Low-intensity Peaks Research Articles

MISCIBILITY AND THERMAL DEGRADATION KINETICS OF POLY-β-ALANINE/POLY(3-HYDROXYPROPIONATE) BLENDS

Poly-β-alanine (PBA) and poly(3-hidroxypropionate) (PHP) were synthesized via base-catalyzed hydrogen transfer polymerization (HTP) of acrylamide and acrylic acid, respectively. Blends of PBA/PHP with different composition (PHP content, 5% to 75%) were studied using FTIR, DSC, TGA, XRD and polarized optical microscope to reveal both miscibility and thermal degradation kinetics of PBA/PHP blends. Optical images of blends were transparent and entirely uniform. Characteristic IR bands of both components shifted in higher frequencies with increasing fraction of other component. Melting temperature (T m ), thermal decomposition temperatures (T d ) and enthalpy of fusion (ΔH f ) of PHP decreased with increasing PBA fraction in blends. Thermal degradation kinetics of both components were studied by Freeman-Carroll method. Activation energies of thermal degradations of blend components were determined with a good regression coefficients (at least 0.994). Activation energies of decomposition decreased from 224.14 to 86.125 kJmol -1 with increasing PHP content. XRD spectra of blends exhibited lower peak intensities than those of neat polymers. The spectroscopic, thermal and optic methods revealed that PBA and PHP were miscible with a good compatibility in amorphous phase.

Substitution Effects on Rare-Earth Ions-Doped Nickel-Zinc Ferrite Nanoparticles

Rare-earth ions (RE3+)-doped Ni-Zn ferrite nanoparticles with a structural formula of Ni0.5Zn0.5Fe1.8RE0.2O4 (RE3+ = Nd, Ce, La and Pr) were synthesized at room temperature by a sol-gel auto-combustion method. The structural and magnetic properties of Ni-Zn ferrite samples were carried out by XRD, vibrating sample magnetometer (VSM), field emission scanning electron microscopy (FE-SEM) and FT-IR spectroscopy. XRD pattern of Ni-Zn ferrite revealed that all the diffraction planes are in agreement with cubic spinel phase and the addition of Fe2O3 phase was also observed. In the case of RE ions-doped Ni-Zn ferrite in addition to the Fe2O3 phase, very low intensity peaks corresponding to some secondary phase are also present. The average crystallite sizes were found to be from 42 to 56 nm using the Scherer formula. The lattice constant (a) values are gradually decreased from 8.378 to 8.349 A with different substitutions of RE3+ ions in the Ni-Zn ferrite samples. VSM analysis revealed that saturation magnetization values are decreased and coercivity values are increased with substitution of different RE3+ ions. FE-SEM images exhibits that particles are spherical in shape. FT-IR interpretation revealed that two main metal oxygen bands (564 and 411 cm−1) are observed in all the substituted Ni-Zn ferrite samples.

Use of waste plastic materials for road construction in Ghana

This paper forms part of research to solve two main problems in Ghana: firstly, the management of municipal solid waste (MSW), particularly with regards to used plastics which have overwhelmed major cities and towns; secondly, the formation of potholes onroads due to excessive traffic and axle weight. This study examines the effect of blending waste thermoplastic polymers, namely High density polyethylene (HDPE) and Polypropylene (PP) in Conventional AC-20 graded bitumen, at various plastic compositions. The plastics were shredded and blended with the bitumen ‘in-situ’, with a shear mixer at a temperature range of 160°C–170°C. Basic rheological parameters such as penetration, ring & ball softening point and viscosity tests were employed to determine the resulting changes from base bitumen.FTIR spectroscopy was also employed to study the chemical functionalities present in the bitumen composite. The properties of the unmodified bitumen were found to be enhanced with the changes recorded in the rheological properties of the polymer modified bitumen (PMB). It was observed that polypropylene polymer, showed profound effect on homogeneity and compatibility with slight linear increment in the viscosity, softening and penetration values as against relatively high changes for HDPE modified bitumen.The viscosity of unmodified bitumen was enhanced with the addition of the polymers and thixotropic effect was observed for both HDPE and PP at 60°C. For all modified binders prepared, the penetration values decrease as polymer-bitumen ratio increases whiles softening temperature generally increases as polymer ratio increases. The most compatible and incompatible blends for HDPE were respectively observed at 2% and 3% polymer loading. The most enhanced, homogenous blend is achieved with PP at 3% polymer loading. Three prominent peaks were identified in the spectrum of the unmodified bitumen, occurring at the 3000–2850cm−1 IR frequency range, typical of aliphatic CH symmetrical and asymmetrical stretches in alkanes. CH2 and CH3 bends were also observed at the characteristic frequencies of 1465cm−1 and 1375cm−1 respectively. A low intensity peak was observed within the 2400cm−1–2100cm−1 range, indicating the presence of a very weak −CC- or −CN group with an absorbance of precisely 0.12.The use of waste commodity plastics in binder modification carries the advantage of a cheap and effective means of enhancing conventional bitumen binder performance characteristics and is an alternative way to utilise plastic waste.

