bluuebunny/crossref_metadata_2025 huggingface dataset:
Electronic and optoelectronic properties of van der Waals heterostructure based on graphene-like GaN, blue phosphorene, SiC, and ZnO: A first principles study
Authors: Idrees M. , Nguyen Chuong V. , Bui H. D. , Amin Bin
Published: June 2020

The combination of two-dimensional materials in the form of van der Waals heterostructures has been proved to be an effective approach for designing electronic and optoelectronic devices. In this work, we investigate the electronic, optical, and photocatalytic properties of vdW heterostructures based on BlueP, SiC, ZnO, and g-GaN using density functional theory. We find that all the g-GaN based vdW heterostructures are energetically and thermally stable at room temperature. The g-GaN–BlueP and g-GaN–SiC heterostructures show indirect bandgaps with the type-II and type-I band alignments, respectively, whereas the g-GaN–ZnO heterostructure shows a direct bandgap with type-II band alignment. Furthermore, the absorption coefficient is also calculated to understand the optical behavior of these hetrostructures. Our results demonstrate that the lowest energy transitions are dominated by excitons, and the blue shift is also observed in these hetrostructures. The g-GaN–BlueP, g-GaN–SiC, and g-GaN–ZnO vdW heterostructures possess outstanding optical absorption in the visible light. The g-GaN–P shows the highest absorption intensity of 105cm−1, which is larger than that of g-GaN–SiC and g-GaN–ZnO vdW heterostructures by three times. These findings demonstrate that these vdW heterostructures are promising candidates for water splitting in the visible light region. Moreover, the heterostructures also show good response to the photocatalytic properties at pH=0 and pH=7.
Run rabbit run: spotted-tailed quoll diet reveals invasive prey is top of the menu
Authors: Linley G. D. , Rypalski A. , Story G. , Ritchie E. G.
Published: June 2020

Information about the ecological functional roles of native predators may help inform the conservation of wildlife and pest management. If predators show preferences for certain prey, such as invasive species, this could potentially be used as a conservation tool to help restore degraded (e.g. overgrazed) ecosystems via the reintroduction of native predators and suppression of exotic prey (e.g. introduced herbivores). The diet of spotted-tailed quolls was studied in a fenced reserve in south-eastern Australia where native mammals have been reintroduced, foxes and cats removed, but invasive European rabbits still persist. A total of 80 scats were collected over 12 months and analysis of macroscopic prey remains was conducted to determine diet. Rabbits were by far the most commonly consumed prey species by volume (~76%) and frequency (~60%), followed by brushtail possums (~11% for both volume and frequency), and other small and medium-sized native mammals in much smaller amounts. Quoll scat analysis revealed 10 mammal species in total, eight of which were native. Bird, reptile and invertebrate remains were uncommon in quoll scats. This suggests that spotted-tailed quolls may show a preference for preying on invasive European rabbits in certain contexts, and this could potentially be used as part of quoll reintroductions to aid rabbit population suppression and ecosystem restoration.
Microstructure and mechanical properties of a copper–stainless-steel dual-phase system prepared by spark plasma sintering
Authors: Teimouri Mahtab , Gao Wenqiang , Godfrey Andy
Published: June 2020

Spark plasma sintering (SPS) has been used to synthesise samples of a model dual-phase (DP) system, consisting of copper and AISI420 martensitic steel. Mixed powders were sintered at different temperatures in the range from 850°C to 1000°C using a loading pressure of 60 MPa. Tensile testing revealed dimpled fracture surfaces in samples sintered at higher temperatures, indicating ductile failure and good interfacial bonding between the phases, with the best results overall obtained for samples sintered from wet-mixed powders. The results show that by control of the mixing, sintering and post-sintering heat treatment conditions, the fabrication of dense samples covering a range of DP microstructures is possible using SPS, with independent control of the microstructure and properties of the two phases.
The influence of cryogenic rolling on a transformation-induced plasticity steel
Authors: Hu Zhiping , Liu Rendong , Lin Li , Wang Guodong
Published: June 2020

Here, a novel cryogenic rolling plus intercritical annealing process was applied to a transformation-induced plasticity (TRIP) steel with a low chemical composition of carbon and manganese. Compared with traditional cold rolling, obvious grain refinement was observed, due to a high amount of dislocations retained. In addition, austenite volume fraction was increased, because of a unique nucleation mechanism. Subjected to cryogenic rolling, strength and ductility were increased, due to the enhanced austenite stability, which provided continuous and active TRIP effect. Consequently, tensile strength was increased to 1030 MPa, and elongation was increased to 38.2%. Thus, a great mechanical combination was obtained in a steel with a relatively low chemical composition with carbon and manganese, only by cryogenic rolling process.
Understanding the underlying mechanisms of Quiet Eye: The role of microsaccades, small saccades and pupil‐size before final movement initiation in a soccer penalty kick
Authors: Piras Alessandro , Timmis Matthew , Trofè Aurelio , Raffi Milena
Published: June 2020

