413 resultados para CROSS-LINKED CHAINS


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Multi-output boost (MOB) converter is a novel DC-DC converter unlike the regular boost converter, has the ability to share its total output voltage and to have different series output voltage from a given duty cycle for low and high power applications. In this paper, discrete voltage control with inner hysteresis current control loop has been proposed to keep the simplicity of the control law for the double-output MOB converter, which can be implemented by a combination of analogue and logical ICs or simple microcontroller to constrain the output voltages of MOB converter at their reference voltages against variation in load or input voltage. The salient features of the proposed control strategy are simplicity of implementation and ease to extend to multiple outputs in the MOB converter. Simulation and experimental results are presented to show the validity of control strategy.

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1,2-Bis[10,15-di(3,5-di-tert-butyl)phenylporphyrinatonickel(II)-5-yl]diazene was synthesised via copper catalysed coupling of aminated nickel(II) 5,10-diarylporphyrin (“corner porphyrin”) and its X-ray crystal structure was determined. Two different crystals yielded different structures, one with the free meso positions in a trans-like orientation, and the other with a cis-like disposition. The free meso positions of the obtained dimer have been further functionalised while the synthesis of a zinc analogue has so far been unsuccessful. The X-ray crystal structure of the dinitro derivative of the dinickel(II) azoporphyrin was determined, and the structure showed a cis-like disposition of the nitro groups.

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The crystal structure of the modified unsymmetrically N, N'-substituted viologen chromophore, N-ethyl- N'-(2-phosphonoethyl)-4, 4'-bipyridinium dichloride 0.75 hydrate. (1) has been determined. Crystals are triclinic, space group P-1 with Z = 2 in a cell with a = 7.2550(1), b = 13.2038(5), c = 18.5752(7) Å, α = 86.495(3), β = 83.527(2), γ = 88.921(2)o. The two independent but pseudo-symmetrically related cations in the asymmetric unit form one-dimensional hydrogen-bonded chains through short homomeric phosphonic acid O-H...O links [2.455(4), 2.464(4)A] while two of the chloride anions are similarly strongly linked to phosphonic acid groups [O-H…Cl, 2.889(4), 2.896(4)Å]. The other two chloride anions together with the two water molecules of solvation (one with partial occupancy) form unusual cyclic hydrogen-bonded bis(Cl...water) dianion units which lie between the layers of bipyridylium rings of the cation chain structures with which they are weakly associated.

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The 1:1 proton-transfer compound of the potent substituted amphetamine hallucinogen (R)-1-(8-bromobenzo[1,2-b; 4,5-b']difuran-4-yl)-2-aminopropane (common trivial name 'bromodragonfly') with 3,5-dinitrosalicylic acid, 1-(8-bromobenzo[1,2-b;4,5-b']difuran-4-yl)-2-mmoniopropane 2-carboxy-4,6-dinitrophenolate, C13H13BrNO2+ C7H3N2O7- forms hydrogen-bonded cation-anion chain substructures comprising undulating head-to-tail anion chains formed through C(8) carboxyl O-H...O(nitro) associations and incorporating the aminium groups of the cations. The intra-chain cation-anion hydrogen-bonding associations feature proximal cyclic R33(8) interactions involving both a N+-H...O(phenolate) and the carboxyl O--H...O(nitro)associations. Also present are aromatic pi-pi ring interactions [minimum ring centroid separation, 3.566(2)A; inter-plane dihedral angle, 5.13(1)deg]. A lateral hydrogen-bonding interaction between the third aminium proton and a carboxyl O acceptor link the chain substructures giving a two-dimensional sheet structure. This determination represents the first of any form of this compound and confirms that it has the (R) absolute configuration. The atypical crystal stability is attributed both to the hydrogen-bonded chain substructures provided by the anions, which accommodate the aminium proton-donor groups of the cations and give cross-linking, and to the presence of cation--anion aromatic ring pi-pi interactions.

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To maintain or achieve competitiveness and profitability, a manufacturing firm or enterprise must respond to a range of challenges, including rapid improvements in technology; declining employment and output; globalisation of markets and environmental requirements. In addition, substantial changes in government policy have had important impacts in many countries, as have the increasing levels of global trade. Manufacturing enterprises need to have a clear understanding of what their customers want and why customers purchase their products rather than purchase from their competitors. They need to fully understand the aims of the business in terms of its customers, market segments, product attributes, geographical markets and performance. Continuous Improvement (CI) methods have become widely adopted and regarded as providing an important component of increased company competitiveness. This article examines the extent to which continuous improvement activities have contributed to the different areas of business performance.

