scholarly journals Columnar Aerosol Extinction Characteristics: Measurements from a Free-Tropospheric Observatory in Western-Himalayas

1970 ◽  
Vol 8 (3) ◽  
pp. 52-57 ◽  
Author(s):  
Mukunda M Gogoi ◽  
Jai Prakash Chaubey ◽  
V Sreekanth ◽  
Sobhan Kumar Kompalli ◽  
S Suresh Babu ◽  
...  
Keyword(s):  
High Altitude ◽  
Spectral Dependence ◽  
Mean Value ◽  
Aerosol Extinction ◽  
Western Himalayas ◽  
Continuous Measurements ◽  
Multi Wavelength ◽  
Very High ◽  
Extinction Characteristics ◽  
Measurement Period

Continuous measurements of spectral aerosol optical depths (AOD) were made over a very high altitude aerosol observatory at Hanle (32.76°N, 78.95°E, 4520 m amsl), during the summer and autumn of 2009 and 2010, by using a 10-channel multi-wavelength radiometer (MWR). The results depicted very low values of AOD (with a mean for the measurement period as ~ 0.071 ± 0.003 at 500 nm), but with a spectral dependence that changed with the months from ~ 0.8 to 1.3, with a mean value of ~ 1.01 ± 0.06. The AODs though were in general comparable to those seen over pristine Antarctic environments, are quite significant when we consider the altitude of the station. The details are presented. DOI: http://dx.doi.org/10.3126/jie.v8i3.5931 JIE 2011; 8(3): 52-57

scholarly journals Halogenated Volatile Organic Compounds in Water Samples and Inorganic Elements Levels in Ores for Characterizing a High Anthropogenic Polluted Area in the Northern Latium Region (Italy)

2021 ◽  
Vol 18 (4) ◽  
pp. 1628
Author(s):  
Mario Vincenzo Russo ◽  
Ivan Notardonato ◽  
Alberto Rosada ◽  
Giuseppe Ianiri ◽  
Pasquale Avino
Keyword(s):  
Organic Compounds ◽  
Mean Value ◽  
Greenhouse Crops ◽  
River Waters ◽  
Liquid Liquid Extraction ◽  
Volatile Organic ◽  
High Concentrations ◽  
Very High ◽  
Inorganic Fraction

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.

scholarly journals Analysis of the coefficient of variation in shear and tensile bond strength tests

2005 ◽  
Vol 13 (3) ◽  
pp. 243-246 ◽  
Author(s):  
Fábio Lourenço Romano ◽  
Gláucia Maria Bovi Ambrosano ◽  
Maria Beatriz Borges de Araújo Magnani ◽  
Darcy Flávio Nouer
Keyword(s):  
Coefficient Of Variation ◽  
Mean Value ◽  
Scientific Article ◽  
A Value ◽  
Statistical Analysis System ◽  
Strength Tests ◽  
Analysis System ◽  
Very High

The coefficient of variation is a dispersion measurement that does not depend on the unit scales, thus allowing the comparison of experimental results involving different variables. Its calculation is crucial for the adhesive experiments performed in laboratories because both precision and reliability can be verified. The aim of this study was to evaluate and to suggest a classification of the coefficient variation (CV) for in vitro experiments on shear and tensile strengths. The experiments were performed in laboratory by fifty international and national studies on adhesion materials. Statistical data allowing the estimation of the coefficient of variation was gathered from each scientific article since none of them had such a measurement previously calculated. Excel worksheet was used for organizing the data while the sample normality was tested by using Shapiro Wilk tests (alpha = 0.05) and the Statistical Analysis System software (SAS). A mean value of 6.11 (SD = 1.83) for the coefficient of variation was found by the data analysis and the data had a normal distribution (p>0.05). A range classification was proposed for the coefficient of variation from such data, that is, it should be considered low for a value lesser than 2.44; intermediate for a value between 2.44 and 7.94, high for a value between 7.94 and 9.78, and finally, very high for a value greater than 9.78. Such classification can be used as a guide for experiments on adhesion materials, thus making the planning easier as well as revealing precision and validity concerning the data.

