Search

This work provides a summary of selected experimental capabilities being developed to support nonnuclear testing and demonstration of technology in support of microreactors under the U.S. Department of Energy's (DOE's) Microreactor Program. Major capabilities include the Single Primary Heat Extraction and Removal Emulator (SPHERE) and the Microreactor Agile Non-nuclear Experimental Test Bed (MAGNET). The SPHERE facility allows for controlled testing of the steady-state and transient heat rejection capabilities of a single heat pipe using electrical heaters that simulate nuclear heating. The facility is capable of monitoring axial temperature profiles along the heat pipe and surrounding test articles during startup, steady-state operation, and transients. Instrumentation includes noncontact infrared thermal imaging, surface thermocouples, spatially distributed fiber optic temperature and strain sensors, electrical power meters, and a water-cooled, gas-gap calorimeter for quantifying heat rejection from the heat pipe. The facility can be operated under both vacuum and inert-gas conditions. The MAGNET facility is a large-scale, 250-kW electrically heated microreactor test bed to enable nonnuclear experimental evaluation of a variety of microreactor concepts. It can be supplied to electrically heat a scaled section of a microreactor and further test the capabilities of heat rejection systems. The initial MAGNET experiments will support technology maturation and reduce uncertainty and risk associated with the design, operation, and deployment of monolithic heat pipe--based reactors. However, this test bed can broadly be applied to multiple microreactor concepts to evaluate a wide range of thermal-hydraulic and structural phenomena such as interface coupling with power conversion units and other collocated systems. MAGNET can evaluate integral thermomechanical effects during electrical heating of an array of heat pipes in a larger test article. Examples of initial testing will include thermal stresses in the monolith and the impact of debonding of a heat pipe from the core block and how that failure could impact surrounding heat pipes, i.e., understanding the potential for cascading failure. This work also discusses some modeling capabilities that can support experiment design, analysis, and interpretation, including the heat pipe code Sockeye and a comparison of thermal-structural simulations performed using ABAQUS and STAR-CCM+. [ABSTRACT FROM AUTHOR]

In this study, aluminum matrix composites reinforced with micro-TiN were fabricated using selective laser melting (SLM) technique. The study investigates the effects of TiN content on densification, microstructure evolution, crystal textures, and mechanical properties. The results show that the relative density of composite samples containing 0-3 wt. % TiN exceeds 98%. However, further increase in TiN content leads to a decrease in relative density. The TiN particles are uniformly distributed and wetted by the AlSi10Mg matrix, forming a graded interfacial layer. The TiN particles refine the matrix grains and significantly reduce the prevalence (001) texture by promoting a heterogeneous nucleation process. In comparison to the AlSi10Mg alloy, the TiN/AlSi10Mg composite exhibits improved microhardness, tensile strength, and wear resistance. The exceptional mechanical properties of the Al matrix composites are attributed to the dispersion strengthening of the TiN particles and the fine-grain strengthening of the matrix. The optimal TiN content is found to be 3 wt. %, resulting in excellent mechanical performance of the fabricated samples (132.4±4.1 HV for hardness and 379.7±4.6 MPa for tensile strength) with a low friction coefficient of 0.49. [ABSTRACT FROM AUTHOR]

In this paper, Ti6Al4V+3 wt.% TiB2 composite powder was used as a raw material to synthesize TiB whiskers in situ and prepare composites reinforced with TiB/Ti6Al4V whiskers by selective laser melting (SLM). The effects of process parameters on the properties of TiB/Ti6Al4V samples were systematically studied. The evolution of the microstructure, including the formation and regulation of whiskers, and the effects on mechanical properties were discussed. The results showed that during the SLM process, adjusting the energy density effectively inhibited cracking in the TiB/Ti6Al4V samples. The TiB2 particles acted as nucleation centers to significantly refine the grains during processing and reacted with elemental Ti to form a needle-like TiB network at the grain boundaries, which strengthened the whiskers. Additionally, TiB played a role in dispersion strengthening. Compared with Ti6Al4V, the microhardness of TiB/Ti6Al4V was 430.6±11.45 HV, an increase of 27.9%, and the wear volume of the sample was 0.85×10-3 mm³, a decrease of 62.64%. [ABSTRACT FROM AUTHOR]

