Compositional Boundary Research Articles

Middle Pennsylvanian (Desmoinesian) Fusulinids of the Bug Scuffle Limestone Member of the Gobbler Formation, Sacramento Mountains, South-Central New Mexico

Analysis of fusulinids from the Bug Scuffle Limestone Member of the Gobbler Formation along the western escarpment of the Sacramento Mountains in south-central New Mexico demonstrates that all four Desmoinesian regional fusulinid zones documented in Midcontinent and Southwest North America are present in the stratigraphic unit. Earliest Desmoinesian (Df1 Zone) fusulinids from the basal Bug Scuffle limestone beds suggest that the carbonate unit transgressed northward on the Sacramento Shelf, with Beedeina insolita in basal beds of the southernmost canyon exposures, and the slightly more advanced B. hayensis and B. curta in basal limestone beds of more northern outcrops. Late early Desmoinesian (Df2 Zone) fusulinids are common and widespread throughout the escarpment outcrop belt indicating that it was the time period with the most widespread normal marine shelf paleoenvironmental conditions. The diverse assemblage of the Df2 Zone is characterized by Beedeina novamexicana, B. euryteines, B. leei, B. socorroensis, B. joyitaensis, Wedekindellina euthysepta, and W. excentrica. The microprobematical branching fossil Komia is also common in this zone. Wedekindellina and Komia do not range above the mid-Desmoinesian CSB1 composite sequence boundary. Above that sequence boundary, the early late Desmoinesian Df3 Zone is characterized by sparse Beedeina haworthi, and the closely related B. illinoisensis and B. tumida. The late late Desmoinesian Df4 Zone is represented by a diverse assemblage of fusulinids in the uppermost part of the Bug Scuffle Limestone Member in the southern canyon exposures, including Beedeina acme, B. megista, B. mysticensis, B. lonsdalenesis, B. bellatula, B. gordonensis, and B. vintonensis. No Beedeina identifiable to species were found in upper part of the Bug Scuffle Limestone Member in the northernmost canyon exposures, demonstrating that late Desmoinesian paleoenvironments became more restricted marine northward along the Sacramento Shelf. Above the CSB2 composite sequence boundary in the uppermost Bug Scuffle Limestone Member, the lower part of the uppermost depositional sequence continues to contain latest Desmoinesian Df4 Zone fusulinids in the southern canyon sections. Early Missourian conodonts have been reported in a limestone unit near the top of the Gobbler clastic detrital member in the north-central part of the outcrop belt(Wahlman and Barrick 2018; Lucas et al. 2021), but no early Missourian conodonts or fusulinids have been reported yet from the uppermost Bug Scuffle Limestone Member in the southern canyons.

Seismic analysis and connection optimization of the side column on modular prefabricated four‐sided connected composite shear wall

SummaryA modular prefabricated four‐side connected composite (MPFC) shear wall that consists of a composite shear wall modular (CSWM) and steel frame boundary elements is proposed. First, the finite element model (FEM) of the MPFC shear wall, which considers a plastic‐damage constitutive model of both concrete and steel materials, is established based on the finite‐element software ABAQUS. Second, the FEM accuracy of the MPFC shear wall is verified by the experimental results of a modular prefabricated two‐sided connected buckling‐restrained (MTB) steel plate shear wall. Third, the seismic performance of the MPFC shear wall is investigated based on the verified FEM. The connection between the CSWM and side column is optimized. Finally, the initial stiffness calculation formula of the MPFC shear wall that considers the impact of that the thickness ratio between the connection steel plate (CSP) and inner steel plate (ISP) is deduced. The results show that the peak bearing capacity, initial stiffness, total energy, and total strain energy of the MPFC shear wall increased by 42.47%, 44.81%, 113.24%, and 58.97%, respectively, compared with those of the MTB steel plate shear wall. The compressive corner damage of the reinforcement concrete faceplate (RCF) of the MPFC shear wall with a side column and CSWM is connected by a middle steel plate is effectively improved. Compared with those of the MPFC shear wall in which the side column and CSWM are connected by bolts, the shearing force, axial force, and bending moment of the side column of the MPFC shear wall in which the side column and CSWM are connected by the middle steel plate are notably decreased by 25.32%, 26.08%, and 39.51%, respectively. The FEM results are compared with the formula calculation results to establish its accuracy in calculating the initial stiffness of the MPFC shear wall.

