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Wireless sensor networks are the core of the Internet of Things and are used in healthcare, locations, the military, and security. Threats to the security of wireless sensor networks built on the Internet of Things (IoT-WSNs) can come from a variety of sources. This study proposes secure attack localization and detection in IoT-WSNs to improve security and service delivery. The technique used blockchain-based cascade encryption and trust evaluation in a hierarchical design to generate blockchain trust values before beacon nodes broadcast data to the base station. Simulation results reveal that cascading encryption and feature assessment measure the trust value of nodes by rewarding each other for service provisioning and trust by removing malicious nodes that reduce localization accuracy and quality of service in the network. Federated machine learning improves data security and transmission by merging raw device data and placing malicious threats in the blockchain. Malicious nodes are classified through federated learning. Federated learning combines hybrid random forest, gradient boost, ensemble learning, K -means clustering, and support vector machine approaches to classify harmful nodes via a feature assessment process. Comparing the proposed system to current ones shows an average detection and classification accuracy of 100% for binary and 99.95% for multiclass. This demonstrates that the suggested approach works well for large-scale IoT-WSNs, both in terms of performance and security, when utilizing heterogeneous wireless senor networks for the providing of secure services.

Security enhancement in wireless sensor networks (WSNs) is significant in different applications. The advancement of routing attack localization is a crucial security research scenario. Various routing attacks degrade the network performance by injecting malicious nodes into wireless sensor networks. Sybil attacks are the most prominent ones generating false nodes similar to the station node. This paper proposed detection and localization against multiple attacks using security localization based on an optimized multilayer perceptron artificial neural network (MLPANN). The proposed scheme has two major part localization techniques and machine learning techniques for detection and localization WSN DoS attacks. The proposed system is implemented using MATLAB simulation and processed with the IBM SPSS toolbox and Python. The dataset is classified into training and testing using the multilayer perceptron artificial neural network to detect ten classes of attacks, including denial-of-service (DoS) attacks. Using the UNSW-NB, WSN-DS, NSL-KDD, and CICIDS2018 benchmark datasets, the results reveal that the suggested system improved with an average detection accuracy of 100%, 99.65%, 98.95%, and 99.83% for various DoS attacks. In terms of localization precision, recall, accuracy, and f-score, the suggested system outperforms state-of-the-art alternatives. Finally, simulations are done to assess how well the suggested method for detecting and localizing harmful nodes performs in terms of security. This method provides a close approximation of the unknown node position with low localization error. The simulation findings show that the proposed system is effective for the detection and secure localization of malicious attacks for scalable and hierarchically distributed wireless sensor networks. This achieved a maximum localization error of 0.49% and average localization accuracy of 99.51% using a secure and scalable design and planning approach.

In food industries worldwide, food processing methods are tremendously needful to meet the present consumer’s demands. There are continuously increasing efforts to develop food preservatives by avoiding chemicals for which natural sources are the only alternative. Morninga oleifera (Moringaceae) is highly nutrious and medicinaly valued plant which will be detoriate with the microbial and environmental factors. The preservation of food materials is really challenged without using the chemical preservatives. The use of spice property of ginger and garlic has a characteristic pungent, hot, flavour that mellows and sweetens considerably with cooking. They both have the radical scavenging activity otherwise considered ideal antioxidants beneficial in many reported diseases including the antifungal, antibacterial and antiviral and antiparasitic agents. Therefore, the present study has been undertaken to investigate the popularly used ginger and garlic in the management of antimicrobial activity of leaves of Morninga oleifera by in vitro as well as in silico approaches.

Magnetic/non-magnetic/heterostructured ultra-thin films' characterisation is highly demanding due to the emerging diverse applications of such films. Diverse measurements are usually performed on such systems to infer their electrical, optical and magnetic properties. We demonstrate that MOKE-based spin-Hall effect of light (SHEL) is a versatile surface characterization tool for studying materials' magnetic and dielectric ordering. Using this technique, we measure magnetic field dependent complex Kerr angle and the coercivity in ultra-thin films of permalloy (Py) and at molybdenum disulphide (MoS$_2$) - permalloy (MSPy) hetero-structure interfaces. The measurements are compared with standard magneto-optic Kerr effect (MOKE) studies to demonstrate that SHEL-MOKE is a practical alternative to the conventional MOKE method, with competitive sensitivity. A comprehensive theoretical model and simulation data are provided to further strengthen the potential of this simple non-invasive optical method. The theoretical model is applied to extract the optical conductivity and susceptibility of non-magnetic ultra-thin layers such as MoS$_2$ ., 15 pages, 7 figure, one supplementary document

