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We present studies of axisymmetric drainage in two-dimensional micromodels of porous media using up to date microfabrication and image analysis methods. Drainage of model oil by aqueous solutions is studied at low capillary numbers (Ca) typically encountered during oil recovery operations. We use two types of oil-wet micromodels: one is based on a deposition method for creating a random monolayer of micronic glass beads, while the other is made using computer generated random networks etched in glass using wet-lithography. Both models have a central injection scheme and a radial geometry, resulting in a continuous variation of the capillary number during the course of drainage. We first carry out an analysis of experiments at global micromodel scale using computer based image analysis coupled with flow rates and pressure drop measurements. Basic relevant parameters such as permeability, porosity of the micromodel and residual oil in place after waterflooding are extracted. We then take advantage of the ease of observation in transparent micromodels to investigate the drainage phenomenon at local scale. Local saturation and front width are measured as a function of the local capillary number. Interestingly, because of the radial flow geometry, our experiments allow a continuous plotting of the micromodels capillary desaturation curve on several decades. As expected but never precisely observed, all points of various experiments collapse on a single capillary desaturation curve for a given micromodel. However, we observe dissimilar behaviors between the two types of micromodels. We discuss this phenomenon in light of the pore scale geometrical differences between the two models. Nous présentons une étude de phénomènes de drainage dans des micromodèles bidimensionnels de milieu poreux s’appuyant sur des méthodes modernes de microfabrication et d’analyse. Le drainage d’huile par des solutions aqueuses est étudié à de faibles nombres capillaires (Ca) communément rencontrés lors des opérations d’extraction pétrolière. Nous utilisons deux types de micromodèles mouillables à l’huile : le premier est basé sur une méthode de déposition innovante permettant d’obtenir des monocouches de billes de verre de taille micronique, tandis que le second est microfabriqué dans du verre à partir de réseaux poreux aléatoires générés informatiquement. Chacun des modèles utilise un schéma d’injection central dans une géométrie radiale, ce qui engendre une variation continue du nombre capillaire pendant le drainage. Nous menons tout d’abord une analyse du drainage à l’échelle globale du micromodèle en couplant analyse d’image et mesures de pression et de débit. Les paramètres de base tels que perméabilité, porosité et saturation résiduelle en huile des modèles sont extraits dans cette première phase. Nous exploitons ensuite les possibilités de visualisation offertes par les micromodèles transparents pour mener une analyse locale du phénomène d’invasion. Les saturations locales et la largeur de front sont mesurées en fonction du nombre capillaire local. De façon intéressante, du fait de la géométrie radiale, nos expériences permettent de tracer continûment les courbes de désaturation capillaire sur plusieurs décades. Comme inféré, mais jamais observé précisément, les mesures de diverses expériences se regroupent sur une courbe maîtresse pour un micromodèle donné. Nous observons cependant des différences notables entre les deux types de micromodèle. Ces observations sont discutées à la lumière des différences géométriques existant entre les deux micromodèles à l’échelle du pore.

The demand for sustainable products and ambitious sustainability goals in the home and beauty care industry are driving innovation, particularly in reducing greenhouse gas emissions. Syensqo (formerly Solvay) is addressing this challenge through its UP Bio-circular product range, which integrates bio-based materials and circular economy principles, supported by life cycle analysis. This approach aims to significantly lower the carbon footprint of consumer goods without compromising on product performance. Syensqo's products blend circular and fossil-based feedstocks using the mass-balance principle, ensuring traceability and sustainability throughout the supply chain. The company's comprehensive Life Cycle Analysis (LCA) plays a crucial role in assessing the environmental performance of our products and can comprehensively measure our products' footprint and identify improvement areas. UP Bio-circular Solutions positively impacts several environmental factors included in life cycle assessments beyond CO2 footprint, such as lower land use, reduced water consumption, and improved waste management. This ensures that shifting to circular materials not only reduces CO2 emissions, but also minimizes harm to ecosystems. The company's UP Bio-circular solutions are particularly suited for consumer goods like shampoos and detergents, offering substantial environmental benefits. Through continuous innovation and collaboration, Syensqo aims to lead the market in sustainable practices, promoting a carbon-neutral future and a lasting positive impact on the planet. [ABSTRACT FROM AUTHOR]

The article "Unlocking the Potential of Circular Mass Balance for Home and Personal Care Ingredients" discusses the challenges that formulators and companies must face in order to achieve sustainable goals. This particularly applies to manufacturers of cleaning products, who need to switch their raw material sources from fossil to natural or circular resources. One way to achieve this is through the use of the Circular Mass Balance approach, which involves using circular resources in existing chemical manufacturing processes. The article showcases Solvay as an example of how this approach can be used to produce sustainable cleaning ingredient. It emphasizes the importance of a balanced consideration of sustainability aspects when transitioning to circular economy resources. [Extracted from the article]

The intensity of an ideal optical pulse train is often modeled as an exact periodic repetition of a given pulse-shape function with constant amplitude and width. Therefore, the ideal intensity power spectrum is a pure line power spectrum. However, spontaneous-emission noise due to amplification media, electronic noise due to modulators, or even intentional modulations result in period-to-period fluctuations of the pulse amplitude, width, or arrival time. The power spectrum of this so-called noisy optical pulse train is then composed of a line spectrum added to a band spectrum. This study shows that the optical pulse train intensity is cyclostationary under usual assumptions on the fluctuations. This property allows us to derive the exact optical pulse train power spectrum. A general closed-form expression that takes into account the three noise manifestations (jitter, amplitude, and width modulations) is provided. Particular expressions are given for usual cases of interest such as the jitter and amplitude modulation model, for given fluctuation probability distributions, and pulse-shape functions. OCIS codes: 140.7090, 140.4050.

