bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Educator as Coach: Supporting Staff to Meet Quality and Safety Competencies
Authors: Altmiller Gerry
Published: April 2019

Direct care nurses are frequently motivated to enhance practice processes but do not always understand the sequential steps that create sustainable improvement. Focusing on a local clinical problem and coaching staff through the steps for sustainable improvement as a learning activity builds competency. Framing learning activities in the Quality and Safety Education for Nurses (QSEN) competencies provides structure that supports the lifelong learning required for competent clinical practice. This article describes a creative teaching strategy clinical educators can use to enhance the knowledge, skills, and attitudes of direct care nurses for quality and safety competencies.

[J Contin Educ Nurs.
2019;50(5):201–204]
A Genetics Learning Program for Nurses Caring for Children Treated With Ex Vivo Autologous Gene Therapy
Authors: Williams Lucinda , Dansereau Colleen , Trainor Bethany
Published: April 2019

As our growing knowledge of genetics and genomics continues to inform, change, and customize health care, an understanding of genetics and genomics is now central to up-to-date and proficient nursing practice. There is a growing need for relevant nursing educational programs that aid practicing nurses in securing genetics/genomics knowledge and an understanding of gene therapy. This article describes a day-long, evidence-based, hands-on genetics learning program developed specifically for practicing nurses caring for children enrolled in ex vivo gene therapy clinical trials.

[
J Contin Educ Nurs.
2019;50(5):218–227.]
Research on the Application of Data Mining Algorithms in Intelligent Transportation
Authors: Zhai Weifang , Jiang Yiran , Ji Song
Published: April 2019

Nowadays, in the field of intelligent transportation, data mining technology has been applied more and more widely. Data mining technology can find valuable data from amongst massive traffic data and analyze traffic conditions according to actual traffic conditions. In order to improve the management and control level of ITMS, effective information can be queried from various query conditions, models suitable for various traffic situations can be found, analyzed and predicted, and accurate information can be provided to traffic managers for decision-making. This article mainly studies the data mining algorithm in intelligent transportation, in order to provide practical reference for the application and research of urban traffic big data technology.
Gamification in Educational Contexts
Authors: Piasecki Stefan
Published: April 2019

Gamification as a tool or procedure to add entertaining and motivating elements to usually non-entertaining environments such as schools or workplaces is becoming more and more popular. E-learning platforms like Moodle provide tools and sets of functions to add elements of gamification. An important factor, especially for education, is technology: individual achievements and progress can be recorded, measured, tracked and visualized and, therefore, identified and honored through bonus points, awards or rankings. This is where gamification can add some challenge and excitement to learning.
Annealing Effects on the Microstructure and Properties of Vanadium and Molybdenum Rich FCC High Entropy Alloy
Authors: Patnamsetty Madan , Saastamoinen Ari , Peura Pasi
Published: April 2019

In the past decade, research into High Entropy alloys (HEAs) have gained significant attention due to their outstanding properties and approach to design alloys for high temperature applications. Strengthening of face centered cubic (FCC) based HEAs, by addition of intermetallic phase or precipitate forming elements is a very captivating direction of alloy designing for high temperature structural applications. However, the knowledge regarding the influence of intermetallic phases on the properties of FCC HEAs is rare. The current study focuses on annealing effects on the microstructure of Cr20Co20Fe25Ni25V5Mo5 (at. %) alloy, this alloy was synthesized using induction melting, and was homogenized at 1200 °C for 12h. X-ray diffraction analysis indicated that the principle phase was (FCC) identified. Scanning electron microscopy (SEM) together with Energy Dispersion X-ray Spectroscopy (EDS) showed that there is an additional phases that is Mo-rich. In order to understand the effect of the high temperature annealing on phase stability, the homogenized samples were annealed at 700 °C, 800 °C, 900 °C, 1000 °C each for 6h and quenched. The annealing treatments had considerable effect on the crystal structure and the elemental distribution. The Mo-rich phase is precipitated at the grain boundaries at all temperatures. Additionally, at 1000 °C annealing temperature Mo-rich phase had precipitated inside the grains. The lower annealing temperatures inhibited diffusion of Mo, which restricted the Mo-rich phase formation. Additionally, the hardness is increased to 195 HV at 1000 °C due precipitation hardening. At other annealing temperatures the hardness is reduced to 145 – 158 HV.
ZrC Based Ceramics by High Pressure High Temperature SPS Technique
Authors: Aydinyan Sofiya , Minasyan Tatevik , Liu Le , Cygan Slawomir , Hussainova Irina
Published: April 2019

Zirconium carbide based materials were consolidated via spark plasma sintering and high-pressure high-temperature (HPHT) sintering methods. Fully dense ZrC-TiC compacts were produced by HTHP SPS technique at 1600-1700°C and were characterized by 370 GPa and 23.7 GPa values of Young’s modulus and Vickers microhardness, respectively. By the addition of 2 wt.% silicon nitride, the compacts of a full density were obtained at 1600°C; however, the further addition of Si3N4 resulted in a decrease in both density and hardness. Oxidation behavior in air of the ZrC-TiC and ZrC-TiC-Si3N4 compacts was explored by high temperature XRD method showing intensive oxidation at ~1000°C. Microstructural analysis certified that the addition of certain amount of Si3N4 increases the phase distribution homogeneity and contributes to the microstructure refinement.
Synthesis of Biocomposite with Different Ratios of Rapeseed Oil Binder/Wood Bark: Mechanical and Hygrothermal Properties
Authors: Kairytė Agnė , Vaitkus Saulius , Kremensas Arūnas
Published: April 2019

