Improving processing by adaption to conditional geostatistical simulation of block compositions

Exploitation of an ore deposit can be optimized by adapting the beneficiation processes to the properties of individual ore blocks. This can involve switching in and out certain treatment steps, or setting their controlling parameters. Optimizing this set of decisions requires the full conditional distribution of all relevant physical parameters and chemical attributes of the feed, including concentration of value elements and abundance of penalty elements. As a first step towards adaptive processing, the mapping of adaptive decisions is explored based on the composition, in value and penalty elements, of the selective mining units. Conditional distributions at block support are derived from cokriging and geostatistical simulation of log-ratios. A one-to-one log-ratio transformation is applied to the data, followed by modelling via classical multivariate geostatistical tools, and subsequent back-transforming of predictions and simulations. Back-transformed point-support simulations can then be averaged to obtain block averages that are fed into the process chain model. The approach is illustrated with a \u27toy\u27 example where a four-component system (a value element, two penalty elements, and some liberable material) is beneficiated through a chain of technical processes. The results show that a gain function based on full distributions outperforms the more traditional approach of using unbiased estimates

Integrin expression profiling identifies integrin alpha5 and beta1 as prognostic factors in early stage non-small cell lung cancer

<p>Abstract</p> <p>Background</p> <p>Selection of early stage non-small cell lung cancer patients with a high risk of recurrence is warranted in order to select patients who will benefit from adjuvant treatment strategies. We evaluated the prognostic value of integrin expression profiles in a retrospective study on frozen primary tumors of 68 patients with early stage non-small cell lung cancer.</p> <p>Methods</p> <p>A retrospective study was performed on frozen primary tumors of 68 early stage non-small cell lung cancer patients with a follow up of at least 10 years. From all tumor tissues, RNA was isolated and reverse transcribed into cDNA. qPCR was used to generate mRNA expression profiles including integrins alpha1, 2, 3, 4, 5, 6, 7, 11, and V as well as integrins beta1, 3, 4, 5, 6, and 8.</p> <p>Results</p> <p>The expression levels of integrins alpha5, beta1 and beta3 predicted overall survival and disease free survival in early stage NSCLC patients. There was no association between integrin expression and lymph node metastases. Comparison between the histological subtypes revealed a distinct integrin signature for squamous cell carcinoma while the profiles of adenocarcinoma and large cell carcinoma were largely the same.</p> <p>Conclusion</p> <p>Integrin expression in NSCLC is important for the development and behavior of the tumor and influences the survival of the patient. Determining the integrin expression profile might serve as a tool in predicting the prognosis of individual patients.</p

Silicon Supported Membranes for Improved Large-Area and High-Density Micro/Nanostencil Lithography

In this paper, the fabrication and use of stencils for full-wafer scale shadow mask (stencil) lithography is described. The stencils fabricated via microelectromechanical systems are mechanically stabilized and show clearly reduced stress-induced membrane deformation, which translates into a more accurate surface pattern definition. Solid-state SiN membranes 500 nm thick and up to 1 mm2 in size having a 20- m-thick silicon support rim following the outline of the stencil apertures were fabricated in a 100-mm Si wafer. The minimum aperture size presented in this paper is 3 m. The increase of membrane stability was confirmed by depositing a highly stressed 35-nm-thick chrome layer. The results demonstrate a stability increase of the Si-supported compared to nonsupported membrane with identical shape by up to 89% as measured by the reduced out-of-plane deflection of overhanging membrane sections. Comparison by scanning electron microscopy and atomic force microscopy of the resulting micropatterns obtained by Cr deposition through both unsupported and Si-rim supported stencils shows better edge sharpness and clearer spatial details for surface patterns deposited through the stabilized stencil compared to those deposited through the nonsupported stencil. The improved stabilized stencils allow for large-area high-density surface patterning while maintaining membrane stability and pattern definition during stencil lithography

Stochastic simulation of soil particle-size curves in heterogeneous aquifer systems through a Bayes space approach

