1,480 research outputs found
Alongshore variability in wave energy transfer to coastal cliffs
The alongshore distribution of wave energy is believed to be an important control on the spatial variability of coastal erosion. There is, however, a lack of field data quantifying the alongshore variability in wave energy on rock coasts, whereby the relative control of coastline geometry versus foreshore characteristics on wave energy delivery remains unclear. A number of studies have identified high-frequency cliff-top ground shaking to be generated by wave impacts at the cliff toe during high tides (HT). To capture the variability of wave-cliff impact energy along-coast, we installed an array of cliff-top seismometers along a 1 km stretch of coastline in North Yorkshire, UK. Our aim is to constrain how wave energy transfer to the cliff toe varies, and to examine the relative energy transfer around typical coastline features, including a bay and headlands. Whilst the greatest HT ground motion energy is recorded at a headland and the lowest at the centre of the bay (5% of that observed at the headland), we identify no systematic alongshore variation in the HT ground motion energy that can be related to coastline morphology. We also note considerable variation between features of similar form: the total HT ground motion energy at one headland is only 49% of the next headland 1 km alongshore. Between neighbouring sites within the bay, separated by only 100 m, we observe up to an order of magnitude difference in ground motion energy transfer. Our results demonstrate the importance of the foreshore in driving the variations in energy delivery that we observe. Local alterations in water depth and foreshore topography control the alongshore distribution of wave energy available to generate cliff HT ground motions. Importantly, this apparently local effect overrides the influence of macroscale coastal planform morphology, which has previously been assumed to be the dominant control. The results show that foreshore characteristics that hold influence over wave energy transfer vary significantly over short (~100 m) distances, and so we expect erosion controlled by wave impacts to vary over similar scales
Comment on: Abou-Ali, H., El-Azony, H., El-Laithy, H., Haughton, J. and Khandker, S., 2010. Evaluating the impact of Egyptian Social Fund for Development Programmes. Journal of Development Effectiveness, 2 (4), 521–555
PRIFPRI3; ISIDG
The Impact of Harvest Frequency on Herbage Yield and Quality of Cynodon nlemfuensis
Ruminants in Ghana experience feed deficit in the dry season leading to loss of weight and condition. To curb this problem of weight loss, there is the need to raise their plain of nutrition in the critical months of the year when feed is low in quantity and quality. This can be achieved by maximising forage production through appropriate harvest management practices. This study sought to find the effect of repeated harvest on dry matter (DM) yield of Cynodon nlemfuensis (Cynodon) in the coastal savanna of Ghana. It was hypothesised that infrequent repeated harvest will improve DM yield and nutritive value of Cynodon. An area of 7.0 m by 5.5 m was used for a two year study (2013 and 2014). The treatments were harvest of Cynodon at 24 (T1), 12 (T2) and 6 (T3) weeks intervals. The Randomised Complete Block Design was used with four replicates per treatment. Dry matter yield and plant cell wall constituents viz. NDF, ADF and Cellulose contents decreased significantly (P < 0.05) in the order T3<T2<T1, indicating that DM yield and plant cell wall constituents decreased with increasing harvest frequency. Crude protein content (CP) decreased significantly (P < 0.05) in the order T1<T2<T3, indicating that CP content increased with increasing harvest frequency. The study has shown that repeated harvest of Cynodon provided lower DM yield of better quality, with harvest at six weeks interval exceeding the minimum CP level required for adequate intake and digestibility by ruminant livestock
Chemical composition, in vitro dry matter digestibility and Gas production of four browse species and their combinations used as feed for small ruminants
Browse species as complete feed for ruminants is uncommon. This may be due to low dry matter (DM) and high condensed tannins (CT) contents limiting its potential to influence weight gain. Drying however improves DM content and reduces CT levels and its astringency. The objective of this study was to determine chemical composition, in vitro parameters and to evaluate the potential benefits of feeding small ruminants on dried browse leaves and their combinations. The browse species were Albizzia lebbek, Gliricidia sepium, Moringa oleifera and Millettia thoningii. Rumen fluid was obtained from two fistulated forest type wethers for the in vitro evaluation. The DM, crude protein (CP), ash, CT, neutral detergent fibre (NDF), acid detergent fibre (ADF), cellulose and lignin were 866-916 g/kg, 101-303 g/kg DM, 74.7-200 g/kg DM, 0.9-1.3 g/kg DM, 202-552 g/kg DM, 205-520 g/kg DM, 94-381 g/kg DM and 105-192 g/kg DM respectively. The organic matter digestibility (OMD), in vitro dry matter digestibility (IVDMD), in vitro gas production (IVGP), metabolisable energy (ME) and short chain fatty acids (SCFA) of the four browse species and their combinations recorded were 314.9-721.6 g/kg DM, 515.4-721 ml/g DM, 139-602 ml/g DM, 314.6-1406.9 ml/g DM and 3.1-14.4 ml/g DM respectively. There were positive associative effects shown by the combined browse leaves between IVDMD and IVGP. The regression analyses revealed that relationships between IVGP and CP and IVDMD and CT and all relationships between OMD, SCFA, ME and IVGP were significant (p<0.05). All the browse species and their combinations had IVDMD values of more than 500 g/kg DM and low gas production. The high CP and ash contents, low CTs, low to moderate fibre components, moderate to high IVDMD and low IVGP of the four browse species and their combinations make them potentially valuable as feed resources for small ruminant production
