An investigation of the aspects of occupant behavior required for evacuation modeling

This article examines occupant behavior exhibited during evacuation conditions. This is based on a review of a wide range of published literature concerned with evacuation. Factors influencing evacuation performance can be categorized into four broad areas, namely, configurational, environmental, procedural, and, most importantly, behavioral. The contributory factors associated with each of the four influencing categories are examined in detail and it is suggested that these factors should be represented within evacuation models.

Aspects of midwifery care 2: 'enhanced role' and social aspects

This is the second in a series of six papers presenting key findings from a national study that was undertaken to investigate the role and responsibilities of midwives and to identify and address continuing educational need. The background to the study and the titles of other papers in the series were outlined in the first paper. This paper focuses on two key aspects of the midwife’s role: ‘enhanced role’ activities and social and emotional care. The implications of the findings for practice and education are discussed.

Aspects of midwifery care 3: organisation of midwifery care

This is the third in a series of six papers presenting key findings from a national study that was undertaken to investigate the role and responsibilities of midwives and to identify continuing educational need. The background to the study and the titles of the other papers in the series have been outlined in the first paper. Issues related to the way midwifery care is organized nationally are discussed in this paper. Midwives and supervisors indicated a strong commitment to providing woman-centred care in a caring and sensitive manner, often in the face of enormous structural and organizational change. This paper addresses key issues that arose for midwives and supervisors when planning and providing an optimum quality service.

Aspects of care 4: views of professionals and mothers

This is the fourth in a series of six papers presenting key findings from a national study that was undertaken to investigate the role and responsibilities of midwives and to identify continuing educational need. The background to the study and the titles of the other papers in the series have been outlined in the first paper. This paper focuses on midwives’, supervisors’, doctors’ and mothers’ views regarding quality of care issues, with particular emphasis on what makes a ‘good’ midwife.

Aspects of care 5: the continuing educational needs of midwives

This is the fifth in a series of six papers presenting key findings from a national study that was undertaken to investigate the role and responsibilities of midwives and to identify continuing educational need. The background to the study and the titles of the other papers in the series have been outlined in the first paper. This paper focuses on the methods used to identify the continuing educational needs of midwives, and provides an overview of the findings related to midwives' perceived confidence/competence to practice and their continuing educational needs.

Aspects of care 6: continuing educational needs of midwives 2

This is the last in a series of six papers presenting key findings from a national study that was undertaken to investigate the role and responsibilities of midwives in England and to identify and address continuing educational needs. The background to the study and the titles of other papers in the series have been outlined in the first paper. The first five papers have provided an overview of the main research findings that have been used to determine the continuing educational needs of midwives. This paper provides a more detailed picture of the issues that were identified in relation to educational need, and an overview of the way in which an educational package was developed on the basis of the research findings for use by midwives nationally.

Aspects of the in vitro bioactivity and antimicrobial properties of Ag+- and Zn2+-exchanged 11 Å tobermorites

11 Å tobermorite, Ca5Si6O16(OH)2 · 4H2O, is a layer lattice ion exchange mineral whose potential as a carrier for Ag+ and Zn2+ ions in antimicrobial, bioactive formulations has not yet been explored. In view of this, the in vitro bioactivity of Ag+- and Zn2+-exchanged 11 Å tobermorites and their bactericidal action against S. aureus and P.aeruginosa are reported. The in vitro bioactivity of the synthetic unsubstituted tobermorite phase was confirmed by the formation of bone-like hydroxycarbonate apatite (HCA) on its surface within 48 h of contact with simulated body fluid. The substitution of labile Ag+ ions into the tobermorite lattice delayed the onset of HCA-formation to 72 h; whereas, the Zn2+-substituted phase failed to elicit an HCA-layer within 14 days. Both Ag+- and Zn2+-exchanged tobermorite phases were found to exhibit marked antimicrobial action against S. aureus and P.aeruginosa, two common pathogens in biomaterial-centred infections.

