A CFD Study of Industrial Double-Cyclone in HDPE Drying Process

Double-cyclone in fluidized bed drying is an important equipment which reflects the conditions of drying in HDPE slurry process. Cyclone is an important unite of fluidized bed drying in order to move the solid particles outward to its wall. Therefore, flow pattern created in fluidized bed will affect industrial cyclones installed in dryer for dust removing. Pressure drop of the cyclones is an effective parameter represents the drying behavior. Substantially, geometry of cyclone, inlet flow rate of gas, density and particle size distribution (PSD) can affect the pressure drop value. Fluidized bed hydrodynamic regime is very complex and must be understood to improve fluidized bed operations through theoretical, industrial and CFD study of double-cyclone. Pressure drop is introduced as parameter related to the cyclone efficiency can be calculated with ANSYS Fluent software in the Eulerian-Lagrangian framework with RNG k-ɛ turbulence model used as a mathematical method. Proper pressure drop concluded from industrial experiments and CFD calculation shows good fluidization of HDPE particles in the bed of nitrogen and powder  to reach the best fluidized bed situation and suitable quality of HDPE powdery product

Thermodynamics of a Bardeen black hole in noncommutative space

In this paper, we examine the effects of space noncommutativity on the thermodynamics of a Bardeen charged regular black hole. For a suitable choice of sets of parameters, the behavior of the singularity, horizon, mass function, black hole mass, temperature, entropy and its differential, area and energy distribution of the Bardeen solution have been discussed graphically for both noncommutative and commutative spaces. Graphs show that the commutative coordinates extrapolate all such quantities (except temperature) for a given set of parameters. It is interesting to mention here that these sets of parameters provide the singularity (essential for $r_h>0$) and horizon ($f(r_h)=0$ for $r_h>0$) for the black hole solution in noncommutative space, while for commutative space no such quantity exists.Comment: 17 pages, 9 figures, accepted for publication in Canadian J. Physic

Exact analytical expression for magnetoresistance using quantum groups

We obtain an exact analytical expression for magnetoresistance using noncommutative geometry and quantum groups.Then we will show that there is a deep relationship between magnetoresistance and the quantum group $su_{q}(2)$, from which we understand the quantum interpretation of the quantum corrections to the conductivity.Comment: 8 pages, 3 figures, replaced with the version published in Physics Letters

Evaluation of the large pelagic fishes (Scomberidae family) for optimum exploitation level in the Persian Gulf

Reproductive biology, Diet and population dynamics parameters of narrow-barred Spanish mackerel, Scomberomorus commerson, in the Persian Gulf were studied during 2011-2012. Fork length frequencies were collected from the commercial catch and from the current fishery nets (gill nets with 9 and 14cm mesh size) at the landing places. During 5 periods in October, December, March, April and July 20-40 specimens were also purchased from the fishermen at several landing sites to investigate and recording of data for feeding and reproductive conditions. Fork length (FL) of 2742 fishes was recorded to the nearest cm and weight of the specimens were measured to the nearest 0.01kg. FiSAT program was used to assess growth and mortality parameters. Reproductive maturity stages were assessed macroscopically using a five element scheme based on gonad size and appearance. The numbers of ovaries were fixed and preserved in 10% formalin. Central sections were embedded in wax, sectioned Hematoxylin–Eosin stains. For this subset, gonad maturation was categorized histological using a simplified five-stage description scheme and compared with the macroscopic assessments for validation. A Gonosomatic index (GSI) was also calculated for each fish. Feeding condition results showed that, sardines are the major prey of S. commerson. Pony fishes, Haltbeak and Indian mackerel were observed in the stomach content. These preys can be assumed as a secondary or accidental food items. Liver Somatic Index (HSI) was maximum in April and minimum in July. The annual instantaneous rate of fishing mortality (F= 0.42 year^−1) was considerably greater than the target (Fopt= 0.28) and limit (Flimit= 0.37) biological reference points, suggesting that the stock is heavily overexploited. Feeding and nutrition results showed that sardines are the major items prey of king S. commerson. Ponyfish, haltbeak and Indian mackerel fishes were observed in diet that can be considered as secondary or accidental foods. Maximum and minimum of Kn index was in October (9.3) and in March respectively. Liver Somatic Index (HSI) was the highest rate in February (1.70) and the lowest in July (0.85) that indicated on the worst and the best condition of fish in the mentioned periods respectively. No difference was observed in the weight stomach index and weight index (SI) in two sexes and it was about 0.09. The smallest of fish was observed 17cm FL and the biggest was 152cm FL. The mean size of fork length frequency was observed from maximum108cm (SD= 24) in February to minimum 29.4cm (SD= 5.5) in September. Based on growth curve analysis, growth parameters, K and L_∞ were estimated 0.23year^−1 and 156.45 cm respectively. Instantaneous total mortality (Z), was 1.13 year^−1 . The estimate of M was 0.43 year^−1 and thus, the estimate of F was0.7 year^−1 . This translates to an exploitation rate (F/Z) of 0.69 year^−1 . Target (Fopt) and limit (Flimit) biological reference points were calculated 0.17 year^−1 and 0.22 year^−1 respectively. The size at capture at a probability of 0.25 (L25), 0.5 (L.5) and 0.75 (L.75) was35.84 cm, 40.28cm and 61.98 cm respectively. Tmax was calculated as 3/K equal to 6 years. Matured females (Stages III, IV) were observed between mostly between April to July. By July, most fishes were in ripped and spent stages (StagesIV, V) indicating the end of the spawning season. The result of GSI avtivity in 153 male and female fish indicated the highest reproductive activity from April to July with the peak of July. The present study results shows that the highest of catch rate were done in 1 and 2 years olds of fish. Although exploitation rate have not indicated over fishing but Fopt and Flimit rates are less than fishing mortality that shows overexploitation was happened. Changes of the mesh size in the gillnet of 9cm and the size of the nets should be considered. Banning of the king mackerel catch in the June and July that is the spawning peak period can be helped to the brood stocks

