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Introdução: A anemia falciforme é uma doença genética que ocorre devido a substituição do ácido glutâmico pela valina, o que gera o aparecimento da hemoglobina S. Em situações de hipóxia, eritrócitos com a mutação sofrem uma mudança estrutural, que gera fragilidade membranar e consequentemente hemólise, expondo o conteúdo intracelular para o plasma e culminando em uma intensa ativação do sistema imune em condições de crise vaso-oclusiva (CVO). Objetivo: Analisar o perfil de biomarcadores hematológicos em pacientes com anemia falciforme atendidos no Hemocentro do Amazonas. Materiais e métodos: Foram incluídos 45 pacientes em estado estacionário (StSt) e 16 pacientes em crise vaso-oclusiva (CVO). Foram coletadas amostras de sangue periférico em tubo de EDTA para análise do hemograma pelo equipamento ADVIA 2120i. Os dados foram tabulados em planilhas do Microsoft Excel e utilizados para posterior análise. A comparação dos dados foi feita com o teste de Mann-Whitney e a correlação pelo teste de Spearman no software GraphPad Prism v.9.0, com intervalo de confiança de 95% e p significativo quando p < 0.05. Para a pesquisa de biomarcadores empregou-se os valores acima do percentil 50 para identificar os alto produtores e construção dos gráficos. Resultados: O grupo dos pacientes em crise vaso-oclusiva foram marcados por menor hematócrito (p = 0,006), maior contagem de leucócitos totais (p = 0,02) e maior valor absoluto de neutrófilos (p = 0,003). Observamos várias correlações positivas nos pacientes em StSt, enquanto durante a crise, a quantidade de correlações significativas entre as células e parâmetros foi reduzida. Na pesquisa de biomarcadores, observamos que pacientes em CVO são alto produtores de neutrófilos, linfócitos e monócitos, bem como de hemoglobina. Discussão: O perfil imunológico guiado pela contagem de leucócitos tem sido muito empregado na rotina clínica, entretanto, nossos resultados demonstraram que na condição StSt, há uma maior confiança na representação dos dados, em comparação da crise, além de uma melhor dinâmica entre os parâmetros. Já na CVO, embora seja marcada por intensa produção de mediadores inflamatórios, e consequente maior participação da imunidade inata, observamos que a hemoglobina acaba também por atuar como um bom marcador de decisão clínica. Fisiologicamente, muitos dos mediadores são recrutados para sítios ativos e, portanto, podem acabar reduzidos no sangue periférico durante a crise, o que poderia justificar a imunomodulação desregulada em quadros de crise, e estímulo inflamatório. Conclusão: Para fins de acompanhamento clínico, observamos que os leucócitos podem ser empregados em momentos de crise do paciente, no entanto possui pouca interferência nos parâmetros gerais. Mais estudos são necessários para comparar exames de melhor acessibilidade e de baixo custo para determinar melhores prognósticos clínicos dentro dos pacientes com anemia falciforme.

