Characterization Of Different Kinds Research Articles

Magneto-structural characterization of different kinds of magnetic nanoparticles

Using well-established measurement techniques like transmission electron microscopy (TEM), dynamic light scattering (DLS), small and wide angle X-ray scattering (SAXS, WAXS), susceptometry, and magnetorelaxometry, the distribution of the physical and magnetic size (magnetic moments) and magnetic anisotropy of a variety of structurally different magnetic nanoparticle samples (MNPs) is analyzed and compared. A term which accounts for the presence of weak magnetic areas (WMAs) within the MNPs was introduced to the widespread analysis model for M(H) data, enabling a consistent interpretation of the data in most of the systems. A comparison of the size distributions as obtained for the physical and the magnetic diameter suggests a multidomain structure for three single core systems under investigation, in all probability evoked by the presence of a wustite phase, as identified by WAXS.Analyzing the relationship d < dm < dc between the average single core diameter d, the effective magnetic (domain) size dm and the cluster diameter dc quantitatively, two qualitatively different magnetic structures in multicore MNP (MCMNP) systems were identified: (i) The magnetic moments of single cores within the MCMNP of fluidMAG tend to build flux closure structures, driven by dipole–dipole interaction. (ii) The magnetic behavior of Resovist® was attributed to the presence of domain sizes of about 12 nm within MCMNP, exceeding the single core diameters of 5 nm. Thereby, WAXS revealed a bimodal crystallite size distribution suggesting a crystallite merging process within the MCMNP. The value of the effective magnetic moment of these MCMNP could be explained within the presented “random moment cluster model” (RMCM).We conclude that the combination of physical and magnetic structure parameters obtained from complementary measurement methods allows a reliable assessment of the magnetic structure of single and multicore MNPs.

Narrative Structure of Herman Melville’s Moby-Dick

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Herman Melville is one of the greatest authors of American literature. His best known book is Moby-Dick. In this article I have tried to provide a brief overview of the narrative strategy used by Melville to create such a great masterpiece. It is focused on Melville’s style which is close to the modernist and post- modernist writings. Melville is ahead of the time he lived. The first phrase of Moby-Dick – “Call me Ismael” – may be considered as a one of the iconic lines in American Literature. The reader follows Ismael from Manhattan to Nantucket through the narration which is full of mysticism. The dark streets and Souter-Inn, crowded with the people of different origin, belief and skin color prepares the reader for a dangerous adventure. Moby-Dick shares also its style with Shakespearean tragedies, for example, King Lear. Both, Captain Ahab and King Lear, represent accursed, obstinate characters who decided to fight against the fate. Melville, using his experience as a member of the crew of whale ship, gives circumstantial description of sailors’ lifestyle and provides characterization of different kinds of whales. It makes this book a very interesting and completed encyclopedia about the whales and the life in the sea in general. Moby-Dick’s narrative structure moves and “floats” like “Pequod” in the deep, endless ocean. Melville’s writing style seems to be quite complex and intricate which captures the reader from the very first sentence and captivates their minds forever.

The Interplay Between Chamber Musicians During Two Public Performances of the Same Piece: A Novel Methodology Using the Concept of "Flow".

The purpose of the study is to explore a new research methodology that will improve our understanding of “flow” through indicators of physiological and qualitative state. We examine indicators of “flow” experienced by musicians of a youth string quartet, two women (25, 29) and two men (23, 24). Electrocardiogram (ECG) equipment was used to record heart rate variability (HRV) data throughout the four movements in one and the same quartet performed during two concerts. Individual physiological indicators of flow were supplemented by assessments of group “state flow” (means from standardized questionnaires) and a group interview in which the musicians provided qualitative data. A matrix was constructed for the characterization of different kinds of demands in the written music in each one of the four movements for each one of the musicians. HRV derived from ECG data showed non-significant trends for group state flow across the eight musical episodes. Individual-level analysis showed that compared to the other players the first violin player had the highest mean heart rate and the lowest increase in high frequency (HF) power in HRV during this particular movement, particularly during the second concert. The qualitative data illustrated how an interplay of synchronized social interactions between this player and their colleagues during the musical performance was associated with a feeling of group state flow and served to support the first violinist. The case illustrates that the proposed mixed methodology drawing on physiological and qualitative data, has the potential to provide meaningful information about experiences of a flow state, both at individual and group levels. Applications in future research are possible.

