Hydrogeological Analysis of Sulfide Tailings at a Uranium Mine Using Geophysical and Hydrochemical Methods

Mine Water and the Environment - A hydrogeological analysis was conducted of aquifer systems within a sulfide-rich tailings pile and underlying rocks at a uranium mine to understand the generation...     

Correction to: Strategic Assessment of Lisbon’s Accessibility and Mobility Problems from an Equity Perspective

Networks and Spatial Economics - A Correction to this paper has been published: https://doi.org/10.1007/s11067-021-09544-7     

The impact of sales and operations planning practices on manufacturing operational performance

There is a lack of rigorous empirical studies directly examining the impact of sales and operations planning (S&OP) practices on manufacturing operational performance. This paper aims to fill this gap by analysing a sample of 725 manufacturers from 34 countries. Hypotheses relate internal S&OP, integration with suppliers (IS) and integration with customers with manufacturing operational performance (delivery, quality and flexibility). The constructs were validated with structural equation modelling and the hypotheses were tested using multiple stepwise regression. Our findings showed a positive and moderate-to-large effect of internal S&OP on manufacturing performance, controlling for firm size, country economic development and market dynamics. There was no significant impact of supply chain integration on manufacturing performance. However, we found that IS positively moderated the relationship between internal S&OP and performance, suggesting that firms with mature IS amplify the effect of internal S&OP on performance. The study is among the first to empirically and rigorously establish the impacts of S&OP practices on manufacturing performance, using a large sample of manufacturers spanning different countries, markets and firm sizes. Results show that S&OP practices have a broad impact across several performance dimensions and are a powerful lever for generating manufacturing performance.     

Ledge-flow-controlled catalyst interface dynamics during Si nanowire growth

Self-assembled nanowires offer the prospect of accurate and scalable device engineering at an atomistic scale for applications in electronics, photonics and biology. However, deterministic nanowire growth and the control of dopant profiles and heterostructures are limited by an incomplete understanding of the role of commonly used catalysts and specifically of their interface dynamics. Although catalytic chemical vapour deposition of nanowires below the eutectic temperature has been demonstrated in many semiconductor-catalyst systems, growth from solid catalysts is still disputed and the overall mechanism is largely unresolved. Here, we present a video-rate environmental transmission electron microscopy study of Si nanowire formation from Pd silicide crystals under disilane exposure. A Si crystal nucleus forms by phase separation, as observed for the liquid Au-Si system, which we use as a comparative benchmark. The dominant coherent Pd silicide/Si growth interface subsequently advances by lateral propagation of ledges, driven by catalytic dissociation of disilane and coupled Pd and Si diffusion. Our results establish an atomistic framework for nanowire assembly from solid catalysts, relevant also to their contact formation.     

Effect of light on the concentration of ethyl carbamate in cachaça stored in glass bottles

This study sought to evaluate the influence of natural light on the concentration of ethyl carbamate (EC) in cachaças aged in wooden barrels and stored in glass bottles for a period of 6 months. The quantification of EC was achieved by HPLC using a fluorescence detector after previous derivation of the samples and standards with 9‐xanthydrol. All of the samples presented an EC concentration below the limit established by Brazilian legislation. The highest concentration found was 79.70 µg L^?1. As for the influence of light and storage period, 70% of the samples exhibited an influence of these parameters. Copyright © 2015 The Institute of Brewing & Distilling     

Contribution to future metropolitan access network planning considering link failures in photonic switched networks

Photonic switching for traffic optimization in Metropolitan Access Optical Networks using technologies of optical packet/burst switching (OPS/OBS) seems to be a future-proof solution considering high capacity and the highly variable traffic in these networks. Looking for this future, we propose a study based on the analyze of survivability of traffic unconsidering protection mechanism but considering mesh and ring efficient topologies with node architecture to OPS. The results are obtained through computer modeling and simulation. The main parameters analyzed are as follows: capacity, average number of hops, packet loss fraction, and link utilization for each topology. These parameters are adopted to evaluate the performance of each topology considering failures. Minimum electronic buffering is included at node ingress (client side) to avoid packet loss in the access to the optical layer: high throughput and low latency. It is also observed that optical buffering is not necessary for adequate network performance.