RESUMO

Soil contamination with chlordecone, an organochlorine pesticide, is causing serious health problems, affecting crop production and local livestock valorization in the French West Indies. In-situ chemical reduction (ISCR) processes for soil remediation have shown promise but need improvement in terms of time, cost and effective treatment, particularly for andosol soil types. Our study shows that a 10-min microwave treatment significantly reduces chlordecone concentrations (50-90%) in contaminated andosol and nitisol soils. Dry andosol soils show the highest removal yields and reach a higher final temperature (350 °C). Microwave treatment is in all cases more effective or at least as effective as 60 min of conventional heating at a target temperature of 200 °C. The thermal response of andosol and nitisol to microwave exposure is different, as the former is likely to undergo thermal runaway, reaching high temperatures in a short time, resulting in highly efficient thermal removal of chlordecone. These results encourage further scale-up, particularly for the treatment of andosol soils due to their strong microwave response.

Assuntos

RESUMO

The pacaya palm (Chamaedorea tepejilote Liebm) is an important food that is commonly consumed in Mexico and Central America due to its nutritive value. It is also used as a nutraceutical food against some chronic diseases, such as hypertension and hyperglycemia. However, few reports have indicated its possible potential. For this reason, the goal of this research was to evaluate the effects of the enzymatic activity of the pacaya palm inflorescence rachis on both hypertension and hyperglycemia and the effects of thermal treatments on the enzymatic activity. The enzymatic inhibition of ACE (angiotensin-converting enzyme), DPP-IV (dipeptidyl peptidase-IV), α-glucosidase and α-amylase were evaluated, all with powder extracts of pacaya palm inflorescences rachis. The results indicated that thermally treated rachis showed increased enzymatic inhibitory activity against α-amylase and DPP-IV. However, all rachis, both with and without thermal treatment, showed low- or no enzymatic activity against α-glucosidase and ACE. Apparently, the mechanism of action of the antidiabetic effect of rachis is mediated by the inhibition of α-amylase and DPP-IV and does not contribute with a significant effect on enzymes involved in the hypertension mechanism. Finally, the properties of the extract were modified via the extraction method and the temperature tested.

RESUMO

ABSTRACT: This study evaluated the impacts of thermal processing on the chemical composition of jackfruit seeds and their toxicity. The ash content of the seeds subjected to roasting was higher (3.21%) compared to the seeds in the other treatments. However, the contents of moisture (5.29%) and protein (10.49%) were lower. The protein content showed a significant difference (P≤ 0.05) among the studied groups (10.49%). The lipid content was lower in the seeds subjected to cooking (1.13%), while the carbohydrate content showed a significant difference (P≤ 0.05) among the groups studied (54.11%). Raw seeds had the highest fiber content (25.20%). Regarding toxicity, only the cooked jackfruit seed flour showed cytotoxic potential. However, none of the samples caused irritation or vascular disorders in fertilized eggs. These results suggested that heat treatment can ensure the safety of seeds against cytotoxicity; although, it reduces the content of some macronutrients.

RESUMO: Este estudo teve como objetivo avaliar os impactos do processamento térmico na composição química das sementes de jaca sua toxicidade. O teor de cinzas das sementes submetida à torra foi maior (3,21%) em comparação com as sementes nos outros tratamentos. No entanto, os teores de umidade (5,29%) e proteínas (10,49%) foram menores. O teor de proteínas apresentou diferença significativa (P≤ 0.05) entre os grupos estudados (10,49%). O teor de lipídeos foi menor nas sementes submetidas ao cozimento (1,13%), enquanto o teor de carboidratos apresentou diferença significativa (P ≤ 0.05) entre os grupos estudados (54,11%). As sementes brutas apresentaram o maior teor de fibras (25,20%). Em relação à toxicidade, apenas a farinha de sementes de jaca cozidas apresentou potencial citotóxico, embora nenhuma das amostras tenha causado irritação ou distúrbios vasculares em ovos fecundados. Esses resultados sugerem que o tratamento térmico pode garantir a segurança das sementes frente à citotoxicidade, embora reduza o teor de alguns macronutrientes.

