Структура электромагнитного поля феррит-диэлектрического резонатора

В роботі отримані вирази для компонентів електромагнітного поля ззовні феритового резонатора для діелектричного спектру коливань в явному вигляді. Розраховані залежності компонентів зовнішнього електромагнітного поля від координат r та θ для основного виду діелектричних коливань сферичного діелектричного резонатора Н110 та побудовані графіки цих залежностей. Проведено порівняння виразів для компонентів електромагнітного поля назовні феритового резонатора для діелектричного спектру коливань, розрахованих за допомогою методики збудження електромагнітного поля струмами поляризації, з відомими виразами, отриманими іншими методами.Introduction. The considered several works explore the question of electromagnetic resonance ferrite and dielectric resonators, the influence of electrodynamics system on the spectrum of magnetostatic oscillations ferrite resonator, the influence of metal wall on the spectrum of cylindrical dielectric resonator vibrations. Calculations of the electromagnetic field ferritedielectric resonator. The expressions for the components of the electromagnetic field outside the ferrite resonator for dielectric spectrum of fluctuations are obtained explicitly. The dependence of components of the external electromagnetic field on the coordinates r and θ for the main type of dielectric fluctuations spherical dielectric resonator H₁₁₀ is calculated. The graphs of these dependencies are constructed. The comparison of expressions for the components of the electromagnetic field outside the ferrite resonator for dielectric spectrum fluctuations is conducted. These components are calculated using the technique of electromagnetic field excitation polarization currents with known expressions obtained by other methods. Conclusions. The investigation of the electromagnetic field ferrite resonator structure as a particular case of ferrite-dielectric resonator is conducted. The investigation of the external electromagnetic fields structure is carried out for the case of the main type of dielectric fluctuations using the method of calculating the excitation polarization currents of these fields. Polarization currents are found from the expression for the internal electromagnetic fields for basic type oscillation of ferrite resonator H₁₁₀.В работе получены выражения для компонентов электромагнитного поля снаружи ферритового резонатора для диэлектрического спектра колебаний в явном виде. Рассчитаны зависимости компонентов внешнего электромагнитного поля от координат r и θ для основного вида диэлектрических колебаний сферического диэлектрического резонатора Н110 и построены графики этих зависимостей. Проведено сравнение выражений для компонентов электромагнитного поля снаружи ферритового резонатора для диэлектрического спектра колебаний, рассчитанных с помощью методики возбуждения электромагнитного поля токами поляризации, с известными выражениями, полученными другими методам

Laboratory Evaluation of the Influence of Aggregate Los Angeles (LA) Abrasion on Performance of Open Graded Friction Course (OGFC) Mixtures

Understanding how the aggregate structure changes during mixing andcompacting are critical for the performance of open graded asphalt designs. Open gradedfriction course (OGFC) consists of approximately 94% aggregate and if breakdownoccurs, the desired properties of the finished product will vary. The purpose of this studywas to investigate the influence of the Los Angeles (LA) abrasion value of the aggregateon the performance of open graded friction course mixtures. Aggregate from nine different sources in South Carolina, with LA abrasion valuesranging from low-20s to mid-50s, were used to create a 12.5mm nominal maximumaggregate size (NMAS) open graded design. Specimens, both with and without theinclusion of binder, were mixed then compacted using a Superpave gyratory compactorand re-analyzed for gradation change. Durability performance was measured using theCantabro abrasion test while functional performance was measured by porosity. Substantial degradation was exhibited after both mixing and compacting foraggregates having higher LA values. All aggregate sources sustained breakdown,especially in the #4, #8 and #30 sized fractions. The inclusion of binder increased theaggregate breakdown rate more so than the aggregate mixtures tested without binder.Higher LA aggregate exhibited a decrease in specimen height and porosity whileimproving the Cantabro abrasion resistance. The aggregate source used in open-graded mixtures will affect the functional anddurability performance of the finished pavement. Under current specifications, there are many opportunities for variability between paving projects using aggregate from different sources. Degradation from mixing and compacting can be predicted if the aggregate behavior is known, therefore, appropriate corrections should be made to OGFC gradations to account for this breakdown of aggregate and enhance the pavement quality

Laboratory Evaluation of the Influence of Aggregate Los Angeles (LA) Abrasion on Performance of Open Graded Friction Course (OGFC) Mixtures

Understanding how the aggregate structure changes during mixing andcompacting are critical for the performance of open graded asphalt designs. Open gradedfriction course (OGFC) consists of approximately 94% aggregate and if breakdownoccurs, the desired properties of the finished product will vary. The purpose of this studywas to investigate the influence of the Los Angeles (LA) abrasion value of the aggregateon the performance of open graded friction course mixtures. Aggregate from nine different sources in South Carolina, with LA abrasion valuesranging from low-20s to mid-50s, were used to create a 12.5mm nominal maximumaggregate size (NMAS) open graded design. Specimens, both with and without theinclusion of binder, were mixed then compacted using a Superpave gyratory compactorand re-analyzed for gradation change. Durability performance was measured using theCantabro abrasion test while functional performance was measured by porosity. Substantial degradation was exhibited after both mixing and compacting foraggregates having higher LA values. All aggregate sources sustained breakdown,especially in the #4, #8 and #30 sized fractions. The inclusion of binder increased theaggregate breakdown rate more so than the aggregate mixtures tested without binder.Higher LA aggregate exhibited a decrease in specimen height and porosity whileimproving the Cantabro abrasion resistance. The aggregate source used in open-graded mixtures will affect the functional anddurability performance of the finished pavement. Under current specifications, there are many opportunities for variability between paving projects using aggregate from different sources. Degradation from mixing and compacting can be predicted if the aggregate behavior is known, therefore, appropriate corrections should be made to OGFC gradations to account for this breakdown of aggregate and enhance the pavement quality