Comparative characterization of different kinds of chromatographic quantification using the double standard addition method

Different algorithms for processing the quantitative gas chromato­gra­­phic ana­lysis data using the double standard addition method are compared for their accuracy. Three principal approaches are possible for such processing: I – simple comparison of values determined by sing­le and double standard additions, II – approximation of «peak area of ana­lyte» (S) – «mass of standard addition» (madd) depen­den­ce by the least squa­res method [linear reg­res­sion, m(S)], and III – independent quantification of analyte with both standard additi­ons follo­wed by the linear extrapolation of two sub-results on the so-cal­led «zero standard addi­tion», mx(madd ® 0). It is concluded that the quantitation results obtained using the various modes of the method are comparable in accuracy, but somewhat underestimated relative to the specified amounts of analytes. The principal reason of such systematic errors is the eva­po­ration of the solvent during the successive injecting of the same samples into the gas chroma­to­graph. Due to this reason the peak are­as, measured after the standard addition, appear to be slight­­ly increased and this leads to the systematic underestimation of the results. The second (less impor­tant) factor is the small increa­se of the samp­le volumes due to the addition of the compo­nents to be determined. It is confirmed that the systematic errors of different modes of standard addition are not exceeding the values of their random uncertainties. The op­ti­mal results (considering their signs of deviations) are provided using the double standard addition method with extrapolation of sub-results on «zero standard addition». In order to exclude the possible influence of «human factor» (increasing the re­sults precision during the series of analyses of similar samples due to the rising experience of analytical chemists) all parallel measurements have been per­for­med by bachelor students of the Chemistry Ins­titute of the St. Petersburg State University in the course of their laboratory practical works in chromatography. Such organization of experiments increases their credibility as it excluded the dependence of the results on the qualification of chemists.

Label-free characterization of different kinds of cells using optoelectrokinetic-based microfluidics.

We report a novel, to the best of our knowledge, method to rapidly characterize different kinds of cells and drug-treated cancer cells using a label-free biomarker of self-rotation in an optoelectrokinetics (OEK)-based microfluidic platform. OEK incorporates optics and electrokinetics into microfluidics, thereby offering a contact-free, label-free, and rapid approach to the cellular manipulation community. Self-rotational behaviors of four different kinds of cells were experimentally investigated by the frequency-sweeping of an AC bias potential in an optically induced nonuniform and irrotational electric field. The results revealed that these kinds of cells displayed a Gaussian distribution versus the AC frequency as well as different self-rotational speeds under the same conditions. Furthermore, the peak self-rotational speed varied from one kind of cell to another, with that of cancer cells higher than that of normal cells. In addition, MCF-7 cells treated by various concentrations of drug showed remarkably different self-rotational speeds. This finding suggests a high potential of developing a new label-free biomarker to rapidly distinguish different kinds of cancer cells and quantitatively monitor the response of cancer patients to various treatments.

Challenges in the use of Near Infrared Spectroscopy for improving wood quality: A review

Aims of study: Forestry-related companies require quality monitoring methods capable to pass a large number of samples. This review paper is dealing with the utilization of near infrared (NIR) technique for wood analysis.Area of study: We have a global point of view for NIR applications and characterization of different kind of wood species is considered.Material and methods: NIR spectroscopy is a fast, non-destructive technique, applicable to any biological material, demanding little or no sample preparation. NIR spectroscopy and multivariate analysis serve well in laboratories where the conditions are controlled. The main challenges to NIR spectroscopy technique in field conditions are moisture content and portability.Results: In this review, the methods and challenges for successfully applying NIR spectroscopy in the field of wood characterization are presented. Portable equipment need to record NIR spectra with low noise and low sensitivity to temperature and humidity variations of the air in forest environments. Studies concerning the sample preparation effects on the robustness of the calibrations are thus required.Research highlights: This paper examines traditional applications and practical aspects as well as innovative modern adaptations applied, for example, in hyperspectral imaging and genetic studies.