Growing economy is a basis of public well-being, and its rapid growth is implemented on the expense of environmental quality; therefore, the harmonization of different aims and interests is one of the most important aspects of sustainable development concept. One of the priorities of sustainable development in Lithuania – the reduction of building and building materials industries’ impact on environment by increasing their eco and energy efficiency; consequently, the use of waste from renewable resources for the synthesis of chemical materials and production of building materials may reduce the usage of limited sources and emission of greenhouse gases. Such waste open up the opportunities to partially or fully replace traditional materials such as petroleum based polymers or cements which production emits many pollutants, uses lots of energy and natural resources. Nowadays, wood and agricultural waste are used for the production of biofuel; however, such heat source provides with short-term benefit. The use of the above mentioned waste materials for the production of bio-based thermal insulating composites would provide with long-term benefit and contribute to the improvement of currently targeted energy performance of buildings. During the study, it was obtained that the ratios of wood bark/rapeseed binder changes the main parameters of biocomposites. The obtained products are characterized by the density ranging from 329 kg/m3 to 378 kg/m3 and thermal conductivity – from 0.0665 W/(m·K) to 0.0781 W/(m·K). The compressive strength and short-term water absorption have shown that biocomposites can be used as a self-bearing structural materials due its sufficient strength which is approx. 2 MPa and water uptake varies from 20 vol.% to 40 vol.%.
The Preparation of TiC/TiN Composites by Selective Laser Melting
Authors: Liu Le , Minasyan Tatevik , Aydinyan Sofiya , Hussainova Irina
Published: April 2019

The concept of manufacturing of near-net-shaped three-dimensional ceramic-based parts with the required geometry is motivated by design and development of advanced ceramics for high-performance applications. It is an incontestable fact, that additive manufacturing (AM), as an intensively developing smart technology, owns a unique position in modern-day product development, proposing new waste-less, cost effective and environmentally friendly pathways for manufacturing of arbitrary geometries.
This work takes a new step for the synthesis of TiC/TiN lattice with geometrically defined porosity by three stage strategy (i) preparation of a TiC/Ti composite by energy saving self-propagating high-temperature synthesis (SHS) technique. (ii) preparation of designed 3D TiC/Ti shape by selective laser melting (SLM); (iii) nitridation of the consolidated samples in nitrogen environment. The influence of synthesis and nitridation conditions on the characteristics of both the powder and produced parts was investigated; set of parameters has been adjusted and optimized. Phase composition and microstructure features were examined after each procedure to reveal the physicochemical transformations and morphology evolution of the composites.
3D Alumina-Graphene Hybrid Nanofibers as a Binder‐Free Cathode for Rechargeable Li‐S Batteries
Authors: Taleb Masoud , Ivanov Roman , Hussainova Irina
Published: April 2019

Lithium-sulfur (Li-S) batteries are promising as a next generation energy-storage device because their energy density is higher than that of current Li-ion devices. Alumina nanofibers coated with graphene is electrochemically active material with tunable graphene flakes and surface area. Combination of this material with sulfur leads to an improved initial discharge capacity and cycle stability, probably due to improved electrical and ionic transport during electrochemical reactions. Based on this understanding, the resulting graphene sulfur composite showed high and stable specific capacities up to ∼900 mAh/g after 50 cycles, representing a promising cathode material for rechargeable lithium batteries with high energy density.
Mathematical Model to Study the Impact Response of a Viscoelastic Auxetic Plate
Authors: Shitikova Marina , Rossikhin Yury , Ajeneza Oleg
Published: April 2019

In the present paper, a mathematical model has been constructed in order to describe the impact response of a linear Kirchhoff-Love plate made of viscoelastic auxetic material possessing fractional viscosity. Auxetic’s Poisson’s ratio is a time-dependent value changing from negative to positive magnitudes with time. In the case of a linear plate, the solution out of the contact domain is found through the Green function, and within the contact zone via the modified Hertz contact theory. Integral equations for the contact force and local indentation have been obtained.
Applying the Fractal Analysis Methods for the Study of the Mechanisms of Deformation and Destruction of Polymeric Material Samples Affected by Tensile Stresses
Authors: Nizina T.A. , Nizin Dmitrii R. , Kanaeva N.S. , Kuznetsov N.M. , Artamonov D.A.
Published: April 2019

The paper proposes an approach to study the mechanism of deformation of epoxy polymers based on the methods of fractal calculations. The advantages of the method for determining the fractality index of the deformation curves of polymer samples using the minimum coverage method are shown. An algorithm for the quantitative determination of the location of the "critical" points of the deformation curves of polymer samples under tension is proposed. It is shown that the use of the developed methodology for the fractal analysis of time series on the basis of a set of points of deformation curves of epoxy polymer samples under tension, provides valuable information about the processes occurring in the structure of composite materials affected by mechanical loads and various aggressive factors.
3D Printing of Plain and Gradient Cermets with Efficient Use of Raw Materials
Authors: Antonov Maksim , Ivanov Roman , Holovenko Yaroslav , Goljandin Dmitri , Rahmaniahranjani Ramin , Kollo Lauri , Hussainova Irina
Published: April 2019

