Recovering Selenium From Sandstone Ores of New Mexico

Investigation has shown that the selenium-bearing sandstone ores from the Morrison and Galisteo formations of New Mexico are amenable to simple froth-flotation procedures. This article discusses the technical and economic aspects of the process.     

Characterization and Discrimination of the Floral Origin of Sidr Honey by Physicochemical Data Combined with Multivariate Analysis

Sidr honey represents one of the most expensive monofloral honeys worldwide. The quality control of such honey types usually depends on pollen analysis or comparison of physicochemical characters. In the presented work, 38 different honey samples of which 13 represented genuine Sidr (Ziziphus spina-christy) honey samples were collected from various areas of Yemen. All samples were characterized by physicochemical parameters including moisture content, pH, electrical conductivity, and free acidity. The physicochemical data was subjected to multivariate data analysis including principal component analysis (PCA) and hierarchical cluster analysis (HCA). The development of partial least square discriminant analysis (PLS-DA) model on validation gave 100 % correct classification of the test set samples. All tested honey samples were within the level permitted by the international standards for honey quality. The application of the discriminant technique PLS-DA presented excellent potential for discriminating the botanical origin of Yemeni Sidr honey from other non-Sidr samples and may serve as a discriminant model to be applied to other honey types worldwide.     

Processing additive suppresses phase separation in the active layer of organic photovoltaics based on naphthalene diimide

The development of non-fullerene electron acceptors for organic photovoltaics is gaining interest, as they offer the promise to overcome the light harvesting and energy tunability limitations of fullerenes. However, to fully take advantage of alternative acceptors, we must identify and achieve the needed morphologies within the active layer to maximize device performance. Here we demonstrate that the microstructure in the active layer of optimized poly(3-hexylthiophene)/naphthalene diimide devices resembles that of poly(3-hexylthiophene)/fullerene mixtures. Previously, we have reported on the synthesis of 2,6-dialkylaminonaphthalene diimides and found that the best performance was obtained with N,N′-di((thiophen-2-yl)methyl)-2,6-di(N-cyclohexylamino)-1,4,5,8-naphthalenetetracarboxydiimide (RF1). In this article, we show that suppressing the crystallization of both the donor and acceptor through the addition of 0.2% 1,8-diiodooctane (DIO) to the casting solution leads to finer morphologies in the active layer and a two-fold enhancement in the device efficiencies. Nevertheless, further increasing the DIO content of the casting solution leads to lower photocurrents and power conversion efficiencies, even though the morphology appears similar by energy-filtered TEM. We hypothesize that higher DIO content breaks up small RF1 aggregates, leading to suppression of charge separation. Continued development of novel non-fullerene acceptors must therefore take into consideration the balance between crystallization and aggregation of donors and acceptors for optimal performance.     

Model Calibration With Censored Data

The purpose of model calibration is to make the model predictions closer to reality. The classical Kennedy–O’Hagan approach is widely used for model calibration, which can account for the inadequacy of the computer model while simultaneously estimating the unknown calibration parameters. In many applications, the phenomenon of censoring occurs when the exact outcome of the physical experiment is not observed, but is only known to fall within a certain region. In such cases, the Kennedy–O’Hagan approach cannot be used directly, and we propose a method to incorporate the censoring information when performing model calibration. The method is applied to study the compression phenomenon of liquid inside a bottle. The results show significant improvement over the traditional calibration methods, especially when the number of censored observations is large. Supplementary materials for this article are available online.