The present investigation explores the chemical modification of natural dry babassu coconut (
Orbignya speciosa) mesocarp (BM), using a quasi solvent-free procedure in which the precursor was added ...to molten succinic (S), maleic (M) or phthalic (P) anhydrides, to give new products named BMS, BMM and BMP (babassu coconut mesocarp modified with succinic, maleic and phthalic anhydride, respectively). These synthesized biopolymers were characterized by infrared spectroscopy and thermogravimetry and the degree of substitution was calculated, based on the number of carboxylic groups covalently attached to the lignocellulosic polymer. The chemically modified biopolymers suspended in aqueous or hydroalcoholic solutions have the ability to remove copper from aqueous or aqueous-alcohol solutions in the order BMS
>
BMP
>
BMM. The kinetic process followed a pseudo-second-order model and the results for sorbents were better represented by the Langmuir sorption model. The effectiveness of these biopolymers for application to real samples of sugar cane spirits reflected in using only 1.0
g
dm
−3 to reduce the copper to a value lower than 5.0
mg
dm
−3 for all sorbents. Thus, these inexpensive chemically modified biopolymers may be useful to permit sugar cane spirits to meet the requirements of Brazilian legislation with respect to copper contamination.
Abstract
A specific class of frequency selective surface (FSS) is the complementary frequency selective surface (CFSS) that has interesting characteristics such as high angular stability, multiple ...transmission and/or reflection bands, and the possibility of miniaturization. The analysis and design of this sort of structure are commonly performed using commercial software, which demands a high computational effort, impacting a longer optimization time. The equivalent circuit model combined with a cascading technique emerges as an alternative method to the use of these softwares, in the optimization of the physical dimensions of these structures, as they model the behavior of a CFSS with low computational effort and optimization time, in addition to being able to be implemented in various programming languages. Thus, this work proposes a CFSS analysis technique that combines the equivalent circuit method with the ABCD matrix. To the best of our knowledge, this is the first reported research on approximate techniques for CFSS analysis. The chosen geometry was the circular ring, due to high angular stability and polarization independence. The modeling of the equivalent circuit for patch and aperture geometries is presented. Some structures are simulated, and the results are compared with results obtained with the HFSS software. Finally, two prototypes are built to validate the analyses performed.
Key Points
The CFSS analysis composed of circular rings is performed through the equivalent circuit model combined with the ABCD matrix
The results of the simulated structures are compared with the ones obtained with the commercial software
The simulated prototypes were built and measured to validate the performed analyses
Abstract Manual acupuncture (MA) has presented analgesic activity against neuropathic pain in patients and animal models, yet a series of questions remain: Is MA effectiveness dependent of acupoint ...selection or combination? Is it equally efficient when treatment starts on the initial (acute) or sub-chronic phase of spinal nerve ligation (SNL)-induced neuropathy? Is MA effect related to the release of endogenous opioids? Does MA produce similar effects to gabapentin? To answer these questions rats submitted to the L5/L6 SNL injury were treated with unilateral MA (ST36 (Zusanli), SP6 (Sanyingjiao) or ST36+SP6 acupoint stimulation); or with gabapentin (30 mg/kg i.p., used as positive control). Both acupoints have been demonstrated to present analgesic activity and are used in clinical practice and basic science research. In addition, we investigated the influence of naloxone (1 mg/kg i.p., a nonselective opioid receptor antagonist) on MA treatment and also the effect of unilateral ST36+SP6 MA treatment beginning acutely (5 days) or sub-chronically (14 days) after SNL. Our results demonstrate that single or combined unilateral stimulation was able to reduce mechanical hypersensitivity with treatment beginning in both acute and sub-chronic phases of SNL-induced neuropathy; MA effect was blocked by naloxone, and finally; SP6+ST36 MA presented similar effect to gabapentin (30 mg/kg). In conclusion, our results demonstrate, for the first time, that unilateral MA (ST36, SP6 or ST36+SP6) reduces hypersensitivity induced by the SNL with effect dependent of the opioid system and comparable with the one obtained with gabapentin (used as positive control).
The roles of the anode material, boron-doped diamond (BDD), with different boron (B) and substrate Silicon (Si) or Niobium (Nb) content, and one dimensionally stable anode (DSA®), were evaluated in ...the oxidation of norfloxacin (NOR) by electrochemical advanced oxidation process (EAOP). The effect of other components in real wastewater on the performance of EAOP was also studied. The anode materials were characterized by cyclic voltammetry, regarding diamond quality, electro-generation of oxidants and NOR oxidation mechanism (direct and/or indirect). The results showed that the anode material influences on the NOR oxidation pathway, due to distinct characteristics of the substrate and the coating. Apparently, low difference in diamond-sp³/sp2-carbon ratio (Si/BDD100 × Si/BDD2500) does not leads to significant differences in the EAOP. On the other hand, the variation in the sp³/sp2 ratio seems to be higher when Si/BDD2500 and Nb/BDD2500 are compared, which would explain the best current efficiency result for Si substrate. However, the Nb substrate presented a similar current efficiency and a 60% lower energy consumption. Dissolved organic matter (DOM) present in the real wastewater affect the EAOP-Nb/BDD due to HO and persulfate ions scavenged. However, when supporting electrolyte was added to a real wastewater spiked with NOR, the NOR decay reaches similar values found to the synthetic one. Due to the energy saving and mechanical properties, Nb substrate presents some technological advantages in relation to Si, which can facilitate the application to industrial levels.
