We show a new approach, based on the utilization of Matlab and Mathematica, for solving liquid-liquid extraction and binary distillation problems. In addition, the author shares his experience using these two softwares to teach equilibrium staged separations at the National Institute of Applied Sciences and Technology. (Contains 7 figures.)

Recent international studies have highlighted the success of students from Hong Kong in mathematics and problem-solving, and have begun to suggest some of the factors associated with this success. Other studies have suggested that Hong Kong students are averse to risk-taking, favouring memorisation and imitation in their solution strategies. Year…

The aim of this experiment is to study and calculate the kinetic constant of a Heck reaction: the arylation of but-3-en-2-ol by iodobenzene catalyzed by palladium acetate in presence of triethylamine in DMF. The reaction leads to a mixture of two ketones. Students use GC analysis to quantify reagents and products of reaction. They control the…

This article presents a new algorithm for computerized adaptive testing (CAT) when content constraints are present. The algorithm is based on shadow CAT methodology to meet content constraints but applies Monte Carlo methods and provides the following advantages over shadow CAT: (a) lower maximum item exposure rates, (b) higher utilization of the…

To date, few studies have investigated the evolution of problem solving and general numeracy abilities during adulthood: skills that have obvious social importance. In this research, evolutions in adults' mental arithmetic skills were investigated using data from the IVQ 2004 French national survey, which tested 9,185 adults aged between 18 and…

Recent advances in testing mediation have found that certain resampling methods and tests based on the mathematical distribution of 2 normal random variables substantially outperform the traditional "z" test. However, these studies have primarily focused only on models with a single mediator and 2 component paths. To address this limitation, a…

The authors propose a concise formula to evaluate the standard error of the estimated latent variable score when the true values of the structural parameters are not known and must be estimated. The formula can be applied to factor scores in factor analysis or ability parameters in item response theory, without bootstrap or Markov chain Monte…

Background: Suicide is a leading cause of death among youths. Comparatively few studies have studied recent trends over time, or examined rates and characteristics of service contact in well-defined national samples. Methods: Data on general population suicides and mid-year population estimates were used to calculate suicide rates (per…

The Wednesday before Thanksgiving presents a challenge to teachers in many U.S. schools. Some students are absent because they are traveling to be with their extended families for the holiday. Other students, assuming that nothing important will happen at school when so many of their peers are absent, may also be absent. One school's solution to…

A standards-based approach to mathematics involves using story problems to allow students to investigate a solution. This approach emphasizes an understanding of concepts and processes and assumes mastery of basic computation skills. This article will encourage teachers to continue teaching standards-based mathematics and to take advantage of…

This paper discusses the reasons why the current official U.S. poverty measure is outdated and nonresponsive to many anti-poverty initiatives. A variety of efforts to update and improve the statistic have failed, for political, technical, and institutional reasons. Meanwhile, the European Union is taking a very different approach to poverty…

In learning mathematics, children must master fundamental logical relationships, including the inverse relationship between addition and subtraction. At the start of elementary school, children lack generalized understanding of this relationship in the context of exact arithmetic problems: they fail to judge, for example, that 12 + 9 - 9 yields…

The National Dropout Prevention Center for Students with Disabilities (NDPC-SD) was assigned the task of compiling, analyzing, and summarizing the data for Indicator 2--Dropout--from the FFY 2009 Annual Performance Reports (APRs) and the revised State Performance Plans (SPPs), which were submitted to the Office of Special Education Programs (OSEP)…

This study was conducted to obtain information related to mental computation from students in Years 3, 5, 7, and 9 in Western Australia. The numbers of subjects were 163, 163, 163 and 152 in years 3, 5, 7, and 9, respectively. The research was designed to provide three different perspectives of mental computation: (1) a survey of the kinds of…

Research on computational estimation and mental computation has received a considerable amount of attention from mathematics educators during the past decade. These proceedings resulted from a meeting to explore dimensions of number sense and its related fields. The participants came from three groups: mathematics educators actively pursuing…