bluuebunny/crossref_metadata_2025 huggingface dataset:
Automatic compensation of tool disturbances, caused by an unstable cutting process
Authors: Gusev Vladimir
Published: November 2019

Modern machining processes are characterized by a separate functioning of the elements of technological system (TS). The cutting mode, that determines the machining efficiency, depends on the functional capability of a low-performance element, and the other higher-performance elements are not able to reduce the workload of the first element. The “strong” element of the TS can not help the “weak” one in reducing the received workload. The transfer of a part of the workload from the “weak” to the “strong” element allows to use the higher cutting mode. In such statement the increase of efficiency of machining processes in the scientific and technical literature was not observed. Is offered to connect a pliable cutting tool with a rigid large-sized workpiece by special contact knot, which allows to compensate the tool perturbations, caused by unstable process of cutting. This knot provides a dissipative and elastic connection between the tool and the workpiece, has been made and tested at holes machining. As a result the increase of efficiency of machining processes of holes was installed.
Simulation of thermal strength of the process of flat grinding of workpieces in intermittent circles
Authors: Vetkasov Nikolai , Ulitin Sergey , Krupennikov Oleg , Sapunov Valeriy , Ankilov Andrey
Published: November 2019

The present article is concerned with numerical schemes of the radial Py and the tangential Pz components of the grinding pressure and with the average contact temperature T, °С. These characteristics give an opportunity to assess the level of the thermal power strain at every path of the operational cycle of the flat pendulum grinding using a standard grinding wheel (SW), an intermittent grinding wheel (IGW) and a composite grinding wheel (CGW). Value forecasting of forces Py,pz and the temperature T will make it possible to manage the grinding process and will give the opportunity to avoid the defects precipitation at the grinding finish of the workpiece.
Technologies for producing syntactic carbon foams with specified operational properties
Authors: Galimov Engel , Sharafutdinova Elmira , Galimova Nazira
Published: November 2019

Technologies for producing two classes of syntactic carbon foams of regular structure were developed: thermal insulating and heat-conducting foams with specific physico-mechanical properties designed for operation under extreme conditions. The possibility of controlled development of porous structure in carbon foams upon their production by selecting the initial components in the form of binders, hollow particles (microspheres) and various additives (solvents, etc.), their optimal combination and ratio, as well as operating parameters of thermal processing. Phenol-formaldehyde resins, melamine and coal or oil pitches filled with hollow particles in the form of phenolic and carbon microspheres were used as starting components for the production of carbon foams. Technologies for producing carbon foams include the sequence of the following stages: preparation and mixing of the starting components, molding of samples, carbonization, graphitization, pyrocompaction and mechanical processing. Thermal insulation foams were obtained using two technologies. The first technology for producing foams involves using phenolic microspheres and a binder in the form of a phenol-formaldehyde resin of the novolac type. The second technology for producing foams through template carbonization involves the use of high porosity melamine with cellular structure as a binder, and hollow phenolic microspheres.
Modeling of process of gear milling for definition of the intense deformed state in replaceable many-sided plates of a worm mill
Authors: Artamonov E.V. , Kireev V.V. , Zyryanov V.A.
Published: November 2019

The tool equipment plays an important role in work of machine-building enterprises. One of the most important elements of equipment is the metal-cutting tool [1]. Replacement of the tool from HSS of steel on the cutting tool with use of WC-Co [2-7] sintered hard alloys gives increase in productivity and overall effectiveness of processing [8-11]. When the cutting ability of material of the tool increases, the universality of its application decreases therefore the most rational is comprehensive research approach which considers design of the tool the used WC-Co hard alloy. Design, production and testing of the toothed cutting tools, working off of the modes of cutting have to be carried out concerning a specific work piece and its material. When developing this kind of the tool it is necessary to consider features of WC-Co alloy as the cutting material, the cutting modes, destruction of the tool and other moments connected with its use. Influence of an initial contour on distribution of tension in the replaceable cutting many-sided plate. Results of calculation of the intense deformed state in a replaceable plate from the material WC-Co. Zones of stretching and compression are observed on the main cutting edge. Concentration of the dangerous stretching tension is located in a transitional zone between the direct side cutting edge to top as in this zone there is the greatest constraint of cutting. Respectively, the greatest destruction will happen in this zone. Important, the fact that in this part of the cutting edge there will be the biggest wear on a back surface. The analysis of isolines of distribution of tension showed that the stretching tension along a front surface of the replaceable cutting plate decreases because each replaceable cutting plate cuts off the part of material. First, work is entered by the made narrower cutting plate which cuts off metal an upper part of the cutting plate, and then the underestimated cutting plate which works with the side cutting edges works. As a result of the conducted researches it was established that with the progressive scheme of cutting in comparison with the standard scheme of cutting at which the initial profile of the making rail is made on DIN3972 at gear milling, dangerous tensile stresses in the cutting hard-alloy plates significantly decrease.
Simulation of repair and technical maintenance processes for power-generating equipment components at chemical factories
Authors: Efimenko Nikolay S. , Sabanaev Ildar A. , Madyshev Ilnur N.
Published: November 2019

