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Search for supersymmetry and leptoquark states at FNAL
Searches have been made for first generation scalar and vector leptoquarks by the D0 collaboration and for second generation scalar leptoquarks by the CDF collaboration. Lower leptoquark mass limits were set. A search for squarks and gluinos, predicted by Supersymmetric models, was made by D0 in the three or more jets plus missing Et channel. The number of events observed was consistent with background. Squark and gluino mass limits were set
An assessment of the risk arising from electrical effects associated with carbon fibers released from commercial aircraft fires
The risks associated with electrical effects arising from carbon fibers released from commercial aviation aircraft fires were estimated for 1993. The expected annual losses were estimated to be about 100,000 (1977 dollars) in 1993 were established to be about one in ten thousand
Increasing compliance with wearing a medical device in children with autism
Health professionals often recommend the use of medical devices to assess the health, monitor
the well-being, or improve the quality of life of their patients. Children with autism may present
challenges in these situations as their sensory peculiarities may increase refusals to wear such
devices. To address this issue, we systematically replicated prior research by examining the
effects of differential reinforcement of other behavior (DRO) to increase compliance with
wearing a heart rate monitor in 2 children with autism. The intervention increased compliance to
100% for both participants when an edible reinforcer was delivered every 90 s. The results
indicate that DRO does not require the implementation of extinction to increase compliance with
wearing a medical device. More research is needed to examine whether the reinforcement
schedule can be further thinned
Robotic Extrusion of Algae-Laden Hydrogels for Large-Scale Applications
A bioprinting technique for large‐scale, custom‐printed immobilization of microalgae is developed for potential applications within architecture and the built environment. Alginate‐based hydrogels with various rheology modifying polymers and varying water percentages are characterized to establish a window of operation suitable for layer‐by‐layer deposition on a large scale. Hydrogels formulated with methylcellulose and carrageenan, with water percentages ranging from 80% to 92.5%, demonstrate a dominant viscoelastic solid–like property with G′ > G″ and a low phase angle, making them the most suitable for extrusion‐based printing. A custom multimaterial pneumatic extrusion system is developed to be attached on the end effector of an industrial multiaxis robot arm, allowing precision‐based numerically controlled layered deposition of the viscous hydrogel. The relationship between the various printing parameters, namely air pressure, material viscosity, viscoelasticity, feed rate, printing distance, nozzle diameter, and the speed of printing, are characterized to achieve the desired resolution of the component. Printed prototypes are postcured in CaCl2 via crosslinking. Biocompatibility tests show that cells can survive for 21 days after printing the constructs. To demonstrate the methodology for scale‐up, a 1000 × 500 mm fibrous hydrogel panel is additively deposited with 3 different hydrogels with varying water percentages
Initial Studies of the Bidirectional Reflectance Distribution Function of Multi-Walled Carbon Nanotube Structures for Stray Light Control Applications
The presentation examines the application of low reflectance surfaces in optical instruments, multi-walled carbon nanotubes (MWCNTs), research objects, MWCNT samples, measurement of 8 deg. directional/hemispherical reflectance, measurement of bidirectional reflectance distribution function (BRDF), and what is current the "blackest ever black"
Studies of the Response of the Prototype CMS Hadron Calorimeter, Including Magnetic Field Effects, to Pion, Electron, and Muon Beams
We report on the response of a prototype CMS hadron calorimeter module to
charged particle beams of pions, muons, and electrons with momenta up to 375
GeV/c. The data were taken at the H2 and H4 beamlines at CERN in 1995 and 1996.
The prototype sampling calorimeter used copper absorber plates and scintillator
tiles with wavelength shifting fibers for readout. The effects of a magnetic
field of up to 3 Tesla on the response of the calorimeter to muons, electrons,
and pions are presented, and the effects of an upstream lead tungstate crystal
electromagnetic calorimeter on the linearity and energy resolution of the
combined calorimetric system to hadrons are evaluated. The results are compared
with Monte Carlo simulations and are used to optimize the choice of total
absorber depth, sampling frequency, and longitudinal readout segmentation.Comment: 89 pages, 41 figures, to be published in NIM, corresponding author: P
de Barbaro, [email protected]
The financial cost of doctors emigrating from sub-Saharan Africa: human capital analysis
Objective To estimate the lost investment of domestically educated doctors migrating from sub-Saharan African countries to Australia, Canada, the United Kingdom, and the United States
Measurement of the Boson Mass
A measurement of the mass of the boson is presented based on a sample of
5982 decays observed in collisions at
= 1.8~TeV with the D\O\ detector during the 1992--1993 run. From a
fit to the transverse mass spectrum, combined with measurements of the
boson mass, the boson mass is measured to be .Comment: 12 pages, LaTex, style Revtex, including 3 postscript figures
(submitted to PRL
Direct Measurement of the Top Quark Mass at D0
We determine the top quark mass m_t using t-tbar pairs produced in the D0
detector by \sqrt{s} = 1.8 TeV p-pbar collisions in a 125 pb^-1 exposure at the
Fermilab Tevatron. We make a two constraint fit to m_t in t-tbar -> b W^+bbar
W^- final states with one W boson decaying to q-qbar and the other to e-nu or
mu-nu. Likelihood fits to the data yield m_t(l+jets) = 173.3 +- 5.6 (stat) +-
5.5 (syst) GeV/c^2. When this result is combined with an analysis of events in
which both W bosons decay into leptons, we obtain m_t = 172.1 +- 5.2 (stat) +-
4.9 (syst) GeV/c^2. An alternate analysis, using three constraint fits to fixed
top quark masses, gives m_t(l+jets) = 176.0 +- 7.9 (stat) +- 4.8 (syst)
GeV/C^2, consistent with the above result. Studies of kinematic distributions
of the top quark candidates are also presented.Comment: 43 pages, 53 figures, 33 tables. RevTeX. Submitted to Phys. Rev.
Search for First Generation Scalar Leptoquark Pairs in ppbar Collisions at sqrt(s)=1.8 TeV
We have searched for first generation scalar leptoquark (LQ) pairs in the
enu+jets channel using ppbar collider data (integrated luminosity= 115 pb^-1)
collected by the DZero experiment at the Fermilab Tevatron during 1992-96. The
analysis yields no candidate events. We combine the results with those from the
ee+jets and nunu+jets channels to obtain 95% confidence level (CL) upper limits
on the LQ pair production cross section as a function of mass and of beta, the
branching fraction to a charged lepton. Comparing with the next-to-leading
order theory, we set 95% CL lower limits on the LQ mass of 225, 204, and 79
GeV/c^2 for beta=1, 1/2, and 0, respectively.Comment: 14 pages, 4 figures, submitted to Physical Review Letters Replaced to
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