Introdução: A COVID-19 tem sido uma doença de grande impacto para a saúde pública desde 2020. Sua causa se dá pela transmissão do SARS-CoV-2, um vírus altamente contagioso, que se desenvolveu rapidamente e evoluiu um quadro de pandemia. Sua veiculação pelo ar facilita a disseminação para muitos indivíduos e gera ampla variedade de sintomas, podendo ser classificados de leves a graves, além de terem alta taxa de mortalidade. Os monócitos foram descritos com uma função primordial no processo inflamatório e de retroalimentação positiva na resposta ao vírus, porém poucos estudos avaliam sua dinâmica na resposta convalescente da COVID-19. Objetivo: Descrever as subpopulações de monócitos circulantes na resposta imunológica de pacientes convalescentes da COVID-19. Material e métodos: Foram incluídos 50 pacientes convalescentes, sem sintomas a 30 dias prévios à coleta, do sexo masculino, e sem outras doenças infecciosas. Também foram incluídos 50 candidatos aptos à doação de sangue. Foi utilizado sangue total para imunofenotipagem dos subtipos de monócitos, com base na expressão de CD14, CD16 e HLA-DR. A aquisição dos dados foi feita por citometria de fluxo, no citômetro FACS Canto II e a estratégia foi feita no software FlowJo v. 10.6. O soro foi coletado e empregado na detecção de anticorpos IgG anti-S e anti-N por quimioluminescência na Fundação HEMOAM. Para análise estatística, foi realizada a comparação dos grupos pelo teste de Kruskall-Wallis, enquanto a correlação foi realizada pelo teste de Spearman. Todas as análises foram feitas no software GraphPad Prism v. 6.0, considerando intervalo de confiança de 95% e p significativo para p < 0.05. Resultados: Não foi identificada diferença estatística quanto aos dados sociodemográficos. Já na quantificação dos monócitos totais, foi observado um aumento significativo dos monócitos (p < 0,03), além das subpopulações, onde foi observada uma redução dos monócitos clássicos (p < 0,0001), e aumento nos monócitos intermediários (p < 0,0003) e não clássicos (p < 0,0001) nos convalescente. A análise de correlação mostrou uma correlação negativa entre os monócitos não clássicos e a produção de anticorpo IgG apenas anti-S. Discussão: Nossos resultados demonstraram um aumento significativo de monócitos totais na fase convalescente, o que parece ser guiado pelos monócitos intermediários e não clássicos. Esses resultados corroboram com diversos outros estudos publicados, os quais podem estar atrelados à função reparadora devido ao dano causado durante a fase aguda da doença. Conclusão: Os dados deste estudo demonstraram uma dinâmica dos monócitos na fase convalescente, mesmo após a cura clínica, que pode estar envolvido no quadro de COVID longa. Porém, mais estudos são necessários a fim de compreender a função dos monócitos durante a fase ativa da doença, bem como no desenrolar da fase convalescente.

Objetivos: A anemia falciforme é uma doença genética inflamatória crônica causada pela substituição da hemoglobina A pela hemoglobina S. Esse quadro leva à produção de mediadores inflamatórios, como o sistema complemento, que podem estar relacionados à condição clínica dos pacientes. Assim, fez-se necessário avaliar a concentração das anafilotoxinas dentro dos aspectos clínicos nestes pacientes. Material e métodos: Foram utilizadas amostras de plasma de pacientes com anemia falciforme: 27 em estado estacionário (EE) e 22 em crise vaso-oclusiva (CVO), além de 53 amostras de doadores saudáveis (DS). O grupo CVO foi acompanhado no período de 90 dias após a recuperação da crise, descritos como convalescentes (CV). Realizou-se a técnica de Cytometric Bead Array com o kit The BD™CBA Human Anaphylatoxin para a quantificação das anafilotoxinas C3a, C4a e C5a, analisados pelo software FCAP Array v.3.0, e a concentração dos analitos foi dada em pg/mL. A análise dos dados foi realizada no software GraphPadPrism v.5.0, com os testes Kruskal-Wallis e pós-teste de Múltiplas Comparações de Dunn. Para análise pareada entre os indivíduos do grupo CVO e CV, foi empregado o teste de Wilcoxon. Para todas as análises foi considerado intervalo de confiança de 95% e valor de p significativo quando p < 0.05. Resultados: Para os dados sociodemográficos não foi identificada diferença estatística entre os grupos. Já para as anafilotoxinas foi observada maior concentração das C3a e C4a no grupo EE em comparação ao grupo DS. Já quanto ao grupo CVO, foi identificada menor concentração dos níveis de C4a e C5a, em comparação ao grupo EE. Na análise pareada entre os grupos CVO e CV, não foi observada alteração significativa. Discussão: Os resultados encontrados descrevem a ativação do sistema complemento nos pacientes falciformes, onde é possível observar a ativação da via clássica do complemento de maneira crônica, que pode estar relacionado com o desenvolvimento de vaso-oclusões e mudança do estado clínico. A participação de outros mediadores inflamatórios pode acabar contribuindo com a taxa de clivagem, e consequentemente, induzir a um perfil inflamatório mais exacerbado. Conclusão: Os dados deste estudo demostram maior grau de ativação da via clássica em pacientes sem sintomas graves, o que pode estar voltado ao agravamento da condição clínica. Poucos estudos são voltados para compreender a participação do sistema complemento em doenças hemolíticas, e assim, mais pesquisas são necessários para avaliar outros parâmetros e descrever sua relação com aspectos imunológicos e clínicos.