Aspects of the in vitro bioactivity of hydraulic calcium (alumino)silicate cement

In response to a burgeoning interest in the prospective clinical applications of hydraulic calcium (alumino)silicate cements, the in vitro bioactivity and dissolution characteristics of a white Portland cement have been investigated. The formation of an apatite layer within 6 h of contact with simulated body fluid was attributed to the rapid dissolution of calcium hydroxide from the cement matrix and to the abundance of pre-existing Si-OH nucleation sites presented by the calcium silicate hydrate phase. A simple kinetic model has been used to describe the rate of apatite formation and an apparent pseudo-second-order rate constant for the removal of HPO42- ions frorn solultion has been calculated (k(2) = 5.8 x 10(-4) g mg(-1)). Aspects of the chemistry of hydraulic cements are also discussed with respect to their potential use in the remedial treatment of living tissue. (C) 2008 Wiley Periodicals, Inc. J Biomed Mater Res 90A: 166-174, 2009

A preliminary investigation of the in vitro bioactivity of white Portland cement

Freshly-mixed and partially-cured ordinary Portland cement (OPC) pastes have been shown to exhibit good biological compatibility with a range of cells and tissue-types; particularly those associated with bone formation. Formulations based on OPC have been used as dental restoratives and are now being investigated for their potential use in orthopaedic repair. Despite the current clinical interest in OPCs, very little is known about their chemistry in the physiological environment. In this respect, research to investigate aspects of the interactions between a white Portland cement (WPC) paste and simulated body fluid (SBF) has been carried out in vitro. Exposure to SBF has been found to promote the precipitation of a layer of 'bone-like' hydroxyapatite on the surface of WPC paste which underpins its ability to integrate with living tissue. The dissolution of portlandite and formation of calcite were also observed on contact with SBF.

Start-up and running forces on bulk solids feeders: experimental findings versus available models

Many different models have been postulated over the years for sizing of feeder drives; these models have different bases, some rationally based and others more rule-of-thumb. Experience of Jenike & Johanson and likewise of The Wolfson Centre in trouble-shooting feeder drives has shown that drive powers are often poorly matched, so there is clearly still some way to go towards establishing a universally-used reliable approach. This paper presents an on-going programme of work designed to measure feeder forces experimentally on a purpose designed testing rig, and to compare these against some of the best known available models, and also against a full size installation. One aspect which is novel is the monitoring of the transition between the “filling stress field” load on the feeder and the “flowing stress field” load.

The effects of cadence and power output upon physiological and biomechanical responses to incremental arm-crank ergometry

The aim of this study was to examine the effects of cadence and power output on physiological and biomechanical responses to incremental arm-crank ergometry (ACE). Ten male subjects (mean +/- SD age, 30.4 +/-5.4 y; height, 1.78 +/-0.07 m; mass, 86.1 +/-14.2 kg) undertook 3 incremental ACE protocols to determine peak oxygen uptake (VO2 peak; mean of 3 tests: 3.07 +/- 0.17 L.min-1) at randomly assigned cadences of 50, 70, or 90 r.min-1. Heart rate and expired air were continually monitored. Central (RPE-C) and local (RPE-L) ratings of perceived exertion were recorded at volitional exhaustion. Joint angles and trunk rotation were analysed during each exercise stage. During submaximal power outputs of 50, 70, and 90 W, oxygen consumption (VO2) was lowest for 50 r.min-1 and highest for 90 r.min-1 (p < 0.01). VO2 peak was lowest during 50 r.min-1 (2.79 +/-0.45 L.min-1; p < 0.05) when compared with both 70 r.min-1 and 90 r.min-1 (3.16 +/-0.58, 3.24 +/-0.49 L.min-1, respectively; p > 0.05). The difference between RPE-L and RPE-C at volitional exhaustion was greatest during 50 r.min-1 (2.9 +/- 1.6) when compared with 90 r.min-1 (0.9 +/- 1.9, p < 0.05). At VO2 peak, shoulder range of motion (ROM) and trunk rotation were greater for 50 and 70 r.min-1 when compared with 90 r.min-1 (p < 0.05). During submaximal power outputs, shoulder angle and trunk rotation were greatest at 50 r.min-1 when compared with 90 r.min-1 (p < 0.05). VO2 was inversely related to both trunk rotation and shoulder ROM during submaximal power outputs. The results of this study suggest that the greater forces required at lower cadences to produce a given power output resulted in greater joint angles and range of shoulder and trunk movement. Greater isometric contractions for torso stabilization and increased cost of breathing possibly from respiratory-locomotor coupling may have contributed increased oxygen consumption at higher cadences.