bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of the Speciation and Mobility of Pb, Zn and Cd in Relation to Transport Processes in a Mining Environment
Authors: Elmayel Intissar , Esbrí José María , Efrén García-Ordiales , García-Noguero Eva-María , Elouear Zouhair , Jalel Bouzid , Farieri Alessandro , Roqueñí Nieves , Cienfuegos Pablo , Higueras Pablo
Published: July 2020

Elements in mining extracts can be potentially toxic if they are incorporated into soils, sediments or biota. Numerous approaches have been used to assess this problem, and these include sequential extractions and selective extractions. These two methods have limitations and advantages, and their combined use usually provides a rough estimate of the availability or (bio)availability of potentially toxic elements and, therefore, of their real potential as toxicants in food chains. These indirect speciation data are interesting in absolute terms, but in the work described here, this aspect was developed further by assessing the evolution of availability-related speciation in relation to the transport processes from the emission source, which are mainly fluvial- and wind-driven. This objective was achieved by characterizing tailings samples as the source of elements in soils and sediments at increasing distances to investigate the evolution of certain elements. The standard procedures employed included a sequential five-step extraction and a selective extraction with ammonium acetate. The results show that the highest percentages of Zn and Pb in tailings, soils and sediment samples are associated with oxyhydroxides, along with a significant presence of resistant mineralogical forms. In the case of Cd, its association with organic matter is the second-most important trapping mechanism in the area. The physicochemical mechanisms of transport did not transform the main mineralogical associations (oxyhydroxides and resistant mineralogical forms) along the transects, but they produced a chaotic evolution pattern for the other minor matrix associations for Zn and a decrease in exchangeable and carbonate-bound forms for Pb in soils. Interestingly, in sediments, these mobile forms showed a decrease in Zn and a chaotic evolution for Pb. The most probable reason for these observations is that Zn2+ can form smithsonite (ZnCO3) or hydrozincite (Zn5(CO3)2(OH)6), which explains the retention of a carbonate-bound form for Zn in the soil transect. In contrast, Pb and Cd can appear as different mineral phases. The order of (bio)availability was Pb > Zn > Cd in tailings but Cd > Pb > Zn in soils. The physicochemical processes involved in transport from tailings to soils produce an increase in Cd (bio)availability. The trend is a decrease in bioavailability on moving away from the source (tailings), with maximum values obtained for Cd near to the source area (200–400 m).
Exploring the Cognitive Load of Expert and Novice Map Users Using EEG and Eye Tracking
Authors: Keskin Merve , Ooms Kristien , Dogru Ahmet Ozgur , De Maeyer Philippe
Published: July 2020

The main objective of this research is to explore the cognitive processes of expert and novice map users during the retrieval of map-related information, within varying difficulty levels (i.e., easy, moderate, hard), by using eye tracking and electroencephalogram (EEG). In this context, we present a spatial memory experiment consisting of a large number of stimuli to study the effect of task difficulty on map users’ behavior through cognitive load measurements. Next to the reaction time and success rate, we used fixation and saccade related eye tracking metrics (i.e., average fixation duration, the number of fixations per second, saccade amplitude and saccade velocity), and EEG power spectrum (i.e., event-related changes in alpha and theta frequency bands) to identify the cognitive load. While fixation metrics indicated no statistically significant difference between experts and novices, saccade metrics proved the otherwise. EEG power spectral density analysis, on the other side, suggested an increase in theta (i.e., event-related synchronization) and a decrease in alpha (except moderate tasks) (i.e., event-related desynchronization) at all difficulty levels of the task for both experts and novices, which is an indicator of cognitive load. Although no significant difference emerged between two groups, we found a significant difference in their overall performances when the participants were classified as good and relatively bad learners. Triangulating EEG results with the recorded eye tracking data and the qualitative analysis of focus maps indeed provided a detailed insight on the differences of the individuals’ cognitive processes during this spatial memory task.
Why Do We Screen Newborn Infants for Cystic Fibrosis?
Authors: Barben Jürg , Southern Kevin W.
Published: July 2020

The introduction and widespread implementation of newborn bloodspot screening (NBS) for cystic fibrosis (CF) has offered earlier diagnosis and better outcomes for children with CF in many countries of the world [...]
Does Commons Grabbing Lead to Resilience Grabbing? The Anti-Politics Machine of Neo-Liberal Agrarian Development and Local Responses
Authors: Haller Tobias , Käser Fabian , Ngutu Mariah
Published: July 2020

This Special Issue contributes to the debate that land grabbing should be discussed as commons grabbing [...]
Sustainable Population Growth in Low-Density Areas in a New Technological Era: Prospective Thinking on How to Support Planning Policies Using Complex Spatial Models
Authors: Gomes Eduardo
Published: July 2020

Urban development is the result of the interaction between anthropogenic and environmental dimensions. From the perspective of its density, it ranges from high-density populated areas, associated with large cities that concentrate the main economic and social thrust of societies, to low-density populated areas (e.g., rural areas, small–medium-sized cities). Against the backdrop of the new technological and environmental era, this commentary offers insights on how to support spatial planning policies for sustainable urban growth in low-density areas. We propose the integration of technological drivers such as Internet networks, telecommuting, distance-learning education, the use of electric cars, etc. into the complex spatial models to project and thus to identify the best locations for urban development in low-density areas. This understanding can help to mitigate the disparities between high- and low-density populated areas, and to reduce the inequality among regions as promoted in the UN 2030 Agenda for Sustainable Development Goals.
3,3,3′,3′-Tetramethyl-2,2′-diphenyl-3H,3′H-5,5′-biindole
Authors: Šachlevičiūtė Urtė , Varvuolytė Gabrielė , Bieliauskas Aurimas , Kleizienė Neringa , Žukauskaitė Asta , Šačkus Algirdas
Published: July 2020