Interdisciplinary marine research is pivotal for addressing ocean sustainability challenges but may exclude diverse socio-economic, cultural, or identity groups. Drawing on perspectives of marine Early Career Researchers, we highlight the importance of Diversity, Equity, and Inclusion (DEI) in advancing interdisciplinary marine science and present ten recommendations to enhance DEI. As our ocean faces increasing threats, fostering DEI within this domain is not merely an aspirational goal but an ethical imperative.

Abstract Nanocomposites based on carbon nanotubes (CNTs) are suitable for sensors, due to matrix ability to incorporate nanotube properties. Thus, we developed a low-cost, nanostructured poly(acrylonitrile-butadiene-styrene) (ABS) polymer piezoresistive sensor produced by additive manufacturing. For this, solution layers of acetone, dimethylformamide and CNTs functionalized with carboxylic acid were pulverized on an ABS substrate using an aerograph. Electrical characterization revealed an anisotropic piezoresistive response of the material, induced by the printing lines direction. Field Emission Gun-Scanning Electron Microscopy showed the nanostructured film spreading after five layers of CNTs as well as the random entanglement of nanotubes on parallel and perpendicular 3D-printed ABS substrates. Raman spectroscopy indicated compression and p-type doping of CNTs in interaction with the polymer, as seen mainly by the blueshift of the G and 2D subbands. The results show that the material is promising for pressure sensors, with potential applications in robotic haptic feedback systems.

Abstract The Yang–Mills–Chern–Simons theory in three-dimensional Minkowski space-time is studied in a gauge-fixing scheme which interpolates between the covariant gauge and light-cone gauge, the interpolating gauge-fixing. The ultraviolet finiteness of the theory is proved via the Becchi–Rouet–Stora (BRS) algebraic renormalization procedure, which allows us to demonstrate the vanishing of all $$\beta $$ β -functions and all anomalous dimensions to all orders in perturbation theory.

Abstract Drosophila suzukii is a pest native to Southeast Asia that causes significant economic losses to soft fruit crops. Phytosanitary irradiation is a promising treatment for D. suzukii hosts; yet an internationally recognized irradiation protocol is lacking. To fulfil specific requirements for proposing an irradiation treatment for D. suzukii, naturally infested blueberries and cherries containing a total of 37,489 late pupae were irradiated with a maximum absorbed dose of 80 Gy. Infested hosts containing a total of 9578 late pupae were considered unirradiated controls. Prevention of egg laying by females that emerged from treated pupae was considered the treatment endpoint. The fecundity and egg viability of females that emerged from treated pupae mated with their siblings were evaluated using blueberries. While females from unirradiated pupae laid a total of 43,142 eggs, no egg was laid by females that emerged from irradiated pupae. In addition, 1-day-old adults were irradiated with nominal doses of 20 and 72 Gy to evaluate whether egg laying could be prevented in flies emerging before the irradiation treatment. Females irradiated with 72 Gy laid eggs that did not hatch. Our findings suggest the minimum absorbed dose of 80 Gy as a phytosanitary irradiation treatment against D. suzukii and may support its inclusion as a treatment option in the annex of the International Standard for Phytosanitary Measures 28 (ISPM 28).

Abstract Whilst the importance of fungal primary biological aerosol particles (PBAPs) has been recognised, few studies have empirically assessed how land-use patterns influence them. Here, we show the impacts of different land-use patterns on fungal PBAPs within the Brazilian Atlantic Forest biodiversity hotspot. Spanning a distance of ca. 600 km within this biome, we collected fungal bioaerosols in the following land-use patterns: a 25-year-old coffee plantation, a 2.5-year-old Eucalyptus plantation, a 3-months-old maize crop, a 2-year-old and another 7-year-old native forest reforestation area, and a native forest fragment. Using the portable Burkard air sampler, a total of 14 morphotype-species were found. Cladosporium sp. comprised as much as about 95% of all fungal spores collected, being present in all samples (frequency of 100%). Forest systems had as much as 5-to-19-fold more fungal spores in the air than maize crops. Sampling height and time (morning vs. afternoon) did not influence fungal concentration and number of species. In addition, using data derived from an eddy covariance tower in the Eucalyptus site, we estimated the emission rate to be 6649 spores m−2 s−1. Our study confirms that land-use patterns affect fungal PBAPs, and that replacing large areas of native Atlantic Forest by monospecific stands, a homogenisation of airborne fungi is occurring, with unknown consequences for climate regulation.

