Preliminary Reduction Research Articles

CYCLIC DEFORMATION UNIT FOR CONTINUOUS SLABS REDUCTION

The usage of units with high reduction in the casting and rolling module would allow to improve the quality of the mill products due to intensive processing of bulk continuous cast slabs along the section and obtainment of homogeneous fi ne-grained metal structure, as well as to increase the cross-section of the continuous cast slab. The analysis of the formation causes of nonmetallic inclusions and liquates in the axial zone of thick-plate steel was carried out. The analysis of the deformation unevenness along the slab height during the reduction of large continuous cast slabs was performed at mill 5000 of JSC “Magnitogorsk Metallurgical Plant”. The design is described and the technological possibilities for defi nition of the cyclical deformation are presented for the preliminary deformation of continuous cast slabs. The technology is described and the parameters of the strikers for preliminary deformation of large continuous slabs were determined. The experimental study results of the deformation process of continuous cast slabs of steel 45 and steel 12Cr18Ni10Ti are given. The evaluation of the structure of continuous cast metal in the process of reduction of continuous cast billets at a cyclic deformation facility was carried out. The main parameters of the installation for preliminary deformation of large continuous cast slabs were determined. The technological possibilities of the installation for cyclic deformation were stated in terms of the essential improvement of the quality of sheet blanks. Based on the analysis of technological possibilities, it was proposed to use the cyclic deformation installation in the continuous casting line for preliminary reduction of large continuous cast slabs in order to fully adjust the speed of continuous casting and cyclic deformation and provision of the one-pass reduction with the degree of deformation 45 – 90 % to obtain a good casting structure along the slab cross-section. It was suggested, when using the installation in the line of a continuous casting machine, to perform reduction of continuous cast slabs using the heat of the cast metal, thereby substantially reducing the energy consumption in the technological process of producing the sheet blanks. The use of a cyclic deformation installation in the lines of thick-plate and wideband mills for preliminary deformation of heated slabs in one pass is proposed, which will improve the quality of sheet blanks and reduce the number of passes in rolling mills.

Conversion of bio-oxygenates into hydrocarbons in the presence of a commercial Pt–Re/Al2O3 catalyst

It was found that the preliminarily reduced commercial platinum–rhenium catalyst PR-71 exhibited high activity in the conversion of ethanol into C4–C12 olefins and in the cross-condensation reactions of ethanol with glycerol, acetone, n-propanol, and isopropanol. Acetone and glycerol exhibited the highest reactivity in the cross-condensation reactions; this manifested itself in an increase in the total yield of the target fraction of C4–C12 hydrocarbons and in a more than 10-fold increase in the yield of products containing the odd numbers of carbon atoms, as compared with the conversion of individual ethanol. The structural studies performed by extended X-ray absorption fine structure (EXAFS) spectroscopy and transmission electron microscopy showed that the high selectivity of PR-71 can be caused by the formation of bimetallic Pt–Re and Pt–Al clusters in the course of the prolonged preliminary reduction of the catalyst.

Calculation of electric conductivity of water of the Aral Sea and correction of the sound salinity of 2002–2009

The Aral Sea is an important water area both for monitoring and oceanological studies, because its salinity and salt composition strongly differ from the oceanic. We offer a semiempiric calculation method of electric conductivity and the coefficient of its temperature dependence k judging from the ionic composition of water. The properties of the solution are considered as the sum of properties of seven binary salts taken based on the ionic composition of the solution. The MgSO4 concentration is thought to be the highest possible, which makes the salt concentration nearly unambiguous. In a salinity range of 46–120‰ and temperature range of 5–25°C (2002–2009), the standard deviation of the calculated and measured electric conductivity was 2.9%. To refine the calculation of salinity from electric conductivity measurements using the “oceanic” formula, we suggest its preliminary reduction to a constant temperature (20°C) using the measured or calculated coefficient k.

Testing the Predictor Effect on a Functional Response

ABSTRACTThis article examines the problem of nonparametric testing for the no-effect of a random covariate (or predictor) on a functional response. This means testing whether the conditional expectation of the response given the covariate is almost surely zero or not, without imposing any model relating response and covariate. The covariate could be univariate, multivariate, or functional. Our test statistic is a quadratic form involving univariate nearest neighbor smoothing and the asymptotic critical values are given by the standard normal law. When the covariate is multidimensional or functional, a preliminary dimension reduction device is used, which allows the effect of the covariate to be summarized into a univariate random quantity. The test is able to detect not only linear but nonparametric alternatives. The responses could have conditional variance of unknown form and the law of the covariate does not need to be known. An empirical study with simulated and real data shows that the test performs well in applications. Supplementary materials for this article are available online.

