Significant Change In Resistance Research Articles

Absolute coronary flow and microvascular resistance before and after TAVR

Abstract Purpose This study aims to investigate microcirculatory changes, both at rest and during hyperemia, using continuous intracoronary thermodilution, before TAVR, immediately post-TAVR, and at 6-month follow-up. Methods We included consecutive patients with high-gradient AS undergoing TAVR with non-obstructive coronary artery disease in the left anterior descending artery (LAD). Absolute coronary flow (Q) and microvascular resistance (R) were measured in the LAD using continuous intracoronary thermodilution at rest (Qrest) and during hyperemia (Qhyper) before and after TAVR, as well as at 6-month follow-up. Echocardiography and cardiac computed tomography (CCT) were used to quantify total myocardial mass and LAD-specific mass. Regional myocardial perfusion (QN) was calculated by dividing absolute coronary flow by the subtended myocardial mass. Results In 51 patients, absolute flow and microvascular resistance were assessed at rest and during hyperemia before and after TAVR. The mean age was 84.1 ± 5.0 years, and 35 participants were male (68.6%). Measurements were also obtained 6 months after TAVR in 20 (39%) patients. Overall, there were no significant changes in resting and hyperemic flow and resistance before and after TAVR (Qrest 68 [55-88] mL/min vs 69 [54 – 92] mL/min, p=0.776; Qhyper 158 [129 – 200] mL/min vs 172 [132, 216] mL/min, p=0.449, before and after TAVR, respectively). Consequently, coronary flow reserve (CFR) and microvascular resistance reserve (MRR) remained unchanged. At 6 months, there were no significant changes in flow and resistance both at rest and during hyperemia compared to baseline (Qrest: 72 [63-84] vs 83 [59-108] mL/min, p=0.658; Qhyper: 181 [158-200] vs 194 [167-222] mL/min, p=0.492; pre-TAVR and at 6 months follow-up, respectively), resulting in unchanged CFR and MRR. However, at follow-up, there was a noteworthy reduction in left ventricular mass of approximately 13% (from 201.9 ± 37.9g to 175.1 ± 46.6 g, p<0.001), leading to an increase in hyperemic perfusion (QN,hyper: 0.86 [0.69-1.06] vs 1.20 [0.99-1.32] mL/min/g, p=0.008; pre-TAVR and follow-up, respectively), but not in resting perfusion (QN, rest: 0.34 [0.30-0.48] vs 0.47 [0.36-0.67] mL/min/g, p=0.06). Conclusion Immediately after TAVR, there are no changes in absolute coronary flow and coronary flow reserve. Over time, LV remodeling is associated with increased hyperemic perfusion, indicating that, in the context of the observed pathophysiological changes in coronary microcirculation in AS patients after TAVR, the reverse LV remodeling has a more significant impact than the acute LV unloading achieved by valve replacement itself.

Pulmonary function using impulse oscillometry system and clinical outcomes at age 4 years in children born extremely preterm with or without bronchopulmonary dysplasia

This study aimed to describe the early assessment of lung function and respiratory morbidity in children born extremely preterm with or without bronchopulmonary dysplasia (BPD). MethodsThis was a prospective study including all the children born at gestational age ≤28 weeks who received treatment in the NICU of the Centre Intercommunal de Créteil in France, from January 2006 to March 2012. Lung function, using the impulse oscillometry system, respiratory morbidity and growth were assessed at age 4 years. Lung function and clinical course of children were compared in children with and without BPD. ResultsWe included 136 extremely premature children; 26 (19 %) had BPD. Children with and without BPD did not significantly differ in resistance measurements at 5 Hz (R5) and 20 Hz (R20) and reactance (X5) measurements at age 4 years. A total of 104 (76 %) pre-term children had respiratory resistance R5 above the 95th percentile for the reference population (z-score >1.64), regardless of BPD status. The mean (SD) R5 z-score for all children was 2.1 (±0.7), whereas the mean (SD) R20 was in the normal range (z-score = 1.1 [±0.3]). After treatment with bronchodilators, all children showed no significant change in resistance. The prevalence of asthma symptoms at age 4 years was common and estimated at 30 % regardless of BPD status. ConclusionEarly assessment of lung function by the impulse oscillometry system revealed that most preschool children who were born extremely preterm had abnormal total airway resistance regardless of BPD status. The system is an essential tool for the early assessment of children born prematurely.

