72 research outputs found

    Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

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    A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

    Flow analysis of particulate suspension on an asymmetric peristaltic motion in a curved configuration with heat and mass transfer

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    This article addresses the influence of particulate-fluid suspension on asymmetric peristaltic motion through a curved configuration with mass and heat transfer. A motivation for the current study is that such kind of theory is helpful to examine the two-phase peristaltic motion between small muscles during the propagation of different biological fluids. Moreover, it is also essential in multiple applications of pumping fluid-solid mixtures by peristalsis, i.e., Chyme in small intestine and suspension of blood in arteriole. Long wavelength, as well as small Reynolds number, have been utilized to render the governing equations for particle and fluid phase. Exact solutions are presented for velocity (uf,p), temperature (θf,p) and concentration distributions (φf,p). All the parameters such as Prandtl number (Pr), particle volume fraction (C), suspension parameter (M1), curvature parameter (k), volumetric flow rate (Q), Schmidt number (Sc), phase difference (φ), Eckert number (Ec), and Soret number (Sr) discussed graphically for peristaltic pumping (Δp), pressure gradient (dp/dx), velocity (uf,p), temperature (θf,p) and concentration distributions (φf,p). The streamlines are also plotted with the aid of contour

    Variation in physico-chemical/analytical characteristics of oil among different flaxseed (Linum usittatissimum L.) cultivars

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    The present study evaluates and compares the proximate parameters of flaxseed, as well as the physicochemical characteristics of the extracted flaxseed oils of locally grown eight cultivars. The oil, protein, fiber and ash content of the seeds ranged from32.56-39.98%, 16.02-18.50%, 23.30-26.88 and 3.20-3.60%, respectively showing considerable variation among cultivars. The quality attributes such as unsaponifiable matter, peroxide value, acid value, para-anisidine value, conjugateddienes and trienes as well as tocopherols content of the tested flaxseed oils varied significantly (p&lt;0.05) among cultivars. The major tocopherol was γ-tocopherol (173.7 to 257.9 mg/L)followed by relatively low quantities of α-tocopherol (8-12 mg/L), while δ-tocopherol was not detected.α-Linolenic acid was found to be the principal fatty acid in the range of 44.51 to 54.87%, while the second major fatty acid present in the oils was oleic acid (21.05 to 30.96%). The variationin the characteristics of oils among different cultivars observed during present investigation might be attributed to difference in genetic makeup and harvesting regimes of the flax plants.</p

    Green nanocomposite for the adsorption of toxic dyes removal from colored waters

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    The discharge of dyes from textile industries led to a broad range of toxicological and environmental effects, posing severe health issues for humans and animals worldwide. These dyes are highly stable and, if not adequately treated, remain in the environment for extended periods. Adsorption, the most efficient and cost-effective method, offers unique advantages for using natural adsorbents, such as marble waste composites, for dye removal. The easy availability of marble waste, its low cost, its eco-friendly nature, its ease of operation, its simplicity of design, its flexibility, and its great affinity for dyes make it a suitable option for dye removal. Golden marble waste nanocomposites are prepared for dye removal. The results from the studies suggested that treated golden marble composite materials exhibit better adsorption efficiency (224.8, 299.5, and 369.2 mg/g) for adsorptive removal of dyes than untreated golden marble composite materials (114.4 mg/g). This research also used isothermic and kinetic models to evaluate the effects of numerous parameters, for example, the initial dye concentration, pH, time, temperature, and adsorbent dose. The highest removal of 369.9 mg/g was achieved during the present study for blue dye at an optimized pH of 7 and a temperature of 30 °C. It was observed that golden marble waste composites gave better R2 (0.99) values for second-order kinetics in the kinetic model. Results obtained from comparing Langmuir, Freundlich, Temkin, Dubinin, and Herkin Jura isotherms showed that the R2 values of the Langmuir isotherm for Foron red (0.97), the Temkin isotherm for Foron blue (0.98), and the Freundlich isotherm for Foron black dye (0.97) fit on adsorption for both treated and untreated composites. Characterization techniques, such as scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), are also discussed for the structural determination of golden marble waste composites

    Advanced treatment of direct dye wastewater using novel composites produced from hoshanar and sunny grey waste

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    The present project is designed to investigate the potential of hoshanar and sunny grey marble wastes to remove direct violet 51 dye from wastewater using adsorption process. The effect of different parameters such as pH, adsorbent dose, initial dye concentration, and contact time were studied to optimize the results of adsorption process. Different isothermic models (Temkin, Langmuir isotherm, Freundlich isotherm, Harkin Jura, and Dubinin-Radushkevich models) and kinetic models (pseudo-first order and pseudo-second order) were employed to adsorption data to find out the best fit model, i.e., Langmuir isotherm and pseudo-second order model. Marble waste composites were also characterized by using different techniques such as scanning electron microscopy (SEM) for surface morphology and Fourier transform infrared spectroscopy (FTIR) to determine chemical arrangements, structure, and functional groups of adsorbents. Hoshanar treated with a mixture of potassium ferricyanide, and sodium meta silicate showed maximum adsorption capacity of 105.31 mg/g as compared to untreated hoshanar (67.19.45 mg/g). So, the conversion of HM into HMPS makes it an affordable, efficient, and available adsorbent for wastewater treatment

    Effective removal of reactive and direct dyes from colored wastewater using low-cost novel bentonite nanocomposites