Experts keep a steady final fixation at a specific location just before final movement initiation, the so‐called “quiet eye” (QE). However, the eyes are rarely “quiet”, and small eye movements occur during visual fixation. The current research investigated the subtle eye movements and underlying mechanisms immediately prior to and during QE. The gaze behaviour of 8 intermediate‐level goalkeepers was recorded as they moved (either left or right) in an attempt to predict the future direction of the ball during a soccer penalty kick. Goalkeepers were more likely to predict the direction of the penalty, which was coupled with delaying movement initiation. The temporal sequence of microsaccade rates dropped ∼1000 ms before goalkeepers’ final movement initiation. Saccade rates increased, reaching a peak ∼500 ms before final movement initiation, concomitant with microsaccades reduction. Microsaccades predicted the goalkeepers’ direction, oriented to the right when goalkeepers moved to the right, and conversely to the left when they moved to the left. Microsaccades may be modulated by attention and appear functionally related to saccadic intrusions. Pupil‐size increased proportionally with the lead up to the instance of the penalty being kicked, reaching a plateau at final movement initiation. In conclusion, microsaccades and small saccades could improve the perception of the soccer penalty kick, helping athletes during the period that precedes the critical movement initiation, shifting from covert to overt attention for identifying the useful cues necessary to guide the action.
Gentle plasma process for embedded silver-nanowire flexible transparent electrodes on temperature-sensitive polymer substrates
Authors: Kinner Lukas , List-Kratochvil Emil J W , Dimopoulos Theodoros
Published: June 2020

The present study investigates processing routes to obtain highly conductive and transparent electrodes of silver nanowires (AgNWs) on flexible polyethylene terephthalate (PET) substrate. The AgNWs are embedded into a UV-curable polymer to reduce the electrode roughness and enhance its stability. For the purpose of device integration, the AgNWs must partially protrude from the polymer, which demands that their embedding is followed by a transfer step from a host substrate to the final substrate. Since the AgNWs require some sort of curing (thermal or plasma) to reduce the electrode sheet resistance, a thermally stable host substrate is generally used. This study shows that both thermally stable polyimide, as well as temperature-sensitive PET can be used as flexible host substrates, combined with a gentle, AgNW plasma curing. This is possible by adjusting the fabrication sequence to accommodate the plasma curing step, depending on the host substrate. As a result, embedded AgNW electrodes, transferred from polyimide-to-PET and from PET-to-PET are obtained, with optical transmittance of ∼80% (including the substrate) and sheet resistance of ∼13 Ω/sq., similar to electrodes transferred from glass-to-glass substrates. The embedded AgNW electrodes on PET show superior performance in bending tests, as compared to indium-tin-oxide electrodes. The introduced approach, involving low-cost flexible substrates, AgNW spray-coating and plasma curing, is compatible with high-throughput, roll-to-roll processing.
Flux pinning and microstructure of a bulk MgB2 doped with diverse additives
Authors: Jirsa M , Rameš M , Miryala M , Svora P , Duchoň J , Molnárová O , Arvapalli S S , Murakami M
Published: June 2020

In bulk high-temperature superconductors, Ag is usually used as an additive thus improving mechanical performance. In MgB2 doped with Ag, the Ag reacts with Mg, forming Mg–Ag phases acting as a vortex pinning medium. In this work, we analyze the electromagnetic and pinning properties of bulk MgB2 doped with 1 wt% MgB4, 4 wt% Ag, and 1 wt% Dy2O3, prepared at the Shibaura Institute of Technology (SIT), Tokyo. In three compounds of MgxB2 + 4 wt% Ag with x = 1, 1.075, and 1.1, the effect of Mg excess was studied. The magnetic moment was measured by a vibrating sample magnetometer (VSM). Pinning was studied in terms of a pinning diagram, i.e. the field dependence of the normalized pinning force density, F
n = F/F
max. In all studied samples, the peak of the F
n (b) dependence (b= B/B
irr, B
irr being the irreversibility field) was observed at around b= 0.2, indicating a prevailing flux pinning at grain boundaries. A slight shift of the peak with decreasing temperature indicated a defect size distribution in the pinning landscape. Transmission electron microscopy (TEM) showed a granular structure of all samples composed of MgB2 grains of about 230 nm (average size), with ensembles of small grains (22 nm in average) of Ag3Mg, AgMg, Ag, Dy2O3, and MgB4. While the large MgB2 grains control the main pinning mechanism, the small precipitates seem to determine details of the current flow through the grain boundaries.
Analysis of the thermodynamic criteria for long-term strength of materials
Authors: Bugrimov A L , Bobrova I A , Chukalovskaya E M
Published: June 2020

Possibility of constructing an entropy criterion for the strength of materials on the basis of a viscoelastic material under conditions of creep and cyclic loads is analyzed.
Kinetics laws as the base for mathematical simulation of microwave vacuum drying process
Authors: Antipov S T , Arapov V M , Kazartsev D A
Published: June 2020

The process of drying food is extremely complex. Therefore, the mathematical modeling of the process needs high requirements. The combination of approaches in modeling is of practical interest. On the one hand, analytical solutions based on the application of physical laws or phenomenological equations are used. On the other hand, experimental identification of the relationship between temperature and body moisture, which is considered as a peculiar characteristic of heat and mass transfer for each material. It is proposed to consider vacuum microwave drying from the standpoint of physical chemistry as a quasitopochemical heterogeneous reaction and perform mathematical modeling of this process based on the laws of chemical kinetics.
Measuring Probability of Failure of Thermoelectric Legs through Lognormal and Weibull Distribution
Authors: Sattar S
Published: June 2020

