The ligating versatility of halides and pseudohalides in copper(II) complexes- monomers, dimers and chains”

The work embodied in this thesis was carried out by the author in the Department of Applied Chemistry, CUSAT, Kochi, during the period 2008-2013. The thesis brings to light, our attempts to evaluate the coordination behavior of some compounds of interest. The biological activities of semicarbazones and their metal complexes have been an active area of research during the past years because of their significant role in naturally occurring biological systems. Tridentate NNO and ONO semicarbazone systems formed from heterocyclic and aromatic carbonyl compounds and their transition metal complexes are well-authenticated compounds in this field and their synthesis, crystal structures and spectral studies are well desirable. Hence, we decided to develop a research program aimed at the syntheses, crystal structures and spectral studies of copper complexes with halides and pseudohalides. In addition to single crystal X-ray diffraction studies, various physico-chemical methods of analysis were also used for the characterization of the complexes

The diversity of postharvest losses in cassava value chains in selected developing countries

The extent of physical and economic postharvest losses at different stages of cassava value chains has been estimated in four countries that differ considerably in the way cassava is cultivated, processed and consumed and in the relationships and linkages among the value chain actors. Ghana incurs by far the highest losses because a high proportion of roots reach the consumers in the fresh form. Most losses occur at the last stage of the value chain. In Nigeria and Vietnam processors incur most of the losses while in Thailand most losses occur during harvesting. Poorer countries incur higher losses despite their capacity to absorb sub-standard products (therefore transforming part of the physical losses into economic losses) and less strict buyer standards. In monetary terms the impact of losses is particularly severe in Ghana and estimated at about half a billion US dollar per annum while in the other countries it is at the most about USD 50 million. This comparison shows that there are no “one-size-fits-all" solutions for addressing postharvest losses but rather these must be tailor-made to the specific characteristics of the different value chains.

Planning and Scheduling Decisions in Supply Chains with Multiple Supply Modes: An Integrated Approach

We address the problem of jointly determining shipment planning and scheduling decisions with the presence of multiple shipment modes. We consider long lead time, less expensive sea shipment mode, and short lead time but expensive air shipment modes. Existing research on multiple shipment modes largely address the short term scheduling decisions only. Motivated by an industrial problem where planning decisions are independent of the scheduling decisions, we investigate the benefits of integrating the two sets of decisions. We develop sequence of mathematical models to address the planning and scheduling decisions. Preliminary computational results indicate improved performance of the integrated approach over some of the existing policies used in real-life situations.

The Complexity of Safety Stock Placement in General-Network Supply Chains

We consider the optimization problem of safety stock placement in a supply chain, as formulated in [1]. We prove that this problem is NP-Hard for supply chains modeled as general acyclic networks. Thus, we do not expect to find a polynomial-time algorithm for safety stock placement for a general-network supply chain.

Technology Supply Chains: An Introductory Essay

This working paper was originally printed in the Working Paper Series of the MIT International Motor Vehicle Program

Two isomeric reaction products: hydrogen-bonded sheets in methyl 4-(5-amino-3-phenyl-1H-pyrazol-1-yl)-3-nitrobenzoate and hydrogen-bonded chains of edge-fused rings in methyl 3-nitro-4-[(5-phenyl-1H-pyrazol-3-yl)amino] benzoate

In methyl 4-(5-amino-3-phenyl-1H-pyrazol-1-yl)-3-nitrobenzoate, C17H14N4O4, the molecules are linked into complex sheets by a combination of N-H center dot center dot center dot N, N-H center dot center dot center dot O and C - H center dot center dot center dot O hydrogen bonds. In the isomeric methyl 3-nitro-4-[(5-phenyl- 1H-pyrazol-3-yl)amino] benzoate, molecules exhibit a polarized molecular-electronic structure and are linked into chains of edge-fused rings by a combination of N-H center dot center dot center dot O and C - H center dot center dot center dot O hydrogen bonds.