We address the problem of stochastic simulation of soil particle-size curves (PSCs) in heterogeneous aquifer systems. Unlike traditional approaches that focus solely on a few selected features of PSCs (e.g., selected quantiles), our approach considers the entire particle-size curves and can optionally include conditioning on available data. We rely on our prior work to model PSCs as cumulative distribution functions and interpret their density functions as functional compositions. We thus approximate the latter through an expansion over an appropriate basis of functions. This enables us to (a) effectively deal with the data dimensionality and constraints and (b) to develop a simulation method for PSCs based upon a suitable and well defined projection procedure. The new theoretical framework allows representing and reproducing the complete information content embedded in PSC data. As a first field application, we demonstrate the quality of unconditional and conditional simulations obtained with our methodology by considering a set of particle-size curves collected within a shallow alluvial aquifer in the Neckar river valley, Germany

Complex oxide nanostructures by pulsed laser deposition through nanostencils

We achieved parallel nanoscale patterning of ferroelectric complex oxides by pulsed laser deposition through a nanostencil (i.e., through a pattern of apertures in a thin free-standing membrane). Ordered arrays of nanostructured barium titanate (BaTiO3) were obtained onto different substrates in a single deposition step, at room temperature, replicating accurately the aperture patterns in the stencil membrane. After a postdeposition annealing treatment, x-ray diffraction pattern showed a nanocrystalline BaTiO3 structure close to the perovskite cubic phase with grains 30-35 nm in size. Their local ferroelectric properties were detected using piezoresponse force microscopy

Reverse transfer of nanostencil patterns using intermediate sacrificial layer and lift-off process

We propose a new process by which patterns produced by nanostencil lithography can be reversed, so that the final pattern on the substrate has the same contrast (filled or empty) as that of the stencil. In this process, the stencil pattern is first formed on an intermediate sacrificial layer, and then transferred onto the underlying substrate in a reverse manner. Using this process, we can form various pattern structures that cannot be produced by the normal stencil process, such as an array of pores or multiple parallel bridges. Because a bridge in the stencil is transferred also as a bridge on the substrate, we can not only avoid the widening of a narrow bridge pattern by the stress-induced bending of the membrane, but also reduce the width of the bridge even further using the pattern blurring. Using SiO2 as an intermediate layer, we have fabricated various reversed Cr patterns on Si, including an array of 800 nm circular pores and a 100-nm-wide and 150-nm-long nanobridge

Reusability of nanostencils for the patterning of Aluminum nanostructures by selective wet etching

One of the major advantages of stencil lithography is the possibility to use stencils many times. However, when stencils contain nanoapertures, the clogging of the membranes limits the useful life time of the stencils. The clogging is due to the accumulation of material deposited inside the apertures of the stencil. Here, we report a study on the effect of the clogging on the life time of stencils after Al depositions through the stencils. Then we present a method to clean the stencils based on Al wet etching to eliminate the clogging. We show that this method allows the reusability of stencils for the repeatable depositions of Al nanostructures

Corrugated membranes for improved pattern definition with micro/nanostencil lithography

We present a MEMS process for the fabrication of arbitrary (adaptable to specific aperture geometries) stabilization of silicon nitride membranes to be used as miniature shadow masks or (nano) stencils. Stabilization was realized by the fabrication of silicon nitride corrugated support structures integrated into large-area thin-film solid-state membranes. These corrugated support structures are aimed to reduce the membrane deformation due to the deposition-induced stress and thus to improve the dimensional control over the surface patterns created by stencil lithography. We have performed physical vapor deposition (PVD) of chromium on unstabilized (standard) stencil membranes and on stabilized (corrugated) stencil membranes to test the proposed stabilization geometry. Both the membrane deformation and the surface structures were analyzed, showing reduced deformation and improved pattern definition for the stabilized stencil membranes. The structures have been modeled using a commercial finite element method (FEM) software tool. The simulation and experimental results confirm that introducing stabilization structures in the membrane can significantly (up to 94%) reduce out-of-plane deformations of the membrane. The results of this study can be applied as a guideline for the design and fabrication of mechanically stable, complex stencil membranes for direct deposition

Provenance report regarding Singalees kanon of Lewuke’s kanon

Colonial and Global Histor