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Background: Very little is known about food products of tropical cattle. This study comprehensively determined composition and physical properties of the Gambian N'Dama cow milk together with the factors affecting them.Methods: Milk samples of 233 cows collected during rainy and early dry seasons were analyzed in triplicates with an ultrasonic milk analyzer for nine parameters. Effects of region of sampling, age, packed red blood cell volume, coat color, number of daily milking, feeding types, and season of milk sampling were investigated. The data were analyzed using general linear model with the univariate procedure. Pairwise comparisons based on estimated marginal means were conducted using the least significant difference option.Results: Concerning coefficient of variation, fat and electrical conductivity have the highest variabilities of 43.29% within milk components and 13.46% within physical properties, respectively. The estimated marginal means for total solids, fat, solids-not-fat, protein, lactose, salts, conductivity, freezing point, and density of N'Dama milk are 14.75 +/- 0.48%, 5.70 +/- 0.39%, 9.05 +/- 0.12%, 3.31 +/- 0.04%, 4.95 +/- 0.07%, 0.75 +/- 0.01%, 3.57 +/- 0.07 mS/cm,-0.599 +/- 0.010 degrees C, and 1030.73 +/- 0.35 kg/m3, respectively.Significance: This study contributes to development of database concerning nutritional importance of milk from tropically adapted cattle., West Africa Livestock Innovation Centre, The Gambia; Ege University Scientific Research Projects Coordination Unit, Tuerkiye [WALIC/EGE/AS/2/2019]; [FDK-2020-20774], This work was partially supported by the West Africa Livestock Innovation Centre, The Gambia [Ref: WALIC/EGE/AS/2/2019] and Ege University Scientific Research Projects Coordination Unit, Tuerkiye [Project Number: FDK-2020-20774].

Expanding suitable severe plastic deformation processes seems essential to design lightweight wire-formed materials for emerging demands. In this regard, 6063 aluminum alloy in the form of wire was processed successfully by polyurethane rubber assisted-equal channel angular pressing up to 16 passes by route BC. It was found that significant improvement of hardness and strength is achieved at the initial passes due to the increment of material’s dislocations density which leads to the crystallite size decrease and lattice microstrain increase. Also, subsequent passes improve the mechanical properties with a gentle rate due to the saturation of dislocation strengthening. The fractography analysis indicated that the ductile fracture mode of the annealed aluminum decreases by imposing the ECAP process. It is related to the formation of cleavage and rive patterns and the reduction in the number and size of the dimples compared to the initial condition. Eventually, X-ray diffraction findings showed that by adding pass numbers, the isotropy degree of the aluminum sample enhances because of the lowest diffraction scattering.

Recent theoretical advances, based on a combination of concepts from Thouless' topological theory of adiabatic charge transport and a newly introduced gauge-invariance principle for transport coefficients, have permitted to connect (and reconcile) Faraday's picture of ionic transport -- whereby each atom carries a well-defined integer charge -- with a rigorous quantum description of the electronic charge-density distribution, which hardly suggests its partition into well defined atomic contributions. In this paper we review these progress and in particular that, by relaxing some general topological conditions, charge may be transported in ionic conductors without any net ionic displacements. After reporting numerical experiments which corroborate these findings, we introduce a new connection between our topological picture and the well-known Marcus-Hush theory of electron transfer, which we are able to connect with the topology of adiabatic paths drawn by atomic trajectories. As a significant byproduct, the results reviewed here permit to classify different regimes of ionic transport according to the topological properties of the electronic structure of the conducting material. We finally report on a few recent applications to energy materials and planetary sciences., 16 pages, 9 figures

Imaging subsurface small-scale features and monitoring transport of tracer plumes at a fine resolution is of interest to characterize transport processes in aquifers. Full-waveform inversion (FWI) of crosshole ground penetrating radar (GPR) measurements enables aquifer characterization at decimeter-scale resolution. The method produces images of both relative dielectric permittivity (εr) and bulk electrical conductivity (σb) that can be related to hydraulic aquifer properties and tracer distributions. To test the potential of time-lapse GPR FWI for imaging tracer plumes, we conducted a numerical tracer experiment by injecting saline water, desalinated water, and ethanol in a heterogeneous aquifer. The saline and desalinated tracers only changed σb, whereas ethanol changed both εr and σb. Tracer concentrations were retrieved from the inverted εr and σb models using information about petrophysical parameters. GPR FWI εr and σb tracer images could recover preferential paths of ∼0.2 m width, while the derived σb structures are smoother. FWI of 50 time-lapse data sets demonstrated the potential of the FWI to derive spatially resolved breakthrough curves of the saline and ethanol tracer in the image plane between the boreholes. Thus, high-resolution imaging with GPR FWI of tracers that produce a high permittivity contrast against the background has a great potential for characterization of heterogeneous transport in aquifers.