HST HOT-JUPITER TRANSMISSION SPECTRAL SURVEY: CLEAR SKIES FOR COOL SATURN WASP-39b

ABSTRACT We present the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) optical transmission spectroscopy of the cool Saturn-mass exoplanet WASP-39b from 0.29-1.025 μm, along with complementary transit observations from Spitzer IRAC at 3.6 and 4.5 μm. The low density and large atmospheric pressure scale height of WASP-39b make it particularly amenable to atmospheric characterization using this technique. We detect a Rayleigh scattering slope as well as sodium and potassium absorption features; this is the first exoplanet in which both alkali features are clearly detected with the extended wings predicted by cloud-free atmosphere models. The full transmission spectrum is well matched by a clear H2-dominated atmosphere, or one containing a weak contribution from haze, in good agreement with the preliminary reduction of these data presented in Sing et al. WASP-39b is predicted to have a pressure-temperature profile comparable to that of HD 189733b and WASP-6b, making it one of the coolest transiting gas giants observed in our HST STIS survey. Despite this similarity, WASP-39b appears to be largely cloud-free, while the transmission spectra of HD 189733b and WASP-6b both indicate the presence of high altitude clouds or hazes. These observations further emphasize the surprising diversity of cloudy and cloud-free gas giant planets in short-period orbits and the corresponding challenges associated with developing predictive cloud models for these atmospheres.

Catalysts of Suzuki Cross-Coupling Based on Functionalized Hyper-cross-linked Polystyrene: Influence of Precursor Nature

This paper describes synthesis of Pd-containing catalysts of Suzuki cross-coupling based on amino-functionalized hyper-cross-linked polystyrene at variation of Pd precursor nature (PdCl2, PdCl2(CH3CN)2, or PdCl2(PhCN)2). The investigation of the influence of palladium oxidation state (Pd(II) or Pd(0)) and form (Pdn clusters or Pd nanoparticles) on the rate of Suzuki cross-coupling of 4-bromoanisole and phenylboronic acid is discussed. Developed catalysts are shown to allow achieving conversion of 4-bromoanisole higher than 98% under mild reaction conditions. Independently of the precursor nature, Pd(II) is mainly responsible for observed catalytic activity. However, preliminary reduction of catalysts with H2 results in formation of a large number of Pdn clusters, the contribution of which in the Suzuki reaction becomes predominant.

Roughness effect for tunable wetting surfaces on metallic substrate

A facile process for controllable fabrication of wetting surfaces with variable hierarchical structures on metallic substrates is proposed in this study. This process, which combines the through-mask electrochemical micromachining with hydrothermal growth method, could be applied on all kinds of type and size of conductive metal. First, the anodic dissolution process is predicted using numerical simulation and experiments. The formulation of electrolyte and the etching conditions in through-mask electrochemical micromachining are optimized. Ordered microstructures and smooth etched surface in large scale are obtained using the optimized parameters. Moreover, a technology has been explored to obtain various styles of multi-level structures through an alignment system or combining with a hydrothermal method of growing ZnO nanorods. The wetting effects of the rough three-dimensional surfaces are evaluated using a contact angle system. Furthermore, the wetting and the preliminary friction reduction effects of the rough three-dimensional surfaces are evaluated using contact angle system.

Multiscale descriptors and metric learning for human body shape retrieval

The aim of this paper was to show the usefulness of applying feature projection or metric learning techniques to multiscale descriptor spaces for the effective retrieval of human bodies of labeled subjects. Using learned subspace projections it is possible to strongly improve the retrieval performance obtained with state-of-the-art global descriptors, and, in some cases, to perform an effective feature fusion. Results obtained on different human scan datasets show that Linear Discriminant Analysis, applied to Histograms of Area Projection Transform and Shape DNA features after a preliminary dimensionality reduction, creates compact descriptors that are quite effective in improving the subject retrieval scores both when class (subject) examples are available in the training set and when only examples of classes not included in the test set are used for training. Other mappings tested are less effective even if still able to improve the results. Retrieval scores obtained in the same experimental settings used in recent related papers show that the approach based on our mapped features largely outperforms the other methods proposed for the task, even those specifically designed for human body characterization.

