Search

Herein, a heterogeneous structure of Ni–Mo catalyst comprising Ni4Mo nanoalloys decorated on a MoOx matrix via electrodeposition is introduced. This catalyst exhibits remarkable hydrogen evolution reaction (HER) activity across a range of pH conditions. The heterogeneous Ni–Mo catalyst showed low overpotentials only of 24 and 86, 21 and 60, and 37 and 168 mV to produce a current density of 10 and 100 mA cm−2 (η10 and η100) in alkaline, acidic, and neutral media, respectively, which represents one of the most active catalysts for the HER. The enhanced activity is attributed to the hydrogen spillover effect, where hydrogen atoms migrate between the Ni4Mo alloys and the MoOx matrix, forming hydrogen molybdenum bronze as additional active sites. Additionally, the Ni4Mo facilitated the water dissociation process, which helps the Volmer step in the alkaline/neutral HER. Through electrochemical analysis, in situ Raman spectroscopy, and density functional theory calculations, the fast HER mechanism is elucidated. [ABSTRACT FROM AUTHOR]

Using a sample of >200 clusters, each with typically 100–200 spectroscopically confirmed cluster members, we search for a signal of alignment between the position angle (PA) of the Brightest Cluster Galaxy (BCG) and the distribution of cluster members on the sky about the cluster centre out to projected distances of 3  R 200. The deep spectroscopy, combined with corrections for spectroscopic incompleteness, makes our sample ideal to determine alignment signal strengths. We also use an SDSS based skeleton of the filamentary large-scale structure (LSS), and measure BCG alignment with the location of the LSS skeleton segments on the sky out to projected distances of 10  R 200. The alignment signal is measured using three separate statistical measures; Rao's spacing test (U), Kuiper's V parameter (V), and the Binomial probability test (P). The significance of the BCG alignment signal with both cluster members and LSS segments is extremely high (1 in a million chance or less to be drawn randomly from a uniform distribution). We investigate a wide set of parameters that may influence the strength of the alignment signal. Clusters with more elliptical-shaped BCGs show stronger alignment with both their cluster members and LSS segments. Also, selecting clusters with closely connected filaments, or using a luminosity-weighted LSS skeleton, increases the alignment signal significantly. Alignment strength decreases with increasing projected distance. Combined, these results provide strong evidence for the growth of clusters and their BCGs by preferential feeding along the direction of the filaments in which they are embedded. [ABSTRACT FROM AUTHOR]

Radio-based vehicular simultaneous localization and mapping (SLAM) aims to localize vehicles while mapping the landmarks in the environment. We propose a sequence of three Poisson multi-Bernoulli mixture (PMBM) based SLAM filters, which handle the entire SLAM problem in a theoretically optimal manner. The complexity of the three proposed SLAM filters is progressively reduced while sustaining high accuracy by deriving SLAM density approximation with the marginalization of nuisance parameters (either vehicle state or data association). Firstly, the PMBM SLAM filter serves as the foundation, for which we provide the first complete description based on a Rao-Blackwellized particle filter. Secondly, the Poisson multi-Bernoulli (PMB) SLAM filter is based on the standard reduction from PMBM to PMB, but involves a novel interpretation based on auxiliary variables and a relation to Bethe free energy. Finally, using the same auxiliary variable argument, we derive a marginalized PMB SLAM filter, which avoids particles and is instead implemented with a low-complexity cubature Kalman filter. We evaluate the three proposed SLAM filters in comparison with the probability hypothesis density (PHD) SLAM filter in 5G mmWave vehicular networks and show the computation-performance trade-off between them. [ABSTRACT FROM AUTHOR]