RESUMO

Alginate encapsulation is a well-known technique used to protect microorganisms from adverse conditions. However, it is also known that the viscosity of the alginate is dependent on its composition and degree of polymerization and that thermal treatments, such as pasteurization and sterilization, can affect the structure of the polymer and decrease its protection efficiency. The goal of this study was to evaluate the protective effect of encapsulation, using alginates of different viscosities treated at different temperatures, on Lactiplantibacillus plantarum 299v under in vitro gastrointestinal conditions and cold storage at 4 °C and -15 °C, respectively. Steady- and dynamic-shear rheological tests were used to characterize the polymers. Thermal treatments profoundly affected the rheological characteristics of alginates with high and low viscosity. However, the solutions and gels of the low-viscosity alginate were more affected at a temperature of 117 °C. The capsules elaborated with high-viscosity alginate solution and pasteurized at 63 °C for 30 min provided better protection to the cells of L. plantarum 299v under simulated gastrointestinal and cold storage conditions.

RESUMO

Titanate nanotubes were synthesized and subjected to an ion exchange reaction with erbium salt aqueous solution to obtain titanate nanotubes exchanged with erbium (3+) ions. In order to evaluate the effects of the thermal treatment atmosphere on the structural and optical properties of erbium titanate nanotubes, we subjected them to heat treatment in air and argon atmospheres. For comparison, titanate nanotubes were also treated in the same conditions. A complete structural and optical characterizations of the samples was performed. The characterizations evidenced the preservation of the morphology with the presence of phases of erbium oxides decorating the surface of the nanotubes. Variations in the dimensions of the samples (diameter and interlamellar space) were promoted by the replacement of Na+ by Er3+ and the thermal treatment in different atmospheres. In addition, the optical properties were investigated by UV-Vis absorption spectroscopy and photoluminescence spectroscopy. The results revealed that the band gap of the samples depends on the variation of diameter and sodium content caused by ion exchange and thermal treatment. Furthermore, the luminescence strongly depended on vacancies, evidenced mainly by the calcined erbium titanate nanotubes in argon atmosphere. The presence of these vacancies was confirmed by the determination of Urbach energy. The results suggest the use of thermal treated erbium titanate nanotubes in argon atmosphere in optoelectronics and photonics applications, such as photoluminescent devices, displays, and lasers.

RESUMO

Ultrasound combined with high temperatures (thermosonication) is an alternative to thermal treatments applied for juice preservation purposes. Blend juices, such as orange-carrot juice, are an interesting option for consumers due to their diversity of unique flavors. The main aim of the present study is to investigate thermosonication's impact on the overall quality of an orange-carrot juice blend over 22-day storage at 7 °C, in comparison to thermal treatment. Sensory acceptance was assessed on the first storage day. The juice blend was prepared based on using 700 mL of orange juice and 300 g of carrot. The effect of ultrasound treatment at 40, 50, and 60 °C for 5 and 10 min, as well as of thermal treatment at 90 °C for 30 s, on the physicochemical, nutritional, and microbiological quality of the investigated orange-carrot juice blend was tested. Both the ultrasound and the thermal treatment could maintain pH, °Brix, total titratable acidity, total carotenoid content, total phenolic compounds, and the antioxidant capacity of untreated juice samples. All ultrasound treatments improved samples' brightness and hue value, and made the juice brighter and redder. Only ultrasound treatments at 50 °C/10 min and at 60 °C/10 min have significantly reduced total coliform counts at 35 °C. Thus, they were selected along with untreated juice for sensory analysis, whereas thermal treatment was used for comparison purposes. Thermosonication at 60 °C for 10 min recorded the lowest scores for juice flavor, taste, overall acceptance, and purchase intention. Thermal treatment and ultrasound at 60 °C for 5 min recorded similar scores. Minimal variations in quality parameters were observed over 22-day storage in all treatments. Thermosonication at 60 °C for 5 min has improved samples' microbiological safety and resulted in good sensorial acceptance. Although thermosonication has the potential to be used in orange-carrot juice processing, further investigations are necessary to enhance its microbial effect on this product.

