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91.
This paper reports an innovative development: concentrating gibbsite via reverse froth flotation in order to obtain a metallurgical-grade bauxite concentrate. Tailings from an industrial plant have undergone attrition scrubbing and desliming; the quartz silica contained in the tailings has undergone flotation. Starch was used as a depressant, and ether-amine as the cationic collector. Optimum pH is around 10.0. In pilot plant scale, a metallurgical-grade concentrate was obtained by assaying 42.3% available alumina with an alumina/insoluble silica mass ratio of 11.1. It contained the gibbsite and the iron and titanium bearing minerals. The concentrate was further upgraded by magnetic separation, leading to 54.0% available alumina, with an alumina/insoluble silica mass ratio of 12.6 at an overall available alumina recovery of 69.3% in the final concentrate (non-magnetic product). 相似文献
92.
Humberto César Chaves Fernandez José de Ribamar Silva Oliveira Attílio José Giarola 《Journal of Infrared, Millimeter and Terahertz Waves》1991,12(5):505-519
The Transverse Transmission Line method is used for the characterization of bilateral and unilateral finlines on a semiconductor substrate and in conjunction with the modal method, for the calculation of the scattering parameters due to a step discontinuity on a unilateral finline with a lossless dielectric substrate. Numerical results of the effective dielectric constant, attenuation constant and characteristic impedance for the bilateral and unilateral finlines on semiconductor substrates, and results of scattering parameters of a step discontinuity for unilateral finline, are presented. 相似文献
93.
94.
Examined the effects of losing and regaining or gaining and relosing body weight in weight cycling (WC) vs weight maintenance (WM) on metabolic control. Ss were 327 adult male outpatient veterans (mean age 62.8 yrs) with non–insulin-dependent diabetes mellitus who were followed an average of 3.4 yrs. When compared with WM, WC, whether defined as a categorical or as a continuous variable, was not associated with deficits in metabolic control or increased need for hypoglycemic medication. Ss who weight cycled had fasting serum glucose and hemoglobin A1c levels comparable to those who remained within 10% of their initial body weights, and these levels of metabolic control were obtained with similar classes and dosages of hypoglycemic medication. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
95.
Ryan G. McClarren D. RyuR. Paul Drake Michael GrosskopfDerek Bingham Chuan-Chih ChouBruce Fryxell Bart van der HolstJames Paul Holloway Carolyn C. KuranzBani Mallick Erica RutterBen R. Torralva 《Reliability Engineering & System Safety》2011,96(9):1194-1207
This work discusses the uncertainty quantification aspect of quantification of margin and uncertainty (QMU) in the context of two linked computer codes. Specifically, we present a physics based reduction technique to deal with functional data from the first code and then develop an emulator for this reduced data. Our particular application deals with conditions created by laser deposition in a radiating shock experiment modeled using the Lagrangian, radiation-hydrodynamics code Hyades. Our goal is to construct an emulator and perform a sensitivity analysis of the functional output from Hyades to be used as an initial condition for a three-dimensional code that will compute the evolution of the radiating shock at later times. Initial attempts at purely statistical data reduction techniques, were not successful at reducing the number of parameters required to describe the Hyades output. We decided on an alternate approach using physical arguments to decide what features/locations of the output were relevant (e.g., the location of the shock front or the location of the maximum pressure) and then used a piecewise linear fit between these locations. This reduced the number of outputs needed from the emulator to 40, down from the O(1000) points in the Hyades output. Then, using Bayesian MARS and Gaussian process regression, we were able to build emulators for Hyades and study sensitivities to input parameters. 相似文献
96.
Roth MJ Plymire DA Chang AN Kim J Maresh EM Larson SE Patrie SM 《Analytical chemistry》2011,83(24):9586-9592
The compatibility of superficially porous (SP) resin for label-free intact protein analysis with online capillary LC/MS is demonstrated to give improved chromatographic resolution, sensitivity, and reproducibility. The robustness of the platform was measured against several samples of varying complexity and sample loading amount. The results indicate that capillary SP columns provide high loading capacities and that ~6 s chromatographic peak widths are typical for standard proteins in simple mixtures and proteins isolated from cell and tissue lysates. Subfemtomole detection limits for standard proteins were consistently observed, with the lowest levels at 12 amol for ubiquitin. The analysis of total heart homogenates shows that capillary SP columns provide theoretical peak capacity of 106 protein forms with 30 min total analysis time and enabled detection of proteins from complex mixtures with a single high-resolution scan. The SPLC/MS platform also detected 343 protein forms from two HeLa acid extract replicate analyses that consumed 5 × 10(4) cells and 30 min analysis time, each. Comparison of all the species observed in each HeLa replicate showed 90% overlap (309 forms) with a Pearson correlation coefficient of 89.9% for the common forms observed in the replicates. Efficient acid extract of 1 × 10(4) HeLa cells allowed reproducible detection of common modification states and members from all five of the histone families and demonstrated that capillary SPLC/MS supports reproducible label-free profiling of histones in <15 min total analysis time. The data presented demonstrate that a capillary LC/MS platform utilizing superficially porous stationary phase and a LTQ-Orbitrap FT-MS is fast, sensitive, and reproducible for intact protein profiling from small tissue and cell amounts. 相似文献
97.
