Search

Recent advancements in 3D printing technology have expanded its application to manufacturing pressure sensors. By harnessing the cost‐effectiveness, streamlined processes, and design flexibility of 3D printing, sensor fabrication can be customized to meet specific performance needs. Thus far, 3D printing in pressure sensor development has been primarily limited to creating molds for transferring patterns onto flexible substrates, restricting both material selection and sensor performance. To fully unlock the potential of 3D printing in advanced pressure sensor fabrication, it is crucial to establish effective design rules focused on enhancing the figure of merit performance. This study introduces a universal design strategy aimed at maintaining high sensitivity across a wide pressure range—a challenging feat, as sensitivity significantly decreases at higher pressures. Our approach centers on engineering the deformability of 3D‐printed structures, achieving a linear increase in contact area between sensor patterns and electrodes without reaching saturation. Sensors designed with high elongation and low stiffness exhibit consistent sensitivity of 162.5 kPa⁻¹ across a broad pressure range (0.05–300 kPa). Mechanistic investigations through finite element analysis confirm that engineered deformability is key to achieving this enhanced linear response, offering robust sensing capabilities for demanding applications such as deep‐sea and space exploration. [ABSTRACT FROM AUTHOR]

Satellite observations have become increasingly important in scientific studies of the Earth's climate, especially for oceanographic science. A next generation sensor known as the Ocean Color Instrument (OCI) was launched in February 2024 onboard the Plankton, Aerosol, Cloud, and ocean Ecosystem (PACE) platform, and will extend the data set of on-orbit scientific observations used for ocean and atmospheric science research. Delivering high quality data from a space-borne sensor requires the instrument to be well calibrated; while much of the calibration can be performed on-orbit, some aspects of the calibration must be measured or the mechanisms verified pre-launch. One aspect of the OCI calibration that is novel to its design (for a space-based sensor) is its ability to perform linearity measurements on orbit. When viewing the Sun reflected off a dim diffuser with ∼2–3% reflectance, the sensor is capable of recording successive pixels with increasing integration times. The result is a series of light levels measured from the same source in a given scan line. These measurements are then used to assess the linearity. During the pre-launch test campaign, this mechanism was verified using a known source in the Earth view portion of the scan. Results from these tests form a baseline that was verified once on-orbit (and the calibration may be replaced if the linearity is shown to change). The linearity measured both prior to launch and post-launch will be assessed in this work. [ABSTRACT FROM AUTHOR]

A linear high‐sensitivity response is crucial for flexible electronic skin, particularly in precision detection for applications like intelligent robotics and human‐machine interactions. Prevailing strategies typically adopt a layered, multifaceted material design to cultivate this response, yet this approach often culminates in a diminished capacity to augment sensing stability. The root causes of these limitations are predominantly material mechanical mismatches and interface incompatibilities inherent in these designs. To address these challenges, an electromechanical integration strategy is introduced that simultaneously enhances linear highsensitivity and stability. This strategy is centered on constructing a robust, integrated mechanical and electrical interface within a polyurethane material system through an in situ growth and adhesion process. The iontronic pressure sensor exhibits a linear high‐sensitivity response (16.24 kPa−1, R2 = 0.999) within a wide range (0–300 kPa). Moreover, the sensor's integrated structure, self‐encapsulated through the adhesion between the electrode and dielectric layers, exhibits robust stability, even under complex mechanical stresses. The applications of the sensors in precision weighing and haptic feedback within intelligent gripping systems demonstrate their advantages of both linearity and stable sensing. This work delineates a strategic pathway for the fabrication of high‐performance flexible pressure sensors, contributing significantly to the field of advanced sensing technologies. [ABSTRACT FROM AUTHOR]

Based on our interest in properties of human movement, we investigated Japanese GPS data, and arrived at the following three observations: (1) there is a strong correlation between the area of polygons created by human movement trajectories and their perimeters; (2) short-distance movement trajectories less than 5 km tend to enclose a large area like a circle; and (3) long-distance movement trajectories over 5 km tend to be straight. We also clarified the following four observations on individual attributes and external factors related to long-distance movements: (1) women tend to travel more linearly than men; (2) linearity is stronger on weekends and national holidays in areas with a large theme park; (3) linearity is weaker on weekends and holidays in areas with many historical tourist attractions; and (4) these variations are created by people visiting such areas. These properties should be incorporated when modeling the movement trajectories of humans. [ABSTRACT FROM AUTHOR]

