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Faraday’s law of electromagnetic induction is one of the four Maxwell’s equations, presented here in vector notation. Its discovery paved the way for a second industrial revolution based on machines powered by electricity. Roughly speaking, it states that the negative (a Lenz‘s contribution) of the temporal rate of change of magnetic fields acts as a source for an electric field of rotational nature. In this paper, we discuss readily replicable experiments demonstrating Faraday’s law in action, using the motion of a neodymium magnet under three natural motions: i) free fall under gravity; ii) pendular motion under gravity and iii) the magnet placed at the free end of a vibrating ruler. Due to their simplicity, these systems allow for a complete theoretical treatment. We consider more than one way of calculating the induced voltage in a circular coil, by the magnet in motion. This way, students can benefit from the multidisciplinary aspects, connecting the knowledge of kinematics of motion and the electrodynamics of particles in motion. The experimental data was obtained using an oscilloscope and contrasted to the theoretical predictions. In practice, these experiments can be used to estimate the magnetic dipole moment of a permanent magnet.

The Brazilian variant of human immunodeficiency virus type 1 (HIV-1) subtype B, (serotype B"-GWGR), has a tryptophan replacing the proline in position 328 the HIV-1 envelope. A longer median time period from infection to acquired immunodeficiency syndrome (AIDS) for serotype B (B"-GWGR) infected subjects compared to the B-GPGR US/European strain was reported. In a cohort study, in São Paulo city, 10 B"-GWGR patients had a statistically significant increased avidity of the anti-V3 antibodies, from 79% ± 33% to 85% ± 75%, versus from 48% ± 59% to 32% ± 17% for the 10 B-GPGR subjects (p = 0.02). The T CD4+ cells showed a mean increase of + 0.45 cells/month for the B-GPGR subjects and for B"-GWGR the slope was + 1.24 cells/month (p = 0.06), for 62 and 55 months of follow up, respectively. RNA plasma viral load decreased from 3.98 ± 1.75 to 2.16 ± 1.54 log10 in the B"-GWGR group while B-GPGR patients showed one log10 reduction in viral load from 4.09 ± 0.38 to 3.17 ± 1.47 log10 over time (p = 0.23), with a decreasing slope of 0.0042 ± log10,/month and 0.0080 ± log10/month, for B-GPGR and B"-GWGR patients, respectively (p = 0.53). Neither group presented any AIDS defining events during the study, according to Center for Diseases Control criteria. Although the sample size is small, these results may indicate that differences in the pathogenicity of the 2 HIV-1 B serotypes which co-circulate in Brazil may be correlated to the avidity of anti-V3 antibodies.

IntroductionUnderstanding human-wildlife interactions is critical to overcoming the socio-environmental crises we face worldwide. Among these interactions, poaching and hunting, human-wildlife conflict, and transmission of zoonotic diseases are major causes of biodiversity loss and detrimental to human well-being. Therefore, this study aimed to analyze wildlife poaching, feral pig hunting, human-wildlife conflict, and health issues in a region of the Brazilian Cerrado, in the state of Mato Grosso do Sul. The study also focused on the lowland tapir (Tapirus terrestris), a poached species listed as vulnerable to extinction.MethodsFrom October 2016 to September 2017, we conducted face-to-face semi-structured interviews with 51 local people from nine stakeholder groups. Interview answers and additional information compiled during the study were evaluated using coding, narrative, and co-occurrence analyses.Results and discussionWe found that the main human-wildlife conflict in the region involves feral pigs, and hunting is practiced as a population control strategy. The lowland tapir is not considered a conflictual species, as it is beloved by most people. However, tapirs are still poached, although less so than in the past, mainly for cultural reasons. Culture was the main motivation behind wildlife poaching in general. We identified 28 species and five taxa currently poached in this Cerrado region, of which 11 are used for medical and aphrodisiac purposes. Historically, wildlife poaching was linked to poor livelihood conditions and lack of support from governmental institutions during the Agrarian Reform process, becoming a cultural habit over the years. Nevertheless, wildlife poaching is less frequent than in the past, and its main barriers are surveillance, poaching prohibition by landowners, and social norm. Therefore, promoting a change in the way people relate to nature, meeting socioeconomic needs, and increasing surveillance appear to be important conservation strategies. Although feral pig hunting may replace wildlife poaching, some hunters still poach wild species, especially peccaries. Hence, it is necessary to keep hunters under surveillance, raise awareness among them, and make them allies in conservation strategies. We found a worryingly low level of awareness about disease transmission risk through bushmeat manipulation and consumption, highlighting the importance of One Health approaches.

Despite the acknowledged importance of interdisciplinarity in biodiversity conservation, there is still resistance to incorporate social science research (SSR) to both conservationist thinking and practice. The reasons for such a resistance can be summarized in three general statements still commonly attributed to SSR, namely: it is of 'little use' and it has 'less methodological rigor' than research in the natural sciences and, above all, it is unreliable because 'people lie'. The current essay was developed based on the experience of participants of a community of practice (formed by professionals from different fields and sectors associated with conservation), as well as on discussions held in this space of collective learning. It addresses the limitations and misconceptions behind the aforementioned statements. SSR is not less useful in conservation and not less methodologically rigorous than research conducted in the natural sciences. When researchers are lied to, the problem does not lie on the research itself, but on the subject-researcher relationship. We herein argue that as conservationists become more familiar with SSR, and as principles like equity and justice are incorporated to conservation values and goals, both the importance and need of SSR in conservation become obvious, making the lack of trust between researcher and subjects no longer a significant concern. Increasing capacity, integrating and supporting are our basic recommendations for researchers, educators, managers and decision-makers in the conservation, teaching, publishing and funding fields, so that SSR can fully fulfill its role in conservation.

