Josephson Junction spectrum analyzer for millimeter and submillimeter wavelengths

A prototype of the Josephson-effect spectrum analyzer developed for the millimeter wave band is described. The measurement results for spectra obtained in the frequency band from 50 to 250 GHz are presented

Observation of Stochastic Resonance in Percolative Josephson Media

Measurements of the electrical response of granular Sn-Ge thin films below the superconducting transition temperature are reported. The addition of an external noise to the magnetic field applied to the sample is found to increase the sample voltage response to a small externally applied ac signal. The gain coefficient for this signal and the signal-to-noise ratio display clear maxima at particular noise levels. We interpret these observations as a stochastic resonance in the percolative Josephson media which occurs close to the percolation threshold.Comment: 4 pages, 5 figure

Josephson frequency meter for millimeter and submillimeter wavelengths

Frequency measurements of electromagnetic oscillations of millimeter and submillimeter wavebands with frequency growth due to a number of reasons become more and more difficult. First, these frequencies are considered to be cutoffs for semiconductor converting devices and one has to use optical measurement methods instead of traditional ones with frequency transfer. Second, resonance measurement methods are characterized by using relatively narrow bands and optical ones are limited in frequency and time resolution due to the limited range and velocity of movement of their mechanical elements as well as the efficiency of these optical techniques decrease with the increase of wavelength due to diffraction losses. That requires a priori information on the radiation frequency band of the source involved. Method of measuring frequency of harmonic microwave signals in millimeter and submillimeter wavebands based on the ac Josephson effect in superconducting contacts is devoid of all the above drawbacks. This approach offers a number of major advantages over the more traditional measurement methods, that is one based on frequency conversion, resonance and interferometric techniques. It can be characterized by high potential accuracy, wide range of frequencies measured, prompt measurement and the opportunity to obtain a panoramic display of the results as well as full automation of the measuring process

Clinical and radiological characteristics of patients with plantar fasciitis

Aim: to study the clinical and radiological parameters of patients with plantar fasciitis.Materials and methods: the study involved 91 patients with plantar fasciitis, 73 (80.2%) women, 18 (19.8%) men. The mean age of the patients was 53.42 ± 9.16 years, disease duration was 30.32 ± 8.06 days, BMI was 24.75 ± 4.55 kg/m2. Patients underwent history taking, pain level and quality of life were assessed using the visual analogue scale, the SF-36 questionnaire and the AOFAS scale. The functional state of the feet was assessed using plantoscopy, Y-balance test, Friedland index. X-ray parameters were assessed using magnetic resonance imaging.Results: the disease is common among women aged 51 to 60 years. In 100% of cases, there is no traumatic etiological factor, 42.9% of the subjects note an increase in body weight as the cause, 35.2% – the relationship of the onset of pain with wearing flat shoes; men are more likely to associate the onset of symptoms with an increase in physical activity (83.3%). Subjective sensation of pain on the VAS does not depend on gender (p = 0.280), age (p = 0.509), disease duration (p = 0.371), BMI (p = 0.974). X-ray parameters of patients are characterized in 49.5% by the absence of heel exostosis, in other cases, the development of a heel spur is more typical for women (p = 0.019), its length does not depend on the duration of the disease (p = 0.845), age (p = 0.054), BMI (p = 0.196), lifestyle (p = 0.324) and does not correlate with the severity of pain (p = 0.691). The level of pain is directly proportional to the thickness of the plantar fascia (p < 0.001, ρ = 0.459). Calcaneal edema is observed in 14.3 % of patients, soft tissue edema — in 18.7 %; there was no relationship between calcaneal edema (p = 0.604) and soft tissue edema (p = 0.541) with the severity of pain, and calcaneal edema directly correlates with BMI (p = 0.029).Conclusion: These studies suggest that among the predictors of the development of plantar fasciitis, the most significant are female gender, overweight, wearing flat shoes, and the disease itself is not always a consequence of the development of a heel spur

Collective dynamics of two-mode stochastic oscillators

We study a system of two-mode stochastic oscillators coupled through their collective output. As a function of a relevant parameter four qualitatively distinct regimes of collective behavior are observed. In an extended region of the parameter space the periodicity of the collective output is enhanced by the considered coupling. This system can be used as a new model to describe synchronization-like phenomena in systems of units with two or more oscillation modes. The model can also explain how periodic dynamics can be generated by coupling largely stochastic units. Similar systems could be responsible for the emergence of rhythmic behavior in complex biological or sociological systems.Comment: 4 pages, RevTex, 5 figure

Оценка экономии электрической энергии от очистки нефтешлама линейной части нефтепровода

The paper presents evaluation method of electric power saving due to periodical cleaning of oil pipeline linear part which is intended to increase an equivalent diameter of the pipeline. The proposed method is based on statistical model developed on the basis of 24-hourly statistics reflecting modes of electric power consumption that take place at an enterprise. Electric power saving is evaluated according to changes of an equivalent diameter in the process of oil pipeline cleaning (and after this process) with respect to changes of an equivalent diameter without pipeline cleaning.Изложен способ оценки экономии электрической энергии от периодической очистки линейной части нефтепровода, направленной на увеличение эквивалентного диаметра нефтепровода. Предложенный способ основывается на статистической модели, построенной на основе суточной статистики, отражающей сложившиеся на предприятии режимы электропотребления. Экономия электрической энергии оценивается по изменению эквивалентного диаметра нефтепровода в процессе очистки нефтепровода (и после нее) относительно изменения эквивалентного диаметра без очистки нефтепровода

СПОСОБ ПОСТРОЕНИЯ МОДЕЛИ РЕЖИМОВ ЭЛЕКТРОПОТРЕБЛЕНИЯ УЧАСТКА НЕФТЕПРОВОДА

The paper proposes a method for model development of power consumption modes at oil pipeline part that makes it possible to reduce uncertainty in behaviour of electric power consumption due to application of a sliding average. In order to estimate economy in electric power as a result of power saving measures in the technological process of oil transportation an expediency is proved to select an averaging period which is equal to 30 days. Предложен способ построения модели режимов электропотребления участка нефтепровода, позволяющий снизить неопределенность в поведении расхода электрической энергии за счет применения скользящего среднего. Для оценки экономии электрической энергии от проведения энергосберегающих мероприятий в технологическом процессе транспортировки нефти доказана целесообразность выбора периода усреднения, равного 30 сут