the mathematical model. These methods and the techniques developed based on them allow for determination of single impact energy both in laboratory and production environment, which is important at the stage of tool creation as well as during its operation in order to reasonably develop the size range of impact wrenches, carry out strength analysis of their striking mechanisms and choose a proper tool for a specific range of threaded connections. The correct choice of the tool can make installation procedure much more efficient due to the reduced time for assembly and ability to control torquing tightness of threaded connections. In hydrotechnical construction a significant amount of work falls on assembling threaded connections in the use of metal structures, products, and in used construction equipment.
Management exploitation condition of Amu-Bukhara machine channel
Authors: Khidirov Sanat , Berdiev Mustafo , Norkulov Bekhzod , Rakhimov Nurbek , Raimova Iqboloy
Published: May 2019

In this article discussed current exploitation condition of the largest irrigation and drainage network of the Republic of Uzbekistan - Amu-Bukhara Machine Channel. Main importance of this work – is to develop of an intensive method for predicting emergencies arising during the exploitation condition during the vegetation period, the possibility of applying the method of mathematical modelling in controlling exploitation condition. The aim of the study is to develop a modern, convenient, simple and accessible mathematical tools, which will give reliable material for predicting the flow dynamics in the channel and making the right decision in emergency situations when complex exploitation of irrigation and drainage systems. The research methodology consists of a review of the existing systems of hydrodynamic equations which describes the flow motion, and adoption from them divergent system of equations. Have been developed mathematical model and a computer program which allows solve a wide spectre of tasks for modelling of flow in an irrigation and drainage system with various difficulties with taking account daily regulation.
Studies of rational methods of water selection in water intake areas of hydroelectric power plants
Authors: Shaazizov Farrukh , Badalov Abdulla , Ergashev Alisher , Shukurov Diyor
Published: May 2019

Up to 2021, 42 new hydropower stations will be created in Uzbekistan and 32 existing hydropower stations will be repaired. Hydraulic engineering designers face a number of problems with the open flow division nodes in the field, which are part of the hydraulic structures of such hydropower plants. Considering the above, the main objectives of the research were determined: a) development of a refined method for the hydraulic calculation of flow division nodes with a quiet flow regime; b) the development of methods for predicting deformation of the channel in the area of the division node. The studies were carried out using theoretical and experimental studies using the equation for changing the amount of movement, laboratory studies on a hydraulic model, field surveys of existing water intake nodes, as well as analysis of experimental data available in the literature on this issue. Based on the theoretical and experimental studies, recommendations were made for the open flow division nodes. These recommendations are valid for division nodes at a division angle not exceeding 90°, for prismatic channels of rectangular cross section with relatively small bottom slopes. These recommendations are intended for flows with values of B / H = 3 ÷7.
Calculation of Water Wheel Design Parameters for Micro Hydroelectric Power Station
Authors: Kodirov Dilshod , Tursunov Obid
Published: May 2019

This paper is devoted to the issues such as modelling the design parameters and operating modes and improving the design of micro hydroelectric power plants operating in low-pressure water flow. Taking into consideration above-mentioned issues, it is possible to increase the efficiency of using low-pressure water energy systems. The main dimensions of the water wheel of a micro hydropower plant depend on the water flow velocityv, water volumeQ, acting at a fixed point in time on the water wheel blade, and also on the depth of the water levelH.
Stress-strain state of earth dam under harmonic effect
Authors: Khusanov Bakhtiyar , Khaydarova Ozodakhon
Published: May 2019