Incidence, Antibiogram, and Comorbid Conditions of Nontyphoidal Salmonella Infections Before and After the COVID-19 Outbreak: A Retrospective, Cross-sectional Study

Abstract Background: The number of patients with diarrheal diseases admitted to the hospital was reduced during the COVID-19 lockdown. Following the relaxation of the lockdown, admissions of nontyphoidal Salmonella (NTS) infection showed a two-fold rise compared to pre-COVID-19 years. This retrospective study aimed to detect the incidence of NTS in the pre-COVID-19 and post-COVID-19 outbreak periods, along with describing the antibiogram and comorbid conditions of the patients. Materials and Methods: Using a retrospective design, from January 2015 to December 2022, we studied stool samples for the presence of NTS. Antibiogram with ampicillin, co-trimoxazole, ceftriaxone, chloramphenicol, and ciprofloxacin were studied. The presence of comorbid conditions was noted. Results: We examined 2312 and 937 stool samples collected during the pre-COVID-19 and post-COVID-19 outbreak period, respectively. The number of samples collected during the outbreak (2020) was 273. During the pre-COVID-19 period (2015–2019), the average annual isolation rate of NTS was 5.63%. During the lockdown of 2020, the corresponding rate was 5.49%. The isolation rate showed a significant rise (11.45%) during the relaxation of the lockdown (P < 0.001). No significant change in resistance to antibiotics other than ciprofloxacin was noted in the present study. Malignancy was the leading comorbid condition (11.91%) followed by chronic liver diseases (10.31%). Conclusions: A significant rise in NTS diarrheal cases was detected following the COVID-19 outbreak. During this period, people were attending more celebrations and feasts. No significant change in antibiotic resistance was noted when comparing pre-COVID-19 and COVID-19 periods. Malignancy was the leading comorbid condition.

Chemically Self-Assembled Monolayer Semiconducting Single-Walled Carbon Nanotube-Based Biosensor Platform for Amyloid-β Detection.

This paper presents a platform for amyloid-β (Aβ) biosensors, employing nearly monolayer semiconducting single-walled carbon nanotubes (sc-SWNTs) via click reaction. A high-purity sc-SWNT ink was obtained by employing a conjugated polymer wrapping method with the addition of silica gel. Aβ detection involved monitoring the electrical resistances of the sc-SWNT layers. Electrical resistances increased rapidly corresponding to the concentration of amyloid-β 1-42 (Aβ1-42) peptides. Furthermore, we introduced Aβ peptides onto the 1-pyrenebutanoic acid succinimidyl ester (PBASE) linker, confirming that only the chemical adsorption of the peptide by the antibody-antigen reaction yielded a significant change in electrical resistance. The optimized sensor exhibited a high sensitivity of 29% for Aβ at a concentration of 10 pM. Notably, the biosensor platform featuring chemically immobilized sc-SWNT networks can be customized by incorporating various bioreceptors beyond Aβ antibodies.

Structural health monitoring of scarf bonded repaired glass/epoxy laminates interleaved with carbon non-woven veil

