Solubility and solvation of monosaccharides in ionic liquids

Herein, solubility experimental data for six monosaccharides, viz. D-(+)-glucose, D-(+)-mannose, D-(-)-fructose, D-(+)-galactose, D-(+)-xylose and L-(+)-arabinose, in four ionic liquids (ILs), at temperatures ranging from 288.2 to 348.2 K, were obtained aimed at gathering a better understanding of their solvation ability and molecular-level mechanisms which rule the dissolution process. To ascertain the chemical features that enhance the solubility of monosaccharides, ILs composed of dialkylimidazolium or tetra-alkylphosphonium cations combined with the dicyanamide, dimethylphosphate or chloride anions were investigated. It was found that the ranking of the solubility of monosaccharides depends on the IL; yet, D-(+)-xylose is always the most soluble while D-(-)-fructose is the least soluble monosaccharide. The results obtained show that both the IL cation and the anion play a major role in the solubility of monosaccharides. Finally, from the determination of the respective thermodynamic properties of solution, it was found that enthalpic contributions are dominant in the solubilization process. However, the observed differences in the solubilities of monosaccharides in 1-butyl-3-methylimidazolium dicyanamide are ruled by a change in the entropy of solution.

Copto-Arabic Universal Chronography. Between Antiquity, Judaism, Christianity and Islam The K. al-Tawārīkh of N. al-Khilāfa Abū Shākir Ibn al-Rāhib (655 Heg. / 973 Mart. / 1257 Chr. / 1569 Alex. / 6750 AM)

La obra histórica del erudito y enciclopedista de la edad de oro de la literatura árabe copta, de la cual el Dr. Samuel Moawad (Munster) está preparando una edición, representa en realidad una colección de tres tratados divididos artificialmente en 51 capítulos secuenciales. El núcleo cronológico es precedido por un largo tratado con 47 capítulos sobre cálculos astronómicos y eclesiásticos así como épocas históricas y calendarios de diferentes naciones. La parte histórica propia (ch. 48-50), de los cuales el llamado Chronicon orientale representa una deficiente revisión anónima, trata sucesivamente de historia universal, dinastías islámicas y patriarcas coptos. Un sumario histórico, así como dogmático, de los primeros siete/ocho concilios de la Iglesia cristiana (cap. 51) termina la compilación entera. El conocido historiador al-Makin Ibn al-.Amid hace un gran uso de la labor de su contemporáneo y, al parecer a través de él, los grandes historiadores musulmanes: Ibn Khaldun, Maqrizi o Qalqashandi hacen mención continua de Ibn al-Rahib. Más tarde en el siglo XVI, el K. al-Tawarikh fue traducido en etiópico y tuvo un gran impacto en la literatura histórica y computacional de los etíopes.

Extração de metais (K, Mg, Ba, Ca, Cr, Mn, Li, Fe) de água produzida utilizando sistema microemulsionado

The produced water is a byproduct formed due to production of petroleum and carries with it a high amount of contaminants such as oil particles in suspension, organic compounds and metals. Thus, these latter pollutants are very difficult to treat because of its high solubility in water. The objective of this work is to use and evaluate a microemulsioned system to remove metals ( K , Mg , Ba , Ca , Cr , Mn , Li , Fe ) of synthetic produced water. For the extraction of metals, it was used a pseudoternary diagram containing the following phases: synthetic produced water as the aqueous phase (AP), hexane as organic phase (OP), and a cosurfactant/surfactant ratio equal to four (C/S = 4) as the third phase, where the OCS (saponified coconut oil) was used as surfactant and n-butanol as cosurfactant. The synthetic produced water was prepared in a bench scale and the region of interest in the diagram for the removal of metals was determined by experimental design called. Ten points located in the phase Winsor II were selected in an area with a large amount of water and small amounts of reagents. The samples were analyzed in atomic absorption spectrometer, and the results were evaluated through a statistical assesment, allowing the efficiency analysis of the effects and their interactions. The results showed percentages of extraction above 90% for the metals manganese, iron, chromium, calcium, barium and magnesium, and around 45% for metals lithium and potassium. The optimal point for the simultaneous removal of metals was calculated using statistical artifact multiple response function (MR). This calculation showed that the point of greatest extraction of metals occurs was the J point, with the composition [72% AP, 9% OP, 19% C/S], obtaining a global extraction percentage about 80%. Considering the aspects analyzed, the microemulsioned system has shown itself to be an effective alternative in the extraction of metals on synthetic produced water remediation

Towards a single crystal Raman spectrum of kaolinite at 77 K

The Raman spectra at 77 K of the hydroxyl stretching of kaolinite were obtained along the three axes perpendicular to the crystal faces. Raman bands were observed at 3616, 3658 and 3677 cm−1 together with a distinct band observed at 3691 cm−1 and a broad profile between 3695 and 3715 cm−1. The band at 3616 cm−1 is assigned to the inner hydroxyl. The bands at 3658 and 3677 cm−1 are attributed to the out-of-phase vibrations of the inner surface hydroxyls. The Raman spectra of the in-phase vibrations of the inner-surface hydroxyl-stretching region are described in terms of transverse and longitudinal optic splitting. The band at 3691 cm−1 is assigned to the transverse optic and the broad profile to the longitudinal optic mode. This splitting remained even at liquid nitrogen temperature. The transverse optic vibration may be curve resolved into two or three bands, which are attributed to different types of hydroxyl groups in the kaolinite.

K-tree : large scale document clustering

We introduce K-tree in an information retrieval context. It is an efficient approximation of the k-means clustering algorithm. Unlike k-means it forms a hierarchy of clusters. It has been extended to address issues with sparse representations. We compare performance and quality to CLUTO using document collections. The K-tree has a low time complexity that is suitable for large document collections. This tree structure allows for efficient disk based implementations where space requirements exceed that of main memory.

The knowledge advantage (K-Adv): unleashing creativity and innovation

The K-Adv has been developed around the concept that it comprises an ICT enabling infrastructure that encompasses ICT hardware and software infrastructure facilities together with an enabling ICT support system; a leadership infrastructure support system that provides the vision for its implementation and the realisation capacity for the vision to be realised; and the necessary people infrastructure that includes the people capabilities and capacities supported by organisational processes that facilitates this resource to be mobilised.

Document clustering with K-tree

This paper describes the approach taken to the XML Mining track at INEX 2008 by a group at the Queensland University of Technology. We introduce the K-tree clustering algorithm in an Information Retrieval context by adapting it for document clustering. Many large scale problems exist in document clustering. K-tree scales well with large inputs due to its low complexity. It offers promising results both in terms of efficiency and quality. Document classification was completed using Support Vector Machines.

The role of timber plantations in U.K. investment portfolios

Although timber plantations and forests are classified as forms of agricultural production, the ownership of this land classification is not limited to rural producers. Timber plantations and forests are now regarded as a long-term investment with both institutional and absentee owners. While the NCREIF property indices have been the benchmarks for the measurement of the performance of the commercial property market in the UK, for many years the IPD timberland index has recently emerged as the U.K. forest and timberland performance indicator. The IPD Forest index incorporates 126 properties over five regions in the U.K. This paper will utilise the IPD Forestry Index to examine the performance of U.K. timber plantations and forests over the period 1981-2004. In particular, issues to be critically assessed include plantation and forest performance analysis, comparative investment analysis, and the role of plantations and forests in investment portfolios, the risk reduction and portfolio benefits of plantations and forests in mixed-asset portfolios and the strategic investment significance of U.K. timberlands.

Random Indexing K-tree

Random Indexing K-tree is the combination of two algorithms suited for large scale document clustering.