Uniform Control Research Articles

Improving the Electro-Optical Deflection Performance of KTN Crystals Based on the Temperature Compensation Effect

The laser deflector is a crucial device used to change the direction of light beam propagation in various fields, including lithography, lidar, and scanning. In this paper, we conduct a systematic study of two KTa(1–x)NbxO3 (KTN) crystals that use different physical deflection mechanisms. We analyze their dielectric properties, entropy, domain structure, and deflection performance. We also address the drawback of the small deflection angle of the compositional gradient KTN deflector crystal by proposing a new temperature-compensated temperature control strategy to improve its deflection performance. The gradient temperature control mechanism maximizes the dielectric constant in different regions of the KTN crystals, leading to a threefold (10.67 mrad) increase in deflection angle compared to conventional uniform temperature control equipment. This optimized temperature control mechanism can significantly enhance the practical application of KTN crystals, providing a new avenue for achieving a large deflection angle beam deflector.

The application of Near-Infrared Spatially Resolved Spectroscopy in scope of achieving continuous real-time quality monitoring and control of tablets with challenging dimensions

In scope of achieving real-time release of tablets, quality attributes need to be monitored and controlled through Process Analytical Technology tools such as near-infrared spectroscopy (NIRS). The authors evaluated the suitability of NIR-Spatially Resolved Spectroscopy (NIR-SRS) for continuous real-time monitoring and control of content uniformity, hardness and homogeneity of tablets with challenging dimensions. A novel user-friendly research and development inspection unit was used as standalone equipment for the analysis of small oblong tablets with deep-cut break lines. A total of 66 tablets varying in hardness and Active Pharmaceutical Ingredient (API) content were inspected, with each tablet being analysed five times and measurements repeated on three different days. Partial Least Squares (PLS) models were developed to assess content uniformity and hardness, of which the former showed higher accuracy. The authors attempted to visualize tablet homogeneity through NIR-SRS spectra by regressing all spectra obtained during a single measurement using a content uniformity PLS model. The NIR-SRS probe demonstrated its potential towards real-time release testing through its ability to quickly monitor content uniformity, hardness and visualize homogeneity, even for tablets with challenging dimensions.

Graded honeycombs with high impact resistance through machine learning-based optimization

Gradient structures with enhanced performance are ubiquitously observed in nature and in engineering materials. In this paper, we studied the impact resistance of two types of broadly used honeycomb structures (HCSs), a hexagonal HCS and an auxetic HCS. We developed a neural network (NN) which could effectively help to find an optimal gradient design for energy absorption of HCSs in contrast with their uniform counterpart. The optimal density gradient for both hexagonal HCS and auxetic HCS was identified, which are 66% and 40% higher in energy absorption than their respective uniform control. Followed finite-element analysis revealed that density gradient of HCSs enables loading transfer among a greater deformation zone, consequentially more cells involving in energy absorption. The initially graded sample promotes a de-gradient process and leads to more homogeneous density; conversely, a uniform sample develops localized deformation when subject to impact loading. Such an equal-load-partition (ELP) strategy in graded HCSs is responsible for their supreme energy absorption. The developed machine learning (ML) method for impact resistance optimization and the revealed deformation mechanisms in graded HCSs would be meaningful for the design of new advanced graded materials.

Large area solid oxide fuel cells with room temperature sputtered barrier layers: Role of the layer thickness and uniformity in the enhancement of the electrochemical performances and durability

We investigate the effects of the layer thickness and uniformity in solid oxide fuel cells with Gd0.1Ce0.9O1.95-δ buffer layers deposited by room temperature sputtering followed by in air annealing. Buffer layers with different thickness (in the range 200–400 nm) have been deposited using two different sputtering configurations resulting in different thickness uniformity and coverage of the Gd0.1Ce0.9O1.95-δ thin layers. By comparing the electrochemical performances at different temperatures of the cells with sputtered and screen printed buffer layers assembled in the same short stack, we have observed improvements, particularly at lower temperatures, of all the analysed properties (current density vs. voltage curves, Area Specific Resistance, Electrochemical Impedance Spectroscopy) in the case of the cells with sputtered buffer layers, with those having better thickness uniformity always showing the higher and more regular values. Percentage voltage changes of about +8% along with polarization resistance percentage reduction around −10% have been observed at 650 °C. Durability test at 750 °C performed over about 3000 h on the cell with 300 nm thick buffer layer having larger thickness uniformity, has shown percentage voltage changes more than halved respect to those observed for cells with screen printed buffer layers. The obtained results address the importance of the thickness uniformity control when fabricating thin buffer layers of few hundreds of nanometers on anode/electrolyte half-cells with surface roughness of the same order of magnitude.

