bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production of spherical titanium alloy powders used in additive manufacturing from titanium scrap
Authors: Yanko Taras , Brener Viktor , Ovchinnikov Olexandr 
Published: October 2020

The main materials for 3D printing of titanium are fine metal alloy powders from which produce final articles with required quality. These powders must have definite chemical compositions, physical/mechanical characteristics, and also necessary operational properties. Key parameters of titanium alloy powders are homogeneity of chemical compositions, microstructures as well as flow ability. Conventional atomisation methods for metal powders like GA, PREP, PA, etc, are complicated and sufficiently expensive. Alternative production route is usage of complex processing technology of titanium alloy scrap as initial raw material. Spheriodised powder manufacturing scheme which includes raw material preparation, preliminary and final treatments have been presented. At the first step titanium scrap was divided according to titanium alloy types, purified from contaminants and oxide films. Then prepared materials were converted to non-spherical powders with definite fractional compositions using hydrogenation/de-hydrogenation (HDH) method.
Experimental HDH equipment allows close cycle of hydrogen recovery almost without losses. Obtained non-spherical powders were treated in the plasma unit yielding spherical titanium alloy. Offered technical solutions permit production of raw materials for 3D printing from scrap with high actual yield of required fractional compositions.
Impact of rolling conditions on the hydriding of grade 2 titanium welded tubes
Authors: LEPEMANGOYE La Chance , CRETON Nicolas , OPTASANU Virgil , DELOYE Elise , MONTESIN Tony , FUNDENBERGER Jean-Jacques , PERROUD Olivier 
Published: October 2020

In this article, we study the impact of rolling conditions on the texture of the commercially pure titanium grade 2. In a previous work, NEOTISS in collaboration with ICB laboratory, shown that the texture highly influences the precipitation of hydrides in Titanium. In order to create different textures, Titanium sheets grade 2 are cold rolled asymmetrically and symmetrically with or without lubricant. The inverse pole figures and direct pole figures obtained allow us to deduce that symmetrical cold rolling does not change the grains orientation but generates a rotation of grains along c-axis (normal to basal plan). However, asymmetrical cold rolling leads to the formation of a new crystallographic texture, which could limit the formation of the hydrides in titanium grade 2 submitted to a hydrogen-rich environment.
Key words: asymmetrical rolling, symmetrical rolling, titanium, hydriding, texture
Characterization of the thermal flux transferred by the plasma arc to the surface of the liquid bath in the Plasma Arc Melting Cold Hearth Refining process (PAMCHR)
Authors: Décultot Léa , Jardy Alain , Hans Stéphane , Doridot Emiliane , Delfosse Jérôme , Ruby-Meyer Fabienne , Bellot Jean-Pierre 
Published: October 2020

Europe is a major provider of titanium scrap but until now there has been no european facility dedicated to the production of aeronautical quality titanium alloys by recycling. UKAD, a joint-venture between Aubert & Duval and UKTMP, ADEME and Crédit Agricole Center France, created the company EcoTitanium, where the recycling of machining scraps is achieved using the Plasma Arc Melting Cold Hearth Refining (PAMCHR) process with the aim of producing such alloy ingots.
The determination of the heat flux transferred from the plasma column to the surface of the liquid bath is an important issue needed for the development of a future 3D process modeling based on Ansys-Fluent CFD software. With this preliminary aim of predicting the heat flux, a study coupling pilot furnace testing and numerical modeling has been performed. Melting tests were carried out in a pilot PAMCHR furnace in MetaFensch, with a stationary torch. In parallel, the different contributions of the heat flux transferred to the surface of the liquid bath were identified and implemented in a simple 2D axisymmetric heat transfer model. Numerical results are compared to the experimental measurements, in order to define the heat flux transferred from the plasma torch.
Revisited: gas-saturated defects in titanium alloys
Authors: Leder M.O. , Puzakov I.Yu. , Tarenkova N.Yu. , Kornilova M.A. , Rusakov K.A. 
Published: October 2020

The simulation results of the internal defects generated during deformation by extrusion and rolling are presented herein. It was demonstrated that end-type deformation defects can result in the formation of internal gas-saturated defects not cropping out the surface under the specific deformation conditions. Key characteristics of the generated defects similar to those of the production defects that have been previously classified as metallurgical are determined.
Key words: defect, deformation, discontinuity.
Structure and Properties of Layered Ti-6Al-4V-Based Materials Fabricated Using Blended Elemental Powder Metallurgy
Authors: Prikhodko S.V. , Ivasishin O.M. , Markovsky P.E. , Savvakin D.G. , Stasiuk O.O. 
Published: October 2020