Fully supersymmetric CP violations in the kaon system

We show that, on the contrary to the usual claims, fully supersymmetric CP violations in the kaon system are possible through the gluino mediated flavor changing interactions. Both $\epsilon_K$ and ${\rm Re} (\epsilon' / \epsilon_K)$ can be accommodated for relatively large $\tan\beta$ without any fine tunings or contradictions to the FCNC and EDM constraints.Comment: Contribution to the Proceedings of ICHEP2000, Osaka, 200

Landau Analog Levels for Dipoles in the Noncommutative Space and Phase Space

In the present contribution we investigate the Landau analog energy quantization for neutral particles, that possesses a nonzero permanent magnetic and electric dipole moments, in the presence of an homogeneous electric and magnetic external fields in the context of the noncommutative quantum mechanics. Also, we analyze the Landau--Aharonov--Casher and Landau--He--McKellar--Wilkens quantization due to noncommutative quantum dynamics of magnetic and electric dipoles in the presence of an external electric and magnetic fields and the energy spectrum and the eigenfunctions are obtained. Furthermore, we have analyzed Landau quantization analogs in the noncommutative phase space, and we obtain also the energy spectrum and the eigenfunctions in this context.Comment: 20 pages, references adde

Observation of the rare decay K_S -> pi^0mu^+mu^-

A search for the decay K_S -> pi^0mu^+mu^- has been made by the NA48/1 Collaboration at the CERN SPS accelerator. The data were collected during 2002 with a high-intensity K_S beam. Six events were found with a background expectation of 0.22^+0.18_-0.11 event. Using a vector matrix element and unit form factor, the measured branching ratio is B(K_S -> pi^0mu^+mu^-)=[2.9^+1.5_-1.2(stat)+/-0.2(syst)]x10^{-9}.Comment: 19 pages, 8 figures, 4 tables. To be published in Physics Letters

Search for direct CP-violation in K+- --> pi+-pi0pi0 decays

A search for direct CP-violation in K+- --> pi+-pi0pi0 decays based on 47.14 million events has been performed by the NA48/2 experiment at the CERN SPS. The asymmetry in the Dalitz plot linear slopes A_g=(g^+ - g^-)/(g^+ + g^-) is measured to be A_g=(1.8 +- 2.6).10^{-4}. The design of the experiment and the method of analysis provide good control of instrumental charge asymmetries in this measurement. The precision of the result is limited by statistics and is almost one order of magnitude better than that of previous measurements by other experiments.Comment: 14 page

Search for the Rare Decay KL --> pi0 ee

The KTeV/E799 experiment at Fermilab has searched for the rare kaon decay KL--> pi0ee. This mode is expected to have a significant CP violating component. The measurement of its branching ratio could support the Standard Model or could indicate the existence of new physics. This letter reports new results from the 1999-2000 data set. One event is observed with an expected background at 0.99 +/- 0.35 events. We set a limit on the branching ratio of 3.5 x 10^(-10) at the 90% confidence level. Combining the results with the dataset taken in 1997 yields the final KTeV result: BR(KL --> pi0 ee) < 2.8 x 10^(-10) at 90% CL.Comment: 4 pages, three figure