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The Global Precipitation Measurement (GPM) mission is an international collaboration to achieve highly accurate and highly frequent global precipitation observations. The GPM mission consists of the GPM Core Observatory jointly developed by U.S. and Japan and Constellation Satellites that carry microwave radiometers and provided by the GPM partner agencies. The GPM Core Observatory, launched on February 2014, carries the Dual-frequency Precipitation Radar (DPR) by the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT).JAXA and NASA started to release the GPM/DPR Experimental product (Version 06X) in June 2020. This Version 06X is the first product to respond to the KaPR scan pattern changes implemented on May 21, 2018. This change in scan pattern allows for a more accurate precipitation estimation method based on two types of precipitation information, Ku-band Precipitation radar (KuPR) and KaPR, to be applied to the entire observation swath. A new version 07 of the GPM/DPR products will appear in 2021.JAXA also develops the Global Satellite Mapping of Precipitation (GSMaP), to distribute hourly and 0.1-degree horizontal resolution rainfall map through the “JAXA Global Rainfall Watch” website (https://sharaku.eorc.jaxa.jp/GSMaP/index.htm). The GSMaP near-real-time version (GSMaP_NRT) product provides global rainfall map in 4-hour after observation, and an improved version of GSMaP near-real-time gauge-adjusted (GSMaP_Gauge_NRT) product has been published since Dec. 2018. Now the JAXA is developing the GPM-GSMaP V05 (algorithm version 8) which will be released in 2021.In the GPM-GSMaP V05, the passive microwave (PMW) algorithm will be improved in terms of retrievals extended to the pole-to-pole, updates of databases for the PMW retrievals, and heavy Orographic Rainfall Retrievals. Normalization module for PMW retrievals (Yamamoto and Kubota 2020) will be implemented. A histogram matching method by Hirose et al. (2020) will be implemented in the PMW-IR Combined algorithm. In the Gauge-adjustment algorithm based upon Mega et al. (2019), artificial patterns appeared in V04 will be mitigated in V05.

This study describes a calculation of the brightness temperature obtained from the spaceborne precipitation radar to utilize possible uses of precipitation estimates. Since the radar viewed from space measures emission and scattering signals from the earth, the brightness temperature at the radar's frequency is obtained from the noise power measured by the radar. The measurement accuracy of the radar's brightness temperature is also computed from the signal characteristics of the noise power. This study analyzes the noise power data of the Dual-frequency precipitation radar (DPR), whose frequency is at 13.6 and 35.5 GHz, onboard the Global Precipitation Measurement mission's (GPM's) core satellite. The calibrated brightness temperature data obtained from the DPR show the regional gradient between ocean and land surfaces and the emission signal from precipitation even if the measurement accuracy of the radar's brightness temperature is about 30 (50) K for the Ku-band (Ka-band) channel.

For the purpose of future visualization of the flow field in superfluid helium-4, clusters of the triplet state excimer

For flow visualization study of quantum turbulence in superfluid $$^4$$ He, He $$_2^*$$ excimers are unique tracers which follow only normal-fluid component flow above 1 K. To generate detectable small He $$_2^*$$ clouds (clusters) required for full-space velocity field measurements, we have adopted a new method based on neutron absorption reaction of $$^3$$ He impurities in $$^4$$ He and conducted proof-of-principle experiments. Generation of the He $$_2^*$$ excimers was detected by laser-induced fluorescence using photomultiplier tubes. The fluorescence was observed to increase proportionally to the neutron flux, suggesting that a sufficient amount of He $$_2^*$$ excimers were generated by neutrons. We also estimated the number of He $$_2^*$$ excimers possibly generated by $$\gamma $$ -rays and found that the relevant contribution was less than 40%. Thus, the majority of the He $$_2^*$$ excimers was confirmed to be generated via n- $$^3$$ He absorption reactions.

