scholarly journals Influence of Supersaturation, Temperature and Rotational Speed on Induction Time of Calcium Sulfate Crystallization

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1236
Author(s):  
Agata Małysiak ◽  
Szymon Orda ◽  
Michał Drzazga
Keyword(s):  
Data Analysis ◽  
Rotational Speed ◽  
Induction Time ◽  
Calcium Sulfate ◽  
Building Materials ◽  
Simple Method ◽  
Turbidimetric Method ◽  
Impression Materials ◽  
Time Calculation ◽  
Tablet Excipients

Calcium sulfate is a very important product of precipitation reactions in various branches of industry. The most common applications include building materials, impression materials in dentistry, immobilizing casts and an inactive ingredient of tablet excipients. It is also used as a drying agent and color glaze. In this paper, influence of various conditions, i.e., substrates concentration (supersaturation), temperature and rotational speed on induction time was investigated. The range of investigated parameters was 0.15–0.35 M for concentration with step of 0.05 M, 298–323 K with step of 5 K for temperature, and 1.67–8.33 s−1 for rotational speed with change every 1.67 s−1. The experiments were performed using visual and turbidimetric methods. It was proven that increase in all three investigated parameters resulted in shorter induction time. The turbidimetric method was found to be more precise, but still insufficient for concentrations below 0.15 M. Moreover, as a result of data analysis, a simple method of induction time calculation was proposed when arbitrary measurements in various concentrations are known.

Kinetic model for calcium sulfate α-hemihydrate produced hydrothermally from gypsum formed by flue gas desulfurization

2015 ◽  
Vol 48 (3) ◽  
pp. 827-835 ◽  
Author(s):  
Mingliang Tang ◽  
Xuerun Li ◽  
Yusheng Shen ◽  
Xiaodong Shen
Keyword(s):  
Flue Gas ◽  
Calcium Sulfate ◽  
High Performance ◽  
Transformation Process ◽  
Flue Gas Desulfurization ◽  
Synthesis Process ◽  
Stable Phase ◽  
Hydrothermal Conditions ◽  
Simple Method ◽  
Kinetics Of

Modeling of the kinetics of the synthesis process for calcium sulfate α-hemihydrate from gypsum formed by flue gas desulfurization (FGD) is important to produce high-performance products with minimal costs and production cycles under hydrothermal conditions. In this study, a model was established by horizontally translating the obtained crystal size distribution (CSD) to the CSD of the stable phase during the transformation process. A simple method was used to obtain the nucleation and growth rates. A nonlinear optimization algorithm method was employed to determine the kinetic parameters. The model can be successfully used to analyze the transformation kinetics of FGD gypsum to α-hemihydrate in an isothermal batch crystallizer. The results showed that the transformation temperature and stirring speed exhibit a significant influence on the crystal growth and nucleation rates of α-hemihydrate, thus altering the transformation time and CSD of the final products. The characteristics obtained by the proposed model can potentially be used in the production of α-hemihydrate.

scholarly journals Intragenic Conflict in Phylogenomic Data Sets

2020 ◽  
Vol 37 (11) ◽  
pp. 3380-3388
Author(s):  
Stephen A Smith ◽  
Nathanael Walker-Hale ◽  
Joseph F Walker
Keyword(s):  
Data Analysis ◽  
Empirical Data ◽  
Evolutionary History ◽  
Phylogenetic Signal ◽  
Phylogenetic Analyses ◽  
Simulated Data ◽  
Data Sets ◽  
Alignment Error ◽  
Biological Processes ◽  
Simple Method

Abstract Most phylogenetic analyses assume that a single evolutionary history underlies one gene. However, both biological processes and errors can cause intragenic conflict. The extent to which this conflict is present in empirical data sets is not well documented, but if common, could have far-reaching implications for phylogenetic analyses. We examined several large phylogenomic data sets from diverse taxa using a fast and simple method to identify well-supported intragenic conflict. We found conflict to be highly variable between data sets, from 1% to >92% of genes investigated. We analyzed four exemplar genes in detail and analyzed simulated data under several scenarios. Our results suggest that alignment error may be one major source of conflict, but other conflicts remain unexplained and may represent biological signal or other errors. Whether as part of data analysis pipelines or to explore biologically processes, analyses of within-gene phylogenetic signal should become common.

A simple method of transient electromagnetic data analysis

Geophysics ◽  
1998 ◽  
Vol 63 (2) ◽  
pp. 405-410 ◽  
Author(s):  
Maxwell A. Meju
Keyword(s):  
Data Analysis ◽  
Time Domain ◽  
Mineral Resources ◽  
Ease Of Use ◽  
Simple Method ◽  
Diagnostic Data ◽  
Electromagnetic Data ◽  
Transient Electromagnetic ◽  
Interpretive Model

Time-domain or transient electromagnetic (TEM) methods are used routinely in environmental, hydrogeological, energy, and mineral resources investigations owing to their ease of use and ability to generate diagnostic data. In some typical field situations, the gross structure of the subsurface may be approximately 1-D, so 1-D interpretation schemes can be used to retrieve an interpretive model for the depth soundings.

scholarly journals Proposition of a simplified method for predicting hourly indoor temperatures in test cells