Bonded repair patches/joints often introduce vulnerabilities in composite laminates, making them prime candidates for structural health monitoring (SHM). In this study, stepped-scarf bonded joints were manufactured using glass fibre-reinforced epoxy laminates as representative repair patches, and a novel SHM approach through the electrical resistance change method was applied. To establish an electrically conductive path within the stepped-scarf joint, non-woven carbon fibre veils with areal weights of 10 g/m² and 20 g/m² were interlaid along the stepped bondline. Two types of tensile tests were performed. In the first set of tests, the stepped-scarf joints underwent monotonic quasi-static tensile loading until the bondline was completely fractured (catastrophic failure) and the change in electrical resistance was continuously monitored. The failure stress of the joint with a 10 g/ m² carbon veil was only marginally decreased (∼2 %) in comparison with that of the joints without a carbon veil, while the failure stress of the joint with a 20 g/m² carbon non-woven veil was considerably decreased (by ∼9 %). However, the joints with 10 g/m² and 20 g/m² carbon veils exhibited a significant change in electrical resistance (∼200 % and ∼1000 %, up to full failure, respectively). Simultaneously, the change in electrical resistance was used for the detection of damage initiation and progression, supported by digital images taken during the tests. In the second set of tests, the joints were subjected to a cyclic tensile loading/unloading regime and the change in electrical resistance was monitored. A significant amount of permanent change in resistance during the unloading phases (up to 120 % in the bondline with a 20 g/m² veil) was observed, providing insights into the laminate and bondline damage evolution. In addition, thermal images obtained with the joule heating method in the cyclic tensile tests were used to confirm the damage detected with the electrical resistance change method. Moreover, the micrographs from the fracture surfaces indicated that the variations in electrical resistance change are largely caused by damage occurring within or near the carbon veils. In conclusion, the results demonstrate that the presented SHM approach, which incorporates carbon non-woven fibre veils within non-conductive laminate composites, holds promise for monitoring damage initiation and propagation in repaired composite laminates as well as adhesively bonded composite laminate joints, without adversely influencing the structural integrity of the bondline.

Significant Changes in Electrical Resistance of Conductive Porous Silicon Films Produced from Thiol-Modified Silicon Nanoparticle Inks

Conductive porous Si films composed of Si nanoparticles were produced by depositing a thiol-modified Si nanoparticle ink and then sublimating the thiol-modification surface, leaving Si–S bonds on the surface. By exchanging atmospheric gas such as N2 and O2, these S-terminated porous Si films reversibly changed electrical resistances in a dynamic range of five orders of magnitude, indicating that the resistance change was due to O2 adsorption/desorption on the S-terminated surface.

Enhanced gas sensing performance of ZnO and Pt-doped ZnO nanostructured films by chemical spray pyrolysis

This study focuses on the preparation and characterization of zinc oxide (ZO) and platinum-doped zinc oxide (Pt-ZO) nanostructured thin films using the chemical spray pyrolysis technique. Structural and morphological properties of the films were investigated via X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). To understand the semiconducting nature and carrier dynamics, UV-Vis spectroscopy, electrical conductivity measurements, and a static gas sensing system were employed. The films exhibited crystallization in the hexagonal wurtzite structure with a preferred orientation along the (002) plane. FESEM images revealed the presence of small bright particles, particularly abundant in the 5 wt% Pt-doped ZO thin film, indicating the presence of platinum catalysts. Electrical conductivity measurements confirmed the semiconducting nature of the films. Optical parameters such as band gap and absorption index were obtained from UV-Vis spectroscopy. Gas sensing performance towards liquefied petroleum gas (LPG) showed that the 5 wt% Pt-doped ZO thin film exhibited a high response (69.9) to a 50 ppm concentration of LPG at 350 °C. The gas response and recovery times were observed to be 8 s and 12 s, respectively. These results are attributed to interactions between LPG molecules and adsorbed oxygen species on the sensor surface. Platinum atoms on the oxide surface facilitate the formation of oxygen vacancies and the dissociation of oxygen molecules at low temperatures, leading to increased adsorption and reaction with LPG molecules. This results in significant changes in the sensor's resistance, thereby amplifying the sensor response. The findings demonstrate the potential of Pt-doped ZO thin films for practical gas sensing applications.

