Er3+-doped tellurite glass containing silver nanoparticles (NPs) has been synthesized. Detailed structural and optical characterizations have been carried out. Infrared to visible frequency ...upconversion (UC) emission has been observed in Er3+-doped tellurite glass on pumping with the 976nm radiation. Further, an enhancement in UC emission intensity of green bands of Er3+ ion has been observed up to four times in presence of silver NPs in the glass annealed at 240 degree C for 40h. Though, there is enhancement in intensity in the red band also but it is smaller. The enhancement in fluorescence intensity is attributed to local field effect due to the silver NPs. Display Omitted
Context.
The detection of the 21 cm signal of neutral hydrogen from the Epoch of Reionization (EoR) is challenging due to bright foreground sources, radio frequency interference (RFI), and the ...ionosphere as well as instrumental effects. Even after correcting for these effects in the calibration step and applying foreground removal techniques, the remaining residuals in the observed 21 cm power spectra are still above the thermal noise, which is referred to as the “excess variance.”
Aims.
We study a number of potential causes of this excess variance based on 13 nights of data obtained with the Low-Frequency Array (LOFAR).
Methods.
We focused on the impact of gain errors, the sky model, and ionospheric effects on the excess variance by correlating the relevant parameters such as the gain variance over time or frequency, local sidereal time (LST), diffractive scale, and phase structure–function slope with the level of excess variance.
Results.
Our analysis shows that the excess variance, at the current level, is neither strongly correlated with gain variance nor the ionospheric parameters. Rather, excess variance has an LST dependence, which is related to the power from the sky. Furthermore, the simulated Stokes
I
power spectra from bright sources and the excess variance show a similar progression over LST with the minimum power appearing at LST bin 6h to 9h. This LST dependence is also present in sky images of the residual Stokes
I
of the observations. In very-wide sky images based on one night of observation after direction-dependent calibration, we demonstrate that the extra power comes exactly from the direction of bright and distant sources Cassiopeia A and Cygnus A with the array beam patterns.
Conclusions.
These results suggest that the level of excess variance in the 21 cm signal power spectra is related to sky effects and, hence, it depends on LST. In particular, very bright and distant sources such as Cassiopeia A and Cygnus A can dominate the effect. This is in line with earlier studies and offers a path forward toward a solution, since the correlation between the sky-related effects and the excess variance is non-negligible.
Purpose We reviewed our experience with and outcome of the largest series to our knowledge of patients who underwent endoscopic laser excision of eroded polypropylene mesh or sutures as a ...complication of previous anti-incontinence procedures. Materials and Methods A total of 12 female patients underwent endoscopic laser excision of suture/mesh erosions at 1 center during a 10-year period. Primary outcome variables were the requirement of additional endoscopic or open surgery to remove mesh/sutures. Secondary outcome variables were persistence of urinary symptoms, postoperative complications, continence status and requirement of additional anti-incontinence procedures. Results The mean interval from previous surgery to erosion was 59 months (range 7 to 144) and the duration of presenting symptoms ranged from 3 to 84 months (mean 19). Ten patients underwent endoscopic excision of the mesh/suture with the holmium:YAG laser and 2 underwent excision with the thulium laser. Mean operative duration was 19 minutes (range 10 to 25) and followup was 65.5 months (range 6 to 134). Postoperatively 6 patients remain asymptomatic and 2 required a rectus fascial sling for recurrent stress urinary incontinence. Four patients underwent a second endoscopic excision due to minor persistence of erosion. Only 1 patient ultimately required open cystotomy to remove the eroded biomaterial. No intraoperative complications were recorded and all patients are currently asymptomatic. Conclusions Endoscopic laser excision is an acceptable first line approach for the management of eroded biomaterials due to its high long-term success rate and minimally invasive nature.
The effect of doping of rare earth Pr3+ ion as a replacement of Sm3+ in Sm0.5Sr0.5MnO3 is investigated. Temperature dependent dc and ac magnetic susceptibility, resistivity, magnetoresistance ...measurements on chemically synthesized (Sm0.5−xPrx)Sr0.5MnO3 show various unusual features with doping level x=0.15. The frequency independent ferromagnetic to paramagnetic transition at higher temperature (∼191K) followed by a frequency dependent reentrant magnetic transition at lower temperature (∼31K) has been observed. The nature of this frequency dependent reentrant magnetic transition is described by a critical slowing down model of spin glasses. From non-linear ac susceptibility measurements it has been confirmed that the finite size ferromagnetic clusters are formed as a consequence of intrinsic phase separation, and undergo spin glass-like freezing below a certain temperature. There is an unusual observation of a 2nd harmonic peak in the non-linear ac susceptibility around this reentrant magnetic transition at low temperature (∼31K). Arrott plots at 10 and 30K confirm the existence of glassy ferromagnetism below this low temperature reentrant transition. Electronic- and magneto-transport measurements show a strong magnetic field—temperature history dependence and strong irreversibility with respect to the sweeping of magnetic field. These results are attributed to the effect of phase separation and kinetic arrest of the electronic phase in this phase separated manganite at low temperatures.
