75 research outputs found
Effectiveness of Enteral Nutrition in Restoring on Immunocompetence Comparing with Naturl Oral Feeding in Malnourished Rats
A protocol for nutritional restoration with estimated amount of nutrients from malnourished state was set up by increasing protein intake at a week interval. Based on this protocol, recovery of hematological, biochemical and immunological parameters in rats nutritionally restored with per os natual diet (PD) and enteral tube feeding of Clinimeal (EN) was described. When these two nutrients were compared, body weight gains showed somewhat delay in EN group but Hb, Ht, and serum total protein level, C3 level, macrophage function and PPD skin reactivity were restored more rapidly and effectively in the group restored with EN than that with PD. From these points, it is preferable to restore the severe malnourished state with enteral nutrient, Clinimeal
ARICA: Demonstration of a Real-time Gamma-Ray Bursts Alert System using the Commercial Satellite Networks
We demonstrate the real-time alert system of the transient astronomical sources such as cosmic gamma-ray bursts (GRBs) using two commercial satellite network devices. One is the Iridium’s Short Burst Data (SBD) and the other is the Globalstar’s STX-3. Although these satellite communication devices have been used in the space environment, it still needs to verify whether the network can be used as a GRB alert system. We are currently developing a 1U CubeSat called AGU Remote Innovative CubeSat Alert system (ARICA) which contains both SBD and STX-3 to demonstrate the real-time GRB alert system. The ARICA has been selected as the JAXA Innovative Satellite Technology Demonstration-2 and scheduled to be launched in the Japanese fiscal year 2021
Flight Model Development of the AGU Remote Innovative CubeSat Alert System - ARICA
We present the flight model development of the 1U CubeSat, AGU Remote Innovative CubeSat Alert system (ARICA), which is scheduled to be launched in the Japanese fiscal year 2021 as the JAXA Innovative Satellite Technology Demonstration-2 project. The main goal of ARICA is to demonstrate the real-time alert system of the transient astronomical sources using commercial satellite network devices. The development of the flight components has been finished in April 2021. The thermal vacuum test was conducted at the end of April 2021. The vibration and shock tests were performed in May 2021. We are currently in the final stage of the development of ARICA to be ready for launch
Development of the ARICA-2 Satellite Using Spresense as an Onboard Computer
Gamma-ray bursts (GRBs) are transient astronomical phenomena that emit enormous amounts of energy in electromagnetic waves, mainly in the gamma-ray range, for several seconds to tens of seconds. GRB observations are challenging because of the difficulty in predicting the location and time of occurrence and its extremely short duration. Therefore, it is necessary to notify about the discovery in space and to conduct follow-up observations by researchers. The AGU Remote Innovative CubeSat Alert system-2 (ARICA-2) has been developed to demonstrate a new alert system using commercial satellite network services. ARICA-2 uses SONY’s Spresense as its onboard computer (OBC). We manufactured the special board to attach two Spresenses as a redundancy of the OBC system. We will present the system development of ARICA-2 using Spresense
Power System Development of the AGU Remote Innovative CubeSat Alert System -2 – ARICA-2
We present the power system development of the 2U CubeSat, AGU Remote Innovative CubeSat Alert system -2(ARICA-2). The main goal of the ARICA-2 project is to demonstrate the real-time alert system of transient astronomical sources using commercial satellite network devices. 1U CubeSat ARICA was launched in November 2021. However, we have not been able to send and receive the data at this point. Therefore, we started developing 2U CubeSat ARICA-2, which is an improved version of ARICA, in April 2022. One of the possible causes of the communication problem of ARICA is the power system, such as a negative power budget or a failure in the installation of the inhibit switches. ARICA-2 is upsized from 1U to 2U to ensure a sufficient power generation and is equipped with improved inhibit switches. The calculation of power consumption and simulation of power supply on orbit have been finished. We confirmed the performance of our Electric Power System (EPS) and the health of the installed batteries. We are currently in the EM development phase with the goal of launching in Japanese fiscal year 2024
Spectral Properties of Prompt Emission of Four Short Gamma-Ray Bursts Observed by the Suzaku-WAM and the Konus-Wind
We have performed a joint analysis of prompt emission from four bright short
gamma-ray bursts (GRBs) with the Suzaku-WAM and the Konus-Wind experiments.
This joint analysis allows us to investigate the spectral properties of
short-duration bursts over a wider energy band with a higher accuracy. We find
that these bursts have a high E, around 1 MeV and have a harder
power-law component than that of long GRBs. However, we can not determine
whether these spectra follow the cut-off power-law model or the Band model. We
also investigated the spectral lag, hardness ratio, inferred isotropic
radiation energy and existence of a soft emission hump, in order to classify
them into short or long GRBs using several criteria, in addition to the burst
duration. We find that all criteria, except for the existence of the soft hump,
support the fact that our four GRB samples are correctly classified as
belonging to the short class. In addition, our broad-band analysis revealed
that there is no evidence of GRBs with a very large hardness ratio, as seen in
the BATSE short GRB sample, and that the spectral lag of our four short GRBs is
consistent with zero, even in the MeV energy band, unlike long GRBs. Although
our short GRB samples are still limited, these results suggest that the
spectral hardness of short GRBs might not differ significantly from that of
long GRBs, and also that the spectral lag at high energies could be a strong
criterion for burst classification.Comment: 23 pages, 6 figures, accepted for Publications of the Astronomical
Society of Japa
- …