bluuebunny/crossref_metadata_2025_split huggingface dataset:
Features of the Surface and Subsurface Waves Application for Ultrasonic Evaluation of Physicomechanical Properties of Solids. Part 2. Strenghtned Inhomogeneous Surface Layer
Authors: Baev A. R. , Mayorov A. L , Levkovich N. V. , Asadchaya M. V. 
Published: April 2019

The propagation of a pulsed signal of a surface wave over an object with a non-uniform surface layer, obtained, for example, as a result of surface hardening, with structural damage, is accompanied by the dispersion of the velocity of the wave carrying important information about the parameters of such a layer. The aim of the work is to study the relationship between the acoustic parameters of a pulsed acoustic signal of a surface and subsurface waves and the surface layer of steel specimens hardened by high-frequency hardening, and gray iron-chill. Features of the surface and subsurface waves application for ultrasonic evaluation of physicomechanical properties of solids. Strenghtned inhomogeneous surface layer.A brief analysis of the known works on determining the depth of hardened surface layers by various methods, including high-frequency hardening, cementation, etc., is carried out. Based on the Oulder integral expression. The dependence connecting the wave velocity, its frequency, the depth of the hardened layer and the spatial distribution of hardness represented as a step with a changing slope of its side surface simulating the transition zone of the hardened layer are calculated.Using the pulse method and low-aperture transducers with a frequency of 1−3.8 MHz, the dependences of the surface wave velocity on the cutting height of a layer hardened by HDTV hardening are obtained. A comparison of experimental data and calculations of the theoretical model showed a good qualitative correspondence between them, demonstrate a high «sensitivity» of the method in relation to the nature of the change in hardness over the depth of the hardened layer. It is shown that the proposed approach is promising for solving the inverse problem of restoring the spatial distribution of hardness based on experimental data.The goniometric method was approbated to determine the dependence between amplitude-angle characteristics and depth of the surface steel layers hardened by high-frequency hardening and depth of hardened gray iron specimens layer – with chill. It is shown that the optimal angle corresponding maximum of excited surface wave amplitude in steel specimens is decreasing up to 24–26'vs. hardened depth layer. But when the tested specimens from cast iron this angle decreasing is nearly of 6°. Recommendations on the use of research results in practice are given.
Plasmatron for Coatings
Authors: Okovity V. A. , Panteleenko F. I. , Okovity V. V. , Astashinsky V. M. 
Published: April 2019

The paper analyzes reasons for application of plasma torches of special design for deposition of heat-resistant layers of thermal barrier coatings that contribute to minimum oxygen content in the zone of spraying. It contains detailed description of design for a plasma torch with a nozzle that allows better protection of a plasma stream against atmospheric exposure.Heated inert gas (Ar) is fed inside the nozzle along its walls through holes in its end part. Air around a plasma jet is displaced, additional compression of the plasma occurs and due to this oxygen content is decreased in a coating and efficiency of material deposition is increased. An additional use of a tungsten insert in an electronic node makes it possible to create a pair of tungsten – tungsten in an electrode assembly and the life of the electrode assembly will be increased due to high erosion resistance, electrical conductivity, thermal conductivity and sufficient strength in 2–2.5 times while increasing spray performance through toughening regimes. The paper presents testing results of the developed plasma torch and its prototype for duration of continuous operation and intensity at 500 A current, 70 V voltage, nitrogen flow rate of 45 l/min (standard mode for deposition of oxide ceramics). Coatings from nickel–chromium–aluminum–yttrium powder have been obtained while using plasma torches with the same parameters of deposition and a comparative analysis of the technological properties have been made in the paper. The developed plasma torch has more qualitative characteristics of subsurface plasma coatings: increase in adhesive strength – by 1.4 times, material utilization ratio – by 1.3 times, micro-hardness – by 1.3 times, porosity decrease – by 2.3 times.
Transdisciplinary models of hydraulic drives of mobile machinery
Authors: Puzanov A. V. 
Published: April 2019

Modern drive engineering requires a comprehensive analysis of all work processes in hydraulic drives, solving the problems of modeling the technological processes of their production using mathematical and software tools of various physicality.The article proposes an approach to the development of hydrodrives of mobile equipment based on transdisciplinary models of instruments and control systems. These models are designed to unite in a single information space a methodical and mathematical apparatus of various physicality: mechanics, kinematic, hydromechanics, heat engineering, and methods for their solution. These measures will increase their adequacy, reduce assumptions and reduce the safety factor as a measure of imperfection of the scientific and technical understanding of the facility.The article gives an example of the use of this approach in the development of volumetric hydraulic drives of mobile equipment a technique for calculating the indicator diagram of an axial-plunger hydraulic machine at a micro level using the Matlab / Simulink, Autodesk Simulation CFD and Autodesk Simulation Mechanical software complexes. The indicator diagram of the hydraulic machine is a clear characteristic of the dynamic qualities of the product. From the correctness of the calculation of this characteristic, the dynamic properties, reliability and resource of the drive as a whole depend.
On Temperature-Falloff Interpretation in the Circulation Phase of the Steam-Assisted-Gravity-Drainage Process
Authors: Irani Mazda , Ghannadi Sahar 
Published: April 2019