The purpose of this study was to help provide data to help to implement effective rehabilitation following surgery for oral cancer by comparing tongue pressure production for water and thickened water from the anterior and posterior parts of the tongue during swallowing. Ten healthy volunteers (7 men, 3 women; age 27.6 ± 1.5 years) participated in the experiments. Tongue pressure during 3 mL water and 3 mL thickened water at the anterior and posterior tongue during swallowing was measured using a sensor sheet system with five measuring points on the hard palate. The sequential order of the points, maximal magnitude and duration of tongue pressure at each point were compared based on water viscosity and tongue ingestion site. There was a common pattern in the sequential order of tongue pressure generation among the two swallowing conditions. The maximal magnitude of tongue pressure was significantly higher when swallowing thickened water than when swallowing water at all points except for the anterior-median and mid-median part. Moreover, the pressure at all sites during posterior ingestions was significantly lower than that during anterior ingestion. The present results provide mean values of tongue pressure during voluntarily triggered swallowing in anterior ingestion and posterior ingestion in young, healthy dentate individuals; these values can be clinically referenced for tongue pressure measurement in the evaluation of patients with dysphagia. The use of reference values may help streamline the diagnosis, treatment and rehabilitation of dysphagia.

Background Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are well-known for preventing cardiovascular disease. Among n-3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) play key roles in preventing cardiovascular diseases. However, the effects of n-3 PUFAs have been examined under conditions of simultaneous administration of EPA and DHA in the majority of clinical investigations and the effect of purified EPA is still controversial. EPA has been reported to improve endothelial dysfunction. Although several mechanisms underlying the effects of EPA on endothelial function have been demonstrated such as the modulation of lipid metabolism including increases in high-density lipoprotein (HDL) and/or decreases in triglyceride (TG) levels, decreases in cytokine production, and inhibition of inflammatory processes, the main mechanisms ameliorating endothelial function have not been fully determined. Purpose We sought to clarify the main factors associated with EPA administration that led to improved endothelial function. Methods Fifty-one consecutive patients with hypertriglyceridemia (mean ± SD age, 60±13 years) with no evidence of coronary artery disease (CAD) were prospectively enrolled and administered purified EPA (1800 mg/day). Forty-eight patients who were not administered EPA were enrolled as age- and sex-matched controls. Clinical variables such as body mass index, HbA1c, fasting glucose level, HDL, low-density lipoprotein, TG, systolic blood pressure, diastolic blood pressure, heart rate, interleukin-6, baseline diameter of the brachial artery, intima-media thickness of the brachial artery, and flow-mediated dilation (FMD) were examined before and after 6 months of treatment. Univariate and multivariate regression analyses were performed to examine the associations between FMD changes and clinical variables. Results FMD was significantly improved from 4.16% ± 1.88% to 6.30% ± 2.24% (p Conclusions EPA treatment improves endothelial dysfunction in patients with hypertriglyceridemia without evidence of CAD. The change in FMD was associated with the change in EPA/AA ratio alone. These finding suggest that a direct effect of EPA on the endothelium may be the predominant factor ameliorating endothelial function. Acknowledgement/Funding This study was supported, in part, by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan (15K08649).

A linewidth reduction of a distributed feedback quantum cascade laser (DFB-QCL) based on optical feedback for a mid-infrared (MIR) cavity ring down spectroscopy (CRDS) 14C spectrometer is presented. A cat-eye reflector as well as a path-length enhancement by a Herriott cell were employed for a compact optical setup. The laser linewidth was evaluated by monitoring the beat frequency between the DFB-QCL and a MIR optical frequency comb (OFC). The linewidth reduction by optical feedback was clearly observed although slow frequency drifts caused by environmental changes were still visible. A low-bandwidth beat-note lock to the OFC was conducted for long-term stabilization as well as for precise frequency scanning and thereby 14C measurement by MIR CRDS with optical feedback was demonstrated successfully.

For the purpose of future visualization of the flow field in superfluid helium-4, clusters of the triplet state excimer 4He2* are generated along the micro-scale recoil tracks of the neutron-absorption reaction n + 3He → 3T + p. This reaction is induced by neutron irradiation of the 3He fraction contained in natural isotopic abundance liquid helium with neutron beams either from the Japan Proton Accelerator Research Complex, Materials and Life Science Experimental Facility (JPARC)/Materials and Life Science Experimental Facility or from the Kyoto University Institute for Integrated Radiation and Nuclear Science. These 4He2* clusters are expected to be ideal tracers of the normal-fluid component in superfluid helium with several advantageous properties. Evidence of the excimer generation is inferred by detection of laser induced fluorescence emitted from the 4He2* clusters excited by a purpose-built short pulse gain-switched titanium:sapphire (Ti:sa) laser operating at a wavelength of 905 nm. The setup and performance characteristics of the laser system including the Ti:sa and two continuous wave re-pumping lasers are described. Detection at the fluorescence wavelength of 640 nm is performed by using optical bandpass filtered photomultiplier tubes (PMT). Electrical noise in the PMT acquisition traces could successfully be suppressed by post-processing with a simple algorithm. Despite other laser-related backgrounds, the excimer was clearly identified by its fluorescence decay characteristics. Production of the excimer was found to be proportional to the neutron flux, adjusted via insertion of different collimators into the neutron beam. These observations suggest that the apparatus we constructed does function in the expected manner and, therefore, has the potential for groundbreaking turbulence research with superfluid helium.

