Critical Parameter Research Papers - Academia.edu (original) (raw)

2025, 2012 Annual Report Conference on Electrical Insulation and Dielectric Phenomena

Partial discharge (PD) activity within a void in a dielectric material is influenced by many factors. One of the factors is the applied voltage waveform on the material. In this paper, a two-dimensional (2D) model of a cylindrical void in polyethylene layers has been developed using finite element analysis (FEA) software. The model was used to simulate PD activity in the void under square waveform applied voltage. The obtained simulation results were compared with the measurement results from literature. It was found that both results are within reasonable agreement but with only slight disagreement. From comparison, critical parameters from the model affecting PD activity under square waveform applied voltage were identified; they include the inception and extinction voltages and electron generation rate. This finding may increase an understanding of PD behaviour within a void in a dielectric material under square waveform applied voltage.

2025, Physica C: Superconductivity

In this study, ceramic oxides are evaluated as substrates for Bi-2212 superconducting thick films. During the partial melt-processing of Bi 2 Sr 2 CaCu 2 O x (Bi-2212) thick films, a liquid phase is formed which might react with the substrate. Generally, reactions between melt and substrate cause degradation of the superconducting properties, form large amounts of secondary phases and destroy the integrity of the superconductor thick film. MgO substrates are inert during partial melt-processing, and high-quality superconducting Bi-2212 thick films can be processed from the partially molten state. Thick films processed on MgO substrates show a high T c;onset of 96 K and high critical current densities. It is essential that the dense MgO is single phase to prevent reactions between film and substrate.

2025, sciencepub.net

The aim of this study was to determine serum concentrations of HGF, Bcl-2 and nitric oxide (NO) in 44 patients with primary breast cancer and 15 healthy individuals as a control group using an ELISA assay for HGF and Bcl-2 while nitric oxide was determined by using colorimetric technique. The measured parameters were correlated with clinicopathological parameters that may affect the outcome of disease. In addition, ROC curve analysis was done to each parameter. The results were as follows, the mean level of HGF was 1198.79 ± 76.32 pg/ml compared with 884.67 ± 66.88 pg/ml for control (p = 0.026). The HGF levels were significantly elevated in the patients with increasing the tumor stage (p = 0.036). In addition, HGF levels were higher in negative estrogen receptor (p = 0.039). The mean level of Bcl-2 in patients was 12.83± 1.97 ng/ml compared with 5.09 ± 0.40 ng/ml for control (p = 0.027). Levels of Bcl-2 were elevated but not statistically significant in patients with GI tumors, negative nodes, ER negative tumors and postmenopausal patients (p = 0.4, 0.8, 0.7 and 0.5, respectively).The patients mean level of the nitric oxide (NO) was 63.07 ± 4.14 μmol/L compared with 43.99 ± 4.21 μmol/L for control (p = 0.014). The levels of NO were elevated but also not statistically significant in patients with tumor size І, GI tumors, ER negative tumors, positive nodes, stage ІІ tumors and postmenopausal patients (p = 0.3, 0.6, 0.3, 0.7, 0.3 and 0.2 respectively). From the ROC curve analysis, it was observed that the area under curve for HGF, Bcl-2 and NO was 0.695, 0.842 and 0.711, respectively. This result indicates the good validity of the above markers especially Bcl-2 parameter to discriminate the positive from the negative samples. In conclusion, this study demonstrates that the serum determination of HGF, Bcl-2 or NO may help in diagnosis of the breast cancer and may aid in disease prognosis. However, larger studies with more patients are required.

2025, ArXiv

We present Kaleidoscope an innovative system that supports live forensics for application performance problems caused by either individual component failures or resource contention issues in large-scale distributed storage systems. The design of Kaleidoscope is driven by our study of I/O failures observed in a peta-scale storage system anonymized as PetaStore. Kaleidoscope is built on three key features: 1) using temporal and spatial differential observability for end-to-end performance monitoring of I/O requests, 2) modeling the health of storage components as a stochastic process using domain-guided functions that accounts for path redundancy and uncertainty in measurements, and, 3) observing differences in reliability and performance metrics between similar types of healthy and unhealthy components to attribute the most likely root causes. We deployed Kaleidoscope on PetaStore and our evaluation shows that Kaleidoscope can run live forensics at 5-minute intervals and pinpoint the...

2025, Physica C: Superconductivity

Internal tin strands for the ITER Toroidal Field Model Coil have been systematically heat treated to form Nb 3 Sn. Resulting superconducting cross-sections and elementary distribution were monitored by SEM and EDX. Variations of the heat treatments with respect to annealing conditions were re¯ected in the ®eld dependence of the critical current values I c (B). Measurements were performed in ®elds up to 12 T at 4.2 K. Also hysteresis and coupling losses of the same wires have been measured at 4.2 K and ramp rates up to 500 mT/s. From these data variations of various critical parameters (I c0 , B c2 ) as well as of the eective time constant ns of the strand could be deduced.

2025, Fluid Phase Equilibria

A group contribution method is proposed for estimating the critical properties and acentric factors of paraffins, naphtenes and aromatics with emphasis on extrapolating to very heavy compounds. Group contributions for sulfurized compounds were added to improve further applications in petroleum engineering or in any other domain. From the experimental normal boiling point, critical temperatures were correlated with a 0.6% average deviation on a set of 268 data and critical pressures with a 2.6% deviation on a 222 data set. The normal boiling points can be estimated without any experimental values. With this method, it was possible to correlate the normal boiling points of 641 hydrocarbons and sulfurized compounds with a deviation of less than 0.9%. From these estimated values, a 1% deviation was obtained at the critical temperatures and 2.8% at the critical pressures. The acentric factors of 160 compounds were correlated with a 6.5% deviation. With the proposed method, experimental vapor pressures were predicted using the Peng-Robinson equation of state for 125 compounds with a deviation of less than 5%. The results are compared with those obtained using other methods.

