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The Solar Ultraviolet Imaging Telescope (SUIT) is one of the payloads onboard the Aditya-L1 mission. It will perform full disk imaging of the Sun in the near-Ultraviolet wavelength range of 200-400 nm. This provides near-simultaneous observations of the Sun from the photosphere and chromosphere. A back-illuminated, enhanced UV Charge Coupled Device (CCD) of size 4096 (H) × 4136 (V) pixels, with a pixel size of 12 μm, is used as an imaging element in SUIT. The CCD characterization and the readout electronics development and testing were performed in-house at the Space Astronomy Group (SAG), UR Rao Satellite centre, ISRO. The test setup and procedures are explained and the measured values of various parameters including noise, dark current, gain, linearity, and cross-talk are presented in this paper. The results show a satisfactory performance from the CCD as well as the readout electronics to meet the specifications required by the SUIT payload.

Background The emerging role of gut microbiota and their metabolites in the modulation of the gut-brain axis has received much attention as a new hope for the treatment of hard-to-treat chronic neurodegenerative diseases like Alzheimer’s Disease. The naturally occurring polyphenols can restore the gut-brain axis by modulating gut microbiota and brain neurotransmitters. However, the mechanism of action remained unclear. The Indian traditional medicine Triphala, a rich source of polyphenols, has been used on humans based on Prakriti or disease conditions for many years. Methods: In this study, the dual mode (morning and evening) action of Triphala was used to provide scientific evidence of its superior preventive and therapeutic efficacy in C57BL/6 and 5xFAD, APP/PS1 transgenic mouse model of Alzheimer’s disease. For behavior analysis, used the Morris water model and Y maze model to assess spatial memory and exploratory behavior. The blood serum and brain lysate were used to evaluate the inflammatory activity and oxidative parameters in the mice. The gut microbiome analysis was done by 16srRNA analysis from mice feces after 60 days of treatment. Results We observed that Triphala treatment has significantly improved cognitive function, by modulating the APP pathway, reducing inflammation, oxidative stress, and restoring the gut-brain axis by increasing the gut microbiota phyla of Bacteroides, Proteobacteria, Actinobacteria, etc., involved in maintaining the gut homeostasis. Conclusions Our study paved a new path for using dual modes of Triphala one or in combination to treat incurable AD.

This work reports the synthesis of bio-carbonaceous electrode material, carbon soot (CS), by molecular growth of hydrocarbons in a simple chain reaction without any artificial environment. The activated CS (ACS) is derived by burning the mustard oil (wick-and-oil flame synthesis) followed by activation using ZnCl2. The ACS possesses more ordered layered structure with spherical morphology with higher carbon content as compared to the raw CS. The electrochemical impedance spectroscopy (EIS) studies reveal superior charge-transfer characteristics of the ACS electrodes. The galvanostatic charge–discharge (GCD) studies reveal that the electric double-layer capacitor (EDLC) utilizing the ACS electrodes delivers superior specific capacity of 50 F g−1 at 0.5 mA cm−2 than that of raw CS (28 F g−1). The EDLC fabricated using activated CS electrode shows excellent power density of 1620 W kg−1 and energy density 20.25 W h kg−1.

Aditya-L1 is India’s first observatory class Solar space mission to study the Sun from Lagrangian 1 position. The Solar Ultra-Violet Imaging Telescope (SUIT) is one of the payloads on-board Aditya-L1. SUIT is an off-axis Ritchey-Chretien (RC) telescope, which images the Sun on to a 4k x 4k CCD covering a field-of-view of 1.5Ro with a plate scale of 0.7'/pixel. One of the primary objectives of SUIT is to study the early evolution of solar flares with high time cadence in Near UV wavelength (200 nm – 400 nm). The SUIT on-board intelligence is developed to achieve this objective. The complete intelligence algorithm is divided into several sub-modules each working on a specific aspect of intelligence. These are, HEL1OS flare trigger module: generates flare trigger using HEL1OS hard X-ray data, flare localization module: locates flare on the SUIT full-disc images, Region of Interest (RoI) tracking module: accounts for shift in RoI coordinates caused due to rotation of the Sun, auto-exposure control module: adjusts the exposure time depending upon the flare intensity for better contrast. In this paper, these on-board intelligence modules are explained in detail. The working principles of these modules are tested using available data from various existing missions and also using synthesized data and the obtained results are presented. The modules are implemented in hardware using Actel RTAX 2000S FPGA and are tested using laboratory setup. From the testing, it is found that, flares are successfully localized in a mean time of 40 seconds from the GOES soft X-ray catalog start time. Also, a time cadence of under 3 seconds for a single filter flare RoI images is achieved.

