Direct synthesized graphene-like film on SiO₂: Mechanical and optical properties

Exploiting CVD technique for carbon deposition from C₂H₂+H₂+N₂ mixture, a graphene-like film synthesized directly on SiO₂ surface of SiO₂-Si structure was obtained. The graphene-like film was grown under thin Ni layer that is easy exfoliated from graphene-SiO₂-Si structure. Surface of the film was sufficiently smooth and reveals no winkles and holes; it has a good homogeneity and perfect adhesion to SiO₂ layer. Studying the micro-Raman spectra showed a graphene-like structure of the film; using atomic force microscopic technique, the thickness of film was determined (0.6 nm). Using spectroscopic ellipsometry and simple Cauchy model enabled us to estimate optical parameters of this graphene-like film

Electrical and light-emitting properties of silicon dioxide co-implanted by carbon and silicon ions

In this paper we explore the electrophysical and electroluminescence (EL) properties of thermally grown 350 nm thick SiO₂ layers co-implanted with Si⁺ and C⁺ ions. The implanting fluencies were chosen in such a way that the peak concentration of excess Si and C of 5-10 at.% were achieved. Effect of hydrogen plasma treatment on electroluminescent and durability of SiO₂ (Si,C) - Si-system is studied. Combined measurements of charge trapping and EL intensity as a function of the injected charge and current have been carried out with the aim of clarifying the mechanisms of electroluminescence. EL was demonstrated to have defect-related nature. Cross sections of both electron traps and hole traps were determined. EL quenching at a great levels of injected charge is associated with strong negative charge capture, following capture of positive charge leading to electrical breakdown of SiO₂ structures

Electroluminescent properties of Tb-doped carbon-enriched silicon oxide

An electroluminescent device utilizing a heterostructure of amorphous terbium doped carbon-rich SiOx (a - SiOx : C : Tb) on silicon has been developed. The a - SiOx : C : Tb active layer was formed by RF magnetron sputtering of a - SiO₁₋x : Cx : H(:Tb) film followed by high-temperature oxidation. It was shown that, depending on the polarity of the applied voltage, the electroluminescence is either green or white, which can be attributed to different mechanisms of current transport through the oxide film – space charge limited bipolar double injection current for green electroluminescence and trap assisted tunneling or Fowler-Nordheim tunneling for white electroluminescence

Study of chemical properties combination chemical method of wastewater treatment by methods IR-spectroscopy and X-ray diffraction

Complex formation processes of sericin compounds with Ni2+, Cu2+, Zn2+, Co2+ salts were studied. The possibility of maximum extraction of sericin was determined when wastewater is purified by the proposed method, and the developed purification method is recommended for amino acid purification of wastewater. By using the coagulants Al2(SO4)3•18H2O and FeCl3•6H2O and flocculant PAA together with the proposed sorbent, the concentration of coagulants in wastewater is 0.75 mg/l, 0.5 mg/l, 0.5 mg/l, and the amount of kaolin bentonite, respectively. An acceptable content of 2.0 g/l has been suggested. When the composition of the dry residue obtained after treatment with a composition consisting of bentonite, kaolin and aluminum sulfate was analyzed using X-ray structural analysis, it was found that the residue contained crystal spheres. The obtained results proved that the diffract grams of dry residue and bentonite samples are almost identical. It was found out in the research that these crystal spheres belong to the mineral contained in bentonite

Physico-chemical properties of calendula flower extract in bitter almond oil elemental composition and microbiological purity

The study used bitter almonds (Amygdalus communis L. Varietas amara D.C.) obtained by cold pressing medicinal nails grown in Navoi region using oil (Calendula officinalis L.) - with the participation of flowers, the extraction process was carried out by maceration (in a ratio of 1:10). The resulting oil extract was studied by its elemental composition, chromatographic analysis of its fatty acids, microbiological purity, chemical and physical constants

Investigation of abnormal absorption of cosmic-ray hadrons in lead calorimeters

A phenomenon of abnormally weak absorption of very high energy cosmic ray hadrons in thick lead blocks is discussed. This phenomenon was first observed in a Tien Shan high altitude experiment to study hadronic cores of extensive air showers (EAS) with a deep ionization calorimeter and encouraged researchers to introduce the hypothesis of the so-called long-flying or penetrating cosmic ray component. A similar effect was detected later with deep uniform lead X-ray emulsion chambers (XREC) at the Pamirs, which we discuss in detail. To establish the nature of the phenomenon we are have carried out dedicated experiments at the Tien Shan and at the Pamirs by exposing two-storey XRECs with large air gaps. According to detailed simulation of the chamber response, these experiments are very sensitive to the production of charmed hadrons in the forward kinematic region and can prove a hypothesis that the phenomenon under study can be explained on the assumption of very high values of charm particle production cross section at 〈ELab〉 ~ 75 TeV in the forward kinematic region at xLab ≳ 0.1 which are near the upper limit of recent results of collider experiments, i.e., σpp→c¯c ~ 8 mb. The same factor makes it possible to fit all the features of the experimental hadron absorption curve observed by means of deep uniform lead XRECs, including its bending at a depth of ~ 70 c.u

Investigation of abnormal absorption of cosmic-ray hadrons in lead calorimeters

A phenomenon of abnormally weak absorption of very high energy cosmic ray hadrons in thick lead blocks is discussed. This phenomenon was first observed in a Tien Shan high altitude experiment to study hadronic cores of extensive air showers (EAS) with a deep ionization calorimeter and encouraged researchers to introduce the hypothesis of the so-called long-flying or penetrating cosmic ray component. A similar effect was detected later with deep uniform lead X-ray emulsion chambers (XREC) at the Pamirs, which we discuss in detail. To establish the nature of the phenomenon we are have carried out dedicated experiments at the Tien Shan and at the Pamirs by exposing two-storey XRECs with large air gaps. According to detailed simulation of the chamber response, these experiments are very sensitive to the production of charmed hadrons in the forward kinematic region and can prove a hypothesis that the phenomenon under study can be explained on the assumption of very high values of charm particle production cross section at 〈ELab〉 ~ 75 TeV in the forward kinematic region at xLab ≳ 0.1 which are near the upper limit of recent results of collider experiments, i.e., σpp→c¯c ~ 8 mb. The same factor makes it possible to fit all the features of the experimental hadron absorption curve observed by means of deep uniform lead XRECs, including its bending at a depth of ~ 70 c.u