bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geometric model of the gas turbine combustion chamber
Authors: Korotkiy V A , Usmanova E A 
Published: September 2019

Abstract
Gas turbine plants operated on a mixture of natural gas and air are widely used for self-contained power supply of buildings and structures both in urban conditions and in temporary settlements. When designing perspective gas turbine plants, we need to develop a non-toxic, environmentally friendly combustion chamber with the minimal emissions of harmful substances in a wide range of changes in operating parameters. It is a complicated engineering challenge to meet this condition: it is necessary to ensure geometrically accurate profiling of special holes in the cylindrical wall of the combustion chamber to insert fuel nozzles. As opposed to the known methods, the article proposes a profiling method, which combines the advantages of the known methods of descriptive geometry and precise methods of three-dimensional computer simulation. The real profile of a hole in the wall of the combustion chamber is a fourth-order spatial algebraic curve. The article proposes an algorithm for profile approximation using second-order curves by means of three-dimensional computer graphics, which allows us to streamline the preparation of a program for a water jet NC machine.
Visualization of amplitude-frequency characteristics of EEG of pathological and cognitive functions of the brain from a position of nonlinear dynamics
Authors: Krysko V A , Papkova I V , Saltykova O A , Yakovleva T V , Pavlov S P , Zhigalov M V , Yu Petrov D , Krysko A V 
Published: September 2019

Abstract
In recent years, medical imaging methods have been intensively developed to provide comprehensive and extensive data for studying the work of the brain, which makes the present study relevant. The purpose of this work is to develop a new approach for analyzing EEG signals based on nonlinear dynamics methods. To achieve this goal, it is necessary to adapt the methods of nonlinear dynamics to solving EEG analysis tasks. In this paper, the following methods are used: the principal component method for noise clearance, the wavelet transform, the Wolf, Kanz, Rosenstein, neural networks methods to calculate the spectrum of the Lyapunov exponent (LCEs). Studies have shown that the chaos of the schizophrenic’s EEG signals is higher than for healthy people. It has been revealed that the best visualization of the amplitude-frequency characteristics of the brain’s EEG pathological functions is provided by the Morle and Gauss 32 wavelets.
Geometric interpretation of modeling calculation of cylinders axial vibration effect on transfer of viscous incompressible fluid
Authors: Panichkin A V , Varepo L G 
Published: September 2019

Abstract
The transfer of viscous incompressible fluid between contacting cylinders is influenced by a large number of factors that can be investigated by numerical simulation based on the use of the most complete mathematical models. One of the factors affecting the transfer of viscous fluid between the contacting cylinders is the axial vibration of one of the cylinders. At the same time, experimental studies cannot be performed to the full because of the inaccessibility and complexity of monitoring fast processes. Along with a number of other factors, a mathematical model was developed and applied for the numerical study of the effects of axial vibrations (oscillations) on the indicators characterizing the transfer of a viscous incompressible fluid on the test example in a two-dimension setting. The practical implementation of the computer geometric modeling algorithm is shown. A computer visualization of the calculation data on viscous incompressible fluid transfer between the rotating cylindrical surfaces on the example of the printing system is presented.
Method of defining region of allowed configurations in multidimensional space of generalized coordinates using hypercube graph
Authors: Pritykin F N , Nefedov D I 
Published: September 2019

Abstract
The work is devoted to the development of a knowledge base on possible positions of an android arm mechanism with allowance for the position of the previously known forbidden zone. The knowledge base is used for intelligent control of the arm movement of an android robot that functions autonomously in an organized space without human-operator assistance. The specified knowledge base is determined by the region of allowed configurations in the multidimensional space of generalized coordinates. Based on the methods of geometrical modeling, a representation method of the allowable configuration region with the use of hypercube graph is proposed.
Areas of existence of ruled surfaces
Authors: Salkov N A , Ivanov G S , Slavin R B 
Published: September 2019