O presente artigo trata-se da exposição de alguns resultados do projeto de extensão “Entre-Laços: Educação Permanente em saúde”, realizado pela PUC Minas campus Poços de Caldas, no ano de 2020. Objetiva-se com esse relato apresentar as ações desenvolvidas pelo projeto na Atenção Básica em Saúde mediante o contexto da pandemia da COVID-19 durante o primeiro semestre de 2020. O projeto coloca em prática, nas Unidades Básicas de Saúde da cidade, a educação permanente em saúde, com intuito de contribuir com os profissionais da rede pública de saúde bem como com a formação de futuros profissionais. As ações desenvolvidas pelo projeto estão de acordo com as metodologias ativas de aprendizagem, sendo elas bases da Política Nacional de Educação Permanente em Saúde, utilizando-se assim a problematização para o processo de ensino-aprendizagem. Decorrente do cenário atual fez-se necessário estudar outras formas para continuidade das ações desenvolvidas pelo projeto. Mediante a isso, as ações se voltaram para o âmbito virtual, utilizando-se assim das redes sociais para a realização de postagens a partir de demandas advindas das unidades parceiras do projeto. Entre os aspectos a serem ressaltados estão as novas oportunidades que surgiram neste momento, tais como o fortalecimento da equipe Entre-Laços no âmbito interprofissional, bem como novas formas de desenvolver as ações do projeto.

This study focuses on the cytotoxic evaluation of functionalized multi-walled carbon nanotubes (MWCNT) and microbial biofilm formation on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanocomposites incorporating MWCNTs functionalized with gamma-aminobutyric acid (GABA) and carboxyl groups. The materials were characterized for cytotoxicity to fibroblasts and antimicrobial effects against Escherichia coli, Staphylococcus aureus and Candida albicans. The functionalization of MWCNTs was performed through oxidation (CNT-Ox) and GABA attachment (CNT-GB). The PHBV/CNT nanocomposites were produced via melt mixing. All MWCNT suspensions showed non-toxic behaviors after 24 h of incubation (viability higher than 70%); however, prolonged incubation and higher concentrations led to increased cytotoxicity. The antibacterial potential of PHBV/CNT nanocomposites against S. aureus showed a reduction in biofilm formation of 64% for PHBV/CNT-GB and 20% for PHBV/CNT-Ox, compared to neat PHBV. Against C. albicans, no reduction was observed. The results indicate promising applications for PHBV/CNT nanocomposites in managing bacterial infections, with GABA-functionalized CNTs showing enhanced performance.

Abstract Prolonged exposure to environmental conditions such as ultraviolet radiation, humidity, and temperature, to which carbon fiber-reinforced thermoplastic polymer components are exposed during their service life, can lead to significant changes in mechanical, physical, and chemicals properties, and can often be irreversible, resulting in premature component failure. This study presents the influence of accelerated weathering exposure times (400 h, 800 h, and 1200 h) on the mechanical, thermal, and structural properties of carbon fiber (CF)/polyamide 6 (PA6) laminates. Analyses of composite surfaces were carried out using microscopy and contact angle measurements, which indicated that the factors of exposure to accelerated only affected the surface of the composites, showing signs of the beginning of degradation. The tensile strength (609 MPa ± 10 MPa) and interlaminar shear strength (27 MPa ± 0.9 MPa) did not present significant changes, showing that the reinforcement, the matrix, and the interface remained stable after exposure to accelerated.

The present study carried out the characterization of carbon nanotubes (CNT) recovered from the biodegradation process of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/CNT nanocomposites and the use of this recovered CNT (CNT-rec) in the production of new PHBV nanocomposites. The results obtained by characterization of CNT-rec were very similar to the CNT. Therefore, it was possible to state that CNT properties were preserved during the biodegradation process; however, CNT-rec contained impurities such as proteins and residual PHBV. Regarding the performance as nanofillers, although both CNT and CNT-rec decreased the thermal stability of nanocomposites compared to neat PHBV, this effect was less intense in the CNT-rec nanocomposites. It is expected that both nanofillers acted as nucleating agents in the PHBV matrix crystallization process but with different effectiveness. There was no significant difference between the electrical conductivity comparing PHBV/CNT 2% and PHBV/CNT-rec 2% nanocomposites. Therefore, the recovery and use of CNT-rec is a feasible process.

The crab-eating fox Cerdocyon thous has a diverse diet ranging from plants to vertebrates, but its diet has never been comprehensively reviewed. Here, we provide the first such review and report the first-ever record of C. thous feeding on the Brazilian lancehead Bothrops moojeni, although other Bothrops species have been documented in the diet of this fox species.