ABSTRACT In this paper, the iCGF−1 mode is proposed to compensate the amplitude‐to‐amplitude modulation (AM/AM) distortion of the traditional continuous class F−1 mode while maintaining the high efficiency. The AM/AM profile of the iCGF−1 mode is mathematically expressed simultaneously as a function of the input nonlinearity parameter γ$$ \gamma $$ and conduction angle α$$ \alpha $$, which makes the iCGF−1 mode more flexible in controlling the AM/AM profile. The first inflection point of the AM/AM profile can be moved to a higher output power level through theoretical deduction by adjusting the second harmonic source impedance Z2S$$ {Z}_{2S} $$ and gate bias voltage to increase the values of γ$$ \gamma $$ and α$$ \alpha $$. This flattens the AM/AM profile while the efficiency profile remains almost the same as that of the traditional continuous class F−1 mode. The performance of the iCGF−1 mode is verified through simulation and experimental measurements. The iCGF−1 PA is fabricated with CGH40010F and has a frequency range of 2–2.6 GHz. The drain efficiency is 70.1%–77.9%, and the output power is 41.1–41.7 dBm. The linearity is tested with a 100 MHz 5G NR signal (the peak average power ratio (PAPR) is 8.5 dB) at 2.3 GHz. The worst adjacent channel power ratio (ACPR) is −32.3 dBc without digital predistortion (DPD) and −52.1 dBc with DPD. The results show that the iCGF−1 mode has successfully compensated the AM/AM distortion of the traditional continuous class F−1$$ {}^{-1} $$ mode and maintaining high efficiency. [ABSTRACT FROM AUTHOR]

Microwave photonic (MWP) systems are inseparable from conversions of microwave electrical signals into optical signals, and their performances highly depend on the linearity of electro-optic modulators. Thin-film lithium niobate (TFLN) is expected to be an ideal platform for future microwave photonic systems due to its compact size, low optical loss, linear electro-optic effect, and high bandwidth. In this paper, we propose a TFLN modulator with a low voltage–length product (VπL) of 1.97 V·cm and an ultra-high-linearity carrier-to-distortion ratio (CDR) of 112.33 dB, using a dual-parallel Mach–Zehnder interferometer configuration. It provides an effective approach to fully suppress the third-order intermodulation distortions (IMD3), leading to 76 dB improvement over a single Mach–Zehnder modulator (MZM) in TFLN. The proposed TFLN modulator would enable a wide variety of applications in integrated MWP systems with large-scale integration, low power consumption, low optical loss, and high bandwidth. [ABSTRACT FROM AUTHOR]

Voltage-controlled oscillators (VCOs) can be an excellent means of converting a magnitude into a readable value. However, their design becomes a real challenge for power-and-area-constrained applications, especially when a linear response is required. This paper presents a VCO for smart dust systems fabricated by 65 nm technology. It is designed to minimize leakage, limit high peak currents and provide an output whose frequency variation is linear with the input voltage, while allowing rail-to-rail input range swing. The oscillator occupies 592 μ m 2 , operates in a frequency range from 43 to 53 Hz and consumes a maximum average power of 210 pW at a supply voltage of 1 V and 4 pW at 0.3 V. In addition, the proposed VCO exhibits a quasi-linear response of frequency vs. supply voltage and temperature, allowing easy temperature compensation with complementary to absolute temperature (CTAT) voltage. [ABSTRACT FROM AUTHOR]

The metachromatic dye dimethylmethylene blue is used to quantify total glycosaminoglycans in urine. Understanding the interaction of dimethylmethylene blue with glycosaminoglycans is pertinent to optimize the assay procedure depending on the type of sample and interpret the findings meaningfully. The present spectrophotometric study determined the optimum sample-to-dye ratio, primary wavelength for measuring absorbance, after studying the interaction of two different chondroitin sulfate species (unfractionated chondroitin sulfate from bovine trachea vs. chondroitin sulfate oligosaccharide with degree of polymerization of 12, from shark cartilage) with dimethylmethylene blue. Respective dye-glycosaminoglycan complexes of the two chondroitin sulfate species showed significantly different absorbance maxima, while that of the chondroitin sulfate oligosaccharide was closer to absorbance maxima of urine glycosaminoglycans. The chondroitin sulfate oligosaccharide showed relatively less stable absorbance readings at higher concentrations in the reaction volume. Furthermore, the chondroitin sulfate reference materials exhibited differences in the linearity of standard curves and hence parallelism. Based on the findings, the method was semiautomated on Beckman Coulter D✕C 700 biochemistry analyzer using the chondroitin sulfate oligosaccharide as the standard. The urine glycosaminoglycan concentration obtained was slightly lower but reasonably close to that obtained through the External Quality Assurance (EQA) scheme administrated by ERNDIM (European Research Network, Inherited Disorders of Metabolism). The findings of the present study can be used to guide the dimethylmethylene blue assay optimization, redevelopment efforts, and harmonization across laboratories. The chondroitin sulfate oligosaccharide is better than the unfractionated chondroitin sulfate from bovine trachea due to its absorbance maxima closer to urine glycosaminoglycans. On the other hand, unfractionated chondroitin sulfate exhibit poor parallelism leading to falsely lower urine glycosaminoglycan levels. [ABSTRACT FROM AUTHOR]