Developing a richer understanding of the various properties of light is central to the field of photonics. One often neglected degree of freedom (DOF) is the second-order correlation of the light field, known as coherence. To make proper use of this DOF, one needs to first obtain information about the field’s coherence, which may be characterized through the cross spectral density (CSD) function. We present a measurement of the CSD of a ubiquitous, partially coherent source: a multiple quantum well device in its near-field region, where a photonic structure would commonly encounter the emitted field. We show a departure from the coherence area that is expected from an incoherent source and demonstrate the application of coherent mode decomposition as a way to further analyze the measured results.

We present an electroreflectance study of the polarization field in semi-polar (10) and (112) oriented InGaN quantum wells (QW). For the () sample, the flat-QW condition (the electric field in the QW is zero) is at a reverse bias voltage. For the (112) sample, the flat-QW condition is at a forward bias voltage larger than the turn on voltage of the diode. However, the flat-barrier condition (the electric field in the barrier region is zero) is at a forward bias voltage less than the turn on voltage of the diode. The flat-QW condition and the flat-barrier condition are determined by examining the zero-crossing and the Franz-Keldysh oscillations in the electroreflectance signal for (10) and (112) InGaN QWs, respectively. From the corresponding bias voltages, we deduce the polarization field in the QWs and conclude that in the semi-polar InGaN/GaN QW there is a crossover angle between the polar and non-polar orientations where the polarization field vanishes. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We demonstrate high power blue and green InGaN/GaN multiple-quantum-well (MQW) light emitting diodes (LEDs) grown on low extended defect density semipolar (10 1 1) and (11 2 2) bulk GaN substrates by metal organic chemical vapor deposition. The output power and external quantum efficiency (EQE) at 20 mA under pulsed operation (10 % duty cycle) were 19.7 mW and 34.4 % for the blue LED and 9.0 mW and 18.9 % for the green LED, respectively. The blue LED showed

Aims: We aimed to validate Mannheim peritonitis index (MPI) for prediction of outcome in patients with perforation peritonitis. Materials and Methods: A prospective study involving 100 subjects operated for perforation peritonitis over the period of 2 years was designed. Postevaluation of predesigned performa, MPI score was calculated and analyzed for each patient with death being the main outcome measure. The MPI scores were divided into three categories; scores 25 (category 3). Results: Our study consisted of 82 males and 18 females (male:female ratio 4.56:1), with the mean patients age of 37.96 ± 17.49 years. 47, 26, and 27 cases belonged to MPI score categories 1, 2, and 3, respectively. The most common origin of sepsis was ileal with small intestine dominating the source of perforation. When the individual parameters of MPI score were assessed against the mortality only, age >50 years (P = 0.015), organ failure (P = 0.0001), noncolonic origin of sepsis (P = 0.002), and generalized peritonitis (P = 0.0001) significantly associated with mortality. The sensitivity of MPI was 92% with a specificity of 78% in receiver operating characteristic curves. Conclusion: MPI is an effective tool for prediction of mortality in cases of perforation peritonitis.

Internet of things is the communication of anything with any other thing, the communication mainly transferring of use able data, for example a sensor in a room to monitor and control the temperature. It is estimated that by 2020 there will be about 50 billion internet-enabled devices. This paper aims to describe a security alarm system using low processing power chips using Internet of things which helps to monitor and get alarms when motion is detected and sends photos and videos to a cloud server. Moreover, Internet of things based application can be used remotely to view the activity and get notifications when motion is detected. The photos and videos are sent directly to a cloud server, when the cloud is not available then the data is stored locally on the Raspberry Pi and sent when the connection resumes. Therefore, advantages like these make this application ideal for monitoring homes in absence.