We measure the spectrum of cosmic rays with energies greater than 10 18.2 eV with the fluorescence detectors (FDs) and the surface detectors (SDs) of the Telescope Array Experiment using the data taken in our first 2.3-year observation from May 27, 2008 to September 7, 2010. A hybrid air shower reconstruction technique is employed to improve accuracies in determination of arrival directions and primary energies of cosmic rays using both FD and SD data. The energy spectrum presented here is in agreement with our previously published spectra and the HiRes results.

15th MST Radar WorkshopSession M2: New radar/radio systems and future MST plansMay 30 (Tue), NIPR Auditorium

The stability of the gain of the photomultiplier (PMT) camera for the Fluorescence Detector (FD) of the Telescope Array experiment was monitored using an 241 Am loaded scintillator pulsers (YAP) and a diffused xenon flasher (TXF) for a selected set of 35 PMT-readout channels. From the monitoring of YAP pulses over four years of FD operation, we found slow monotonic drifts of PMT gains at a rate of −1.7~+1.7%/year. An average of the PMT gains over the 35 channels stayed nearly constant with a rate of change measured at −0.01±0.31(stat)±0.21(sys)%/year. No systematic decrease of the PMT gain caused by the night sky background was observed. Monitoring by the TXF also tracked the PMT gain drift of the YAP at 0.88±0.14(stat)%/year.

We present a measurement of the energy spectrum of ultra-high-energy cosmic rays performed by the Telescope Array experiment using monocular observations from its two new FADC-based fluorescence detectors. After a short description of the experiment, we describe the data analysis and event reconstruction procedures. Since the aperture of the experiment must be calculated by Monte Carlo simulation, we describe this calculation and the comparisons of simulated and real data used to verify the validity of the aperture calculation. Finally, we present the energy spectrum calculated from the merged monocular data sets of the two FADC-based detectors, and also the combination of this merged spectrum with an independent, previously published monocular spectrum measurement performed by Telescope Array’s third fluorescence detector [T. Abu-Zayyad et al., The energy spectrum of Telescope Array’s middle drum detector and the direct comparison to the high resolution fly’s eye experiment, Astroparticle Physics 39 (2012) 109-119, http://dx.doi.org/10.1016/j.astropartphys.2012.05.012 , Available from: ]. This combined spectrum corroborates the recently published Telescope Array surface detector spectrum [T. Abu-Zayyad, et al., The cosmic-ray energy spectrum observed with the surface detector of the Telescope Array experiment, ApJ 768 (2013) L1, http://dx.doi.org/10.1088/2041-8205/768/1/L1 , Available from: ] with independent systematic uncertainties.

LiCaAlF6 scintillators are one of the attractive scintillators for neutron detection. To reduce the effect on gamma-rays, the Ce doped LiCaAlF6 scintillators can discriminate the neutron and gamma-ray events based on the pulse shape discrimination technique. To apply the scintillators for the oil logging, the high temperature characteristics must be investigated. In this paper, the temperature dependence of the neutron-gamma discrimination based on pulse shape discrimination technique in the Ce:LiCaAlF6 scintillator is investigated as one of the high temperature characteristics. The property of pulse shape discrimination in the Ce:LiCaAlF6 has small temperature dependence ranging from 25°C to 150°C. We concluded that the Ce:LiCaAlF6 scintillators can discriminate neutron and gamma-ray events under high temperature condition up to 150°C .