For the simultaneous measurement of trifluridine and tipiracil in pure and in their pharmaceutical dose form, a new reversed-phase high performance liquid chromatographic technique has been developed and validated. It is straightforward, accurate, fast, selective, and stable. Based on a Phenomenex Gemini C18 (4.6×250mm) 5µ column, the procedure operates. Isocratic elution using a 65:35% v/v methanol:TEA buffer ratio, pumped at 1.0 ml/min, and UV detection at 230 nm is used to produce the separation. The analysis is conducted with the column maintained at 40°C. About six minutes have passed in total. According to the guidelines set out by the International Conference on Harmonisation (ICH), the technique has been validated for specificity, accuracy, precision, and linearity as well as for robustness and ruggedness, system adaptability, limit of detection, and limit of quantitation. For the measurement of trifluridine and tipiracil between 10-50 µg/ml and 20-100 µg/ml respectively, the technique is linear and accurate. Additionally, good outcomes are also demonstrated in terms of robustness, intra-day and inter-day accuracy (<2%), and mean percentage recovery (100.37% for trifluridine and 100.34% for tipiracil). This approach has the advantages of adequate accuracy and fine resolution with sharper peaks. The findings show that the approach is appropriate for regular quality control testing of tablet formulations that are sold. [ABSTRACT FROM AUTHOR]

To improve the thermodynamic and mechanical properties of asymmetric polyimide (PI), a method to enhance the linearity of PI by using a structural reorganization approach was designed. First, two novel diamines containing benzimidazole and benzoxazole groups, namely PADBZ and PDBOA, were constructed and synthesized. Thereafter, two new kinds of PI films (PADBZ‐PMDA and PDBOA‐PMDA) were prepared and polymerized with 1,2,4,5‐benzenetetracarboxylic anhydride (PMDA). Based on structural reorganization, PADBZ‐PMDA and PDBOA‐PMDA had repeating units of the same chemical composition and different linearity with PABZ‐BPDA and BOA‐BPDA, respectively. Comparing PADBZ‐PMDA and PABZ‐BPDA, due to the transfer in the position of benzene, PADBZ‐PMDA with high linearity showed the improved heat resistance (Tg up to 448°C), dimensional stability (CTE down to 2.3 ppm/K) and mechanical properties. PDBOA‐PMDA and BOA‐BPDA had the same situation. This study provided a unique solution to enhance the performances of PI by increasing the linearity using a structural reorganization approach. [ABSTRACT FROM AUTHOR]

Given the increasing application of eddy current sensors for measuring turbine tip clearance in aero engines, enhancing the performance of these sensors is essential for improving measurement accuracy. This study investigates the influence of coil shape on the measurement performance of planar eddy current sensors and identifies an optimal coil shape to enhance sensing capabilities. To achieve this, various coil shapes—specifically circular, square, rectangular wave, and triangular wave—were designed and fabricated, featuring different numbers of turns for the experiment at room temperature. By employing a method for calculating coil inductance, the performance of each sensor was evaluated based on key metrics: measurement range, sensitivity, and linearity. Experimental results reveal that the square coil configuration outperforms other shapes in overall measurement performance. Notably, the square coil demonstrated a measurement range of 0 mm to 8 mm, a sensitivity of 0.115685 μH/mm, and an impressive linearity of 98.41% within the range of 0 mm to 2 mm. These findings indicate that the square coil configuration enhances measurement capabilities. The conclusions drawn from this study provide valuable insights for selecting coil shapes and optimizing the performance of planar eddy current sensors, thereby contributing to the advancement of turbine tip clearance measurement techniques in aero engines. [ABSTRACT FROM AUTHOR]

GaN high electron mobility transistor (HEMT)‐based low noise amplifiers (LNAs) are an integral part of microwave receiver systems to enhance signal‐to‐noise ratio (SNR). The noise of LNA itself becomes critical for systems requiring high SNR, such as imaging and satellite communication systems. This paper discusses the design of a three‐stage LNA operating at the X‐band in the frequency range of 8.0–12.0 GHz. The amplifier's design and small signal, noise, and linearity characterizations are discussed. Stagewise analysis for gain, noise figure (NF), and matching network losses at the design stage results in achieving promising results. The proposed LNA provides a gain of 23.2 dB with ± 1.0 $\pm \ 1.0$ dB gain ripple. Its NF is below 1.5 dB, output power at 1 dB gain compression is 16.4 dBm, and third‐order intercept point is 24.7 dBm at 10 GHz. LNA's survivability is validated to input stress as high as 42 dBm. This LNA is the best reported NF and survivability combination in the 8.0–12.0‐GHz frequency range. The reverse recovery time of LNA is measured under two different pulse conditions, and it has been shown that LNA has better recovery times for lower pulse width signals. This LNA finds its applications in radars and satellite communication systems. [ABSTRACT FROM AUTHOR]

