Atomic and electronic structure of amorphous and crystalline hafnium oxide: X-ray photoelectron spectroscopy and density functional calculations

The atomic structure of amorphous and crystalline hafnium oxide ͑HfO 2 ͒ films was examined using x-ray diffractometry and Hf edge x-ray absorption spectroscopy. According to the x-ray photoelectron spectroscopy and band data calculated by the density functional method, we found that the valence band of HfO 2 consists of three subbands separated by ionic gaps. The upper subband is formed by O 2p, Hf 4f, and Hf 5d states; the intermediate subband is formed by O 2s and Hf 4f states, whereas the lower narrow subband is mainly formed by Hf 5p states. The energy gap of amorphous HfO 2 is 5.7 eV as determined by electron energy loss spectroscopy. The band calculation results indicate the existence of light ͑0.3m 0 ͒ and heavy ͑8.3m 0 ͒ holes in the HfO 2 film and the effective mass of electron lies in the interval of 0.7m 0 -2.0m 0

Jumps in Option Prices and Their Determinants: Real-Time Evidence from the E-Mini S&P 500 Option Market

We study the real-time characteristics and drivers of jumps in option prices. To this end, we employ high frequency data from the 24-hour E-mini S&P 500 options market. We find that option prices do not jump simultaneously across strikes and maturities and are uncorrelated with jumps in the underlying futures price. 14% to 28% of detected option price jumps occur around scheduled news releases. However, it is illiquidity rather than the news content that drives jumps. Evidence suggests that option traders increase bid-ask spreads to account for trading against investors who are skilled processors of public releases

Reactions of dl-homocystine and 3,3′-dithiodipropionic acid with Pd(II) in aqueous hydrochloric solutions. Part I: coordination model

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Stoichiometry of Pd(II) interactions with dl-homocystine and 3,3′-dithiodipropionic acid were investigated spectrophotometrically in strong hydrochloric acidic media. It was established that thiolate and sulfinate complexes are products of a disulfide bond cleavage. It is shown that formation of S,S′-binuclear complexes is necessary for the disproportionation reaction. A multi-spectroscopic (UV-Vis, Raman, NMR, EXAFS) investigation on a disulfide bond state in organic disulfides in complexation processes with Pd(II) was developed. A DFT study on geometry of forming complex species was performed

Extension of the Combustion Stability Range in Dry Low NO x Lean Premixed Gas Turbine Combustor Using a Fuel Rich Annular Pilot Burner

The present work is concerned with improving combustion stability in lean premixed (LP) gas turbine combustors by injecting free radicals into the combustion zone. The work is a joint experimental and numerical effort aimed at investigating the feasibility of incorporating a circumferential pilot combustor, which operates under rich conditions and directs its radicals enriched exhaust gases into the main combustion zone as the means for stabilization. The investigation includes the development of a chemical reactors network (CRN) model that is based on perfectly stirred reactors modules and on preliminary CFD analysis as well as on testing the method on an experimental model under laboratory conditions. The study is based on the hypothesis that under lean combustion conditions, combustion instability is linked to local extinctions of the flame and consequently, there is a direct correlation between the limiting conditions affecting combustion instability and the lean blowout (LBO) limit of the flame. The experimental results demonstrated the potential reduction of the combustion chamber's LBO limit while maintaining overall NO x emission concentration values within the typical range of low NO x burners and its delicate dependence on the equivalence ratio of the ring pilot flame. A similar result was revealed through the developed CHEMKIN-PRO CRN model that was applied to find the LBO limits of the combined pilot burner and main combustor system, while monitoring the associated emissions. Hence, both the CRN model, and the experimental results, indicate that the radicals enriched ring jet is effective at stabilizing the LP flame, while keeping the NO x emission level within the characteristic range of low NO x combustors

MASS IN THE RIGHT ATRIUM IMITATING A TUMOR IN BEHCET’S DISEASE

The objective is to describe a rare clinical case of Behcet’s disease with right atrium thrombosis and suspicion of a heart tumor.Materials and methods. Woman,  34 years old, in December of 2015 sought medical help at a local outpatient facility, and then from a gynecologist at the Central Clinical Hospital of Civil Aviation due to painful ulcers in the genital area and fever. Her state was considered a nonherpetic infection, antiviral therapy was administered. Ulcers in the oral cavity and genital area were first diagnosed in August of 2015. In April of 2016, aphthous stomatitis developed. The patient also complained of oral ulcers, fatigue, body temperature increase up to subfebrile values, slight shortness of breath during physical activity, discomfort in the upper part of the stomach. Ultrasound of the abdominal organs and heart had shown a mass resembling a thrombus in the hepatic vein and inferior vena cava which reached the right atrium. The size of the non-mobile mass in the atrium was 38 × 25 mm. The patient was hospitalized in a cardiological department.The following examinations were performed: standard laboratory tests, electrocardiogram, repeat ultrasound of the abdominal organs and heart, X-ray of the chest, oncocytomarker tests, magnetic resonance imaging (MRI),  spiral computed tomography (SCT) with contrast of the pelvic and abdominal organs.Subsequently, due to uncertain diagnosis the patient was consulted at the A.N. Bakoulev Scientific Center for Cardiovascular Surgery, N.N. Blokhin Russian Cancer Research Center, V.A. Nasonova Research Institute of Rheumatology.Results. Ultrasound of the heart and abdominal organs had shown a large mass in the inferior vena cava extending to the right atrium, which lead to a suspicion of a myxoma or thrombosis. After MRI of the heart and abdominal organs, an infectious thrombus in the heart and inferior vena cava was suggested. SCT with contrast of the pelvic and abdominal organs, oncocytomarker tests didn’t show any pathology. The combination of aphtous ulcers of the mouth and genitalia and inferior vena cava thrombosis allowed to suspect the Behcet’s disease. This diagnosis was confirmed at the V.A. Nasonova Research Institute of Rheumatology. Prescribed immunosuppressive therapy (meripred, azathioprine, colchicine), which is still ongoing, led to a decrease in inflammatory activity (С-reactive protein), reduction of the thrombus in the right atrium and inferior vena cava. Currently, the patient continues to receive the prescribed immunosuppressive therapy. No complaints, feeling healthy, working. The patient remains under the care of physicians.Conclusion. This clinical case demonstrates diagnostic complications of detection of masses in the heart which can represent a tumor or a thrombus. In the described case, diagnosis of the Behcet’s disease was facilitated by typical aphtous ulcers of the mucosa of the mouth and genitalia and development of vasculitis with subsequent thrombosis of the inferior vena cava and right atrium

Reactions of dl-homocystine and 3,3′-dithiodipropionic acid with Pd(II) in aqueous hydrochloric solutions. Part I: coordination model

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.Stoichiometry of Pd(II) interactions with dl-homocystine and 3,3′-dithiodipropionic acid were investigated spectrophotometrically in strong hydrochloric acidic media. It was established that thiolate and sulfinate complexes are products of a disulfide bond cleavage. It is shown that formation of S,S′-binuclear complexes is necessary for the disproportionation reaction. A multi-spectroscopic (UV-Vis, Raman, NMR, EXAFS) investigation on a disulfide bond state in organic disulfides in complexation processes with Pd(II) was developed. A DFT study on geometry of forming complex species was performed