Thermoelectric devices are potential candidates to recover energy from dissipated waste heat and are environmentally friendly. It produces energy through temperature differences. Regarding to its fundamental characters, heat plays a significant role for effective energy conversion. At the same moment, creating high-performance thermoelectric generators at higher temperature with a reliable operational life is one of the main challenges. When the temperature of the device goes up, in order to get maximum output, the device encounters stress at his edges and within volume. This whole phenomenon makes calculation of reliability complex, especially measuring the operational life of thermoelectric device. In this paper TE materials composed of Bismuth Telluride were studied. Stress data was collected from different experiments and analyzed through Lognormal and Weibull distribution in order to calculate probability of failure of TE legs. The simulation was done on MATLAB.
Software for analysis of parameters and characteristics of Semiconductor Optical Amplifier
Authors: Kozhanova E R , Belyaev V V , Tkachenko I M , Yazbeck H
Published: June 2020

The article discusses the prospects of modernization of the author’s software «labpraktikum_osnov_wavelet» for studying and analyzing the parameters and characteristics of a semiconductor optical amplifier (SOA) by expanding the list of wavelet analysis types in order to select the most informative type of wavelet analysis and wavelet function to interpret the results.
The dielectric properties of nematic LC-1289 in microwave range
Authors: Emelianov V A , Gevorkyan E V , Barabanova N N , Zhachkin V A
Published: June 2020

The paper presents data on the anisotropic complex dielectric permeability of nematic LC-1289 in microwave range. The obtained data allow us to build a Cole-Cole diagram. It indicates the existence of two dispersion regions for transversal permittivity and one dispersion region for longitudinal permittivity and corresponding relaxation times.
Investigation of the effect of electric pulse heat treatment of rapid-quenched Ti50Ni25Cu25 alloy ribbons with a thin surface crystal layer on the structure formation from an amorphous state
Authors: Sitnikov N N , Khabibullina I A , Shelyakov A V , Mashchenko V I , Sivtsova G V
Published: June 2020

This work is devoted to the study of the influence of electric pulse heat treatment of rapid-quenched Ti50Ni25Cu25 alloy ribbons (at. %) with a surface crystal layer. The object of the study was a rapid-quenched layered amorphous-crystal ribbon with a thickness of about 30 µm and a width of about 1.5 mm, in which a thin surface crystal layer (2.5 µm) was present on the non-contact side relative to the quenching wheel. The alloy samples were subjected to electric pulse treatment by passing a single pulse of electric current through the sample with a variable duration. For comparison, samples of the alloy were obtained, crystallized by standard isothermal heat treatment. The samples were characterized by means of scanning electron microscopy techniques, energy dispersive X-ray analysis and differential scanning calorimetry. It was shown that electric pulse treatment with an exposure time of less than 1 second leads to a significant change in the formed crystalline structure in comparison with the structure obtained by isothermal treatment. The microstructure of such samples in cross section is characterized by an uneven distribution of crystals over the thickness of the ribbon: columnar crystals are observed from the contact and non-contact sides of the ribbon, and large crystals are present in the inner part of the ribbon.
Procedure for determining the dye solution concentration distribution in laminar water flow in glass channel
Authors: Sultanov F O , Bykhalo I B , Levchenko A A
Published: June 2020

An experimental technique has been developed aimed at determining a dependence of the distribution of Rhodamine G concentration in a water solution flow in a glass channel. It has been demonstrated that in the water flow moving in the glass channel, a stationary pattern of the distribution of solution concentration in water along the channel is established. The dye concentration is distributed uniformly over the channel due to molecular diffusion.
The kinetic inductance of single-walled carbon nanotube metal type
Authors: Ivliev P A
Published: June 2020

The results of theoretical studies of the kinetic inductance Lk metallic single-walled carbon nanotube type, taking into account the electron-electron interaction in the approximation of a right circular cylinder are presented. The system under consideration is a cylindrically symmetric potential well with a final height of the wall. As part of the response of the theory of two-dimensional electron gas in the external electromagnetic disturbance obtained in the form of kinetic inductance depending on the nanotube diameter, frequency and intensity of the radiation. Established that Lk value increases with increasing frequency, and decreases with increasing radiation intensity.
Registration of vortex motion in the bulk of superfluid helium by injected charges
Authors: Sultanova M R , Remizov I A
Published: June 2020

We developed a technique for studying the vortex motion created by waves on the surface of superfluid helium-4 using charges injected into the bulk of the liquid. The charges move from the source to the five sectional collector mounted on the opposite side. The interaction of charges with vortices formed by the waves on the surface leads to a change in the distribution of currents recorded by the collector segments.
Calculation of aerodynamic characteristics of light aircraft with distributed electric propulsion
Authors: Vlasov A V , Ovdienko M A
Published: June 2020

This paper describes a numerical calculation method of the aerodynamic characteristic of an aircraft with distributed electric propulsion system (DEPS) taking into account influence of a blown wing. In addition, the studies of DEPS impact on aerodynamic characteristics of the light aircraft are represented.
Study of light-scattering properties of protein-containing microparticles with a small difference in refractive indices
Authors: Chirikov S N , Shkirin A V , Konnova A S , Savchenko I V , Vasilievich N V , Bunkin N F
Published: June 2020

