Stress analysis of buried pipes

Pipeline plays a vital role in transporting water, gas and oil from one place to another. Over the years, several failures have been reported in pipeline mainly due to aging (i.e., corrosion). The failure occurs when the stresses in a pipe segment due to applied loads exceed the capacity of the pipe. Therefore, it is important to predict the realistic pipe stress at the design and assessment stages to ensure the safety across the entire lifetime. As significant portion of the pipeline is buried in the underground in most of the occasions, the soil-structure interaction analysis is important as part of the stress analysis. Depending on the location of the network, the pipe will be subjected to varying levels of traffic and pressure loads that need to be accurately determined in order to perform reliable pipe stress estimations. Several pipe stress prediction methods have been developed over the years and reported in the literature. However, these methods are either analytical or empirical based models. The former uses the structural mechanics of the pipe by discarding the complex soil-structure interaction effect while the later fully depends on the experimental results. To overcome these problems, the numerical methods can be used to incorporate the soil-structure interaction effect more efficiently in pipe stress analysis together with traffic and internal pressure loads. In this study, the finite element method is used to analyse the pipe-soil system subjected to external traffic and internal pressure loads. Further, the model developed is used to understand the effect of soil properties, pipeline characteristics, and loading on pipe stress through sensitivity analysis. Finally, the response surface method is used to develop a new pipe stress predictive equation using the results of finite element analyses

Investigation of rising nitrate concentrations in groundwater in the Eden Valley, Cumbria. 3, saturated zone studies

This component Work Package of the Eden Valley Project was undertaken with the objective of determining the hydrogeological regime and hydrochemical stratification in selected boreholes. The subsequent aim is to apply this to better understand timescales for water movement through the saturated zone along a transect ending near to the River Eden where the Permo-Triassic sandstone aquifer is exposed or underlies thin superficial deposits. A previous report in this series confirmed rising nitrate trends in groundwater in the study area, and suggested that with continued land use practices and with no evidence of denitrification, that this trend would continue. Another concluded that the average recharge rate is probably in the range 425-470 mm/y and the rate of water movement through the unsaturated zone is c. 3.5-3.85 m/y. Based on this estimate of water movement in the unsaturated zone, the travel time for recharge to migrate from the soil to the water table (or the delay imposed by the unsaturated zone) over most of the area where the sandstone is free of superficial deposits in the Eden Valley is c. 14 years. However if the higher fells are not considered - closer to 10 years. Given the inherent uncertainties and limitations associated with the various methods for determining the hydrogeological regime in a boreholem, methods proposed were: (i) to date the pore water profile within the saturated zone using CFC and SF6 tracers (ii) to determine the variation of aquifer properties with depth, for the matrix (using laboratory techniques) and the aquifer (using field pumping techniques). (iii) To use groundwater models to estimate groundwater travel times in the saturated zones (this part of the project has not yet been funded). A transect approach was adopted using existing boreholes to the east of Penrith to the Eden floodplain and addressing gaps with infill drilling. Despite early promise other boreholes (on a ‘southern’ transect) were discounted due to inaccessibility or unsuitable construction. A c. 4km transect from the east of Penrith in a north-western direction to the floodplain of the River Eden was selected starting at previously drilled project borehole

Preventive measures in infancy to reduce under-five mortality: a case-control study in The Gambia.

OBJECTIVE: To investigate the relationship between child mortality and common preventive interventions: vaccination, trained birthing attendants, tetanus toxoid during pregnancy, breastfeeding and vitamin A supplementation. METHODS: Case-control study in a population under demographic surveillance. Cases (n = 141) were children under five who died. Each was age and sex-matched to five controls (n = 705). Information was gathered by interviewing primary caregivers. RESULTS: All but one of the interventions - whether the mother had received tetanus toxoid during pregnancy - were protective against child mortality after multivariate analysis. Having a trained person assisting at child birth (OR 0.2 95% CI 0.1-0.4), receiving all vaccinations by 9 months of age (OR 0.1; 95% CI 0.01-0.3), being breastfed for more than 12 months (Children breastfed between 13 and 24 months OR 0.1 95% CI 0.03-0.3, more than 25 months OR 0.1 95% CI 0.01-0.5) and receiving vitamin A supplementation at or after 6 months of age (OR 0.05; 95% CI 0.01-0.2) were protective against child death. CONCLUSIONS: This study confirms the value of at least four available interventions in the prevention of under-five death in The Gambia. It is now important to identify those who are not receiving them and why, and to intervene to improve coverage across the population

‘Media events’ reconsidered: from ritual theory to simulation and performativity

This paper re-examines the long-established notion of ‘media events’ by contrasting and critically appraising three distinct approaches to the question of media events. These are: ritual theory associated with Daniel Dayan and Elihu Katz, secondly, Jean Baudrillard’s approach rooted in his notions of simulation and ‘non-events’ and, finally, the more recent performative approaches to media and mediation. I take Sarah Kember and Joanna Zylinska’s reading of media events presented in Life After New Media (2012) as exemplary of the performative approach. An argument is made that the accounts of media events offered by performative approaches add very little, and, indeed, lack the critical insightfulness of the earlier approaches. Both ritual theory and Baudrillard’s thought are briefly reappraised and, against Nick Couldry, I try to show that these accounts are not characterised by binary and reductive thinking. The major misunderstandings concern the nature of the sacred and profane dualism and the further dualisms developed in Baudrillard’s thought, particularly the figures of implosion and reversibility. Finally, Baudrillard’s position on technology is addressed and the paper concludes with the suggestion that his account is not solely negative, since technological developments are not only at the mercy of ironic reversals they may also enable new rituals of disappearance

Harsh parenting among veterans: parents' military-related PTSD, mentalization, and pre-military trauma

