Structural and magnetic diversity in alkali-metal manganate chemistry: evaluating donor and alkali-metal effects in co-complexation processes

By exploring co-complexation reactions between the manganese alkyl Mn(CH2SiMe3)2 and the heavier alkalimetal alkyls M(CH2SiMe3) (M=Na, K) in a benzene/hexane solvent mixture and in some cases adding Lewis donors (bidentate TMEDA, 1,4-dioxane, and 1,4-diazabicyclo[2,2,2] octane (DABCO)) has produced a new family of alkali-metal tris(alkyl) manganates. The influences that the alkali metal and the donor solvent impose on the structures and magnetic properties of these ates have been assessed by a combination of X-ray, SQUID magnetization measurements, and EPR spectroscopy. These studies uncover a diverse structural chemistry ranging from discrete monomers [(TMEDA) 2MMn(CH2SiMe3)3] (M=Na, 3; M=K, 4) to dimers [{KMn- (CH2SiMe3)3·C6H6}2] (2) and [{NaMn(CH2SiMe3)3}2(dioxane)7] (5); and to more complex supramolecular networks [{NaMn(CH2SiMe3)3}1] (1) and [{Na2Mn2(CH2SiMe3)6- (DABCO)2}1] (7)). Interestingly, the identity of the alkali metal exerts a significant effect in the reactions of 1 and 2 with 1,4-dioxane, as 1 produces coordination adduct 5, while 2 forms heteroleptic [{(dioxane)6K2Mn2(CH2SiMe3)4(O(CH2)2- OCH=CH2)2}1] (6) containing two alkoxide-vinyl anions resulting from a-metalation and ring opening of dioxane. Compounds 6 and 7, containing two spin carriers, exhibit antiferromagnetic coupling of their S=5/2 moments with varying intensity depending on the nature of the exchange pathways

Smell, Taste, and Temperature Interfaces

Everyday life hinges on smell, taste, and temperature-based experiences, from eating to detecting potential hazards (e.g., smell of rotten food, microbial threats, and non-microbial threats such as from hazardous gases) to responding to thermal behavioral changes. These experiences are formative as visceral, vital signals of information, and contribute directly to our safety, well-being, and enjoyment. Despite this, contemporary technology mostly stimulates vision, audition, and - more recently - touch, unfortunately leaving out the senses of smell taste and temperature. In the last decade, smell, taste, and temperature interfaces have gained a renewed attention in the field of Human Computer Interaction, fueled by the growth of virtual reality and wearable devices. As these modalities are further explored, it is imperative to discuss underlying cultural contexts of these experiences, how researchers can robustly stimulate and sense these modalities, and in what contexts such multisensory technologies are meaningful. This workshop addresses these topics and seeks to provoke critical discussions around chemo- and thermo-sensory HCI

The transition to aeration in two-phase mixing in stirred vessels

We consider the mixing of a viscous fluid by the rotation of a pitched blade turbine inside an open, cylindrical tank, with air as the lighter fluid above. To examine the flow and interfacial dynamics, we utilise a highly-parallelised implementation of a hybrid front-tracking/level-set method that employs a domain-decomposition parallelisation strategy. Our numerical technique is designed to capture faithfully complex interfacial deformation, and changes of topology, including interface rupture and dispersed phase coalescence. As shown via transient, three-dimensional direct numerical simulations, the impeller induces the formation of primary vortices that arise in many idealised rotating flows as well as several secondary vortical structures resembling Kelvin-Helmholtz, vortex breakdown, blade tip vortices, and end-wall corner vortices. As the rotation rate increases, a transition to `aeration' is observed when the interface reaches the rotating blades leading to the entrainment of air bubbles into the viscous fluid and the creation of a bubbly, rotating, free surface flow. The mechanisms underlying the aeration transition are probed as are the routes leading to it, which are shown to exhibit a strong dependence on flow history.Comment: 14 pages, 9 figure

Natural ventilation in underground wine cellars

Abstrat The main objective of this research is to promote passive thermal design techniques in the construction of wineries. Natural ventilation in underground cellars is analyzed, focusing on the entrance tunnel, the ventilation chimney and the cave. A monitoring system was designed in order to detect changes in the indoor conditions and outdoor air infiltration. Monitoring process was carried out during one year. Results show the influence of outside temperature, ventilation chimney and access tunnel on the conditions inside the underground cellar. During hot periods, natural ventilation has a negligible influence on the indoor ambience, despite the permanently open vents in the door and chimney. The tunnel and ventilation chimney work as a temperature regulator, dampening outside fluctuations. Forced ventilation is necessary when a high air exchange ratio is needed. During cold periods, there is greater instability as a result of increased natural ventilation. The temperature differences along the tunnel are reduced, reflecting a homogenization and mixing of the air. The ventilation flow is sufficient to modify the temperature and relative humidity of the cave. Forced ventilation is not necessary in this period. During the intermediate periods --autumn and spring--occurs different behaviors based on time of day

Estratificación en bodegas catedral para la crianza de vinos generosos.