Stress-strain state of earth dams under the effect of harmonic (seismic) load from the base of the dam is numerically studied in the paper. Rock fill dam has good culvert properties and its water saturation is considered to have no effect on mechanical characteristics and strength properties of rock; filtration flow mainly forms on the low-permeable core of the dam. Usually, the dam core consists of soft (loess) soil, therefore its water saturation significantly influences physical and mechanical properties of soil. A two-dimensional problem is considered for the cross section of a dam using the equation of state with allowance for structural changes in rock fill and moisture content of a dam core with low-permeable trapezium properties. For earth dams, as is known, a filtration flow is formed in the dam body. The problem is solved numerically - by the method of finite differences. The results are presented in the form of graphs and are analyzed.
The Ensuring of Survivability of Wave Energy Stations Constructive Elements in Extreme Weather Conditions
Authors: Solovyev Alexander , Solovyev Dmitriy , Shilova Liubov
Published: May 2019

Current problems and the tasks of increasing the reliability of the equipment designs for utilizing the energy of sea waves are described in the article. The requirements for the protection of float and buoy structures from storm impacts by immersing them in undisturbed water layers using rotary engines articulated with a wave power station are formulated. Ways to protect wave converters from storm impacts are proposed.
The calculation of anchors in steel-concrete overlaps with precast slab
Authors: Tusnin Alexander , Kolyago Alexey
Published: May 2019

Reinforced concrete floors and steel beams are widely used in buildings and structures for various purposes. Reinforced concrete overlaps can be cast-in or precast of hollow-core slabs. The most effective floors in which the concrete slab is located in the compressed area of cross-section, in steel beams in the tension zone, and shifting forces, arising between concrete slab and the steel beam, are perceived by anchors. Precast slabs in comparison with cast-in ones have less labor-intensive performance, the beam spacing is equal to the span of reinforced concrete slabs, there are no intermediate beams in such overlaps, that allows to reduce the floor thickness. The inclusion of precast in steel-concrete cross-section requires joints with steel beams, which requires using of special anchors. Anchor perceives shear forces and ensures the joint operation of the plate and the steel beam. In addition, for beams with narrow flange, the anchor device can provide the required width of the support slabs. The calculation of the attachment points of the anchors to the steel beam is carried out using three variants of calculation methods, which allow to determine the forces acting on the anchor. For practical application, a wire-element model has been proposed and managed to get forces in a steel beam, slab and anchors the width of the slab recommended by the standards should be included in the calculation model.
The growth of silver nanostructures on porous silicon for enhanced photoluminescence: The role of AgNO3 concentration and deposition time
Authors: Cetinel Alper , Artunç Nurcan , Tarhan Enver
Published: May 2019

Silver nanostructures were obtained by using the electrodeposition method on n-type porous silicon (PSi) under different deposition times and concentrations of AgNO3 solutions. The analyses of the structural and photoluminescence properties of PSi/Ag were studied by SEM, XRD and photoluminescence spectroscopy. SEM analysis showed that the shape and size of Ag nanostructures significantly depend on the deposition time and concentration. It was found that spherical nanoparticles and thin Ag dendrites were obtained in short deposition times at 1 and 5 mM AgNO3 concentrations, whereas, Ag complex dendrite nanostructures formed in long deposition times. It was also found that only micro-sized Ag particles were formed at 10 mM. XRD results revealed that the degree of crystallization increases with increasing concentration. Photoluminescence analysis showed that the deposition time and concentration of AgNO3 remarkably affect the PL intensity of PSi/Ag samples. We determined a PL enhancement of ∼2.7 for the PSi/Ag deposited at 120 s for 1 mM AgNO3. The improved PL intensity of PSi/Ag nanostructures can be explained by the combination of quantum confinement and surface states. PL analyses also indicated that with increasing deposition time and AgNO3 concentrations, the PL intensity of PSi/Ag structures significantly decreases due to the auto-extinction phenomenon.
Enhancement in electron transport and exciton confinement in OLEDs: role of n-type doping and electron blocking layers
Authors: Soman Anjaly , Unni K.N. Narayanan
Published: May 2019

