Conceptual delimitations regarding the terminology used in the methods of investigating the future paper title

The authors propose the conceptual delimitation regarding the terminology used in the methods of investigating the future on the basis of a set of 7 variables. To this end, the hierarchical clusters? method will be used. The outcome of the research will be presented under the form of some clusters of terms with homogeneous meanings, almost synonyms, that would constitute the conceptual delimitation of the termsconceptual delimitation, anticipated future, cluster method

PREPARATION AND CHARACTERIZATION OF COMPOSITES COMPRISING MODIFIED HARDWOOD AND WOOD POLYMERS/POLY(VINYL CHLORIDE)

Chemical modification of hardwood sawdust from ash-tree species was carried out with a solution of maleic anhydride in acetone. Wood polymers, lignin, and cellulose were isolated from the wood sawdust and modified by the same method. Samples were characterized by Fourier transform infrared spectroscopy (FTIR), providing evidence that maleic anhydride esterifies the free hydroxyl groups of the wood polymer components. Composites comprising chemically modified wood sawdust and wood polymers (cellulose, lignin)-as variable weight percentages-, and poly (vinyl chloride) were obtained and further characterized by using FTIR spectroscopy and scanning electron microscopy (SEM). The thermal behavior of composites was investigated by using the thermogravimetric analysis (TGA). In all cases, thermal properties were affected by fillers addition

Synthesis and Characterization of New Ferrite-Lignin Hybrids

The paper presents the synthesis and characterization of new cobalt ferrite-lignin hybrids. The hybrids were obtained through the combustion of cobalt nitrate and ferric nitrate, two kinds of lignin being used as combustion agents. The temperatures of calcination were 500 °C and 900 °C, respectively. The hybrids were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS). The magnetic properties were also assessed by vibrating sample magnetometer system (VSM). This facile synthesis method made it possible to obtain cobalt ferrite-lignin hybrids with a spinel structure. Their particle sizes and crystallite sizes have increased with an increment in the calcination temperature. A different occupancy of cations at octahedral and tetrahedral sites also occurred upon the increase in temperature. The hybrids comprising organic lignin presented the best magnetic properties

Development and Characterization of Novel Cellulose Composites Obtained in 1-Ethyl-3-methylimidazolium Chloride Used as Drug Delivery Systems

Two polysaccharides (cellulose and chitosan) and polyurethane dissolved in 1-ethyl-3-methylimidazolium chloride represented the matrix for the obtainment of new composite formulations comprised of lignin, ferrite–lignin hybrid and ketoconazole. The mechanical performances (Young’s modulus and compressive strength) increased with the filler addition. The nature of the filler used in the studied formulations influenced both bioadhesion and mucoadhesion parameters. It was found that the incorporation of lignin and ferrite–lignin hybrid into the matrix has influenced the in vitro rate of ketoconazole release, which is described by the Korsmeyer–Peppas model. All materials exhibited activity against Gram positive (Staphylococcus aureus ATCC 25923) and Gram negative (Escherichia coli ATCC 25922) bacteria

Design, characterization and preliminary biological evaluation of new lignin-PLA biocomposites

The study focuses on the obtainment of new poly (lactic acid)-lignin biocomposites. The effect of lignin loading on the morphology and mechanical properties, as well as the water uptake behaviour of the obtained biocomposites, was investigated in order to elucidate the influence of lignin incorporation into a poly (lactic acid) matrix. The addition of 7% lignin improved the Young modulus and led to a decrease in the tensile strength in comparison with the corresponding values of the poly (lactic acid) matrix, while the water sorption capacity slowly decreased. A subsequent increment in lignin loading from 7 to 15wt% resulted in an increase in tensile strength, as well as in a decline in the water sorption capacity. These results show the importance of the lignin content in controlling the properties of such composites. Furthermore, the behaviour of the PLA-lignin biocomposites in SBF was another concern for evaluation of mechanical performance and biological activity. The mechanical performance declined after immersion in simulated body fluid, but the properties of the biomaterials remained sufficiently high for the perspective of their use in medical applications. In-vitro biocompatibility studies evidenced that the addition of lignin to a poly (lactic acid) matrix can allow tailoring the final properties of the composites without inducing any significant change in cell metabolic activity (compared to poly (lactic acid) itself)

Some preliminary data on the enzymatic hydrolysis of Pinus pinaster kraft pulp

Enzymes' applications in pulp and paper manufacturing processes and products is gaining global attention. In fact, several applications, including pitch deposits, drainage enhancement, deinking of wastepapers, pulp bleaching enhancement and modification of fibers' characteristics are already used at industrial level. Enzymes are being produced on a commercial scale and are available at a relatively low price. Research to establish the effect of enzymatic treatment continues in an effort to increase knowledge about the action of enzymes. The present paper, an additional contribution to this field, studies the potential utilization of hydrolytic enzymes to enhance the fiber characteristics derived from Pinus pinaster kraft pulp

PLA/chitosan/keratin composites for biomedical applications

Novel composites based on PLA, chitosan and keratin was obtained via blend preparation. The goal of this contribution was to evaluate mechanical and in vitro behavior of the composites. The results point out composites with improved Young modulus and decreased tensile strength, significant increase in hardness (compared to PLA) and a good uptake of the surface properties. Biological assessments using human osteosarcoma cell line on these composites indicate a good viability/proliferation outcome. Hence preliminary results regarding mechanical behavior and in vitro osteoblast response suggest that these composites might have prospective application in medical field

Insight into Potential Biomedical Application of Mesoporous Materials

The physicochemical properties of many drugs have a decisive impact on their bioavailability, as well as the pharmacokinetic efficiency in various disease therapeutics. That is why mesoporous materials have attracted a special interest in the drug delivery field, facilitating the loading of drugs into their pores due to their high surface area and porosity. The interfacial interactions established with drug molecules represent the driving force for efficient drug loading and controlled release kinetics. Moreover, these materials offer an optimal design for implantable local-delivery devices or for improving the accuracy of imaging techniques in clinical diagnosis. Their use is validated by improvements in therapeutic outcome and prevention of side effects. This review discusses the role of mesoporous materials in different biomedical applications

CHEMICAL MODIFICATION OF BEECH WOOD: EFFECT ON THERMAL STABILITY

Beech sawdust was reacted with phthalic (PA) and maleic (MA) anhydrides for chemical modification. The influence of reaction time and anhydride amount was investigated. IR spectra gave evidence of wood esterification. Thermogravimetric investigation of chemically modified wood indicated a better thermal stability (mainly for wood treated with phthalic anhydride) in comparison with the untreated wood

Influence of xilanase treatment on Pinus pinaster kraft pulp

In Portugal, pulp and paper industry uses especially two wood species, Eucalyptus globules and Pinus pinaster. The second species gives pulps with low bleachability (compared with other common softwood species, like Pinus silvester), utilised for packaging papers. It is known that treatments with different hydrolytic enzymes could improve the bleaching capacity of softwood pulp. That is why, xylanases were used to improve Pinus pinaster kraft pulp characteristics. The enzymatic hydrolysis improved brightness and some papermaking properties