Seepage and pore pressures around contiguous pile retaining walls

Diaphragm and bored pile retaining walls are often used for the construction of basements, metro station boxes and cut-and-cover tunnels in urban areas. While diaphragm and secant pile walls are generally intended (and assumed in analysis) to be effectively impermeable, contiguous piles may allow through-the-wall seepage even when preventative measures have been undertaken. Provided the flowrates can be tolerated or dealt with, through-the-wall seepage should result in a reduction in pore water pressures behind the retaining wall compared with an impermeable construction, giving the potential for reductions in the depth of embedment and wall thickness, hence cost. However, this potential is rarely realised owing to the difficulty in quantifying with sufficient confidence the hydraulic regime associated with a leaky retaining wall. This paper reports the results of laboratory investigations and numerical analyses carried out to assess the effect of the inter-pile gaps on the pore pressure distribution around a contiguous pile retaining wall. The results show that the pore pressures behind the piles reduce significantly as the pile spacing is increased. Long-term field monitoring confirms that the pore water pressures are much lower than would be expected for an impermeable retaining wall in similar soil. The applicability of a simple expression linking the pile diameter, pile spacing and the effective permeability of an equivalent uniform wall is demonstrated

Artificial Intelligence: A Promised Land for Web Services

6 page(s

METC Combustion Research Facility

The objective of the Morgantown Energy Technology Center (METC) high pressure combustion facility is to provide a mid-scale facility for combustion and cleanup research to support DOE`s advanced gas turbine, pressurized, fluidized-bed combustion, and hot gas cleanup programs. The facility is intended to fill a gap between lab scale facilities typical of universities and large scale combustion/turbine test facilities typical of turbine manufacturers. The facility is now available to industry and university partners through cooperative programs with METC. Currently two combustion rigs are operating and one additional project is under construction for the facility. Space is available in the test cells for at least one additional test rig. A pressurized pulsed combustor began operating in July of 1993. The combustor will carry out pulsed combustion of natural gas at pressures up to 10 atmospheres. A high pressure steady flow rig is currently completely fabricated. The objective of this rig is to test novel, steady-flow, pressurized combustors that produce very low NO{sub x} and other emissions. An evaporation rig currently is in startup. This rig will test the concept of water injection in an externally fired cycle. The specific technical issue that the unit will address is evaporation rates of water droplets in high pressure flows

The High Redshift Integrated Sachs-Wolfe Effect

In this paper we rely on the quasar (QSO) catalog of the Sloan Digital Sky Survey Data Release Six (SDSS DR6) of about one million photometrically selected QSOs to compute the Integrated Sachs-Wolfe (ISW) effect at high redshift, aiming at constraining the behavior of the expansion rate and thus the behaviour of dark energy at those epochs. This unique sample significantly extends previous catalogs to higher redshifts while retaining high efficiency in the selection algorithm. We compute the auto-correlation function (ACF) of QSO number density from which we extract the bias and the stellar contamination. We then calculate the cross-correlation function (CCF) between QSO number density and Cosmic Microwave Background (CMB) temperature fluctuations in different subsamples: at high z>1.5 and low z<1.5 redshifts and for two different choices of QSO in a conservative and in a more speculative analysis. We find an overall evidence for a cross-correlation different from zero at the 2.7\sigma level, while this evidence drops to 1.5\sigma at z>1.5. We focus on the capabilities of the ISW to constrain the behaviour of the dark energy component at high redshift both in the \LambdaCDM and Early Dark Energy cosmologies, when the dark energy is substantially unconstrained by observations. At present, the inclusion of the ISW data results in a poor improvement compared to the obtained constraints from other cosmological datasets. We study the capabilities of future high-redshift QSO survey and find that the ISW signal can improve the constraints on the most important cosmological parameters derived from Planck CMB data, including the high redshift dark energy abundance, by a factor \sim 1.5.Comment: 20 pages, 18 figures, and 7 table

A Fragmented Parallel Stream: The Bass Lines of Eddie Gomez in the Bill Evans Trio

Eddie Gomez was the bassist in the Bill Evans Trio for eleven years. His contribution to the group’s sound was considerable, but while there has been some recognition of his virtuoso solos in the trio there has been little academic interest in his bass lines. This essay examines bass lines from the album Since We Met, recorded in 1974 by Evans, Gomez and drummer Marty Morell. Analysis of the bass accompaniments to the piano solos on “Since We Met” and “Time Remembered” reveals that they form a fragmented two-feel. A traditional two-feel employs two notes to emphasise the first and third beats in bar of 4/4 time. In Gomez’s bass lines these two notes are frequently replaced with short rhythmic motifs. These motifs occur in a variety of forms and at different metric displacements that alternately propel and retard the forward motion of the music. Additionally, Gomez uses a wide range of register and varied articulations to create a richly diverse bass line. The resulting effect has often been interpreted as interactive or conversational with the soloist. However there is very little interaction between the bass line and Evans’ solo. The bass line is a parallel stream to the solo that energises and colours the music

