The late-time development of the Richtmyer–Meshkov instability

Measurements have been made of the growth by the Richtmyer–Meshkov instability of nominally single-scale perturbations on an air/sulfur hexafluoride (SF6) interface in a large shock tube. An approximately sinusoidal shape is given to the interface by a wire mesh which supports a polymeric membrane separating the air from the SF6. A single shock wave incident on the interface induces motion by the baroclinic mechanism of vorticity generation. The visual thickness delta of the interface is measured from schlieren photographs obtained singly in each run and in high-speed motion pictures. Data are presented for delta at times considerably larger than previously reported, and they are tested for self-similarity including independence of initial conditions. Four different initial amplitude/wavelength combinations at one incident shock strength are used to determine the scaling of the data. It is found that the growth rate decreases rapidly with time, ddelta/dt[proportional]t–p (i.e., delta[proportional]t1–p), where 0.67<~p<~0.74 and that a small dependence on the initial wavelength lambda0 persists to large time. The larger value of the power law exponent agrees with the result of the late-time-decay similarity law of Huang and Leonard [Phys. Fluids 6, 3765–3775 (1994)]. The influence of the wire mesh and membrane on the mixing process is assessed

Exposure to NO2 in occupational built environments in urban centre in Lahore

Increased economic growth, urbanisation and substantial rise in automobile vehicles has contributed towards the elevated levels of air pollution in major cities in Pakistan. Aone week study was conducted by using passive samplers to assess NO2 concentration in occupational built environments at two most congested and populated sites of Lahore. Both sites were locatedon the busy roads of Lahore. At Site-I the highest concentration was in outdoors followed by corridor and indoor. While at Site II all the sampling location wereindoors and level were comparable to that of outdoor levelsat Site I. The results suggest the likely contribution of ambient sources in exposure to indoor NO2 in educational and other occupational built environments in urban centres

Dizajniranje, sinteza, kinetika hidrolize i farmakodinamski profili konjugata aceklofenaka s histidinom i alaninom

The gastrointestinal toxicity associated with aceclofenac can be reduced by condensing its carboxylic acid group with methyl esters of amino acids like histidine and alanine to give amide linkage by the Schotten-Baumann method. Physicochemical characterization of the conjugates was carried out by various analytical and spectral methods. The synthesized conjugates were also subjected to in vitro hydrolysis in simulated gastric fluid (SGF) at pH 1.2, simulated intestinal fluid (SIF) at pH 7.4 and SIF + 80 % human plasma at pH 7.4. The release of free aceclofenac from histidine and alanine conjugated aceclofenac showed negligible hydrolysis in SGF compared to SIF. This indicated that the conjugates do not break in stomach, but release aceclofenac in SIF. Both synthesized conjugates showed excellent pharmacological response and encouraging hydrolysis rate in SIF and SIF + 80 % human plasma. Marked reduction of the ulcer index and comparable increase in analgesic and anti-inflammatory activities were obtained in both cases compared to aceclofenac alone. These findings suggest that the conjugates are better in action compared to the parent drug and have fewer gastrointestinal side-effects.Gastrointestinalna toksičnost aceklofenaka može se umanjiti kondenzacijom karboksilne skupine aceklofenaka s metilnim esterima aminokiselina poput histidina i alanina, pri čemu se stvaraju nove amidne veze po Schotten-Baumannovoj metodi. Fizikokemijska karakterizacija konjugata provedena je različitim analitičkim i spektralnim metodama. Nadalje, praćena je hidroliza sintetiziranih konjugata in vitro u simuliranoj gastričnoj tekućini (SGF) pri pH 1,2, simuliranoj intestinalnoj tekućini (SIF) pri pH 7,4 i simuliranoj intestinalnoj tekućini s 80 % humane plazme pri pH 7,4. Oslobađanje aceklofenaka iz konjugata s histidinom, odnosno alaninom, bilo je zanemarivo u SGF-u, u odnosu na oslobađanje u SIF-u. To ukazuje da su konjugati stabilni u želucu, dok se u SIF-u iz njih oslobađa aceklofenak. Oba konjugata daju izvrstan farmakološki odgovor i zadovoljavajući stupanj hidrolize u SIF-u i smjesi SIF-a i humane plazme. Oba konjugata pokazala su značajno smanjenu ulcerogenost i pojačano analgetsko i protuupalno djelovanje u odnosu na aceklofenak. Rezultati ukazuju na prednost konjugata u odnosu na samu ljekovitu tvar

Fracture studies on synthetic fiber reinforced cellular concrete using acoustic emission technique

Cellular lightweight concrete (CLC) is increasingly used for low strength non-structural and structural applications. The effects of synthetic fiber reinforcement on the fracture behavior of CLC is investigated. In particular, acoustic emission (AE) technique is employed to study the influence of macro (structural), micro polyolefin synthetic fibers and their combinations on the fracture behavior of CLC beams. Notched fiber reinforced CLC beams were tested to study the crack initiation and propagation characteristics using AE sensors. Different AE parameters are correlated with the crack growth and damage accumulation. An attempt has been made to correlate the crack mouth opening displacement (CMOD) with the number of AE hits. The variation of cumulative acoustic energy release of the cracks is studied with respect to applied load and CMOD. Three dimensional source location of cracks is carried out based on the AE events picked by the sensors bonded to the CLC specimens. The analysis of AE results indicates that the crack source location identification from AE is consistent with the actual crack development. Analysis of AE signals reveal that the CLC matrix cracking produces signals with less number of hits that lie in the notched plane in bending. Moreover, the signals from the post peak regime correspond to more number of hits which tend to be scattered around the plane of notch due to the fiber pull out