Assuntos

RESUMO

Abstract This study aimed to evaluate the influence of temperature on torsional strength and angular deflection of two experimental NiTi rotary instruments manufactured from Blue and Gold thermal treatments and with identical cross-sections. A total of 40 experimental NiTi instruments 25.06 and with a triangular cross-section and manufactured from Blue and Gold thermal treatments were used (n=20). The torsional test was performed in the 3 mm from the tip of the instrument according to ISO 3630-1. The torsional test evaluated the torsional strength and angular deflection to failure at room temperature (21°C ± 1° C) and body temperature (36°C ±1°C). The fractured surface of each fragment was observed by using scanning electron microscopy (SEM). Data were analyzed using an unpaired t test for inter and intra-group comparison and the level of significance was set at 5%. The results showed that the body temperature did not affect the torsional strength and angular deflection of the instruments when compared with room temperature (P>0.05). However, at body temperature, the Blue NiTi instruments presented significantly lower angular deflection in comparison with Gold NiTi instruments (P<0.05). There was no significant difference regarding the torsional strength of the instruments at body temperature (P>0.05). The temperature did not affect the torsional strength of the instruments manufactured from Blue and Gold technology. However, the Blue NiTi instruments presented significantly lower angular deflection than Gold instruments at 36°C temperature.

Resumo O objetivo deste estudo foi avaliar a influência da temperatura nas propriedades de torção (resistência à torção e deflexão angular) de dois instrumentos rotatórios experimentais de NiTi fabricados com secção triangu.ar e tratamentos térmicos Blue e Gold. Quarenta instrumentos experimentais de NiTi 25.06 com tratamento térmico Blue e Gold foram usados (n= 20). Foi avaliada a resistência torcional e a deflexão angular até a fratura na temperatura ambiente (21°C ± 1°C) e corporal (36°C ± 1°C). O teste torcional foi realizado nos 3 mm da ponta dos instrumentos de acordo com a ISO 3630-1. A superfície fraturada de cada instrumento foi observada pelo microscópio eletrônico de varredura (MEV). Os dados foram analisados por meio do teste t não pareado para a comparação inter e intragrupos e o nível de significância à 5%. Os resultados demonstraram que a temperatura corporal não afetou a resistência a torção e deflexão angular quando comparada com a temperatura ambiente (P>0.05). No entanto, na temperatura de 36°C o instrumento com tratamento térmico Blue apresentou menor deflexão angular quando comparado com o Gold (P<0.05). Não houve diferença significante entre os dois instrumentos em relação a resistência à torção. A temperatura corporal não modificou a resistência torcional dos instrumentos fabricados com tecnologia Blue e Gold. No entanto, os instrumentos com NiTi Blue apresentaram menor deflexão angular do que o Gold a 36°C.

RESUMO

The meat greening is an abnormal pigmentation related to microbiological contamination and lipid oxidation during storage. This color change results from sulfmyoglobin (SulfMb) production promoted by the reaction between metmyoglobin (MetMb), H2O2, and thiol compounds. Spectral studies on cooked meat suggested the production of SulfMb, probably due to the increment of free radicals during thermal treatment. Thus, we evaluated the involvement of free radicals and heme iron in the SulfMb production from horse MetMb and free cysteine (Cys) during thermal treatment. The results confirm that the reaction of SulfMb production at meat muscle pH (5.7-7.2) during heat treatment is a product of free radicals formed from Cys oxidation (SH) and reactive oxygen species (O2-, H2O2). This is catalyzed by the release of heme iron, thus promoting a consecutive reaction having MbFe(IV)O as a reaction intermediate.

