4,881 research outputs found
Nutrition knowledge of high school senior students in Northwest Arkansas
Though there are many complex factors influencing diet, nutrition knowledge correlates with healthier food choices in older adolescents and can play a pivotal role in health. Nutrition curriculum was addressed in the state of Arkansas through Arkansas Act 1220 of 2003. Numerous changes have been seen in the school environment regarding nutrition, but there is no means of testing nutrition curriculum effectiveness in terms of nutrition knowledge of students. It is the purpose of this descriptive study to improve understanding of the nutrition knowledge of high school seniors. High school senior students (n = 25; males = 12, females = 13) successfully completed a validated Survey to Assess the Knowledge of Conventional and Unconventional Dietary Methods of Weight Control based on the Dietary Guidelines for Americans 2010. The survey also included demographic questions and items regarding sources of nutrition information. The mean nutrition knowledge score (out of 24) was 8.7 ± 2.8 or 36% (min. score = 4, max. score = 14). There was no significant difference in nutrition knowledge scores based on ethnicity, those on specialized diets, frequency of eating out, physical activity, gender, source of nutrition information, thoughts about food, or for any criteria based categorizing scores by High/Low. Though the study indicates better education is needed, this pilot test should be followed up with a larger sample size to confirm these results
Moisture and heat budgets of a cirrus cloud from aircraft measurements during FIRE
Increasing knowledge of cirrus cloud properties can contribute to general circulation model development and ultimately to a better understanding of climate. The objective was to gain a better understanding of cirrus cloud characteristics. Observations from different sensors during the First ISCCP (International Satellite Cloud Climatology Program) Regional Experiment (FIRE) which took place in Wisconsin over Oshkosh together with pertinent calculations are used to understand the dynamical, microphysical, and radiative characteristics of these clouds
The Colorado/Missouri 1989 cirrus mini IFO
A series of experiments with aircraft were planned for Nov. and Dec. 1989 to study cirrus ice crystal nucleation mechanisms and to test new aircraft instrumentation. The measurements were conducted using the NCAR Sabreliner and King Air. Sampling was conducted near Boulder, Colorado, in lenticular (mountain wave) clouds, and over Missouri in cirrus generating cells. Field samples of aerosol and ice crystal replicas and melt water from these cirrus clouds were collected and studied. Aircraft instrumentation and sampling techniques are discussed
A scheme for parameterizing cirrus cloud ice water content in general circulation models
Clouds strongly influence th earth's energy budget. They control th amount of solar radiative energy absorbed by the climate system, partitioning the energy between the atmosphere and the earth's surface. They also control the loss of energy to space by their effect on thermal emission. Cirrus and altostratus are the most frequent cloud types, having an annual average global coverage of 35 and 40 percent, respectively. Cirrus is composed almost entirely of ice crystals and the same is frequently true of the upper portions of altostratus since they are often formed by the thickening of cirrostratus and by the spreading of the middle or upper portions of thunderstorms. Thus, since ice clouds cover such a large portion of the earth's surface, they almost certainly have an important effect on climate. With this recognition, researchers developing climate models are seeking largely unavailable methods for specifying the conditions for ice cloud formation, and quantifying the spatial distribution of ice water content, IWC, a necessary step in deriving their radiative characteristics since radiative properties are apparently related to IWC. A method is developed for specifying IWC in climate models, based on theory and measurements in cirrus during FIRE and other experiments
CFD Model for Ventilation in Broiler Holding Sheds
Broiler production in Arkansas was valued at over $3.6 billion in 2013 (University of Arkansas Extension of Agriculture). Consequently, improvement in any phase of the production process can have significant economic impact and animal welfare implications. From the time poultry leave the farm and until they are slaughtered, they can be exposed to harsh environmental conditions, both in winter and in summer. After road transportation, birds are left to wait in holding sheds once they arrive at the processing plant, for periods of approximately 30 minutes to two hours. This project was interested in this holding shed waiting time during hot summer conditions. A computational fluid dynamics (CFD) model was developed using the commercial package ANSYS Fluent and used to analyze the effect of six different scenarios of varying inlet velocity and inlet temperature on the airflow, temperature, and humidity within the trailer parked in the holding shed. A temperature-humidity-velocity index (THVI) was used to assess the possible effects of local conditions on chicken welfare. Results showed that increasing airflow into the trailer module had a significant effect on reducing temperature and humidity within the module, potentially improving welfare of the poultry. While the model was too simplified to accurately compare to field measurements, this study showed the potential of CFD software to solve problems in this area. A more robust CFD model could be used to test the effects of alternative solutions such as the placement and number of cooling fans within the holding shed, making it a powerful decision making tool