Summary
Steam-assisted gravity drainage (SAGD) is the preferred method to extract bitumen from Athabasca oil-sand reservoirs in western Canada. Bitumen at reservoir conditions is immobile because of high viscosity, and its saturation is typically large, which limits the injectivity of steam at in-situ conditions. In current industry practice, steam is circulated within injection and production wells. In theory, wells should be converted to SAGD production mode after a period when bitumen is mobile and communication is established between the injector and the producer. Operators use temperature-falloff data to predict successful conversion time. But temperature-falloff data are evaluated qualitatively, and there is not an analytical/numerical framework in which one can use such data. Although the bitumen heating sounds simple, approach wells are failing after steam injection because of steam breakthrough or sand production. Most of these wells are periodically returned to circulation/bullheading to ramp up production rates and heal the hot spots. Most of such failures are associated with early conversion to full SAGD, which shows the need to formulate an analytical/numerical framework to predict the right timing for conversion to full SAGD. In this presentation, the time of flight (ToF) is effectively used to convert spatial variations of temperature into time response of temperature variation at the well sandface. ToF defines the time an oil droplet needs to travel through a medium—more specifically, from its current location to the well sandface. By solving the heat transfer and Darcy's law simultaneously, the ToF is converted to a relationship of the temperature vs. time profile at the producer. This approach has been applied to SAGD well pairs with different geology, and the temperature-falloff trends are presented.
A Semianalytic Solution for Temporal Pressure and Production Rate in a Shale Reservoir With Nonuniform Distribution of Induced Fractures
Authors: Sheng Guanglong , Javadpour Farzam , Su Yuliang , Liu Jinghua , Li Kunjie , Wang Wendong 
Published: April 2019

Summary
The network of induced fractures and their properties control pressure propagation and fluid flow in hydraulically fractured shale reservoirs. We present a novel fully fractal model in which both the spacing and the porosity/permeability of induced fractures are distributed according to fractal dimensions (i.e., fractal decay of fracture density and the associated porosity/permeability away from the main induced fracture). The fractal fracture distribution is general, and handles exponential, linear, power, and uniform distributions. We also developed a new fully fractal diffusivity equation (FDE) using the fractal distribution of fractures and their properties. We then used, for the first time, the semianalytic Bessel spline scheme to solve the developed diffusivity equation. Our proposed model is general and can capture any form of induced-fracture distribution for better analysis of pressure response and production rates at transient- and pseudosteady-state conditions. We compared the unsteady-state and pseudosteady-state pressure responses calculated by our fully fractal model with former models of limited cases: uniform fracture spacing and uniform porosity/permeability [conventional diffusivity equation (CDE)]; variable fracture spacing and uniform porosity/permeability [modified CDE (MCDE)]; and uniform fracture spacing and fractal porosity/permeability distribution (FPPD). We used these models to match and predict the production data of a multifractured horizontal gas well in the Barnett Shale. Our results showed that the fractal distribution of fracture networks and their associated properties better matches the field data. Uniform distribution of induced-fracture networks underestimates production rate, especially at early time.
Intra-operative red blood cell transfusion and mortality after cardiac surgery
Authors: Vlot Eline A , Verwijmeren Lisa , de Garde Ewoudt M.W. Van , Kloppenburg Geoffrey T.L. , Dongen Eric P.A. Van , Noordzij Peter G. 
Published: April 2019

Abstract
Background

Anemia in cardiac surgery patients has been associated with poor outcomes. Transfusion of red blood cells during surgery is common practice for perioperative anemia, but may come with risks. Little is known about the association between intra-operative transfusion and mortality in patients undergoing cardiac surgery.

Methods

Single centre historical cohort study in 2933 adult patients undergoing coronary surgery with or without aortic valve replacement from June 2011 until September 2014. To estimate the odds ratio for mortality in patients receiving intra-operative transfusion, a propensity score based logistic regression analysis was performed.

Results

Intra-operative transfusion was associated with a more than three-fold increased risk of 30-day mortality. Patients in the highest quartile of probability of transfusion were older (age 75 vs 66; P<0.001), had a higher EuroSCORE (6 vs 3; P<0.001), had lower preoperative hemoglobin levels (7.6 vs 8.9 mmol/l; P<0.001), had combined surgery more often (CABG + AVR in 33.4% of cases vs 6.6% (P<0.001) and a longer duration of surgery (224 vs 188 minutes; P<0.001). The association between intra-operative transfusion and mortality persisted after adjustment for these risk factors (adjusted OR 2.6; P=0.007).