Comparative Analysis of Zeolite Y From Nigerian Clay and Standard Grade

Zeolite Y catalyst with silica/alumina mola•· ntio of 4.70 was synthesized from Elefun (Nigel"ia) clay unde•· hydwthe•·mal tJ·eatment of calcined kaolin with aqueous NaOH at atmosphel"ic p•·essm·e. This pape•· descl"ibed the p•·epantion of zeolite Y catalyst fmm metakaolin of quality Elefun kaolin by ageing at 34oC fo•· 7days, and then n·ystallized at lOOoC fm· 24 hom·s. The synthesized zeolite NaY was modified by exchanging with NH4Cl to obtain its hydwgen fo•·m with silica/alumina ntio of 3.18. Both developed and standa1·d zeolite Y catalyst we1·e then chanctel"ized by a val"iety of physicochemical methods, including XRD, XRF spectwscope. The mm·phologies we1·e examined using SEM. Similar results we1·e obtained, thus confi•·ming the synthesis of zeolite Y

Primary outcome measures used in interventional trials for ankle fractures : a systematic review

Background Ankle fractures cause considerable pain, loss of function and healthcare resource use. High quality randomised controlled trials are required to evaluate the optimal management protocols for ankle fracture. However, there is debate regarding the most appropriate outcome measure to use when assessing patients with ankle fractures. The aim of this systematic review is to identify and summarise primary outcome measure use in clinical trials of non-pharmacological interventions for adults with an ankle fracture. Methods We performed comprehensive searches of the Medline, Embase, CINAHL, AMED and Cochrane CENTRAL databases, as well as ISRCTN and ClinicalTrials.gov online clinical trial registries on 19/06/2019 with no date limits applied. The titles and abstracts were initially screened to identify randomised or quasi-randomised clinical trials of non-pharmacological interventions for ankle fracture in adults. Two authors independently screened the full text of any articles which could potentially be eligible. Descriptive statistics we used to summarise the outcome measures collected in these articles including an assessment of trends over time. Secondary analysis included a descriptive summary of the multi-item patient reported outcome measures used in this study type. Results The searches returned a total of 3380 records. Following application of the eligibility criteria, 121 records were eligible for inclusion in this review. The most frequently collected primary outcome measures in this type of publication was the Olerud Molander Ankle Score, followed by radiographic and range of movement assessments. There was a total of 28 different outcome measures collected and five different multi-item, patient reported outcome measures collected as the primary outcome measure. There was a sequential increase in the number of this type of study published per decade since the 1980’s. Conclusion This review demonstrates the wide range of measurement methods used to assess outcome in adults with an ankle fracture. Future research should focus on establishing the validity and reliability of the outcome measures used in this patient population. Formulation of a consensus based core outcome set for adults with an ankle fracture would be advantageous for ensuring homogeneity across studies in order to meta-analyse trial results

Modeling an Academic Test by Practicing Google Drive Cloud Computing

In Considering of technological development Awarded in all aspects of life, especially in education and university education in particular, and starting from the principle of modernity and innovation in the educational process, the idea of this research generated to use the cloud computing applications in the preparation of tests for university students, advanced, accessible and relevant newness in devising the scientific of students to determine their scientific level in accuracy, without being bound by traditional tests, Where we\u27ll prepare tests using a cloud computing applications which prepare ready models tests using Google drive ready test models, in several ways including selections or writing census paragraphs or short answers or complete vacuum or Pauline. Then after arranged and prepared the models test sent online to the students at various means of communication via the Internet, such as different kinds of email, Facebook, Twitter or Google Plus, and then the students answer and respond to the mail sender. The cloud computing technology is very useful for tests, especially as the availability of new services in testing, but nevertheless, we find that the number of tests that take advantage of cloud computing technology is still a few, perhaps this is because of submit to the tests through techniques will lead to a significant change in the test method, in addition to that it is not easy to move to the use of new technology with no able people to deal with those techniques , but perhaps in the near future, we will find many of the tests carried out by cloud computing techniques, This service can give you the free storage space of up to 5 GB is (Google Drive), so featuring that you can share files with your friends or make them public watched all the people, it is suitable service for a lot work because you can edit the MS Office files, and create files such as Word and PowerPoint and Excel, it supports multiple files and formats, to access this service must have a Gmail account, the service is available on the Mac or Windows devices and also you can reach them by phone. Also features by submit a form questionnaire or question by email, and participation the result of tests or questionnaire in an Excel paper, with the possibility of filtering, mathematical operations and other without the need for a program on your computer. And get a graphical summary of the result of questionnaire or test. Also can apply a theme to give a nice seen for the tests or questionnaire form. These tests constitute a clear difference from traditional tests in terms of the accuracy of assessing students, and their level of knowledge to be accurate, in addition to overcome all the problematic and cons of traditional tests. It is also developing the student\u27s personality, spirit, minds, bodies and affection. Also develop the student talent tendencies, and provide a flexible learning environment, and prepare qualified and skilled teaching staff in the use of modern teaching strategies and methods