Caring at a distance: Gift Theory, aid chains and social movements

This paper takes as its starting point recent work on caring for distant others which is one expression of renewed interest in moral geographies. It examines relationships in aid chains connecting donors/carers in the First World or North and recipients/cared for in the Third World or South. Assuming predominance of relationships between strangers and of universalism as a basis for moral motivation I draw upon Gift Theory in order to characterize two basic forms of gift relationship. The first is purely altruistic, the other fully reciprocal and obligatory within the framework of institutions, values and social forces within specific relationships of politics and power. This conception problematizes donor-recipient relationships in the context of two modernist models of aid chains-the Resource Transfer and the Beyond Aid Paradigms. In the first, donor domination means low levels of reciprocity despite rhetoric about partnership and participation. The second identifies potential for greater reciprocity on the basis of combination between social movements and non-governmental organizations at both national and trans-national levels, although at the risk of marginalizing competencies of states. Finally, I evaluate post-structural critiques which also problematize aid chain relationships. They do so both in terms of bases-such as universals and difference-upon which it might be constructed and the means-such as forms of positionality and mutuality-by which it might be achieved.

The potential for competitive and healthy food chains of benefit to the countryside

Agricultural policy liberalisation, concern about unhealthy diets and growing recognition of the importance of sustainable land use have fostered interest in the development of competitive food chains based around products that are beneficial to the rural environment. We review the potential for foods with enhanced health attributes based on alternative varieties/breeds and production systems to traditional agriculture which has been predominantly motivated by yields. We concentrate on soft fruit, which is an important source of polyphenols, and grazing livestock systems that have the potential for improving fatty acid profiles in meat products and find there to be clear scientific potential, but limited research to date. Consumer research suggests considerable acceptance of such products and willingness to pay sufficient to cover additional production costs. Purchase of such foods could have major implications for agricultural land use and the rural environment. There is little research to date on specific healthier food products, but spatially explicit models are being developed to assess land use and environmental implications of changing demand and husbandry methods.

Trust and governance of global value chains: The case of a Brazilian beef processor

Purpose - The purpose of this paper is to offer an exploratory case study comparing one Brazilian beef processor's relationships supplying two different distribution channels, an EU importer and an EU retail chain operating in Brazil. Design/methodology/approach - The paper begins with a short review of global value chains and the recent literature on trust. It gives the background to the Brazilian beef chain and presents data obtained through in-depth interviews, annual reports and direct observation with the Brazilian beef processor, the EU importer and the retailer. The interviews were conducted with individual firms, but the analysis places them in a chain context, identifying the links and relationships between the agents of the chains and aiming to describe each distribution channel. Findings - Executive chain governance exercised by the domestic retailer stimulates technical upgrading and transferring of best practices to local. suppliers. Consequently, this kind of relationship results in more trust within the global value chain. Practical implications - There are difficulties and challenges facing this Brazilian beef processor that are party related to the need to comply with increasingly complex and demanding food safety and food quality standards. There is still a gap between practices adopted for the export market and practices adopted locally. The strategies of transnational retailers in offering differentiated beef should be taken in account. Originality/value - The research outlines an interdisciplinary framework able to explain chain relationships and the kind of trust that emerges in relationships between EU importer/retail and a developing country supplier.

PDBSprotEC: A web-accessible database linking PDB chains to EC numbers via SwissProt

A mapping between chains in the Protein Databank and Enzyme Classification numbers is invaluable for research into structure-function relationships. Mapping at the chain level is a non-trivial problem and we present an automatically updated Web-server, which provides this link in a queryable form and as a downloadable XML or flat file.

Synthesis of the ester side chains of some potently antileukemic harringtonia alkaloids from chiral citrates

The selective reduction of one of the three carboxyl groups of two chiral citric acid derivatives to the corresponding aldehydes, under Rosenmund conditions, are reported together with the application of these aldehydes to the syntheses of the ester side chains of some potently antileukemic Cephalotaxus alkaloids e.g. anhydroharringtonine.