The present paper analyzes and discusses specific methodological aspects instrumental in promoting the teaching of Green Chemistry (GC); it examines proposals and teaching experience reports from 284 papers published in the "Journal of Chemical Education" (JChemEd), until 2019. Using Discursive Textual Analysis and drawing upon previous studies, 143 papers were selected for containing nontraditional teaching activities for the incorporation of GC into chemistry teaching, which were grouped into seven (emerging) categories, focusing on: learning subjects, curriculum, integrative contents, context, other education environments, use of instructional materials, and comparison between GC and Traditional Chemistry. Most proposals focus on the learning subject, followed by curriculum discussions and integrative contents. Several papers brought aspects related to the systemic vision for the interconnection of GC with sustainability/sustainable development, revealing a new methodological challenge by proposing integrative content as teaching strategies. Despite their good intentions, most teaching experiences and intervention proposals still remain attached to occasional and poorly evaluated events.

The increase in the penetration of inverter based renewable energy resources comes with several challenges. For one, the power quality can be cited as an issue due to the impact of the electronic devices in the grid voltage profile, which can cause harmonic disturbances and then affect all other installations nearby. Considering the issue previously described,} this paper analyzes the effects of grid voltage harmonic disturbances in the operation of a grid-connected Voltage Source Converter (VSC) with current control in the stationary reference frame. A mathematical model is derived and validated both through simulations and experiments in order to associate the voltage harmonic magnitude disturbance with the respective current harmonic magnitude response from the grid-connected VSC. The model is also utilized to tune paralleled resonant controllers to mitigate the effect. Furthermore, the results and analyses highlight not only the effectiveness but also the limitations from the proposal.

Abstract COVID-19 is a multisystemic disease caused by the SARS-CoV-2 airborne virus, a member of the Coronaviridae family. It has a positive sense single-stranded RNA genome and encodes two non-structural proteins through viral cysteine-proteases processing. Blocking this step is crucial to control virus replication. In this work, we reported the synthesis of 23 statine-based peptidomimetics to determine their ability to inhibit the main protease (Mpro) activity of SARS-CoV-2. Among the 23 peptidomimetics, 15 compounds effectively inhibited Mpro activity by 50% or more, while three compounds (7d, 8e, and 9g) exhibited maximum inhibition above 70% and IC50

Abstract Water is a scarce, strategic resource and the most important input for economic development, especially in agricultural countries such as Brazil. Cocoa production is directly related to water availability, and, as climate changes, selecting drought-tolerant genotypes is vital to keep cacao crops sustainable. Here, we evaluated cacao genotypes under irrigated and water-stressed conditions and selected drought-tolerant ones based on nutritional and physiological traits. Thirty-nine genotypes were monitored for three years for agronomic traits and higher fruit yield. After this evaluation, the 18 most promising genotypes were evaluated in a randomized block design, under a 2 (with and without irrigation) $$\times$$ × 18 (genotypes) factorial arrangement, with three replicates and five plants per plot. We evaluated seven physiological and 11 nutritional traits, selecting genotypes based on the Genotype-by-Trait Biplot approach. Significant effects (p

Abstract The present study modeled the adsorption process of the drug diclofenac sodium on activated charcoal. For this purpose, a mass balance-based model was used considering a fixed bed column. The mass transfer rate in the solid phase was represented by a driving force model proposed in this study, and a gamma exponent with a range of 0 > γ ≤ 2 was assigned to the model. Different isotherms were adopted to represent the equilibrium at the solid/liquid interface: the Langmuir, Freundlich, Sips and Redlich-Peterson isotherms. The modeling was approached from the perspective of Bayesian statistics, and the Markov chain Monte Carlo method was used for parameter estimation. Model validation was performed with experimental data obtained under different operating conditions of initial concentration ($C_{0

