6,821 research outputs found
Solar Activity and the Sea-surface Temperature Record-evidence of a Long-period Variation in Solar Total Irradiance
There have been many suggestions over the years of a connection between solar activity and the Earth's climate on time scales long compared to the 11-year sunspot cycle. They have remained little more than suggestions largely because of the major uncertainties in the climate record itself, and the difficulty in trying to compile a global average from an assembly of measurements that are uneven in both quality and distribution. Different climate time response to solar activity, some suggesting a positive correlation, some a negative correlation, and some no correlation at all. The only excuse for making yet another such suggestion is that much effort has been devoted in recent years to compiling climate records for the past century or more that are internally consistent and believable, and that a decadal-scale record of solar total irradiance is emerging from spacecraft measurements, and can be used to set limits on the variation that is likely to have occurred on these time scales. The work described here was originally inspired by the observation that the time series of globally averaged sea-surface temperatures over the past 120 years or so, as compiled by the British Meteorological Office group (Folland and Kates, 1984), bore a resonable similarity to the long-term average sunspot number, which is an indicator of the secular variability of solar activity. The two time series are shown where the sunspot number is shown as the 135-month running mean, and the SST variation is shown as the departure from an arbitrary average value. The simplest explanation of the similarity, if one accepts it as other than coincidental, is that the sun's luminosity may have been varying more or less in step with the level of solar activity, or in other words that there is a close coupling between the sun's magnetic condition and its radiative output on time scales longer than the 11-year cycle. Such an idea is not new, and in fact the time series shown can be regarded as a modern extension of the proposal put forward by Eddy (1977) to explain the covariance between various global climate indicators and solar activity as revealed by the C-14 record over the past millenium
Isomerization as a Key Path to Molecular Products in the Gas-Phase Decomposition of Halons
The decomposition of halons remains controversial concerning the branching between radical and molecular products. The latter channel, where it has been found, is presumed to occur via a constrained symmetric multicenter transition state. Isomerization pathways in the gas-phase chemistry of halons have rarely been considered, despite the fact that the iso-halons, which feature a halogenâhalogen bond, are widely recognized as important reactive intermediates in condensed phases. In this Letter, detailed calculations and modeling of the unimolecular decomposition of several important halons, including CF2Cl2, CF2Br2, and CHBr3, reveal that isomerization is a key pathway to molecular products. This path is important for both halons and their primary radicals as the barrier to isomerization in these compounds is typically isoenergetic with the threshold for bond fission
Supply Chain Information Systems and Organisational Performance in Economic Turbulent Times
Supply Chain Information Systems and their impact on organisational performance has been studied by a number of studies. This study seeks to extend this body of knowledge by adopting a fresh lens to explore empirically the relationship between organizational performance and SCIS in circumstances of economic downturn and financial turbulence. The statistical relationship between Supply Chain Information Systems (SCIS) ĂËEffectiveness and ĂËOrganisational Performance is tested and measured by multidimensional financial and non-financial variables. So even though complexities associated with measuring SCIS efficiency and Organisational Performance continue to dominate research discussions these are somewhat limited to just explaining the phenomenon without addressing the misalignment of the information provided by SCIS, business expectations and Organisational Performance. In consequence this papers reports findings from a large survey of 168 SCIS managers in Greek SMEs where even through economic downturn a strong correlation between SCIS and non-financial Organisational Performance is evidenced. In considering the findings this study proposes guidance to enhance SCIS Effectiveness and Organisational Performance
Limits of contraction groups and the Tits core
The Tits core G^+ of a totally disconnected locally compact group G is
defined as the abstract subgroup generated by the closures of the contraction
groups of all its elements. We show that a dense subgroup is normalised by the
Tits core if and only if it contains it. It follows that every dense subnormal
subgroup contains the Tits core. In particular, if G is topologically simple,
then the Tits core is abstractly simple, and if G^+ is non-trivial then it is
the unique minimal dense normal subgroup. The proofs are based on the fact, of
independent interest, that the map which associates to an element the closure
of its contraction group is continuous.Comment: 11 page
Locally normal subgroups of totally disconnected groups. Part II: Compactly generated simple groups
We use the structure lattice, introduced in Part I, to undertake a systematic
study of the class consisting of compactly generated,
topologically simple, totally disconnected locally compact groups that are
non-discrete. Given , we show that compact open subgroups of
involve finitely many isomorphism types of composition factors, and do not
have any soluble normal subgroup other than the trivial one. By results of Part
I, this implies that the centraliser lattice and local decomposition lattice of
are Boolean algebras. We show that the -action on the Stone space of
those Boolean algebras is minimal, strongly proximal, and micro-supported.