Doped transport layers are essential for achieving high efficiency in organic light emitting diodes (OLEDs). We have studied the effect of doping the electron transport layer (ETL), tris-(8-hydroxyquinoline) aluminum (Alq3) with different percentages of lithium fluoride (LiF). We have also studied the effect of different electron blocking layers (EBLs) such as Tris (4-carbazoyl-9-ylphenyl)amine (TCTA), N,N'-Bis (naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine(NPB), and Di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane (TAPC) in an Alq3:2,3,6,7-Tetrahydro-1,1,7,7,-tetramethyl-1H, 5H, 11H −10-(2-benzothiazolyl)quinolizino[9,9a, 1gh] coumarin (C545T) based organic light emitting diode (OLED) with optimized ETL doping. TCTA was found to effectively block the electrons and influence the recombination region in the process. At a brightness of 1000 cd/m2, an improvement of 27.8% was observed in external quantum efficiency (EQE) for the device with TCTA as the EBL and doped Alq3 as the ETL, compared to the one with just NPB as both EBL and HTL.
Financial and economic security system strategic management as an independent direction of management
Authors: Cherevko Oleksandr , Nazarenko Serhiy , Zachosova Nataliia , Nosan Nataliia
Published: May 2019

The scientific views of domestic researchers regarding the definition of financial and economic security using the basics of the systematic approach are generalized. The author's vision on the definition of financial and economic security system is proposed. The main shortcomings of existing approaches to the process of formation of financial and economic security system as an object of management are revealed and systematized. The main defects and miscalculations in security management both – at the micro and macro levels are identified. The 16-component model of management of financial and economic security (PROM) was proposed. The conceptual foundations of security oriented strategic management are specified. Three strategies offered for achieving economic and financial security: Strategy for achieving financial and economic security on the basis of branding, image and reputation (BIR strategy), Strategy for achieving financial and economic security through partnerships with stakeholders and ensuring their interests (Strategy of PIS), Strategy for achieving the state of financial and economic security through the interconnection of experts, control and standardization (Strategy of ECS).
Price regulation of agrarian markets in the context of food security in Ukraine
Authors: Shebanina Olena , Burkovska Anna
Published: May 2019

The article deals with the problems of price regulation of the agrarian markets in the context of food security in Ukraine. The seasonal dynamics of the indexes on the consumer prices for the agricultural products are analyzed. The influence of the factors of foreign trade activity of Ukraine on the state of prices on the domestic market is determined. The conclusion on the need for increasing the state regulation of prices for agricultural products in Ukraine is made. The analysis of influence of the dynamics in the volumes of the export and import on the fluctuations of prices for agricultural products on the domestic market is carried out.
The price competition simulation at the trading market in the presence of electronic and traditional trade
Authors: Pursky Oleg , Dubovyk Tatiana , Moroz Iryna , Buchatska Iryna , Savchuk Anastasiia
Published: May 2019

In the present work, an attempt has been made to apply economic and mathematical methods for the simulation of electronic trading market operation based on price competition between e-trade companies and traditional trade enterprises. The developed price competition model based on the concept of symmetric product differentiation. The results obtained in the present investigation demonstrate that in a mixed strategy, firms sell products at different prices, depending on the price strategy or the volume release strategy. The company that sets the volume, sells more, but at a lower price than its competitor which sets prices. The influence of strategic output exceeds price influence. Thus, the company that sets prices, falls into an unfavorable situation and receives lower profits compared with its competitor with the strategy for the volume of production. The company that has decided to introduce electronic trading technology initially will bear losses.
Investment attractiveness modeling using multidimensional statistical analysis methods
Authors: Shinkarenko Volodymyr , Matskul Maksym , Linok Dean
Published: May 2019