The palladium-catalyzed homocoupling of 5-iodo-3,3-dimethyl-2-phenyl-3H-indole afforded 3,3,3′,3′-tetramethyl-2,2′-diphenyl-3H,3′H-5,5′-biindole in 65% yield. This previously unreported compound was fully characterized by NMR, IR and HRMS data and its optical properties were studied by UV/vis and fluorescence spectroscopy.
Use of Polycarbonate Waste as Aggregate in Recycled Gypsum Plasters
Authors: Pedreño-Rojas Manuel Alejandro , Rodríguez-Liñán Carmen , Flores-Colen Inês , de Brito Jorge
Published: July 2020

The use of gypsum as an indoor coating material for buildings is very extensive. This means that huge amounts of gypsum waste are generated daily worldwide. Therefore, many researchers in the last years have been working on the generation of new gypsum-related materials and products that incorporate recycled gypsum waste as a replacement for the commercial one. On the other hand, trying to reduce the large amounts of plastic generated globally each year, several studies have used different types of plastic waste as aggregates for the development of new construction and building materials. However, up to now, no previous studies have been found in which any type of plastic waste has been used as an aggregate in a recycled gypsum matrix. This paper presents a study in which two different types of waste were mixed for the development of new gypsum plasters: unheated gypsum waste from industrial plasterboard production (GPW) and polycarbonate (PC) waste from rejected compact discs (CDs) and digital versatile discs (DVDs). In this sense, the mechanical and thermal performance of plasters was evaluated. Finally, in order to evaluate the changes in the microstructure of the composites, a scanning electron microscopy (SEM) analysis was conducted. The results showed a good performance of the new composites when both types of waste were combined in the mixes. New lightweight eco-efficient plasters, completely recycled, with enhanced flexural strength (by 14.8%), compressive strength (by 26.8%), and thermal conductivity (42.8% less), compared to the reference material, were achieved.
A Continuous Fiber-Reinforced Additive Manufacturing Processing Based on PET Fiber and PLA
Authors: Yao Yuan , Li Meng , Lackner Maximilian , Herfried Lammer
Published: July 2020

Continuous fiber-reinforced manufacturing has many advantages, but the fabrication cost is high and its process is difficult to control. This paper presents a method for printing fiber-reinforced composite on the common fused filament fabrication (FFF) platform. Polylactic Acid (PLA) and Polyethylene terephthalate (PET) fibers are used as printing materials. A spatial continuous toolpath planning strategy is employed to reduce the workload of post-processing without cutting the fiber. Experimental results show that this process not only enables the printing of models with complex geometric shapes but also supports material recycling and reuse. A material recovery rate of 100% for continuous PET fiber and 83% for PLA were achieved for a better environmental impact. Mechanical tests show that the maximum tensile strength of continuous PET fiber-reinforced thermoplastic composites (PFRTPCs) is increased by 117.8% when compared to polyamide-66 (PA66).
The Effect of Transverse Shear in Symmetric and Asymmetric End Notch Flexure Tests–Analytical and Numerical Modeling
Authors: Dadej Konrad , Valvo Paolo Sebastiano , Bieniaś Jarosław
Published: July 2020

This paper focuses on the effects of transverse shear and root rotations in both symmetric and asymmetrical end-notched flexure (AENF) interlaminar fracture toughness tests. A theoretical model is developed, whereas the test specimen is subdivided into four regions joined by a rigid interface. The differential equations for the deflection and rotations of each region are solved within both the Euler–Bernoulli simple beam theory (SBT) and the more refined Timoshenko beam theory (TBT). A concise analytical equation is derived for the AENF deflection profile, compliance, and transverse shearing forces as a function of the specimen geometry, stacking sequence, delamination length, and fixture span. Modeling results are compared with numerical finite element analyses, obtaining a very good agreement. Performed analyses suggest that even in the case of symmetrical and unidirectional laminates considered as pure mode II fracture, a complex compression/tension and bending moment state is present, as well as a slight contribution of anti-planar shear at the vicinity of the crack tip.
The Tensile Properties, Scratch Behaviors and Sliding Wear of Oxide Scale Formed on Titanium Grade 2
Authors: Aniołek Krzysztof , Barylski Adrian , Kupka Marian , Leszek Iwona
Published: July 2020

The tensile properties, scratch behaviors and sliding wear of an oxide scale obtained on the surface of titanium Grade 2 in the process of isothermal oxidation at 600, 700 and 800 °C were determined in the study. It was shown that the intensity of the oxidation process increased along with an increase in temperature and extension of the oxidation time, which translated directly into the thickness of the deposited oxide layers. The tests showed that isothermal oxidation had an adverse effect on the tensile properties of titanium. After oxidation, it was found that the maximum reduction in tensile strength, Rm, was approximately 17.5%, and of the yield point, Rp0.2, approximately 13.9%. Examination of scratch behaviors of the oxide scale showed that the layers obtained at temperatures of 700 (72 h) and 800 °C (2 and 6 h) had the best adhesion properties. The best resistance to scratching was exhibited by the layer obtained after 6 h oxidation at 800 °C (critical load: Lc1 = 63 N, Lc2 = 85 N). The study showed that after oxidation, a considerable reduction in wear factor of a disc made of titanium Grade 2 was observed for both the friction couples used (Al2O3, steel 100Cr6). The maximum reduction in wear factor of the oxidized titanium disc during interaction with Al2O3 balls was ca. 79%, and with 100Cr6 balls, ca. 96%.
Blending Powder Process for Recycling Sintered Nd-Fe-B Magnets
Authors: Prokofev Pavel A. , Kolchugina Natalia B. , Skotnicova Katerina , Burkhanov Gennady S. , Kursa Miroslav , Zheleznyi Mark V. , Dormidontov Nikolay A. , Cegan Tomas , Bakulina Anna S. , Koshkidko Yurii S. , Smetana Bedřich
Published: July 2020