The refractive indices of fodder yeast grown on oil paraffins (paprin) and natural gas (gaprin) were measured by phase microscopy. The scattering matrices of aqueous suspensions of paprin and gaprin are calculated within the framework of the model of spherically symmetric particles. The possibility of identifying the suspensions by their scattering matrices is analyzed for a small difference in the real parts of the refractive index. Experimental measurements of the light scattering matrices show that in the region of small values of the size parameter (≈ 1) the identification of paprin and gaprin can be based only on the difference in the shapes of the particles, and the difference in the refractive indices is manifested for the values of the size parameter greater than 3.
Programming teaching methodological foundation improvement
Authors: Gramakov D A , Shevchuk M V , Shevchenko V G , Chukalovskaya E M
Published: June 2020

Annotation. In the paper an analysis of various programming languages previously used for educational process are carried out. Criteria are proposed to be followed for choosing a language in programming courses that will result in the improvements in the study. The basic methodological approaches to teaching programming in the course “Languages and programming methods” are described. The requirements for training tasks are developed, which will gain the interest in programming. Ways of further improvements to the teaching process are discussed.
Faber polynomial coefficient estimates for a subclass of bi-univalent functions involving q-analogue of Ruscheweyh operator
Authors: Elhaddad Suhila , Darus Maslina
Published: June 2020

In this article, we introduce a new subclass of analytic bi-univalent functions using the Ruscheweyh type q-analogue operator. In addition, we estimate upper bounds for general and early bounds of Taylor-Maclaurin coefficients in functions of the class which is considered by using Faber polynomial expansions.
The Fekete-Szegö Problem for Subclasses of Analytic Functions Associated With Touchard Polynomials
Authors: AlShaqsi Khalifa
Published: June 2020

In this paper, we solve the Fekete-Szegö problem for a new subclasses of analytic functions defined by the integral operator I(n, m)( f ).
Survey on topological indices and graphs associated with a commutative ring
Authors: Abdussakir  , Sudarman  , Jauhari M N , Ali F
Published: June 2020

The researches on topological indices are initially related to graphs obtained from biological activities or chemical structures and reactivity. Recently, the research on this topic has evolved on graphs in general and even on graphs obtained from algebraic structures, such as groups, rings or modules. This paper will present various topological index concepts, various graph concepts obtained from a commutative ring and some previous studies that are relevant to those two concepts. Based on the various concepts presented, research topics related to topological indices of a graph associated with a commutative ring can be found and carried out.
Segmentation of Leaf Spots Disease in Apple Plants Using Particle Swarm Optimization and K-means Algorithm
Authors: Anam Syaiful
Published: June 2020

Leaf spot disease is one of the causes of a decrease in apple production. Early detection of this disease will increase the quality and amount of apple production. Monitoring the health of apple plants in larger area is traditionally a job that requires a lot of time and effort. The use of drones to detect the leaf spot disease is an alternative technology to monitor the health of apple plants in large areas. The image of an apple leaf taken by a drone needs to be processed by segmenting the apple leaves into the infected and the healthy leaves to detect apple leaf spot disease. K-means clustering offers an algorithm that is simple, fast and works unsupervised to segment images compared to level set algorithms. Random selection of centroid will cause K-means to be trapped at the local optimum point and result in unsatisfactory image segmentation. To solve this problem, Particle Swarm Optimization offers a good solution to optimization problems to avoid convergence problems at the local optimum. Therefore, in this paper, we study how to segment leaf spot disease on apple leaves using the Particle Swarm Optimization and K-means algorithm. The objective function of K-means algorithm optimized by Particle Swarm Optimization is used for segmenting the leaf spot disease. The first step in this proposed method is to convert the leaf image from RGB to CIE L * a * b format. The a component’s of L * a * b format are taken and clustered by using the Particle Swarm Optimization. The global best of the Particle Swarm Optimization becomes an initial centroid of K-means algorithm. The experimental results show that the Particle Swarm Optimization-K-means (PSOK) has a better performance than the K-means algorithm in segmenting leaf spot disease.
Hardness optimization of epoxy filled PTFE with/without TiO2 filler
Authors: Hidayah Ibrahim Nur , Zafir Romli Dr. Ahmad , Noor Idayu Nik Ibrahim Dr Nik
Published: June 2020

Osteoporosis is one of the bone diseases that have the highest number of patients. Throughout the years, there are multiple choices of material that has been used for bone implant such as metals or plastics. The uses of these materials in medical implant are not permanent and they needed to be changed because of its low hardness that would cause pain. In this paper, a new micro bearing concept system by using polymer composite was introduced where epoxy was used as the matrix to improve hardness of micro filler and this composite later can be used in medical implant. PTFE powder filler was used and incorporated at 1%, 3%, 5%, 7% and 10% in the epoxy system respectively. Acetone was used as diluents in the epoxy to improve filler dispersion. Another set of epoxy filled PTFE at 1%, 3%, 5%, 7% and 10% was added with 2% of titanium oxide (TiO2) and results were compared in terms of hardness and density. Result showed composite with TiO2 incorporation obtained highest values which were 5% increase at 3%PTFE loading and 1% increase at 10%PTFE loading for hardness and density respectively compared to the composite without TiO2.
Stress-strain behaviour and strength properties of ambient cured geo-polymer concrete
Authors: Talha Junaid M , Saboor Karzad Abdul , Altoubat Salah
Published: June 2020