The article examines the investment attractiveness of the main branches of the food industry of Ukraine as a latent variable. For the first time in this area, a combination of various methods of multivariate statistical analysis is used for research (cluster analysis and factor analysis – the principal component method). These methods made it possible to use a large number of various indicators of the activities of industries to characterize investment attractiveness. As a result, the set of the branches was divided into three groupsclusters: “leaders” are the most attractive sectors for investment, “middle peasants” are attractive branches for investment, and “outsiders” are the least attractive branches for investment. The generalizing factors (principal components), which influence the resulting factor - investment attractiveness, were found. The interrelation of the generalizing factors and initial indicators is established. As a result of the research, it was possible to make an objective assessment of the investment attractiveness (as a latent indicator) of the main branches of the food industry in Ukraine, using instead of a multitude of indicators only three latent factors.
Сompany’s sales simulation based on the use of SWOT analysis and Ishikawa charts
Authors: Ivanov Sergey
Published: May 2019

Marketing research at an enterprise is carried out by marketing units in order to determine a possible increase in the marketing activity of the enterprise. To identify the strengths and weaknesses of the sales management of the enterprise, the SWOT-analysis method was applied. A matrix of SWOT analysis of company’s sales activity was built, which forms squares in the form of a combination of the following factors: “Strengths-Opportunities” (SO), “Strengths-Threats” (ST), “Weaknesses-Possibilities” (WO), “Weaknesses-Threats” (WT). The most significant intersections of the SWOT matrix factors of the analysis were analyzed, and it was proposed to use four types of strategies on their basis. To formalize cause-and-effect relations Ishikawa diagram was used.
Global trends in the development of labour markets and employment in the focus of innovation change
Authors: Pasieka Stanislava , Pasieka Anna , Bil Mariana , Humeniuk Oleksandra
Published: May 2019

The article focuses on the main trends of innovation change effects on the labour markets and employment, value and mental characteristics, relation formation, regulation mechanisms, competitive relations, the distribution of rights and movement freedom, leading the formation of a new era of “the planet man” development. The world trends in the development of the labour markets and employment are analyzed. The ratification dynamics of international regulatory legal documents in the field of the world employment in 2006-2017 is investigated. Over 8,000 ratifications are found to be carried out by different states in 2017. This indicator increased constantly, gaining the highest rate acceleration in 2011-2012. Based on the United Nations Human Development Report, the polarization of the world's countries in terms of employment and unemployment (including among young people) is studied, with shares of employees less than $ 3.10 of PPP per day. The lack of a direct correlation between the Human Development Index and the employment rate is established: the highest employment rate is found for a group of countries with a low index; it means that the improvement of the state employment policy should be oriented towards qualitative indicators. The structure of the employed by status is analyzed. On average, 54.8% of the world employed population is found to work on the basis of employment, and the higher the level of state development, the higher the proportion of such individuals. The analysis of GDP indicator per capita employed shows the high polarization of the modern world: the difference between countries with high- and low-income levels is about 25 times; this indicator for Ukraine is 47% of the world average and 18% of high-income countries. As a generalization of the analysis, the main problems of the development of the global labour market are considered and ways of their solution are proposed.
Supported Employment im Routinebetrieb: Evaluation des Berner Job Coach Placement-Programms 2005 – 2016
Authors: Richter Dirk , Hunziker Markus , Hoffmann Holger
Published: May 2019

Ziel Die Studie berichtet über die Evaluation des Berner Job Coach Placement-Programms im Routinebetrieb.

Methode Administrative Daten der Teilnehmenden aus den Jahren 2005 – 2016 wurden hinsichtlich der Integration in den allgemeinen Arbeitsmarkt und hinsichtlich der Aufnahme einer regulären Beschäftigung analysiert.

Ergebnisse 46 % aller Teilnehmenden (N = 420) erreichten das primäre Erfolgsziel der Integration in den allgemeinen Arbeitsmarkt, 33 % schafften den Übergang in eine reguläre Anstellung.