Theoretical aspects and experience of using the mathematical modeling and computerized simulation technology for solving the problems of installation and repair of process equipment of chemical and petrochemical industries are considered in this scientific paper. Computational model of restoring process to working condition of pipeline section has been developed. It is shown that if you use the developed model, then the labor-intensive installation activities, related to the repair works on heat and power networks of chemical industries, can be performed in a more efficient way.
The gas-dynamic antifriction coating of babbitt for bearings of the turbine rotor
Authors: Tsareva Irina , Berdnik Olga , Krivina Lyudmila , Levanov Yuri
Published: November 2019

The application of the anti-friction coating of babbitt on the working surface of sliding bearings is an important technological procedure necessary both for their manufacture and for their repair. To extend the service life and restore the performance of bearings, the coating is preferably applied by gas-dynamic spraying, The coating formed by this method has a low porosity, high adhesion strength and low friction coefficient.
Process of soil destruction: experimental results
Authors: Troyanovskaya Irina , Grebenshchikova Olga , Zhitenko Ivan
Published: November 2019

The article presents the results of experimental studies of the ripping resistance force on a tracked bulldozer-ripper manufactured by the Chelyabinsk Tractor Plant. The experiment covers three ripping depths and eight angles. It has been experimentally established that the dependence of the ripping resistance force on each of these parameters is quadratic. The authors propose the use of a complex parameter which is equal to the product of the ripping depth by the angle when studying the ripping process. The use of the complex parameter for two-factor analysis allowed them to reduce the degree of the studied dependence while preserving the required accuracy. The complex parameter reflects the relationship between the design parameters of the ripper tooth, the ripping depth, and angle.
Design basis development for centrifugal turbo machines with a coaxial impellers location for mining-and-metallurgical industry conditions
Authors: Podbolotov S.V. , Kolga A.D. , Gabbasov B.M. , Kurochkin A.I.
Published: November 2019

The article considers the main ways to improve the modern designs of centrifugal turbo machines. The existing methods of their design are analyzed. One of the development options is considered which consists in using the coaxial impellers location in centrifugal turbo machines. A technique for designing a coaxially mounted impeller is presented.
Use of numerical modeling methods in desing of combined rectification column
Authors: Ibragimova Ramilya , Afanasenko Vitaliy , Kudryavtsev Gleb , Mazidullin Denis
Published: November 2019

The article is devoted to the study of methods for modeling the operation of rectification columns using the HYSIS application software package. Such studies are very important not only for design, but also for the functioning of existing industries. The article proposes to use for combining nozzle devices in the concentration part of the column, and plate-shaped structures in the distant part of the column for more efficient and stable operation of distillation columns. To determine the hydrodynamic parameters of the operation of distillation column, a technique of determining the range of stable loads and the position of the operating point inside or outside the range of stable loads was taken. A column model was constructed using the HYSYS software package for separating gas mixtures with various contact devices: sieve trays, Rashig ring nozzles. Experiments for the same type and combined contact devices were carried out and their comparison was carried out in terms of hydraulic calculation and operating range. As a result of experiments with the use of the HYSYS software package, it was shown that the combined arrangement of contact devices can provide a stable hydraulic mode, in contrast to the use of similar contact devices.
Research on technological capabilities of double-electrode welding of long fillet welds
Authors: Fiveyskiy Andrei , Mosin Aleksei , Zverev Sergey , Polevoy Ilya
Published: November 2019

The article presents the results of a research of the technological capabilities of double-electrode submerged arc welding of elongated fillet welds with a leg of 8 mm or more in one pass while ensuring high-quality and stable formation of weld. As the result of the research we reviewed the features of the fillet weld formation during welding of metal strips with a thickness of 14 mm with different locations of the welding wires in the torch relative to the axis of the welded joint. Consequently we determined the best option in terms of the quality of the weld formation and increase in welding productivity as compared with the two-pass single-arc welding. The conditions and parameters of the single-pass double-electrode (“split electrode welding”) submerged arc welding are established, providing a welding speed of up to 35 m / h.
Simulation of thermal treatment of mineral wool blanket
Authors: Pilipenko Anton , Bobrova Ekaterina , Efimov Boris
Published: November 2019

This article describes results of modelling of heat treatment of mineral wool blanket. The properties of mineral wool products are largely determined by the conditions of heat treatment, which is carried out by suction of the heat carrying agent through a layer of mineral wool blanket. The choice of technological parameters and optimization solutions determines both the energy costs of manufacturing mineral wool products and their properties and the stability of these properties over time when used in structures. Optimizing the heat treatment parameters of a mineral wool blanket is a labor-intensive and time-consuming task. The development of accelerated methods based on the analysis of the results of previously conducted and new studies can significantly reduce the time for choosing technological parameters, as well as increase the reliability and adequacy of decisions.
Research of materials of Fe-C-Si and Fe-C-Al systems
Authors: Bikulov Rinat
Published: November 2019