Ultrasensitive and wide-range MXene/PDMS piezoresistive sensors inspired by rose petals

Flexible pressure sensors are crucial in a variety of applications, including artificial intelligence (AI), the Internet of Things (IoT), and electronic skin (e-Skin), due to their ability to convert mechanical stimuli into electrical signals. However, achieving both high sensitivity and a wide detection range simultaneously remains challenging, often limiting their practical applications. To address this, we designed a three-dimensional contact interface with Ti3C2 MXene/polydimethylsiloxane (MP) inspired by rose petals, which allows for significant strain and resistance changes across a broad range of stress levels. The innovative design significantly extends the pressure detection range (0.033–535 kPa), enhances pressure sensitivity (0.432 kPa−1), offers a fast response/recovery times (57/4 ms), and ensures exceptional long-term durability (up to 2950 cycles). The structured MP sensor demonstrates the capability to detect human physiological movements, distinguish various voices and map real-time pressure distributions. Notably, it achieves real-time tracking of handwriting processes with high recognition accuracy through a machine learning module. The work offers a new strategy and inspiration for designing and manufacturing innovative structured pressure sensors with reliable performance, paving the way for their application in next-generation wearable and portable electronics.

Electrical conduction of ferroelectric domains and domain walls in polycrystalline BiFeO3 and Bi5Ti3FeO15 thin films

The unique properties of domain wall conductivity have garnered significant interest for their potential application in non-volatile ferroelectric domain wall memory. In this study, we investigated the electrical conduction within ferroelectric domains and domain walls of polycrystalline BiFeO3 (BFO) and Bi5Ti3FeO15 (BTFO) thin films, which were deposited on Pt/Ta/glass substrates via pulsed laser deposition. BFO thin film consistently demonstrated a (111) orientation, while BTFO thin film exhibited mixed crystallinity, featuring both c-axis and a-axis orientations. This mixed crystallinity in BTFO thin film contributed to a higher remanent polarization of 38.2 μC/cm2 compared to 20.3 μC/cm2 in BFO thin film, which is attributed to the a-oriented crystallinity within the Bi-layered perovskite structure of BTFO thin film. Additionally, BTFO thin film displayed a greater prevalence of 90° domain walls, which enhanced electrical conduction due to charge accumulation, particularly when compared to 180° domain walls. A significant change in resistance was observed when the domain wall was present versus absent, with a more pronounced effect in the BTFO capacitor compared to the BFO capacitor. This is attributed to the higher domain wall conductivity in BTFO thin film, confirming their superiority for use in ferroelectric capacitor devices that leverage domain wall conductivity.

Flexible All-Inorganic Thermoelectric Yarns.

Achieving both formability and functionality in thermoelectric materials remains a significant challenge due to their inherent brittleness. Previous approaches, such as polymer infiltration, often compromise thermoelectric efficiency, underscoring the need for flexible, all-inorganic alternatives. This study demonstrates that the extreme brittleness of thermoelectric bismuth telluride (Bi2Te3) bulk compounds can be overcome by harnessing the nanoscale flexibility of Bi2Te3 nanoribbons and twisting them into a yarn structure. The resulting Bi2Te3 yarn, with a Seebeck coefficient of -126.6µVK-1, exhibits remarkable deformability, enduring extreme bending curvatures (down to 0.5mm-1) and tensile strains of ≈5% through over 1000 cycles without significant resistance change. This breakthrough allows the yarn to be seamlessly integrated into various applications-wound around metallic pipes, embedded within life jackets, or woven into garments-demonstrating unprecedented adaptability and durability. Moreover, a simple 4-pair thermoelectric generator comprising Bi2Te3 yarns and metallic wires generates a maximum output voltage of 67.4mV, substantiating the effectiveness of thermoelectric yarns in waste heat harvesting. These advances not only challenge the traditional limitations posed by the brittleness of thermoelectric materials but also open new avenues for their application in wearable and structural electronics.