Next-generation implantable devices such as sensors, drug-delivery systems, and electroceuticals require efficient, reliable, and highly miniaturized power sources. Existing power sources such as the Li-I-2 pacemaker battery exhibit limited scale-down potential without sacrificing capacity, and therefore, alternatives are needed to power miniaturized implants. This work shows that ceramic electrolytes can be used in potentially implantable glucose fuel cells with unprecedented miniaturization. Specifically, a ceramic glucose fuel cell-based on the proton-conducting electrolyte ceria-that is composed of a freestanding membrane of thickness below 400 nm and fully integrated into silicon for easy integration into bioelectronics is demonstrated. In contrast to polymeric membranes, all materials used are highly temperature stable, making thermal sterilization for implantation trivial. A peak power density of 43 mu W cm(-2), and an unusually high statistical verification of successful fabrication and electrochemical function across 150 devices for open-circuit voltage and 12 devices for power density, enabled by a specifically designed testing apparatus and protocol, is demonstrated. The findings demonstrate that ceramic-based micro-glucose-fuel-cells constitute the smallest potentially implantable power sources to date and are viable options to power the next generation of highly miniaturized implantable medical devices., Advanced Materials, 34 (24), ISSN:0935-9648, ISSN:1521-4095

An ohmic assisted vacuum evaporation (OAVE) processes was used to concentrate orange juice from 11.4% total soluble solid content (TSSC) to 42% TSSC by applying 13 V/cm constant voltage gradient at different temperatures. The evaporation temperatures were adjusted to 100 degrees C, 85 degrees C, 75 degrees C and 65 degrees C by setting absolute system pressures of 101.32 kPa, 58 kPa, 39 kPa and 25 kPa, respectively. The total time for the processes, including heating and evaporation, was 34, 40, 48, and 54 min for 100, 85, 75, and 65 degrees C, respectively. As the evaporation temperature increased, the applied energy required for phase change decreased while maximum current values increased from 0.6 A at 65 degrees C to 2.52 A at 100 degrees C. During any given run, the current value increased as the orange juice pulp heated up, but then decreased after it began to boil, leading to a reduction in the rate of heat generation. Increasing evaporation temperature has a positive effect on evaporation rates, energy efficiency, specific water removal ratio (SWRR), exergy efficiency, and Improvement Potential (IP) (p < 0.05). The reduced energy requirement with higher temperature is partially due to reduced work from the vacuum pump at the higher absolute pressure. (c) 2021 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.

The skin depth delta describes the ability of electromagnetic radiation (particularly microwave) to penetrate a material. This ability is relevant to radar-related applications, electromagnetic interference shielding and telecommunication. However, the values of delta have not been adequately reported for cement-based materials and the effect of the absorption distance (thickness) on delta has not been previously addressed. This work reports and clarifies delta (3.5 mm-12 mm) of cured cement paste. The previously and scantily reported delta values of cement-based materials are mostly incorrect, with discrepancy as large as three orders of magnitude, due to the flaws in the method of delta determination. In addition, this work reports the thickness dependence of delta of a cement-based material for the first time. Due to the Skin effect, delta increases with increasing thickness, with the fractional increase in delta per unit thickness 1.15, which is high because delta (3.5-12 mm) exceeds the thickness (2.61-8.26 mm), so that the electric field decays precipitously as it traverses through the thickness. In contrast, for aluminum, the fractional increase in delta per unit thickness is 0.080, which is low because the thickness exceeds delta, so that the electric field decays gradually. The delta of cement paste tends to decrease slightly with increasing frequency (8.5-11.5 GHz).

In the realm of solids, metal–organic frameworks (MOFs) offer unique possibilities for the rational engineering of tailored physical properties. These derive from the modular, molecular make-up of MOFs, which allows for the selection and modification of the organic and inorganic building units that construct them. The adaptable properties make MOFs interesting materials for photocatalysis, an area of increasing significance. But the molecular and porous nature of MOFs leaves the field, in some areas, juxtapositioned between semiconductor physics and homogeneous photocatalysis. While descriptors from both fields are applied in tandem, the gap between theory and experiment has widened in some areas, and arguably needs fixing. Here we review where MOFs have been shown to be similar to conventional semiconductors in photocatalysis, and where they have been shown to be more like infinite molecules in solution. We do this from the perspective of band theory, which in the context of photocatalysis, covers both the molecular and nonmolecular principles of relevance.

Magnetic fields provide a window into a planet’s interior structure and evolution, including its atmospheric and space environments. Satellites at Mars have measured crustal magnetic fields indicating an ancient dynamo. These crustal fields interact with the solar wind to generate transient fields and electric currents in Mars’s upper atmosphere. Surface magnetic field data play a key role in understanding these effects and the dynamo. Here we report measurements of magnetic field strength and direction at the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) landing site on Mars. We find that the field is ten times stronger than predicted by satellite-based models. We infer magnetized rocks beneath the surface, within ~150 km of the landing site, consistent with a past dynamo with Earth-like strength. Geological mapping and InSight seismic data suggest that much or all of the magnetization sources are carried in basement rocks, which are at least 3.9 billion years old and are overlain by between 200 m and ~10 km of lava flows and modified ancient terrain. Daily variations in the magnetic field indicate contributions from ionospheric currents at 120 km to 180 km altitude. Higher-frequency variations are also observed; their origin is unknown, but they probably propagate from even higher altitudes to the surface. We propose that the time-varying fields can be used to investigate the electrical conductivity structure of the martian interior. The magnetic field measured by the InSight lander on Mars varies daily and is ten times stronger than expected. The field is inferred to originate from components of basement rocks magnetized by an ancient dynamo of Earth-like strength.