Treatment of dispersive clay soil by ZELIAC

Dispersive clays are prone to erosion and could cause significant problems in geotechnical and geo-environmental projects. In this research, a new additive - the ZELIAC – was investigated for treating a Malaysian dispersive clay soil where an appreciable decrease in dispersivity was achieved due to treatment with 8% ZELIAC. The curing time was found to be significant that after 28days, the initially dispersive samples became non-dispersive. Furthermore, due to the treatment, the samples had increased unconfined compressive strength (UCS), permeability, and optimum moisture content; and decreased fines content, plasticity index, maximum dry density, and compressibility index. The UCS increased nearly 7.3 times for sample treated with 8% ZELIAC and cured for 90days. The X-ray fluorescence (XRF) results showed a cementitious structure with calcium content 10.8 times more in the treated sample than in the untreated one, reflecting the constructive cation exchange reaction taking place during the curing process. The sodium ion was noticeably replaced by calcium ion which resulted in a decreased thickness of the diffused double layer and the subsequent reduction in the dispersivity of the sample. These results were also reflected by the lower peak intensity as measured by the X-ray diffraction test (XRD) for the treated sample, as compared to the higher peak intensity for the un-treated sample. Finally, the SEM images indicate that the flocculated structures of the treated dispersive clay were surrounded by the ZELIAC particles. Thus, the ZELIAC was proven to be effective in improving the studied Malaysian dispersive clay.

Quantitative Differences Between the First and Second Injection of Contrast Agent in Contrast-Enhanced Ultrasonography of Feline Kidneys and Spleen

Contrast-enhanced ultrasound is a valuable and safe technique for the evaluation of organ perfusion. Repeated injections of ultrasound contrast agent are often administered during the same imaging session. However, it remains unclear if quantitative differences are present between the consecutive microbubble injections. Therefore, the first and second injection of contrast agent for the left renal cortex, renal medulla and the splenic parenchyma in healthy cats were compared. A lower peak intensity and area under the curve were observed for the first injection of contrast agent in the feline kidney, both for the renal cortex and medulla, and spleen. Moreover, for the renal cortex, the time-intensity curve was steeper after the second injection. Findings from the present study demonstrate that a second injection of contrast agent provides stronger enhancement. The exact mechanism behind our findings remains unclear; however, saturation of the lung macrophages is believed to play an important role.

Effects of Concentration and Substrate Type on Structure and Conductivity of p-Type CuS Thin Films Grown by Spray Pyrolysis Deposition

Copper sulphide (CuS) thin films were grown upon Ti, indium tin oxide (ITO), and glass substrates by using spray pyrolysis deposition at 200°C. The films exhibited good adhesion compared to chemical bath deposition. CuCl2·2H2O and Na2S2O3·5H2O precursors were used as Cu2+ and S2− sources, respectively. Two concentrations (i.e., 0.2 M and 0.4 M) were selected in this study. X-ray diffraction analysis reveals that the films with 0.2 M showed only the formation of a covellite CuS phase having a hexagonal crystal structure with diffraction peaks of low intensity. For 0.4 M concentration, in addition to the covellite CuS phase, chalcocite Cu2S phase having a hexagonal crystal structure also appeared with relatively higher intensity peaks for all thin films. Field-emission scanning electron microscopy observations showed the formation of small grains for 0.2 M, whereas a mixture of grains with square-like shape and nanoplates were formed for 0.4 M. Depending on the 0.2 M and 0.4 M thin films thicknesses (3.2 μm and 4 μm, respectively), the band gap energy was obtained from optical measurements to be approximately 2.64 eV for 0.2 M (pure CuS phase), which slightly decreased up to 2.56 eV for 0.4 M concentration. Hall effect measurements showed that all grown films are p-type. The 0.2 M film exhibited much lower sheet resistance (R sh = 33.96 Ω/Sq–55.70 Ω/Sq) compared to 0.4 M film (R sh = 104.33 Ω/Sq–466.6 Ω/Sq). Moreover, for both concentrations, the films deposited onto ITO substrate showed the lowest sheet resistance (R sh = 33.96 Ω/Sq–104.33 Ω/Sq).