Given the high environmental impact of OPC concrete on CO2 emissions, the construction industry is moving towards low carbon alternate binders. In recent years geo-polymer concrete (GPC) has come to the forefront of such efforts. However, challenges remain for GPC to be considered as a main-stream construction material. Since GPC is relatively new material in construction industry, many of its mechanical properties are still not fully understood. The current work looks at the strength properties of ambient cured GPC. This research paper is part of an ongoing investigation on GPC and reports some results of the mechanical properties of ambient-cured GPC. In this study, the stress-strain behavior and compressive strength of such GPC and its dependency on various parameters (ratio and type of activator and proportions & type of pre-cursor materials) is investigated. The results indicate that the compressive strength of GPC is greatly dependent on the proportion of Ground Granulated Blast Furnace Slag (GGBFS) and ratio of activators. It was found that increasing the percentage of GGBFS increased the compressive strength but at the expense of setting time of the mix. The mixes that had GGBFS around 20% of the binder material returned a compressive strength of less than 25 MPa which may not be suitable for structural applications. Whereas, the increase in percentage of GGBFS from 20 to 80% resulted in compressive strength of 40 MPa and higher. The stress-strain relationship of the mixes was compared to two analytical models existed in the literature.
Stress corrosion cracking for dissimilar capacitive discharge welding joint with varied surface preparation and inputted energy
Authors: Lobo Osmar B , Darmadi Djarot B , Novareza Oyong
Published: June 2020

In this article is presented dissimilar welding joint that joins steel and brass bars. Due to its varied melting point the welding process of dissimilar metal has a higher degree of difficulties. Naturally, welding process embeds residual stress and provides voids at least in micro scale. The voids then act as a trigger to develop initial cracks which will grow under external load. Once, the welding joint is exposed to corrosive environment, it will be susceptible to Stress-Corrosion-Cracking (SCC) failure. The quality of the welded joints is considered based on SCC resilience. Two parameters of the Capacitive Discharge Welding Joint which have prominent effects were evaluated: surface preparation and inputted energy. With a proper surface preparation it is hoped optimum welded joints can be obtained. The experiment results show that the oc1 surface preparation, i.e. the sharpened steel interface while the brass is kept on perpendicular edge, provides better performance under SCC load. Highest inputted energy (120J) always provides the longest duration for joint exposed to SCC load before the failure. The high inputted energy gives high heat to melt the interface which in turn produces compact joint at the interface.
Modeling of cleaning up forest debris technology from wood natural mortality
Authors: Karpachev S P , Shadrin A A , Burmistrova O N , Diev R I
Published: June 2020

The article considers the problem of cleaning up forest debris caused by fallen dead wood or wood natural mortality (WNM). Solution to the problem of cleaning and utilization of the WNM and quality control of these sanitary measures in forest was proposed. For conditions of “Medynskiy forestry” enterprise it was proposed technological process of cleaning forest from the WNM. A mathematical model and a conceptual model of the technological process were developed. The maximum values of the utilization coefficients of the winch and the feller are achieved at 30-meter length of the rope (Figure 8). With the increase in the volume of the WNM, the utilization coefficient of the winch increases, and the utilization coefficient of the feller are falls (Figure 9). However, these changes are insignificant (no more than 3.5%) and may not be taken into account in practice. Therefore, for the conditions adopted in the experiments, the length of the traction rope equal to 30 m can be considered optimal for portable hand winches.
Compressive strength and truck run over ability of plastic/sand paving block composites
Authors: Mashudi I , Suardana N P G , Arya Thanaya I N , Bandem Adnyana I W , Kencanawati C I P K
Published: June 2020

Plastic waste has a negative effect on the environment since it could not be decomposed easily, and it could decrease soil fertility. One way to decrease plastic waste is by mixing it with sand to make paving blocks, because the characteristic of plastic is elastic and flexible, so it is expected that the material will be ductile and strong. Material of this study used LDPE (Low Density Polyethylene) plastic which was chopped and mixed with 6 mesh sand with variation of 1 kg (plastic): 5 kg (sand) and 1 kg (plastic): 7 kg (sand) (1:5 and 1:7). The sand was inserted into mixing machine with 200 °C temperature for 5-10 minutes, after that the chopped plastic was inserted and mixed for 30-35 minutes. Molding process was done by pressure tool. After that testing was done by using compressive machine and run over vehicle. The research result showed that the lowest damage occurred on plastic and sand composition of 1:5 as much as 0.113% and had compressive strength 16.667 MPa, and the highest damage occurred on plastic and sand composition of 1:7 as much 0.267% and had compressive strength 12.963 MPa.
Beneficiation opportunities for osmium: A review
Authors: Nkomo Duduzile , Mwamba Alain
Published: June 2020

