Structural studies of ambient temperature plastic crystal ion conductors

A number of novel organic ionic compounds based on the pyrrolidinium cation are described which have been found to be ion conductors in their solid states around room temperature. The properties of the compounds are consistent with their exhibiting plastic crystal phases. In order to understand some of the molecular origins of the plastic crystal behaviour and the ion conductivity that it promotes, a number of related compounds based on the imidazolium and ammonium cations are also described which have structural elements in common with the pyrrolidinium cation, but which do not show the plastic behaviour. It is found therefore that the nature of the cation is quite critical to the development of this behaviour. The alkyl methyl pyrrolidinium cation is found to produce plastic crystal phases when the alkyl chains are short, thereby preserving the ability of the cation to rotate with minimal steric hindrance. The ammonium and imidazolium cations of comparable size and structure are less able to produce these plastic phases, in many cases because the low temperature phase proceeds to melt rather than forming a stable rotator phase.

Conductivity, NMR and crystallographic study of N,N,N,N-tetramethylammonium dicyanamide plastic crystal phases : an archetypal ambient temperature plastic electrolyte material

N,N,N,N-Tetramethylammonium dicyanamide (Me₄NDCA) has been examined via differential scanning calorimetry (DSC), thermogravimetric analysis, conductivity, single crystal X-ray diffraction and ¹H nuclear magnetic resonance (NMR) analyses, and was found to be highly conductive in the solid state (σ =10−3 S cm⁻² at 420 K) and to also exhibit unusual plastic crystal behaviour. To investigate the correlation between such behaviour and the occurrence of molecular rotations in the crystal, ¹H NMR second moment measurements are compared with calculated values predicted from the crystal structure. While DSC analysis indicates a number of solid–solid transitions at ambient temperatures, subsequent ¹H NMR analysis of the Me₄N⁺ cation shows that a variety of rotational motions become active at low (<240 K) temperatures, and that such transitions in rotational states occur over a range of temperatures rather than in a sharp transition. Conductivity analysis reveals that between 320 K and 420 K the conductivity increases by more than six orders of magnitude in the solid state, in line with the transition of the Me₄N⁺ cation to a diffusive state, and that other phase transitions observed in this temperature range have no marked effect on the conductivity. Conduction in this solid state is therefore envisaged to involve a vacancy-diffusion model, involving Me₄N⁺ cation vacancies.

Synthesis and properties of ambient temperature molten salts based on the quaternary ammonium ion

The synthesis of 16 tetraalkyl ammonium bis(trifluoromethane sulfonyl) imide salts, (C_nH_2n+1)₄ +N -N (SO₂CF₃)₂ (n = 1, 2, 3, 4),  (C₂H₅)₂(i-C₃H₇)₂ +N -N(SO₂CF₃)₂, (C₂H₅)(CH₃)(i-C₃H₇)₂+N-N(SO₂CF₃)₂, (n-C₇H₁₅)(C₂H₅)i-C₃H₇)₂+N-N(SO₂CF₃)₂ and (C_nH_2n+1)(C_mH_2m+1)₃+N-N(SO₂CF₃)₂ (n = 6,7,8; m = 1, 2, 4) are reported in this paper. Trends in properties of these salts are discussed. The symmetrical tetraalkyl ammonium salts with the bis(trifluoromethyl sulfonyl) imide anion exhibited a lower melting point than that of corresponding ammonium halides. The salts with low symmetry ammonium cations were found to be of generally lower melting point, and many were stable liquids at room temperature. Several of these did not crystallize during cooling below room temperature and exhibited glass transition temperatures in the region of −60 °C∼−80 °C. A comparison of properties between the ammonium imide salts and corresponding trifluoromethane sulfonates is also presented.

N,N-Dimethylpyrrolidinium hydroxide : a highly conductive solid material at ambient temperature

N,N-Dimethylpyrrolidinium hydroxide (P₁₁OH·4H₂O) was found to exhibit high ionic conductivity in the solid state (7 × 10⁻³ S cm⁻¹ at 25°C) and unusual thermal properties, and ²H solid state NMR measurements indicate liquid-like mobility of the deuterium species in the solid state of P₁₁OD·4.5D₂O.

