Simulating uranium sorption onto inorganic particles: The effect of redox potential.

An analytical expression is proposed to simulate the effects of pH and redox potential (E) on the sorption of uranium onto model inorganic particles in aquatic environments instead of following an experimental approach providing a list of empirical sorption data. The expression provides a distribution coefficient (Kd) as function of pH, E and ligand concentration (complex formation) applying a surface complexation model on one type of surface sites (>SuOH). The formulation makes use of the complexation and hydrolysis constants for all species in solution and those sorbed at the surface, using correlations between hydrolysis constants and surface complexation constants, for the specific sorption sites.

Characteristics of Teeth: A Review of Size, Shape, Composition, and Appearance of Maxillary Anterior Teeth.

Although digital technologies play an increasingly integral role in dentistry, there remains a need for dental professionals to understand the fundamentals of tooth anatomy, form, occlusion, and color science. In this article, the size, shape, composition, and appearance of maxillary anterior teeth will be discussed from esthetic and functional perspectives. A total of 600 extracted maxillary incisors were studied: 200 each of central incisors, lateral incisors, and cuspids.

Development of a comprehensive plan for utilization of digester gas moves towards energy self-sufficiency in Chicago, USA.

The Metropolitan Water Reclamation District (MWRD) of Greater Chicago's Stickney Water Reclamation Plant (SWRP) anaerobically digests approximately 430 dry tons per day (dtpd) (390 dry metric tons per day) of solids and produces 3.4 million ft(3)/day (96 thousand m(3)/day) of biogas from the anaerobic digesters, making it one of the largest municipal digester gas complexes in the world. Installation of new treatment processes, as well as future increases in flows and loads to the plant, are expected to significantly increase production of biologically degradable sludge and biogas.

The effect of hydrofluoric acid surface treatment and bond strength of a zirconia veneering ceramic.

Statement Of Problem: Clinicians are frequently faced with a challenge in selecting materials for adjacent restorations, particularly when one tooth requires a zirconia-based restoration and the next requires a veneer. While it may be desirable to use the same veneering ceramic on adjacent teeth, little information is available about the use of veneering ceramics over a zirconia-based material.

Purpose: The purpose of this study was threefold: (1) to study the influence of hydrofluoric acid-etched treatment on the surface topography of the zirconia veneering ceramic, (2) to test the bond strength of zirconia veneering ceramic to enamel, and (3) to evaluate the flexural strength and the elemental composition of ceramic veneers.

Diagnostically generated anterior tooth preparation for adhesively retained porcelain restorations: rationale and technique.

A diagnostically based protocol for anterior tooth preparations for adhesively retained porcelain restorations offers dentists and laboratory technicians new options to approaching these restorations. Rather than designing a preparation and restoration based more on the needs of the products used than on the preservation of the remaining tooth structure, practitioners can enhance the predictability of these restorations by concentrating simultaneously on three distinct zones of the tooth (incisal, middle, and cervical) and four diagnostic categories (periodontal, biomechanical, functional, and dentofacial). The result of following the technique presented in this article is achieving an individualized design that offers a predictable option with minimal risks to the remaining tooth structure.