The results of studies on the development technological methods for formation low-resistivity contact systems to n- and p-SiC based single multilayer Ni-, Al- Ti-compositions 4H-SiC bipolar devices are presented. It is shown that contacts Ni n-4H-SiC (rho c =3.6·10 -4 Ohm·cm 2 ) Ni/Al p-4H-SiC =5.9·10 -5 possible within a cycle vacuum annealing at 1000 o C 120 s. This solution makes it reduce n...

Printed circuit boards (PCBs) are the main components of electrical and electronic equipment (EEE). Waste PCBs contain several kinds of heavy metals, including Cu, Pb and Zn. We characterize the leaching of heavy metals (Cu, Pb, Zn and Ni) from waste PCBs in a pH range of 3.0 to 5.6 using a novel approach based on batch pH-static leaching experiments in this work. The results indicate that the ...

Štúdium viazania stopových prvkov v sedimente vodnej nádrže Ružín Pre účely posúdenia možnosti využitia fyzikálnych a fyzikálno-chemických metód separácie, vybraná vzorka sedimentu z Ružína bola podrobené 5-stupňovej procedúre sekvenčnej extrakcie (SE) podľa Tessiera (Tessier et al., 1979) a Horowitza (Horowitz, 1991). Vo výluhoch bolo stanovované zastúpenie konštitučných (Fe, Mn, Ca a Mg) ako ...

We report the synthesis and magnetic characterisation of a series of planar [M₇] (M= Ni(II), Zn(II)) disc complexes [Ni₇(OH)₆(L₁)₆](NO₃)₂ (1), [Ni₇(OH)₆(L₁)₆](NO₃)₂·2MeOH (2), [Ni₇(OH)₆(L₁)₆](NO₃)₂·3MeNO₂ (3), [Ni₇(OH)₆(L₂)₆](NO₃)₂·2MeCN (4), [Zn₇(OH)₆(L₁)₆](NO₃)₂·2MeOH·H₂O (5) and [Zn₇(OH)₆(L₁)₆](NO₃)₂·3MeNO₂ (6) (where HL₁ = 2-iminomethyl-6-methoxy-phenol, HL₂ = 2-iminomethyl-4-bromo-6-methox...

Bu çalışmada akım sinterleme yöntemi ile üretilen Çinko (% 73 Zn)-Alüminyum 27 Al) alaşımlarına Silisyum Karbür (SiC) ve Grafit(Gr) katkısının sıcaklık değişimleri karşısındaki boyutsal kararlılığa etkileri incelenmiştir. Ayrıca değişimlerinin mikroyapı mekanik özelliklere etkileride gözlemlenmiştir. Mekanik alaşımlama ağırlıkça % Zn- 27Al orana sahip, alaşıma %13 (hacimce %20) SiC farklı oranl...

The ability of water hyacinth ( Eichhornia crassipes Mart. Solms.) to absorb and translocate cadmium (Cd), lead (Pb), copper (Cu), zinc (Zn), and nickel (Ni) was studied in the Erh-Chung wetlands. Translocation ability was defined as the quantity of Cu, Pb, Cd, Ni, and Zn translocated in the plant’s tissues, and was expressed as a root/shoot ratio. The ratio results were in the order of Cu>Pb>C...

The objective of this study was to determine if exposure to divalent cations, Cd(2+), Ni(2+), and Co(2+) would lead to malformations in Xenopus laevis embryos, and whether addition of Mg(2+) and Zn(2+); separately and in combination, would reduce their toxicity and teratogenicity on the embryos of Xenopus laevis as assessed by 96-h FETAX tests. Results indicate that exposure to Cd(2+), Ni(2+) o...

In this study, interfacial reactions of electrolytic Ni and electroless Ni(P) metallization of the ball-grid-array (BGA) substrate with the molten n–9Zn (wt.%) eutectic solder alloy were investigated, focusing on the shear strengths and the identification of the intermetallic compound IMC) phases at various reflow periods. Zn-containing Pb-free solder alloys were kept in molten condition (240 ◦...

Pheophorbide a was prepared from a mixture o f chlorophylls a and b by differential extrac­ tion with HC1 and saponification. The insertion o f the following metal ions was investigated: Mg, Zn, Co, Cu, Ni. In the enzyme test with chlorophyll synthetase, the metallopheophorbides fall into two categories: the Mgand Zn-complexes are good substrates, the Co-, Cuand Ni-complexes are neither substra...