Optimization of two-phased anaerobic sludge digestion using the pressurized ultra filtration membrane with a mesh screen (MS-PUFM)

To alleviate problems of membrane bioreactors with membrane fouling control, the optimization of the two-phased anaerobic mesophilic bioreactors coupling with the MS-PUFM system was evaluated. The chemical oxygen demand (COD) removal efficiency of anaerobic sludge digestion with the MS-PUFM system was raised from 40% to 97%. VFA concentration was sustained to be in the range 110–138mgL−1, which was within the optimum range. In the methanogenic bioreactor, methane generation was improved due to the effective reduction of methanogene washout with the MS-PUFM system, and the optimum operating pressure of the MS-PUFM system resulted less than 3kgfcm−2. Mesh screen contributed 20% decrease of operating cost and 33% increase of permeate flux from 10 to 15Lm−2h−1 with preliminary solids reduction. As a result, the MS-PUFM system showed practical feasibilities for the digestion of sewage sludge, where current commercial system processes utilizing higher biomass density are not appropriate.

A Novel Enhanced-Oil-Recovery Screening Approach Based on Bayesian Clustering and Principal-Component Analysis

Summary We present and test a new screening methodology to discriminate among alternative and competing enhanced-oil-recovery (EOR) techniques to be considered for a given reservoir. Our work is motivated by the observation that, even if a considerable variety of EOR techniques was successfully applied to extend oilfield production and lifetime, an EOR project requires extensive laboratory and pilot tests before fieldwide implementation and preliminary assessment of EOR potential in a reservoir is critical in the decision-making process. Because similar EOR techniques may be successful in fields sharing some global features, as basic discrimination criteria, we consider fluid (density and viscosity) and reservoir-formation (porosity, permeability, depth, and temperature) properties. Our approach is observation-driven and grounded on an exhaustive database that we compiled after considering worldwide EOR field experiences. A preliminary reduction of the dimensionality of the parameter space over which EOR projects are classified is accomplished through principal-component analysis (PCA). A screening of target analogs is then obtained by classification of documented EOR projects through a Bayesian-clustering algorithm. Considering the cluster that includes the EOR field under evaluation, an intercluster refinement is then accomplished by ordering cluster components on the basis of a weighted Euclidean distance from the target field in the (multidimensional) parameter space. Distinctive features of our methodology are that (a) all screening analyses are performed on the database projected onto the space of principal components (PCs) and (b) the fraction of variance associated with each PC is taken as weight of the Euclidean distance that we determine. As a test bed, we apply our approach on three fields operated by Eni. These include light-, medium-, and heavy-oil reservoirs, where gas, chemical, and thermal EOR projects were, respectively, proposed. Our results are (a) conducive to the compilation of a broad and extensively usable database of EOR settings and (b) consistent with the field observations related to the three tested and already planned/implemented EOR methodologies, thus demonstrating the effectiveness of our approach.

High-selectivity partial oxidation of methane into synthesis gas: the role of the red-ox transformations of rare earth — alkali earth cobaltate-based catalyst components

La1+xSr1−xCoO4 (x=0; 0.25) and NdCaCoO3.96 compounds with a layered perovskite-like structure synthesized by the solid state method and characterized by XRD, XPS, EDAX and H2-TPR were used as catalyst precursors for the partial oxidation of methane to synthesis gas. Catalytic tests were carried out in a quartz flow reactor using a CH4/O2 mixture without dilution with inert gases. The higher activity of the NdCaCoO4±δ-based catalyst in comparison with La1+xSr1−xCoO4 is associated with the easier formation of Nd and Ca oxides and metallic cobalt in the course of NdCaCoO4±δ reduction in the POM environment. Preliminary reduction of the catalysts with hydrogen leads to a significant increase in synthesis gas production at 800–850°С. Different activity and selectivity of NdCaCoO4±δ and La1+xSr1−xCoO4-based catalysts can also be related to the different morphologies of metal-oxide nanocomposites that appear in the course of the reductive decomposition of cobaltates.

