Correlation between the golden ratio and nanowire transistor performance

An observation was made in this research regarding the fact that the signatures of isotropic charge distributions in silicon nanowire transistors (NWT) displayed identical characteristics to the golden ratio (Phi). In turn, a simulation was conducted regarding ultra-scaled n-type Si (NWT) with respect to the 5-nm complementary metal-oxide-semiconductor (CMOS) application. The results reveal that the amount of mobile charge in the channel and intrinsic speed of the device are determined by the device geometry and could also be correlated to the golden ratio (Phi). This paper highlights the issue that the optimization of NWT geometry could reduce the impact of the main sources of statistical variability on the Figure of Merit (FoM) of devices. In the context of industrial early successes in fabricating vertically stacked NWT, ensemble Monte Carlo (MC) simulations with quantum correction are used to accurately predict the drive current. This occurs alongside a consideration of the degree to which the carrier transport in the vertically stacked lateral NWTs are complex

Does a Nanowire Transistor Follow the Golden Ratio? A 2D Poisson-Schrödinger/3D Monte Carlo Simulation Study

In this work, we observed the signatures of isotropic charge distributions showing the same attributes as the golden ratio (Phi) described in art and architecture, we also present a simulation study of ultra-scaled n-type silicon nanowire transistors (NWT) for the 5nm CMOS application. Our results reveal that the amount of mobile charge in the channel is determined by the device geometry and could also be related to the golden ratio (Phi). We also established a link between the main device characteristics, such as a drive and leakage current, and cross-sectional shape and dimensions of the device. We discussed the correlation between the main Figure of Merit (FoM) and the device variability and reliability

Feedbacks Among Climate, Soils, Vegetation, and Erosion Drive Valley Asymmetry Development in the Mountains of Central Idaho

Aspect has long been recognized as a significant source of landscape variability, which is induced by the orientation of land surfaces relative to solar incidence. Insolation differences on opposing aspects (e.g., north and south-facing slopes) act as localized climatic perturbations, altering surface energy balances and temperatures. Over shorter timescales, aspect-induced changes to the energy balance alter snow pack dynamics, soil water input rates and seasonality, and plant available water and water stress. Over longer timescales, aspect-induced insolation variability affects bedrock weathering rates and depths, soil and regolith development, vegetation type and density, erosion rates and processes, and ultimately hillslope and drainage forms. In turn, differences in landscape evolution on the opposite sides of valleys lead to valley asymmetry development. The primary goals of this work are to 1) summarize available aspect-related hydrologic, ecologic and pedologic data for the Dry Creek Experimental Watershed (DCEW), fill knowledge gaps by investigating aspect-related differences in geomorphic characteristics and processes, and develop an integrative conceptual framework for how landscapes respond to aspect-induced insolation variability and how valley asymmetry develops. In particular, we assess 1) how aspect drives differences in fire and erosion rates, 2) how critical zone characteristics vary with aspect and how aspect-sensitivity changes with elevation, and 3) how aspect-related differences in critical zone response alter runoff production, drainage incision, and catchment competition, which drive valley asymmetry development. Surprisingly, erosion rates for north and south-facing catchments do not appear to have varied significantly during the Holocene, despite dramatic differences in landscape characteristics (e.g., vegetation cover, soils, hydrologic processes, and landforms). This suggests that the valley asymmetry has not been actively developing, and is a relict feature of either initial landscape response to aspect, or specific climate intervals (e.g., glacial periods). Erosion rates for the margin of the Idaho batholith are lower than those in the interior batholith, reflecting lower rates of incision. Elevation appears to modify the sensitivity of landscapes to aspect-induced climate perturbation. Critical zone properties appear to be most sensitive to aspect-induced climate perturbation at lower elevations (~1,100 m), and aspect-sensitivity diminishes towards higher elevations (~2,100 m). Changes in precipitation and temperature with increasing elevation appear to alleviate moisture stress, causing aspect-induced insolation and temperature variability to have less of an effect. Reduced landscape sensitivity to aspect at higher elevations explains why previously mapped slope asymmetry diminishes towards these elevations throughout the region. Drainage incision and expansion are more pronounced on south-facing valley sides. South-facing catchments have shallower, coarser soils that yield more runoff per unit drainage area. Changes to the water balance at pedon-scales appear to influence how fluvial process scale with drainage area, which impacts catchment-scale erosive efficiency. Enhanced drainage incision in south-facing catchments, in conjunction with more effective diffusive erosion, appears to have promoted divide migration and land surface elongation. Importantly, land surface degradation and elongation reduce geomorphic gradients, which serve as negative feedbacks by reducing denudation differences between north and south-facing valley sides, and effectively drive valley asymmetry development towards dynamic equilibrium. This suggests that although valley asymmetry clearly reflects differences in past erosion, it may actually develop as a landscape response to counteract aspect-induced differences in erosion. Where valley asymmetry is most pronounced, we suspect there may be little difference in rates of erosion. Valley asymmetry may be a remotely measurable characteristic of landscapes that reflect their proximity to stable states

