2,444 research outputs found
Measurements of turbulence at stratocumulus top
No full textUsing 1m resolution airborne data from research flights we divide stratocumulus top region into sublayers and characterize properties of turbulence in each sublayer. Results indicate, that there are no clear differences of turbulence properties between thermodynamically different "calassical" and "non-classical" stratocumulus regimes, but there are clear signs of turbulence ainsotropy in stably stratified sublayers in the cloud top region
High resolution performance analysis of micro-trigeneration in an energy-efficient residential building
No full textTrigeneration has long been proposed as a means to improve energy-efficiency for large and medium sized buildings. To curb increasing energy demand in the residential sector, researchers are now focusing their attention on adapting trigeneration to residential buildings. Literature is full of examples pertaining to the performance of trigeneration in large and medium sized commercial buildings, however little is known on the performance of micro-trigeneration inside residential buildings, particularly under a range of operating conditions. To understand the influence that parameters such as changes in thermal and electrical loading or different plant configurations have on the performance of micro-trigeneration, this research makes use of a detailed model of a Maltese apartment building, and associated micro-trigeneration system. The performance of the model is simulated using a whole building simulation tool run at high-resolution minute time frequency over a number of different operating conditions and scenarios. Each scenario was then assessed on the basis of the system's energetic, environmental and economic performance. The results show that, compared to separate generation the use of a residential micro-trigeneration system reduces primary energy consumption by about 40%, but also that the system's financial performance is highly susceptible to the operating conditions
Implicit large-eddy simulation of the stratocumulus-topped boundary layer: A grid sensitivity study
No full textA range of implicit large-eddy simulations of the stratocumulus-topped boundary layer is performed to study the influence of grid resolution on selected parameters including liquid water path and second and third moments of vertical velocity fluctuations. The simulations are based on two sets of aircraft measurements, which are also used to evaluate the results of the simulations. The specific case presented here indicates that simulations with a grid aspect ratio accounting for the anisotropic nature of the turbulence near the surface and at the top of the boundary layer lead to better agreement with measurements than simulations with an isotropic grid
Entrainment and detrainment rates from the piv measurements at the top of laboratory analogs of stratocumulus and cumulus clouds
No full textWe analyze mixing at the top of laboratory analogs of convective clouds: stratocumulus and cumulus to investigate entrainment of environmental air into the cloud. We retrieve two components of air velocity using Particle Image Velocimetry technique. Suitable image processing allows to determine cloud–clear air interface. Using velocity differences between cloudy and clear sides of the interface we calculate entrainment / detrainment rates
Site-Specific Topoisomerase I-Mediated DNA Cleavage Induced by Nogalamycin: A Potential Role of Ligand-Induced DNA Bending at a Distal Site
No full textSai Peng Sim, Daniel S. Pilch and LEroy F. Li
Prof. S.P. Fedorov — founder of urology in Russia (150th anniversary of the birthday)
No full textThis article presents the important scientific achievements of S.P. Fedorov as a urologist. S.P. Fedorov is the author of over 120 scientific papers. It was noted that in 1892 he was the first in Russia to prepare and use cholera antitoxin for the treatment of patients, then tetanus toxin and antitoxin, found that antitoxin protects against tetanus if it is administered simultaneously with the toxin. Abroad S.P. Fedorov studied the system of aseptic mode of operation from K. Schimmelbush, and L. Casper studied the method of cystoscopy and catheterization of the ureters and other endoscopic methods that appeared at that time. It was shown that S.P. Fedorov developed new surgeries — in situ pyelotomy, subcapsular nephrectomy, and new surgical instruments were proposed. He is rightly called the father of Russian urology. The circumstance is analyzed that the main direction of S.P. Fedorov's scientific activity was the problems of surgery of the urinary and biliary tracts. He summarized the extensive experience of the surgeon in the Atlas of Cystoscopy and Rectoscopy (1911), the Surgery of the Kidneys and Ureters (1923-1925), and others. Galpernom edition of the surgical journal «New Surgical Archive», essentially the first Soviet surgical journal, created in the difficult years of the Civil War and post-war devastation. He was the editor of the 1st edition of the BME, together with S.S. Girgolavom and A.V. Martynov was the editor of the multivolume Guide to Practical Surgery. S.P. Fedorov created a major domestic surgical school, from which dozens of specialists, heads of surgical departments of medical universities in various cities of the USSR graduated. The name of S.P. Fedorov was given to the department of hospital surgery of the Military Medical Academy. S.M. Kirov. It is noted that he was the first of the Soviet surgeons to be awarded the Order of Lenin (1933)
Autonomous operation of a tunable vibration based energy harvester
