The Anarchist in the Coffee House: A Brief Consideration of Local Culture, the Free Culture Movement, and Prospects for a Global Public Sphere

Jürgen Habermas\u27 influential historical work, The Structural Transformation of the Public Sphere, describes a moment in the social and political history of Europe in which a rising bourgeoisie was able to gather in salons and cafes to discuss matters of public concern. The public sphere represented a set of sites and conventions in the eighteenth century in which (almost exclusively male) members of the bourgeoisie could forge a third space to mediate between domestic concerns and matters of state. Here, Vaidhyanathan examines one particular Public Sphere experiment--the rise of a global Free Culture Movement that aims to limit the spread of strong intellectual property regimes by considering the complications encountered by the movement when it crosses a very different value set at work in global cultural policy debates--the protection of native or local culture exemplified by the Native Culture Movement

Microwave and flash processing of functional materials: Are there (m)any similarities?

Electroceramic devices such as varistors and capacitors are used in most of the modern day electronic appliances and constitute a multi-billion$ market. Conventional fabrication methods of these devices involve high sintering temperatures and long processing time. Since sintering controls the electrical properties, it is necessary to develop simpler and less demanding processing methods. Microwave sintering (MS) was demonstrated to be a viable alternative for rapid processing electroceramics as they respond to the E-field component of the electromagnetic radiation. In a recent report on ‘flash sintering’ (FS) it was demonstrated that full sintering of dog-bone shaped zirconia ceramics can be achieved at 850oC in just 5 seconds (at moderate E-fields) rather than normally used 1450oC for few hours. This opens up the possibility of achieving significant energy savings during manufacture and the ability to produce fine grained ceramics. However the exact mechanisms by which this phenomena occur is not fully clear yet and the methodology is untested for the sintering of other complex functional materials. At Loughborough we investigated the feasibility of sintering nanocrystalline ZnO-varistors, BaTiO3-capacitors and CCTO dielectrics using both MS and FS methods along with simultaneous measurements of shrinkage, online thermal distribution mapping and atmospheric control. This allowed the fabrication of disc-shaped functional ceramic devices using both these techniques and the properties of the devices are compared with conventionally sintered components. This talk will review these new developments on FS along with the operative mechanisms in comparison with microwave processing

New open-framework layered tin(II ) phosphates intercalated with amines

Two new Sn(II) phosphate materials, I and II, have been synthesized hydrothermally using 1,3-diaminopropane and 1,3-diamino-2-hydroxypropane as structure-directing organic amines. The solids I and II have layered architectures and are isostructural. The structures consist of vertex sharing trigonal-pyramidal SnO and tetrahedral PO moieties forming infinite layers possessing 4- and 8-membered apertures. The interlamellar space is occupied by the protonated amine molecules which interact with the framework through hydrogen bonding. Crystal data for compound I: [NH(CH)NH]2[SnPO], M=501.9, monoclinic, space group C2/c, a=18.097(1), b=7.889(1), c=9.151(1)Å, β=111.84(1)°, V=1212.6(2)Å, Z=4, R=0.033 and R=0.061 [791 observed reflections with I=2σ(I )]; compound II [NH(CHCHOHCH)NH] 2[SnPO], M=517.9, monoclinic, space group C2/c, a=18.133(1), b=7.858(1), c=9.344(1)Å, β=111.3(1)°, V=1240.5(2)Å, Z=4, R=0.040 and R=0.11 [867 observed reflections with I=2σ(I)]

Problems Of Improving Spoken Language Skills In Teaching Russian As A Foreign Language

While teaching Russian as a foreign language to undergraduate and postgraduate students in India, we observed that the learners quickly pick up writing skills, whereas their spoken language skills are not at the same level. There are many issues which need to be sorted out in order to improve spoken language skills. As written and spoken skills are different, we need to use different methods of teaching for each one of them. Since the first thing that is taught to students, who are learning a language, are alphabets, hence, initially the whole attention is turned towards improving their writing skills. Though, in the beginning, the students also do pick up an elementary level of spoken language, in the intermediate and advanced levels of learning, their spoken language skills suffer due to various factors. One of the main factors being the lack of exposure to the foreign language once the learners are out of the classroom. Since they continue to do homework, they keep in touch with the written skills. However, once they are out of the classroom, the learners and people around them use their own mother tongue or other native languages to speak. As a result, their spoken skills of the foreign language do not improve.Measures need to be taken for improving spoken skills: showing feature, as well as animation films; involving the students in discussions with the help of native speakers; providing audio books; showing them TV programs after class hours; involving learners in enacting Russian plays, etc. On the whole, artificial foreign language surroundings need to be created. Let us see how to motivate learners to speak as well as to write foreign language of their choice. Keywords: spoken skills, teaching Russian as a foreign language, learning problem

