8 research outputs found
Contamination aux metaux lourds de la matrice eau-sediment et muscle du tilapia Oreochromis niloticus de trois fermes piscicoles en Cote dâIvoire
La prĂ©sente Ă©tude a pour objectif de dĂ©terminer le niveau de contamination du mercure, du cadmium, de lâarsenic et du plomb dans lâeau, les sĂ©diments et le muscle du tilapia Oreochromis niloticus dans trois fermes piscicoles en CĂŽte dâIvoire. Lâeau, les sĂ©diments et les spĂ©cimens de poisson ont Ă©tĂ© prĂ©levĂ©s par mois de fĂ©vrier Ă juillet 2017 en cage dans la lagune Aghien (ST1), en Ă©tang continental (ST2) Ă Agboville et en cage dans le barrage de Taabo (ST3). Les paramĂštres physico-chimiques mesurĂ©s ont montrĂ© quâĂ lâexception de la conductivitĂ©, des matiĂšres en suspension et des solides totaux dissous, aucune variation saisonniĂšre nâa Ă©tĂ© observĂ©e. En revanche, les valeurs moyennes des paramĂštres physico-chimiques calculĂ©es sont significativement diffĂ©rentes entre les fermes. Les valeurs de chaque mĂ©tal mesurĂ©es dans la matrice eau-sĂ©diment-muscle varient significativement entre les deux saisons dans toutes les fermes. Cependant, aucune diffĂ©rence entre les fermes Ă©chantillonnĂ©es nâa Ă©tĂ© observĂ©e. Les concentrations des mĂ©taux lourds mesurĂ©es dans le muscle sont infĂ©rieures aux valeurs seuils Ă©tablies par lâOMS Ă lâexception de lâAs. Cette contamination Ă©levĂ©e en arsenic pourrait porter atteinte Ă lâintĂ©gritĂ© biologique et Ă la santĂ© humaine.Mots clĂ©s : MĂ©taux lourds, Accumulation, Oreochromis niloticus, Ferme piscicole ivoirienn
Design and Simulation of a Transmon Qubit Chip for Axion Detection
Quantum Sensing is a rapidly expanding research field that finds one of its applications in Fundamental Physics, as the search for Dark Matter. Devices based on superconducting qubits have already been successfully applied in detecting few-GHz single photons via Quantum Non-Demolition measurement (QND). This technique allows us to perform repeatable measurements, bringing remarkable sensitivity improvements and dark count rate suppression in experiments based on high-precision microwave photon detection, such as for Axions and Dark Photons search. In this context, the INFN Qub-IT project goal is to realize an itinerant single-photon counter based on superconducting qubits that will exploit QND for enhancing Axion search experiments. In this study, we present Qub-IT's status towards the realization of its first superconducting qubit device, illustrating design and simulation procedures and the characterization of fabricated Coplanar Waveguide Resonators (CPWs) for readout. We match target qubit parameters and assess a few-percent level agreement between lumped and distributed element simulation models. We reach a maximum internal quality factor of 9.2Ă105 for -92 dBm on-chip readout power
Challenges of elementary science teaching: an Australian perspective
This chapter profiles research that has explored the role of affect in the teaching of science in Australia particularly on primary or elementary science education. Affect is a complex set of characteristics that relate to the interactions between an individualâs knowledge and emotional responses to a stimulus. Thus, there are many dimensions and theoretical frameworks that inform our understanding of how and why people behave in particular ways
Broodâstock management and early hatchery rearing of Arctic charr (Salvelinus alpinus (Linnaeus))
Arctic charr (Salvelinus alpinus (Linnaeus)) is a stenothermic coldâwater fish, which has been cultured in Northern Europe and North America since the 1980s. The industry has remained relatively small with an annual production between 6000 and 10 000 tonnes, and is still challenged by an unreliable offspring production. This review focuses on offspring production in Arctic charr aquaculture including holding conditions for broodâstock, fertilisation and egg rearing until hatch. Broodâstock requires low temperatures during summer (<12°C) with the optimum still unknown. The temperature maximum for egg incubation lies between 6 and 8°C. The composition of an optimal broodâstock diet is debated regarding fatty acids. A demand for a freshwaterâbased diet rich in omegaâ6 fatty acids is indicated, but results remain inconclusive. Extensive knowledge has been gained on the timing of spawning and its manipulation through photoperiod, temperature and hormone treatments; spawning can be induced by shortâday photoperiod; and temperature drops to 5°C. Eggs are fertilised dry in ovarian fluid. Egg quality is highly variable and positively related to egg size and energy density. Contrary, little information is available on sperm quality and its impact on egg survival. There may also be profound differences between Arctic charr of stationary or anadromous origin regarding requirements for holding conditions of broodâstock and their diet. However, these differences have received little attention, and direct comparative studies are in demand