Fundamental Principles of Workforce Management

This paper was written to fill a void created by the absence of fundamental principles of site construction management. Efficient workforce utilization is essential to managing a productive and cost efficient site. For more than 25?years, the senior author has been observing and writing about inefficient labor productivity practices resulting from poor site management practices. Using deductive reasoning, fundamental principles were developed to avoid poor practices. General and fundamental principles related to performance measures and daily work schedules are cited. Additional principles are cited in the categories of work assignments, crew structure, disruptions, multiskilling, preassemblies and modules, and symbiotic crew relationships. The principles have been intentionally left general so as to apply to a broad range of situations.     

Qualitative Methods and the Evaluation of Community Renewal Programs in Australia: Towards a National Framework

The emergence of public housing estate renewal programs in Australia in the last decade has been one of the most prominent developments in social housing policy. These programs have undertaken a broad mix of renewal activity, ranging from outright physical redevelopment and stock replacement for sale, to community development type initiatives to improve social and employment outcomes for residents. However, while a number of evaluations of these programs have been undertaken, the development of evaluation methodology has lagged behind that of other countries. This in part is due to the lack of federal government interest or involvement in these programs which are essentially state specific. The article reviews the evaluations that have been undertaken in the last 10 years in Australia and assesses the relative importance of qualitative methodologies in these evaluations. Despite a strong focus among policy makers on value-for-money aspects of renewal, the authors show that qualitative methods have been commonplace, if limited in range, and argue this is a result of both the difficulty of obtaining comparative quantitative information especially when comparing dissimilar programs between states. In this context, qualitative methods are more easily managed by researchers and offer more insightful assessments than quantitatively based approaches. The article concludes by arguing for a national evaluation methodology to assist in more rigorous evaluations and the extension of qualitative evaluation methods.     

Preparation and in vitro characterization of gentamycin-impregnated biodegradable beads suitable for treatment of osteomyelitis

A new method for preparing poly(L-lactide) (PLA) biodegradable beads impregnated with an ionic aminoglycoside, gentamycin, is described. The process employs hydrophobic ion pairing to solubilize gentamycin in a solvent compatible with PLA, followed by precipitation with a compressed antisolvent (supercritical carbon dioxide). The resulting precipitate is a homogeneous dispersion of the ion-paired drug in PLA microspheres. The microspheres are approximately 1 microm in diameter and can be compressed into beads (3-6 mm in diameter) strung on surgical sutures for implantation. The bead strings exhibit no significant change in release kinetics upon sterilization with a hydrogen peroxide plasma (Ster-Rad). The kinetics of gentamycin release from the PLA beads are consistent with a matrix-controlled diffusion mechanism. While nonbiodegradable poly(methyl methacrylate) (PMMA) beads initially release gentamycin in a similar manner, the drug release from PMMA ceases after 8 or 9 weeks, while the PLA beads continue to release drug for over 4 months. Moreover, only 10% of the gentamycin is released from the PMMA beads, while PLA beads release more than 60% of their load, if serum is present in the release medium. The PLA system displays improved release kinetics relative to PMMA, is biodegradable, is unaltered by gas sterilization, can be used for a range of antibiotics, and can be manipulated without disintegration. These are all desirable properties for an implantable drug delivery system for the prevention or treatment of osteomyelitis.     

PET validation of a novel prefrontal task: Delayed response alteration.

Deficits in working memory have been proposed to explain the performance failures of frontally lesioned primates on delayed alternation (DA) and delayed response (DR) tasks. The authors examined a computerized test of delayed response alternation (DRA), which combines elements of DR and DA in a sample of 18 normal volunteers who underwent oxygen-15 PET regional cerebral blood flow scans during the DRA and a sensorimotor control task. Significant activations were observed in a network of frontal, parietal, occipital, and temporal regions during initial task performance. A qualitatively similar but somewhat reduced set of activations was observed in a subset of participants who repeated the task after practice and instruction. These results are consistent with distributed models of working memory derived from studies of nonhuman primates and suggest that the frontal lobes contribute to human working memory function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of adaptive grid refinement for badly behaved elliptic partial differential equations

Adaptive grid refinement is potentially a very powerful means of dealing with singularities and other types of misbehavior in the solutions of elliptic partial differential equations. Combined with the multi-level iterative technique for solving the matrix equations, the method can be implemented in a reasonably efficient fashion.     