Projection to latent structures (PLS) and concurrent PLS are approaches for solving quality-relevant process monitoring. In this paper, a new approach called concurrent kernel PLS (CKPLS) is presented to detect faults comprehensively for nonlinear processes. The new model divides the nonlinear process and quality spaces into five subspaces: the co-varying, process-principal, process-residual, quality-principal, and quality-residual subspaces. The co-varying subspace reflects nonlinear relationship between quality variables and original process variables. The process-principal and process-residual subspaces reflect the principal variations and residuals, respectively, in the nonlinear process space. Further, the quality-principal and quality-residual subspaces reflect the principal variations and residuals, respectively, in the quality space. The proposed approach is demonstrated by a numerical simulation and an application of the Tennessee Eastman process. [ABSTRACT FROM AUTHOR]

Source rocks generate and expel hydrocarbon with thermal evolution, which lead to a decrease of total organic carbon (TOC) content. A new quantitative model for original total organic carbon (TOCo) content evolution and recovery was proposed, and then was used to the carbonate source rocks with different TOCs (CSRDTOC) in the Tazhong area, Tarim Basin, China. Studies showed that the higher the TOC of source rocks, the bigger the range of TOC reduction and recovery coefficient. When vitrinite reflectance (VR) is equal to 2.5%, recovery coefficients of TOCo= 0.2%, 0.4%, and 1.0% are 1.43, 1.66, and 2.01, respectively. It must restore TOCowhen we evaluate source rocks at the stage of high overmaturity and predict oil and gas resources. [ABSTRACT FROM PUBLISHER]

Electrically biased graphene has been studied experimentally as a novel emitter of thermal radiation. However, there is as yet no systematic theory that quantifies the thermal radiation, heat transfer, and electrical properties of electrically biased graphene. To study the thermal transport properties systematically, a heat conduction model is developed and exploited in this paper. The temperature distribution and heat conduction coefficient of graphene under different bias voltages are obtained using our theoretical model. The I–V curve and the relationship between the radiant power and input voltage of graphene are then obtained. This work could help design a novel efficient wavelength-adjustable thermal radiation source. [ABSTRACT FROM AUTHOR]

Unexpected or time-varying deterministic type load disturbances are often encountered when performing identification tests in practical applications. A bias-eliminated subspace identification method is proposed in this paper by developing an orthogonal projection approach to guarantee consistent estimation on the deterministic part of the plant, in combination with a Maclaurin time series approximation on the output response arising from deterministic type load disturbance. The rank condition for such an orthogonal projection is disclosed in terms of the state-space model structure adopted for identification. Using principal component analysis (PCA), the extended observability matrix and the lower triangular Toeplitz matrix of the state-space model are explicitly derived. Accordingly, the plant state-space matrices can be retrieved from the above matrices through a shift-invariant algorithm. A benchmark example from the literature and an illustrative example of industrial injection molding are used to demonstrate the effectiveness and merit of the proposed identification method. [ABSTRACT FROM AUTHOR]