Quantile-quantile plots in the precise sense of scatterplots showing corresponding quantiles of two variables have long been supported by official command qqplot. That command is generalized here in several ways in a new command, qqplotg. In this article, I explain the major features of qqplotg and give several examples of its use. Themes include the use of quantile-quantile plots to explore the possibilities for working on a transformed scale and the value of plotting difference between quantiles versus mean quantile or plotting position. Various historical and methodological remarks are sprinkled throughout. [ABSTRACT FROM AUTHOR]

This article is concerned with the assumption of linear temporal development that is often advanced in structural equation modeling-based longitudinal research. The linearity hypothesis is implemented in particular in the popular intercept-and-slope model as well as in more general models containing it as a component, such as longitudinal structural models with covariates, or models for the study of predictors and correlates of change. In empirical research applications, currently behavioral and social scientists typically evaluate only overall goodness of fit for a considered model. However, this omnibus fit assessment may miss violations of the underlying linearity assumption. To respond to this limitation, the present article discusses a testing procedure for examining the hypothesis of linear growth or decline separately from the widely used overall fit evaluation process. The method is readily utilized with popular latent variable modeling software and is illustrated using a numerical example. [ABSTRACT FROM AUTHOR]

In this computer simulation study, we examine four different statistical approaches of linearity assessment, including two variants of deviation from linearity (individual (IDL) and averaged (AD)), along with detection capabilities of residuals of linear regression (individual and averaged). From the results of the simulation, the following broad suggestions are provided to laboratory practitioners when performing linearity assessment. A high imprecision can challenge linearity investigations by producing a high false positive rate or low power of detection. Therefore, the imprecision of the measurement procedure should be considered when interpreting linearity assessment results. In the presence of high imprecision, the results of linearity assessment should be interpreted with caution. Different linearity assessment approaches examined in this study performed well under different analytical scenarios. For optimal outcomes, a considered and tailored study design should be implemented. With the exception of specific scenarios, both ADL and IDL methods were suboptimal for the assessment of linearity compared. When imprecision is low (3 %), averaged residual of linear regression with triplicate measurements and a non-linearity acceptance limit of 5 % produces <5 % false positive rates and a high power for detection of non-linearity of >70 % across different types and degrees of non-linearity. Detection of departures from linearity are difficult to identify in practice and enhanced methods of detection need development. [ABSTRACT FROM AUTHOR]

We develop low-order triangular virtual elements for linear Kirchhoff–Love shells from an engineering point of view. Flat element geometry is considered, which enables a direct shell discretization with no need for a curvilinear coordinate system or predefined initial mapping. Along with the assumed linearity of the problem, the superposition of the uncoupled membrane and plate energies is performed by unifying aspects of the virtual element method when applied to linear two-dimensional elasticity and plate bending problems. We explore low-order cases, namely linear to quadratic membrane displacements and quadratic to cubic deflection polynomial approximations such that no internal degrees of freedom are needed. For all elements, a single stabilization available in the literature is employed to stabilize the element formulations. Numerical examples of static problems show that the presented formulation is capable of solving complex shell problems. Possible extensions are discussed in future works. [ABSTRACT FROM AUTHOR]

Introduction. Darunavir as an effective antiretroviral drug is widely used in clinical practice, including for the treatment of pediatric patients, as well as pregnant women, and for personalized therapy. Currently darunavir is used in the production of finished dosage forms, both in the form of crystalline ethanolate and in the form of an amorphous substance. In this regard, there is a need to develop and improve methods for the quantitative determination of darunavir. As an inexpensive and effective alternative to common chromatographic and titrimetric methods, spectrophotometric determination of darunavir in the ultraviolet region of the spectrum (UV spectrophotometry) may be used.Aim. To develop and validate a method for the quantitative determination of amorphous darunavir in the substance by UV spectrophotometry.Materials and methods. The following substances and consumables were used for the research: powdered amorphous darunavir substance (USP); darunavir reference standard (MSN Pharmachem Pvt. Ltd., India); methanol for HPLC Gradient Grade 99.9 % (High purity); acetonitrile for HPLC Gradient Grade 99.9 %; glacial acetic acid for HPLC; 0.1 M perchloric acid solution (in anhydrous acetic acid) for titration in non-aqueous media; nylon syringe filters with a pore diameter of 0.22 microns. Spectrophotometric determination of darunavir was carried out using an Cary 60 spectrophotometer (Agilent Technologies, USA) and a UNICO 2800 spectrophotometer (United Products & Instruments, Inc., USA). To prepare standard solutions, we used analytical balance Analytical Balance MS105/A (METTLER TOLEDO, Switzerland), analytical balance GH-120 (AND, Japan) class A measuring glassware, graduated pipettes ISOLAB.Results and discussion. The method was developed and validated for the following characteristics: specificity, linearity, accuracy, precision, analytical range. According to the study results, the main validation characteristics of the method meet the acceptance criteria.Conclusion. A new method for the quantitative determination of amorphous darunavir by UV spectrophotometry was successfully developed and validated. The method may be used to control the quality of substances of amorphous darunavir, including the intrapharmaceutical control.