Ambient temperature plastic crystal electrolyte for efficient, all-solid-state dye-sensitized solar cell

Doping the molecular plastic crystal of succinonitrile with solid N-methyl-N-butylpyrrolidinium iodide salt and iodine has produced a highly conductive solid iodide/triiodide conductor. Furthermore, it was employed for a highly efficient, all-solid-state dye-sensitized solar cell.

A decision-making model to choose business intelligence platforms for organizations

In recent time, technology applications in different fields, especially Business Intelligence (BI) have been developed rapidly and considered to be one of the most significant uses of information technology with special position reserved. The application of BI systems provides organizations with a sense of superiority in the competitive environment. Despite many advantages, the companies applying such systems may also encounter problems in decision-making process because of the highly diversified interactions within the systems. Hence, the choice of a suitable BI platform is important to take the great advantage of using information technology in all organizational fields. The current research aims at addressing the problems existed in the organizational decision-making process, proposing and implementing a suitable BI platform using Iranian companies as case study. The paper attempts to present a solitary model based on studying different methods in BI platform choice and applying the chosen BI platform for different decisionmaking processes. The results from evaluating the effectiveness of subsequently implementing the model for Iranian Industrial companies are discussed.

Critical success factors for business intelligence systems

The implementation of a business intelligence (BI) system is a complex undertaking requiring considerable resources. Yet there is a limited authoritative set of critical success factors (CSFs) for management reference because the BI market has been driven mainly by the IT industry and vendors. This research seeks to bridge the gap that exists between academia and practitioners by investigating the CSFs influencing BI systems success. The study followed a two-stage qualitative approach. Firstly, the authors utilised the Delphi method to conduct three rounds of studies. The study develops a CSFs framework crucial for BI systems implementation. Next, the framework and the associated CSFs are delineated through a series of case studies. The empirical findings substantiate the construct and applicability of the framework. More significantly, the research further reveals that those organisations which address the CSFs from a business orientation approach will be more likely to achieve better results.

Effect of CHO ingestion on exercise metabolism and performance in different ambient temperatures

Two series of experiments were conducted to examine the effect of ingesting beverages with differing carbohydrate (CHO) concentrations and osmolalities on metabolism and performance during prolonged exercise in different environmental conditions. In series 1, 12 subjects performed three cycling exercise trials to fatigue at 70% ·VO_2peak in either 33°C(N = 6) (HT1) or 5°C (N = 6) (CT). Subjects ingested either a 14% CHO solution (osmolality = 390 mosmol·l^-1) (HCHO); a 7% CHO solution (330 mosmol·l^-1) (NCHO) or a placebo (90 mosmol·l^-1) (CON1). In series 2, six subjects performed the same three trials at 33°C (HT2), while ingesting either NCHO, a 4.2% CHO solution (240 mosmol·l^-1) (LCHO) or a placebo) (240 mosmol·l^-1) (CON2). Plasma glucose was higher (P < 0.05) in HCHO than NCHO, which in turn was higher (P < 0.05) than CON1 in both CT and HT1. Plasma glucose was lower (P < 0.05) in CON2 compared with NCHO and LCHO in HT2. The fall in plasma volume was greater(P < 0.05) in HCHO than other trials in both CT and HT1 but was not different when comparing the three trials in HT2. Exercise time was not different when comparing the trials in either HT1 or HT2 but was longer(P < 0.05) in NCHO compared with HCHO, which, in turn, was longer(P < 0.05) than CON1 in CT. These data demonstrate that, during prolonged exercise in the heat, fatigue is related to factors other than CHO availability. In addition, during exercise in 5°C a 7% CHO solution is more beneficial for exercise performance than a 14% CHO solution.

An artificial intelligence examination of the influence of geological conditions and changes in climate on damage to light structures in Victoria

Damage to light structures in the state of Victoria can be caused by movements of expansive soils. The presentation will present the results of an examination of reports of increasing complaints of house damage in Victoria and particularly in the Melbourne area. The examination analyses the influence of geology and change in climate using Neural Network and Genetic Algorithm approaches and assesses their relative importance in contributing to the cause of the damage.