Evidence for a three-nucleon-force effect in proton-deuteron elastic scattering
Developments in spin-polarized internal targets for storage rings have
permitted measurements of 197 MeV polarized protons scattering from vector
polarized deuterons. This work presents measurements of the polarization
observables A_y, iT_11, and C_y,y in proton-deuteron elastic scattering. When
compared to calculations with and without three-nucleon forces, the
measurements indicate that three-nucleon forces make a significant contribution
to the observables. This work indicates that three-body forces derived from
static nuclear properties appear to be crucial to the description of dynamical
properties.Comment: 8 pages 2 figures Latex, submitted to Phys. Rev. Letter
Priorities for Pig Research in Southeast Asia and the Pacific to 2010
Livestock Production/Industries, Research and Development/Tech Change/Emerging Technologies,
Solid state synthesis of BiFeO3 occurs through the intermediate Bi25FeO39 compound
The solid-state synthesis of perovskite BiFeO3 has been a topic of interest for decades. Many studies have reported challenges in the synthesis of BiFeO3 from starting oxides of Bi2O3 and Fe2O3, mainly associated with the development of persistent secondary phases such as Bi25FeO39 (sillenite) and Bi2Fe4O9 (mullite). These secondary phases are thought to be a consequence of unreacted Fe-rich and Bi-rich regions, that is, incomplete interdiffusion. In the present work, in situ high-temperature X-ray diffraction is used to demonstrate that Bi2O3 first reacts with Fe2O3 to form sillenite Bi25FeO39, which then reacts with the remaining Fe2O3 to form BiFeO3. Therefore, the synthesis of perovskite BiFeO3 is shown to occur via a two-step reaction sequence with Bi25FeO39 as an intermediate compound. Because Bi25FeO39 and the Îł-Bi2O3 phase are isostructural, it is difficult to discriminate them solely from X-ray diffraction. Evidence is presented for the existence of the intermediate sillenite Bi25FeO39 using quenching experiments, comparisons between Bi2O3 behavior by itself and in the presence of Fe2O3, and crystal structure examination. With this new information, a proposed reaction pathway from the starting oxides to the product is presented
Effects of a beta-agonist treatment, Vitamin D3 supplementation and electrical stimulation on meat quality of feedlot steers
In this study, 20 young steers received no beta-agonist (C), 100 animals all received zilpaterol hydrocholoride (Z), with 1 group only receiving Z while the other 4 groups received zilpaterol and vitamin D3 at the following levels (IU/animal/day) and durations before slaughter: 7 million for 3 days (3D7M); 7 million for 6 days (6D7M); 7 million for 6 days with 7 days nor supplementation (6D7M7N) and 1 million for 9 days (9D1M). Left carcass sides were electrically stimulated (ES) and the right side not stimulated (NES). Samples were aged for 3 or 14 days post mortem. Parameters included Warner –Bratzler shear force (WBSF), myofibril filament length, sarcomere length and calpastatin and calpain enzyme activity.
Both ES and prolonged aging reduced WBSF (P<0.001). 6D7M, 6D7M7N and Z remained significantly tougher than C (P<0.001), while 3D7M and 9D1M improved WBSF under NES conditions. ES is more effective to alleviate beta-agonist induced toughness than high vitamin D3 supplements.THRIP and the RMRDT.http://www.elsevier.com/locate/meatscinf201
Effect of dietary beta-agonist treatment, vitamin D-3 supplementation and electrical stimulation of carcasses on colour and drip loss of steaks from feedlot steers
In this study, 20 young steers received no beta-agonist (C) and 100 animals all received zilpaterol hydrochloride
(Z), with 1 group receiving Z while the other 4 groups receiving Z and vitamin D3 at the following levels
(IU/animal/day) and durations before slaughter: 7 million for 3 days (3D7M) or 6 days (6D7M), 7 million
for 6 days with 7 days no supplementation (6D7M7N) and 1 million for 9 days (9D1M). Left carcass sides
were electrically stimulated (ES) and right sides not (NES). Samples were analysed fresh or vacuum-aged
for 14 days post mortem. Parameters included drip loss and instrumental colour measurements. In general,
zilpaterol showed increased drip loss, lighter meat, and reduced redness. Vitamin D3 supplementation
could not consistently overcome these negative effects. All vitamin D3 treatments reduced drip loss of
stimulated aged steaks.THRIP and the RMRDT.http://www.elsevier.com/locate/meatscinf201
Observation of Parity Violation in the Omega-minus -> Lambda + K-minus Decay
The alpha decay parameter in the process Omega-minus -> Lambda + K-minus has
been measured from a sample of 4.50 million unpolarized Omega-minus decays
recorded by the HyperCP (E871) experiment at Fermilab and found to be [1.78 +/-
0.19(stat) +/- 0.16(syst)]{\times}10^{-2}. This is the first unambiguous
evidence for a nonzero alpha decay parameter, and hence parity violation, in
the Omega-minus -> Lambda + K-minus decay.Comment: 10 pages, 7 figure
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