Transport properties of ionic liquid electrolytes with organic diluents

Ionic liquids (ILs) form a novel class of electrolytes with unique properties that make them attractive candidates for electrochemical devices. In the present study a range of electrolytes were prepared based on the IL <i>N</i>-methyl-<i>N</i>-propylpyrrolidinium bis(trifluoromethylsulfonyl) amide ([C₃mpyr][NTf₂]) and LiNTf2 salt. The traditional organic solvent diluents vinylene carbonate (VC), ethylene carbonate (EC), tetrahydrofuran (THF) and toluene were used as additives at two concentrations, 10 and 20 mol%, leading to a ratio of about 0.6 and 1.3 diluent molecules to lithium ions, respectively. Most promisingly, the lithium ions see the greatest effect in the presence of all the diluents, except toluene, producing a lithium self-diffusion coefficient of almost a factor of 2.5 times greater for THF at 20 mol%. Raman spectroscopy subtly indicates that THF may be effectively breaking up a small portion of the lithium ion&ndash;anion interaction. While comparing the measured molar conductivity to that calculated from the self-diffusion coefficients of the constituents indicates that the diluents cause an increase in the overall ion clustering. This study importantly highlights that selective ion transport enhancement is achievable in these materials. <br />

On the role of cyclic unsaturated additives on the behaviour of lithium metal electrodes in ionic liquid electrolytes

Three cyclic vinyl based additives, based respectively on oxygen, sulphur and fluorine, are tested for their ability to improve the cycling of lithium in a hostile ionic liquid medium. Oxygen based vinylene carbonate is found to offer the best protection of the lithium metal whilst allowing very consistent lithium cycling to occur. The vinylene carbonate based system under study is, however, imperfect. Lithium metal is deposited in a dendritic morphology, and vinylene carbonate is rapidly consumed during lithium cycling if it is present in a small quantity. Our results suggest that ionic liquid systems critically relying on a small amount of additive to protect a lithium electrode are not viable for long cycle life secondary batteries. It is suggested that an ionic liquid which itself is lithium metal compatible be used instead.<br />

The electrochemistry of lithium in ionic liquid/organic diluent mixtures

The electrochemistry of lithium is investigated in a number of electrolytes that consist of a lithium salt dissolved in a combined ionic liquid-organic diluent medium. We find that ethylene carbonate and vinylene carbonate improve electrochemical behaviour, while toluene and tetrahydrofuran are less promising.We also present insights into the electrode passivation caused by these diluents in an ionic liquid electrolyte during lithium cycling. We observe that during lithium cycling those electrolytes with carbonate based diluents are the most able to utilise their previously reported improved lithium ion diffusivities. Conversely, tetrahydrofuran, the most promising diluent of those studied in terms of its known ability to increase lithium ion diffusivity is found not to be as advantageous as a diluent. It appears that the poor electrochemical interfacial properties of the tetrahydrofuran electrolyte prevented the realisation of the benefits of the high solution lithium ion diffusivity.<br />

A haptically enabled CAN-based steering wheel controller

As the portable entertainment and mobility technologies migrate into the car, driver distraction has become recognized as a major factor in road crashes around the world. To help alert drivers to their distraction, active safety technologies such as lane departure warning systems and collision avoidance systems are being implemented. One issue with the implementation of yet another technology into the vehicle is how to cut through the competing demands of the mobile phone, navigation systems and other technologies. Haptic alerts present just such a method that may enable the system to short-circuit the normal auditory or visual communication channels. This paper presents a low cost haptic steering wheel controller that has been designed developed and tested and may be used as a communication device by a lane departure, collision avoidance, or other type of safety system.

When is collaboration not collaboration? When it's militarized

In adopting the medical lobby&rsquo;s preferred definition of collaboration where midwives are legally compelled to seek endorsement for their care plan from an obstetrician, Determination 2010 connotes a form of militarized collaboration and thus negates all that genuine collaboration stands for&ndash;&mdash;equality, mutual trust and reciprocal respect. Using Critical Discourse Analysis, the first half of this paper analyses the submissions from medical, midwifery and consumer peak organisations to the Maternity Services Review and Senate reviews held between 2008 and 2010 showing that Determination 2010 privileges the medical lobby worldview in adopting a vertical definition of collaboration. The second half of the paper responds to the principal assumption of Determination 2010&ndash;&mdash;that midwives do not voluntarily collaborate. It argues by reference to a qualitative inquiry conducted into select caseload maternity units in South Australia, Victoria and New South Wales during 2009&mdash;2010 that this presupposition is erroneous. The evidence shows that genuine collaboration is possible without legislative force but it requires a coalition of the willing among senior midwives and obstetricians to institute regular interdisciplinary meetings and clinical reviews and to model respectful behaviour to new entrants.<br />

Identification of a by-product of nitric oxide synthase activity in human acute brain injury with in vivo proton magnetic resonance spectroscopy

