A novel, nonreversible surface relief (SR) system was developed using polymerizable low‐molecular‐weight compounds containing two or three ...(E)‐3‐4‐(6‐methyl‐2,4‐dihydro‐1,3‐benzoxazin‐3‐yl)phenylprop‐2‐enoyloxy units in which photoreactive cinnamate moieties and thermally curable benzoxazine moieties are included. The SR structure formation was conducted using thin films (thickness: 1.5 μm) on silicon wafers through a two‐step procedure including micropatterned ultraviolet irradiation at 23°C and then heating to induce the SR pattern formation. All of the four compounds synthesized in this study showed submicron‐height SR structure on their films. After being thermally treated at 200°C for 1 h, the thin films became insoluble, which ensured the formation of crosslinked network structures. The obtained nonreversible SR system is expected to be a candidate for microfluidic channel materials for cooling semiconductor chips as well as an alternative option for photolithography.
Ni‐base alloys has been widely used for chemical plants because of their high strength and excellent oxidation resistance. In particular, the addition of Sn and Sb in Ni‐base alloys significantly ...improves the metal dusting resistance. It is indicated that Sn and Sb are segregated on the alloy surface in the metal dusting environment; however, the details have not been clarified yet. The behavior of the Ni‐Sn and Ni‐Sb alloys under a high‐temperature oxidation environment was investigated by in situ X‐ray photoelectron spectroscopy (XPS). It was confirmed that Sn and Sb have been segregated at the surface of their alloys during oxidation in low oxygen potential, PO2, environment. These results indicate that Sn and Sb segregation improves the metal dusting resistance.
Electrochemical ellipso-microscopy was combined with the channel flow triple electrode method to evaluate the active-passive transition behavior of Fe-6 mass% Cr in acidic sodium sulfate solutions ...under the control of mass-transport reaction. During potentiodynamic polarization of the Fe-6 mass% Cr specimen electrode (SE), the SE surface was monitored by ellipso-microscopy and generated Fe(II) and Cr(III) species from the SE were detected at two detector electrodes arranged downstream in parallel. Forced convection of the electrolyte solution affected the mass-transport process of Cr(III) species on the SE surface in the latter half of the active region. In addition, the electrolyte solution flow resulted in enhancement of the passivation process and Cr enrichment on the passive surface. The effects of the electrolyte solution flow on active-passive transition and improvement of the passive film resistance are discussed.
Previously, we had developed a new negative-type phenolic polymer-based photosensitive resin composition ROD-100, patternable by photolithography and having low coefficient of thermal expansion ...(CTE), low residual stress, and high heat resistance after thermally treated at 260 ℃. We had confirmed an interesting phenomenon in which the phenolic resin itself, without crosslinking agents and photochemical acid generators, had showed further lower CTE and residual stress than ROD-100. In the current study, to study the applicability of the phenolic resin as a semiconductor packaging insulating material, we utilized laser ablation to examine the pattern formation on thin films of the phenolic resin as well as investigated the effects of the heat-treatment temperature and the addition of crosslinking agents on the residual stress and the chemical resistance. The combination of laser ablation and desmear treatment resulted in successful pattern formation. This material is a good candidate as an insulating material for fan-out wafer-level packaging (FO-WLP).
Carbon steels are widely used as infrastructure components owing to their high strength, ductility, and weldability. However, as corrosion degrades critical infrastructure components, exploring the ...relationship between the microstructure and corrosion resistance of carbon steel is of particular interest in engineering. To analyze this relationship, it is first essential to evaluate the corrosion resistance of each microstructure in a carbon steel specimen with a single chemical composition to eliminate the effects of alloying elements. In this study, we compared the pitting corrosion resistance of four microstructures (water‐quenched martensite, tempered martensite, bainite and degenerate pearlite, and ferrite–pearlite) of an AISI 1045 medium‐carbon steel. The pitting corrosion resistances of the microstructures in near‐neutral pH solutions containing NaCl were ordered as follows: (high) water‐quenched martensite > bainite and degenerate pearlite > tempered martensite > ferrite–pearlite (low). Elucidating the effect of the microstructure on the pitting corrosion resistance may contribute to the development of corrosion‐resistant carbon steels with excellent mechanical properties.
