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In this work, we report the synthesis of magnetic zeolite A using fly ash as the main sources of SiO₂ and Al₂O₃, by hydrothermal use in the adsorption of Pb2, Cd2, Zn2⁺ and Cu2. The composite synthesis was successful, and the obtained material was characterised by using different techniques, such as X-ray diffraction (XRD), X-ray fluorescence (XRF), Infrared vibrational spectroscopy (FTIR), Electron Microscopy (SEM), and pH point of zero charge (pHpzc). XRD measurements confirm zeolites A as the main crystalline phases (98.5%), with the presence of a small amount of sodalite (1.5%). In the SEM of magnetic composite, the characteristic morphology for zeolite A was noted, with magnetite nanoparticles dispersed on its surface, resulting in a composite with magnetic properties. In the adsorption study, the magnetic composite showed a fast rate of adsorption, in which the pseudo second order model was the one that best described the experimental data of the metal ions under study. The Redlich-Peterson isotherm model best represented the experimental data of Pb2⁺ and Cd2⁺, while the Langmuir and Sips models fitted Zn2⁺ and Cu2⁺, respectively. Thus, the results showed that the magnetic composite presented high magnetic quality, facilitating its separation from the aqueous medium, as well as being a promising adsorbent in the adsorption of metal ions in aqueous medium. [ABSTRACT FROM AUTHOR]

This study aimed to verify the efficiency of an electrocoagulation reactor to generate low carbon hydrogen and treat textile effluent simultaneously. The electrolytic cell comprised a hermetically sealed polypropylene container containing 800 mL of effluent and a pair of immersed stainless steel 304 L electrodes powered by a photovoltaic solar panel (540 W). A gas chromatograph with a dielectric-barrier discharge ionization detector (GC-BID) measured the hydrogen gas produced. The efficiency of the textile effluent treatment was evaluated using the parameters of dissolved organic carbon, turbidity, pH, conductivity, and color. The electrical energy consumed by hydrogen generation and effluent treatment was also measured. The maximum concentration of hydrogen produced was 89.87% (v/v) with 898676.9 ppm. The process removed 100% of color, 92% of dissolved organic carbon, and 99.53% of turbidity. The electrical energy consumed for hydrogen generation ranged from 19.02 to 55.74 KW h/m3H 2. • Simultaneous electrolytic process of low carbon hydrogen generation and textile effluent treatment. • Hydrogen concentration values were obtained in the 475773.3 ppm (47.57 %) to 898676.9 ppm (89.87 %) range. • The process removed 100%, 99.53%, and 92% of color, turbidity, and dissolved organic carbon, respectively. • The energy per volume of hydrogen produced was 19.02–55.74 KW h/m3H 2. [ABSTRACT FROM AUTHOR]

Novas tecnologias em radiologia digital são uma realidade no país e avançam substituindo o sistema filme/écran. Em mamografia o sistema de maior preferência é de radiografia computadorizada, CR. Este sistema tem características de utilizar doses elevadas para obter imagens com contraste adequado. Desta forma, métodos para avaliar dose glandular média, DG, e Razão Contraste Ruído, CNR, são aplicados para otimizar o sistema de imagem. O serviço de mamografia de um Hospital Universitário no Rio de Janeiro foi selecionado para este estudo, porque utiliza dois sistemas CR diferentes. Com objetivo de avaliar os valores de DG e CNR aplicados nestes sistemas, medidas foram realizadas em cinco conjuntos diferentes. Os resultados mostram variações de DG e CNR entre os sistemas e foi observado que o Controle Automático de Exposição, CAE, não permite equilíbrio de dose em toda a faixa de espessura de mama comprimida gerando assim, valores de CNR inferiores aos necessários. Foi possível concluir que a otimização da dose na paciente deve ser buscada, porém a qualidade da imagem deve ser a melhor possível. O equilíbrio entre a dose e a CNR contribui para a otimização do sistema e pode ser alcançado através das medidas de controle de qualidade, da calibração do sistema e da avaliação dos critérios de qualidade da imagem clínica.

Pollution of water bodies from improper disposal of toxic metal contaminated effluents causes several problems for the environment. Several processes can be used to remove these metal ions from aqueous media, and the adsorption being the most efficient technique. In this process, a diversity of adsorbent materials is used, with the use of zeolite 4A emphasized in this study. This study aimed to evaluate the efficiency of zeolite 4A as an adsorbent material for the removal of Cu2+, Cd2+, Pb2+, and Zn2+ from aqueous media. For this, zeolite 4A was synthesized by the hydrothermal route starting from two sources of precursors, one from standard reagents (ZA-P) and the other from coal fly ash (ZA), a residue from a thermoelectric industry plant in the state of Ceará (Brazil). Both materials were characterized by X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and cation exchange capacity techniques. The materials were subjected to batch adsorption tests with multi-element synthetic solutions of Pb2+, Cu2+, Zn2+, and Cd2+. The parameters investigated in the adsorption experiments were the dosage effect, contact time, and adsorption equilibrium. Flame atomic absorption spectroscopy was used for metal ion quantitation. The characterization results showed that both ZA-P and ZA yielded mainly the crystalline phase of zeolite 4A. In the dosage test, a weight of 100 mg promoted the best results for both ZA-P and ZA, with ZA achieving superior removal results. Pb2+ was more efficiently removed at 95% for ZA and 93% for ZA-P. In addition, at the time of contact, it was observed that ZA reached equilibrium faster (10 min) than ZA-P (50 min). In the adsorption equilibrium, the Langmuir model was able to describe almost all results, only the Zn2+ for ZA was modeled by the Freundlich isotherm. The affinity of metal ions for materials followed the order (Pb2+ > Cd2+ > Zn2 > Cu2+) for ZA-P and (Pb2+ > Cd2+ > Cu2+ > Zn2+) for ZA. Finally, it is concluded that both products have potential for application as metal adsorbents of Cu2+, Cd2+, Pb2+, and Zn2+ in aqueous solutions and that coal fly ash can be recycled to obtain zeolite. [ABSTRACT FROM AUTHOR]