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In the structure of the title compound, the salt 2(C12H10N3O4+) (C12H8O6S2)2- . 3H2O, determined at 173 K, the biphenyl-4,4'-disulfonate dianions lie across crystallographic inversion centres with the sulfonate groups interacting head-to-head through centrosymmetric cyclic bis(water)-bridged hydrogen-bonding associations [graph set R4/4(11)], forming chain structures. The 2-(2,4-dinitrobenzyl)pyridinium cations are linked to these chains through N+-H...O(water) hydrogen bonds and a two-dimensional network structure is formed through water bridges between sulfonate and 2-nitro O atoms, while the structure also has weak cation--anion pi-pi aromatic ring interactions [minimum ring centroid separation 3.8441(13)A].

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In the structure of the 1:1 proton-transfer compound of 4-methylpyridine (\g-picoline) with 4,5-dichlorophthalic acid, C6H8N+ C8H3Cl2O4- . H2O, determined at 200 K, the 4,5-dichlorophthalate anions are bridged by the water molecule through O--H...O~carboxyl~ hydrogen bonds, giving zig-zag chains which extend along the c axial direction of the unit cell. The 4-methylpyridine cations are linked to the chains through single N--H...O~water~ hydrogen bonds and occupy the voids within the chains in the one-dimensional structure. The anions have the common 'planar' conformation with the short intramolecular O--H...O(carboxyl) hydrogen bond.

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The crystal structure of the 2:1 proton-transfer compound of brucine with biphenyl-4,4’-disulfonate, bis(2,3-dimethoxy-10-oxostrychnidinium) biphenyl-4,4'-disulfonate hexahydrate (1) has been determined at 173 K. Crystals are monoclinic, space group P21 with Z = 2 in a cell with a = 8.0314(2), b = 29.3062(9), c = 12.2625(3) Å, β = 101.331(2)o. The crystallographic asymmetric unit comprises two brucinium cations, a biphenyl-4,4'-disulfonate dianion and six water molecules of solvation. The brucinium cations form a variant of the common undulating and overlapping head-to-tail sheet sub-structure. The sulfonate dianions are also linked head-to-tail by hydrogen bonds into parallel zig-zag chains through clusters of six water molecules of which five are inter-associated, featuring conjoint cyclic eight-membered hydrogen-bonded rings [graph sets R33(8) and R34(8)], comprising four of the water molecules and closed by sulfonate O-acceptors. These chain structures occupy the cavities between the brucinium cation sheets and are linked to them peripherally through both brucine N+-H...Osulfonate and Ocarbonyl…H-Owater to sulfonate O bridging hydrogen bonds, forming an overall three-dimensional framework structure. This structure determination confirms the importance of water in the stabilization of certain brucine compounds which have inherent crystal instability.

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This paper analyzes the effects of internal and external social norms on tax morale and tax compliance behavior. Field data and data derived from laboratory experiments are used to examine tax morale and tax compliance behavior in Costa Rica and Switzerland. The results indicate that internal and external social norms have a significant effect on tax morale and tax compliance.

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The call for the cross cultural examination and validation of commonly accepted relationships within consumer behaviour is strengthening. Consequently, this paper seeks to address this call by examining consumer risk perceptions, reliance on country of origin information and willingness to buy Genetically Modified (GM) food products on Australian and South Korean consumers. Findings indicate a number of cross cultural similarities and differences that have both theoretical and practical implications.

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Recent studies have shown that human papillomavirus (HPV) DNA can be found in circulating blood, including peripheral blood mononuclear cells (PBMCs), sera, plasma, and arterial cord blood. In light of these findings, DNA extracted from PBMCs from healthy blood donors were examined in order to determine how common HPV DNA is in blood of healthy individuals. Blood samples were collected from 180 healthy male blood donors (18-76 years old) through the Australian Red Cross Blood Services. Genomic DNA was extracted and specimens were tested for HPV DNA by PCR using a broad range primer pair. Positive samples were HPV-type determined by cloning and sequencing. HPV DNA was found in 8.3% (15/180) of the blood donors. A wide variety of different HPV types were isolated from the PBMCs; belonging to the cutaneous beta and gamma papillomavirus genera and mucosal alpha papillomaviruses. High-risk HPV types that are linked to cancer development were detected in 1.7% (3/180) of the PBMCs. Blood was also collected from a healthy HPV-positive 44-year-old male on four different occasions in order to determine which blood cell fractions harbor HPV. PBMCs treated with trypsin were negative for HPV, while non-trypsinized PBMCs were HPV-positive. This suggests that the HPV in blood is attached to the outside of blood cells via a protein-containing moiety. HPV was also isolated in the B cells, dendritic cells, NK cells, and neutrophils. To conclude, HPV present in PBMCs could represent a reservoir of virus and a potential new route of transmission.