Conclusions

Intra-operative transfusion of red blood cells was found to be associated with increased mortality in adults undergoing coronary surgery. Preoperative patient optimization may improve perioperative outcomes by reducing the likelihood of requiring transfusion and thus its associated risk.
Effects of intravenous infusion of lidocaine and dexmedetomidine on inhibiting cough during the tracheal extubation period after thyroid surgery
Authors: Hu Shenghong , Li Yuanhai , Wang Shengbin , Xu Siqi , Ju Xia , Ma Li 
Published: April 2019

Abstract
Background：Intravenous lidocaine and dexmedetomidine treatments have been proposed as methods for inhibiting cough. We compared the efficacy of intravenous lidocaine and dexmedetomidine treatments on inhibiting cough during the tracheal extubation period after thyroid surgery. Methods：One hundred eighty patients undergoing thyroid surgeries were randomly allocated to the LIDO group (received lidocaine 1.5 mg/kg loading, 1.5 mg/kg/h infusion), the DEX group (received dexmedetomidine 0.5 µg/kg loading, 0.4 µg/kg/h infusion) and the CON group (received saline), with 60 cases in each group. The primary outcomes of cough were recorded. Secondary outcomes included hemodynamic variables, awareness time, volume of drainage, the postoperative visual analogue scale and adverse effects were recorded. Results: The incidence of cough were significantly lower in the LIDO group (28.3%) and the DEX group (31.7%) than that in the CON group (66.7%) (P=0.000). Additionally, both moderate and severe cough were significantly lower in the LIDO group (13.3%) and the DEX group (13.4%) than these in the CON group (43.4%) (P<0.05). Compared with the two treatment groups, both mean arterial blood pressure and heart rate were significantly increased in the CON group during tracheal extubation (P<0.05). Compared with the CON group, the volume of drainage was significantly reduced in the two treatment groups within 48 hours after surgery (P<0.05). compared with the CON group, the postoperative visual analogue scale was significantly lower in groups LIDO and DEX after surgery(P<0.05). Compared with the LIDO group and the CON group, the time to awareness was longer in the DEX group (P<0.05). In the DEX group, bradycardia was noted in 35 patients, while no bradycardia was noted in LIDO group and CON group. Conclusion: Compared with intravenous infusions of normal saline, both lidocaine and dexmedetomidine had equal effectiveness in attenuating cough and hemodynamic changes during the tracheal extubation period after thyroid surgery, and both of these treatments were able to reduce the volume of postoperative bleeding and provide better analgesic effect after surgery. But intravenous infusions of dexmedetomidine resulted in bradycardia and delayed time to awareness when compared with lidocaine and normal saline.
Informative Supraglottic Airway versus Endotracheal Tube During Interventional Pulmonary Procedures – A Retrospective Study
Authors: Behrens Kyle M , Galgon Richard E 
Published: April 2019

Abstract
Background: As the field of interventional pulmonology (IP) expands, anesthesia services are increasingly being utilized when complex procedures of longer duration are performed on sicker patients with high risk co-morbidities and lung pathology. Yet, evidence on the optimal anesthetic management for these patients remains lacking. Our aim was to characterize the airway management and, secondarily anesthetic maintenance patterns used for IP procedures at our institution.

Methods: From 2894 identified encounters, charts of 783 patients undergoing an IP procedure with general anesthesia over a 5-year period, employing an endotracheal tube (ETT) or a supraglottic airway (SGA) for airway maintenance, were identified and reviewed after exclusions. Patients posted for a concurrent thoracic surgical procedure and those already intubated at presentation were excluded. Baseline patient demographics, procedure, proceduralist type, anesthesia maintenance modality, neuromuscular blocking drug (NMBD) use, and airway management characteristics were extracted and analyzed.

Results: Inhaled general anesthesia with an ETT for airway maintenance was most commonly employed; however, SGAs were used in one-third of patients with a very low conversion rate (0.4%), and their use was associated with a significant reduction in NMBD use.

Conclusions: In this large series of patients receiving general anesthesia for IP procedures, inhaled anesthetic agents and ETTs were favored. However, in appropriately selected patients, SGA use was effective for airway maintenance and allowed for a reduction in NMBD use, which may have implications in this patient population who may have an increased risk for pulmonary complications and warrants further investigation.
Prognostic value of endothelial biomarker in refractory cardiogenic shock with ECLS: a prospective monocentric study
Authors: Tsai Tsung-Yu , Tu Kun-Hua , Tsai Feng-Chun , Nan Yu-Yun , Fan Pei-Chun , Chang Chih-Hsiang , Tian Ya-Chung , Fang Ji-Tseng , Yang Chih-Wei , Chen Yung-Chang 
Published: April 2019

Abstract
Background

Extracorporeal membrane oxygenation (ECMO) is often used in critical patients with severe myocardial failure. However, patients on ECMO often have high mortality rate. Recent studies suggest that endothelial activation with subsequent vascular barrier breakdown is a critical pathogenic mechanism in organ damage and related to the outcome in critical illness. This study aimed to determine whether the endothelial biomarkers could serve as prognostic factors for the outcome of patients on ECMO.