3D printing of plastic materials is very popular nowadays, while printing of wear resistant hard materials is still an issue. Gradient or functionally graded structures are providing improved performance in impact-abrasive application (tunnelling, geothermal drilling, mining, etc.) through the optimal positioning of areas providing high wear resistance and high resistance against impacts. However, printing of such structures by widely used powder bed selective laser sintering leads to the high consumption of raw materials (powders) that cannot be used again for next printing. A method to overcome this problem is explored in current work. The cermets were produced from following powders: (1) commercial, (2) obtained by disintegration of cutting tool inserts (recycled) and (3) reused recycled ones. Tungsten and cobalt used for the production of the majority of cermets are critical raw materials and their consumption should be reduced while the rate of recycling needs to be increased. The surfaces were studied with the help of optical microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. The hardness and wear rate of samples in abrasive conditions were measured.
Effect of Powder Type and Particles Size on Microstructure of Selective Laser Sintered Parts
Authors: Jankus Simonas Mindaugas , Bendikiene Regita
Published: April 2019

The goal of this work was to investigate microstructure of the selective laser sintering (SLS) produced parts evaluating effect of powder type and fraction size. Studies have shown that printed samples of 316L and GP1 metal powders had a higher defect content compared to printed components from MP1 powder material. From scanning electron microscopy (SEM), it was found that iron-based printed parts melted worse than Co-Cr alloy components. Iron-based 316L and GP1 metal powders did not get enough energy from laser to perform a better microwelding between particles. Surface roughness Ra numerical values for samples 316L, GP1, MP1 respectively are Ra = 13.7 μm; 11.4 μm; 3.0 μm. Stainless steel powder material contains particles which size varies between 20 – 120 μm. The Co-Cr alloy and the maraging steel powder materials are made of 10 – 80 μm particles. The chemical and elemental composition of powder materials were examined using SEM-EDS technology.
Additive Manufacturing as a Technique for In Situ Repair and Renovation of Marine Crankshaft Journals
Authors: Morales Casas Adrián , Torims Toms , Gutierrez Santiago Carlos
Published: April 2019

This article presents the analysis and redesign of an equipment aimed at repairing in-situ the journal surface of a marine diesel engine crankshaft, based on laser cladding technology. The paper outlines the comprehensive research conducted to study the device, identify its weaknesses and establish a strategy to improve it. To address this task, we shall describe (i) a study of the working environment, (ii) performance of functional analysis using computer-aided engineering tools and finite element analysis of the current prototype, (iii) a study of the results and identification of problematic areas, (iv) proposed improvements based on the results, (v) the presentation of a 3D model with the proposed improvements.
Investigating the Impacts of Heterogeneous Infills on Structural Strength of 3D Printed Parts
Authors: Sajjad Ramisha , Butt Sajid Ullah , Mahmood Khalid , Saeed Hasan Aftab
Published: April 2019

Additive Manufacturing is a manufacturing process based on layers for making three dimensional scaled physical parts directly from 3D CAD data. Fused Deposition Modeling (FDM) is widely used technology that provides functional prototypes in various thermoplastics. In additive manufacturing, filling patterns are of two types; External and Internal filling patterns. Multiple patterns are developed for both filling categories. In this work, a heterogeneous infill strategy is used by choosing developed patterns in order to improve strength to weight ratio, material usage and build time for parts. A rectilinear pattern combination with triangular and rectangular pattern has been chosen for 3D printing. The tensile testing is performed on the printed specimens to calculate the strength to weight ratio. By comparing the obtained results, a strategy based on maximum strength to weight ratio, minimum material usage and reduced build time is recommended for FDM technology.
Rheological Behavior and Mix Design for 3D Printable Cement Paste
Authors: Slavcheva Galina , Artamonova Olga Vladimirovna
Published: April 2019

This paper presents the theoretical analysis and experimental results concerning the rheological behavior and mix design of a 3d printable cement paste as matrix for printing concrete. From the point of view of classical rheology of disperse systems, the application of 3D printing technology in construction has been analyzed. The general scientific concept for optimization of admixtures for 3D printable materials has been developed in terms of viscosity, consistency, and parameters of flocculation and structural built-up. The technological tools to control rheological behavior of visco-plastic admixtures are identified in all stages of 3D printing such as mixing, pumping, extrusion, multilayer casting and structural built-up in the printing layers. The relevant considerations include the concentration, size, morphology, chemical and mineralogical composition, the physical and chemical activity of the solid phase’s surface, and the ionic composition, viscosity, and density of the liquid phase. The squeezing test is used in this paper as a rheological behaviour identification tool of cement-based materials in order to evaluate the extrudability and buildability. It is shown that these properties are significantly influenced by the mix proportions such as W/C-ratio, concentration of plasticizer additives and viscosity modifier additives as factors of changes in the concentration of the dispersed phase and properties of the dispersion liquid.
Electron and Laser Beam Additive Manufacturing with Wire - Comparison of Processes
Authors: Weglowski Marek S. , Błacha Sylwester , Jachym Robert , Dutkiewicz Jan , Rogal Łukasz , Antoszewski Bogdan , Danielewski Hubert
Published: April 2019