Abstract
Ruled surfaces are used in mechanical engineering, in aircraft and motor-vehicle constructions, in agriculture, in construction and light industries. It is easier to denominate areas where ruled surfaces are not applied than to list them all. The value of ruled surfaces in human activities can not be overestimated. In this paper the consideration of the formation of ruled surfaces with a uniform way of setting them, which was proposed earlier in two articles with the same title “General Principles of Defining Ruled Surfaces”, is continued.
The concept of a limit ruled surface is introduced in this article, and on the basis of a single method for defining ruled surfaces, the question of identifying the areas of their existence that lie between two limiting ruled surfaces is considered. These areas of existence are, in fact, a line congruence.
Study of the stress-strain state of the wheel pair of a freight car during braking
Authors: Vorobev A A , Krutko A A , Shadrina N U , Badamshin A M 
Published: September 2019

Abstract
Objective: study of the stress-strain state of the wheel pair of a freight car in the process braking. Methods: to determine the stress-strain state of the wheel pairs of a freight car. Results: A volumetric finite element model of a wheel pair with rail sections was created using a finite element of the ten knot tetrahedron type, and maximum shear stresses and maximum equivalent stresses were determined according to the Mises and Dang Wan theory. Practical significance: It is shown that the maximum tangential stresses are observed at a point located at a depth of 4.5-5.3 mm below the rolling surface of the wheel. In case of emergency (short) braking, maximum stresses occur on the rolling surface of the wheel. During prolonged braking (movement of the train along a prolonged descent), maximum stresses occur at the point of transition from the disk to the rim on the inner side of the wheel, and the magnitude of these stresses is 2.5 times higher than in the emergency braking mode.
Parametric geometric model of a spherical helical platform
Authors: Yanishevskaya A G , Dyakonov N V 
Published: September 2019

Abstract
The paper presents a parametric spherical model of a helical surface, which is used in the design of structures of helical platforms. This design is intended to serve the inner surface of spherical tanks. Presentation of the control program using dependent and mathematical models for constructing external and internal contours of the sites.
Information and analytical system for assessing the quality of planning and monitoring of the process of teaching students during the semester
Authors: Liberman A E , Kozlov V V , Alonceva E A 
Published: September 2019

Abstract
Monitoring the student learning process is the basis of feedback in the management of the quality of specialist training, which determines its relevance and relevance. The aim of the work is to develop a model of continuous monitoring of the quality of student training in the semester in the context of student-teacher interaction. The monitoring is built on the basis of a special mathematical model that allows solving problems of forming the recommended student assessment and assessment of the teacher’s performance discipline implemented in the corresponding information system. Formation of the recommended assessment of a student in a discipline is carried out as an accumulation from individual stages of a discipline based on data grouping methods, work with associative data sets, data convolution, database manipulation. Statistical methods allow to monitor the performance discipline of university teachers on the basis of numerical convolutions, getting it in measurable indicators. Thus, a feedback model in the student-teacher chain was obtained, which is necessary to substantiate management decision-making in the educational process.
Thermal escape from a trap over the parabolic barrier: Langevin type approach to energy diffusion regime
Authors: Gontchar I I , Chushnyakova M V , Blesman A I 
Published: September 2019

Abstract
Thermally activated escape from a metastable state is a useful tool to account for some features of the micro/nano-motors or superconducting nanowires. In the present work, we consider the case of week friction (action diffusion regime) which corresponds to the latter example. To describe the thermal decay, we apply two approaches both based on the Langevin type equations: the action diffusion (approximate) and the phase space diffusion (exact). For the first time, the quasistationary decay rates obtained numerically for the parabolic barrier from these two approaches are compared quantitatively with each other as well as with the analytical formula.
Causes of future Mediterranean precipitation decline depend on the season
Authors: Brogli Roman , Sørland Silje Lund , Kröner Nico , Schär Christoph 
Published: September 2019

