Dussertite BaFe3+3(AsO4)2(OH)5 : a Raman spectroscopic study of a hydroxy-arsenate mineral

The mineral dussertite, a hydroxy-arsenate mineral of formula BaFe3+3(AsO4)2(OH)5, has been studied by Raman complimented with infrared spectroscopy. The spectra of three minerals from different origins were investigated and proved quite similar, although some minor differences were observed. In the Raman spectra of Czech dussertite, four bands are observed in the 800 to 950 cm-1 region. The bands are assigned as follows: the band at 902 cm-1 is assigned to the (AsO4)3- ν3 antisymmetric stretching mode, at 870 cm-1 to the (AsO4)3- ν1 symmetric stretching mode, and both at 859 cm-1 and 825 cm-1 to the As-OM2+/3+ stretching modes/and or hydroxyls bending modes. Raman bands at 372 and 409 cm-1 are attributed to the ν2 (AsO4)3- bending mode and the two bands at 429 and 474 cm-1 are assigned to the ν4 (AsO4)3- bending mode. An intense band at 3446 cm-1 in the infrared spectrum and a complex set of bands centred upon 3453 cm-1 in the Raman spectrum are attributed to the stretching vibrations of the hydrogen bonded (OH)- units and/or water units in the mineral structure. The broad infrared band at 3223 cm-1 is assigned to the vibrations of hydrogen bonded water molecules. Raman spectroscopy identified Raman bands attributable to (AsO4)3- and (AsO3OH)2- units.

catena-Poly[[[diaquacobalt(II)]-mu-(3,5-dinitro-2-oxidobenzoato)-kappa3O1,O2:O1'-[tetraaquacobalt(II)]-mu-(3,5-dinitro-2-oxidobenzoato)-kappa3-O1:O1',O2] dihydrate]

In the structure of polymeric title compound, {[Co2(C7H2N2O7)2(H2O)6] . 2H2O}n from the reaction of 3,5-dinitrosalicylic acid with cobalt(II) acetate, both slightly distorted octahedral Co(II) centres have crystallographic inversion symmetry. The coordination sphere about one Co centre comprises four O donors from two bidentate chelate O(phenolate), O(carboxyl) and bridging dianionic ligands and two water molecules [Co-O range, 2.0249(11)-2.1386(14)A] while that about the second Co centre has four water molecules and two bridging carboxyl O donor atoms [Co-O range, 2.0690(14)-2.1364(11)A]. The coordinated water molecules as well as the water molecules of solvation give water-water and water-carboxyl hydrogen-bonding interactions in the three-dimensional framework structure.

Reverse engineering and finite element analysis of a 3-wheeler automotive structure

Auto rickshaws (3-wheelers) are the most sought after transport among the urban and rural poor in India. The assembly of the vehicle involves assemblies of several major components. The L-angle is the component that connects the front panel with the vehicle floor. Current L-angle part has been observed to experience permanent deformation failure over period of time. This paper studies the effect of the addition of stiffeners on the L-angle to increase the strength of the component. A physical model of the L-angle was reversed engineered and modelled in CAD before static loading analysis were carried out on the model using finite element analysis. The modified L-angle fitted with stiffeners was shown to be able to withstand more load compare to previous design.

A review of rationale for allocating costs and payments in producing and supplying public sector information PART A of 2 Parts – Chapters 1, 2 and 3) 13 March 2011 version

This work reviews the rationale and processes for raising revenue and allocating funds to perform information intensive activities that are pertinent to the work of democratic government. ‘Government of the people, by the people, for the people’ expresses an idea that democratic government has no higher authority than the people who agree to be bound by its rules. Democracy depends on continually learning how to develop understandings and agreements that can sustain voting majorities on which democratic law making and collective action depends. The objective expressed in constitutional terms is to deliver ‘peace, order and good government’. Meeting this objective requires a collective intellectual authority that can understand what is possible; and a collective moral authority to understand what ought to happen in practice. Facts of life determine that a society needs to retain its collective competence despite a continual turnover of its membership as people die but life goes on. Retaining this ‘collective competence’ in matters of self-government depends on each new generation: • acquiring a collective knowledge of how to produce goods and services needed to sustain a society and its capacity for self-government; • Learning how to defend society diplomatically and militarily in relation to external forces to prevent overthrow of its self-governing capacity; and • Learning how to defend society against divisive internal forces to preserve the authority of representative legislatures, allow peaceful dispute resolution and maintain social cohesion.

