Large Number Of Components Research Articles

Overview of the applications of thermodynamic databases to steelmaking processes

Computerized thermodynamic databases for solid and liquid steel, slags and solid oxide solutions, for large numbers of components, have been developed over the last three decades by critical evaluation/optimization of all available phase equilibrium and thermodynamic data. The databases contain model parameters specifically developed for molten slags, liquid and solid steel and solid oxide solutions. With user-friendly software, which accesses these databases, complex chemical reactions and phase equilibria occurring throughout the steelmaking process can be calculated over wide ranges of temperature, oxygen potential and pressure. In the present article, the thermodynamic models and databases for molten slag and liquid steel included in well-known thermochemical packages and their applications to complex steelmaking processes involving molten slag, steel, inclusions, refractories and gases are reviewed.

Development of a matrix test board for capacitor reliability testing

For statistically reliable results, a large number of components must be tested. This research sought to find an efficient method to test the reliability of a large number of components; consequently, an 8 × 8 matrix test board was developed. On this test board, a failed component causes a voltage change in two measuring channels, enabling exact failure monitoring of several components by a reduced number of test channels. Commercial ceramic capacitors from seven different vendors and a test with overvoltage and high temperature were used to evaluate the test structure. The large amount of test data could then be statistically analyzed. Results proved this board to be an efficient way to test a large number of components.

Process-condition-driven Automatic Location of Components

In order to reduce the development cycle of mechanical products and corresponding toolings, a large number of components are utilized in these structures. Accordingly, automatic location method for components is a key issue in the research on intelligent computer aided design (CAD) techniques. Integrated with the investigation into intelligent design techniques for aircraft manufacturing toolings, in-depth researches on this issue are conducted. Formalized automatic location principles, representative methods and implementation algorithms are proposed and established. First, several terms and their formalized representative methods including process condition, location base and location operator are defined. Second, computation modeling of components automatic location and methods of location transformation are proposed. Then, definition of base structure and some key algorithms for automatic location are introduced. These principles and algorithms are developed, applied and verified in research project “Jig Intelligent CAD (JigICAD) System”.

Regenerable Multifunctional Sorbent Development for Sulfur and Chloride Removal from Coal-Derived Synthesis Gas

A large number of components in coal form corrosive and toxic compounds during coal gasification processes. These contaminants have to be reduced to the parts-per-million range to use the fuel gas in an integrated gasification combined cycle. Even more stringent requirements are expected if the fuel gas is to be used in fuel cell or chemical production applications. Impurity removal may be even more cost-effective if multiple impurities can be removed in a minimum number of steps. To accomplish this goal, a regenerable sorbent capable of removing both hydrogen chloride (HCl) and hydrogen sulfide (H2S) was investigated. The results of the thermogravimetric analyzer tests and bench-scale fixed-bed flow reactor tests conducted with the sorbent to evaluate the feasibility of both H2S and HCl sorption will be discussed in this paper.

Emergence of equilibrium thermodynamic properties in quantum pure states. II. Analysis of a spin model system

A system composed of identical spins and described by a quantum mechanical pure state is analyzed within the statistical framework presented in Part I of this work. We explicitly derive the typical values of the entropy, of the energy, and of the equilibrium reduced density matrix of a subsystem for the two different statistics introduced in Part I. In order to analyze their consistency with thermodynamics, these quantities of interest are evaluated in the limit of large number of components of the isolated system. The main results can be summarized as follows: typical values of the entropy and of the equilibrium reduced density matrix as functions of the internal energy in the fixed expectation energy ensemble do not satisfy the requirement of thermodynamics. On the contrary, the thermodynamical description is recovered from the random pure state ensemble (RPSE), provided that one considers systems large enough. The thermodynamic limit of the considered properties for the spin system reveals a number of important features. First canonical statistics (and thus, canonical typicality as long as the fluctuations around the average value are small) emerges without the need of assuming the microcanonical space for the global pure state. Moreover, we rigorously prove (i) the equivalence of the "global temperature," derived from the entropy equation of state, with the "local temperature" determining the canonical state of the subsystems; and (ii) the equivalence between the RPSE typical entropy and the canonical entropy for the overall system.