2025, Journal of Chromatography A

The combination of microwave-assisted solvent extraction (MASE) and reversed-phase liquid chromatography (RPLC) with UV detection has been investigated for the efficient determination of phenylurea herbicides in soils involving the single-residue method (SRM) approach (linuron) and the multi-residue method (MRM) approach (monuron, monolinuron, isoproturon, metobromuron, diuron and linuron). Critical parameters of MASE, viz. extraction temperature, water content and extraction solvent were varied in order to optimise recoveries of the analytes while simultaneously minimising co-extraction of soil interferences. The optimised extraction procedure was applied to different types of soil with an organic carbon content of 0.4-16.7%. Besides freshly spiked soil samples, method validation included the analysis of samples with aged residues. A comparative study between the applicability of RPLC-UV without and with the use of column switching for the processing of uncleaned extracts, was carried out. For some of the tested analyte / matrix combinations the one-column approach (LC mode) is feasible. In comparison to LC, coupled-column LC (LC-LC mode) provides high selectivity in single-residue analysis (linuron) and, although less pronounced in multi-residue analysis (all six phenylurea herbicides), the clean-up performance of LC-LC improves both time of analysis and sample throughput. In the MRM approach the developed procedure involving MASE and LC-LC-UV provided acceptable recoveries (range, 80-120%) and RSDs (,12%) at levels of 10 mg / kg (n59) and 50 mg / kg (n57), respectively, for most analyte / matrix combinations. Recoveries from aged residue samples spiked at a level of 100 mg / kg (n57) ranged, depending of the analyte / soil type combination, from 41-113% with RSDs ranging from 1-35%. In the SRM approach the developed LC-LC procedure was applied for the determination of linuron in 28 sandy soil samples collected in a field study. Linuron could be determined in soil with a limit of quantitation of 10 mg / kg.

2025

An experimental study has been carried out to explore the effect of propeller induced slipstream on the flow field of a fixed wing micro air vehicle (MAV). Tests were conducted at freestream velocity of 10m/s, corresponding to Reynolds number based on root chord of about 160000. Flow pattern on the surface of MAV planform with propeller-on and off condition was captured using oil flow visualization at four angles of incidence. Mean flow field on the MAV planform at four chordwise planes with propeller-on and off condition were measured using stereo PIV technique at angle of incidence of 24°. Little difference has been seen on the oil flow pattern at 10° and 15° angle of incidence between propeller-off and on condition. Small asymmetry in the flow topology was observe at 20° angle of incednce. Significant difference in flow field was observed at 24° between propeller-on and off condition. The induced slipstream from the propeller makes the flow well attached over the wing planform.

2025

s of the Workshop of November 17-18, 1999 at Bitterfeld / Germany Holger Weiß 1, Huub Rijnaarts 2, Sjef Staps 2, Peter Merkel 3 (Editors) 1 Centre for Environmental Research LeipzigHalle, Interdisciplinary Department of Industrial and Mining Landscapes 2 Netherlands Organization for Applied Scientific Research, TNO Institute of Environmental Sciences, Energy Research and Process Innovation 3 Eberhard-Karls-University of Tübingen, Geological Institute, Applied Geology Group Abstracts Workshop SAFIRA projects Workshop SAFIRA project Editor’s Note: The opinions expressed in this paper are those of the authors and do not necessarily reflect the views of the editors. Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. Abstracts Workshop SAFIRA projects Workshop SAFIRA project

2025

Manukan Island is a small island located in North-West of Sabah, Malaysia was used as a case study area for numerical modeling of an aquifer response to recharge and pumping rates. The results in this study present the variations of recharge into the aquifer under the prediction simulations. The recharge rate increases the water level as indicated by hydraulic heads. This shows that it can alter groundwater of Manukan Island which has been suffering from an overexploration in its unconfined the aquifer. The increase in recharge rate (from 600 mm/year to 750 mm/year) increases the water level indicated by hydraulic heads. A reduction in pumping rate (from 0.072 m 3 /day to 0.058 m 3 /day) not only increases the amount of water levels in aquifer but also reduces the supply hence a deficit in supply. The increase in hydraulic heads depends on the percentage reduction of pumping and recharges rates. The well water has 1978.3 mg/L chloride with current pumping (0.072 m 3 /day) and recharge rates (600 mm/year). However, with an increased of recharge rate and current pumping rate it has decreased about 1.13%. In addition, reduction in pumping rate made the chloride concentration decreased about 2.8%. In general, a reduction in pumping with an increase in recharge rate leads to a decreased in chloride concentrations within the vicinity of cone of depression. Next, to further develop the numerical model, the model should focus on climate change variables such as consequences of climate change are increase in air temperature, increase in sea surface temperature, and more extreme weather conditions. These parameters are considered critical parameters for climate change impact modeling in aquifers. The behavior of the aquifer and its sustainable pumping rate can be done by applying a computer modeling component.

2025

The American Physical Society Superconductivity and magnetism in small attractive and repulsive Hubbard clusters ARMEN KOCHARIAN, California State University, GAYANATH FERNANDO, KALUM PALANDAGE, University of Connecticut, JAMES DAVENPORT, Brookhaven National Laboratory -The existing mapping between the ground state properties of U > 0 and U < 0 Hubbard models are extended to finite temperatures, arbitrary magnetic field and electron doping or chemical potential for small two and four sites clusters. The microscopic origin of charge-spin separation effect and pseudogap formation are studied in response thermodynamics for spin and charge susceptibilities, using exact analytical diagonalization technique and grand canonical ensemble method. In the limiting case of non-interacting particles there are no temperature or magnetically driven driven spin-charge separation. The obtained knowledge we use to compare the thermodynamic phase diagrams of U > 0 and U < 0 clusters in a multidimensional parameter space of temperature, magnetic field and chemical potential. Magnetism and superconductivity are often thought to be incomparable with one another, however, we found many identical features for U > 0 and U < 0 at various range of doping level in the specific heat, spin and charge pseudogaps, Mott-Hubbard and antiferromagnetic crossovers, when these physical characteristics are monitored as a function of chemical potential or doping level. The developed bottom up approach for small clusters displays important intrinsic characteristics of highT c superconductors.

