Preparation and thermal decomposition of zinc/copper trimellitates and pyromellitates

The aim of this research was to prepare and characterise zinc, copper and mixed zinc/copper trimellitates (1,2,4-benzene tricarboxylates) and pyromellitates (1,2,4,5- benzene tetracarboxylates). The characterisation included a study of the thermal decomposition for selected salts. The literature is reviewed, discussing the synthesis, structural properties, and thermal decompostions of carboxylate salts. This review highlights the growing interest in benzene carboxylates, and a summary of the applications of such salts is given at the end of the review. The preparative route investigated in the work reported here involved reacting zinc/copper hydroxycarbonate, (Zn(_x)Cu(_1-x))(_n)(CO(_2))(_p)(OH)q, with the carboxylic acid. This preparation was chosen in an attempt to overcome problems encountered during previous projects, which are discussed in the introduction. The preparation and characterisation of zinc/copper hydroxycarbonates were studied, concentrating on the preparation of single phase products. The hydroxycarbonate route was successful in producing single metal and mbced metal salts of trimellitic and pyromellitic acid. Limits of the solid solution series were deduced for the mixed metal carboxylates. Three trimelitate crystal structures, Zn(_2)OH(C(_6)H(_3)(COO)(_3)) . 2H(_2)O, ZnCuOH(C(_6)H(_3)(COO)(_3)) . 2H(_2)O, CuH(C(_6)H(_3)(COO)(_3)) . 2.5H(_2)O, and one pyromellitate structure, ZnH(_2)(C(_6)H(_2)(COO)(_4)) . 6H(_2)O, were determined. The trimellitate structures were all polymeric layers, with the anion bridging between the metal sites. The pyromellitate had an ionic structure with [Zn(H(_2)O)(_6)](^2+) cations and [H(_2)(C(_6)H(_2)(COO)(_4))](^2)- anions. The dianion had very strong, intramolecular H-bonding. Using these and other crystal structures, it was possible to deduce a correlation between IR absorptions for carboxylate groups and the type of carboxylate coordination. The thermal decomposition of the metal salts was studied. An investigation was undertaken using DSC and temperature programmed decomposition to deduce the mechanism for the thermal decomposition of selected salts. The effect of the cation ratio (for the mixed metal salts) upon the decomposition was also studied. The work reported here has shown the success of the hydroxycarbonate route for the formation of polycarboxylate salts. Characterisation for a number of new zinc/copper salts is reported. A study of the thermal decompositions for selected salts has deduced the mechanism and factors affecting the decomposition

Object categorisation, object naming, and viewpoint-independence in visual remembering: Evidence from young children's drawings of a novel object

A simple object-drawing task confirms a three-way association between object categorisation, viewpoint independence, and longer-term visual remembering. Young children (5- to 7-year-olds) drew a familiar object or a novel object, immediately after it had been hidden from view or on the following day. Both objects were shown from a full range of viewpoints or from just two viewpoints, from neither of which would either object normally be drawn after unrestricted viewing. When drawing from short-term memory after restricted viewing, both objects were most likely to be depicted from a seen viewpoint. When drawing from longer-term memory after restricted viewing, the novel object continued to be drawn from a seen viewpoint, but the mug was now most likely to be drawn from a preferred viewpoint from which it had not been seen. Naming the novel object with a novel count noun ("Look at this. This is a dax"), to signal that it belonged to an object category, resulted in it being drawn in the same way as the familiar object. The results concur with other evidence indicating that short-term and longer-term visual remembering are differentially associated with viewpoint-dependent representations of individual objects and viewpoint independent representations of object categories, respectively

Finite volume approach for fragmentation equation and its mathematical analysis

peer-reviewedThis work is focused on developing a finite volume scheme for approximating a fragmentation equation. The mathematical analysis is discussed in detail by examining thoroughly the consistency and convergence of the numerical scheme. The idea of the proposed scheme is based on conserving the total mass and preserving the total number of particles in the system. The proposed scheme is free from the trait that the particles are concentrated at the representative of the cells. The verification of the scheme is done against the analytical solutions for several combinations of standard fragmentation kernel and selection functions. The numerical testing shows that the proposed scheme is highly accurate in predicting the number distribution function and various moments. The scheme has the tendency to capture the higher order moments even though no measure has been taken for their accuracy. It is also shown that the scheme is second-order convergent on both uniform and nonuniform grids. Experimental order of convergence is used to validate the theoretical observations of convergence