If a magnetic dipole is placed above the surface of the earth, the Electromagnetic Induction (EMI) effect, encoded in Maxwell's equations, causes eddy currents in the soil which, on their turn, induce response electromagnetic fields. The magnetic field can be measured in geophysical surveys to determine the conductivity profile of the ground in a non-destructive manner. The forward model used in the inversion of experimental data usually consists of a set of horizontal homogeneous layers. A frequently used analytical model, proposed by McNeill, does not include the interaction between the eddy currents, and therefore fails for larger conductivities. In this paper we construct a new forward, analytical, model to estimate the magnetic field caused by a horizontally stratified earth but which approximates the interaction between eddy currents. This makes it valid for a broader range of parameters than the current state of the art. Furthermore, the error with the (numerically obtainable) exact result is substantially decreased. We also calculate the vertical sensitivity ("depth of exploration") of the model and observe that it is in good agreement with the values obtained from the exact model., Comment: Accepted for publication in Exploration Geophysics

We report the electronic structure of two metal-organic frameworks (MOFs) with copper paddle wheel nodes connected by a N2(C2H4)3 (DABCO) ligand with accessible nitrogen lone pairs. The coordination is predicted, from first-principles density functional theory, to enable electronic pathways that could facilitate charge carrier mobility. Calculated frontier crystal orbitals indicate extended electronic communication in DMOF-1, but not in MOF-649. This feature is confirmed by bandstructure calculations and effective masses of the valence band egde. We explain the origin of the frontier orbitals of both MOFs based on the energy and symmetry alignment of the underlying building blocks. The effects of doping on the bandstructure of MOF-649 are considered. Our findings highlight DMOF-1 as a potential semiconductor with 1D charge carrier mobility along the framework

[EN] In this study, real-time and in-situ permittivity measurements under intense microwave electromagnetic fields are proposed as a powerful technique for the study of microwave-enhanced thermal processes in materials. In order to draw reliable conclusions about the temperatures at which transformations occur, we address how to accurately measure the bulk temperature of the samples under microwave irradiation. A new temperature calibration method merging data from four independent techniques is developed to obtain the bulk temperature as a function of the surface temperature in thermal processes under microwave conditions. Additionally, other analysis techniques such as Differential Thermal Analysis (DTA) or Raman spectroscopy are correlated to dielectric permittivity measurements and the temperatures of thermal transitions observed using each technique are compared. Our findings reveal that the combination of all these procedures could help prove the existence of specific non-thermal microwave effects in a scientifically meaningful way., The authors wish to thank the project MAT2017-86450-C4-1-R.

Graphene/polymer composites can be spun into fibers with remarkable mechanical, thermal and electrical properties, but few studies have considered requirements for the pilot-scale production of such fibers using commercially available graphene nanoplatelets (GnP). To address this limitation, we fabricated melt-spun polyamide 6 (PA6) multifilament yarns in which 3% or 5% (w/w) GnP was incorporated into the PA6 matrix by melt compounding during the initial process step. We tested a range of melt-spinning process parameters and analyzed the properties of the resulting fibers in detail. We were able to fabricate yarns containing 24 single filaments at a maximum winding speed of 1800 m/min while applying a draw ratio of 2.5. The electrical conductivity of the as-spun yarns was in the 10 mS/m range, which is suitable for the production of anti-static textiles. Furthermore, the degree of crystallization declined as the GnP content increased, reducing the tenacity of the yarn but improving its elastic modulus, allowing the production of composite textiles. In conclusion, we confirmed that large amounts of graphene can be incorporated into PA6 polymers by melt spinning and that the resulting composite fibers are suitable for multiple downstream applications in the textile industry. (C) 2018 The Authors. Published by Elsevier Ltd.

In the framework of Higgs inflation, we consider the electromagnetic field nonminimally coupled to gravity via the parity-preserving $\propto RF^{2}$ and parity-violating $\propto RF\tilde{F}$ terms. Using the perturbation theory to the leading order in these couplings, we study the generation of the electromagnetic field during the inflation stage. We derive the effective kinetic and axial coupling functions arising in the Einstein frame in the usual metric as well as Palatini formulations of gravity. For both formulations, we determine the power spectrum, energy density, and helicality of the generated electromagnetic fields for different values of the nonminimal coupling constants. Finally, we estimate the maximal present-day magnitude of the magnetic field as $10^{-14}-10^{-15}\,$G with the correlation length of order 10 pc., 23 pages, 10 figures

The thermal environment can affect the evolution of morpho-behavioral adaptations of ectotherms. Heat is transferred from substrates to organisms by conduction and reflected radiation. Because brightness influences the degree of heat absorption, substrates could affect the evolution of integumentary optical properties. Here, we show that vipers (Squamata:Viperidae) inhabiting hot, highly radiative and superficially conductive substrates have evolved bright ventra for efficient heat transfer. We analyzed the brightness of 4161 publicly available images from 126 species, and we found that substrate type, alongside latitude and body mass, strongly influences ventral brightness. Substrate type also significantly affects dorsal brightness, but this is associated with different selective forces: activity-pattern and altitude. Ancestral estimation analysis suggests that the ancestral ventral condition was likely moderately bright and, following divergence events, some species convergently increased their brightness. Vipers diversified during the Miocene and the enhancement of ventral brightness may have facilitated the exploitation of arid grounds. We provide evidence that integument brightness can impact the behavioral ecology of ectotherms., Jonathan Goldenberg et al. use photographic data and ancestral state reconstruction of 126 viper species to show that substrate type influences the evolution of ventral brightness for efficient heat transfer. Their results suggest that these patterns may have been involved in the diversification of vipers during the Miocene, and highlight the importance of ventral body regions when considering behavioral ecology and evolution.

