A quantitative review of the transition salt concentration for inhibiting bubble coalescence

Some salts have been proven to inhibit bubble coalescence above a certain concentration called the transition concentration. The transition concentration of salts has been investigated and determined by using different techniques. Different mechanisms have also been proposed to explain the stabilizing effect of salts on bubble coalescence. However, as yet there is no consensus on a mechanism which can explain the stabilizing effect of all inhibiting salts. This paper critically reviews the experimental techniques and mechanisms for the coalescence of bubbles in saline solutions. The transition concentrations of NaCl, as the most popularly used salt, determined by using different techniques such as bubble swarm, bubble pairs, and thin liquid film micro-interferometry were analyzed and compared. For a consistent comparison, the concept of TC95 was defined as a salt concentration at which the "percentage coalescence" of bubbles reduces by 95% relative to the highest (100% in pure water) and lowest (in high-salt concentration) levels. The results show a linear relationship between the TC95 of NaCl and the reciprocal of the square root of the bubble radius. This relationship holds despite different experimental techniques, salt purities and bubble approach speeds, and highlights the importance of the bubble size in bubble coalescence. The available theoretical models for inhibiting effect of salts have also been reviewed. The failure of these models in predicting the salt transition concentration commands further theoretical development for a better understanding of bubble coalescence in salt solutions

Encapsulation of gases in powder solid matrices and their applications: A review

Gas encapsulation in solid matrices can be an important means to sequester harmful or greenhouse gases and to store useful gases for their subsequent release for a targeted application. In this review, recent developments, the characteristics and gas adsorption capacity of non-organic and organic solid powder matrices (e.g. activated carbons, carbon nanotubes, zeolites, metal-organic frameworks, and cyclodextrins); and potential applications of their complexes in various fields (energy, environment protection, nano-device production, medicine, and food and agriculture productions) are described

Encapsulation of CO<inf>2</inf> into amorphous and crystalline α-cyclodextrin powders and the characterization of the complexes formed

Carbon dioxide complexation was undertaken into solid matrices of amorphous and crystalline α-cyclodextrin (α-CD) powders, under various pressures (0.4-1.6 MPa) and time periods (4-96 h). The results show that the encapsulation capacity of crystalline α-CD was significantly lower than that of amorphous α-CD at low pressure and short time (0.4-0.8 MPa and 4-24 h), but was markedly enhanced with an increase of pressure and prolongation of encapsulation time. For each pressure level tested, the time required to reach a near equilibrium encapsulation capacity of the crystalline powder was around 48 h, which was much longer than that of the amorphous one, which only required about 8 h. The inclusion complex formation of both types of α-CD powders was confirmed by the appearance of a CO2 peak on the FTIR and NMR spectra. Moreover, inclusion complexes were also characterized by DSC, TGA, SEM and X-ray analyses

Water quality measurements in Buzzards Bay by the Buzzards Bay Coalition Baywatchers Program from 1992 to 2018

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Jakuba, R. W., Williams, T., Neill, C., Costa, J. E., McHorney, R., Scott, L., Howes, B. L., Ducklow, H., Erickson, M., & Rasmussen, M. Water quality measurements in Buzzards Bay by the Buzzards Bay Coalition Baywatchers Program from 1992 to 2018. Scientific Data, 8(1), 2021: 76, https://doi.org/10.1038/s41597-021-00856-4.The Buzzards Bay Coalition’s Baywatchers Monitoring Program (Baywatchers) collected summertime water quality information at more than 150 stations around Buzzards Bay, Massachusetts from 1992 to 2018. Baywatchers documents nutrient-related water quality and the effects of nitrogen pollution. The large majority of stations are located in sub-estuaries of the main Bay, although stations in central Buzzards Bay and Vineyard Sound were added beginning in 2007. Measurements include temperature, salinity, Secchi depth and concentrations of dissolved oxygen, ammonium, nitrate + nitrite, total dissolved nitrogen, particulate organic nitrogen, particulate organic carbon, ortho-phosphate, chlorophyll a, pheophytin a, and in lower salinity waters, total phosphorus and dissolved organic carbon. The Baywatchers dataset provides a long-term record of the water quality of Buzzards Bay and its sub-estuaries. The data have been used to identify impaired waters, evaluate discharge permits, support the development of nitrogen total maximum daily loads, develop strategies for reducing nitrogen inputs, and increase public awareness and generate support for management actions to control nutrient pollution and improve water quality.We thank the more than 1,500 volunteer Baywatchers citizen monitors who helped collect this information over 27 years. Since its inception, funding for this program has been provided through grants from the Commonwealth of Massachusetts, the U.S. Environmental Protection Agency, Buzzards Bay municipalities, private foundations, and members of the Buzzards Bay Coalition. Thank you to Paul Lefebvre for producing the station map. Amy Costa of the Center for Coastal Studies kindly provided data for comparison. Brian Howes of the School for Marine Science and Technology, University of Massachusetts, Dartmouth kindly provided the data for West Falmouth Harbor collected through the Falmouth Pond Watchers program. We thank the Marine Biological Laboratory and the Woodwell Climate Research Center for support to C. Neill, R. McHorney and L. Scott

Preparation of ibuprofen microparticles by antisolvent precipitation crystallization technique: characterization, formulation, and in vitro performance