The paper presents the results of a study of tests for wear resistance, thermal stability and heat resistance of materials based on Fe-C-Si and Fe-C-Al systems (the first graphitization zone). When conducting research, a distinctive feature of obtaining materials of Fe-C-Si and Fe-C-Al systems (the first graphitization zone) is the use of particulate of iron-containing dispersed wastes of machine-building production. The results of the study showed the promise of using particulate wastes of mechanical engineering as charge materials for thermal stability, heat-resistant and wear-resistant castings.
Analysis of operating conditions of heavy-loaded and heat-stressed friction units of powerful internal combustion engines and development of copper nanocomposite powder materials for them
Authors: Shalunov Evgeny , Shalunov Sergey , Vladimirova Yulia
Published: November 2019

The article provides analysis of operating conditions for the «valve – valve guide» heavy-loaded and heat-stressed friction unit of the gas distribution mechanism of powerful internal combustion engines and establishes requirements to materials for valve guides. It describes nanoc omposite materials based on copper powder with aluminum, carbon, iron and oxygen additives developed by the authors of the present article. The reactionary mechanical alloying method and powder metallurgy technologies in use made it possible to develop materials having a dispersion-strengthened structure with nano-disperse level sizes of structural components (dispersoids, subgrains). They have a recrystallization temperature of over 950оС, good therm-conductivity, a low linear thermal expansion coefficient and excellent tribotechnical properties. For example, a copper nanocomposite material containing 0.9 wt % aluminum, 0.3 wt % carbon, 0.4 wt % iron and 0.017 wt % oxygen, by its tribotechnical properties, greatly surpasses CuNi2Si (F65 DIN 17666) bronze widely used by many leading engine-making companies for production of valve guides. By their properties, the developed materials meet requirements that have to be imposed on modern and promising materials for valve guides of powerful internal combustion engines.
The model of control of reliability using the parameters of survivability in terms of innovation
Authors: Ponikarova Anna , Zotov Maksim , Ponikarov Sergey
Published: November 2019

Research of modern processes of ensuring reliability of innovative development become more and more actual recently as more and more often the organizations should make decisions in the conditions of the growing uncertainty. This creates the need for new approaches in the study of management of innovative reliability of economic systems and their search for new mechanisms and tools to achieve it. According to the authors, one of the tools of such management in modern conditions can be structural and functional survivability. It can be used to determine the most effective innovative projects for organizations, taking into account their internal characteristics and the specifics of changes in the external environment. In addition, the dynamics of the values of this integral indicator allows us to assess the effectiveness of management decisions, allowing us to consider it a regulator in the model of innovation management of economic systems. This model, along with internal factors, assumes some change in the existing insitutional environment. It is proposed to implement it on the basis of the principles of open innovation, in order to increase the efficiency and security of innovative development of modern companies.
Testing the efficiency of abrasive treatment of reconditioned parts using coolant cleaning in a magnetic sump
Authors: Avdeyev Boris , Vyngra Aleksey , Bordiug Aleksander
Published: November 2019

This article discusses pilot study of effectiveness of abrasive machining of the recoverable parts for cleaning cooling lubricants involved in technological processes of processing of the parts. One of the cleaning methods is a magnetic sump, which has high efficiency at relatively low cost of operation and maintenance. Laboratory tests of the magnetic sump were carried out according to a full-factor experiment, varying with certain parameters in order to identify the purity index of cooling lubricant when cleaning from mechanical impurities. Dependencies are obtained that connect the value of purity index of coolant with the technological and structural parameters of the magnetic sump. The influence of the cooling lubricant purity index in the magnetic sump on the roughness of grinded surface of the samples was revealed. The most rational parameters of the magnetic sump have been determined at which optimum surface roughness is observed when processing the engine crankshaft using cooling lubricant cleaned in the magnetic sump.
Research of modes and work of a combined unit for subsoil application of protective-stimulating liquids in spaces between rows of gardens and vineyards
Authors: Borisova Svetlana M. , Papusha Sergey K. , Papusha Vladimir K. , Nikitenko Nikolay A.
Published: November 2019

The combined unit is used for tillage and subsurface belt application of protective and stimulating liquids and microorganisms into the soil. New technology offers for the task to use pneumatic slotted sprayers with jet-forming device that is linked with a compressor that delivers air to transform the operation fluid from the tank in the aerial-droplet jet processing lower layers of the soil simultaneously with cultivation. Protective shields save the sprayer from deformation and breakage. To obtain the required range of the jet, the angle of inclination of the sprayer is adjusted. The supply line of operation fluid has an equalizing capacity to change the flow rate of the operation fluid. The basis of the development of sprayers was the task of development of a plane-parallel jet capable of spreading to a distance to 2 m with an adjustable width of a grip m/s. there were conducted the researches of performance (charge) of pneumatic slotted sprayer depending on air pressure given to in slotted nozzles of the sprayer.
The impact analysis of the gaps in kinematic pairs on dynamic processes in cyclic mechanisms
Authors: Telegin Viktor
Published: November 2019