This review summarises the safe production of osmium and its compounds and its functionality from both the chemistry and materials perspectives. A review of the available data shows that there is a lot of potential for osmium (II) compounds to be used for traffic signalling as molecular signal gates using electrochemical generated power. Osmium (II) compounds can also be used for biomedical applications such as the development of anti-cancer drugs. Organic compounds of osmium have also been found to possess excellent electrochemical properties which are useful for redox flow battery. Different synthesis routes to produce these compounds and implementation thereof into the redox flow battery systems are described in details. This review of osmium and its compounds possess a variety of correlated properties with a potential to put an emergent demand on osmium for various applications.
Influence of organoclay on behaviour of polylactic acid (PLA)/polypropylene (PP) blend
Authors: Hafizah Abdul Halim Noor , Zaharah Engku Zawawi Engku , Zafir Romli Ahmad , Mohd Dahan Rozana , Yuliana Yuhana Nor
Published: June 2020

In this study, thermoplastic composite by blending of Polylactic acid (PLA) and Polypropylene (PP) was prepared with fixed ratio of 75:25 % by weight. Varying content of organoclay were studied with different loading of 1, 3, 5 and 7 wt.% in order to study the potential of this nanofiller in the composite. The composites were prepared by using twin screw extruder. Characterizing of PLA/PP-Clay (PLA/PP-C) composites were analyzed by focusing on physical, thermal and morphological properties. Water absorptions was analyze to observe the percentage of water uptake when percentage loading of organoclay added were increased. Differential scanning calorimetry (DSC) was performed to analyze the thermal stability and thermal sensitivity of the composite. Meanwhile, x-ray diffraction (XRD) were observed to study the fracture surfaces of PLA/PP-Clay composites. In water absoptions analysis it was found that the percentage of water uptake were decreased when organoclay added at 7 wt.%. DSC results showed that melting temperature (Tm) were decreased when the loading of organoclay increased and the thermal stability was improved by addition of organoclay. Morphological analysis by XRD showed that exfoliation and intercalation happened in the system. It is suggested that these combination of PLA/PP-Clay have a good potential for the fabrication of nanocomposites.
Experimental study on the shear behavior of GFRP reinforced concrete beams strengthened using CFRP sheets
Authors: Talha Junaid M , Saboor Karzad Abdul , Elbana Abdalla
Published: June 2020

This paper presents the results of an experimental investigation on the shear capacity of reinforced concrete beams. The beams under consideration are reinforced with glass fiber-reinforced polymer (GFRP) bars. Also, the effect of shear strengthening on such beams is studied. For this purpose a total of four beams were tested where two served as control beams, while the other two were strengthened using U shape carbon fiber-reinforced polymer (CFRP) sheets, bonded externally. Each beam is 2.4 m long, simply supported and subjected to a four-point load under displacement control mode. The strengthened beams showed a noticeable increase in the load-bearing capacity of the specimen. The failure load recorded of these specimens was 208 kN, an increase of 25%. Moreover, the mode of failure changed from pure shear to concrete crushing in the compression zone. The results indicate that using CFRP sheets to strengthen GFRP reinforced beams in shear is a viable option. However, the results also suggest that the known adverse interaction between EB-CFRP and conventional steel stirrups could be applicable between EB-CFRP and GFRP shear reinforcement in strengthened beams. Therefore the predicted EB-CFRP shear capacity by ACI 440.2R turned to be unconservative when compared to the experimental results.
Study of the hardness and microstructure profiles of SKD61 steel plunger tip (local material) after plasma nitriding
Authors: Sudjadi Usman , Sinaga R V
Published: June 2020

The Hardness and Microstructure Profiles of SKD61 Steel Plunger Tip (local material) after Plasma Nitriding have studied. To improve SKD61 quality for high temperature use, a plunger tip can be hardened through surface treatment using a plasma/ion nitriding technique. To test the success of the surface treatment, the nitriding temperature was varied from 350°C to 550°C with step for 50 °C for the nitriding process completed for 10 hours. The results, it can be seen that the optimum surface hardness was achieved when the nitriding temperature was 500°C with Vickers hardness (HV) was 955.29 HV with a depth of up to 100 μm from the surface of the specimen. At such a nitriding temperature, the hardness increased 1.79 times in comparison with that after hardening only, and it increased 2.076 times in comparison with that of the initial hardness. From the results of the study, it can be concluded that plasma nitriding temperature affects the amount of nitrogen concentration diffused into the substrate material. Nitride layer formed was possibly of Fe N, Cr2N, VN, δ Fe, and γ Fe.
The U.S. Supreme Court: A Very Short Introduction
Authors: Greenhouse Linda
Published: June 2020

The U.S. Supreme Court: A Very Short Introduction draws on the Court’s history and its written and unwritten rules to show how it operates in the early twenty-first century. Today’s Supreme Court, housed in a majestic building on Capitol Hill, bears little resemblance to the institution launched by the Framers of the Constitution and was originally seen as the weakest of the three branches of government. Over the next 200 years, the Court put the independence the Framers gave it to use and now largely defines itself. How do cases reach the Supreme Court? What features have other courts around the world taken from the Supreme Court, and what have they left?
4. Governing
Authors: Wright Tony
Published: June 2020

‘Governing: still the strong centre?’ looks at the British reputation for strong government, and whether this is the same as effective government. Britain is a traditional example of a ‘power-hoarding’ polity, and the power of the British government was evident in the response to the financial crisis. However, there are tensions, not least between the priorities of ministers and civil servants. Historically, disagreements between prime ministers and their chancellors have led to breakdowns. Policy formulation is not the same as policy delivery, and governments have struggled to square their departmental structure and the need for collective strategy when actions are required outside the nation state.
1. The elements of fire
Authors: Scott Andrew C.
Published: June 2020