► A SG like transition (∼31K) besides the FM-PM transition (∼191K) is observed. ► A glassy ferromagnetic type magnetic transition is observed at low temperature. ► Resistivity of the sample shows strong thermo-magnetic history effect. ► The time dependence resistivity increases logarithmically with time after FC. ► The entire phenomena has been explained by the kinetic arrest of electronic phase.
The evidence and prevalence of multidrug-resistant (MDR)
spp. poses a serious global threat to public health and the economy. Food- or water-borne MDR
spp. demands an alternate strategy to counteract ...this threat. In this regard, phage therapy has garnered great interest from medical practitioners and researchers as a potential way to combat MDR pathogens. In this observation, we isolated
phages from environmental water samples and tested against various clinically isolated MDR
spp. In this study, we have defined the isolation and detailed physical and genomic characterizations of two phages
and
from environmental water samples. The phages exhibited potent lytic activity against
, and
. They showed absorption within 5-10 min, a burst size ranging from ~74 to 265 PFU/cell, and a latent period of 5-20 min. The phages were stable at a broad pH range and survived an hour at 50°C. The purified phages
and
belong to the
family with an isometric head (64.90 ± 2.04 nm and 62.42 ± 4.04 nm, respectively) and a non-contractile tail (145 ± 8.5 nm and 148.47 ± 14.5 nm, respectively). The
analysis concluded that the size of the genomic DNA of the
phage is 50,390 bp with a GC content of 44.90%, while the genome size of the
phage is 50,523 bp with a GC content of 48.30%. A total of 85 and 83 putative open reading frames (ORFs) were predicted in the
and
phages, respectively. Furthermore, a comparative genomic and phylogenetic analysis revealed that both phages represented different isolates and novel members of the T1-like phages.
and
phages, either individually or in a cocktail form, showed a significant reduction in the viable
count on raw chicken samples after 72 h of incubation. Therefore, these results indicate that these phages might have a potential role in therapeutic approaches designed for shigellosis patients as well as in the biological control of MDR
spp. in the poultry or food industry during the course of meat storage.
•Jafari et al.’s (2017) model is extended by including a backup supplier.•Back up supplier can supply raw materials to meet shortages at the recycler.•Different game theoretic models are developed to ...obtain optimal decisions of CLSC.•In presence of the recycler, CLSC’s profit surpasses Jafari et al.’s (2017) profit.
In a recent article, Jafari et al. (2017) considered dual-channel recycling in a closed-loop supply chain (CLSC) consisting one collector, one recycler and one manufacturer. In this paper, their model is extended with a backup supplier considering uncertainty of collection of used products. The shortfall quantity of collection is met up by the backup supplier with the estimated fresh raw materials. Under various power structures or interactions of the supply chain entities, different game theoretic models are developed. It is observed from the numerical study that, depending on the fractional part of the manufacturer’s requirements of recyclable wastes supplied by the collector, the performance of the supply chain increases compared to that of Jafari et al.’s (2017) model in the absence of the recycler. However, in the presence of the recycler, the whole supply chain’s profit surpasses Jafari et al.’s (2017) profit for any amount of used product collection.
