Constant Coverage Research Articles

Fronts in Minds: A Phenomenological Study on the Effects of War News on Collective Mental Health.

War has been recognized throughout history for its devastating effects on societies, and these effects have not been limited to physical destruction. In the modern era, even wars in remote regions have profound psychological effects on large masses due to the instant information transfer brought about by globalization and technology. This study aims to examine in depth the effects of exposure to war news on the collective mental health of individuals through a phenomenological approach. In this qualitative study using a phenomenological research design, one of the purposive sampling methods, criterion sampling, was employed. Face-to-face in-depth interviews lasting approximately 35-45 min were conducted with 20 participants. Colaizzi's phenomenological analysis method was used to analyze the obtained data. Data were collected according to COREQ criteria. According to the analysis results, three main categories emerged as follows: echoes of collective anxiety, keys to maintaining spiritual resilience, and navigating the media storm. This research provides important findings on the psychological and social effects of the media by examining the impact of war news on public mental health in depth. It was determined that war news has the potential to spread social anxiety and fear. Participants expressed the negative effects of war news on psychological and physical health and stated that this situation creates a wide wave of anxiety and psychological storms. The constant coverage of war news in the media also affects social empathy, shaping society's ability to support each other in times of crisis.

Monitoring the Amazon River plume from satellite observations

ABSTRACT Most of our knowledge about the Amazon River plume is limited from the field experiments or modeling due to various challenges for satellite remote sensing, i.e., constant cloud coverage, atmospheric correction, and difficulties to differentiate the Amazon River plume from normal Atlantic Ocean water. In this study, observations of ocean properties from the Visible Infrared Imaging Radiometer Suite (VIIRS) and sea surface salinity (SSS) from the Soil Moisture Active Passive (SMAP) missions in 2021 are used as an example to demonstrate the capability to monitor the Amazon River plume on daily basis and characterize the change of the ocean environment driven by the offshoots and migration of the plume in the western tropical Atlantic Ocean. The start, development, evolvement, dispersion, and dissipation of the Amazon River plume in 2021 in the western tropical Atlantic Ocean were effectively monitored. The extensive influence of the Amazon River runoff mostly occurred between June and November. The water diffuse attenuation coefficient at 490 nm (K d (490)) and SSS were significantly impacted by the Amazon River plume in the vast region of the western tropical Atlantic Ocean. The routes of the Amazon River plume that flowed into the Atlantic Ocean were highly variable. High turbidity, low salinity plume water with K d (490) reaching ~1.0 m−1 and SSS ~25 practical salinity unit (psu) was found in a region over 500 km from the Amazon River Estuary. The comparison of the Amazon River plume in 2020 and 2022 further shows the complication of the driving forcing and inter-annual variability of the Amazon River plume. The combination of gap-free satellite ocean color and SSS observations provided a new tool to monitor the short-term variability of the Amazon River plume and assess its seasonal and interannual impact on the ocean environment in the western tropical Atlantic Ocean.

Calcined Nickel Oxide Nanostructures at Different Temperatures Onto Graphite for Efficient Electro‐Oxidation of Ethylene Glycol in Basic Electrolyte

ABSTRACTFabricating a highly active and stable nanocatalyst material displays a great concern when constructing a commercially viable ethylene glycol (EG) fuel cell. Herein, nickel oxide nanostructures were grown onto graphite (NO/T) using coprecipitation and calcination protocol at different temperatures. Techniques for XRD, TEM, SEM, and EDX investigations were used to look into the produced crystal planes, shape, and elemental mapping of synthesized nickel oxide nanoparticles. Different NO/T nanocatalyst electroactivities were examined in order to oxidize EG molecules in basic electrolyte. The surface area values of calcined nanostructures at 200°C and 300°C were much higher than those measured at NO/T‐400 by 7.62 and 3.71 folds to explain their outstanding performance. Some kinetic information for varied NO/T nanocatalysts was derived including the electron transfer coefficient, rate constant, and surface coverage values. Electron transfer rate constants of 0.1946, 0.3734, 0.0113, and 0.0303 s−1 were calculated at NO/T‐200, NO/T‐300, NO/T‐400, and NO/T‐500, respectively. Increased oxidation current densities could be achieved when NO/T nanomaterials were subjected to lowered calcination temperatures. NO/T‐200 and NO/T‐300 nanocatalysts also displayed decreased Eonset for alcohol oxidation process by 20 and 41 mV in relation to that at NO/T‐400. Moreover, chronoamperometric experiments revealed the prevalence of the stable behavior during EG oxidation at these nanostructures, especially for calcined ones at 200°C and 300°C. Much reduced poisoning rates were measured at NO/T‐200 (0.171 s−1) and NO/T‐300 (0.067 s−1) when contrasted to that at NO/T‐500 (0.727 s−1). Increasing the alcohol and supporting electrolyte concentrations was beneficial in improving the charge transfer characteristics of NO/T nanocatalysts as demonstrated by EIS measurements. This study supports the promising activity of NiO nanoparticles onto graphite as anode materials for direct alcohol fuel cells.