scholarly journals Comparison Between Pressure Swing Adsorption and Liquid Oxygen Enrichment Techniques in the Atacama Large Millimeter/Submillimeter Array Facility at the Chajnantor Plateau (5,050 m)

2021 ◽  
Vol 12 ◽  
Author(s):  
Ivan Lopez ◽  
Reinaldo Aravena ◽  
Daniel Soza ◽  
Alicia Morales ◽  
Silvia Riquelme ◽  
...  
Keyword(s):  
High Altitude ◽  
Pressure Swing Adsorption ◽  
Large Scale ◽  
High Mobility ◽  
Oxygen Enrichment ◽  
Oxygen Availability ◽  
Liquid Oxygen ◽  
High Altitudes ◽  
Pressure Swing ◽  
Very High

The Chilean workforce has over 200,000 people that are intermittently exposed to altitudes over 4,000 m. In 2012, the Ministry of Health provided a technical guide for high-altitude workers that included a series of actions to mitigate the effects of hypoxia. Previous studies have shown the positive effect of oxygen enrichment at high altitudes. The Atacama Large Millimeter/submillimeter Array (ALMA) radiotelescope operates at 5,050 m [Array Operations Site (AOS)] and is the only place in the world where pressure swing adsorption (PSA) and liquid oxygen technologies have been installed at a large scale. These technologies reduce the equivalent altitude by increasing oxygen availability. This study aims to perform a retrospective comparison between the use of both technologies during operation in ALMA at 5,050 m. In each condition, variables such as oxygen (O2), temperature, and humidity were continuously recorded in each AOS rooms, and cardiorespiratory variables were registered. In addition, we compared portable O2 by using continuous or demand flow during outdoor activities at very high altitudes. The outcomes showed no differences between production procedures (PSA or liquid oxygen) in regulating oxygen availability at AOS facilities. As a result, big-scale installations have difficulties reaching the appropriate O2 concentration due to leaks in high mobility areas. In addition, the PSA plant requires adequacy and maintenance to operate at a very high altitude. A continuous flow of 2–3 l/min of portable O2 is recommended at 5,050 m.

scholarly journals SAFETY OF USE OF HIGH ALTITUDE PROTECTION SUITS FOR KINESITHERAPY – PRELIMINARY REPORT

2020 ◽  
Vol 25 (1) ◽  
pp. 50-54
Author(s):  
Maciej Abakumow ◽  
◽  
Krzysztof Kowalczuk ◽  
Keyword(s):  
Blood Pressure ◽  
Healthy Volunteers ◽  
High Altitude ◽  
Cardiovascular System ◽  
Preliminary Report ◽  
Pressure Increase ◽  
Blood Pressure Increase ◽  
Safety Considerations ◽  
Very High

Abstract: Apart from protection from very high altitude or influence of increased gravitational accelerations protective suits sometimes are used for another applications like supporting kinesitherapy. Because of some safety considerations connected with possible cardiovascular system overload and dangerous blood pressure increase we tested if these concerns are valid. Main aim ot presented research performed with participation of healthy volunteers was to confirm that use of High Altitude Protection (HAP) suit is safe in terms of increased cardiovascular.

scholarly journals Water Masers Outburst in the Massive Stellar Cluster W49A

2015 ◽  
Vol 12 (S316) ◽  
pp. 155-156
Author(s):  
Busaba H. Kramer ◽  
Karl M. Menten ◽  
Tomasz Kamiński ◽  
Bo Zhang ◽  
Nimesh A. Patel ◽  
...  
Keyword(s):  
Stellar Cluster ◽  
Star Forming ◽  
Physical Conditions ◽  
Long Baseline ◽  
Major Flare ◽  
Multi Wavelength ◽  
Remarkable Result ◽  
Water Masers ◽  
Very Long Baseline Array ◽  
Very High