Diskussion Das Berner Job Coach Placement Programm erreicht auch im Routinebetrieb eine im internationalen Vergleich sehr gute Integrationsquote.
Targeted Neonatal Echocardiography-Guided Therapy in Vein of Galen Aneurysmal Malformation: A Report of Two Cases with a Review of Physiology and Approach to Management
Authors: Giesinger R. E. , Elsayed Y. N. , Castaldo M. P. , McNamara P. J.
Published: May 2019

Vein of Galen malformation results in predictable changes in physiology which exist on a continuum. Severe pulmonary hypertension may present as hypoxemia; however, excessive reduction in pulmonary vascular resistance may precipitate progressive pulmonary overcirculation and impaired systemic blood flow. Right ventricular performance and the patency and direction of the ductus arteriosus may play a crucial role in postductal organ perfusion. Physiological stabilization may be complex and variable over time. The utilization of targeted neonatal echocardiography to guide treatment decisions may improve the ability to provide therapy tailored to the specific disease pathophysiology and monitor serially as conditions change. An enhanced approach to physiological stabilization may reduce the risk of unexpected decompensation and allow for thoughtful, controlled endovascular embolization in appropriate candidates.
Radioscapholunate Fusion for Radiocarpal Osteoarthritis: Prognostic Factors of Clinical and Radiographic Outcomes
Authors: Degeorge Benjamin , Montoya-Faivre David , Dap François , Dautel Gilles , Coulet Bertrand , Chammas Michel
Published: May 2019

Background Radioscapholunate (RSL) fusion is a surgical option to manage radiocarpal osteoarthritis. Many authors upgrade the procedure by adding distal scaphoid excision with or without excision of the triquetrum. Our objective was to identify the prognostic factors for good clinical and radiographic outcomes of RSL arthrodesis.

Purpose Distal scaphoid excision improves both scaphotrapeziotrapezoidal osteoarthritis and radiocarpal fusion, and excision of the triquetrum is not critical to achieving satisfactory outcomes.

Methods In this retrospective and bicentric investigation, all wrists were managed with RSL fusion for posttraumatic radiocarpal osteoarthritis. A total of 85 patients were included and evaluated at the revision by clinical (pain, wrist motion, and strength), functional (Disabilities of the Arm, Shoulder, and Hand questionnaire, Patient-Related Wrist Evaluation score, and Modified Mayo Wrist Score), and radiological (scaphotrapeziotrapezoidal, midcarpal osteoarthritis, and radiocarpal nonunion) examinations. We assessed prognostic factors for clinical and radiographic (osteoarthritis and nonunions) outcomes.

Results The average follow-up was 9.1 years (1–21.4). Work-related accidents adversely impacted the clinical outcomes, and distal scaphoid excision significantly improved them and decreased scaphotrapeziotrapezoidal osteoarthritis and nonunion. Neither distal scaphoid excision nor excision of the triquetrum influenced midcarpal osteoarthritis. Radiocarpal fusion was significantly promoted by memory staples and bone grafting.

Discussion Distal scaphoid excision should be preferred to improve the functional results while decreasing scaphotrapeziotrapezoidal osteoarthritis and radiocarpal nonunion rates. Excision of the triquetrum appears to be an alternative to radioulnar resection–arthroplasty to solve ulnocarpal impaction syndrome. Strict surgical procedure must be observed to promote RSL fusion combining solid bone fixation and the use of bone graft.

Level of evidence This is a level IV, case series, retrospective series.
Diagnostic Ultrasound Detection of Changes in Femoral Muscle Mass Recovery after Tibial Plateau Levelling Osteotomy in Dogs
Authors: Frank Ilan , Duerr Felix , Zanghi Brian , Middleton Rondo , Lang Linda
Published: May 2019

Objective The goal of this study was to develop a clinically feasible ultrasound (US) protocol that can detect changes in thigh muscle mass in dogs after stifle surgery. The primary aim of this study was to compare previously described US measurement locations of the canine thigh for detecting changes in muscle mass in dogs recovering from tibial plateau levelling osteotomy (TPLO).