In this article, we explore patterns of R2 across data sets to reveal a fundamental equivalence. If any set of bivariate data is rotated, the R2 value changes and defines a curve as a function of the rotation angle θ. We show that for any data set whose rotated R2 curve has the same maximum value, the entire curve is identical up to a shift in the rotation angle. We also find that a recently introduced measure of linearity, Q2, provides a definitive relation between these data sets, with equal Q2 values resulting in identically rotated R2 curves. Finally, we also show that we can consider R2 as the combination of two components, the linearity of the data and a rotation angle. While rotating data or axes for non spatial data loses the specific meaning of the variables, these results may provide additional understanding of the relationships within the data and can reveal similarities between data sets, the role of sensitivity in correlation, and the nature of correlation itself. [ABSTRACT FROM AUTHOR]

This work investigates a Gate-Stacked negative capacitance field-effect transistor with a high dielectric material layer in the substrate region (GS-NCFET). Also, the effect of different types of spacers is taken into account. Spacers are differentiated based on their dielectric constant, i.e., GS-NCFET with no spacer is denoted as S0, with air spacer is denoted as S1, with SiO2 specified as S2, and with HfO2 noted as S3 device architecture. Self-consistent LCAO-based DFT analysis is done for the spacer materials in terms of band structure, PDOS, and Hartree potential. Further, the switching ratio (Ion/Ioff) is discussed for S0, S1, S2, and S3. Further, the short channel effects (SCEs) like subthreshold swing (SS) and drain-induced barrier lowering (DIBL) are extracted at drain-source voltage (Vds) of 0.5 V. In addition, the voltage transfer characteristic (VTC) curve of GS-NCFET with a spacer-based inverter is considered for digital application purposes, and the transition region is drawn out for all the device architecture-based inverters. Essential parameters like propagation time delay and rise/fall time are evaluated to study the application purposes. In GS-NCFET, a dielectric layer as a buried oxide (BOX) is inserted in the substrate region to reduce the leakage current. [ABSTRACT FROM AUTHOR]

This paper presents a detailed design of a broadband power amplifier (PA) utilizing 0.18-μm CMOS technology, operating in the frequency range of 2–5 GHz. This ultra-wideband (UWB) power amplifier uses a cascode topology with current reuse to enhance gain over the desired frequency band, utilizing an inductive source degenerate design to achieve the best linearity and output power and gain while maintaining a wide bandwidth. The inductive source degenerate adopts bondwire and microstrip line design. The paper includes extensive analysis, simulation results, and measurements to verify the performance of the amplifier and demonstrate its suitability for broadband power amplifier applications. The measured results for the proposed UWB power amplifier show excellent performance, with an impressive third-order input intercept point (IIP3) ranging from 15 to 18.7 dBm over the frequency range of 2–5 GHz. The output third-order intercept point (OIP3) ranges from 33 to 35 dBm. Additionally, the gain flatness is specified as 12.5 ± 1.5 dB. The reverse isolation is greater than or equal to − 40 dBm. The PA has a P1dB output power (OP1dB) of 10.2 dBm at 3 GHz, 9.2 dBm at 4 GHz, and 9.2 dBm at 5 GHz, respectively. The PA has a P1dB power-added efficiency of 30.5% at 3 GHz, 23% at 4 GHz, and 22% at 5 GHz with a 50 Ω load termination. The power dissipation is 33.3 mW at a supply voltage of 1.8 V. In addition, the PA has an excellent small group delay variation of ± 65 ps. The chip area is 1.01 × 1.08 mm2, including the pads. The proposed UWB PA demonstrates exceptional linearity, efficiency, and group delay in the 2–5 GHz frequency band. [ABSTRACT FROM AUTHOR]

The law of superposition underpins first-order linear pharmacokinetic relationships. Most drugs, therefore, after a single dose can be described by first-order or linear processes, which can be superposed to understand multiple-dose regimen behavior. However, there are a number of situations where drugs could display behaviors after multiple dosing that leads to capacity-limited or saturation non-linear kinetics and the law of superposition is overruled. This review presents a practical guide to understand the equations and calculations for single and multiple-dosing regimens after intravenous and oral administration. It also provides the pharmaceutical basis for saturation in ADME processes and the consequent changes in the area under the concentration–time curve, which represents drug exposure that can lead to the modulation of efficacy and/or toxic effects. The pharmacokineticist must implicitly understand the principles of superposition, which are a central tenet of drug behavior and disposition during drug development. [ABSTRACT FROM AUTHOR]