Assuntos

RESUMO

The demand for products from wood has been expanding, because of this, there is a need for studies related to the quality and application of these materials. Thus, the present research aimed to evaluate theextractive and cellulose content of Ipê wood submitted to the thermal modification process. To carry out the study, fourindividuals of Handroanthus chrysotrichus(Mart. ex DC.) Mattos, 11 years old, were slaughtered. Subsequently, samples measuring 2.5 x2.5 x 41 cm were prepared and placed in an oven with forced air circulation, at temperatures of 120, 150, 180 and 210 ºC, for a period of 4 h. Then, random portions of the specimens were sectioned and ground in a knife mill, and then, sieved in the 40/60 mesh fraction, to carry out the chemical tests of total extractives and cellulose content. The data were processed and submitted to the Tukey average test, using the R software. The results of the chemical properties studied indicated variations according to the temperatures, not showing a stabilization trend between the treatments applied. A relationship between the behavior of these properties and the other technological characteristics of the works available in the literature was observed. In general, further studies are recommendedon the chemical properties of wood of this species associatedwith the application of high temperatures.(AU)

A demanda de produtos oriundos da madeira vem se expandindo, por conta disso, há a necessidade de estudosrelacionados à qualidade e aplicação desses materiais. Com isso, a presente pesquisa teve como objetivo avaliaro teor de extrativos e de celulose da madeirade Ipê submetida ao processo de modificação térmica. Para realização do estudo foram abatidos quatroindivíduos de Handroanthuschrysotrichus (Mart. ex DC.) Mattos, com 11 anos de idade. Posteriormente, confeccionaram-se amostras de 2,5 x 2,5 x 41 cm, as quais foram acondicionadas em estufa com circulação de ar forçada, nas temperaturas de 120, 150, 180 e 210 ºC, por um período de 4 h. Em seguida, porções aleatórias dos corpos de prova foram seccionadas e trituradas em moinho de facas, e então, peneiradas nafração de 40/60 mesh, para arealização dos ensaios químicos de teor de extrativos totais e teor de celulose. Os dados foram processados e submetidos ao teste de médias de Tukey, utilizando o software R. Os resultados das propriedades químicas estudadas indicaramvariações de acordo com as temperaturas, não apresentando uma tendência de estabilização entre os tratamentos aplicados. Uma relação entre o comportamento dessas propriedades com as demais características tecnológicas dos trabalhos disponíveis na literatura foi observada. De modo geral, são recomendados mais estudos acerca das propriedades químicas da madeira dessa espécie associados a aplicação de altas temperaturas.(AU)

Assuntos

RESUMO

Soybean seeds (Glycine max) were dried under real scale conditions to different final moisture content (m.c.) (9.1, 9.7, 10.9 %, and control with 16.2 %) and processed through extruding-expelling. Results indicated that soybean seed m.c. affected the composition of the soybean expeller and, thus, the oil extraction efficiency (OEE), which increased as the seed m.c. decreased. A polynomic model was proposed for predicting OEE as a function of soybean m.c., indicating that drying soybean to 10 % resulted in an OEE of approximately 65 %. A thin layer drying experiment of soybean seeds indicated that the protein dispersibility index (PDI) was not affected as regards drying air temperatures up to approximately 69 °C, and a bi-linear model with a non-pre-established break point was fitted. The real scale drying treatment in a rack type dryer (mixed flow) did not show any effect (p > 0.05) on the PDI at 80 °C, while at 115 °C a reduction (p < 0.05) was observed (PDI reduction was 0.8 and 2.1 percentage points, respectively).(AU)

Assuntos

RESUMO

The heat treatment of a metal is a set of heating and cooling cycles that a metal undergoes to change its microstructure and, therefore, its properties. Temperature-time-transformation (TTT) diagrams are an essential tool for interpreting the resulting microstructures after heat treatments. The present work describes a novel proposal to predict TTT diagrams of the γ' phase for the Ni-Al alloy using artificial neural networks (ANNs). The proposed methodology is composed of five stages: (1) database creation, (2) experimental design, (3) ANNs training, (4) ANNs validation, and (5) proposed models analysis. Two approaches were addressed, the first to predict only the nose point of the TTT diagrams and the second to predict the complete curve. Finally, the best models for each approach were merged to compose a more accurate hybrid model. The results show that the multilayer perceptron architecture is the most efficient and accurate compared to the simulated TTT diagrams. The prediction of the nose point and the complete curve showed an accuracy of 98.07% and 86.41%, respectively. The proposed final hybrid model achieves an accuracy of 96.59%.