Anion-directed synthesis of metal-organic frameworks based on 2-picolinate Cu(II) complexes: a ferromagnetic alternating chain and two unprecedented ferromagnetic fish backbone chains

Three new polynuclear copper(II) complexes of 2-picolinic acid (Hpic), {[Cu-2(pic)(3)(H2O)]ClO4}(n) (1), {[Cu-2(pic)(3)(H2O)]BF4}(n) (2), and [Cu-2(pic)3(H2O)(2)(NO3)](n) (3), have been synthesized by reaction of the "metalloligand" [Cu-(pic)(2)] with the corresponding copper(II) salts. The compounds are characterized by single-crystal X-ray diffraction analyses and variable-temperature magnetic measurements. Compounds 1 and 2 are isomorphous and crystallize in the triclinic system with space group P (1) over bar, while 3 crystallizes in the monoclinic system with space group P2(1)/n. The structural analyses reveal that complexes 1 and 2 are constructed by "fish backbone" chains through syn-anti (equatorial-equatorial) carboxylate bridges, which are linked to one another by syn-anti (equatorial-axial) carboxylate bridges, giving rise to a rectangular grid-like two-dimensional net. Complex 3 is formed by alternating chains of syn-anti carboxylate-bridged copper(II) atoms, which are linked together by strong H bonds involving coordinated nitrate ions and water molecules and uncoordinated oxygen atoms from carboxylate groups. The different coordination ability of the anions along with their involvement in the H-bonding network seems to be responsible for the difference in the final polymeric structures. Variable-temperature (2-300 K) magnetic susceptibility measurement shows the presence of weak ferromagnetic coupling for all three complexes that have been fitted with a fish backbone model developed for 1 and 2 (J = 1.74 and 0.99 cm(-1); J' = 0.19 and 0.25 cm(-1), respectively) and an alternating chain model for 3 (J = 1.19 cm(-1) and J' = 1.19 cm(-1)).

Bending, twisting, and breaking CuCN chains to produce framework materials: the reactions of CuCN with alkali-metal halides

The reactions of the low-temperature polymorph of copper(I) cyanide (LT-CuCN) with concentrated aqueous alkali-metal halide solutions have been investigated. At room temperature, KX (X = Br and I) and CsX (X = Cl, Br, and I) produce the addition products K[Cu-2(CN)(2)Br](H2O)-H-. (I), K-3[Cu-6(CN)(6)I-3](.)2H(2)O (II), Cs[Cu-3(CN)(3)Cl] (III), Cs[Cu-3(CN)(3)Br] (IV), and Cs-2[Cu-4(CN)(4)I-2](H2O)-H-. (V), with 3-D frameworks in which the -(CuCN)- chains present in CuCN persist. No reaction occurs, however, with NaX (X = Cl, Br, I) or KCl. The addition compounds, I-V, reconvert to CuCN when washed. Both low- and high-temperature polymorphs of CuCN (LT- and HT-CuCN) are produced, except in the case of Cs[Cu-3(CN)(3)Cl] (III), which converts only to LT-CuCN. Heating similar AX-CuCN reaction mixtures under hydrothermal conditions at 453 K for 1 day produces single crystals of I-V suitable for structure determination. Under these more forcing conditions, reactions also occur with NaX (X = Cl, Br, I) and KCl. NaBr and KCl cause some conversion of LT-CuCN into HT-CuCN, while NaCl and NaI, respectively, react to form the mixed-valence Cu(I)/Cu(II) compounds [Cu-II(OH2)(4)][Cu-4(I)(CN)(6)], a known phase, and [Cu-II(OH2)(4)][Cu-4(I)(CN)(4)I-2] (VI), a 3-D framework, which contains infinite -(CuCN)- chains. After 3 days of heating under hydrothermal conditions, the reaction between KI and CuCN produces [Cu-II(OH2)(4)][Cu-2(I)(CN)I-2](2) (VII), in which the CuCN chains are broken into single Cu-CN-Cu units, which in turn are linked into chains via iodine atoms and then into layers via long Cu-C and Cu-Cu interactions.