Fe-doped TiO2 prepared by mechanical alloying

The effect of different milling conditions on the formation of Fe-doped TiO₂ powders by mechanical alloying was investigated by Mössbauer spectrometry. The milling conditions investigated were ball to powder weight ratio, milling time, rotation velocity of supporting disc, and the type of starting reactive iron and its concentration. X-ray diffraction shows that high energy mechanical milling of undoped anatase TiO₂ induce the anatase to rutile phase transformation via high pressure srilankite. Mössbauer spectra for the majority of the doped samples were decomposed into one sextet and one or two doublets. The sextets was attributed to the presence of α-Fe or hematite impurities. The doublets were assigned to Fe^3?+? incorporated in the TiO₂ structure, and to the Fe^2?+? located either at the surface or the interstitial sites of TiO₂. A greater incorporation of Fe in the TiO₂ structure was observed when samples were prepared from hematite instead of α-Fe.     

DTA/TGA/DSC and densification data for iron phosphate glasses having natural UO2.67 or surrogate Bi2O3 added

Journal of Thermal Analysis and Calorimetry - A new set of iron-uranium phosphate glasses containing (1–20) UO2.67. (10–20) Fe2O3. (55–68) P2O5 (mass/%) were melted adequately....     

Soy protein–nanocellulose composite aerogels

Organic aerogels based on two important and widely abundant renewable resources, soy proteins (SP) and nanofibrillar cellulose (NFC) are developed from precursor aqueous dispersions and a facile method conducive of channel- and defect-free systems after cooling and freeze-drying cycles that yielded apparent densities on the order of 0.1 g/cm³. NFC loading drives the internal morphology of the composite aerogels to transition from network- to fibrillar-like, with high density of interconnected cells. Composite aerogels with SP loadings as high as ca. 70 % display a compression modulus of 4.4 MPa very close to that obtained from reference, pure NFC aerogels. Thus, the high compression modulus of the composite system is not compromised as long as a relatively low amount of reinforcing NFC is present. The composite materials gain moisture (up to 5 %) in equilibrium with 50 % RH air, independent of SP content. Furthermore, their physical integrity is unchanged upon immersion in polar and non-polar solvents. Fast liquid sorption rates are observed in the case of composite aerogels in contact with hexane. In contrast, water sorption is modulated by the chemical composition of the aerogel, with an important contribution from swelling. The potential functionalities of the newly developed SP–NFC composite green materials can benefit from the reduced material cost and the chemical features brought about the amino acids present in SPs.     

Considerations for Maintenance of Postural Alignment for Voice Production

There is general agreement that postural alignment is important in optimizing voice function. A number of articles have illuminated the way in which posture, particularly of the cervical spine, is directly related to vocal resonance and pitch control. Despite frequent involvement in muscle training, few speech pathologists have the background in exercise physiology necessary to appreciate the contribution of muscular length-tension relationships to postural alignment. The purpose of this article is to provide voice therapists with information to help them formulate appropriate recommendations for improving postural alignment. This article synthesizes information from the literature regarding the role of muscular length-tension balance in the attainment and maintenance of postural alignment. Important considerations in the assessment of muscle tension and weakness are presented along with advice regarding application to the treatment of voice-disordered patients. Concepts detailed include agonist/antagonist relationships, the biomechanics of stretching, postural assessment, and the relationship between muscle tension and muscle weakness. The role of both stretching and strength-based training is discussed. Specific exercises with emphasis on altering the alignment of the cervical and thoracic spine are presented with suggestions for their use in the clinic. There is growing understanding of the physiology behind recommendations of voice teachers and therapists to maintain optimal alignment. To effectively mediate postural misalignment, clinicians must have knowledge of the length-tension relationships between muscles. This understanding will lead to better interventions for postural alignment.     

Enhanced thermal conductivity of rheologically percolated carbon nanofiber reinforced polypropylene composites

Three different types of carbon nanofibers (CNF) were incorporated in the same polypropylene (PP) matrix by twin‐screw extrusion. The rheological and thermal properties were investigated. The rheological characterization of CNFs/PP composites as function of their volume fraction shows different microstructures: percolated and non‐percolated behaviors of their CNF's networks. In this work, the laser flash technique is employed in the experimental determination of the thermal diffusivity and conductivity of composites at room temperature. The ultimate aim is to correlate microstructure described by rheological analysis with final thermal properties. The results show that thermal diffusivity and conductivity are clearly higher for rheologically percolated composites suggesting that above certain critical content of nanofibers thermal transport is mainly controlled by percolated structures caused by interconnected CNFs' networks. Finally, thermal conductivity results are described by means of percolation theory from which an intrinsic thermal conductivity for the CNFs' network of approximately 6.5 W/m K, i.e. close to three times lower than some values reported in literature for SWCNTs' networks, was calculated. Copyright © 2015 John Wiley & Sons, Ltd.     

Scientometric Overview of Coffee By-Products and Their Applications

As coffee consumption is on the rise, and the global coffee production creates an excess of 23 million tons of waste per year, a revolutionary transition towards a circular economy via the transformation and valorization of the main by-products from its cultivation and preparation (Coffee Husk (CH), Coffee Pulp (CP), Coffee Silverskin (CS), and Spent Coffee Grounds (SCG)) is inspiring researchers around the world. The recent growth of scholarly publications in the field and the emerging applications of coffee by-products published in these scientific papers encourages a systematic review to identify the knowledge structure, research hotspots, and to discuss the challenges and future directions. This paper displays a comprehensive scientometric analysis based on 108 articles with a high level of influence in the field of coffee by-products and their applications. According to our analysis, the research in this field shows an explosive growth since 2017, clustered in five core applications: bioactive compounds, microbial transformation, environmental applications, biofuels from thermochemical processes, and construction materials.