8,224 research outputs found
A model for - kaon cross section
We calculate the cross section for the dissociation of by kaons
within the framework of a meson exchange model. We find that, depending on the
values of the coupling constants used, the cross section can vary from 5 mb to
30 mb at GeV.Comment: 4 pages, 3 eps figure
-kaon cross section in meson exchange model
We calculate the cross section for the dissociation of by kaons
within the framework of a meson exchange model including anomalous parity
interactions. Off-shell effects at the vertices were handled with QCD sum rule
estimates for the running coupling constants. The total -kaon cross
section was found to be mb for 4.1\leq\sqrt{s}\leq5 \GeV.Comment: 13 pages, 4 eps figure
Encapsulation of alpha-amylase into starch-based biomaterials : an enzymatic approach to tailor their degradation rate
This paper reports the effect of a-amylase encapsulation on the degradation rate of a starch-based biomaterial. The encapsulation
method consisted in mixing a thermostable a-amylase with a blend of corn starch and polycaprolactone (SPCL), which were processed
by compression moulding to produce circular disks. The presence of water was avoided to keep the water activity low and consequently
to minimize the enzyme activity during the encapsulation process. No degradation of the starch matrix occurred during processing and
storage (the encapsulated enzyme remained inactive due to the absence of water), since no significant amount of reducing sugars was
detected in solution. After the encapsulation process, the released enzyme activity from the SPCL disks after 28 days was found to be
40% comparatively to the free enzyme (unprocessed). Degradation studies on SPCL disks, with a-amylase encapsulated or free in solution,
showed no significant differences on the degradation behaviour between both conditions. This indicates that a-amylase enzyme was
successfully encapsulated with almost full retention of its enzymatic activity and the encapsulation of a-amylase clearly accelerates the
degradation rate of the SPCL disks, when compared with the enzyme-free disks. The results obtained in this work show that degradation
kinetics of the starch polymer can be controlled by the amount of encapsulated a-amylase into the matrix.This work was partially supported by Portuguese Foundation for Science and Technology (FCT) through funds from the POCTI and/or FEDER Programmes. This work was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283)
Understanding the enzymatic degradation of biodegradable polymers and strategies to control their degradation rate
Adapted raised cosine window function for array factor control with dynamic range ratio limitation
The use of window functions to improve the side
lobe level of antenna arrays is hindered by high value of
excitation currents dynamic range ratio. This paper proposes a
fast and iterative window function generation strategy aimed
at achieving improved side lobe level starting from a preset
current dynamic range ratio. Based on this strategy a new
window function is developed for standard set of conditions.info:eu-repo/semantics/publishedVersio
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