Real-time information processing via volatile resistance change in scalable protonic devices

Biological neural systems operate on multiple time scales, enabling real-time interaction with their environment. However, replicating this in electronic systems is challenging, as scalable devices that operate on similar time scales, particularly from seconds to minutes, are lacking. This study addresses this gap by exploiting proton dynamics to achieve volatile resistance changes over long time scales, and developed a neuromorphic system that can predict biomedical data, such as blood glucose levels, in real time. By applying a low voltage (below 1 V) to a two-terminal device, the Pd electrode hydrogenates or dehydrogenates the mixed conductor WO3, resulting in significant changes in electronic resistance. The device is scalable due to the uniform proton distribution, leading to high impedance and minimal power consumption. Utilizing these volatile protons for short-term memory in an Echo State Network (ESN), this approach demonstrates low-power, efficient real-time information processing, paving the way for future neuromorphic computing applications.

Bioelectrical Insight: Correlation Cell Count and Electrical Impedance of Whole Blood throughout Storage with an Impedance Analyzer Methode

Blood, a vital tissue comprising blood cells within the plasma matrix, plays a crucial role in transporting oxygen, nutrients, and functional components throughout the body. Insufficient blood levels can lead to disorders or life-threatening conditions, necessitating blood transfusions for those experiencing deficiencies. Blood banks store blood products to meet transfusion needs, emphasizing safety, donor health, patient conditions, cross-matching accuracy, and storage quality. Examining stored blood indicates an individual's physiological response to environmental changes, with quantitative and qualitative changes visible through whole blood cell count and impedance parameters. Electrical impedance spectroscopy, which measures these biological properties, shows that although blood cell count remains stable over 35 days, impedance characteristics change significantly. Analysis of the Nyquist Zriil plot reveals a consistent decrease in Zriil values, indicating reduced extracellular resistance (Res) over time. These impedance changes reflect alterations in blood morphology, providing crucial insights into the quality of stored blood. In conclusion, electrical impedance spectroscopy effectively monitors stored blood quality, detecting significant changes in extracellular resistance over extended storage periods. These findings underscore the importance of regular monitoring and proper management of stored blood to ensure its safety and effectiveness for transfusions.

Redox gating-induced modulation of charge carrier density and lattice expansion in LaNiO3 thin films

Redox gating involves the use of reversible redox functionalities combined with ionic electrolytes to substantially alter the charge carrier density in functional condensed materials. This modification leads to the emergence of physical properties not observed in the original material. In our study, we focus on redox gating applied to a LaNiO3 (001) film within a field-effect device and identify a critical gate voltage of 0.7 V. Hall measurements indicate that redox gating markedly increases the charge carrier density in LaNiO3, reaching over 1014 cm−2. This increase is primarily due to the injection of electrons into LaNiO3, which offsets the existing hole carriers. These adjustments in the carrier concentration result in reversible lattice expansion in LaNiO3 when gate voltages are below 0.7 V. This expansion correlates well with theoretical models that consider adjustments to the Ni–O bond length, influenced by oxygen ligand holes. Conversely, at gate voltages above 0.7 V, there are significant changes in resistivity, lattice structure, and Ni valence, stemming from the formation of oxygen vacancies in the LaNiO3 film.

Application of the Point Defect Model to the Oscillatory Anodic Oxidation of Illuminated n-Type Silicon in the Presence of Fluoride Ions Using Electrochemical Impedance Spectroscopy

This work aims to provide insight into the oscillations occurring during the anodic electrooxidation of Si in fluoride-containing electrolytes using electrochemical impedance spectroscopy (EIS). The EIS measurements were conducted within less than a tenth of the oscillation periods allowing changes in the electrical properties of the silicon/oxide/electrolyte interfaces to be monitored during an oscillatory cycle. Application of the power law model to the experimental data revealed a significant change in resistivity at the oxide/semiconductor interface while the properties at the oxide/electrolyte interface remained constant and the oxide layer varied only by about 1 nm around an average value of about 4.9 nm. The application of the point defect model to the semiconductor/oxide/F−-containing electrolyte interface suggests that the oscillations are linked to the time delay between the production of oxygen vacancies at the Si/oxide interface and their consumption at the oxide/electrolyte interface.