The wide application of Nd-Fe-B permanent magnets, in addition to rare-earth metal resource constraints, creates the necessity of the development of efficient technologies for recycling sintered Nd-Fe-B permanent magnets. In the present study, a magnet-to-magnet recycling process is considered. As starting materials, magnets of different grades were used, which were processed by hydrogen decrepitation and blending the powder with NdHx. Composition inhomogeneity in the Nd2Fe14B-based magnetic phase grains in the recycled magnets and the existence of a core-shell structure consisting of a Nd-rich (Dy-depleted) core and Nd-depleted (Dy-enriched) shell are demonstrated. The formation of this structure results from the grain boundary diffusion process of Dy that occurs during the sintering of magnets prepared from a mixture of Dy-free (N42) and Dy-containing magnets. The increase in the coercive force of the N42 magnet was shown to be 52%. The simultaneous retention of the remanence, and even its increase, were observed and explained by the improved isolation of the main magnetic phase grains as well as their alignment.
In Vitro Production of Calcified Bone Matrix onto Wool Keratin Scaffolds via Osteogenic Factors and Electromagnetic Stimulus
Authors: Bloise Nora , Patrucco Alessia , Bruni Giovanna , Montagna Giulia , Caringella Rosalinda , Fassina Lorenzo , Tonin Claudio , Visai Livia
Published: July 2020

Pulsed electromagnetic field (PEMF) has drawn attention as a potential tool to improve the ability of bone biomaterials to integrate into the surrounding tissue. We investigated the effects of PEMF (frequency, 75 Hz; magnetic induction amplitude, 2 mT; pulse duration, 1.3 ms) on human osteoblast-like cells (SAOS-2) seeded onto wool keratin scaffolds in terms of proliferation, differentiation, and production of the calcified bone extracellular matrix. The wool keratin scaffold offered a 3D porous architecture for cell guesting and nutrient diffusion, suggesting its possible use as a filler to repair bone defects. Here, the combined approach of applying a daily PEMF exposure with additional osteogenic factors stimulated the cells to increase both the deposition of bone-related proteins and calcified matrix onto the wool keratin scaffolds. Also, the presence of SAOS-2 cells, or PEMF, or osteogenic factors did not influence the compression behavior or the resilience of keratin scaffolds in wet conditions. Besides, ageing tests revealed that wool keratin scaffolds were very stable and showed a lower degradation rate compared to commercial collagen sponges. It is for these reasons that this tissue engineering strategy, which improves the osteointegration properties of the wool keratin scaffold, may have a promising application for long term support of bone formation in vivo.
Mechanical Properties of Natural Fiber Reinforced Foamed Concrete
Authors: Castillo-Lara Joaquin F. , Flores-Johnson Emmanuel A. , Valadez-Gonzalez Alex , Herrera-Franco Pedro J. , Carrillo Jose G. , Gonzalez-Chi P. I. , Li Q. M.
Published: July 2020

The mechanical characterization of plain foamed concrete (PFC) and fiber-reinforced foamed concrete (FRFC) with a density of 700 kg/m3 was performed with compression and tension tests. FRFC was reinforced with the natural fiber henequen (untreated or alkaline-treated) at volume fractions of 0.5%, 1% and 1.5%. Polypropylene fiber reinforcement was also used as a reference. For all FRFCs, the inclusion of the fibers enhanced the compressive and tensile strengths and plastic behavior, which was attributed to the increase of specimen integrity. Under compressive loading, after the peak strength, there was no considerable loss in strength and a plateau-like regime was observed. Under tensile loading, the fibers significantly increased the tensile strength of the FRFCs and prevented a sudden failure of the specimens, which was in contrast to the brittle behavior of the PFC. The tensile behavior enhancement was higher when treated henequen fibers were used, which was attributed to the increase in the fiber–matrix bond produced by the alkaline treatment. The microscopic characterization showed that the inclusion of fibers did not modify the air-void size and its distribution. Higher energy absorption was observed for FRFCs when compared to the PFC, which was attributed to the enhanced toughness and ductility by the fibers. The results presented herein warrant further research of FRFC with natural henequen fibers for engineering applications.
Porous Gelatin Membranes Obtained from Pickering Emulsions Stabilized with h-BNNS: Application for Polyelectrolyte-Enhanced Ultrafiltration
Authors: Nafti Mateur Molka , Gonzalez Ortiz Danae , Jellouli Ennigrou Dorra , Horchani-Naifer Karima , Bechelany Mikhael , Miele Philippe , Pochat-Bohatier Céline
Published: July 2020