Growth of Porous Anodic Alumina on Low-Index Surfaces of Al Single Crystals

The pseudoepitaxial growth of amorphous anodic alumina with ordered porous structure within single crystal grains of aluminum substrates is an amazing feature of the self-organization process, which occurs during anodization. Here, we used single crystal Al(100), Al(110), and Al(111) substrates to inspect the effect of aluminum crystallography on anodization rates and the morphology of the resulting alumina films grown under different anodization conditions. The difference in the kinetics of porous film growth on various substrates is described in terms of the activation barrier of aluminum atom release from the metal surface to the oxide layer. Scanning electron microscopy and small-angle X-ray scattering are applied for quantitative characterization of different kinds of ordering in anodic alumina films. The highest number of straight channels was found in porous anodic alumina grown on Al(100) substrates, whereas Al(111) was proved to induce the best orientational order in anodic alumina with the forma...

A multifunctional plasma and deposition sensor for the characterization of plasma sources for film deposition and etching

Our recently reported multifunctional plasma and deposition sensor [Welzel et al., Appl. Phys. Lett. 102, 211605 (2013)] was used for the characterization of two different plasma sources: a magnetron sputtering deposition source and an ion beam source. The multifunctional sensor, based on a conventional quartz crystal monitor (microbalance) for mass increase/decrease measurements, can measure quasi-simultaneously the deposition/etching flux, the energy flux, and the charged particle flux. By moving the sensor or the plasma source stepwise against each other, the lateral (radial) flux profiles of the different sources can be measured with a lateral resolution of about 8 mm, the diameter of aperture in front of the quartz crystal. It is demonstrated that this compact and simple multifunctional sensor is a versatile tool for the characterization of different kinds of plasma sources for deposition and etching purposes. By combining the different measured quantities, the ion-to-neutral ratio and the mean energy per deposited atom can be calculated, parameters that are essential for the characterization of plasma deposition and etch processes.

Chemically Integrated Inorganic-Graphene Two-Dimensional Hybrid Materials for Flexible Energy Storage Devices.

State-of-the-art energy storage devices are capable of delivering reasonably high energy density (lithium ion batteries) or high power density (supercapacitors). There is an increasing need for these power sources with not only superior electrochemical performance, but also exceptional flexibility. Graphene has come on to the scene and advancements are being made in integration of various electrochemically active compounds onto graphene or its derivatives so as to utilize their flexibility. Many innovative synthesis techniques have led to novel graphene-based hybrid two-dimensional nanostructures. Here, the chemically integrated inorganic-graphene hybrid two-dimensional materials and their applications for energy storage devices are examined. First, the synthesis and characterization of different kinds of inorganic-graphene hybrid nanostructures are summarized, and then the most relevant applications of inorganic-graphene hybrid materials in flexible energy storage devices are reviewed. The general design rules of using graphene-based hybrid 2D materials for energy storage devices and their current limitations and future potential to advance energy storage technologies are also discussed.

A portable versus micro‐Raman equipment comparison for gemmological purposes: the case of sapphires and their imitations

In the last decade, Raman spectroscopy has been used for routine investigation for gemmological purposes, being non‐destructive and non‐invasive. In addition, this technique grants short measurement times without any sample preparation. In this context, this work is focused on the spectroscopic characterization of different kinds of blue gems, including sapphires, by comparing the performance of a handheld Raman instrumentation along with a micro‐Raman spectrometer, with the aim to provide gemmological certification and to get information on the provenance of the gems. The main goal of the present study is to identify imitation gems and to distinguish between natural and synthetic sapphire; in this latter case, micro‐Raman measurements were fundamental for the characterization of the inclusions. Moreover, the chemical composition of blue gems has been obtained by portable XRF technique. The obtained data show that a portable Raman spectrometer can be recommended as a fast and easy instrument to discriminate sapphire from imitations. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Histological skin morphology enhancement base on molecular hyperspectral imaging technology