Two-layer multiplexed peristaltic pumps for high-density integrated microfluidics

The integration and operation of a large number of components is needed to enable ever more complex and integrated chemical and biological processes on a single microfluidic chip. The capabilities of these chips are often limited by the maximum number of pumps and valves that can be controlled on a single chip, a limitation typically set by the number of pneumatic interconnects available from ancillary hardware. Here, we report a multiplexing approach that greatly reduces the number of external pneumatic connections needed for the operation of a large number of peristaltic pumps. The utility of the approach is demonstrated with a complex microfluidic network capable of generating and routing liquid droplets in a two-phase flow. We also report a set of design rules for the design and operation of multiplexed peristaltic pumps, based on a study of the effect of the number of valves per pump and the valve-to-valve distance on the performance of peristaltic pumps. The multiplexing approach reported here may find application in a wide range of microfluidic chips for chemical and biological applications, especially those that require the integration of many different operations on a single chip and those that need to perform similar operations massively in parallel, in sub-nanoliter volumes.

Comprehensive description of the photodegradation of bromophenols using chromatographic monitoring and chemometric tools

A general procedure for the study of complex photodegradation processes of environmental pollutants based on chromatographic monitoring and chemometric method is proposed. The procedure consists of multiset data analysis of aliquots collected at different reaction times and injected in High-Performance Liquid Chromatography coupled to diode array detection and mass spectrometry (HPLC–DAD-MS). In this study, photodegradation of six bromophenols with different degrees of bromination has been investigated in order to find out their photodegradation pathways and kinetics and to show the potential of the procedure proposed. Multivariate curve resolution-alternating least squares (MCR-ALS) has been used to resolve chromatographic elution profiles and pure spectra of species involved in the photodegradation process and, hence, to elucidate the photodegradation mechanism and to propose the chemical structure of the main photoproducts. This study shows that chromatographic monitoring is the preferred option when photochemical systems with large number of components with similar spectra and kinetic evolution are analyzed. This work reveals the advantages of the double DAD and MS detection to provide mechanistic and structural information about these complex photodegradation processes.

Programmable matter by folding

Programmable matter is a material whose properties can be programmed to achieve specific shapes or stiffnesses upon command. This concept requires constituent elements to interact and rearrange intelligently in order to meet the goal. This paper considers achieving programmable sheets that can form themselves in different shapes autonomously by folding. Past approaches to creating transforming machines have been limited by the small feature sizes, the large number of components, and the associated complexity of communication among the units. We seek to mitigate these difficulties through the unique concept of self-folding origami with universal crease patterns. This approach exploits a single sheet composed of interconnected triangular sections. The sheet is able to fold into a set of predetermined shapes using embedded actuation. To implement this self-folding origami concept, we have developed a scalable end-to-end planning and fabrication process. Given a set of desired objects, the system computes an optimized design for a single sheet and multiple controllers to achieve each of the desired objects. The material, called programmable matter by folding, is an example of a system capable of achieving multiple shapes for multiple functions.

Complexity, collective effects, and modeling of ecosystems: formation, function, and stability

We discuss the relevance of studying ecology within the framework of Complexity Science from a statistical mechanics approach. Ecology is concerned with understanding how systems level properties emerge out of the multitude of interactions among large numbers of components, leading to ecosystems that possess the prototypical characteristics of complex systems. We argue that statistical mechanics is at present the best methodology available to obtain a quantitative description of complex systems, and that ecology is in urgent need of "integrative" approaches that are quantitative and nonstationary. We describe examples where combining statistical mechanics and ecology has led to improved ecological modeling and, at the same time, broadened the scope of statistical mechanics.

Gaussian decomposition of $\ion{H}{i}$ surveys

In the previous papers of this series, we have decomposed into Gaussian components all the HI 21-cm line profiles of the Leiden-Argentina-Bonn (LAB) database, and studied statistical distributions of the obtained Gaussians. Now we are interested in separation from the general database of the components the "clouds" of closely spaced similar Gaussians. In this paper we describe the new cloud-finding algorithm. To separate the clouds of similar Gaussians, we start with the single-link hierarchical clustering procedure in five-dimensional (longitude, latitude, velocity, Gaussian width and height) space, but make some modifications to accommodate it to the large number of components. We also use the requirement that each cloud may be represented at any observed sky position by only one Gaussian and take into account the similarity of global properties of the merging clouds. As a test, we apply the algorithm for finding the clouds of the narrowest HI 21-cm line components. Using the full sky search for cold clouds, we easily detect the coldest known HI clouds and demonstrate that actually they are a part of a long narrow ribbon of cold clouds. We model these clouds as a part of a planar gas ring, deduce their spatial placement, and discuss their relation to supernova shells in the solar neighborhood. We conclude that the proposed algorithm satisfactorily solves the posed task. We guess that the study of the narrowest HI 21-cm line components may be a useful tool for finding the structure of neutral gas in solar neighborhood.

