25 research outputs found
Dispersion of multi-walled carbon nanotubes in an aqueous medium by water-dispersible conjugated polymer nanoparticles
Vertically aligned multi-walled carbon nanotubes (MWCNTs) synthesized by the alcohol catalytic CVD (ACCVD) technique are dispersed in water with the aid of water-dispersible conjugated polymer nanoparticles (CPNs). The interactions between CPNs and CNTs are studied with spectroscopy (UV-Vis, fluorescence and Raman) and electron microscopy techniques are used to confirm attachment of CPNs to the CNT sidewalls. © 2010 The Royal Society of Chemistry
The Sariçiçek Howardite Fall in Turkey: Source Crater of HED Meteorites on Vesta and İmpact Risk of Vestoids
The Sariçiçek howardite meteorite shower consisting of 343 documented stones
occurred on 2 September 2015 in Turkey and is the first documented howardite fall. Cosmogenic
isotopes show that Sariçiçek experienced a complex cosmic ray exposure history, exposed during
~12–14 Ma in a regolith near the surface of a parent asteroid, and that an ~1 m sized meteoroid
was launched by an impact 22 ± 2 Ma ago to Earth (as did one third of all HED meteorites). SIMS
dating of zircon and baddeleyite yielded 4550.4 ± 2.5 Ma and 4553 ± 8.8 Ma crystallization ages
for the basaltic magma clasts. The apatite U-Pb age of 4525 ± 17 Ma, K-Ar age of ~3.9 Ga, and
the U,Th-He ages of 1.8 ± 0.7 and 2.6 ± 0.3 Ga are interpreted to represent thermal metamorphic
and impact-related resetting ages, respectively. Petrographic, geochemical and O-, Cr- and Tiisotopic
studies confirm that Sariçiçek belongs to the normal clan of HED meteorites. Petrographic
observations and analysis of organic material indicate a small portion of carbonaceous chondrite
material in the Sariçiçek regolith and organic contamination of the meteorite after a few days on
soil. Video observations of the fall show an atmospheric entry at 17.3 ± 0.8 kms-1 from NW,
fragmentations at 37, 33, 31 and 27 km altitude, and provide a pre-atmospheric orbit that is the
first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data
indicate the similarity of Sariçiçek with the Vesta asteroid family (V-class) spectra, a group of
asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of
meteoroid delivery to Earth shows that the complete disruption of a ~1 km sized Vesta family
asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids ≤4
m in size to account for the influx of meteorites from this HED clan. The 16.7 km diameter Antonia
impact crater on Vesta was formed on terrain of the same age as given by the 4He retention age of
Sariçiçek. Lunar scaling for crater production to crater counts of its ejecta blanket show it was
formed ~22 Ma ago
Laryngoscopic Examination During the COVID-19 Pandemic: Turkish Voice Speech and Swallowing Disorders Society and Turkish Professional Voice Society Recommendations
COVID-19 is highly transmissible and spreads rapidly in the population. This increases the occupational risk for health care workers. In otolaryngology clinic practice, patients with upper respiratory tract infection symptoms are common. Also, routine head and neck examinations such as oral cavity examination, nasal/nasopharyngeal examination, or video laryngostroboscopic evaluation are highly risky because of the aerosol formation. To emphasize this issue, two leading otolaryngology organizations in Turkey; 'Voice Speech and Swallowing Disorders Society', and 'Professional Voice Society' gathered a task force. This task force aimed to prepare a consensus report that would provide practical recommendations of the safety measurements during routine clinical care of laryngology patients. To fulfill this, universal aim, on the 2nd and 9th of May 2020, two web-based meetings were conducted by 20 expert physicians. This eighteen items list was prepared as an output
Algal treatment of pulp and paper industry wastewaters in SBR systems