Due to the high specific strength of Ti, materials on its base are indispensable when high-strength and low-weight requests are a chief demand from the industry. Reinforcement of Ti-alloys with hard and light particles of TiC and TiB is a credible pathway to make metal matrix composites (MMC) with enhanced elastic moduli without compromising the material’s low-weight. However, reinforcement of the alloy with hard particles inevitably lowers the value of toughness and plasticity of material. Yet, in many applications simultaneous high hardness and high plasticity are not required through the entire structure. For instance, parts that need enhanced wear resistance or resistance upon ballistic impact demand high hardness and strength at the surface, whereas their core necessitates rather high toughness and ductility. Such combination of mechanical properties can be achieved on layered structures joining two and more layers of different materials with different chemical composition and/or microstructure within each individual layer.Multi-layered structures of Ti-6Al-4V alloy and its metal-matrix composites (MMC) with 5 and10% (vol.) of TiC and TiB were fabricated in this study using blended elemental powder metallurgy (BEPM) of hydrogenated Ti. Post-sintering hot deformation and annealing were sometimes also employed to improve the microstructure and properties. Structure of materials were characterized using light optical microscopy, scanning electron microscopy, electron backscattered diffraction, x-ray microscopy, tensile and 3-point flexural tests. The effect of various fabrication parameters was investigated to achieve desirable microstructure and properties of layered materials. Using optimized processing parameters, relatively large multilayered plates were made via BEPM and demonstrate superior anti-ballistic performance compared to the equally sized uniform Ti-6Al-4V plates fabricated by traditional ingot and wrought technology.
Cyclic creep behaviour of two-phase Ti-6Al-2Mo-2Cr alloy
Authors: Ziaja Waldemar , Motyka Maciej , Kubiak Krzysztof , Sieniawski Jan 
Published: October 2020

One of the important criteria for selection titanium alloys for discs and blades of turbine engine compressor is their fatigue and creep strength at room and elevated temperature. Fatigue and creep properties of two-phase titanium alloys show strong dependence on microstructure, especially morphology of the α and β phases which can be controlled to certain extent by proper selection of hot working and heat treatment conditions. Quantitative description of two-phase titanium alloys behaviour under loading and environmental conditions leading to combined creep and fatigue processes has been always very challenging task due to large number of factors affecting deformation and fracture behaviour of the material.
In the course of the research cyclic creep behaviour of Ti-6Al-2Mo-2Cr alloy (VT3-1) was investigated and compared to low-cycle fatigue and static creep properties at the temperature of 450°C. Microstructure of the alloy was varied by means of the heat treatment. Constant load tensile creep tests were carried out. Tension-tension cyclic loading was applied at the constant stress ratio with and without hold time at maximum load. The effect of test parameters on the creep-fatigue life at elevated temperature was estimated. Characteristic features of fracture surfaces were identified by scanning electron microscopy methods.
Microstructure and texture in cryomilled and spark plasma sintered Ti Grade 2
Authors: Kozlík Jiří , Stráský Josef , Harcuba Petr , Chráska Tomáš , Janeček Miloš 
Published: October 2020

Titanium (Grade 2) was processed by cryogenic milling and subsequently sintered by spark plasma sintering (SPS) method with the aim of creating and preserving the ultra-fine grained (UFG, < 1 μm) microstructure. Microstructural investigation was performed after both cryogenic milling and spark plasma sintering. An advanced technique of transmission Kikuchi diffraction (TKD) was used to characterize the individual milled powder particles.Investigations of milled powders showed significant grain refinement down to 50 nm after milling in liquid argon with tungsten carbide balls. We assume that this is the equilibrium grain size resulting from the balance of deformation, recovery and dynamic recrystallization. A texture, resembling the rolling texture in Ti, was also found in the milled particles, which can be explained by the nature of deformation during milling.UFG microstructure was not maintained after sintering, with the mean grain size of 2.6 μm. Although the grains are completely recrystallized, a texture, similar to the powder texture, was also found in these samples as a result of packing of the powder particles and the nature of the recrystallization process (continuous static recrystallization).
Herausforderungen in der Behandlung später antikörpermediierter Abstoßung
Authors: Eskandary Farsad-Alexander , Böhmig Georg A. 
Published: October 2020