Integrated Optimal Fingerprinting: Method Description and Illustration

AbstractThe present paper introduces and illustrates methodological developments intended for so-called optimal fingerprinting methods, which are of frequent use in detection and attribution studies. These methods used to involve three independent steps: preliminary reduction of the dimension of the data, estimation of the covariance associated to internal climate variability, and, finally, linear regression inference with associated uncertainty assessment. It is argued that such a compartmentalized treatment presents several issues; an integrated method is thus introduced to address them. The suggested approach is based on a single-piece statistical model that represents both linear regression and control runs. The unknown covariance is treated as a nuisance parameter that is eliminated by integration. This allows for the introduction of regularization assumptions. Point estimates and confidence intervals follow from the integrated likelihood. Further, it is shown that preliminary dimension reduction is not required for implementability and that computational issues associated to using the raw, high-dimensional, spatiotemporal data can be resolved quite easily. Results on simulated data show improved performance compared to existing methods w.r.t. both estimation error and accuracy of confidence intervals and also highlight the need for further improvements regarding the latter. The method is illustrated on twentieth-century precipitation and surface temperature, suggesting a potentially high informational benefit of using the raw, nondimension-reduced data in detection and attribution (D&A), provided model error is appropriately built into the inference.

Measuring the Quality of Life of Visually Impaired Children: First Stage Psychometric Evaluation of the Novel VQoL_CYP Instrument.

PurposeTo report piloting and initial validation of the VQoL_CYP, a novel age-appropriate vision-related quality of life (VQoL) instrument for self-reporting by children with visual impairment (VI).MethodsParticipants were a random patient sample of children with VI aged 10–15 years. 69 patients, drawn from patient databases at Great Ormond Street Hospital and Moorfields Eye Hospital, United Kingdom, participated in piloting of the draft 47-item VQoL instrument, which enabled preliminary item reduction. Subsequent administration of the instrument, alongside functional vision (FV) and generic health-related quality of life (HRQoL) self-report measures, to 101 children with VI comprising a nationally representative sample enabled further item reduction and evaluation of psychometric properties using Rasch analysis. Construct validity was assessed through Pearson correlation coefficients.ResultsItem reduction through piloting (8 items removed for skewness and individual item response pattern) and validation (1 item removed for skewness and 3 for misfit in Rasch) produced a 35-item scale, with fit values within acceptable limits, no notable differential item functioning, good measurement precision, ordered response categories and acceptable targeting in Rasch. The VQoL_CYP showed good construct validity, correlating strongly with HRQoL scores, moderately with FV scores but not with acuity.ConclusionsRobust child-appropriate self-report VQoL measures for children with VI are necessary for understanding the broader impacts of living with a visual disability, distinguishing these from limited functioning per se. Future planned use in larger patient samples will allow further psychometric development of the VQoL_CYP as an adjunct to objective outcomes assessment.

Methanol dehydrogenation over Cu/SiO<SUB align="right">2 catalysts

Methanol dehydrogenation was carried out over impregnated Cu/SiO2 catalysts. It was found that the temperature of the catalyst's preliminary reduction by hydrogen could play a dramatic role. The interaction of copper ions with silica during the reduction at ≥300°C was observed. Metallic copper species obtained at low reduction temperature were found to be responsible for the methyl formate formation. The catalysts containing copper in the oxidised state showed low selectivity because of a side reaction of coke formation and were deactivated rapidly. The optimal temperature of reduction was found to be 250°C.

Способы повышения энергоэффективности электропривода стана холодной прокатки труб

Different ways to improve energy efficiency of electric drives of cold reducing mill are considered. Studies based on mathematical modelling result in quantitative evaluation of the energy saving. With the example of the KhPT-450 cold reducing mill, the dependence of the root-mean- square current of the motor armature of the main stand drive on the cutoff frequency of the speed loop has been obtained. The paper considers possible energy savings by means of preliminary motor field reduction before the rolling duty cycle. It defines points of field-reduction pulse supply and termination that are optimal for power saving. The paper specifies conditions for substantiation of correlated parameters of the dynamic units and changing operation schedule of the electric drive, thus, providing the greatest reduction of losses in the main drive of the cold reducing mill. These measures under consideration are aimed to improve energy efficiency of electric drives of these mills and reduce power consumption for a rolling cycle by 20–25 %.