Background: Study TR03 evaluated the safety and efficacy of nalbuphine ER for prurigo nodularis (PN; NCT02174419). Objective: We conducted supplementary analyses to assess the psychometric properties of the Worst Itch Numeric Rating Scale (WI‐NRS), the TR03 primary endpoint. Methods: Study TR03 was a double‐blind, placebo‐controlled, phase 2 trial in PN patients with documented scores ≥5 on the WI‐NRS (0 [no itch]–10 [worst itch imaginable]) on ≥5 of 7 days before baseline. Using TR03 data, the WI‐NRS's psychometric properties, including reliability, validity and ability to detect change, were evaluated. A responder threshold was estimated to facilitate interpretation of WI‐NRS score changes. Results: Amongst 62 treated patients, improvements in mean [SD] (median) WI‐NRS scores were observed between baseline (8.2 [1.21] (8.1)) and week 10 (5.8 [2.43] (6.0)). The WI‐NRS had an intraclass correlation coefficient of 0.96 (95% confidence interval, 0.93–0.98) in 42 patients who had stable Itch verbal rating scale (VRS) scores from week 9–10, supporting strong test–retest reliability. Construct validity was supported, with strong correlations at week 10 with Average Itch NRS (r = 0.87) and Itch VRS single‐day/weekly mean scores (r = 0.81/0.89) and moderate correlations with ItchyQoL™ total/domain scores (r = 0.41–0.43). The WI‐NRS discriminated between predefined severity subgroups based on the Itch VRS and detected changes in itching severity (effect‐size estimate: −2.05; standardized response mean: −1.21). An anchor‐based threshold based on a two‐category improvement in the single‐day Itch VRS suggests a responder threshold of ≥3.8 points (~40% improvement). Conclusions: The WI‐NRS demonstrates good measurement properties, supporting its use in evaluating treatment change in PN. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicle (UAV)-based commercial services, exemplified by drone delivery, have captured wide interest in tech companies, entrepreneurs, and policymakers. Structured route-based UAV operations have been implemented for traffic management of UAVs in support of commercial delivery services in cities. Yet, its essence, multi-path planning with constraints is not well solved in the existing literature. Centralized planning might result in inefficiencies and unfairness in the allocation of precious urban airspace to individual routes. This paper describes a novel distributed route planning method to support UAV operations in a high-density urban environment. The method allows each origin–destination (OD) pair to compete against other OD pairs for an optimized route (e.g. shortest distance), coordinated by a system-level evaluation, leading to a network design that maximizes the performance of not only the individual routes but also the entire system. The core concept is the introduction of congestion pricing, a soft constraint to coordinate the allocation of airspace. The method is tested in standard 2D scenarios and compared with other state-of-the-art methods. The results show that (1) the method is able to generate routes with short individual distances as well as occupying the least airspace by the route network; (2) in some complex scenarios, the method is able to find a solution in a short period of time while other state-of-the-art method fails. The method has also been applied to a real urban environment (Mong Kok in Hong Kong) to demonstrate its capability. • Presented a multi-path method to design air route networks for urban drone delivery. • Introduced congestion cost as a flexible constraint for airspace allocation. • Employed a distributed approach for resolving conflicts between origin-destination pairs. • Outperformed other leading methods in balancing efficiency and computation speed. • Validated the proposed system through tests in real-world settings. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents an overview of results and future challenges related to temperature control and cost optimization in building energy systems. Control and economic optimization issues are discussed and illustrated through simulation examples. The paper concludes with results from model predictive control solutions and identification of important directions for future work. [Copyright &y& Elsevier]

Mesenchymal stromal cells (MSCs) from gestational tissues represent promising cell populations with stem cell-like properties for use in regenerative medicine. Previously, we reported that MSCs in the chorionic villi of the human placenta reside in a vascular niche. However, the niche(s) in which MSCs reside in the fetal membranes, another rich source of MSCs, remains to be determined. The cell surface markers STRO-1 and 3G5 were previously employed to identify niches in a variety of tissues and here we use these markers to report the location of the MSC niche in the human decidua parietalis. The cultured decidua parietalis MSCs (DPMSCs) isolated from the choriodecidua component of the fetal membranes possessed stem cell-like properties such as adherence to plastic, colony forming ability, and multipotent differentiation potential. Fluorescence in situ hybridization analysis showed cultured DPMSCs were of maternal origin. Immunocytochemistry demonstrated that cultured DPMSCs stained positively with stem cell surface markers 3G5, CD105, CD106, STRO-1, CD146, CD49a, and α-SMA but were negative for hematopoietic markers (CD117, CD34) and vascular markers (CD34, von Willebrand factor [vWF]). Immunohistochemistry with antibodies to stem cell surface markers and the endothelial markers on term fetal membranes revealed a vascular niche for DPMSCs, which was confirmed by immunofluorescence analysis. Both STRO-1 and vWF fluorescence signals showed substantial overlap, while CD146 and vWF signals showed partial overlap. These observations were consistent with a vascular niche. [ABSTRACT FROM AUTHOR]

Synechococcus is one of the most abundant photoautotrophic picoplankton in the marine ecosystem. However, it is not clear how Synechococcus assemblages respond to light intensity variation in a genus group. Here, enriched Synechococcus assemblages from in situ coastal seawater were subjected to light intensity simulation experiments in a range of 9-243 µmol(photon) m-2 s-1. Characteristics concerning physiology, genomics, and metatranscriptomics were analyzed. Physiologically, the fitting model predicted photosynthesis indications and pigment contents increased with different trends following the light intensity. Genomic sequencing demonstrated that both the phylogenetic and phenotypic compositions of Synechococcus assemblage exhibited population succession. Especially, the proportion of Synechococcus pigment type 2 was changed significantly. In metatranscriptomics, most genes were downregulated in the high-light intensity group, while photosynthesis-related genes were entirely upregulated. The high upregulation of photosynthesis-related genes, such as psbO, psbA, apcB, and cpcB, corresponded to the succession of Synechococcus genotype and was responsible for the physiological shift in response to light intensity. [ABSTRACT FROM AUTHOR]

