FORMULATION, DEVELOPMENT AND IN-VITRO RELEASE EFFECTS OF ETHYL CELLULOSE COATED PECTIN MICROSPHERES FOR COLON TARGETING

Objective: The objective of present investigation is to design a colon targeted microspheres of 5-flourouracil by using natural polysaccharide based carrier which is inexpensive and naturally occurring and also having hydrophilic and swelling properties. Methods: The pectin microspheres were prepared by ionotropic-external gelation technique and drug loaded pectin microspheres were coated with ethyl cellulose by co-acervation phase separation method. Results and Conclusion: The in-vitro drug release effects behavior of 5-flourouracil microspheres done in various pH conditions for pectin microspheres, ethyl cellulose coated pectin microspheres and ethyl cellulose coated pectin microspheres in presence of pectinase enzyme up to 12 hr. The prepared microspheres were characterized by entrapment efficiency, particle size, micromeritic properties, in-vitro release behavior, scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) etc. It was observed that increasing the polymer concentration along with the cross-linking time given the better affect of microspheres characteristic and percentage release of drug.   Key words: 5-Flourouracil; Natural Polysaccharide; Ethyl cellulose; Ionotropic gelatination; Pectinase enzyme

Single-vehicle data of highway traffic - a statistical analysis

In the present paper single-vehicle data of highway traffic are analyzed in great detail. By using the single-vehicle data directly empirical time-headway distributions and speed-distance relations can be established. Both quantities yield relevant information about the microscopic states. Several fundamental diagrams are also presented, which are based on time-averaged quantities and compared with earlier empirical investigations. In the remaining part time-series analyses of the averaged as well as the single-vehicle data are carried out. The results will be used in order to propose objective criteria for an identification of the different traffic states, e.g. synchronized traffic.Comment: 12 pages, 19 figures, RevTe

On generalized cluster algorithms for frustrated spin models

Standard Monte Carlo cluster algorithms have proven to be very effective for many different spin models, however they fail for frustrated spin systems. Recently a generalized cluster algorithm was introduced that works extremely well for the fully frustrated Ising model on a square lattice, by placing bonds between sites based on information from plaquettes rather than links of the lattice. Here we study some properties of this algorithm and some variants of it. We introduce a practical methodology for constructing a generalized cluster algorithm for a given spin model, and investigate apply this method to some other frustrated Ising models. We find that such algorithms work well for simple fully frustrated Ising models in two dimensions, but appear to work poorly or not at all for more complex models such as spin glasses.Comment: 34 pages in RevTeX. No figures included. A compressed postscript file for the paper with figures can be obtained via anonymous ftp to minerva.npac.syr.edu in users/paulc/papers/SCCS-527.ps.Z. Syracuse University NPAC technical report SCCS-52

Twenty five years after KLS: A celebration of non-equilibrium statistical mechanics

When Lenz proposed a simple model for phase transitions in magnetism, he couldn't have imagined that the "Ising model" was to become a jewel in field of equilibrium statistical mechanics. Its role spans the spectrum, from a good pedagogical example to a universality class in critical phenomena. A quarter century ago, Katz, Lebowitz and Spohn found a similar treasure. By introducing a seemingly trivial modification to the Ising lattice gas, they took it into the vast realms of non-equilibrium statistical mechanics. An abundant variety of unexpected behavior emerged and caught many of us by surprise. We present a brief review of some of the new insights garnered and some of the outstanding puzzles, as well as speculate on the model's role in the future of non-equilibrium statistical physics.Comment: 3 figures. Proceedings of 100th Statistical Mechanics Meeting, Rutgers, NJ (December, 2008

Single-particle and collective excitations in Zn 66

Single-particle and collective excitations in Zn66 have been investigated via the multinucleon transfer reaction, Mg26(Ca48, α4nγ) using the Gammasphere multidetector array and the Fragment Mass Analyzer. In addition to confirming and complementing the previously known low-spin structure, a new quasirotational band comprising several stretched E2 transitions has been established to high spins. However, due to fragmentary nature of its decay, it was not possible to link this sequence to the low-lying states and, thus, determine the absolute excitation energies, spins, and parities unambiguously. Large-scale shell-model calculations employing the JUN45 and jj44b effective interactions are able to successfully describe the low-spin structure and herewith confirm that it is dominated by single-particle excitations. The newly established rotational cascade is compared with known superdeformed bands in the A≈60-70 mass region, and with results of calculations performed within the frameworks of the cranked shell model and the adiabatic and configuration-fixed constrained covariant density functional theory and the quantum particle-rotor model