In situ crystallization of non-cotectic and foliated igneous rocks on a magma chamber floor

Layered mafic intrusions commonly contain non-cotectic, foliated igneous rocks that are traditionally attributed to processes involving settling, transport, and redeposition of crystals. Here we examine the chemistry of magnetitite layers of the Bushveld Complex using a portable XRF spectrometer on drill core and dissolution ICP-MS analysis on pure magnetite separates. While magnetitites contain foliated plagioclase grains in non-cotectic proportions, the magnetite is characterized by a regular upwards-depletion of Cr which is best explained by in situ crystallization. We suggest that plagioclase nucleation in thin residual compositional boundary layers atop a solidification front causes in situ growth of plagioclase in proportions much lower (<10%) than those expected from cotectic crystallization (±85%). Crystallization in such a boundary layer also favours lateral growth of the plagioclase, producing the foliation. We suggest that some non-cotectic, foliated rocks that are commonly interpreted to arise from gravity-induced sedimentary processes may instead be produced by in situ crystallization.

Applying lead (Pb) isotopes to explore mobility in humans and animals.

Lead (Pb) isotopes provide a complementary method to other provenance tools for tracking the origin and movement of humans and animals. The method is founded in the geographic distribution of Pb isotope ratios. However, unlike the Sr isotope method that is closely linked to the lithology of underlying rocks, Pb more closely reflects the tectonic regimes. This makes it particularly pertinent to use in Britain as there is major tectonic boundary (the Iapetus Suture) that runs between Berwick-upon-Tweed and the Solway Firth providing a compositional boundary in Pb isotope domains that approximates to the geographic areas of Scotland versus England and Wales. Modern pollution makes it difficult to use modern floral or faunal samples to characterize biosphere variation, and so we use geological datasets to define isoscape variation and present the first Pb isotope map of Britain. We have validated the use of these data form biosphere studies using well provenanced samples. Reference fields of diagnostic compositions, are created in μ-T space and these have been used in a test case to assess the geographic origins of Neolithic animals in Great Britain.

Unraveling an enigmatic boundary along the Sunda-Banda volcanic arc

This study utilizes a range of complementary geological, geophysical, and geochemical data to analyze the structural, deformational, and compositional variations along the Sunda-Banda volcanic arc transitional zone from oceanic to continental subduction. The core component is a synthesis of three station-based anisotropy inferences and two 3-D shear wave velocity models in the crust and upper mantle, all of which are derived based on ∼5 years of broadband seismic data collected across eastern Indonesia. These seismic results are based on receiver functions, shear wave splitting, ambient noise tomography, and a new teleseismic surface wave tomography model. We observe distinct along-arc spatial variations in the shear wave velocity and anisotropic structure within the crust and mantle wedge above the subducting slab. An intriguing arc-perpendicular orientation is observed in crustal fabrics and mantle anisotropy consistently in central Flores, contrasting with the arc-parallel orientations on the western and eastern sides. The orientations correlate with the change in strike of the highest topography as well as the presence of ∼N-S aligned cinder cones in central Flores. The 3-D shear wave velocity model in the crust and uppermost mantle also presents a sharp structural change in central Flores that indicates a relatively thinner crust. At deeper depths, the newly imaged upper mantle structure exhibits along-arc variations, but the change across central Flores appears to be distributed more broadly and outlines a relatively slow mantle wedge beneath eastern Flores. These new observations roughly correlate with previously identified changes in volcanic geochemistry characteristics across central Flores. Our study links the surface topography, geology, and volcanism with subsurface crust and mantle structures, unraveling an enigmatic structural and/or compositional boundary along the Banda volcanic arc.

Stress Control of Dike Deflection and Flank Eruption at Akaroa Volcano, New Zealand.