Abstract: The continuous annealing process line (CAPL) has complex process characteristics, such as strong correlation of a large number of process variables and interconnected multi-subsystems and multiple operation zones. Practitioners are concerned with typical process faults, such as strip-break and roll-slippage, whose effects are often confined in a specific zone. Considering the large-scale process characteristics and fault characteristics, a multi-block fault diagnosis method is proposed. A novel reconstruction-based block contribution (RBBC) is first proposed in order to diagnose the faulty block. The reconstruction-based variable contribution (RBVC) within a block is also proposed to determine the faulty variables. The proposed RBBC–RBVC hierarchical scheme is applied successfully to a real CAPL on two fault cases. A finite state machine is utilized to diagnose strip-break and reconstructed combined index is studied to diagnose roll-slippage. [Copyright &y& Elsevier]

Abstract: The present study sought to investigate if p53 mediates autophagy activation and mitochondria dysfunction in primary striatal neurons in kainic acid (KA)-induced excitotoxicity. The excitotoxic model of primary striatal neurons was established with KA. The levels of p53, microtubule-associated protein 1 light chain 3 (LC3), Beclin1, and p62 were examined by Western blot and immunostaining. Autophagy activation was also determined with electron microscope. To evaluate the contribution of p53 to autophagy activation and mitochondria dysfunction in KA-induced excitotoxicity, the protein levels of LC3, Beclin1, and p62, the mitochondrial transmembrane potential and the mitochondrial Reactive oxygen species (ROS) after pretreatment with the p53 inhibitor pifithrin-alpha (PFT-α) and the autophagy inhibitor 3-methyladenine (3-MA) were analyzed. Excitotoxic neuronal injury was induced after KA treatment as demonstrated by increases in lactate dehydrogenase (LDH) leakage and was significantly inhibited by PFT-α. Western blot and immunostaining showed that the induction of p53 protein occurred in the cytosol and the nucleus. Increases in autophagic proteins LC3 and Beclin1 were observed, whereas the protein levels of p62 decreased after KA treatment. Electron microscope analysis showed increased autophagosomes in the cytoplasm. The changes in LC3, Beclin1, and p62 levels were blocked by PFT-α, PFT-μ, 3-MA, and E64d but not Z-DEVD-FMK. JC-1 staining showed the depolarization of mitochondrial membrane potential after excitotoxic insult. Mito-tracker and RedoxSensor Red CC-1 staining showed an increased production of mitochondrial ROS after excitotoxic insult. These effects were significantly suppressed after pretreatment with PFT-α and 3-MA. This study suggests that p53 mediates KA-induced autophagy activation and mitochondrial dysfunction in striatal neurons. [Copyright &y& Elsevier]

Abstract: In the first four parts of this series a three-dimensional model was developed for transport and reaction of gaseous mixtures in a landfill. An optimization technique was also utilized in order to determine a landfill''s spatial distributions of the permeability, porosity, the tortuosity factors, and the total gas generation potential of the wastes, given a limited amount of experimental data. In the present paper we develop an artificial neural network (ANN) in order to make accurate short-term predictions for several important quantities in a large landfill in southern California, including the temperature, and the CH4, CO2, and O2 concentration profiles. The ANN that is developed utilizes a back-propagation algorithm. The results indicate that the ANN can be successfully trained by the experimental data, and provide accurate predictions for the important quantities in the sector of the landfill where the data had been collected. Thus, an ANN may be used by landfills'' operators for short-term plannings. Moreover, we showed that a novel combination of the three-dimensional model of gas generation, flow, and transport in landfills developed in Parts I, II, and IV, the optimization technique described in Part III, and the ANN developed in the present paper is a powerful approach for developing an accurate model of a landfill for long-term predictions and planning. [Copyright &y& Elsevier]

