Novel ferrofluids coated with a renewable material obtained from cashew nut shell liquid

In this work, we present the synthesis and characterization of a new surfactant molecule obtained from a byproduct of the cashew nut processing (diphosphorylated cardol, DPC). It is herein used to overcoat magnetic nanoparticles showing spinel structures in order to create new ferrofluids. The nanoparticle structure and magnetic properties have been deeply investigated. DPC-functionalized Fe₃O₄ and NiFe₂O₄ samples exhibit higher magnetic saturation than DPC–CoFe₂O₄. These new ferrofluids reveal appealing as possible nanoparticle stabilizing molecules, magnetic resonance imaging agents, storage systems or in any material science field that requires the employment of biocompatible magnetic stable fluids.     

Use of the nitrification inhibitor dicyandiamide (DCD) does not mitigate N2O emission from bovine urine patches under Oxisol in Northwest Brazil

Nutrient Cycling in Agroecosystems - Animal production systems are important sources of greenhouse gases (GHGs), especially methane (CH4) and nitrous oxide (N2O). GHG emissions from urine patches...     

Ecofriendly modification of acetosolv lignin from oil palm biomass for improvement of PMMA thermo‐oxidative properties

The environmentally friendly esterification of acetosolv lignin (AL), obtained from pressed oil palm mesocarp fibers, is described, for the improvement of thermo‐oxidative properties of poly(methyl methacrylate) (PMMA) films. Acetylation of AL was performed in ecofriendly conditions using acetic anhydride in the absence of catalysts. Acetylated acetosolv lignin (AAL) was successfully obtained in only 12 min with a solvent‐free and catalyst‐free microwave‐assisted procedure. Lignins were characterized by Fourier transform infrared spectroscopy, size exclusion chromatography, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC), confirming the efficacy of the methodology employed. AL and AAL as fillers in different concentrations (1% and 5%) were added to PMMA films. The thermal and mechanical properties of the lignin‐incorporated films were analyzed by TGA, DSC, and dynamic mechanical analysis (DMA). The films incorporated with lignin and acetylated lignin presented initial degradation temperature (T_onset) and onset oxidative temperature (OOT) values higher than pure PMMA films, contributing thus to an enhancement of thermo‐oxidative stability of PMMA. The DMA analyses showed that incorporation of AL or AAL increased the storage modulus (E′) of PMMA films, but did not affect their glass‐transition temperatures (T_g). The results indicate the potential use of oil palm mesocarp lignin to enhance the thermo‐oxidative properties of PMMA without compromising its mechanical response. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45498.     

Study of the temperature and organic bindings effects in the dielectric and structural properties of the lithium ferrite ceramic matrix (LiFe5O8)

In this study, the effects of the calcination temperature and of the organic bindings in the structural and dielectric properties of lithium ferrite (LiFe₅O₈) were investigated. The organic bindings used were glycerol, PVA (polyvinyl alcohol) and Galactomannan (Adenanthera pavonina). The investigated calcination temperature range was from 773 K to 1073 K. The structural properties were analyzed using differential scanning calorimetry, thermogravimetry, X-ray diffraction and infra-red spectroscopy. The electrical and magnetical properties were investigated using impedance dielectric spectroscopy and Mössbauer spectroscopy. The study of the structural and electrical properties of the lithium ferrites is an important issue in view to their attractive technological properties and low cost of fabrication. This work shows that the binding type, affects significantly the dielectric constant and loss of the LiFe₅O₈ ceramics.     

An experimental model for the measurement of renal function after temporary ureteral obstruction in the rat

We investigated semantic and emotional priming of lexical decision-making in 20 school refusers and 20 attenders aged 11-16 years, matched for sex and reading ability. We hypothesised that: semantic and emotional priming would be demonstrable in both samples; and that the school refusers would show emotional priming of school-related words to aversive primes. Both samples showed semantic priming; emotional priming was shown by the attenders and 11 school refusers without a history of depression. School-refusing children did not show emotional priming for school-related words. Nine school-refusing children with either current or past depression showed a general reduction in their priming. These results show that both semantic and emotional priming can be detected in this age-range. They do not support school refusal being typically associated with anxiety about school. The reduction in priming in those with a depressive history is similar to inhibition in information processing in depressed adults. Priming is therefore sensitive to at least some psychiatrically relevant states or traits in this age-range. It is concluded that priming could be a useful measure of information processing in this age-group, and further research is warranted.     