Electron beam (EBAM) and laser beam (LBAM) additive manufacturing processes with a deposited material in the form of a wire are an efficient methods enabling the making of component parts. The scope of the presented work was to investigate the influence of technological process on microstructure and mechanical properties such as tensile strength, microhardness and elongation of the fabricated components. The achieved results and gained knowledge will enable the production of a whole structure from stainless steel in the future. The metallographic examination revealed that the microstructure is not fully homogenies, the cell-dendritic areas occurred. Moreover, the microhardness profiles indicated that some fluctuation in the microstructure as well as mechanical properties can be observed on the cross section of deposited components. However, the mechanical tests showed that the tensile strength as well as elongation fulfil the requirement of producer of deposited wire.
Production of Thermal Spray Cr3C2-Ni Powders by Mechanically Activated Synthesis
Authors: Tkachivskyi Dmytro , Juhani Kristjan , Surzhenkov Andrei , Kulu Priit , Viljus Mart , Traksmaa Rainer , Jankauskas Vytenis , Leišys Rimtautas
Published: April 2019

The aim of this research was to optimize the mechanically activated synthesis (MAS) technology of the Cr3C2-Ni powder intended for thermal spraying. The MAS production route included ball milling for 72 h (ball-to-powder ratio 20:1) and sintering under 1075 °C in vacuum for 4 h. Sintered compact was crushed, classified by sieving to obtain the fraction suitable for thermal spraying (20–45 μm). The morphology and the phase composition of the powder were analyzed by a scanning electron microscope (SEM) and X-ray diffraction (XRD). The optimal Cr:C ratio found was 7:1. The powder had an equiaxial or a slightly elongated lamellar shape, Cr3C2 carbides in a single powder particle had an elongated shape. The principal phases in the optimized powder were Cr3C2, Cr7C3 and Ni (Cr) solid solution. Coatings from the manufactured powder were produced by the high velocity oxy-fuel (HVOF) spraying. The abrasive wear tests were carried out according to standard ASTM G65. The wear tests showed that the sprayed coatings from the experimental powder exhibited about five times higher wear rate at abrasive wear conditions than the coatings from the reference commercial powder.
Features of Creating Nanostructured Intermetallic Ti-Al-Si-Cr Coatings for the Hot Section Part of Gas Turbine Engines
Authors: Urbahs Alexanders , Savkovs Konstantins
Published: April 2019

The paper deals with the results of a research study into Ti-Al-Si-Cr-based thin heat resistant ion-plasma coatings for titan alloy-based parts of a gas turbine engine (GTE). The research involved the use of three Ti-Al-Si-Cr-based alloys – intermetallic, with different Cr-Ti priority. The analysis of surface oxidation process in the range of 600-850°C with the help of scanning electron microscopy was performed, and the key features of coating fracture process under high-temperature oxidation conditions were identified.
Influence of Water Absorption on Static Friction of Pure and Friction-Modified PA6 Polymers
Authors: Velkavrh Igor , Klien Stefan , Voyer Joel , Ausserer Florian , Diem Alexander
Published: April 2019

In the present study, static coefficients of friction of pure and friction modified (FM) polyamide 6 (PA6) polymers against primer-coated steel surfaces were investigated under a series of nominal contact pressures and by considering the influences of water absorption by the polymer, temperature, counter-body surface roughness and lubrication conditions. Under the majority of the test conditions investigated, FM PA6 exhibited lower static friction than pure PA6. Under unlubricated conditions, this was due to the low adhesion of the FM PA6 provided by its friction modifying inclusions; while under lubricated conditions, a combination of softening due to water absorption and decreased adhesion provided by its friction modifiers enabled lower static friction, especially at medium and high contact pressures.
A Brief Review of Abrasive Wear Modelling Using a Numerical-Experimental Approach
Authors: Badisch Ewald , Varga Markus , Eder Stefan J.
Published: April 2019

Abrasive wear limits the lifetime of key components and wear parts used in various applications. Damage is caused by indentation of harder particles into the wearing materials and subsequent relative motion resulting in ploughing, cutting, and fracture phenomena. The wear mechanisms depend mainly on the applied materials, loading conditions, and abrasives present in the tribosystem, hence material choice is often a difficult task and requires careful evaluation. For this, a variety of laboratory abrasion tests are available of which the scratch test is discussed in this work as the most fundamental abrasive interaction. For further insight into the acting wear mechanisms and microstructural effects, large-scale molecular dynamics simulations were carried out as well as meso-/macroscopic scratch simulations with the mesh-free Material Point Method. The prediction of abrasive wear is of high relevance for industrial applications. Up to now, no general one-to-one match between field application and lab system is known. Here, a simulation-based transfer of experimentally determined wear rates via a lab-2-field approach enables the prediction of wear rates in real applications.
Raman Spectroscopy of Multilayered AlCrN Coating under High Temperature Sliding/Oxidation
Authors: Baronins Janis , Antonov Maksim , Bereznev Sergei , Raadik Taavi , Hussainova Irina
Published: April 2019