Abstract The objective was to evaluate the behavior of melon genotypes (Cucumis melo L.) in the physical, chemical and biochemical quality of melon fruits as a function of electrical conductivity irrigation water levels (ECw). The experimental design adopted was randomized blocks in a 5 x 3 factorial scheme with five replications. The first factor was represented by five salinity levels (0.5, 1.5, 3.0, 4.5, and 6.0 dS m-1) and the second factor by accessions A35, and A24, and the hybrid Sancho. The physical, chemical and biochemical variables showed a reduction in production, with smaller fruits, with less weight, smaller cavity, with increased pulp thickness for Sancho. Vitamin C and yellow flavonoids increased indicating antioxidant power against ROS. The genotypes showed similar post-harvest behavior, however, the hybrid Sancho stood out over the others, possibly because it is an improved material. Accession A24 presented physiological and biochemical responses that classify it as intolerant.

In this article, exact expressions are presented for the probability density function, cumulative distribution function, moment generating function, and higher-order moments of the instantaneous signal-to-noise ratio, considering the product and the sum of the products of $N$ $\alpha$-$\mathcal {F}$ variates with pointing errors. New expressions for the outage probability (OP), bit error probability (BEP), ergodic channel capacity, and the area under the receiver operating characteristics (AUC) are deduced, as well as the asymptotic ones. The obtained expressions are used to assess the influence of various channels and system parameters on the system performance. We analyze a scenario considering dual-hop terahertz links and another regarding reconfigurable intelligent surfaces (RIS)-assisted systems. All expressions derived in this work are new, and Monte Carlo simulations corroborate the analytical curves shown.

Abstract The formation of groups of interacting individuals improves performance and fitness in many decentralised systems, from micro-organisms to social insects, from robotic swarms to artificial intelligence algorithms. Often, group formation and high-level coordination in these systems emerge from individuals with limited information-processing capabilities implementing low-level rules of communication to signal to each other. Here, we show that, even in a community of clueless individuals incapable of processing information and communicating, a dynamic environment can coordinate group formation by transiently storing memory of the earlier passage of individuals. Our results identify a new mechanism of indirect coordination via shared memory that is primarily promoted and reinforced by dynamic environmental factors, thus overshadowing the need for any form of explicit signalling between individuals. We expect this pathway to group formation to be relevant for understanding and controlling self-organisation and collective decision making in both living and artificial active matter in real-life environments.

Abstract The fibroblast growth factor (FGF) family regulates various and important aspects of nervous system development, ranging from the well-established roles in neuronal patterning to more recent and exciting functions in axonal growth and synaptogenesis. In addition, FGFs play a critical role in axonal regeneration, particularly after spinal cord injury, confirming their versatile nature in the nervous system. Due to their widespread involvement in neural development, the FGF system also underlies several human neurological disorders. While particular attention has been given to FGFs in a whole-cell context, their effects at the axonal level are in most cases undervalued. Here we discuss the endeavor of the FGF system in axons, we delve into this neuronal subcompartment to provide an original view of this multipurpose family of growth factors in nervous system (dys)function. Video Abstract

Abstract Bacterial contamination causes irreparable losses in the performance of alcoholic fermentation. Antibiotics are used to control these microorganisms, but they generate residues and cause microbial resistance. Today the only commercial product used by the mills is hops, but it is very expensive. As an alternative, the objective of this work was to evaluate the feasibility of using extracts from plants grown in the Cerrado for antimicrobial control during an alcoholic fermentation to replace antibiotics. Hydraethanolic extracts of leaves and essential oil of the following species were tested: Schinus terebinthifolius Raddi, Serjania erecta, Serjania marginata, Campomanesia adamantium and Syzygium cumini. Only the extract of Serjania marginata did not show any activity against the bacterium Bacillus sp. Both the essential oils as well as the hydroalcoholic extracts of S. terebinthifolius and C. adamantium and the extract of S. erecta showed antibacterial activity without harming the yeast, with potential to replace the hops.