Single-particle and dipole excitations in Co 62

An extensive study of the level structure of Co62 has been performed following a complex multinucleon transfer reaction, Mg26(Ca48, 2α3npγ)Co62, at beam energies of 275, 290, and 320 MeV. The combination of the Gammasphere array, the fragment mass analyzer, and a focal-plane ionization chamber was used to identify and delineate excited levels in Co62. A considerable extension to the Co62 level scheme is proposed with firm spin-parity values assigned on the basis of angular distribution and correlation analyses. Various level sequences built upon states of single-particle character have been observed, and an interpretation of these structures in the framework of the spherical shell model is presented. At moderate spins, two dipole bands have been observed and, based on their phenomenological study, a possible magnetic rotation character is suggested. However, theoretical calculations performed using the particle rotor model support magnetic rotation for only one of these dipole bands

Classical Open String Integrability

We present a simple procedure to construct non-local conserved charges for classical open strings on coset spaces. This is done by including suitable reflection matrices on the classical transfer matrix. The reflection matrices must obey certain conditions for the charges to be conserved and in involution. We then study bosonic open strings on $AdS_5\times S^5$. We consider boundary conditions corresponding to Giant Gravitons on $S^5$, $AdS_4\times S^2$ D5-branes and $AdS_5 \times S^3$ D7-branes. We find that we can construct the conserved charges for the full bosonic string on a Maximal Giant Graviton or a D7-brane. For the D5-brane, we find that this is possible only in a SU(2) sub-sector of the open string. Moreover, the charges can not be constructed at all for non-maximal Giant Gravitons. We discuss the interpretation of these results in terms of the dual gauge theory spin chains.Comment: 23 pages, JHEP styl

γ -ray spectroscopy of Tl 209

States in Tl209 were populated using a multinucleon transfer reaction with a Xe136 beam impinging on a thick Pb208 target at E=785 MeV. The beam was pulsed at 825-ns intervals in order to perform isomer decay spectroscopy. The known Jπ=17/2+ isomer in Tl209 was located at 1228(4) keV and measured to have a half-life of T1/2=146(10) ns. A second isomer with Jπ=13/2+ was found to have T1/2=14(5) ns. The previously suggested low-energy X and Y transitions were found to have energies 57(2) and 47(2) keV respectively, while the measurement of conversion coefficients and a new decay path make the spin assignments below the isomers experimentally firm. Correlating the delayed γ transitions with the prompt beam flash allowed the decay of states above the isomer to be found. The longer-lived isomer represents full alignment of the simplest two-particle, one-hole configuration and illuminates the remarkably weak coupling of the proton hole to the Pb210 core

Ground-state and decay properties of neutron-rich Nb 106

The ground-state properties of neutron-rich Nb106 and its β decay into Mo106 have been studied using the CARIBU radioactive-ion-beam facility at Argonne National Laboratory. Niobium-106 ions were extracted from a Cf252 fission source and mass separated before being delivered as low-energy beams to the Canadian Penning Trap, as well as the X-Array and SATURN β-decay-spectroscopy station. The measured Nb106 ground-state mass excess of -66202.0(13) keV is consistent with a recent measurement but has three times better precision; this work also rules out the existence of a second long-lived, β-decaying state in Nb106 above 5 keV in excitation energy. The decay half-life of Nb106 was measured to be 1.097(21) s, which is 8% longer than the adopted value. The level scheme of the decay progeny, Mo106, has been expanded up to ≈4MeV. The distribution of decay strength and considerable population of excited states in Mo106 of J≥3 emphasizes the need to revise the adopted Jπ=1- ground-state spin-parity assignment of Nb106; it is more likely to be J≥3