Segmented YSO scintillation detectors as a new β-implant detection tool for decay spectroscopy in fragmentation facilities

A newly developed segmented YSO scintillator detector was implemented for the first time at the RI-beam Factory at RIKEN Nishina Center as an implantation-decay counter. The results from the experiment demonstrate that the detector is a viable alternative to conventional silicon-strip detectors with its good timing resolution and high detection efficiency for β particles. A Position-Sensitive Photo-Multiplier Tube (PSPMT) is coupled with a 48 × 48 segmented YSO crystal. To demonstrate its capabilities, a known short-lived isomer in Ni and the β decay of Co were measured by implanting those ions into the YSO detector. The half-lives and γ-rays observed in this work are consistent with the known values. The β-ray detection efficiency is more than 80 % for the decay of Co.The present experiment was carried out at the RI Beam Factory operated by RIKEN Nishina Center, RIKEN and CNS, University of Tokyo. This research was supported in part by the Offce of Nuclear Physics, U.S. Department of Energy under Award No. DE-FG02-96ER40983 (UTK)

Evaluating stream water quality through land use analysis in two grassland catchments: impact of wetlands on stream nitrogen concentration.

We evaluated the impacts of natural wetlands and various land uses on stream nitrogen concentration in two grassland-dominated catchments in eastern Hokkaido, Japan. Analyzing land use types in drainage basins, measuring denitrification potential of its soil, and water sampling in all seasons of 2003 were performed. Results showed a highly significant positive correlation between the concentration of stream NO3–N and the proportion of upland area in drainage basins in both catchments. The regression slope, which we assumed to reflect the impact on water quality, was 24% lower for the Akkeshi catchment (0.012 ± 0.001) than for the Shibetsu catchment (0.016 ± 0.001). In the Akkeshi catchment, there was a significant negative correlation between the proportion of wetlands in the drainage basins and stream NO3–N concentration. Stream dissolved organic nitrogen (DON) and carbon (DOC) concentrations were significantly higher in the Akkeshi catchment. Upland and urban land uses were strongly linked to increases in in-stream N concentrations in both catchments, whereas wetlands and forests tended to mitigate water quality degradation. The denitrification potential of the soils was highest in wetlands, medium in riparian forests, and lowest in grasslands; and was significant in wetlands and riparian forests in the Akkeshi catchment. The solubility of soil organic carbon (SOC) and soil moisture tended to determine the denitrification potential. These results indicate that the water environment within the catchments, which influences denitrification potential and soil organic matter content, could have caused the difference in stream water quality between the two catchments

Modeling the Water Balance Processes for Understanding the Components of River Discharge in a Non-conservative Watershed

The study was conducted in the Shibetsu watershed, eastern Hokkaido, Japan, to examine the possibility of using the Soil and Water Assessment Tool (SWAT) model in a non-conservative watershed (the surface watersheds are lying on a discontinuous impervious horizon) with external contribution (EXT). After confirming the capability of model simulation, the EXT was estimated to understand the components of river discharge. The EXT is difficult to measure directly and simulate by SWAT due to its subsurface circulation. In this study, the EXT was roughly estimated from the water balance equation using measured data. The average daily flux of EXT (1.38 mm d^[-1]) was assumed as a point-source discharge in SWAT. The simulation of daily streamflow during the calibration and validation periods produced satisfactory results, with R2 values of 0.65 and 0.66, respectively. In addition, the simulated daily baseflow, monthly streamflow, surface runoff, and evapotranspiration (ET) all showed good agreement with the corresponding observations. Our simulation suggested that the EXT assigned as the assumed discharge in SWAT can help us to reasonably simulate the streamflow in the Shibetsu watershed. The EXT was then investigated indirectly by considering the difference between the observed streamflow and simulated streamflow using calibrated SWAT without adding the assumed EXT. The result indicated that the EXT was an important water source in the Shibetsu watershed, accounting for 47% of streamflow during the study period

Sonographic features differentiating follicular thyroid cancer from follicular adenoma–a meta-analysis

Certain ultrasound features are associated with an increased risk of thyroid malignancy. However, they were studied mainly in papillary thyroid cancers (PTCs); these results cannot be simply extrapolated for the differentiation of follicular thyroid adenomas and cancers (FTAs and FTCs). The aim of our study was to perform a meta-analysis to identify sonographic features sug-gesting malignancy in the case of follicular lesions, potentially differentiating FTA and FTC. We searched thirteen databases from January 2006 to December 2020 to find all relevant, full-text jour-nal articles written in English. Analyses assessed the accuracy of malignancy detection in case of follicular lesions, potentially differentiating FTA and FTC included the odds ratio (OR), sensitivity, specificity, positive and negative predictive values. A random-effects model was used to summarize collected data. Twenty studies describing sonographic features of 10,215 nodules met the inclusion criteria. The highest overall ORs to increase the risk of malignancy were calculated for tumor protrusion (OR = 10.19; 95% confidence interval: 2.62–39.71), microcalcifications or mixed type of calcifications (coexisting micro and macrocalcifications): 6.09 (3.22–11.50), irregular margins: 5.11 (2.90– 8.99), marked hypoechogenicity: 4.59 (3.23–6.54), and irregular shape: 3.6 (1.19–10.92). The most crucial feature associated with an increased risk of FTC is capsule protrusion, followed by the presence of calcifications, irrespectively of their type

Polarimetric Optical Fiber Sensors for Dynamic Strain Measurement in Composite Materials

Polarimetric optical ber sensors possess possibility of temperature compensation, dynamic and integral system of strain monitoring, as well as low cost of photo-detecting elements. In the paper we present results of the sensor analysis with dierent kinds of birefringent optical bers leading to an optimal setup for dynamic strain monitoring in composite materials. A great attention is put on parameters of the light sources like coherence and width of spectrum and their inuence on dynamics of the strain sensor

Photonic Liquid Crystal Fibers with Polymers

Photonic liquid crystal bers with polymers constitute a new solution based on liquid crystals and microstructured polymer optical bers opening up new areas in innovative sensing and photonic devices applications. Compared with their silica-based microstructured bers, it is easier to fabricate exotic microstructured polymer optical bers by extrusion or drilling at low temperature; their nonlinearity is potentially stronger, the range of available polymers that may be drawn is more diverse and the biocompatibility of polymers is often better. Liquid crystals due to their attractive properties i.e., the high birefringence, high electro-optic and thermo-optic eects are a very good candidate for microstructured polymer optical ber inltration to obtain tunable all-in-ber innovative photonic devices. The paper will discuss basic properties and possible applications of the polymer photonic liquid crystal bers that will arise from their high optical tunability with external and internal factors. Current research eort is directed towards two main solutions: photonic crystal bers and microstructured polymer optical ber--based structures, both inltrated with liquid crystals of tailored optical properties