Millimeter wave (mmWave) signals are useful for simultaneous localization and mapping (SLAM), due to their inherent geometric connection to the propagation environment and the propagation channel. To solve the SLAM problem, existing approaches rely on sigma-point or particle-based approximations, leading to high computational complexity, precluding real-time execution. We propose a novel low-complexity SLAM filter, based on the Poisson multi-Bernoulli mixture (PMBM) filter. It utilizes the extended Kalman (EK) first-order Taylor series based Gaussian approximation of the filtering distribution, and applies the track-oriented marginal multi-Bernoulli/Poisson (TOMB/P) algorithm to approximate the resulting PMBM as a Poisson multi-Bernoulli (PMB). The filter can account for different landmark types in radio SLAM and multiple data association hypotheses. Hence, it has an adjustable complexity/performance trade-off. Simulation results show that the developed SLAM filter can greatly reduce the computational cost, while it keeps the good performance of mapping and user state estimation. [ABSTRACT FROM AUTHOR]

This paper proposes a new approach to modeling heterogeneity in choice data that can accommodate fixed-point ratings data and text. This paper proposes a new approach to modeling heterogeneity in choice data that can accommodate fixed-point ratings data and text. Respondent choices, survey responses, and narratives are combined to form latent archetypes that provide an integrated description of respondents in terms of the objects and drivers of their wants. We propose a measure of coherence to assess the value of integrating these data elements and demonstrate the value of integrating text data into an analysis of choice and scaled response data. A conjoint data set is used to illustrate the model where we find that the text data helps clarify the origin of demand. [ABSTRACT FROM AUTHOR]

A diverse range of studies have investigated microplastics in indoor and outdoor air. However, where and how the air was collected differ between studies, as did the methods of separation and analysis. The difference makes it difficult to compare the results of the studies, because the quantity, size, shape, and type of microplastics detected are widely diverse and depend on the detection method. Herein, we studied the number, type, size, and shape of microplastics in air samples collected from the outdoor environment and the indoor environment of buildings with active human activities, such as apartment buildings and offices. The average number of microplastics in the indoor environment was approximately 1.5 times higher than that in the outdoor environment. The indoor ventilation volume affected the amount of microplastics generated, indicating that appropriate ventilation is important for reducing microplastics in indoor environments. This study also sought ways to manage microplastics at their primary sources, which is closely linked with the living environment, by comparing how they are generated in indoor and outdoor environments. [ABSTRACT FROM AUTHOR]

5G new radio will provide a new paradigm in high accurate vehicle localization, reinforced by the use of large antenna arrays along with carefully designed broadband radio technology. However, a high computational load still remains unravelled in the context of cooperative localization, albeit with its advantages of high-precision localization. To alleviate such the computational burden, we develop a reliable technique of cooperative localization, addressed as a constraint satisfaction problem. A constraint satisfaction formalism for cooperative localization readily enables to recast a formulation of the decentralized optimization. Its efficient solution of the optimization is developed in a distributed manner. Simulation results demonstrate that the proposed approach saves the requested computational loads significantly while sustaining the satisfactory accuracy of cooperative localization. [ABSTRACT FROM AUTHOR]

Fossil cluster A2261 is well studied, but previous studies give contradictory results on its dynamical states, such as its X-ray central entropy and magnitude gap. To improve our understanding of its dynamical state, we conduct multiobject spectroscopic observations with Hectospec on the MMT, covering an area out to 5 virial radii from the cluster center, and get improved completeness and membership. Using these new data, we calculate multiple dynamical indicators, including Gaussianity, distance offset, and velocity offset. These indicators suggest that A2261 is moderately relaxed. However, a Dresslerâ€"Shectman test reveals a group candidate to the south at a projected distance that is near the virial radius and overlaps with an X-ray tail-like feature. One of the galaxies associated with that group would be sufficiently bright to reduce the fossil magnitude gap. This raises the possibility that A2261 could have recently transited in fossil status, if the group had previously crossed the cluster and is only now found outside. In the cluster outskirts, we see an extended feature of galaxies located on the opposite side of the cluster from the group candidate. On even larger scales, we find that this feature connects, both on the sky and in velocity space, with a long (4.4 Mpc) filamentary structure in the Sloan Digital Sky Survey data. This could support the idea that a group was fed into the cluster through the filament, temporarily breaking the fossil status and resulting in a minor merger that weakly disturbed the intracluster medium of the cluster. [ABSTRACT FROM AUTHOR]

