2,841 research outputs found
Drivers for innovation in production management
The aim of this paper is to examine the effectiveness of innovative programmes in construction. The term 'best practice' is commonly used in industry in to describe and disseminate cases where high levels of performance have been achieved. Several terminologies are used to describe this phenomenon, the best practice being the most widely used term. Best practices usually stimulate a desire in other companies to achieve similar levels of performance or gains that have been obtained by those best practice companies. This desire for better performance commonly triggers an innovation adoption programme by other companies. However, there are two kinds of drivers to innovation adoption: one is usually started by normative pressures applied by customers, suppliers, regulators or senior management. This type of adoption is called push-driven. On the other hand, there is a pull-driven innovation adoption decision, which is triggered strictly by an internal need associated with a performance gap. Based on this background this paper explores the generation, development and adoption of innovative
programmes by industry
Is agile project management applicable to construction?
This paper briefly summarises the evolution of Agile Project Management (APM) and differentiates it from lean and agile production and âleagileâ construction. The significant benefits being realized through employment of APM within the information systems industry are stated. The characteristics of APM are explored, including: philosophy, organizational attitudes and practices, planning, execution and control and learning. Finally, APM is subjectively assessed as to its potential contribution to the pre-design, design and construction phases.
In conclusion, it is assessed that APM offers considerable potential for application in predesign and design but that there are significant hurdles to its adoption in the actual construction phase. Should these be overcome, APM offers benefits well beyond any individual project
Local effective dynamics of quantum systems: A generalized approach to work and heat
By computing the local energy expectation values with respect to some local
measurement basis we show that for any quantum system there are two
fundamentally different contributions: changes in energy that do not alter the
local von Neumann entropy and changes that do. We identify the former as work
and the latter as heat. Since our derivation makes no assumptions on the system
Hamiltonian or its state, the result is valid even for states arbitrarily far
from equilibrium. Examples are discussed ranging from the classical limit to
purely quantum mechanical scenarios, i.e. where the Hamiltonian and the density
operator do not commute.Comment: 5 pages, 1 figure, published versio
Thermodynamics of Blue Phases In Electric Fields
We present extensive numerical studies to determine the phase diagrams of
cubic and hexagonal blue phases in an electric field. We confirm the earlier
prediction that hexagonal phases, both 2 and 3 dimensional, are stabilized by a
field, but we significantly refine the phase boundaries, which were previously
estimated by means of a semi-analytical approximation. In particular, our
simulations show that the blue phase I -- blue phase II transition at fixed
chirality is largely unaffected by electric field, as observed experimentally.Comment: submitted to Physical Review E, 7 pages (excluding figures), 12
figure
Sequential epiretinal membrane removal with internal limiting membrane peeling in brilliant blue G-assisted macular surgery
Purpose
To assess the selectivity of brilliant blue G (BBG) staining by analysing the morphological components of unstained and stained tissue obtained during epiretinal membrane (ERM) removal with internal limiting membrane (ILM) peeling in BBG-assisted macular surgery.
Methods
Twenty-six surgical specimens were removed from 13 eyes with epiretinal gliosis during vitrectomy using BBG for ERM and ILM peeling. We included eyes with idiopathic macular pucker, idiopathic macular hole and vitreomacular traction syndrome. The dye was injected into the fluid-filled globe. Unstained and stained epiretinal tissue was harvested consecutively and placed into separate containers. All specimens were processed for conventional transmission electron microscopy.
Results
The first surgical specimen of all eyes showed no intraoperative staining with BBG and corresponded to masses of cells and collagen. The second surgical specimen demonstrated good staining characteristics and corresponded to the ILM in all patients included. In seven eyes, the ILM specimens were seen with minor cell proliferations such as single cells or a monolayer of cells. Myofibroblasts, fibroblasts and astrocytes were present. In five cases, native vitreous collagen fibrils were found at the ILM. In six of the eyes, ILM specimens were blank.
