992 resultados para creep behaviour of rocks
Resumo:
Mixed flocks of pale-bellied Brent geese (Branta bernicla hrota) and wigeon (Anas penelope L.) feeding on intertidal Zostera spp were studied during October 1993 with respect to tidal position, feeding method and duration, and competitive: interactions within and between species. Owing to many disturbance incidents affecting the use of the site by wildfowl, only complete data on flow tides were presented. Brent geese fed over a greater period of the tidal cycle than wigeon. Differences in feeding methods indicated that Brent geese exploited the rhizomes, which are energetically more profitable than the shoot on which wigeon fed. Aggressive interactions were recorded within species but there were no records of aggression between species. More subtle competition for space, however, may have occurred during feeding. Brent geese could reach Zostera spp For a short period after increasing depth of water prevented access by wigeon. However, individual wigeon were observed foraging near feeding Brent geese, picking up the scraps oi material discarded by the latter, and small numbers of wigeon may benefit from the presence of the geese. These benefits for some individual wigeon are not considered to compensate for the disadvantages to the latter species population as a whole in feeding on poorer-quality food for a shorter period of the tidal cycle. This disadvantage is likely to have contributed to the decline in the wigeon population on Strangford Lough, Co. Down, while numbers of Brent geese have been maintained at a high level.
The effect of construction pattern and unit interlock on the structural behaviour of block pavements
Resumo:
The maintenance or even replacement of cracked pavements requires considerable financial resources and puts a large burden on the budgets of local councils. In addition to these costs, local councils also face liability claims arising from uneven or cracked pedestrian pavements. These currently cost the Manchester City Council and Preston City Council around £6 million a year each. Design procedures are empirical. A better understanding of the interaction between paving blocks, bedding sand and subbase was necessary in order to determine the mode of failure of pavements under load. Increasing applied stress was found to mobilise ‘‘rotational interlock’’, providing increased pavement stiffness and thus increased load dissipation resulting in lower transmitted stress on the subgrade. The indications from the literature
review were that pavements are designed to fail by excessive deformation and that paving blocks remained uncracked at failure. This was confirmed with experimental data which was obtained from tests on segments of pavements that were laid/constructed in a purpose built test frame in the laboratory.
Resumo:
Synopsis: Bonded-in rod timber joints off er several advantages over conventional types of joint, including high local force transfer, very stiff connections, and improved ?re and aesthetic properties since the connection is completely hidden in the insulating timber members. More recently, the use of ?bre reinforced polymer (FRP) as a connecting rod, alternative to steel rods, in bonded-in rod connections for timber structures has been investigated. However, the investigation into the behaviour of such joints is limited, in particular, connections involving basalt ?bre reinforced polymers (BFRP) bars - which is the primary focus of this research. This paper presents an experimental programme conducted to investigate the behaviour of bonded-in BFRP bars loaded parallel to the grain of glulam members. Tensile pull-out tests were conducted to examine the effect of bonded length and bond stress-slip on the structural capacity of the connection. An analytical design expression for predicting pull-out capacity is proposed and the results have been compared with some established design equations. It was found that pull-out load increased approximately linearly with the bonded length, up to maximum which occurred at a bonded length of 15 times the hole diameter, and did not increase beyond this bonded length. The most signi?cant failure modes were failure at the timber/adhesive interface followed by pullout of the BFRP rod. Increased bonded lengths resulted in higher bond slip values compared to lower equivalent bonded lengths. The proposed design model gave the best predictions of pull-out capacity compared with other existing models.
Resumo:
Aim. This paper is a report of a study exploring and comparing the experience of men and women with colorectal cancer at diagnosis and during surgery.
Background. Men have higher incidence and mortality rates for nearly all cancers and frequently use health behaviours that reflect their masculinity. There has been minimal investigation into the influence of gender on the experience of a ‘shared’ cancer.
Methods. From November 2006 to November 2008, a qualitative study was conducted involving 38 individuals (24 men, 14 women) with colorectal cancer. Data were generated using semi-structured interviews at four time points over an 18-month period. This paper reports the participants’ experience at diagnosis and during surgery (time point 1) with the purpose of examining the impact of gender on this experience.
Findings. In general, men appeared more accepting of their diagnosis. The majority of females seemed more emotional and more affected by the physical side effects. However, there was variation in both gender groups, with some men and women portraying both ‘masculine’ and ‘feminine’ traits. There was also individual variation in relation to context.
Conclusions. It appears that many men may have been experiencing side effects and/or psychological distress that they were reluctant to discuss, particularly as some men portrayed typical ‘masculine’ traits in public, but felt able to open up in private. Nurses should not make assumptions based on the traditional view of masculinity, and should determine how each man wants to deal with their diagnosis and not presume that all men need to ‘open up’ about their illness.
Resumo:
Objectives: Men have higher incidence and mortality rates for nearly all cancers. They are less likely than women to utilise cancer information services and other social support services. The aim of this study was to explore and compare the experience and coping behaviour of men and women after treatment for colorectal cancer (CRC). Methods: A longitudinal qualitative study was conducted involving 38 individuals (24 men and 14 women) with CRC. Data were generated using semi-structured interviews at four time points over an 18-month period, post-diagnosis. Interviews focused on participant's experience of CRC and on how gender affected their coping. This paper reports the findings of interviews 3 and 4 which examined the participant's experience after chemotherapy. Results: Three themes emerged from the interviews ('new normal', living with uncertainty and support needs). Many men and women reacted similarly; however, there was some variation evident between and within sexes. The main difference was with regard to the long-term physical side effects of the illness. Many women admitted to still experiencing side effects, whereas many men indicated that they had no problems. These men engaged in practices that aligned with their gender identity and view of masculinity. It must be noted that some men and women were still experiencing an impact. Conclusions: Recovery from the physical and psychological effects of CRC does not occur simultaneously. Healthcare professionals should be aware that not all men (or women) conform to the social stereotypes of masculinity (or femininity). Copyright © 2010 John Wiley & Sons, Ltd.
Resumo:
This paper is concerned with understanding the behaviour of Polyethylene Terephthalate (PET) in the injection stretch blow moulding (ISBM) process where it is typically bi-axially stretched to form bottles for the packaging industry. Preforms which have been pre sprayed with a pattern and heated in an oil bath have been stretched and blown in free air using a lab scale ISBM machine whilst being monitored via high speed video. The images have subsequently been analysed using a digital image correlation system (VIC 3D). Results are presented showing the typical deformation modes and strain rates encountered in the ISBM process.