Methods

This prospective study enrolled total 23 critically ill patients on veno-arterial ECMO in the intensive care units of a tertiary care hospital between March 2014 and February 2015. Serum samples were tested for thrombomodulin, angiopoietin (Ang)-1, Ang-2, and vascular endothelial growth factor (VEGF). Demographic, clinical, and laboratory data were also collected.

Results

The overall mortality rate was 56.5%. The combination of Ang-2 at the time of ECMO support (day 0) and VEGF at day 2 had the ability of discriminating mortality (area under receiver operating characteristic curve [AUROC], 0.854; 95% confidence interval: 0.645-0.965).

Conclusions

In this study, we found that the combination of Ang-2 at day 0 and VEGF at day 2 was a modest model for mortality discrimination in this group of patients.
Patterns of Uveitis in Children According to Age: Comparison of Visual Outcomes and Complications in a Tertiary Center
Authors: Al-Haddad Christiane , BouGhannam Alaa , Fattah Maamoun Abdul , Tamim Hani , Moussawi Zeinab Ali El , Hammam Rola 
Published: April 2019

Abstract
Background: Uveitis in the pediatric population is uncommon, accounting for 2 to 14% of all uveitis cases, yet resulting in significant ocular morbidity. A number of studies have focused on patterns and complications of uveitis in the pediatric age group (≤ 16 years). In this report, we studied children with uveitis syndromes focusing on demographics, anatomic distribution, etiologies, treatment, and complications. We additionally divided subjects into two age groups to look into any differential characteristics pertaining to the younger age group and the role of amblyopia as a cause of visual loss. Methods: Retrospective chart review of 80 eyes of 49 uveitis patients aged ≤16years. Subjects were categorized by age of onset into visually immature (≤8 years) and visually mature group (>8 years). Data compared between the two age groups included demographics, disease characteristics, visual outcomes and complications. Results: Idiopathic uveitis was the most common diagnosis (51%). Anterior uveitis complications (posterior synechiae and band keratopathy) were more common in the younger group (p=0.002 and p=0.03 respectively) while posterior uveitis manifestations (vitreous haze and vasculitis) were more common in the older age group (p=0.04 and p<0.001 respectively). Amblyopia was the most common cause of vision loss in the visually immature versus cataract in the visually mature. Conclusion: Anterior uveitis and its complications were more common in visually immature group in our cohort. Amblyopia was identified as the main cause of visual loss in the younger population.
Association between High Cumulative Numbers of Elevated Heart Rate and Mortality in Neurological ICU patients: Retrospective Analysis of eICU Collaborative Research Database
Authors: Zhou Dawei , Li Zhimin , Zhang Shaolan , Zhou Jianxin , Shi Guangzhi 
Published: April 2019

Abstract
Background

Heart rate is routinely measured in Neurological intensive care unit(NICU), but its prognostic value remains debated. We sought to evaluate the association of high cumulative numbers of elevated Heart Rate (HcneHR) with mortality in NICU patients.

Methods

We used a large observational eICU Collaborative Research Database (eICU-CRD), where continous heart rate monitoring every 5 minute was available. We collected periodic heart rate, disease severity (APACHE IV score), NICU and hospital mortality and other information in 8347 patient admissions from the eICU-CRD. The cumulative numbers of Heart Rate (cneHR) were defined as >100 beats/min in first admittion 24 hours, and if cneHR ≥10,then was defined as higt cneHR(HcneHR). The primary outcome was NICU mortality. The other outcomes were hospital mortality, length of NICU stay and APACHE IV score. Multivariable logistic regression was used to assess for association for HcneHR and other covariance with NICU and hospiltal discharge status.

Results

The mean age of patients were 63 years, and the most frequent disease categories of NICU in eICU-CRD were postoperation (25%), stroke(19%), traumatic brain injury(14%). The mean APACHE IV score was 50. Overall NICU mortality of the cohort at discharge was 4%, and hospital mortality was 8%. The NICU mortality of HcneHR patients was 7%. Adjusted logistic regression for HcneHR showed a significantly increased risk of NICU death with odds ratio 1.61(confidence interval, 1.26-2.06; P <0 .001).

Conclusions

In adult neurocritically ill patients, we found a significant association for HcneHR with elevated mortality and several others important patient-centered outcomes.