Porous polymeric scaffolds provide a physical substrate for cells to attach and proliferate, allowing the formation of new tissue. These materials are broadly used in the tissue engineering field due to their ability to mimic native tissue. Each application requires specific morphologies and resistance, among other several features. To accomplish these requirements, various techniques are available, each one with its advantages and disadvantages. Among the most relevant techniques are salt leaching, solvent casting, gas foaming, thermally induced phase separation, freeze-drying, electrospinning, thermally induced self-agglomeration, and three-dimensional (3D) printing. In this review, a brief and simple explanation of each method is described, along with some recent results and each technique’s advantages and disadvantages. It is expected that this review will bring important guidance in the production of polymer scaffolds for tissue engineering.

Abstract The demands for dental materials continue to grow, driven by the desire to reach a better performance than currently achieved by the available materials. In the dental restorative ceramic field, the structures evolved from the metal-ceramic systems to highly translucent multilayered zirconia, aiming not only for tailored mechanical properties but also for the aesthetics to mimic natural teeth. Ceramics are widely used in prosthetic dentistry due to their attractive clinical properties, including high strength, biocompatibility, chemical stability, and a good combination of optical properties. Metal-ceramics type has always been the golden standard of dental reconstruction. However, this system lacks aesthetic aspects. For this reason, efforts are made to develop materials that met both the mechanical features necessary for the safe performance of the restoration as well as the aesthetic aspects, aiming for a beautiful smile. In this field, glass and high-strength core ceramics have been highly investigated for applications in dental restoration due to their excellent combination of mechanical properties and translucency. However, since these are recent materials when compared with the metal-ceramic system, many studies are still required to guarantee the quality and longevity of these systems. Therefore, a background on available dental materials properties is a starting point to provoke a discussion on the development of potential alternatives to rehabilitate lost hard and soft tissue structures with ceramic-based tooth and implant-supported reconstructions. This review aims to bring the most recent materials research of the two major categories of ceramic restorations: ceramic-metal system and all-ceramic restorations. The practical aspects are herein presented regarding the evolution and development of materials, technologies applications, strength, color, and aesthetics. A trend was observed to use high-strength core ceramics type due to their ability to be manufactured by CAD/CAM technology. In addition, the impacts of COVID-19 on the market of dental restorative ceramics are presented.

Abstract In this work, the surfaces of silver nanowires (AgNWs) were modified by silanization process to improve the mechanical and antibiofilm properties of polymethylmethacrylate (PMMA) dental resins. A two‐route methodology was used to silanize the AgNWs: first, a surface treatment using tetraethyl orthosilicate (TEOS) was performed to act as interface agent; and then, γ‐methacryloxypropyltrimethoxysilane (MPS) was used to insert functional groups compatible to the acrylic resin. PMMA/AgNWs composites were obtained using pristine (AgNWP) and modified AgNWs (AgNWM) at concentrations of 0.5 and 1.0 wt%. The mechanical (flexural and impact strength) and antibiofilm properties against Candida albicans was investigated. AgNWM showed an enhancement in the dispersion and adhesion within the PMMA matrix, which were responsible for improvements in the mechanical properties. Results of flexural strength showed significant improvements for the sample with incorporation of 0.5 wt% of AgNWM and no significative changes for the sample with AgNWP. In addition, a reduction of about 50% in the biofilm formation by C. albicans was observed for the samples with 0.5 and 1.0 wt% of AgNWM. The incorporation of silanized‐AgNWs into PMMA dental resins can combine improvements in antimicrobial activity and in the flexural strength, being a potential antimicrobial biomaterial for dental applications.

BackgroundIn medicine, the transversus abdominis plane (TAP) block has been shown as an effective method of analgesia in several surgical procedures. In this context, this prospective, randomized, blinded study aimed to evaluate the analgesic efficacy of TAP block, guided by ultrasound in female dogs submitted to ovariectomy.MethodsTherefore, 32 animals randomly assigned in two groups (n = 16) were used. Groups consisted of TAP block control (TBC) which received water injection (0.2 ml kg−1 point), and TAP block bupivacaine (TBB) which received bupivacaine (0.2 ml kg−1 point at 0.25%); both groups were submitted to four-point approach. Animals were pre-medicated with acepromazine (0.03 mg kg−1) and meperidine (2 mg kg−1) IM, propofol was used as anesthetic induction (3–5 mg kg−1) IV, and isoflurane was used to maintain. To standardize groups, the animals received a continuous infusion of remifentanil (0.2μg kg−1 min) and rocuronium (0.6 mg kg−1) IV in the intraoperative period. Variables measured were the heart and respiratory rates, blood pressure, temperature, peripheral oxyhemoglobin saturation, exhaled carbon dioxide concentration, exhaled isoflurane concentration, serum cortisol, analgesia, and sedation. Before the pre-anesthetic medication (Baseline) and 1, 2, 4, 6, and 8 h after extubation, pain and sedation were assessed using a numeric rating scale (NRS), Glasgow composite measure pain scale (GCMPS-SF), and sedation scale. Moreover, serum cortisol was measured at different moments.ResultsThe results show that in the intraoperative period, there was no significant difference between groups. After surgery, in TBC, 13 out of 16 animals required analgesic rescue, whereas, in TBB, this occurred only in one animal. Regarding the measurement of serum cortisol, the TBC group showed a significant difference when compared to the baseline time in the traction of the first ovary (p < 0.0001), 2 h (p = 0.0441), and 8 h (p = 0.0384) after extubation. In TBB, cortisol showed a significant increase only in the traction of the first ovary and 2 h after extubation (p < 0.0001).ConclusionThe technique using ultrasound-guided TAP block in two points approach by hemiabdomen with 0.2 ml kg−1 bupivacaine 0.25% was effective in providing post-operative analgesia in dogs undergoing ovariectomy.