ObjectivesVeteran parents experiencing posttraumatic stress disorder (PTSD) may resort to harsh parenting. The indirect pathway from parental military-related PTSD to harsh parenting, and the moderating role of parents' pre-military trauma histories, has been less explored. Informed by mentalization theory, as well as trauma-sensitive and posttraumatic growth perspectives, we aim to explore the associations between veteran parents' military-related PTSD, mentalization, harsh parenting, and prior trauma before military service.MethodsData were collected from an online research panel of 509 veteran parents with children under 10. We employed Structural Equation Models to test indirect and moderating effects.ResultsWe identified an indirect effect of parental pre-mentalization from military PTSD to harsh parenting [corporal punishment: b = 0.35, p < 0.001, 95% CI (0.23, 0.46); psychological aggression: b = 0.14, p < 0.001, 95% CI (0.09, 0.19)]. Multi-group analysis on four parent groups (parents with only pre-military physical trauma, parents with only pre-military psychological trauma, parents with both pre-military physical and psychological trauma, and parents with no pre-military physical or psychological trauma) highlighted differences in these associations, particularly between parents with only pre-military physical trauma and those without any physical and psychological trauma. The military-related PTSD effects on psychological aggression, corporal punishment, and pre-mentalization were all significantly higher for parents without pre-military physical and psychological trauma.ConclusionModifying parents' interpretation of their child's mental states can potentially counteract the effects of veterans' military PTSD on harsh parenting. Family-based programs should be created considering veteran parents' pre-military trauma histories

Social-Ecological Predictors of Homophobic Name-Calling Perpetration and Victimization Among Early Adolescents

Bias-based aggression at school in the form of homophobic name-calling is quite prevalent among early adolescents. Homophobic name-calling is associated with low academic performance, higher risky sexual behaviors, and substance abuse, among other adverse outcomes. This longitudinal study examined risk and protective factors across multiple domains of the social ecology (individual, peer, family, school and community) and levels of analysis (within- and between-person) associated with homophobic name-calling perpetration and victimization. Students from four middle schools in the U.S. Midwest (N = 1,655; (Formula presented.) age = 12.75; range = 10–16 years) were surveyed four times (Spring/Fall 2008, Spring/Fall 2009). For homophobic name-calling perpetration, significant risk factors included impulsivity, social dominance, traditional masculinity, family violence, and neighborhood violence; while empathy, peer support, school belonging, and adult support were significant protective factors. For homophobic name-calling victimization, significant risk factors included empathy (between-person), impulsivity, traditional masculinity, family violence, and neighborhood violence, while empathy (within-person), parental monitoring, peer support, school belonging, and adult support were significant protective factors

A 2 R_⊕ Planet Orbiting the Bright Nearby K Dwarf Wolf 503

Since its launch in 2009, the Kepler telescope has found thousands of planets with radii between that of Earth and Neptune. Recent studies of the distribution of these planets have revealed a gap in the population near 1.5–2.0 R⊕, informally dividing these planets into "super-Earths" and "sub-Neptunes." The origin of this division is difficult to investigate directly because the majority of planets found by Kepler orbit distant, dim stars and are not amenable to radial velocity follow-up or transit spectroscopy, making bulk density and atmospheric measurements difficult. Here, we present the discovery and validation of a newly found 2.03^(+0.08)_(-0.07) R⊕ planet in direct proximity to the radius gap, orbiting the bright (J = 8.32 mag), nearby (D = 44.5 pc) high proper motion K3.5V star Wolf 503 (EPIC 212779563). We determine the possibility of a companion star and false positive detection to be extremely low using both archival images and high-contrast adaptive optics images from the Palomar observatory. The brightness of the host star makes Wolf 503b a prime target for prompt radial velocity follow-up, and with the small stellar radius (0.690 ± 0.025R⊙), it is also an excellent target for HST transit spectroscopy and detailed atmospheric characterization with JWST. With its measured radius near the gap in the planet radius and occurrence rate distribution, Wolf 503b offers a key opportunity to better understand the origin of this radius gap as well as the nature of the intriguing populations of "super-Earths" and "sub-Neptunes" as a whole

WASP-107b’s Density Is Even Lower: A Case Study for the Physics of Planetary Gas Envelope Accretion and Orbital Migration

With a mass in the Neptune regime and a radius of Jupiter, WASP-107b presents a challenge to planet formation theories. Meanwhile, the planet's low surface gravity and the star's brightness also make it one of the most favorable targets for atmospheric characterization. Here, we present the results of an extensive 4 yr Keck/HIRES radial-velocity (RV) follow-up program of the WASP-107 system and provide a detailed study of the physics governing the accretion of the gas envelope of WASP-107b. We reveal that WASP-107b's mass is only 1.8 Neptune masses (M_b = 30.5 ± 1.7 M_⊕). The resulting extraordinarily low density suggests that WASP-107b has a H/He envelope mass fraction of >85% unless it is substantially inflated. The corresponding core mass of <4.6 M_⊕ at 3σ is significantly lower than what is traditionally assumed to be necessary to trigger massive gas envelope accretion. We demonstrate that this large gas-to-core mass ratio most plausibly results from the onset of accretion at gsim1 au onto a low-opacity, dust-free atmosphere and subsequent migration to the present-day a_b = 0.0566 ± 0.0017 au. Beyond WASP-107b, we also detect a second, more massive planet (M_c sin i = 0.36 ± 0.04MJ ) on a wide eccentric orbit (e _c = 0.28 ± 0.07) that may have influenced the orbital migration and spin–orbit misalignment of WASP-107b. Overall, our new RV observations and envelope accretion modeling provide crucial insights into the intriguing nature of WASP-107b and the system's formation history. Looking ahead, WASP-107b will be a keystone planet to understand the physics of gas envelope accretion