1,016 research outputs found
Acquisition of acid vapor and aerosol concentration data for use in dry deposition studies in the South Coast Air Basin
An atmospheric monitoring network was operated throughout the South Coast Air Basin in the greater Los Angeles area during the year 1986. The primary objective of this study was to measure the spatial and temporal concentration distributions of atmospheric gas phase and particulate phase acids and bases in support of the California Air Resources Board's dry deposition research program. Gaseous pollutants measured include HNO_3, HCl, HF, HBr, formic acid, acetic acid and ammonia. The chemical composition of the airborne particulate matter complex was examined in three size ranges: fine particles (less than 2.2 μm aerodynamic diameter, AD), PM_(10) (less than 10 μm AD) and total particles (no size discrimination).
Upwind of the air basin at San Nicolas Island, gas phase acids concentrations are very low: averaging 0.3 μg m^(-3) (0.1 ppb) for HNO_3, 0.8 μg m^(-3) for HCl, 0.13 μg m^(-3) for HF, and 2.6 μg m^(-3) for formic acid. Annual average HN03 concentrations ranged from 3.1 μg m^(-3) (1.2 ppb) near the Southern California coast to 6.9 μg m^(-3) (2.7 ppb) at an inland site in the San Gabriel Mountains. HCl concentrations within the South Coast Air Basin averaged from 0.8 μg m^(-3) to 1.8 μg m^(-3) during the year 1986. Long-term average HF concentrations within the air basin are very low, in the range from 0.14 to 0.22 μg m^(-3) between monitoring sites. Long-term average formic acid concentrations are lowest near the coastline (5.0 μg m^(-3) at Hawthorne), with the highest average concentrations (10.7 μg m^(-3)) observed inland at Upland.
Ammonia concentrations at low elevation within the South Coast Air Basin average from 2.1 μg m^(-3) to 4.4 μg m^(-3) at all sites except Rubidoux. Rubidoux is located directly downwind of a large ammonia source created by dairy farming and other agricultural activities in the Chino area. Ammonia concentrations at Rubidoux average 30 μg m^(-3) during 1986, a factor of approximately 10 higher than elsewhere in the air basin.
Annual average PM_(10) mass concentrations within the South Coast Air Basin ranged from 47.0 μg m^(-3) along the coast to 87.4 μg m^(-3) at Rubidoux, the farthest inland monitoring site. Five major aerosol components (carbonaceous material, NO_3^-, SO_4^-, NH_4^+ and soil-related material) accounted for greater than 80% of the annual average PM_(10) mass concentration at all on-land monitoring stations. A peak 24-h average PM_(10) mass concentration of 299 μg m^(-3) was observed at Rubidoux during 1986. That value is a factor of 2 higher than the federal 24-h average PM_(10) concentration standard, and a factor of 6 higher than the State of California PM_(10) standard. More than 40% of the PM_(10) aerosol mass measured at Rubidoux during that peak day event consisted of aerosol nitrates plus ammonium ion. Reaction of gaseous nitric acid to form aerosol nitrates was a major contributor to the high PM_(10) concentrations observed in the Rubidoux area near Riverside, California
In search of Insights from Community of Practice and Use of Telemedicine in Low income Countries: The case of Ethiopia
The use of ICT for exchange of medical records in provision of health care services appears to be a viable option for enhancing the capacity of low income developing countries struggling with shortage of qualified medical personnel. This study seeks to gain a preliminary assessment of whether health professionals who work in the health facilities covered by the Ethio-Indian Telemedicine program have adopted and used the Telemedicine technology to enhance health care services. Among other things, the study also aims to understand the extent to which health professionals in the study area consider Telemedicine as a viable option for delivery of health care services. Survey will be conducted to gather information from users in the study area. The study is primarily informed by literature on Community of Practice, Unified Theory of Acceptance and Use of Technology, and Case Study Research
Mangrove microflora as potential source of hydrolytic enzymes for commercial applications
678-684The purpose of this study was to isolate and characterize mangrove microflora based on their hydrolytic enzyme production. A collection of 100 microorganisms including bacteria, actinomycetes, fungi and yeasts was isolated. The ability of microbial isolates to degrade hydrolytic enzymes such as amylase, cellulase, chitinase, glutaminase, laccase, ligninase, lipase, protease and tyrosinase were tested and the potent strains were identified based on 16S rRNA and ITS sequencing. More than 90% of the isolates exhibited amylolytic and proteolytic activity. Potent isolates were identified as: Bacillus subtilis (MB1), Bacillus amyloliquefaciens (MB11), Bacillus megaterium (MB23), Bacillus mojavensis (MB28), Streptomyces galbus (MA7), Streptomyces sp. (MA3), Candida parapsilopsis (MY6), Candida etchellsi (MY1), Penicillium citrinum (MF5), Aspergillus stellifer (MF12) and Emericella sp. (MF18). These microbes as well as the enzymes are of potential importance for commercial applications as bioremediators, detergent additives and nutritional supplements
A high-resolution daily global dataset of statistically downscaled CMIP6 models for climate impact analyses
THE USE OF ICT FOR SECURITY AND THEFT PREVENTION IN TWO UNIVERSITY LIBRARIES IN NIGERIA