Numerical investigation of the impact of various parameters on blowing accuracy in the XRT intelligent ore sorting machine blowing process

XRT separation equipment is attracting much attention as the mining industry increasingly uses pre-sorting technology. Its sorting accuracy is affected by differences in ore shape and particle size during operation. This paper, in which numerical simulations are conducted to investigate the resistance of ores under various situations, including varying blowing distances, cross-sections, and practical sizes, Additionally, this paper conducts validation tests. The test results indicate that within the 0.1-0.25 m section from the nozzle exit, there is a rapid decrease in velocity, accompanied by a significant change in ore resistance. Beyond the 0.25 m mark, the velocity reduction slows down, while the ore resistance becomes smaller. There exists a notable disparity in the resistance of ores with varying cross-sectional geometries. The size of the jet velocity surface caused by blowing distance significantly influences the resistance of ore with varying particle sizes. Furthermore, the resistance of the ore remains constant subsequent to the impact surface of the ore surpassing the surface of the jet velocity. Consequently, appropriately modifying the blowing distance, inlet pressure, and jet speed in accordance with the cross-sectional area and particle size of the majority of the ores stream can enhance the precision of the sorting process.

Influence of α-lipoic acid on longevity and stress resistance in Drosophila melanogaster fed with a high-fat diet.

Consumption of a high-fat diet is accompanied by the risks of obesity and early onset of age-associated complications for which dietary interventions are imperative to combat. α-lipoic acid has been shown to hinder diet-induced obesity and induce lifespan-extending efficacy in model organisms. In this study, α-lipoic acid was investigated for its efficacy in improving lifespan and stress resistance in the Canton-S strain of Drosophila melanogaster fed with a high-fat diet. Furthermore, as mating status significantly impacts survival in fruit flies, flies were reared in two experimental groups-group one, in which males and females were bred together, and group two, in which males and females were bred separately. In group one, α-lipoic acid improved the mean lifespan, reduced the fecundity of females, and reduced the mean body weight of flies at a dose range of 2-2.5mM, respectively. In group two, α-lipoic acid improved the mean lifespan, reduced the fecundity of females, and reduced the mean body weight of flies at a dose range of 1-2.5mM, respectively. Improved climbing efficiency was observed with α-lipoic acid at the dose range of 1.5-2.5mM in flies of group one and 1-2.5mM in flies of group two, respectively. Administration of α-lipoic acid improved resistance to oxidative stress in only female flies of group one at 2.5mM, whereas in group two, both male and female flies exhibited enhanced resistance to oxidative stress with α-lipoic acid at a dose range of 2-2.5mM, respectively. Male and female flies of only group one showed improved resistance to heat shock stress with α-lipoic acid at a dose range of 2-2.5mM. Only female flies of group two exhibited a slight improvement in recovery time following cold shock with α-lipoic acid only at 2.5mM. No significant change in resistance to starvation stress was observed with any dose of α-lipoic acid in either group of flies. To summarize, data from this study suggested a probable dose and gender-dependent efficacy of α-lipoic acid in flies fed with a high-fat diet, which was significantly influenced by the mating status of flies due to varied rearing conditions.

Thermo-Mechanical and Thermo-Electric Properties of a Carbon-Based Epoxy Resin: An Experimental, Statistical, and Numerical Investigation.

