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[en] The purification, crystallization and preliminary X-ray structure analysis of the laccase from G. lucidum are reported. The ligninolytic enzymes of the basidiomycetes play a key role in the global carbon cycle. A characteristic property of these enzymes is their broad substrate specificity, which has led to their use in various biotechnologies, thus stimulating research into the three-dimensional structures of ligninolytic enzymes. This paper presents the purification, crystallization and preliminary X-ray analysis of the laccase from the ligninolytic basidiomycete Ganoderma lucidum
[en] This review summarizes the key topics in the field of large-area fabrication of superhydrophobic surfaces, concentrating on substrates that have been used in commercial applications. Practical approaches to superhydrophobic surface construction and hydrophobization are discussed. Applications of superhydrophobic surfaces are described and future trends in superhydrophobic surfaces are predicted. (topical review)
[en] An overview of the various types of litography is presented and discussed (optical, X-rays, electron beam, ion beam etc.). (A.C.A.S.)
[pt]Apresenta-se uma revisao e discute-se os varios tipos de litografia (otica, raios-X, feixes de eletrons, feixes de ions etc.). (A.C.A.S.)
[en] The highly conserved domain of unknown function in the cyanobactin superfamily has a novel fold. The protein does not appear to bind the most plausible substrates, leaving questions as to its role. Patellamides are members of the cyanobactin family of ribosomally synthesized and post-translationally modified cyclic peptide natural products, many of which, including some patellamides, are biologically active. A detailed mechanistic understanding of the biosynthetic pathway would enable the construction of a biotechnological ‘toolkit’ to make novel analogues of patellamides that are not found in nature. All but two of the protein domains involved in patellamide biosynthesis have been characterized. The two domains of unknown function (DUFs) are homologous to each other and are found at the C-termini of the multi-domain proteins PatA and PatG. The domain sequence is found in all cyanobactin-biosynthetic pathways characterized to date, implying a functional role in cyanobactin biosynthesis. Here, the crystal structure of the PatG DUF domain is reported and its binding interactions with plausible substrates are investigated
[en] This article deals with the assembly of SMD chip components onto a flexible substrate by using non-conductive adhesives. In the experiments, two electrically conductive adhesives (ECA) and two non-conductive adhesives (NCA) were used. The verification of the properties and usability of NCAs for connecting the components to the flexible substrates as an alternative for ECA was the main goal of the experiment. The results show that NCAs can be used as an alternative for ECAs and that the properties and reliability of NCA joints are comparable or better than ECA joints. The results also show that UV-curable NCAs can be recommended for the applications of attaching the components on flexible substrates, especially for the prototypes, where the application of the UV adhesive and the connection of components by this technology is much easier and faster than with ECA.
[en] Small drops sliding down a partially wetting substrate bifurcate between different shapes depending on their capillary number Ca . At low Ca , they are delimited by a rounded, smooth contact line. At intermediate values they develop a corner at the trailing edge, the angle of which evolves from flat to 60o with increasing velocity. Further up, they exhibit a cusped tail that emits smaller drops (''pearls''). These bifurcations may be qualitatively and quantitatively recovered by considering the dynamic contact angle along the contact line
[en] Highlights: → The thickness of the compound layer increases with increasing in temperature and groove width. → Surface layer at the remote regions from the edge is thinner than that of closer regions. → The hardness and the case depth of the nitrided layer increase with increasing the width of the groove. → Intensity of ε phase increases with increasing the width of the groove in both methods. → The ASPN specimens are covered by hexagonal particles and for the CPN by cauliflower shape nitrides. -- Abstract: The main aim of this work was to investigate the effect of the sample geometry on properties of the conventional plasma nitrided (CPN) and active screen plasma nitrided (ASPN) steel. Sample assemblies consisting of rectangular grooved steel blocks with different groove dimensions of 2, 4, 6, 8 and 10 (W) x 40 (H) x 20 (L) mm3 and AISI 4340 steel plates (substrates) with dimensions of 10 x 40 x 60 mm3, to serve as groove cover, were prepared. The sample assemblies were conventional and active screen plasma nitrided under the gas mixture of 75%N2 + 25%H2, at temperatures of 500 oC and 540 oC, pressure of 4 torr, for 5 h. Properties of the nitrided substrates were investigated by evaluating compound layer thickness, case depth, phase composition and hardness profile. Results of the experiments showed that the thickness of the compound layer, hardness and nitrided case depth increased with increasing the width of the groove for both methods. Also, in each sample, nitrogen atoms penetrated more deeply in the regions of the groove closer to the edge. Hallow cathode effect occurred at the sample with 2 mm width groove, in the CPN method, leading to the overheating of the sample. In ASPN, the hardness and the nitrided case depth are lower in comparison with CPN. The surface morphology of the CPN treated samples consists of cauliflower shape surface nitrides while the surface of the AS plasma nitrided samples are covered by the hexagonal particles with uniform distribution.
[en] Highlights: •IMC growth at the SAC/Cu–xZn solder interfaces strongly depends on the Zn concentration. •IMC morphology changed from scallop to layered type at the SAC/Cu–xZn–yNi interface. •Neither Cu3Sn nor microvoids was formed on both Cu–xZn and Cu–xZn–yNi substrates. •Zn-rich layer at the IMC/Cu–xZn or IMC/Cu–xZn–yNi was effective in suppressing the IMC growth. •IMC growth behavior is controlled by the Zn rather than Ni content in the Cu–xZn–yNi substrates. -- Abstract: The interfacial reactions of Sn–3.0Ag–0.5Cu (SAC 305) solder on Cu–xZn (x = 0 wt%, 10 wt%, 15 wt%, 30 wt%, and 35 wt%) substrates and Cu–xZn–yNi (x = 20 wt% and 25 wt%, y = 10 wt% and 15 wt%) were investigated after soldering and isothermal aging. SAC 305 solder was reacted with Cu–xZn and Cu–xZn–yNi substrates by dipping Cu–xZn or Cu–xZn–yNi wires into molten solder at 250 °C for 90 s. After soldering, Cu6Sn5-based intermetallic compound (IMC) formed at the solder interfaces. After aging at 150 °C, a bi-layer structure of Cu6Sn5/Cu3Sn formed, and microvoids were observed in the Cu3Sn layer at the SAC/Cu solder interfaces. For SAC/Cu–Zn samples, Cu6(Sn, Zn)5 was the predominant reaction product, and formation of Cu3Sn was not observed. Interfacial IMC growth was delayed as the Zn concentration increased. In addition, the Cu(Zn, Sn) phase formed at the Cu6(Sn, Zn)5/Cu–Zn interfaces in the Cu–xZn substrates with a high Zn concentration (30 wt% and 35 wt%). In the case of the Cu–xZn–yNi samples, the major interfacial IMC was (Cu, Ni)6(Sn, Zn)5 phase. The Ni atoms from the Cu–xZn–Ni substrates participated in the interfacial reaction at the SAC/Cu–xZn–yNi interfaces and resulting in the formation of a thick and layered IMC phase, comparing to those at the SAC/Cu–Zn interfaces. Although the effect of Ni addition to the Cu–Zn substrates exhibited delayed IMC growth, the Zn concentration in the Cu–xZn–yNi substrates influenced the IMC growth behavior more than the Ni concentration