Enabling Faster Locomotion of Planetary Rovers with a Mechanically-Hybrid Suspension

The exploration of the lunar poles and the collection of samples from the martian surface are characterized by shorter time windows demanding increased autonomy and speeds. Autonomous mobile robots must intrinsically cope with a wider range of disturbances. Faster off-road navigation has been explored for terrestrial applications but the combined effects of increased speeds and reduced gravity fields are yet to be fully studied. In this paper, we design and demonstrate a novel fully passive suspension design for wheeled planetary robots, which couples a high-range passive rocker with elastic in-wheel coil-over shock absorbers. The design was initially conceived and verified in a reduced-gravity (1.625 m/s$^2$) simulated environment, where three different passive suspension configurations were evaluated against a set of challenges--climbing steep slopes and surmounting unexpected obstacles like rocks and outcrops--and later prototyped and validated in a series of field tests. The proposed mechanically-hybrid suspension proves to mitigate more effectively the negative effects (high-frequency/high-amplitude vibrations and impact loads) of faster locomotion (>1 m/s) over unstructured terrains under varied gravity fields. This lowers the demand on navigation and control systems, impacting the efficiency of exploration missions in the years to come.Comment: 8 pages, 13 figure

大型核融合試験施設におけるメガワットミリ波ジャイロトロン発振器周辺の電磁環境調査

将来のエネルギー源として開発が進められている磁場閉じ込め方式の核融合研究では，高温プラズマの生成や制御，プラズマ加熱及び計測のために大電力高周波発振機器が利用されている．本論文では，核融合科学研究所の大型ヘリカル装置で使用されているメガワットミリ波ジャイロトロン発振器(周波数: 77 GHz，最大出力: 1～1.5 MW/2秒)を対象とし，作業従事者の安全管理を目的に，ホーンアンテナを用いて機器周辺での電磁環境を定点調査した．その結果，77 GHz発振器からおよそ30 m離れた場所で観測された漏洩電界の周波数は，77 GHzが最も強く，そこから数GHz離れた両側の周波数領域にも微弱なスプリアススペクトルが確認された．また，同じ場所で，数十秒から数百秒の発振運転に伴う漏洩電界(最大実効値: 数V/m)が観測された．電界の漏洩箇所は，ジャイロトロン発振器を構成する接地電位の電子ビームコレクターと，その他の部位とを電気的に絶縁するために具備された窒化ケイ素製絶縁部と推定された．本研究により，大型核融合試験施設におけるメガワットジャイロトロン発振器周辺のミリ波帯での漏洩電界の実態を初めて明らかにした

A New Strategy for Surgical Intervention of Bisphosphonate-Related Osteonecrosis of the Jaw : A retrospective study.

Bisphosphonates (BPs) are now widely used to treat various skeletal complications. Although the number of reported cases ofbisphosphonate-related osteonecrosis of the jaw (BRONJ) is rapidly increasing worldwide, therapeutic strategies remain controversial.Conservative treatments including antibacterial mouth rinses, the systemic administration of antibiotics, and superficial debridement in stage II BRONJ have been recommended by the American Association of Oral and Maxillofacial Surgeons position paper. However, these treatments are only partially successful. We performed a surgical intervention that consisted of osteotomy and primary wound closure in patients with stages II and III BRONJ. Forty-three out of 44 cases were treated effectively by this strategy, leading to improvements in quality of life. All BRONJ patients treated with oral BPs were treated successfully by the surgical intervention. We also proposed a surgical intervention for patients with stage II BRONJ

Biological, clinical and population relevance of 95 loci for blood lipids.

Plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with plasma lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 x 10(-8)), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (for example, CYP7A1, NPC1L1 and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and have an impact on lipid traits in three non-European populations (East Asians, South Asians and African Americans). Our results identify several novel loci associated with plasma lipids that are also associated with CAD. Finally, we validated three of the novel genes-GALNT2, PPP1R3B and TTC39B-with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD

Water Vapor Adsorption Properties of Honeycomb-Type Zeolites for Tritium Removal Systems

We have proposed the application of a honeycomb-type adsorbent and catalyst for an advanced tritium removal system. Honeycomb-type materials exhibit a much lower pressure drop than pellet-type materials. In this study, the water vapor adsorption properties of various types of honeycomb adsorbents were evaluated using the breakthrough method at a constant flow rate of 307 cm3/min under various temperature and water vapor partial pressure conditions. The results revealed that the adsorption capacity of water vapor on the honeycomb-type zeolite increased with the water vapor partial pressure and the zeolite content of the honeycomb adsorbents. Furthermore, the honeycomb-type zeolite was found to have a higher adsorption rate than the pellet-type zeolite, and the temperature required for regeneration of the honeycomb-type zeolite was at least 450 K. From the viewpoint of practical use, the honeycomb-type adsorbent that contained 50% zeolite with 200 cells per square inch was considered to have superior adsorption properties and a lower pressure drop among a series of honeycomb-type adsorbents

Technique for enhanced rare earth separation

A process is demonstrated for the efficient separation of rare earth elements, using a combination of selective reduction and vacuum distillation of halides. The large differences in the redox chemistry of the rare earth elements and in the vapor pressures of rare earth di- and trihalides are exploited for separation. Experimental proof of concept is provided for the binary systems praseodymium-neodymium and neodymium-samarium. This process enhances the separation factor for the isolation of samarium and neodymium from their mixture by more than an order of magnitude

Hydrogen generation from water using Mg nanopowder produced by arc plasma method

We report that hydrogen gas can be easily produced from water at room temperature using a Mg nanopowder (30–1000 nm particles, average diameter 265 nm). The Mg nanopowder was produced by dc arc melting of a Mg ingot in a chamber with mixed-gas atmosphere (20% N2–80% Ar) at 0.1 MPa using custom-built nanopowder production equipment. The Mg nanopowder was passivated with a gas mixture of 1% O2 in Ar for 12 h in the final step of the synthesis, after which the nanopowder could be safely handled in ambient air. The nanopowder vigorously reacted with water at room temperature, producing 110 ml of hydrogen gas per 1 g of powder in 600 s. This amount corresponds to 11% of the hydrogen that could be generated by the stoichiometric reaction between Mg and water. Mg(OH)2 flakes formed on the surface of the Mg particles as a result of this reaction. They easily peeled off, and the generation of hydrogen continued until all the Mg was consumed