46 research outputs found
Comparison of four skeletal methods for the estimation of age at death on white and black adults
No full textWhen analyzing human adult skeletal remains, it is often difficult to decide whether a single aging method will give a more reliable age estimation than a combination of methods. This study evaluates four macroscopic indicators for age estimation on 218 American White and Black individuals, ranging in age from 25 to 90 years of age, from the Terry collection. Individuals in the sample were selected to have a balanced race, sex, and age distribution. The following aging methods were applied to each skeleton by one experienced observer: the Suchey-Brooks (SB) pubic symphysis method, the Lovejoy auricular surface method, the monoradicular teeth Lamendin (LM) method, and the Işcan (IC) method for fourth ribs. The statistical study involved the evaluation of inaccuracy and bias (based on median age) for each age indicator and the combination of methods using Principal component analysis (PCA). Analysis was performed on the entire sample, then by race, then sex, and then age group (25-40 years, 41-60 years, and >60 years). PCA was the most accurate method for both racial groups when all age groups are analyzed together. When the sample was divided into age groups, SB was the most accurate for young adults (25-40 years) and LM was the most accurate for middle adults (41-60 years). After the age of 60, all methods are highly inaccurate, although IC gives the lowest inaccuracy. As regards bias, the study highlights the tendency of all methods to overestimate the age of young individuals and to underestimate in the older age group. No single skeletal indicator of age at death is ever likely to reflect accurately the many factors that accumulate with chronological age. In fact, one must use as many dental and skeletal indicators as possible. However, in order to maximize the potential of each method, in the final evaluation one should consider mainly the method or methods that have a higher accuracy for a particular age range
Eléments de dimensionnement pour la nitrification en lit bactérien
No full textThe influence of various parameters on trickling filter nitrification is assessed. In particular, the importance of the temperature, the hydraulic loading, the irrigation force (SK), the recirculation rate, the concentrations and the organic loading are discussed. This review is based upon previous studies published so far, as well as a recent European program coordinated by Cemagref. The trickling filters can achieve either partial or full nitrification. Design data are derived for the cases of tertiary nitrification as well as combined nitrification and BOD removal. / Après avoir rappelé le principe de la nitrification dans les lits bactériens, on cherche à montrer l'influence de divers paramètres sur le fonctionnement de ces lits, en particulier la température, la charge hydraulique, l'intensité d'irrigation (SK), la recirculation, les concentrations et la charge organique. Cette mise au point est basée sur les études publiées jusqu'ici, ainsi que sur une récente étude européenne à laquelle le Cemagref a participé. Les lits bactériens permettent de produire des effluents partiellement ou totalement nitrifiés. Des éléments de dimensionnement sont suggérés pour le cas de la nitrification tertiaire, ainsi que pour la nitrification avec élimination de la DBO simultanée
L'hydrodynamique des lits bactériens : expériences de traçage dans des stations en vraie grandeur et modèles d'écoulement
No full text[Departement_IRSTEA]GMA [TR1_IRSTEA]GMA5-Epuration des eaux uséesThis document presents the results of plotting carried out on life-sized beds of bacteria with a lining colonised by the biomass. The methodology applied for the determination of the distribution of time spent (DTS) is recalled and discussed, a method of calculation is suggested for the instances where recycling occurs. A ratio between time spent/hydraulic load is presented for the materials and lining that is not colonised, its application in the case of colonised materials is discussed. The principal models applicable to the hydraulics of beds of bacteria are presented and their aptitude for translating experimental results analysed. Two models lead to a good representation of the DTS.Ce document présente les résultats de traçages réalisées sur des lits bactériens en vraie grandeur avec un garnissage colonisé par la biomasse. La méthodologie appliquée pour la détermination des distributions des temps de séjour (DTS) est rappelée et discutée, une méthode de calcul est proposée dans les cas où il existe un recyclage. Une relation temps séjour/charge hydraulique est présentée pour les matériaux et garnissage non colonisés, son application au cas des matériaux colonisés est discutée. Les principaux modèles applicables à l'hydraulique des lits bactériens sont présentés et leur aptitude à traduire les résultats expérimentaux analysés. Deux modèles conduisent à une bonne représentation de la DTS
DISSOLUTION OF AEROSOL IRON IN SEA WATER USING FLOW-INJECTION WITH CHEMILUMINESCENCE DETECTION
