Henry's Method Research Articles

Target Synthesis of an Azo (N═N) Based Covalent Organic Framework with High CO2-over-N2 Selectivity and Benign Gas Storage Capability

An azo (N═N) based covalent organic framework (COF-TpAzo) has been synthesized via a Schiff base condensation reaction. The Braunauer–Emmett–Teller (BET) specific surface area up to 1552 m2·g–1 was obtained for the framework with a pore volume of 0.97 cm3·g–1. The COF-TpAzo exhibits a high selectivity in CO2/N2 (127/145 at 273/298 K, respectively, Henry method) due to the N2-phobic and CO2-philic feature of COF-TpAzo. Furthermore, hydrogen and methane storage capacities of the nitrogen-rich COF-TpAzo have been investigated. The COF-TpAzo shows high H2 and CH4 storage capacity at 1 bar (10.6 mg·g–1 at 77 K for H2, 11.2 mg·g–1 at 273 K for CH4, and 5.5 mg·g–1 at 298 K for CH4).

Combined CO2-philicity and Ordered Mesoporosity for Highly Selective CO2 Capture at High Temperatures.

Various dry sorbents have been lately introduced as promising media to capture carbon dioxide (CO2). However, it is still desirable to further improve their performance in diverse aspects, and high temperature selectivity of CO2 over other gases is clearly one of them. Here, we report a co-assembly approach to turn nonporous melamine resin to a highly ordered mesoporous polymeric network (space group: Im3̅m) containing high nitrogen content (∼18 at%). This mesoporous network shows anomalously increasing CO2/N2 selectivity with temperature rise, with the selectivity at 323 K reaching 117 (Henry method). This selectivity behavior is attributed to a combined effect of the high nitrogen content allowing for high binding affinity with CO2 and well-defined mesopores (2.5-2.9 nm) accelerating release of N2 with temperature rise. The given orthogonal approach suggests a new direction in designing dry sorbents with excellent selectivities at high temperatures.

Simplified Method for Calculating Lateral Distribution Factors for Live Load Shear

The simplified equal distribution factor (EDF) method for live load shear presented in this study originates from Henry's method, a method that has been used in Tennessee for nearly forty years. Henry's method allows for equal distribution of live load effects in all beams. This study focused on a careful examination and modification of Henry's method by comparing shear distribution factors obtained from Henry's method with those from finite element analysis and other code-specified methods for actual bridges. Twenty-four Tennessee bridges with six different types of superstructures were used in the study. The effects of structural parameters on the shear distribution factors were also studied. Modification factors to Henry's method were proposed based on the comparison study. The proposed modification factors include structure type factors that are applied to different types of superstructures and a skew correction factor that is used to account for the effects of skew angle for skewed bridges. With proper modifications, the simplified EDF method can produce very reasonable and reliable distribution factors for live load shear.

Closure to “Simplified Method of Lateral Distribution of Live Load Moment” by Xiaoming Sharon Huo, Edward P. Wasserman, and Pingsheng Zhu

A closure to a discussion of an article with the aforementioned title, published in this journal (Volume 9, No. 4, July/August 2004), is presented. The closure, by Peter Kocsis, was published in the current issue. The authors of the original paper confirm that they believe that Henry's method and the modified Henry's method include the most dominant factors, employ equal distribution concepts and provide reasonable and reliable distribution factors. Although the discusser recommends a program, SECAN4, for analyzing a bridge for any kind of loading, the authors have no experience with this program. They also agree with the discussers' comments on line load distribution for curbs, railings and sidewalks, but emphasize that their research was on the moment distribution under the AASHTO live load or truck load, rather than on line load distribution.

Discussion of “Simplified Method of Lateral Distribution of Live Load Moment” by Xiaoming Sharon Huo, Edward P. Wasserman, and Pingsheng Zhu

A discussion of an article with the aforementioned title, published in this journal (Vol. 9, No. 4, July/August 2004), is presented. The discusser comments on Henry's method, the simplified method of live load distribution and the research results presented in the original paper. He concludes that Henry's method, AASHTO load and resistance factor design and a computer program SECAN4 can provide the bridge engineer with an excellent set of tools for load distribution analysis.

Long-term Mortality Patterns in Chinese History: Evidence from a Recorded Clan Population

Humans have lived on earth for millions of years, yet the study of population history only began to be established in the mid-twentieth century. Henry's method of family reconstitution, which relies onparish registers, has resulted in considerable progress in the study of historical demography in Europe and other areas. But because data arelacking, there were hardly any detailed studies of fertility and mortality before the sixteenth century, and very little is known about demographic changes in early human history. This paper consists of an analysis of a set of Chinese genealogies to examine long-term mortalitypatterns in a selected clan population over a period of more than 1,000 years. By using these data, as well as findings reported by other scholars, we shall present some tentative suggestions about long-termmortality change in Chinese history.

Radically simplifying the Henry function.

We recently established that every ion has two radii - a geometrical one and an electrokinetic one. Using this principle, and in accordance with Henry's method of determining his function, f(ka), we have discovered that the Henry function can be radically simplified. The graphs of the proposed equation are plotted at different argument values. They are identical with the graphs plotted according to the Henry function.

The interpretation of electrokinetic potentials and the inaccuracy of the DLVO theory for anatase sols

The surface charge density, electrophoretic mobility, and colloidal stability were measured for hydroxide-dispersed anatase (TiO 2) sols at 6.2% solids. The results of ζ calculations from electrophoretic mobility indicated that the Wiersema-Loeb-Overbeek method of correcting for retardation and relaxation effects is more accurate than Henry's method. At a given electrolyte concentration, the hydrodynamic shear plane was at a constant distance from the surface over a wide range of pH and ψ δ . The distance decreased with increasing salt content and ranged between 12Åat 0.01 M Na + to 25Åat 0.0004 M Na +. The resulting relationships between ζ and ψ δ and the location of the shear plane were best explained by the Lyklema-Overbeek case III, immobilized water at the surface, with small corrections for viscosity variation with the electric field outside the ordered region. Dispersion stability was not satisfactorily indicated by any of the double-layer potentials [ζ, ψ δ, or ψ 0] when they were substituted into the DLVO theory of colloidal stability. The DLVO theory gave inadequate quantitative results based on the large and widely varying values of the Hamaker constant required. A more exact mathematical description of double-layer interaction for spherical particles is apparently needed, and/or the effect of water structure on double-layer interaction and the Poisson-Boltzmann equation needs clarification.

A Note on Henry's Method

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