Stability of vacancies in β-type Ti-15Mo-5Zr-3Al alloy fabricated via laser powder bed fusion

The structural instability in the β-type titanium alloys could affect the stability of vacancies. The stability of vacancies in a β-type Ti-15Mo-5Zr-3Al alloy, fabricated via laser powder bed fusion (LPBF), was investigated using positron annihilation spectroscopy and first-principles calculations. The observed positron lifetimes were close to the experimental and calculated bulk lifetime of Ti-15Mo-5Zr-3Al, which indicates that vacancies were not detected in Ti-15Mo-5Zr-3Al by positron lifetime measurements. Therefore, for the first time, it has been confirmed that quenched-in vacancies are not introduced in the LPBF-manufactured β-type Ti-15Mo-5Zr-3Al despite the fast cooling rate in LPBF process. This feature is preferable for the structural stability in biomedical and industrial applications. The calculated atomic displacement from the ideal bcc lattice positions decreased in β-type Ti-Mo alloys with increasing Mo concentration, indicating that the bcc structure was stabilized by the added Mo. The calculated vacancy formation energies of Ti atoms in β-type Ti-14.5Mo and Ti-27.0Mo alloys exhibited an increasing trend with an increasing number of neighboring Mo atoms. Mo atoms also increased the migration energies of the neighboring paths of vacancies. The calculated results for Ti-15Mo-5Zr-3Al suggest that, while the bcc structure was stabilized by the Mo atoms in Ti-15Mo-5Zr-3Al, the migration and formation energies were still low enough for the diffusion of vacancies.Mizuno M., Sugita K., Do K., et al. Stability of vacancies in β-type Ti-15Mo-5Zr-3Al alloy fabricated via laser powder bed fusion. Additive Manufacturing Letters 7, 100162 (2023); https://doi.org/10.1016/j.addlet.2023.100162

Detection of Neodymium-Rich Phase for Development of Coercivity in Neodymium-Iron-Boron-Based Alloys with Submicron-Sized Grains Using Positron Lifetime Spectroscopy

In order to evaluate the relationship between positron lifetime and microstructure, which contributes to the development of coercivity in hydrogenation-disproportionation-desorption-recombination (HDDR)-processed Nd-Fe-B-based alloys, detailed studies of positron lifetime spectroscopy were performed on HDDR-processed Nd-Fe-B-based alloys during desorption-recombination (DR) treatment. After the onset of coercivity, the change in positron lifetime closely corresponded to the change in intrinsic coercivity (H cJ ) with the progress of DR treatment. This result can be explained in terms of the grain size of the recombined Nd 2 Fe 14 B phases and the diffusion length of positrons, which annihilate in the matrix before reaching the grain boundary. Furthermore, positron lifetime spectroscopy was able to detect small changes in the grain boundary region very sensitively compared with thermal desorption spectroscopy (TDS) and X-ray diffraction (XRD). These changes in the grain boundary region caused the onset of coercivity attributed to the formation of Nd-rich intergranular phases. These results indicate that formation of a small amount of the Nd-rich intergranular phase during the DR process, which could be detected by positron lifetime spectroscopy, contributes to the onset of coercivity, even if NdH x phases remain

A Low-Tech Bioreactor System for the Enrichment and Production of Ureolytic Microbes

Ureolysis-driven microbially induced carbonate precipitation (MICP) has recently received attention for its potential biotechnological applications. However, information on the enrichment and production of ureolytic microbes by using bioreactor systems is limited. Here, we report a low-tech down-flow hanging sponge (DHS) bioreactor system for the enrichment and production of ureolytic microbes. Using this bioreactor system and a yeast extract-based medium containing 0.17 M urea, ureolytic microbes with high potential urease activity (> 10 μmol urea hydrolyzed per min per ml of enrichment culture) were repeatedly enriched under non-sterile conditions. In addition, the ureolytic enrichment obtained in this study showed in vitro calcium carbonate precipitation. Fluorescence in situ hybridization analysis showed the existence of bacteria of the phylum Firmicutes in the bioreactor system. Our data demonstrate that this DHS bioreactor system is a useful system for the enrichment and production of ureolytic microbes for MICP applications

A Low-Tech Bioreactor System for the Enrichment and Production of Ureolytic Microbes

Ureolysis-driven microbially induced carbonate precipitation (MICP) has recently received attention for its potential biotechnological applications. However, information on the enrichment and production of ureolytic microbes by using bioreactor systems is limited. Here, we report a low-tech down-flow hanging sponge (DHS) bioreactor system for the enrichment and production of ureolytic microbes. Using this bioreactor system and a yeast extract-based medium containing 0.17 M urea, ureolytic microbes with high potential urease activity (> 10 μmol urea hydrolyzed per min per ml of enrichment culture) were repeatedly enriched under non-sterile conditions. In addition, the ureolytic enrichment obtained in this study showed in vitro calcium carbonate precipitation. Fluorescence in situ hybridization analysis showed the existence of bacteria of the phylum Firmicutes in the bioreactor system. Our data demonstrate that this DHS bioreactor system is a useful system for the enrichment and production of ureolytic microbes for MICP applications