No full textIron is an essential micronutrient for the metabolism of marine organisms and impacts on primary productivity and hence indirectly on climate change. The dominant source of iron to the sea surface in open ocean regions is from the atmosphere by aeolian dust transport but the solubility of iron from dust is poorly constrained. In this thesis, chemical and physical factors impacting on the process of dust dissolution and iron release in seawater were investigated using FI-CL detection. A manual FI manifold was automated and optimised for the determination of iron, at nanomolar concentrations, released from aerosols in seawater. The limit of detection was 0.04 ± 0.03 nM and the precision (rsd) ranged from 0.2 to 10.8%. Protocols, maintenance find troubleshooting sections were documented for effective utilisation o f the technique. A seawater treatment system to produce low DOC (dissolved organic carbon) and dFe (dissolved iron) seawater was adapted and optimised. This UV photo-oxidation system was poorly efficient in removing DOC (-40%), complexing ligands (~60%) and dFe (apparent removal 90%). An autosampler was designed, validated, and integrated with an incubation system for sub-sampling during dissolution experiments of aerosol iron in seawater. Fast release of iron f r om the aerosol particles occurred within the first 2 h, followed by a decrease over 1 day. Preliminary experiments w i t h UV-irradiated seawater exhibited lower solubilities compared w i t h non UV-irradiated seawater. High dust concentrations gave lower final solubilities compared with low dust concentrations. A 24 h kinetic study was carried out using NIST 1648 under contrasting light and dark regimes. Dissolution of the endmember under dark conditions released 0.36% of the iron whilst the addition of 20 nM to 200 nM Desferrioxamine B (DFOB) stimulated a release of 0.90 to 1.6%. In light, the release of iron was 0.50% with aerosol, whilst the addition of DFOB (20 nM) induced an adsorption (-1.18%). Iron release from aerosol samples from three sites around the Eastern Mediterranean: Erdemli, Tel-Shikmona and Heraklion was determined in a NATO funded project. The solubility of contrasting aerosol populations from crustal and anthropogenic sources was investigated. Crustally derived aerosol samples exhibited a variable kinetic profile of iron release with an average of maximum solubility of 0.39 ± 0.52%. The anthropogenically influenced aerosol samples exhibited consistent kinetic profiles (fast release \u3c 2 h) with an average of maximum solubility of 10.6 ± 8.9%. From these results, an approximation of the atmospheric dry inputs of soluble iron in seawater to the Levantine Basin was calculated for the first time, ranging from 804 ± 910 t for the Northern Levantine Basin to 2,670 ± 3,050 t for the Southern Levantine Basin
Exploration de l'hydrodynamique d'un biofiltre de nitrification tertiaire en grandeur réelle
No full text[Departement_IRSTEA]GMA [TR1_IRSTEA]21 - TECHNEAU / EPURENational audienceThe hydrodynamic behaviour of a biofilter used for nitrification of domestic effluents in tertiary treatment is explored. The plant is an industrial prototype of a horizontal suface of 144 m2. It is filled with a media whose granulometry is 3,5 mm, on a height of 4 m. The residence time distributions were obtained from lithium chloride tracer experiments. The space variability of the average residence times of the tracer measured at the surface of biofilter is very significant and is explained mainly by the geometry of system of distribution of the effluent under the biofilter, the residence times within the material bed being on the contrary homogeneous. The hydrodnamic behaviour of the biofilter is close to a plug flow with axial dispersion. The consequences of the measured heterogeneity on the quality of the treated effluent are evaluated using a model of nitrification by the biofilm.Le comportement hydrodynamique d'un biofiltre de nitrification tertiaire d'effluents domestiques est exploré. Il s'agit d'un prototype industriel d'une surface horizontale de 144 m2. Il est rempli d'un matériau dont la granulométrie est de 3,5 mm, sur une hauteur de 4 m. Les distributions des temps de séjour ont été obtenues à partir de traçages au chlorure de lithium. La variabilité spatiale des temps de séjour moyens du traceur mesurés à la surface du matériau est très importante et s'explique principalement par la géométrie de système de distribution de l'effluent sous le lit, les temps de séjour au sein du lit de matériau étant au contraire homogènes. Le comportement du lit est proche d'un réacteur piston avec dispersion axiale. Les conséquences de l'hétérogénéité mesurée sur la qualité du traitement sont évaluées à l'aide d'un modèle de nitrification par le biofilm
Typologie de l’activité des établissements français de Soins de suite et de réadaptation à partir des données 2016 du Programme de médicalisation des systèmes d’information
No full textMesure de la capacité d'oxygénation en eau claire des systèmes d'aération de la station d'épuration de l'union des producteurs de Saint Emilion les 1 et 2 Mars 1995 : Compte rendu n°100
No full text[Type_IRSTEA]Rapport d'expertis
Mesure de la capacité d'oxygénation en eau claire des systèmes d'aération de la station d'épuration de l'union des producteurs de Saint Emilion les 1 et 2 Mars 1995 : Compte rendu n°100
No full text[Type_IRSTEA]Rapport d'expertis
Mesure de la capacité d'oxygénation en eau claire des systèmes d'aération de la station d'épuration de l'union des producteurs de Saint Emilion les 1 et 2 Mars 1995 : Compte rendu n°100
No full text[Type_IRSTEA]Rapport d'expertis