We present a new numerical scheme for solving one-dimensional conduction problems and in the radial direction of a spherically symmetric body or shell with variable spatial domain. This numerical scheme adopts a solution of the conduction equation in each interval of the chosen discretization which is valid if the fluxes at the interval boundaries are constant in time. This ‘piece-wise steady flux’ (PWSF) numerical scheme is continuous and differentiable in the space domain. These smoothness properties are convenient for implementing the numerical scheme in an energy-conserved thermal evolutionapproach for a terrestrial core in which a conductive thermally stratified layer is considered that develops below the core-mantle boundary when the heat flux drops below the adiabatic heat flux. The influence of a time-variable thermally stratified region on the general evolution of the planetary body is examined, in comparison to imposing an adiabatic temperature profile for the entire core. Also, the dependence of the model's accuracy to the applied grid size of the numerical scheme is studied. We showed that a very low numerical resolution of this approach suffices for obtaining a thermal evolution of a partially conductiveplanetary corewith high accuracy. By considering thermal stratification in a planetary core where the heat flux is lower than the adiabatic heat flux, radial variations in the cooling rate are accounted for whereas otherwise the distribution of energy in the core is fixed by the imposed adiabat. During the growth of the thermally stratified region, the deep part of the core cools more rapidly than the outer part of the core. Therefore, the inner core grows to a larger size and the temperature and heat flux at the core-mantle boundary are higher and larger, respectively, if a thermally stratified region is considered. For the Earth, the implications are likely very minor and can be neglected in thermal evolution studies that are not specifically interested in the thermally stratified region itself. For Mercury, however, these implications are larger. For example, the age of Mercury's inner core can be underestimated by about a billion of years if thermal stratification is neglected. The consideration of thermal stratification in Mercury's core is also important for the evolution of Mercury's mantle. It increases the mantle temperature, leads to a higher Rayleigh numberand therefore a larger heat flux into the lithosphere and prolongationof mantle convection.