The heterogeneity of attention-deficit/hyperactivity disorder (ADHD) traits (inattention vs. hyperactivity/impulsivity) complicates diagnosis and intervention. Identifying how the configuration of large-scale functional brain networks during cognitive processing correlate with this heterogeneity could help us understand the neural mechanisms altered across ADHD presentations. Here, we recorded high-density EEG while 62 non-clinical participants (ages 18-24; 32 male) underwent an inhibitory control task (Go/No-Go). Functional EEG networks were created using sensors as nodes and across-trial phase-lag index values as edges. Using cross-validated LASSO regression, we examined whether graph-theory metrics applied to both static networks (averaged across time-windows: -500–0ms, 0–500ms) and dynamic networks (temporally layered with 2ms intervals), were associated with hyperactive/impulsive and inattentive traits. Network configuration during response execution/inhibition was associated with hyperactive/impulsive (mean R2across test sets = .20, SE = .02), but not inattentive traits. Post-stimulus results at higher frequencies (Beta, 14-29Hz; Gamma, 30-90Hz) showed the strongest association with hyperactive/impulsive traits, and predominantly reflected less burst-like integration between modules in oscillatory beta networks during execution, and increased integration/small-worldness in oscillatory gamma networks during inhibition. We interpret the beta network results as reflecting weaker integration between specialized pre-frontal and motor systems during motor response preparation, and the gamma results as reflecting a compensatory mechanism used to integrate processing between less functionally specialized networks. This research demonstrates that the neural network mechanisms underlying response execution/inhibition might be associated with hyperactive/impulsive traits, and that dynamic, task-related changes in EEG functional networks may be useful in disentangling ADHD heterogeneity.

Learning to read requires children to link print (orthography) with its corresponding speech sounds (phonology). Yet, most EEG studies of reading development focus on emerging functional specialization (e.g., developing increasingly refined orthographic representations), rather than directly measuring the functional connectivity that links orthography and phonology in real time. In this proof-of-concept study we relate children's reading skill to both orthographic specialization for print (via the N170, also called the N1, event related potential, ERP) and orthographic-phonological integration (via dynamic/event-related EEG phase synchronization - an index of functional brain network connectivity). Typically developing English speaking children (n = 24; 4-14 years) and control adults (n = 20; 18-35 years) viewed pseudowords, consonants and unfamiliar false fonts during a 1-back memory task while 64-channel EEG was recorded. Orthographic specialization (larger N170 for pseudowords vs. false fonts) became more left-lateralized with age, but not with reading skill. Conversely, children's reading skill correlated with functional brain network connectivity during pseudoword processing that requires orthography-phonology linking. This was seen during two periods of simultaneous low frequency synchronization/high frequency desynchronization of posterior-occipital brain network activity. Specifically, in stronger readers, left posterior-occipital activity showed more delta (1-3Hz) synchronization around 300-500 ms (simultaneous with gamma 30-80 Hz desynchronization) and more gamma desynchronization around 600-1000 ms (simultaneous with theta 3-7Hz synchronization) during pseudoword vs. false font processing. These effects were significant even when controlling for age (moderate - large effect sizes). Dynamic functional brain network connectivity measures the brain's real-time sound-print linking. It may offer an under-explored, yet sensitive, index of the neural plasticity associated with reading development.

To recognize the human activity is considered very essential in human-to-human interaction and interpersonal relations due to its nature of providing information regarding the identity of a people, their individuality, and psychological state. The extraction of this information is very challenging. The extraction of this information is very challenging. The major subject of study of the scientific areas of computer vision and ML is the potential of human for identifying the activities of another person. A sequence of human body movements in which different body parts are engaged in a concurrent manner is known as action. According to computer vision perception, any kind of observation is matched with earlier defined patterns and then it is labeled while recognizing the action. In this research work, the 3 D Skelton-based technique is proposed for human activity reorganization. The proposed technique will improve performance for the human activity detection in terms of accuracy, precision and recall also the proposed technique will compared with the other techniques which authenticates reliability of the model.