The multilayered AlCrN coating physical vapour deposited (PVD) over the stainless steel (SS) substrate was studied. Raman spectroscopy was used to determine the resistance of the coating under high temperature oxidative conditions (25–800 °C). Static oxidation tests of the AlCrN PVD coating mainly leads to the formation of Cr2O3 at temperatures up to 800 °C. The results of the sliding tests indicate the development of oxides layers in the wear tracks on the surface of AlCrN PVD coated samples at the room temperature, which is critically dependant on the sliding speed against Si3N4 counter balls. The maximum reliable sliding speeds against Si3N4 counter balls under applied normal load of 3 N at 20, 300/500 and 800 °C was determined to be 0.486, 0.162 and 0.054 m·s-1, respectively.
Twist1 and Twist2 Induce Human Macrophage Memory upon Chronic Innate Receptor Treatment by HDAC-Mediated Deacetylation of Cytokine Promoters
Authors: Sun Rui , Hedl Matija , Abraham Clara
Published: April 2019

Intestinal tissues are continuously exposed to microbial products that stimulate pattern-recognition receptors (PRRs). Ongoing PRR stimulation can confer epigenetic changes in macrophages, which can then regulate subsequent immune outcomes and adaptation to the local environment. Mechanisms leading to these changes are incompletely understood. We found that short-term stimulation of the PRR NOD2 in primary human monocyte-derived macrophages resulted in increased H3 and H4 acetylation of cytokine promoters, consistent with the increased cytokine secretion observed. However, with prolonged NOD2 stimulation, both the acetylation and cytokine secretion were dramatically decreased. Chronic NOD2 stimulation upregulated the transcription factors Twist1 and Twist2, which bound to the promoters of the histone deacetylases HDAC1 and HDAC3 and induced HDAC1 and HDAC3 expression. HDAC1 and HDAC3 then mediated histone deacetylation at cytokine promoters and, in turn, cytokine downregulation under these conditions. Similar regulation was observed upon chronic stimulation of multiple PRRs. Consistent with the chronic microbial exposure in the intestinal environment, TWIST1, TWIST2, HDAC1, and HDAC3 were upregulated in human intestinal relative to peripheral macrophages. Importantly, complementing HDAC1 and HDAC3 in Twist1/Twist2-deficient monocyte-derived macrophages restored the reduced histone acetylation on cytokine promoters and the decreased cytokine secretion with chronic NOD2 stimulation. Taken together, we identify mechanisms wherein Twist1 and Twist2 promote chromatin modifications, resulting in macrophage instruction and adaptation to conditions in the intestinal microenvironment.
The role of dividend policy in share price volatility
Authors: Pelcher Lydia
Published: April 2019

Orientation: A key objective of a company is to maximise shareholder wealth. Distribution of created wealth is achieved either through reinvestment in the company, which increases share value, or through dividend payouts. This encapsulates the dividend policy of a company. In order to realise a cash return, the former requires an investor to liquidate part of the investment, while the latter provides an immediate cash return.Research purpose: The objective was to establish whether relationships exist between share price volatility and dividend policy for shares listed on the Johannesburg Stock Exchange Limited (JSE).Motivation for the study: Dividend policy is an important consideration in the wealth creation process, particularly whether or not to distribute dividends to shareholders. Dividend policy is often structured to cater for shareholders’ expectations.Research design, approach and method: Panel data analysis was employed on a sample of the top 40 JSE-listed shares from 2007 to 2016.Main findings: The results indicated that the association between share price volatility and dividend yield is positive and significant but that between share price volatility and payout ratio is insignificant.Practical/managerial implications: Dividends were proven to be relevant to shareholders and have an association with share price volatility.Contribution/value-add: Dividend policy for the top 40 companies listed on the JSE is a contributor to share price volatility. In order to minimise share price volatility, managers of dividend-paying companies should structure the dividend policy to have consistent dividend payments but also able to reinvest excess cash within the company.
Spontaneous subdural hematoma of dorsal spine secondary to dengue fever: A rare case report with review of literature
Authors: Maheshwari Vikas , Kumar Sanjay , Kumar Arun , Kumar Ashok
Published: April 2019

A 54-year-old female patient had a sudden onset of febrile illness following which she developed low backache and sudden onset paraplegia with urinary retention. Her hemogram, biochemistry, and coagulation profile was within normal limits. Her dengue serology was positive for IgG antibodies but negative for NS1 Ag. Magnetic resonance imaging of dorsolumbar spine revealed extensive subdural bleed from D6–D12 with cord compression. She underwent emergency laminectomy D6–D12 along with complete evacuation of hematoma. There was complete recovery of sensations in the immediate postoperative period though her motor weakness showed only marginal improvement.
Staged endovascular treatment of ruptured vertebral artery dissection involving the posterior inferior cerebellar artery
Authors: Yamao Yukihiro , Ogino Eiji , Torikoshi Sadaharu , Taki Waro , Nishimura Masaki
Published: April 2019