Reliability analysis of defence vehicles gear box assembly under preventive maintenance

In the era of advancement in technology and global competitiveness the traditional maintenance practices have become obsolete. Also in recent years sophisticated and more advanced equipments have been augmented in the armed forces hence, the role of maintenance workshops/ engineers has become very challenging. Therefore, analyzing various maintenance issues and the associated risk has become very important in the armed forces. Preventive maintenance practices assist in improving the reliability of assemblies and how it will be effective for the equipments of armed forces is illustrated in this article. Gear box assembly used in the medium size vehicles are considered for the analysis and the failure data in various operating conditions is taken from the logbooks of the vehicles. For modeling purposes the Weibull distribution has been chosen (since it has practical utility-ability to model products/systems consisting of large number of components and may have increasing/decreasing or a constant failure rate). The result will be useful to the maintenance engineer to find the unreliability of the gear box assemblies and also for future strategic decision making. Keywords: Weibull distribution; reliability; preventive maintenance; strategic decision making.

Reliability Analysis of Defence Vehicles Gear Box Assembly under Preventive Maintenance

In the era of advancement in technology and global competitiveness the traditional maintenance practices have become obsolete. Also in recent years sophisticated and more advanced equipments have been augmented in the armed forces hence, the role of maintenance workshops/ engineers has become very challenging. Therefore, analyzing various maintenance issues and the associated risk has become very important in the armed forces. Preventive maintenance practices assist in improving the reliability of assemblies and how it will be effective for the equipments of armed forces is illustrated in this article. Gear box assembly used in the medium size vehicles are considered for the analysis and the failure data in various operating conditions is taken from the logbooks of the vehicles. For modeling purposes the Weibull distribution has been chosen (since it has practical utility-ability to model products/systems consisting of large number of components and may have increasing/decreasing or a constant failure rate). The result will be useful to the maintenance engineer to find the unreliability of the gear box assemblies and also for future strategic decision making.

Simplifying Mixture Models Through Function Approximation

The finite mixture model is widely used in various statistical learning problems. However, the model obtained may contain a large number of components, making it inefficient in practical applications. In this paper, we propose to simplify the mixture model by minimizing an upper bound of the approximation error between the original and the simplified model, under the use of the L (2) distance measure. This is achieved by first grouping similar components together and then performing local fitting through function approximation. The simplified model obtained can then be used as a replacement of the original model to speed up various algorithms involving mixture models during training (e.g., Bayesian filtering, belief propagation) and testing [e.g., kernel density estimation, support vector machine (SVM) testing]. Encouraging results are observed in the experiments on density estimation, clustering-based image segmentation, and simplification of SVM decision functions.

Toward failure analyses in systems biology

Parallels between designed and biological systems with respect to formal failure analyses have been presented. Failure analysis in designed systems depends on an identified, limited set of parameters or operation variables with high predictive value. In contrast, the biological systems pose problems in identification of operation variables and the identified variables may not be accurate predictors of failure. The difficulty in parameter identification is because of large numbers of components and the inability to envelope variables at each compartment or contour level. Contour level maps for biological systems are currently non-existent, and most failure models are based on very limited, unilateral operation variables (a mutant gene). Operation variable identification within each contour level will enhance failure analyses of complex biological systems.

Modeling Conditional Densities Using Finite Smooth Mixtures

Smooth mixtures, i.e. mixture models with covariate-dependent mixing weights, are very useful flexible models for conditional densities. Previous work shows that using too simple mixture components for modeling heteroscedastic and/or heavy tailed data can give a poor fit, even with a large number of components. This paper explores how well a smooth mixture of symmetric components can capture skewed data. Simulations and applications on real data show that including covariate-dependent skewness in the components can lead to substantially improved performance on skewed data, often using a much smaller number of components. Furthermore, variable selection is effective in removing unnecessary covariates in the skewness, which means that there is little loss in allowing for skewness in the components when the data are actually symmetric. We also introduce smooth mixtures of gamma and log-normal components to model positively-valued response variables.

The representation of module interfaces

Modular design issues are receiving increased attention from companies interested in reducing the costs from carrying large numbers of components while, at the same time, increasing product quality and providing customers with greater product variety. Existing research has focused mainly on optimising product platforms and product offerings, with little attention being given to the interfaces between modules. This research presents an investigation into how module interfaces are best represented in a Computer-Aided Design/Product Data Management (CAD/PDM) environment. The representation decisions are identified and the advantages and limitations for each option are presented. Representation decisions revolve around issues such as the use of higher abstraction models, the use of ports, and referencing interface components in interface definitions. We conclude that higher abstraction models are necessary, ports should be represented explicitly and interface hardware should not be included directly with the interfaces. The research considers a large number of components from representative products offered by a home appliance manufacturer.