Understanding the stress evolution of extinct volcanoes can improve efforts to forecast flank eruptions on active systems. Field, petrographic, and seismic data are combined with numerical modeling to investigate the paleo‐stress field of New Zealand's Akaroa Volcano, or Akaroa Volcanic Complex. Field mapping identifies 86 radially oriented dikes and seven lava domes found only within a narrow elevation range along Akaroa's erosional crater rim. These observations suggest that crater rim dike emplacement resulted from lateral deflection of vertically ascending intrusions from a centralized magma source, which in turn may have facilitated formation of the lava domes, as well as two scoria cones. We postulate that dike deflection occurred along a stress barrier, as neither a compositional change nor structural boundary are present. We use a finite element model (FEM) simulating Akaroa to test how different factors may have influenced the system's stress state and dike geometry. Elastic, non‐flexural (“roller”) model configurations containing a large, oblate, and shallow magma chamber produce stress barriers most conducive to radial dike emplacement along Akaroa's crater rim. These configurations also simulate rapid edifice construction above a preexisting lithospheric “bulge.” Conversely, simulating flexural stresses exerted on the lithosphere by Akaroa's large mass hinder rather than promote radial dike emplacement. Temperature‐dependent viscoelastic relaxation promotes gradual increases in stress barrier elevation, though this effect is strongly dependent on magma chamber parameters. These results suggest that Akaroa was constructed rapidly (within ∼100 kyr) prior to crater rim dike emplacement, which occurred throughout the volcano's remaining active lifespan.

CdS Coated Mn Doped ZnO Nanospheres as Textile Catalyst: Fabrication, Physicochemical Techniques and Dye Removal Under Natural Light

ZnO as a promising photocatalyst has gained much attention for the removal of organic pollutants from water. However, the main drawbacks of the relatively low photocatalytic activity and high recombination rate of photo excited electronhole pairs, restrict its potential applications. Promoting the spatial separation of photo excited charge carriers is of paramount signi? cance for photocatalysis, because the dierence in the band positions make the potential gradient at the composite boundary. In this work, our aim is to enhance the photocatalytic efficiency of CdS coated Mn doped ZnO nanospheres under solar light irradiation. Objectives in this work are, to fabricate the CdS coated Mn doped ZnO nanospheres by a simple ethanolic dispersion method, and its applied for testing the photocatalytic activity of methylene blue (MB) dye. The fabricated binary composites were analyzed with different physicochemical techniques like PXRD, SEM with EDX, UV-DRS, PL and TEM. The photocatalytic degradation results have revealed that, the CdS coated Mn doped ZnO nanospheres exhibits admirable activity toward the photocatalytic degradation of the MB. The remarkably enhanced photocatalytic activity of CdS coated Mn doped ZnO nanospheres can be interpreted in terms of lots of active sites, which efficiently separate the photo generated electron and holes. A plausible mechanism is also elucidated via active species trapping experiments with various scavengers, which indicating that the photo generated O2 -and. OH radicals play a crucial role in photo degradation reactions under visible light irradiation. This work suggests that, the rational design and construction of heterostructures is powerful for developing highly efficient, and reusable visible-light photocatalysts for environmental purification and energy conversion. The enhanced photo degradation activity indicates the potential of the nanocomposite for the treatment of organic pollutants from the textile wastewater.

CdS Coated Mn Doped ZnO Nanospheres as Textile Catalyst: Fabrication, Physicochemical Techniques and Dye Removal Under Natural Light

ZnO as a promising photocatalyst has gained much attention for the removal of organic pollutants from water. However, the main drawbacks of the relatively low photocatalytic activity and high recombination rate of photo excited electronhole pairs, restrict its potential applications. Promoting the spatial separation of photo excited charge carriers is of paramount signi? cance for photocatalysis, because the dierence in the band positions make the potential gradient at the composite boundary. In this work, our aim is to enhance the photocatalytic efficiency of CdS coated Mn doped ZnO nanospheres under solar light irradiation. Objectives in this work are, to fabricate the CdS coated Mn doped ZnO nanospheres by a simple ethanolic dispersion method, and its applied for testing the photocatalytic activity of methylene blue (MB) dye. The fabricated binary composites were analyzed with different physicochemical techniques like PXRD, SEM with EDX, UV-DRS, PL and TEM. The photocatalytic degradation results have revealed that, the CdS coated Mn doped ZnO nanospheres exhibits admirable activity toward the photocatalytic degradation of the MB. The remarkably enhanced photocatalytic activity of CdS coated Mn doped ZnO nanospheres can be interpreted in terms of lots of active sites, which efficiently separate the photo generated electron and holes. A plausible mechanism is also elucidated via active species trapping experiments with various scavengers, which indicating that the photo generated O2 -and. OH radicals play a crucial role in photo degradation reactions under visible light irradiation. This work suggests that, the rational design and construction of heterostructures is powerful for developing highly efficient, and reusable visible-light photocatalysts for environmental purification and energy conversion. The enhanced photo degradation activity indicates the potential of the nanocomposite for the treatment of organic pollutants from the textile wastewater.