Cyclic mechanisms (cam, crank and others) are most vulnerable to the growth of dynamic (oscillatory) processes, especially at high speeds of their movement. Many factors affect the reliability and performance of these mechanisms, determined primarily by their dynamic characteristics. The main ones are the elastic-inertial and dissipative properties of the links, external forces acting on the elements of the mechanisms, as well as the gaps in the kinematic pairs of the links of the links. The paper studies impact of gaps in the kinematic pairs of link, design features of these links, all other things being equal, on the cyclic mechanical systems dynamics. Three computational models of kinematic pairs are considered in the article, the results of studying the influence these models parameters on the level of dynamic processes in the cam-lever mechanism during transfer workpieces between the cold-stamping automatic machine (CSAM) AB1818 positions.
Automation of assessment of the strain state of metal cutting machine mechanism elements on the basis of response function application
Authors: Kosov Mikhail , Lukina Svetlana , Ametova Maria
Published: November 2019

The article dwells upon the assessment of the strain state of metal-cutting machines with the help of the numerical method of finite elements in the form of displacements. A metal-cutting machine is considered as a system consisting of a set of structural elements taking a set position in space in relation to each other, and a part of them may execute relative motions (displacements). The paper suggests a modification of the finite element method on the basis of combining a set of finite elements into a group with the use of the response function. The author provides an analytical calculation method to resolve the problem of assessing the strain state of the machine mechanism elements in linear and non-linear settings. The developed algorithm allows analyzing geometrical, physical and contact non-linearity of metal working. The research provides a practical implementation of the developed method by the examples of assessing the strain state of a rod element modeling the roughness of the contact surface of the machine mechanism elements under temperature and tensile loads.
Application of ultrasonic testing method for determining defects of hot-deformed powder materials
Authors: Egorov Maxim S. , Atrokhov Andrey A. , Nedostup Evgeniy A. , Vasilyeva Ekaterina V.
Published: November 2019

The article is devoted to the analysis of elastic and plastic characteristics of composite materials during hot stamping. The purpose of this work is to offer optimal conditions for hot plasticity of composite porous material with determination of temperature conditions of hot stamping excluding the appearance of defects in the structure. Production of details of the difficult form by method of hot stamping from preparations of the cylindrical form is followed by development of barrel on a peripheral surface. Sludge sintered porous blanks, and sediment compact material, accompanied by a nonuniform height lateral deformation. In connection with the action of friction forces on the contact surfaces, this leads to the formation of a “barrel”. The heterogeneity of the deformed state is associated with the appearance of tangential tensile stresses on the free surface of the workpiece. If they exceed some critical degree of transverse deformation, cracks appear on the side surface, which leads to gas saturation (oxidation) of the inner layers of the forging, to the ingress of grease into them and its pressing into the volume of the part during hot stamping. In the end, this significantly reduces the properties of hot-stamped parts. Conclusion: the methods of determining the elastic characteristics depending on the geometric parameters of the workpieces, the applied strain energy, body density and temperature dependence of the plasticity characteristics of the hot deformation of the powder material are сonsidered.
Die Nachsorge des Lungenkarzinoms
Authors: Tufman Amanda , Duell Thomas , Schneider Christian
Published: November 2019

Ziel dieses Beitrags ist es, die aktuellen Leitlinien bzw. Empfehlungen zur Nachsorge des Lungenkarzinoms zu präsentieren und eine evidenzbasierte Herangehensweise für die Erstellung von individualisierten Nachsorgepläne aufzuzeigen.
Perinatal Outcomes of Women Aged 50 Years and Above
Authors: Maoz-Halevy Erez , Pariente Gali , Sheiner Eyal , Wainstock Tamar
Published: November 2019

Objective Pregnancies among women aged 40 and above are increasing in frequency. Nevertheless, little is known about the perinatal outcomes of women aged 50 years and above. The purpose of the study was to evaluate pregnancy outcomes in women at an extremely advanced maternal age of 50 years or above.

Study Design In a population-based cohort study, perinatal outcomes of women aged 50 years and above were compared with pregnancies in women according to maternal age. All singleton deliveries that occurred between the years 1991 and 2014 in a tertiary medical center were included. We excluded fetuses with congenital anomalies and chromosomal abnormality. Logistic regression models were used to control for confounders.