Conclusion
Our clinicopathological correlation underlines the selective staining properties of BBG. The residual ILM is selectively stained by BBG even when a small amount of cells and collagen adheres to its vitreal side. To reduce the retinal exposure to the dye, the surgeon might choose to remove the ERM without using the dye, followed by a BBG injection to identify residual ILM
Quantum oscillations in adsorption energetics of atomic oxygen on Pb(111) ultrathin films: A density-functional theory study
Using first-principles calculations, we have systematically studied the
quantum size effects of ultrathin Pb(111) films on the adsorption energies and
diffusion energy barriers of oxygen atoms. For the on-surface adsorption of
oxygen atoms at different coverages, all the adsorption energies are found to
show bilayer oscillation behaviors. It is also found that the work function of
Pb(111) films still keeps the bilayer-oscillation behavior after the adsorption
of oxygen atoms, with the values being enlarged by 2.10 to 2.62 eV. For the
diffusion and penetration of the adsorbed oxygen atoms, it is found that the
most energetically favored paths are the same on different Pb(111) films. And
because of the modulation of quantum size effects, the corresponding energy
barriers are all oscillating with a bilayer period on different Pb(111) films.
Our studies indicate that the quantum size effect in ultrathin metal films can
modulate a lot of processes during surface oxidation
Activated O2 dissociation and formation of oxide islands on the Be(0001) surface: Another atomistic model for metal oxidation
By simulating the dissociation of O2 molecules on the Be(0001) surface using
the first-principles molecular dynamics approach, we propose a new atomistic
model for the surface oxidation of sp metals. In our model, only the
dissociation of the first oxygen molecule needs to overcome an energy barrier,
while the subsequent oxygen molecules dissociate barrierlessly around the
adsorption area. Consequently, oxide islands form on the metal surface, and
grow up in a lateral way. We also discover that the firstly dissociated oxygen
atoms are not so mobile on the Be(0001) surface, as on the Al(111) surface. Our
atomistic model enlarges the knowledge on metal surface oxidations by perfectly
explaining the initial stage during the surface oxidation of Be, and might be
applicable to some other sp metal surfaces.Comment: 5 pages, 4 figure
Effect of perch access on perching, health and production outcomes in commercial broiler breeder flocks.
There is a need for more knowledge about perch use in broiler breeders and the potential effects of perches on health and production outcomes. The aim of this study was to investigate the use of perches by commercial broiler breeders, effect of perch access on keel bone fractures (KBF), footpad dermatitis (FPD) and number of floor eggs. Two commercial breeder flocks (Ross 308) reared at the same facility were observed during the production period. Half of each flock was provided with 15 cm perch/bird and the other half had no perches. The perch group had two types of perches; a steel plate mounted on the hen feeder lines "feeder perch" (15 cm high) and elevated plastic perches (5 cm high). Perching by hens and roosters was recorded during the dark period by counting birds on each of the two perch types in 10 sections and in the corresponding patches on the control side at 25, 35, and 45 wk of age (WOA). FPD was scored in 100 random hens in each group at 30 WOA and end of lay, KBF was scored by postmortem in 100 random hens in each group at end of lay, and number of floor eggs (n) in each treatment was scored daily. More hens perched on the feeder perch with the steel plate mounted, compared to the feeder line without the steel plate, but this difference decreased with age (P < 0.0001). Within the perch treatment, more hens perched on the feeder lines compared to the plastic perches at all ages (P < 0.0001). When combining number of hens on the plastic and feeder perches, on average 6.7 birds perched per meter perch, which is full capacity given an average shoulder width of 15 cm/bird. Perch use among the roosters was low overall, but more roosters perched in the perch group compared to the control group at 35 WOA (PÂ =Â 0.007). Between 47 and 53% of the hens had KBF at the end of the lay. At 30 WOA, birds housed with perches were more likely to have lower FPD. Perch treatment did not affect number of floor eggs. In conclusion, broiler breeder hens perch when the perches are sufficiently high and allow all birds to perch simultaneously, and access to perches may have positive effects on FPD
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