In recent years, numerous studies have been conducted to develop biopolymer-based membranes, highlighting the challenges to prepare porous structures with control porosity. In this paper an innovative method that relies on the generation of Pickering emulsions was developed to prepare porous membranes from gelatin for filtration purpose. Hexagonal boron nitride nanosheets (h-BNNS) were used to stabilize micro-droplets of castor oil in a continuous homogeneous gelatin solution. Two steps in the membrane preparation process strongly influenced the porous structure. Specifically, the duration of the drying time after emulsion casting and the duration of the cross-linking step affected membrane pore size, hydrophobicity, water swelling, and water permeability. By controlling these two steps, membranes could be designed with pore size between 0.39 and 1.60 μm and display pure water permeability between 150 and 506 L h−1 m−2 bar−1. These membranes have been tested for complexation–ultrafiltration experiments in which iron ions were removed from aqueous solutions with/without poly (acrylic acid) (PAA). Without PAA, the removal of free iron (II) ions was low (not more than 14%). The addition of PAA (200 ppm) allowed obtaining high removal rates (97%) at pH ≥ 5 with 3 bars of transmembrane pressure.
Influence of Surface Modification of MK-40 Membrane with Polyaniline on Scale Formation under Electrodialysis
Authors: Andreeva Marina A. , Loza Natalia V. , Pis’menskaya Natalia D. , Dammak Lasaad , Larchet Christian
Published: July 2020

A comprehensive study of the polyaniline influence on mineral scaling on the surface of the heterogeneous MK-40 sulfocationite membrane under electrodialysis has been conducted. Current-voltage curves and chronopotentiograms have been obtained and analyzed for the pristine MK-40 membrane and the MK-40 membrane which is surface-modified by polyaniline. The study of the electrochemical behavior of membranes has been accompanied by the simultaneous control of the pH of the solution outcoming from the desalination compartment. The mixture of Na2CO3, KCl, CaCl2, and MgCl2 is used as a model salt solution. Two limiting states are observed on the current-voltage curve of the surface-modified membrane. There is the first pseudo-limiting state in the range of small values of the potential drop. The second limiting current is comparable with that of the limiting current for the pristine membrane. It is shown that chronopotentiometry cannot be used as a self-sufficient method for membrane scaling identification on the surface-modified membrane at high currents. A mineral scale on the surfaces of the studied membranes has been found by scanning electron microscopy. The amount of precipitate is higher in the case of the surface-modified membrane compared with the pristine one.
Microstructure Evolution and Mechanical Properties of the 2195 Al-Li Alloy via Different Annealing and Ramp Heating-Up Treatments
Authors: Liu Tian-Le , Li Jin-Feng , Liu Dan-Yang , Ma Yun-Long
Published: July 2020

In this paper, the microstructure evolution of the 2195 Al-Li alloy under different isothermal annealing schedules and ramp heating-up heat treatments prior to solution heat treatment and the tensile properties of the aging alloy were investigated. The grain structure characteristics of the aging alloy could be influenced by the change of different heat treatment schedules prior to the solution heat treatment. Meanwhile, the mechanical properties of the aging alloy including strength, heterogeneity, and anisotropy were closely related to the grain structure characteristics. There were evident differences in the mechanical properties of aging samples, attributed to the mutual effect of grain structure evolution and texture change. Annealing at a lower temperature (300–350 °C) resulted in the growth of the grain size and the aspect ratio as well as the decrease of the deformation texture components, related to the decline of the strength and the heterogeneity. While grains refined and the deformation texture components increased as the annealing temperature rose (350–400 °C), the strength along the transverse direction decreased, and the heterogeneity increased. Fibrous and overall texture components significantly strengthened in the grain structure of aging samples treated with the low heating-up rate, resulting in a higher strength in the longitudinal direction.
Effect of Gas Nitriding on Interface Adhesion and Surface Damage of CL60 Railway Wheels under Rolling Contact Conditions
Authors: Wu Qiang , Qin Tao , Shen Mingxue , Rong Kangjie , Xiong Guangyao , Peng Jinfang
Published: July 2020

The influence of surface gas nitriding on wheel/rail rolling contact fatigue and wear behavior of CL60 wheel was studied on a new rolling contact fatigue/wear tester (JD-DRCF/M). The failure mechanisms of the wheel/rail surface after the gas nitriding and without gas nitriding on the wheel surface were compared and analyzed. The results show that the wheel with gas nitriding could form a dense and hard white bright layer which was approximately 25 μm thick and a diffusion layer which was approximately 70 μm thick on the wheel surface. Thus, the gas nitriding on the railway wheel not only significantly improved the wear resistance on the surface of the wheel, but also effectively reduced the wear of the rail; the results show that the material loss reduced by 58.05% and 10.77%, respectively. After the wheel surface was subjected to gas nitriding, the adhesive coefficient between the wheel/rail was reduced by 11.7% in dry conditions, and was reduced by 18.4% in water media, but even so, the wheel with gas nitriding still could keep a satisfactory adhesive coefficient between the wheel/rail systems, which can prevent the occurrence of phenomena such as wheel-slip. In short, the gas nitriding on the wheel surface can effectively reduce the wear, and improve the rolling contact fatigue resistance of the wheel/rail system. This study enlarges the application field of gas nitriding and provides a new method for the surface protection of railway wheels in heavy-duty transportation.
Study on the Relationship between Root Metal Flow Behavior and Root Flaw Formation of a 2024 Aluminum Alloy Joint in Friction Stir Welding by a Multiphysics Field Model
Authors: Luo Jian , Wang Jiafa , Lin Hongxin , Yuan Lei , Gao Jianjun , Geng Haibin
Published: July 2020

