3,440 research outputs found
A comparative study of techniques used for porous membrane characterization: pore characterization
A range of commerical UF membranes have been characterized by thermoporometry, biliquid permporometry and molecular weight cut-off experiments. A comparison of results from these three independent techniques for the same types of membrane shows an indication of the strength and weakness of the methods. MWCO values determined from actual rejection values using PEG and dextran were significantly lower than the manufacturer supplied data. The data obtained using the biliquid permporometry and solute rejection tests produced contrasting results for Amicon polysulfone (PM30) and regenerated cellulose (YM30) membranes. While MWCO determination resulted in sharper cut-off curves, the biliquid permporometry offered a broader size distribution with the PM30 and vice versa with the YM30. The pore sizes obtained by thermoporometry were significantly larger than those by the biliquid permporometry. The biliquid permporometry and thermoporometry give significantly higher values than the MWCO method. The closest comparison is obtained between the EM values and the MWCO method. This suggests that the controlling pore dimension for separation is the surface skin dimension
Effect of laser-welding parameters on the heat input and weld-bead profile
Laser butt-welding of medium carbon steel was investigated using CW 1.5 kW CO2 laser. The effect of laser power (1.2 - 1.43 kW), welding speed (30 - 70 cm/min) and focal point position (-2.5 - 0 mm) on the heat input and the weld-bead geometry (i.e. penetration (P), welded zone width (W) and heat affected zone width (WHAZ)) was investigated using Response Surface Methodology (RSM). The experimental plan was based on Box-Behnken design. Linear and quadratic polynomial equations for predicting the heat input and the weld-bead geometry were developed. The results indicate that the proposed models predict the responses adequately within the limits of welding parameters being used. It is suggested that regression equations can be used to find optimum welding conditions for the desired criteria
Higgs Phenomenology of Scalar Sequestering
The light Higgs mass in the MSSM is highly constrained and is predicted to be
close to M_Z which causes a tension between the LEP II Higgs mass bound 114 GeV
and the natural electroweak symmetry breaking in the MSSM. The usual way to
increase the light CP even Higgs mass was to increase the quartic coupling of
the up type Higgs. We point out that the light Higgs mass can be increased by
reducing the off-diagonal term in the mass matrix when tan beta is moderate,
which is about 5 to 10. As a result no mixing and/or a Higgs mixing angle of
the opposite sign arises and the branching ratio of Higgs decay is drastically
changed. This is possible in scalar sequestering scenario in which mu parameter
can be large independently of the electroweak symmetry breaking. We also
discuss the same effect in the BMSSM.Comment: 20 pages, 6 figure
Email Intervention Following Traumatic Brain Injury: Two Case Reports
An email intervention for two individuals with TBI was conducted to investigate if this electronic medium would show potential as a therapeutic delivery method. Specifically, this study measured participantsâ compliance to a plan that incorporated email and a reading assignment. Prior to the email intervention, a clinician and participants designed an intervention plan, which included specific guidelines for scheduled email correspondence regarding a daily reading task. After reviewing the daily emails the clinician provided therapeutic feedback. The participantsâ compliance to the plan was measured by punctuality of email correspondence and completion of tasks as detailed in the plan. Over a 4-week intervention period, both participants demonstrated improvement in task completion and time adherence. With these individuals, email proved to be a feasible option as a therapeutic delivery method. Â Â Â Â Keywords: email intervention, individuals with TBI, task completion, time adherence
Studies on Hypoxia: XII. Detrimental Effects of Synthetic Polyribonucleotides on Epiphyseal Plates of Rats Exposed to Hypoxia
The effect of different doses of polyadenylic and polyuridylic acids (poly A:U) was studied in control rats and in rats exposed to hypoxia. In the control rats, administration of different doses of poly A:U did not change the thickness of the epiphyseal plate or increase the incorporation of 3H-phenylalanine as judged using radioautography. Rats exposed to hypoxia showed a significant dose-related reduction in the thickness of the epiphyseal plate and 3H-phenylalanine incorporation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67926/2/10.1177_00220345760550041701.pd