Introduction Laparoscopic approach in horseshoe kidney (HSK) is a challenge because of the aberrant vessels, the renal isthmus and the renal ectopia are all unique features of this anomaly encountered during the surgery. We report our single center experience with this technique in managing three patients with HSK. Methods A total of 15 cases (9 males and 6 females) were operated between June 2011 and December 2016 for various indications. Of these four patients were managed laparoscopically, two patients with HSK had non-functioning renal moiety underwent transperitoneal heminephrectomy. The third patient with a mass in right moiety with thin fibrous isthmus was successfully managed with laparoscopic heminephrectomy. Fourth patient with pelvi-ureteric junction obstruction with multiple renal calculi was managed with pyeloplasty and complete clearance of all calyceal the stones. Result Mean operating time was 140 ± 1.8 (100-180) min, and estimated blood loss was 131 ± 12.6 (30-320) ml. The mean hospital stay was 2.3 ± 1.4 (1-5) days. There were no major intra- and post-operative complications except minimal postoperative discomfort. Conclusion Laparoscopic nephrectomy is technically feasible, safe, and reliable for benign and malignant diseases in a HK with mainly three factors posing challenges during the surgery are the abnormal vasculature, division of the isthmus, and lower location of the kidney.

We demonstrate the first blue AlInGaN-based laser diodes (LDs) grown on semipolar (33) free-standing GaN substrates. Etched facet ridge waveguide LDs were fabricated and tested under pulsed operation. Lasing was achieved at 477.5 nm with a threshold current density of 12.2 kA/cm2. The peak electroluminescence wavelength was shown to blue-shift from approximately 494 nm to 477 nm upon reaching threshold. Initial experimental data also show the (33) plane to have higher indium incorporation efficiency than the (33) plane, suggesting that (33) GaN substrates may be more suitable for growth and fabrication of long-wavelength AlInGaN-based LDs than (33) GaN substrates. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The first semipolar nitride laser diodes (LDs) have been realized on low extended defect density semipolar (10) GaN bulk substrates. The LDs were grown by conventional metal organic chemical vapor deposition (MOCVD). Broad area lasers with uncoated etched facets were fabricated and tested under pulsed conditions. Lasing was observed at a duty cycle of 0.025% with the threshold current density (Jth) being 24.5 kA/cm2 for a 5 µm × 800 µm device. An output power of 65 mW was measured from a single facet of the device at a drive current of 1.5 A, with the calculated differential quantum efficiency (ηdiff) being 8%. Stimulated emission was observed at 405.9 nm with a narrow full width half maximum (FWHM) of less than 0.3 nm. The lowest measured Jth was 16.5 kA/cm2 for a 10 µm × 800 µm device. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We demonstrate a high power green InGaN/GaN multiple-quantum-well (MQW) light emitting diode (LED) with a peak emission wavelength of 516 nm grown on low extended defect density semipolar (112) bulk GaN substrate by metal organic chemical vapor deposition. The output power and external quantum efficiency (EQE) at drive currents of 20 and 100 mA under direct current (DC) operation were 5.0 mW, 10.5% and 15.6 mW, 6.3%, respectively. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

We report the fabrication of violet InGaN/GaN light-emitting diodes (LEDs) on semipolar (1011) GaN bulk substrates. The LEDs have a dimension of 300 ×300 µm2 and are packaged in an epoxy resin. The output power and external quantum efficiency (EQE) at a driving current of 20 mA were 20.58 mW and 33.91% respectively, with peak electroluminescence (EL) emission wavelength at 411 nm. The LEDs show minimal shift in peak EL wavelength with increasing drive current along with a high EQE.

A very large number of localization algorithms have been used till under various domains. But the subject of our research paper deals with the domain of VPR i.e. vehicle plate recognition system. The accuracy of the license plate recognition system depends on the performance of the localization algorithm. It is a computationally intensive process which takes a lot of time to localize the license plate. In our research paper we will discuss different types of localization algorithms and which of them should be used for a particular application. Different countries have their own types of license plates for instance some use single line horizontal license plates while others use multi line non horizontal and differently located number plates. Some of the widely used localizations algorithms which are used in the neural network recognizer are global threshold scheme, NiBlack's threshold.