Study Design This was a prospective, exploratory pilot study. Adult dogs (n = 7) undergoing pet-owner elected TPLO were enrolled. Twelve different US measurements were performed in triplicate by a single experienced observer. Measurements were performed at 0, 2, 4 and 8 weeks after surgery at a proximal and distal location along the femur. Data from all available time points and locations were analysed for the main effect of time within modalities.

Results A total of 1,008 US measurements were performed. Measurements of the transverse sectional area of the rectus femoris muscle detected significant (p  ≤  0.05) muscle loss between weeks 0 and 2 at the lateral and medial aspects of the distal location (19% and 15% respectively). Measurements of the thigh muscle thickness were significantly (p < 0.01) increased between 2nd- and 8th- week time points at the lateral aspect of the proximal location (26%).

Conclusion The proximal femoral location, measured from the lateral aspect, appears to be the most suitable US measurement for detecting increases in femoral muscle mass in dogs recovering from TPLO. The provided pilot data suggest that further research evaluating this outcome measure is indicated.
Nosocomial Infection Outbreak with Enterobacter aerogenes at a Neonatal Intensive Care Unit and Its Outcomes
Authors: Ulubaş Işık Dilek , Bas Ahmet Yagmur , Kulali Ferit , Ozcan Beyza , Unal Sezin , Yucel Husniye , Demirel Nihal
Published: May 2019

Objective Health care associated infections (HAIs) in the neonatal intensive care unit (NICU) are a significant cause of neonatal morbidity and mortality. Enterobacter aerogenes, a gram-negative bacterium, rarely causes HAI in the pediatric and NICUs. We report the case of a HAI outbreak of E. aerogenes in an NICU and discuss the clinical spectrum and outcome of the affected preterm newborns and successful prevention measures.

Materials and Methods A retrospective study was conducted in a level III NICU of Etlik Zubeyde Hanım Women's Health Teaching and Research Hospital. The infants with blood cultures positive for E. aerogenes during the outbreak were enrolled. Perinatal risk factors, laboratory findings, symptoms, treatment, and prognosis were recorded. Clinical applications and prevention measures were identified.

Results A preterm infant of 27 weeks of gestation who was diagnosed on the eighth postnatal day was the initial case of the reported outbreak of health care associated E. aerogenes infection. Subsequently, 12 more infants were diagnosed in the next 3 months. Infants' mean gestational age was 27.1 ± 2.3 weeks, and mean birthweight was 902 ± 161 g. The clinical symptoms at presentation were respiratory distress, sclerema, circulatory failure, and shock, which appeared at a mean age of 7.6 ± 5.8 days. Analysis of E. aerogenes strains revealed that all strains were of the same clonal type. Eight patients died in follow-up due to E. aerogenes septicemia during this outbreak. The mean interval between the onset of symptoms and death was 1.5 ± 1 days.

Conclusion Outbreaks of health care associated E. aerogenes infection result in a high mortality rate among very low birthweight infants. Awareness of adjustable risk factors and preventive measures to control the outbreak decreases both morbidity and mortality.
Pott's Disease: An Emerging Source of Potentially Inappropriate Treatment
Authors: Esposito Silvia , Moscatelli Marco , Schiariti Marco Paolo , Viganò Ilaria , Pantaleoni Chiara , Marucci Gianluca
Published: May 2019

Spinal Tuberculosis in children is uncommon, even more so in cases of involvement of posterior vertebral elements, and its diagnosis is often delayed. Here we report the case of a young female presenting neuroradiological features and clinical symptoms suspicious for malignant tumor. Histological examination of biopsy specimen evidenced a Pott's disease. We highlight the importance of suspecting this disorder in children with both aspecific systemic and neurological symptoms, in order to reach a timely diagnosis for appropriate and targeted intervention, avoiding the risk of overtreatment and malpractice claims.
Is Hawking effect short-lived in polymer quantization?
Authors: Barman Subhajit , Hossain Golam Mortuza , Singha Chiranjeeb
Published: May 2019

