•Explored the linear and nonlinear optical interaction in the Bi2Se3 single-crystal cleaved flake.•Kramer’s Kronig approach and DFT calculations confirm the prominent 2 eV OBT from the Ɛ1 and Ɛ2 ...simulations.•Concurrently, the TRUS measurements are done to explore the excited-state dynamics of the states populating due to the Moss-Burstein shifts.•With the same excitation, probing in the NIR region shows the occurrence of the Pauli blocking.•The low temperature study give a clear evidence of presence of second surface state and a broad absorbance of 1.2 eV can be easily seen through TRUS.
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We report the optical response and temperature-dependent excited-state carrier dynamics in the flake of Bi2Se3, which is cleaved from its single crystal. The optical properties are explored using the visible-near infrared (VIS-NIR), infrared (IR), and photoluminescence (PL) spectroscopies. The VIS-NIR spectra are then used to find the Ɛ1 and Ɛ2 using Kramer’s Koning relations, confirming OBT of 2 eV and 1.4 eV. The DFT (density functional theory) calculations are also carried out to confirm the experimental optical transitions (OBT). To probe these OBT in the bismuth selenide, we have studied the temperature, fluence, and excitation dependent ultrafast transient reflectance over a wide spectral range from 2.58–0.77 eV (VIS-NIR) with different excitation energies 3.02 eV, 2.61 eV, 1.9 eV, and 1.4 eV to explore several previously unseen transitions that do not appear in PL spectroscopy and room temperature carrier analysis. The temperature-dependent excited-state dynamics are investigated at 5–300 K. This study clearly indicates the existence of Moss-Burstein shift in the visible region and Pauli blocking effect in the NIR region in the Bi2Se3 topological insulator. Moreover, the low-temperature TRUS confirms the transition to the second surface state present in bismuth selenide.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
A study of a silicon photomultiplier (SiPM) coupled with a
GGAG:Ce,B scintillator detector for environmental gamma radiation
monitoring is presented in this paper. FLUKA based Monte Carlo
...simulations were carried out for the optimization of scintillator
material and geometry for this application. Based on the simulation
study, the dimensions of GGAG:Ce,B scintillator crystal were
finalized and the scintillator was prepared. The detector was
assembled by optically coupling to a commercially available
SiPM. The analog output pulses of the SiPM were amplified by a
voltage sensitive amplifier and subsequently counted using a
microcontroller. The linearity of the detector response with gamma
dose rate was verified using
137
Cs standard gamma source. The
radiation response of the detector for different gamma energies was
investigated using standard
137
Cs,
241
Am and
60
Co
sources. The variation of detector sensitivity with SiPM overvoltage
was measured for choosing an optimal overvoltage for the SiPM
operation. The experimentally observed response of the
SiPM-GGAG:Ce,B detector was very linear in the measurement range of
3.5–300 μGy/h with a sensitivity of
2.44 cps/μGy/h. The gamma response study of the detector
confirm the suitability of the developed detector for making a
compact and low power gamma monitor for environmental gamma
radiation monitoring network.
The pre-monsoon convective atmosphere over Kolkata (22.52°N, 88.37°E) during STORM field phase 2006-2008 is investigated using 12 UTC radiosonde data and thermodynamic indices. In the present study, ...an attempt has been made to assess the skill of various indices and parameters and to propose suitable threshold values in forecasting the occurrence of thunderstorm activity at Kolkata. The thermodynamic indices and parameters used in the present study are lifted index (LI), K index (KI), severe weather threat index (SWEAT), total totals index (TTI), convective available potential energy (CAPE), deep convection index (DCI), humidity index (HI), Boyden index (BI), dew point temperature at 850 hpa (DEW), relative humidity at 700 hpa (RH), and bulk Richardson number (BRN). Validation of the suggested threshold values of indices was conducted on the days of thunderstorm activity. It was found that one index alone cannot predict the occurrence of thunderstorm over Kolkata region. The present study suggests that the indices with highest skill for thunderstorm prediction are KI, DCI, SWEAT, DEW, HI, RH, LI, TTI, while the prediction efficiency is poor for CAPE, BRN, and BI. Observed values of these indices also reveal that scattered, multi-cellular thunderstorms are possible over Kolkata during pre-monsoon months.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this manuscript, gel-combustion synthesis of Al5BO9:xTb3+ (x = 0.0%, 0.05%, 0.1%, 0.2% and 1.5%) phosphor along with the detailed structural characterizations using a host of techniques such as ...XRD, SEM, EDS, IR, EXAFS and PL etc. has been reported. XRD analysis confirmed the phase pure formation and also the nanocrystalline nature of the materials. Detailed EXAFS analysis explained the oxidation state and the coordination behaviour of Tb3+ ion in the Al5BO9 matrix. PL study showed that the material can be a potential green light emitting phosphor. Thermoluminescence (TL) study revealed the presence of a wide shoulder peak and a broad dosimetry peak situating at 551 K. Net TL response from 10B and 11B enriched Al5BO9:0.1%Tb3+ thin pellets showed prolonged linearity within the thermal neutron fluence range of 3.2 × 1010 to 1.6 × 1011 n/cm2. Also, the maximum fading of the TL signal is only 9% during the storage period of 112 days. These indicates that the developed material can be a potential candidate for dosimetry applications involving high intensity slow neutron beams. The TL glow curve was deconvoluted which revealed the presence of five individual peaks whose kinetic parameters viz. activation energy (E), order of kinetics (b) and frequency factor (s) were evaluated using both glow curve deconvolution and Chen's peak shape method and the results were found to be in good agreement.