Study on path planning method for unknown 3D environment exploration driven by compound boundary points

Aiming at the low exploration level, slow speed and repeated exploration of UAVs in unknown environments, this paper improves the selection of boundary points based on the boundary driving method, and proposes a method suitable for UAVs to quickly explore in unknown environments. Planning method: while using the depth image (RGBD) sensor to receive environmental information, the octree map of the known environment is constructed in real time, and the common indoor environment is divided into six local environmental types. The drone observes according to the RGBD camera on board. The local environment type generates instantaneous speed commands, and designs composite boundary points, from which the point with the largest information gain and the smallest yaw angle is weighed as the boundary guide point. Finally, a simulation experiment was carried out and comparing with the existing methods. The time required to explore the apartment environment in the next best viewpoint (NBV) in Document with the present method is 68.7% less than the exploration time in the paper. In addition, this paper designs There are four types of environments. In these environments, the present method reduces the average exploration time by 97.1% comparing with the method in Document. The experimental results show that the present method can effectively improve the exploration efficiency and has strong feasibility.

Analytical well-test model for hydraulicly fractured wells with multiwell interference in double porosity gas reservoirs

Interference resulting from infill wells in multiwell systems becomes a common issue in interpreting well tests data from hydraulicly fractured wells in tight carbonate gas reservoirs. Current single-well pressure transient approaches may falsely interpret well interferences as the composite reservoir or boundary effects, leading to significant errors in reservoir parameter estimation. Additionally, the most semi-analytical and numerical solutions used for fractured wells are computationally demanding and inconvenient to use. This work presents a novel and simple analytical well-test model for hydraulicly fractured wells with multiwell interference in double porosity gas reservoirs with significantly less computational time and effort than the existing methods. The analytical solution for a hydraulically fractured well with finite conductivity fracture in a multiwell system with well interference is presented based on the superposition principle, the early-time approximate solutions of trilinear flow and the infinite-conductivity fracture model. A systematic verification is conducted to ensure the validity of the presented solution. The solution is valid when the dimensionless fracture conductivity is greater than 1 (FcD>1) with ∼1% error in pressure and derivative. Furthermore, we offer a criterion of identifying well interference using the pressure derivative of the late-time approximation of the proposed analytical solution. Finally, a case study is conducted in the Sichuan Basin, indicating the proposed solution's applicability.

Light weight object detector based on composite attention residual network and boundary location loss

The object detector based on deep learning has received extensive attention, but the high computational cost has become an obstacle to its large-scale application. It is a great challenge for object detection to further reduce the hardware requirements on the premise of ensuring high detection accuracy. We propose a one-stage lightweight object detector and a new regression loss. In this method, ResNet is improved and combined with attention mechanism to ensure the maximum integrity of feature information with fewer parameters; The multi-scale feature fusion network is improved to reduce the reasoning complexity of the structure. In addition, the bounding box regression loss is improved, and the specific position of the bounding box is adjusted by considering the balance of multiple factors in the regression process. The experimental results show that: 1) the combination of most detectors and improved loss can further improve the performance of detectors; 2) As a whole, our improved network and loss can give consideration to both speed and accuracy on Pascal VOC and COCO; 3) in the addition of other new training tricks such as DropBlock and Mosaic, we can achieve better overall performance on the coco test development set, 38.42 AP (average accuracy) at 40.3 FPS.