It is widely believed that the Hawking effect might hold clues to the possible, yet unknown, trans-Planckian physics. On the other hand, one could ask whether the effect itself might be altered by such trans-Planckian physics. We seek an answer to this question within a framework where matter field is quantized using polymer quantization, a canonical quantization technique employed in loop quantum gravity. We provide an exact derivation of the Hawking effect using canonical formulation by introducing a set of near-null coordinates which allows one to overcome the challenges posed by a Hamiltonian-based derivation of the Hawking effect. Subsequently, we show that in polymer quantization, the Hawking effect is short-lived and it eventually disappears for an asymptotic future observer. Such an observer finds the duration of the Hawking effect to be few milliseconds for a solar mass black hole, whereas it is few years for an ultramassive black hole. Consequently, it provides a new way to resolve the so-called information loss paradox.
The modeling of delayed-onset Rayleigh-Taylor and transition to mixing in laser-driven HED experiments
Authors: Di Stefano C. A. , Doss F. W. , Rasmus A. M. , Flippo K. A. , Haines B. M.
Published: May 2019

In this work, we discuss simulations, along with a benchmarking experiment, performed using the xRAGE code which demonstrate the ability of a laser model to predict laser-driven, high-energy-density shock hydrodynamics with good fidelity. This directly contributes to our ability to model hydrodynamic-instability dynamics produced by a laser drive typical of those available at OMEGA, OMEGA-EP, NIF, and similar facilities. In particular, we show how the laser model is essential for predicting deceleration-phase Rayleigh-Taylor arising from laser turn-off. We do this using the experimental case of a seeded single-mode perturbation. Then, we turn to a seeded multimode perturbation to show how the above result permits us to access the modeling of hydrodynamic mixing, a topic of interest for future work.
Hot electron mediated enhancement in the decay rates of persistent photocurrent in gold nanoparticles embedded indium oxide films
Authors: Sen Prabal , Kar Durgesh , Laha Ranjit , Balasubrahmaniyam M. , Kasiviswanathan S.
Published: May 2019

A major factor that hinders the realization of indium oxide (IO) as a potential gas/photosensor is the response time, which is quite poor. For instance, the photoresponse of dc sputtered IO films under UV and sub-bandgap illumination is known to exhibit bi-exponential decay with fast (10–100 min) and slow (∼3000 min) time constants. We demonstrate here that the response time can be greatly improved by the hot carriers generated through localized surface plasmon decay. Our study shows that when IO films are incorporated with gold nanoparticles (AuNPs), the fast and slow decay time constants are reduced by a factor of 20 and 30, respectively, at excitation wavelengths close to the localized surface plasmon resonance (LSPR) wavelength. We also show the possibility to achieve wavelength tunable reduction in the time constants by tuning the LSPR wavelength. We attribute the changes to the strong enhancement in the recombination rates facilitated by plasmon decay-mediated excess hot electrons injected into the conduction band of IO. We use a simple analytical model to explain the role of plasmon-mediated hot electrons in enhancing the recombination rate. We believe that the present results are of great significance to improve the response time of metal oxide based photodetectors/sensors, in general, since the underlying physical process depends primarily on the plasmonic nature of the AuNPs.
Impact of superlinear defect-related recombination on LED performance at low injection
Authors: Gfroerer T. H. , Chen Ruiming , Watt Grace , Liu Zhiqiang , Zhang Yong
Published: May 2019

We investigate the temperature and injection dependence of the electroluminescence from an InGaN/GaN LED to characterize the defect-related recombination mechanism in this system. In contrast to the standard ABC recombination model, we show that the defect-related recombination rate varies superlinearly with carrier density. The elevated loss rate with injection indicates that defect states are less detrimental at low injection, only becoming available for occupation via carrier delocalization or more dynamic Shockley–Read–Hall statistics. This characteristic alleviates defect-related losses by making the radiative mechanism more competitive such that high dislocation density devices can perform better at low injection.
Axial silicon-germanium nanowire heterojunctions: Structural properties and carrier transport
Authors: Wang X. , Tsybeskov L. , Kamins T. I. , Wu X. , Lockwood D. J.
Published: May 2019