Data from the TRMM precipitation radar is providing unprecedented information on the 3D structure of precipitation systems and estimates of precipitation rates over the oceans and land of the global tropics and subtropics. Algorithms for estimating precipitation rates from observations of apparent radar reflectivity depend on procedures for correcting for attenuation, especially in regions where intense deep convection occurs. The well-known problem of non-uniform beam filling is a source of error in the estimates, caused by unresolved horizontal variability in highly correlated characteristics of precipitation, such as specific attenuation, rain rate, and the effective radar reflectivity factor, that are fundamentally related to the size distribution of hydrometeors. This paper presents an empirical test of a theoretically based procedure for correcting for attenuation by means of a simulation study. Data for simulating spaceborne radar observations were obtained from a ground based scanning radar in Okinawa during a field experiment in June 2004. The correction procedure, reviewed briefly here, has been developed by formulating and analytically solving a statistically based model of non-uniform beam filling. The empirical test shows that the correction has the potential to improve retrievals of rain rate in intense convection, provided that reasonable estimates of a governing parameter can be obtained from the satellite data.

We study the anisotropy of Ultra-High Energy Cosmic Ray (UHECR) events collected by the Telescope Array (TA) detector in the first 40 months of operation. Following earlier studies, we examine event sets with energy thresholds of 10 EeV, 40 EeV, and 57 EeV. We find that the distributions of the events in right ascension and declination are compatible with an isotropic distribution in all three sets. We then compare with previously reported clustering of the UHECR events at small angular scales. No significant clustering is found in the TA data. We then check the events with E>57 EeV for correlations with nearby active galactic nuclei. No significant correlation is found. Finally, we examine all three sets for correlations with the large-scale structure of the Universe. We find that the two higher-energy sets are compatible with both an isotropic distribution and the hypothesis that UHECR sources follow the matter distribution of the Universe (the LSS hypothesis), while the event set with E>10 EeV is compatible with isotropy and is not compatible with the LSS hypothesis at 95% CL unless large deflection angles are also assumed. We show that accounting for UHECR deflections in a realistic model of the Galactic magnetic field can make this set compatible with the LSS hypothesis., 10 pages, 9 figures

In order to measure the 2.5 MeV neutrons produced by DD nuclear fusion reactions, we have developed a compact neutron detector based on nuclear emulsion. After optimization of development conditions, we evaluated the response of the detector to an accelerator-based DD neutron source. The absolute efficiency at an energy of 2.5 MeV was estimated to be (4.1±0.2)×10 -6 tracks/neutron.

The Telescope Array (TA) is a large scale ground experiment in Utah, USA for the measurement of extensive air showers from the ultra-high energy cosmic rays. Its construction is completed in March, 2008 and the data taking started.

The TA observatory is a hybrid detector system consisting of both a surface detector array as well as a set of fluorescence detectors. The observatory will measure the energy spectrum, anisotropy and composition of ultra-high energy cosmic rays. The surface detectors are being deployed and the array should be complete by the end of February, 2007. We will soon be collecting hybrid data at the Telecope Array.

Aromatic material extracted from the Murchison meteorite shows an absorption atλ2200 A similar to the well-known interstellar absorption feature at this wavelength. This suggests a link between interstellar grain clumps containing organics and the presolar component of carbonaceous chondrites.

The effect of natural variation of raindrop size distribution (DSD)on the retrieval of rainfall rate from the dual-frequency (13.6/35.5 GHz,as will be in the Global Precipitation Measurement Mission) Precipitation Radar (DPR) measurements is studied by utilizing a large set of disdrometer-measured DSD data through a simple simulation framework. A DPR inversion technique(DPR-IT) that focuses on the retrieval of DSD information from the non-Rayleigh backscattering characteristic of the hydrometeors and a conventional DPR technique(DPR-CT) that focuses on the independent retrieval of rainfall rate from the attenuation measurement are considered in this analysis. The preliminary results show that at different rainfall rate regions these methods have different responses to the DSD variability. For instance, it appears that DPR-IT suffers relatively less from the DSD variability in the regions of weak to moderate rainfall rate ( /spl bsol/ mm /spl middot/ h/sup -1/),while in the strong rainfall rate (>/spl sim/10 mm /spl middot/ h/sup -1/) region the DPR-CT generally has less sensitivity to DSD variations than the DPR-IT.