2025, Physical Review B

An exact study of charge-spin separation, pairing fluctuations and pseudogaps is carried out by combining the analytical eigenvalues of the four-site Hubbard clusters with the grand canonical and canonical ensemble approaches in a multidimensional parameter space of temperature (T ), magnetic field (h), on-site interaction (U ) and chemical potential (µ). Our results, near the average number of electrons N ≈ 3, strongly suggest the existence of a critical parameter Uc(T ) for the localization of electrons and a particle-hole binding (positive) gap ∆ e-h (T ) > 0 at U > Uc(T ), with a zero temperature quantum critical point, Uc(0) = 4.584. For U < Uc(T ), particle-particle pair binding is found with a (positive) pairing gap ∆ P (T ) > 0. The ground state degeneracy is lifted at U > Uc(T ) and the cluster becomes a Mott-Hubbard like insulator due to the presence of energy gaps at all (allowed) integer numbers (1 ≤ N ≤ 8) of electrons. In contrast, for U ≤ Uc(T ), we find an electron pair binding instability at finite temperature near N ≈ 3, which manifests a possible pairing mechanism, a precursor to superconductivity in small clusters. Rigorous criteria for the existence of many-body Mott-Hubbard like particle-hole and particle-particle pairings, spin-spin pairing, (spin) pseudogap and (spin) antiferromagnetic critical crossover temperatures, at which the corresponding pseudogaps disappear, are also formulated. In particular, the resulting phase diagram consisting of charge and spin pseudogaps, antiferromagnetic correlations, hole pairing with competing hole-rich ( N = 2), hole-poor ( N = 4) and magnetic ( N = 3) regions in the ensemble of clusters near 1/8 filling closely resembles the phase diagrams and inhomogeneous phase separation recently found in the family of doped high Tc cuprates.

2025, Journal of Sciences, Islamic Republic of

Nowadays, 5-aminolevulinic acid (5-ALA) plays an influential role in the detection of malignant tumors as a photodynamic diagnosis tool. Nevertheless, an outlook regarding 5-ALA applicability in magnetic resonance imaging (MRI) has recently emerged. Many studies confirmed the impact of 5-ALA on promoting intracellular Heme synthesis and iron metabolism, which support the capability of 5-ALA in MRI owing to the susceptibility effect of iron. Therefore, concerning the high safety and high affinity of 5-ALA to tumor cells, 5-ALA-based MRI could be an intriguing method for malignant foci identification.

2025, Cryogenics

In the present concept of ITER fusion reactor the toroidal field and the central solenoid coils are made of Nb 3 Sn based strands with the cable-in-conduit-conductor (CICC) technology. It is well known that the critical parameters of the Nb 3 Sn strand material are strain sensitive; experimental investigations on short samples of basic strands and subsize CICC cables already demonstrated significant effects of residual strain on the critical parameters. In this paper a method is proposed to analyse in detail the thermal strain induced by the cool down from the strand reaction temperature to the coil working conditions. The superconducting strand can be regarded as a very good example of a hierarchical structure, since there is a clear distinction between the micro-scale of the Nb 3 Sn filaments, the meso-scale of the SC filament groups and the macro-scale of the strand, where it can be regarded as homogeneous. A constitutive relation for the homogenised micro-and meso-components is deduced from the knowledge of the respective internal structures, starting from an accurate description of the single representative cells. This two-scales homogenisation technique is associated with an efficient finite element procedure for computing effective material coefficients to be used with standard orthotropic 3D elements in structural codes. Finally the finite elements routines developed for the unsmearing process provide the real stress and strain values over each single material, which are essential to catch the local features needed for engineering design.

2025, Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

In this article, the authors measure throughput of sonic diamond microtubes and micronozzles that can work as passive gas flow controllers and flow meters under choking conditions. The behavior of the outlet pressure through the microdevices using an experimental setup with constant volume and constant temperature was determined in order to obtain the critical throughput, the critical mass flow rate, and the discharge coefficients of the diamond sonic microdevices.

2025, Automated Highway Systems

In Automated Highway Systems (AHS), vehicles will be able to follow each other automatically by using their own sensing and control systems, effectively reducing the role of the human driver in the operation of the vehicle. Such systems are therefore capable of reducing one source of error, human error, that diminishes the potential capacity of the highways and in the worst case becomes the cause of accidents. The inter-vehicle separation during vehicle following is one of the most critical parameters of the AHS system, as it affects both safety and highway capacity. To achieve the goal of improved highway capacity, the inter-vehicle separation should be as small as possible. On the other hand, to achieve the goal of improved safety and elimination of rear end collisions, the inter-vehicle separation should be large enough that even under a worst case stopping scenario, no vehicle collisions will take place. These two requirements demand diametrically opposing solutions and they have to be traded off. Since safety cannot be compromised for the sake of capacity, it becomes a serious constraint in most AHS design decisions. The trade-off between capacity and safety gives rise to a variety of different AHS concepts and architectures. In this study we consider a family of six AHS operational concepts. For each concept we calculate the minimum inter-vehicle spacing that could be used for collision-free vehicle following, under different road conditions. For architectures involving platoons we also use the alternative constraint of bounded energy collisions to calculate the spacing that can be applied if we allowed collisions at a limited relative velocity. In every case, the minimum spacing in turn, is used to calculate the maximum possible capacity that could be achieved for each operational concept.

2025, Food Research International

A rapid, easy to handle and low cost assay of ascorbic acid was developed, which consists in miniaturization on microplate of a redox reaction monitored spectrophotometrically, the signal being directly related to the concentration of ascorbic acid in the sample. This method was investigated in accordance with the prerogative of regulation covering food additives in terms of linear range/linearity, limits of detection and quantification, accuracy (including trueness and precision), robustness and selectivity. The application of the method was tested to determine ascorbic acid diffusivity in agar gel used as an aqueous food simulant. The diffusivity value obtained was 0.31 Â 10 À9 m 2 s À1 , with a confidence interval of 20% at 95% level. Accuracy of the assay and of the point's location on ascorbic acid profiles were examined by Monte-Carlo method to assess their influence on accuracy of diffusivity value obtained. Assay uncertainty was clearly demonstrated to be a critical parameter.