Photosynthesis, chlorophyll (Chl) a fluorescence, and nitrogen metabolism of hawthorn ( Crataegus pinnatifida Bge.), subjected to exogenous L-glutamic acid (GLA) (200 mg l, 400 mg l, and 800 mg l) that possibly affect secondary metabolic regulation, were measured. The results indicated that photosynthetic and fluorescence characteristics of hawthorn exhibited positive responses to the application of GLA. Different concentrations of GLA caused an increase in Chl content, net photosynthetic rate ( P) and stomatal conductance ( g) as well as transpiration rate ( E), and improved the carboxylation efficiency (CE), apparent quantum yield (AQY) and maximum carboxylation velocity of Rubisco (V). Application of GLA could also enhance the maximum ratio of quantum yields of photochemical and concurrent non-photochemical processes in PSII (F/F), the maximal quantum yield of PSII (F/F), the probability that an absorbed photon will move an electron into the electron transport chain beyond Q (Φ) as well as the performance index on absorption basis (PI), but decreased the intercellular CO concentration ( C) and the minimal fluorescence (F). Application of GLA also induced an increase in nitrate reductase (NR; EC 1.6.6.1) and glutamine synthetase (GS; EC 6.3.1.2) activities, and increased the soluble protein content, leaf nitrogen (N) content and N accumulation in leaves as well as the plant biomass. However, the effects were different among different concentrations of GLA, and 800 mg l GLA was better. This finding suggested that application of GLA is recommended to improve the photosynthetic capacity by increasing the light energy conversion and CO transfer as well as the photochemical efficiency of PSII, and enhanced the nitrogen metabolism and growth and development of plants. [ABSTRACT FROM AUTHOR]

An efficient method for wide-band analysis of antennas radiating in the presence of an electrically large conducting platform is proposed. The method is based upon the well known method of moments-physical optics (MoM-PO) hybrid formulation combined with the Maehly approximation. Compared with the asymptotic waveform evaluation (AWE) technique, the major advantage of the Maehly approximation is that it does not require the complex computation concerning dense impedance matrix, and it can be easily implemented into an existing MoM-PO computer code. Numerical results show that the proposed method is superior, in terms of CPU time, to the traditional MoM-PO. [ABSTRACT FROM AUTHOR]

Abstract: Exponentially weighted moving average (EWMA) controllers are the most commonly used run-to-run controllers in semiconductor manufacturing industry. An EWMA controller can be implemented in two different ways. One way is to keep the process gain as its off-line estimate and update the intercept term at each run, which is termed EWMA with intercept adaptation; the other is to keep the intercept term as its off-line estimate and update the process gain at each run, which is termed EWMA with gain adaptation. Despite the fact that gain variation and adaptation is typical in semiconductor industry, most EWMA formulations are for intercept adaptation and few results exist on the stability and sensitivity of EWMA with gain adaptation. In this paper, we propose a general formulation to analyze the stability of both EWMA controllers. The proposed state-space representation not only reveals the similarities and differences between two types of EWMA controllers, but also explains why the stability conditions for both types of EWMA controllers are independent of process disturbances. In addition, we propose a general framework that unifies the analysis of the optimal control performance for both types of EWMA controllers. The proposed framework is different from existing approaches in that it decouples the state estimation from the control law, and derives the optimal weighting based on the state estimation performance. The proposed framework significantly simplifies the analysis procedure, especially for EWMA with gain adaptation. Using this framework, we derive the optimal EWMA weighting through solving the discrete-time algebraic Riccati equation (DARE) for various process disturbances that are encountered in semiconductor manufacturing industry. Simulation examples are given to illustrate the optimality of the EWMA weighting derived using the framework. Some practical aspects of controller tuning are also discussed based on the simulation results. [Copyright &y& Elsevier]

The structural stability of marcasite-type FeP2 at high pressure has been studied by X-ray diffraction, Raman spectroscopy, and theoretical calculations. Experimental results show that no phase transitions happen up to 28 GPa at room temperature. The shortest axis of the marcasite-type FeP2 cell, the c-axis, is the most compressible, due to the softening of edge-shared octahedra along the c-axis. The linear pressure coefficients and Gruneisen parameters of four Raman modes are determined. Theoretical calculations further support the experimental results and indicate that FeP2 is still a semiconductor up to 35 GPa. [ABSTRACT FROM AUTHOR]