RESUMO

The study aimed to evaluate the nanoparticles (ECW) containing tamarind trypsin inhibitor (TTI) concerning the storage effect under different conditions on antitrypsin activity and the bioactive potential in a preclinical model. ECW was exposed to different pH and temperatures to evaluate the interaction between TTI and its encapsulating agents, monitored by antitrypsin activity. Wistar rats (n = 25) with obesity induced by diet were divided into groups: untreated; treatment with nutritionally adequate diet; treatment with nutritionally adequate diet and ECW/12.5 mg/kg; treatment with ECW/12.5 mg/kg; and treatment with TTI/25 mg/kg. The groups were evaluated over ten days with regards to satiety, zoometric, biochemical, and inflammatory parameters, using ten times less TTI (2.5 mg/kg) contained in ECW. TTI was protected and encapsulated in ECW without showing residual inhibitory activity. Only at gastric pH did ECW show antitrypsin activity. At different temperatures, it showed high antitrypsin activity, similar to TTI. The animals treated with ECW had significantly reduced body weight variation (p < 0.05), and only TTI treatment reduced the inflammatory parameters significantly (p < 0.05). The study showed that by using lower concentrations of TTI in ECW it was possible to perceive promising effects with perspectives of use in functional products for managing obesity and its complications.

RESUMO

Abstract To evaluate the flexural strength (FS) and flexural modulus (FM) of a commercial 3Y-TZ0P ceramic after artificial aging and either without or with two application times of non-thermal plasma treatments (NTP). In addition, changes in crystalline phase transformation and surface nano-topography after NTP application, during different aging periods, were evaluated. Ninety 3Y-TZP bars (45x4x3 mm) were made for FS and FM testing, and assigned to nine groups (n=10): no NTP/no aging (Control); no NTP/4h aging; no NTP/30h aging; 10s NTP/no aging; 10s NTP/4h aging; 10s NTP/30h aging; 60s NTP/no aging; 60s NTP/4h aging and 60s NTP/30h aging. Artificial accelerated aging was simulated using an autoclave (134º C at 2 bar) for up to 30h. FS and FM were assessed using a universal testing machine and data analyzed using a ANOVA and Tukey test (α=0.05). The volume change in zirconia monoclinic phase (MPV) was evaluated using X-ray diffraction and surface nano-topography was assessed using atomic force microscopy (baseline until 30h-aging). NTP application did not influence the FS and FM of zirconia. Compared to the Control (no NTP/no aging), the FS of zirconia samples treated for 30 hours in autoclave ("no NTP/30h aging" group) increased. Artificial aging for 30 hours significantly increased the FM of zirconia, regardless of NTP application. MPV tended to increase following the increase in aging time, which might result in the surface irregularities observed at 30h-aging. NTP did not alter the zirconia properties tested, but 30h-aging can change the zirconia FS, FM and MPV.