A thermogravimetric analysis of biomass wastes from the northeast region of Brazil as fuels for energy recovery

In this study, the energy potential of five types of biomass waste from cultures of banana (Musa spp.), cashew (Anacardium occidentale L.), babassu coconut (Orbignya speciosa), mango (Mangifera indica), and several flowers from the central hinterland of Ceará, Brazil was evaluated, to investigate their applicability as potential sources of alternative energy, for example, Briquettes. Many countries have been looking for new types of energy that are sustainable and clean, and biomass energy has been attracted attention in the last years because, is a renewable resource that, can be transformed in gaseous, liquid, and solid fuel. However, there are still many points that need investigation, for example, physicochemical properties and analytical characterization, energy efficiency, and cost. Therefore, the evaluation of the energy potential of biomass derived from a specific region is necessary. The thermal and oxidative behavior of the samples were evaluated by thermogravimetric (TG-DTG) analysis in atmospheres of nitrogen (N2) and synthetic air. For biomass characterization, the following analyses were done: immediate chemical analysis and high calorific value. The results showed that all the samples of biomass residues displayed high calorific values (>11 MJ/kg) and the immediate analysis showed that these residues displayed acceptable reactivities with a high volatile content (>70%). Average percentages were calculated for each parameter, and the following relationships were obtained for the different samples of biomass waste: Moisture (M): Mnitrogen > Mair; Volatile Matter (VM): VMair > VMnitrogen, and Ash Content (AC): ACair > ACnitrogen. The differences in the temperatures and decomposition rates of cellulose and hemicellulose enabled the investigation of the influence of oxidative and inert gas (synthetic air and nitrogen) upon the characteristics of waste decay, as well as inferences regarding the use of the thermogravimetric techniques in the study of the decomposition of different biomasses, for possible application as energy sources, as a quick, effective, and accurate tool.     

Development of Fully Bio‐Based Lubricants from Agro‐Industrial Residues under Environmentally Friendly Processes

Biolubricants are becoming interesting alternatives to mineral lubricants. Despite their advantages, development of lubricants from vegetable oils may compete with food production, turning their use impractical due to socio‐economic aspects. Here, cardanol is used as raw material in the synthesis of novel biolubricants under environmentally friendly conditions. These compounds are characterized by NMR and Fourier transform infrared spectroscopy. Thermal‐oxidative studies show the elevated stability and higher onset oxidative temperatures. Tribological analyses performed under high‐frequency linear‐oscillation motion indicate lower coefficients of friction and wear rates compared to a synthetic oil. Therefore, cardanol, under simple, fast, and sustainable processes can be transformed into valuable alternatives for petroleum‐based lubricants. Practical Applications: The novel cardanol‐based biolubricants presented in this work show interesting chemical and lubricity properties superior to standard synthetic oils, which make them potential substitutes for the current oil‐based products used as lubricants. Additionally, the ecofriendly methodologies employed reduce significantly the reaction time as well as eliminating the need for catalysts or solvents, making these processes viable alternatives for the traditional methods reported in literature for the synthesis of this class of compounds.     

Magnetic nanoparticles coated with anacardic acid derived from cashew nut shell liquid

Magnetic nanoparticles functionalized with biomolecules have received special attention due to their various biomedical applications, such as drug delivery and magnetic hyperthermia treatment for cancer. In this study, we present the synthesis and characterization of new nanoparticles coated with anacardic acid derived from cashew nut shell liquid. The results showed that Fe₃O₄ nanoparticles coated with anacardic acid (AA-MAG) have superparamagnetic behavior and the magnetization is almost equal when compared with the pure Fe₃O₄. This coating provides stability by preventing the aggregation nanoparticles without losing its magnetization potential. The AA-MAG demonstrates excellent and fast magneto-temperature response which can be used as high-performance hyperthermia agents.     

Grain Size Control of the Magnetic Nanoparticles by Solid State Route Modification

The CoFe₂O₄ and NiFe₂O₄ nanoparticles were synthesized exploiting a co-precipitation method and afterward calcinated at 400 °C through two different experimental apparatus: a conventional muffle and rotatory oven. X-ray diffraction (XRD) analysis revealed that nanocrystalline ferrites grew with a face center cubic structure (fcc) and Fd3m symmetry space group. XRD, transmission electron microscopy, and magnetic measurements confirmed the compositional homogeneity and the narrow size particle distribution (6-8 nm) of the sample thermally treated in a rotary oven, in all likelihood due to the sample’s constant turning movement. The size of the magnetic particles is extremely important and influences the choice of a potential technological application. For this reason, our study emerges as a new and simple innovating procedure to control the size of magnetic nanoparticles.     

Cardanol biocomposites reinforced with jute fiber: Microstructure,biodegradability, and mechanical properties

This work aims at studying the preparation and characterization of composites of phenolic resin (matrix) based on cashew nut shell liquid, reinforced by natural jute fibers. The fibers were chemically modified using alkaline treatment with solutions of NaOH (5 and 10%) and bleached with sodium hypochlorite NaClO/H₂0 (1:1) at 60–75°C. The microstructure was investigated by Scanning Electron Microscopy to observe the fiber surface after the treatment. As a result, there was an improvement in the thermal stability of the fiber, which was verified by Thermogravimetric Analysis. The jute fiber composites showed an improvement in their mechanical properties due to chemical treatment with 5% NaOH. Their biodegradability level depended on the employed alkali solution concentration. This study is important to evaluate the application of the fibers as renewable materials. POLYM. COMPOS., 31:1928–1937, 2010. © 2010 Society of Plastics Engineers.