Wyniki wyszukiwania - Biblioteka Nauki

Ten serwis zostanie wyłączony 2025-02-11.

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 4

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Spectroscopic and Polarographic Studies of Novel Imidazole Adduct of Ammonium Trioxovanadate(V). A Solution and Solid State Study

100%

Çakir S. , Biçer E. , Naumov P. , Çakir O.

2001

tom Vol. 75, nr 2

209-214

Complex formation between ammonium trioxovanadate(V) and imidazole has been studied and characterized by FT IR, UV/Vis, thermal analysis (TG, DTA, DTG) and polarographic techniques. Species formed in solid phase yield a yellow coloured product exhibiting an absorbance maximum at 400 nm. The FT IR spectra show that the inclusion of imidazole has a significant influence on the structure and the hydrogen bonding pattern inNH4VO3. Species formed in aqueous solution has been examined by voltammetry. Formation of an adduct of trioxovanadate(V) with imidazole onto dropping mercury electrode followed by reduction of the sample in DCP of the complex in 0.05 M NH3/NH4Cl buffer (pH 9.08) resulted in a single peak at -0.875 V.

Chemical machining

100%

Çakir O. , Yardimeden A. , Özben T.

Archives of Materials Science and Engineering

2007

tom Vol. 28, nr 8

499-502

Purpose: Nontraditional machining processes are widely used to manufacture geometrically complex and precision parts for aerospace, electronics and automotive industries. There are different geometrically designed parts, such as deep internal cavities, miniaturized microelectronics and fine quality components may only be produced by nontraditional machining processes. This paper is aiming to give details of chemical machining process, industrial applications, applied chemical etchants and machined materials. Advantages and disadvantages of the chemical machining are mentioned. Design/methodology/approach: In this study, chemical machining process was described its importance as nontraditional machining process. The steps of process were discussed in detail. The tolerances of machined parts were examined. Findings: Paper describes the chemical machining process, industrial applications, applied chemical etchants and machined materials. Practical implications: The machining operation should be carried out carefully to produce a desired geometry. Environmental laws have important effects when chemical machining is used. Originality/value: The importance of nontraditional machining processes is very high.

Voltammetric and Spectroscopic Behaviour of the Copper Adducts of Thiol and Thioether Ligands under Aerobic and Anaerobic Conditions

88%

Çakir S. , Biçer E. , Coşkun E. , Naumov P. , Çakir O.

2002

tom Vol. 76 / nr 5

663-669

Joint spectroscopic (ESR, electronic absorption and FT IR) and voltammetric (squarewave and cyclic voltammetry) techniques were employed to investigate the properties of copper adducts with cysteine, N-acetylcysteine and methionine under aerobic and anaerobic conditions. The metal oxidation state in the solid and solvated adducts adheres to the presence of oxygen, whereas ESR results (g__ = 2.245, g_ = 2.059,A__= 170 Gauss) reveal tetragonally distorted octahedral copper(II) environment under aerobic circumstances. In presence of the thiol and thioether ligands under nitrogen voltammetric measurements evidence formation of copper(I) species.

Synthesis and Spectroscopic Studies of the Nicotinamide Adducts of Cobalt(II), Nickel(II) and Zinc(II) Chlorides

75%

Çakir S. , Biçer E. , Içbudak H. , Naumov P. , Korkmaz H. , Çakir O.

2001

tom Vol. 75, nr 3

371-377

Nicotinamide (na) adducts of Co(II), Ni(II) and Zn(II) chlorides are synthesized and characterized by thermoanalytical methods (TG, DTG, DTA), FT IR (4000-400 cm-1) and UV/Vis spectroscopy. Structural similarity is inferred between the octahedral Co and Ni compounds of type [M(na)2(H2O)4]Cl2. The tetrahedral Zn complex [Zn(na)2Cl2] presents a different structure. The coordination of the metal ions in the Co and Ni adducts modelled by semiempirical theoretical methods compares well with the structural data for [Ni(na)2(H2O)4](NO3)2_2H2O.