Si:SrTiO3-Al2O3-Si:SrTiO3 multi-dielectric architecture for metal-insulator-metal capacitor applications

Metal-insulator-metal (MIM) capacitors comprised of amorphous Si:SrTiO3-Al2O3-Si:SrTiO3 multi-dielectric architecture have been fabricated employing a combination of pulsed laser and atomic layer deposition techniques. The voltage linearity, temperature coefficients of capacitance, dielectric and electrical properties upon thickness were studied under a wide range of temperature (200 – 400 K) and electric field stress (± 1.5 MV/cm). A high capacitance density of 31 fF/µm2, a low voltage coefficient of capacitance of 363 ppm/V2, a low temperature coefficient of capacitance of < 644 ppm/K and an effective dielectric constant of ~133 are demonstrated in a MIM capacitor with ~1.4 nm capacitance equivalent thickness in a ~40 nm thick ultra high-k multi-dielectric stack. All of these properties make this dielectric architecture of interest for next generation highly scaled MIM capacitor applications.PostprintPeer reviewe

Disorder driven structural and dielectric properties of silicon substituted strontium titanate

Financial support from NSF Grant No. NSF-RII-0701525 was acknowledged. S.D. is thankful to DOD for doctoral fellowship under Grant No. W911NF-11-1-0204. S.P.P. is grateful to NSF for financial assistance under Grant No: NSF-EFRI RESTOR # 1038272.A systematic study on structural, microstructural, optical, dielectric, and electrical properties of phase-pure silicon-modified SrTiO3 polycrystalline electroceramics synthesized using high energy solid state reaction techniques is presented. The asymmetry and splitting in the x-ray diffractometer spectra and the observation of first order transverse optical TO2 and longitudinal optical LO4 modes in Raman spectra (nominally forbidden) revealed the distortion in the cubic lattice as a result of breaking of inversion symmetry due to doping. A bandgap Eg of 3.27 eV was determined for the sample by diffuse reflectance spectroscopy. A high dielectric constant of -400 and very low dielectric loss of -0.03 were obtained at 100 kHz near ambient conditions. The temperature dependence of the dielectric data displayed features of high temperature relaxor ferroelectric behavior as evidence of existence of polar nano-regions. The ac conductivity as a function of frequency showed features typical of universal dynamic response and obeyed a power law σac = σdc+Aωn . The temperature dependent dc conductivity followed an Arrhenius relation with activation energy of 123 meV in the 200–500 K temperature range. The linear dielectric response of Pt/SrSi0.03Ti0.97O3/Pt dielectric capacitors was well characterized. The measured leakage current was exceptionally low, 13 nA/cm2 at 8.7 kV/cm, revealing an interface blocked bulk conduction mechanism.Publisher PDFPeer reviewe

Effects of whole body cryotherapy on serum mediators of inflammation and serum muscle enzymes in athletes

Whole-body cryotherapy (WBC) covers a wide range of therapeutic applications and consists of briefly exposing the body to extremely cold air. In sports medicine, WBC is used to improve recovery from muscle injury; however, empirical studies on its application to this area are lacking. To fill this gap, we compared changes in immunological parameters (C3, IgA, IgM, IgG, C-reactive protein, PGE2), cytokines (IL-2, IL-8, IL-10), adhesion molecules (sICAM-1), and muscle enzymes (creatine kinase [CK], lactate dehydrogenase [LAD]) before and after WBC in 10 top-level Italian National team rugby players. The subjects underwent five sessions on alternate days once daily for 1 week. During the study period, the training workload was the same as that of the previous weeks. Compared to baseline values, immunological parameters remained unchanged, while CK and LAD levels significantly decreased after treatment. No alterations in immunological function were observed but there is a decrease in pro-inflammatory cytokine/chemokine and an increase in anti-inflammatory cytokine. As measured by changes in serum CK and LAD concentrations, and cytokines pathway, short-term cold air exposure was found to improve recovery from exercise-induced muscle injury and/or damage associated with intense physical training

ÅTERANVÄNDA AOD-SLAGG I LJUSBÅGSUGNEN

Melting steel scrap and alloys in an electric arc furnace (EAF) is the first step in stainless steel production. Further processing of the liquid steel is then carrying out in an Argon Oxygen Decarburisation (AOD) converter. The main objective of the treatment in the AOD converter is to reduce the carbon content to a target value by injecting an oxygen-argon mixture. During this decarburisation step unavoidably some chromium and other alloying elements with high affinity to oxygen are oxidised and ends up in the slag. To obtain an acceptable yield of these alloying elements is necessary to reduce the slag in the AOD converter after the decarburisation with either aluminium or ferrosilicon. In the case of aluminium reduction, the final slag after reduction is generally composed of lime (CaO) and aluminium oxide (Al2O3). The denomination of the slag is Al-reduced AOD-slag and at the moment this has no practical use and is stored as landfill. Therefore, the slag ought to be recycled due to financial and environmental reasons. Within the present work, recirculation of Al-reduced AOD-slag to the EAF as slag former has been examined by theoretical analysis and practical trial using a small rotating kiln. The main aim of the thermodynamic calculations was to investigate how much of the Al-reduced AOD-slag is needed to reduce the activity of silicate in the slag and thereby depressing the loss of chromium to the slag. The second phase of the study was designed to investigate the effect of added Al-reduced AOD slag on refractory wear during trials in a rotary kiln. During these trials the kiln was lined with four different types of bricks, supplied by the three companies participating in this project – Vargön Alloys AB, Outokumpu Stainless AB Avesta and Sandvik Materials Technology. The thermodynamic calculations disclose that a significant decrease of the activity of SiO2 could be observed with only 5 weights per cent addition of Al-reduced AOD-slag. Furthermore, the result showed that 15 weight per cent of Al-reduced AOD-slag in the EAF slag can be recycled to the EAF without a large impact on the refractory material. Additionally, X-ray diffraction investigations of the Al-reduced AOD-slag showed that there was no metal contamination.Key words: AOD-slag, slag recycling, refractory wear, slag activities, EAF-slag.Validerat; 20151119 (global_studentproject_submitter