Temporary streams and their dynamics have often been largely overseen in hydrological research and there is relatively little knowledge about how the occurrence of flow in these streams varies temporally and spatially. Temporary streams are important from a hydro- logical perspective because they affect water quantity and quality in downstream peren- nial reaches, and from an ecological perspective because they provide habitat to unique species. In order to gain knowledge about these important streams, this maser thesis was conducted, within the Msc program in Water and Environmental Engineering at Uppsala University and the Swedish University of Agricultural Sciences, in collaboration with the Hydrology and Climate group at the University of Zurich. In this study, the temporal and spatial variation of the temporary streams in a small pre-Alpine catchment in Switzerland were investigated, both in terms of the presence of flowing water and stream chemistry. The 20 ha Studibach catchment is typical for the pre-Alpine area, with frequent precipi- tation. The streams in the lower part of the Studibach catchment were mapped in the field during September 2020. The temporal and spatial variations of the presence of flow and stream chemistry within the stream network was investigated in September and October 2020 during varying weather conditions. During ten field campaigns the flow state of the streams was classified and the Electrical Conductivity (EC) of the streams was mea- sured approximately every 20 meter. The findings from the field campaigns were related to topographic indices, in particular the Topographic Wetness Index (TWI) and Upslope Accumulated Area (A), in order to see how topography influenced the presence of stream- flow and stream EC. The results show a high temporal and spatial variation in both stream chemistry and streamflow. The active network length expanded by a factor of two in re- sponse to precipitation events. The stream EC also had a large spatial variation, and the streams in the southeast part of the catchment had a higher EC than the other streams. This spatial variation is expected to reflect the large variability in groundwater EC within the catchment. The spatial variation of the streamflow demonstrated a difference between the north-middle and the south part of the catchment, where the south part responded quicker to events and drained and retracted faster after the event. The findings also indicate that topographic indices can predict the occurrence of flow in the stream network, with sites with higher topographic index values having a higher probability of flowing water in the stream. Topography also influences the stream chemistry. The variation in stream chem- istry was smaller for sites with higher values for the topographic indices, something that can be explained by the Representative Elementary Area (REA) concept, because sites with higher topographic index values are located further downstream and water at these locations is a mixture of the smaller streams that feed these streams. Temporära bäckar och dess dynamik har länge varit förbisedda inom hydrologisk forskn- ing, och en djupgående kunskap rörande temporära och rumsliga variationer saknas. Tem- porära bäckar är viktiga utifrån ett hydrologisk perspektiv eftersom de påverkar både kvantitet och kvalitet på vattnet nedströms, och från ett ekologiskt perspektiv eftersom de bidrar med habitat till unika arter. Detta examensarbete har genomförts för att öka kunskapen kring dynamiken i dessa temporära nätverk. Examensarbetet genomfördes inom Civilingenjörsprogrammet i Miljö och Vattenteknik vid Uppsala Universitet och Sveriges Lantbruksuniversitet, i ett samarbete med Hydrologi- och Klimatgruppen vid University of Zurich. Studien har undersökt temporära och rumsliga variationer i ett tem- porärt bäcknätverk med avseende på flöden och kemin i vattnet, i ett mindre pre-alpint avrinningsområde i centrala Schweiz. Bäckarna i den nedre delen av avrinningsområdet Studibach karterades i fält för hand med karta och kompass under september 2020. Avrin- ningsområdet är på 20 ha och räknas som typiskt för ett pre-Alpint område, med frekvent nederbörd. Tio fältkampanjer genomfördes där temporära och rumsliga variationer un- dersöktes genom klassificering av flöden och mätningar av Elektrisk Konduktivitet (EC) i bäckarna ungefär var 20e meter, under september och oktober 2020 i varierande väder- förhållanden. Resultaten från fältkampanjerna relaterades till de topografiska indexen Topographic Wetness Index (TWI) och Upslope Accumulated Area (A) för att undersöka hur topografin påverkar flöden och bäckkemin. Studien kom fram till att bäckarna i den nedre delen av Studibach visar både en temporär och en rumslig variation för både flöde och bäckkemi. De aktiva bäckarna i nätverket visade på en expansion med en faktor två som svar på nederbörd. En rumslig variation för flödet påträffades även mellan den södra och nord-centrala delen av nätverket där den södra svarade snabbare mot event och även drogs ihop snabbare. Kemin i bäckvattnet visade på en stor rumslig variation, med högt EC i den sydöstra delen av avrinningsområdet, vilket förmodas bero på den stora rumsliga variationen av EC i grundvattnet. Resultaten visar även på att topografiska index kan till viss del förutspå flöden i bäckarna, där platser med högre topografiska index har högre sannolikhet att det flödar i bäcken. Topografin påverkar även bäckkemin. Variationen i bäckkemin var mindre för platser med högre topografiska index, vilket kan förklaras med Representative Elementary Area (REA) konceptet, eftersom platser med högre to- pogragiska index värden återfinns längre nedströms och vattnet på dessa platser är en blandning av de mindre bäckarna som tillför vattnet till de större.

Ohmic evaporation is a complex process in which heat and mass transfers take in place simultaneously. In this study, finite difference-FD and finite volume-FV models simulating the changes of temperature and water removed from tomato juice during the vacuum ohmic evaporation process (VOEP) were developed. Models considering the heat and mass transfer equations were combined. Experimental effective electrical conductivity and specific heat capacity relations were taken into account. For heating period, final temperature was predicted with errors of 3.4 ± 1.3 °C and 0.7 ± 1.3 °C, while the evaporation time prediction errors were 1.3 ± 1.6 min and ? 2.1 ± 1.6 min for FV and FD models, respectively. It was concluded the effect of mixing was not important on temperature distribution for such a high consistency tomato paste compared to the heat generation effect during the ohmic evaporation process. The developed models could be used to predict process time, temperature history, and volume fraction at any time during the ohmic evaporation process. © 2020 Elsevier Ltd, 217O069 Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK, This research was supported financially by the Scientific and Technical Research Council of Turkey , TUBITAK, Project No: 217O069 .

We report a new, open-source, MATLAB-based 3D code for numerically simulating the self-potential (SP) in subsurface reservoirs. The code works as a post-processor, using outputs from existing reservoir flow and transport simulators at a selected timestep to calculate the SP throughout the reservoir model. The material properties required to calculate the SP are user defined and may be constant or vary in each cell. The code solves the equations governing flow and transport of electrical charge and global charge conservation using a control-volume-finite-difference scheme. Electrical currents associated with the SP may spread beyond the reservoir model domain, and the code allows for the domain to be extended vertically and laterally to account for this. Here, we present the governing equations and the numerical method used and demonstrate application of the code using an example in which we predict the SP signals associated with oil production from a subsurface reservoir supported by water injection.

Sub-microfibers and nanofibers produce more breathable fabrics than coarse fibers and are therefore widely used in the textiles industry. They are prepared by electrospinning using a polymer solution or melt. Solution electrospinning produces finer fibers but requires toxic solvents. Melt electrospinning is more environmentally friendly, but is also technically challenging due to the low electrical conductivity and high viscosity of the polymer melt. Here we describe the use of colorants as additives to improve the electrical conductivity of polylactic acid (PLA). The addition of colorants increased the viscosity of the melt by &gt, 100%, but reduced the electrical resistance by &gt, 80% compared to pure PLA (5 G&Omega, ). The lowest electrical resistance of 50 M&Omega, was achieved using a composite containing 3% (w/w) indigo. However, the thinnest fibers (52.5 &micro, m, 53% thinner than pure PLA fibers) were obtained by adding 1% (w/w) alizarin. Scanning electron microscopy revealed that fibers containing indigo featured polymer aggregates that inhibited electrical conductivity, and thus increased the fiber diameter. With further improvements to avoid aggregation, the proposed melt electrospinning process could complement or even replace industrial solution electrospinning and dyeing.