Results During the study period, 242,771 deliveries were included, of which 234,824 (96.7%) occurred in women aged < 40 years, 7,321 (3.0%) in women aged 40 to 44 years, 558 (0.2%) in women aged 45 to 49 years, and 68 (0.03%) in women aged 50 years and above. Maternal age of 50 years and above was noted as an independent risk factor for gestational diabetes mellitus (GDM), low Apgar scores, and cesarean delivery. Nevertheless, among pregnancies of women aged 50, pregnancy outcomes including GDM, preterm delivery, cesarean delivery, lower Apgar scores at 5 minutes (<7), and perinatal mortality were not significantly different than pregnancy outcomes of women aged 40 to 49 years.

Conclusion Pregnancy at the maternal age of 50 years and older is independently associated with higher rates of GDM, cesarean delivery, and lower Apgar scores at 5 minutes; however, most perinatal complications were not higher compared with pregnant women aged 40 to 49 years. These findings suggest that while there is an increased risk of perinatal complications in pregnancies of women aged 40 years or above compared with younger women, there are no significant increased risks in women aged over 50 years.
Time of Pediatric Intensive Care Unit Admission and Mortality: A Systematic Review and Meta-Analysis
Authors: Williams Vijai , Jaiswal Nishant , Chauhan Anil , Pradhan Pranita , Jayashree Muralidharan , Singh Meenu
Published: November 2019

The aim of this study was to determine the association between the time of admission (day, night, and/or weekends) and mortality among critically ill children admitted to a pediatric intensive care unit (PICU). Electronic databases that were searched include PubMed, Embase, Web of Science, CINAHL (Cumulative Index of Nursing and Allied Health Literature), Ovid, and Cochrane Library since inception till June 15, 2018. The article included observational studies reporting inhospital mortality and the time of admission to PICU limited to patients aged younger than 18 years. Meta-analysis was performed by a frequentist approach with both fixed and random effect models. The GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach was used to evaluate the quality of evidence. Ten studies met our inclusion criteria. Five studies comparing weekday with weekend admissions showed better odds of survival on weekdays (odds ratio [OR]: 0.77; 95% confidence interval [CI]: 0.60–0.99). Pooled data of four studies showed that odds of mortality were similar between day and night admissions (OR: 0.93; 95% CI: 0.77–1.13). Similarly, three studies comparing admission during off-hours versus regular hours did not show better odds of survival during regular hours (OR: 0.77; 95% CI: 0.57–1.05). Heterogeneity was significant due to variable sample sizes and time period. Inconsistency in adjusting for confounders across the included studies precluded us from analyzing the adjusted risk of mortality. Weekday admissions to PICU were associated with lesser odds of mortality. No significant differences in the odds of mortality were found between admissions during day versus night or between admission during regular hours and that during off-hours. However, the evidence is of low quality and requires larger prospective studies.
Heart Failure in a Patient with Leprosy
Authors: SriKrishna Srikakulapu
Published: November 2019

Leprosy, also known as Hansen's disease, is a chronic infection caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Though leprosy predominantly involves peripheral nerves and skin, visceral involvement was recognized as early as 1894 by Hansen and Looft. It is known that the bacilli can lie dormant in some tissues of the body long after the skin smears have become negative. We describe a case of leprosy in an Indian male who presented to us with heart failure. This is likely the first report of showing the possible association of leprosy with heart failure from India. The cardiovascular involvement in leprosy is briefly reviewed.
Prediction of H2O PVT relations at high temperatures by VHL equation of state
Authors: Liu Qin , Han Yong , Long Xinping , Duan Yingliang
Published: November 2019

Based on the VHL equation of state(EOS) described by the L-J potential function, the water in the high-temperature situation is depicted by medium-high pressure thermodynamic states. The L-J potential function parameters of water adopt a temperature-dependent function form, and by using complex configuration optimization method, the specific value is obtained from the date in NIST during the range of 800K-1275K and 0.1GPa-1.0GPa. In order to test the suitability of VHL equation of state in high -temperature and medium-high pressure state, the theoretical and experimental data of higher temperature and pressure range are investigated. What’s more, the theoretical calculation results of VLW, DMW, BS and TIP4P equations of state are compared. The results show that, during the high-temperature and medium-high pressure section, the volumetric error of water calculated by VHL equation of state is less than 7%. Considering the uncertainty of the experimental data, it can be thought that the VHL equation of state and the temperature-dependent potential function form proposed in this paper can describe the state of water in high temperature, medium-high pressure better.
Learning the tangent space of dynamical instabilities from data
Authors: Blanchard Antoine , Sapsis Themistoklis P.
Published: November 2019

For a large class of dynamical systems, the optimally time-dependent (OTD) modes, a set of deformable orthonormal tangent vectors that track directions of instabilities along any trajectory, are known to depend “pointwise” on the state of the system on the attractor but not on the history of the trajectory. We leverage the power of neural networks to learn this “pointwise” mapping from the phase space to OTD space directly from data. The result of the learning process is a cartography of directions associated with strongest instabilities in the phase space. Implications for data-driven prediction and control of dynamical instabilities are discussed.
Nonequilibrium path-ensemble averages for symmetric protocols
Authors: Nguyen Trung Hai , Ngo Van , Castro Zerba João Paulo , Noskov Sergei , Minh David D. L.
Published: November 2019