2025

Vacuum systems play a crucial role in experimental physics, semiconductor fabrication, and space simulations. The efficiency of vacuum pumps and chamber design directly impacts system performance. This study models a vacuum chamber's pressure behavior, considering molecular and viscous flow regimes, outgassing, and periodic leak events. This report documents the theoretical and computational work done to simulate pressure decay in a vacuum chamber.

2025, British Journal of Cancer

Considerable research has been aimed at improving the efficacy of chemotherapeutic agents for cancer therapy. A promising twostep approach that is designed to minimize systemic drug toxicity while maximizing activity in tumours employs monoclonal antibody (mAb)-enzyme conjugates for the activation of anticancer prodrugs. We present, analyse and numerically simulate a mathematical model based on the biology of the system to study the biodistribution, pharmacokinetics and localization properties of mAb-enzyme conjugates in tumour tissue. The model predictions were compared with experimental observations and an excellent correlation was found to exist. In addition, the critical parameters affecting conjugate half-life were determined to be the inter-capillary half-distance and the antibody-antigen binding affinity. An approximation is presented relating the per cent injected dose per gram to inter-capillary half-distance and time. Finally, the model was used to examine various dosing strategies in an attempt to determine which regimen would provide the best biodistribution results. We compared the results of administering a uniform dose of fusion protein via bolus injection, multiple injections and continuous infusion. The model predicts that dosing strategy has little effect on the amount of conjugate that localizes in the tumour.

2025, Proceedings of the …

With the advent of large-scale parallel computing systems, making parallel programs fault-tolerant becomes an important problem, be- cause the probability of a failure increases with the number of proces- sors. In this paper, we describe... more

2025, Electrochimica Acta

The objective of this work was to determine the parameters that affect the mass transport and the distribution of species in microcapillaries close to the specimen surface. Local experiments were carried out under static and flow conditions on type 316L stainless steel in 1.7 M NaCl, pH = 3, by means of the electrochemical microcell and the scanning droplet cell technique. The polarisation behaviour of pure iron (used as a model system) in an aqueous environment was calculated adopting a finite element approach and was compared to the experimental results. The corrosion system consists of three parallel electrochemical reactions: the oxygen reduction reaction (ORR), the hydrogen evolution reaction (HER) and iron dissolution.

2025, Journal of Applied Physics

Doped Si is a promising candidate for quantum computing due to its scalability properties, long spin coherence times, and the astonishing progress on Si technology and miniaturization in the past few decades. This proposal for a quantum computer ultimately relies on the quantum control of electrons bound to donors near a Si/barrier (e.g., SiO2) interface. We address here several important issues and define critical parameters that establish the conditions that allow the manipulation of donor electrons in Si by means of external electric and magnetic fields.

2025

An analysis of phase variation and phase range of concentric split ring square element for broadband reflectarray antenna is presented in this paper. This element is the combination of a single square element and a ring element where the square element is the modification of the conventional annular ring element which instead of using annul as the hole, this new idea presents a square as the hole in the ring. This will varies the current distribution in the element which will then improves the performance of the bandwidth. The analysis and the design of this reflectarray element is presented based on variable size which operates at the first resonant frequency of 13.44 GHz and a t the second resonant frequency of 18.36 GHz. The design procedure and critical parameters consist of phase range and phase slope (or varibion) are also discussed. Modifying the current distribution of square ring element, leads to a less steep phase variation and also enhancement on the bandwidth performance (up to 67.6%). The practical phase range is achieved through the use of RF35 as the substrate with the dielectric constant of 3.54 and the thicltness of 1.524 mm. CST Microstripes is used as the software tool to get the simulation results.

2025

Construction of an aged-structured bioeconomic model with : *M and q-at-aged parameters *Multifleet & multispecies *Distributed delay model (gamma PDF) for recruitment seasonality (Anderson and Seijo, 2010). Shrimp fishery data in Sinaloa sur for the 2014-2015 season : *Fleet effort in days/number units *Catch structure in sizes per species per fleet *Biological data (growth, weight, reproduction).

2025, Journal of entomology and zoology studies

Clean to slight pollution in biological water quality was observed in River Yamuna at Yamunotri and Hanuman chetti, in terms Biological Water Quality Criteria. River Yamuna was moderately polluted from Okhla Barrage to Allahabad throughout the year. At Etawah, the water quality became severely polluted during summer season. Water quality of River Yamuna at Yamunotri, meets the Primary Water Quality Criteria in terms of pH of 8.1, DO of 7.8 mg/l, BOD of <2 mg/l and Total Coliform count of <2 MPN/100 ml used for drinking water without conventional treatment but after disinfection Class A and Outdoor bathing Class B and Class 'C' and drinking water source after conventional treatment. Average Total Coliform counts of 24775 -66357500 MPN/100 ml did not meet the criteria of Total Coliform counts of 5000 MPN/100ml for drinking water source with conventional treatment followed by disinfection(Class 'C') in River Yamuna at downstream Yamunotri. Free Ammonia levels of 1.4-6.6 mg/l were unsuitable for propagation of wildlife, fisheries under Class 'D' in River Yamuna from Okhla Barrage to Etawah. Entire stretch of River Yamuna was found to meet the desired criteria for irrigation, industrial cooling and controlled waste disposal (Class 'E') in terms of conductivity levels of 83-1087 µmhos/cm.