We analyzed structural and electrical properties of axial Si-Ge nanowire heterojunctions produced by the vapor-liquid-solid growth method using Au nanoclusters as catalysts. The observed nonlinear current-voltage characteristics, strong flicker noise, and damped current oscillations with frequencies of 20–30 MHz are explained using a proposed Si-Ge nanowire heterojunction energy band diagram that includes energy states associated with structural imperfections, as revealed by transmission electron microscopy.
Destructive mechanisms in laser induced forward transfer
Authors: Jalaal Maziyar , Li Shuai , Klein Schaarsberg Martin , Qin Yigong , Lohse Detlef
Published: May 2019

Laser Induced Forward Transfer (LIFT) is an additive direct-writing technique, in which a piece of material (ink) is transferred from a donor to a receiver surface, utilizing a laser impulse. In practice, the process of jet formation can suffer from irreproducibility. We identify two possible destructive mechanisms due to multiple optical breakdowns (originating from imperfections of the optical system) and rarefaction waves (originating from impurities), both with harmful consequences caused by cavitation. Based on experiments in a model system that allows for visualization and numerical simulations employing the boundary integral method, we reveal the underlying fluid dynamics of both mechanisms. Finally, to overcome the irreproducibility, we provide recommendations for the industrial use of LIFT.
Thermal balance of tungsten monocrystalline nanoparticles in high pressure magnetron discharges
Authors: Arnas C. , Chami A. , Couëdel L. , Acsente T. , Cabié M. , Neisius T.
Published: May 2019

Nanoparticles are produced in sputtering magnetron discharges operating with a tungsten cathode at an argon pressure of 30 Pa. Structure analyses show that they are of core-shell type. The core is a monocrystal mainly in the metastable beta-tungsten phase, and the shell is made of tungsten oxide. The origin of the metastable phase is attributed to the presence of residual oxygen in the device. Since this phase transforms into the stable alpha-tungsten phase by annealing, a standard model on the thermal balance of nanoparticles was used to find the temperature that they can reach under the considered experimental conditions. It is shown that this temperature is significantly higher than the gas one but not high enough to transform the monocrystalline metastable beta-phase during the plasma process.
Comparing indicators of recreational fishing in Port Phillip Bay, Australia, from 2008 to 2011 with variability from a background period (2003–07)
Authors: Ryan Karina L. , Conron Simon C.
Published: May 2019

Understanding the effects of anthropogenic disturbances on marine environments that support recreational fisheries requires suitable monitoring data. Although catch rates are frequently considered to inform resource status for commercial fisheries, similar time series data are generally unavailable for recreational fisheries. This study is based on 9 years of data from boat-based recreational fishing surveys in Port Phillip Bay, Australia. Harvest rates and length distributions of the retained catches for three target species were statistically compared over 4 years following commencement of shipping channel dredging (2008–11) with variability from a background period (2003–07). Mean harvest rates were generally within historical ranges, with increases for snapper (Chrysophrys auratus) and King George whiting (Sillaginodes punctatus) and decreases for sand flathead (Platycephalus bassensis). Length–frequency distributions were not significantly different to the background period, except for increased mean length of snapper and King George whiting in 2011. This study demonstrates that data obtained from sampling recreational fishers can provide valuable information to monitor harvested resources and maintain social amenity for recreational fisheries during periods of anthropogenic disturbance. Trends in harvest rates from recreational fishing surveys may also complement catch rates from commercial fisheries for assessments of multisector fisheries or stand-alone assessments for recreational-only fisheries.