In the treatment of vertebral artery (VA) dissection involving the origin of the posterior inferior cerebellar artery (PICA), the prevention of rebleeding and the preservation of VA and PICA patency are challenging. We report a case with ruptured VA dissection involving the origin of the PICA. In the acute stage, the fusiform dilatation of the dissection was first treated by means of stent-assisted coil embolization. Dual-antiplatelet therapy was administered just before stent placement. Seven days after the first treatment, two additional stents without coils were added. Rebleeding did not occur, and the lesion was thrombosed successfully 4 days after the second treatment, with the preservation of VA and PICA patency. This staged therapy appears to be beneficial in preventing rebleeding and in preserving VA and PICA patency.
Bespoke gelfoam wafers: A practical and inexpensive alternative to oxycel for hemostasis during neurosurgery
Authors: Prabhu Santosh , Prabhu Sujata
Published: April 2019

Background: Since the beginning of neurosurgery, intraoperative parenchymal bleeding has been a major problem. Achievement of hemostasis is the endpoint of any cranial or spinal neurosurgical exercise and is mandatory to avoid postoperative hematomas which mar the ultimate outcome of the surgery. Several biosurgical agents are used to achieve this goal. Agents such as oxidized cellulose, gelatin foam, fibrillar collagen, fibrin sealants, and antifibrinolytic agents are used, each having a different mechanism of action. Materials and Methods: The authors describe a simple technique for substituting oxidized regenerated cellulose (Surgicel) for lining the surgical cavities after excising brain lesions, with customized gelfoam wafers fashioned on the surgical trolley. This has been used in over 8000 cases with excellent hemostatic results over the last 25 years. No complications are noted with use of these wafers. Results: In a randomized trial done by us, similar hemostatic effect was found between oxycel and the gelfoam wafers described by us with satisfactory outcomes of surgeries. No previous use of such custom-fashioned wafers has been described for neurosurgical hemostasis in the literature.
Spinal cord stimulation in pregnant patients: Current perspectives of indications, complications, and results in pain control: A systematic review
Authors: Camporeze Bruno , Simm Renata , Maldaun Marcos , Pires de Aguiar Paulo
Published: April 2019

Spinal cord stimulation (SCS) has been described as a valuable neuromodulator procedure in the management of chronic medically untreated neuropathic pain. Although the use of this technique has been published in many papers, a question still remains regarding its applicability in pregnant patients. The goal of this paper is to discuss the risks, complications, and results as well as the prognosis of SCS in pregnant patients. We performed a systematic review from 1967 to 2018 using the databases MEDLINE, LILACS, SciELO, PubMed, and BIREME, utilizing language as selection criteria. Eighteen studies that met our criteria were found and tabulated. SCS is a reversible and adjustable surgical procedure, which results in patients that demonstrated a significant effect in the reduction of pain intensity in pregnant patients. The etiologies most frequent were complex regional pain and failed back pain syndromes, which together represented 94% of analyzed cases. The technical complications most frequent were lead migration (3%, n = 1). Regarding the risks, the authors did not show significative factors among the categorical variables that can suggest a teratogenicity, while the maternal risks have been associated to the consequences of technical complications due to, among other factors, improvement of abdominal pressure during pregnancy and delivery. Finally, although there are not significative cohorts of pregnant patients, the procedure is still an effective surgical approach of neuropathic pain associated to lower rates of complications and significative improvement in the quality of life of patients during pregnancy.
Continuous electrochemical reactor improved by the addition of Moringa oleífera lam extract: optimization of operational conditions for Blue 5G dye removal
Authors: Santos Bruna Souza dos , Eyng Eduardo , Bittencourt Paulo Rodrigo Stival , Frare Laercio Mantovani , Flores Éder Lisandro de Moraes , Costa Michelle Budke
Published: April 2019

Wastewaters from textile industries are known for their difficulty to treat, several alternative technologies are applied for their treatment. In this context, the study examined a hybrid treatment system, composed of electrocoagulation combined with a natural coagulant (extract of Moringa oleífera lam seeds) to remove reactive dye Blue 5G aqueous solutions. The work evaluated the use of milder operating conditions to improve the efficiency of treatment, with reduced demands for electrical power and coagulant.  The following factors were evaluated: electric current intensity, natural coagulant concentration and hydraulic retention time. A quadratic model was adjusted and validated at a 5% significance level. The overall optimization resulted in conditions of 0.28 A for electrical current intensity, 1000.00 mg L-1 of aqueous extract of Moringa oleífera lam and 5 min for hydraulic retention time. While operating under optimal conditions, the removal of 71.38% of color and 5.22 mg L-1 of iron residual concentration was achieved.
Newforms of Half-integral Weight: The Minus Space Counterpart
Authors: Baruch Ehud Moshe , Purkait Soma
Published: April 2019

