7,105 research outputs found
Organisational commitment among software developers
If software developers are to be taken as prototypes of the new knowledge worker, we need look no further for working hypotheses about their attachment to their work and their employing organization than those contained in the human resource management agenda. For the diffusion of information and communication technologies (ICTs) as the supposed base of the knowledge economy has been synchronous with the launch and promotion of human resource management (HRM) as the new orthodoxy in employment practice and many of the assumptions and values within each model are shared. Indeed, HRM is often portrayed as if it were in some way a reflection of the shift to non-adversarial work relationships in the new information-based service society (Baldry 2003)
Comment on ``Density Matrix Renormalization Group Study of the Haldane Phase in Random One-Dimensional Antiferromagnets"
In a recent Letter (PRL 83, 3297 (1999)), Hida presented numerical results
indicating that the Haldane phase of the Heisenberg antiferromagnetic spin-1
chain is stable against bond randomness, for box distributions of the bond
strength, even when the box distribution stretches to zero bond strength. The
author thus concluded that the Haldane phase is stable against bond randomness
for any distribution of the bond strength, no matter how broad. In this
Comment, we (i) point out that the randomness distributions studied in this
Letter do not represent the broadest possible distributions, and therefore
these numerical results do not lead to the conclusion that the Haldane phase is
stable against any randomness; and (ii) provide a semiquantitative estimate of
the critical randomness beyond which the Haldane phase yields to the Random
Singlet phase, in a specific class of random distribution functions for the
bond strength.Comment: A comment on PRL 83, 3297 (1999). One pag
How Much Do Fruits and Vegetables Cost?
Federal dietary guidance advises Americans to consume more vegetables and fruits because most Americans do not consume the recommended quantities or variety. Food prices, along with taste, convenience, income, and awareness of the link between diet and health, shape food choices. We used 2008 Nielsen Homescan data to estimate the average price at retail stores of a pound and an edible cup equivalent (or, for juices, a pint and an edible cup equivalent) of 153 commonly consumed fresh and processed fruits and vegetables. We found that average prices ranged from less than 20 cents per edible cup equivalent to more than 2 to $2.50 per day, or approximately 50 cents per edible cup equivalent.food prices, food budgeting, fruit and vegetable consumption, 2010 Dietary Guidelines for Americans, Consumer/Household Economics, Food Consumption/Nutrition/Food Safety,
A new perspective on GCRT J1745-3009
Two WSRT observations were performed and five archival VLA data were reduced
in order to redetect the enigmatic radio transient GCRT J1745-3009. The source
was not redetected. We were, however, able to extract important new information
from the discovery dataset. Our reanalysis excludes models that predict
symmetric bursts, but the transient white dwarf pulsar is favoured. Although we
now have more contraints on the properties of this source, we are still unsure
about its basic model.Comment: 11 pages, 5 figure
Dynamics and Transport in Random Antiferromagnetic Spin Chains
We present the first results on the low-frequency dynamical and transport
properties of random antiferromagnetic spin chains at low temperature (). We
obtain the momentum and frequency dependent dynamic structure factor in the
Random Singlet (RS) phases of both spin-1/2 and spin-1 chains, as well as in
the Random Dimer phase of spin-1/2 chains. We also show that the RS phases are
unusual `spin-metals' with divergent low-frequency conductivity at T=0, and
follow the spin conductivity through `metal-insulator' transitions tuned by the
strength of dimerization or Ising anisotropy in the spin-1/2 case, and by the
strength of disorder in the spin-1 case.Comment: 4 pages (two-column format). Presentation substantially revised to
accomodate new result
Hydrogen thermal conductivity at temperatures from 2000 to 4000 deg F Final report
Hydrogen thermal conductivity at temperatures from 2000 to 4600 deg
Short message service (SMS) language and written language skills: educatorsâ perspectives
SMS language is English language slang, used as a means of mobile phone text messaging. This practice may impact on the written language skills of learners at school. The main aim of this study was to determine the perspectives of Grade 8 and 9 English (as Home Language) educators in Gauteng regarding the possible influence of SMS language on certain aspects of learners’ written language skills. If an influence was perceived by the educators, their perceptions regarding the degree and nature of the influence were also explored. A quantitative research design, utilising a questionnaire, was employed. The sample of participants comprised 22 educators employed at independent secondary schools within Gauteng, South Africa. The results indicated that the majority of educators viewed SMS language as having a negative influence on the written language skills of Grade 8 and 9 learners. The influence was perceived as occurring in the learners’ spelling, punctuation, and sentence length. A further finding was that the majority of educators address the negative influences of SMS language when encountered in written tasks.Keywords: English Home Language teaching; SMS language; text messaging; written language skill
Ion thruster system (8-cm) cyclic endurance test
This report describes the qualification test of an Engineering-Model 5-mN-thrust 8-cm-diameter mercury ion thruster which is representative of the Ion Auxiliary Propulsion System (IAPS) thrusters. Two of these thrusters are scheduled for future flight test. The cyclic endurance test described herein was a ground-based test performed in a vacuum facility with a liquid-nitrogen-cooled cryo-surface and a frozen mercury target. The Power Electronics Unit, Beam Shield, Gimal, and Propellant Tank that were used with the thruster in the endurance test are also similar to those of the IAPS. The IAPS thruster that will undergo the longest beam-on-time during the actual space test will be subjected to 7,055 hours of beam-on-time and 2,557 cycles during the flight test. The endurance test was successfully concluded when the mercury in the IAPS Propellant Tank was consumed. At that time, 8,471 hours of beam-on-time and 599 cycles had been accumulated. Subsequent post-test-evaluation operations were performed (without breaking vacuum) which extended the test values to 652 cycles and 9,489 hours of beam-on-time. The Power Electronic Unit (PEU) and thruster were in the same vacuum chamber throughout the test. The PEU accumulated 10,268 hr of test time with high voltage applied to the operating thruster or dummy load
- âŠ