This study was conducted to determine the milk yield and quality of Kivircik sheep under breeders' conditions. A total of 38 heads of Kivircik sheep in 3th or 4th lactation were used in the study. According to the results the mean daily milk yield was 495.5 g/day which was considered as a very wide variation in terms of milk control periods. Similar satiation was seen in somatic cell count which was ranged between 25.231 - 8.000.000 units/ml. Fat, solids not fat, protein, lactose, density, conductivity and pH values of milk samples taken during the control periods were found as 7.7%, 11.2%, 5.8%, 4.51%, 1.033 gcm(3-1), 3.9 mS cm(-1) and 6.90, respectively. Bu araştırma yetiştirici koşullarında bulunan Kıvırcık koyunlarında süt verim ve kalitesini ortaya koymak amacıyla yürütülmüştür. Araştırmada yaşları 3. ve 4. laktasyondaki toplam 38 baş Kıvırcık koyunu kullanılmıştır. Elde edilen sonuçlara göre günlük ortalama süt verimi 495.5 g/gün olup, süt kontrol dönemleri itibariyle çok geniş bir varyasyon göstermiştir. Benzer durum somatik hücre sayısında da görülmüş ve bu değer 25.231-8.000.000 adet/ml arasında değişim göstermiştir. Kontrol dönemlerinde alınan süt örneklerinde yağ, yağsız kuru madde, protein, laktoz, yoğunluk, iletkenlik ve pH değerleri sırasıyla %7.7, %11.2, %5.8, %4.51, 1.033 gcm3 -1, 3.9 mS cm-1 ve 6.90 olarak bulunmuştur.

Polymer-derived ceramics (PDC) have recently gained increased interest in the field of bioceramics. Among PDC's, carbon-rich silicon oxycarbide ceramics (SiOC) possess good combined electrical and mechanical properties. Their durability in aggressive environments and proposed cytocompatibility makes them an attractive material for fabrication of bio-MEMS devices such as pacemaker electrodes. The aim of the present study is to demonstrate the remarkable mechanical and electrical properties, biological response of PDCs modified with titanium (Ti) and their potential for application as pacemaker electrodes. Therefore, a new type of SiOC modified with Ti fillers was synthesized via PDC route using a Pt-catalyzed hydrosilylation reaction. Preceramic green bodies were pyrolyzed at 1000 degrees C under an argon atmosphere to achieve amorphous ceramics. Electrical and mechanical characterization of SiCxO2(1-x)/TiOxCy ceramics revealed a maximum electrical conductivity of 10 S cm(-1) and a flexural strength of maximal 1 GPa, which is acceptable for pacemaker applications. Ti incorporation is found to be beneficial for enhancing the electrical conductivity of SiOC ceramics and the conductivity values were increased with Ti doping and reached a maximum for the composition with 30 wt % Ti precursor. Cytocompatibility was demonstrated for the PDC SiOC ceramics as well as SiOC ceramics modified with Ti fillers. Cytocompatibility was also demonstrated for SiTiOC20 electrodes under pacing conditions by monitoring of cells in an in vitro 3D environment. Collectively, these data demonstrate the great potential of polymer-derived SiOC ceramics to be used as pacemaker electrodes.

An approach to induce conductivity in immiscible polystyrene/polypropylene (PS/PP) blends is described using a percolated conducting polyaniline/polyamide (PANI/PA) filler combined with a polystyrene‐block‐poly(ethylene‐ran‐butylene)‐block‐polystyrene‐graft‐maleic anhydride compatibilizer. The approach is based on the ability of the compatibilizer to concomitantly stabilize the cocontinuous morphology and to improve the state of dispersion of the PANI/PA filler. Selective localization of PANI/PA in the PS phase with improved filler dispersion is achieved with the optimal master batch (MB) preparation technique followed by its optimized sequence addition to the blend components. This results in an increase in the dc conductivity by six decades as compared with that of the neat compatibilized blend at an effective 4.8‐wt % PANI concentration. An investigation of the effect of functionality and concentration of the filler and the compatibilizer on the filler connectivity in the blend is performed. The prevailing specific interactions are analyzed by Fourier transform infrared spectroscopy and thermogravimetric analysis of the MBs. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48433.

Polymer derived SiOC and SiCN ceramics (PDCs) are interesting candidates for additive manufacturing techniques to develop micro sized ceramics with the highest precision. PDCs are obtained by the pyrolysis of crosslinked polymer precursors at elevated temperatures. Within this work, we are investigating PDC SiOC ceramic monoliths synthesized from liquid polysiloxane precursor crosslinked with divinylbenzene for fabrication of conductive electromechanical devices. Microstructure of the final ceramics was found to be greatly influenced by the pyrolysis temperature. Crystallization in SiOC ceramics starts above 1200 degrees C due to the onset of carbothermal reduction leading to the formation of SiC and SiO2 rich phases. Microstructural characterisation using ex-situ X-ray diffraction, FTIR, Raman spectra and microscopy imaging confirms the formation of nano crystalline SiC ceramics at 1400 degrees C. The electrical and mechanical properties of the ceramics are found to be significantly influenced by the phase separation with samples becoming more electrically conducting but with reduced strength at 1400 degrees C. A maximum electrical conductivity of 10(1) S cm(-1) is observed for the 1400 degrees C samples due to enhancement in the ordering of the free carbon network. Mechanical testing using the ball on 3 balls (B3B) method revealed a characteristic flexural strength of 922 MPa for 1000 degrees C amorphous samples and at a higher pyrolysis temperature, materials become weaker with reduced strength.