Single quantum wells of low InN concentration InGaN grown on high quality nonpolar and semipolar substrates cut from bulk GaN boules are studied by time-resolved photoluminescence techniques. Data is presented for different well widths at varying pump fluence and sample temperature to study nonlinear non-radiative recombination, radiative lifetimes, and carrier localization or separation. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Violet InGaN/GaN light emitting diodes (LEDs) was fabricated on semipolar GaN bulk substrates. The output power and external quantum efficiency at a driving current of 20 mA were measured. The first nonpolar m-plane nitride laser diodes (LDs) were realized on low extended defect bulk m-plane GaN substrates.

We report on violet-emitting III-nitride light-emitting diodes (LEDs) grown on bulk GaN substrates employing a flip-chip architecture. Device performance is optimized for operation at high current density and high temperature, by specific design consideration for the epitaxial layers, extraction efficiency, and electrical injection. The power conversion efficiency reaches a peak value of 84% at 85 °C and remains high at high current density, owing to low current-induced droop and low series resistance.

The first semipolar nitride laser diodes (LDs) have been realized on low extended defect density semipolar (1011) GaN bulk substrates. The LDs were grown by conventional metal organic chemical vapor deposition (MOCVD). Broad area lasers were fabricated and tested under pulsed conditions. Lasing was observed at a duty cycle of 0.025% with a threshold current density (Jth) of 18 kA/cm2. Stimulated emission was observed at 405.9 nm with a full width at half maximum (FWHM) of less than 0.3 nm.

We present experimental results on III–nitride light-emitting diodes emitting at 410 nm, grown on low-defectivity bulk GaN substrates. The epitaxial layers are optimized for high peak efficiency and maintain efficiency at very high current densities. We use a volumetric device architecture with surface roughness to maximize light extraction efficiency. We report an external quantum efficiency of 68% at 180 A cm−2. No current crowding is observed at high current density. We also demonstrate flat-line reliable operation to over 1000 h.

This article presents a theoretical analysis of dislocation behavior and stress relaxation in semipolar III-nitride heteroepitaxy, e.g., for AlxGa1−xN and InyGa1−yN layers grown on {hh2−h−m}- or {h0h−m}-type semipolar planes of GaN substrates. We demonstrate that the shear stresses on the unique inclined basal (0001) plane do not vanish for such growth geometries. This leads to the onset of relaxation processes in semipolar III-nitride heterostructures via dislocation glide in the basal slip systems 〈1−1−20〉(0001) and to the formation of misfit dislocations (MDs) with Burgers vectors of (a/3)〈1−1−20〉-type at the semipolar heterointerface. Next we calculate the Matthews-Blakeslee critical thickness for MD formation in semipolar III-nitride layers together with the MD equilibrium spacings for complete misfit relaxation. The component of the MD Burgers vector normal to the film/substrate interface will cause a crystal lattice tilt in the epilayer with respect to the GaN substrate. The calculated magnitudes o...

Semipolar GaN-based light emitting devices show great promise because of reduced polarization-related electric fields in the quantum wells and the potential for high indium uptake in InxGa1−xN quantum wells. In semipolar GaN, the (0001) slip plane is inclined with respect to the film normal, thus shear stresses are present on this plane for nominally misfitting layer growth. We present scattering contrast transmission electron microscopy studies of (112¯2) and (202¯1) semipolar GaN-based laser diode structures. Misfit dislocations were observed at the nominally misfitting heterointerfaces in the (112¯2) structures with line direction [11¯00] and Burgers vector in the (0001) plane. Similar observations are reported for the (202¯1) structures. Overall, the results are consistent with stress relaxation by threading dislocation glide.

Stress relaxation via misfit dislocation formation by slip in lattice mismatched semipolar wurtzite GaN alloys is viable due to the presence of resolved shear stresses on the basal (0001) plane. The critical thicknesses hc for misfit dislocation formation in AlGaN films grown by molecular-beam epitaxy on two semipolar orientations of GaN, (2021) and (1122), are investigated using high-resolution X-ray diffraction, confirmed with transmission electron microscopy, and compared with Matthews–Blakeslee calculations of theoretical hc as a function of alloy composition. The experimentally observed and calculated critical thickness values are larger for the (2021) oriented films, consistent with the lower resolved shear stresses compared with the (1122) orientation.

