Estrone direct photolysis: by-product identification using LC-Q-TOF

The identification of degradation products generated upon photolysis of estrone (E1), a natural estrogenic hormone, under simulated UV irradiation conditions was addressed by the use of LC-Q-TOF mass spectrometry. The structures of the main degradation products were elucidated, demonstrating how the use of model molecules 5,6,7,8-tetrahydro-2-naphtol (THN), 2-methylcyclopentanone (MCP), labeled molecule estrone D(4) (E1-D(4)), the investigation of the fragmentation pathways of the parent E1, the concurrent use of CID and exact mass measurements permit the characterization of structural modifications induced by photodegradation processes. In the present study, we identified nine major by-products of which seven photoproducts correspond to E1H(+) modified in positions other than the C-2, C-4 and C-16 of E1. Most of them showed one to three additional hydroxylations preferentially located on the aromatic ring of the parent E1, which confirms that these products may present environmental risk. Applications to real water samples have been conducted to extend the validity of the present study to environmental samples.     

Statistical method for the determination of the ignition energy of dust cloud-experimental validation

Powdery materials such as metallic or polymer powders play a considerable role in many industrial processes. Their use requires the introduction of preventive safeguard to control the plants safety. The mitigation of an explosion hazard, according to the ATEX 137 Directive (1999/92/EU), requires, among other things, the assessment of the dust ignition sensitivity. PRISME laboratory (University of Orléans) has developed an experimental set-up and methodology, using the Langlie test, for the quick determination of the explosion sensitivity of dusts. This method requires only 20 shots and ignition sensitivity is evaluated through the E₅₀ (energy with an ignition probability of 0.5). A Hartmann tube, with a volume of 1.3 l, was designed and built. Many results on the energy ignition thresholds of partially oxidised aluminium were obtained using this experimental device (Baudry, 2007) and compared to literature. E₅₀ evolution is the same as MIE but their respective values are different and MIE is lower than E₅₀ however the link between E₅₀ and MIE has not been elucidated.In this paper, the Langlie method is explained in detail for the determination of the parameters (mean value E₅₀ and standard deviation σ) of the associated statistic law. The ignition probability versus applied energy is firstly measured for Lycopodium in order to validate the method. A comparison between the normal and the lognormal law was achieved and the best fit was obtained with the lognormal law.In a second part, the Langlie test was performed on different dusts such as aluminium, cornstarch, lycopodium, coal, and PA12 in order to determine E₅₀ and σ for each dust. The energies E₀₅ and E₁₀ corresponding respectively to an ignition probability of 0.05 and 0.1 are determined with the lognormal law and compared to MIE find in literature. E₀₅ and E₁₀ values of ignition energy were found to be very close and were in good agreement with MIE in the literature.     

Rheological Studies of Microfibrillar Cellulose Water Dispersions

The rheological behaviour of microfibrillar cellulose (MFC) water dispersions has been investigated. For the first time a detailed study of shear dependent viscosity at low and high shear rate is presented. A peculiar time dependent behaviour measured in the area between 0 and 1000 s⁻¹ was identified. The study shows a hysteresis loop in the shear rate–viscosity relationship at low shear rate. Additional time dependent shear rate measurements were performed, and a hypothesis for a mechanism of interaction and formation of a fibrils network was suggested. Higher temperature caused lower viscosity values, and this difference was increased at higher shear rate values. Oscillatory measurements showed how the closeness of the fibrils helps network creations. Data obtained from high shear measurements showed that 1% MFC water dispersions had a dilatant behaviour at ultra high shear rates with values increasing from 120 to 300 Pa s in the area between 180,000 and 330,000 s⁻¹ .     

Phosphorous in the environment: characteristics with distribution and effects,removal mechanisms,treatment technologies,and factors affecting recovery as minerals in natural and engineered systems

Environmental Science and Pollution Research - Phosphorus (P), an essential element for living cells, is present in different soluble and adsorbed chemical forms found in soil, sediment, and water....     

Effect of potassium and phosphorus on the transport of radiocesium by arbuscular mycorrhizal fungi

Potassium, a chemical analogue of cesium, and phosphorus, an essential macronutrient transported by arbuscular mycorrhizal fungi (AMF), have been suggested to influence the transport of radiocesium by AMF. However, no study investigated the effects of increasing concentrations of both elements on the importance of this transport. Here, the arbuscular mycorrhizal-plant (AM-P) in vitro culture system associating Medicago truncatula plantlets with Glomus intraradices was used to evaluate this effect.Using three concentrations of K (0, 1, 10 mM) and two concentrations of P (30 and 3000 μM) added to a compartment only accessible to the AMF, we demonstrated that K and P individually and in combination significantly influenced radiocesium transport by AMF. Whilst increased concentration of K decreased the amount of radiocesium transported, the opposite was observed for P. Although the exact mechanisms involved need to be assessed, both elements were identified as important factors influencing the transport of radiocesium by AMF.     