According to the nonequilibrium work relations, path-ensembles generated by irreversible processes in which a system is driven out of equilibrium according to a predetermined protocol may be used to compute equilibrium free energy differences and expectation values. Estimation has previously been improved by considering data collected from the reverse process, which starts in equilibrium in the final thermodynamic state of the forward process and is driven according to the time-reversed protocol. Here, we develop a theoretically rigorous statistical estimator for nonequilibrium path-ensemble averages specialized for symmetric protocols, in which forward and reverse processes are identical. The estimator is tested with a number of model systems: a symmetric 1D potential, an asymmetric 1D potential, the unfolding of deca-alanine, separating a host-guest system, and translocating a potassium ion through a gramicidin A ion channel. When reconstructing free energies using data from symmetric protocols, the new estimator outperforms existing rigorous unidirectional and bidirectional estimators, converging more quickly and resulting in a smaller error. However, in most cases, using the bidirectional estimator with data from a forward and reverse pair of asymmetric protocols outperforms the corresponding symmetric protocol and estimator with the same amount of simulation time. Hence, the new estimator is only recommended when the bidirectional estimator is not feasible or is expected to perform poorly. The symmetric estimator shows similar performance to a unidirectional protocol of half the length and twice the number of trajectories.
The static local field correction of the warm dense electron gas: An ab initio path integral Monte Carlo study and machine learning representation
Authors: Dornheim T. , Vorberger J. , Groth S. , Hoffmann N. , Moldabekov Zh. A. , Bonitz M.
Published: November 2019

The study of matter at extreme densities and temperatures as they occur in astrophysical objects and state-of-the-art experiments with high-intensity lasers is of high current interest for many applications. While no overarching theory for this regime exists, accurate data for the density response of correlated electrons to an external perturbation are of paramount importance. In this context, the key quantity is given by the local field correction (LFC), which provides a wave-vector resolved description of exchange-correlation effects. In this work, we present extensive new path integral Monte Carlo (PIMC) results for the static LFC of the uniform electron gas, which are subsequently used to train a fully connected deep neural network. This allows us to present a representation of the LFC with respect to continuous wave-vectors, densities, and temperatures covering the entire warm dense matter regime. Both the PIMC data and neural-net results are available online. Moreover, we expect the presented combination of ab initio calculations with machine-learning methods to be a promising strategy for many applications.
Experimental and theoretical study of swept-wing boundary-layer instabilities. Three-dimensional Tollmien-Schlichting instability
Authors: Borodulin V. I. , Ivanov A. V. , Kachanov Y. S. , Mischenko D. A. , Örlü R. , Hanifi A. , Hein S.
Published: November 2019

Extensive combined experimental and theoretical investigations of the linear evolution of three-dimensional (3D) Tollmien-Schlichting (TS) instability modes of 3D boundary layers developing on a swept airfoil section have been carried out. The flow under consideration is the boundary layer over an airfoil at 35° sweep and an angle of attack of +1.5°. At these conditions, TS instability is found to be the predominant one. Perturbations with different frequencies and spanwise wavenumbers are generated in a controlled way using a row of elastic membranes. All experimental results are deeply processed and compared with results of calculations based on theoretical approaches. Very good quantitative agreement of all measured and calculated stability characteristics of swept-wing boundary layers is achieved.
Complex viscosity of helical and doubly helical polymeric liquids from general rigid bead-rod theory
Authors: Piette J. H. , Giacomin A. J. , Kanso M. A.
Published: November 2019

With general rigid bead-rod modeling, we recreate shapes of complex macromolecular structures with beads, by rigidly fixing bead positions relative to one another. General rigid-bead rod theory then attributes the elasticity of polymeric liquids to the orientation that their macromolecules develop during flow. For linear viscoelastic behaviors, this theory has been evaluated for just a few very simple structures: rigid rings, the rigid tridumbbell, and three quadrafunctional branched structures. For oscillatory shear flow, the frequency dependencies of both parts of the complex viscosity are, at least qualitatively, predicted correctly. In this paper, we use general rigid-bead rod theory for the most complex macromolecular architectures to date. We thus explore the role of helix geometry on the complex viscosity of a helical polymeric liquid. Specifically, for both singly and doubly helical structures, we investigate the effects of helix radius, flight length, helix length, and the number of beads per flight on the complex viscosity function, the fluid relaxation time, and the zero-shear values of the steady shear viscosity and of the first normal stress coefficient. As a worked example, we examine specifically deoxyribonucleic acid (DNA). Using general rigid bead-rod theory, we dissect the DNA to see how the first helix, second helix, and then the base pairs each contribute to the complex viscosity. We next explore the rheological implications of gene replication to find that the unzipping of DNA into a pair of single strands is viscostatic.
Piezo-optomechanical coupling of a 3D microwave resonator to a bulk acoustic wave crystalline resonator
Authors: Carvalho N. C. , Bourhill J. , Goryachev M. , Galliou S. , Tobar M. E.
Published: November 2019