This paper reports the pitting corrosion resistance of four types of microstructures (water‐quenched martensite, tempered martensite, bainite and degenerate pearlite, and ferrite–pearlite) in AISI 1045 medium‐carbon steel. The pitting corrosion resistances of the microstructures in near‐neutral pH solutions containing chloride ions are ordered as follows: (high) water‐quenched martensite > bainite and degenerate pearlite > tempered martensite > ferrite–pearlite (low).
In a molten zinc bath in a continuous galvanizing line, the top dross particles crystallize as a Zn-containing intermetallic Fe2Al5 compound, which generates surface defects in the final product by ...easily adhering to the steel sheets. The present study focused on analysis of the crystal structure of a top dross by first principles calculation and synchrotron X-ray diffraction of the top dross prepared in a laboratory. The following results were obtained: first principles calculation on the top dross suggested that two Al atoms at four of the partially occupied Al sites in the Fe2Al5 structure proposed by Mihalkovič et al., were replaced by two Zn atoms. In addition, the Al atoms at both the types of partially occupied Al sites in Fe2Al5 proposed by Burkhardt et al., were equally replaced by Zn atoms. The proposed crystal structure of the top dross was verified by conducting X-ray diffraction profile analysis using RIETAN-FP simulations as well as the experimentally determined lattice constant of the Zn-containing top dross.
The initiation site and morphology during the early stage of pitting on AISI 1045 carbon steel that has a microstructure of primary ferrite and pearlite were investigated in boric-borate buffer ...solutions with and without NaCl at pH 8.0. The pits initiated by micro-scale polarization were in the pearlite only and not in primary ferrite. In situ real-time observations during the micro-scale polarization of pearlite in a boric-borate buffer solution with 100 mM NaCl indicated that the pits were polygonal or rod-like in shape. In addition, it was found that the pit growth direction was the same as that of the pearlite lamellae that consisted of ferrite and cementite. Field-emission electron probe micro analysis detected segregated points of sulfur in the ferrite lamellae. On the basis of their etching behavior in 3% nital, the corrosion resistance of the cementite was estimated to be higher than that of the ferrite lamellar structure. Thus, pits readily initiated in the ferrite lamellae and proceeded along the ferrite lamellae.
Congenital diaphragmatic hernia (CDH) is a relatively common and life-threatening birth defect, characterized by incomplete formation of the diaphragm. Because CDH herniation occurs at the same time ...as preacinar airway branching, normal lung development becomes severely disrupted, resulting almost invariably in pulmonary hypoplasia. Despite various research efforts over the past decades, the pathogenesis of CDH and associated lung hypoplasia remains poorly understood. With the advent of molecular techniques, transgenic animal models of CDH have generated a large number of candidate genes, thus providing a novel basis for future research and treatment. This review article offers a comprehensive overview of genes and signaling pathways implicated in CDH etiology, whilst also discussing strengths and limitations of transgenic animal models in relation to the human condition.
The early stage of electrochemically-induced Fe(001) passivation is investigated via a sub-second resolution real-time X-ray reflectivity technique. Static measurements clearly demonstrate that the ...passive layer is composed of two distinct layers comprising a dense inner oxide layer and a loosely packed outer layer. The growth of the inner passive layer is mostly completed within 1 s, while the growth rate in the later process is much slower and is qualitatively consistent with typical growth models such as the high-field model and point defect model. The rate-determining mechanism in the early stage is clearly different from that in the later stage.
The pitting corrosion resistance of AISI 1045 carbon steel with as-quenched, tempered, and low-carbon martensitic microstructures was investigated in boric-borate buffer solutions with and without ...NaCl. Analysis by micro-scale polarization found that tempering and decarburizing treatments decreased the pitting corrosion resistance of as-quenched martensite. The high corrosion resistance of the as-quenched martensite was likely due to the large amount of interstitial carbon. The pitting corrosion resistances of as-quenched martensite, primary ferrite, and pearlite were compared using micro-scale polarization measurements. It was determined that the pitting corrosion resistances of the typical steel structures were ordered as follows: (high) as-quenched martensite > tempered martensite ≈ primary ferrite > pearlite (low). The pitting corrosion resistance of steel was shown to depend on its microstructure.
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