Preparation and investigation of two-component silica-modified hydrophobic layer for minimizing retention loss of reversed-phase chromatographic columns using fully aqueous mobile phases

Chromatographers often employ fully aqueous mobile phases to retain highly polar compounds in reversed-phase liquid chromatography (RPLC). However, when the flow rate is interrupted, either accidentally or intentionally, a substantial loss in retention occurs due to the spontaneous dewetting of water from the hydrophobic surface of conventional RPLC-C18 particles. Previous studies have shown that maintaining a low C18 surface coverage (approximately 1.5 μmol/m2) can mitigate water dewetting by increasing chain disorder, facilitating the intercalation of water clusters between the C18-bonded chains, and keeping the mesopores wetted. In this research, we explore the potential and additional benefits of using two-component surface bonding materials (C8/C18 and PhenylHexyl (PhHx)/C18) at a constant and low total surface coverage of 1.51 ± 0.15 μmol/m2. We synthesized seven one- and two-component modified silica particles with a volume average particle size of 5.22 μm and an average mesopore size of 104 Å. The surface coverage was increased from 0 to 0.54, 1.00, and to 1.66 μmol2 for C8 chains and from 0 to 0.52, 0.70, and to 1.65 μmol2 for PhHx ligands. To prevent interactions between water and any unreacted silanols, all seven derivatized particles were heavily endcapped with trimethylsilane (TMS) reagent. The fraction of the surface area remaining in contact with water was determined by measuring the retention times of weakly (thiourea) and strongly (thymine) retained compounds at intervals of 1, 2, 4, 8, 16, 32, and 64 minutes following the cessation of flow. Two distinct column temperatures, 24°C and 60°C, were employed in the experiments. Retention losses were found to be minimized in the presence of a small quantity of C8 chains (less than 40% of the total surface coverage). Additionally, it is essential to consider substantial fractions of PhHx chains, as long as the presence of the PhHx ligand does not significantly impact retention and selectivity. Combining mixed RPLC bondings with a low total surface coverage of approximately 1.5 μmol/m2 emerges as a viable solution for further minimizing retention loss in standard C18-bonded RPLC columns, particularly within the surface coverage range of 2.5-3.0 μmol/m2.

Reaction intermediates recognized by in situ FTIR spectroscopy in CO2 hydrogenation over the Cu/ZnO/SPP-zeolite catalyst

SPP was used to confine the nanosized (2–8 nm) Cu/ZnO composite. The Cu surfaces maintains a constant carbonate coverage and low H2O adsorption during the reaction, while carbonyls and formates are rapidly formed and converted.

Nationwide urban ground deformation in Japan for 15 years detected by ALOS and Sentinel-1

InSAR time series analysis has become a major tool for nationwide land deformation monitoring. Sentinel-1 SAR data have enabled us to measure and monitor ground deformation globally with high accuracy and resolution through InSAR time series analysis, due to its constant and frequent global coverage and open data policy since 2014. Although several datasets from previous SAR satellites were available before Sentinel-1, such comprehensive deformation monitoring was not performed due to several limitations such as data quality, analysis technique, data policy, and processing capacity at that time. However, since a large amount of ALOS InSAR products and an open-source InSAR time series analysis tool LiCSBAS have become openly and freely available, we can easily derive the deformation from 2006 to 2011 by using them. In this study, we detected the deformation time series and velocity in all major urban areas in Japan from 2006 to 2011 and compared the results with the deformation from 2014 to 2020 detected by Sentinel-1 data. The two deformation datasets with different time periods revealed various 15-year deformation histories, such as long-term constant subsidence in Tomakomai and Niigata, changes in deformation areas and/or velocities in Hirosaki, Kujyukuri, Kanazawa, and Matsushiro, and appearance or disappearance of deformation in Joso, Yoyogi, and Kyoto. Future abundant and continuous SAR data acquisitions will reveal more long-term deformation transitions and help to understand the details of the mechanisms.

