A Confounder is a variable whose presence affects the variables being studied so that the results do not reflect the actual relationship. There are various ways to exclude or control confounding variables including Randomization, Restriction and Matching. But all these methods are applicable at the time of study design. When experimental designs are premature, impractical, or impossible, resear...

Although common in the educational and developmental areas, multilevel models are not often utilized in the analysis of data from experimental designs. This article illustrates how multilevel models can be useful with two examples from experimental designs with repeated measurements not involving time. One example demonstrates how to properly examine independent variables for experimental stimu...

In this Data in Brief paper, a central composite experimental design was planned to collect the surface roughness of an end milling operation of AISI 1045 steel. The surface roughness values are supposed to suffer some kind of variation due to the action of several factors. The main objective here was to present a multivariate experimental design and data collection including control factors, n...

Background & Aims: High concentrations of selenite have carcinogenetic, cytotoxic and genotoxic effects. Therefore, removal of this toxic pullutant from the environment has a particular importance in maintaining public health. In this study, with the aim of optimization of selenite removal process, the design Box-Behnken method was used to estimate th...

nanocrystalline ceria has been considered as support for carbon monoxide preferentially oxidation. in this study ceria was prepared by precipitation method and the effects of preparation conditions, such as ph of solution (8-10), aging time (1-12 hr), drying temperature (80-120 °c), calcination time (2-6 hr) and temperature (400-600 °c) were investigated on ceria synthesized powders properties....

the current investigation presents the role of gooseberry (phyllanthus acidus) seeds as an effective biosorbent for remediating chromium (vi)), a toxic heavy metal pollutant commonly found in effluents from tanneries and relevant industries. biosorption was affected by ph, temperature and initial metal concentration. furthermore, there is a need to understand the holistic effect of all variable...

We present a novel experimental scheme for two-dimensional fluorescence-detected coherent spectroscopy (2D-FDCS) using a non-collinear beam geometry with the aid of "confocal imaging" of dynamic (population) grating and 27-step phase-cycling to extract the signal. This arrangement obviates the need for distinct experimental designs for previously developed transmission detected non-collinear tw...

We compute the posterior distributions of the initial population and parameter of binary branching processes, in the limit of a large number of generations. We compare this Bayesian procedure with a more näıve one, based on hitting times of some random walks. In both cases, central limit theorems are available, with explicit variances.