2025, arXiv: Computational Physics

We present preliminary results on a novel numerical method describing wave propagation in non-uniform media. Following Huygens-Fresnel' principle, we model the wavefront as an array of point sources that emit wavelets, which interfere. We then identify a set of new points where the electric field has equal phase. In fact, without losing generality, we find zeros of the electric field, by means of the bisection method. This obviously corresponds to a specific phase-advance, but is easily generalized, e.g. by phase-shifting all sources. The points found form the new wavefront. One of the advantages of the method is that it includes diffraction. Two examples provided are diffraction around an obstacle and the finite waist of a focused Gaussian beam. Refraction is also successfully modeled, both in slowly-varying media as well as in the presence of discontinuities. The calculations were performed in two dimensions, but can be easily extended to three dimensions. We also discuss the ...

2025, Journal of Computational Physics

Coating flows, with a few exceptions, need to be steady and two-dimensional flows. Moreover, the flow states need to be stable at the operating conditions chosen. The goal of stability analysis of coating flows is to determine the region in the parameter space at which the flow is stable and therefore the coated layer uniform. To determine the stability of liquid flows, a generalized eigenvalue problem has to be solved. This paper describes a formulation for a linear, three-dimensional stability analysis of free surface flows that reduces the size of the eigenproblem, decreasing the computational cost, with no further simplification, when compared with the methods reported in the literature. This formulation is used to study the instability that arises in film-splitting flows between counter-rotating rolls in a deformable gap. This flow instability leads to nonuniform coating characterized by a wavy thickness profile in the transverse direction. This patterning is usually referred to as "ribs." This type of instability has received a lot of attention in the literature. However, all previous work has addressed the flow between two rigid rolls. Often, in practice, one of the rolls of a pair is covered by a layer of elastomer. The deformation of the roll cover alters the conformation of the gap, the pressure gradient at the film-split meniscus, and, consequently, the critical parameters at the onset of ribbing change. The results indicate how a deformable cover can be used to delay the onset of ribbing in forward-roll coating.

2025

Transparent conducting oxides are used as a contacting layer to liquid crystal (LC) based single wavelength optical phased array (OPA) infrared beam steerers. To investigate TCO optimization for this application, a numerical model based on the Drude (heelectron) theory is used to calculate the optical absorption at 1550 nm for layers with a fixed sheet resistance, Rs, as a function of conducting electron concentration and carrier mobility. For fixed Rs, carrier mobility is found to be the critical parameter. In short, increased mobility allows for reduced carrier concentration and hence less absorption for a given sheet resistance. For Rs = 3000 QISq., as is used in current prototype LC-OPA devices, the use of high conductivity commercial I T 0 would require using a very thin, -1 nm thick, IT0 layer. However, the conventionally worse TCO Zn-Sn-0 has good mobility but with a much lower carrier concentration than I T 0 which allows for a more robust layer thickness of 20 nm while still keeping the absorption minimal.

2025

Effect of various atomization techniques such as droplet size and velocity on the morphology of spray dried powders is investigated. Four types of atomizers are characterized and used to produce MgSO 4 and ZrO 2 powders: (a) a vibrating mesh nebulizer, (b) a splash plate nozzle, (c) an air mist atomizer, and (d) a pressure atomizer. Several types of particle morphologies are identified. Particle morphologies depend on the precursor type, droplet size and velocity, and operating conditions. Spray characteristics, such as droplet number density, droplet size and velocity distribution, and accompanying atomizing air are found to have major influence on the drying and morphology of the powders. In addition, the final particle size and wall thickness of zirconia powders are correlated with the reactor pressure, temperature, and the initial concentration of the solute. Increasing any of above mentioned parameters results in an increase in the final particle size and a decrease in the particle wall thickness.

2025, DergiPark (Istanbul University)

In this study, the optical properties of AlInN/AlN high electron mobility transistor (HEMT) structure, grown on c-oriented sapphire with Metal-Organic Chemical Vapor Deposition (MOCVD) technique, being investigated. Optical characterization is made Kubelka-Munk method. Transmittance, absorbance, and reflectance are investigated in detail. Also, the Kubelka-Munk theory is employed to determine the forbidden energy band gap of InN by using special functions. The energy band gap obtained by this method was compared.

2025, Water Resources Research

Because of uncertainty and variability in input parameter values, watershed-scale water quality modeling can result in significant output uncertainty. Quantifying this uncertainty is very important for policy makers and stakeholders who rely on the output of these models for watershed management. Given the large number of parameters in these complex models, a preliminary sensitivity analysis is needed before the uncertainty analysis. A few sensitivity studies have been conducted for watershed models, but efficiently selecting critical parameters for the uncertainty analysis remains an issue. This study aimed to (1) develop a framework for systematically conducting a preliminary sensitivity analysis for complex watershed models using generalized sensitivity analysis (GSA) as a global technique and (2) evaluate the relevance of incorporating management concerns in the preliminary sensitivity analysis and its impact on parameter selection. Although the proposed approach is valid for any complex watershed model, for this study the Watershed Analysis Risk Management Framework (WARMF) model was implemented using data from the Santa Clara River in southern California. To simulate hydrology, sediment, and pesticide transport, 121 parameters are needed for a single catchment/reach combination; an efficient selection method is paramount for an uncertainty analysis. The results show that GSA can be implemented efficiently, yielding insights into model and parameter behavior. The sensitivity analysis must consider management concerns early on in the process to identify parameters and parameter values that can influence management decisions. The number of parameters that must be considered in a subsequent uncertainty analysis was significantly reduced. This study also provides guidance for future research on parameter sensitivity and uncertainty in complex watershed models.

