Similarity and curvature effects in pool film boiling

Similarity and curvature effects in pool film boilin

Film boiling of mercury droplets

Vaporization times of mercury droplets in Leidenfrost film boiling on a flat horizontal plate are measured in an air atmosphere. Extreme care was used to prevent large amplitude droplet vibrations and surface wetting; therefore, these data can be compared to film boiling theory. Diffusion from the upper surface of the drop appears as a dominant mode of mass transfer from the drop. A closed-form analytical film boiling theory is developed to account for the diffusive evaporation. Reasonable agreement between data and theory is seen

Effect of ice contamination of liquid-nitrogen drops in film boiling

Previously reported vaporization time data of liquid nitrogen drops in film boiling on a flat plate are about 30 percent shorter than predicted from standard laminar film boiling theory. This theory, however, had been found to successfully correlate the data for conventional fluids such as water, ethanol, benzene, or carbon tetrachloride. Experimental evidence that some of the discrepancy for cryogenic fluids results from ice contamination due to condensation is presented. The data indicate a fairly linear decrease in droplet evaporation time with the diameter of the ice crystal residue. After correcting the raw data for ice contamination along with convection, a comparison of theory with experiment shows good agreement

Online gaming addiction: the role of sensation seeking, self-control, neuroticism, aggression, state anxiety and trait anxiety

Research into online gaming has steadily increased over the last decade, although relatively little research has examined the relationship between online gaming addiction and personality factors. This study examined the relationship between a number of personality traits (sensation seeking, self-control, aggression, neuroticism, state anxiety, and trait anxiety) and online gaming addiction. Data were collected over a 1-month period using an opportunity sample of 123 university students at an East Midlands university in the United Kingdom. Gamers completed all the online questionnaires. Results of a multiple linear regression indicated that five traits (neuroticism, sensation seeking, trait anxiety, state anxiety, and aggression) displayed significant associations with online gaming addiction. The study suggests that certain personality traits may be important in the acquisition, development, and maintenance of online gaming addiction, although further research is needed to replicate the findings of the present study

Grating-coupled excitation of multiple surface plasmon-polariton waves

The excitation of multiple surface-plasmon-polariton (SPP) waves of different linear polarization states and phase speeds by a surface-relief grating formed by a metal and a rugate filter, both of finite thickness, was studied theoretically, using rigorous coupled-wave-analysis. The incident plane wave can be either p or s polarized. The excitation of SPP waves is indicated by the presence of those peaks in the plots of absorbance vs. the incidence angle that are independent of the thickness of the rugate filter. The absorbance peaks representing the excitation of s-polarized SPP waves are narrower than those representing p-polarized SPP waves. Two incident plane waves propagating in different directions may excite the same SPP wave. A line source could excite several SPP waves simultaneously

On the maximal overgroups of Sylow subgroups of finite groups

In this paper, we determine the finite groups with a Sylow $r$-subgroup contained in a unique maximal subgroup. The proof involves a reduction to almost simple groups, and our main theorem extends earlier work of Aschbacher in the special case $r=2$. Several applications are presented. This includes some new results on weakly subnormal subgroups of finite groups, which can be used to study variations of the Baer-Suzuki theorem.Comment: 50 pages; to appear in Advances in Mathematic

Nutritional ecology of millipedes in Pacific Northwest conifer forests

Comminution of forest leaf litter by millipedes affects litter decomposition and nutrient cycling. The millipede Harpaphe haydeniana Wood (Polydesmida: Xystodesmidae) is common in low to mid-elevation forests on the Pacific Coast of North America. In a series of experiments, the suitability of broadleaf and conifer tree litters for growth of juvenile H. haydeniana was investigated. First, in a 14 day feeding trial, feeding rates for adult and juvenile H. haydeniana on red alder (Alnus rubra Bong.), big-leaf maple (Acer macrophyllum Pursh) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) litter were measured gravimetrically. All three litters were consumed at similar rates. Next, the three litters, along with two others and an equal-part litter mixture, were used to rear juvenile H. haydeniana for 99 days. Multiple regression was used to relate millipede growth and litter chemistry (%N and %Ca). Litter %Ca was significantly related to millipede growth. Within the three conifer litters, litter %N had no significant relationship to growth. Growth was poor in alder, possibly because of the phenolic content. In a second experiment, the nutrient content of Douglas-fir litter was modified by adding N, Ca and cellulose. Growth of juvenile H. haydeniana was increased by both cellulose or Ca and decreased by N. Millipede carbon and nitrogen stable isotope ratios suggested that cellulose increased millipede growth by increasing microbial biomass, while Ca increased millipede growth by increasing millipede assimilation of plant C and N. Although the low N content of leaf litter is generally cited as the reason for slow growth rates in detritivores, adding exogenous N did not increase millipede growth, nor were 615N values in millipedes consistent with N-limitation. And finally, stable isotope ratios in millipedes and other detritivores in a natural system were described. Three age classes of millipede (Nearctodesmus insulanus (Polydesmida: Nearctodesmidae) were present. The 515N of adult N. insulanus was significantly higher than 6th or 7th stadium juvenile millipedes, suggesting that adults may have been feeding on a different resource than the juveniles, or that their N balance may differ from the juveniles

Use of long-term microdialysis subcutaneous glucose monitoring in the management of neonatal diabetes - A first case report

In neonatal diabetes mellitus (NDM), a rare genetic disorder, insulin therapy is required but the management is difficult. Frequent blood glucose determinations are necessary in most cases. Microdialysis subcutaneous glucose monitoring (MSGM) is feasible in neonates and has been proposed to reduce painful blood sampling and blood loss. We have applied long-term MSGM to a small-fordate female newborn with transient NDM. We found a good correlation of subcutaneous and blood glucose concentration over a wide range of values. MSGM enabled a reduction in blood glucose determinations during optimization of intravenous insulin treatment and initiation of continuous subcutaneous insulin infusion. We conclude that long-term MSGM is feasible and may reduce painful blood sampling and blood loss in NDM. Furthermore, long-term MSGM may hold a potential for avoiding hypoglycemic episodes and earlier discharge. Copyright (C) 2006 S. Karger AG, Basel