In friction stir welding (FSW), many defects (such as kissing bond, incomplete penetration, and weak connection) easily occur at the root of the welded joint. Based on the Levy–Mises yield criterion of the Zener–Hollomon thermoplastic constitutive equation, a 3D thermal–mechanical coupled finite element model was established. The material flow behavior and the stress field at the root area of a 6 mm thick 2024-T3 aluminum alloy FSW joint were studied. The influence of pin length on the root flaw was investigated, and the formation mechanism of the “S line” defects and non-penetration defects were revealed. The research results showed that the “S line” defect forms near the bottom surface of the pin owing to the insufficiently mixed material from the advancing side (AS) and retreating side (RS) near the weld center. The non-penetration defect forms near the bottom surface of the workpiece owing to the insufficient driving force to make the material flow through the weld center. With the continual increase of pin length, the size of the “S line” defect and non-penetration defect reduces, and finally, the defect-free welded joint can be obtained with an optimized suitable length of the pin in this case.
Torque-Based Temperature Control in Friction Stir Welding by Using a Digital Twin
Authors: Sigl Martina E. , Bachmann Andreas , Mair Thomas , Zaeh Michael F.
Published: July 2020

Friction stir welding (FSW) is an innovative solid-state welding technology that produces high quality joints and is widely used in the aerospace industry. Previous studies have revealed welding temperature to be a decisive factor for joint quality. Consequently, several temperature control systems for FSW have been developed. These output feedback control systems usually require delicate and expensive temperature measuring equipment, which reduces their suitability for industrial practice. This paper presents a novel state feedback system of the welding temperature to remedy this shortcoming. The system uses a physical model of the FSW process (digital twin) for the determination of the welding temperature signal from the process torque signal. The digital twin is based on a multi-input nonlinear time invariant model, which is fed with the torque signal from the spindle motor. A model-based ℒ1 adaptive controller was employed for its robustness with respect to model inaccuracies and fast adaption to fluctuations in the controlled system. The experimental validation of the feedback control system showed improved weld quality compared to welded joints produced without temperature control. The achieved control accuracies depended on the results of the temperature calculation. Control deviations of less than 10 K could be achieved for certain welding parameters, and even for a work piece geometry, which deliberately caused heat accumulation.
In-Pixel Temperature Sensors with an Accuracy of ±0.25 °C, a 3σ Variation of ±0.7 °C in the Spatial Domain and a 3σ Variation of ±1 °C in the Temporal Domain
Authors: Abarca Accel , Theuwissen Albert
Published: July 2020

This article presents in-pixel (of a CMOS image sensor (CIS)) temperature sensors with improved accuracy in the spatial and the temporal domain. The goal of the temperature sensors is to be used to compensate for dark (current) fixed pattern noise (FPN) during the exposure of the CIS. The temperature sensors are based on substrate parasitic bipolar junction transistor (BJT) and on the nMOS source follower of the pixel. The accuracy of these temperature sensors has been improved in the analog domain by using dynamic element matching (DEM), a temperature independent bias current based on a bandgap reference (BGR) with a temperature independent resistor, correlated double sampling (CDS), and a full BGR bias of the gain amplifier. The accuracy of the bipolar based temperature sensor has been improved to a level of ±0.25 °C, a 3σ variation of ±0.7 °C in the spatial domain, and a 3σ variation of ±1 °C in the temporal domain. In the case of the nMOS based temperature sensor, an accuracy of ±0.45 °C, 3σ variation of ±0.95 °C in the spatial domain, and ±1.4 °C in the temporal domain have been acquired. The temperature range is between −40 °C and 100 °C.
Electrospun Cadmium Selenide Nanoparticles-Loaded Cellulose Acetate Fibers for Solar Thermal Application
Authors: Angel Nicole , Vijayaraghavan S. N. , Yan Feng , Kong Lingyan
Published: July 2020

Solar thermal techniques provide a promising method for the direct conversion of solar energy to thermal energy for applications, such as water desalination. To effectively realize the optimal potential of solar thermal conversion, it is desirable to construct an assembly with localized heating. Specifically, photoactive semiconducting nanoparticles, when utilized as independent light absorbers, have successfully demonstrated the ability to increase solar vapor efficiency. Additionally, bio-based fibers have shown low thermal conductive photocorrosion. In this work, cellulose acetate (CA) fibers were loaded with cadmium selenide (CdSe) nanoparticles to be employed for solar thermal conversion and then subsequently evaluated for both their resulting morphology and conversion potential and efficiency. Electrospinning was employed to fabricate the CdSe-loaded CA fibers by adjusting the CA/CdSe ratio for increased solar conversion efficiency. The microstructural and chemical composition of the CdSe-loaded CA fibers were characterized. Additionally, the optical sunlight absorption performance was evaluated, and it was demonstrated that the CdSe nanoparticles-loaded CA fibers have the potential to significantly improve solar energy absorption. The photothermal conversion under 1 sun (100 mW/cm2) demonstrated that the CdSe nanoparticles could increase the temperature up to 43 °C. The CdSe-loaded CA fibers were shown as a feasible and promising hybrid material for achieving efficient solar thermal conversion.
The Indirect Tribological Role of Carbon Nanotubes Stimulating Zinc Dithiophosphate Anti-Wear Film Formation
Authors: Kałużny Jarosław , Kulczycki Andrzej , Dzięgielewski Wojciech , Piasecki Adam , Gapiński Bartosz , Mendak Michał , Runka Tomasz , Łukawski Damian , Stepanenko Oleksandr , Merkisz Jerzy , Kempa Krzysztof
Published: July 2020