Finite element analysis of polymer-encapsulated ZnO nanowire-based sensor array intended for pressure sensing in biometric applications

This work presents results of finite element analysis of an array of ZnO nanowires with bottom-bottom electrode configuration, which are integrated onto a multi-layer chip stack and encapsulated within a polymer. The dynamically-deformed array constitutes a representative part of a high-resolution pressure sensor intended for reliable identification of the smallest fingerprint features such as shape of the ridges and pores. Parametric study was performed in order to predict the most rational values of the Young's modulus and thickness of the encapsulation layer in terms of magnitude and variability of the piezoelectric signals. The results also demonstrate the impact of nanowire aspect ratio and load orientation on the generated electrical signals

Probabilistic representations in perception: Are there any, and what would they be?

Nick Shea’s Representation in Cognitive Science commits him to representations in perceptual processing that are about probabilities. This commentary concerns how to adjudicate between this view and an alternative that locates the probabilities rather in the representational states’ associated “attitudes”. As background and motivation, evidence for probabilistic representations in perceptual processing is adduced, and it is shown how, on either conception, one can address a specific challenge Ned Block has raised to this evidence

Simulations of Contrail Optical Properties and Radiative Forcing for Various Crystal Shapes

The aim of this study is to investigate the sensitivity of radiative-forcing computations to various contrail crystal shape models. Contrail optical properties in the shortwave and longwave ranges are derived using a ray-tracing geometric method and the discrete dipole approximation method, respectively. Both methods present good correspondence of the single-scattering albedo and the asymmetry parameter in a transition range (3–8 µm). There are substantial differences in single-scattering properties among 10 crystal models investigated here (e.g., hexagonal columns and plates with different aspect ratios, and spherical particles). The single-scattering albedo and the asymmetry parameter both vary by up to 0.1 among various crystal shapes. The computed single-scattering properties are incorporated in the moderate-resolution atmospheric radiance and transmittance model(MODTRAN) radiative transfer code to simulate solar and infrared fluxes at the top of the atmosphere. Particle shapes have a strong impact on the contrail radiative forcing in both the shortwave and longwave ranges. The differences in the net radiative forcing among optical models reach 50% with respect to the mean model value. The hexagonal-column and hexagonal-plate particles show the smallest net radiative forcing, and the largest forcing is obtained for the spheres. The balance between the shortwave forcing and longwave forcing is highly sensitive with respect to the assumed crystal shape and may even change the sign of the net forcing. The optical depth at which the mean diurnal radiative forcing changes sign from positive to negative varies from 4.5 to 10 for a surface albedo of 0.2 and from 2 to 6.5 for a surface albedo of 0.05. Contrails are probably never that optically thick (except for some aged contrail cirrus), however, and so will not have a cooling effect on climate

Topographic controls on the invasion of Pteronia incana (Blue bush) onto hillslopes in Ngqushwa (formerly Peddie) district, Eastern Cape, South Africa

The role of topographic factors in the invasion of hillslopes by Pteronia incana, an unpalatable shrub, was investigated. The study combined field observations with image analysis based on high-resolution infrared imagery. A Digital Elevation Model (DEM) of 20 m spatial resolution was used to derive terrain parameters. The Topographic Wetness Index (WI), a component of the TOPMODEL, was derived from the DEM and its relationship with the spatial distribution of P. incana was explored. The absence/presence of P. incana was noted to be strongly influenced by slope angle and aspect. The probability for P. incana occurrence increased with slope steepness and southerly slope orientation. Abandoned and grazing lands were identified as the main invasion hotspots on hillslopes. The combined influence of slope gradient and aspect, and land use was noted to have promoted the invasion. This is borne out by the concentration of the invasion on abandoned steep slopes with a southerly orientation. The WI confirmed the bearing local topographic variations have on P. incana spatial distribution such that, P. incana was associated with the low WI values of convexities. The coupling between local topography and soil surface crusting underpins soil moisture variability. This in turn determines the competition between the patchy P. incana and grass species and the eventual replacement of the latter by the former. Restoration efforts of the invaded lands should focus on trapping of sediment and litter, and moisture retention on the inter-patch bare areas