Exploring the limits of spatiotemporal and design-based index standardization under reduced survey coverage

Abstract Indices of abundance derived from fisheries-independent surveys play a crucial role in sustainable fisheries management. While design-based methods provide unbiased indices in theory, logistical constraints may introduce biases in practice. Spatiotemporal models offer potential for mitigating such bias, but their limitations remain poorly understood. In this study, we compare the performance of model-based and design-based indices using 200 simulated populations representing two virtual species. We simulate stratified-random surveys under various scenarios, including constant effort and coverage, reduced set density, and reduced spatial coverage (e.g. closed areas). We consider three closed-area scenarios: no population recovery, population recovery, and population recovery with spillover. With consistent survey coverage, correctly specified spatiotemporal models demonstrated comparable bias, accuracy, and confidence interval coverage to design-based methods. Spatiotemporal models incorporating appropriate covariates and observation families could mitigate the impact of reduced spatial coverage. However, poorly specified models were sometimes outperformed by design-based methods. Our results, therefore, highlight the potential for spatiotemporal models to mitigate the effects of survey effort reduction on population assessment and the provision of scientific advice. However, they also present a cautionary tale about the critical importance of model evaluation and comparison.

Identifying Adsorbed OH Species on Pt and Ru Electrodes with Surface-Enhanced Infrared Absorption Spectroscopy through CO Displacement.

OH adspecies are involved in numerous electrocatalytic reactions, such as CO, H2, methanol, and ethanol oxidation and oxygen reduction reactions, as a reaction intermediate and/or reactant. In this work, we have, for the first time, identified the OH stretching band of OH adspecies on Pt, Ru, and Pt/Ru electrodes with surface-enhanced infrared absorption spectroscopy (SEIRAS) in a flow cell through potential modulation and CO displacement. We found that while Ru had a relatively constant OH coverage at potentials between 0.1 and 0.8 V, Pt had a maximum OH coverage at 0.6 V in 0.1 M HClO4 and 0.7 V in 0.1 M KOH. CO oxidation kinetics on Ru were sluggish, although adsorbed OH appeared on Ru at very low potentials. Binary Pt/Ru electrodes promote CO oxidation through a synergistic effect in which Ru promotes OH adsorption and Pt catalyzes the reaction between the CO and OH adspecies. In addition, water coadsorbed with CO at Ru sites of Pt/Ru also plays an important role. These new spectroscopic results about OH adspecies could advance the understanding of the mechanism of fuel cell related electrocatalysis.

Gradient Microstructure and Properties of Surface Mechanical Attrition–Treated AZ91D Alloy: An Effect of Colliding Balls Velocity

The surface properties of the AZ91D alloy are altered using surface mechanical attrition treatment (SMAT), a promising method of severe surface deformation, where the role of process parameters is crucial. In this study, specimens are SMATed using ≈3 and ≈10 m s−1 ball velocities (maintaining a constant percentage coverage). The SMATed specimens show higher twin density near the surface, which is reduced gradually, and twin thickness is increased with increasing depth. Further, high‐velocity balls cause more twin density and better grain refinement (≈32 nm grain size at the surface). The higher ball velocity helps form a considerably thicker gradient layer (≈3500 μm) with higher hardness (≈1.98 GPa) and compressive residual stress (≈281 MPa) within a shorter SMAT duration (≈10 min). Ball velocity also influences nanomechanical properties such as nanohardness, creep resistance, strain rate sensitivity (SRS), etc. The non‐SMATed alloy's SRS is about 0.037–0.040. The gradient microstructure affects SRS. The SRS value near the SMATed surface (where the reduced grain size plays a dominating role) is about 0.018–0.027; however, it drops suddenly to ≈0.01 (with a slight increase in depth), and subsequently, it rises with an increased distance in the SMATed layer (where twins play a dominating role).