Galaxy clusters contain a diffuse stellar component outside the cluster's galaxies, which is observed as faint intracluster light (ICL). Using Gemini/GMOS-N deep imaging and multiobject spectroscopy of a massive fossil cluster at a redshift of z = 0.47, RX J105453.3+552102 (J1054), we improve the observational constraints on the formation mechanism of the ICL. We extract the ICL surface brightness and colour profiles out to 155 kpc from the brightest cluster galaxy (BCG) with a detection limit of 28.7 mag arcsec−2 (1 σ , 4.8 × 4.8arcsec2; i band). The colour of the diffuse light is similar to that of the BCG and central bright galaxies out to ∼ 70 kpc, becoming slightly bluer toward the outside. We find that the ICL distribution shows better agreement with the spatial distribution of member galaxies than with the BCG-dominated cluster luminosity distribution. We report the ICL fraction of J1054 as |$15.07 \pm 4.57 {{\ \rm per\ cent}}$| in the range of 60 ∼ 155 kpc from the BCG, which appears to be higher than the ICL fraction-redshift trend in previous studies. Our findings suggest that intracluster stars seems not to be explained by one dominant production mechanism. However, a significant fraction of the ICL of J1054 may have been generated from the outskirts of infalling/satellite galaxies more recently rather than by the BCG at the early stage of the cluster. [ABSTRACT FROM AUTHOR]

Although filtration devices are already widely used for stormwater runoff treatment, there are much to be improved to ensure the required performance. Additionally, the performance of a device should be verified before on-site installation. In this context, an upflow filtration system using novel high porosity floating fibrous media formed into spherical shape was proposed and evaluated for solid capture and backwashing. At filtration velocities of 20–40 m/h, the maximum head loss was about 2 cm even under a solid load of 30 kg/m2, and suspended solid (SS) removal efficiency was >96% throughout 300 min. A considerable amount of SS was removed in the pretreatment chamber, so the load on the media was reduced. Several models were tried to describe the solid capture in the media. The coefficients of solid attachment/detachment showed good correlations with filtration velocity. Other parameters indicated a variation of solid capture and permeability, which is unique to the media in this study. The backwashing with air and water for 1–2 min each showed good head loss recovery under the SS load up to 550–600 kg/m2, and the SS discharge was more efficient when the stagnant water was drained before water backwashing. The results in this study suggest the high potential of the combination of fibrous media and upflow filtration system for the efficient control of the nonpoint source pollutants in stormwater runoff. [ABSTRACT FROM AUTHOR]

Traditional beam tracking has severe performance loss under the high mobility and narrow beam scenario. To alleviate the tracking performance degradation, we propose an adaptive beamwidth control for millimeter wave beam tracking. Using the particle filter, we perform the beam tracking, i.e., which is to estimate the channel gain and the angle-of-arrival (AoA). Based on the updated estimate standard deviation of AoA, the adequate beamwidth is set via the partial activation of the antenna array. Simulation results show that the beam tracking with the proposed beamwidth control maintains a higher received signal-to-noise ratio (SNR) than that of the beam tracking without the beamwidth control while the SNR gain leads to a smaller AoA tracking error under high mobility. [ABSTRACT FROM AUTHOR]

The identification of product attributes and features that are essential for a benefit to exist is critical to new product development and formulation. Some attributes are benefit enabling in the sense that their presence indicates that an offering is responsive to a need, and their absence points out that the product is not responsive. Not all agricultural products, for example, are seen as having safety advantages, and specific organic certification such as the USDA organic label may be needed for some consumers to consider an offering as providing a benefit of reducing the level of health risks. Benefit formation hinges on these critical attributes being present, while other attributes may only enhance a benefit that has already been formed. Benefit-forming attributes therefore create a specific form of interaction among product attributes that may be heterogeneously distributed in the population. We develop a model to identify benefit-forming attributes and apply it to three conjoint datasets where we provide evidence of their interactive effects on preferences. The counter-factual exercises across three datasets highlight the importance of benefit-forming attributes in product design as well as in preference segments. [ABSTRACT FROM AUTHOR]

