Effect of the applied magnetic field on formation of complex polyaniline films

Formation of complex polyaniline (PANI) films with diamagnetic TCNQ and paramagnetic metal ion impurities cast under applied magnetic field was studied. It has been found that the applied magnetic field affects interaction of PANI chains with the impurities and induces formation of magnetically ordered regions in the complex film doped by paramagnetic metal ions in contrast to the reference film of the same composition but prepared under ambient conditions. The magnetically ordered regions have been observed directly by scanning magnetic force microscopy. It was found a correlation in distribution of the magnetically ordered regions and peculiarities of the surface relief of a film. Electronic absorption spectra and conductivity measurements showed that an applied stationary magnetic field can suppress the interaction of PANI chains and paramagnetic metal ions and lowers conductivity of the resulting complex film up to one order of magnitude as compared with the reference film. An alternating magnetic field was found to improve interaction of PANI and diamagnetic TCNQ molecules. The mechanisms of the magnetic field influence on the complex film formation are discussed.Comment: 15 pages, 10 figure

Borophosphosilicate glass component analysis using secondary neutral mass spectrometry

In the present study the SNMS technique for the quantitative component analysis of the borophosphosilicate glass layers was used. These layers were deposited on the silicon substrate by chemical vapor deposition method. The charge-up of the surface is compensated by plasma gas electrons in the high frequency mode sputtering. It is shown that modes of such sputtering significantly influence on the macro- and microrelief of the crater during the process of the depth component distribution analysis. An on-off time ratio change of the voltage applied to the sample results in changing the crater shape. At the same time the increase of the sputtering frequency results in appearance of thin protrusions at the crater bottom. Improvement of the depth resolution requires optimization both on-off time ratio and frequency of voltage applied to the sample

Ferromagnetism in Co-doped ZnO films grown by molecular beam epitaxy: magnetic, electrical and microstructural studies

We studied structural, optical and magnetic properties of high-quality 5 and 15% Co-doped ZnO films grown by plasma-assisted molecular beam epitaxy (MBE) on (0001)-sapphire substrates. Magnetic force microscopy (MFM) and magnetic measurements with SQUID magnetometer show clear ferromagnetic behavior of the films up to room temperature whereas they are antiferromagnetic below 200 K approximately. Temperature dependence of the carrier mobility was determined using Raman line shape analysis of the longitudinal-optical-phonon-plasmon coupled modes. It shows that the microscopic mechanism for ferromagnetic ordering is coupling mediated by free electrons between spins of Co atoms. These results bring insight into a subtle interplay between charge carriers and magnetism in MBE-grown Zn(1-x)CoxO films.Comment: 10 pages, 9 figures, 2 table

Surgical treatment of combined biliary and vascular injury following cholecystectomy

Institutul Naţional de Chirurgie şi Transplantologie “A.Shalimov”, Kiev, Ucraina, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Leziunile combinate ale vaselor şi căilor biliare extrahepatice reprezintă una dintre cele mai serioase complicaţii după colecistectomie. Efectuarea rezecţiei sau transplantului hepatic a fost necesară la 13,2-57,0% dintre pacienţii cu leziuni bilio-vasculare combinate (LBV).Materiale şi metode: Au fost incluşi 31 pacienţi cu LBV după colecistectomie în perioada ianuarie 1984 - ianuarie 2015. La 21 (67,7%) pacienţi leziunile au apărut după colecistectomia deschisă, la 10 (32,3%) – după cea laparoscopică. Intraoperator au fost înregistrate 6 (19,4%) leziuni ale ducturilor biliare. În perioada postoperatorie precoce (pînă la 7 zile) prezenţa unei stenoze de ramură a arterei hepatice este stabilită la 4 (12,9%) pacienţi, în perioada tardivă (8 zile – 3 ani) – la 21 (67,7%). În 5 (16,1%) cazuri a fost înregistrată stenoza arterei hepatice comune, în 24 (77,4%) – a ramurii drepte şi în 2 (6,5%) – a ramurii stîngi. Rezultate: La 2 pacienţi s-au efectuat tentative de restabilire a stenozei arteriale. Datorită dezvoltării colateralelor arterei hepatice comune 19 pacienţi au reluat fluxul hepatic arterial şi au suportat numai hepaticojejunoanastomoză. În 2 cazuri preventiv s-a efectuat embolizarea anevrismului arterei hepatice. Rezecţia de ficat s-a efectuat la 9 (29,0%) pacienţi. La 16 pacienţi cu LBV s-a dezvoltat necroza ficatului cu abcese. Concluzii: Rezultate pozitive în termen de 10 ani sunt înregistrate la 27 (86,2%) bolnavi, rezultate nesatisfăcătoare – la 4 (13,8%), un pacient a decedat. Astfel, pacienţii cu LBV combinate necesită tratament multimodal ţinînd cont de caracteristicile clinice actuale.Introduction: The combined damage of extra hepatic biliary ducts and vessels are the most serious complication of a cholecystectomy. Performance of the resection or liver transplantation was required 13.2-57.0% of patients with the combined biliovascular injury (BVI). Methods: 31 patients with the BVI after cholecystectomy, from January 1984 till January 2015. In 21 (67.7%) patients damage occured during open cholecystectomy, at 10 (32.3%) – laparoscopic. Intraoperatively injury of biliary duct is diagnosed in 6 (19.4%) cases. In the early postoperative period (to 7 days) existence of an occlusion of branches of the hepatic artery is established in 4 (12.9%) patients, in late (8 days-3 years) – in 21 (67.7%). In 5 (16.1%) cases the occlusion of the common hepatic artery, 24 (77.4%) – right brunch and 2 (6.5%) – left brunch was found. Results: Two patients had attempts of restoration of an arterial blood groove. Owing to hepatic artery collaterals development 19 patients resumed hepatic artery flow and underwent hepaticojejunostomy as a result only. In two cases it was preceded by embolization of hepatic artery aneurism. Liver resection is performed in 9 (29.0%) patients. At 16 patients with the BVI developed liver necrosis with abscesses. Conclusion: Positive results in terms to 10 years are received at 27 (86.2%), unsatisfactory – 4 (13.8%), one patient died. Thus, patients with the combined BVI need multimodal tactic of treatment taking into account features of their clinical current