ZUSAMMENFASSUNGDerzeit gibt es keine Behandlung, die nachweislich in der späten und/oder chronischen antikörpervermittelten Abstoßung (ABMR) wirksam ist. Für Bortezomib und die kombinierte Anwendung von intravenösen Immunglobulinen (IVIG)/Rituximab haben doppelblinde randomisiert-kontrollierte Studien (RCTs) keine signifikante Wirkung auf deren Progression nachgewiesen. Der Antikörper Eculizumab konnte in einer kontrollierten Pilotstudie keine oder nur marginale klinische Wirkungen zeigen. Die größte Hoffnung stellen derzeit Therapien dar, welche die IL-6/IL-6R-Achse (IL-6R: Interleukin-6-Rezeptor) blockieren oder in der Lage sind, CD38-positive Zellen wie Plasma- und natürliche Killer-Zellen (NK-Zellen) zu depletieren.
Immunmodulatoren (Biologicals) in der Therapie von Patienten mit chronischen Dermatosen in der dermatologischen Praxis
Authors: Jahn S. , Föhr J. , Herbst M. 
Published: October 2020

ZusammenfassungWir fassen Erfahrungen zusammen, die in unserer dermatologischen Praxis in den letzten Jahren, besonders seit der Einrichtung einer Spezialsprechstunde Immundermatologie, mit dem Einsatz von Biologicals gemacht wurden. Dazu charakterisieren wir mittels retrospektiver Auswertung die behandelten Patienten mit Psoriasis (mit und ohne Psoriasis-Arthritis), Neurodermitis, Urtikaria und Akne inversa. Es werden klinische Aspekte der Immunmodulation mittels der Blockade von Zytokinen (TNFα, IL-17, IL-23), deren Rezeptoren (IL-4/13R, IL-17R) bzw. IgE analysiert. Wir zeigen, dass der konsequente Einsatz von Biologicals eine klare organisatorische Entscheidung mit mannigfaltigen Konsequenzen für die gesamte Praxis und das Team darstellt.
Conservative Treatment of Iatrogenic Ascending Aortic Hematoma Post-Rotablator Coronary Procedure
Authors: Doutriaux Maxime , Pariente Benjamin , Zahnan Jad , Marchand Xavier 
Published: October 2020

Abstract
Background Aortic intramural hematoma due to coronary artery dissection is a rare and serious complication during percutaneous coronary intervention.
Case Presentation A 78-year-old female patient was admitted for diagnostic coronarography in the context of stable angina. The coronarography showed an asymmetric and significate calcification in the ostium of the right coronary requiring Rotablator (Boston Scientific) procedure complicated by iatrogenic ascending aortic hematoma. After surgical advice, a conservative approach was decided with total hematoma resorption and recovery 1 week later.
Conclusion With stable patient, conservative treatment may be suitable after aortic hematoma due to coronary dissection.
Inpatient Biophysical Profiles and the Effect on Clinical Decision Making
Authors: Racusin Diana A. , Chauhan Suneet P. , Sibai Baha , Chen Han-Yang , Adimorah Nesochi , Piro Mica , Heye Kristen , Sharp Charlotte , WHNP-BC MSN , Blackwell Sean , Refuerzo Jerrie 
Published: October 2020

Abstract
Objective Our primary objective was to determine whether biophysical profiles (BPP) performed on the antepartum unit result in changes in clinical decision making.
Study Design A retrospective cohort chart review was performed among women who had a BPP during hospital admission. BPP status was categorized as normal (8/8 points) and abnormal (6/8 or less points). The primary outcome, clinical decision making, was the need for prolonged external fetal monitoring (defined as > 2 hours) or decision to proceed with delivery. Secondary outcomes included mode of delivery, indicated preterm delivery, birth weight, 5-minute Apgar's score <7, and neonatal intensive care unit (NICU) admission.
Results Among our cohort (n = 186), 85.5% (n = 159) had a normal BPP. Delivery management was altered in one case (0.54%) by the BPP findings, and there were no BPPs that resulted in need for prolonged monitoring. Compared with women with normal BPP, women with abnormal BPPs were more likely to deliver at <37 weeks, to be admitted to the NICU, or have a 5-minute Apgar's score <7.
Conclusion In-hospital BPPs alter clinical decision making in less than 1% of cases.
Management of COVID-19
Authors: John Mary 
Published: October 2020