Abstract Polymer compatibilizer agents are crucial for industrial materials development. Compatibilizer agents may be prepared by melt-grafting in the reactive extrusion process which is cheaper and environmentally friendly. Maleic anhydride-grafted acrylonitrile-butadiene-styrene (ABS-g-MA) has emerged as a relevant compatibilizer agent for immiscible blends, like polycarbonate (PC)/ABS. In this work, ABS-g-MA was prepared by a simple reactive extrusion process using ABS, maleic anhydride (MA) and benzoyl peroxide (BPO). The MA:BPO ratios of 1:0.5 and 1:1 varying the content of MA by 1, 2 and 5 wt% were investigated. The grafting reaction was confirmed through Fourier transform infrared spectroscopy (FT-IR), grafted degree (GD%), thermal and rheological analysis. The effectiveness of the compatibilizer agent was evaluated in PC/ABS blends (70/30 and 85/15 blend ratios). The addition of 5 wt% of ABS-g-MA (5 MA:2.5 BPO) in the PC/ABS blends promoted an expressive reduction of ABS domain sizes and better dispersion in the PC matrix.

Abstract Nanoparticles demonstrate an important role in the protection of bioactive compounds from external factors such as temperature, oxygen and light. In this study, poly-ε-caprolactone (PCL) nanoparticles entrapped β-carotene was produced using the nanoprecipitation method. Firstly, was evaluated the lipophilic surfactant effect and carrier agent of the active compound in the nanocapsules formulation. After choosing the most stable formulation, the nanocapsules production was optimized using β-carotene, caprylic/capric triglycerides (CCT) and soybean lecithin. Response surface methodology (RSM) was adopted to evaluate the influence of soy lecithin concentration, volume of CCT and β-carotene concentration in the particle size, zeta potential, polydispersity index (PDI), encapsulation efficiency and recovery. Formulations containing soy lecithin and CCT demonstrated better stability comparing to the other formulations tested. The nanoparticle formulations presented an optimized particle size below 200 nm, PDI lower than 0.1 and encapsulation efficiency above 95%. Based on the results obtained, the optimum conditions to prepare PCL nanocapsules were 0.2160 mg/mL of β-carotene, 232.42 μL of CCT and 2.59 mg/mL of soy lecithin, suggesting an applicability to promote controlled released of β-carotene in food system.

Abstract: The objective of this work was to standardize and validate an indirect competitive enzyme-linked immunosorbent assay (ic-Elisa), as a low-cost tool, to monitor the presence of aflatoxin in common and blanched peanuts (Arachis hypogaea) in the production chain. The presence of aflatoxin B1, moisture content, and water activity were analyzed in 60 samples of the peanut cultivar Runner IAC 886, from the 2014/2015 and 2015/2016 harvests of the region of Alta Paulista, in the state of São Paulo, Brazil. The validation showed an adequate linearity (R2 = 0.999), and limits of detection and quantification of 1.13 and 3.59 μg kg-1, respectively. Recovery rates of 104, 102, and 107% at the concentrations of 4, 10, and 20 μg kg-1 aflatoxin B1, respectively, were also recorded. The ic-Elisa showed a good reproducibility with a high-intraday precision, with 1.87% coefficient of variation (CV), and interday precision with 6.75% CV. The moisture content ranged from 4.0 to 7.2% (mean of 5.8%), and the water activity from 0.4848 to 0.6997 (mean of 0.5990) for the tested samples. Aflatoxin B1 was present in concentrations ranging from 1.13 to 29.2 μg kg-1, with only two samples (3.3%) exceeding the maximum allowed limit of 20 μg kg-1. The ic-ELISA developed here is an accessible tool for the rapid monitoring of aflatoxin contamination in the peanut production chain.

In this study, chitosan hydrogels were produced with 0, 2, 4 and 6 wt% of cellulose nanocrystals (CNC) using hexahydrate zinc nitrate (Zn(NO3)2.6H2O) as a catalyst for chitosan crosslinking reaction. CNC´s size was estimated by dynamic light scattering (DLS) and surface charge by zeta potential. Hydrogels were characterized by rotational rheometer, swelling test, uniaxial compression test, in vitro degradation, scanning electron microscopy (SEM) and microtomography. Results showed that zinc nitrate and CNC addition did not influence mechanical properties, degradation, and morphology of the hydrogels. However, zinc nitrate decreased 36.54% of the gel time and 41.37% of the swelling degree, and increased the crosslinking degree of the chitosan hydrogels, proving not only its catalytic effect but also its participation in the crosslinking reaction. Porosity was slightly reduced after addition of zinc nitrate and incorporation of CNC. In the mechanism of crosslinking reaction, a competition between CNC and zinc nitrate was observed.