LiMn 2 O 4 is used as the cathode material in large lithium ion batteries for industrial and other uses because of its low cost, excellent thermal stability, and other attributes. Nevertheless, LiMn 2 O 4 has weak points including severe capacity, deterioration at high temperatures, and low energy density. To overcome these points we conducted our research and development with a focus on LiCo x Ni y Mn z O 2 composite oxides (layered lithium manganese composite oxides). We developed an industrial synthesis technology for layered lithium manganese composite oxides, and employed them as the new cathode material for the EX25A, an industrial lithium ion battery. Compared with the lithium ion batteries that used LiMn 2 O 4 as their cathode material, the EX25A has double cycle life characteristics at high-temperature (according to our standards), and is capable of large 10 C discharges.

For the development of 45w%Pb-55w%Bi cooled direct contact boiling water small fast reactor (PBWFR), Pb-Bi-water direct contact boiling two-phase flow loop has been fabricated and operated. The loop consists of a Pb-Bi flow loop (four heater pin bundle, a chimney, an upper plenum, a level meter tank, an air-water cooler, and an electromagnetic flow meter) and a water-steam flow loop (a pump, a preheated, an injection nozzle, the chimney, the upper plenum with mist separators and dryers, a condenser, a buffer tank, and an air-water cooler). At the rated operating condition system pressure is 7 MPa. The sub-cooled water was injected into a Pb-Bi flow in the chimney. A power of the heater pin bundle was controlled to obtain the inlet and outlet temperatures of the heater bundle. The Pb-Bi and steam flows were simulated analytically using one-dimensional models of frictional and form losses and a drag force. The Pb-Bi-steam two-phase frictional pressure loss was calculated by means of the two-phase flow multiplication factor of Lockhart-Martinelli model. It was found that Pb-Bi temperature decreased quickly in the chimney due to high heat transfer rate of Pb-Bi-water direct contact boiling. The volumetric overall heat transfer coefficient was 60–310 kW/m 3 K, and decreased with the superheat.

Pulse patterns are designed by adopting variable pulse repetition frequency (VPRF) for space missions involving beam scans in the cross-track direction, especially intended for the Global Precipitation Measurement Project (GPM). To cope with large variance in range from a satellite, which is caused by the beam swing and the Earth oblateness, a systematic algorithm is proposed, increasing sampling rates.

Seven solvent-free solid polymer electrolytes based on cross-linked polyethers and doped with LiN(CF 3 SO 2 ) 2 , were investigated for usage in large-scale rechargeable lithium batteries. They are classified into two categories: one contains five poly(ethyleneoxide-co-propyleneoxide) (poly(EO-co-PO)) network polymers with different degrees of cross-linking and precursor molecular weight and the other includes two polyethers with borate structure having a Lewis acid functionality as an anion trap. The ionic conductivity, direct current characteristics, thermal properties and transference numbers were measured. To evaluate the battery performance for the polymer electrolytes, test cells of the typical Li/solvent-free solid polymer electrolyte/LiCoO 2 , were fabricated. High discharge performance was obtained for the solvent-free electrolytes made of the less cross-linked poly(EO-co-PO) and for the PEO including borate structure. A 10 Wh class lithium battery was entirely fabricated from solid components, and 500 charge–discharge cycles with 100% capacity retention was demonstrated. The present limitations and problems for further improvement of polymer batteries are also discussed.

Neutron and γ-ray (n-γ) discrimination with a digital signal processing system has been used to measure the neutron emission profile in magnetic confinement fusion devices. However, a sampling rate must be set low to extend the measurement time because the memory storage is limited. Time jitter decreases a discrimination quality due to a low sampling rate. As described in this paper, a new charge comparison method was developed. Furthermore, automatic n-γ discrimination method was examined using a probabilistic approach. Analysis results were investigated using the figure of merit. Results show that the discrimination quality was improved. Automatic discrimination was applied using the EM algorithm and k-means algorithm.