AbstractThe SARS-CoV-2 (COVID-19) pneumonia was first seen in Wuhan province, China, in December 2019. Since then, there has been great efforts toward understanding the pathophysiology and management of this disease, which was declared as a pandemic in March 2020. Medications which were initially used have been removed and newer ones are under clinical evaluation. Oxygen therapy, anti-inflammatory and antiviral medication, along with awake proning are currently being used in the management of COVID-19.
Effect of Cd/As flux ratio and annealing process on the transport properties of Cd3As2 films grown by molecular beam epitaxy
Authors: Zhang Sheng Xi , Zhang Jian , Wu Yan , Kang Ting Ting , Li Ning , Qiu X F , Chen P P 
Published: October 2020

Abstract
To study how the Cd/As flux ratio affects the microstructure and transport properties for Cd3As2 films, we used molecular beam epitaxy (MBE) to grow Cd3As2 (224) thin films on CdTe (111)/GaAs (001) virtual substrates. The effects of Cd/As flux ratio, during the grown process, on the electrical properties and surface morphology of the sample was studied. The films grown at lower Cd/As flux ratio have higher electron mobility and longer effective dephasing length. With decreasing Cd/As flux ratio, the magnetoresistance (MR) of the film changes from negative to positive. These results show that a lower beam ratio is beneficial to improve the crystal quality. In order to optimize the electrical properties of the films, the effect of annealing on the electron mobility and MR have been studied. After annealing, the MR changes from negative to positive, the electron mobility increase by 8 times, and the MR increase from 15% to 360% at 9 T. These results indicate that annealing is an effective method to optimize the electrical properties of Cd3As2 epitaxial films.
Effect of pressure on the geometric, electronic structure, elastic, and optical properties of the normal spinel MgFe2O4: a first-principles study
Authors: Kora Hamada H , Taha Mohamed , Abdelwahab Abdalla , Farghali Ahmed A , El-dek S I 
Published: October 2020

Abstract
First-principles computation was used to study the effect of pressure on the elastic properties, magnetic properties, optical properties, and electronic structure of the normal spinel magnesium ferrite (MgFe2O4) at different pressures (0, 10, 20, 50, 70, and 100 GPa). The normal spinel MgFe2O4 has a direct bandgap of 1.62 eV which significantly decreased to 0.42 eV with increasing the pressure to 100 GPa. The values of the elastic constants were coherent with the mechanical stability norms for cubic crystals, which revealed that MgFe2O4 was mechanically stable. The values of Pugh’s ratio indicate that MgFe2O4 is ductile at all pressure values except at 100 Gpa MgFe2O4 shows brittle behavior. The computed values of the Zener anisotropy factor at different pressures were not equal to 1.0, which indicates that MgFe2O4 is elastically anisotropic. The optical properties (refractive index, reflectivity, dielectric function, optical conductivity, and loss function) for the normal spinel MgFe2O4, as well as its magnetic moment, were calculated and discussed at different pressures.
Understanding polyploid banana origins. A commentary on: ‘Unravelling the complex story of intergenomic recombination in ABB allotriploid bananas’
Authors: Tomaszewska Paulina 
Published: October 2020

This article comments on:
Alberto Cenci, Julie Sardos, Yann Hueber, Guillaume Martin, Catherine Breton, Nicolas Roux, Rony Swennen, Sebastien Christian Carpentier and Mathieu Rouard, Unravelling the complex story of intergenomic recombination in ABB allotriploid bananas, Annals of Botany, Volume 127, Issue 1, 01 January 2021, Pages 7–20, https://doi.org/10.1093/aob/mcaa032
Chemical Composition and Antimicrobial Activity of Teucrium Capitatum L. Subsp. Lusitanicum (Schreb.) T. Navarro & Rosua Essential Oil
Authors: Debbabi Haïfa , El Mokni Ridha , Jlassi Ibrahim , Joshi Rajesh K , Hammami Saoussen 
Published: October 2020

Abstract
Chemical composition and antimicrobial activity of Teucrium capitatum L. subsp. lusitanicum essential oil was investigated for the first time in the present study. Qualitative and quantitative analyses of the chemical composition by gas chromatography and mass spectrometry (GC–FID and GC–MS) revealed the presence of 60 compounds representing 97.6% of the whole constituents. The main compounds were germacrene D (47.1%), spathulenol (5.8%), α-selinene (5.3%), germacrene A (2.9%), δ-cadinene (2.8%) and cubenol (2.7%). In vitro, the antimicrobial activity was investigated against five bacterial strains along with the yeast Candida albicans using broth microdilution assay. T. capitatum subsp. lusitanicum essential oil showed significant activity against the gram-positive bacteria Staphylococcus aureus (MIC = MBC = 78 μg mL−1), Bacillus subtilis (MIC = MBC = 156 μg mL−1) and the yeast C. albicans (MIC = MFC = 156 μg mL−1). The great potential of antimicrobial effects is most likely due to the very high percentage of sesquiterpene hydrocarbons particularly to germacrene D, for which the antimicrobial properties have been previously reported.
Availability and Prices of WHO Essential Diagnostics in Laboratories in West Africa: A Landscape Survey of Diagnostic Testing in Northern Ghana
Authors: Ward Caleb L , Guo Marissa Z , Amukele Timothy K , Abdul-Karim Abass , Schroeder Lee F 
Published: October 2020