We demonstrate the first electrically-injected InGaN/GaN laser diodes (LDs) grown on semipolar (3031) free-standing GaN substrates. The lowest threshold current density (Jth) was 5.6 kA/cm2 with a clear lasing peak at 444.7 nm. The peak electroluminescence (EL) wavelength blue-shifted 4 nm below threshold and the characteristic temperature was ~135 K. These results suggest that the semipolar (3031) plane may be a potential candidate for growing high performance nitride-based LDs.

Two-dimensional optical waveguide mode simulations have been employed to investigate the optimized device structures for ridge-waveguide (Al, In, Ga) N-based green (520nm) laser diodes (LDs). The effects of thicknesses, alloy compositions, and doping densities of each epitaxially grown layers as well as ridge geometries on optical confinement factors (Γ) and waveguide absorption (α) were comprehensively surveyed. InyGa1−yN (y=0.07–0.1) guiding layers (GLs) with thickness more than 50nm were effective for realizing high Γ and low α. To minimize the absorption by the anode metal, p-cladding layer (p-CL) was required to be more than 500nm. At the same time, low index insulator such as SiO2 was preferable for the narrow ridge, where the thickness at the sidewall had to be more than 60nm. We also found that InGaN barriers layers between the quantum wells (QWs) were superior to GaN barriers to increase Γ and reduce α. Moreover, a thicker last barrier between the topmost QW and the electron blocking layer was al...

Epilayer lattice tilt has been observed by X-ray diffraction for heteroepitaxial AlGaN and InGaN films on (1122) semipolar GaN substrates. Complementary transmission electron microscopy demonstrates that epilayer tilt is a consequence of interfacial misfit dislocations with Burgers vectors a/3[1120] that glide on the (0001) basal plane [inclined ~58° to (1122)]. The dislocation lines are parallel to [1100], consistent with the anisotropy of the tilt observed in X-ray scans parallel to orthogonal in-plane directions. The dislocations had an in-plane Burgers vector component that relieved misfit strain, and a perpendicular component responsible for lattice tilt. Dislocation densities predicted by tilt agree well with TEM measurements.

We report on the observation of rotation of spontaneous emission polarization resulting in polarization tilted with respect to transverse electric (TE) mode, in m-axis oriented semipolar (1122) (Al,In,Ga)N waveguide structures. The principle polarizations were aligned parallel and perpendicular to the c-axis, i.e., at an angle of ~30 and ~120°, respectively, with respect to TE mode. This phenomenon was attributed to birefringence of uniaxial GaN wurtzite structure. This birefringence property is an important consequence for m-axis oriented (1122) laser diode structures, since it is expected to reduce the optical gain by a factor of ~0.5–0.75.

We demonstrate electrically driven InGaN based laser diodes (LDs), with a simple AlGaN-cladding-free epitaxial structure, grown on semipolar (2021) GaN substrates. The devices employed In0.06Ga0.94N waveguiding layers to provide transverse optical mode confinement. A maximum lasing wavelength of 506.4 nm was observed under pulsed operation, which is the longest reported for AlGaN-cladding-free III-nitride LDs. The threshold current density (Jth) for index-guided LDs with uncoated etched facets was 23 kA/cm2, and 19 kA/cm2 after application of high-reflectivity (HR) coatings. A characteristic temperature (T0) value of ~130 K and wavelength red-shift of ~0.05 nm/K were confirmed.

Misfit strain relaxation via misfit dislocation (MD) generation was observed in heteroepitaxially grown (Al,In)GaN layers on free-standing semipolar (112¯2) GaN substrates. Cross-section transmission electron microscope images revealed MD arrays at alloy heterointerfaces, with the MD line direction and Burgers vector parallel to [11¯00] and [112¯0], respectively. The MD structure is consistent with plastic relaxation by dislocation glide on the (0001) plane. Since (0001) is the only slip plane, the plastic relaxation is associated with tilt of the epitaxial (Al,In)GaN layers. The tilt, measured via high-resolution x-ray diffraction, can be used to quantify the relaxation.