Variants within the human UGT1A1 gene are associated with irinotecan induced severely adverse reactions and hyperbilirubinemia. Intra-ethnic differences in the genetic variation and haplotypes of UGT1A1 gene have been analyzed in the present study. Relationship between the concentrations of total serum bilirubin (T-bil) and haplotype structure of UGT1A1 in healthy people were also evaluated. We genotyped five functional polymorphisms including −3279T>G and −3156G>A in the enhancer region, (TA)6>7 in the TATA box, and 211G>A (G71R), 686C>A (P229Q) in the exon1 region of UGT1A1 in three groups of healthy Chinese ethnic populations, consisting of 264 subjects of She origin, 539 of Han origin and 273 of Dong origin. The distribution of −3279T>G, (TA)6>7, 211G>A of UGT1A1 differed greatly as between the three ethnic groups. All of six haplotypes differed considerably between at least two of the three groups, which highlighted the need to analyze clinically irinotecan toxicity relevant SNPs and haplotypes in a variety of different racial groups within the Chinese population. Total bilirubin concentration in homozygous carriers of the −3279G and (TA)7 allele were significantly higher than those in heterozygous carriers or homozygous carriers of wild-type alleles. Carriers of the variant haplotypes (−3279G; −3156A; (TA)7; 211G; 686C) had higher serum T-Bil concentrations compared with the other groups. Our results indicate that heterogeneity among different ethnic populations is possibly the result of microevolution and is relevant to studies into the effect of tailored drug treatment.The Pharmacogenomics Journal (2007) 7, 333–338; doi:10.1038/sj.tpj.6500424; published online 24 October 2006 [ABSTRACT FROM AUTHOR]

This paper presents the results of a study of endangered plants using remote sensing data. The aim of this study was to investigate and assess spatial distribution changes and temporal coverage changes of the following endangered rare plants: Tetraena mongolica, Helianthemum soongolicum, Reaumuria trigyna, Reaumuria soongorica, Potaninia mongolica, and Ammopiptanthus mongolicus, in the West Ordos Plateau National Conservation Region in Inner Mongolia, China. Using ETM+ (August 1999) remote sensing data, DEM data, and data from 25 field samples collected from Gangdeger Mountain in July 1999, digital maps highlighting endangered plant populations (1994) were processed using the ‘MPH feature extraction method’ to view the current spatial distribution pattern of the endangered plants. The ‘radiometric normalization’ and ‘vegetation change detection’ methods were then used to reveal temporal coverage changes of the endangered plants, using TM (September 1987) and ETM+ (August 1999) data. [ABSTRACT FROM AUTHOR]

The serum soluble cytotoxic T lymphocyte associated antigen-4 (sCTLA-4) concentration is significantly elevated in patients with asthma, and sCTLA-4 concentration correlate with the severity of asthma. The aim of the present study was to investigate effects of allergen inhalation and oral glucocorticoid on concentration of serum sCTLA-4 in patients with allergic asthma.Allergen inhalation challenge was conducted in allergic asthmatics with isolated early asthma response and those with dual asthma response. In a randomized, double-blind, placebo-controlled, parallel group fashion, prednisolone or placebo was give orally once a day for 2 weeks. Venous blood samples were collected before and after allergen inhalation or prednisolone administration for obtaining sera. The serum sCTLA-4 concentrations were determined using enzyme-linked immunosorbent assay.The serum sCTLA-4 concentrations in the dual responder group increased from 29.0 (14.5–43.7) μg/l [median (25–75 percentiles)] before allergen inhalation to 44.0 (24.3–61.3) μg/l 24 h after allergen inhalation. In the isolated early responders, there were no significant increase in serum sCTLA-4 concentrations after allergen inhalation compared with baseline levels. There was a significant decrease in serum sCTLA-4 concentrations after 2 weeks of glucocorticoid therapy [22.0 (15.5–31.0) μg/l] compared with baseline values [37.0 (19.5–53.0) μg/l], whereas there was no significant difference in the placebo group.This study has demonstrated that serum sCTLA-4 concentrations increased after allergen inhalation in sensitized asthmatic subjects, and that serum sCTLA-4 concentrations were downregulated by prednisolone therapy. [ABSTRACT FROM AUTHOR]