Direct road mortality and the barrier effect of roads are typically identified as one of the greatest threats to wildlife. In addition, collisions with large mammals are also a threat to human safety and represent an economic cost to society. We documented and explored the effects of animal-vehicle crashes on human safety in São Paulo State, Brazil. We estimated the costs of these crashes to society, and we summarized the legal perspectives. On average, the Military Highway Police of São Paulo reported 2,611 animal-vehicle crashes per year (3.3% of total crashes), and 18.5% of these resulted in human injuries or fatalities. The total annual cost to society was estimated at R$ 56,550,642 (US $ 25,144,794). The average cost for an animal-vehicle crash, regardless of whether human injuries and fatalities occurred, was R$ 21,656 (US $ 9,629). The Brazilian legal system overwhelmingly (91.7% of the cases) holds the road administrator liable for animal-vehicle collisions, both with wild and domestic species. On average, road administrators spent R$ 2,463,380 (US $ 1,005,051) per year compensating victims. The logical conclusion is that the Brazilian legal system expects road administrators to keep animals, both wild and domestic species, off the road. We suggest an improved coordination between the laws that relate to animal-vehicle collisions and human safety, and the process for environmental licenses that focusses on reducing collisions with wildlife and providing habitat connectivity. In addition, we suggest better management practices, raising awareness and social change with regard to abandoned domesticated animals including horses, cattle, and dogs. This should ultimately result in a road system with improved human safety, reduced unnatural mortality for both domestic and wild animal species, safe crossing opportunities for wildlife, and reduced monetary costs to society.

A brief review reporting the recent advances on the carbon nanostructured materials-based sensors covering recently published works is presented. Several works dealing with experimental and theoretical data are reviewed and discussed. The main results for carbon nanotubes, nanodiamonds, fullerene, graphene, and hybrid carbon-nanostructured devices that show sensing properties in different fields were considered for the discussions. The goal of this paper was to highlight sensor mechanisms, and the best results reached up to now are creating bases for further applications.

A compatibilizer agent was successfully produced by grafting maleic anhydride (MA) to poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) chains on a reactive processing by mechanical mixing, using a mixture of PHBV, MA and dicumyl peroxide (DCP) as initiator. The resulting PHBV grafted MA (PHBV-g-MA) was characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and gel permeation chromatography (GPC), and its properties were compared to neat PHBV. FTIR showed an absorption band at 699 cm-1 for PHBV-g-MA, related to CH group of grafted anhydride ring. The initial thermal degradation temperature of the compatibilizer agent was reduced when compared to neat PHBV. DSC analysis showed that after grafting MA onto PHBV the crystallization temperature was about 20ºC higher than neat PHBV, and the degree of crystallinity was increased. GPC analysis showed that MA when grafted onto PHBV led to a reduction of molecular weight and polydispersity.

Carbon nanotubes (CNT)-reinforced polymeric composites are being studied as promising materials due to their enhanced properties. However, understanding the behavior of polymers during non-isothermal crystallization is important once the degree of crystallinity and crystallization processes are affected when nanoparticles are added to matrices. Usually, crystallization kinetics studies are performed using a model-fitting method, though the isoconversional method allows to obtain the kinetics parameter without assuming a crystallization model. Therefore, in this work, CNTs were oxidized (CNT-Ox) and functionalized with gamma-aminobutyric acid (GABA) (CNT-GB) and incorporated into a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) matrix. The influence of the addition and functionalization of CNT in the crystallization kinetics of PHBV was evaluated using the isoconversional method with differential scanning calorimetry (DSC), and by polarized light optical microscopy (PLOM) and Shore D hardness. The incorporation and functionalization of CNT into PHBV matrix did not change the Šesták and Berggren crystallization model; however, the lowest activation energy was obtained for the composite produced with CNT-GB, suggesting a better dispersion into the PHBV matrix. PLOM and Shore D hardness confirmed the results obtained in the kinetics study, showing the smallest crystallite size for CNT-containing nanocomposites and the highest hardness value for the composite produced with CNT-GB.

Embora represente um importante reservatório de água subterrânea com significativa abrangência regional, as características e parâmetros hidráulicos dos aquíferos da Formação Serra Geral não são bem compreendidos. O presente trabalho demonstra a importância da aplicação de testes de bombeamento como subsídio ao aprimoramento de modelos hidrogeológicos conceituais, bem como de se monitorar dois poços simultaneamente durante o teste de bombeamento, priorizando a análise derivativa para eliminação de ambiguidades durante a interpretação dos mesmos. Os resultados obtidos indicam que analisar apenas o rebaixamento do poço bombeado pode induzir a interpretações equivocadas. As sucessivas tentativas de se ajustar as diversas soluções aos resultados do teste de bombeamento, mostram que o Aquífero Serra Geral neste ponto de Campina Verde/MG é do tipo confinado drenante, concordante com um modelo geológico de sucessão de derrames de lavas.

The influence of different contents, 0.25, 0.50, and 1.00 wt%, of graphite nanosheets (GNS) on the properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanocomposites obtained by solution casting method has been studied. GNS were prepared by three steps: intercalation (chemical exfoliation), expansion (thermal treatment), and the GNS obtainment (physical treatment by ultrasonic exfoliation). X-ray diffraction (XRD), Raman spectroscopy, and field emission gun-scanning electron microscopy (FE-SEM) showed that the physical, chemical, and thermal treatments preserved the graphite sheets structure. XRD and Raman results also showed that GNS were dispersed in the PHBV matrix. The degree of crystallinity (Xc) of the nanocomposites did not change when the graphite nanosheets were added. However, the GNS acted as nucleation agent for crystallization; that is, in the second heating the samples containing GNS showed two melting peaks. The addition the GNS did not change the thermal stability of the PHBV.