Building upon those results, we obtain partial answers to the following key
problems: Are all groups in abstractly simple? Can a group in
be amenable? Can a group in be such that the
contraction groups of all of its elements are trivial?Comment: 82 page
Locally normal subgroups of simple locally compact groups
We announce various results concerning the structure of compactly generated
simple locally compact groups. We introduce a local invariant, called the
structure lattice, which consists of commensurability classes of compact
subgroups with open normaliser, and show that its properties reflect the global
structure of the ambient group.Comment: 6 page
Using an Experimental Online Digital Collection with Interactive Features to Investigate Attitudes Towards Archives 2.0
Research Problem: The concept of Archives 2.0 is currently generating much interest within academic and professional discourse in the cultural heritage sector. As yet, however, little research has been done in New Zealand on what potential users and implementers of Archives 2.0 perceive as being the advantages or disadvantages with this idea.
Methodology: This study used a two stage approach. In the first stage an experimental prototype of an Archives 2.0 website was constructed using local cultural heritage resources. This was intended to served as a reference point for discussions about the practical possibility and value of sites of this kind. In the second stage nine qualitative semi-structured interviews were conducted with practitioners and others having a professional interest in cultural heritage collections. They were asked about their perceptions of the practices associated with Archives 2.0 and the current situation in New Zealand
Results: This study found considerable interest in the possibilities represented by Archives 2.0. However, there was also concern about the extra burden on staff resources it was seen to entail. Given this it was generally felt that major projects of this kind would not be feasible within the current economic climate.
Implications: This study suggests that the Archives 2.0 concept does have potential for development within the New Zealand cultural heritage sector. However ways will have to be found around concerns over resource constraints before further progress is made
Impact of Knowledge Management Processes Upon Job Satisfaction and Job Performance
While we might know anecdotally that the implementation of knowledge management in an organization improves job satisfaction and job performance, there are limited empirical studies that assess this assumption. There have been studies done in this area but the results vary in terms of which knowledge management processes have an impact upon job satisfaction and which do not. Similarly, many studies make assumptions that job satisfaction leads to improved job performance without testing for that variable. The goal of this dissertation is to assess whether the knowledge management processes have a positive impact upon job satisfaction and job performance and if job satisfaction itself impacts job performance. A secondary goal is to examine if the results vary based upon demographic factors such as job classification, location or functional group. This research is a survey-based, cross sectional quantitative study which examined knowledge management workers in one organization with multiple locations with a focus on North America but included other areas as well.
Of the five knowledge management processes studied (acquisition, sharing, creation, codification and retention) only knowledge sharing and knowledge retention demonstrated a positive impact upon worker job satisfaction. This finding supports, in part, previous findings in other studies of the impact of knowledge management processes.
Knowledge management worker job satisfaction overall showed a positive impact on worker job performance. Prior studies have made the assumption that there is a connection between job satisfaction and job performance without actually measuring this connection. This study, however, did measure this connection and verifies that a connection exists. Separately this study found that none of the five knowledge management processes individually showed a positive direct impact upon worker job performance when measured collectively or by job level.
In a new finding, this study demonstrates that the impact of knowledge management processes on job satisfaction varies based upon job level, location, and functions
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