2025, Journal of Lightwave Technology

Experimental measurements are described characterizing the nonlinear index change over the range from 500 to 1550 nm induced in an ytterbium (Yb 3+ )-doped twin-core fiber by a 980 nm pump. At 1550 nm, a phase change of is induced with as little as 14 mW of pump power for a signal loss of only 0.2 dB. By allowing the doped fiber to lase and observing the associated clamping of the induced phase change, we show that a digital nonlinear response can be achieved in which a constant, pump-power-insensitive, phase change is induced for all pump powers above a certain threshold. This lasing induced clamping of the phase change also demonstrates that the nonlinear effect is population dependent as opposed to thermal. The pumpinduced phase change is observed to increase for shorter signal wavelengths, which suggests that the effect is due principally to pump-induced changes in the strong ultraviolet (UV) absorptions of Yb 3+ . This observation is accurately predicted by a theoretical analysis that takes into account absorptions in both infrared and ultraviolet regions. This analysis shows that Yb 3+ may be suitable for low-power all-optical switching applications in both 1300 and 1550 nm telecommunications windows when the speed of response is not a critical parameter.

2025, Journal of Contaminant Hydrology

Predictions of natural attenuation of volatile organic compounds (VOCs) in the unsaturated zone rely critically on information about microbial biodegradation kinetics. This study aims at determining kinetic rate laws for the aerobic biodegradation of a mixture of 12 volatile petroleum hydrocarbons and methyl tert-butyl ether (MTBE) in unsaturated alluvial sand. Laboratory column and batch experiments were performed at room temperature under aerobic conditions, and a reactive transport model for VOC vapors in soil gas coupled to Monod-type degradation kinetics was used for data interpretation. In the column experiment, an acclimatization of 23 days took place before steady-state diffusive vapor transport through the horizontal column was achieved. Monod kinetic parameters K s and v max could be derived from the concentration profiles of toluene, m-xylene, noctane, and n-hexane, because substrate saturation was approached with these compounds under the experimental conditions. The removal of cyclic alkanes, isooctane, and 1,2,4-trimethylbenzene followed first-order kinetics over the whole concentration range applied. MTBE, n-pentane, and chlorofluorocarbons (CFCs) were not visibly degraded. Batch experiments suggested first-order disappearance rate laws for all VOCs except n-octane, which decreased following zero-order kinetics in live batch experiments. For many compounds including MTBE, disappearance rates in abiotic batch experiments were as high as in live batches indicating sorption. It was concluded that

2025, ArXiv

2025, Vadose Zone Journal

Transport of chlorofluorocarbon (CFC) gases through the unsatu-1995), and groundwater-surface water interactions (Katz rated zone to the water table is affected by gas diffusion, air-water et al., 1995). A critical component in such analyses is the exchange (solubility), sorption to the soil matrix, advective-dispersive transport in the water phase, and, in some cases, anaerobic degrada-consideration of the transport and fate of the CFC tracers tion. In deep unsaturated zones, this may lead to a time lag between in the overlying unsaturated zone. For example, what entry of gases at the land surface and recharge to groundwater. Data are the CFC concentrations in recharge water and how from a Danish field site were used to investigate how time lag is aflong were the CFC gases in the unsaturated zone before fected by variations in water content and to explore the use of simple reaching the groundwater system? The residence time analytical solutions to calculate time lag. Numerical simulations demof a CFC tracer in the unsaturated zone is also called onstrate that either degradation or sorption of CFC-11 takes place, the time lag (Cook and Solomon, 1995). An accurate whereas CFC-12 and CFC-113 are nonreactive. Water flow did not estimate of the age of a groundwater sample also relies appreciably affect transport. An analytical solution for the period with on an accurate estimate of the time lag. a linear increase in atmospheric CFC concentrations (approximately For very shallow unsaturated zones of only a few early 1970s to early 1990s) was used to calculate CFC profiles and time lags. We compared the analytical results with numerical simulations. meters thickness, diffusion and barometric pumping suf-The time lags in the 15-m-deep unsaturated zone increase from 4.2 to ficiently mix the gases in the unsaturated zone so soilbetween 5.2 and 6.1 yr and from 3.4 to 3.9 yr for CFC-11 and CFC-12, gas CFC concentrations are similar to those in the trorespectively, when simulations change from use of an exponential to posphere. The input to the groundwater system is thus a linear increase in atmospheric concentrations. The CFC concentravery close to the atmospheric changes in CFC concentions at the water table before the early 1990s can be estimated by trations. This simple approach often has been used for P. Engesgaard and K.H. Jensen, Geological Institute, Univ. of Copensoil in Germany. A clear damping of the annual changes

2025, Proceedings of SPIE

The electrical and optical properties of mesoporous gold are compared to those of thin porous gold films and a simulated thin film made by randomly distributing voids in gold, until the voids fill 76% of film volume. All layers are electrically conducting but in some cases the critical percolation thresholds are close to zero, so conduction is possible at very high void content. Significant qualitative differences are apparent between the properties of mesoporous gold, and very thin sputtered gold containing voids, in plasmonic responses at optical frequencies and in dc resistance, both as a function of fill factor. The mesoporous films have an effective plasma frequency determined by void fill factor and structure, but do not support surface plasmons. In contrast thin porous gold layers display optical features associated with localized and de-localized surface plasmons. Sputtered porous gold is 2-dimensional and its percolation threshold requires a "Swisscheese" rather than particle cluster model. Thicker mesoporous layers have critical parameters consistent with very high connectivity, or equivalently large hyper-dimensionality. Our meso-gold samples display various hyper-dimensionalities from 3 to above 10.

2025, The World Bank Economic Review

respectively. The authors would like to thank George McAndless and Guillermo Escudé for comments, Christian Castro and Matías Gutierrez Girault for assistance, and two anonymous referees for invaluable comments. All remaining errors remain their own. The opinions expressed in this article are entirely those of the authors and do not necessarily reflect those of the Central Bank of Argentina or any other institution with which they are affiliated.