The development of high-efficiency catalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is essential to lower the energy losses during water electrolysis. Herein, a highly porous Ni–P (HP Ni–P) electrode, prepared by an ultrafast electrodeposition within only ten seconds, is presented with superior electrocatalytic activity towards both HER and OER in alkaline media: overpotentials of 96 and 323 mV are required to reach a current density level of 100 mA cm−2 for HER and OER, respectively, with corresponding Tafel slopes of 32.9 and 44.0 mV dec−1. Experimental analyses and theoretical calculations show that charge transfer occurs from Ni to P and the HER kinetics is accelerated by the increased hydrogen coverage, enhanced water dissociation ability, and optimized hydrogen adsorption energy on the HP Ni–P. Under OER conditions, surface P is oxidized into PO43−, promoting oxidation of Ni to OER-active NiOOH and exposing abundant OER-active sites on the HP Ni–P surface. An alkaline electrolysis cell was constructed with HP Ni–P as the cathode and anode (Ni–P‖Ni–P) and outperformed the Pt/C‖IrO2 cell at cell voltages exceeding 1.68 V. This work provides a practically applicable method to prepare HER and OER electrodes for use in industrial water electrolyzers, with insight into the activities of the catalysts. [ABSTRACT FROM AUTHOR]

A high-performance bifunctional Co–P foam catalyst was successfully synthesized by facile one-step electrodeposition at a high cathodic current density. The synthetic approach includes fast generation of hydrogen bubbles as well as fast deposition of Co–P, which played a key role in forming a porous Co–P foam structure. The Co–P foam exhibits remarkable electrocatalytic activity and stability in both acidic and alkaline solution. Its HER activity was recorded with an overpotential of 50 mV in 0.5 M H2SO4 and 131 mV in 1 M KOH at 10 mA cm−2, which is comparable to that of commercial Pt/C (η@10 mA cm−20.5 M H2SO4: 33 mV, η10 mA, 1 M KOH: 80 mV). The Co–P foam (η@10 mA cm−2: 300 mV) exhibits better OER activities than Ir/C (η@10 mA cm−2: 345 mV) and RuO2 (η@10 mA cm−2: 359 mV) in 1 M KOH solution. The excellent performance of the Co–P foam as an HER and OER catalyst can be attributed to the charge separation between Co and P in Co–P foam as well as the porous foam structure providing a large electrochemically active surface area (ECSA). The ECSA of the Co–P foam was calculated to be 118 cm2, which was 2.4 times higher than that of a Co–P film (49 cm2). [ABSTRACT FROM AUTHOR]

Apoptosis serves to protect normal cells during the processes of development, aging, tissue homeostasis, immunity, and inflammation. Molecules such as caspases, the Bcl-2 family proteins, cytochrome c, APAF-1, and apoptotic endonucleases are concerned with and regulate different stages of apoptosis. DNA fragmentation factor (DFF) is a key final molecule in chromosomal DNA fragmentation during the last step of apoptosis, and is a heterodimeric complex consisting of alpha/inhibitor of caspase-activated DNase (DFFA/ICAD) and beta/caspase-activated DNase (DFFB/CAD) subunits. DFFB/CAD is normally combined with the inhibitor, DFFA/ICAD, in healthy cells. However, after cleavage of the DFF complex by effector caspases, DFFB/CAD acts as an apoptotic nuclease and induces DNA fragmentation in apoptotic cells. The study of DFF proteins is focused on the roles of the apoptotic pathway in mammals. However, gene expression and functions under immune stimulation are not well known in other species. In the present study, we first characterized teleost DFFA/ICAD and DFFB/CAD from rock bream at the molecular level and analyzed the transcriptional expression pattern under immune challenges, to understand their role in immunity. These putative proteins have shown conserved domains and interaction sites orthologous to those of other species. High mRNA expression of both genes was found in the gills and blood of tissues involved in the immune response. The increased expression of DFF genes upon bacterial and viral stimulation was confirmed by qPCR analysis. DFFA/ICAD and DFFB/CAD of rock bream may play a pivotal role in apoptosis and may be involved in host immunity against bacterial and viral infection. [ABSTRACT FROM AUTHOR]