Conductive metal-organic frameworks are opening new perspectives for the use of these porous materials for applications traditionally limited to more classical inorganic materials, such as their integration into electronic devices. This has enabled the development of chemiresistive sensors capable of transducing the presence of specific guests into an electrical response with good selectivity and sensitivity. By combining experimental data with computational modelling, a possible origin for the underlying mechanism of this phenomenon in ultrathin films (ca. 30 nm) of Cu-CAT-1 is described. ispartof: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION vol:57 issue:46 pages:15086-15090 ispartof: location:Germany status: published

The mechanical properties of traditional dispersion-strengthened composites are greatly limited because of the weak interfacial bonding between the metal matrix and ex situ reinforcement. Here we report a copper matrix composite with high hardness strengthened by high-density dispersed nanoscale in situ boron, having great potential in structural and functional materials, such as wear-resistant bearings. The hardness of the composite can reach 3.04 GPa by a nanoindentation test. The composite was fabricated by a powder metallurgical process, in which the boron was produced in a copper melt directly. Nanotwins and lattice distortion zones observed in the phase boundaries may contribute to the ultrahigh hardness.

In this study, the effects of Cu and Fe additives on the structural, dielectric, magnetic, thermal and morphology of hydroxyapatite (HAp) samples were investigated and reported in detail for the first time. The prepared systems were also modeled and examined theoretically. It can be said that both additives affect the thermal behavior of the HAp structure. The addition of Cu affected the morphology of submicron-sized particles with spherical-like shapes with a low degree of agglomeration. Diffuse reflection data revealed that the energy band gap values decreased as Cu was added to the Fe-based HAp structure. The dielectric constant (epsilon') had high values at low frequencies in all samples and decreased with increasing frequency. It could be concluded that Fe/Cu incorporation to hydroxyapatites enhanced its thermal, magnetic, and dielectric properties required for mimicking natural HAps to open a successful venue for medical application in the healing regeneration of bone. Deanship for Scientific Research of Imam Abdulrahman Bin Faisal University [2020-170-IRMC] The authors acknowledge the financial supports provided by the Deanship for Scientific Research of Imam Abdulrahman Bin Faisal University (Project application No. 2020-170-IRMC) . Also, the authors acknowledge the facilities used at Institute for Research and Medical consultations (IRMC) at Imam Abdulrahman Bin Faisal University. WOS:000715133400001 2-s2.0-85118341098

In this paper, flow and heat transfer in a horizontal channel with isothermal walls has been investigated. The upper and lower plate have been kept at the two constant different temperatures, micropolar fluid is electrically conducting, while the channel plates have arbitrary electrical-conductivity. Applied magnetic field is perpendicular to the flow and the full MHD model is investigated. The general equations that describe the discussed problem under the adopted assumptions are reduced to ODE and closed-form solutions are obtained. The profiles of velocity, microrotation, induced magnetic and temperature fields in function of electrical-conductivity and the coupling parameter and the spin-gradient viscosity parameter together with electrical-conductivity, are graphically shown and discussed. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR 35016: Research of MHD flow in the channels, around the bodies and application in the development of the MHD pump]

In order to explore effect of structure on the temperature sensitivity of partially carbonized carbon fibers, different heat treatment temperatures (700, 750 and 800 °C) and heat treatment times (3 and 9 min) were used to prepare fibers with different structures. The electrical resistivities were monitored whilst the room temperature was increased from 30 to 100 °C, which was used to characterize the temperature sensitivity. The fibers showed negative temperature coefficients in the temperature range. Infrared spectra, an element analysis, a scanning electron microscope (SEM), Raman spectroscopy and X-ray diffraction measurements were used to study the microstructure of the fibers. Through the analysis, the proportions of the graphite-like structure, graphitization degree and size of the graphite-like structure crystallite influenced the temperature sensitivity. The main electron transfer method used for the fibers was variable-range hopping. This indicated that the fibers had a potential application of preparing thermistors in polymer composites.

Thermotropic liquid crystalline polymer (LCP) was melt-mixed with multi-walled carbon nanotubes (MWCNTs) in a conical micro-compounder. The state of dispersion of MWCNTs in the LCP matrix was characterized using transmission electron microscopy. FIR spectroscopic analysis revealed the nature of interaction between the LCP phase and the MWCNTs. The rheological properties of the nanocomposites showed a significant dependence on the MWCNTs content. The 'network-like' structures could be assigned to 'nanotube-nanotube' and 'polymer-nanotube' interactions. Nanoindentation studies indicated an increase in Young's modulus and hardness of LCP/MWCNTs composites. DMTA studies showed an increase in the storage modulus in the composites as a function of nanotube content. (C) 2017 Elsevier Ltd. All rights reserved.