We present an electroreflectance study of the piezoelectric field in a semipolar (1011¯) oriented In0.15Ga0.85N quantum well (QW). The flatband condition is precisely determined by examining the zero-crossing of the electroreflectance signal. The polarization field determined by the flatband condition is 840±150 kV/cm, in the direction opposite to the built-in field. The corresponding polarization charge at the heterointerface is 0.008±0.002 C/m2. Our experimental result indicates that in the semipolar InGaN/GaN QW there is a crossover angle between the C-axis and the growth direction where the polarization field vanishes.

Quantization effects on optical polarization switching in (1122)-oriented InGaN/GaN quantum-well (QW) structures, which were not evident in the previous report by Ueda et al., have been firmly confirmed. The present study found that polarization ratios became more negative as the luminescence photon energy was decreased from 2.6 eV. Enhancement in optical polarization was found in thin QW structures, which is believed to be a result of quantization effects. Sample structures containing thick InGaN and AlGaN layers showed polarization ratios shifted towards positive values; these samples exhibited in-plane luminescence inhomogeneity with stripe morphologies parallel to [1100] and dark lines appearing at angles between 50 and 62° with respect to [1100].

We present an electroreflectance study of the polarization field in a semipolar (112¯2) oriented In0.12Ga0.88N quantum well. We demonstrate that the polarization field in a quantum well can be determined by the electric field in the barrier region measured by Franz–Keldysh oscillations. The polarization field is found to be 575±150kV∕cm, in the same direction as the built-in field. The corresponding polarization is 0.006±0.002C∕m2. Our experimental result indicates that in the semipolar InGaN∕GaN QW there is a crossover angle where the polarization field vanishes, and this crossover angle is less than 58°.

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To enhance light extraction from a blue semipolar (1011) multiple-quantum-well light emitting diode (LED), surface patterning was performed on the backside of a GaN substrate on which LED epitaxial layers had previously been grown. After circular photoresist etching masks were defined, the surface was patterned with conical features by inductively-coupled plasma (ICP) etching. A substantial increase (100% before packaging and 33% after) in output power was observed in comparison with a reference sample which had a smooth backside at a drive current of 20 mA. Since ICP etching is a non-equilibrium process, this technique can potentially be applied to LEDs grown on nonpolar m- or a-plane GaN substrates.

Stimulated emission (SE) in the blue-green (480 nm) and green (514 nm) regime has been observed, at room temperature (RT) under optical pumping, from nonpolar m-plane (1010) and semipolar (1122) InGaN multi-quantum well (MQW) laser diode (LD) structures, respectively, grown on bulk GaN substrates. The emission intensity exhibited a clear threshold behavior with respect to the pump power. Optical anisotropy was also observed between the two perpendicular in-plane directions [1123] and [1010] for semipolar LD structures, with significantly lower pump thresholds for emission along [1123]. The SE wavelength, measured just above threshold, was blue-shifted with respect to the spontaneous emission wavelength measured just below threshold. These initial results indicate that semipolar (1122) GaN is a promising orientation for the realization of blue-green and green LDs.

Blue InGaN∕GaN multiple-quantum-well light emitting diodes with a peak emission wavelength of 444nm were grown on low extended defect density semipolar (101¯1¯) bulk GaN substrates by conventional metal-organic chemical vapor deposition. The calculated external quantum efficiency and output power at a drive current of 20mA under pulsed operations (10% duty cycle) were 29% and 16.21mW, respectively. The device exhibited virtually no peak electroluminescence wavelength shift with increasing drive currents, indicating a significant reduction of polarization-related internal electric fields.

Blue-green InGaN/GaN multiple-quantum-well light emitting diodes with peak emission wavelength of 480 nm were grown on low extended defect density semipolar (1122) bulk GaN substrates by conventional metal organic chemical vapour deposition. The calculated external quantum efficiency and output power at a drive current of 20 mA under pulsed operations (10% duty cycle) were 18% and 9 mW, respectively. The device exhibited small electroluminescence wavelength shift (4.5 nm) with drive currents ranging from 30 to 100 mA, indicating significant reduction of polarisation-related internal electric fields.

We present time-resolved photoluminescence on InGaN/GaN multiple-quantum well LEDs grown on nonpolar and semipolar bulk GaN substrates and investigate increasing indium concentrations toward higher power, longer wavelength light emitters.