The injection of spin-polarized electrons from a magnetic material into semiconductor is currently one of the foremost challenges in semiconductor spin electronics. Here, we have studied the efficient electrical spin injection and detection from nickel doped Fe3O4 (NFO) into the p-Si having (100) crystal orientation via MgO thin insulating tunnel barrier with the help of three-terminal Hanle measurement. The NFO/MgO/p-Si heterojunction has been prepared using pulsed laser deposition (PLD) technique. Clear Hanle and Inverted Hanle signals have been noticed in spin injection and detection condition of the heterojunction. A large value of Hanle signal (ΔV = 2.4 mV) has been detected at room temperature (300 K). Pure spin accumulation in p-Si resulted from spin injection from strong ferromagnetic NFO via MgO tunnel barrier has been corroborated by a meticulous experiment incorporating a non-magnetic Ag/MgO/p-Si heterostructure. The bias dependent ΔV and spin lifetime (τ) suggest that the transport of the heterojunction is governed by the spin tunnelling via pin-hole free MgO tunnel barrier. Hence the oxide magnetic materials establish a decent platform in spin injection and detection for the development and improvement of room temperature spin-based electronic devices.

As we listen to speech, our ability to understand what was said requires us to retrieve and bind together individual word meanings into a coherent discourse representation. This so-called semantic unification is a fundamental cognitive skill, and its development relies on the integration of neural activity throughout widely distributed functional brain networks. In this proof-of-concept study, we examine, for the first time, how these functional brain networks develop in children. Twenty-six children (ages 4-17) listened to well-formed sentences and sentences containing a semantic violation, while EEG was recorded. Children with stronger vocabulary showed N400 effects that were more concentrated to centroparietal electrodes and greater EEG phase synchrony (phase lag index; PLI) between right centroparietal and bilateral frontocentral electrodes in the delta frequency band (1-3 Hz) 1.27-1.53 s after listening to well-formed sentences compared to sentences containing a semantic violation. These effects related specifically to individual differences in receptive vocabulary, perhaps pointing to greater recruitment of functional brain networks important for top-down semantic unification with development. Less skilled children showed greater delta phase synchrony for violation sentences 3.41-3.64 s after critical word onset. This later effect was partly driven by individual differences in nonverbal reasoning, perhaps pointing to non-verbal compensatory processing to extract meaning from speech in children with less developed vocabulary. We suggest that functional brain network communication, as measured by momentary changes in the phase synchrony of EEG oscillations, develops throughout the school years to support language comprehension in different ways depending on children's verbal and nonverbal skill levels.

The present study is focused on the integration of microreactors to synthesize visible light active nanophotocatalysts for inline photocatalytic degradation of organic dye and antibacterial activity. A wire-assisted and a rapid laser micromachining technique has been employed for the fabrication of polydimethylsiloxane (PDMS) and poly(methyl methacrylate) (PMMA)-based microreactors, respectively. By varying the design and chemical reagents involved, different sizes of visible light active Ag

Graphene, with its excellent electrical, mechanical, and optical properties, has emerged as an exceptional material for flexible and transparent nanoelectronics. Such versatility makes it compelling to find new pathways to lay graphene sheets onto smooth, flexible substrates to create large-scale flexible transparent graphene conductors. Here, we report the realization of flexible transparent graphene laminates by direct adhesion of chemical vapor deposition (CVD) graphene on a polyethylene naphthalate (PEN) substrate, which is an emerging standard for flexible electronics. By systematically optimizing the conditions of a hot-press technique, we have identified that applying optimum temperature and pressure can make graphene directly adhere to flexible PEN substrates without any intermediate layer. The resultant flexible graphene films are transparent, have a standard sheet resistance of 1 kΩ with high bending resilience, and high optical transmittance of 85%. Our direct hot-press method is achieved below the glass transition temperature of the PEN substrate. Furthermore, we demonstrate press-assisted embossing for patterned transfer of graphene, and hence it can serve as a reliable new means for creating universal, transparent conducting patterned films for designing flexible nanoelectronic and optoelectronic components.

Graphene, with its excellent electrical, mechanical, and optical properties, has emerged as an exceptional material for flexible and transparent nanoelectronics. Such versatility makes it compelling to find new pathways to lay graphene sheets onto smooth, flexible substrates to create large-scale flexible transparent graphene conductors. Here, we report the realization of flexible transparent graphene laminates by direct adhesion of chemical vapor deposition (CVD) graphene on a polyethylene naphthalate (PEN) substrate, which is an emerging standard for flexible electronics. By systematically optimizing the conditions of a hot-press technique, we have identified that applying optimum temperature and pressure can make graphene directly adhere to flexible PEN substrates without any intermediate layer. The resultant flexible graphene films are transparent, have a standard sheet resistance of 1 k Omega with high bending resilience, and high optical transmittance of 85%. Our direct hot-press method is achieved below the glass transition temperature of the PEN substrate. Furthermore, we demonstrate press-assisted embossing for patterned transfer of graphene, and hence it can serve as a reliable new means for creating universal, transparent conducting patterned films for designing flexible nanoelectronic and optoelectronic components.