The thermo-aerodynamic performance of turbulent channel flow over dimples of different sizes

Dimples were introduced as a passive method for heat transfer enhancement and a potential drag reduction tool. However, besides the flow parameters, dimples have several design parameters that control their thermal and dynamic performance. To find the optimal design to improve dimples' performance, each parameter's effect has to be investigated. In this study, we show the effect of different dimples' sizes and flow Reynolds numbers on heat transfer and drag performance of a turbulent channel flow. Wall-resolved Large Eddy Simulation has been used to simulate the flow over the dimples fitted only on the bottom wall of the channel. The flow is simulated over three different sizes with dimensionless diameters D+=2.5, 4π/3, and 5 along with three different friction Reynolds numbers Reτ ≅180, 395, and 590. The dimples are arranged in a staggered form with smooth rounded edges of radius equal to half dimple's base radius along with constant maximum allowable coverage ratio and depth-to-diameter ratio of 5%. The thermo-aerodynamic performance of the cases under study shows an increase in drag for all the cases but accompanied by heat transfer enhancement. The thermo-aerodynamic efficiency, represented in area and volume goodness factors, shows an increase up to around 2%, and 6.8% compared to the flat channel, respectively, with the area goodness factor to be affected by the dimple size more than Reynolds number.

Bayes-optimal prediction with frequentist coverage control

This article illustrates how indirect or prior information can be optimally used to construct a prediction region that maintains a target frequentist coverage rate. If the indirect information is accurate, the volume of the prediction region is lower on average than that of other regions with the same coverage rate. Even if the indirect information is inaccurate, the resulting region still maintains the target coverage rate. Such a prediction region can be constructed for models that have a complete sufficient statistic, which includes many widely-used parametric and nonparametric models. Particular examples include a Bayes-optimal conformal prediction procedure that maintains a constant coverage rate across distributions in a nonparametric model, as well as a prediction procedure for the normal linear regression model that can utilize a regularizing prior distribution, yet maintain a frequentist coverage rate that is constant as a function of the model parameters and explanatory variables. No results in this article rely on asymptotic approximations.

Standard-state entropies and their impact on the potential-dependent apparent activation energy in electrocatalysis

The apparent activation energy, Eapp, is a common measure in thermal catalysis to discuss the activity and limiting steps of catalytic processes on solid-state materials. Recently, the electrocatalysis community adopted the concept of Eapp and combined it with the Butler-Volmer theory. Certain observations though, such as potential-dependent fluctuations of Eapp, are yet surprising because they conflict with the proposed linear decrease in Eapp with increasing overpotential. The most common explanation for this finding refers to coverage changes upon alterations in the temperature or the applied electrode potential. In the present contribution, it is demonstrated that the modulation of surface coverages cannot entirely explain potential-dependent oscillations of Eapp, and rather the impact of entropic contributions of the transition states has been overlooked so far. In the case of a nearly constant surface coverage, these entropic contributions can be extracted by a dedicated combination of Tafel plots and temperature-dependent experiments.

Fabrication and modeling of laser ablated NiO nanoparticles decorated SnO2 based formaldehyde sensor

In this study, we have reported the fabrication of p-NiO/n-SnO2 heterojunction based formaldehyde (HCHO) sensor by decorating the surface of pre-deposited SnO2 thin film with laser ablated NiO nanoparticles (NPs). In atmospheric air, NiO NPs were produced by a moving laser beam on the surface of pure (99.99%) Ni pellet to decorate sputtered deposited SnO2 thin film directly to form NiO/SnO2 p-n heterojunction. After fabrication, gas sensing properties of NiO/SnO2 sensor were investigated systemically towards HCHO and it exhibited higher response (Ra/Rg) of about 31.04 towards 50 ppm HCHO at 210 °C with good selectivity compared with pristine SnO2 sensor. Moreover, adsorption (Ka) and desorption rate constant (Kd), response time (τres), recovery time (τrec) and surface coverage (θ) of NiO/SnO2 sensor were extracted from experimental data using Langmuir gas adsorption-desorption model via curve fitting method and the models demonstrated the irreversible type of gas sensing behaviour towards HCHO. The experimental results revealed that the laser ablation method has a great potential to use as alternative chemical free surface decoration route to fabricate metal oxide heterojunction based sensors for the detection of formaldehyde or other toxic gases.