We report the observation of coupling between a 3D microwave cavity mode and a bulk mechanical resonator mediated by piezoelectric and radiation pressure effects. The system is composed of a quartz bulk acoustic wave resonator placed inside a microwave re-entrant cavity, which is designed to act as both the electrodes for piezoelectric actuation and a 3D resonator. The cavity electromagnetic mode is modulated by a 5 MHz bulk acoustic wave shear mode, which is modeled and experimentally verified using the input-output formalism. Through finite element method simulations, we calculate the various contributions to the electromechanical coupling and discuss the potential of the system to reach high cooperativities as well as suitable applications.
Self-cleaning organic solar cells based on micro/nanostructured haze films with optical enhancement effect
Authors: Ren Zhongyang , Zheng Qiao , Chen Xuexian , Wang Haobin , Guo Hang , Miao Liming , Wan Ji , Xu Chen , Cheng Shuying , Zhang Haixia
Published: November 2019

We present a self-cleaning organic solar cells (OSCs) with a light-trapping structure by introducing a groove-shaped micro/nanostructured haze thin films (GHFs). The GHF with periods larger than wavelengths of incident light can broaden the effective optical paths and promote the diffused lights, while keeping high (low) total transmission (reflectance) properties. When laminated GHF on top of the light-in side of OSCs, the power conversion efficiency of OSCs is improved more than 10%. Simultaneously, the superhydrophobic GHF composed of the groove structure allows the droplets to successfully remove dust particles from the polydimethylsiloxane (PDMS) surface during the roll-off process of the drop. Under 10 cycles of dust contamination and cleaning treatment, OSCs with GHF can still guarantee an initial efficiency of 84% (76%), showing great potentials of OSCs in practical applications.
Combined mTORC1/mTORC2 inhibition blocks growth and induces catastrophic macropinocytosis in cancer cells
Authors: Srivastava Ritesh K. , Li Changzhao , Khan Jasim , Banerjee Nilam Sanjib , Chow Louise T. , Athar Mohammad
Published: November 2019

Significance

We report that cell lines of rhabdomyosarcoma (RMS) and cancer cell lines of skin, breast, lung, and cervix are highly sensitive to mTORC1/2 dual inhibitors. mTORC1/2 complexes regulate protein synthesis, cell proliferation, growth, stress responses and survival. The cancer cells died by a catastrophic process, called macropinocytosis, in which numerous single-membrane vacuoles filled with watery fluid formed, merged, and ruptured, killing the cells. Consistent with the findings in cultured cells, the growth of RMS cells implanted in immunocompromised mice was significantly reduced, especially in combination with cyclophosphamide, a standard chemotherapeutic drug to treat RMS.
Children’s acceptance of social robots
Authors: de Jong Chiara , Peter Jochen , Kühne Rinaldo , Barco Alex
Published: November 2019

Social robots progressively enter children’s lives, but little is known about children’s acceptance of social
robots and its antecedents. To fill this research gap, this narrative review surveyed 34 articles on child-robot interaction
published between 2000 and 2017. We focused on robot, user, and interaction characteristics as potential antecedents of children’s
intentional and behavioral social robot acceptance. In general, children readily accept robots. However, we found that social,
adaptive robot behavior, children’s sex and age, as well as frequency of the interaction seem to affect acceptance. Additionally,
we found various theoretical and methodological shortcomings in the field. The review concludes with recommendations and
directions for future research on children’s acceptance of social robots.
The graphical abstract as a new genre in the promotion of science
Authors: Hendges Graciela Rabuske , Florek Cristiane Salete
Published: November 2019

This study explores an increasingly popular Internet genre, the graphical abstract, and its relations to verbal abstracts and to the images used in research articles. We develop a preliminary description of the form and function of GAs, based on a sample of texts from chemistry and engineering and on journal editors and authors’ perceptions about the genre. The results show significant variation among the texts, yet some discipline-internal regularities could be observed. These findings do not necessarily reflect editors and authors’ perceptions. The frequent use of color and drawings is related to the promotional role of graphical abstracts in attracting a wide range of readers, which approximates the genre to verbal abstracts, but dissociates it from scientific images. Graphical abstracts seem to combine the best of its precedent part-genres to optimize the journal readership.
The multimodal bridge between academics and practitioners in the Harvard Business Review’s digital context
Authors: Maier Carmen Daniela , Engberg Jan
Published: November 2019

In this chapter we study adjusting strategies employed in the transition from research-based articles to other generic forms when the same knowledge is constructed and (re)mediated for different audiences and purposes. The empirical evidence is represented by a series of articles and related digital materials about and for the practice of management from the digital context of the Harvard Business Review.