Experimental studies reveal that the simultaneous addition of zinc dialkyl dithiophosphates (ZDDPs) and multi-wall carbon nanotubes (MWCNTs) to a poly-alpha-olefin base oil strongly reduces wear. In this paper, it is shown that MWCNTs promote the formation of an anti-wear (AW) layer on the metal surface that is much thicker than what ZDDPs can create as a sole additive. More importantly, the nanotubes’ action is indirect, i.e., MWCNTs neither mechanically nor structurally strengthen the AW film. A new mechanism for this effect is also proposed, which is supported by detailed tribometer results, friction track 3D-topography measurements, electron diffraction spectroscopy (EDS), and Raman spectroscopy. In this mechanism, MWCNTs mediate the transfer of both thermal and electric energy released on the metal surface in the friction process. As a result, this energy penetrates more deeply into the oil volume, thus extending the spatial range of tribochemical reactions involving ZDDPs.
Implementing Defects for Ratiometric Luminescence Thermometry
Authors: Drabik Joanna , Ledwa Karolina , Marciniak Łukasz
Published: July 2020

In luminescence thermometry enabling temperature reading at a distance, an important challenge is to propose new solutions that open measuring and material possibilities. Responding to these needs, in the nanocrystalline phosphors of yttrium oxide Y2O3 and lutetium oxide Lu2O3, temperature-dependent emission of trivalent terbium Tb3+ dopant ions was recorded at the excitation wavelength 266 nm. The signal of intensity decreasing with temperature was monitored in the range corresponding to the 5D4 → 7F6 emission band. On the other hand, defect emission intensity obtained upon 543 nm excitation increases significantly at elevated temperatures. The opposite thermal monotonicity of these two signals in the same spectral range enabled development of the single band ratiometric luminescent thermometer of as high a relative sensitivity as 4.92%/°C and 2%/°C for Y2O3:Tb3+ and Lu2O3:Tb3+ nanocrystals, respectively. This study presents the first report on luminescent thermometry using defect emission in inorganic phosphors.
Plasma-Assisted Chemical Vapor Deposition of F-Doped MnO2 Nanostructures on Single Crystal Substrates
Authors: Bigiani Lorenzo , Maccato Chiara , Gasparotto Alberto , Sada Cinzia , Bontempi Elza , Barreca Davide
Published: July 2020

MnO2 nanostructures were fabricated by plasma assisted-chemical vapor deposition (PA-CVD) using a fluorinated diketonate diamine manganese complex, acting as single-source precursor for both Mn and F. The syntheses were performed from Ar/O2 plasmas on MgAl2O4(100), YAlO3(010), and Y3Al5O12(100) single crystals at a growth temperature of 300 °C, in order to investigate the substrate influence on material chemico-physical properties. A detailed characterization through complementary analytical techniques highlighted the formation of highly pure and oriented F-doped systems, comprising the sole β-MnO2 polymorph and exhibiting an inherent oxygen deficiency. Optical absorption spectroscopy revealed the presence of an appreciable Vis-light harvesting, of interest in view of possible photocatalytic applications in pollutant degradation and hydrogen production. The used substrates directly affected the system structural features, as well as the resulting magnetic characteristics. In particular, magnetic force microscopy (MFM) measurements, sensitive to the out-of-plane magnetization component, highlighted the formation of spin domains and long-range magnetic ordering in the developed materials, with features dependent on the system morphology. These results open the door to future engineering of the present nanostructures as possible magnetic media for integration in data storage devices.
Pharmacist Prescriptive Authority: Lessons from Idaho
Authors: Adams Alex J.
Published: July 2020

Pharmacist prescriptive authority continues to increase at the state level in the United States. Recently, the Idaho Board of Pharmacy (BOP) finalized regulations that expanded autonomous prescriptive authority in its state to a range of preventative care as well as acute and chronic conditions. This manuscript reviews the key decision points made by the BOP regarding drug categories included, education requirements, protocols, access to data, and use of standards of care. Overall, Idaho’s approach closely reflects the medical model of regulation and may prove useful to other states and jurisdictions as they consider similar issues.
Evaluating a specialist primary care service for patients experiencing homelessness: a qualitative study
Authors: Clark Emily , Player Emily , Gillam Tara , Hanson Sarah , Steel Nicholas
Published: July 2020

Background

People experiencing homelessness (PEH) often experience poor health, multimorbidity, and early mortality and experience barriers to accessing high quality health care. Little is known about how best to provide specialist primary care for these patients.

Aim

To evaluate the health care provided to patients experiencing homelessness who were seen in a specialist primary care service.

Design & setting

A qualitative evaluation of a city centre primary healthcare service for excluded and vulnerable people, such as rough sleepers, who find it difficult to visit mainstream GP services.

Method

Data on patient characteristics and service use were extracted from primary care records using electronic and free-text searches to provide context to the evaluation. Semi-structured interviews with 11 patients and four staff were used to explore attitudes and experiences.

Results

Patients had high needs compared with the general population. Patients valued continuity of care, ease of access, multidisciplinary care, and person-centred care. Staff were concerned that they lacked opportunities for reflection and learning, and that low clinical capacity affected service safety and quality. Staff also wanted more patient involvement in service planning.

Conclusion

PEH’s complex health and social problems benefited from a specialist primary care service, which is thought to reduce barriers to access, treat potentially challenging patients in a non-judgmental way, and provide personal continuity of care in order to develop trust.
Social distancing, population density, and spread of COVID-19 in England: a longitudinal study
Authors: Tammes Peter
Published: July 2020

Background

The UK government introduced social distancing measures between 16–22 March 2020, aiming to slow down transmission of COVID-19.

Aim

To explore the spreading of COVID-19 in relation to population density after the introduction of social distancing measures.