Modeling the Transmission Dynamics of Hepatitis A with Combined Vaccination and Sanitation Mitigation.

A mathematical model for the Hepatitis A Virus (HAV) epidemiology with dual transmission mechanisms is developed and presented. The model considers vaccination and sanitation as mitigation strategies. The effective reproductive number was derived and employed to study the stability of the model. Using Routh's stability criteria, the local stability of a disease-free equilibrium was determined, whereas the global stability of the endemic equilibrium was attained through a suitable Lyapunov function. Furthermore, bifurcation analysis is carried out using the centre manifold theory to ascertain its nature and implication for disease control. It was revealed that the model exhibits a forward bifurcation indicating the possibility of disease eradication when the effective reproduction number is kept below unity. Numerical results indicate that infection rates decrease quantitatively when at least one control measure is effectively implemented. It was deduced that combining vaccination and sanitation yields even fewer cases, making it the best alternative for eliminating Hepatitis A (HA) infection from the community. A sensitivity analysis was conducted to ascertain the parameters of the strong influence that could significantly affect the system. It was revealed that constant recruitment and vaccination coverage were the most critical parameters affecting the system. In addition, the study found that direct transmission plays an essential role in the occurrence of HA infection. In contrast, indirect transmission contributes marginally but significantly to the prevalence of HA infection.

TOWARDS MORE RESILIENT SMART CITIES: MT-InSAR MONITORING OF URBAN INFRASTRUCTURE USING MACHINE LEARNING TECHNIQUES

Abstract. Global climate change makes the maintenance and resilience of cities one of the greatest challenges facing civilization. Constant monitoring is essential work to determine if the city and its infrastructure are well preserved. This monitoring has become increasingly simple and affordable, thanks to the advancement of technology, so the current trend is to systematically monitor the entire city (this concept is the paradigm of the smart city). There are several methods for infrastructure monitoring including GPS, mobile-mapping, video-surveillance, etc. However, this type of method has a series of disadvantages, such as the impossibility of obtaining large-scale data or the unavailability of information of the previous, current or after state that an event has occurred in the study-area. This can be solved with monitoring based on satellite images, since these have historical and constant coverage over time, with good resolution to identify urban structures and cover large study areas. The use of satellite radar images through MT-InSAR is booming because it is a powerful remote sensing technique capable of detecting displacements on the earth's surface. This technique can be combined with Machine-Learning to perform predictive analysis in urban environments and detect infrastructure failures. This predictive monitoring capable of anticipating risks is one of the objectives of the new urbanism. For this reason, this work analyzes the collapse of a pier, which occurred in Vigo, a city in NW Spain, through radar satellite images (Sentinel-1), MT-InSAR and Machine-Learning. The result is the possibility of anticipating structural failures thanks to the predictive monitoring.

Understanding the Origin of Gas Transport Resistance in Fuel Cell Catalyst Layers