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Field emission is one of the critical issues in the superconducting radio frequency (SRF) cavities and can degrade their accelerating gradient during operation. The contamination present at top ...surface of the SRF cavity is one of the foremost reasons for field emission. Plasma based surface processing can be a viable option to eliminate such surface contaminants and enhance performance of the SRF cavity especially for in-situ applications. These days, 1.3 GHz nine-cell SRF cavity has become baseline standard for many particle accelerators, it is of interest to develop plasma cleaning technique for such SRF cavities. In the development of the plasma processing technique for SRF cavities, the most challenging task is to ignite and tune the plasma in different cells of the SRF cavity. At Daresbury laboratory, UK, we have successfully achieved plasma ignition in different cells of a 1.3 GHz nine-cell SRF cavity. The plasma ignition in different cells of the cavity was accomplished at room temperature towards room temperature plasma cleaning of the SRF cavity surface. Here, we report the successful demonstration of the plasma ignition in different cells of a 1.3 GHz nine-cell SRF cavity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Kidneys as well as urinary tracts are the major excretory organs of the human body and removes waste products of protein metabolism.They also remove surplus water and salts from the blood.Kidneys as ...well as urinary tracts also important for survival as they are crucial for preserving the fluid-electrolyte balance of the body tissue fluids.The inaccuracies in the embryogenesis of the outflow tractsalong with thekidneys are vulnerable to the environmental endargements and disturb the development throughout gestation.Mutations in the patient with CAKUT are responsible for the chronic renal diseases in the 1st three decades of life.Fetus dose not survive in severe cases of CAKUT as a result of non formation of kidneys and outflow tract, but in less severe cases there are more chances to survive and may identified in adulthood.Though the critical cases of CAKUT are infrequent, marginal nephron number is considerablyfrequent disorder exerting its effect on renal functions with increasing age.
Congenital anomalies of kidney and urinary tract have a wide range ofabnormalities inclusive offatalagenesis of both the kidneys andasymptomatic ectopic kidneys.Hence patient with the solitary kidney should follow-up regularly for better and close monitoring.
The clinical presentation of CAKUT along with its long term outcomes and epidemiology is covered in this review.With a comphrehensive knowledge of the roots of CAKUT and marginal nephron numbers, identification of preventive treatment and establishment of clinical guidelines for the patients can be begun.Comphrehension of relevant endangerments and changes in the epidemiological trends especially modified maternal factors and delivery services is vital for prompt detection and prediction of prognosis in the course of pregnancy due to subsequent morbidity and mortality as a result of the presence of CAKUT.
The antileprosy drug clofazimine was recently repurposed as part of a newly endorsed short-course regimen for multidrug-resistant tuberculosis. It also enables significant treatment shortening when ...added to the first-line regimen for drug-susceptible tuberculosis in a mouse model. However, clofazimine causes dose- and duration-dependent skin discoloration in patients, and the optimal clofazimine dosing strategy in the context of the first-line regimen is unknown. We utilized a well-established mouse model to systematically address the impacts of duration, dose, and companion drugs on the treatment-shortening activity of clofazimine in the first-line regimen. In all studies, the primary outcome was relapse-free cure (culture-negative lungs) 6 months after stopping treatment, and the secondary outcome was bactericidal activity, i.e., the decline in the lung bacterial burden during treatment. Our findings indicate that clofazimine activity is most potent when coadministered with first-line drugs continuously throughout treatment and that equivalent treatment-shortening results are obtained with half the dose commonly used in mice. However, our studies also suggest that clofazimine at low exposures may have negative impacts on treatment outcomes, an effect that was evident only after the first 3 months of treatment. These data provide a sound evidence base to inform clofazimine dosing strategies to optimize the antituberculosis effect while minimizing skin discoloration. The results also underscore the importance of conducting long-term studies to allow the full evaluation of drugs administered in combination over long durations.