Study for Bonding Technology by Electroplated Nano porous Cu Structure

The various kinds of the packaging technologies such as 2.nD, 2.5D, 3D are highly studied with the rapid development of miniaturization and high density of semiconductor packaging. This trend increases the importance of fine pitch interconnect. To achieve fine pitch interconnect, Cu-Cu direct bonding or hybrid bonding which has no solder in bonding layer is the promising technologies. There are some difficulties in the solderless bonding such as the control of bump uniformity, high accuracy CMP (Chemical Mechanical Polishing) process and so on. In particular, the exact surface shape control is the essential issue. To solve these problems, we are proposing Nano porous (NP) Cu materials for interconnect material. One of the technical challenges is the process for formation of NP Cu µ-bump structure. We are focusing on electroplating process for µ-bump formation. Firstly, we developed the plating chemicals for formation of NP Cu structure. We consider two types of plating chemicals for NP Cu formation, de-alloying and direct porous plating process. For de-alloying process, Cu-Zn alloy bumps were plated, and NP Cu bumps were obtained by de-alloying the Cu-Zn alloy. For direct porous plating process, NP Cu bumps were plated by using unique additives which can form NP structure directly. By using electroplated NP Cu, we studied its various properties, and carried out bonding tests. As the results, NP Cu structure shows unique properties such as electrical conductivity and the hardness, and we consider that these unique properties should widen the bonding process margin. We would like to present our recent research of NP Cu which is promising materials for advanced bonding technology.

Dispersing small Ru nanoparticles into boron nitride remodified by reduced graphene oxide for high-efficient electrocatalytic hydrogen evolution reaction

Ruthenium (Ru) electrocatalysts suffer from excessive aggregation during the hydrogen evolution reaction (HER), which hinders their practical application for hydrogen production. Hexagonal boron nitride (h-BN) is a potential carrier that could solve the above problem, but its wide band gap and low conductivity become obstacles. Herein, we provide a new, facile, low-cost, and effective strategy (killing two birds with one stone) to overcome the above issues. After modifying h-BN with reduced graphene oxide (rGO), a small amount of Ru nanoparticles (NPs) (2.2 %) are dispersed into BN with approximately uniform distribution and size control of Ru nanoparticles (∼3.85 nm). The strong synergy between Ru NPs and BN@C in the optimal Ru/BN@C (Ru wt.% = 2.22 %) electrocatalyst endows it an outstanding HER activity, with small HER overpotentials (η10 = 32 mV, 35 mV) and low Tafel slopes (33.89 mV dec−1, 37.66 mV dec−1) in both 1 M KOH and 0.5 M H2SO4 media, respectively, along with good long-term stability for 50 h. Based on density functional theory (DFT) calculations, the addition of Ru to BN has been successful in creating fresh active sites for H*, with good possible adsorption/desorption ability (ΔGH* = −0.24 eV) while preserving low water dissociation (ΔGb = 0.46 eV) in an alkaline environment. As a result, the Ru/BN composite exhibits outstanding HER activity in both acidic and alkaline conditions. Furthermore, this study provides, for the first time, a template-free strategy to develop a good and low-cost supporter (BN) for dispersing other noble metals and the formation of highly efficient HER/OER electrocatalysts.

Electrochemical behavior and anti-corrosion property of Ti3C2Tx MXene/LDH heterostructured coating on aluminum alloy

Two-dimensional (2D) materials show potential applications in anti-corrosion on metals in aggressive medium. However, it remains a challenge in uniform dispersion, complex functionalization, and structure control of 2D nanosheets in composite coatings. Herein, a Ti3C2Tx/layered double hydroxide (LDH) heterostructured coating for corrosion protection on Al alloy is proposed by in situ growth and dip coating process. Without complex functionalization, dispersion, and structure control, the heterostructured coating provides an enhanced corrosion resistance confirmed by electrochemical tests and microstructure characterization. As a result, the incorporation of Ti3C2Tx MXene can decrease the corrosion current density by ~40-fold and increase the coating resistance by 54-fold compared to bare Al alloy. Furthermore, the Ti3C2Tx/LDH coating still exhibits a self-healing ability after immersion in 3.5 wt% NaCl solution over 3 days, thereby providing long-term corrosion protection on Al alloy for 30 days. The protective behavior is attributed to the blocking effect and the feature of participating in electrochemical corrosion reaction and losing electrons of 2D MXene prior to the metal. This strategy provides a facile and effective approach to designing 2D materials-based anticorrosion coatings on Al alloy used in aggressive environments.