Estimation of Transport Parameters during Ultrafiltration of Pickling Effluent from a Tannery

Pickling effluent, being an industrial one, contains a large number of components with unknown transport coefficients. A combined model based on osmotic pressure and the Kedem-Katchalsky mechanism is used to predict these coefficients relevant to this process, e.g., effective osmotic coefficient, solute diffusivity, solute permeability, and reflection coefficient. These coefficients are evaluated utilizing the model and a large number of experimental data generated during ultrafiltration of pretreated pickling effluent. The performance criteria are evaluated in terms of the chemical oxygen demand (COD), the total dissolved solids (TDS), the total solids (TS), pH, and the conductivity of the permeate. The experiments also reveal that the proposed scheme is successfully reducing the COD to well below the prescribed limits and underscore the importance of transmembrane pressure drop and cross flow velocity on the permeate flux and quality.

On the Maxwell−Stefan Approach to Diffusion: A General Resolution in the Transient Regime for One-Dimensional Systems

The diffusion process in a multicomponent system can be formulated in a general form by the generalized Maxwell-Stefan equations. This formulation is able to describe the diffusion process in different systems, such as, for instance, bulk diffusion (in the gas, liquid, and solid phase) and diffusion in microporous materials (membranes, zeolites, nanotubes, etc.). The Maxwell-Stefan equations can be solved analytically (only in special cases) or by numerical approaches. Different numerical strategies have been previously presented, but the number of diffusing species is normally restricted, with only few exceptions, to three in bulk diffusion and to two in microporous systems, unless simplifications of the Maxwell-Stefan equations are considered. In the literature, a large effort has been devoted to the derivation of the analytic expression of the elements of the Fick-like diffusion matrix and therefore to the symbolic inversion of a square matrix with dimensions n x n (n being the number of independent components). This step, which can be easily performed for n = 2 and remains reasonable for n = 3, becomes rapidly very complex in problems with a large number of components. This paper addresses the problem of the numerical resolution of the Maxwell-Stefan equations in the transient regime for a one-dimensional system with a generic number of components, avoiding the definition of the analytic expression of the elements of the Fick-like diffusion matrix. To this aim, two approaches have been implemented in a computational code; the first is the simple finite difference second-order accurate in time Crank-Nicolson scheme for which the full mathematical derivation and the relevant final equations are reported. The second is based on the more accurate backward differentiation formulas, BDF, or Gear's method (Shampine, L. F. ; Gear, C. W. SIAM Rev. 1979, 21, 1.), as implemented in the Livermore solver for ordinary differential equations, LSODE (Hindmarsh, A. C. Serial Fortran Solvers for ODE Initial Value Problems, Technical Report; https://computation.llnl.gov/casc/odepack/odepack_ home.html (2006).). Both methods have been applied to a series of specific problems, such as bulk diffusion of acetone and methanol through stagnant air, uptake of two components on a microporous material in a model system, and permeation across a microporous membrane in model systems, both with the aim to validate the method and to add new information to the comprehension of the peculiar behavior of these systems. The approach is validated by comparison with different published results and with analytic expressions for the steady-state concentration profiles or fluxes in particular systems. The possibility to treat a generic number of components (the limitation being essentially the computational power) is also tested, and results are reported on the permeation of a five component mixture through a membrane in a model system. It is worth noticing that the algorithm here reported can be applied also to the Fick formulation of the diffusion problem with concentration-dependent diffusion coefficients.

Simplified critical-point criteria for some multicomponent systems

Stability theory for multicomponent fluid mixtures is used to calculate the spinodal and the critical locus for a multicomponent mixture. Upon using well-defined simplifying assumptions, the criteria developed here are suitable for mixtures whose properties are described by a molecular-thermodynamic model where the Helmholtz energy depends on composition-average model parameters. Such mixtures are typically encountered in systems that contain homologues. Our method is especially useful when the homologue-mixture contains a large number of components. Different from our previous work (Fluid Phase Equilibria, 206, 41–59, 2003), the criteria developed here do not require that the model parameters depend on moments of a characteristic property (e.g. molecular weight) used to characterize the distribution of components. The spinodal lines and the critical points obtained by our method are identical to those obtained from the less-computer-efficient Gibbs traditional method. To illustrate, the Soave–Redlich–Kwong equation of state is used to calculate critical properties of mixtures containing carbon dioxide, hydrogen sulphide, and alkanes.

Deubiquitylating Enzyme USP-7, a Novel Therapeutic Target in Multiple Myeloma.

