Three dimensional pseudomanifolds on eight vertices

A normal pseudomanifold is a pseudomanifold in which the links of simplices are also pseudomanifolds. So, a normal 2-pseudomanifold triangulates a connected closed 2-manifold. But, normal $d$-pseudomanifolds form a broader class than triangulations of connected closed $d$-manifolds for $d \geq 3$. Here, we classify all the 8-vertex neighbourly normal 3-pseudomanifolds. This gives a classification of all the 8-vertex normal 3-pseudomanifolds. There are 73 such 3-pseudomanifolds, 38 of which triangulate the 3-sphere and other 35 are not combinatorial 3-manifolds. These 35 triangulate six distinct topological spaces. As a preliminary result, we show that any 8-vertex 3-pseudomanifold is equivalent by proper bistellar moves to an 8-vertex neighbourly 3-pseudomanifold. This result is the best possible since there exists a 9-vertex non-neighbourly 3-pseudomanifold ($B^3_9$ in Example 7 below) which does not allow any proper bistellar moves.Comment: 19 pages, Revised version. To appear in the `International Journal of Mathematics and Mathematical Sciences

Tapping Economies of Scale and Scope in Consumer Cooperation - A Case Analysis of Possible Cooperation among selected Cooperatives

Because of its narrow and negative perspective of safeguarding the interests of only poor consumers against unethical practices of the private traders, consumer cooperation in India seems to have failed, except probably in some isolated pockets. A number of social welfare functions like poverty alleviation and public distribution of essential items of consumption have been imposed on them at the cost of their basic economics. With the basic micro and macro-economic rationale for consumer cooperatives as a positive form of economic organization being lost sight of, they seem to be facing enormous problems both historically as well as currently in a era of economic liberalization. Their worries seem to have been compounded with the threat of impending competition from large private enterpriss - both domestic and foreign, which highlights the need for evolving strategies to rectivy their systemic weaknesses and tackling the competition head on. This case has attempted to document just such an initiative through a round table conference with several doyens of the consumer cooperative movement in India such as Warana Bazar and Amalsad Mandali as well as some fledging consumer cooperatives from West Bengal which are already in existence for some time or contemplating entry into this field. The roundtable conference organized in the spirit of Cooperation among Cooperatives attempted to evolve strategies to capture economies of scale and scope in order to take on the competition, as well as to facilitate dissemination of ideas and information across the country.

Epoch profiles: microarchitecture-based application analysis and optimization

The performance of data-intensive applications, when running on modern multi- and many-core processors, is largely determined by their memory access behavior. Its most important contributors are the frequency and latency of off-chip accesses and the extent to which long-latency memory accesses can be overlapped with useful computation or with each other. In this paper we present two methods to better understand application and microarchitectural interactions. An epoch profile is an intuitive way to understand the relationships between three important characteristics: the on-chip cache size, the size of the reorder window of an out-of-order processor, and the frequency of processor stalls caused by long-latency, off-chip requests (epochs). By relating these three quantities one can more easily understand an application’s memory reference behavior and thus significantly reduce the design space. While epoch profiles help to provide insight into the behavior of a single application, developing an understanding of a number of applications in the presence of area and core count constraints presents additional challenges. Epoch-based microarchitectural analysis is presented as a better way to understand the trade-offs for memory-bound applications in the presence of these physical constraints. Through epoch profiling and optimization, one can significantly reduce the multidimensional design space for hardware/software optimization through the use of high-level model-driven techniques

Synthesis, characterization and photophysical studies of cyclometalated Au(III) complexes

We report here a series of room temperature emissive biphenyl cyclometalated gold (III) diethyl dithiocarbamate complexes (DEDT) having H, CF3, OMe and tBu substitutions on the biphenyl moiety. Synthesis of these complexes was accomplished by a single step reaction of the appropriate dilithiobiphenyl reagent with Au(DEDT)Cl2. The Au(DEDT)Cl2 complex played an important role in the success of our reaction, where the chelating sulfur ligand stabilizes the Au(III) center and keeps it intact without reducing to Au(I) or colloidal gold during the course of its reaction with the lithium compound. In comparison with other literature reported procedures for analogous Au(III) complexes, this methodology gave better yields with lesser number of reaction steps as well as without using toxic chemicals such as sodium cyanide or tin compounds. All of these complexes exhibit phosphorescence at room temperature as well as in low temperature glasses. While substitution on the biphenyl moiety by electron donating OMe and tBu groups red shifted the emission band when compared with hydrogen counterparts, the electron withdrawing CF3 groups made no difference. The emission from these complexes is mainly governed by the metal perturbed 3??* transitions of biphenyl and this assignment is well supported by the observed photo physical properties such as vibronic structured emission, lifetime in microseconds, large stokes shift, solvent independent emission spectrum as well as the oxygen quenching of the emission spectrum. Further DFT studies on these complexes also showed that the transition from LUMO+2 to HOMO. (3pi-pi*) is responsible for the emission. This is in contrast with lowest energy absorption which is mainly from HOMO-L+1 (LLCT). This is rationalized by the existence of a relaxed 3pi-pi* (-3.31 eV) state in lower energy when compared with the relaxed 3LLCT state (-1.61 eV) as well as the large energy difference between singlet and triplet pi-pi* states. We also hereby report the synthesis of a bis(diethyldithiocarbamate(DEDT) -S,S)-(naphthyl-1,8) digold(II) complex with a formal Au-Au bond. Our synthetic strategy involved reductive coupling via lithiation of dibromonaphthalene precursor followed by reaction with Au(DEDT)Cl2. This digold complex is unique when compared with known digold(II) complexes, which are traditionally synthesized by oxidative addition of halogen to digold(I) complexes. The digold complex has been characterized by NMR, XRD, UV-Vis and elemental analysis. DFT reasoned the UV-Vis absorption of complex 3 at 379 nm to the transition from sigmaAu-Au) orbital into sigma*(Au-Au) orbital with some contributions from the dithiocarbamate ligand (LMCT). However this complex shows no emission at 298 or 77 K. The lack of emission could possibly be due to low-lying non-emissive d-d states

Development of Test Methods for Measuring Fiber Misalignment and Warping in Honeycomb-Core Composite Panels

Zodiac Aerospace manufactures honeycomb-core composite panels to be used in aircraft cabin interior components. During the manufacturing process, some panels become warped such that they cannot be used for their designated aircraft cabin components. As a result, these panels are scrapped because they cannot be recycled. About 44 to 90% of panels become warped during manufacturing. Warping is caused by many factors, including layer misalignment, processing parameters such as temperature and pressure gradients, and fiber misalignment in the prepregs. Currently, Zodiac does not have any data on the effect of fiber misalignment on panel warpage, so a testing protocol was developed to determine if there was a correlation between these parameters. Fiber misalignment measurements were performed on a selection of glass fiber/phenolic prepregs obtained from multiple shipments. To determine fiber misalignment in the prepregs, the phenolic resin was removed, leaving the raw fibers exposed and able to be measured. Warpage measurements were performed on cured composite panels cut from the same prepreg rolls. Test methods for the maximum deflection and twist angle of the panels was developed, then this data was plotted to determine if a relationship existed between the measurements. The plots showed no correlation between the fiber misalignment and warpage measurements. To provide additional conformation, a one-way analysis of variance (ANOVA) was conducted using an alpha value of 0.05. The ANOVA analysis confirmed that there was no correlation between the fiber misalignment and warpage measurements. Recommendations for further study would be to analyze the effects of temperature and pressure gradients on warping of the panels and construct a fixture to hold the prepreg in the acetone bath