We study genuine local Hecke algebras of the Iwahori type of the double cover of $\operatorname{SL}_{2}(\mathbb{Q}_{p})$ and translate the generators and relations to classical operators on the space $S_{k+1/2}(\unicode[STIX]{x1D6E4}_{0}(4M))$, $M$ odd and square-free. In [9] Manickam, Ramakrishnan, and Vasudevan defined the new space of $S_{k+1/2}(\unicode[STIX]{x1D6E4}_{0}(4M))$ that maps Hecke isomorphically onto the space of newforms of $S_{2k}(\unicode[STIX]{x1D6E4}_{0}(2M))$. We characterize this newspace as a common $-1$-eigenspace of a certain pair of conjugate operators that come from local Hecke algebras. We use the classical Hecke operators and relations that we obtain to give a new proof of the results in [9] and to prove our characterization result.
The fallacy of the natural rate of interest and zero lower bound economics: why negative interest rates may not remedy Keynesian unemployment
Authors: Palley Thomas I.
Published: April 2019

This paper provides a critique of zero lower bound (ZLB) economics which has become the new orthodoxy for explaining stagnation. ZLB economics is an extension of pre-Keynesian economics which attributes macroeconomic dysfunction to rigidities and market imperfections. The ZLB is the latest rigidity in that pre-Keynesian tradition. The paper argues negative nominal interest rates, even if feasible, may be unable to remedy Keynesian demand shortage unemployment, and might even aggravate the problem. That is because there exist non-reproduced assets whose return dominates that of investment, and saving may also increase in response to negative rates. Consequently, there may be no natural rate of interest.
Negative interest rates: a Keynesian perspective
Authors: Maclachlan Fiona
Published: April 2019

One of the most surprising recent developments in financial markets has been the emergence of negative yields on long-term debt. This development contradicts the notion of the zero lower bound which, until recently, was taken as a given in monetary policy discussions. In this paper, I look at the phenomenon of negative yields through the lens of Keynes's liquidity-preference theory of interest. I review changes to the financial market environment that have led to a shift in the liquidity of government bonds relative to bank deposits, and with this empirical context in place, I argue Keynes's theory is consistent with the phenomenon of negative bond yields. Finally, I consider Keynes's thought in relation to a negative interest-rate policy (NIRP) and argue that while he would be opposed to a NIRP as a temporary expedient, a mildly negative policy rate fits with his long-run vision for a world with a zero risk-free long-term interest rate.
Negative interest rates in the eurozone
Authors: Tropeano Domenica
Published: April 2019

This paper reviews the eurozone's negative rate deposit facility and seeks to explain its rationale. The paper rejects the conventional explanation that the negative rate deposit facility improves the transmission mechanism of monetary policy and contributes to the economic recovery of the area. Instead, the paper argues that the rationale for the policy is to be found in the interbank market. The European unsecured interbank market has malfunctioned since the beginning of the global financial crisis in 2007. The negative policy rate is an extreme attempt to revive that market, but that attempt has failed. Rather than being a conventional policy, as some scholars have argued, the paper maintains that the policy is deeply unconventional because it does not target the overnight interest rate as the interbank market has effectively become irrelevant.
Estimation of hourly land surface heat fluxes over the Tibetan Plateau by the combined use of geostationary and polar-orbiting satellites
Authors: Zhong Lei , Ma Yaoming , Hu Zeyong , Fu Yunfei , Hu Yuanyuan , Wang Xian , Cheng Meilin , Ge Nan
Published: April 2019

Abstract. Estimation of land surface heat fluxes is important for
energy and water cycle studies, especially on the Tibetan Plateau (TP),
where the topography is unique and the land–atmosphere interactions are
strong. The land surface heating conditions also directly influence the
movement of atmospheric circulation. However, high-temporal-resolution
information on the plateau-scale land surface heat fluxes has been lacking for a
long time, which significantly limits the understanding of diurnal
variations in land–atmosphere interactions. Based on geostationary and polar-orbiting satellite data, the surface energy balance system (SEBS) was used
in this paper to derive hourly land surface heat fluxes at a spatial
resolution of 10 km. Six stations scattered throughout the TP and equipped
for flux tower measurements were used to perform a cross-validation. The
results showed good agreement between the derived fluxes and in situ
measurements through 3738 validation samples. The root-mean-square errors
(RMSEs) for net radiation flux, sensible heat flux, latent heat flux and
soil heat flux were 76.63, 60.29, 71.03 and
37.5 W m−2, respectively; the derived results were also found to be
superior to the Global Land Data Assimilation System (GLDAS) flux products
(with RMSEs for the surface energy balance components of 114.32,
67.77, 75.6 and 40.05 W m−2, respectively). The
diurnal and seasonal cycles of the land surface energy balance components
were clearly identified, and their spatial distribution was found to be
consistent with the heterogeneous land surface conditions and the general
hydrometeorological conditions of the TP.
Laboratory assessment of the influence of rice straw mulch size on soil loss
Authors: de Lima João L. M. P. , Santos Lara , Mujtaba Babar , de Lima M. Isabel P.
Published: April 2019

Abstract. Application of crop residues (mulch) over the soil surface is a
common practice to control soil erosion and promote infiltration. This
laboratory study aimed at investigating the effect of different rice straw
mulch sizes on runoff and sediment transport. The experimental runs were
conducted using a soil flume of adjustable slope and a rainfall simulator,
considering bare soil and three different soil covers: 1, 2 and 5 t ha−1
application rates, for three sizes of rice straw mulch (10, 30
and 200 mm). The experimental results showed that for the same mulch
application rate (by weight), the smaller mulch sizes (i.e. high surface
coverage percentage) presented less soil loss. For example, 90 % soil loss
reduction was achieved for smaller sizes of rice straw mulch and 80 % for
the bigger size. The results of this study are an important contribution to
the understanding of the soil loss process in small basins and to the
definition of relevant soil conservation measures, at the plot/field scale.
Ice crystal number concentration from measurements of lidar, cloud radar and radar wind profiler
Authors: Bühl Johannes , Seifert Patric , Radenz Martin , Baars Holger , Ansmann Albert
Published: April 2019