Due to their remarkable intrinsic physical properties, carbon nanotubes (CNTs) can enhance mechanical properties and confer electrical and thermal conductivity to polymers currently being investigated for use in advanced applications based on thermal management. An epoxy resin filled with varying concentrations of CNTs (up to 3 wt%) was produced and experimentally characterized. The electrical percolation curve identified the following two critical filler concentrations: 0.5 wt%, which is near the electrical percolation threshold (EPT) and suitable for exploring mechanical and piezoresistive properties, and 3 wt% for investigating thermo-electric properties due to the Joule effect with applied voltages ranging from 70 V to 200 V. Near the electrical percolation threshold (EPT), the CNT concentration in epoxy composites forms a sparse, sensitive network ideal for deformation sensing due to significant changes in electrical resistance under strain. Above the EPT, a denser CNT network enhances electrical and thermal conductivity, making it suitable for Joule heating applications. Numerical models were developed using multiphysics simulation software. Once the models have been validated with experimental data, as a perfect agreement is found between numerical and experimental results, a simulation study is performed to investigate additional physical properties of the composites. Furthermore, a statistical approach based on the design of experiments (DoE) was employed to examine the influence of certain thermal parameters on the final performance of the materials. The purpose of this research is to promote the use of contemporary statistical and computational techniques alongside experimental methods to enhance understanding of materials science. New materials can be identified through these integrated approaches, or existing ones can be more thoroughly examined.

Flexible micro-strain graphene sensors enhanced by laser-induced cracks for health monitoring

In-situ fabrication of patterned laser-induced graphene (LIG) has unique advantages, holding broad application prospects in the preparation of flexible electronic devices. However, a facile strategy is still demanded to improve the sensitivity of LIG-based sensors in detecting micro-strains. Herein, we propose a flexible graphene strain sensor enhanced by laser-induced cracks, which is capable of detecting small deformations. When the scanning spacing was expanded from 100 μm to 140 μm, abundant micro-cracks formed between adjacent LIG stripes, providing more sensing units. The open and close of cracks lead to significant change of resistance, enhancing the sensitivity of LIG-based sensors. The average gauge factors of sensors were improved to 98 (0–2 % strain), increasing nearly 20 times. The strain sensors exhibit high performance response to subtle signals of the human body. High-quality seismocardiography (SCG), pulse wave and respiration curves were achieved by our sensors, providing a lot of useful information for screening chronic diseases. Overall, this research highlights an effective method for fabricating high performance flexible strain sensors for long-term health monitoring.

Magnetoresistance and Magnetocapacitance Effect in Magnetic Tunnel Junction with Perpendicular Anisotropy of Magnetic Electrodes Tb22−δCo5Fe73/Pr6O11/Tb19−δCo5Fe76

This paper presents the results of studies of the effects of magnetoresistance and magnetocapacitance in magnetic tunnel junctions [Formula: see text]Co5[Formula: see text]/Pr6[Formula: see text]/[Formula: see text]Co5[Formula: see text] with perpendicular anisotropy of magnetic electrodes and a paramagnetic barrier layer. Experimentally measured values of tunnel magnetic resistance and tunnel magnetic capacitance in such contacts exceed 100% at room temperature. The paper analyzes the effect of magnetization reversal of one of the electrodes on the conductivity of magnetic tunnel junctions with electrodes that have perpendicular anisotropy. It is shown that significant changes in tunnel magnetic resistance and tunnel magnetic capacity in such contacts can be explained by the separation of electrons with major and minor spin polarization in the inverse nanolayer in the interface region. The separation of polarized electrons is caused by the magnetomotive force acting on the electron spin in a strongly gradient magnetic field. Such a magnetomotive force occurs with antiparallel magnetization of the magnetic electrodes and it has opposite directions for major and minor polarized electrons. As a result of the spatial separation of polarized electrons in the inversion layer, an inhomogeneous distribution of the electron density along the direction of magnetization of the magnetic contacts occurs. As a result, an additional Coulomb barrier between the magnetic electrodes and the dielectric nanolayer appears in the tunnel contacts and an additional spin capacitance appears.

Pixelated large area rGO on silicon based x-ray detector

In this work, the possibility of using reduced Graphene oxide for x-ray detection has been explored. A highly conductive reduced Graphene Oxide (rGO) synthesized using a hybrid method was used to fabricate a pixelated Si/SiO2 bottom gate field effect transistor. The fabricated device is a 3×3 pixelated large area detector and was tested for its response to x-rays at room temperature and low temperatures by irradiating it with x-rays from top. Significant change in resistance of rGO is observed during irradiation which shows its sensitivity to x-rays.