Silicon, a candidate as an abundant-element thermoelectric material for low-temperature thermal energy scavenging applications, generally suffers from rather low thermoelectric efficiency. One viable solution to enhancing the efficiency is to boost the power factor (PF) of amorphous silicon (a-Si) while keeping the thermal conductivity sufficiently low. In this work, we report that PF >1 m Wm−1 K−2 is achievable for boron-implanted p-type a-Si films dispersed with ultrafine crystals realized by annealing with temperatures ≤600 °C. Annealing at 550 °C initiates crystallization with sub-5-nm nanocrystals embedded in the a-Si matrix. The resultant thin films remain highly resistive and thus yield a low PF. Annealing at 600 °C approximately doubles the density of the sub-5-nm nanocrystals with a bimodal size distribution characteristic and accordingly reduces the fraction of the amorphous phase in the films. Consequently, a dramatically enhanced electrical conductivity up to 104 S/m and hence PF > 1 m Wm−1 K−2 measured at room temperature are achieved. The results show the great potential of silicon in large-scale thermoelectric applications and establish a route toward high-performance energy harvesting and cooling based on silicon thermoelectrics.

Establishing ultimate spin current efficiency in graphene over industry-standard substrates can facilitate research and development exploration of spin current functions and spin sensing. At the same time, it can resolve core issues in spin relaxation physics while addressing the skepticism of graphene's practicality for planar spintronic applications. In this work, we reveal an exceptionally long spin communication capability of 45 mu m and highest to date spin diffusion length of 13.6 mu m in graphene on SiO2/Si at room temperature. Employing commercial chemical vapor deposited (CVD) graphene, we show how contact-induced surface charge l transfer doping and device doping contributions, as well as spin relaxation, can be quenched in extremely long spin channels and thereby enable unexpectedly long spin diffusion lengths in polycrystalline CVD graphene. Extensive experiments show enhanced spin transport and precession in multiple longest channels (36 and 45 mu m) that reveal the highest spin lifetime of similar to 2.5-3.5 ns in graphene over SiO2/Si, even under ambient conditions. Such performance, made possible due to our devices approaching the intrinsic spin-orbit coupling of similar to 20 mu eV in graphene, reveals the role of the D'yakonov-Perel' spin relaxation mechanism lin graphene channels as well as contact regions. Our record demonstration, fresh device engineering, and spin relaxation insights unlock the ultimate spin current capabilities of graphene on SiO2/Si, while the robust high performance of commercial CVD graphene can proliferate research and development of innovative spin sensors and spin computing circuits.

The low temperature spin accumulation in p-Si using Co2CrAl/SiO2 tunnel junction has been investigated in detail. The heterojunction has been fabricated using electron beam evaporation (EBE) technique. The 3-terminal contacts in Hanle geometry has been made for spin transport measurements. The electrical transport properties have been investigated at different isothermal conditions in the temperature range of 10-300 K. The current-voltage characteristics of the junction shows excellent rectifying magnetic diode like behaviour in lower temperature range (below 200 K). At higher temperature, the junction shows nonlinear behaviour without rectifying characteristics. We have observed spin accumulation signal in p-Si semiconductor using SiO2/Co2CrAl tunnel junction in the low temperature regime (30-100 K). Hence the highly spin polarized Full Heusler alloys compounds, like Co2CrAl etc., are very attractive and can act as efficient tunnel device for spin injection in the area of spintronics devices in near future. The estimated spin life time is τ = 54 pS and spin diffusion length inside p-Si is LSD = 289 nm at 30 K for this heterostructure.

Despite structural and processing-induced imperfections, wafer-scale chemical vapor deposited (CVD) graphene today is commercially available and has emerged as a versatile form that can be readily transferred to desired substrates for various nanoelectronic and spintronic applications. In particular, over the past decade, significant advancements in CVD graphene synthesis methods and experiments realizing high-quality charge and spin transport have been achieved. These include growth of large-grain graphene, new processing methods, high-quality electrical transport with high-carrier mobility, micron-scale ballistic transport, observations of quantum and fractional quantum Hall effect, as well as the spintronic performance of extremely long spin communication over tens of micrometers at room temperature with robust spin diffusion lengths and spin lifetimes. In this short review, we discuss the progress in recent years in the synthesis of high-quality, large-scale CVD graphene and improvement of the electrical and spin transport performance, particularly towards achieving ballistic and long-distance spin transport that show exceptional promise for next-generation graphene electronic and spintronic applications.

