An investigation on the mechanics of homogeneous expansion in gas-fluidized beds

The Richardson and Zaki (1954, Sedimentation and fluidization. Trans. Inst. Chem. Eng. 32, pp. 35–53.) equation has been used extensively to investigate the expansion profiles of homogeneous gas-fluidized beds. The experimental value of the parameter n appearing in the equation indicates how significantly interparticle forces affect the expansion of these beds, revealing the relative importance of these forces with respect to the fluid dynamic ones. In this work, we modeled the stable expansion of gas-fluidized beds of different diameter, accounting for enduring contacts among particles and wall effects. We solved the model numerically to obtain the bed expansion profiles, back-calculating from them the values of the parameter n. For all the cases considered, we observed that the values of n are higher than those obtained by purely fluid dynamic correlations, such as those advanced by Richardson and Zaki, and Rowe (1987, A convenient empirical equation for estimation of the Richardson and Zaki exponent. Chem. Eng. Sci. 42, pp. 2795.). This effect was more pronounced in beds of smaller diameter. To validate our model, we carried out fluidization and defluidization experiments, analyzing the results by means of the Richardson and Zaki equation. We obtained a reasonable agreement between numerical and experimental findings; this suggests that enduring contacts among particles, which are manifestations of cohesiveness, affect homogeneous bed expansion. This effect is amplified by wall friction

Supernova 1972 e in NGC 5253

New absolute energy distributions of the Type 1 supernova 1972e in NGC 5253 extending to about 700 days after maximum light were obtained. A physical model of the expanding envelope, based on the identification of the feature at 6550 A with H-alpha, is proposed. It is described as a differentially expanding atmosphere, with electron density ranging from 10 to the 10th power near maximum light to about 10 to the 7th power, 340 days later, illuminated by a photosphere with temperature in the range 10,000 K to 7,000 K. More than 200 days after maximum, the spectrum was dominated by four features between 4200 A and 5500 A. Three of these four features matched the blended emissions from over 100 lines of Fe II. Possible identifications of the fourth feature with Mg I lambda 4571 or permitted lines of Fe II are also discussed

A Case of Bacterial Postpartum Metritis in a 4-Year Old Duroc Sow

The attention of the Animal Health team of Swine Research Unit of Swine and Rabbit Research Programme of National Animal Production Research Institute (NAPRI) was drawn to a farrowing pen with a complaint of pus discharge from the vulva of a Duroc sow which farrowed 9 piglets 10 days earlier. Microbiological survey identified the presence of Escherichia coli, Staphylococcus and Proteus species from the sterile vaginal swab was taken from the sow. Antibiogram revealed the susceptibility of the three identified bacteria to ofloxacin, streptomycin and gentamicin in the order of increasing susceptibility. Staphylococcus species was also found to be susceptible to ciprofloxacin while Proteus species was susceptible to augmentin® and chloramphenicol. All the three species of bacteria were resistant to nitrofuratoin, rocephin® and ampiclox®. The sow was treated with deep intramuscular administration of streptomycin at 20 mg/kg once daily for 5 days and 10 IU of oxytocin once daily for 2 days. There was expulsion of macerated feotus about 24 hours following administration of the last dose of oxytocin and the macerated feotus was properly disposed and the entire pen was cleaned and disinfected. The vulva was noticed to be completely devoid of the mucous discharges after the course of the antibiotic regimen.Key words: Metritis, Postpartum, Duroc, Sow, NAPRI

Fertility Parameters in Crossbred Sows Treated with Cloprostenol Sodium (Synchromate®) in Zaria, Nigeria

This study was carried out to evaluate fertility parameters in crossbred sows in Zaria, following treatment with Cloprostenol sodium (Synchromate®). Ten (n = 10) apparently healthy crossbred sows were randomly assigned to two equal treatment groups based on number of injections of 500μg Synchromate®. Group 1 received two injections on days 0 and 13, while Group 2 received three injections on days 0, 7 and 13. Oestrus was monitored visually for signs of oestrus twice daily from 0700 – 1000h and 1500 – 1800h. The fertility parameters evaluated were: oestrus response rate (ORR), time to onset of oestrus (TOO), duration of oestrus (DOO), conception rate (CR), pregnancy rate (PR), farrowing rate (FR) and litter size (LS). Data on ORR, CR, PR and FR were expressed in percentages while TOO, DOO and LS were expressed as mean ± SEM. Student t-test and Tukey’s post-hoc test were used to compare the percentages and mean values between the groups. The Graphpad Prism® data package was used for statistical analysis and values of P<0.05 were considered significant. Fertility parameters TOO, DOO, LS, ORR, CR, PR, FR for Group 1 (187.20 ± 8.98h, 87.60 ± 4.49h, 7.25 ± 1.44, 100 %, 60 %, 80 % and 100 % respectively) and Group 2 (176.00 ± 40.00h, 86.60 ± 13.36h, 7.50 ± 1.50, 60 %, 100 %, 80 % and 66.67 % respectively). The differences in fertility parameters between the groups were not statistically significant. It is recommended therefore that double injections of cloprostenol sodium (Synchromate®) should be used for oestrus synchronization as it increases fertility parameters in cross bred sows at 13 days apart.Key words: Fertility parameters, crossbred sows, cloprostenol sodium, Zaria

TOPAZ4: an ocean-sea ice data assimilation system for the North Atlantic and Arctic

