COMPARATIVE PHYSICOCHEMICAL, PHYTOCHEMICAL AND HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHY EVALUATION OF HEART WOOD AND SMALL BRANCHES OF AQUILARIA AGALLOCHA ROXB.

Aquilaria agallocha Roxb. commonly called as Agaru is a medicinal plant. Heartwood of this tree is widely used in Ayurveda for various diseases. Removal of heart wood from trunk of this tree may make this plant weak and susceptible to damage due to which availability of this plant may be difficult in near future. Present study outlines the concept of plant part substitution. Heart wood and small branches of A. agallocha are compared on the basis of physicochemical analysis, phytochemical analysis, total phenolic contents, total flavonoid contents and high performance thin layer chromatography (HPTLC) to evaluate the possibilities of using small branches instead of heart wood. Physicochemical parameters of heartwood and small branches and phytochemical analysis of n-hexane, ethyl acetate and ethanol extract of both heart wood and small branches were carried out using standard methods. Total phenolics and total flavonoids were estimated spectrophotometrically using Folin-ciocalteu assayand aluminum chloride assaymethods, respectively. CAMAG HPTLC system equipped with semi-automatic applicator was used for HPTLC of n-hexane, ethyl acetate and ethanol extracts of stem bark and small braches using suitable mobile phases. Results of phytochemical analysis and HPTLC of n-hexane, ethyl acetate and ethanol extracts showed many similarities whichsuggest that small branches may have nearly similar active potency like heart wood and may be used as a substitute of heart wood after comparison and confirmation of same for pharmacological activities

Corrosion behavior of ultrafine-grained AA2024 aluminum alloy produced by cryorolling.

The objectives of this study were to produce ultrafine-grained (UFG) AA2024 aluminum alloy by cryorolling followed by aging and to evaluate its corrosion behavior. Solutionized samples were cryorolled to ~85% reduction in thickness. Subsequent aging resulted in a UFG structure with finer precipitates of Al2CuMg in the cryorolled alloy. The (1) solutionized and (2) solutionized and cryorolled samples were uniformly aged at 160°C/24 h and were designated as CGPA and CRPA, respectively; these samples were subsequently subjected to corrosion studies. Potentiodynamic polarization studies in 3.5wt% NaCl solution indicated an increase in corrosion potential and a decrease in corrosion current density for CRPA compared to CGPA. In the case of CRPA, electrochemical impedance spectroscopic studies indicated the presence of two complex passive oxide layers with a higher charge transfer resistance and lower mass loss during intergranular corrosion tests. The improved corrosion resistance of CRPA was mainly attributed to its UFG structure, uniform distribution of fine precipitates, and absence of coarse grain-boundary precipitation and associated precipitate-free zones as compared with the CGPA alloy

Techniques for measuring aerosol attenuation using the Central Laser Facility at the Pierre Auger Observatory

The Pierre Auger Observatory in Malargüe, Argentina, is designed to study the properties of ultra-high energy cosmic rays with energies above 10(18) eV. It is a hybrid facility that employs a Fluorescence Detector to perform nearly calorimetric measurements of Extensive Air Shower energies. To obtain reliable calorimetric information from the FD, the atmospheric conditions at the observatory need to be continuously monitored during data acquisition. In particular, light attenuation due to aerosols is an important atmospheric correction. The aerosol concentration is highly variable, so that the aerosol attenuation needs to be evaluated hourly. We use light from the Central Laser Facility, located near the center of the observatory site, having an optical signature comparable to that of the highest energy showers detected by the FD. This paper presents two procedures developed to retrieve the aerosol attenuation of fluorescence light from CLF laser shots. Cross checks between the two methods demonstrate that results from both analyses are compatible, and that the uncertainties are well understood. The measurements of the aerosol attenuation provided by the two procedures are currently used at the Pierre Auger Observatory to reconstruct air shower data

The rapid atmospheric monitoring system of the Pierre Auger Observatory

The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10(17) eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e. g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or 'rapid') monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction

The Rapid Atmospheric Monitoring System of the Pierre Auger Observatory

The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10^17 eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e.g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or "rapid") monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction

Ultrahigh energy neutrinos at the pierre auger observatory

The observation of ultrahigh energy neutrinos (UHEs) has become a priority in experimental astroparticle physics. UHEs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ) or in the Earth crust (Earth-skimming ), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and criteria established to search for UHEs in the data collected with the ground array of the Pierre Auger Observatory.This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEs in the EeV range and above

Description of Atmospheric Conditions at the Pierre Auger Observatory using the Global Data Assimilation System (GDAS)

Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements and numerical weather predictions. GDAS provides altitude-dependent profiles of the main state variables of the atmosphere like temperature, pressure, and humidity. The original data and their application to the air shower reconstruction of the Pierre Auger Observatory are described. By comparisons with radiosonde and weather station measurements obtained on-site in Malarg\"ue and averaged monthly models, the utility of the GDAS data is shown

US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017

Ultrahigh energy neutrinos at the Pierre Auger observatory

The observation of ultrahigh energy neutrinos (UHEνs) has become a priority in experimental astroparticle physics. UHEνs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ν) or in the Earth crust (Earth-skimming ν), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and criteria established to search for UHEνs in the data collected with the ground array of the Pierre Auger Observatory. This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEνs in the EeV range and above.P. Abreu ... K. B. Barber ... J. A. Bellido ... R. W. Clay ... M. J. Cooper ... B. R. Dawson ... T. A. Harrison ... A. E. Herve ... V. C. Holmes ... J. Sorokin ... P. Wahrlich ... B. J. Whelan ... et al