57,203 research outputs found
Batch and column adsorption of reactive dye by eggshell powder–chitosan gel core-shell material
In this study, eggshell powder-chitosan gel (EPCG) material was synthesized and tested as an adsorbent for two commercial reactive dyes in batch and dynamic modes. The EPCG material was a novel core-shell material in which the eggshell core particles were coated by a thin layer of chitosan. SEM images of dried EPCG powder showed a porous structure of the surface. In adsorption batch tests, Langmuir and Freundlich equations well described the adsorption isotherms with a maximum capacity of 2.3 mg/g at pH 4 and equilibrium time of 60 min (r2> 0.98). The adsorption process followed pseudo-second-order kinetics. Adsorption behaviour of EPCG toward the reactive dyes in fixed-bed adsorber was better described by the Clark model (r2> 0.92) than by the Bohart – Adam model (r2> 0.82). These results suggest that EPCG, as an environment-friendly material produced from waste eggshell, is very promising for wastewater treatment applications
The perimeter of large planar Voronoi cells: a double-stranded random walk
Let be the probability for a planar Poisson-Voronoi cell to have
exactly sides. We construct the asymptotic expansion of up to
terms that vanish as . We show that {\it two independent biased
random walks} executed by the polar angle determine the trajectory of the cell
perimeter. We find the limit distribution of (i) the angle between two
successive vertex vectors, and (ii) the one between two successive perimeter
segments. We obtain the probability law for the perimeter's long wavelength
deviations from circularity. We prove Lewis' law and show that it has
coefficient 1/4.Comment: Slightly extended version; journal reference adde
In an Ising model with spin-exchange dynamics damage always spreads
We investigate the spreading of damage in Ising models with Kawasaki
spin-exchange dynamics which conserves the magnetization. We first modify a
recent master equation approach to account for dynamic rules involving more
than a single site. We then derive an effective-field theory for damage
spreading in Ising models with Kawasaki spin-exchange dynamics and solve it for
a two-dimensional model on a honeycomb lattice. In contrast to the cases of
Glauber or heat-bath dynamics, we find that the damage always spreads and never
heals. In the long-time limit the average Hamming distance approaches that of
two uncorrelated systems. These results are verified by Monte-Carlo
simulations.Comment: 5 pages REVTeX, 4 EPS figures, final version as publishe
Well-Rounded ideal lattices of cyclic cubic and quartic fields
In this paper, we find criteria for when cyclic cubic and cyclic quartic
fields have well-rounded ideal lattices. We show that every cyclic cubic field
has at least one well-rounded ideal. We also prove that there exist families of
cyclic quartic fields which have well-rounded ideals and explicitly construct
their minimal bases. In addition, for a given prime number , if a cyclic
quartic field has a unique prime ideal above , then we provide the necessary
and sufficient conditions for that ideal to be well-rounded. Moreover, in
cyclic quartic fields, we provide the prime decomposition of all odd prime
numbers and construct an explicit integral basis for every prime ideal.Comment: 26 page
The Central Regions of M31 in the 3 - 5 micron Wavelength Region
Images obtained with NIRI on the Gemini North telescope are used to
investigate the photometric properties of the central regions of M31 in the 3 -
5 micron wavelength range. The light distribution in the central arcsecond
differs from what is seen in the near-infrared in the sense that the difference
in peak brigh tness between P1 and P2 is larger in M' than in K'; no obvious
signature of P3 is dete cted in M'. These results can be explained if there is
a source of emission that contributes ~ 20% of the peak M' light of P1 and has
an effective temperature of no more than a few hundred K that is located
between P1 and P2. Based on the red K-M' color of this source, it is suggested
that the emission originates in a circumstellar dust shell surrounding a single
bright AGB star. A similar bright source that is ~ 8 arcsec from the center of
the galaxy is also detected in M'. Finally, the (L', K-L') color-magnitude
diagram of unblended stars shows a domin ant AGB population with photometric
characteristics that are similar to those of the most luminous M giants in the
Galactic bulge.Comment: To appear in the Astronomical Journa
Well-Rounded Twists of Ideal Lattices from Imaginary Quadratic Fields
In this paper, we investigate the properties of well-rounded twists of a
given ideal lattice of an imaginary quadratic field . We show that every
ideal lattice of has at least one well-rounded twist lattice. Moreover,
we provide an explicit algorithm to compute all well-rounded twists of .Comment: 24 page
Differential diagnosis of dna viruses related to reproductive disorder on sows by multiplex-pcr technique
The newly emerged diseases caused by ASFV and PCV3 and their confirmed prevelance in Vietnam whereas most of available common commercial methods such as ELISA or realtime PCR designed for detecting single pathogen per reaction, highlighted a necessity for another diagnostic method to simultaneously detect and differentiate DNA viruses that are related to reproductive failures in sow herds including PCV2, PCV3, PPV, ASFV. In this communication, a diagnostic multiplex-PCR (mPCR) was established with pathogen-specific primers selected from previous studies and another set of primers designed for COX1 gene serving as an internal amplification control (IAC). The predicted products of PCV2, PCV3, PPV, ASFV and IAC were 702 bp, 223 bp, 380 bp, 278 bp and 463 bp, respectively. After optimization, the mPCR functioned specifically at 62°C. Results revealed the consistent detection limit at 100 copies/gene/reaction. In application, 185 serum samples from sows were used to examine the presence of the related pathogens. mPCR results showed that the mono-infection rate of PCV2, PCV3, PPV, and ASFV was 0% (0/185), 40% (74/185), 28.1% (52/185), and 48.1% (89/185), respectively. Regarding coinfection rate, the data indicated that coinfections of 2, 3 and 4 pathogens were 20%, 8.1% and 0% accordingly. In conclusion, the mPCR assay was successfully established and ready to serve for diagnosis of PCV2, PCV3, PPV and ASFV infection in reality with high specificity and sensitivity. It is a good contribution to a better understanding of the epidemiology of these diseases in swine
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