4,552 research outputs found
Sea turtle nesting activity along Eglin Air Force Base on Cape San Blas and Santa Rosa Island, Florida from 1994 to 1997.
Along EAFB on Cape San BIas, the only sea turtle species nest observed has been
the loggerhead turtle. The first green turtle nest documented along the Florida panhandle
coast was observed on EAFB property, however (D. Atencio, EAFB, pers. comm). Santa
Rosa Island, located approximately 150 miles west of Cape San BIas supports a small but
consistent, group of nesting green turtles (Fig. 2). Although erosion is not as severe along
Santa Rosa Island as it is on Cape San BIas, and vehicular traffic is not permitted, sea
turtles nesting on this barrier island must survive severe tropical storms, predation, and
artificial lighting to be successful. Because this area supports a rare group of nesting green
turtles and is disturbed by intense artificial lighting from Air Force missions and adjacent
resort towns, continued monitoring is necessary. The sea turtle species that nest along this
barrier island, and the human activities that disturb those sea turtles present unique
circumstances for management ofthis area. Protection ofthe significant nesting
populations of sea turtles on EAFB properties on Cape San BIas and Santa Rosa Island
requires yearly monitoring of the nesting activity and the natural and human disturbances
influencing the nesting females.
The objectives ofthis study were to monitor sea turtle nesting along EAFB on
Cape San BIas to determine number of nests and hatching success, assess disturbances,
and determine proper management to ensure successful nesting and hatching.(56 page document
HPLC and capillary electrophoresis for determination of acids, terpenes and aldehydes in natural rosins
Rosins are natural compounds derived from pine tree resin. They have many uses in industry, including paints, adhesives and soldering fluxes. In this work HPLC and CE was used to characterise rosin samples which are composed of 90% acidic compounds and 10% neutral compounds including aldehydes and terpenes. Cyclodextrin-modified CE methods were developed for the separation of acids, terpenes and aldehyde groups. The presence and concentration of acids in several rosin samples was investigated
The Cape San Blas Ecological Study
Eglin AFB on Cape San Blas consists of approximately 250 acres located about
180 miles east of the main Eglin reservation. This area lies on the S1. Joseph peninsula,
part of a dynamic barrier island chain that extends across the northern Gulf of Mexico.
Due to the natural forces that formed Cape San Blas and those that maintain this area, St.
Joseph Peninsula has experienced severe land form change over time (see GIS land form
change maps). These changes allow for fluctuations in habitat types along Cape San Blas
(see GIS land cover change maps)that influence the floral and faunal species using this
area.
The dynamic environment along Cape San Blasincludes flatwoods, interdunal
swale, rosemary scrub, and beachfront. These habitats support a wide array of species,
including several threatened and endangered species such as the loggerhead sea turtle
(Caretta caretta), PipingPlover (Charadnus melodus), Least Tern (Sterna antillarum),
and Bald Eagle (Haliaeetus leucocephalus). Proper management of these species and their
habitats require knowledge of their abundance and distribution, and the effects
disturbances have on their survival.
In addition to threatened and endangered flora and fauna, Cape San Blas also
supports tourists and recreationists. Although Gulf County is sparsely populated, with
approximately 13,000 inhabitants throughout 578 square miles, summer tourism and heavy
recreational use of beaches for fishing, crabbing, and shelling place continued and
increasing pressure on the natural resources of these areas (Rupert 1991). Gulf County is
also one of the few remaining counties in Florida that permits vehicular traffic on its
beaches, including Cape San Blas. In addition to recreational use of these habitats;EAFB
also uses the area for military missions. Air Force property on Cape San Blas is primarily
used for radar tracking of flying missions over the Gulf of Mexico, although in recent
years it has been used for missile launchings and other various military activities.
To allow continued military and public use of Air Force property while also
protecting the unique flora and fauna of the area,EAFB proposed a characterization of the
resources found along Cape San Blas. A complete inventory of the physical features of the
area included investigating topography, soil chemistry, hydrology, archeology, and the
dynamics of land mass and land cover change over time. Various thematic layers within a
geographic information system (GIS) were used to spatially portray georeferenced data.
Large scale changes over time were assessed using stereo aerial photography. Vegetation
transects, soil samples, elevation transects, an archeological survey, freshwater wells, and
a tidal monitor were used to investigate the remaining features. (247 page document
Determination of the composition of natural rosins using cyclodextrin-modified capillary electrophoresis
Natural rosins are derived from pine tree resin. Their composition is complex and varied depending on the geographical source of the rosin and the part of the tree it is sourced from. They are used widely in industry in paints and varnishes, drug coating and as flux in soldering. Random crystallization of rosins in finished products results in problems e.g. in circuit boards, and the cause is still unclear.
Rosins are composed of 90% acidic compounds and 10% neutrals. The acidic compounds are primarily abietic acid, neoabietic acid, dehydroabietic acid palustric acid and pimaric acid. The neutral compounds compose mainly of aldehydes and terpenes. The acidic composition of rosins has been reported on widely since the early 90âs through the analysis of their methyl esters by GC-MS. However, the neutral compounds of rosins have not been thoroughly investigated.
