Biosorption of Nickel (II) from aqueous solution onto activated carbon prepared from chicken feather

Industrial waste water is a potential threat to human health mainly because of the presence of nonbiodegradable, hazardous heavy metals. This research focuses on the use of Activated Carbon from Chicken Feathers (ACCF) in the removal of Ni (II) ions from aqueous solution. Fourier Transform Infrared (FTIR) analysis was carried out on ACCF to reveal the functional groups present which will aid adsorption. The optimization of factors such as initial metal ion concentration, pH, and contact time were investigated at ambient temperature. The optimum pH, initial metal ion concentration and contact time were therefore determined. The experimental data obtained for Ni2+ sorption were treated using pseudo first order and second order kinetic models. The adsorption behavior was found to follow pseudo second order kinetics. This study demonstrates the effectiveness of ACCF in the removal of Ni (II) ion from aqueous solution.Keywords: adsorption, chicken feather, kinetic

Echolocation activity of harbour porpoises (phocoena phocoena) around an offshore gas-production platform-drilling-rig complex.

Harbour porpoises (Phocoena p. phocoena L.) are vocal animals and their activity can be monitored effectively using underwater, autonomous, passive-acoustic cetacean-click detectors called T-PODs [e.g. 1, 2, 3]. The characteristics of porpoise-echolocation clicks have been described in great depth over the last forty years [4-10]; clicks can be emitted singularly or in groups known as “trains”. There is a linear correlation between porpoise-echolocation pulse intervals and target range [11, 12] with a peak in repetition rate as the animal nears the target, analogous to the “terminal buzzes” repeatedly observed in echolocating bats [13]. Determination of a successful prey-capture event in wild echolocating bats has been achieved effectively [e.g. 14] but for wild porpoises, underwater filming of prey-capture attempts is extremely tedious. Moreover, in the wild, without visual confirmation, any correlation between porpoise buzz activity and feeding success cannot be assumed a priori without experimental evidence, because a high buzz rate may simply be associated with increased foraging effort for the same amount of prey. Nonetheless, it is conceivable that by using acoustics alone, a proxy of feeding activity could be surmised by examining the relative incidence of increasing click rates, emitted during range-locking echolocation behaviour, and the associated decreasing interval between clicks, known as “inter-click-intervals (ICI)” [see 2]. A link between feeding and decreasing ICI has been established for foraging Blainville's beaked whales, Mesoplodon densirostris [15] and harbour porpoises [16]

AgriBenchmark: Benchmarking Sustainable Nutrient Management on Irish Farms

AgriBenchmark explored the possibilities for benchmarking of nutrient management performance on Irish farms. Teagasc National Farm Survey (NFS) data (2008–2015; 1446 farms) were used to characterise and explore the potential for improvement of farm nutrient management performance and resultant aspects of environmental and economic sustainability through the derivation of three key performance indicators (KPIs) at the farm-gate level: farm nutrient balance (kgha–1), nutrient use efficiency (NUE; %) and profitability (gross margin; €ha–1). In this report, the farm nutrient balance is defined as the farm-gate nutrient imports (fertiliser, feed, animals, etc.) minus the exports (animals, crops, wool and milk). A positive balance (surplus) is considered to represent a nutrient source pressure in terms of the risk of nutrient losses to the wider environment. The data and analyses in this report cover the main, more intensive agricultural systems in Ireland (excluding pig and poultry farms) and are representative of, on average, 61% of farms nationally and 76% of the total utilised agriculture area (UAA; excluding commonage)

Assessing hearing loss in older adults with a single question and person characteristics; Comparison with pure tone audiometry in the Rotterdam Study

INTRODUCTION: Hearing loss (HL) is a frequent problem among the elderly and has been studied in many cohort studies. However, pure tone audiometry-the gold standard-is rather time-consuming and costly for large population-based studies. We have investigated if self-reported hearing loss, using a multiple choice question, can be used to assess HL in absence of pure tone audiometry. METHODS: This study was performed within 4,906 participants of the Rotterdam Study. The question (in Dutch) that was investigated was: 'Do you have any difficulty with your hearing (without hearing aids)?'. The answer options were: 'never', 'sometimes', 'often' and 'daily'. Mild hearing loss or worse was defined as PTA0.5-4(Pure Tone Average 0.5, 1, 2 & 4 kHz) ≥20dBHL and moderate HL or worse as ≥35dBHL. A univariable linear regression model was fitted with the PTA0.5-4 and the answer to the question. Subsequently, sex, age and education were added in a multivariable linear regression model. The ability of the question to classify HL, accounting for sex, age and education, was explored through logistic regression models creating prediction estimates, which were plotted in ROC curves. RESULTS: The variance explained (R2) by the univariable regression was 0.37, which increased substantially after adding age (R2 = 0.60). The addition of sex and educational level, however, did not alter the R2 (0.61). The ability of the question to classify hearing loss, reflec

Production of Massless Fermions during Inflation

We compute the one loop self energy, in a locally de Sitter background, for a massless fermion which is Yukawa-coupled to a massless, minimally coupled scalar. We then solve the modified Dirac equation resulting from inclusion of the self energy. We find faster-than-exponential growth in the fermion wave function, consistent with the production of fermions through a process in which a scalar and a fermion-anti-fermion pair are ripped out of the vacuum by inflation.Comment: 17 pages, LaTeX 2e, 1 figure. The first 15 pages gives the text of version 1, which matches the published version. The erratum appended on page 15 corrects a crucial sign error which COMPLETELY CHANGES THE PHYSICAL CONCLUSION

Deformations of calibrated D-branes in flux generalized complex manifolds

We study massless deformations of generalized calibrated cycles, which describe, in the language of generalized complex geometry, supersymmetric D-branes in N=1 supersymmetric compactifications with fluxes. We find that the deformations are classified by the first cohomology group of a Lie algebroid canonically associated to the generalized calibrated cycle, seen as a generalized complex submanifold with respect to the integrable generalized complex structure of the bulk. We provide examples in the SU(3) structure case and in a `genuine' generalized complex structure case. We discuss cases of lifting of massless modes due to world-volume fluxes, background fluxes and a generalized complex structure that changes type.Comment: 52 pages, added references, added comment on ellipticity in appendix B, made minor changes according to instructions referee JHE

Scalar cosmological perturbations from inflationary black holes

We study the correction to the scale invariant power spectrum of a scalar field on de Sitter space from small black holes that formed during a pre-inflationary matter dominated era. The formation probability of such black holes is estimated from primordial Gaussian density fluctuations. We determine the correction to the spectrum by first deriving the Keldysh propagator for a massless scalar field on Schwarzschild-de Sitter space. Our results suggest that the effect is strong enough to be tested -- and possibly even ruled out -- by observations.Comment: 41 pages, 11 figures, published versio

Knots in Charged Polymers

The interplay of topological constraints and Coulomb interactions in static and dynamic properties of charged polymers is investigated by numerical simulations and scaling arguments. In the absence of screening, the long-range interaction localizes irreducible topological constraints into tight molecular knots, while composite constraints are factored and separated. Even when the forces are screened, tight knots may survive as local (or even global) equilibria, as long as the overall rigidity of the polymer is dominated by the Coulomb interactions. As entanglements involving tight knots are not easy to eliminate, their presence greatly influences the relaxation times of the system. In particular, we find that tight knots in open polymers are removed by diffusion along the chain, rather than by opening up. The knot diffusion coefficient actually decreases with its charge density, and for highly charged polymers the knot's position appears frozen.Comment: Revtex4, 9 pages, 9 eps figure