Most traditional skin histological analysis methods are based on the light microscopy images, which can only provide limited information and low contrast results for pathology evaluation. Molecular hyperspectral imaging technology can provide both spatial and spectral information of skin sections, which is a new method for histological skin analysis. The molecular hyperspectral imaging system was developed by coupling an acousto-optic tunable filters adapter to microscopy and the molecular hyperspectral images were analyzed by home-written software with image processing algorithms. Then, the histological structures in skin sections were investigated in several locations to evaluate the potential application of the molecular hyperspectral imaging technique to dermatology. Molecular hyperspectral images of skin sections were obtained. Single-band images, false color images, virtual 3D surface view images, and color-coded spectral clustering results were produced to highlight the skin structures for histological evaluation. Unlike traditional histological analysis with light microscopy, the molecular hyperspectral imaging technology can enhance the visualization of skin structures using their spectral signatures and their gray values. This technology has potential for the diagnosis and histopathologic characterization of different kind of skin cells.

The first fully functional 3D CMOS chip with Deep N-well active pixel sensors for the ILC vertex detector

This work presents the characterization of Deep N-well (DNW) active pixel sensors fabricated in a vertically integrated technology. The DNW approach takes advantage of the triple well structure to lay out a sensor with relatively large charge collecting area (as compared to standard three transistor MAPS), while the readout is performed by a classical signal processing chain for capacitive detectors. This new 3D design relies upon stacking two homogeneous tiers fabricated in a 130nm CMOS process where the top tier is thinned down to about 12μm to expose through silicon vias (TSV), therefore making connection to the buried circuits possible. This technology has been used to design a fine pitch 3D CMOS sensor with sparsification capabilities, in view of vertexing applications to the International Linear Collider (ILC) experiments. Results from the characterization of different kind of test structures, including single pixels, 3×3 and 8×8 matrices, are presented.

Review on measurement techniques of transport properties of nanowires.

Physical properties at the nanoscale are novel and different from those in bulk materials. Over the last few decades, there has been an ever growing interest in the fabrication of nanowire structures for a wide variety of applications including energy generation purposes. Nevertheless, the study of their transport properties, such as thermal conductivity, electrical conductivity or Seebeck coefficient, remains an experimental challenge. For instance, in the particular case of nanostructured thermoelectrics, theoretical calculations have shown that nanowires offer a promising way of enhancing the hitherto low efficiency of these materials in the conversion of temperature differences into electricity. Therefore, within the thermoelectrical community there has been a great experimental effort in the measurement of these quantities in actual nanowires. The measurements of these properties at the nanoscale are also of interest in fields other than energy, such as electrical components for microchips, field effect transistors, sensors, and other low scale devices. For all these applications, knowing the transport properties is mandatory. This review deals with the latest techniques developed to perform the measurement of these transport properties in nanowires. A thorough overview of the most important and modern techniques used for the characterization of different kinds of nanowires will be shown.

Comparative Response of Biosensing Platforms Based on Synthesized Graphene Oxide and Electrochemically Reduced Graphene

AbstractIn this work, we report the synthesis and characterization of different kinds of graphene nanomaterials and their applicability to the development of biosensing platforms. We have synthesized graphene oxide (GO) following a modified Hummer’s method, which has been subsequently reduced by electrochemical procedures. This reduction strategy precludes the employment of toxic solvents, leading to a product, electrochemically reduced graphene (ERG), free of contaminants. The characterization of the synthesized nanomaterials has been performed by different techniques such as X‐ray diffraction spectroscopy (XRD), Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The information gathered by this combination of techniques confirms that i) the synthesis methodology affords the production of GO nanosheets, which present a typical lateral dimension of several hundreds of nanometers and a thickness value of 1.3±0.1 nm, ii) the reduction step has been successfully achieved leading to graphene nanosheets free of oxygen functionalities with an average lateral dimension of at least 1 micrometer and a thickness value of 2.8±0.2 nm. Once we have confirmed that both materials have been successfully synthesized, we have studied the effect of the effect of their inclusion in biosensing platforms on the analytical response, selecting a lactate oxidase based biosensor as a model system. We have demonstrated that although the incorporation of GO or ERG to the device results in an enhancement of the analytical response of the resulting biosensing platform, the former system offers slightly better analytical properties and a more reproducible response than the ERG one.