Field assisted processing of 3D printed ceramics

Advanced ceramic products for highly demanding applications in electronics, energy, healthcare and defence sectors require densification/sintering, a high temperature process (~1000–2000oC) that in industry can take days. The amount of energy needed, and CO2 emitted, is therefore very significant. Conventional processing of these functional devices/components are often plagued by interfacial issues, unwanted grain growth and limitations of co-firing dissimilar materials. Thus, rapid and efficient sintering methods such as SPS, Microwave Assisted Sintering (MAS) and Flash Sintering (FS) are continuously being developed. These approaches referred as Field Assisted Sintering Techniques (FAST) use an external field that was demonstrated to have a positive effect on densification. For example, the FS method, for reasons that are far from fully understood, has yielded full densification in very short periods (5 s) at very low furnace temperatures (850oC) for zirconia, and at a surprisingly low temperature of 325oC for Co2MnO4 spinel ceramics. The associated time and energy advantage is estimated to be staggering, as well as the ability to tailor the microstructure. In this talk, we will have a closer look at MAS and FS methods– one a well-established and the other a newly emerging densification method. The MAS method can be suitable for the processing of various simple and complex shaped engineering components, the early use of FS method was restricted to dog-bone shaped ceramic specimens – that are both difficult to make and do not have much industrial applicability. However, the recent developments have demonstrated that FS can also be used to sinter different sample shapes. We investigated the feasibility of sintering of 3D printed ultra-low loss 5G microwave dielectrics, YSZ/ZTA biomedical components using MS and FS methods along with measurements of shrinkage and thermal mapping. This talk will review these developments on FS along with the operative mechanisms in comparison with MAS

Processing of bulk nanostructured ceramics

Conventional ceramic forming routes have been adapted for the processing of ~16 nm, 3 mol% yttria stabilized zirconia nanopowders leading to the production of ~99% dense nanostructured ceramics that display average grain sizes as fine as ~65 nm. The precursor material is in the form of ~5 vol% solids content nanosuspensions produced commercially; these can now be concentrated up to ~37 vol% whilst retaining the viscosity at ~0.05 Pa s. A patent application has been submitted related to the process. The concentrated suspensions have then been used to produce granulated powders suitable for dry forming via spray-freeze drying. Whilst powders have been produced that will yield green bodies with densities of ~50% of theoretical, currently the powders suffer from either poor flow and low fill densities or granules that are too strong to crush during pressing, even at pressures up to 500 MPa. The same suspensions have also been slip cast into extremely homogeneous green bodies with densities of ~54% of theoretical after drying using a humidity drier. Higher densities are currently blocked by cracking of the samples during drying and/or burnout of the organics if the solids content of the suspensions exceeds ~20 vol%. Radiant and hybrid pressureless sintering experiments have been performed on the dry and wet processed green bodies using both conventional single step and two-step sintering cycles. Whilst densities >98% of theoretical were achievable by all combinations, a nanostructure could only be retained using the two stage sintering approach. With hybrid heating the average grain sizes for die pressed samples were in the range 70 – 80 nm whilst for the more homogeneous slip cast samples a final average grain size of just 64 nm was achieved for a body with a final density of ~99.5%. It is believed that the primary advantage offered by hybrid heating is the ability to use a much faster initial heating rate, 20 versus just 7oC min-1, without risking damage to the samples. Whilst detailed characterisation of the properties of these nanostructured ceramics has begun, preliminary results have suggested that the toughness is lower and hardness roughly equivalent to submicron grain-sized 3-YSZ, although the resistance to wear and hydrothermal ageing may have been improved. As a result of detailed crystallographic characterisation this is believed to be due to a grain size dependent shift in the phase boundary composition for nano YSZ ceramics leading to ‘over stabilisation’ at any given yttria content. Current work is focused on investigating the effect of both yttria content and average grain size on the properties of these new materials