Design & setting

Longitudinal design with 5-weekly COVID-19 incidence rates per 100 000 people for 149 English Upper Tier Local Authorities (UTLAs), between 16 March and 19 April 2020.

Method

Multivariable multilevel model to analyse weekly incidence rates per 100 000 people; time was level-1 unit and UTLA level-2 unit. Population density was divided into quartiles. The model included an interaction between week and population density. Potential confounders were percentage aged ≥65, percentage non-white British, and percentage in two highest classes of the National Statistics Socioeconomic Classification. Co-variates were male life expectancy at birth, and COVID-19 prevalence rate per 100 000 people on March 15. Confounders and co-variates were standardised around the mean.

Results

Incidence rates per 100 000 people peaked in the week of March 30–April 5, showing higher adjusted incidence rate per 100 000 people (46.2; 95% confidence interval [CI] = 40.6 to 51.8) in most densely populated ULTAs (quartile 4) than in less densely populated ULTAs (quartile 1: 33.3, 95% CI = 27.4 to 37.2; quartile 2: 35.9, 95% CI = 31.6 to 40.1). Thereafter, incidence rate dropped in the most densely populated ULTAs resulting in rate of 22.4 (95% CI = 16.9 to 28.0) in the week of April 13–19; this was lower than in quartiles 1, 2, and 3, respectively 31.4 (95% CI = 26.5 to 36.3), 34.2 (95% CI = 29.9 to 38.5), and 43.2 (95% CI = 39.0 to 47.4).

Conclusion

After the introduction of social distancing measures, the incidence rates per 100 000 people dropped stronger in most densely populated ULTAs.
BEBAN KERJA MENTAL, FISIK DAN WAKTU PERAWAT DI POLI RSUD dr. SLAMET GARUT
Authors: Maulana Indra , Surya Mediawati Ati , Permana Egis
Published: July 2020

Beban kerja mental merupakan suatu perbedaan antara kapasitas dan kemampuan dalam melakukan pekerjaan atau tugas-tugasnya. Beban kerja yang tinggi bisa menyebabkan beban kerja mental, fisik, dan waktu sedangkan beban kerja yang rendah bisa menyebabkan kebosanan dan kejenuhan. Tujuan penelitian ini untuk mengetahui gambaran beban kerja mental, fisik, dan waktu perawat di ruangan poli RSU dr, Slamet Garut. Metode Penelitian ini menggunakan deskriptif kuantitatif, Populasi penelitian ini adalah seluruh perawat di ruangan poli RSU dr Slamet Garut. Teknik pengambilan sampel total sampling, dengan besar sampel yaitu 62 orang perawat. Pengukuran beban kerja mental menggunakan NASA TLX yang dinilai oleh peneliti dari lembar kuesioner. Analisis data menggunakan analisis deskritif kuantitatif. Hasil penelitian menunjukkan beban kerja mental kategori tinggi sebanyak 58 responden (100,0%), beban kerja fisik  kategori tinggi sebanyak 57 responden (98,3%), dan beban kerja waktu kategori tinggi sebanyak 57 responden (98,3%). Kesimpulan penelitian ini menggambarkan bahwa beban kerja perawat di ruangan poli RSU dr Slamet Garut kategori tinggi baik beban kerja mental, fisik, dan waktu. Perlunya perbaikan manajemen keperawatan perawat perlu menjaga kondisi fisik dan mental dalam memberikan pelayanan keperawatan karena beban kerja yang tinggi.

 

Mental workload is a difference between capacity and ability to do work or tasks. High workload can cause mental workload, physical, time and low workload can cause boredom and burnout. This study is to find out how the mental, physical and nurse workload depictions in the poly room of dr. Slamet Garut Hospital. The research method used quantitative descriptive design. The population of the study was all nurses in the poly room of dr. Slamet Garut Hospital. The sampling technique was total sampling, with 62 nurses. The measurement of mental workload using NASA TLX which was assessed by researchers from the questionnaire sheet. The data analysis used quantitative descriptive analysis. The results showed that mental workload in the high category was 58 respondents (100.0%), physical workload in the high category was 57 respondents (98.3%), and the time workload in the high category was 57 respondents (98.3%). The conclusion was the workload of nurses in the poly room of dr. Slamet Garut Hospital in a high category both mental, physical, and time workloads. There needs to be an improvement in nursing management and nurses need to maintain physical and mental conditions in providing nursing services because of high workloads.
PENGHAMBATAN PERTUMBUHAN Klebsiella pneumoniae DENGAN EKSTRAK ETANOL DARI LIMBAH KULIT PISANG KEPOK (Musa paradisiaca L.)
Authors: Stephen Dewangga Vector , Taufiq Qurrohman Muhammad
Published: July 2020