Abstract. A new method for the retrieval of ice particle number concentrations from combined active remote-sensing measurements of Raman lidar, cloud radar and radar wind profiler is presented. We exploit – for the first time – measurements of terminal fall velocity together with radar reflectivity factor and/or lidar-derived particle extinction coefficient in clouds for retrieving the number concentration of pristine ice particles with presumed particle shapes. A lookup table approach for the retrieval of the properties of the particle size distribution from observed parameters is presented. Analysis of methodological uncertainties and error propagation are performed, which shows that a retrieval of ice particle number concentration is possible within the order of magnitude. Comparison between a retrieval of number concentration based on terminal fall velocity on the one hand and lidar and cloud radar on the other shows agreement within the uncertainties of the retrieval.
Characteristics of ionospheric irregularities near the northern equatorial anomaly crest
Authors: Li Jinghua , Ma Guanyi , Hocke Klemens , Wan Qingtao , Fan Jiangtao , Wang Xiaolan
Published: April 2019

Abstract. This paper detects the ionospheric irregularities with rate of total electron content (TEC) change index, ROTI from GPS observation at Taoyuan (24.95° N, 121.16° E) for the solar medium and minimum years of 2003 and 2008 in the declining phase of cycle 23, the solar maximum of 2014 in solar cycle 24. Local occurrence rate (LOR) is proposed to clarify the characteristics of the irregularities together with monthly occurrence rate (MOR) and ROTI maximum for 3 latitude belts, 20–23° N, 23–26° N, 26–29° N, around the equatorial anomaly crest. MOR in May/June is larger than those in equinoxes in 2008 and 2003, which is different from that of equatorial plasma bubbles. In 2014 although MOR maximum is observed in equinoxes, the MOR in May and June is much larger than that in September. Moreover, MORs in May to August at higher latitude belt 26–29° N are larger than those in lower latitude belts and smaller in the equinoxes. The latitudinal dependence of the LORs tends to be similar to that of MORs. Seasonal variations of LORs have a similar trend for different solar activities. Maximum LORs are observed in Feb/Mar and Sep/Oct, and moderate around June, which resemble those of plasma bubbles in seasonal variations, except for latitude belt 26–29° N where maximum LORs are seen in May–Jul. The seasonal variation of ROTI maximum conforms to that of the LOR. The results suggest that irregularities near the crest in May to August are mainly originated from nonequatorial process, which is more frequently happened but weaker than plasma bubble in both spatiotemporal scale and strength.
A statistical and process-oriented evaluation of cloud radiative effects in high-resolution global models
Authors: Thomas Manu Anna , Devasthale Abhay , Koenigk Torben , Wyser Klaus , Roberts Malcolm , Roberts Christopher , Lohmann Katja
Published: April 2019

Abstract. This study evaluates the impact of atmospheric horizontal resolution on the
representation of cloud radiative effects (CREs) in an ensemble of global
climate model simulations following the protocols of the High Resolution
Model Intercomparison Project (HighResMIP). We compare results from four
European modelling centres, each of which provides data from “standard”-
and “high”-resolution model configurations. Simulated radiative fluxes are
compared with observation-based estimates derived from the Clouds and Earth's
Radiant Energy System (CERES) dataset. Model CRE biases are evaluated using
both conventional statistics (e.g. time and spatial averages) and after
conditioning on the phase of two modes of internal climate variability,
namely the El Niño–Southern Oscillation (ENSO) and the North Atlantic
Oscillation (NAO). Simulated top-of-atmosphere (TOA) and surface CREs show
large biases over the polar regions, particularly over regions where seasonal
sea-ice variability is strongest. Increasing atmospheric resolution does not
significantly improve these biases. The spatial structure of the cloud
radiative response to ENSO and NAO variability is simulated reasonably well
by all model configurations considered in this study. However, it is
difficult to identify a systematic impact of atmospheric resolution on the
associated CRE errors. Mean absolute CRE errors conditioned on the ENSO phase
are relatively large (5–10 W m−2) and show differences between
models. We suggest this is a consequence of differences in the
parameterization of SW radiative transfer and the treatment of cloud optical
properties rather than a result of differences in resolution. In contrast,
mean absolute CRE errors conditioned on the NAO phase are generally smaller
(0–2 W m−2) and more similar across models. Although the regional
details of CRE biases show some sensitivity to atmospheric resolution within
a particular model, it is difficult to identify patterns that hold across all
models. This apparent insensitivity to increased atmospheric horizontal
resolution indicates that physical parameterizations play a dominant role in
determining the behaviour of cloud–radiation feedbacks. However, we note
that these results are obtained from atmosphere-only simulations and the
impact of changes in atmospheric resolution may be different in the presence
of coupled climate feedbacks.