Treatment of humerus supracondylar nonunion with pin and plate fixation as a simple device

Introduction Pin and plate fixation as an effective internal fixation for humerus supracondylar fracture has been introduced. It is especially useful in difficult cases with comminuted fractures or very low fracture line. We used this technique for treatment of difficult cases of humerus supracondylar nonunions and reviewed its results. Material and methods From October 2008 to September 2014, 27 patients with humerus supracondylar nonunion underwent open reduction and internal fixation with pin and plate in one or both column with or without bone grafting. Results and complications were evaluated. Surgical technique of pin and plate After preliminary reduction two or more 1.2 mm pin inserted cross nonunion site like a preliminary fixation. Pins were bent to be placed on the humeral posterior cortex, a 3.5 mm three or four holes reconstruction plate put on the pins and was fixed to humerus with two screws. In the cases with very small distal segment as an alternative, the pins inserted parallel to articular surface and were bent at both side and be placed on humerus as a delta frame and were fixed with a plate on them. Results In 6 years we had 27 patients with supracondylar humerus nonunion that pin and plate fixation was used as fixation device for one column in 12 of them and for both column in 15 of them. Age of the patients was 19 to 68 (mean 51) years. Union has been achieved in all of the cases but nonunion of olecranon osteotomy occurred in three patient till last follow-up and we had to remove the implants in 11 patients. Conclusion Pin and plate fixation is a simple and effective technique for fixation of the humeral supracondylar nonunions.

Calculation Method and Distribution Characteristics of Fracture Hydraulic Aperture from Field Experiments in Fractured Granite Area

Knowledge of the fracture hydraulic aperture and its relation to the mechanical aperture and normal stress is urgently needed in engineering construction and analytical research at the engineering field scale. A new method based on the in situ borehole camera measurement and borehole water-pressure test is proposed for the calculation of the fracture hydraulic aperture. This method comprises six steps. The first step is to obtain the equivalent hydraulic conductivity of the test section from borehole water-pressure tests. The second step is a tentative calculation to obtain the qualitative relation between the reduction coefficient and the mechanical aperture obtained from borehole camera measurements. The third step is to choose the preliminary reduction coefficient for obtaining the initial hydraulic aperture. The remaining three steps are to optimize, using the genetic algorithm, the hydraulic apertures of fractures with high uncertainty. The method is then applied to a fractured granite engineering area whose purpose is the construction of an underground water-sealed storage cavern for liquefied petroleum gas. The probability distribution characteristics of the hydraulic aperture, the relationship between the hydraulic aperture and the mechanical aperture, the hydraulic aperture and the normal stress, and the differences between altered fractures and fresh fractures are all analyzed. Based on the effects of the engineering applications, the method is proved to be feasible and reliable. More importantly, the results of the hydraulic aperture obtained in this paper are different from those results elicited from laboratory tests, and the reasons are discussed in the paper.

Multi-stage design space reduction and metamodeling optimization method based on self-organizing maps and fuzzy clustering

Design space exploration and metamodeling techniques have gained rapid dominance in complex engineering design problems. It is observed that the modeling efficiency and accuracy are directly associated with the design space. In order to reduce the complexity of the design space and improve modeling accuracy, a multi-stage design space reduction and metamodeling optimization methodology based on self-organizing maps and fuzzy clustering is proposed in this paper. By using the proposed three-stage optimization approach, the design space is systematically reduced to a relatively small promising region. Self-organizing maps are introduced to act as the preliminary reduction approach through analyzing the underlying mapping relations between design variables and system responses within the original samples. GK (Gustafson & Kessel) clustering algorithm is employed to determine the proper number of clusters by utilizing clustering validity indices, and sample points are clustered using fuzzy c-means (FCM) clustering method with the known number of clusters, so that the search can focus on the most promising area and be better supported by the constructed kriging metamodel. Empirical studies on benchmark problems with multi-humps and two practical nonlinear engineering design problems show the accurate results can be obtained within the reduced design space, which improve the overall efficiency significantly.

ChemInform Abstract: Rhodium Complexes in Homogeneous Catalytic Systems for Oxidative Functionalization of Alkanes: Experiment and Quantum‐chemical Calculations

AbstractReview: 71 refs.

Virtual Screening for HIV Protease Inhibitors Using a Novel Database Filtering Procedure.

A virtual screening to find novel inhibitors for HIV protease was performed on the ZINC database.1 A critical part in virtual screening and associated techniques is preliminary database filtering and size reduction and for that purpose a novel feature matrix matching procedure was used. The reduction of ∼14 million available ligands to a subset of 14299 ligands was achieved with a structure based approach where the analysis of the 3D structure of the active site of the protease produced a graph with hydrogen bond donor, hydrogen bond acceptor and hydrophobic subsites represented as graph nodes. A similar treatment was also applied to the compound database content and the comparison of binding site and ligand graphs was used to preselect potentially active ligands. The resulting set was further subjected to docking. The algorithm used was able to find several novel as well as previously known and experimentally tested ligands, demonstrating the validity of the approach.