Patient-level predictors of enrollment in pediatric biorepositories are poorly described. Especially in pandemic settings, understanding who is likely to enroll in a biorepository is critical to ...interpreting analyses conducted on biospecimens. We describe predictors of pediatric COVID-19 biorepository enrollment and biospecimen donation to identify gaps in COVID-19 research on pediatric biospecimens.
We compared data from enrollees and non-enrollees aged 0-25 years with suspected or confirmed COVID-19 infection who were approached for enrollment in the Massachusetts General Hospital pediatric COVID-19 biorepository between April 12, 2020, and May 28, 2020, from community or academic outpatient or inpatient settings. Demographic and clinical data at presentation to care were from automatic and manual chart extractions. Predictors of enrollment and biospecimen donation were assessed with Poisson regression models.
Among 457 individuals approached, 214 (47%) enrolled in the biorepository. A COVID-19 epidemiologic risk factor was recorded for 53%, and 15% lived in a US Centers for Disease Control and Prevention-defined COVID-19 hotspot. Individuals living in a COVID-19 hotspot (relative risk (RR) 2.4 95% confidence interval (CI): 1.8-3.2), with symptoms at presentation (RR 1.8 95% CI: 1.2-2.7), or admitted to hospital (RR 1.8 95% CI: 1.2-2.8) were more likely to enroll. Seventy-nine percent of enrollees donated any biospecimen, including 97 nasopharyngeal swabs, 119 oropharyngeal swabs, and 105 blood, 16 urine, and 16 stool specimens, respectively. Age, sex, race, ethnicity, and neighborhood-level socioeconomic status based on zip code did not predict enrollment or biospecimen donation.
While fewer than half of individuals approached consented to participate in the pediatric biorepository, enrollment appeared to be representative of children affected by the pandemic. Living in a COVID-19 hotspot, symptoms at presentation to care and hospital admission predicted biorepository enrollment. Once enrolled, most individuals donated a biospecimen.
In addition to many other well-documented factors, local conditions are rudimentary conditions of sharp change observed in wastewater characteristics from place to place. The monitoring of 3 million ...liters per day-capacity full-scale Sequencing Batch Reactor (SBR) at Roorkee (India) drew attention to the processes involving simultaneous nitrification and denitrification (SND) and biological phosphorous removal (BPR) undergoing with the variations in influent wastewater, particularly the readily biodegradable chemical oxygen demand (rbCOD). Regular monitoring of all the units revealed that the nutrient removal efficiencies were 94.9 ± 3.6% Chemical Oxygen Demand (COD) (17.9 ± 7.7 mg/L in effluent), 95.4 ± 2.7% Biochemical Oxygen Demand (BOD
5
) (6.0 ± 2.2 mg/L in effluent), 95.4 ± 1.6% Total Suspended Solids (TSS) (9.4 ± 2.1 mg/L in effluent), 96.7 ± 2.6% Ammonia-N (0.7 ± 0.5 mg/L in effluent), 69.1 ± 11.5% Total Nitrogen (TN) (9.7 ± 3.0 mg/L in effluent), 31.3 ± 24.9% orthophosphate (1.8 ± 0.7 mg/L in effluent) and 42.0 ± 15.3% Total Phosphorus (TP) (3.6 ± 1.8 mg/L in effluent) and achieved < 50 MPN/100 mL fecal coliform in the final effluent after disinfection. Anoxic tri-sectional selector and an aeration tank constituted one SBR followed by the other, availed 76.4 ± 9.2% SND at rbCOD/COD of 0.12 ± 0.04 and showed linear relationship at
R
2
> 0.8, and COD/TN of 12.3 ± 4.7. The study clarifies the degree of variations in key factors included in design guidelines for laying out an optimized treatment system for COD, Nitrogen, and Phosphorus removal in the Indian scenario.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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