Abstract 610 Background and Rationale:Ubiquitin-Proteasome Signaling (UPS) pathway is mediated via a large number of components, suggesting many potential sites of pharmacological intervention. Therapeutic targeting of UPS is exemplified by the recent FDA approval of dipeptidyl boronic acid bortezomib first-in-class proteasome inhibitor for the treatment of relapsed/refractory, relapsed, and newly diagnosed multiple myeloma (MM). As with other agents, however, dose-limiting toxicities and the development of resistance limit its long-term utility. Recent efforts have been devoted to discovery and development of small molecule inhibitors of the major components of UPS, such as E1-conjugating enzyme inhibitors, E3 ubiquitin ligase inhibitors (e.g inhibitors of TRAF6, SCF-p27, POSH, MDM2-P53) or Deubiquitylating enzyme (DUB) inhibitor. Therapeutic strategies using these small molecule inhibitors will allow for specific targeting of the UPS and therefore may be less likely than proteasome inhibitors to trigger off-target activities and associated toxicities. In this context, Ubiquitin Specific Protease-7 (USP-7), a deubiquitylating enzyme, is of particular interest since it regulates activity of key biological signaling pathways such as p53, the transcription factor FOXO-4, Cdk inhibitor p27, and PI3K/Akt. In the present study, we examined the anti-tumor activity of a novel USP-7 inhibitor P5091 (Progenra, Inc., Malvern, PA) in MM cells using both in vitro and in vivo model systems. Results:We first confirmed the functional specificity of P5091 using different experimental strategies: 1) Cell-free based experiments using a novel reporter (Ub-PLA2)-based assay showed a potent, specific and selective deubiquitylating activity of P5091 against USP-7 (EC50 = 5.6 mM) versus other DUBs and proteases (EC50 25 to > 50 mM); 2) Treatment of MM.1S MM cells with P5091 blocked USP-7 deubiquitylating activity, without altering proteasome activity; and 3) treatment of HCT-116 (wild type) cells with P5091 markedly decreased viability; conversely, knockout of USP-7 in HCT-116 conferred resistance to P5091 (P < 0.001; n=2). Taken together, these data demonstrate that P5091 targets USP-7. We next examined the effects of P5091 in MM cells. Protein expression analysis showed that USP-7 is highly expressed in MM cells. Treatment of MM cell lines (MM.1S, MM.1R, RPMI-8226, U266, KMS-12BM, and INA-6) and primary patient cells for 72h significantly decreased their viability (IC50 range 5-10 mM) (P < 0.001; n=3) without affecting the viability of normal peripheral blood mononuclear cells, suggesting specific anti-MM activity and a favorable therapeutic index for P5091. P5091-induced apoptosis was confirmed in MM.1S and RPMI-8226 cells, as evidenced by marked increase in Annexin V+ and PI- cell population (P < 0.001, n=3). Importantly, transfection of USP-7 siRNA, but not scrambled (genome control) siRNA, inhibits growth of MM.1S cells, similar to USP-7 inhibitor P5091 (P < 0.001; n=2). In addition, p5091 triggered apoptosis in MM cells even in the presence of MM bone marrow stromal cells. Mechanistic studies further showed that P5091-triggered apoptosis in MM cells is associated with 1) activation of caspase-8, caspase-9, caspase-3, and PARP; 2) activation of Noxa, PUMA, and Bid; 3) downregulation of MM cell growth and survival proteins: Akt, Bclxl, phospho-S6 ribosomal protein, and c-Myc; 4) inhibition of migration of MM cells and angiogenesis; and 5) suppression of USP-7 specific substrate HDM2 with concurrent increased expression of CDK inhibitor p21. Importantly, blockade of HDM2 and p21 using siRNA strategy significantly abrogates P5091-induced MM.1S cell death (P value <0.001; n=2). We next examined the in vivo efficacy of p5091 using human plasmacytoma xenograft mouse model. Treatment of tumor-bearing mice with P5091 (10 mg/kg IV, twice a week for three weeks), but not vehicle alone, significantly (P < 0.001) inhibits MM tumor growth and prolongs survival of these mice (P < 0.001; 13.6 days prologation of survival in mice receiving P5091 vs. vehicle-treated mice). The concentrations of P5091 were well tolerated by mice, without significant weight loss. Conclusions:These preclinical studies will allow for the development of next generation UPS-based therapies and provide the rationale for novel therapeutics targeting USP7 to improve patient outcome in MM. Disclosures:Chauhan:Progenra, Inc: Consultancy. Nicholson:Progenra, Inc: Employment.