Run-toe run (RtR) control technology has received tremendous interest in semiconductor manufacturing. Exponentially weighted moving average (EWMA), double-EWMA, and internal model control (IMC) filters are recognized methods for online RtR estimation. In this paper, we consider recursive least squares (RLS) as an alternative for online estimation and RtR control. The relationship between EWMA-type and RLS-type estimates is analyzed and verified with simulations. Because measurement delay is almost inevitable in semiconductor manufacturing, we discuss and compare the performance of EWIVIA, RtR-IMC, and RLS controllers in handling measurement delay and measurement noise for processes with a deterministic drift. An ad hoc solution is proposed to handle measurement delay for processes with time-varying drifts. The results are illustrated through several simulations and a shallow trench isolation (S TI) etch process as an industrial example. [ABSTRACT FROM AUTHOR]

In this paper, a closed-loop subspace identification approach through an orthogonal projection and subsequent singular value decomposition is proposed. As a by-product of this development, it explains why some existing subspace methods may deliver a bias in the presence of the feedback control and suggests a remedy to eliminate the bias. Furthermore, as the proposed method is a projection based method, it can simultaneously provide extended observability matrix, lower triangular block-Toeplitz matrix, and Kalman filtered state sequences. Therefore, using this method, the system state space matrices can be recovered either from the extended observability matrix/the block-Toeplitz matrix or from the Kalman filter state sequences. [Copyright &y& Elsevier]

Chemical process plant safety, production specifications, environmental regulations, operational constraints, and plant economics are some of the main reasons driving an upward interest in research and development of more robust methods for process monitoring and control. Principal component analysis (PCA) has long been used in fault detection by extracting relevant information from multivariate chemical data. The recent success of wavelets and multi-scale methods in chemical process monitoring and control has catalyzed an interest in the investigation of wavelets based methods for fault detection. In the present work, multi-scale principal component analysis (MSPCA) is used for fault detection and diagnosis. MSPCA simultaneously extracts both, cross correlation across the sensors (PCA approach) and auto-correlation within a sensor (wavelet approach). Using wavelets, the individual sensor signals are decomposed into approximations and details at different scales. Contributions from each scale are collected in separate matrices, and a PCA model is then constructed to extract correlation at each scale. The multi-scale nature of MSPCA formulation makes it suitable to work with process data that are typically non-stationary and represent the cumulative effect of many underlying process phenomena, each operating at a different scale. The proposed MSPCA approach is able to outperform the conventional PCA based approach in detecting and identifying real process faults in an industrial process, and yields minimum false alarms. Additionally, the advantage of MSPCA, over the traditional PCA approach for sensor validation, is also demonstrated on an industrial boiler data set. [Copyright &y& Elsevier]

We searched for shocked carbon chain chemistry (SCCC) sources with C3S abundances surpassing those of HC5N toward the dark cloud L1251, using the Effelsberg telescope at the K band (18–26 GHz). L1251-1 and L1251-3 are identified as the most promising SCCC sources. The two sources harbor young stellar objects. We conducted mapping observations toward L1251-A, the western tail of L1251, at λ ∼ 3 mm with the Purple Mountain Observatory 13.7 m and the Nobeyama Radio Observatory 45 m telescopes in lines of C2H, N2H+, CS, HCO+, SO, HC3N, and C18O as well as in CO 3–2 using the James Clerk Maxwell Telescope (JCMT). The spectral data were combined with archival data including Spitzer and Herschel continuum maps for further analysis. Filamentary substructures labeled as F1–F6 were extracted in L1251, with F1 being associated with L1251-A hosting L1251-1. The peak positions of dense gas traced by HCO+ are misaligned relative to those of the dust clumps. Episodic outflows are common in this region. The twisted morphology of F1 and velocity distribution along L1251-A may originate from stellar feedback. SCCC in L1251-1 may have been caused by outflow activities originated from the infrared source IRS1. The signposts of ongoing SCCC and the broadened line widths of C3S and C4H in L1251-1 as well as the distribution of HC3N are also related to outflow activities in this region. L1251-1 (IRS1) together with the previously identified SCCC source IRS3 demonstrate that L1251-A is an excellent region to study SCCC. [ABSTRACT FROM AUTHOR]