The aim of this study was to validate an HPLC-UV method to assess vitamin D status by determining the linearity and precision of the 25-hydroxyvitamin D3 (25(OH)D3) calibration curve, the limits of detection, quantitation and robustness of the method, and its accuracy. A second stock solution of 25(OH)D3 was prepared (500 ng/mL), and working dilutions (5, 10, 20, 30, 40, and 50 ng/mL) were prepared for a calibration curve. The HPLC equipment had a UV-Vis diode-array detector and utilized an AcclaimTM 120 C18 column (5 µm, 4.6 × 250 mm) with a flow rate of 1.2 mL/min, a column temperature of 30 °C, and the standards and samples were maintained at 4 °C, with an injection volume of 100 µL. Detection of 25(OH)D3 was determined at 265 nm, with a retention time of 4.0 min. The validation was conducted according to the FDA Validation of Analytical Procedures: Guidance for Industry. Vitamin D was extracted from plasma samples using acetonitrile (ACN)–0.1% formic acid (2:1 v/v), and the percentage of recovery was calculated. The proposed method conditions gave excellent linearity (R2 = 0.9989) and the linearity coefficient was R2 > 0.99 for 25(OH)D3. The detection and quantification limits were 1.1703 ng/mL and 3.5462 ng/mL, respectively. Decreasing or increasing the reading temperature by 1 °C decreased the response units (AU) of vitamin D, 25(OH)D3. When the current flow rate decreased by 0.2 mL/min (1.0 mL/min), the retention time increased to 4.913 min, whereas an increase of 0.2 mL/min of the proposed flow rate (1.4 mL/min) decreased the retention time to 3.500 min. The percentage of recovery varied from 92.2% to 97.1%. The proposed method to quantify a vitamin D metabolite (25(OH)D3) in human plasma samples was reliable and validated. [ABSTRACT FROM AUTHOR]

This article centers its attention on the phenomenon of electrostatics, linearity, analogue, and RF performance of a 0.5 μm × (2 × 100) μm double heterojunction AlGaAs/InGaAs/GaAs pHEMT using on‐wafer DC and RF measurements up to 50 GHz. With a high ION/IOFF ratio (1.21 × 107) and low subthreshold slope (72.7 mV/dec), a flat and high transconductance over a wide range of Vgs has been achieved for the tested device. Furthermore, the input intercept and higher‐order voltage intercept point both attained large values with low intermodulation and harmonic distortion. Regarding RF parameters, the intrinsic gain has been achieved up to 28 dB. The GBW up to 750 GHz was attained, with the highest fT and fmax values being 24.5 GHz and 99.3 GHz, respectively. Since the device has very low intrinsic capacitance, parameters like TFP, GFP, and GTFP also showed excellent results. The high intrinsic gain and TGF indicate ample potential of the device for use as an amplifier. Investigating the parameters reveals the device to have very good linearity and amplifying capability. [ABSTRACT FROM AUTHOR]

Aim: A precise, linear and specific liquid chromatography-tandem mass spectrometry procedure was executed and subjected for validation for the quantification of plasma. Materials and Methods: The chromatography elution was carried out using a C18-Discovery column of 15 cm in length and 2.1 mm in internal diameter, packed with stationary phase particles of 5 µm size, at a flow rate of 0.80 mL/min. An isocratic elution process was conducted with a mobile phase solution consisting of methanol and 0.10% V/V HCOOH in a ratio of 90:10. The separation of Abametapir and Metformin was achieved by a liquid-liquid extraction process using ethyl acetate as the solvent. Results: A triple quadrupole mass spectrometer was used for the measurement of ions. Electrospray ionization is a technology that ionizes positively, and it was used in Multiple Reaction Monitoring (MRM) with parent/product ionic transitions m/z 185.1→106.06 for Abametapir and 130.1→60.20 for the Metformin internal standard. A calibration graph was constructed with values ranging from 2.05 to 82.00 ng/mL, resulting in the equation y=0.0149x+0.00221, with a r2 value above 0.99. The recovery values of Abametapir exceeded 94.27%, with its accuracy assessed in terms of relative error ranging from -4.04% to 6.52%. Conclusion: The accuracy, recovery and sensitivity values of Abametapir in the plasma sample, as shown by the established approach, highlight its significance in pharmacokinetic and bioequivalence research. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, AlGaN/GaN HEMTs with Au-free Ti/Al/Ni/Ti ohmic contacts were fabricated. The device presents a contact resistance (R c) of 0.64 Ω·mm and high linearity characteristics. The two-tone measurement at 28 GHz shows that the 2 × 50 μ m device exhibits an excellent third-order intercept point (OIP3) value of 41.64 dBm at V DS = 28 V, and an OIP3/ P DC of 24.2. An OIP3 of 46.59 dBm was achieved when the device's gate width was increased to 8 × 50 μ m at V DS = 48 V. These results demonstrate that AlGaN/GaN HEMTs with Ti/Al/Ni/Ti ohmic contacts have potential for Ka-band applications. [ABSTRACT FROM AUTHOR]

