Examining the Effectiveness of Computer Animations As a tool in Teaching High School Introductory Chemistry

Computer animations may provide educators with a viable way to address chemistry\u27s abstract nature. Current research suggests that students benefit from even short exposure to computer animations of molecular events. This applied study examined the potential benefit of using computer animations to enhance traditional teaching techniques. Two groups of students, one taught with computer animations and one taught without computer animations, completed the same assessments. Statistical analysis of the assessments provides evidence that the use of computer animations leads to improved student comprehension of microscopic processes and their relationship to macroscopic phenomena occurring in gases

A revision of the black basses (Micropterus and Huro) with descriptions of four new forms

http://deepblue.lib.umich.edu/bitstream/2027.42/56293/1/MP048.pd

Use of Motion Pictures in Laboratory Dynamical Studies

In student laboratory experiments in dynamics, as, for example, Newton\u27s second law of motion or the conservation of momentum, it is, of course, highly desirable to allow motion with the least possible constraint and to observe the displacements of moving parts without using perturbing markers. This circumstance has led us to use motion pictures in the student laboratory for quantitative observation of rapid dynamic processes, a technique which is used in a well-known textbook.\u27 The photographic method combines maximum freedom of movement with accurate observation of position as a function of time, if the camera frame speed is sufficiently high. A double pendulum apparatus, with which we have studied the conservation of momentum in the student laboratory, is shown in Fig. 1. It consists of two wooden blocks, each suspended by a steel rod from a common free-swing pivot and counter-weighted in such a way that the center of mass of each pendulum is at the center of its wooden block. A spring is compressed between the two blocks, and they are tied together with a thread. When this thread is burned, the pendulums recoil. The mass of each block can be varied at will. The motion is photographed with a motion picture camera at 64 frames per second. The camera used in this work was a war-surplus gun-point aiming camera, adapted only to the extent of adding a viewfinder. Since there is a coordinate screen behind the pendulums, the student can determine the heights to which the blocks rise by examining the film with a magnifying viewer

Use of Motion Pictures in Laboratory Dynamical Studies

In student laboratory experiments in dynamics, as, for example, Newton\u27s second law of motion or the conservation of momentum, it is, of course, highly desirable to allow motion with the least possible constraint and to observe the displacements of moving parts without using perturbing markers. This circumstance has led us to use motion pictures in the student laboratory for quantitative observation of rapid dynamic processes, a technique which is used in a well-known textbook.\u27 The photographic method combines maximum freedom of movement with accurate observation of position as a function of time, if the camera frame speed is sufficiently high. A double pendulum apparatus, with which we have studied the conservation of momentum in the student laboratory, is shown in Fig. 1. It consists of two wooden blocks, each suspended by a steel rod from a common free-swing pivot and counter-weighted in such a way that the center of mass of each pendulum is at the center of its wooden block. A spring is compressed between the two blocks, and they are tied together with a thread. When this thread is burned, the pendulums recoil. The mass of each block can be varied at will. The motion is photographed with a motion picture camera at 64 frames per second. The camera used in this work was a war-surplus gun-point aiming camera, adapted only to the extent of adding a viewfinder. Since there is a coordinate screen behind the pendulums, the student can determine the heights to which the blocks rise by examining the film with a magnifying viewer

The Di-Photon Background to a Light Higgs Boson at the LHC

Recent years have seen a significant advance in our ability to calculate two-loop matrix elements. In this talk we describe an application of this breakthrough to improve our understanding of the background to the search for a light Higgs boson at the LHC. In particular, we focus on the QCD corrections to the gluon fusion subprocess gg to gamma gamma, which forms an important component of the background in the di-photon channel. We find that the K factor for this subprocess is significantly smaller than estimated previously.Comment: Invited talk at RADCOR 2002/Loops and Legs in Quantum Field Theory (September 2002, Kloster Banz, Germany

Pre-Trial Order No. 3

Twenty-two (22) stipulation of issues to be considered by the court in this case; each stipulation is agreed to by counsel for the petitioner and the respondent. Each of the stipulations (questions) presented frame the issue of a violated constitutional right of Sam Sheppard

Hermetic on-farm storage for maize weevil control in East Africa

Maize (Zea mays L.) consumption makes up over half of daily caloric intake of persons in East Africa and adequate supply is necessary for food security for subsistence farmers, as well as for domestic stability. Hermetic post-harvest maize storage is an attractive non-chemical control strategy for maize weevil,Sitophilus zeamais (Motsch.), which is the principal cause of insect damage to stored maize grain. Laboratory experiments were conducted on instrumented hermetic and non-hermetic containers to measure effects of temperature (10 vs. 27°C) and maize moistures (6.3 to 16%) on maize weevil biology and mortality rate, and to quantify weevil oxygen consumption. Ten days weevil mortality was significantly higher in hermetic vs. non-hermetic storage, in 6.3% moisture maize vs. 16%, and at 27°C storage temperature vs. 10°C. Oxygen depletion results allow estimation of days to 100% adult weevil mortality as a function of weevil infestation level, storage temperature and maize moisture for East Africa conditions

Carbon Dioxide Evolution from Fresh and Preserved Soybeans

Carbon dioxide evolution has proven to be a good indicator of deterioration in studies of stored cereal grains and oilseeds. Since little work has been done with stored soybeans, a study was conducted measuring carbon dioxide from stored soybeans using freshly harvested and preserved soybean samples. The objective of the study was to determine the effects of harvesting method, storage temperature, storage moisture content, and storage time on soybean deterioration. Following storage treatment, samples were held under aeration in a respirometer at 26°C and 21% moisture, and evolved carbon dioxide mass was measured until samples had lost 1.0% of original dry matter. At high harvest moistures, combine-harvested soybeans deteriorated faster, but at low harvest moistures, the deterioration rate of hand-harvested soybeans was greater. After 48 weeks of storage, the soybeans harvested at 22% moisture and preserved at -18°C deteriorated in a respirometer like freshly harvested soybeans, but soybeans harvested at 9% deteriorated in a respirometer significantly faster than those freshly harvested at 13% moisture