Charged Higgs bosons in the Next-to MSSM (NMSSM)
The charged Higgs boson decays and
are studied in the framework of the next-to Minimal Supersymmetric Standard
Model (NMSSM). It is found that the decay rate for can
exceed the rates for the and channels both below and above
the top-bottom threshold. The dominance of is most readily
achieved when has a large doublet component and small mass. We also study
the production process at the LHC followed by the decay
which leads to the signature . We suggest
that is a promising discovery channel for a light charged
Higgs boson in the NMSSM with small or moderate and dominant decay
mode . This signature can also arise from
the Higgsstrahlung process followed by the decay . It is shown that there exist regions of parameter space where these
processes can have comparable cross sections and we suggest that their
respective signals can be distinguished at the LHC by using appropriate
reconstruction methods.Comment: 20 pages, 22 eps figures, more reference adde
Neutrinos in 5D SO(10) Unification
We study neutrino physics in a 5D supersymmetric SO(10) GUT. We analyze
several different choices for realizing the See-Saw mechanism. We find that the
"natural" scale for the Majorana mass of right-handed neutrinos depends
critically on whether the right-handed neutrinos are located in the bulk or
localized on a brane. In the former case, the effective Majorana mass is
"naturally" of order the compactification scale, about 10^{14} GeV. Note, this
is the value necessary for obtaining a light tau neutrino mass approximately
10^{-2} eV which, within the context of hierarchical neutrino masses, is the
right order of magnitude to explain atmospheric neutrino oscillations. On the
other-hand when the right-handed neutrino is localized on the brane, the
effective Majorana mass is typically larger than the compactification scale.
Nevertheless with small parameters of order 1/10 - 1/30, an effective Majorana
mass of order 10^{14} GeV can be accommodated. We also discuss the constraints
on model building resulting from the different scenarios for locating the
right-handed neutrinos.Comment: 24 page
Experimental Entanglement Concentration and Universal Bell-state Synthesizer
We report a novel Bell-state synthesizer in which an interferometric
entanglement concentration scheme is used. An initially mixed polarization
state from type-II spontaneous parametric down-conversion becomes entangled
after the interferometric entanglement concentrator. This Bell-state
synthesizer is universal in the sense that the output polarization state is not
affected by spectral filtering, crystal thickness, and, most importantly, the
choice of pump source. It is also robust against environmental disturbance and
a more general state, partially mixedpartially entangled state, can be
readily generated as well.Comment: Minor update (Newer data
Integrated CO2 capture-fixation chemistry via interfacial ionic liquid catalyst in laminar gas/liquid flow
Simultaneous capture of carbon dioxide (CO2) and its utilization with subsequent work-up would significantly enhance the competitiveness of CO2-based sustainable chemistry over petroleum-based chemistry. Here we report an interfacial catalytic reaction platform for an integrated autonomous process of simultaneously capturing/fixing CO2 in gas-liquid laminar flow with subsequently providing a work-up step. The continuous-flow microreactor has built-in silicon nanowires (SiNWs) with immobilized ionic liquid catalysts on tips of cone-shaped nanowire bundles. Because of the superamphiphobic SiNWs, a stable gas-liquid interface maintains between liquid flow of organoamines in upper part and gas flow of CO2 in bottom part of channel. The intimate and direct contact of the binary reagents leads to enhanced mass transfer and facilitating reactions. The autonomous integrated platform produces and isolates 2-oxazolidinones and quinazolines-2,4(1H,3H)-diones with 81-97% yields under mild conditions. The platform would enable direct CO2 utilization to produce high-valued specialty chemicals from flue gases without pre-separation and work-up steps. ? 2017 The Author(s).1115Ysciescopu
Experimentally realizable characterizations of continuous variable Gaussian states
Measures of entanglement, fidelity and purity are basic yardsticks in quantum
information processing. We propose how to implement these measures using linear
devices and homodyne detectors for continuous variable Gaussian states. In
particular, the test of entanglement becomes simple with some prior knowledge
which is relevant to current experiments.Comment: 4 pages, This paper supersedes quant-ph/020315
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