For the widespread use of proton exchange membrane fuel cells (PEMFCs), cost reduction of the stack is indispensable. For this purpose, it is effective to reduce the use of Pt and other cell components by reducing the cell area with a high-power density of the cell while reducing the use of Pt catalyst per geometric area. However, automobile manufacturers have reported that reducing the amount of Pt used per geometric area increases the resistance of gas transport in the catalyst layer, resulting in greater performance loss during high power generation.(1-3) This gas transport resistance is found to be inversely proportional to the electrochemical Pt surface area per geometric area (ECSA), and is considered to stem from near the Pt surface.(4) Previously, our group proposed a mechanism in which a high-density layer of ionomer formed at the ionomer / Pt interface is the cause of the increase in gas transport resistance at a low Pt content (low Pt area) based on the analysis of oxygen transport resistance using a microelectrode and the molecular dynamics calculation.(5-9) In this presentation, we report the results of investigating the origin of gas transport resistance in the cathode catalyst layer (CL) using CLs with a low Pt loading using Vulcan® as the catalyst support. In the case of a catalyst layer using a solid carbon support such as Vulcan®, the resistance can be divided into two categories: resistance independent of pressure and Pt surface area (Knudsen diffusion resistance in secondary pores formed among carbon particles) and resistance independent of pressure and dependent on Pt surface area (resistance near Pt surface). We modified a method of Katayama et al.,(10) which uses CO to control the ECSA of an identical catalyst layer and measures the limiting current of oxygen reduction reaction, and examined a method of separating the Knudsen diffusion resistance and the resistance near Pt using the limiting current of hydrogen oxidation reaction.(11) Furthermore, this technique was applied to catalyst layers with different ionomer-to-carbon weight ratios with a constant ionomer coverage to separate the contribution of gas transport resistance in the ionomer from that at the ionomer / Pt interface. This electrochemical analysis revealed that the gas transport resistance at the interface of ionomer and Pt surface is dominant in the range of practical ionomer-to-carbon weight ratio. The small contribution of the secondary pores was supported by a microscopic model of the porous CL. In this analysis, the microscopic secondary porous model was reconstructed from 3-dimensional scanning electron microscopy (3D-SEM) images, and the molecular and Knudsen oxygen diffusion in the reconstructed model was simulated. The combined analyses indicate that the ionomer-Pt interfacial structure is a key for the design of the cathode CL. Y. Ono, T. Mashio, S. Takaichi, A. Ohma, H. Kanesaka and K. Shinohara, ECS Trans., 28, 69 (2010). N. Nonoyama, S. Okazaki, A. Z. Weber, Y. Ikogi and T. Yoshida, Journal of The Electrochemical Society, 158, B416 (2011). T. A. Greszler, D. Caulk and P. Sinha, Journal of the Electrochemical Society, 159, F831 (2012). A. Kongkanand and M. F. Mathias, J Phys Chem Lett, 7, 1127 (2016). R. Jinnouchi, K. Kudo, K. Kodama, N. Kitano, T. Suzuki, S. Minami, K. Shinozaki, N. Hasegawa and A. Shinohara, Nat Commun, 12, 4956 (2021). R. Jinnouchi, K. Kudo, N. Kitano and Y. Morimoto, Electrochimica Acta, 188, 767 (2016). K. Kudo, R. Jinnouchi and Y. Morimoto, Electrochimica Acta, 209, 682 (2016). T. Suzuki, K. Kudo and Y. Morimoto, Journal of Power Sources, 222, 379 (2013). T. Suzuki, H. Yamada, K. Tsusaka and Y. Morimoto, Journal of the Electrochemical Society, 165, F166 (2018). S. Katayama and S. Sugawara, Journal of Power Sources, 483, 229178 (2021). T. Schuler, A. Chowdhury, A. T. Freiberg, B. Sneed, F. B. Spingler, M. C. Tucker, K. L. More, C. J. Radke and A. Z. Weber, Journal of the Electrochemical Society, 166, F3020 (2019).

The DNA Storage Channel: Capacity and Error Probability Bounds

The DNA storage channel is considered, in which the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$M$ </tex-math></inline-formula> Deoxyribonucleic acid (DNA) molecules comprising each codeword are stored without order, sampled <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$N$ </tex-math></inline-formula> times with replacement, and then sequenced over a discrete memoryless channel. For a constant coverage depth <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$M/N$ </tex-math></inline-formula> and molecule length scaling <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Theta (\log M)$ </tex-math></inline-formula> , lower (achievability) and upper (converse) bounds on the capacity of the channel, as well as a lower (achievability) bound on the reliability function of the channel are provided. Both the lower and upper bounds on the capacity generalize a bound which was previously known to hold only for the binary symmetric sequencing channel, and only under certain restrictions on the molecule length scaling and the crossover probability parameters. When specified to binary symmetric sequencing channel, these restrictions are completely removed for the lower bound and are significantly relaxed for the upper bound in the high-noise regime. The lower bound on the reliability function is achieved under a universal decoder, and reveals that the dominant error event is that of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">outage</i> – the event in which the capacity of the channel induced by the DNA molecule sampling operation does not support the target rate.