The World of Principle, or Pure Capitalism : Exteriority and Suspension in Uno Kôzô

The analysis undertaken by Uno Kozo on the question of the (im)possibility or "nihil of reason" (muri)characterizing the commodification of labor power operates as a theoretical pivot which exposes two exteriorities, two suspensions. On the one hand, this moment discloses the theoretical physics of contamination between the logic of capital as a putatively closed circle and the history of capitalism as a developmental process. On the other hand, the fact that this (im)possibility is always "passing through" or "traversing" the gap of logic and history reveals another exteriority in the form of the apparatuses that allow or permit this "traversal," a suspension that ruptures the apparently smooth cycle of exchange. The leap or inversion-rever-sal of capital past its developmental boundaries, and the leap of the commodity into the form of money within exchange, are two moments that are coextensive on a planar surface, implied or interlocking within each other. What seals together these moments is the volatile and hazardous undercurrent of capitalist dynamics that operates under the name of "the agrarian question." In turn, this historical pivot leads us back into the unstable logical core of capital. Placing Uno\u27 s theoretical innovations into divergent lexical and genealogical sequences, we will attempt to re-read and re-write his theoretical work as a critique of political economy by means of the dynamics that inhere in this (im)possibility

Re-writing human consciousness in the plays of Edward Bond

There is evidence to suggest that Bond criticism has begun to abandon certain preoccupations which have held it in a stalemate. Such commentary, however, is tentative and incomplete. Indeed, uncertainty about Bond dates back to the beginning of Bond’s career when, in the mid sixties, commentators endeavoured to establish a critical discourse which secured Bond’s importance as a British dramatist. But while no one, either then or now, denies Bond’s fame, criticism hesitates between a defence of Bond's political intentions and an actual account of his plays as dramatic structures which may, or may not, embody the avowed ideas of the dramatist

Bangsa yang maju adalah bangsa yang celik sejarah

Telah menjadi kebiasaan bagi rakyat Malaysia setiap 31 Ogos kita akan merayakan sambutan kemerdekaan. Bangga sungguh kita menjadi rakyat Malaysia yang mana negaranya aman, makmur dan sejahtera. Orang luar pun suka datang dan tinggal di sini dan mereka juga mengiyakan bahawa Malaysia sungguh aman dan sejahtera. Apa yang penting, di sini tidak ada bom yang jatuh di sana dan jatuh di sini. Sebab itulah hari kemerdekaan dapat disambut dengan penuh meriah. Harus diingat sambutan kemerdekaan bukan sahaja cukup dengan meraikannya, memperingati perjuangan orang-orang terdahulu, pengisian ceramah, pertandingan esei sempena kemerdekaan, dan mengibarkan bendera. Asas untuk seseorang itu menghargai kemerdekaan dan keamanan yang dikecapi selama ini adalah dengan mempelajari dan menghayati perjalanan sejarah negara

Experimental investigation of nanoparticles concentration, boiler temperature and flow rate on flow boiling of zinc bromide and acetone solution in a rectangular duct

Despite the increase in heat transfer properties of nano-fluids, they are not currently used in vapour absorption refrigeration systems (VARS), and there is little literature on the flow boiling behaviour of concentrated salt solutions with nano-particle suspension. A potential novel working fluid solution for a vapour absorption refrigeration unit capable of utilising very low grade waste heat is acetone and zinc bromide, and this fluid is investigated here as the salt solution with graphene nanoparticles in suspension in flow boiling similar to that found in VARS. Nanoparticle concentration, boiler temperature, and flow rate are investigated. The Rohsenow constant in the flow boiling correlation for the nanofluid acetone/ZnBr2 with graphene on a stainless steel surface is found to be 0.217. By increasing the particle concentration from 0 to 05 vol%, heat flux and heat transfer coefficient on the heated surface increase from 8638 W/m2 and 106 W/m2 K to 13164 W/m2 and 167 W/m2 K, respectively. The steady pressure of the system increases with increasing loading of the nanoparticles and consequently the saturation temperature increases. This is because of the increased vapour generation as a consequence of improved heat transfer properties. Heat transfer coefficient is linearly proportional to temperature difference between the fluid and wall (e.g. increases from 78 W/m2 K to 145 W/m2 K when the temperature difference increase from 102 K to 135 K) in the range tested and the heat flux correspondingly reflects a quadratic relationship with temperature difference. Increasing nanofluid flow rate reduces both the production of acetone in the condenser and the salt concentration in the strong solution reservoir. Regarding properties of the fluid, the density and the specific heat follow the simple mixture combination rule; the thermal conductivity of the nanofluid increases by 4.5% with increasing the loading the particles to 0.5 vol%, following reasonably well the correlation of Suganthi et al. (2014); the viscosity increases linearly with concentration of nanoparticles (e.g. increases from 3.22 m Pa s to 4.5 m Pa s by increasing the concentration from 0 to 0.5 vol%); the stability of the nano-salt-fluid is affected by the density of the base fluid. The nanofluid showing good stability for 4 h and during the circulation of the fluid in the rig. Over the range of temperatures tested, the salt solution demonstrates characteristics of nucleate boiling behaviour and offers significant improvement over the properties of the base fluid in terms of boiling effectiveness, indicating that it will provide improved operation in a VARS situation

