The Antarctica Showa Base has been powered primarily by diesel power generation. However, heavy oil fossil fuel is used for power generation by diesel generators. The Showa base is located in ...Antarctica, so there is heat demand throughout the year. Therefore, the capacity of transportation of fuel and emissions of carbon dioxide has become an issue. For these reasons, the construction of clean energy systems using renewable energy in order to locally produce energy for local consumption is being planned. In this study, we will design a microgrid based on the introduction of renewable energy (photovoltaics generation and wind power generators) and solid oxide fuel cell (SOFC), which does not emit carbon dioxide during power generation and can use heat cascades. However, there is a risk of a power failure because the power quality decreases with the introduction of renewable energy. In this paper, we clarified the introduction rate of renewable energy with the lowest frequency fluctuation and clarified the introduction limit of renewable energy in summer and winter.
Abstract
We present the results of a search for MeV-scale electron antineutrino events in KamLAND coincident with the 60 gravitational wave events/candidates reported by the LIGO/Virgo collaboration ...during their second and third observing runs. We find no significant coincident signals within a ±500 s timing window from each gravitational wave and present 90% C.L. upper limits on the electron antineutrino fluence between 10
8
and 10
13
cm
−2
for neutrino energies in the energy range of 1.8–111 MeV.
ABSTRACT In the late stages of nuclear burning for massive stars (M > 8 M ), the production of neutrino-antineutrino pairs through various processes becomes the dominant stellar cooling mechanism. As ...the star evolves, the energy of these neutrinos increases and in the days preceding the supernova a significant fraction of emitted electron anti-neutrinos exceeds the energy threshold for inverse beta decay on free hydrogen. This is the golden channel for liquid scintillator detectors because the coincidence signature allows for significant reductions in background signals. We find that the kiloton-scale liquid scintillator detector KamLAND can detect these pre-supernova neutrinos from a star with a mass of 25 M at a distance less than 690 pc with 3 significance before the supernova. This limit is dependent on the neutrino mass ordering and background levels. KamLAND takes data continuously and can provide a supernova alert to the community.
The aims of this study were to estimate tube current values for each X-ray projection angle used in adult chest computed tomography (CT) and abdomen-pelvis CT examinations with tube current ...modulation (TCM) and to validate organ doses determined using Monte Carlo (MC) simulations through comparisons with the doses measured using in-phantom dosimetry. For dose simulations, dose distribution images were obtained by inputting the geometry of a CT scanner, scan parameters including estimated TCM curves and CT images of an adult anthropomorphic phantom into MC simulation software. Organ doses were then determined from the dose distribution images. For dose measurements, organ doses were evaluated using radio-photoluminescence glass dosemeters located at various organ positions within the phantom. Relative differences between the simulated and measured organ doses were -2.5 to 11.0% and -1.5 to 10.5% for organs in chest and abdomen-pelvis CT scan ranges, respectively. Thus, the simulated and measured doses agreed well.
Abstract
KamLAND-Zen searches for neutrinoless double-beta decay with
136
Xe loaded liquid scintillator (LS). The LS container, a 25-
μ
m-thick clean nylon inner balloon is a key of the experiment ...since one of the main backgrounds in the ROI is
214
Bi from the inner balloon. In KamLAND-Zen 400 (operated from 2011 to 2015), dust contamination of the inner balloon from the environment limited the sensitivity, although the inner balloon was fabricated at a class-1 super clean room. We improved the production method of the inner balloon for KamLAND-Zen 800 (started DAQ in January, 2019) and successfully reduced the
214
Bi background level to one fifteenth as compared to the 2nd phase of KamLAND-Zen 400. The inner balloon film material and requirements, improved fabrication scheme, including establishment of clean environment and dust control, will be described.
OBJECTIVE:Hyperaldosteronism have been reported to be associated with higher prevalence of nonalcoholic fatty liver disease (NAFLD). To clarify prevalence of NAFLD in two subtypes of primary ...aldosteronism (PA), we compared hepatic fat content evaluated by computed tomography (CT).
DESIGN AND METHOD:This retrospective observational study comprised 95 patients diagnosed with PA. We divided participants into two subtypes, aldosterone producing adenoma (APA) (n = 36) and idiopathic hyperaldosteronism (IHA) (n = 59). We evaluated hepatic fat content by the ratio of liver to spleen (L/S) Hounsfield units in unenhanced CT. We compared L/S ratio, visceral fat percentage (VF%), visceral fat area (VFA), hepatic steatosis index (HSI), fatty liver index (FLI), NAFLD fibrosis score, fibrosis-4 index (FIB4 index), and homeostasis model assessment insulin resistance (HOMA-R) between the two subtypes.
