Adhesion attenuation and enhancement in aqueous solutions

When two surfaces confine water layers between them at the nanoscale, the behaviour of these confined water molecules can deviate significantly from the behaviour of bulk water, and it could reflect on the adhesion of such surfaces. This study assesses the role of confined water layers on the adhesion of hydrophilic surfaces and how sensitive this adhesion is to the presence of contaminants. Our methodology used atomic force microscopy adhesion measurements, whereby an alumina-sputtered sphere-tipped cantilever was interacted versus a flat alumina single crystal. Testing was performed under immersed conditions using (i) water, (ii) water/dimethylformamide mixtures, (iii) water/ethanol mixtures, and (iv) water/formamide mixtures. These solutions were intended to assess the influence of dielectric constant, molecule size, and the number of hydrogen bonding opportunities available to molecules upon confinement between surfaces. It was found that dilute concentrations of ethanol and formamide decreased the adhesion. In contrast, the adhesion increased in the presence of dilute concentrations of dimethylformamide. The adhesion was attenuated by in excess of two orders of magnitude for high concentrations of the organic solutes

Numerical analysis of the thermal energy storage in cellular structures filled with phase-change material

This paper reports the results of a numerical study on the thermal performance of metal cellular structures that can be obtained by additive manufacturing (selective laser melting) when they are impregnated with phase change material (PCM) for possible applications in electronic cooling. Two body-centered cubic (BCC) periodic structures with cell sizes of 5 mm and 10 mm and a porosity of 87%, made of two solid materials (aluminum alloy and copper), and two paraffins with characteristic melting temperatures of 55 and 64 °C were considered. The numerical simulations are carried out using the commercial code ANSYS Fluent and are based on a previously validated purely conductive heat transfer model. The computational domains include just small repetitive portions of the considered composite structures, thus allowing substantial savings of computational time. Computed results show that, with both paraffins, the copper made finer BCC structure (5 mm) yields the best thermal performances, i.e, the shortest PCM melting time and the highest rate of thermal energy storage during transients

A spatially distributed, physically-based modeling approach for estimating agricultural nitrate leaching to groundwater

Nitrogen-nitrate, while being fundamental for crop production, is of particular concern in the agricultural sector, as it can easily leach to the water table, worsening groundwater quality. Numerical models and Geographic Information System may support the estimation of nitrate leaching rates in space and time, to support sustainable agricultural management practices. In this paper, we present a module for the simulation of the processes involved in the nitrogen cycle in the unsaturated zone, including nitrate leaching. This module was developed taking steps from the ANIMO and EPIC model frameworks and coupled to the hydrological models integrated within the FREEWAT platform. As such, the nitrogen cycle module was then included in the FREEWAT platform. The developed module and the coupling approach were tested using a simple synthetic application, where we simulated nitrate leaching through the unsaturated zone for a sunflower crop irrigated district during a dry year. The results of the simulation allow the estimation of daily nitrate concentration values at the water table. These spatially distributed values may then be further used as input concentration in models for simulating solute transport in aquifers

Determinación de parámetros reproductivos de padrillos de raza criolla en entrenamiento intensivo

El estrés asociado con el entrenamiento intensivo puede afectar la eficiencia reproductiva de los padrillos de raza Criolla. El objetivo de este estudio fue comparar la calidad seminal y parámetros hormonales, mediante la evaluación de la movilidad progresiva de los espermatozoides, número total de espermatozoides normales, tipo de anormalidades espermáticas y mediciones de niveles hormonales de cortisol, estrógenos y testosterona entre padrillos de raza Criolla con y sin entrenamiento intensivo de competición. Se utilizaron 18 padrillos evaluados reproductivamente durante tres meses (desde agosto hasta octubre, del año 2014). Se dividieron en 2 grupos de 9 padrillos, Grupo Ejercicio integrado por padrillos en entrenamiento intensivo de competición y Grupo Control integrado por padrillos bajo condición de no entrenamiento. Los padrillos del Grupo Ejercicio mantuvieron una rutina de entrenamiento de 1 hora diaria, 6 días a la semana, y participaron en competencias durante el periodo de estudio. Las mediciones se realizaron en ambos grupos, previo al inicio del mismo, a los padrillos de ambos grupos experimentales se les colectó semen 2 veces por día durante 7 días consecutivos, para vaciar sus reservas espermáticas y así tenerlos en “daily sperm output”. Los datos se analizaron con el software SAS. De los resultados obtenidos, se observó una mejor calidad seminal en términos de número total de espermatozoides normales con movilidad progresiva y viabilidad espermática, en muestras provenientes de padrillos en el Grupo Control. El primer objetivo específico se alcanzó exitosamente. El segundo objetivo, determinación de niveles de testosterona, estrógenos y cortisol, fueron analizados por la técnica RIA (Radioinmunoensayo) en el Laboratorio de Reproducción, FCV-UNLPam. Estos resultados fueron enviados para su publicación al congreso ICAR (International Congress On Animal Reproduction) en el año 2020