2017 ◽  
Vol 17 (3) ◽  
pp. 57-70 ◽  
Author(s):  
Eduardo Leite Krüger ◽  
Leandro Fernandes ◽  
Grace Tibério Cardoso ◽  
Emilio Eiji Kavamura
Keyword(s):  
Indoor Air ◽  
High Performance ◽  
Building Materials ◽  
Thermal Conditions ◽  
Climatic Conditions ◽  
Measured Data ◽  
Indoor Temperature ◽  
Simple Method ◽  
Air Temperatures ◽  
Test Cells

Abstract Test cells can be used for testing the thermal performance of different passive systems and building components. Predictive methods for estimating indoor air temperatures can further enhance the number of configurations tested without increasing the amount of test cells to be built. Thus, direct comparisons can be drawn for identical background climatic conditions. In its most basic form, formulas are generated by linear regression from relatively short data sets, which provide daily indoor temperature conditions. However, for more detailed analyses, daily indoor temperature predictions may not suffice. In this paper, a method for obtaining hourly indoor air temperature predictions is proposed. It is based on rising and decreasing rates of the indoor temperature fluctuation relative to outdoors, which translates to warming or cooling trends of indoor thermal conditions. The applicability of the method is for test cells. It is a simple method yet capable of predicting the thermal behavior of complex physical processes. The method was tested using measured data from experiments in a test cell, built with conventional building materials in Brazil. Results showed high performance with mean bias of 0.27 °C to measured data and Pearson's r 0.99. When compared to traditional regression-based models, the method proposed showed better results.

scholarly journals A Practical Guide for Gas Turbine Performance Field and Test Data Analysis

1992 ◽  
Author(s):  
Francoise M. Krampf
Keyword(s):  
Data Analysis ◽  
Gas Turbine ◽  
Test Data ◽  
Performance Data ◽  
Test Cell ◽  
Simple Cycle ◽  
Simple Method ◽  
Practical Guide ◽  
Turbine Performance

This paper provides a simple method for correcting and analyzing the performance data from a simple cycle, two shaft gas turbine. This data may have been collected in a test cell, in the field or by a user who desires to closely monitor the performance of an engine.

scholarly journals A simple method for automated equilibration detection in molecular simulations

2015 ◽  
Author(s):  
John D Chodera
Keyword(s):  
Data Analysis ◽  
Molecular Simulation ◽  
Molecular Simulations ◽  
Equilibration Time ◽  
Simulation Data ◽  
Traditional Practice ◽  
Initial Portion ◽  
Simple Method ◽  
Initial Transient ◽  
Reference Implementation

Molecular simulations intended to compute equilibrium properties are often initiated from configurations that are highly atypical of equilibrium samples, a practice which can generate a distinct initial transient in mechanical observables computed from the simulation trajectory. Traditional practice in simulation data analysis recommends this initial portion be discarded to equilibration, but no simple, general, and automated procedure for this process exists. Here, we suggest a conceptually simple automated procedure that does not make strict assumptions about the distribution of the observable of interest, in which the equilibration time is chosen to maximize the number of effectively uncorrelated samples in the production timespan used to compute equilibrium averages. We present a simple Python reference implementation of this procedure, and demonstrate its utility on typical molecular simulation data.

scholarly journals A Comparative Study to Determine the Wettability and Castability of Different Elastomeric Impression Materials

2012 ◽  
Vol 13 (3) ◽  
pp. 356-363 ◽  
Author(s):  
N Simhachalam Reddy ◽  
G Vivekananda Reddy ◽  
Jayaprkash Itttigi
Keyword(s):  
Contact Angle ◽  
Comparative Study ◽  
Calcium Sulfate ◽  
Clinical Importance ◽  
Contact Angles ◽  
Impression Material ◽  
Calcium Sulfate Dihydrate ◽  
Impression Materials ◽  
Removable Prosthesis ◽  
Hydrophobic Nature

ABSTRACT Aim The aim of this study was to determine the wettability of different hydrophilic and hydrophobic elastomeric impression materials and the gypsum castability. Materials and methods The wettability was evaluated by determining the contact angles of different elastomeric impression materials. The contact angle was determined by placing a drop of aqueous solution of calcium sulfate dihydrate on the flat surface of impression material and specimens were measured using a profile projector. Gypsum castability was determined by counting the number of voids formed in the die stone cast made from the impressions of a aluminum die. The voids were counted using an diopter magnifying lens. Results Polyether, different viscosities of polyvinyl siloxane, and condensation silicone impression materials exhibited low contact angle values and least number of voids in the die stone cast when compared with polysulfide impression material. Conclusion There was significant correlation between the contact angle and voids formed in the die stone casts when fabricating die stone casts from various elastomeric impression material impressions. Clinical significance Accurate reproduction of prepared tooth or edentulous arch is of clinical importance in the fabrication of a fixed or removable prosthesis. Inaccuracies in the replication processes will ultimately have an adverse effect on the fit and adaptation of final restoration. The interaction is determined in part by hydrophilic and hydrophobic nature of the elastomeric impression material. Inadequate wetting of an impression results in voids in the stone casts. How to cite this article Reddy GV, Reddy NS, Itttigi J, Jagadeesh KN. A Comparative Study to Determine the Wettability and Castability of Different Elastomeric Impression Materials. J Contemp Dent Pract 2012;13(3):356-363.

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