A recent genome-wide association study (GWAS) identified association with variants in X-linked CLDN2 and MORC4, and PRSS1-PRSS2 loci with chronic pancreatitis (CP) in North American patients of ...European ancestry. We selected 9 variants from the reported GWAS and replicated the association with CP in Indian patients by genotyping 1807 unrelated Indians of Indo-European ethnicity, including 519 patients with CP and 1288 controls. The etiology of CP was idiopathic in 83.62% and alcoholic in 16.38% of 519 patients. Our study confirmed a significant association of 2 variants in CLDN2 gene (rs4409525-OR 1.71, P = 1.38 x 10-09; rs12008279-OR 1.56, P = 1.53 x 10-04) and 2 variants in MORC4 gene (rs12688220-OR 1.72, P = 9.20 x 10-09; rs6622126-OR 1.75, P = 4.04x10-05) in Indian patients with CP. We also found significant association at PRSS1-PRSS2 locus (OR 0.60; P = 9.92 x 10-06) and SAMD12-TNFRSF11B (OR 0.49, 95% CI 0.31-0.78, P = 0.0027). A variant in the gene MORC4 (rs12688220) showed significant interaction with alcohol (OR for homozygous and heterozygous risk allele -14.62 and 1.51 respectively, P = 0.0068) suggesting gene-environment interaction. A combined analysis of the genes CLDN2 and MORC4 based on an effective risk allele score revealed a higher percentage of individuals homozygous for the risk allele in CP cases with 5.09 fold enhanced risk in individuals with 7 or more effective risk alleles compared with individuals with 3 or less risk alleles (P = 1.88 x 10-14). Genetic variants in CLDN2 and MORC4 genes were associated with CP in Indian patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
There are a lot of problems with the conventional fusion welding process, so ultrasonic welding has been used for about 20 years and has helped a lot of manufacturing industries, including aviation, ...medicine, and microelectronics. Ultrasonic welding takes less than one second, making it suitable for mass production. Poor weld quality and joint strength are common issues that industries encounter as a result of this process. Actually, the success and quality of the welding are determined by its control parameters. This research examines the impacts of weld time, vibrational amplitude, and weld pressure on the welding of 0.6 mm thick sheets of two different metals, specifically copper and aluminum (AA2024). Responses, including tensile shear stress, weld area, and T-peel stress, are acquired through experiments that follow a full factorial design including four replicas. The highest recorded tensile shear stress was 4.34 MPa, the maximum weld area measured was 63.6 mm2, and the peak T-peel stress reached 1.22 MPa. A second-order non-linear regression model was constructed using all of these data points, which related the responses to the predictors. Due to the importance of quality in the production sector, the process parameters were determined by the combination of genetic algorithm (GA) and fuzzy logic (FL) approaches. The impact of the weld zone temperature on various quality characteristics has been investigated through experiments. It has been noted from the confirmatory test that FL produces superior output outcomes compared to the genetic algorithm, with FL achieving a fuzzy multi-performance index of 0.94 compared to 0.61 for GA. By conducting microstructural analysis, weld quality levels, including “under-weld,” “good weld,” and “over-weld,” were established.
A detailed investigation on the effect of grain size on formation of Griffiths phase, and glassy mixed phase in CE-type antiferromagnetic Sm0.5Ca0.5MnO3 manganite are carried out. A rigorous ...measurement of linear and non-linear ac magnetic susceptibilities, time dependent relaxation and aging phenomena in Sm0.5Ca0.5MnO3 nanomanganite confirm the existence of a glassy mixed phase in the low temperature regime. The signature of Griffiths phase in nanosized manganite has been confirmed from the detailed ac and dc magnetization studies. The existence of Griffiths phase is verified through the anomalous behavior of the low field temperature dependent an inverse ac and dc magnetic susceptibility. Based on experimental results, the glassy phase of nanomanganites has been attributed to the phase separation effect and interaction between the ferromagnetic clusters. A phenomenological core/shell model has also been proposed based on the surface disorder to explain the observed Griffiths phase in these nanosized manganites. Fig. 1: (Left) The plot of inverse of ac susceptibility χac-1 measured at f=1Hz and Hac=2Oe as a function of temperature for S750 sample. Inset shows the same for S550 sample. (Right) A schematic of the proposed model to describe the magnetic state of the Sm0.5Ca0.5MnO3 system at different average sizes. Display omitted
•Effect of grain size on Griffiths phase and glassy mixed phase is discussed.•GP is confirmed by dc, linear and non-linear ac magnetization in nanomanganites.•Glassy mixed phase is discussed by time dependent relaxation and aging phenomena.•The existence of GP is verified through an inverse ac and dc magnetic susceptibility.•A phenomenological core/shell model has been proposed based on surface disorder.
A detailed investigation on the effect of grain size on formation of Griffiths phase (GP), and glassy mixed phase in CE-type antiferromagnetic Sm0.5Ca0.5MnO3 manganite are carried out. A rigorous measurement of linear and non-linear ac magnetic susceptibilities, time dependent relaxation and aging phenomena in Sm0.5Ca0.5MnO3 nanomanganite confirm the existence of a glassy mixed phase in the low temperature regime. A strong evidence of GP has been identified in Sm0.5Ca0.5MnO3 nanomanganites having ferromagnetic spin–spin correlation above Curie temperature (TC) without possessing any spontaneous magnetization. The signature of GP in nanosized manganite has been confirmed from the detailed ac and dc magnetization studies. The existence of GP is verified through the anomalous behavior of the low field temperature dependent ac and dc magnetic susceptibility (χ) – viz., an inverse magnetic susceptibility characterized by χ-1=(T-TCRand)1-λ with λ=0.85±0.02. Based on experimental results, the glassy phase of nanomanganites has been attributed to the phase separation effect and interaction between the ferromagnetic clusters. A phenomenological core/shell like model has also been proposed based on the surface disorder to explain the observed GP-like properties in these nanosized manganites.
PDF