Designing a Model-Based Systems Engineering (MBSE) Template for Satellites

The goal of this project has been to digitally transform SDL systems engineering methods for scoping small satellite missions, developing system architectures, documenting the engineering solution, and verifying design solutions from being document-intensive (gathering non-transformable information in discrete, disjoint documents) to being model-based (employing cohesive, traceable, transformable graphical models). We have produced a set of models that give satellite development programs (and any model-based program) a head start that enables the modeling effort to drive the systems engineering process instead of catching up with a document-driven design. We plan to use these models to develop, train, and encourage consistent modeling techniques across the Lab and lower the barrier of entry for creating focused, useful models

Catalysis and evolution on cycling of nano-structured magnesium multilayer thin films

This paper explores the hydrogen cycling properties of Mg/Cr and Mg/V multilayer thin films and studies the effect of chromium and vanadium transition metal catalysts on the cycling properties of thick magnesium coatings. Two transition-metal catalysed magnesium-based multilayer PVD coatings are compared with a non-catalysed magnesium control sample. The (micro-)structural evolution of the thin film coatings into fine, flakey powders is studied in depth using XRD, SEM and TEM and the hydrogen storage properties of all three materials are assessed using volumetric, gravimetric and calorimetric methods focussing on the effect of the microstructure and composition of the coatings on the hydrogen storage kinetics. It was found that the chromiumcatalysed coating had the most favourable hydrogen storage kinetics with an activation energy for the dehydrogenation reaction of 65.7±2.5 kJ mol-1 and a hydrogen capacity of 6.1±0.3 wt%. The mechanism of the dehydrogenation reaction of the catalysed samples was studied using the CV and JMAK kinetic models and it was found that the catalyst material influenced not only the hydrogen storage kinetics but also the mechanism of the reaction

The Sociology of Sexual Polarity

This thesis presents an attempt to create a general approach to the sexes in society through the sociology of Max Weber. This falls into three main sections: a consideration of methodological issues; a set of comparative historical studies located in the Ancient Civilization; and, between them, an essay in sociological theory. The first section diagnoses a traditional paralysis in the general theory of gender due to the irrational relationship between sociology and anthropology, and turns to Weber's methodological practice for the cure: the comparative historical method of enquiry and a formal conception of the relationship of biology to society in Interpretive terms. This last entails seeing biology not as supervising society, but as an input into social action under the supervision of history; this entails replacing the strategic notion of "reproduction" with a treatment of demographics. Under this strategy, the biological basis is developed through Jungian psychology to give the conception of "sexual polarity" in four elements: fertility and maternity, maturation, sexuality, and aggression; and a basic typology of social action based on or oriented to these is raised. The second section develops these conceptions and compares them in City-states and Bureaucratic Kingdoms. The first issue is how different power systems impact upon the economy to produce different demographic regimes, in which sex, fertility, and women must either be controlled or accepted; the struggle for control of the state then makes for different types of family, household, and community arrangements - here the family sociology of Zimmerman is recalled. Local community, household, and family patterns are then compared on their own account; then contrasting patterns in motherhood, childhood and adolescence, sexual relationships, and violence, the protection of personal security, and citizenship. Finally, sexual divisions are examined: in the structures of the state apparatus, the various aspects of the economy, and the "bearing of these for stratification. The third section presents three studies in the position of women in Antiquity: New Kingdom Egypt, classical Athens, and the Roman Empire. Finally, two appendices present, respectively, an outline of the general sociology of Antiquity, and a "brief account of the Analytical Psychology of Carl Jung