On a Conjecture of De Giorgi About the Phase-Field Approximation of the Willmore Functional

In 1991 De Giorgi conjectured that, given lambda >0, if mu _varepsilon stands for the density of the Allen-Cahn energy and v_varepsilon represents its first variation, then int [v_varepsilon ^2 + lambda ] dmu _varepsilon should Gamma -converge to clambda {text {Per}}(E) + k mathcal {W}(Sigma ) for some real constant k, where {text {Per}}(E) is the perimeter of the set E, Sigma =partial E, mathcal {W}(Sigma ) is the Willmore functional, and c is an explicit positive constant. A modified version of this conjecture was proved in space dimensions 2 and 3 by Röger and Schätzle, when the term int v_varepsilon ^2 , dmu _varepsilon is replaced by int v_varepsilon ^2 {varepsilon }^{-1} dx, with a suitable k>0. In the present paper we show that, surprisingly, the original De Giorgi conjecture holds with k=0. Further properties of the limit measures obtained under a uniform control of the approximating energies are also provided.

Twin-screw continuous mixing: Effect of mixing elements and processing parameters on properties of aerosol powders

Twin-screw continuous mixing was used to prepare aerosol powders containing 1% budesonide, 0.3% magnesium stearate, and 98.7% α-lactose monohydrate. The effect of mixing configuration was studied using three screw profiles containing either a combing element, 30° forward kneading element, or a 60° forward kneading element. The impact of screw speed, feed rate, and multiple passes through the mixer on powder quality was investigated. The impact of specific energy on aerosol performance was dependent on the mixing configuration, and high energy input was detrimental to FPF for the 30° kneading element. Control of content uniformity was demonstrated by varying the mixing element in the screw profile. Passing the material through the mixer multiple times improved the aerosol performance. The robust and tunable nature of twin-screw mixing makes it a process well suited for continuous manufacturing of aerosol powders.

UACA: Unified Access Control Approach For Heterogeneous Database Based-on Service Data Object

Abstract: The requirement for data interchange, access, and retrieval from diverse databases. This requirement is getting more and more crucial. However, retrieving this data from a heterogeneous database necessitates juggling many kinds of query languages, data models, and structure. The goal of this project is to create a unified access control approach (UACA), which will be managed by service data object (SDO) technologies and will be based on an agent mechanism for application access to business databases. To create a unified data access control, applications must be submitted through a UACA. To prevent a direct link to the database and application security threats, unified access control isolates applications from databases. Application systems submit a request for identity authentication to the database access control system using the data access protocol of the access control system. Data are finally transmitted to the application system after identity authentication, data gathering, and data transmission. This investigation led to the creation of a client-middle layer, which is also in charge of transformation and optimization, to ensure uniform data access control and access to the heterogeneous database. It also manages system communication using the TCP/IP protocol to guarantee the accuracy and reliability of the connection. SDO data retrieval offers strong adaptability and system compatibility.

Electrochemical Ionic Synapses: Progress and Perspectives.

Artificial neural networks based on crossbar arrays of analog programmable resistors can address the high energy challenge of conventional hardware in artificial intelligence applications. However, state-of-the-art two-terminal resistive switching devices based on conductive filament formation suffer from high variability and poor controllability. Electrochemical ionic synapses are three-terminal devices that operate by electrochemical and dynamic insertion/extraction of ions that control the electronic conductivity of a channel in a single solid-solution phase. They are promising candidates for programmable resistors in crossbar arrays because they have shown uniform and deterministic control of electronic conductivity based on ion doping, with very low energy consumption. Here, the desirable specifications of these programmable resistors are presented. Then, an overview of the current progress of devices based on Li+ , O2- , and H+ ions and material systems is provided. Achieving nanosecond speed, low operation voltage (≈1V), low energy consumption, with complementary metal-oxide-semiconductor compatibility all simultaneously remains a challenge. Toward this goal, a physical model of the device is constructed to provide guidelines for the desired material properties to overcome the remaining challenges. Finally, an outlook is provided, including strategies to advance materials toward the desirable properties and the future opportunities for electrochemical ionic synapses.