Abstract

Background
We determined the availability and pricing of laboratory testing in the Northern Region of Ghana to identify current gaps with respect to the WHO's Essential Diagnostics List (EDL).

Methods
A representative sample of facilities offering diagnostic testing within the Northern Region was geographically mapped and evaluated, with random sampling stratified by population density. Data were collected on testing menus, volumes, turn-around times, and out-of-pocket test prices. A total of 27 health centers and 39 clinical laboratories were surveyed between June and August 2019.

Results
Health centers offered a median of 2 of 20 tests recommended by the WHO for facilities without laboratories. The most common tests offered included point-of-care tests for malaria, HIV, and pregnancy. Clinical laboratories offered a median of 11 of 72 tests on the EDL. These facilities most commonly provided testing for malaria, HIV, pregnancy, HBsAg, urinalysis, HCV Ab, syphilis, glucose, and CBC. Urban laboratories had a total of 36 EDL tests available while rural laboratories had 12. Test prices were higher in private compared to public laboratories. National Health Insurance reimbursements were lower than out-of-pocket prices (38%), and when controlling for test price, test availability was negatively associated with this gap in reimbursement.

Conclusions
Availability of diagnostic testing in Ghana’s Northern Region is severely limited compared to the WHO's EDL. The disparity is pronounced in rural facilities. Reimbursement rates should be reset to more closely match out-of-pocket test prices in order to achieve the Universal Health Coverage target of the Sustainable Development Goals.
Case study: diagnosis and operative management of de Garengeot hernia without appendectomy during the COVID-19 pandemic
Authors: Chagares Stephen A , Patel Tushar R , Fotopoulos Nicholas 
Published: October 2020

Abstract
de Garengeot herniae have been reported in &lt;100 cases in literature. They are characterized by an incarcerated femoral hernia containing the appendix. We present the case of a 45-year-old female who, upon emergency intraoperative consultation to a general surgeon while having a right groin exploration by a plastic surgeon, was found to have an appendix incarcerated within a femoral hernia. There was no evidence of appendicitis; thus, appendix was reduced and the hernia was repaired with a mesh plug. The patient did well postoperatively, with no complications and returned to complete activities. This occurred during the coronavirus disease (COVID-19) pandemic. Due to the common failure in preoperative diagnosis, it is important for surgeons to have a clinical suspicion for de Garengeot herniae for patients, presenting with a right groin bulge. Appendectomy may be safely avoided, eliminating appendectomy-associated morbidity and avoiding hospital transfer and the associated risk of COVID-19 exposure.
Differential associations of hypoxia, sleep fragmentation, and depressive symptoms with cognitive dysfunction in obstructive sleep apnea
Authors: Alomri Ridwan M , Kennedy Gerard A , Wali Siraj Omar , Ahejaili Faris , Robinson Stephen R 
Published: October 2020

AbstractObstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete cessation of breathing during sleep and increased effort to breathe. This study examined patients who underwent overnight polysomnographic studies in a major sleep laboratory in Saudi Arabia. The study aimed to determine the extent to which intermittent hypoxia, sleep disruption, and depressive symptoms are independently associated with cognitive impairments in OSA. In the sample of 90 participants, 14 had no OSA, 30 mild OSA, 23 moderate OSA, and 23 severe OSA. The findings revealed that hypoxia and sleep fragmentation are independently associated with impairments of sustained attention and reaction time (RT). Sleep fragmentation, but not hypoxia, was independently associated with impairments in visuospatial deficits. Depressive symptoms were independently associated with impairments in the domains of sustained attention, RT, visuospatial ability, and semantic and episodic autobiographical memories. Since the depressive symptoms are independent of hypoxia and sleep fragmentation, effective reversal of cognitive impairment in OSA may require treatment interventions that target each of these factors.