Transient Acoustic Wave Propagation in Porous Media

International audienceTransient Acoustic Wave Propagation in Porous Medi

Dataset anonymization and road signs detection

Micro mobility vehicles and renting services have seen an unprecedented spike due to the growth of the population in urban areas. Simultaneously, automotive technology for autonomous driving has drastically improved and entered the global market. In this thesis we propose the testbed for a future assisted driving application. This prototype is based on an object detector using a Region-Based Convolutional Neural Network trained to detect traffic road signs specific to micro-mobility vehicles. In order to train this model, it’s necessary to use a dataset that contains confidential data of many citizens, we also introduce a solution to manage this sensitive data under the General Data Protection Regulation using pre-trained models for face and number plate detection

Androgens, oestrogens, and progesterone concentrations in wastewater purification processes measured with capillary electrophoresis

A novel analytical-scale concept to improve reliability of detection and analysis of natural and processed wastewater samples from a purification plant was developed. A sequential sample clean-up system of polymer-based octadecyl and silane-based quaternary amine sorbents were used for concentrating human based steroid hormones and their metabolites and detecting them by UVabsorption with capillary electrophoresis (CE). The water samples were collected from influent and effluent processes of the water purification plant in Helsinki, Finland. TheCEmethodswerepartial-fillingmicellarelectrokinetic chromatographyand capillary zoneelectrophoresis.Theanalysis times and method concentration levels were optimized with eight steroids at the range of 0.5–10 mg/L. Since in CE the detectable quantities were higher than the existing amountsintheprocesswaters,therealsamplesneededmatrix removalcombinedwithsteroidenrichment.After20,000-fold concentration testosterone-glucoside, androstenedione, progesterone, and estradiol-glucoside could be determined in theprocesswatersamples.Theamountsofindividualsteroids in influent and effluent waters were 0–429 and 0–207 ng/L, respectively. Correspondently, their total amounts were 735 and212ng/Lwithexcellentindayandinter-dayrepeatability.Peer reviewe

Extraction of male steroids and progesterone from water by vegetable oil gels and their determination by partial filling capillary micellar electrokinetic chromatography

Microemulsion gels were synthetized from macadamia, linseed, olive, walnut, rapeseed, sesame, and coconut oils and frying oil made from sunflower, palm, and rapeseed oils. The gels were similar as polyacrylamide-based gels with exception of replacing dodecyl sulfate with vegetable oils. The gels were modified with celluloses, cotton, or lignin to make the emulsions sustainable for water purification. They were used to compare sorption properties when they were used as solid-phase adsorbents in isolation of steroids from water. Hydrophobicity features of the gels were compared by detecting adsorption and extraction efficiency of nonpolar androstenedione, testosterone, and progesterone, which exist in wastewater and drinking water. Quantification was done with partial filling-micellar electrokinetic chromatography with 29.5 mM sodium dodecyl sulfate-3.4 mM sodium taurocholate as the micelle and 20 mM ammonium acetate (pH 9.68) as the electrolyte. UV-detection was used. Methanol was the best eluent for extraction of steroids from gels. The highest recoveries were from frying oil and rapeseed oil gels modified with celluloses. They also possessed the best floating properties on water surface. Lignin modified gels were too hydrophilic, when in touch with water they filled up with water. They also had the lowest capacity.Peer reviewe

Generalized equation for transient-wave propagation in continuous inhomogeneous rigid-frame porous materials at low frequencies

International audienceThis paper provides a temporal model for the propagation of transient acoustic waves in continuous inhomogeneous isotropic porous material having a rigid frame at low frequency range. A temporal equivalent fluid model in which the acoustic wave propagates only in the fluid saturating the material, is considered. In this model, the inertial effects are described by the inhomogeneous inertial factor [A.N. Norris., J. Wave Mat. Interact. 1 365 (1986)]. The viscous and thermal losses of the medium are described by two inhomogeneous susceptibility kernels which depend on the viscous and thermal permeabilities . The medium is one dimensional and its physical parameters (porosity, inertial factor, viscous and thermal permeabilities) are depth dependent. A generalized wave propagation equation in continuous inhomogeneous material is established and discussed

Ultrasound Measuring of Porosity in Porous Materials

This chapter provides a temporal method for measuring the porosity and the tortuosity of air-saturated porous materials using experimental reflected waves. The direct problem of reflection and transmission of acoustic waves by a slab of porous material is studied. The equivalent fluid model has considered in which the acoustic wave propagates only in the pore-space. Since the acoustic damping in air-saturated porous materials is important, only the reflected waves by the first interface are taken into account, and the multiple reflections are neglected. The study of the sensitivity analysis shows that porosity is much more sensitive than tortuosity to reflection, especially when the incident angle is less than its critical value, at which the reflection coefficient vanishes. The inverse problem is solved using experimental data at a different incidence angle in reflection. Some advantages and perspectives of this method are discussed