High-entropy alloy nanopatterns by prescribed metallization of DNA origami templates

High-entropy multimetallic nanopatterns with controlled morphology, composition and uniformity hold great potential for developing nanoelectronics, nanophotonics and catalysis. Nevertheless, the lack of general methods for patterning multiple metals poses a limit. Here, we develop a DNA origami-based metallization reaction system to prescribe multimetallic nanopatterns with peroxidase-like activities. We find that strong coordination between metal elements and DNA bases enables the accumulation of metal ions on protruding clustered DNA (pcDNA) that are prescribed on DNA origami. As a result of the condensation of pcDNA, these sites can serve as nucleation site for metal plating. We have synthesized multimetallic nanopatterns composed of up to five metal elements (Co, Pd, Pt, Ag and Ni), and obtained insights on elemental uniformity control at the nanoscale. This method provides an alternative pathway to construct a library of multimetallic nanopatterns.

Electrical Control of Uniformity in Quantum Dot Devices.

Highly uniform quantum systems are essential for the practical implementation of scalable quantum processors. While quantum dot spin qubits based on semiconductor technology are a promising platform for large-scale quantum computing, their small size makes them particularly sensitive to their local environment. Here, we present a method to electrically obtain a high degree of uniformity in the intrinsic potential landscape using hysteretic shifts of the gate voltage characteristics. We demonstrate the tuning of pinch-off voltages in quantum dot devices over hundreds of millivolts that then remain stable at least for hours. Applying our method, we homogenize the pinch-off voltages of the plunger gates in a linear array for four quantum dots, reducing the spread in pinch-off voltages by one order of magnitude. This work provides a new tool for the tuning of quantum dot devices and offers new perspectives for the implementation of scalable spin qubit arrays.

Do Dosiomic Features Extracted From Planned 3-Dimensional Dose Distribution Improve Biochemical Failure-Free Survival Prediction: an Analysis Based on a Large Multi-Institutional Data Set

The objective of this work was to investigate whether including additional dosiomic features can improve biochemical failure-free survival prediction compared with models with clinical features only or with clinical features as well as equivalent uniform dose and tumor control probability. This retrospective study included 1852 patients who received diagnoses of localized prostate cancer between 2010 and 2016 and were treated with curative external beam radiation therapy in Albert, Canada. A total of 1562 patients from 2 centers were used for developing 3 random survival forest models: Model A included only 5 clinical features; Model B included 5 clinical features, equivalent uniform dose, and tumor control probability; and Model C considered 5 clinical features and 2074 dosiomic features derived from the planned dose distribution of the clinical target volume and planning target volume with further feature selection to determine prognostic features. No feature selection was performed for models A and B. Two hundred ninety patients from another 2 centers were used for independent validation. Individual model-based risk stratification was examined, and the log-rank tests were performed to test statistically significant differences between the risk groups. The 3 models' performances were evaluated using Harrell's concordance index (C-index) and compared using one-way repeated-measures analysis of variance with post hoc paired t test. Model C selected 6 dosiomic features and 4 clinical features to be prognostic. There were statistically significant differences between the 4 risk groups for both training and validation data sets. The C-index for the out-of-bag samples of the training data set was 0.650, 0.648, and 0.669 for models A, B, and C, respectively. The C-index for the validation data set for models A, B, and C was 0.653, 0.648, and 0.662, respectively. Although gains were modest, Model C was statistically significantly better than models A and B. Dosiomics contain information beyond common dose-volume histogram metrics from planned dose distributions. Incorporation of prognostic dosiomic features in biochemical failure-free survival outcome models can lead to statistically significant although modest improvement in performance.

Dataset underlying the manuscript: Electrical control of uniformity in quantum dot devices

Dataset underlying the manuscript: Electrical control of uniformity in quantum dot devices

COVID-19 Epidemic in the Kaliningrad Region: Incidence and Infection Control Measures

Introduction: Combating the epidemic of the novel coronavirus disease required decision-making at the state level and joining efforts of medical workers of all specialties. The experience of the Kaliningrad Region deserves special attention since this region is located in Central Europe and the first COVID-19 cases were imported here in March 2020. Objective: To assess COVID-19 epidemic manifestations and effectiveness of preventive measures at the regional level. Materials and methods: We performed a retrospective epidemiological analysis of COVID-19 incidence in the Kaliningrad Region from March 2020 to December 2022. All registered cases were confirmed by PCR or immunochromatography assay. The study included 193,259 cases, 1,879 fatal cases, 1,168 samples with the established SARS-CoV-2 genetic variant, and information on 693,627 people vaccinated against COVID-19. The data were analyzed in Microsoft Excel and WinPepi (version 11.65). Results: In 2020, the COVID-19 incidence rate in the Kaliningrad Region was lower than that in the Russian Federation while in the years 2021 and 2022 the regional rates were, on the opposite, higher than the respective national ones (p < 0.05). All age groups of the population were involved in the outbreak. Periodic rises in the incidence were associated with the replacement of the Delta variant of SARS-CoV-2 with Omicron. We established high efficacy of vaccination against COVID-19: incidence and mortality rates among the unvaccinated were significantly higher than those among vaccinated individuals (p < 0.05). Conclusion: Organization of uniform infection control measures has enabled timely interdepartmental managerial decision-making to control the epidemic. Russian regions have accumulated unique experience in implementing a set of preventive and anti-epidemic measures to combat the epidemic of the novel infection.