Tuberculosis/HIV/AIDS coinfection in Porto Alegre, RS/Brazil - invisibility and silencing of the most affected groups

OBJECTIVE: To analyze how belonging to certain social groups contributes to constituting the vulnerabilities associated with illnesses due to tuberculosis/HIV/AIDS coinfection. METHODOLOGYThis is a qualitative study carried out in the city of Porto Alegre, state of Rio Grande do Sul, in regions of high social vulnerability. Twenty coinfected people were interviewed in specialized health services between August and December 2016. The analysis was based on the frameworks The Sound of Silence and Vulnerability and Human Rights. RESULTS: Socioeconomic conditions were decisive for the constitution of the vulnerability conditions. Processes of people invisibilization, and the silencing of their voices, in a scenario marked by economic, racial and gender inequalities, contributed for their health needs not to be understood and effectively taken into account in the services actions. FINAL CONSIDERATIONS: The more effective strategies are to legitimize voices and to understand the needs of those affected by coinfection, the greater the chances that programmatic responses to the problem will be successful

Efecto de 1000 UI de eCG recombinante para la superestimulación folicular y la recuperación de embriones en llamas

El objetivo de este estudio fue evaluar el efecto de la eCG recombinante sobre la superestimulación folicular y la producción de embriones, como alternativa de la eCG nativa en llamas. Se utilizaron para este estudio veinte llamas no gestantes y no lactantes entre 4 y 12 años de edad, las cuales fueron examinadas diariamente por ecografía transrectal (tUS) para realizar el seguimiento de la onda folicular (MyLab One Vet, ESAOTE, Pie medical) hasta observar un folículo en crecimiento de ≥7 mm de diámetro, considerado ovulatorio en esta especie. En ese momento, las hembras recibieron 8 μg de un análogo de GnRH (EV, acetato de buserelina, Gonaxal® Biogénesis Bagó, Argentina, día 0). El día 3, se realizó una ecografia transrectal para confirmar la ausencia de folículos > 5 mm de diámetro y los animales fueron divididos en 2 grupos: eCG-N (n= 10) recibieron 1000 IU de eCG nativa (IM, Novormon®, Syntex, Argentina), y eCG-R (n= 10) recibieron 1000 IU de eCG recombinante (IM, Syntex, Argentina). El día 7, todas las llamas recibieron una inyección de 112,5 μg of cloprostenol (IM, Enzaprost®, Biogénesis Bagó). El día 10, se determinó el número de folículos por ecografía transrectal y luego las llamas recibieron servicio natural con un macho de fertilidad probada. Luego del servicio las llamas recibieron una inyección de 8 μg de acetato de buserelina (EV) y 24 h más tarde, se repitió el servicio natural con un macho diferente, para minimizar el efecto macho. El día 18, se realizó una nueva ecografía para contar el número de cuerpos lúteos (CLs) que se formaron después de la monta y luego se realizó un lavaje uterino para la recuperación de los embriones. El número de folículos desarrollados después del tratamiento y el número de embriones recuperados, de ambos grupos, fueron comparados por el test Mann-Whitney. El número de CLs que desarrollaron después del servicio fueron analizados por la prueba de t no pareada. Los valores fueron expresados como promedio ± SEM. No se encontraron diferencias significativas entre grupos en el número de folículos desarrollados al día 10 (10,5±2,9 vs. 8,4±1,3 eCG-N y eCG-R, respectivamente), ni en el número de CLs desarrollados luego del servicio (9,2±3 vs. 8,2±1,2 eCG-N y eCG-R, respectivamente). No hubo diferencia en el número de embriones recuperados entre grupos (2,6±1,1 y 3,3±1,1 eCG-N y eCG-R, respectivamente). El presente estudio demostró que los efectos de la eCG recombinante son similares a la eCG nativa, en la respuesta de la superestimulación folicular y en la recuperación de embriones

Moisture degradation of open-faced single lap joints

To obtain experimental data in short time on the degradation of adhesives exposed to moisture, a valuable technique is represented using the open-face configuration. With this technique, a layer of adhesive is first applied on one adherend and exposed to the humid environment; then, the second adherend is bonded and the joint can now undergo mechanical testing. Apart from the acceleration of moisture uptake which is obtained due to the larger area exposed, a further advantage is the uniformity of degradation. A further acceleration can be obtained by adding a hygroscopic contaminant at the adhesive/adherend interface, which speeds up moisture uptake and accentuates the interfacial nature of the failure. The main aim of this work was to evaluate the decay of the mechanical strength in the absence or presence of a contaminating agent. The specimens studied were single lap joints, tested under static shear loading. Two sets of specimens were considered; in the first set, the adhesive was applied in standard way and in the second set, the adhesive/adherend interface was contaminated with droplets of CaCl2 aqueous solution. Both sets were subjected to humid and warm environment (100% relative humidity, 50 °C). After the desired exposure times in the range 1–5 weeks, groups of specimens were dried and bonding of the second adherend was carried out. Then, mechanical testing was performed; the fractured surfaces were examined by scanning electron microscopy. The results show that before degradation the failure type is cohesive, but it changes to interfacial failure as the degradation proceeds. Uncontaminated specimens exhibit gradual degradation during the exposure time; contaminated specimens achieve almost half of the degradation in less than one week; after that, the process continues at lower speed and at the end of the observed period both methods show similar values of failure loads. Additional tests were carried out to assess the moisture absorption in the adhesive layer and relate it to the exposure time

Redução da viabilidade de esporângios de Plasmopara viticola por bactérias nativas do filoplano da videira.