Textile effluents are known to be complex matrices, requiring a combination of treatment techniques to achieve conditions that allow effluent to be discarded into environment. The electrocoagulation technique manages to remove most of the pollutants present in textile effluents, but generally does not achieve complete removal. This work studied the efficiency of combined electrochemical oxidation and ozonation techniques in the post-treatment of a real textile effluent after electrocoagulation and decantation processes. The experiments were carried out in batch mode using Ti/RuO2 electrodes (2 plates) and an ozone generator (0.875 g·h-1·L-1). Three current densities were studied, 33.3, 66.6, and 133.3 A·m-2. The turbidity, color, dissolved organic carbon, and pH were analyzed to evaluate the treatment process. The results showed higher efficiency for removing color and dissolved organic carbon with increasing current density. Applying the ozonation process alone had the lowest color and dissolved organic carbon removal efficiencies. The best experiment was with the current density of 66.6 A·m-2 integrated with O3 promoted removal percentages of 91.77%, 33.02%, and 91.09% for turbidity, dissolved organic carbon, and color, respectively. [ABSTRACT FROM AUTHOR]

Objective: This study analyzes the association of information sharing with the risk and performance of cooperatives' strategic alliance, mediated by knowledge sharing and information leakage. Method: A survey research was conducted in agricultural cooperatives listed in the Organization of Brazilian Cooperatives [OCB] (2018), involving managers (manager, supervisor, coordinator and controller) registered in the LinkedIn network. The questionnaire was sent through the SurveyMonkey platform to the 516 managers who accepted the invitation and the final sample totaled 96 valid responses. To test the research hypotheses, the structural equation modeling technique was applied. Results: The results showed that information sharing is directly associated with knowledge sharing, but the association of variables is not observed in the interaction between information sharing and information leakage. Information leakage is directly associated with the risk of the strategic alliance, as is knowledge sharing with alliance performance. Knowledge sharing presented partial mediation in the relationship of strategic alliance risk-information sharing and alliance performance, while information leakage did not meet the mediation requirements. Contributions: The study contributes by highlighting the association of information sharing with knowledge sharing in cooperatives' collaborative environment. It also provides indications on the consequences of information sharing and information leakage. It also highlights the importance of strengthening strategic alliances to reduce risk and increase performance. [ABSTRACT FROM AUTHOR]

Copyright of Geologia USP: Série Científica is the property of Geologia USP and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Raw water was submitted to a treatment process using electro-oxidation and ozonation, evaluating the parameters color, dissolved organic carbon (DOC), turbidity, UV-Vis adsorption spectrum, SUVA, and energy consumption. In the electro-oxidation process were used two current densities (22 and 44 A m–2) ruthenium electrodes and two types of current, (direct and pulsed). The percentages of removal of apparent and true color varied from 40.84 to 70.17% and from 47.09 to 80.06%, respectively. The electro-oxidation by direct current in the presence of ozone had the best removal efficiencies. DOC removal reached levels of 1.55–15.69%. The use of the electro-oxidation by pulsed current has obtained lower values of energy consumption. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos de Neuro-Psiquiatria is the property of Thieme Medical Publishing Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of the pulsed current can be an alternative to decrease the electrode polarization, as well as achieving lower energy consumption. This study investigated the electrocoagulation through pulsed current for the removal of natural organic matter from water. The experiments were carried out using Box-Behnken factorial design with the response surface methodology for the design of experiments, modeling and interpreting of the results. The electrocoagulation cell consisted of an acrylic reactor with 4 L capacity with four electrodes of aluminum, in parallel connection mode. The experimental independent variables studied were: current density (5.5 to 44.5 A m -2 ), electrodes spacing (2 to 7.6 mm), stirring rate (200 to 1,000 rpm), frequency (500 to 5,000 Hz), humic acid concentration (5 to 20 mg L -1 ) and NaCl (100 to 300 mg L -1 ) as supporting electrolyte, evaluating the residual apparent color (RAC) and electric energy consumption (EEC). The pH of the solution increased during the experiments, reaching basic values. The response surface regression procedure was employed to fit the second-order polynomial, and the model fitted well to the obtained values, reaching R 2 0.9995 (RAC) and R 2 0.9989 (EEC). The lowest RAC was 11.8 Hazen units (96.2% color removal), where the EEC was 0.393 kWh m -3 .

Objective: To describe the most important coma scales developed in the last fifty years., Method: A review of the literature between 1969 and 2009 in the Medline and Scielo databases was carried out using the following keywords: coma scales, coma, disorders of consciousness, coma score and levels of coma., Results: Five main scales were found in chronological order: the Jouvet coma scale, the Moscow coma scale, the Glasgow coma scale (GCS), the Bozza-Marrubini scale and the FOUR score (Full Outline of UnResponsiveness), as well as other scales that have had less impact and are rarely used outside their country of origin., Discussion: Of the five main scales, the GCS is by far the most widely used. It is easy to apply and very suitable for cases of traumatic brain injury (TBI). However, it has shortcomings, such as the fact that the speech component in intubated patients cannot be tested. While the Jouvet scale is quite sensitive, particularly for levels of consciousness closer to normal levels, it is difficult to use. The Moscow scale has good predictive value but is little used by the medical community. The FOUR score is easy to apply and provides more neurological details than the Glasgow scale.