Evidence of multiwall carbon nanotube deformation caused by poly(3-hexylthiophene) adhesion

We show that when a soft polymer like Poly(3-hexyl-thiophene) wraps multiwall nanotubes by coiling around the main axis, a localized deformation of the nanotube structure is observed. High resolution transmission electron microscopy shows that radial compressions of about 4% can take place, and could possibly lead to larger interlayer distance between the nanotube inner walls and reduce the innermost nanotube radius. The mechanical stress due to the polymer presence was confirmed by Raman spectroscopic observation of a gradual upshift of the carbon nanotube G-band when the polymer content in the composites was progressively increased. Vibrational spectroscopy also indicates that charge transfer from the polymer to the nanotubes is responsible for a peak frequency relative downshift for high P3HT-content samples. Continuously acquired transmission electron microscopy images at rising temperature show the MWCNT elastic compression and relaxation due to polymer rearrangement on the nanotube surface.

Critical literacy finds a "Place": Writing and social action in a low-income Australian grade 2/3 classroom

In a study of socioeconomically disadvantaged children's acquisition of school literacies, a university research team investigated how a group of teachers negotiated critical literacies and explored notions of social power with elementary children in a suburban school located in an area of high poverty. Here we focus on a grade 2/3 classroom where the teacher and children became involved in a local urban renewal project and on how in the process the children wrote about place and power. Using the students' concerns about their neighborhood, the teacher engaged her class in a critical literacy project that not only involved a complex set of literate practices but also taught the children about power and the possibilities for local civic action. In particular, we discuss examples of children's drawing and writing about their neighborhoods and their lives. We explore how children's writing and drawing might be key elements in developing "critical literacies" in elementary school settings. We consider how such classroom writing can be a mediator of emotions, intellectual and academic learning, social practice, and political activism.

The legal role of medical professionals in decisions to withhold or withdraw life-sustaining treatment : part 3 (Victoria)

This is the final article in a series of three that examines the legal role of medical professionals in decisions to withhold or withdraw life-sustaining treatment from adults who lack capacity. This article considers the position in Victoria. A review of the law in this State reveals that medical professionals play significant legal roles in these decisions. However, the law is problematic in a number of respects and this is likely to impede medical professionals’ legal knowledge in this area. The article examines the level of training that medical professionals receive on issues such as refusal of treatment certificates and substitute decision-making, and the available empirical evidence as to the state of medical professionals’ knowledge of the law at the end of life. It concludes that there are gaps in legal knowledge and that law reform is needed in Victoria. The article also draws together themes from the series as a whole, including conclusions about the need for more and better medical education and about law reform generally.

Year 3 Media Arts : teaching the key concepts through video editing

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Stiffness and damping coefficients of 3-axial groove water lubricated bearing using perturbation technique

A Computational fluid dynamics (CFD) approach is used to model fluid flow in a journal bearing with three equi-spaced axial grooves and supplied with water from one end. Water is subjected to both velocity (Couette) & pressure induced (Poiseuille) flow. The working fluid passing through the bearing clearance generates driving force components that may increase the unstable vibration of the rotor. It is important to know the accurate rotor dynamic force component for predicting the instability of rotor bearing systems. In this paper a study has been made to obtain the stiffness and damping coefficients of 3 axial groove bearing using Perturbation technique.

Towards automated and in-situ, near-real time 3-D reconstruction of coral reef environments

Coral reefs are biologically complex ecosystems that support a wide variety of marine organisms. These are fragile communities under enormous threat from natural and human-based influences. Properly assessing and measuring the growth and health of reefs is essential to understanding impacts of ocean acidification, coastal urbanisation and global warming. In this paper, we present an innovative 3-D reconstruction technique based on visual imagery as a non-intrusive, repeatable, in situ method for estimating physical parameters, such as surface area and volume for efficient assessment of long-term variability. The reconstruction algorithms are presented, and benchmarked using an existing data set. We validate the technique underwater, utilising a commercial-off-the-shelf camera and a piece of staghorn coral, Acropora cervicornis. The resulting reconstruction is compared with a laser scan of the coral piece for assessment and validation. The comparison shows that 77% of the pixels in the reconstruction are within 0.3 mm of the ground truth laser scan. Reconstruction results from an unknown video camera are also presented as a segue to future applications of this research.