When a negatively charged muon stopped in a material, muonic atom, which has one muon in place of an electron in the atomic system, is formed. After muon deexcitation process with muonic X-ray ...emission, the muon reaches to the muonic 1 s state, and the muon is absorbed in the nucleus. As a result, highly excited nucleus is produced, and the nucleus emits neutrons and gamma-rays. In this work, we determined elemental depth profiling of gold concentrations on archeological sample, an old Japanese coin, by measuring gamma-ray intensities emitted from activated nucleus with various incident muon energies.
Since metabolic pathway and enzymatic clarification of poly-phosphate accumulating organisms (PAOs) are still unclear, biological phosphorus removal (BPR) sometimes become unstable. We have focused ...on nitrite as one of unknown factors deteriorating BPR performance. And we obtained some findings from previous studies, namely 1) nitrite inhibits phosphate uptake and growth of PAOs, 2) nitrite inhibition persists even after nitrite disappearance, 3) PAOs with the higher relative anoxic activity are less sensitive to nitrite exposure. This study provides the modified Activated Sludge Model No.2d (ASM2d) to express nitrite inhibition properly by incorporating the assumed intracellular reaction product (reaction complex) of nitrite. The model also considers the tolerance mechanism of nitrite inhibition by the denitrifying activity of PAOs. From the results of previous experiments and relevant references, the modified model called "Nitrite-Complex model" incorporates new components, namely nitrite (S(NO(2) )) and reaction complex (X(complex)), to ASM2d. The model incorporation only nitrite inhibition was able to fit with measured phosphate concentration while nitrite exists. Whereas, this model couldn't describe the persistence of nitrite inhibition after nitrite disappeared. However, result of nitrite-complex model incorporating nitrite and reaction complex inhibition, it fits well with measured phosphate concentration not only before nitrite disappeared but also after nitrite disappeared.
•The influence of Gd substitution was investigated in the magnetic and magnetocaloric properties of HoB2.•The introduction of Gd leads to higher TC values up to 30 K.•The refrigerant capacity is ...enhanced up to 6.07 J cm−3 for a field change of 5 T.•The addition of Gd also leads to broader “table-like” entropy curves.
To optimize the giant magnetocaloric properties of HoB2, we synthesized and characterized the magnetocaloric properties of Ho1-xGdxB2 (0.1 ≤ x ≤ 0.4) alloys. We found out that Gd enters stoichiometrically and randomly into the Ho site, leading to a Vegard-type structural change. The addition of spherical S7/2 Gd3+ moments prompts an enhancement in Curie temperature from 15 K to 30 K (at x = 0.4), a reduction in peak value of the magnetic entropy change, from 0.35 (40.1) to 0.17 (20.2) J cm−3 K−1 (J kg−1 K−1), and a broadening of the magnetic entropy change curves. The overall influence is a relatively high refrigerant capacity and relative cooling power, peaking at 6.07 (711) and 7.68 (899) J cm−3 (J kg−1) for x = 0.2, and an extension of the thermal working range to higher temperatures. Unlike Ho1−xDyxB2 alloys, the Gd substituted samples show no magnetic hysteresis. Furthermore, scaling analysis of the entropy curves suggests a second-order phase transition for the ferromagnetic transition in these alloys. Thus, Ho1-xGdxB2 alloys are potential candidates for cryogenic refrigeration applications.
Inductive coupled plasma (ICP) etching with Ar/O
2 plasma system has been investigated for diamond device fabrication. High etch rate of 40 μm/h and etch selectivity of diamond to aluminium, which ...acts as a hard mask, of 50 were obtained. Dot patterns of aluminium with 1-μm diameters were prepared by lift-off or conventional photolithography and etching processes. Gas flow rates of Ar and O
2 were 30 and 90 sccm, respectively, and total pressure was between 2 and 7 Pa. ICP power was in the range of 700–1000 W. It was found that the change of power supplied to substrate allowed the change in diamond feature after etching. During anisotropic etching, bias power of 200 W was supplied and cylindrical shape with vertical wall was formed. On the contrary, isotropic etching without bias power formed eroded sidewall underneath the aluminium-masks. By combining these two conditions, we succeeded in forming top-recessed cylinders and bottom eroded ones. Conical structures of diamond with sharp tip, of which the minimum radius of curvature was less than 10 nm, were also fabricated by using tapered aluminium mask or partial sidewall etching on diamond cylinder.
Maeda H, Tomokiyo A, Koori K, Monnouchi S, Fujii S, Wada N, Kono K, Yamamoto N, Saito T, Akamine A. An in vitro evaluation of two resin‐based sealers on proliferation and differentiation of human ...periodontal ligament cells. International Endodontic Journal, 44, 425–431, 2011.
Aim To evaluate the effects of a polymethyl methacrylate resin–based sealer Superbond sealer (SB) on the proliferation and osteogenic differentiation of human periodontal ligament cells (HPDLCs) in vitro, compared with a methacrylate resin–based sealer Epiphany SE sealer (EP).
Methodology Human periodontal ligament cells were obtained from of healthy third molar teeth of two participants with informed consent. To determine the effects of the eluent from set resin sealers on HPDLCs, the 7‐day‐washed (washed) or non‐washed freshly prepared (fresh) set SB or EP discs were prepared. Cells cultured on these discs were evaluated by the WST‐1 proliferation assay and scanning electron microscopy (SEM). The osteogenic differentiation of HPDLCs on washed SB discs was then evaluated by gene expression analysis of osteopontin (OPN) and osteocalcin (OCN) by using quantitative RT‐PCR.
Results Human periodontal ligament cells exhibited growth on washed SB discs, whereas fresh SB and EP discs and washed EP discs inhibited proliferation of HPDLCs. SEM observation revealed that HPDLCs tightly attached and spread on the surface of washed SB discs, whilst no HPDLCs were observed on the surface of fresh and washed EP discs. Furthermore, HPDLCs significantly upregulated gene expressions of OPN and OCN when cultured on washed SB discs in osteogenic differentiation medium for 2 weeks.
Conclusions Although Superbond sealer initially exerted cytotoxic effects on HPDLCs, these effects were reduced during washing for 7 days compared to EP, which continued to be cytotoxic even though the specimens were washed for the same period of time. Washed Superbond allowed HPDLCs to differentiate into osteogenic cells.
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