Mechanical, viscoelastic, and flammability properties of polymer composites reinforced with novel Sirisha bark filler

Today is the era of advanced materials to resolve the issue due to ecological hazards. Research is being carried out to find the alternative of the existing materials with a low cost and eco-friendly nature. Polypropylene (PP) is one of the major commodity thermoplastics having wide applications worldwide. The neat PP is extremely sensitive to flame and therefore it is a challenging task for the researchers to reduce the flame sensitivity of PP composites for safe applications. Though the artificial flame retardant filler reduces the flame propagation, these are hazardous, costly, not environment friendly and, they reduce the mechanical strength of the polymer composites upon higher percentage loading. To overcome this difficulty, in this work, the novel natural Sirisha bark filler was reinforced to the coir fiber/PP hybrid composites to enhance the flame retardant and mechanical properties. The time to ignite (TTI) of the hybrid composites increased due to bark filler reinforcement in the composites and the flame spread reduced to zero. The impact strength of hybrid composites was found to be increased due to the strong interfacial adhesion of the bark filler with the PP matrix. The scanning electron microscope (SEM) micrographs revealed the well-defined grain boundaries of hybrid composites. The carbonaceous char coating over the surface of the hybrid composite was observed from the char morphology that acts as a hindrance to flame. The viscoelastic properties such as storage modulus, loss modulus, and loss tangent of the hybrid composites were studied by using dynamic mechanical analysis (DMA).

Experimental investigation on flow boiling heat transfer characteristics of endothermic hydrocarbon fuel and its visualization at high-temperature conditions

The endothermic hydrocarbon fuel is used as a coolant to realize active cooling for the high-heat-flux components of air-breathing hypersonic vehicles. Because of its complex composition and severe thermal boundary conditions, the unstable heat transfer and coking are usually the major problems. Flow boiling heat transfer of a kind of endothermic hydrocarbon fuel named EHF-204 and its visualization were experimentally investigated in mini-channels with 2.0 mm internal diameter at heat flux of 250 kW/m2 and 500 kW/m2. It is found that the heat transfer enhancement and heat transfer deterioration would occur obviously during the flow boiling heat transfer process at subcritical and near-critical pressures of 1.0 MPa and 2.5 MPa. After the fuel was completely vaporized, the heat transfer coefficient would slowly increase again with the increasing fuel temperature. The heat transfer enhancement and heat transfer deterioration process at subcritical temperatures were not existed at the supercritical pressure of 4.0 MPa. The flow patterns of bubbly flow, slug flow, and churn flow were clearly observed at the subcritical pressures. Flow pattern visualization proved that the constant wall temperature heat transfer processes at subcritical pressures were subcooled boiling and saturation boiling flow. The bigger bubbles were formed at lower pressures, which caused higher heat transfer coefficient. The bubbly flow, slug flow caused the heat transfer enhancement, and the appearance of churn flow was a feather that made the boiling heat transfer transition from heat transfer enhancement to heat transfer deterioration. Some interesting visualization phenomena were observed in this study including the twice vaporization during flow boiling.

Uncovering strengthening and softening mechanisms of nano-twinned CoCrFeCuNi high entropy alloys by molecular dynamics simulation

High-entropy alloys (HEAs) break the design concept of traditional alloys and exhibit excellent mechanical properties. However, as a new member of the alloy family in recent years, the dependence of the deformation behavior of the HEAs on alloy composition and twin boundary (TB) is still unclear, and many phenomena urgently need to be revealed. Here, the effects of TB spacing and Ni concentration on the mechanical properties and deformation behavior of the nano-twinned (CoCrFeCu)1−XNiX HEA (nt-HEA) under tensile loading are investigated by molecular dynamics simulation. The results show that with the decrease in TB spacing, the average flow stress of the nt-HEA changes from Hall–Petch strengthening to inverse Hall–Petch softening. When the TB spacing is greater than a critical value, the plastic deformation mechanism is dominated by the slip of partial dislocations. However, when the TB spacing is less than the critical value, the plastic deformation mechanism is transformed into the formation of voids induced by the amorphous phase, which becomes the key factor for the softening of the nt-HEA. It is also found that the mechanical properties of the nt-HEA can also change from strengthening to softening by adjusting Ni concentration, which is closely related to the change of stacking fault energy of the nt-HEA. In addition, the plastic deformation mechanism and voids formation mechanism of the nt-HEA are also discussed in detail.