The cross-linked poly(ether) electrolytes were prepared by the polymerization of a macro-monomer (tri-acryroyl terminated ethyleneoxide–co-propyleneoxide (EO–PO)) containing LiN(CF3SO2)2 for the three different salt concentrations (O/Li=10/1, 20/1 and 30/1). The self-diffusion coefficients (D) of the anions ( 19 F NMR) measured by the pulsed gradient spin-echo (PGSE) NMR method showed the time dependency. The short-range anion diffusion is faster than the long-range diffusion. The accurate measurement of the diffusion for lithium ( 7 Li NMR) was difficult but the lithium diffusion seems slower than that of the anion. The fast hopping motion of lithium ions is correlated to the segment motion of the polymer. The ion conduction is closely related to the anion diffusion in the longer range. The transport number of the lithium ion can also be estimated from the electrochemical measurements.

Data from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar represent the first global rain-rate dataset acquired by a spaceborne weather radar. Because the radar operates at an attenuating wavelength, one of the principal issues concerns the accuracy of the attenuation correction algorithms. One way to test these algorithms is by means of a statistical method in which the probability distribution of rain rates at the high end is inferred by measurements at the low to intermediate range and by the assumption that the rain rates are lognormally distributed. Investigation of this method and the area–time integral methods using a global dataset provides an indication of how well methods of this kind can be expected to perform over different space–timescales and climatological regions using the sparsely sampled TRMM radar data. Identification of statistical relationships among the rain parameters and an understanding of the rain-rate distribution as a function of time and space may h...

The Tropical Rainfall Measuring Mission (TRMM) satellite was launched on 27 November 1997, and data from all the instruments first became available approximately 30 days after the launch. Since then, much progress has been made in the calibration of the sensors, the improvement of the rainfall algorithms, and applications of these results to areas such as data assimilation and model initialization. The TRMM Microwave Imager (TMI) calibration has been corrected and verified to account for a small source of radiation leaking into the TMI receiver. The precipitation radar calibration has been adjusted upward slightly (by 0.6 dB Z) to match better the ground reference targets; the visible and infrared sensor calibration remains largely unchanged. Two versions of the TRMM rainfall algorithms are discussed. The at-launch (version 4) algorithms showed differences of 40% when averaged over the global Tropics over 30-day periods. The improvements to the rainfall algorithms that were undertaken after launch are presented, and intercomparisons of these products (version 5) show agreement improving to 24% for global tropical monthly averages. The ground-based radar rainfall product generation is discussed. Quality-control issues have delayed the routine production of these products until the summer of 2000, but comparisons of TRMM products with early versions of the ground validation products as well as with rain gauge network data suggest that uncertainties among the TRMM algorithms are of approximately the same magnitude as differences between TRMM products and ground-based rainfall estimates. The TRMM field experiment program is discussed to describe active areas of measurements and plans to use these data for further algorithm improvements. In addition to the many papers in this special issue, results coming from the analysis of TRMM products to study the diurnal cycle, the climatological description of the vertical profile of precipitation, storm types, and the distribution of shallow convection, as well as advances in data assimilation of moisture and model forecast improvements using TRMM data, are discussed in a companion TRMM special issue in the Journal of Climate (1 December 2000, Vol. 13, No. 23).

This paper describes the TRMM standard algorithm 2A25 which estimates the instantaneous vertical profile of rain from Precipitation Radar (PR) data. Major challenges in rain profilling from the TRMM PR lie in the corrections for the effects of rain attenuation and non-uniform beam filling (NUBF) and in the rejection of surface clutter. A combination of the Hitschfeld-Bordan and surface reference methods is used to correct the attenuation effect in radar returns. The NUBF effects are estimated from the spatial variations of the estimated total path integral of attenuation from the top of the rain to the surface in the vicinity of the radar beam concerned. This paper outlines the critical part of the algorithm, and shows some results of comparisons of data taken nearly simultaneously by the TRMM PR and a ground-based radar.

The hydrogen solubility in UNiAl has been studied at a hydrogen pressure up to 2 MPa at temperatures ranging from 50 to 250°C. In the UNiAl–H system, there exist α (dilute solid solution), β (UNiAlH hydride), and γ (UNiAlH 2 hydride) phases. The enthalpy of solution of hydrogen into the α phase and the standard enthalpy of formation of the β phase were estimated from the equilibrium pressure–hydrogen concentration isotherms. The lattice parameters of the hydride were examined by X-ray diffraction analysis. The anisotropic lattice expansion was observed for the hydrogenation of UNiAl. It was found from DTA and TG analyses that the hydride of UNiAl showed no marked oxidation up to 300°C in air and appears to have excellent thermal stability in air.