Resumo Avaliar a resistência à flexão (FS) e o módulo de flexão (FM) de uma cerâmica comercial 3Y-TZP após envelhecimento artificial, e com ou sem dois tempos de aplicação de plasma não térmico (NTP). Além disso, a transformação de fase cristalina e a nano-topografia de superfície após a aplicação de NTP, durante diferentes períodos de envelhecimento, foram avaliadas. Noventa barras 3Y-TZP (45x4x3 mm) foram feitas para testes de FS e FM, e distribuídas em nove grupos (n=10): sem NTP/sem envelhecimento (Controle); sem NTP/4h de envelhecimento; sem NTP/30h de envelhecimento; 10sNTP/sem envelhecimento; 10sNTP/4h; 10sNTP/30h; 60sNTP/sem envelhecimento; 60sNTP/4h e 60sNTP/30h. O envelhecimento artificial acelerado foi simulado em autoclave (134º C a 2 bar) por até 30 horas. FS e FM foram avaliados em máquina de ensaio universal e os dados analisados ​​pela ANOVA e teste de Tukey (α = 0,05). A mudança de volume da fase monoclínica de zircônia (MPV) foi avaliada usando difração de raios-X e nano-topografia de superfície foi avaliada utilizando microscopia de força atômica (baseline até 30h). A aplicação do NTP não influenciou a FS e FM da zircônia. Comparado ao Controle ("sem NTP/sem envelhecimento"), a FS das amostras de zircônia tratadas por 30 horas em autoclave ("sem NTP/30h de envelhecimento") aumentou. O envelhecimento artificial por 30 horas aumentou significativamente a FM da zircônia, independente do tempo de aplicação do NTP. O MPV tendeu a aumentar em função do aumento do tempo de envelhecimento para todos os grupos, que pode ter resultado nas irregularidades superficiais observadas com 30 horas de envelhecimento. O NTP não afetou as propriedades da zircônia testadas, mas o envelhecimento por 30 horas pode alterar a FS, FM e MPV da zircônia.

RESUMO

Enrichment of biochars to produce slow nutrient release fertilizers with minimal losses to the environment is a promising strategy. However, the release of potassium (K) from biochar-based fertilizer produced from sewage sludge (SS) is still poorly studied. In the present 30-day incubation study, the dynamics of K release were evaluated from SS biochar-based fertilizers enriched with potassium chloride (KBF) in different forms, subjected to two levels of silica sand moisture (10 and 20%). The KBF was evaluated in the form of granules, pellets and powder, in addition to pure KCl mineral fertilizer. During the incubation period water-soluble K extractions were performed, where the K contents were adjusted to K release kinetic models. An additional experiment was performed to assess the effect of KBFs and KCl on K leaching. In general, at both moisture levels all KBFs presented a slower K release compared to pure KCl mineral fertilizer, reducing the release rate by up to 77%. The K release dynamics were affected by the type of biochar fertilizer (granule, pellet and powder) and the silica sand moisture level. The behavior of KBFs as slow-release fertilizers is strongly dependent on the silica sand moisture level. At the 10% moisture level, biochar fertilizers in the form of pellets and granules can be classified as slow-release fertilizers with the potential to increase the efficiency of K use in agriculture. Furthermore, compared to the chemical fertilizer, KBF reduced the amount of leached K, diminishing the risk of this nutrient polluting the groundwater. Our results must be further assessed in real conditions using soil as a suitable medium for agronomic and environmental evaluation. Therefore, future studies should consider the dynamic of K and other nutrients from KBFs in distinct soil types.

Assuntos

RESUMO

In this research, we have synthesized carbon dots (CDs) co-doped with nitrogen and sulfur by facile hydrothermal method, using citric acid and cysteine as carbon source. The effect of solid-state thermic treatment (STT) at 303-453 K on the size, surface, fluorescence and cellular cytotoxicity of the CDs were systematically investigated. Through a simple STT, it was possible to tune surface states and the average size of the CDs, causing a permanent red shift. Initially, CDs showed a decrease in cell viability with increasing concentration. However, after STT, its viability remained constant with an increase in concentration. Here, we show the possibility to label the cells cytoplasm according to the CDs fluorescence emission before (blue emission) and after STT (red emission). The CDs studied in this paper show selective luminescence properties, which are fundamental for any cell imaging application.