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The structures of proton-transfer compounds of 4,5-dichlorophthalic acid (DCPA) with the aliphatic Lewis bases triethylamine, diethylamine, n-butylamine and piperidine, namely triethylaminium 2-carboxy-4,5-dichlorobenzoate C~6~H~16~N^+^ C~8~H~3~Cl~2~O~4~^-^ (I), diethylaminium 2-carboxy-4,5-dichlorobenzoate C~4~H~12~N^+^ C~8~H~3~Cl~2~O~4~^-^ (II), bis(n-butylaminium) 4,5-dichlorophthalate monohydrate 2(C~4~H~12~N^+^) C~8~H~2~Cl~2~O~4~^2-^ . H~2~O (III) and bis(piperidinium) 4,5-dichlorophthalate monohydrate 2(C~5~H~12~N^+^) C~8~H~2~Cl~2~O~4~^2-^ . H~2~O (IV)have been determined at 200 K. All compounds have hydrogen-bonding associations giving in (I) discrete cation-anion units, linear chains in (II) while (III) and (IV) both have two-dimensional structures. In (I) a discrete cation-anion unit is formed through an asymmetric R2/1(4) N+-H...O,O' hydrogen-bonding association whereas in (II), one-dimensional chains are formed through linear N-H...O associations by both aminium H donors. In compounds (III) and (IV) the primary N-H...O linked cation-anion units are extended into a two-dimensional sheet structure via amide N-H...O(carboxyl) and ...O(carbonyl) interactions. In the 1:1 salts [(I) and (II)], the hydrogen 4,5-dichlorophthalate anions are essentially planar with short intramolecular carboxylic acid O-H...O(carboxyl) hydrogen bonds [O...O, 2.4223(14) and 2.388(2)A respectively]. This work provides a further example of the uncommon zero-dimensional hydrogen-bonded DCPA-Lewis base salt and the one-dimensional chain structure type, while even with the hydrate structures of the 1:2 salts with the primary and secondary amines, the low dimensionality generally associated with 1:1 DCPA salts is also found.

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The rhetoric of the pedagogic discourses of landscape architectural students and interior design students is described as part of a doctoral study undertaken to document practices and orientations prior to cross-disciplinary collaboration. We draw on the theoretical framework of Basil Bernstein, an educational sociologist, and the rhetorical method of Kenneth Burke, a literary dramatist, to study the grammars of ‘landscape’ representation employed within these disciplinary examples. We investigate how prepared final year students are for working in a cross-disciplinary manner. The discursive interactions of their work, as illustrated by four examples of drawn images and written text, are described. Our findings suggest that we need to concern ourselves aspects of our pedagogic discourse that brings uniqueness and value to our disciplines ,as well as that shared discourses between disciplines.

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Purpose: The purpose of this paper is to explore the role of cross-functional teams in the alignment between system effectiveness and operational effectiveness after the implementation of enterprise information systems (EIS). In addition, it aims to explore the contribution of cross-functional teams to improvement in operational performance. ---------- Design/methodology/approach: The research uses a combination of qualitative and quantitative methods, in a two-stage methodological approach, to investigate the influence of cross-functional teams on the alignment between system effectiveness and operational effectiveness and the impact of the stated alignment on the improvement in operational performance. ---------- Findings: Initial findings suggest that factors stemming from system effectiveness and the performance objectives stemming from operational effectiveness are important and significantly well correlated factors that promote the alignment between the effectiveness of technological implementation and the effectiveness of operations. In addition, confirmatory factor analysis has been used to find the structural relationships and provide explanations for the stated alignment and the contribution of cross-functional teams to the improvement in operational performance. ---------- Research limitations/implications: The principal limitation of this study is its small sample size. ---------- Practical implications: Cross-functional teams have been used by many organisations as a way of involving expertise from different functional areas in the implementation of innovative technologies. An appropriate use of the dimensions that emerged from this research, in the context of cross-functional teams, will assist organisations to properly utilise cross-functional teams with the aim of improving operational performance. ---------- Originality/value: The paper presents a new approach to measure the effectiveness of EIS implementation by adding new dimensions to measure it.