REMOVED: Use of Membrane Potential Measurements for Electrochemical Characterization of Different Kinds of Membranes

REMOVED: Use of Membrane Potential Measurements for Electrochemical Characterization of Different Kinds of Membranes

Preserving mappings in fuzzy predicate logics

In this article, we develop the method of diagrams for fuzzy predicate logics and give a characterization of different kinds of preserving mappings in terms of diagrams. Our work is a contribution to the model-theoretic study of fuzzy predicate logics. We present a reduced semantics and we prove a completeness theorem of the logics with respect to this semantics. The main concepts being studied are the Leibniz congruence and the structure-preserving relation. On the one hand, the Leibniz congruence of a model identifies the elements that are indistinguishable using equality-free atomic formulas and parameters from the model. A reduced structure is the quotient of a model modulo this congruence. On the other hand, the structure-preserving relation between two structures plays the same role that the isomorphism relation plays in classical predicate languages with equality.

Using the 19F NMR Chemical Shift Anisotropy Tensor To Differentiate between the Zigzag and Chiral Forms of Fluorinated Single-Walled Carbon Nanotubes

The structural characterization of different kinds of zigzag and chiral single-walled carbon nanotubes (SWNTs) has been investigated theoretically using (19)F NMR spectroscopy. The chemical shift anisotropy (CSA) tensor is computed at different levels of theory for the (19)F nuclei in different forms of functionalized fluorinated carbon nanotubes (CNT). A set of fluorine CSA parameters comprising the span, skew, and isotropic chemical shift is computed for each form of the fluoronanotubes and multidimensional CSA parameter correlation maps are constructed. We show that these correlations are able to clearly distinguish between the chiral and zigzag forms of fluorinated carbon nanotubes (F-SWNTs). Implications for solid-state and liquid-state NMR experiments are discussed.

Anharmonic Interaction Signals for Acoustic Detection of Analyte

The challenges with frequency-based acoustic detection systems in sensitive, selective, and reliable quantitative estimation of surface-bound analyte are well-known. These systems are traditionally used in their linear incarnations; i.e., the measurement frequency is the same as the driving frequency. However, it was found in this work that interactions of adsorbents with sensor surface show significant anharmonicity even at low drive amplitudes. In particular, using streptavidin-coated polystyrene microbeads on an oscillating quartz surface in air, it has been demonstrated through modeling and experiments that the anharmonic signal from microparticle to surface interaction is significantly higher relative to that from bare quartz and orders of magnitude higher than relative shifts in resonant frequency. The signal is proportional to the number of microparticles and holds a well-defined functional relationship with the amplitude of oscillation, distinct to the nature of interaction with the surface for a given analyte. This approach, thus, can be used for ultrasensitive and quantitative detection of surface adsorbents and characterization of different kinds of surface interactions, distinguishing specific from nonspecific adsorbents. The modeling also reveals a direct functional relationship between the measured anharmonic signal and the interaction potential of the adsorbent with the surface.