RESUMO

RESUMO Mais de dez anos depois da implantação da Política Nacional de Resíduos Sólidos, por meio da Lei federal n° 12.305/2010, a elaboração e a execução de políticas públicas com resultados positivos na gestão dos resíduos sólidos urbanos são precárias. O coprocessamento desses produtos em fornos de clínquer pode ser uma alternativa viável para melhorar esse cenário, mas encontra diversas dificuldades de ordem técnica e econômica. Neste trabalho, estimou-se a composição e a gravimetria dos resíduos no Brasil com base em dados secundários, de forma a estimar o poder calorífico inferior resultante de diferentes formas de pré-tratamento desses produtos: triagem de orgânicos, triagem de orgânicos e inertes, secagem para redução da umidade e combinação das três estratégias. Com base nos valores obtidos de poder calorífico, estima-se a capacidade de coprocessamento de resíduos pré-tratados pelas indústrias nacionais que possuem licenciamento ambiental para essa atividade. O tratamento prévio dos resíduos resultou em aumentos entre 20 e 56% em relação ao cenário-base. Observou-se que, para o cenário sem triagem, mas com secagem térmica do resíduo, até 8% dos resíduos com destinação inadequada no Brasil atualmente podem ser recebidos por indústrias de cimento para o coprocessamento, desde que haja viabilidade técnica para sua substituição e transporte.

ABSTRACT More than ten years after the implementation of the Solid Waste Nacional Policy by Brazilian Federal Law nº 12.305/2010, elaboration and execution of public policies with positive results in Municipal Solid Waste management is precarious. Coprocessing of Municipal Solid Waste in cement kilns can be a viable alternative for improving this scenario, but still encounters many technical and economical challenges. In this study, an estimate of the mean gravimetric composition of Municipal Solid Waste in Brazil is presented, based on secondary data, so as to estimate the resultant lower heating value resultant of different Municipal Solid Waste pre-treatment alternatives; separation of the organic fraction, separation of organic and inert fraction, drying of Municipal Solid Waste and all strategies combined. Based on the obtained lower heating value, an estimate of the yearly potential of Municipal Solid Waste coprocessing in industries already licensed for coprocessing of waste in Brazil is presented. Pre-treatment of Municipal Solid Waste resulted in lower heating value improvements ranging from 20 to 56% when compared to the base scenario. It is observed that, in the scenario where the Municipal Solid Waste is dried but not triaged, up to 8% of the Municipal Solid Waste that is currently disposed inappropriately in Brazil could be received by cement industries for coprocessing, as long as there is technical feasibility for the substitution and transportation.

RESUMO

A introdução de sistemas rotatórios mecanizados utilizando instrumentos de níquel- titânio (NiTi) trouxe significativo progresso e agilidade ao tratamento endodôntico, minimizando a ocorrência de iatrogenias. Com o avanço da tecnologia, novos sistemas foram introduzidos no mercado a fim de melhorar o desempenho das limas de níquel-titânio. Alguns desses sistemas utilizam uma cinemática diferente, o movimento reciprocante, e prometem apresentar vantagens em suas propriedades físicas como maior resistência à fratura. Ao mesmo tempo, novos tratamentos térmicos foram desenvolvidos a fim de aprimorar as propriedades mecânicas e aumentar ainda mais a resistência à fratura dos instrumentos, e assim, proporcionar uma rotina clínica mais segura. Dentre as inovações mais recentes no campo dos instrumentos endodônticos estão os sistemas que preconizam um menor desgaste dentinário, tratamentos mais conservadores visando manter o máximo de estrutura dental sadia. Estes novos tipos de limas têm a particularidade de serem instrumentos finos e flexíveis, de forma a conseguir uma instrumentação segura, minimamente invasiva e suficientemente eficaz. Este trabalho irá abordar os sistemas TruNatomy, tratado termicamente e com características de preparo conservador, e Reciproc Blue, que agrega segurança devido a sua maior resistência à fratura e simplicidade de uso por se tratar de um único instrumento reciprocante. Será ainda proposto um passo a passo clínico sistemático para instrumentação mecanizada utilizando estes dois sistemas, visando a orientação de profissionais quanto aos seus protocolos de utilização.

