4,585 research outputs found
Braidwood L.S., Braidwood R.J., Howe В., Reed C.A. and Watson P.J. 1983. — Prehistoric Archeology along the Zagros flanks.
No full textHours Francis. Braidwood L.S., Braidwood R.J., Howe В., Reed C.A. and Watson P.J. 1983. — Prehistoric Archeology along the Zagros flanks.. In: Paléorient, 1984, vol. 10, n°2. pp. 129-130
Braidwood L.S., Braidwood R.J., Howe В., Reed C.A. and Watson P.J. 1983. — Prehistoric Archeology along the Zagros flanks.
No full textHours Francis. Braidwood L.S., Braidwood R.J., Howe В., Reed C.A. and Watson P.J. 1983. — Prehistoric Archeology along the Zagros flanks.. In: Paléorient, 1984, vol. 10, n°2. pp. 129-130
R.J. Sommers
No full textThe single-spaced paragraph on the “About the Author” page of R.J. Sommers’ latest novel says she lives in a one-story house on the edge of a city. It says she is renowned for writing relatable characters and compelling relationships. It says nothing about her own friends.
Gazing from a photo at the top of the page, R.J. Sommers appears to point a camera toward her readers..
Assessment of tertiary reed beds in chemically-dosed wastewater treatment plants for phosphorus removal
No full textEutrophication is one of the problems affecting the environmental quality standards of fresh waters. Phosphorus (P) is considered a main nutrient contributing to this. In the UK, the Water Industry is responsible for c. 50% of the total phosphorus load to freshwater ecosystems. Within this, small wastewater treatment plants (WwTPs) (<2,000 population equivalent) have a significant role since they represent 75% of all WwTPs in the UK.
The current option for P removal from wastewater is chemical precipitation through the dosing of iron (Fe) salts in combination with a tertiary filtration treatment step. This study aims to determine the transformation processes whereby tertiary reed beds permanently store or release iron and phosphorus in chemically-dosed sites to provide recommendations regarding the conditions where reed beds can be used as such final filtration treatment in small WwTPs. This was carried out through sampling campaigns in 14 full-scale tertiary reed beds.
Chemically-dosed WwTPs with tertiary reed beds can perform satisfactorily achieving phosphorus removals above 85% and average P and Fe final effluent concentrations of 0.7 mg P/L and 0.2 mg Fe/L, respectively, both well below consents (2 mg TP/L and 4 mg Fe/L). The majority of the total phosphorus in the reed bed influents was associated to either suspended solids or dissolved fractions, whereas 60¬90% of the effluent TP is in the dissolved form. Occasional episodes of phosphorus release from the reed bed can occur, as evidenced in an increase in soluble reactive phosphorus in the effluent. The main mechanism for trapping of Fe and P in mature beds was settlement of suspended particles, with phosphorus and iron concentrations in the accumulated sludge being up to 55.9 g P/kg dry matter and 246.6 g Fe/kg DM. The removal of particulate pollutants was successful in the reed beds studied, but colloidal and dissolved particles passing through the beds untreated. This could compromise the use of reed beds with future tightening P consents if the current chemical dosing practices are unchanged
Four centuries and other poems /
No full textIncludes index.Foreword by Laura Coates Reed precedes t.p.Cover title: Poems / by R.J. Lewis; spine title: Lewis' poems.Mode of access: Internet
The numerical modelling of rockbolts in geomechanics by finite element methods
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 15/03/1999.In tunnel excavation, the use of rockbolts has long been a popular means of reinforcement in rock masses to prevent the rock opening from caving in. The idea has evolved from the earliest form of rockbolt made of wood to the more up-to-date form of pre-tensioned or grouted steel rockbolts.
A major breakthrough in the design of rockbolt models was made by Aydan (1989). This rockbolt element was modelled in coupled form, with one sub-element representing the steel bolt, and the other sub-element the grout. This representation was necessary to model the complex action in the continuous rock mass near the joint.
In elasticity problems, the large displacement formulation of a beam element is derived from the fundamental theory, and the bending phenomenon of a thin rod is analysed by the finite element discretizations of the bar elements and the beam elements. Experiments show that the deformation characteristics of the latter representation resemble a more realistic life behaviour. Based on this finding, this thesis proposes a modification to Aydan's two-dimensional rockbolt element, with the beam elements discretising the steel bolt.
The different mechanical responses of a perfectly elastic rockbolt are considered, and the large displacement formulation of the new rockbolt element is derived by combining those of Aydan's rockbolt element and the beam element.
The mechanics of the Aydan element and the new rockbolt element are described, and their performances are compared in an identical situation. It is found that in the two two-dimensional examples used in this thesis, the modified element ensures the continuity of curvature of the rockbolt, and in general, can act as support across a discontinuity or joint between rock masses well.
In conjunction with the displacement method in the finite element procedures, a conventional iteration solution procedure is first described to solve the nonlinear incremental stiffness equation. However, it is found that this procedure is cumbersome, and requires a large amount of comptutations. Some limited storage quasi-Newton minimization algorithms are considered as an alternative
Fuel pellet production from reed canary grass
No full textThis thesis focuses on two main areas: methods for assessing regional supply potentials of reed canary grass (Phalaris arundinacea L.) (RCG); and process technology for the production of high-quality RCG pellets. Partial equilibrium modelling, incorporating a break-even price approach, was used to examine supply potentials for RCG in Västerbotten County, northern Sweden. A remote sensing method, using black and white orthophoto interpretation, was developed, by which abandoned fields with low preparation costs (on average 173 SEK (ha)-1) could be distinguished from fields with high preparation costs (on average 3990 SEK (ha)-1). Based on the assumptions made, RCG production would predominantly be viable in the coastal area of Västerbotten County, and production equal to 1.3 TWh could be supplied at a farmgate fuel price of 116 SEK MW-1h-1. Pelletizing RCG allows it to be transported, stored and handled more easily. To determine the optimum conditions for RCG pelletizing, experiments were performed in an experimental design incorporating the factors: moisture content, steam addition, raw material density, and die temperature. Pre-compaction of the raw material was an efficient method for avoiding uneven pellet production. Through multiple response optimization, process settings were identified for the production of RCG pellets with a bulk density ≥ 650 kg m-3 and a durability ≥ 97.5%. To clarify the underlying mechanisms in the pelletizing process, the influences of moisture content and normal stress on the kinematic wall friction properties of RCG powder were studied. A steep increase in the kinematic wall friction with increasing normal stress was found in the normal stress interval 50-150 MPa. Multiple linear regression modelling of kinematic wall friction measurements at high normal stresses (65 to 376 MPa) revealed a local maximum at moisture contents of 13–16% and normal stresses of 150–225 MPa. Kinematic wall friction and pellet durability maxima occurred in overlapping moisture content ranges; it was, therefore, hypothesised that the two properties were correlated
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