No full textVibration-based energy harvesters transduce kinetic energy into electrical energy, which is then utilized to power small electronic systems, like wireless sensor nodes. Vibration-based harvesters are designed with high Q-factor to maximize their power generation capability; however, this results in low bandwidth of operation. Different tuning mechanisms have been previously presented, but none is integrated as an autonomous system. The work described in this thesis outlines the development of a tunable vibration-based energy harvester that adjusts its resonant frequency to coincide with the base frequency and it is powered exclusively by the harvester.This work builds upon an electromagnetic vibration-based energy harvester and a non-contact tuning mechanism previously developed in this research group. This thesis presents the integration of the different mechanical and electronic components required to operate the tuning mechanism with the lowest overhead power feasible; an optimal range of operation for the harvester, where the frequency bandwidth is maximized while the power used for tuning is minimized, is proposed. A closed loop frequency tuning system is presented that identifies when the base frequencies have changed and adjust the harvester resonant frequency in consequence, using the mathematical model of the harvester and the period difference between the harvester voltage and the base acceleration. Analysis of the operation of the harvester when exposed to a real application was performed. The system was modified to allow its operation under this condition.The optimization of the power extraction and conversion was also evaluated. The flexibility of the tunable harvester to adjust its resonant frequency increases by increasing the power available to perform this adjustment. Passive extraction and conversion is preferred due to the reduced overhead power compared to active conversion.The combined result of tuning and power extraction is a fully functional tunable energy harvester that operates autonomously. Its use as a power source for a wireless sensor node is demonstrated in this thesis
S.P. Breckinridge letter to Lucile Atcherson, April 1, 1914
No full textOn April 1, 1914, S.P. Breckinridge, an educator and activist, sent this letter to Lucile Atcherson, a suffragist in central Ohio and executive secretary for the Franklin County Woman Suffrage Association, informing Atcherson of the letter Breckinridge sent to the wife of William O. Thompson, President of the Ohio State University. Breckinridge's hope was that college women at Ohio State would make an impact in the Ohio women's suffrage movement.
The Franklin County Woman Suffrage Association was formed in 1912, after the Ohio Constitutional Convention elected to bring to a vote the question of removing the words "white male" from the state constitution with regard to voting rights. Headquartered in the Chamber of Commerce building in Columbus, Ohio, the organization put out regular publications, organized public speeches and meetings, distributed literature and held parades in support of the suffrage movement. Women's suffrage in Ohio was defeated in a special election in 1912 and again in 1914 and 1916 before a resolution narrowly passed in 1917 allowing municipal voting by women in Columbus. In 1920, the 19th Amendment passed, extending the vote to women and prohibiting state and federal government from denying suffrage on the basis of sex
S.P. Breckinridge letter to Mrs. W.O. Thompson, April 1, 1914
No full textThis is a copy of a letter written on April 1, 1914, by S.P. Breckinridge, an educator and activist from Illinois, to Mrs. W.O. Thompson, the wife of the president of the Ohio State University. Breckinridge wrote to Mrs. Thompson to congratulate her on recent resolutions passed by the Conference of College Women. She also wrote about her hope for all women to experience the the right to vote, a right which women in Illinois had already achieved. Breckinridge informed Mrs. Thompson that she admired the work Ohio college women were doing.
The Franklin County Woman Suffrage Association was formed in 1912, after the Ohio Constitutional Convention elected to bring to a vote the question of removing the words "white male" from the state constitution with regard to voting rights. Headquartered in the Chamber of Commerce building in Columbus, Ohio, the organization put out regular publications, organized public speeches and meetings, distributed literature and held parades in support of the suffrage movement. Women's suffrage in Ohio was defeated in a special election in 1912 and again in 1914 and 1916 before a resolution narrowly passed in 1917 allowing municipal voting by women in Columbus. In 1920, the 19th Amendment passed, extending the vote to women and prohibiting state and federal government from denying suffrage on the basis of sex
An improved thick-film piezoelectric material by powder blending and enhanced processing parameters
No full textThis paper details improvements of the d33 coefficient for thick-film lead zirconate titanate (PZT) layers. In particular, the effect of blending ball and attritor milled powders has been investigated. Mathematical modeling of the film structure has produced initial experimental values for powder combination percentages. A range of paste formulations between 8:1 and 2:1 ball to attritor milled PZT powders by weight have been mixed into a screen-printable paste. Each paste contains 10% by weight of lead borosilicate glass and an appropriate quantity of solvent to formulate a screen printable thixotropic paste. A d33 of 63.5 pC/N was obtained with a combination of 4:1 ball milled to attritor milled powder by weight. The improved paste combines the high d33 values of ball and the consistency of attritor milled powder. The measured d33 coefficient was further improved to 131 pC/N by increasing the furnace firing pro-file to 100
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