We performed theoretical studies on the systems NH[subscript 3] times HF times mH[subscript 2]O, NH[subscript 3] times HCl times mH[subscript 2]O, with m = 0, 1, 2, and 6. The molecules with m = 0 form hydrogen-bonded adducts with little tendency to form an ion-pair structure. The molecule NH[subscript 3] times HCl times H[subscript 2]O cannot be…

More often than one might at first imagine, a simple trick involving integration by parts can be used to compute indefinite integrals in unexpected and amusing ways. A systematic look at the trick illuminates the question of whether the trick is useful enough to be called an actual technique of integration.

In "The Theory of Almost Everything", Robert Oerter asserts the following: "Take a beam of electrons that are all spinning in the same direction and fire it at, say, a brick. If you could keep this up for long enough, and if there were no other forces acting on the brick, the electrons would transfer their rotation to the brick, and it would begin…

We find the correlation of two jointly distributed random variables connected with a coin tossing experiment. The marginal distributions are binomial and negative binomial.

For a test that consists of dichotomously scored items, several approaches have been reported in the literature for estimating classification consistency and accuracy indices based on a single administration of a test. Classification consistency and accuracy have not been studied much, however, for "complex" assessments--for example,…

Time perception has long been known to be affected by numerical representations. Recent studies further demonstrate that when participants estimate the duration of Arabic numbers, number magnitude, though task-irrelevant, biases duration judgment to produce underestimation for smaller numbers and overestimation for larger numbers. Such effects…

Rayleigh's criterion states that a pair of point sources are barely resolved by an optical instrument when the central maximum of the diffraction pattern due to one source coincides with the first minimum of the pattern of the other source. As derived in standard introductory physics textbooks, the first minimum for a rectangular slit of width "a"…

We examined preschool children's use of count information in making quantity judgments. Study 1 involved 35 children 3-5 years old using a balance-scale task to judge relative quantity with or without count information provided. Study 2 replicated and extended the exploration as 54 children 3-4 years old judged relative quantity in multiple…

Derivation of the second- and higher-order virial coefficients for models of the gaseous state is demonstrated by employing a direct differential method and subsequent term-by-term comparison to power series expansions. This communication demonstrates the application of this technique to van der Waals representations of virial coefficients.…

Incorrect handling of item parameter drift during the equating process can result in equating error. If the item parameter drift is due to construct-irrelevant factors, then inclusion of these items in the estimation of the equating constants can be expected to result in equating error. On the other hand, if the item parameter drift is related to…

In 2007, only 32% of Georgia's fourth grade students were considered at or above the proficient level in mathematics. The purpose of this study was to examine the effectiveness of the TouchMath program at one elementary school. The TouchMath program was developed based on the constructivist learning theory and includes aspects of theories from…

A review of net price calculators--a financial aid tool mandated by the "Higher Education Opportunity Act" of 2008--reveals that students from low-, moderate-, and middle-income families face record-level net prices at 4-year public colleges today. These net prices will translate into levels of average total loan burden far in excess of…

Doubly bounded continuous data are common in the social and behavioral sciences. Examples include judged probabilities, confidence ratings, derived proportions such as percent time on task, and bounded scale scores. Dependent variables of this kind are often difficult to analyze using normal theory models because their distributions may be quite…

This study explores the utility of a set of tablet-based personal computers in the K-12 science, technology, engineering, and mathematics classroom. Specifically, a lesson on food-chain dynamics and predator-prey population controls was designed on the Apple® iPad platform and delivered to three sophomore-level ecology classes (roughly 30 students…

This paper reports the results of an online survey done by Global Game Jam (GGJ) participants in January 2012. This is an expansion of an earlier survey of a local game jam event and seeks to validate and extend previous studies. The objectives of this survey were collecting demographic information about the GGJ participants, understanding their…