Women, men and coronary heart disease: a review of the qualitative literature

Aim. This paper presents a review of the qualitative literature which examines the experiences of patients with coronary heart disease. The paper also assesses whether the experiences of both female and male patients are reflected in the literature and summarizes key themes. Background. Understanding patients' experiences of their illness is important for coronary heart disease prevention and education. Qualitative methods are particularly suited to eliciting patients' detailed understandings and perceptions of illness. As much previous research has been 'gender neutral', this review pays particular attention to gender. Methods. Published papers from 60 qualitative studies were identified for the review through searches in MEDLINE, EMBASE, CINAHL, PREMEDLINE, PsychINFO, Social Sciences Citation Index and Web of Science using keywords related to coronary heart disease. Findings. Early qualitative studies of patients with coronary heart disease were conducted almost exclusively with men, and tended to generalize from 'male' experience to 'human' experience. By the late 1990s this pattern had changed, with the majority of studies including women and many being conducted with solely female samples. However, many studies that include both male and female coronary heart disease patients still do not have a specific gender focus. Key themes in the literature include interpreting symptoms and seeking help, belief about coronary 'candidates' and relationships with health professionals. The influence of social roles is important: many female patients have difficulties reconciling family responsibilities and medical advice, while male patients worry about being absent from work. Conclusions. There is a need for studies that compare the experiences of men and women. There is also an urgent need for work that takes masculinity and gender roles into account when exploring the experiences of men with coronary heart disease

Clinical consensus recommendations for the non-surgical treatment of children with Perthes’ disease in the UK

Aims The aim of this study was to produce clinical consensus recommendations about the non-surgical treatment of children with Perthes’ disease. The recommendations are intended to support clinical practice in a condition for which there is no robust evidence to guide optimal care. Methods A two-round, modified Delphi study was conducted online. An advisory group of children’s orthopaedic specialists consisting of physiotherapists, surgeons, and clinical nurse specialists designed a survey. In the first round, participants also had the opportunity to suggest new statements. The survey included statements related to ‘Exercises’, ‘Physical activity’, ‘Education/information sharing’, ‘Input from other services’, and ‘Monitoring assessments’. The survey was shared with clinicians who regularly treat children with Perthes’ disease in the UK using clinically relevant specialist groups and social media. A predetermined threshold of ≥ 75% for consensus was used for recommendation, with a threshold of between 70% and 75% being considered as ‘points to consider’. Results A total of 40 participants took part in the first round, of whom 31 completed the second round. A total of 87 statements were generated by the advisory group and included in the first round, at the end of which 31 achieved consensus and were removed from the survey, and an additional four statements were generated. A total of 60 statements were included in the second round and 45 achieved the threshold for consensus from both rounds, with three achieving the threshold for ‘points to consider’. The recommendations predominantly included self-management, particularly relating to advice about exercise and education for children with Perthes’ disease and their families. Conclusion Children’s orthopaedic specialists have reached consensus on recommendations for non-surgical treatment in Perthes’ disease. These statements will support decisions made in clinical practice and act as a foundation to support clinicians in the absence of robust evidence. The dissemination of these findings and the best way of delivering this care needs careful consideration, which we will continue to explore

Constraining Primordial Non-Gaussianity with High-Redshift Probes

We present an analysis of the constraints on the amplitude of primordial non-Gaussianity of local type described by the dimensionless parameter $f_{\rm NL}$. These constraints are set by the auto-correlation functions (ACFs) of two large scale structure probes, the radio sources from NRAO VLA Sky Survey (NVSS) and the quasar catalogue of Sloan Digital Sky Survey Release Six (SDSS DR6 QSOs), as well as by their cross-correlation functions (CCFs) with the cosmic microwave background (CMB) temperature map (Integrated Sachs-Wolfe effect). Several systematic effects that may affect the observational estimates of the ACFs and of the CCFs are investigated and conservatively accounted for. Our approach exploits the large-scale scale-dependence of the non-Gaussian halo bias. The derived constraints on {$f_{\rm NL}$} coming from the NVSS CCF and from the QSO ACF and CCF are weaker than those previously obtained from the NVSS ACF, but still consistent with them. Finally, we obtain the constraints on $f_{\rm NL}=53\pm25$ ($1\,\sigma$) and $f_{\rm NL}=58\pm24$ ($1\,\sigma$) from NVSS data and SDSS DR6 QSO data, respectively.Comment: 16 pages, 8 figures, 1 table, Accepted for publication on JCA