Highly colored and highly polluted pulp and paper industry wastewaters are proposed to be treated by using algae in sequential batch reactors (SBR). Results of batch studies revealed that up to 74% COD; 74% color removal could be attained in about 40 days of incubation, From the preliminary SBR experiments, filling period was found to be a critical step affecting the overall efficiency when mixing and aeration is applied during filling. Therefore, 5 different filling periods (4, 6, 8, 10 and 12 days) were studied with a total SBR cycle of 15 days. For all filling periods; COD, color and AOX removal efficiencies increased with increasing filling time. Maximum removal efficiencies achieved were 60 to 85% for COD, 42 to 75% for color and 82 to 93% for AOX for the filling periods of 4 to 12 days. For 8 days or longer filling periods, no additional reaction time was required. Results showed that, organics in the wastewater were both chlorinated and non-chlorinated; algae removed these mainly by metabolism; and chlorine cleavage from chlorinated organic molecules was more rapid than the degradation of non-chlorinated and colored organics. Adsorbed lignin on algal biomass was found to be varying between 10-20% depending on filling period applied
Colour and AOX removal from pulping effluents by algae
A mixed culture of algae was used to treat pulping mill effluent in terms of removing both colour and adsorbably organic halides (AOX). The removal of AOX from pulping effluent increased with increasing initial colour Value of the effluent. However, for the total mill effluent (composed of both pulping and bleaching effluents), AOX removal was found to be independent of initial colour value, and was around 70%. Up to 80% removal of colour from pulping effluent was achieved within 30 days under continuous lighting conditions. It was found that algae reduced the colour of pulping effluent of relatively low initial colour more efficiently than that of high initial colour. Under simulated field lighting conditions, up to 60% colour removal from pulping, effluent was observed after 60 days of exposure, whereas for the total mill effluent it was up to 64% after 45 days. Total organic carbon and lignin (UVA(280)) were also removed to a significant extent, suggesting that the mechanism of colour removal might not be transformation of the coloured lignin molecules to non-coloured ones. Analysis of alkaline extraction of the algal biomass and material balance findings indicated that the main colour removal mechanism was metabolism rather than adsorption. The experimental results were also analysed using multiple regression techniques and a mathematical model was developed to express the removal of colour from pulping effluents in terms of initial colour value, exposure time and lighting periods as well as interactions between these variables
Using Rasch measurement to evaluate the Organizational Climate Index
School climate has been acknowledged as a construct with impact on important aspects of educational outcomes, such as student achievement, school effectiveness, and school completion. The Organizational Climate Index was an instrument developed to measure school climate (W.Hoy, 2001). This study evaluated this instrument by using Rasch measurement. The sample consisted of 110 teachers in 4 schools. Results indicate that items generally were working well, with a high reliability of 0/96. The only two items of concern referred to parent involvement in the school. This may be explained by the low community interaction in sample schools
Radiation Treatment of Wastewater for Reuse with Particular Focus on Wastewaters Containing Organic Pollutants
In this period of the research, aerobic and anaerobic digestion, characterization of alkaloids present and radiolysis products formed after irradiation, under different conditions of ambient and additives, optimization of dose to achieve desired end characteristics for discharge of waste water were aimed. In this regard, unirradiated and irradiated wastewaters were subjected to aerobic and anaerobic digestions. Substrate removal efficiencies of unirradiated and irradiated wastewater with various initial COD values were determined with SBR aerobic digestion treatment method. On the other hand Fenton’s advanced oxidation treatment method was also applied for pre-treatment. BMP tests of anaerobic digestion were also completed. LC/MS studies were carried out on unirradiated and irradiated alkaloid standard solutions of morphine, codeine, thebaine, papaverine, and noscapine to determine the degradation mechanisms and byproducts. Dose optimization studies were completed and found to be a lower dose of 5 kGy rather than 40 kGy for ambient irradiation condition
Comparison of Multiple Sclerosis Patients Using First Line Treatment vs Second Line Treatment
Conference of the Pan-Asian-Committee-for-Treatment-and-Research-in-Multiple-Sclerosis (PACTRIMS) -- NOV 13-15, 2019 -- Singapore, SINGAPORE[No Abstract Available]Pan Asian Comm Treatment & Res Multiple Sclerosi