La zona de producción de vinos generosos conocida como Marco de Jerez cuenta con un tipo particular de bodegas, las “catedrales del vino”. Estos edificios de extraordinarias dimensiones que vivieron su apogeo durante el siglo XIX reciben su nombre por la similitud que muestran con los templos de la cristiandad. Este trabajo desvela el fenómeno de la estratificación vertical, a través de la monitorización de temperatura y humedad relativa a diferentes alturas. Los resultados del estudio demuestran que la estratificación vertical es notable en primavera y verano. En los meses más calurosos, las diferencias durante la tarde superan los 4⁰C y 15% HR en la zona de barricas, y los 15⁰C y 35% HR. considerando toda la altura de la bodega. Este comportamiento justifica las técnicas utilizadas en el sistema tradicional de crianza, situando el vino con más edad en la zona inferior. El diseño característico de las bodegas catedral hace posible estratificar el aire y proteger al vino de los incrementos de temperatura y las bajadas de humedad relativa; su comportamiento podría servir de inspiración y referencia para un diseño más eficiente de nuevas construcciones para la crianza del vino tinto.

Secondary messenger signalling influences Pseudomonas aeruginosa adaptation to sinus and lung environments

Pseudomonas aeruginosa is a cause of chronic respiratory tract infections in people with cystic fibrosis (CF), non-CF bronchiectasis, and chronic obstructive pulmonary disease. Prolonged infection allows the accumulation of mutations and horizontal gene transfer, increasing the likelihood of adaptive phenotypic traits. Adaptation is proposed to arise first in bacterial populations colonizing upper airway environments. Here, we model this process using an experimental evolution approach. Pseudomonas aeruginosa PAO1, which is not airway adapted, was serially passaged, separately, in media chemically reflective of upper or lower airway environments. To explore whether the CF environment selects for unique traits, we separately passaged PAO1 in airway-mimicking media with or without CF-specific factors. Our findings demonstrated that all airway environments-sinus and lungs, under CF and non-CF conditions-selected for loss of twitching motility, increased resistance to multiple antibiotic classes, and a hyper-biofilm phenotype. These traits conferred increased airway colonization potential in an in vivo model. CF-like conditions exerted stronger selective pressures, leading to emergence of more pronounced phenotypes. Loss of twitching was associated with mutations in type IV pili genes. Type IV pili mediate surface attachment, twitching, and induction of cAMP signalling. We additionally identified multiple evolutionary routes to increased biofilm formation involving regulation of cyclic-di-GMP signalling. These included the loss of function mutations in bifA and dipA phosphodiesterase genes and activating mutations in the siaA phosphatase. These data highlight that airway environments select for traits associated with sessile lifestyles and suggest upper airway niches support emergence of phenotypes that promote establishment of lung infection.</p

Gender equality in STEM programs: a proposal to analyse the situation of a university about the gender gap

[EN]According to the Global Gender Gap Report 2020, most of the countries have achieved gender parity in educational attainment. Furthermore, Latin America and Europe have more women than men enrolled in tertiary education. The problem arises when those numbers are analysed by degree studies. There is a gender gap in science, technology, engineering and mathematics (STEM), with a low number of women enrolled in those programs and even lower numbers of graduates. The universities have a key role to steer new conceptions and understanding of the females in STEM . The higher education institutions have to define measures and policies to reduce the gender gap in the careers of the future. This work aims to provide a proposal to analyse the gender equality gap in STEM as a first step to define gender equality action plans focused on processes of attraction, access and retention and guidance in STEM programs. The proposal was applied in ten Latin American universities from Chile, Colombia, Costa Rica, Ecuador and Mexico, and five European universities from Finland, Ireland, Italy, Spain, United Kingdom

Modelo de la estructura de basamento e identificación de fuentes sismogenéticas en la Depresión del Bajo Segura (Murcia-Alicante)

In this work we have carried out a geophysical and seismotectonic study in order to identify and characterise the seismogenetic sources or Bajo Segura actives faults. The main method used is the structural interpretation of gravity data. This method is combined with geological-structural and geomorphological studies, as well as historical and instrumental seismicity data. Several of the strongest earthquakes recorded in the Spanish historical catalogue occurred in this region, among them, the Torrevieja earthquake of 1829. Often, this activity is related to blind faults in the basin interior, that are covered by neogene and plioquaternary deposits. Different faults systems related to the neotectonic stress field and coherent with border structures, may explain this activity