Sidon sets have several applications in mathematics and in real-world problems, including the generation of secret keys in cryptography, error-correcting codes, and the physical problem of compression of signals in telecommunications. In particular, in cryptography, the design of cryptographic functions with optimal properties like nonlinearity and differential uniformity plays a fundamental role in the development of secure cryptographic systems. Based on the construction of Bose-type Sidon sets, in this paper we present the construction of a new cryptographic function with good properties of nonlinearity and differential uniformity. [ABSTRACT FROM AUTHOR]

This paper proposes the ultra−generalized continuous class F (UCCF) mode, which combines the influences of the drain current conduction angle and overdriven transistor on the drain current waveform to achieve a broader finite third-harmonic load impedance space. The UCCF mode uses α to describe the magnitude of the drain current conduction angle and p c r to describe the drain current peak-clipped ratio. An analysis of the effects of p c r and α on the linearity and efficiency of the UCCF model is presented, establishing a robust theoretical foundation for achieving a balance between these two characteristics. Additionally, an examination of how p c r and α influence the load impedance design space is conducted, demonstrating that the UCCF mode not only offers a broader finite third-harmonic load impedance space but also expands the fundamental and second-harmonic load impedance design space. For practical validation, a PA with frequency of 2.05–2.65 GHz is designed based on CGH40010F. The test results show that S 11 is less than −15 dB, the drain efficiency is 67.0–73.2%, and the output power is 40.1–41.0 dBm. The linearity is tested using a 5G NR (New Radio) signal with a bandwidth of 100 MHz and a peak-to-average power ratio of 8 dB at 2.35 GHz. The worst adjacent channel power ratio (ACPR) is −34.8 dBc without digital predistortion (DPD), and −57.8 dBc with DPD. An average output power ( P a v e ) of around 32.4 dBm and an average DE ( D E a v e ) of 34.39% were obtained. [ABSTRACT FROM AUTHOR]

This study investigates the luminescent properties and dosimetric potential of YCa 4 O(BO 3) 3 :0.5%Sm3+ phosphor synthesized via the combustion method. Dose-response investigations unveil a noteworthy linear increment in thermoluminescence (TL) intensity, emphasizing a remarkable linearity spanning a broad dose range from 0.1 to 300 Gy. Unusual heating rate effects are explored, revealing a shift in TL glow curve peak temperature (i.e 200 °C) towards higher temperatures with increasing heating rate. Speculative models, including Kinetic Trapping Effect, Thermal Quenching Compensation, and Defect Activation Energy Changes, are proposed. The study employs the T max - T stop method to identify characterize glow curve peaks, and the Initial Rise method for the low-temperature segment analysis, revealing seven distinct trap levels at various depths within the bandgap. Glow curve deconvolution using the Complex Glow Curve Deconvolution (CGCD) method delineates a multi-peak structure, offering valuable insights into luminescent mechanisms. The model exhibits a Figure of Merit (FOM) of 1.71%, within an acceptable range, affirming its reliability. However, interpretation of the activation energy and frequency factor values suggests intricate site processes, necessitating a nuanced analysis to understand the material's luminescent characteristics. The YCa 4 O(BO 3) 3 :0.5%Sm3+ phosphor demonstrates promising characteristics for precise dosimetry, with linear dose response, absence of saturation effects, and intriguing heating rate behavior. [ABSTRACT FROM AUTHOR]

The nonlinear characteristics of avalanche photodiodes (APDs) inhibit their performance in high-speed communication systems, thereby limiting their widespread application as optical detectors. Existing theoretical models have not fully elucidated complex phenomena encountered in actual device structures. In this study, actual APD structures exhibiting lower linearity than their ideal counterparts were revealed. Simulation analysis and physical inference based on GaN APDs reveal that electrode size is a noteworthy factor influencing response linearity. This discovery expands the nonlinear theory of APDs, suggesting that APD linearity can be enhanced by suppressing the electrode size effect. A physical model was developed to explain this phenomenon, which is attributed to charge accumulation at the edge of the contact layer. Therefore, we proposed an improved APD design that incorporates an additional gap layer and a buffer layer to stabilize the internal gain under high-current-density conditions, thereby enhancing linearity. Our improved APD design increases the linear threshold for optical input power by 4.46 times. This study not only refines the theoretical model for APD linearity but also opens new pathways for improving the linearity of high-speed optoelectronic detectors. [ABSTRACT FROM AUTHOR]