Arginine vasotocin (AVT) is a neurohypophysial hormone of non-mammal vertebrates functions in various physiological processes and homologous to mammal vasopressin. In this study, a full-length cDNA coding for a putative AVT precursor was isolated from flounder, Paralichthys olivaceus by rapid amplification of cDNA ends. It was 641 bp long, coding 153 amino acids, and consisted in 69 bp long 5′-untranslated region (UTR), 462 bp open reading frame and 110 bp 3′-UTR. The putative amino acid sequence of flounder AVT was determined, and compared with other AVTs from different species. Also, 1,447 bp of flounder AVT gene, corresponding to the isolated cDNA region with 2 introns within it, was isolated. Reverse transcription polymerase chain reaction result showed that flounder AVT was strongly expressed in the brain but not in the any other tissues examined, confirming it is brain-specific gene. Expression profile of the AVT, together with arylalkylamine N-acetyltransferase, heat shock protein 70, interferon-stimulated gene 15 and natural resistance-associated macrophage protein genes were surveyed from Streptococcus iniae infected flounders by real-time quantitative PCR. It revealed that flounder AVT is up-regulated under acute stress compared to the non-challenged control. [ABSTRACT FROM AUTHOR]

5G communication systems operating above 24 GHz have promising properties for user localization and environment mapping. Existing studies have either relied on simplified abstract models of the signal propagation and the measurements, or are based on direct positioning approaches, which directly map the received waveform to a position. In this study, we consider an intermediate approach, which consists of four phases—downlink data transmission, multi-dimensional channel estimation, channel parameter clustering, and simultaneous localization and mapping (SLAM) based on a novel likelihood function. This approach can decompose the problem into simpler steps, thus leading to lower complexity. At the same time, by considering an end-to-end processing chain, we are accounting for a wide variety of practical impairments. Simulation results demonstrate the efficacy of the proposed approach. [ABSTRACT FROM AUTHOR]

This work develops a deep-learning-based cooperative localization technique for high localization accuracy and real-time operation in vehicular networks. In cooperative localization, the noisy observation of the pairwise distance and the angle between vehicles causes nonlinear optimization problems. To handle such a nonlinear optimization task at each vehicle, a deep neural network (DNN) technique is to replace a cumbersome solution of nonlinear optimization along with the saving of the computational loads. Simulation results demonstrate that the proposed technique attains some performance gain in localization accuracy and computational complexity as compared to existing cooperative localization techniques. [ABSTRACT FROM AUTHOR]

Many cities are facing various water-related challenges caused by rapid urbanization and climate change. Moreover, a megacity may pose a greater risk due to its scale and complexity for coping with impending challenges. Infrastructure and governance also differ by the level of development of a city which indicates that the analysis of Integrated Water Resources Management (IWRM) and water governance are site-specific. We examined the status of IWRM of Seoul by using the City Blueprint® Approach which consists of three different frameworks: (1) Trends and Pressures Framework (TPF), (2) City Blueprint Framework (CBF) and (3) the water Governance Capacity Framework (GCF). The TPF summarizes the main social, environmental and financial pressures that may impede water management. The CBF assesses IWRM of the urban water cycle. Finally, the GCF identifies key barriers and opportunities to develop governance capacity. The results indicate that nutrient recovery from wastewater, stormwater separation, and operation cost recovery of water and sanitation services are priority areas for Seoul. Furthermore, the local sense of urgency, behavioral internalization, consumer willingness to pay, and financial continuation are identified as barriers limiting Seoul’s governance capacity. We also examined and compared the results with other mega-cities, to learn from their experiences and plans to cope with the challenges in large cities. [ABSTRACT FROM AUTHOR]