Ультразвуковое исследование в комплексной диагностике заболеваний плевры и легких

An analysis was performed of results of complex radiological examination of 576 patients (346 males and 230 females) with different lung and pleura diseases. There were 76.6% of patients with various clinical forms of respiratory tuberculosis and post-tubercular changes of lungs, pleura and intrathoracic lymphatic nodes among them. The rest 23.4% of the patients had non-tubercular chest diseases.Two hundred and seven patients (35.9%) having pleural syndrome were undergone ultrasonic examination of pleura, pleural cavities, subpleural lung zones. Ultrasonic signs of free and encapsulated effusion were studied including signs of pleural empyema of different eti-ologies and long-standing. A new ultrasonic diagnostic symptom of "air vacuoli" was found which had not been known before. It is an evidence of a pleural and bronchial fistula formation in chronic pleural empyema patients. Ultrasonic differential diagnostic features of pleura and lung volumetric processes were also established.Проведен анализ результатов комплексного лучевого обследования 576 больных (346 мужчин и 230 женщин) различными заболеваниями плевры и легких. Из них 76,6% составили пациенты с различными клиническими формами туберкулеза органов дыхания и посттуберкулезными изменениями в легких, плевре, внутригрудных лимфатических узлах. У остальных 23,4% больных отмечены нетуберкулезные заболевания органов грудной полости.207 (35,9%) больным с наличием плеврального синдрома выполнено ультразвуковое исследование плевры, плевральных полостей, субплевральных отделов легких. Изучены ультразвуковые признаки свободного и осумкованного выпота, в том числе эмпиемы в плевральной полости в зависимости от этиологии и сроков давности заболевания. Установлен новый (ранее неизвестный) ультразвуковой диагностический признак – симптом «воздушных вакуолей», свидетельствующий о развитии плевробронхиального свища у больных хронической эмпиемой плевральной полости. Определены ультразвуковые дифференциально-диагностические признаки различных объемных образований плевры и легких

The Aerotactic Response of Caulobacter crescentus

Many motile microorganisms are able to detect chemical gradients in their surroundings to bias their motion toward more favorable conditions. In this study, we observe the swimming patterns of Caulobacter crescentus, a uniflagellated bacterium, in a linear oxygen gradient produced by a three-channel microfluidic device. Using low-magnification dark-field microscopy, individual cells are tracked over a large field of view and their positions within the oxygen gradient are recorded over time. Motor switching events are identified so that swimming trajectories are deconstructed into a series of forward and backward swimming runs. Using these data, we show that C. crescentus displays aerotactic behavior by extending the average duration of forward swimming runs while moving up an oxygen gradient, resulting in directed motility toward oxygen sources. Additionally, the motor switching response is sensitive both to the steepness of the gradient experienced and to background oxygen levels, exhibiting a logarithmic response

Актуальные проблемы туберкулеза органов дыхания: эпидемиология, диагностика, клиника, лечение

Statistic data of respiratory tuberculosis epidemiology in Russian Federation and in Moscow are shown in the article. A special attention is given to early detection of tuberculosis in general practice including a minimal obligatory diagnostic set with direct microscopy of sputum smear and its staining by Zihl-Nilsen method, chest X-ray examination, tuberculin testing of children and a dolescents.Diagnostic methods are indicated which prove tuberculosis activity in patients with radiological changes in lungs and negative result of sputum microscopic examination.An important role of modern imagining methods, such as computed tomography and ultrasonic examination, for complex tuberculosis diagnostics is emphasized.Three patients’ groups were selected according to clinical peculiarities of respiratory tuberculosis.A great attention is paid for treatment of tuberculosis patients, especially when drug resistance of micobacteria and concomitant diseases take place.WHO recommendations concerning selection of different patients’ categories for chemo therapy are given.В статье приводятся статистические данные по эпидемиологии туберкулеза органов дыхания в Российской Федерациии в г.Москве. Особое внимание уделено вопросу раннего выявления туберкулеза в учреждениях общей лечебной сети с выполнением обязательного диагностического минимума (исследование мокроты методом прямой микроскопии мазка при окраске его по Цилю—Нильсену, рентгенофлюорографическое исследование органов грудной клетки, проведение туберкулинодиагностики среди детей и подростков).Указаны методы диагностики, подтверждающие активность туберкулеза у лиц с рентгенологическими изменениями в легких при отрицательной микроскопии мазка мокроты.Отмечена важная роль современных методов визуализации в комплексной диагностике туберкулеза, в частности, компьютерной томографиии ультразвукового исследования.Выделены 3 группы больных по характеру клинических проявлений туберкулеза органов дыхания.Важное место отводится вопросу лечения больных туберкулезом, особенно в случаях лекарственной устойчивости микобактерий туберкулеза и наличия сопутствующих заболеваний.Приведены рекомендации ВОЗ по выделению различных категорий больных при проведении химиотерапии