Room temperature spin injection and detection in non-magnetic p-Si semiconductor have been studied in details in our Co2CrAl (CCA)/MgO/p-Si heterojunction. The electrical transport properties have ...

Typically, a limited number of dynamic pressure sensors is employed to determine the unsteady aerodynamic forces on large, slender aerospace structures. This paper describes a robust calculation pr...

Several clinical applications rely on accurate guiding information when drilling along the femoral neck (e.g., pin insertion in case of neck fracture). Currently, applications rely on real-time X-ray imaging, which results in irradiation issues for the surgeon conducting the operation. The goal of this paper was to develop an X-ray-free method that would allow for a pathway to be drilled between the lateral aspect of the femoral diaphysis (the so-called piercing point), the femoral neck and the head centres. The method is based on on-the-fly computational predictions relying on a biomechanical database that includes morphological data related to the femoral neck and head and various palpable anatomical landmarks located on the pelvis and the femoral bone. From the spatial location of the anatomical landmarks, scalable multiple regressions allow for the prediction of the most optimal drilling pathway. The method has been entirely validated using in vitro experiments that reproduce surgical conditions. Further, a surgical ancillary prototype that integrates the method of guiding the pin drilling has been developed and used during in vitro and in situ validation using nine hip joints. Pin insertion was controlled after drilling using medical imaging and show successful result for each of the nine trials. The mean accuracy of the estimated hip joint centre and neck orientation was 6.0 ± 2.8mm and 7.1 ± 3.8°, respectively.

The magnetic heterojunction diode has been fabricated by growing Co 0.65 Zn 0.35 Fe 2 O 4 (CZFO) on well cleaned p-Si substrate using pulsed laser deposition technique, and its behavior under magnetic field is experimentally studied in details. The magnetic field dependent current–voltage characteristics (I–V) have been studied at different isothermal conditions in the range of 5–300 K. The junction shows magnetic diode like rectifying behavior at low temperature, whereas at high temperatures the junction shows nonlinear I–V characteristics. Magnetic field shows a strong effect on junction resistance (CZFO/p-Si). It is interesting that the positive junction magnetoresistance (MR) thus produced, remains very large at low temperature regime (590% at 5 K) and gradually decreases at higher temperatures. In contrast, CZFO magnetic thin film shows negative MR behavior, whereas the junction shows large positive junction magnetoresistance (JMR) behavior throughout the temperature range. The origin of JMR has been best explained by standard spin injection theory. The temperature dependent spin life time (τ) has been estimated for our heterostructure. The value of τ decreases with increasing temperature. The spin life time (183 ps), spin polarization (0.71) and spin diffusion length (375 nm) have been estimated of the heterostructure at 10 K.

The low temperature spin accumulation in p-Si using Co2CrAl/SiO2 tunnel junction has been investigated in detail. The heterojunction has been fabricated using electron beam evaporation (EBE) technique. The 3-terminal contacts in Hanle geometry has been made for spin transport measurements. The electrical transport properties have been investigated at different isothermal conditions in the temperature range of 10-300 K. The current-voltage characteristics of the junction shows excellent rectifying magnetic diode like behaviour in lower temperature range (below 200 K). At higher temperature, the junction shows nonlinear behaviour without rectifying characteristics. We have observed spin accumulation signal in p-Si semiconductor using SiO2/Co2CrAl tunnel junction in the low temperature regime (30-100 K). Hence the highly spin polarized Full Heusler alloys compounds, like Co2CrAl etc., are very attractive and can act as efficient tunnel device for spin injection in the area of spintronics devices in near future. The estimated spin life time is τ = 54 pS and spin diffusion length inside p-Si is LSD = 289 nm at 30 K for this heterostructure.