Pisang kepok (Musa paradisiaca L.) adalah buah yang mudah ditemukan, akan tetapi kulit buahnya selama ini jarang dimanfaatkan. Pada kulit buah M. paradisiaca L. terkandung flavonoid, alkaloid, tanin, saponin, dan terpenoid yang berperan sebagai senyawa antibakteri. Penelitian ini bertujuan untuk mengetahui apakah ekstrak etanol limbah kulit M. paradisiaca L. mampu menghambat pertumbuhan Klebsiella pneumoniae. Metode penelitian yang digunakan adalah analitik eksperimental, sampel kulit M. paradisiaca L. diperoleh dari pedagang keripik pisang kepok di Kabupaten Karanganyar. Ekstrak etanol 96% kulit M. paradisiaca L. dibuat dengan menggunakan metode perkolasi, sedangkan uji aktivitas antibakteri dilakukan dengan metode Kirby-Bauer. Hasil penelitian menunjukkan bahwa ekstrak etanol 96% limbah kulit M. paradisiaca L. mampu menghambat pertumbuhan bakteri K. pneumoniae, pada konsentrasi 20%; 40%; 60%; 80% dan 100%, dengan rata-rata zona hambat berturut-turut 6,10 mm; 6,35 mm; 6,95 mm; 7,35 mm; dan 7,80 mm. Ekstrak etanol 96% kulit M. paradisiaca L. mampu membentuk zona hambat radikal pada semua konsentrasi terhadap pertumbuhan K. pneumoniae, namun tidak mampu menghasilkan zona hambat radikal setara dengan  kriteria sensitif antibiotik ciprofloxacin 5 µg berdasarkan CLSI 2018 terhadap pertumbuhan K. pneumoniae.

 

Banana kepok (Musa paradisiaca L.) is a fruit that is easily found, but the peel of the fruit has rarely been used. The peel of M. paradisiaca L. contains flavonoids, alkaloids, tannins, saponins, and terpenoids which act as antibacterial compounds. This study aims to determine whether the ethanol extract of M. paradisiaca L. peel can inhibit the growth of Klebsiella pneumoniae. The research method used was an experimental analytic, M. paradisiaca L. peel samples were obtained from banana chips traders in Karanganyar. Ethanol extract 96% of the skin of M. paradisiaca L. was prepared using the percolation method, whereas the antibacterial activity test was carried out by the Kirby-Bauer method. The results showed that the 96% ethanolic extract of M. paradisiaca L.peel was able to inhibit the growth of K. pneumoniae in 20%; 40%; 60%; 80% and 100% concentrations, with mean inhibitory zones in order 7,46 mm; 7,52 mm; 7,60 mm; 8,52 mm; dan 8,98 mm. 96% of ethanolic extract M. paradisiaca L. skin was able to form radical inhibitory zones at all concentrations of K. pneumoniae growth, but was unable to produce radical inhibitory zones equivalent to the 5µg ciprofloxacin antibiotic sensitive criteria based on CLSI 2018 on the growth of K. pneumoniae.
AMY2B Gene Copy-Number Variation Studied by Droplet Digital PCR (ddPCR) in Three Canids: Red Fox, Arctic Fox, and Chinese Raccoon Dog
Authors: Antkowiak Michal , Nowacka-Woszuk Joanna , Szczerbal Izabela , Switonski Marek , Szydlowski Maciej
Published: July 2020

Copy-number variation (CNV) is an important source of genetic variation, and one that played a role in the process of domestication. The adaptation to a new diet is a characteristic feature of dog domestication. We therefore sought genomic signatures of this process. The pancreatic
alpha-amylase gene (AMY2B), expressed in the pancreas, exhibits a variable number of copies. It has been shown that the multiplication of this gene is associated with the adaptation of dogs to a starch-rich diet. To date, there has been no information made available on the copy-number
variation of AMY2B in canid farm animals. The aim of the present study was to examine the AMY2B copy number in the red fox, the arctic fox, and in the Chinese raccoon dog. Droplet digital PCR (ddPCR) was used to count the gene copies in 152 animals (60 red foxes, 53 arctic foxes,
and 39 Chinese raccoon dogs). We found that the majority (91%) of the animals had two copies of this gene. Of the red foxes and Chinese raccoon dogs, only 8% had three copies, while 32% of the arctic foxes had three copies. Our study showed that the multiplication of the AMY2B gene
did not occur over several decades of breeding selection, which may reflect the low-starch feeding regime.
Removal of Broken Intramedullary Femoral Nail with Broken Distal Locking Bolt – A Case Report
Authors: Sharma Prof. Sanjeev , Sharma Dr. Suman , Singh Dr. Manorma , Sharma Dr. Rahul
Published: July 2020

Non-union after closed femoral interlock nailing is an uncommon complication and occurs when a patient starts early weight-bearing, due to faulty surgical technique or after re-trauma. Removal of broken with broken locking bolt is a difficult and challenging procedure. The present case report deals with a case of the broken intramedullary nail with a broken distal locking bolt. A 30 years male patient was inserted interlocking nail for fracture shaft femur five years back. He presented with pain with instability and inability in weight-bearing after re-trauma. An X-ray revealed a broken nail with a broken distal locking bolt. The far fragment of the broken bolt was engaging bone and nail both and was the main obstacle. His nail with the broken bolt removed and re-nailing did in a single sitting. Steinmannpin (St.pin) was inserted through the distal piece of the nail to push the trapped small screw piece.
Software Defined Networks: Review and Architecture
Authors: Alam Tanweer , Aljohani Mohammed
Published: July 2020

In the fifth-generation communication system, secured and reliable data packets will rely on the network with high availability and low latency. The 5G network enables the dynamic control of nodes with low latency. Ultra-reliability is one of the challenging tasks in software-defined networks. The ultra-reliability feature is an interface working with high availability and low latency that brings in fifth-generation networks. The Internet of Things will work in the societies so that it required ultra-reliability features to empower the peoples as well as machines for collaborating with their neighbors. The connections among ultra-reliability networks are extremely hard situations to keep low packets corruption. The Software Defined Networks (SDN) will provide a platform for measuring, controlling, monitoring and scaling the smart objects in reality or virtually. Virtualization enables IT, specialists, to combine or separate the considerable networking or create new programmable networking among virtual machines. In this article, the authors are reviewed the architecture of SDN based on virtualization under the umbrella of 5G networks.