Herein, we describe a phytosynthetic, additive-free, economically viable, environmentally sustainable and rapid methodology for the formation of sphere-shaped Ag-SnO2 nanocomposites of 9 nm average particle size employing the stem extracts of Saccharum officinarum. Employing various spectroscopic techniques, the morphology, size, crystallinity, elemental conformation, and functional groups liable for surface stabilization as well as capping were depicted. Considerably, the Ag-SnO2 nanocomposite in aqueous phase revealed excellent removal efficiency for the abatement of four industrially emerging pollutants (Methylene Blue, Rose Bengal, Methyl Violet 6B, and 4-nitrophenol) and probable mechanisms were also suggested. Nearly, 99.1, 99.6, 99.5, and 98.4% of Methylene Blue, Rose Bengal, Methyl Violet 6B, and 4-nitrophenol were eradicated respectively, within 60, 75, 75, and 58.3 min using the synthesized nanocomposite. Moreover, the spent nanocomposites were renewed and their photocatalytic proficiencies were assessed for three consecutive cycles. The spent nanocomposite and the degraded products were respectively analyzed using X-ray diffraction and liquid chromatography-mass spectrometry spectroscopic methods. Additionally, the nanocomposite displayed comparative antimicrobial action against Pseudomonas aeruginosa, Escherichia coli, and Bacillus subtilis and indicated fair activity on 2,2-diphenyl-1-picrylhydrazyl scavenging with IC50 values 0.73 mM depicting its efficient antimicrobial and antioxidant activity. Thus, the present article has disclosed a revolutionary way for fabricating Ag-SnO2 nanocomposites and depicted their multifunctional efficacy as photocatalysts and reducing and prospective antibacterial and antioxidant agents.

Metal-Organic Frameworks (MOFs) have gained much interest due to their intrinsic tunable nature. In this work, we study how linker functionalization modifies the electronic structure of the host MOF, more specifically the MIL-47(V)-R (R=-F, -Cl, -Br, -OH, -CH$_3$, -CF$_3$, and -OCH$_3$). It is shown that the presence of a functional group leads to a splitting of the $\pi$-orbital on the linker. Moreover, the upward shift of the split-off $\pi$-band correlates well with the electron withdrawing/donating nature of the functional groups. For halide functional groups the presence of lone-pair back donation is corroborated by calculated Hirshfeld-I charges. In case of the ferromagnetic configuration of the host MIL-47(V$^{\mathrm{+IV}}$) material a half-metal to insulator transition is noted for the -Br, -OCH$_3$, and -OH functional groups, while for the anti-ferromagnetic configuration only the hydroxy-group results in an effective reduction of the band gap., Comment: 11 pages, 4 figures, 3 Tables

The archetypal silica- and aluminosilicate-based zeolite-type materials are renowned for wide-ranging applications in heterogeneous catalysis, gas-separation and ion-exchange. Their compositional space can be expanded to include nanoporous metal chalcogenides, exemplified by germanium and tin sulfides and selenides. By comparison with the properties of bulk metal dichalcogenides and their 2D derivatives, these open-framework analogues may be viewed as three-dimensional semiconductors filled with nanometer voids. Applications exist in a range of molecule size and shape discriminating devices. However, what is the electronic structure of nanoporous metal chalcogenides? Herein, materials modeling is used to describe the properties of a homologous series of nanoporous metal chalcogenides denoted np-MX2, where M = Si, Ge, Sn, Pb, and X = O, S, Se, Te, with Sodalite, LTA and aluminum chromium phosphate-1 structure types. Depending on the choice of metal and anion their properties can be tuned from insulators to semiconductors to metals with additional modification achieved through doping, solid solutions, and inclusion (with fullerene, quantum dots, and hole transport materials). These systems form the basis of a new branch of semiconductor nanochemistry in three dimensions.

Electrospinning is widely used for the manufacture of fibers in the low-micrometer to nanometer range, allowing the fabrication of flexible materials with a high surface area. A distinction is made between solution and melt electrospinning. The former produces thinner fibers but requires hazardous solvents, whereas the latter is more environmentally sustainable because solvents are not required. However, the viscous melt requires high process temperatures and its low conductivity leads to thicker fibers. Here, we describe the first use of the biobased dyes alizarin, hematoxylin and quercetin as conductive additives to reduce the diameter of polylactic acid (PLA) fibers produced by melt electrospinning, combined with a biobased plasticizer to reduce the melt viscosity. The formation of a Taylor cone followed by continuous fiber deposition was observed for all PLA compounds, reducing the fiber diameter by up to 77% compared to pure PLA. The smallest average fiber diameter of 16.04 &micro, m was achieved by adding 2% (w/w) hematoxylin. Comparative analysis revealed that the melt-electrospun fibers had a low degree of crystallinity compared to drawn filament controls&mdash, resembling partially oriented filaments. Our results form the basis of an economical and environmentally friendly process that could ultimately, provide an alternative to industrial solution electrospinning