Owing to their unprecedented electronic properties, graphene and two-dimensional (2D) crystals have brought fresh opportunities for advances in planar spintronic devices. Graphene is an ideal medium for spin transport while also being an exceptionally resilient material for flexible electronics. However, these extraordinary traits have never been combined to create flexible graphene spin circuits. Realizing such circuits could lead to bendable strain-based spin sensors, a unique platform to explore pure spin current based operations and low power flexible nanoelectronics. Here, we demonstrate graphene spin circuits on flexible substrates for the first time. These circuits, realized using chemical vapour deposited (CVD) graphene, exhibit large spin diffusion coefficients ~0.19-0.24 m2s-1 at room temperature. Compared to conventional devices of graphene on Si/SiO2 substrates, such values are 10-20 times larger and result in a maximum spin diffusion length ~10 um in graphene achieved on such industry standard substrates, showing one order enhanced room temperature non-local spin signals. These devices exhibit state of the art spin diffusion, arising out of a distinct substrate topography that facilitates efficient spin transport, leading to a scalable, high-performance platform towards flexible 2D spintronics. Our innovation unlocks a new domain for the exploration of strain-dependent spin phenomena and paves the way for flexible graphene spin memory-logic units and surface mountable sensors., Comment: Figures made compatible with all operating systems and PDF viewers

The objective of this model is to investigate the inventory system for perishable items where time proportional deterioration rate is considered. The Economic order quantity is determined for minimizing the average total cost per unit time. Time dependent demand rate is used with finite time horizon. Nonlinear holding cost with shortage is considered. The result is illustrated with numerical example.

This work reports the investigation of critical behavior of Co50−xNixCr25Al25 (x = 0 and 5) and magneto caloric effect (MCE) of bulk Co2CrAl full Heusler alloy system. The alloy series of Co50−xNixCr25Al25 (x = 0, 1, 2, 3, 4 and 5) have been prepared using arc melting technique. The magnetic properties of all the samples have been studied in the temperature range of 5–300 K. The value of Curie temperature (TC) is found to decrease with increasing doping concentration of the Ni (substitution of Ni at Co site). The critical exponents behavior and scaling relation have been investigated using magnetic isotherms in Co50−xNixCr25Al25 (x = 0 and 5) alloys. The critical exponents are estimated by various techniques such as, Modified Arrott plot, Kouvel–Fisher plot and critical isotherm technique. The value of critical exponents vicinity to the second order magnetic phase transition of Co50Cr25Al25 were found to be β = 0.488 (7), γ = 1.144 (16) and δ = 3.336 (5) with TC = 328.64 (5) K whereas for Co50Ni5Cr25Al25 the values are β = 0.522 (13), γ = 1.014 (6) and δ = 3.043 (7) with TC = 285.71 (11). The critical exponent values for both the samples are almost similar to the value as predicted by mean field theory. This has been best explained by long range mean field like ferromagnetic interaction in the entire Co50−xNixCr25Al25 (x = 0, 5) highly spin polarized full Heusler alloy system. Under an external magnetic field maximum up to 5 T, normal magneto caloric effect (MCE) have been observed with a maximum magnetic entropy change of 2.55 J/kg K at 328.5 K (near the ferromagnetic → paramagnetic second order magnetic phase transition in the austenite phase) in Co2CrAl full Heusler alloy system.

Oxide dielectric present in metal oxide semiconductor high electron mobility transistor plays an important role during formation of two dimensional electron gas (2DEG). The sheet charge concentration $$(\hbox {n}_{{\mathrm{s}}})$$(ns) is dependent on the Eigenenergy states present in triangular quantum well at AlGaN/GaN interface. The energy states are in fact functions of vertical electric field at the edge of the well. Therefore in this paper a model is developed to find out Electric field and flat-band voltage $$(\hbox {V}_{{\mathrm{T}}})$$(VT) by adopting energy band approach to incorporate oxide parameters in it unlike the conventional method of solving Poisson's equation, which is the uniqueness of this paper. The Eigenenergy states are dependent non-linearly on electric field. In the present case, three quantum states in the well are considered along with the Fermi---Dirac distribution function to obtain $$\hbox {n}_{\mathrm{s}}$$ns. The dependence of 2DEG density, electric field and flat-band voltage on the oxide parameters such as thickness and electrical permittivity is analyzed. With respect to thickness in $$\hbox {SiO}_{2}$$SiO2 and $$\hbox {Al}_{2}\hbox {O}_{3},\, \hbox {n}_{\mathrm{s}}$$Al2O3,ns shows inverse relationship; whereas in $$\hbox {HfO}_{2}$$HfO2 it is direct due to positive charges accumulated at oxide/barrier interface. To the best of author's knowledge the work is first of its kind and due to lack of experimental data; the obtained results are compared with TCAD results to validate the model.