Abstract
Future mean precipitation in the Mediterranean is projected to decrease year-round in response to global warming, threatening to aggravate water stress in the region, which can cause social and economic difficulties. We investigate possible causes of the Mediterranean drying in regional climate simulations. To test the influence of multiple large-scale drivers on the drying, we sequentially add them to the simulations. We find that the causes of the Mediterranean drying depend on the season. The summer drying results from the land-ocean warming contrast, and from lapse-rate and other thermodynamic changes, but only weakly depends on circulation changes. In contrast, to reproduce the simulated Mediterranean winter drying, additional changes in the circulation and atmospheric state have to be represented in the simulations. Since land-ocean contrast, thermodynamic and lapse-rate changes are more robust in climate simulations than circulation changes, the uncertainty associated with the projected drying should be considered smaller in summer than in winter.
Cost of Unnecessary Amylase and Lipase Testing at Multiple Academic Health Systems
Authors: Ritter Jacob P , Ghirimoldi Federico M , Manuel Laura S M , Moffett Eric E , Novicki Thomas J , McClay James C , Shireman Paula K , Brimhall Bradley B 
Published: September 2019

Abstract

Objectives
To determine adherence to Choosing Wisely recommendations for using serum lipase to diagnose acute pancreatitis rather than amylase, avoiding concurrent amylase/lipase testing and avoiding serial measurements after the first elevated test as both are ineffective for tracking disease course.

Methods
Deidentified laboratory data from four large health systems were analyzed to determine concurrent testing rates, serial testing rates, and provider-ordering patterns.

Results
While most providers adhered to recommendations with 58,693 lipase-only tests ordered and performed, 86% of amylase tests were performed concurrently with lipase. Ambulatory, inpatient, and emergency department settings revealed concurrent rates of 51%, 41%, and 8%, respectively. Services with order sets containing both amylase and lipase were associated with higher rates of concurrent testing.

Conclusions
Concurrent amylase/lipase testing is an area of opportunity to improve compliance, especially in ambulatory settings. Revision of order sets and provider education could be interventions to reduce unnecessary testing and save costs.
Evaluation of Pesticides Found in Oregon Cannabis from 2016 to 2017
Authors: Evoy Richard , Kincl Laurel 
Published: September 2019

Abstract
Pesticide use and worker exposures to pesticides in the US cannabis industry have not been studied due to cannabis being illegal at the federal level. Without knowing the types of pesticides being used in this industry, it is difficult to assess whether workers are being exposed to potentially dangerous pesticides. When recreational cannabis became legal in the state of Oregon in 2014, the Oregon Department of Agriculture (ODA) published a list of recommended pesticides for use in the cannabis industry and developed the state's pesticide testing regulations for all cannabis products, medicinal and recreational. Using the state's pesticide testing data, the aim of this study was to investigate the types of pesticides being used in the Oregon cannabis industry and if they present a hazard to cannabis workers. Both recreational and medicinal cannabis samples contained high levels of residual pesticides and pesticides not legally allowed to be used on cannabis products. Medicinal cannabis products were found to have mean levels of residual pesticides that were 3–12 times higher than recreational products. Nine of the 50 pesticides identified were classified highly or extremely hazardous by the World Health Organization.
Symbiosis at its limits: ecophysiological consequences of lichenization in the genus Prasiola in Antarctica
Authors: Fernández-Marín Beatriz , López-Pozo Marina , Perera-Castro Alicia V , Arzac Miren Irati , Sáenz-Ceniceros Ana , Colesie Claudia , de los Ríos Asunción , Sancho Leo G , Pintado Ana , Laza José M , Pérez-Ortega Sergio , García-Plazaola José I 
Published: September 2019