Resumo: O míldio é uma das principais doenças da videira, capaz de causar danos significativos à cultura e aumentar os custos de produção. Seu controle demanda o uso intensivo de agrotóxicos, cujos resíduos são indesejáveis. Este trabalho teve como objetivo investigar o potencial uso de bactérias do filoplano em reduzir a viabilidade de esporângios de Plasmopara viticola. Foram testados trinta e cinco isolados bacterianos obtidos do filoplano de videira. Os testes de antagonismo foram feitos em lâminas de microscopia e em discos de folha, adicionando-se 50 microL de uma suspensão bacteriana e 50 microL de uma suspensão de esporângios. Nos testes em lâmina de microscopia, vinte e nove isolados inibiram a germinação dos esporângios de Plasmopara viticola. Destes, os isolados 1, 37 e 12 se destacaram, por serem capazes de inibir também a liberação de zoósporos. Em discos de folha, o isolado 1 foi o único capaz de inibir a liberação dos zoósporos, significativamente em relação à testemunha. Nesta condição, não houve a germinação dos esporângios, apenas a liberação de zoósporos. Abstract: The downy mildew is one of the main grapevine diseases, able to cause significant damage to the crop and increase production costs. It?s control demand intensive use of pesticides, which residues are undesirable. This study aimed to investigate the potential of phylloplane bacteria in reducing the viability of sporangia of Plasmopara viticola. Thirty-five bacterial isolates from phylloplane of grapevine were tested. The antagonism tests were conducted on microscopy glass blades and on leaf discs, adding microL of a bacterial suspension and 50 microL of a suspension of sporangia. Twenty-nine isolates inhibited the germination of the sporangia of Plasmopara viticola in tests conducted on glass blades. Of these, isolates 1, 37 and 12 were able to inhibit the release of zoospores. In the leaf discs test, the isolate 1 was the single able to inhibit the release of zoospores, significant compared to the control. In this condition, there wasn?t germination of sporangia, only zoospores release

Interactive Search and Exploration in Online Discussion Forums Using Multimodal Embeddings

In this paper we present a novel interactive multimodal learning system, which facilitates search and exploration in large networks of social multimedia users. It allows the analyst to identify and select users of interest, and to find similar users in an interactive learning setting. Our approach is based on novel multimodal representations of users, words and concepts, which we simultaneously learn by deploying a general-purpose neural embedding model. We show these representations to be useful not only for categorizing users, but also for automatically generating user and community profiles. Inspired by traditional summarization approaches, we create the profiles by selecting diverse and representative content from all available modalities, i.e. the text, image and user modality. The usefulness of the approach is evaluated using artificial actors, which simulate user behavior in a relevance feedback scenario. Multiple experiments were conducted in order to evaluate the quality of our multimodal representations, to compare different embedding strategies, and to determine the importance of different modalities. We demonstrate the capabilities of the proposed approach on two different multimedia collections originating from the violent online extremism forum Stormfront and the microblogging platform Twitter, which are particularly interesting due to the high semantic level of the discussions they feature

Qualidade sanitária de grãos de amendoim submetidos a tratamentos com produtos naturais.

Resumo: Este trabalho teve por objetivo avaliar a ação do extrato de canela (Cinnamomum zeylanicum Blume) no controle de fungos de armazenamento de grãos de amendoim (Arachis hypogaea L.) em duas metodologias de aplicação (aplicação direta no papel germitest e imersão) e quatro tipos de tratamento (Testemunha, extrato aquoso de canela 5% no tempo zero, extrato aquoso de canela 5% preparado com 24 horas de antecedência, extrato etanólico 1%). Foi utilizada a técnica do Blotter test, por sete dias em fotoperíodo automático e temperatura de 25º C ± 1. O delineamento experimental foi o inteiramente casualizado (DIC) em esquema fatorial 2 x 2 x 4, sendo dois lotes, duas metodologias de aplicação e quatro tratamentos, com 20 repetições de 10 sementes, totalizando 200 sementes por tratamentos. Os resultados obtidos mostraram que, para Rhizopus stolonifer, o extrato etanólico de canela a 1% aplicado diretamente no papel Germitest apresentou o menor percentual de incidência fúngica. O tratamento de imersão não é indicado para o controle deste fungo. Para Penicillium spp e Aspergillus spp, o extrato aquoso de canela a 5% com os grãos de amendoim resulta em grãos com melhor qualidade sanitária. Uma concentração superior a 5% pode vir a conferir um maior percentual de inibição, podendo chegar à totalidade