Correlation between Crystallographic Alignment of Self-induced GaN Nanowires and Features of Si(111) Nitridation

Formation and spatial ordering of self-induced GaN nanowires grown by molecular beam epitaxy on a spatially pre-nitridazed Si(111) substrate have been studied. It was found the close correlation between Si substrate nitridation parameters and crystallographic alignment of NWs. Conditions for NWs nucleation and in- plane orientation are predefined by a structural anisotropy of silicon nitride nanolayer. Mechanism of NWs orderly emergence suggested. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3540

Особенности влияния условий роста на структурные и оптические свойства пленок Zn0.9Cd0.1O

The influence of the magnetron power and the gas ratio Ar/O2 on the microstructure and the optical properties of Zn0.9Cd0.1O films is studied. The films were deposited with the use of the dc magnetron sputtering technique at a temperature of 250 ◦C. Atomic force microscopy (AFM) and X-ray diffraction (XRD) researches of a surface morphology demonstrated a strong influence of deposition procedure parameters on the film microstructure. The XRD analysis revealed that all grown films were polycrystalline and single-phase. The increase of the gas ratio Ar/O2 was found to be beneficial for the crystalline structure of Zn0.9Cd0.1O ternary alloys. Peculiarities of the control over the band gap and the surface morphology for Zn0.9Cd0.1O ternary alloys by varying the growth parameters are discussed.Дослiджено вплив потужностi магнетрона i спiввiдношення тискiв робочих газiв Ar/O2 на мiкроструктуру та оптичнi властивостi плiвок Zn0.9Cd0.1O. Плiвки осаджено методом магнетронного розпилювання на постiйному струмi при температурi пiдкладки 250 C. Дослiдження морфологiї поверхнi, здійснені за допомогою атомно-силової мiкроскопiї (АСМ), i рентгено-фазовий аналiз (РФА) виявили сильний вплив технологічних параметрiв осадження на мiкроструктуру плiвок. РФА аналiз показав, що всi вирощенi плiвки є полiкристалiчними i однофазними. Встановлено, що зростання парцiального тиску аргону в газовiй сумiшi Ar/O2 сприятливо впливає на кристалічну структуру твердих розчинiв Zn0.9Cd0.1O. Обговорено особливостi контролю ширини забороненої зони та морфологiї поверхнi твердих розчинiв Zn0.9Cd0.1O шляхом змiни параметрiв вирощування.В работе исследовано влияние мощности магнетрона и соотношения давлений рабочих газов Ar/O2 на микроструктуру и оптические свойства пленок Zn0.9Cd0.1O. Пленки осаждены методом магнетронного распыления на постоянном токе при температуре подложки 250 C. Исследования морфологии поверхности, проведенные с помощью атомно-силовой микроскопии (АСМ), и рентгенофазовый анализ (РФА) выявили сильное влияние технологических параметров роста на микроструктуру пленок. РФА анализ показал, что все выращенные пленки являются поликристаллическими и однофазными. Было установлено, что рост парциального давления аргона в газовой смеси Ar/O2 благоприятно влияет на кристаллическую структуру твердых растворов Zn0;9Cd0;1O. Обсуждены особенности контроля ширины запрещенной зоны и морфологи поверхности твердых растворов Zn0;9Cd0;1O путем изменения параметров осаждени

Micropatterning in bistable cholesteric device with Bragg’s reflection

In this work, the method to form bistable patterning in a cholesteric cell with Bragg’s reflection in the visible spectral range is demonstratedyesBelgorod State Universit