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In 2009, Religious Education is a designated key learning area in Catholic schools in the Archdiocese of Brisbane and, indeed, across Australia. Over the years, though, different conceptualisations of the nature and purpose of religious education have led to the construction of different approaches to the classroom teaching of religion. By investigating the development of religious education policy in the Archdiocese of Brisbane from 1984 to 2003, the study seeks to trace the emergence of new discourses on religious education. The study understands religious education to refer to a lifelong process that occurs through a variety of forms (Moran, 1989). In Catholic schools, it refers both to co-curricula activities, such as retreats and school liturgies, and the classroom teaching of religion. It is the policy framework for the classroom teaching of religion that this study explores. The research was undertaken using a policy case study approach to gain a detailed understanding of how new conceptualisations of religious education emerged at a particular site of policy production, in this case, the Archdiocese of Brisbane. The study draws upon Yeatman’s (1998) description of policy as occurring “when social actors think about what they are doing and why in relation to different and alternative possible futures” (p. 19) and views policy as consisting of more than texts themselves. Policy texts result from struggles over meaning (Taylor, 2004) in which specific discourses are mobilised to support particular views. The study has a particular interest in the analysis of Brisbane religious education policy texts, the discursive practices that surrounded them, and the contexts in which they arose. Policy texts are conceptualised in the study as representing “temporary settlements” (Gale, 1999). Such settlements are asymmetrical, temporary and dependent on context: asymmetrical in that dominant actors are favoured; temporary because dominant actors are always under challenge by other actors in the policy arena; and context - dependent because new situations require new settlements. To investigate the official policy documents, the study used Critical Discourse Analysis (hereafter referred to as CDA) as a research tool that affords the opportunity for researchers to map and chart the emergence of new discourses within the policy arena. As developed by Fairclough (2001), CDA is a three-dimensional application of critical analysis to language. In the Brisbane religious education arena, policy texts formed a genre chain (Fairclough, 2004; Taylor, 2004) which was a focus of the study. There are two features of texts that form genre chains: texts are systematically linked to one another; and, systematic relations of recontextualisation exist between the texts. Fairclough’s (2005) concepts of “imaginary space” and “frameworks for action” (p. 65) within the policy arena were applied to the Brisbane policy arena to investigate the relationship between policy statements and subsequent guidelines documents. Five key findings emerged from the study. First, application of CDA to policy documents revealed that a fundamental reconceptualisation of the nature and purpose of classroom religious education in Catholic schools occurred in the Brisbane policy arena over the last twenty-five years. Second, a disjuncture existed between catechetical discourses that continued to shape religious education policy statements, and educational discourses that increasingly shaped guidelines documents. Third, recontextualisation between policy documents was evident and dependent on the particular context in which religious education occurred. Fourth, at subsequent links in the chain, actors created their own “imaginary space”, thereby altering orders of discourse within the policy arena, with different actors being either foregrounded or marginalised. Fifth, intertextuality was more evident in the later links in the genre chain (i.e. 1994 policy statement and 1997 guidelines document) than in earlier documents. On the basis of the findings of the study, six recommendations are made. First, the institutional Church should carefully consider the contribution that the Catholic school can make to the overall pastoral mission of the diocese in twenty-first century Australia. Second, policymakers should articulate a nuanced understanding of the relationship between catechesis and education with regard to the religion classroom. Third, there should be greater awareness of the connections among policies relating to Catholic schools – especially the connection between enrolment policy and religious education policy. Fourth, there should be greater consistency between policy documents. Fifth, policy documents should be helpful for those to whom they are directed (i.e. Catholic schools, teachers). Sixth, “imaginary space” (Fairclough, 2005) in policy documents needs to be constructed in a way that allows for multiple “frameworks for action” (Fairclough, 2005) through recontextualisation. The findings of this study are significant in a number of ways. For religious educators, the study highlights the need to develop a shared understanding of the nature and purpose of classroom religious education. It argues that this understanding must take into account the multifaith nature of Australian society and the changing social composition of Catholic schools themselves. Greater recognition should be given to the contribution that religious studies courses such as Study of Religion make to the overall religious development of a person. In view of the social composition of Catholic schools, there is also an issue of ecclesiological significance concerning the conceptualisation of the relationship between the institutional Catholic Church and Catholic schools. Finally, the study is of significance because of its application of CDA to religious education policy documents. Use of CDA reveals the foregrounding, marginalising, or excluding of various actors in the policy arena.