Fortification of edible oil with vitamin A is a widely adopted intervention to minimize the effects of vitamin A deficiency in vulnerable groups and mitigate some of its deleterious consequences. Regulatory monitoring is an important prerequisite to ensure that the fortification program is implemented effectively. Standard laboratory analysis methods for vitamin A in oils to assess adequate addition levels remain expensive and time-consuming. Portable testing devices are relatively less expensive in terms of capital investment and cost per test. However, the reliability of results needs to be assured to ensure acceptability and confidence. This study compared a portable device to high-performance liquid chromatography (HPLC) in terms of quantification of vitamin A in both spiked and commercially fortified oils. Nine oils (soybean, palm, cottonseed, rapeseed, corn, peanut, coconut, sunflower, and rice bran oils) were selected and spiked with retinyl palmitate at six different concentrations, and 112 commercially fortified oils were quantified for their vitamin A content using both methods. A good indicator of intra-day and inter-day repeatability (< 10% CV) was obtained for the measurement of vitamin A in the spiked oils for both methods, which denotes a high agreement between them. Vitamin A recoveries were 97–132% for HPLC and 74–127% for the portable device. A strong positive correlation, r = 0.88, is observed between the two methods for the quantification of vitamin A in the commercially fortified oils. The portable device provides a relatively low-cost, quick, and user-friendly alternative to HPLC. [ABSTRACT FROM AUTHOR]

A partially extended germanium-source double-gate tunnel field-effect transistor (PEGeDG-TFET) utilizes line and point tunneling phenomena to achieve low ambipolar current and high ON-state current. These advantages are accompanied by an exceptionally low OFF-state current (IOFF) and subthreshold swing with resilience against short-channel effects. However, PEGeDG-TFETs face challenges in terms of large variations in IOFF and changes in electrical characteristics with temperature due to the change in the bandgap of semiconductor material. In this article, we explore the temperature-associated variations of a PEGeDG-TFET under the influence of interface trap charges (ITCs) for reliability assessment. Results revealed that the Shockley–Read–Hall phenomenon is dominant at lower gate bias voltage, leading to IOFF degeneration at high temperature. The band-to-band tunneling (BTBT) phenomenon experiences minor variations at higher temperature and gate voltage. Additionally, at high temperature (500 K), it is discovered that the threshold voltage, cut-off frequency, gain–bandwidth product, transconductance–frequency product, intrinsic gain, and transit time decrease, thus limiting the device reliability in the avionics sector where temperatures fall below 410 K with consistent performance of analog/radio-frequency (RF) parameters. This investigation was conducted via simulations on a Silvaco ATLAS simulator considering ITCs and temperature variations. [ABSTRACT FROM AUTHOR]

Calibration of an analytical measurement procedure is an important basis for the reliability of patient results. Many publications and as well as procedures on how to estimate quality control and interpret those results have been become available over the years. In this publication we are focusing on the critical part of the calibration as there are no clear communication or guidelines on how to perform it. Usually only the recommendation of the reagent or instrument manufacturer is available. We would like to point out this gap to invite for a discussion and improvement of the current situation. [ABSTRACT FROM AUTHOR]

In the recent past, at Brazilian radiology services, direct digital radiography (DR) systems are replacing Computed Radiography (CR). This situation provides several significant advantages such as improving digital image quality, patient effective dose reduction, and improved speed of examinations performed. To evaluate DR systems, various organizations have published protocols with guidelines concerning quality assurance and acceptance tests for DRs. In these protocols, there are methodologies for evaluating several parameters, such as the detector linearity response (DLR). To test the DLR, different methodologies are proposed by the organizations, such as the application of different additional filters on the X-ray beams spectrum to promote the X-ray doses suitable to produce the latent image in the DR. The objective of this work was to evaluate the results of different protocol methodologies for carrying out the DLR test of a DR flat panel. An analogic radiology equipment, a primary ionization chamber, a DR system and images unprocessed were used in this study. As indicated by the protocols, the spectra of the X-rays were modified by additional filters of copper (Cu) with aluminum (Al); Al; Cu; and polymethylmethacrylate (PMMA). The spectra of the X-rays were modified to achieve the exposure range of 0.1 to 7 mR. The results showed that the DLR curves adjustment were R²>0.99, for a logarithmic equation, type y=a.ln(x)+b. For the filters of 0.5 mmCu with 1.0 mmAl; 11.5 mmAl; 1.0 mmCu; 21 mmAl the mean pixel values showed 0.9% of the coefficient of variation (COV), while for 10 cm PMMA filters, the COV increased to 2.7%. The study showed that methodologies using Al, Cu and Al with Cu filters DLR have similar responses while using PMMA, the response was slightly different.