Impact of Polymer Liners on Crosstalk Induced Delay of Different TSV Shapes

The performance of a through silicon via (TSV) based 3D integrated circuit technology is primarily dependent on the choice of an appropriate liner material. The most commonly used liner material, SiO2, is undergoing considerable reliability challenges such as coefficient of thermal expansion (CTE) mismatch, scallop formation, and interfacial delamination related problems. Therefore, TSVs employed with a polymer liner have achieved significant attention in recent years due to their low dielectric constant and excellent step coverage along the via surface that can effectively reduce thermal stress and crosstalk induced delay. This paper presents a comprehensive and accurate RLGC model for different via shapes, considering the impact of various liner materials on the crosstalk induced delay. Considering an accurate via geometry and material properties at 32 and 45 nm technology, the proposed equivalent RLGC parameters include the cumulative effects of TSV metal, liner, bump, and the silicon substrate. The aforementioned parameters are used to model a novel T-type equivalent electrical network of cylindrical, tapered, and coaxial TSVs considering a coupled driver-via-load (DVL) setup. The proposed equivalent models of different via shapes are used to demonstrate the worst-case crosstalk induced delay in TSVs under the influence of various liner materials. Considering a tapered TSV, a significant improvement in crosstalk induced delay at 32 nm w.r.t. 45 nm technology is observed as 53.5%, 33.76%, and 19.12% at aspect ratios of 2.4, 3, and 4, respectively for the BCB liner.

Analysis of multitemporal compositing techniques from regular and non-regular intervals using MODIS daily images in the Amazon region with a high percentage of cloud cover

One challenge in the study of optical remotely sensed time series in the Amazon is the constant cloud cover. The present study evaluates different compositing techniques using regular and non-regular intervals to obtain cloud-free images over large areas. The study area was the municipality of Capixaba in the State of Acre, belonging to the Amazon region. The tests considered four compositing algorithms (maximum, minimum, mean, and median) for daily MODIS sensor data (b1 and b2, 250m). The compositing technique from regular intervals adopted the following periods: 8, 16, 24, 32, 40, and 48 days. The irregular interval composite images adopted different composition intervals for dry seasons (April to September) and rainy (October to March). The cloud mask and viewing angle constraint allowed to obtain information without atmospheric interference and closest to nadir view. The composite images using regular intervals did not allow to overcome the high frequency of cloud cover of the region. The composite images from non-regular intervals presented a higher percentage of cloud-free pixels. The mean and median methods provided the better visual appearance of the images, corroborating with the homogeneity test. Therefore, composite images from non-regular intervals may be an appropriate alternative in places with constant cloud coverage.

Laminar transpiration cooling experiments in hypersonic flow

The mixing between the coolant and the boundary-layer gas downstream of an injector—for transpiration/film cooling—has been extensively studied for turbulent flows; however, only a handful of studies concerning laminar mixing exist, particularly in hypersonic flows. In this paper, the concentration of the coolant gas at the wall and the heat flux reduction downstream of a transpiring injector in a hypersonic laminar flow are experimentally measured and examined. Experiments are performed in the Oxford High Density Tunnel at Mach 7. A flat-plate model is coated with pressure-sensitive paint (PSP) to spatially resolve the film and obtain a film effectiveness based on coolant concentration. Thin-film arrays are installed to measure the heat flux reduction. Six different cases are studied featuring nitrogen and helium as the coolant gas, where the blowing ratio is varied from 0.0406% to 0.295%. The unit Reynolds number of the flow is 12.9times 10^6;mathrm {m^{-1}}. A coolant concentration of up to 95% is achieved immediately (2 mm) downstream of the injector. The film concentration drops in a monotonic fashion farther downstream; however, a constant film coverage of 5–20 mm immediately downstream of the injector is observed in cases with a higher blowing ratio. A film coverage above 15% over three injector lengths is present even for the lowest blowing ratio. Heat flux reduction is achieved in all cases. The concentration effectiveness obtained from PSP is compared with the thermal film effectiveness calculated from the heat flux reduction. The latter is found to be higher than the former for all data points. Finally, a collapse of the thermal effectiveness is achieved and a modified analytical correlation is proposed.Graphical abstract