AbstractBackground and AimsLichens represent a symbiotic relationship between at least one fungal and one photosynthetic partner. The association between the lichen-forming fungus Mastodia tessellata (Verrucariaceae) and different species of Prasiola (Trebouxiophyceae) has an amphipolar distribution and represents a unique case study for the understanding of lichen symbiosis because of the macroalgal nature of the photobiont, the flexibility of the symbiotic interaction and the co-existence of free-living and lichenized forms in the same microenvironment. In this context, we aimed to (1) characterize the photosynthetic performance of co-occurring populations of free-living and lichenized Prasiola and (2) assess the effect of the symbiosis on water relations in Prasiola, including its tolerance of desiccation and its survival and performance under sub-zero temperatures.MethodsPhotochemical responses to irradiance, desiccation and freezing temperature and pressure–volume curves of co-existing free-living and lichenized Prasiola thalli were measured in situ in Livingston Island (Maritime Antarctica). Analyses of photosynthetic pigment, glass transition and ice nucleation temperatures, surface hydrophobicity extent and molecular analyses were conducted in the laboratory.Key ResultsFree-living and lichenized forms of Prasiola were identified as two different species: P. crispa and Prasiola sp., respectively. While lichenization appears to have no effect on the photochemical performance of the alga or its tolerance of desiccation (in the short term), the symbiotic lifestyle involves (1) changes in water relations, (2) a considerable decrease in the net carbon balance and (3) enhanced freezing tolerance.ConclusionsOur results support improved tolerance of sub-zero temperature as the main benefit of lichenization for the photobiont, but highlight that lichenization represents a delicate equilibrium between a mutualistic and a less reciprocal relationship. In a warmer climate scenario, the spread of the free-living Prasiola to the detriment of the lichen form would be likely, with unknown consequences for Maritime Antarctic ecosystems.
The Utility of the Repeatable Battery of Neuropsychological Status in Patients with Temporal and Non-temporal Lobe Epilepsy
Authors: Maiman Moshe , Del Bene Victor A , Farrell Eileen , MacAllister William S , Sheldon Sloane , Rentería Miguel Arce , Slugh Mitchell , Gazzola Deana M , Barr William B 
Published: September 2019

AbstractObjectiveThe Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) is a brief neuropsychological battery that has been validated in the assessment of dementia and other clinical populations. The current study examines the utility of the RBANS in patients with epilepsy.MethodsNinety-eight patients with epilepsy completed the RBANS as part of a more comprehensive neuropsychological evaluation. Performance on the RBANS was evaluated for patients with a diagnosis of temporal lobe epilepsy (TLE; n = 51) and other epilepsy patients (non-TLE, n = 47) in comparison to published norms. Multivariate analysis of variance compared group performances on RBANS indices. Rates of impairment were also compared across groups using cutoff scores of ≤1.0 and ≤1.5 standard deviations below the normative mean. Exploratory hierarchical regressions were used to examine the relations between epilepsy severity factors (i.e., age of onset, disease duration, and number of antiepileptic drugs [AEDs]) and RBANS performance.ResultsTLE and non-TLE patients performed below the normative sample across all RBANS indices. Those with TLE performed worse than non-TLE patients on the Immediate and Delayed Memory indices and exhibited higher rates of general cognitive impairment. Number of AEDs was the only epilepsy severity factor that significantly predicted RBANS total performance, accounting for 14% of the variance.ConclusionsThese findings suggest that the RBANS has utility in evaluating cognition in patients with epilepsy and can differentiate TLE and non-TLE patients. Additionally, number of AEDs appears to be associated with global cognitive performance in adults with epilepsy.
Reclassifying Pseudopolyps in Inflammatory Bowel Disease: Histologic and Endoscopic Description in the New Era of Mucosal Healing
Authors: Rezapour Mona , Quintero Maria Alejandra , Khakoo Nidah S , Sussman Daniel A , Barkin Jodie A , Clarke Jennifer , Varma Tanya , Deshpande Amar R , Kerman David H , Damas Oriana , Abreu Maria T 
Published: September 2019

Abstract

Introduction
In this study, we identify the frequency of pseudopolyps (PPs) with normal histology and their association to surrounding tissue.

Methods
Patients were enrolled in a study identifying endoscopic characteristics of PPs (n = 29) or were collected as part of our IBD biobank (n = 16). Statistical analysis included Stata v.15.0. chi-square and Student t-test.

