398 research outputs found
Rich methane laminar flames doped with light unsaturated hydrocarbons. Part II: 1,3butadiene
In line with the study presented in the part I of this paper, the structure
of a laminar rich premixed methane flame doped with 1,3-butadiene has been
investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen and
3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a
ratio C4H6 / CH4 of 16 %. The flame has been stabilized on a burner at a
pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner
of 36 cm/s at 333 K. The temperature ranged from 600 K close to the burner up
to 2150 K. Quantified species included usual methane C0-C2 combustion products
and 1,3-butadiene, but also propyne, allene, propene, propane, 1,2-butadiene,
butynes, vinylacetylene, diacetylene, 1,3-pentadiene, 2-methyl-1,3-butadiene
(isoprene), 1-pentene, 3-methyl-1-butene, benzene and toluene. In order to
model these new results, some improvements have been made to a mechanism
previously developed in our laboratory for the reactions of C3-C4 unsaturated
hydrocarbons. The main reaction pathways of consumption of 1,3-butadiene and of
formation of C6 aromatic species have been derived from flow rate analyses. In
this case, the C4 route to benzene formation plays an important role in
comparison to the C3 pathway
A Comparative Study of the Formation of Aromatics in Rich Methane Flames Doped by Unsaturated Compounds
For a better modeling of the importance of the different channels leading to
the first aromatic ring, we have compared the structures of laminar rich
premixed methane flames doped with several unsaturated hydrocarbons: allene and
propyne, because they are precursors of propargyl radicals which are well known
as having an important role in forming benzene, 1,3-butadiene to put in
evidence a possible production of benzene due to reactions of C4 compounds,
and, finally, cyclopentene which is a source of cyclopentadienylmethylene
radicals which in turn are expected to easily isomerizes to give benzene. These
flames have been stabilized on a burner at a pressure of 6.7 kPa (50 Torr)
using argon as dilutant, for equivalence ratios (?) from 1.55 to 1.79. A unique
mechanism, including the formation and decomposition of benzene and toluene,
has been used to model the oxidation of allene, propyne, 1,3 butadiene and
cyclopentene. The main reaction pathways of aromatics formation have been
derived from reaction rate and sensitivity analyses and have been compared for
the three types of additives. These combined analyses and comparisons can only
been performed when a unique mechanism is available for all the studied
additives
Political brand image: an investigation into the operationalisation of the external orientation of David Cameron’s Conservative brand
This paper seeks to address the limited understanding of how to operationalise the external brand image of a political brand. More specifically, this research critically assesses the transfer potential of the six variables of brand image by Bosch, Venter, Han and Boshoff to deconstruct the UK Conservative Party brand from the perspective of young people aged 18–24 years during the 2010 UK General Election campaign. This research demonstrates the applicability of the six variables otherwise known as the ‘brand image framework’ to the political environment. However, the application of the brand image framework in its original conceptualisation proved problematic. Many of the brand image variables were clarified, rearticulated and simplified to address the political context. This refined conceptualisation provided an in-depth understanding of how to investigate the political brand image of David Cameron’s Conservative Party. This study addresses the paucity of research that operationalises external brand image and provides practitioners and academics within and beyond the context of political branding a mechanism to understand the external orientation of brands. This research may also be used by political and non-political brands as a basis to explore external brand image and compare its consistency with internal brand identity
An experimental and kinetic modelling study of the oxidation of the four isomers of butanol
Butanol, an alcohol which can be produced from biomass sources, has received
recent interest as an alternative to gasoline for use in spark ignition engines
and as a possible blending compound with fossil diesel or biodiesel. Therefore,
the autoignition of the four isomers of butanol (1-butanol, 2-butanol,
iso-butanol, and tert-butanol) has been experimentally studied at high
temperatures in a shock tube and a kinetic mechanism for description of their
high-temperature oxidation has been developed. Ignition delay times for
butanol/oxygen/argon mixtures have been measured behind reflected shock waves
at temperatures and pressures ranging from approximately 1200 to 1800 K and 1
to 4 bar. Electronically excited OH emission and pressure measurements were
used to determine ignition delay times. A detailed kinetic mechanism has been
developed to describe the oxidation of the butanol isomers and validated by
comparison to the shock tube measurements. Reaction flux and sensitivity
analysis indicate that the consumption of 1 butanol and iso-butanol, the most
reactive isomers, takes place primarily by H-atom abstraction resulting in the
formation of radicals, the decomposition of which yields highly reactive
branching agents, H-atoms and OH radicals. Conversely, the consumption of tert
butanol and 2-butanol, the least reactive isomers, takes place primarily via
dehydration, resulting in the formation of alkenes, which lead to resonance
stabilized radicals with very low reactivity. To our knowledge, the ignition
delay measurements and oxidation mechanism presented here for 2-butanol,
iso-butanol, and tert butanol are the first of their kind.
The interactive effect of influence tactic, applicant gender, and type of job on hiring recommendations
Recommended from our members
Reconceptualising product life-cycle theory as stakeholder engagement with non-profit organisation
The paper critically re-examines product life-cycle (PLC) theory, developed over fifty years ago. Despite prevalence in marketing pedagogy and continued popularity within empirical research, PLC is seldom challenged. The paper identifies the organisation-centric construct underpinning the theory and highlights a disconnection between PLC theory and the recent academic insight around customer engagement.
It reconceptualises the life-cycle concept based on engagement between stakeholder and non-profit organisation (NPO), structured upon both the market orientation and social exchange constructs. The revised framework maps stakeholder engagement with the NPO through the five stages of incubation, interaction, involvement, immersion, and incapacitation. The paper concludes with identifying a roadmap for future empirical research to develop and validate the re-envisaged conceptual model. The methodology used is narrative literature review supported by secondary research from specialist practitioner reports
Brand champion behaviour: Its role in corporate branding
yesBrand champions are responsible for encouraging employee commitment to the corporate brand strategy. They strongly believe in and identify with the brand concept—the company’s selected brand meaning, which underpins corporate brand strategy implementation. We conducted research to explore why and how brand champion behaviour operates within companies implementing a new corporate brand strategy. Against a backdrop of growing interest in brand champion behaviour in corporate branding research, we grounded our study in social identity theory and rhetorical theory from change management literature. Our findings show that articulating a compelling brand vision, taking responsibility, and getting the right people involved are the most widely used strategies by brand champions. We uncover how rhetorical strategies within brand champion behaviour generate employee commitment to a new corporate brand strategy. The dimension of brand champion behaviour that is effective depends on the type of brand evolution, involving shifts in the brand concept. We make suggestions for further studies underpinned by social identity theory and rhetorical theory to investigate brand champion behaviour processes within companies introducing a new corporate brand strategy
- …