AbstractWe report a multi-wavelength study of a recent major flare (~ 80,000 Jy at VLSR ~ -98.1 km s−1) of the 22-GHz water maser in W49A. In February 2014, we started monthly monitoring with the Effelsberg 100-m radio telescope. In May 2014, we carried out the nearly simultaneous observations of the 22-GHz transition with selected submillimeter water transitions using the IRAM 30-m telescope (at 183 GHz) and the Atacama Pathfinder Experiment (APEX) 12-m telescope (from 321 to 475 GHz). We have also performed interferometric observations using the NRAO Very Long Baseline Array (VLBA) at 22 GHz and the Submillimeter Array (SMA) at 321 and 325 GHz. One remarkable result is the detection of very high velocity emission features in several transitions. Our data also represent its first detection of the 475-GHz water transition in a star-forming region. Studying these multiple masing transitions in conjunction with theoretical modeling of their excitation not only places strong constraints on the physical conditions of the masing gas but also allows us to study their association with the embedded massive stellar cluster in W49A.

Holocene palaeoenvironmental records from the high-altitude Wular Lake, Western Himalayas

The Holocene ◽  
2020 ◽  
Vol 30 (5) ◽  
pp. 733-743 ◽  
Author(s):  
Rayees Ahmad Shah ◽  
Hema Achyuthan ◽  
Aasif Mohmad Lone ◽  
Sanjeev Kumar ◽  
Pankaj Kumar ◽  
...  
Keyword(s):  
High Altitude ◽  
North Atlantic ◽  
Sedimentation Rate ◽  
Lake Level ◽  
Western Himalayas ◽  
Kashmir Valley ◽  
Climate Conditions ◽  
Wular Lake ◽  
Wet Climate ◽  
Lake Margin

We present a comprehensive record of Holocene (11,590–628 cal. yr BP) climate and hydrographic changes around the Wular Lake located in Kashmir Valley, India. Based on the multi-proxy investigations, we have identified three phases of wet climate conditions that prevailed from the commencement of the Holocene Epoch – 9000 cal. yr BP, 8100–6650 cal. yr BP and 6350–5000 cal. yr BP, whereas periods of dry climate were observed during 9000–8100 cal. yr BP, 6650–6350 cal. yr BP and ~5000 to 4000 cal. yr BP. The results also suggested that the lake widened and deepened significantly around 6350–5000 cal. yr BP. The results indicated desiccation and the exposure of the lake margin around 5000–4500 cal. yr BP. The sedimentation rate since 4500–628 cal. yr BP was quite low for detailed paleoclimate interpretations. Oscillations in lake extension and deepening appear to be due to changing intensity of westerly moisture in the region, and we correlate several of the low lake-level phases to the Bond events caused by North Atlantic ice rafting events.

scholarly journals Monitoring the Extragalactic High Energy Sky

Galaxies ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 9 ◽  
Author(s):  
Jean-Philippe Lenain
Keyword(s):  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
High Energy ◽  
Line Of Sight ◽  
Data Sets ◽  
High Energies ◽  
Multi Wavelength ◽  
Rich Data ◽  
Very High

Blazars are jetted active galactic nuclei with a jet pointing close to the line of sight, hence enhancing their intrinsic luminosity and variability. Monitoring these sources is essential in order to catch them flaring and promptly organize follow-up multi-wavelength observations, which are key to providing rich data sets used to derive e.g., the emission mechanisms at work, and the size and location of the flaring zone. In this context, the Fermi-LAT has proven to be an invaluable instrument, whose data are used to trigger many follow-up observations at high and very high energies. A few examples are illustrated here, as well as a description of different data products and pipelines, with a focus given on FLaapLUC, a tool in use within the H.E.S.S. collaboration.

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