656 research outputs found
Factors affecting cleanup of exhaust gases from a pressurized, fluidized-bed coal combustor
The cleanup of effluent gases from the fluidized-bed combustion of coal is examined. Testing conditions include the type and feed rate of the coal and the sulfur sorbent, the coal-sorbent ratio, the coal-combustion air ratio, the depth of the reactor fluidizing bed, and the technique used to physically remove fly ash from the reactor effluent gases. Tests reveal that the particulate loading matter in the effluent gases is a function not only of the reactor-bed surface gas velocity, but also of the type of coal being burnt and the time the bed is operating. At least 95 percent of the fly ash particules in the effluent gas are removed by using a gas-solids separator under controlled operating conditions. Gaseous pollutants in the effluent (nitrogen and sulfur oxides) are held within the proposed Federal limits by controlling the reactor operating conditions and the type and quantity of sorbent material
Lewis Research Center's coal-fired, pressurized, fluidized-bed reactor test facility
A 200-kilowatt-thermal, pressurized, fluidized-bed (PFB) reactor, research test facility was designed, constructed, and operated as part of a NASA-funded project to assess and evaluate the effect of PFB hot-gas effluent on aircraft turbine engine materials that might have applications in stationary-power-plant turbogenerators. Some of the techniques and components developed for this PFB system are described. One of the more important items was the development of a two-in-one, gas-solids separator that removed 95+ percent of the solids in 1600 F to 1900 F gases. Another was a coal and sorbent feed and mixing system for injecting the fuel into the pressurized combustor. Also important were the controls and data-acquisition systems that enabled one person to operate the entire facility. The solid, liquid, and gas sub-systems all had problems that were solved over the 2-year operating time of the facility, which culminated in a 400-hour, hot-gas, turbine test
Morphometric characteristics of the small and large intestines of Mus musculus during postnatal development
The objective of this study was to investigate the size of the small and large intestine
in postnatal development of Mus musculus mice. The gut was obtained from
2-, 4-, 6-, and 12-week-old animals. The morphometric analysis was performed
at microscopic level. Measurements and calculations included dimensions of villi
(height, diameter) and their number per 1 mm2 surface area in the proximal,
middle, and distal section of the small intestine, as well as the length and surface
area (external and internal) of the small and large intestines.
To find the allometric relationship between the size of the small and large intestines
and body mass, reduced major axis regression was applied. The length and
surface area of both intestinal segments gradually increased with age. The increase
in the internal surface area of the small intestine was the result of lengthening
of the intestine and increasing diameter of the villi in its proximal and middle
sections. No increase in villus height during the studied period was detected.
A marked increase in the size of the intestinal segments was observed between
the 2nd and 4th weeks of life, when the length doubled and the surface area
tripled in size. Allometric analysis revealed that the increase in length and internal
surface area of the small and large intestines was more rapid than the body mass
increase during the weaning period, while it was not different from isometry after
the weaning. In conclusion, the greatest changes in the structure and size of the
small and large intestines of mice occurred in the weaning period. During this
period these two segments of intestine grew faster than the rest of the body and
reached adult proportions. (Folia Morphol 2011; 70, 4: 252–259
A Comparison of Aquatic- vs. Land-Based Plyometrics on Various Performance Variables
International Journal of Exercise Science 8(2) : 134-144, 2015. The purpose of this study was to compare the effects of an aquatic- (W) and land-based (L) plyometric program on balance, vertical jump height, and isokinetic quadriceps and hamstring strength. Thirty-four participants were randomized into three groups, W (n = 12), L (n = 11), and control (n = 11). The W and L groups completed an eight-week plyometric program. A two-way repeated measures ANOVA revealed a significant main effect of condition (F = 346.95, p \u3c 0.001) and interaction between condition by time (F = 1.88, p = 0.01). Paired samples t-tests revealed statistically significant improvements from pre- to post-testing in the L group for isokinetic quadriceps strength at 60 degrees per second (p = 0.02) and hamstring strength at 120 degrees per second (p = 0.02). Statistically significant improvements were observed from pre- to post-testing in the W group for balance (p = 0.003), vertical jump height (p = 0.008), isokinetic quadriceps strength at 60 and 120 degrees per second (p \u3c 0.001), and hamstring strength at 120 degrees per second (p = 0.03). Results demonstrate that aquatic-based plyometric training can be a valid form of training by producing improvements in balance, force output, and isokinetic strength while concurrently decreasing ground impact forces
The Effects of a 12-Week Faculty and Staff Exercise Program on Health-Related Variables in a University Setting
International Journal of Exercise Science 8(1) : 49-56, 2015. The obesity epidemic has grown in the past decade due to physical inactivity (i.e., having a sedentary job) and an increase in caloric intake. This problem combined with the reluctance of many faculty and staff members exercising in the same environment as student’s presents a unique challenge in an academic setting. The purpose of this study was to examine the effectiveness of a 12-week exercise program focused toward the faculty and staff in improving several health-related variables such as curl-ups, push-ups, sit-and-reach, and balance. Fifty-seven faculty and staff participated in the current study. Participants engaged in a variety of exercise classes taught by certified instructors three days a week for 12-weeks. Paired samples t-tests illustrated a significant (p \u3c 0.001) decrease in body mass and significant (p \u3c 0.001) improvements in curl-ups, push-ups, sit-and-reach, and balance. This data demonstrates that a 12-week faculty and staff exercise program has the potential to improve performance in several health-related variables such as curl-ups, push-ups, sit-and-reach, and balance. The ability of this program to improve health-related variables and possibly delay or prevent the development of overweight and/or obesity, sarcopenia, and other chronic diseases is encouraging
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