at.% Fe doped In2O3 dilute magnetic semi- conducting (DMS) nanoparticles are synthesized using low temperature 'pyrophoric reaction processes'. X-ray dif- fraction studies at room temperature have revealed single- phase cubic bixbyite structure of the sample. Nano size grain distribution has been observed by FESEM. The recorded temperature dependent magnetization curve exhibits concave nature in the low temperature range for both FC and ZFC conditions revealing insulating DMS like behavior. No phase transition has been noticed within the studied temperature range. Study of magnetic properties in detail confirms the weak ferromagnetic ordering along with paramagnetic behavior of the nanometric sample. From the temperature dependence of inverse magnetic susceptibility (χ −1 (T)) using Curie-Weiss plot, the effective Bohr mag- neton (μeff) has been estimated to be ~3.715 μB/Fe ion. Observed photoluminescence spectrum of Fe doped In2O3 nanostructures mainly results from the recombination of electrons occupying oxygen vacancies or Fe 3+ ions with photo-excited holes.

Spin injection and detection in non magnetic p-Si semiconductor have been studied in details in Co45Ni5Cr25Al25(CNCA)/MgO/p-Si heterojunction fabricated using Electron Beam Evaporation (EBE) technique. The 3-terminal tunnel contacts in Hanle geometry have been made on the device for transport measurements. The current-voltage characteristics of the junction shows excellent rectifying magnetic diode like behaviour in lower temperature range (below 200 K). The spin accumulation in non magnetic p-Si semiconductor has been observed at different bias current under the applied magnetic field parallel to the film plane in the temperature range of 30-300 K. The Hanle effect is used to control the reduction of spin accumulation by applying magnetic field perpendicular to the carrier spin in the p-Si. The accumulated spin decaying as a function of applied magnetic field for fixed bias current has been recorded. The spin life time (67 pS) and spin diffusion length (227 nm) have been estimated of the heterostructure ...

The room temperature spin injection and detection in non magnetic p-Si semiconductor have been studied in details in our CoFe2O4 (CFO)/MgO/p-Si heterojunction. The 3-terminal tunnel contacts have been made on the device for transport measurements. The electrical transport properties have been investigated at different isothermal conditions in the temperature range of 10-300 K. The spin accumulation in non magnetic p-Si semiconductor has been observed at different bias current under the applied magnetic field parallel to the film plane in the temperature range of 40-300 K. We have observed a giant spin accumulation in p-Si semiconductor using MgO/CFO tunnel contact. The Hanley effect is used to control the reduction of spin accumulation by applying magnetic field perpendicular to the carrier spin in the p-Si. The accumulated spin signal decays as a function of applied magnetic field for fixed bias current. These results will enable utilization of the spin degree of freedom in complementary Si devices and its further development.

Electronic- and magnetic-transport properties of NiFe2O4 (NFO)–SiO2–Si heterojunction fabricated by depositing NFO thin films on silicon substrates with the intermediate native oxide (SiO2) layer have been investigated in details. The current–voltage (I–V) characteristics across the junction have been recorded in the temperature range of 10–300 K. All I–V curves show non-linear behavior throughout the temperature range. The dominating current transport mechanism is found to be temperature dependent tunneling assisted by Frenkel–Poole type emission. In this paper, we report the junction magnetoresistance (JMR) properties of this heterojunction in the temperature range of 10–300 K. With increasing temperature, the JMR of the heterojunction increases accordingly. The high positive JMR (~54%) has been observed at room temperature (RT). The origin of high positive JMR at RT is attributed to efficient spin-polarized carrier transport across the junction.

A detailed experimental investigation on magnetic field dependent electronic transport across epitaxial Ni nanoparticles embedded in metallic epitaxial TiN matrix grown on p-type (001) Si substrate heterojunction employing sequential exposure of pulsed excimer laser is reported here. The non-linear current–voltage characteristics along with good rectifying diode like behavior of the junction have been obtained in the range of 100–300 K. The ideality factor, reverse saturation current, series resistance and turn-on voltages have been estimated for the heterojunction at different operating temperatures. The dominating current transport mechanism is found to be temperature dependent tunneling assisted Frenkel–Poole type emission. A crossover from negative to positive junction magnetoresistance (JMR) has been observed at ~ 190 K (blocking temperature of the Ni nanodots). The JMR attains a peak with high positive JMR value at 250 K, the origin of which has been best explained using standard spin injection theory.