2025, Journal of Geophysical Research

The launch of ADEOS in August 1996 with POLDER, TOMS, and OCTS instruments on board and the future launch of EOS-AM 1 in mid-1998 with MODIS and MISR instruments on board start a new era in remote sensing of aerosol as part of a new remote sensing of the whole Earth system (see a list of the acronyms in the Notation section of the paper). These platforms will be followed by other international platforms with unique aerosol sensing capability, some still in this century (e.g., ENVISAT in 1999). These international spaceborne multispectral, multiangular, and polarization measurements, combined for the first time with international automatic, routine monitoring of aerosol from the ground, are expected to form a quantum leap in our ability to observe the highly variable global aerosol. This new capability is contrasted with present single-channel techniques for AVHRR, Meteosat, and GOES that although poorly calibrated and poorly characterized already generated important aerosol global maps and regional transport assessments. The new data will improve significantly atmospheric corrections for the aerosol effect on remote sensing of the oceans and be used to generate first real-time atmospheric corrections over the land. This special issue summarizes the science behind this change in remote sensing, and the sensitivity studies and applications of the new algorithms to data from present satellite and aircraft instruments. Background information and a summary of a critical discussion that took place in a workshop devoted to this topic is given in this introductory paper. In the discussion it was concluded that the anticipated remote sensing of aerosol simultaneously from several space platforms with different observation strategies, together with continuous validations around the world, is expected to be of significant importance to test remote sensing approaches to characterize the complex and highly variable aerosol field. So far, we have only partial understanding of the information content and accuracy of the radiative transfer inversion of aerosol information from the satellite data, due to lack of sufficient theoretical analysis and applications to proper field data. This limitation will make the anticipated new data even more interesting and challenging. A main concern is the present inadequate ability to sense aerosol absorption, from space or from the ground. Absorption is a critical parameter for climate studies and atmospheric corrections. Over oceans, main concerns are the effects of white caps and dust on the correction scheme. Future improvement in aerosol retrieval and atmospheric corrections will require better climatology of the aerosol properties and understanding of the effects of mixed composition and shape of the particles. The main ingredient missing in the planned remote sensing of aerosol are spaceborne and ground-based lidar observations of the aerosol profiles.

2025, Measurement Automation Monitoring

The paper presents a method for minimization of finite state machines (FSMs) with unspecified values of output variables. The proposed method is based on merging of two states. In addition to reduction of the FSM states, the method also allows reducing the number of FSM transitions and FSM input variables. This method enables reducing the number of internal states of the initial FSM by 1.22 times on the average, and by 2.75 times on occasion. An average reduction of the number of FSM transitions makes up 1.32 times, and on occasion may amount to 2.27 times. The comparison of the method with the program STAMINA shows that the offered method allows decreasing the number of FSM transitions by 1.55 times on the average, and by 3.92 times on occasion.

2025, Waste Management

This paper describes the design and testing of a trommel for separation of batteries from solid waste. A trommel is a cylindrical separation device that rotates and performs size separation. It has also been used in areas such as municipal solid waste (MSW) processing, classifying construction and demolition debris, screening mass-burn incinerator ash and compost processing. A trommel has been designed based on size separation to separate household batteries from solid waste, which can then be used as feedstock for alternative applications of solid waste combustion, particularly where the metal content of the product is also a critical parameter, such as the Co-Co process for integrated cement and power production. This trommel has been tested with batches of university office and restaurant wastes against various factors. The recovery efficiency of batteries increases with decreasing inclination angle of the trommel and decreasing rotational speed. A physical characterization of the university solid waste has been performed with a 20-kg sample of the tested waste. It was found that there is a trend of decreasing recovery of batteries with increasing paper composition, and a trend of increasing recovery of batteries with increasing organic materials composition.

2025, Geochemistry Geophysics Geosystems

Realistic models of past climate and ocean chemistry depend on reconstructions of the Earth's surface environments in the geologic past. Among the critical parameters is the geologic makeup of continental drainage. Here we show, for the present, that the isotope composition of dissolved strontium in rivers increases linearly with the age of bedrock in drainage basins, with the notable exception of the drainage area of Arabia, India, and Southeast Asia that is affected by unusually radiogenic dissolved Sr from the Himalaya. We also demonstrate that the neodymium isotope compositions of suspended matter in rivers as well as clastic sediments deposited along the ocean margins decrease linearly with the bedrock ages of river drainage basins and large-scale continental drainage regions, as determined from digital geologic maps. These correlations are used to calculate the present-day input of dissolved Sr (4.7 × 10 10 mol yr -1 , 87 Sr/ 86 Sr of ∼0.7111) and particulate Nd isotopes (" Nd of approximately -7.3 ± 2.2) to the oceans. The fact that the regionally averaged " Nd of the global detrital input to the global coastal ocean is identical to globally averaged seawater (" Nd of -7.2 ± 0.5) lends credence to the importance of "boundary exchange" for the Nd isotope composition of water masses. Regional biases in source areas of detrital matter and runoff are reflected by the observation that the average age of global bedrock, weighted according to the riverine suspended sediment flux, is significantly younger (∼336 Myr) than the age of global bedrock weighted according to water discharge (394 Myr), which is younger than the average bedrock age of the nonglaciated, exorheic portions of the continents (453 Myr). The observation that the bedrock age weighted according to Sr flux is younger (339 Myr) than that weighted according to water flux reflects the disproportionate contribution from young sedimentary and volcanic rocks to the dissolved Sr load. Neither the isotope composition of the dissolved nor the particulate continental inputs to the ocean provide unbiased perspectives of the lithologic makeup of the Earth's surface. Temporal changes in bedrock geology as well as the shifting focal points of physical erosion and water discharge will undoubtedly have exerted strong controls on temporal and spatial changes in the isotope chemistry of past global runoff and thus seawater.

2025, International Archives of Allergy and Immunology

Background: Recombinant allergens with a native conformation represent an alternative to natural extracts for immunotherapy and diagnostic purposes. Methods: We produced the Der p 2 mite allergen in Pichia pastoris and Escherichia coli. After purification by cation exchange chromatography, recombinant molecules were compared to their natural counterpart based upon structural (disulfide bonds, secondary structure, thermal stability) and immunological properties (antibody reactivity, basophil and T cell activation, tolerance induction in a murine sublingual immunotherapy model). Results: The Der p 2.0101 isoform was confirmed to be prevalent in Dermatophagoides pteronyssinus extracts. It was then produced as a secreted molecule in P. pastoris or refolded from E. coli inclusion bodies. The yeast-expressed rDer p 2 molecule exhibits a natural-like disulfide bridge distribution and secondary structure, whereas the E. coli-derived rDer p 2 presents some heterogeneity in cysteine bonds and...