ÅTERANVÄNDA AOD-SLAGG I LJUSBÅGSUGNEN

Melting steel scrap and alloys in an electric arc furnace (EAF) is the first step in stainless steel production. Further processing of the liquid steel is then carrying out in an Argon Oxygen Decarburisation (AOD) converter. The main objective of the treatment in the AOD converter is to reduce the carbon content to a target value by injecting an oxygen-argon mixture. During this decarburisation step unavoidably some chromium and other alloying elements with high affinity to oxygen are oxidised and ends up in the slag. To obtain an acceptable yield of these alloying elements is necessary to reduce the slag in the AOD converter after the decarburisation with either aluminium or ferrosilicon. In the case of aluminium reduction, the final slag after reduction is generally composed of lime (CaO) and aluminium oxide (Al2O3). The denomination of the slag is Al-reduced AOD-slag and at the moment this has no practical use and is stored as landfill. Therefore, the slag ought to be recycled due to financial and environmental reasons. Within the present work, recirculation of Al-reduced AOD-slag to the EAF as slag former has been examined by theoretical analysis and practical trial using a small rotating kiln. The main aim of the thermodynamic calculations was to investigate how much of the Al-reduced AOD-slag is needed to reduce the activity of silicate in the slag and thereby depressing the loss of chromium to the slag. The second phase of the study was designed to investigate the effect of added Al-reduced AOD slag on refractory wear during trials in a rotary kiln. During these trials the kiln was lined with four different types of bricks, supplied by the three companies participating in this project – Vargön Alloys AB, Outokumpu Stainless AB Avesta and Sandvik Materials Technology. The thermodynamic calculations disclose that a significant decrease of the activity of SiO2 could be observed with only 5 weights per cent addition of Al-reduced AOD-slag. Furthermore, the result showed that 15 weight per cent of Al-reduced AOD-slag in the EAF slag can be recycled to the EAF without a large impact on the refractory material. Additionally, X-ray diffraction investigations of the Al-reduced AOD-slag showed that there was no metal contamination.Key words: AOD-slag, slag recycling, refractory wear, slag activities, EAF-slag.Validerat; 20151119 (global_studentproject_submitter

Quality changes of sardine (Sardine pilchardus W.,1792) during frozen storage

Bu çalışmada -18°C donmuş depoda bekletilmeden önce -40°C'de şoklanan bütün (Grup A) ve fileto (Grup B) halindeki sardalya balıklarının fiziksel, kimyasal mikrobiyolojik ve duyusal değişimleri belirlenmiştir, istatistik analiz sonuçlarına göre, iki grubun donmuş depolama esnasındaki TBA, FA (ex) ve FA (dest) değerleri arasında farklar önemli (P0.05) olarak saptanırken, iki grubun pH ve TVB-N değerleri arasında farklar önemsiz (P>0.05) olarak bulgulanmıştır. Grup A'nm toplam canlı sayısı donmuş depolama sonunda başlangıçtaki değerini korurken, Grup B'nin toplam canlı sayısı depolama esnasında azalma göstermiştir. Grup A ve Grup B'nin koliform bakteri sayısı depolama esnasında aşağı yukarı aynı değerlerde kalmasına karşın, depolama esnasında koagülaz-pozitif S. aureus saptanmamıştır. İki grup arasında renk, koku, kas yapısı ve tat özelikleri açısından farklar önemsiz (P>0.05) olarak bulgulanmıştır.In the present study, physical, chemical, microbiological and sensory changes of sardine as whole (Group A) and fillet (Group B) forms were determined during frozen storage at -18;deg;C, but all samples were shocked at -40;deg;C before. According to the statistical analysis results, there were significant differences (P;lt;0.05) between TBA, FA (ex), FA (dest) values of two groups during the frozen storage while there were no significant differences (P;gt;0.05) between pH and TVB-N values of two groups. It was found that, total viable count of Group A kept its initial value at the end of the frozen storage while total viable count of Group B showed a decrease during the storage period. Coliform bacteria count stayed almost at the same level for Group A and Group B during the storage and coagulase-positive 5. aureus was not detected. No significant differences (P;gt;0.05) were observed in the colour, smell, chewy texture and flavor properties of two groups