We present a detailed description of TOPAZ4, the latest version of TOPAZ – a coupled ocean-sea ice data assimilation system for the North Atlantic Ocean and Arctic. It is the only operational, large-scale ocean data assimilation system that uses the ensemble Kalman filter. This means that TOPAZ features a time-evolving, state-dependent estimate of the state error covariance. Based on results from the pilot MyOcean reanalysis for 2003–2008, we demonstrate that TOPAZ4 produces a realistic estimate of the ocean circulation in the North Atlantic and the sea-ice variability in the Arctic. We find that the ensemble spread for temperature and sea-level remains fairly constant throughout the reanalysis demonstrating that the data assimilation system is robust to ensemble collapse. Moreover, the ensemble spread for ice concentration is well correlated with the actual errors. This indicates that the ensemble statistics provide reliable state-dependent error estimates – a feature that is unique to ensemble-based data assimilation systems. We demonstrate that the quality of the reanalysis changes when different sea surface temperature products are assimilated, or when in-situ profiles below the ice in the Arctic Ocean are assimilated. We find that data assimilation improves the match to independent observations compared to a free model. Improvements are particularly noticeable for ice thickness, salinity in the Arctic, and temperature in the Fram Strait, but not for transport estimates or underwater temperature. At the same time, the pilot reanalysis has revealed several flaws in the system that have degraded its performance. Finally, we show that a simple bias estimation scheme can effectively detect the seasonal or constant bias in temperature and sea-level

Decadal changes in the South Pacific western boundary current system revealed in observations and ocean state estimates

Observations and ocean state estimates are used to investigate the nature and mechanism of decadal variability in the East Australian Current (EAC) system and South Pacific subtropical gyre. A 62 year record on the Tasmanian continental shelf shows decadal variations of temperature and salinity, as well as a long‐term trend, which has been related to wind‐driven variations in the poleward extension of the EAC. Repeat expendable bathythermograph lines spanning the last 15 years suggest that low‐frequency variations in the transport of the EAC extension and Tasman Front are anticorrelated, but the time series are too short to draw firm conclusions. Here we use two ocean state estimates spanning the past 50 years to diagnose the physical mechanisms and spatial structure of the decadal variability of the South Pacific subtropical gyre. The observations and state estimates paint a consistent picture of the decadal variability of the gyre and EAC system. Strengthening of the basin‐wide wind stress curl drives a southward expansion of the subtropical gyre. As the gyre shifts south, the EAC extension pathway is favored at the expense of the Tasman Front, resulting in the observed anticorrelation of the these two major currents. The results suggest that the subtropical gyre and western boundary current respond to decadal variability in basin‐scale wind stress curl, consistent with Island Rule dynamics; that strong decadal variability of the South Pacific gyre complicates efforts to infer trends from short‐term records; and that wind stress curl changes over the South Pacific basin drive changes in the EAC system that are likely to have implications for marine ecosystems and regional climate

A z=5.34 Galaxy Pair in the Hubble Deep Field

We present spectrograms of the faint V-drop (V(606) = 28.1, I(814) = 25.6) galaxy pair HDF3-951.1 and HDF3-951.2 obtained at the Keck II Telescope. Fernandez-Soto, Lanzetta, & Yahil (1998) derive a photometric redshift of z(ph) = 5.28 (+0.34,-0.41; 2 sigma) for these galaxies; our integrated spectrograms show a large and abrupt discontinuity near 7710 (+- 5) Angstroms. This break is almost certainly due to the Lyman alpha forest as its amplitude (1 - fnu(short) / fnu(long) > 0.87; 95% confidence limit) exceeds any discontinuities observed in stellar or galaxian rest-frame optical spectra. The resulting absorption-break redshift is z=5.34 (+- 0.01). Optical/near-IR photometry from the HDF yields an exceptionally red (V(606)-I(814)) color, consistent with this large break. A more accurate measure of the continuum depression blueward of Lyman alpha utilizing the imaging photometry yields D(A) = 0.88. The system as a whole is slightly brighter than L*(1500) relative to the z~3 Lyman break population and the total star formation rate inferred from the UV continuum is ~22 h(50)^-2 M(sun) yr^-1 (q(0) = 0.5) assuming the absence of dust extinction. The two individual galaxies are quite small (size scales < 1 h(50)^-1 kpc). Thus these galaxies superficially resemble the Pascarelle etal (1996) ``building blocks''; if they comprise a gravitationally bound system, the pair will likely merge in a time scale ~100 Myr.Comment: 18 pages, 4 figures; accepted to A

Smoking cessation and survival in lung, upper aero-digestive tract and bladder cancer: cohort study

Background: The aim was to examine the association between smoking cessation and prognosis in smoking-related cancer as it is unclear that cessation reduces mortality. Methods: In this retrospective cohort study from 1999 to 2013, we assessed the association between cessation during the first year after diagnosis and all-cause and cancer- specific mortality. Results: Of 2,882 lung, 757 upper aero-digestive tract and 1,733 bladder cancer patients 27%, 29% and 21% of lung, UAT and bladder cancer patients quit smoking. In lung cancer patients that quit, all-cause mortality was significantly lower (HR 0.82 (0.74-0.92), while cancer-specific mortality (HR 0.89 (0.76-1.04) and death due to index cancer (HR 0.90 (0.77-1.05) were nonsignificantly lower. In UAT cancer, all-cause mortality (HR 0.81 (0.58-1.14), cancer-specific mortality (HR 0.84 (0.48-1.45), and death due to index cancer (HR 0.75 (0.42-1.34) were non-significantly lower. There was no evidence of an association between quitting and mortality in bladder cancer. The HRs were 1.02 (0.81 1.30) for all-cause, 1.23 (0.81-1.86) for cancer specific, and 1.25 (0.71-2.20) for death due to index cancer. These showed a nonsignificantly lower risk in sensitivity analyses. Conclusion: People with lung and possibly UAT cancer who quit smoking have a lower risk of mortality than people who continue smoking