Fire is an exothermic chemical reaction that produces energy in the form of heat and light. ‘The elements of fire’ explains its composition through a ‘triangle’ of heat, fuel, and oxygen, and the processes of ignition and combustion. Large, accidental urban catastrophes like the Great Fire of London have led to redesigns and safety measures, but most wildfires start in the fuels on the ground surface and there is no ‘one size fits all’ model for suppressing wildfires such as the recent outbreaks in Portugal, Australia, and America. As the population encroaches into formerly wild areas, fire at the Wildland–Urban (or Wildland–Rural) Interface is an increasing problem.
3. Fire and humankind
Authors: Scott Andrew C.
Published: June 2020

It is often impossible to determine from charcoal records whether fires had environmental or human causes; historically, it is also difficult to identify whether human-started fires were intended as methods of attack or started as controlled fires that then became uncontrolled. ‘Fire and humankind’ examines the relationship humans have with fire, starting with the discoveries that fire could be used for cooking, weapon-making, and socializing. While ‘slash and burn’ agriculture is often frowned upon, fire can be used in regular crop rotation, and often is. Fire has been used as a weapon of war, from the destruction of cities and ‘scorched earth’ approach to chemical weapons in the twentieth century.
5. New technologies and changing fire policies
Authors: Scott Andrew C.
Published: June 2020

Fire is a natural part of some ecosystems, but not others. ‘New technologies and changing fire policies’ explores our comparatively recent use of satellite monitoring to transcend the limitations of observing fire on the ground. A surface fire can drastically alter the structure of soil and affect how it responds to rainfall, meaning that heavy rainfall after fires can lead to massive destruction through flowing sediment far away from the burn site. Fire suppression and prevention legislation is important, as is the development of ‘fire-wise’ or ‘fire-smart’ communities. Suppression is prioritized in urban areas, but tragedies such as the Grenfell Tower fire show that progress has still to be made.
Clinical Performance of Mycobacterial Immunohistochemistry in Anatomic Pathology Specimens
Authors: Crothers Jessica W , Laga Alvaro C , Solomon Isaac H
Published: June 2020

Objectives

Diagnosis of mycobacterial infections poses significant challenges in anatomic pathology. We recently described the use of antimycobacteria immunohistochemistry (IHC) as a sensitive, efficient diagnostic tool and now report the clinical performance of this assay among general, noninfectious disease pathology-trained anatomic pathologists.

Methods

Over a 2-year period, all cases were retrospectively identified in which mycobacterial IHC was performed during routine diagnostic workup.

Results

From October 2017 to September 2019, mycobacterial IHC was evaluated for 267 cases, resulting in 58 (22%) positive stains. Compared with culture and molecular results, the sensitivity and specificity of IHC were 52% and 80%, respectively. IHC performed significantly better than acid-fast bacilli (AFB) staining (Ziehl-Neelsen) (P < .0001; sensitivity 21%, specificity 92%) but similarly to modified AFB staining (mAFB; Fite-Faraco) (P = .9; sensitivity 61%, specificity 84%). In cases with discordant IHC and mAFB staining, there were no differences in rates of culture or polymerase chain reaction–confirmed positivity.

Conclusions

Mycobacterial IHC was well adopted with superior clinical performance to AFB and comparable performance to mAFB. These results support the use of IHC as an adjunctive tool in the diagnosis of mycobacterial infections and suggests its potential role as a rapid screening test for molecular testing.
Memory Impairment and Hippocampal Volume after Carbon Monoxide Poisoning
Authors: Tamura Takehiro , Sugihara Genichi , Takahashi Hidehiko
Published: June 2020

Objective

We report longitudinal changes in neuroimaging and neuropsychological measurements in a case of carbon monoxide (CO) poisoning showing reversible changes in hippocampal volume, which was closely linked to the degree of memory impairment.

Methods

The current study presents a female in her early 20s, with a high school level of education. She became aware of headaches and drowsiness while working in a restaurant that operated charcoal braziers, and she was urgently transported to our hospital. Her high blood carboxyhemoglobin concentration led to a diagnosis of CO poisoning, but no obvious abnormalities were found by brain magnetic resonance imaging (MRI) and physical examinations. She underwent a series of hyperbaric oxygen therapies. One year after CO poisoning, she consulted a psychiatrist due to her own awareness of gradually worsening memory function. She was assessed by brain MRI and standard neuropsychological tests every 6 months for 1 year.

Results

Her neuropsychological profile showed the impairment of memory function according to a low score of Delayed Recall Index of Wechsler Memory Scale-Revised. At 320 days after CO poisoning, her hippocampal volume had decreased by 3%. Her memory function was found to have improved at 530 days after CO poisoning. Of note, during this period, her hippocampal volume had increased by approximately 7%.

Conclusions

This report suggests that a clinician should conduct careful neuropsychological examinations to avoid overlooking mild sequelae of CO poisoning, even if a general assessment of brain MRI is normal.
Patient Selection for Pedal Soft Tissue Augmentation
Authors: Baron Marissa E , Minteer Danielle M , Gusenoff Beth R , Gusenoff Jeffrey A
Published: June 2020

Background

Pedal fat grafting has been shown to improve pain and functional impairment from forefoot fat pad atrophy.