OBJECTIVE: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Delta variant was classified as a variant of concern in May 2021 due to its increased transmissibility. It became dominant in Europe during the summer, raising concerns on the effectiveness of vaccines. We assessed the vaccine effectiveness (VE) of mRNA BNT162b2 (BioNTech-Pfizer) against SARS-CoV-2 Delta variant during an outbreak affecting long-term care facility (LTCF) residents in southern France, May 2021. MATERIALS AND METHODS: We conducted a retrospective cohort study among LTCF residents. We described sex, age, dependency level, reverse transcription PCR and sequencing results, clinical evolution, vaccination status. We compared attack rates of SARS-CoV-2 infection, symptomatic coronavirus disease 2019 (COVID-19), and severe COVID-19 (respiratory support, hospitalization, and/or death) by vaccination status (two doses administered vs. none) to estimate VE (1 - Relative Risk [RR]) with 95% confidence intervals (CI). VE was adjusted by age (Poisson regression). RESULTS: Among 72 LTCF residents, 75.0% (n=54) were women, mean age was 88.7 (SD 8.1) years, 69% (n=49/71) were severely dependent. SARS-CoV-2 infections were identified in 39 residents (54.2%), 11 with symptomatic, and eight with severe COVID-19. All sequenced samples (n=19, 48.7%) had the same Delta variant genomic sequence. Age-adjusted BNT162b2 VE against SARS-CoV-2 Delta variant infection was 11.2% (95% CI: 0.0-61.1%), it was 88.4% (95% CI: 59.9-96.7%) against symptomatic, and 93.5% (95% CI: 67.2-98.7%) against severe COVID-19. CONCLUSIONS: We found a high BNT162b2 VE against symptomatic and severe COVID-19 caused by SARS-CoV-2 Delta variant among LTCF elderly residents, but not against Delta variant infection. This supports vaccination rollout and the implementation of control measures for close contacts among vaccinated LTCF elderly residents. [ABSTRACT FROM AUTHOR]

Vorgestellt wird ein neues, natürliches und biologisch abbaubares Suspensionsmittel, das mit seiner starken Suspensionskraft ohne wahrnehmbare Auswirkungen auf die Viskosität neue Möglichkeiten bei der Formulierung von Haushaltspflegeprodukten schafft. Das Mittel basiert auf aktivierten Cellulosefasern, die durch die Fermentierung von Stärke mit bestimmten Bakterienstämmen gewonnen werden. Es werden Rheologiemessungen beschrieben, die es ermöglichen, die Suspensionskraft einer mit dem Mittel hergestellten Reinigungsmittelformulierung anhand ihres rheologischen Verhaltens bei niedrigen Scherraten vorherzusagen. Der aus Bingham-Diagrammen abgeleitete Fließgrenzwert korreliert gut mit der Dichte und Größe der Objekte, die mit dem Mittel suspendiert werden können. Es werden Anwendungen des Mittels in verschiedenen Formulierungen von Haushaltspflegeprodukten gezeigt, insbesondere zur Suspendierung dekorativer optischer Kügelchen und von Duftstoffkonzentrat in einer typischen Flüssigwaschmittelformulierung. Auf die einfache Zusetzung des Suspensionsmittels zu einer Formulierung dank seines voraktivierten Flüssigformats wird eingegangen. Die mit dem Suspensionsmittel angereicherte Formulierung ist bei anhaltender Suspensionskraft und ohne Entmischung oder Veränderung des Aussehens über mehrere Monate bei 45 °C stabil. Damit wird die Anwendbarkeit des Suspensionsmittels in kommerziellen Verbraucherprodukten beispielhaft demonstriert. [ABSTRACT FROM AUTHOR]

We present an innovative, natural and readily biodegradable suspension agent that opens new possibilities to homecare formulators. When added to detergent formulas, it brings a very powerful suspension capacity without any perceivable impact on viscosity. The agent is based on activated cellulose fibers obtained through the fermentation of starch using specific bacterial strains. We present rheology measurements that allow us to predict the suspension power of a detergent formula supplemented with the agent, based on its rheology at low shear rates. The yield stress value extracted from Bingham plots highly correlates with the density and size of the objects that can be suspended with the agent. We show the application of the agent in multiple home care formulations, in particular the suspension of decorative visual beads and concentrated fragrance in a typical liquid laundry formula. We describe how it is simple to add the suspension agent to a formula due to its pre-activated liquid format. A formula supplemented with the suspension agent is stable for several months at 45°C, with sustained suspension power and no demixion or change in aspect, highlighting the suitability of the suspension agent for commercial consumer products. [ABSTRACT FROM AUTHOR]