Steroid hormones, inorganic ions and botrydial in drinking water : Determination with capillary electrophoresis and liquid chromatography-orbitrap high resolution mass spectrometry

Steroid hormones, botrydial, and inorganic ions were studied from cold and hot tap water samples with capillary electrophoresis techniques using UV detection. Identification of the steroids and botrydial was made with ultra-high -performance liquid chromatography (UHPLC) coupled to electrospray ionization orbitrap high-resolution mass spectrometry. Solid phase extraction with nonpolar and ion-exchange sorbents was needed to enrich the compounds for CE and UHPLC studies. The steroids identified from the drinking water samples were estradiol glucoside, androstenedione, testosterone, and progesterone. However, only progesterone could be quantified in both cold and hot tap water samples from Helsinki households. Its concentration varied from 0.031 ng/L to 0.135 ng/L and from 0.054 ng/L to 0.191 ng/L, respectively. Chloride and nitrate amounts were 25 mg/L. Calcium, potassium, magnesium, and sodium were 20, 1, 1, and 17 mg/L at the highest, respectively. Copper, iron, sulphate, and ammonium were below the methods concentration limits. Botrydial from Botrytis cinerea mould was identified in all drinking waters. In both cold and hot tap waters its concentration was 861-3900% higher than in a drilled well water that was also used as the household tap water. The mould was also confirmed by identification of its metabolite abscisic acid. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

Recent Developments in Capillary Electrophoresis of Steroids and Sterols

Steroid hormones are intensively studied from environmental water systems. In environmental samples their concentrations are very low, but their quantities are not meaningless since steroids belong to the group of endocrine disruptors, causing cancer and developmental disorders in humans. On the contrary, only a few recent articles deal with the research of plant steroid alcohols (sterols) in biological and environmental water systems. The reason may be that sterols are not categorized as high-risk contaminants, although their chemical structures are similar with the human steroids. Mostly, steroids are analyzed with chromatography and mass spectrometry. In addition, capillary electrophoresis has shown to be a promising separation technique in metabolic studies because of the possibility to obtain simultaneous differentiation of glucosides and the corresponding native steroids. That is not easily processed in chromatography. This review highlights the determination of human and plant steroids detected in biological samples and environmental water systems with capillary electrophoresis

Les Clubs D’environnement Dans Les Établissements Scolaires Au Maroc: Une Voie Prometteuse Pour L’ancrage De L’éducation À L’environnement

This article aims to diagnose the factors of activing and creating environment clubs as unavoidable educational structures helping to anchor environmental education in the Moroccan schools. In order to achieve this objective, questionnaires were distributed to 40 teachers practicing in fifteen schools distributed in three provincial directorates belonging to the regional academy of education and training of Tanger – Tetouan – Al Hoceima. According to the qualitative and quantitative analysis of the results of these questionnaires, environmental clubs constitute important educational structures able to ensure the development of the environmental culture in the educational practices within schools. However, many constraints to the activation of these clubs were reported by the interviewed teachers, in particular those related to the hourly load and the overload of the school curricula, the lack of supervision and the training of teachers and the absence of the teaching and learning materials necessary for environmental education activities. The key element of activating the environmental clubs in schools appears to be initial and continuous training of teachers. This training should focus on the techniques of the integration of the environmental dimension which includes educational projects and innovative activities with attractive scientific, ethical and civic purposes involving all actors and partners

Executive Compensation, CPS and Firm Performance

The purpose of the study is to research the relation between executive compensation and firm performance, as well as the significance of equal pay within the executive team. As well as total CEO compensation, the paper uses a measure known as CEO Pay Slice, which is the fraction of compensation that the CEO receives out of total pay to other executives. Executive compensation and firm performance is widely studied, but there is little research employing data from the Nordic countries. Previous studies have examined CPS either on data from the U.S. or the UK. This study uses data from Finnish listed firms to research the effectiveness of executive compensation strategies, and examine the compensation culture in Finland and Nordic countries. The data set consist of all non-financial firms listed in the OMX Helsinki stock exchange from 2010 to 2017. The main performance measures in the regressions are industry-adjusted Tobin’s Q for firm value, and industry-adjusted ROA for accounting profitability. Main findings are that CEO compensation has a significant positive association with future firm value. This suggests that Finnish CEOs are able to increase firm value in accordance with their compensation level. The correlation with accounting profitability is positive but not significant. Compensation differences within executives seem to have no effect on firm value or accounting profitability. These findings provide useful reference for future research on executive compensation, particularly on the Nordic countries.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format