Objectives

The authors aimed to determine if patient demographics and foot characteristics play a role in the level of impact that is achieved following surgery.

Methods

The authors performed a retrospective review of patients who received forefoot autologous fat injections for the treatment of pedal fat pad atrophy. Patient improvement of pain and functional impairment were evaluated for correlation with patient characteristics, including gender, age, BMI, unilateral vs bilateral injections, flexible vs rigid arch, previous foot deformity or surgery, and presence of callus.

Results

Forty-four patients received fat injections into the ball of their foot; 73% of them were women; their mean age was 61 years, and mean BMI was 26.6 kg/m2; 75% had injections performed bilaterally; 41% had a flexible arch, 73% had a past history of pedal deformity or surgery, and 43% had callus. Only female gender was found to correlate with an improvement in pain from the time of surgery to 12 months later (P = 0.02).

Conclusions

Bilateral rigid, high arched foot type is a risk factor for foot pain and disproportionately represented among these patients. The only patient characteristic found to be correlated with improvement in pain at 12 months post-surgery was female gender. BMI and laterality of injections impacted the course of improvement after surgery. Given current data, all patients with suspected pedal fat pad atrophy should be considered for soft tissue augmentation.

Level of Evidence: 4
Roles of gonad-inhibiting hormone in the protandric simultaneous hermaphrodite peppermint shrimp†
Authors: Shi Wenyuan , Liu Fang , Liu An , Huang Huiyang , Lin Qi , Zeng Chaoshu , Ye Haihui
Published: June 2020

To date, the molecular mechanisms of the unique gonadal development mode known as protandric simultaneous hermaphroditism (PSH) are unclear in crustaceans. In this study, cDNA of a gonad-inhibiting hormone (Lv-GIH1) was isolated from the PSH peppermint shrimp Lysmata vittata, and its expression was exclusively found in the eyestalk ganglion. Real-time quantitative polymerase chain reaction (qRT-PCR) revealed that the expression of Lv-GIH1 increased during gonadal development of the functional male stages but decreased significantly at subsequent simultaneous hermaphroditism stage. Further in vitro experiment showed that recombinant GIH1 protein (rGIH1) effectively inhibited Vg expression in the cultured hepatopancreas tissues while the short-term injection of GIH1-dsRNA resulted in reduced expression of Lv-GIH1 and upregulated expression of Vg in the hepatopancreas. Moreover, long-term rGIH1 injection led to significantly reduced expression of Lv-Vg, Lv-VgR, and Lv-CFSH1, subdued growth of oocytes, and feathery setae as a secondary sexual characteristic in females. Interestingly, while germ cells in testicular part were suppressed by rGIH1 injection, the expression of Lv-IAGs showed no significant difference; and long-term GIH1-dsRNA injection results were contrary to those of rGIH1 injection. Taken together, the results of this study indicate that Lv-GIH1 is involved in gonadal development and might also participate in controlling secondary sexual characteristic development in L. vittata by inhibiting Lv-CFSH1 expression.
Chemical profiling of Dioscorea septemloba by High Performance Liquid Chromatography Coupled to Electrospray Ionization and Quadrupole Time-of-Flight Mass Spectrometry
Authors: Ling Yun , Chen Lu , Wang Dan , Xiao Xin , Xu Wenjing , Yan Hui , Yu Hongling , Zhang Qing , Qu Weihong , Chen Jian , Ji Xiaohong , Yu Qunying
Published: June 2020

The rhizomes of Dioscorea septemloba (DS) is one of traditional Chinese medicine, which can be used for treatments of urethral and renal infections, as well as rheumatism. Nevertheless, detailed information on DS chemical compositions is still scarce. Therefore, the present work is aimed at investigating the phytochemical components of DS using high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry in negative ion mode. The proposed method provided tentative identification of 32 components, 6 of which were determined to be new. The present study highlighted the importance of DS as a promising source of medicinal ingredients and provides valuable information on the new potential components in DS.
WellExplorer: an integrative resource linking hydraulic fracturing chemicals with hormonal pathways and geographic location
Authors: Wetherbee Owen , Meeker Jessica R , DeVoto Caroline , Penning Trevor M , Moore Jason H , Boland Mary Regina
Published: June 2020

Exposure to hydraulic fracturing fluid in drinking water increases the risk of many adverse health outcomes. Unfortunately, most individuals and researchers are unaware of the health risks posed by a particular well due to the diversity of chemical ingredients used across sites. We constructed WellExplorer (http://WellExplorer.org), an interactive tool for researchers and community members to use for retrieving information regarding the hormonal, testosterone and estrogen modulators located at each well. We found that wells in Alabama use a disproportionately high number of ingredients targeting estrogen pathways, while Illinois, Ohio and Pennsylvania use a disproportionately high number of ingredients targeting testosterone pathways. Researchers can utilize WellExplorer to study health outcomes related to exposure to fracturing chemicals in their population-based cohorts. Community members can use this resource to search their home or work locations (e.g. town or zip code) to determine proximity between where they live or work and specific hormonal exposures.