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    The present study was aimed to remove direct violet-51, reactive green-5, reactive red, and acid red dyes by novel bentonite clay nanocomposites prepared using sodium metasilicate and potassium ferricyanide. The effect of temperature, pH, adsorbent amount, contact time, and initial concentration were studied to optimize the removal process. Various adsorption isotherms (Temkin, Freundlich isotherm, Langmuir isotherm, Harkin Jura, and Dubinin Radushkevich models) and kinetic models (pseudo-first order and pseudo-second order) were applied to adsorption data to find out the best fit model, i.e., Freundlich isotherm and pseudo-second order model. The prepared samples of bentonite nanocomposites were characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Bentonite treated with sodium metasilicate and potassium ferricyanide removed 96.6% of direct violet-51 dye, bentonite treated with sodium metasilicate removed 95%, bentonite treated with potassium ferricyanide removed 94%, and pure bentonite removed 80% of the dye from the solution

    Effective Removal of Reactive and Direct Dyes from Colored Wastewater Using Low-Cost Novel Bentonite Nanocomposites

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    The present study was aimed to remove direct violet-51, reactive green-5, reactive red, and acid red dyes by novel bentonite clay nanocomposites prepared using sodium metasilicate and potassium ferricyanide. The effect of temperature, pH, adsorbent amount, contact time, and initial concentration were studied to optimize the removal process. Various adsorption isotherms (Temkin, Freundlich isotherm, Langmuir isotherm, Harkin Jura, and Dubinin Radushkevich models) and kinetic models (pseudo-first order and pseudo-second order) were applied to adsorption data to find out the best fit model, i.e., Freundlich isotherm and pseudo-second order model. The prepared samples of bentonite nanocomposites were characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Bentonite treated with sodium metasilicate and potassium ferricyanide removed 96.6% of direct violet-51 dye, bentonite treated with sodium metasilicate removed 95%, bentonite treated with potassium ferricyanide removed 94%, and pure bentonite removed 80% of the dye from the solution

    Enhanced Solar Photocatalytic Reduction of Cr(VI) Using a (ZnO/CuO) Nanocomposite Grafted onto a Polyester Membrane for Wastewater Treatment

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    Among chemical water pollutants, Cr(VI) is a highly toxic heavy metal; solar photocatalysis is a cost-effective method to reduce Cr(VI) to innocuous Cr(III). In this research work, an efficient and economically feasible ZnO/CuO nanocomposite was grafted onto the polyester fabric ZnO/CuO/PF through the SILAR method. Characterization by SEM, EDX, XRD, and DRS confirmed the successful grafting of highly crystalline, solar active nanoflakes of ZnO/CuO nanocomposite onto the polyester fabric. The grafting of the ZnO/CuO nanocomposite was confirmed by FTIR analysis of the ZnO/CuO/PF membrane. A solar photocatalytic reduction reaction of Cr(VI) was carried out by ZnO/CuO/PF under natural sunlight (solar flux 5&ndash;6 kW h/m2). The response surface methodology was employed to determine the interactive effect of three reaction variables: initial concentration of Cr(VI), pH, and solar irradiation time. According to UV/Vis spectrophotometry, 97% of chromium was removed from wastewater in acidic conditions after four hours of sunlight irradiation. ZnO/CuO/PF demonstrated reusability for 11 batches of wastewater under natural sunlight. Evaluation of Cr(VI) reduction was also executed by complexation of Cr(VI) and Cr(III) with 1, 5-diphenylcarbazide. The total percentage removal of Cr after solar photocatalysis was carried out by AAS of the wastewater sample. The ZnO/CuO/PF enhanced the reduction of Cr(VI) metal from wastewater remarkably

    Exploring the efficiency of Ethyl Methane Sulfonate (EMS) and Sodium Azide (SA) to induce mutation in chili (Capsicum annuum L.) germplasm

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    Background: Exploring genetic diversity in traits of interest and utilizing it to breed high yielding, disease-resistant and high market value varieties is the prime objective of plant breeders. Unfortunately, genetic diversity in most of the crops has declined due to selection and reutilization of already adapted germplasm. Chemical mutagens are widely used to create novel changes in germplasm; however, these have been rarely tested for chili germplasm in Pakistan. Methods: We used ethyl methane sulfonate (EMS) and sodium azide (SA) to induce mutations for obtaining novel alterations in morphological and yield-related traits of four chili genotypes (i.e., ‘Mexi’, ‘Dandi Cut’, ‘Nageena’ and ‘Talhari’). Firstly, concentrations of both mutagens were calibrated, i.e., 1.5 % EMS and 0.5 % SA. Afterwards, seeds of four chili cultivars were treated and grown in peat trays. As the nursery was established, seedlings were transferred to media (sand: silt: clay + 1 kg well-decomposed FYM) after 30 days of germination. Different mutants were isolated based on differential morphological and phenotypic expressions. Results: It was found that efficiency of EMS was greater than SA and more variants were noticed in case of EMS-treated populations. Genetic analysis showed that almost all the traits were affected by mutagens in the M1 generations although the stability of isolated mutants was not checked in later generations. All the traits showed higher estimates of heritability but in some traits genetic advance was non-significant. Conclusion: It is recommended that isolated mutants could be used as rich genetic diversity source to breed new varieties. Furthermore, EMS proved a suitable mutagen for targeted mutations
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