A Case Study of the Induced Magnetosphere Boundary at the Martian Subsolar Region

Abstract One Martian induced magnetosphere boundary (IMB) crossing at the subsolar region is analyzed here with multiple instruments on board MAVEN. Properties of the magnetic field and particles around the IMB are evaluated. We find different trends of variation in magnetic field components at the two sides of an interface coincident with the previously defined ion composition boundary. This case shows the IMB at the Martian dayside could be divided into three parts: two regions (denoted as R1 and R2), with different field and plasma properties, and an interface between them. Currents found in R1 and R2 are flowing in antiparallel, and the current density in R2 (at lower altitude) is significantly larger than that in R1 (at higher altitude). Results indicate the interaction between Mars and the solar wind could induce strong currents in the IMB, which are with antiparallel current directions and separated by an interface where the ion composition changes. This could be a typical feature that occurred during the interaction between the solar wind and the nonmagnetized planets.

Atomically Resolved Electrically Active Intragrain Interfaces in Perovskite Semiconductors.

Deciphering the atomic and electronic structures of interfaces is key to developing state-of-the-art perovskite semiconductors. However, conventional characterization techniques have limited previous studies mainly to grain-boundary interfaces, whereas the intragrain-interface microstructures and their electronic properties have been much less revealed. Herein using scanning transmission electron microscopy, we resolved the atomic-scale structural information on three prototypical intragrain interfaces, unraveling intriguing features clearly different from those from previous observations based on standalone films or nanomaterial samples. These intragrain interfaces include composition boundaries formed by heterogeneous ion distribution, stacking faults resulted from wrongly stacked crystal planes, and symmetrical twinning boundaries. The atomic-scale imaging of these intragrain interfaces enables us to build unequivocal models for the ab initio calculation of electronic properties. Our results suggest that these structure interfaces are generally electronically benign, whereas their dynamic interaction with point defects can still evoke detrimental effects. This work paves the way toward a more complete fundamental understanding of the microscopic structure–property–performance relationship in metal halide perovskites.

Dve nové lokality pyromorfitu v Slovenskej republike: Chvojnica a Hnilčík

Two new localities of pyromophite were recently discovered at the Chvojnica base metals occurrence in the Strážovské vrchy Mts. (Tatric Unit), and at the supergene zone of the Piata siderite-type hydrothermal vein near Hnilčík (Spišsko-gemerské rudohorie Mts., Gemeric Unit), Slovak Republic. At the Chvojnica occurrence pyromorphite occurs as bright green crystalline crusts and radial aggregates up to 3 mm developed in cavities and fractures in the porous quartz gangue with relicts of primary galena. It is associated with minor crystalline coatings of cerussite. The refined unit-cell parameters of pyromorphite from Chvojnica (for the hexagonal space group P63/m) are a 9.9750(2) Å, c 7.3569(2) Å and V 633.93(2) Å3. Except of dominant contents of Pb, P and Cl, only minor amounts of Ca (up to 0.10 apfu), Al (up to 0.05 apfu), Fe (up to 0.04 apfu), As (up to 0.05 apfu) and S (up to 0.02 apfu) were detected in studied pyromorphite. At the Hnilčík, pyromorphite occurs rarely in the cavities of the cavernous quartz-limonite gangue in the supergene zone of the Piata vein. It forms colourless to very light green prismatic crystals up to 2 mm in size, or crystalline aggregates associated with goethite, Mn oxides and malachite. The refined unit-cell parameters of pyromorphite from Hnilčík (for the hexagonal space group P63/m) are a 9.9484(15) Å, c 7.315(2) Å, V 627.0(2) Å3 (Ca-poor) and a 9.8983(6) Å, c 7.2589(8) Å, V 615.92(9) Å3 (Ca-rich). Pyromorphite from Hnilčík shows strong chemical zoning caused by variation of Pb and Ca contents, with outer parts of the crystals enriched in Ca. Contents of Ca are ranging between 0.09 to 0.96 apfu, with the atomic Pb/(Pb+Ca) ratio ranging from 0.98 to 0.81, which is close to the compositional boundary with phosphohedyphane. Interesting are also elevated concentrations of Cu reaching up to 0.07 apfu. Other minor elements detected in pyromorphite from Hnilčík are As (up to 0.12 apfu), Al, V and S (all up to 0.02 apfu).

Facile Fabrication of Anisotropic Multicompartmental Microfibers Using Charge Reversal Electrohydrodynamic Co-Jetting.