Flow unit modeling and fine-scale predicted permeability validation in Atokan sandstones: Norcan East field, Kansas

Characterizing the reservoir interval into flow units is an effective way to subdivide the net-pay zone into layers for reservoir simulation. Commonly used flow unit identification techniques require a reliable estimate of permeability in the net pay on a foot-by-foot basis. Most of the wells do not have cores, and the literature is replete with different kinds of correlations, transforms, and prediction methods for profiling permeability in pay. However, for robust flow unit determination, predicted permeability at noncored wells requires validation and, if necessary, refinement. This study outlines the use of a spreadsheet-based permeability validation technique to characterize flow units in wells from the Norcan East field, Clark County, Kansas, that produce from Atokan aged fine- to very fine-grained quartzarenite sandstones interpreted to have been deposited in brackish-water, tidally dominated restricted tidal-flat, tidal-channel, tidal-bar, and estuary bay environments within a small incised-valley-fill system. The methodology outlined enables the identification of fieldwide free-water level and validates and refines predicted permeability at 0.5-ft (0.15-m) intervals by iteratively reconciling differences in water saturation calculated from wire-line log and a capillary-pressure formulation that models fine- to very fine-grained sandstone with diagenetic clay and silt or shale laminae. The effectiveness of this methodology was confirmed by successfully matching primary and secondary production histories using a flow unit-based reservoir model of the Norcan East field without permeability modifications. The methodologies discussed should prove useful for robust flow unit characterization of different kinds of reservoirs.

Nature and origin of carbonate particles along a transect on the western margin of Great Bahama Bank (Middle Miocene): sedimentary processes and depositional model

Abstract During ODP Leg 166, Middle Miocene sediments were collected along the western margin of the Great Bahama Bank (GBB) at four sites, distributed along a proximal-distal transect. Site 1006 is located in the basin, Site 1007 at the toe-of-slope and Sites 1003 and 1005 on the mid and upper slope. The carbonate slope deposits of GBB consist of periplatform oozes, an admixture of platform-derived aragonite and high-magnesium calcite particles, and pelagic low-magnesium calcite. An assessment of carbonate sedimentation is made in order to estimate the proportion of platform-derived versus pelagic components. The originality of this study is based on the application of a separation method giving access to homogeneous granulometric fractions, ranging from 63 to 3 μm in grain diameter. This method, associated with a multidisciplinary approach (micropaleontology, optical and electronic microscopy, mineralogy – X-ray diffractometry, and trace elements geochemistry – strontium and magnesium), allows the quantification and characterization of different kinds of carbonate particles. In Miocene sediments, three types of particles display a biogenic structure: planktonic foraminifera, calcareous nannofossils and fragments of neritic organisms. Two types of particles do not exhibit any structures that allow for a determination of their origin. Based on their size and their mineralogy, we have distinguished macroparticles (calcite and dolomite) and microparticles (calcite and aragonite). The detailed study of the composition of the separated fractions highlights major differences in carbonate ooze composition between the different sites along the transect. The unlithified samples of Sites 1006 and 1007 are dominated by pelagic components (planktonic foraminifera and calcareous nannofossils) and contain aragonite microparticles. In contrast, lithified sediments of Sites 1003 and 1005 (and 1007) are characterized by higher proportions of neritic debris and particles without biologic structure, the pelagic phase is impoverished and aragonite needles are absent. The origin of particles without biological structure has been demonstrated by their spatial distribution and by mineralogical as well as geochemical criteria. The rhombohedral calcitic microparticles mainly occur at slope sites. Their high magnesium contents support a formation on the bank implying an allochthonous origin. This suggests that calcitic microparticles correspond to the bank micrite exported towards slope environments. Rhomboedral calcitic macroparticles, which fill sediment voids, originate from in situ transformations of metastable carbonates due to pore fluids, which preferentially flow in the slope permeable sediments. Two sedimentary sources are proposed: 1) an autochthonous pelagic source with low-magnesium calcitic components and 2) an allochthonous neritic source with both aragonitic and calcitic components. Export and depositional processes can be differentiated for the allochthonous particles. The neritic debris and calcitic microparticles in slope Sites 1003 and 1005 (and less frequently in Site 1007) were probably exported by gravity currents whereas the aragonite microparticles, due to their shape and granulometry, were perhaps transported as suspension and deposited at the distal Sites 1006 and 1007.