2,026 research outputs found
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
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)
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
Secreted enzymes of Aeromonas
No full textA hallmark characteristic of species of Aeromonas is their ability to secrete a wide variety of enzymes associated with pathogenicity and environmental adaptability. Among the most intensively studied are β-lactamases, lipases, hemolytic enterotoxins, proteases, chitinases, nucleases and amylases. Multiple copies of genes encoding each type of enzyme provide additional biological diversity. Except for the chitinases, these multiple copies show little evolutionary relatedness at the DNA level and only limited similarity at the protein level. Indeed a number of the genes, such as nuclease H of A. hydrophila, have no similarity to known prokaryotic or eukaryotic sequences. The challenge is to determine how these genes evolved, where they originated and why Aeromonas possesses them in such abundance and variety.John M Pemberton, Stephen P Kidd, Radomir Schmid
Cysteine and resistance to oxidative stress: implications for virulence and antibiotic resistance
No full textPublished: July 19, 2023Reactive oxygen species (ROS), including the superoxide radical anion (O2 •–), hydrogen peroxide (H2O2), and the hydroxyl radical (• HO), are inherent components of bacterial metabolism in an aerobic environment. Bacteria also encounter exogenous ROS, such as those produced by the host cells during the respiratory burst. As ROS have the capacity to damage bacterial DNA, proteins, and lipids, detoxification of ROS is critical for bacterial survival. It has been recently recognised that low-molecular-weight (LMW) thiols play a central role in this process. Here, we review the emerging role of cysteine in bacterial resistance to ROS with a link to broader elements of bacterial lifestyle closely associated with cysteine-mediated oxidative stress response, including virulence and antibiotic resistance.Alexandra Tikhomirova, Mohammad M. Rahman, Stephen P. Kidd, Richard L. Fererro, and Anna Roujeinikov
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
Two-phase anaerobic digestion in leach bed reactors coupled to anaerobic filters: A review and the potential of biochar filters
No full textBiochar addition in anaerobic digesters is an emerging technique for enhancing high-solids anaerobic digestion. Recycling of biochar can further enhance performance and reduce costs for biochar production; however, mixing biochar with feedstock and separating from digestate is impractical. A more pragmatic method of applying biochar for high-solids digestion could be coupling a leach bed reactor (LBR) with a biochar-packed anaerobic filter (AF) to form a two-phase system. Separating the anaerobic digestion process between reactors can improve process efficiency by enhancing hydrolysis and acidogenesis in the LBR and producing higher quality biogas in the AF. However, two-phase systems can be inefficient if separation of the anaerobic digestion process between reactors – referred to as phase separation – is poor. This article aims to: (i) integrate current knowledge from literature investigating batch LBR-AF systems to improve understanding of the role of different process parameters on phase separation and process efficiency; and (ii) explore the idea of biochar as a filter medium in an LBR-AF system. Feedstocks that rapidly degrade and have ongoing VFA production are particularly suitable for phase separation in LBR-AF systems. Controllable process parameters identified as critical for phase separation and process inhibitor mitigation include co-digestion, recirculation parameters, filter media properties, inoculation method and temperature. The application of biochar in other systems highlights the potential for LBR-AF application. Future research should consider trade-offs between biogas production and digestate quality when optimising LBR-AF performance, and assess economic viability considering the additional expenses of LBR-AF systems.B.A. Collins, C.H. Birzer, P.W. Harris, S.P. Kidd, B.K. McCabe, P.R. Medwel
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