The objective of the present investigation was to determine the seroprevalence of Coxiella burnetii infection in free-range yaks in China. A total of 552 serum samples were collected from yaks in Gansu province, northwest China between April 2013 and January 2014, and antibodies against C. burnetii were evaluated using enzyme-linked immunosorbent assay (ELISA). Overall, 13.59% (75/552, 95% CI: 10.73-16.45) of the examined animals were positive for C. burnetii antibodies. There was no significant difference in C. burnetii seroprevalence between female yaks (13.78%, 95% CI: 10.36-17.19) and male yaks (13.13%, 95% CI: 7.89-18.36) (P>0.05). Coxiella burnetii seroprevalence in yaks in different age groups ranged from 10.88% to 15.26%, but the difference was not statistically significant (P>0.05). Coxiella burnetii seroprevalence in yaks sampled in different seasons ranged from 12.06% (autumn) to 18.33% (summer), but the difference was not statistically significant (P>0.05). This is the first report of C. burnetii seroprevalence in free-range yaks in China, indicating the need for measures to be taken to control C. burnetii infection in free-range yaks in China. [ABSTRACT FROM AUTHOR]

We theoretically demonstrate a polarizer with an electrically controllable polarizing direction in the far infrared range using two orthogonal periodic arrays of graphene ribbons, which have different widths and are supported on a dielectric film placed on a thick piece of metal. The operation mechanism originates from the polarization-dependent resonant absorption of the two orthogonal graphene ribbons, which can be respectively controlled with different external bias voltages. The operation wavelength can be expanded to terahertz (THz) radiation. [ABSTRACT FROM AUTHOR]

The ELAV/Hu family is a conserved multigene family of pan‐neuronal RNA‐binding protein involved in post‐transcriptional regulation in metazoans. In Drosophila, three members of this family, ELAV, RBP9 and FNE, are involved in neuronal differentiation, gene expression regulation and so on. This family is less well characterized in Bombyx mori. Two orthologs BmELAV‐like‐1 (BmEL‐1) and BmELAV‐like‐2 (BmEL‐2) share 55%–71% and 47%–62% identity with that of in Drosophila and humans, respectively. Bmel‐1 is ubiquitously expressed while Bmel‐2 is expressed in the head and ovaries specifically. Proteins encoded by both genes are localized in nuclear and cytoplasm. The weight of body, cocoon, pupae and cocoon shell are differently affected in Bmel‐1−/−2− mutants created using CRISPR/Cas9 technology. Mutations of both genes increase the expression of four silk protein genes, Fib‐L, Fib‐H, P25 and Ser‐1. In addition, the oviposition ability of Bmel‐2− females is decreased. This study not only provides valuable insights into the functional roles of Bmelav‐like genes in the growth, cocoon characters and regulation of silk protein genes expression, but also provides useful information for silkworm variety breeding. [ABSTRACT FROM AUTHOR]

Based on the design and preparation of the electrically assisted drawing die, the electric-assisted deep-drawn tests were carried out on high-strength steel plates with different strengths to study the electroplastic effect on high-strength steel drawing. The temperature distribution, macro-morphology, and hardness variation of deep-drawing workpieces undergone different electrical parameters were analyzed. The results showed that the Joule heat generated by the electrically assisted drawing die on the sample was symmetrically distributed along the center of the circular sheet, and the electrical pulse heat effect had little effect on the temperature rise of sheets (same material) with different strength levels. The introduction of pulse current could improve the forming performance of high-strength steel to a certain extent, as well as enhance its deep-drawing deformation ability. The hardness of the work-piece increased after it was deep-drawn. The Joule heat generated by the pulse current did not cause changes in the microstructure of the high-strength steel. The electroplastic effect improved the mechanical properties of the work-piece while increasing the formability of the high-strength steel plates. [ABSTRACT FROM AUTHOR]

In this work, a generalized form for the augmented electric field integral equation with perturbation method is studied. By implementing Taylor expansion on all the frequency‐dependent matrix terms and the unknowns, the current coefficients on each frequency order can be obtained in the perturbation method, where the accuracy can be guaranteed near the zero frequency or within the static frequency region. When the frequency goes higher, more expanding terms are required to obtain the accurate results. In order to obtain a wideband solution, a general formulation for the perturbation method is derived and analyzed for the first time. As a result, the improved method can be further extended to dynamic region. Numerical results show that the achieved results for both capacitive circuit problems and plane wave scattering problems are more accurate in comparison with those obtained from the traditional solutions, where the number of the required expanding terms can be determined according to the corresponding error analysis. [ABSTRACT FROM AUTHOR]