Long-term peritoneal dialysis and encapsulating peritoneal sclerosis in children

Encapsulating peritoneal sclerosis (EPS) is the most serious complication of long-term peritoneal dialysis (PD), with a mortality rate that exceeds 30%. There have been many reports of the incidence of EPS being strongly correlated to the duration of PD. Patients on PD for longer than 5 years, and especially those receiving this treatment for more than 8 years, should undergo careful and repeated surveillance for risk factors associated with the development of EPS. The development of ultrafiltration failure, a high dialysate/plasma creatinine ratio, as determined by the peritoneal equilibration test, peritoneal calcification, a persistently elevated C-reactive protein level, and severe peritonitis in patients on PD for longer than 8 years are signals that should prompt the clinician to consider terminating PD as a possible means of preventing the development of EPS. The impact of the newer, biocompatible PD solutions on the incidence of EPS has not yet been determined

Operational Review of the First Wireline In Situ Stress Test in Scientific Ocean Drilling

Scientific ocean drilling’s first in situ stress measurement was made at Site C0009A during Integrated Ocean Drilling Program (IODP) Expedition 319 as part of Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) Stage 2. The Modular Formation Dynamics Tester (MDT, Schlumberger)wireline logging tool was deployed in riser Hole C0009A to measure in situ formation pore pressure, formation permeability (often reported as mobility=permeability/viscosity), and the least principal stress (S3) at several isolated depths (Saffer et al., 2009; Expedition 319 Scientists, 2010). The importance of in situ stress measurements is not only for scientific interests in active tectonic drilling, but also for geomechanical and well bore stability analyses. Certain in situ tools were not previously available for scientific ocean drilling due to the borehole diameter and open hole limits of riserless drilling. The riser-capable drillship, D/V Chikyu,now in service for IODP expeditions, allows all of the techniques available to estimate the magnitudes and orientations of 3-D stresses to be used. These techniques include downhole density logging for vertical stress, breakout and caliper log analyses for maximum horizontal stress, core-based anelastic strain recovery (ASR, used in the NanTroSEIZE expeditions in 2007–2008), and leak-off test (Lin et al., 2008) and minifrac/hydraulic fracturing (NanTroSEIZE Expedition319 in 2009). In this report, the whole operational planning process related to in situ measurements is reviewed, and lessons learned from Expedition 319 are summarized for efficient planning and testing in the future

Drift assesment of pressure gauges for longterm subseafloor observation

Poster OS11A-1466 presented at 2011 Fall Meeting, AGU, San Francisco, Calif., 5-9 Dec. / Poster title: Depthmeter drift calibration for longterm obseervatio

Double bundle arthroscopic Anterior Cruciate Ligament reconstruction with remnant preserving technique using a hamstring autograft

<p>Abstract</p> <p>Background</p> <p>Preservation of the Anterior Cruciate Ligament (ACL) remnant is important from the biological point of view as it enhances revascularization, and preserves the proprioceptive function of the graft construct. Additionally, it may have a useful biomechanical function. Double bundle ACL reconstruction has been shown to better replicate the native ACL anatomy and results in better restoration of the rotational stability than single bundle reconstruction.</p> <p>Methods</p> <p>We used the far anteromedial (FAM) portal for creation of the femoral tunnels, with a special technique for its preoperative localization using three dimensional (3D) CT. The central anteromedial (AM) portal was used to make a longitudinal slit in the ACL remnant to allow visualization of the tips of the guide pins during anatomical creation of the tibial tunnels within the native ACL tibial foot print. The use of curved hemostat allow retrieval of the wire loop from the apertures of the femoral tunnels through the longitudinal slit in the ACL remnant thereby, guarding against impingement of the reconstruction graft against the ACL remnant as well as the roof of the intercondylar notch.</p> <p>Conclusion</p> <p>Our technique allows for anatomical double bundle reconstruction of the ACL while maximally preserving the ACL remnant without the use of intra-operative image intensifier.</p

創造都市におけるコミュニケーションデザイン/神戸ビエンナーレ2013 の視点から

神戸ビエンナーレ2013 のメイン会場・メリケンパークに、会期限定でオープンした輸送用コンテナを利用した公式デザインショップの企画とデザイン、及びその展開についての研究。このプロジェクトは、これまでのアートの概念を越えた新しい表現や価値、都市の魅力の創生をコンセプトに開催される神戸ビエンナーレにおいて、神戸芸術工科大学が保有するリソースを活かし地元企業との連携で、オリジナルグッズの企画・開発から空間デザイン、運営までをトータルに行った、地場産業と地域活性化のための新しい試みである。開発プロダクトをプレゼンテーションするためのショップとスタンドを併設し、アートを接点に都市に集う多種多様な人々の交流をテーマにデザインした。また、同じくビエンナーレ会場である灘区・ミュージアムロードの公共施設で、研究で制作した３基の展示什器を使用し、市民を対象にしたデザインとアートによる地域交流や体験を深めるコンテンツを展開した。This study is about the planning, design and deployment at Meriken Park, the main venue for KOBE Biennale 2013, featured official design shop housed in shipping container, operating only for the duration of the event. Drawing on the resources of Kobe Design University, this project was a new attempt at revitalizing the region and local industry for which we provided a total service, from the planning of the original goods to the spatial design and actual operation stages. Our design theme was the exchange of the great diversity of people who congregate in cities, with art as their contact point. In addition, at the Museum Road in Nada-ku where is also the venue of KOBE Biennale 2013, we installed three display furniture in public facilities along the road and, in the spaces created by their placement, worked with students and artists to hold exhibits and workshops on design and art aimed at local residents