Control of the ion flux and energy distribution of dual-frequency capacitive RF plasmas by the variation of the driving voltages

Due to its advantages of spatial uniformity and ion energy control, a dual-frequency (DF) capacitive-coupled plasma is widely used in semiconductor etching and deposition processes. In low-pressure discharges, the mean free path of ions is longer than the sheath width, and the ion energy distribution function is sensitive to the driving voltage waveform. In this respect, it is necessary to use a particle-in-cell (PIC) simulation to observe ion movement according to the time-varying electric field in the sheath. This study uses a two-dimensional PIC simulation parallelized with a graphics processing unit to monitor the ion energy distribution and flux according to the DF voltage waveform. We suggested a method to control the ion energy through a phase-resolved ion energy distribution in the region, where the ion transit time is longer than the high-frequency period and shorter than the low-frequency period.

Panoramic UAV Image Mosaic Method and Its Application in Pavement Paving Temperature Monitoring

The low-altitude technology of unmanned airborne infrared detection system is used to effectively monitor the temperature segregation in the paving stage and realize the temperature uniformity control of asphalt pavement construction. The image mosaic method can splice two images with overlapping areas together to form a panoramic image. In order to solve the problems of long time-consuming and low accuracy of aerial image mosaic algorithm, the low-temperature area of the whole pavement can be obtained quickly and accurately. In this paper, threshold segmentation technology is introduced to convert the image captured by the unmanned aerial vehicle (UAV) into a binary greyscale image so as to compensate for the mosaic error caused by temperature difference. In order to improve the efficiency and accuracy of splicing, a reference plate is used, which can provide enough feature points for splicing. Finally, the image mosaic method proposed in this paper can quickly obtain the image of the whole low-temperature area of the newly paved asphalt pavement, which has practical value and positive significance for the quality control of asphalt pavement.

Fault-tolerant control for full-state error constrained attitude tracking of uncertain spacecraft

This paper explores the fault-tolerant control (FTC) problem for full-state error constrained attitude tracking of an uncertain spacecraft. The existing FTC solutions to this problem generally rely on an uniform strong controllability (USC) assumption that may not hold in the presence of multiplicative actuator faults. In this work, a sufficient condition for the USC assumption is presented to help evaluate the applicability of existing FTC solutions. Then, based on the unified error transformation method and symmetric barrier Lyapunov functions, a saturated adaptive robust FTC algorithm is proposed, which can eliminate the USC assumption without requiring the multiplicative actuator faults to be differentiable, while ensuring that (i) full-state error constraints are never violated; (ii) all closed-loop signals are bounded, despite the simultaneous presence of inertia uncertainties, disturbances, and actuator faults. Finally, simulation results are provided to verify our theoretical findings.

Validation of a pelvic surgery difficulty risk model to predict difficult pelvic dissection and poor outcomes

BackgroundWe previously developed the Pelvic Surgery Difficulty Index for predicting intraoperative events and postoperative outcomes associated with rectal mobilization with or without proctectomy (“deep pelvic dissection”). The aim of this study was to validate the scoring system as a prognostic tool for outcomes of pelvic dissection, regardless of the cause of dissection. MethodsConsecutive patients who underwent elective deep pelvic dissection at our institution from 2009 to 2016 were reviewed. Pelvic Surgery Difficulty Index score (0–3) was calculated from the following parameters: male sex (+1), prior pelvic radiotherapy (+1), and linear distance from sacral promontory to pelvic floor >13 cm (+1). Patient outcomes stratified by Pelvic Surgery Difficulty Index score were compared. The outcomes assessed included operative blood loss, operative time, length of hospital stay, cost, and postoperative complications. ResultsA total of 347 patients were included. Higher Pelvic Surgery Difficulty Index scores were associated with significantly more blood loss, operative time, postoperative complications, hospital costs, and hospital stay. The model achieved good discrimination with area under the curve ≥0.7 for most outcomes. ConclusionPreoperative prediction of the morbidity associated with difficult pelvic dissection is possible with an objective, feasible, and validated model. Such a tool may facilitate preoperative preparation and allow for better risk stratification and uniform quality control across centers.