Damiano Caputo Erica Quagliarini Daniela Pozzi Giulio Caracciolo 《International journal of molecular sciences》2022,23(18)
In recent years nanotechnology has opened exciting opportunities in the struggle against cancer. In 2007 Dawson and coworkers demonstrated that nanomaterials exposed to biological fluids are coated with plasma proteins that form the so-called “protein corona”. A few years later our joint research team made of physicists, chemists, biotechnologists, surgeons, oncologists, and bioinformaticians introduced the concept of “personalized protein corona” and demonstrated that it is unique for each human condition. This concept paved the way for the development of nano-enabled blood (NEB) tests for the diagnosis of pancreatic ductal adenocarcinoma (PDAC). These studies gave an impetus to serious work in the field that came to maturity in the late 2010s. In this special issue, we provide the reader with a comprehensive overview of the most significant discoveries of our research team in the field of PDAC detection. We focus on the main achievements with an emphasis on the fundamental aspects of this arena and how they shaped the integration of different scientific backgrounds towards the development of advanced diagnostic technologies. We conclude the review by outlining future perspectives and opportunities to transform the NEB tests into a reliable clinical diagnostic technology for early diagnosis, follow-up, and management of PDAC patients. 相似文献
98.
Benjamin T. Lobel Casey A. Thomas Peter M. Ireland Erica J. Wanless Grant B. Webber 《Advanced Powder Technology》2021,32(6):1823-1832
Liquid marbles may be traditionally formed by rolling a droplet on a bed of non-wetting particles resulting in encapsulation and stabilisation. Particles used in this process may range from nanometre to millimetre if handled with sufficient care. This method, however, runs the risk of droplet coalescence and is limited to non-wetting particles. Currently there exist some alternative methods of formulation including using electrostatics to either deliver a particle bed to the droplet or pull the droplet to the particles. The former has shown some promise in potential batch processes but is hindered by interparticle forces. Additional production methods include a form of blender, but this has shown to be unable to produce marbles of a narrow size distribution. Once formed, liquid marbles have demonstrated value as potential blood typing devices, as micro-reaction vessels due to the inherent barrier between the internal phase and the substrate whilst maintaining gas permeability, and as contaminant sensors. Liquid marbles also demonstrate a remarkable level of elasticity under compressive force and reduced evaporation rates when compared to bare water droplets, a function of the size and composition of the stabilising particles. In addition to this, liquid marbles have been proposed as actuators. Locomotion may easily be induced in these structures, using electrostatics, sound, magnetism or light depending on the particle/liquid combinations used in formation, and the environment of deployment. This review seeks to present and summarise recent advances in the field of liquid marble manufacture and methods for actuation. We also aim to highlight potential future avenues of further study within this arena. 相似文献
99.
C Chaves Lopez L Vannini R Lanciotti ME Guerzoni 《Canadian Metallurgical Quarterly》1998,61(8):994-999
BACKGROUND: The role of nitric oxide in the ischemia/reperfusion injury of the pancreas is still unclear. In other organs, protective as well as aggravating effects have been described. We have, therefore, investigated the effect of the nitric oxide donor sodium nitroprusside on pancreatic ischemia/reperfusion injury. METHODS: In Landrace pigs, after transsection of the pancreas, complete vascular isolation of the pancreatic tail was performed. The tail was subjected to 3 hr of warm ischemia and thereafter reperfusion (6 hr). The animals were divided into a control group (n=7) and a treatment group (n=7) that received 15 mg of sodium nitroprusside after reperfusion intra-arterially into the splenic artery. RESULTS: The morphological tissue damage and lipase activity in the venous effluent of the pancreas were significantly lower in the treatment group. Partial oxygen tension in the tissue after reperfusion was markedly reduced in the control group, indicating an impairment of microcirculation. In the treatment group, however, partial oxygen tension in the tissue was significantly higher (43 vs. 20 mmHg; P<0.014). Furthermore, total blood flow through the pancreatic tail in the treatment group was found to be significantly higher in the late reperfusion period (14 vs. 9.5 ml/min at 5 hr after reperfusion; P<0.05). CONCLUSION: There is a marked impairment of pancreatic microcirculation after reperfusion. Sodium nitroprusside counteracts this impairment and has a protective effect on ischemia/reperfusion injury of the pancreas. 相似文献
100.