This study tested a social-ecological model of adolescent substance use. Multilevel modeling was used to investigate how systems, such as parents, peers, schools, and communities, directly influence and interact together to influence adolescent substance use. Participants included 14,548 (50.3% female) middle school students who were 78.6% White, 5.4% Biracial, 4.8% Asian, 4.8% Black, and 3.6% ...

the kinetic study of methylene blue (mb) adsorption using acid-activated spent tea (aast) as an adsorbent from aqueous solution with the aim of comparing linear and non-linear regression analysis methods was performed at varying initial mb concentrations (10-100 mg/l). hence, spent tea leaves, which were activated using concentrated sulfuric acid, were prepared. the physicochemical characterist...

OPINION article Front. Sustain., 01 August 2022Sec. Quantitative Sustainability Assessment https://doi.org/10.3389/frsus.2022.957017

Subdivision schemes are efficient computational methods for the design, representation and approximation of 2D and 3D curves, and of surfaces of arbitrary topology in 3D. Subdivision schemes generate curves/surfaces from discrete data by repeated refinements. While these methods are simple to implement, their analysis is rather complicated. The first part of the talk presents the “classical” ca...

abstract prediction of input flow into water resources is regarded as one of the most important issues in optimum planning and management in producing electro-water energy and optimum allocation of water into different consumption sources. different parameters affect on input discharge into dams. climate variables including temperature and rainfall have the most effect on input runoff rate to w...

Structural equation modeling (SEM) grows out of and serves purposes similar to multiple regression, but in a more powerful way which takes into account the modeling of interactions, nonlinearities, correlated independents, measurement error, correlated error terms, multiple latent independents each measured by multiple indicators, and one or more latent dependents also each with multiple indica...

this paper presents a class of theoretical and iterative method for linear partial differential equations. an algorithm and analytical solution with a initial condition is obtained using the reduced differential transform method. in this technique, the solution is calculated in the form of a series with easily computable components. there test modeling problems from mathematical mechanic, physi...