<b>BACKGROUND AND PURPOSE: </b>Laboratory studies have been used to identify nitric oxide as a notable mediator in neuronal death after acute brain injury. To our knowledge, this has not previously been confirmed with in vivo study in humans. Our purpose was to seek in vivo evidence for the induction of nitric oxide synthase (NOS) in human acute brain injury by using proton MR spectroscopy. <br /><br /><b>METHODS:</b> In vitro proton MR spectra were obtained in neural extracts from 30 human cadavers, and in vivo spectra were obtained in 20 patients with acute brain injury and in a similar number of control subjects. <br /><br /><b>RESULTS:</b> We identified a unique peak at 3.15 ppm by using in vivo proton MR spectroscopy in eight of 20 patients with acute brain injury but not in 20 healthy volunteers (P &lt; .002). On the basis of in vitro data, we have tentatively assigned this peak to citrulline, a NOS by-product. <br /><b><br />CONCLUSION:</b> To our knowledge, our findings suggest, for the first time, that excitotoxicity may occur in human acute brain injury. Confirmation with the acquisition of spectra in very early acute cerebral injury would provide a rationale for the use of neuroprotective agents in these conditions, as well as a new noninvasive method for quantification. <br />

Undoing lithium ion association in ionic liquids through the complexation by oligoethers

Tetraglyme (TG) and the recently developed trimethylsilyl capped analogue (1NM3) when used as additives in a <i>N</i>-methyl-<i>N</i>-propylpyrrolidinium bis(trifluoromethylsulfonyl) amide [C₃mpyr][NTf₂]/0.65 M LiNTf₂ electrolyte have been shown to dramatically enhance the transport properties of this electrolyte. In fact, at a concentration of 20 mol % tetraglyme (leading to a ratio of<b> </b>~1:1 ether molecule per lithium ion), viscosity, conductivity, and the diffusion coefficients of the C₃mpyr⁺ and NTf₂^&minus; are practically reinstated to the values observed in the absence of lithium, thereby negating the structuring effects of the lithium ion. The ⁷Li <i>T</i>₁ relaxation times also indicate that these additives strongly interact with the lithium ions. Furthermore, although TG has twice the viscosity of 1NM3, the greatest improvement in transport properties was observed for TG.

Ionic liquid electrolyte for lithium metal batteries : physical, electrochemical, and interfacial studies of N-Methyl-N-butylmorpholinium Bis(fluorosulfonyl)imide

The ionic liquid (IL) <i>N</i>-methyl-<i>N</i>-butylmorpholinium bis(fluorosulfonyl)imide (C₄mmor FSI) is examined from physical and electrochemical perspectives. Pulsed field gradient NMR spectroscopy shows that ion diffusivities are low compared with similar, non-ethereal ILs. Ionicity values indicate that above room temperature, less than 50% of ions contribute to conductivity.<br /><br />Lithium cycling in symmetrical cells using a C₄mmor FSI-based electrolyte is best demonstrated at elevated temperatures. Specific capacities of 130 mAh g^&minus;1 are achieved in a Li&minus;LiFePO₄ battery at 85 &deg;C. FT-IR spectroscopic investigations of lithium electrodes suggest the presence of alkoxide species in the solid electrolyte interphase (SEI), implying a ring-opening reaction of C₄mmor with lithium metal. In contrast, the SEI derived from <i>N</i>-methyl-<i>N</i>-propylpiperidinium FSI lacks the alkoxide signature but shows signs of alkyl unsaturation, and the activation energy for Li+ transport through this SEI is slightly lower than that for the C₄mmor-derived SEI. Our detailed findings give insight into the capabilities and limitations of rechargeable lithium metal batteries utilizing a C₄mmor FSI electrolyte.<br />

Battlers fail to gain a solid foothold at universities

New analysis suggests universities do not have as many disadvantaged students as they thought, according to equity expert Trevor Gale.<br /><br />On a new measure of socioeconomic status, involving a smaller geographic unit of analysis, these students made up 15.2 per cent of total domestic numbers last year, statistics released by the federal Department of Education, Employment and Workplace Relations have revealed. The familiar postcode analysis, a cruder measure, had the proportion as 16.2 per cent.

Transnational yoga and western identities : culture, health and spirituality

The thesis examines the varied interpretations of Yoga within the context of contemporary Western cultures and lifestyles. Using the work of sociological theorists- namely Bourdieu - and a qualitative research design, the thesis explores modern Yoga practices as they are interpreted by practitioners, teachers and within the fluid nature of social practices.<br />

Cultural barriers for female jockeys – the biggest hurdle

This thesis argues that inclusion of women jockeys at the elite level was enabled by the equal opportunity legislation when it was first enacted but the legislation has failed to live up to its' initial promise. Cultural barriers continue to inform and authorise unfair work practices.