Los métodos geofísicos constituyen una herramienta ampliamente utilizada en exploración mineral. Este trabajo presenta y discute los resultados de estudios geológicos y geofísicos desarrollados en un yacimiento de manganeso de origen supergénico, localizado en la región sudeste de Brasil. La zona mineralizada descrita en levantamientos geológicos fue caracterizada por bajos valores de resistividad (20Ω.m) y altos valores de cargabilidad (30ms), en un patrón similar al descrito en diversos trabajos en depósitos minerales de óxidos y sulfuros en rocas. Modelos geofísicos pseudo-3D permita la generación de mapas para diversas profundidades. Las áreas de alta cargabilidad y baja resistividad definen un patrón de mineralización gonditica con altos niveles de Mn. Áreas considerables con elevados valores de cargabilidad y baja resistividad probablemente resulten de la acumulación de hidróxido de manganeso y hierro, originados del intemperismo en cuerpos de mineral gonditico, disolución, percolación y precipitación. doi: https://doi.org/10.1016/S0016-7169(14)71500-4

Despite the aging of the population in general and in particular in Brazil, there is not yet research on the thermal perception of Brazilian elderly. The available information is based on studies conducted in climates very different from those in Brazil. This study's purpose was to evaluate if there are significant differences in the thermal perception of the elderly in comparison with younger subjects. In an air-conditioned room, there were measured their thermal variables and applied a questionnaire to a sample of elderly. The answers to the questions about the reported thermal perception (TP), thermal comfort and preference, personal acceptability and tolerance, were related to the respective operational temperatures and with those calculated by the PMV (reference for non-elderly population). The mean operative temperature for neutrality (TP = 0) was lower than those calculated by the PMV, i.e., smaller than preferred by non-elderly; furthermore, the range of operative temperature for thermal comfort for elderly is also wider than for non-elderly. These results diverge, in principle, from those found in the international literature, by finding lower comfort temperatures for the elderly than for the non-elderly, but they may be supported by more recent studies involving circadian thermometry. Other answers to the questions show that PMV is not a good predictor of thermal comfort conditions for the elderly. As this is the first work on the subject in Brazil, it opens a discussion and invites researchers to carry out similar studies to verify its validity.

In this work, chitosan hydrogels crosslinked with genipin and reinforced with cellulose nanocrystals (CNC) were developed and characterized with the aim of future biomedical applications. CNC was produced by acid hydrolysis and characterized by atomic force microscopy (AFM). Chitosan/CNC nanocomposite hydrogels were produced with different CNC concentrations (w/w): 0%, 2%, 4%, and 6%. The genipin was used as a crosslinking agent in a genipin/chitosan molar proportion of 1:8. The hydrogels were characterized by porosity measurements, scanning electron microscopy (SEM), swelling test, and mechanical compression test. No significant differences were observed concerning the porosity of the hydrogels; however, a trend of decreasing porosity was observed with increasing CNC content. The SEM images showed a better pore structure as the CNC concentration increased. A decrease in the swelling degree with increasing CNC content in the chitosan/CNC nanocomposite hydrogel was verified in the swelling tests. An increase in the CNC concentration in the chitosan/CNC nanocomposite hydrogel caused a gradual increase in the maximum stress and maximum strain as observed in the compression tests, showing a significant difference between chitosan/CNC 6 wt % and neat chitosan hydrogel.

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a widely studied polymer and it has been found that porous PHBV materials are suitable for substrates for cell cultures. A crucial factor for scaffolds designed for tissue engineering is the water uptake. This property influences the transport of water and nutrients into the scaffold, which promotes cell growth. PHBV has significant hydrophobicity, which can harm the production of cells. Thus, the addition of α-wollastonite (WOL) can modify the PHBV scaffold’s water uptake. To our knowledge, a kinetics study of water uptake of α-wollastonite phase powder and the PHBV matrix has not been reported. In this work, PHBV and WOL, (PHBV/WOL) films were produced with 0, 5, 10, and 20 wt % of WOL. Films were characterized, and the best concentrations were chosen to produce PHBV/WOL scaffolds. The addition of WOL in concentrations up to 10 wt % increased the cell viability of the films. MTT analysis showed that PHBV/5%WOL and PHBV/10%WOL obtained cell viability of 80% and 98%, respectively. Therefore, scaffolds with 0, 5 and 10 wt % of WOL were fabricated by thermally induced phase separation (TIPS). Scaffolds were characterized with respect to morphology and water uptake in assay for 65 days. The scaffold with 10 wt % of WOL absorbed 44.1% more water than neat PHBV scaffold, and also presented a different kinetic mechanism when compared to other samples. Accordingly, PHBV/WOL scaffolds were shown to be potential candidates for biological applications.

