Parametric amplification with weak-link nonlinearity in superconducting microresonators

Nonlinear kinetic inductance in a high Q superconducting coplanar waveguide microresonator can cause a bifurcation of the resonance curve. Near the critical pumping power and frequency for bifurcation, large parametric gain is observed for signals in the frequency band near resonance. We show experimental results on signal and intermodulation gain which are well described by a theory of the parametric amplification based on a Kerr nonlinearity. Phase dependent gain, or signal squeezing, is verified with a homodyne detection scheme.Comment: Submitted to Physica Scripta, topical issue: Nobel Symposium on Quantum Bits, 2009. 10 pages, 5 figures. Version 2 contains a few new sentences about the current-phase relation of weak link

Yttria-Stabilized Zirconia Assisted Green Electrochemical Preparation of Silicon from Solid Silica in Calcium Chloride Melt

A novel integrated cell with O2-|YSZ|Pt|O2(air) reference and counter electrodes was constructed using a short yttria-stabilized zirconia solid electrolyte (YSZ) tube. Combining with cyclic voltammetry and potentiostatic electrolysis methods, green electrochemical preparation of Si from solid SiO2 in CaCl2 melt at 1173 K was studied via an experimental apparatus containing the novel integrated cell under completely carbon-free conditions; the effect of electrolysis time on the morphology of the Si product was also investigated by scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM-EDS). The results show that the morphology of the product obtained from potentiostatic electrolysis at a low overpotential (− 1.6 V) undergoes an evolution from SiO2 raw powder with different sizes to aggregates of spherical particles and small particles with partial reduction, and then to Si nuclei, and finally to Si wires or flakes. The morphology of electrolytic products has little relation with that of SiO2 raw powder and may be controlled by applying different potentials. Furthermore, the longer the electrolysis time, the more the Si wires grow, and the higher the Si purity overall. It is feasible that the experimental apparatus without the sealed stainless steel reactor and any carbonaceous materials can be used to prepare Si from solid SiO2 in CaCl2 melt and release O2 gas at the same time

Perceptions of health status and the importance of health in coal enterprise workers [Kömür işletmesinde çalişan işçilerin saglik durumlarini ve sagligin önemini algilamalari]

AIM: To determine perception of health status and the importance of health in coal enterprise workers'. METHOD: Descriptive research was conducted at one coal enterprise, between November 2008 and January 2009. The universe includes 745 male workers. Sample size was determined as 207 workers with 95.0% confidence interval, 5.0% standard error. The workers were chosen stratified random sampling method according to the department in the workplace. Data were collected by using the questionnaire including sociodemographic characteristics of workers, the stories of health and disease, health behaviors, behaviors for occupational health and safety, Perception of Health Status Scale and the Importance of Health Scale. RESULTS: All workers were male, 53.1% of workers were high school graduates. Mean age was 43.81±7.57 and working year average was 18.43±7.80. Of the workers 43.0% were had regular health checkup by workplace doctor, 28.5% used medicine permanently, 15.0% had cancer history in the family. Approximately one of every five workers had occupational accidents (19.3%). 60.4% of the workers perceive health as "bad", while the mean score of perception of health was 3.65 ± 0.64. Mean score of importance of health scale was 8.48 ±2.41. There was a difference between occupational accident and the mean score of perception of health status (t=2.81, p0.05). CONCLUSION: More than half of workers perceive physical health as "bad", on the other hand to be physically and mentally healthy were adopted as an important value. Workers who had occupational accident perceive health as "bad". Although not statistically significant, workers who had occupational accident have shown positive difference on health importance

Effect of sintering parameters on mechanical properties of injection moulded Ti-6Al-4V alloys

This paper describes the microstructural and mechanical properties of injection moulded Ti-6Al-4V parts. Ti-6Al-4V powder was injection moulded with wax based binder. The critical powder loading for injection moulding was 67.5 vol.-% for feedstock. Binder debinding was performed with solvent and thermal method. After debinding the samples were sintered at different temperatures and times in vacuum atmosphere (10(-4) torr). Metallographic studies were conducted to determine to extend densification and the corresponding microstructural changes. The results show that Ti-6Al-4V powder could be sintered to a maximum 99% of theoretical density. Maximum ultimate tensile strength and hardness were obtained 704 MPa and 38.6 HRC at 1275 degrees C for 10 h

Investigation of Nanoantenna Geometries for Maximum Field Enhancements at Optical Frequencies

We present a comparative study of nanoantennas for maximum power enhancements at their feed gaps. Due to frequency-dependent plasmonic properties of metals at optical frequencies, removing the frequency-size relationship used in perfectly conducting models, two-dimensional analysis involving both frequency and geometric scaling is performed to accurately assess the performances of different geometries. Computationally intensive simulations involving thousands of full-wave solutions are carried out by employing surface integral equations and the multilevel fast multipole algorithm. Tens of different structures, which demonstrate diverse enhancement properties, are considered and compared with each other. Numerical simulations show favorable properties of different geometries depending on the range of the optical frequency

Lack of association of plasma factor XI with bleeding and report of two novel factor VII mutations

#nofulltext# --- Berber, Ergül (Arel Author)7th International Eurasian Hematology Congres