Abstract Objective This study aimed at investigating a set of peripheral cytokines in elderly female patients with MDD, comparing them to controls, and assessing the potential influence of clinical comorbidities on inflammatory markers. Methods Twenty-five elderly female patients diagnosed with MDD and 19 age-matched female controls were enrolled on this study. Plasma levels of interleukin (IL)-4, IL-6, IL-10, interferon (IFN)-γ and tumor necrosis factor (TNF)-α were evaluated with commercially-available assays. Results Elderly female patients with MDD exhibited higher plasma IL-6 and IL-4 levels when compared to controls. In a logistic regression model taking cytokine levels, comorbidities, and age into account, only type 2 diabetes mellitus (DM2) remained associated with MDD. Conclusion Diabetes influences the association between MDD and higher levels of cytokines in elderly female patients. Future studies should take this evidence into account in order to mitigate confounding factors.

IntroductionThe inflammatory response after spinal cord injury (SCI) is an important contributor to secondary damage. Infiltrating macrophages can acquire a spectrum of activation states, however, the microenvironment at the SCI site favors macrophage polarization into a pro-inflammatory phenotype, which is one of the reasons why macrophage transplantation has failed.MethodsIn this study, we investigated the therapeutic potential of the macrophage secretome for SCI recovery. We investigated the effect of the secretome in vitro using peripheral and CNS-derived neurons and human neural stem cells. Moreover, we perform a pre-clinical trial using a SCI compression mice model and analyzed the recovery of motor, sensory and autonomic functions. Instead of transplanting the cells, we injected the paracrine factors and extracellular vesicles that they secrete, avoiding the loss of the phenotype of the transplanted cells due to local environmental cues.ResultsWe demonstrated that different macrophage phenotypes have a distinct effect on neuronal growth and survival, namely, the alternative activation with IL-10 and TGF-β1 (M(IL-10+TGF-β1)) promotes significant axonal regeneration. We also observed that systemic injection of soluble factors and extracellular vesicles derived from M(IL-10+TGF-β1) macrophages promotes significant functional recovery after compressive SCI and leads to higher survival of spinal cord neurons. Additionally, the M(IL-10+TGF-β1) secretome supported the recovery of bladder function and decreased microglial activation, astrogliosis and fibrotic scar in the spinal cord. Proteomic analysis of the M(IL-10+TGF-β1)-derived secretome identified clusters of proteins involved in axon extension, dendritic spine maintenance, cell polarity establishment, and regulation of astrocytic activation.DiscussionOverall, our results demonstrated that macrophages-derived soluble factors and extracellular vesicles might be a promising therapy for SCI with possible clinical applications.

Abstract The use of residues from coffee production to obtain biochar is a sustainable approach, which aims to minimize the environmental impact of these materials. In this study, the effect of adding coffee straw biochar on the physiological quality of lettuce and sorghum seeds was investigated. Thus, the objective of this work was to study the effect of adding different concentrations of coffee biochar in the substrate composition on the physiological quality of lettuce (Lactuca sativa) and sorghum (Sorghum bicolor) seeds. The experimental design used was completely randomized, with five concentrations of biochar (0; 7.5; 15; 30 and 60%), conducted with four replications of 25 seeds. The use of biochar in the concentrations studied does not provide an increase in the average germination percentage and vigor of lettuce and sorghum seeds. The increase in the concentration of biochar caused less seed vigor, suggesting a toxic effect. For seed germination, there was no significant difference between lettuce and sorghum species, regardless of treatment. For the germination speed index, sorghum seeds have higher means, except for the treatment with the addition of 15% coffee straw biochar. Lettuce seeds have higher shoot length averages, except for treatment with 100% commercial substrate. The sorghum seeds have higher mean root length and dry mass than lettuce, regardless of the treatment.