Maleic anhydride (MA) grafted with poly(trimethylene terephthalate) (PTT)—abbreviated as PTT-g-MA—can be used as a compatibilizing agent to improve the compatibility and dispersion of nanofillers and a dispersed polymer phase into PTT matrix. This work suggests the preparation of PTT-g-MA using a mixture of PTT, MA, and benzoyl peroxide (BPO) by a reactive extrusion process. PTT-g-MA was characterized to confirm the grafting reaction of maleic anhydride on PTT chains by Fourier transform infrared (FTIR) spectroscopy. Thermal properties (differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)) and rheological analysis (parallel plates rheology) were used to prove the changes that occurred after the graphitization reaction. The reactive processing route allowed the production of the compatibilizing agent (PTT-g-MA) with good thermal properties and with lower viscosity compared to neat PTT, and this could be an alternative for the compatibilization of polymer blends, as example for PTT/ABS (acrylonitrile butadiene styrene) blends and nanocomposites based on PTT matrix.

The introduction of multi-walled carbon nanotubes (MWCNTs) into polymer matrixes has been an important tool to alter and improve some properties in polymer nanocomposites, including biodegradable polymers such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). In this work, PHBV nanocomposites with 0.05, 0.50, 1.00, 1.50 and 2.00 wt % of MWCNTs were produced by solvent casting. MWCNT morphology and structure were characterized by Raman spectroscopy, and transmission electron microscopy (TEM). It was observed that MWCNTs have a considerable amount of amorphous carbon (AC) onto their surface and a wide distribution of the tube diameter. MWCNTs act as the nucleating agent in the PHBV matrix, as verified by differential scanning calorimetry (DSC). Thermogravimetric analysis (TGA) showed that thermal stability was not significantly affected. The nanofiller dispersion into the PHBV matrix was not effective for concentrations from 1 wt % according to the micrographs obtained in scanning electron microscopy (SEM). The contact angle was changed with the introduction of MWCNTs, turning the nanocomposites hydrophobic and improving the mechanical tensile properties of the PHBV matrix.

O objetivo do trabalho foi avaliar os parâmetros da extração de β-glucanas de cevada e caracterizar parcialmente o amido residual da extração. Foi desenvolvida metodologia para extração de β-glucanas de cevada sem degradação do amido, avaliando as variáveis pH e temperatura de extração. O percentual de β-glucanas extraída variou de 44,21 a 53,38%, sendo influenciado pela temperatura, e o de amido extraído variou de 65,98% a 77,54%, sendo influenciado pelo pH. O amido residual da extração de β-glucanas de cevada apresentou poder de inchamento e solubilidade de 8,54±0,29% e 6,04±0,073%, respectivamente. O amilograma de ARV desse amido apresentou viscosidade máxima de 164,67±1,30 RVU e quebra de viscosidade de 45,79±2,06 RVU. O espectro de infravermelho do amido residual é típico de amido de cevada nativo e semelhante ao de amidos isolados de milho, trigo e mandioca. De acordo com as micrografias eletrônicas de varredura da fração amido, foi possível visualizar uma mistura de grânulos grandes e lenticulares, com um diâmetro médio de 19,15µm e de granulos pequenos com forma esférica, de 4,78µm. As características demonstradas pelo amido residual da extração de β-glucanas de cevada sugerem sua viabilidade para utilização na indústria de alimentos.The objective of the study was to evaluate the parameters of the extraction of barley´s β-glucans and partially characterize the residual starch after extraction. A method was developed for the extraction of barley β-glucans without damaging the residual starch, assessing the variables pH and extraction temperature. The percentage of β-glucans in the extracted fraction varied from 44,21 to 53,38% , being influenced by temperature and the extracted starch varied from 65,98% a 77,54%, being influenced by pH. The residual starch from barley's β-glucan extraction had a swelling power and solubility of 8.54±0.29% and 6.04±0.07%, respectively. The RVA´s amylograph for this starch showed a maximum viscosity of 164.67±1.30 RVU and breakdown viscosity of 45.79±2.06 RVU. The infrared spectrum of the residual starch was typical of native barley starch and similar to isolated starch from corn, wheat and cassava. According to the scanning electron micrographs fraction of starch, it was possible to see a mixture of large lenticular granules with an average diameter of 19.15µm and small spherically shaped ones, with 4.78µm. The characteristics showed by the residual starch from barley´s β-glucan extraction, suggest a possible application in the food industry.

Some occurrences of massive volcanic glass have been recorded in the western region of São Paulo State duringgeological mapping and prospecting and technological characterization of pozzolanic materials. The massive volcanic glassis associated with trachydacites from the Serra Geral Formation. The geometry of these layers has not been determined yetbecause they are covered by sediments. These rocks were identified as natural pozzolans because their active component,volcanic glass, reacted with lime forming a calcium silicate. The technological properties of the cement produced using suchpozzolans were improved. Furthermore, the use of pozzolans reduces carbon dioxide emission and limestone extractionsince pozzolans replace part of the portland clinker in the final product. This paper presents results of some studies onmassive volcanic glass as an active component of pozzolans. In addition to that, this paper discusses the importance of thisfinding for construction industry and the great potential of pozzolanic materials, due to the considerable size of Serra GeralFormation in Brazil.