The observation of giant positive junction magnetoresistance (JMR) in our cobalt ferrite (CFO)/p-Si heterojunction has been reported here. The pulsed laser deposition technique has been used for fabrication of the heterojunction. The junction confirms a very good rectifying magnetic diode like behavior at low temperature, whereas at high temperatures the junction shows nonlinear I–V characteristics. The magnetic field-dependent magnetoresistance (MR) of both CFO film and across the heterojunction have been studied in detail. The CFO film shows negative MR behavior, whereas the junction shows large positive JMR behavior throughout the temperature range. The spin lifetime (142 ps) and spin diffusion length (331 nm) have been estimated of the heterostructure at 10 K. The highest JMR value (~1600 %) has been observed at 10 K, and it gradually decreases at higher temperature range. The origin of positive JMR in our heterojunction has been best explained by the standard spin injection theory.

In this paper the behavior of Gate Capacitance with the nanoscale variation of barrier thickness in Gallium Nitride (GaN) based metal oxide semiconductor High electron mobility transistor (MOSHEMT) is presented. The Gate Capacitance has been calculated for Aluminum Nitride/Gallium Nitride (AlN/GaN) and Aluminum Indium Nitride/Gallium Nitride (AlInN/GaN) MOSHEMT through TCAD simulation. AlN/GaN MOSHEMT has an advantage of significant decrease in gate capacitance with increase in barrier thickness compared to AlInN/GaN MOSHEMT. This decrease in gate capacitance leads to improve the RF performance and hence reduce the propagation delay.

A new high performance normally-on AlGaN/GaN high electron mobility transistor (HEMT) is proposed. Its DC and microwave characteristics are observed by introducing aluminum oxide (Al 2 O 3 ) as surface passivation layer. This layer reduces the trapped charge carriers for improving the two dimensional electron gas (2DEG) confinement over the Gallium Nitride (GaN) channel layer. Aluminum Nitride (AlN) layer is grown above the substrate, as nucleation layer which not only potentially improves transconductance by reducing the acceptor state trap densities but also eventually increases the on state drain current. This depletion mode AlGaN/AlN/GaN HEMT device having gate length of 1.2µm has maximum transconductance of 160ms/mm.

Automated flowcytometric analysers are used to analyse complete blood count (CBC) in most patients. They differentiate WBC depending on their size, internal granularity, and nuclear content by producing various scattergrams. In malaria, haemozoin pigment-containing cells (parasitized RBC and phagocytic cells) are able to depolarize the laser beam and therefore exhibit abnormal scattergram.A study was conducted to evaluate the diagnostic utility and to determine the sensitivity and specificity of flowcytometric haematology analysers [Sysmex XE-2100 (System 1) and Cell-Dyn 3700 (System 2)] in comparison with the conventional microscopy (QBC, AO, Giemsa) and ICT (Immunochromatographic test) for detection of the malaria parasite.Fifty-eight of 320 samples were found to be positive for malaria by conventional methods. Considering atypical scattergram, System 1 showed the sensitivity and specificity of 68.9% and 90.6%, respectively; whereas System 2 showed a sensitivity of 100% and specificity of 98.8%.System 2 (Cell-Dyn 3700) was found to be a highly sensitive and specific tool compared to System 1 and conventional methods. Hence, it may be preferred for automated detection of malaria in the blood samples of patients with a differential diagnosis of malaria and those who are subjected to CBC analysis.

The kinetics and mechanism of oxidation of cetirizine hydrochloride by Mn(VII) in acidic medium was studied spectrophotometrically. The electron transfer reaction between MnO 4 - and the drug have been studied over the range 2.0 ? 10 3 [cetirizine hydrochloride] ? 6.0, 2.5 ? pH ? 4.5 and 295 K ? T ? 313 K in aqueous medium. The electron transfer reaction shows first order dependence in [MnO 4 - ] T and [cetirizine hydrochloride]. The rate of the reaction was found to increase with increasing pH of the medium. The conjugate base of the reactant drug and MnO 4 - reacts to produce products. The activation parameters ?H ? (kJ mol -1 ) and ?S ? (JK -1 mol -1 ) for the electron transfer reaction was found to be 33.93 and -143.00. The product of the reaction was cetirizine N-oxide. Keywords : Cetirizine, Oxidation, Kinetics, Cetirizine N-Oxide, Spectrophotometer.

The half metallic ferromagnet Co2CrAl full Huesler alloy was successfully prepared by arc melting process. The electrical and magnetic properties of Co2CrAl alloy have been studied in the temperature range of 5 – 300 K. The ferromagnetic Curie temperature Tc of the same alloy has been observed at 329.8 K. The alloy shows semiconducting like electronic transport behavior throughout the studied temperature range. The origin of the semiconducting behavior of Co2CrAl alloy can be best explained by the localization of conduction electrons and the presence of an energy gap in the electronic spectrum near the Fermi level EF.