2025

We document strong seismic scattering from around the top of the mantle Transition Zone in all available high resolution explosion seismic profiles from Siberia and North America. This seismic reflectivity from around the 410 km discontinuity indicates the presence of pronounced heterogeneity in the depth interval between 320 and 450 km in the Earth's mantle. We model the seismic observations by heterogeneity in the form of random seismic scatterers with typical scale lengths of kilometre size (10^40 km by 2^10 km) in a 100^140 km thick depth interval. The observed heterogeneity may be explained by changes in the depths to the K^L^Q spinel transformations caused by an unexpectedly high iron content at the top of the mantle Transition Zone. The phase transformation of pyroxenes into the garnet mineral majorite probably also contributes to the reflectivity, mainly below a depth of 400 km, whereas we find it unlikely that the presence of water or partial melt is the main cause of the observed strong seismic reflectivity. Subducted oceanic slabs that equilibrated at the top of the Transition Zone may also contribute to the observed reflectivity. If this is the main cause of the reflectivity, a substantial amount of young oceanic lithosphere has been subducted under Siberia and North America during their geologic evolution. Subducted slabs may have initiated metamorphic reactions in the original mantle rocks.

2025, International Journal of Nanomanufacturing

Micro mechanical milling plays a significant role in fabrication of miniature features in a variety of materials with capability for producing three dimensional (3D) freeform surfaces. A major challenge for micro machining of hardened material is a high tool wear rate and unpredictable tool life. In addition, surface roughness and burr formation are factors to be closely controlled. In this paper, the statistical analysis of critical parameters for micro milling of hardened tool steel is presented. The parameters included spindle speed, depth of cut, ratio of undeformed chip thickness to cutting edge radius and lubrication/environment conditions. The significance of these parameters on surface finish, burr formation and tool wear are reported. The study shows that machining environment is the most significant factor in controlling surface finish and tool wear. While, selection of appropriate spindle speed and the ratio of undeformed chip thickness to cutting edge radius is more critical in limiting burr size. The work reported in this paper is important, because industry needs to know key process variables (KPVs) that are critical in the control of micro machining performance. Additionally, the methodology enabled identification of optimum cutting values for these cutting parameters within the identified process window.

2025, Optimal control applications & methods

In this computational study we consider a generalized minimal model structure for the intravenously infused insulin-blood glucose dynamics, which can represent a wide variety of diabetic patients, and augment this model structure with a glucose rate disturbance signal that captures the aggregate effects of various internal and external factors on blood glucose. Then we develop a model-based, switching controller, which attempts to balance between optimal performance, reduced computational complexity and avoidance of dangerous hypoglycaemic events. We evaluate the proposed algorithm relative to the widely studied proportional-derivative controller for the regulation of blood glucose with continuous insulin infusions. The results show that the proposed switching control strategy can regulate blood glucose much better than the proportional-derivative controller for all the different types of diabetic patients examined. This new algorithm is also shown to be remarkably robust in the eve...

2025, Journal of Geophysical Research: Solid Earth

Red, hematite-bearing sedimentary rocks are an important source of paleomagnetic data, particularly for continental apparent polar wander paths during the Paleozoic. This study presents magnetic anisotropy data from the Mississippian Mauch Chunk Formation of eastern Pennsylvania, indicating that these red beds have suffered from a significant amount of paleomagnetic inclination shallowing. Fourteen oriented block samples were collected from normal and reversed polarity strata identified in a previous study. Thermal demagnetization isolated the characteristic remanent magnetization at seven normal polarity horizons at unblocking temperatures greater than 670°C (mean direction, D = 354.0°, I = À18.4°, a 95 = 10.2°). Anisotropy of remanence measurements (anisotropy of isothermal remanent magnetization and thermal remanent magnetization) indicate a bedding parallel, foliated magnetic fabric with foliations ranging from 1.1 to 1.35. Thermal demagnetization at 670°C of the isothermal remanent magnetization isolates the magnetic fabric of the characteristic remanence-carrying grains and indicates stronger foliations (1.15-1.48). Anisotropy of magnetic susceptibility (AMS) also indicates bedding parallel magnetic foliations of 1.01-1.04, typical of red beds. Chemical leaching isolates the AMS of the characteristic remanence-carrying grains to range from 1.02 to 1.07. This AMS fabric was used to correct the characteristic remanence inclination isolated by thermal demagnetization. The critical parameter needed for an accurate inclination correction, the individual particle anisotropy a c , was determined from the correlation between the normalized principal axes of remanence and susceptibility anisotropy to be 1.06. The corrected Mauch Chunk direction, D = 354.5°, I = À56.4°r esults in a corrected Mauch Chunk Formation paleopole (12°N, 108°E) that is consistent with a European igneous paleopole.

2025, The Journal of Supercritical Fluids

The role of excess molar enthalpies (H E m ) in the supercritical antisolvent (SAS) micronizations using dimethylsulfoxide (DMSO) as the polar solvent was investigated. Excess molar enthalpies for CO 2 + DMSO mixtures were measured using an isothermal high-pressure flow calorimeter under conditions of temperature and pressure typically used in SAS micronizations. In most cases, mixtures showed very exothermic mixing. A local temperature increase can be expected in the precipitation chamber as a consequence of the heat evolved when CO 2 dissolves in DMSO. Based on the H E m measurements, local temperature increases were calculated and shown to explain immiscibility of CO 2 and DMSO and agglomerated or irregular particles for average temperature and pressure conditions where complete miscibility and uniform particles could have been expected. H E m data were also discussed in terms of molecular interactions, phase equilibria, density and critical parameters previously reported for CO 2 + DMSO.