This study demonstrates the preparation and characterization of ibuprofen (IBP) microparticles with some excipients by a controlled crystallization technique with improved dissolution performance. Using the optimum concentrations pluronic F127, hydroxypropyl methyl cellulose, D-mannitol, and L-leucine in aqueous ethanol, the IBP microparticles were prepared. The dissolution tests were performed in phosphate buffer saline using a United States Pharmacopoeia dissolution tester at 37°C. The Raman spectroscopy was used to investigate the interactions and distribution of the IBP with the additives in the microcrystals. The prepared IBP microparticles showed higher dissolution compared to that of the smaller sized original IBP particles. The Raman data revealed that the excipients with a large number of hydroxyl groups distributed around the IBP particle in the crystal enhanced the dissolution of the drug by increasing the drug-solvent interaction presumably through hydrogen bonding. The Raman mapping technique gave an insight into the enhanced dissolution behavior of the prepared IBP microparticles, and such information will be useful for developing pharmaceutical formulations of hydrophobic drugs. The controlled crystallization was a useful technique to prepare complex crystals of IBP microparticles along with other additives to achieve the enhanced dissolution profile

A study protocol for a randomised controlled feasibility trial of an intervention to increase activity and reduce sedentary behaviour in people with severe mental illness: Walking fOR Health (WORtH) Study

Abstract Background People with severe mental illness (SMI) are less physically active and more sedentary than healthy controls, contributing to poorer physical health outcomes in this population. There is a need to understand the feasibility and acceptability, and explore the effective components, of health behaviour change interventions targeting physical activity and sedentary behaviour in this population in rural and semi-rural settings. Methods This 13-week randomised controlled feasibility trial compares the Walking fOR Health (WORtH) multi-component behaviour change intervention, which includes education, goal-setting and self-monitoring, with a one-off education session. It aims to recruit 60 inactive adults with SMI via three community mental health teams in Ireland and Northern Ireland. Primary outcomes are related to feasibility and acceptability, including recruitment, retention and adherence rates, adverse events and qualitative feedback from participants and clinicians. Secondary outcome measures include self-reported and accelerometer-measured physical activity and sedentary behaviour, anthropometry measures, physical function and mental wellbeing. A mixed-methods process evaluation will be undertaken. This study protocol outlines changes to the study in response to the COVID-19 pandemic. Discussion This study will address the challenges and implications of remote delivery of the WORtH intervention due to the COVID-19 pandemic and inform the design of a future definitive randomised controlled trial if it is shown to be feasible. Trial registration The trial was registered on clinicaltrials.gov ( NCT04134871 ) on 22 October 2019

Survival Strategies and Power amongst the Poorest in a West Bengal Village

SUMMARY Focusing on ‘people's history’ challenges the assumption that poor people are passive, followers, or apolitical, by identifying ways in which poor people are makers of their own histories. By adapting a ‘people's history’ approach to the geographical study of one village in West Bengal, and concentrating particularly on survival strategies used by poorest women and children, this article shows that the rural poorest are active in an informal economy through which they operate much of their business, and that they have clear views on the characteristics of rich people. Survival strategies considered include the use of common property resources; changes in consumption patterns; share?rearing of livestock; and mutual support networks. Each is put in the context of a wider literature, and policy implications evaluated to determine the possibility of external support for such indigenous coping mechanisms. Resumé Stratégies de survie et pouvoir parmi les catégories sociales les plus démunies du Bengale de l'Ouest Prendre comme point de départ ‘l'histoire individuelle’ remet en question l'hypothèse que les pauvres sont passifs, soumis et sans conviction politique, lorsque l'on identifie les différentes manières dont ils ont construit leur propre destin. Par l'adaptation de l'approche qui prend en considération les données d'une ‘histoire personnelle’, et son utilisation dans l'analyse géographique d'un village du Bengale de l'Ouest qui se concentre tout particulièrement sur les stratégies développées par les femmes et les enfants les plus pauvres afin de survivre, cet article démontre que les pauvres dans l'environment rural sont actifs dans le secteur informal de l'économie dans lequel ils conduisent la plupart de leurs affaires, et qu'ils ont une perspective claire sur les caractéristiques des gens riches. Les stratégies de survie analysées comprennent l'exploitation des ressources des propriétés communales, les changements dans les rythmes de consommation, le partage des tâches dans le domaine de l'élevage, et des réseaux de support mutuel. Chacune de ces stratégies présentée dans le contexte d'une littérature plus élaborée, et dans celui des conséquences des mesures prises et réalisées, est évaluée de manière à déterminer les possibilités d'une aide externe à chacun de ces mécanismes de défense utilisés. Resumen Estrategias de sobrevivencia y poder entre los más pobres en una aldea de Bengala Occidental El enfoque “historia de la gente” desafía el supuesto de que los despodeídos son pasivos, sumisos y apolíticos, mediante la identificación de vías a través de las cuales estas personas hacen su propia historia. Este artículo adapta el enfoque “historia de la gente” a un estudio geográfico de una aldea de Bengala occidental, concentrándose especialmente en las estrategias de sobrevivencia usadas por mujeres y niños desposeídos demostrando que en el área rural los más pobres son activos en una economía informal a través de la cual operan la mayor parte de sus quehaceres y que tienen visiones claras sobre las características de los ricos. Las estrategias de sobrevivencia consideradas incluyen el uso de racursos de propiedad comunitaria, cambios en los patrones de consumo, crianza del ganado compartida y redes mutuales de apoyo. Cada una es colocada en el contexto de una literatura amplia e implicaciones políticas evaluadas para determinar la posibilidad de obtener apoyo externo para estos mecanismos de lucha nativos

Self-organization with traveling waves: A case for a convective torus

A traveling wave of BaSO4 in the chlorite-thiourea reaction has shown concentric precipitation patterns upon being triggered by the autocatalyst HOCl. The precipitation patterns show circular rings of alternate null and full precipitation regions. This self-organization appears to be the result of the formation of a convective torus. The formation of the convective torus can be described as a Benard-Marangoni instability with lateral heating