•Electrochemical advanced Oxidation process is proposed for Norfloxacin oxidation.•Higher boron concentration favored NOR oxidation by persulfate and direct oxidation.•Persulfate and direct oxidation were more intense for the Nb/BDD than for Si/BDD.•Low difference in diamond-sp3/sp2-carbon ratio do not notably change NOR oxidation.•Nb/BDD showed similar current efficiency but lower energy consumption than Si/BDD.
Bonded tubular joints are currently found in many different engineering applications, ranging from large scale structures to smaller technological subsystems, providing an efficient method for ...joining dissimilar materials while ensuring excellent sealing capabilities. In the present work, a flexible tubular metal-polymer adhesive joint was studied. This joint is used in the construction of a liquid cooling system, and is designed to withstand large torsional deflections. Three different layouts were considered, in order to assess the influence of the manufacturing procedure on joint performance, especially with regards to the optimal surface treatment and the geometrical parameters of the adhesive layer. The substrate materials were characterized to better understand the joint behaviour and a custom bonding fixture was designed to produce this type of joint. Results show that the layout of the joint, considering its geometry and materials, has a major influence on the mechanical performance of the joint and the torsion test results allowed to identify an effective overlap length, supporting numerically obtained results from a complementary work.
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Chalcones form a class of compounds that belong to the flavonoid family and are widely distributed in plants. Their simple structure and the ease of preparation make chalcones ...attractive scaffolds for the synthesis of a large number of derivatives enabling the evaluation of the effects of different functional groups on biological activities. In this Letter, we report the successful synthesis of a series of novel prenylated chalcones via Claisen–Schmidt condensation and the evaluation of their effect on the viability of the Trypanosomatidae parasites Leishmania amazonensis, Leishmania infantum and Trypanosoma cruzi.
This study aimed to estimate the prevalence of the main perceived barriers to leisure‐time physical activity (LTPA) and their associations with the frequency of LTPA in a representative sample of ...industrial workers from Brazil (n = 47 477), according to their income strata (low income: ≤$US280, middle income: $US281–$US1400, and high income: ≥$US1401). Data were collected between 2006 and 2008 via questionnaires about the main perceived barrier to LTPA and the frequency of LTPA. Multinomial logistic regression was performed to evaluate differences among groups. There was a lower prevalence of regular practice of LTPA in the low‐ (15.8%) and middle‐income strata (18.2%) than among the individuals of the high‐income stratum (27.6%). A large proportion of workers who regularly participated in LTPA reported no barriers (low: 43.1%; middle: 46.8%; high: 51.6%). Additional obligations and fatigue were the two most common perceived barriers in all family income strata among participants who engaged in different frequencies of LTPA. The odds for all perceived barriers showed a positive trend related to frequency of LTPA (from regular to no LTPA), with higher values according to income. In summary, the ordering of the main perceived barriers to LTPA differed according to workers' income stratum and frequency of engaging in LTPA.
The contribution of chronological age, skeletal age (Fels method) and body size to variance in peak velocity derived from the Carminatti Test was examined in 3 competitive age groups of Brazilian ...male soccer players: 10-11 years (U-12, n=15), 12-13 years (U-14, n=54) and 14-15 years (U-16, n=23). Body size and soccer-specific aerobic fitness were measured. Body composition was predicted from skinfolds. Analysis of variance and covariance (controlling for chronological age) were used to compare soccer players by age group and by skeletal maturity status within of each age group, respectively. Relative skeletal age (skeletal age minus chronological age), body size, estimated fat-free mass and performance on the Carminatti Test increased significantly with age. Carminatti Test performance did not differ among players of contrasting skeletal maturity status in the 3 age groups. Results of multiple linear regressions indicated fat mass (negative) and chronological age (positive) were significant predictors of peak velocity derived from the Carminatti Test, whereas skeletal age was not a significant predictor. In conclusion, the Carminatti Test appears to be a potentially interesting field protocol to assess intermittent endurance running capacity in youth soccer programs since it is independent of biological maturity status.
Este estudo analisou a intensidade dos jogos Kinect Sports® em universitários através das variáveis hemodinâmicas e da percepçao subjetiva de esforço. Tratou-se de um estudo experimental, com 34 ...jovens estudantes (21.5±1.9anos) que foram submetidos a tres sessÐes consecutivas de jogos, divididas em jogos de boxe, boliche, beisebol e tenis; vôlei de areia, golfe, atletismo e esqui; tenis de mesa, futebol, dardos e futebol americano. A frequencia cardíaca (FC), pressao arterial (PA) e percepçao subjetiva de esforço (PSE) foram registradas a cada dois minutos de cada jogo. One-way ANOVA for repeated measurements was used to verify differences in HR, BP and PSE at each time of the game and the effect size (p<0.05). Houve diferenças significativas na FC (p<0.01, r|2p<0.284) nos jogos de boxe, atletismo e beisebol; na PAS (p<0.01, r|2p<0.203) no atletismo e beisebol, bem como na PSE (p<0.01, q2p<0.309) no boxe, atletismo, esqui, vôlei de areia, tenis, futebol americano e tenis de mesa. Quanto a classificaçao dos jogos por intensidade, através do percentual de proximidade da Frequencia Cardíaca Máxima (FCmáx), apenas o jogo de Boxe se apresentou com intensidade forte (70 a 89% da FCmáx), 50% como intensidade moderada (55 a 69% FCmáx), e 42% dos jogos em intensidade leve (35 a 54% da FCmáx). Conclui-se que uma tabela de classificaçao que identifique a intensidade dos jogos Kinect Sports® em universitários, possibilita selecionar jogos que estejam voltados a condiçao física do sujeito, tornando a prática dessa atividade uma alternativa para que o indivíduo passe de um estado de repouso para ativo gerando impactos benéficos a sua saúde.
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