Abstract Salinity is harmful to crops when the concentration of soluble salts overcomes the salinity threshold of the crop, causing osmotic stress and limitations in plant growth. In this scenario, adopting tolerant cultivars is the most adequate strategy to minimize agricultural losses. However, the inheritance of tolerance depends on the genotype. From this perspective, this study assessed the tolerance to severe salt stress in 11 cotton cultivars based on gas exchange parameters and the free proline content. The cultivars were grown in a greenhouse and subjected to 34 days of saline irrigation (10 dS m-1), starting 45 days after seedling emergence (B1 phase). Plant growth was monitored weekly until the end of the salt stress period. The treatments consisted of a combination of two factors: eleven cultivars associated with two electrical conductivity levels of irrigation water (ECw: 0.3 and 10.0 dS m-1). The experimental design was in randomized blocks in a 11 × 2 factorial arrangement with three replications (66 plots), with the experimental unit consisting of one plant per plot. Salinity impacted plant growth, being reflected on the gas exchange and free proline data of most cultivars. However, BRS 286, FMT 705, BRS 416, and BRS Acácia, and CNPA 7MH withstood the effects of stress and osmotically adjusted to the salt stress conditions, thus minimizing the damage to growth. Those cultivars are the most indicated for improvement programs aiming at tolerance to salt stress based on the results found in this research.

This paper presents an adsorption cooler (AC) driven by the surplus heat of a solar thermal domestic hot water system to provide cooling to residential buildings. A cylindrical tube adsorber using granular silica gel as adsorbent and water as adsorbate was considered. The AC was modelled using a two-dimensional distributed parameter model implemented in previous adsorption heating and cooling studies. The performance coefficients of the resultant thermally driven cooling system were obtained for a broad range of working conditions. The thermally driven AC was found to have coefficient of performance (COP) of 0.5 and a specific cooling power (SCP) of 44 W·kg−1 when considering condenser, evaporator, and regeneration temperatures of 30 °C, 15 °C, and 70 °C, respectively. Moreover, the results showed that the AC could be used for refrigeration purposes at temperatures as low as 2 °C and that it could also operate during hotter days under temperatures of 42 °C.

In heat pumps and refrigeration systems, copper parts play a crucial role. Since heat pumps for space and water heating work under high pressure and are susceptible to vibrations, it is crucial to perfectly weld the copper pipes and heat exchangers to avoid system failures and prevent the leakage of the circulating refrigerants, which are harmful to the environment. The welding of the copper pipes is usually performed by the brazing process in a furnace. The components are subjected to a period of approximately 50 min inside a continuously open oven, varying the temperature from 710 °C to 830 °C. The oven inlets and outlets are protected by nitrogen curtains to guarantee a suitable internal environment and prevent the contamination of the gas inside the oven. This work analyses which welding methods are most suitable for welding copper, the best joint shape, process time, brazing specimens of a copper alloy, tightness tests, and mechanical properties and composition of the welding samples. From the tests carried out, the appearance of small and large defects is reduced by using a 1 mm thick external ring of filler material and a brazing temperature of 820 °C.

Establishment of interseeded alfalfa (Medicago sativa L.) under corn (Zea mays L.) silage is enhanced with foliar applications of prohexadione (PHD) followed by fungicide plus insecticide (FI), but the lowest effective rates must be determined. We evaluated stand characteristics of alfalfa interseeded into corn at Arlington, Wisconsin, USA in response to PHD applied at 0 to 0.423 kg a.e. ha−1 followed two weeks later with FI (none vs. 0.147 kg a.i. ha−1 fluxapyroxad-pyraclostrobin plus 0.018 kg a.i. ha−1 lambda-cyhalothrin). Application of PHD reduced etiolation, while FI treatment increased plant health and vigor. Following corn harvest, non-treated alfalfa stands averaged 4.2 plants m−2 and 1.2% groundcover under wet growing conditions in 2019 compared with 71.3 plants m−2 and 15.9% groundcover under normal growing conditions in 2020. Stand density in 2019 reached 130 plants m−2 but failed to plateau with combined PHD-FI treatments, while in 2020, stand density averaged 177 plants m−2 with FI regardless of the PHD rate. Alfalfa groundcover plateaued at 63% in 2019 and 71% in 2020 when 0.16 to 0.30 kg a.e. PHD ha−1 was applied prior to FI. The results indicate that FI enables excellent alfalfa establishment under normal conditions, but both PHD and FI should be applied during wet growing conditions.