We adopt a multimodal approach in our qualitative analysis, addressing the way semiotic modes interact and are combined across genres to identify the roles of the semiotic interplay in the adjusting strategies employed for enabling the knowledge construction and (re)mediation processes. Furthermore, we demonstrate how the level of complexity of the knowledge communicated in the articles and their digital context may be investigated.
Must/need, may/can and the scope of the modal auxiliary
Authors: Duffley Patrick
Published: November 2019

This article argues that the logical paraphrases used to describe the meanings of must, need,
may, and can obscure the natural-language semantic interaction between these verbs and negation. The
purported non-negatability of must is argued to be an illusion created by the indicative-mood paraphrase ‘is
necessary’, which treats the necessity as a reality rather than a non-reality. It is proposed that negation coalesces with the
modality that must itself expresses to produce a negatively-charged version of must’s modality:
the subject of musn’t is represented as being in a state of constraint in which the only possibility open to the
subject is oriented in the opposite direction to the realization of the infinitive’s event. The study also constitutes an argument
against a lexicalization analysis: in the combination mustn’t, must and not each contribute
their own meaning to the resultant sense, but according to their conceptual status as inherently irrealis notions.
Norms of language
Authors: Zlatev Jordan , Blomberg Johan
Published: November 2019

After decades dominated by a focus on the “individual speaker” and the “mind/brain” in both generative and cognitive linguistics, recent years have reinstated an older view on language as primarily social, i.e. as taking place between people more than within them. Within such a social conception of language, it is natural to reconsider the notion of language norm, but there have been few efforts in this direction. Two eminent exceptions are Eugenio Coseriu and Esa Itkonen, whose approaches to linguistic normativity we here focus on. Even given a combination of their insights, we find that some puzzles remain, especially concerning the question where language norms derive from. We pose this question in the spirit of (generative) phenomenology where the task is “precisely to inquire after how historical and intersubjective structures themselves become meaningful at all, how these structures are and can be generated” (Steinbock 2003: 300). Following earlier work where we have argued for the value of a phenomenological approach to language, we show how the philosophical tradition emanating from Edmund Husserl can both help resolve conceptual puzzles surrounding language norms and clear up the ground for further empirical studies.
Norms of correctness and rationality in research on code-switching
Authors: Mäkilähde Aleksi
Published: November 2019

Among different types of norms, two of perhaps the most relevant for linguistics are those of correctness and rationality. The aim of this chapter is to demonstrate the relevance of both to research on code-switching. I approach the topic from the perspective of the philosophy of linguistics in an analysis of certain ontological and epistemological problems in CS research, and use this analysis to draw methodological implications for the field in general. In particular, a methodological synthesis between intuition and observation is discussed and illustrated with an analogy between languages and games.
Thermal analysis of a high-power glow discharge in flowing atmospheric air by combining Rayleigh scattering thermometry and numerical simulation
Authors: Kong Chengdong , Li Zhongshan , Aldén Marcus , Ehn Andreas
Published: November 2019

The thermal state of a glow discharge with intermediate current in flowing atmospheric air is investigated by a combination of Rayleigh scattering thermometry imaging and numerical simulation. Results from the simulation indicate that during the initial breakdown the local translational temperature can reach a huge value (e.g. 6000 K) but decreases quickly due to strong heat transfer to the surrounding cold air. In the gliding stage, the translational temperature of plasma is balanced by the input power density and the heat dissipation rate. As the gas flow rate is increased, the translational temperature in the glow plasma column diminishes. The flow affects the thermal state of plasma from two aspects. First, it promotes elongation of the plasma column to decrease the input power density. Second, the flow enhances local heat dissipation. As a result, the translational temperature is lowered due to flow. Using a two-temperature model, which considers the translational temperature, the vibrational temperature and their transitions, the non-thermal state of plasma is further analyzed. The gas flow is found to reduce the translational temperature and the vibrational–translational relaxation rate, and thus prevent thermalization of the plasma column.
Comparison of Elemental Analysis Techniques for Fly Ash from Municipal Solid Waste Incineration using X-rays and Electron Beams
Authors: An S , Norlin B , Hummelgård M , Thungström G
Published: November 2019

With the rapid expansion of the waste incineration business both in Europe and globally, there is a growing need for the elemental analysis for fly ash from municipal solid waste incineration. In this work, samples of washed and unwashed ash from municipal solid waste incineration in Sundsvall are evaluated. Qualitative analysis and semi-quantitative analysis are used to compare two elemental analysis methods, scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) and X-ray fluorescence (XRF) measurement. Both methods are used to retrieve the difference in elemental composition between washed and unwashed fly ash. SEM-EDS accurately detects light elements from well-prepared samples in a vacuum environment, while, for online measurements, XRF is a potential method that analyses hazardous metal content in the fly ash.