Universality in snowflake aggregation
Aggregation of ice crystals is a key process governing precipitation. Individual ice crystals exhibit considerable diversity of shape, and a wide range of physical processes could influence their aggregation; despite this we show that a simple computer model captures key features of aggregate shape and size distribution reported recently from cirrus clouds. The results prompt a new way to plot the experimental size distributions leading to remarkably good dynamical scaling. That scaling independently confirms that there is a single dominant aggregation mechanism at play, albeit our model (based on undeflected trajectories to contact) does not capture its form exactly
Vertical velocities within a Cirrus cloud from Doppler lidar and aircraft measurements during FIRE: Implications for particle growth
A large and comprehensive data set taken by the NOAA CO2 Doppler lidar, the NCAR King Air, and rawinsondes on 31 October 1986 during the FIRE (First ISCCP Regional Experiment) field program which took place in Wisconsin are presented. Vertical velocities are determined from the Doppler lidar data, and are compared with velocities derived from the aircraft microphysical data. The data are used for discussion of particle growth and dynamical processes operative within the cloud
Difficulties in early ice detection with the Small Ice Detector 2 HIAPER (SID-2H) in maritime cumuli
© Copyright 2014 American Meteorological Society (AMS).The Small Ice Detector 2 HIAPER (SID-2H) was used to attempt to detect small ice particles in the early stages of ice formation in the high liquid water environment of tropical maritime cumulus clouds sampled during the Ice in Clouds Experiment - Tropical (ICE-T) field campaign. Its performance in comparison to other probes, and the development of new corrections applied to the data, are presented. The SID-2H detected small ice crystals among larger particles. It correctly identified water drops, and discriminated between round and irregular particle shapes in water-dominated clouds with errors less than 5%. Remaining uncertainties in the sensing volume, and the volume over which coincidence of particles occurred, result in the data being used here in a qualitative manner to identify the presence of ice, its habits and sizes.Peer reviewe
The October 27-28, 1986, FIRE cirrus case study: Cloud microstructure
Using aircraft in-situ measurements, the microphysics of cirrus clouds observed on 28 Oct. 1986 during FIRE were examined. Results are presented as one component of a coordinated study of the cirrus on the day. The study contributes to the understanding of cold clouds by: (1) providing microphysical data to supplement satellite and aircraft data for investigating cirrus cloud radiative effects; (2) providing more complete information on ice particle evolution and cloud forcing mechanisms than has been available through the use of instrumentation with higher resolution and more accurate calibration; (3) expanding the knowledge of the particle characteristics in cold liquid water clouds, through improved instrumentation and by making use of sensors on other platforms, such as lidar; and (4) by estimating the ice nucleus concentrations active at low temperatures in the upper troposphere from the concentrations of ice particles in colloidally stable liquid water clouds
Evidence of nitric acid uptake in warm cirrus anvil clouds during the NASA TC4 campaign
Uptake of HNO3 onto cirrus ice may play an important role in tropospheric NOx cycling. Discrepancies between modeled and in situ measurements of gas-phase HNO3 in the troposphere suggest that redistribution and removal mechanisms by cirrus ice have been poorly constrained. Limited in situ measurements have provided somewhat differing results and are not fully compatible with theory developed from laboratory studies. We present new airborne measurements of HNO3 in cirrus clouds from anvil outflow made during the Tropical Composition, Cloud, and Climate Coupling Experiment (TC4). Upper tropospheric (\u3e9 km) measurements made during three flights while repeatedly traversing the same cloud region revealed depletions of gas-phase HNO3 in regions characterized by higher ice water content and surface area. We hypothesize that adsorption of HNO3 onto cirrus ice surfaces could explain this. Using measurements of cirrus ice surface area density and some assumptions about background mixing ratios of gas-phase HNO3, we estimate molecular coverages of HNO 3 on cirrus ice surface in the tropical upper troposphere during the TC4 racetracks to be about 1 × 1013 molecules cm-2. This likely reflects an upper limit because potential dilution by recently convected, scavenged air is ignored. Also presented is an observation of considerably enhanced gas-phase HNO3 at the base of a cirrus anvil suggesting vertical redistribution of HNO3 by sedimenting cirrus particles and subsequent particle sublimation and HNO3 evaporation. The impact of released HNO3, however, appears to be restricted to a very thin layer just below the cloud. Copyright 2010 by the American Geophysical Union
- …