RESULTS:Age and sex distribution were not different between the two subtypes. Plasma aldosterone concentration (PAC) was significantly higher in patients with APA than patients with IHA (p < 0.01). VF% and VFA were not different between the two subtypes (p = 0.06, p = 0.74). L/S ratio was not different between the two subtypes (APA vs IHA; 1.1 ± 0.2 vs 1.2 ± 0.2, p = 0.40). HSI, FLI, NAFLD fibrosis score, and FIB4 index were not different between the two subtypes (p = 0.32, p = 0.67, p = 0.87, p = 0.95, respectively). HOMA-R was significantly higher in patients with IHA than patients with APA (p = 0.04). L/S ratio was neither correlated with PAC nor HOMA-R in each subtype. In both subtypes, L/S ratio was negatively correlated with VF% (APAr = −0.55, p < 0.01, IHAr = −0.58, p < 0.01), with VFA (APAr = −0.49, p < 0.01, IHAr = −0.54, p < 0.01).
CONCLUSIONS:L/S ratio was not different between two subtypes of PA. Not insulin resistance or PAC but the amount of visceral fat was associated with L/S ratio in both subtypes. Those data suggested that prevalence of NAFLD was not different between two subtypes of PA, and it was affected by the amount of visceral fat.
Abstract
We present the results of a search for core-collapse supernova neutrinos, using long-term KamLAND data from 2002 March 9 to 2020 April 25. We focus on the electron antineutrinos emitted from ...supernovae in the energy range of 1.8–111 MeV. Supernovae will make a neutrino event cluster with the duration of ∼10 s in the KamLAND data. We find no neutrino clusters and give the upper limit on the supernova rate to be 0.15 yr
−1
with a 90% confidence level. The detectable range, which corresponds to a >95% detection probability, is 40–59 kpc and 65–81 kpc for core-collapse supernovae and failed core-collapse supernovae, respectively. This paper proposes to convert the supernova rate obtained by the neutrino observation to the Galactic star formation rate. Assuming a modified Salpeter-type initial mass function, the upper limit on the Galactic star formation rate is <(17.5–22.7)
M
⊙
yr
−1
with a 90% confidence level.
Abstract
We present the results of a time-coincident event search for low-energy electron antineutrinos in the KamLAND detector with gamma-ray bursts (GRBs) from the Gamma-ray Coordinates Network and ...Fermi Gamma-ray Burst Monitor. Using a variable coincidence time window of ±500 s plus the duration of each GRB, no statistically significant excess above the background is observed. We place the world’s most stringent 90% confidence level upper limit on the electron antineutrino fluence below 17.5 MeV. Assuming a Fermi–Dirac neutrino energy spectrum from the GRB source, we use the available redshift data to constrain the electron antineutrino luminosity and effective temperature.
Abstract
We report the result of a search for neutrinos in coincidence with solar flares from the GOES flare database. The search was performed on a 10.8 kton-year exposure of KamLAND collected from ...2002 to 2019. This large exposure allows us to explore previously unconstrained parameter space for solar flare neutrinos. We found no statistical excess of neutrinos and established 90% confidence level upper limits of 8.4 × 10
7
cm
−2
(3.0 × 10
9
cm
−2
) on the electron antineutrino (electron neutrino) fluence at 20 MeV normalized to the X12 flare, assuming that the neutrino fluence is proportional to the X-ray intensity.
Although the Modified Observer's Assessment of Alertness and Sedation (MOAA/S) is frequently used in sedation-related drug and device studies, a major shortcoming is that it does not differentiate ...between lighter and deeper levels of general anaesthesia because the only noxious stimulus of the MOAA/S is a trapezius squeeze. The primary aim of this investigation was to expand the MOAA/S score to include truly noxious stimulation, thereby extending the dynamic range of the assessment to include sedation states consistent with deeper levels of general anaesthesia.
Twenty healthy volunteers received target controlled infusions of fentanyl (target=0.8 ng ml−1) and propofol (starting at 0.5 µg ml−1 and gradually increasing to 5 µg ml−1). At each propofol concentration, a MOAA/S score was obtained before and after tetanic electrical stimulation. The tetanic electrical stimulation current was gradually increased until the subject responded or until 50 mA was delivered without a response. A pharmacodynamic model was constructed to characterize the concentration–effect relationship between propofol and the MOAA/S scores.
All subjects required a significantly higher propofol concentration to produce unresponsiveness to tetanic electrical stimulation at 50 mA compared with a standardized trapezius squeeze. The pharmacodynamic model adequately characterized the concentration–effect relationship.
The Extended Observer's Assessment of Alertness and Sedation (or EOAA/S) extends the range of the widely used MOAA/S score to include truly noxious stimulation, thereby enabling the identification of drug-induced central nervous system depression representative of surgical anaesthesia.
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