Results
A total of 45 patients with 117 PP biopsies were identified. More patients with healed PP were in endoscopic remission compared with those with inflammatory PP (82.6% vs 17.4%, respectively).

Conclusion
This is the first study to find mucosal healing of PPs and its association with deep remission.
The role of primary surgical repair technique on late outcomes of Tetralogy of Fallot: a multicentre study
Authors: Padalino Massimo A , Pradegan Nicola , Azzolina Danila , Galletti Lorenzo , Pace Napoleone Carlo , Agati Salvatore , Palma Gaetano , Marianeschi Stefano Maria , Seddio Francesco , Cascarano Maria Teresa , Carro Cristina , Gregori Dario , Vida Vladimiro Lorenzo , Stellin Giovanni 
Published: September 2019

AbstractOBJECTIVESRepair of Tetralogy of Fallot (TOF) has currently excellent results with either transventricular or transatrial approach. However, it is unclear as to which has better late outcomes and what role of residual pulmonary valve (PV) regurgitation in the long term is. We report on late clinical outcomes after repair in a large series of patients with TOF, focusing on the type of surgical technique.METHODSThis analysis is a retrospective multicentre study on patients undergoing TOF repair in infancy. The exclusion criteria of the study were TOF with pulmonary atresia or absent PV.RESULTSWe selected 720 patients who had undergone TOF repair (median age 5.7 months, interquartile range 3.7–11.7). Preoperative cyanotic spells occurred in 18%. A transatrial repair was performed in 433 (60.1%) patients. The PV was preserved in 249 (35%) patients, while the right ventricular outflow tract was reconstructed with a transannular patch (60.4%) or a conduit (4.6%) in the rest of the patients. At a median follow-up of 4 years (range 1–21, 86% complete), 10 (1.6%) patients died, while 39 (6.3%) patients required surgical reoperation and 72 (11.7%) patients required an interventional procedure. The propensity match analysis showed that the incidence of postoperative complications and adverse events at follow-up were significantly increased in patients undergoing transventricular approach repair with transannular patch (P = 0.006) and PV preservation was a significant protective factor against postoperative complications (P = 0.009, odds ratio 0.5) and late adverse events (P = 0.022).CONCLUSIONSSurgical repair of TOF in infancy is a safe procedure, with good late clinical outcomes. However, transatrial approach and PV preservation at repair are associated with lower early and late morbidity.
Favourable changes in physical working conditions and the risk of all-cause sickness absence: a pseudo-experiment
Authors: Shiri Rahman , Hiilamo Aapo , Pietiläinen Olli , Mänty Minna , Rahkonen Ossi , Lallukka Tea 
Published: September 2019

Abstract

Background
We determined whether favourable changes in physical workload and environmental factors reduce sickness absence (SA) days using observational cohort data as a pseudo-experiment.

Methods
The data from the Finnish Helsinki Health Study included three cohorts of employees of the City of Helsinki [2000/2002–07 (N = 2927), 2007–12 (N = 1686) and 2012–17 (N = 1118), altogether 5731 observations]. First, we estimated the propensity score of favourable changes (reduction in exposures) in physical workload and environmental factors during each 5-year follow-up period on the baseline survey characteristics using logistic regression. Second, we created and stabilized inverse probability of treatment weights for each participant using the propensity scores. Lastly, we used generalized linear model and fitted negative binomial regression models for over-dispersed count data to estimate whether the favourable changes decrease the risk of short-term (1–3 days), intermediate-term (4–14 days) and long-term (&gt;14 days) SA using employer’s register data.

Results
During a 5-year follow-up, 11% of the participants had favourable changes in physical workload factors, 13% in environmental factors and 8% in both factors. The incidence of short-term, intermediate-term and long-term SA were lower in employees with favourable workplace changes compared with those without such changes. The reductions were largest for long-term SA. Reporting favourable changes in both workload and environmental factors reduced the number of SA days by 41% within 1 year after the changes and by 32% within 2 years after the changes.

Conclusion
This pseudo-experimental study suggests that improving physical working conditions reduces SA.