The study investigated the use of ICT for security and theft prevention in two university libraries in Nigeria. Population of the study is made up of 80 library staff of the two universities, 40 library staff from Umaru Musa Yar’adua University, Katsina and 40 library staff from Al-Qalam University Katsina. Five research questions guided the study. The data was analyzed with the use of simple statistical tools like frequencies and percentages. Findings of the study revealed that maximum security in the libraries will prevent theft mutilation. It also revealed that a video surveillance system working in conjunction with a barcode and magnetic book control system could help prevent book theft and monitor the move of books and other resources as it moves from one user to another. Lack of literate or skilled personnel: libraries and information Centre’s lack skilled personnel that can operate, teach and instruct the use of these telecommunication security systems even when they are made available in the library. Poor power supply: These telecommunication security systems or devices need electricity to power them and due to the poor power supply, these systems often time are not working and as such are incapable of performing their expected task of securing the library and its collection. Hardware and software failure: This is major threat to the use of telecommunication security system in the library. When there is software failure or hardware breakdown that may require the need for an engineer who may not be available to put them in place as at when due, then the library system and its collections is at risk. Based on the findings of the study, it was recommended that the librarian and information experts should take out time to educate their parent organization on the benefits associated with libraries and information Centre’s in the use of telecommunication security systems and devices so that the library parent body can release adequate fund which will be used for the purchase of telecommunication security devices in the librar
HCN Observations of Dense Star-Forming Gas in High Redshift Galaxies
We present here the sensitive HCN(1-0) observations made with the VLA of two
submillimeter galaxies and two QSOs at high-redshift. HCN emission is the
signature of dense molecular gas found in GMC cores, the actual sites of
massive star formation. We have made the first detection of HCN in a
submillimeter galaxy, SMM J16359+6612. The HCN emission is seen with a signal
to noise ratio of 4 and appears to be resolved as a double-source of
\approxlt 2'' separation. Our new HCN observations, combined with previous
HCN detections and upper limits, show that the FIR/HCN ratios in these high
redshift sources lie systematically above the FIR/HCN correlation established
for nearby galaxies by about a factor of 2. Even considering the scatter in the
data and the presence of upper limits, this is an indication that the FIR/HCN
ratios for the early Universe molecular emission line galaxies (EMGs) deviate
from the correlation that fits Galactic giant molecular cloud cores, normal
spirals, LIRGs, and ULIRGs. This indicates that the star formation rate per
solar mass of dense molecular gas is higher in the high- objects than in
local galaxies including normal spirals LIRGs and ULIRGs. The limited HCN
detections at high-redshift show that the HCN/CO ratios for the high-
objects are high and are comparable to those of the local ULIRGs rather than
those of normal spirals. This indicates that EMGs have a high fraction of dense
molecular gas compared to total molecular gas traced by CO emission.Comment: 14 pages including 4 figures; ApJL accepte
Intersection theory on the moduli space of holomorphic curves with Lagrangian boundary conditions
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2006.Includes bibliographical references (p. 107-109).We define a new family of open Gromov-Witten type invariants based on intersection theory on the moduli space of pseudoholomorphic curves of arbitrary genus with boundary in a Lagrangian submanifold. We assume the Lagrangian submanifold arises as the fixed points of an anti-symplectic involution and has dimension 2 or 3. In the strongly semi-positive genus 0 case, the new invariants coincide with Welschinger's invariant counts of real pseudoholomorphic curves. Furthermore, we calculate the new invariant for the real quintic threefold in genus 0 and degree 1 to be 30. The techniques we introduce lay the groundwork for verifying predictions of mirror symmetry for the real quintic.by Jake P. Solomon.Ph.D
On the interaction of Jupiter's Great Red Spot and zonal jet streams
In this paper, Jupiter's Great Red Spot (GRS) is used to determine properties
of the Jovian atmosphere that cannot otherwise be found. These properties
include the potential vorticity of the GRS and its neighboring jet streams, the
shear imposed on the GRS by the jet streams, and the vertical entropy gradient
(i.e., Rossby deformation radius). The cloud cover of the GRS, which is often
used to define the GRS's area and aspect ratio, is found to differ
significantly from the region of the GRS's potential vorticity anomaly. The
westward-going jet stream to the north of the GRS and the eastward-going jet
stream to its south are each found to have a large potential vorticity
``jump''. The jumps have opposite sign and as a consequence of their
interaction with the GRS, the shear imposed on the GRS is reduced. The
east-west to north-south aspect ratio of the GRS's potential vorticity anomaly
depends on the ratio of the imposed shear to the strength of the anomaly. The
aspect ratio is found to be 2:1, but without the opposing jumps it
would be much greater. The GRS's high-speed collar and quiescent interior
require that the potential vorticity in the interior be approximately half that
in the collar. No other persistent geophysical vortex has a significant minimum
of potential vorticity in its interior and laboratory vortices with such a
minimum are unstable.Comment: Manuscript accepted to Journal of the Atmospheric Sciences, March
2007. v2: minor stylistic changes (after journal proof reading
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