In this project, rosin samples were analysed by Capillary Electrophoresis (CE) and High Performance Liquid Chromatography (HPLC). A CE method using cyclodextrin-modified buffers was developed and optimised in order to achieve the best separation of the three chemical groups of compounds present in this complex matrix. Having previously identified and quantified the acids present in the samples, this talk focuses on the identification of the neutral compounds present. Spiked samples and various simultaneous UV detection wavelengths were used to determine the identity of compound peaks. Possible links between the differences in composition of rosin samples, and their uses in industry were also addressed
An investigation into the sample preparation procedure and analysis of cyanoacrylate adhesives using capillary electrophoresis
In this study, the trace acid profile of cyanoacrylate adhesives was studied using capillary electrophoresis. Liquidâliquid extraction was employed as the sample preparation step before separation by capillary electrophoresis. The solubility of the adhesives was investigated using various organic solvents, e.g. hexane and dichloromethane, and chloroform was determined to be the optimum solvent as it enabled the full dissolution of the adhesive. A comprehensive stability study was performed over a 3-year period and results indicate that the adhesives were stable for 2 years after which their stability and performance degraded
Lumbar posture and trunk muscle activation during static and dynamic seated tasks on a novel dynamic ergonomic chair
peer-reviewedLow back pain (LBP) is a common musculoskeletal disorder and prolonged sitting often aggravates LBP. A novel dynamic ergonomic chair (âBack Appâ), which facilitates less hip flexion while sitting on an unstable base has been developed. This study compared lumbar posture and trunk muscle activation on this novel chair with a standard backless office chair. Twelve painfree participants completed a typing task on both chairs. Lumbar posture and trunk muscle activation were collected simultaneously and were analysed using paired t-tests. Sitting on the novel dynamic chair significantly (p 0.05) between chairs. Maintaining lordosis with less muscle activation during prolonged sitting could reduce the fatigue associated with upright sitting postures. Studies with longer sitting durations, and in people with LBP, are required.
Practitioner Summary: Sitting on a novel dynamic chair resulted in less lumbar flexion and less back muscle activation than sitting on a standard backless office chair during a typing task among pain-free participants. Facilitating lordotic sitting with less muscle activation may reduce the fatigue and discomfort often associated with lordotic sitting postures.ACCEPTEDpeer-reviewe
Towards a Cosmological Hubble Diagram for Type II-P Supernovae
We present the first high-redshift Hubble diagram for Type II-P supernovae
(SNe II-P) based upon five events at redshift up to z~0.3. This diagram was
constructed using photometry from the Canada-France-Hawaii Telescope Supernova
Legacy Survey and absorption line spectroscopy from the Keck observatory. The
method used to measure distances to these supernovae is based on recent work by
Hamuy & Pinto (2002) and exploits a correlation between the absolute brightness
of SNe II-P and the expansion velocities derived from the minimum of the Fe II
516.9 nm P-Cygni feature observed during the plateau phases. We present three
refinements to this method which significantly improve the practicality of
measuring the distances of SNe II-P at cosmologically interesting redshifts.
These are an extinction correction measurement based on the V-I colors at day
50, a cross-correlation measurement for the expansion velocity and the ability
to extrapolate such velocities accurately over almost the entire plateau phase.
We apply this revised method to our dataset of high-redshift SNe II-P and find
that the resulting Hubble diagram has a scatter of only 0.26 magnitudes, thus
demonstrating the feasibility of measuring the expansion history, with present
facilities, using a method independent of that based upon supernovae of Type
Ia.Comment: 36 pages, 16 figures, accepted for publication in Ap
Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV
The t t-bar production cross section (sigma[t t-bar]) is measured in
proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS
experiment, corresponding to an integrated luminosity of 2.3 inverse
femtobarns. The measurement is performed in events with two leptons (electrons
or muons) in the final state, at least two jets identified as jets originating
from b quarks, and the presence of an imbalance in transverse momentum. The
measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/-
2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction
of the standard model.Comment: Replaced with published version. Included journal reference and DO
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Combined search for the quarks of a sequential fourth generation
Results are presented from a search for a fourth generation of quarks
produced singly or in pairs in a data set corresponding to an integrated
luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in
2011. A novel strategy has been developed for a combined search for quarks of
the up and down type in decay channels with at least one isolated muon or
electron. Limits on the mass of the fourth-generation quarks and the relevant
Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a
simple extension of the standard model with a sequential fourth generation of
fermions. The existence of mass-degenerate fourth-generation quarks with masses
below 685 GeV is excluded at 95% confidence level for minimal off-diagonal
mixing between the third- and the fourth-generation quarks. With a mass
difference of 25 GeV between the quark masses, the obtained limit on the masses
of the fourth-generation quarks shifts by about +/- 20 GeV. These results
significantly reduce the allowed parameter space for a fourth generation of
fermions.Comment: Replaced with published version. Added journal reference and DO
- âŚ