The introduction of mechanized rotary systems using nickel-titanium (NiTi) instruments brought significant progress and agility to endodontic treatment, minimizing the occurrence of iatrogenic events. With the advancement of technology, new systems were introduced in order to improve the NiTi files performance. Some of these systems use a different kinematics, the reciprocating motion, and promise to present advantages in their physical properties, such as greater resistance to fracture. At the same time, new heat treatments were developed in order to improve the mechanical properties and increase even more the fracture resistance of the instruments, and thus, provide a safer clinical routine. Among the most recent innovations in the field of endodontic instruments are systems that advocate less dentin wear, more conservative treatments aimed at maintaining maximum healthy tooth structure. These new types of files have the particularity of being thin and flexible instruments, in order to achieve a safe, minimally invasive and sufficiently effective instrumentation. This work will address the TruNatomyTM systems, thermaly treated and conservative, and Reciproc Blue, which adds safety due to its greater resistance to fracture and simplicity of use because it is a single reciprocating instrument. A systematic clinical step-by- step for mechanized instrumentation using these two systems will also be proposed, aiming to guide professionals regarding their use protocols.

Assuntos

RESUMO

Abstract The sewage sludge (SS) use in agriculture has been limited by the Brazilian legislation to a few situations, mainly as a precautionary measure due to inorganic pollutants and pathogens. Thus, a large amount of SS has been accumulated in landfills, with no prospect of use, generating great concern for governments and society. Thermal treatment via pyrolysis has stood out as an option for SS recycling, transforming it into a carbon-rich product known as SS biochar (SSB). Biochar from SS showed good potential to be used for agricultural and environmental purposes. The present study aimed to evaluate the influence of pyrolysis at 300°C on the physical, chemical, morphological and mineralogical characteristics of SSB. In general, pyrolysis increased total carbon, total nitrogen, macro and micronutrient contents, except potassium. Pyrolysis also increased heavy metals (HMs) concentration in SSB. However, HMs values remained below the maximum limits allowed according to the legislation on SS agricultural use. X-ray analysis showed that both SS and SSB present silica (SiO2) as the main mineral. Pyrolysis also increased the SS surface area (SA) and porosity. In general, results of the present study prove showed that pyrolysis is a technological alternative to enable SS use as a sustainable input in agriculture.

RESUMO

Sewage sludge biochar (SSB) is a multi-nutrient fertilizer with very low K concentration. This study presents a novel K-enriched SSB fertilizer with the potential to increase K use efficiency by crops. The object of this work was therefore to evaluate the physical-chemical, morphological and mineralogical characteristics of a SSB organomineral fertilizer (OSSB) enriched with K. SSB was enriched with KCl and K2SO4 using three technological methods (granules, pellets and powders). The enrichment of SSB with K ensured a K2O content about 75 times higher than the pure SSB. Organominerals in powder form had higher levels of total nitrogen, calcium, sulfur, phosphorus and higher pH than granules and pellets. The morphology and physical characteristics of enriched OSSBs were more influenced by the form of the fertilizer than by the source of K. In general, the enriched OSSBs are influenced by the quantities of feedstocks and the enrichment technology.

Assuntos

RESUMO

The entire route from anodic oxidation and surface characterization, including in vitro experiments and finally in vivo osseointegration assays were performed with the aim to evaluate nanotubular and crystalline annealed titanium oxides as a suitable surface for grade 2 titanium permanent implants. Polished titanium (T0) was compared with anodized surfaces obtained in acidic media with fluoride, leading to an ordered nanotubular structure of titanium oxide on the metal surface, characterized by tube diameter of 89 ± 24 nm (Tnts). Samples were thermally treated in air (TntsTT) to increase the anatase crystalline phase on nanotubes, with minor alteration of the structure. Corrosion tests were performed to evaluate the electrochemical response after 1, 14, and 28 days of immersion in simulated body fluid. Based on the in vitro results, heat-treated titanium nanotubes (TntsTT) were selected as a promissory candidate to continue with the osseointegration in vivo assays. The in vivo results showed no major improvement in the osseointegration process when compared with untreated Ti after 30 days of implantation and there also was a lower increase in the development of new osseous tissue.

Assuntos