Inclusive education for children with disabilities in a refugee camp

Children in refugee camps, and particularly those with disabilities, face unique challenges in accessing education and are at high risk of being marginalised. Best practices suggest that main-streaming is the optimal strategy for serving students with disabilities. This study examines the extent to which mainstreaming in a refugee camp helps to promote children's prosocial behaviours, taking into account their emotional and behavioural problems. In Kakuma Refugee Camp, Kenya, researchers collected data from the parents of children currently enrolled in special needs education centres (n=65) and from those formerly enrolled at these facilities who transitioned to mainstream classrooms (n=81). Children in mainstream schools functioned better in terms of prosocial behaviours, but this relationship disappeared when factoring in children's emotional and behavioural difficulties. In the context of a refugee camp, mainstreaming alone is not likely to help children's psychosocial and educational functioning, which requires dedicated supports, appropriate facilities and infrastructure, and a dual focus on disability-specific and disability-inclusive initiatives.     

The internal brain drain: foreign aid,hiring practices,and international migration

Building on empirical material gathered in Haiti, this paper advances a new and innovative understanding of the internal brain drain phenomenon—the poaching of local skilled workers by international organisations (IOs) or international non-governmental organisations (INGOs)— by conceptualising it as an equilibrium. This equilibrium is composed of two sets of tensions: (i) those between the salary conditions in the public sector and those on offer to local personnel working for IOs and INGOs; and (ii) those inherent in the dual salary scale used by IOs and INGOs for local and international staff. These two sets of tensions contribute in their specific ways to international migration, and, as such, the internal brain drain has a bearing on external brain drain dynamics. In addition, the paper addresses the difficult policy choices facing development and humanitarian organisations, since every set of policies that impacts on one side of the equilibrium is bound to affect its other side.     

Elimination of phenol and aromatic compounds by zero valent iron and EDTA at low temperature and atmospheric pressure

This work deals with a new abiotic oxidation process designed as a suitable pre-treatment step within a biological depuration of wastewater containing phenol or its derivatives (o-cresol, 2-chlorophenol and p-nitrophenol) or aniline. The reaction was carried out in a stirred tank reactor at 20 degrees C and atmospheric pressure in presence of the organic compound, 150mgl(-1), zero valent iron particles (10g), ethylenediamine tetraacetic acid (EDTA, 101mgl(-1)) and air. The experimental results show that 85% of phenol conversion can be achieved after 360min. 2-Chlorophenol was found to be more easily degradable and it is completely eliminated after 300min. The oxidation of o-cresol and aniline behaved more closely to phenol obtaining after 360min 70% and 68% of conversion respectively. p-Nitrophenol was a very refractory compound, giving only 28% of conversion after 360min. Moreover, the influence of some operating variables was studied over the following ranges: temperature from 20 to 50 degrees C, initial phenol concentration from 150 to 1000mgl(-1), EDTA concentration from 50 to 200mgl(-1) and iron particles from 5 to 20g. As expected, temperature strongly enhances phenol conversion. Also, an increase of the catalyst to phenol ratio or the iron or EDTA to phenol ratio improves the reaction rate. A preliminary kinetic analysis of the data shown that the rate of phenol disappearance is not first order with respect to the phenol.     

Estimation of riverine loads of nitrogen and phosphorus to the Baltic Sea, 1970–1993

This article presents the results of the first critical examination of time series of riverine nutrient-load data for the entire Baltic Sea drainage area. Water quality data collected by or for the different national environmental agencies were compiled and analysed statistically to identify and remove inconsistent or obviously incorrect observations. Moreover, sampling tours were undertaken to acquire additional information about the present nutrient concentrations in the largest rivers in the study area. Gaps in the time series of approved data were then filled in by employing statistical interpolation and extrapolation methods. Thereafter, the concentration and runoff data were combined to obtain estimates of monthly nutrient loads for the time period 1970–93. The results of the calculations showed that although there had been substantial changes in land use, atmospheric deposition and wastewater treatment in many parts of the study area, the total riverine loads of nitrogen (N) and phosphorus (P) to the Baltic Sea have been fairly constant since 1980, and most likely also since 1970. Moreover, the interannual variation was clearly correlated to the runoff. The mean annual loads for the time period 1980–93 were found to be about 825 000 tonnes N and 41 000 tonnes P, respectively. This implies that (i) several other investigators have strongly underestimated the riverine loads of nutrients, especially the nitrogen, and that (ii) the riverine loads by far exceed the input to the Baltic Sea from other sources, {i.e.} atmospheric deposition, direct emissions from cities and industries along the Baltic Sea coast and nitrogen fixation by marine algae.