Large volumes of waste materials are produced by crushing of basaltic rocks for aggregate production, which is widely used in regions that lack rocks of granitic or gneissic composition. Two types of waste materials are produced (a) quarry fines, which are in part used as fine aggregates in concrete and (b) vesicular basalt, a porous variety of basalt that is useless as aggregate. This paper presents a procedure to use basaltic mine-tailings as raw-mixtures for Portland cement by adjusting the proportion of the other raw-materials (limestone, clay, iron ore). It is demonstrated that there is no need for additional fluxes to the basalt-bearing raw-mixtures, since the setting of the chemical parameters is enough to guarantee clinker formation. Two series of experimental clinkers were synthesized with raw-mixtures containing residues from a basalt quarry that produces aggregates for concrete. Experimental clinkers were produced from raw-mixtures with similar lime saturation factors, silica and alumina modules, which were set by adjusting the proportions of limestone, clay and iron ore to the varying proportions of basaltic materials added to them. One series of clinkers was made with basalt quarry fines, which are in part used as fine aggregate, but also accumulate as mine-tailings. Other series was made using vesicular (porous) basalt, a variety not resistant enough to be used as aggregate. It is demonstrated that the basaltic composition is fully compatible with clinker production, and no addition of fluxes or other additions is required. Composition of the raw-mixtures was checked by chemical analysis. Quantitative phase analysis of the clinkers was made by optical microscopy point counting, together with qualitative X-ray diffraction. All mixtures produced clinkers with acceptable proportions of major and minor crystalline phases, inside the range of common industrial Portland clinkers.Duas séries de clínqueres experimentais foram sintetizadas com matérias-primas contendo rejeitos da mineração de basalto para a produção de agregados para concreto. Os clínqueres experimentais foram produzidos a partir de uma farinha crua padrão com adições de teores variáveis de materiais basálticos, sendo que o fator de saturação em cal e os módulos de sílica e alumina da farinha crua foram mantidos constantes pelo ajuste das proporções de calcário, argila e minério de ferro em relação ao teor de material basáltico adicionado. Uma das séries de clínqueres foi produzida com finos de pedreira, usados em parte como agregados finos, mas também acumulados como pilhas de rejeitos no pátio da mina. A outra série foi feita com basalto vesicular, uma variedade de basalto poroso e de baixa resistência, não aproveitada como agregado. O estudo revela que a composição dos materiais basálticos é plenamente compatível com a produção de clínquer, não sendo necessária a adição de fundentes ou outros corretivos químicos. A composição dos clínqueres experimentais produzidos foi determinada por análises químicas, por análise quantitativa de fases em microscopia óptica (contagem de pontos) e por difratometria de raios X. Os clínqueres experimentais produzidos a partir de farinhas contendo materiais basálticos são similares aos clínqueres industriais convencionais, em termos de composição química e de proporção entre fases cristalinas.

This paper aims to present some of the Livros de Compromisso and other books generated by lay catholic brotherhoods in the 18th Century in the cities of Ouro Preto and Mariana, Minas Gerais State, Brazil, nowada ys belonging to the Arquivo Eclesiástico da Paróquia de N.S. do Pilar de Ouro Preto, the Museu da Inconfidência, the Arquivo Casa dos Contos and the Arquivo Eclesiástico da Arquidiocese de Mariana. The Compromisso is a written commitment that allows the brotherhood to exist. These brotherhoods, known in Portuguese as irmandades, were officially recognized institutions by the religious and royal instances by means of these books. Their activities were registered in a variety of different books with specific purpose that provide us with an important heritage of manuscript documentation still little studied in the philologic domain. A brief historical view on the institution brotherhood is presented and extracts from different Compromissos are analysed in order to emphasize the singularity of this document. A proposal to understand the role and the structure of this book is produced. Some recurrent aspects on the Compromissos are singled out, examined and exemplified: the spelling variation, the ownership and the occasions when these books ought to be read, the existence of different kinds of written reproduction of the same book, the ordinary thematic prescriptions and the provisions made by ecclesiastical and/or royal power.This paper aims to present some of the Livros de Compromisso and other books generated by lay catholic brotherhoods in the 18th Century in the cities of Ouro Preto and Mariana, State of Minas Gerais, Brazil, nowadays belonging to the Arquivo Eclesiástico da Paróquia de N.S. do Pilar de Ouro Preto, the Museu da Inconfidência, the Arquivo Casa dos Contos and the Arquivo Eclesiástico da Arquidiocese de Mariana. The Compromisso is a written commitement that allows the brotherhood to exist. These brotherhoods, known in Portuguese as irmandades, were officially recognized institutions by the religious and royal instances by means of these books. Their activities were registered in a variety of different books with specific purpose that bequeathed us with an important heritage of manuscript documentation still little studied in the philologic domain. A brief historical view on the institution brotherhood is presented and extracts from different Compromissos are analysed in order to emphasize the singularity of this document. A proposal to understand the role and the structure of this book is produced. Some recurrent aspects on the Compromissos are singled out, examined and exemplified: the spelling variation, the ownership and the occasions when these books ought to be read, the existence of different kinds of written reproduction of the same book, the ordinary thematical prescriptions and the provisions made by ecclesiastical and/or royal power.

The capacity of natural zeolites and its host rock (dacite) to remove Pb2+ and Cr3+ from aqueous solutions has been investigated. Results showed that both samples prefer to remove Pb2+ instead of Cr3+. Almost 100% of Pb2+ was removed from solutions with concentration until 50 mg L-1 and 100 mg L-1 of this metal, respectively by dacite and zeolite. The equilibrium of metals adsorption process was reached during the first 30 min by both materials. Na+ can be used to recover Pb2+, but not to remove Cr3+ from the treated samples. The Sips model showed a good fit for experimental data of this study.