Anisotropic microstructures are utilized in various fields owing to their unique properties, such as reversible shape transitions or on-demand and sequential release of drug combinations. In this study, anisotropic multicompartmental microfibers composed of different polymers are prepared via charge reversal electrohydrodynamic (EHD) co-jetting. The combination of various polymers, such as thermoplastic polyurethane, poly(D,L-lactide-co-glycolide), poly(vinyl cinnamate), and poly(methyl methacrylate), results in microfibers with distinct compositional boundaries. Charge reversal during EHD co-jetting enables facile fabrication of multicompartmental microfibers with the desired composition and tunable inner architecture, broadening their spectrum of potential applications, such as functional microfibers and cell scaffolds with multiple physical and chemical properties.

Future Venus missions and flybys: A collection of possible measurements with mass spectrometers and plasma instruments

This study contains predictions for mass spectrometry and plasma instrument measurements during upcoming Venus flybys of BepiColombo and Solar Orbiter and discusses the possibility of a phosphine detection with mass spectrometry in Venus’ upper atmosphere. The results extend the ones published previously in Gruchola et al. (2019) , where predictions for the proposed ESA mission EnVision and the Venus flyby of JUICE were included. Both the Venus flyby of BepiColombo and the one of Solar Orbiter will take place in August 2021, only 1 day apart. BepiColombo, carrying the neutral mass gas spectrometer STROFIO, could probe the atmosphere around closest approach and obtain data on the thermal and hot neutral particle populations in the upper atmosphere. According to this study, the thermal hydrogen population as well as the hot species H, C, N and O, including isotopes, should be visible to STROFIO. Especially data on the abundance of the hot species would yield important insight into the planetary escape processes. The Solar Orbiter on the other hand carries the plasma instrument SWA-HIS, designed to measure the energetic solar wind ions. During its second Venus gravity assist it will traverse the magnetosheath, the region between bow shock and ion composition boundary, where in addition to the solar wind ions energetic planetary ions are present. The planetary pickup ions can be measured by SWA-HIS, providing important information on the outflow of planetary ions and the ionization processes in the upper atmosphere itself. The recent reports of phosphine in Venus’ cloud decks with an abundance of 20 ppb at 80 km probably overestimate the actual PH 3 abundance, as the data are currently being reanalyzed (Greaves et al., 2021). However, even with this upper limit of 20 ppb a phosphine detection with a mass spectrometer e.g. on-board ESA’s proposed EnVision mission, seems unlikely. To resolve the PH 3 peak and the 16 O 18 O peak a mass resolution of almost 10’000 is required, and the PH 2 D peak is masked by the Cl fragment peak of HCl. Furthermore, NGMS on-board Pioneer Venus with a mass resolution of around 440 did most likely not detect phosphine, as it scanned only a few masses in the mass range of interest where more abundant species than phosphine are present.

Development of Composite Motorcycling Safety Index along Urban Roads in Malaysia

&#x0D; &#x0D; &#x0D; Motorcycle is a preferred private transportation mode (45%) among Malaysian due to its affordability and eases to move around especially in the hectic urban areas. These vulnerable road users are exposed to greater risk in road collisions due to sharing the roadway with other motor vehicles and unprotected. Worse still, the road was designed without concern for the motorcycle's characteristics. No doubt, segregating motorcycles exclusively from the roadway is an effective engineering measure to address motorcycle safety. But it may not be feasible to introduce in the well-built urban areas. Identification of the road and traffic variables that affecting safe motorcycling in the urban roadway is an initiative to create a safer riding environment. The initial study was carried out to identified traffic and roadway variables that affecting safe motorcycling. The seven pre-determined variables that were found to significantly influencing Malaysian motorcycle riders' safety perception are: pavement condition, paved shoulder width, posted speed limit, mixed traffic volume, type of roadway, lane width, and parking condition. These pre-determined variables were further investigated in the subsequent study, questionnaire with fourteen short video clips representing different traffic and roadway conditions was aired to 483 respondents to rate the motorcycling safety score (MSS) based on their safe riding perception. The response on MSS was further developed into Motorcycling Safety Index (MSI). Lastly, 114 combinations of different traffic and roadway conditions for seven pre-determined variables were formed to establish the Composite MSI boundary. The development of Composite MSI is to enable the road authorities and agencies and/or practitioners to assess the problematic road segments that required immediate remedial actions.&#x0D; &#x0D; &#x0D;