1H MAS NMR (magic-angle spinning nuclear magnetic resonance) techniques for the quantitative determination of hydrogen types in solid catalysts and supports

Distinct hydrogen species are present in important inorganic solids such as zeolites, silicoaluminophosphates (SAPOs), mesoporous materials, amorphous silicas, and aluminas. These H species include hydrogens associated with acidic sites such as Al(OH)Si, non-framework aluminum sites, silanols, and surface functionalities. Direct and quantitative methodology to identify, measure, and monitor these hydrogen species are key to monitoring catalyst activity, optimizing synthesis conditions, tracking post-synthesis structural modifications, and in the preparation of novel catalytic materials. Many workers have developed several techniques to address these issues, including 1H MAS NMR (magic-angle spinning nuclear magnetic resonance). 1H MAS NMR offers many potential advantages over other techniques, but care is needed in recognizing experimental limitations and developing sample handling and NMR methodology to obtain quantitatively reliable data. A simplified approach is described that permits vacuum dehydration of multiple samples simultaneously and directly in the MAS rotor without the need for epoxy, flame sealing, or extensive glovebox use. We have found that careful optimization of important NMR conditions, such as magnetic field homogeneity and magic angle setting are necessary to acquire quantitative, high-resolution spectra that accurately measure the concentrations of the different hydrogen species present. Details of this 1H MAS NMR methodology with representative applications to zeolites, SAPOs, M41S, and silicas as a function of synthesis conditions and post-synthesis treatments (i.e., steaming, thermal dehydroxylation, and functionalization) are presented.     

Computational Techniques and Shear Band Development for Cylindrical and Spherical Penetrometers in Strain-Softening Clay

This paper addresses numerical simulation of deep penetration of full-flow penetrometers in strain-softening, rate-dependent, cohesive soil, and the observed phenomenon of periodic shear bands. The analysis was conducted using a large deformation finite element approach, modifying the simple elastic–perfectly plastic Tresca soil model to allow strain-softening, with strain-rate dependency being incorporated in order to avoid spurious mesh dependency. Parametric analyses were carried out varying the strain-softening parameters (hence the relative brittleness of the soil), the rigidity index of the soil, and the strain-rate parameter. Increased brittleness of the soil led to reduction in the penetration resistance, but also to increasingly significant oscillations in the resistance–penetration responses. The oscillation was found to result from periodic shear bands evolving cyclically ahead of the advancing cylindrical and spherical penetrometers. Analyses with different values of rigidity index confirmed further that the periodic shear bands were a real material phenomenon, rather than due to errors in numerical simulation. Similar phenomena have been observed for continuous flow problems in granular materials. However, rising strain-rate dependency tended to suppress the oscillations.     

Bake induced charge gain in NOR flash cells

Charge gain, caused by localized defects in the tunnel oxide of floating gate devices, is one of the central reliability concerns of flash memory. In this work, we show that charge motion in the poly sidewall spacers of flash cells can also result in substantial charge gain, for nonoptimized processes. Data showing the time, temperature, and field dependencies of this charge gain mechanism are presented. It is shown that the threshold voltage shift caused by charge motion in the poly sidewall spacers follows the simple factorial expression: ΔV _th=C·V_fg·t^α ·e^-ϵ(a)kT/     

Schedule Acceleration, Work Flow, and Labor Productivity

This paper details how construction labor efficiency is affected by deviations from the normal flow of work. A methodology is presented to estimate the loss of labor efficiency, based on variations in the percentage of labor hours used each week. The procedure can be used without the need for contractor production records. The theoretical basis for the method rests on the assumption that the rate of manpower utilization is consistent with the amount of work available for the contractor to perform. Using productivity data from three electrical projects that were accelerated, the labor efficiency is shown to be correlated to changes in the percentages of weekly work hours. Loss of efficiency curves are developed for various project phases. A case study is presented of an actual electrical construction project. Losses of efficiency are calculated for each phase, and it is shown that the contractor incurred an estimated loss of productivity of 25%. The analysis is validated by comparing a weekly inefficient work-hour profile to the chronology of events that occurred on the project.