Characterization of sputtered zirconium nitride films deposited at various argon:nitrogen ratio

Zirconium nitride films were deposited by reactive magnetron sputtering using argon as inert gas and nitrogen as reactive gas. The nitrogen flow rate in argon:nitrogen ratio was increased from 4sccm to 20sccm by an increment of 4sccm. The effect of increment in nitrogen flow rate on various properties of deposited zirconium nitride films are reported in this paper. The structural characterization was done by X-Ray diffraction which confirms (011) peak of Zr3N4 and a very low intensity (111) peak of Zr3N4. Optical properties was investigated by Uv-Vis-NIR spectrophotometer which showed that the films were transparent and maximum transmittance observed was around 82%. The wettability properties was investigated by contact angle goniometer which showed the films were hydrophobic and maximum contact angle achieved was 99.50.

UV Cure Enabled Robust STI Oxide Gap Fill Solution for Thermally Limited Flow in Advanced Logic Devices

High mobility channel materials such as Si1-xGex (x = 0.1-0.5) are important to achieve performance targets for FinFET devices at dimensions scaled beyond 14nm. Previously, flowable (FCVD) SiO2 deposition processes have been developed to achieve adequate fill for Shallow Trench Isolation in FinFET structures. However, the thermal budget for curing FCVD oxide with SiGe fins must be limited to avoid out-diffusion of Ge. This restricts the processing options for achieving a robust material which is compatible with subsequent wets processing steps. FCVD oxide deposition employs an amine-based silicon precursor which, upon exposure to NH3 radicals, forms short chain -Si-N-Si- oligomers with terminal Si-H or N-H bonds. These oligomers flow into and fill deep isolation trenches. Once the trenches are filled, it is critical to stabilize the film and initiate cross linking for densification to SiO2. To this end, a cure while still under vacuum, such as O3 oxidation, is commonly used before a subsequent furnace steam anneal. This paper describes an alternate curing process using broadband UV light to densify FCVD oxide. Material properties were studied using cure by microwave-powered Hg lamps at 10 degC with broadband (200-450nm) spectrum and compared to the existing O3 cure. To achieve the desired FCVD film properties, it is beneficial to remove -OH terminations during the post-dep cure to promote a dense final -Si-O-Si- matrix. Fig. 1 shows high frequency FTIR spectra from UV-cured FCVD oxide films as a function of UV power post-steam anneal. Data from O3 cured FCVD oxide is plotted for comparison. The spectrum from the non-oxidizing UV cure process shows lower peak intensities for –OH and H-OH stretch peaks. For promoting densification, UV curing is also effective in breaking N-H bonds. The number of NH/NH2 bonds is reduced with increasing UV power and a corresponding increase in Si-H bonding is observed. Figure 2 shows FTIR spectra of cured FCVD films treated with a subsequent steam anneal. The film with O3cure show more residual silanols (Si-OH) relative to UV cured films. Also, the -Si-O-Si- bonding peak is higher in UV cured films, suggesting a denser -Si-O-Si- network. During the steam anneal process, we observed that UV cured films densify more rapidly than O3 cured films. For anneals at 500°C, a dense SiO2 surface layer is formed, blocking further O2diffusion and leaving a less dense film below which has a higher wet etch rate (Fig. 3). This effect is evident in Fig. 4a where FCVD oxide has been recessed using an etching technique. The oxide between fins is weaker and has recessed more than the oxide in the field region outside of the array (see reference lines). A two-step steam anneal was then developed to achieve uniform properties through film depth: 400°C for 1 hour followed by 500°C for 2 hours. Fig 4b shows a structure with oxide annealed in this way and then recessed through etching; it was observed that the recess is now equivalent in the field and between fins. The impact of UV power on the cure process was also explored. Fig. 5 shows the WERR as a function of thickness for blanket O3 cured FCVD films and UV cured films after steam anneal. The UV cure again shows significantly lower WERR compared to O3 cure, with more densification and improved film uniformity through depth with increased power. Fig. 6 compares cumulative electrical breakdown behavior for O3 cured and UV cured films after steam anneal obtained using MIS structures. The UV cured films show a higher breakdown voltage (Vbd ~10MV/cm) relative to O3 cured films (~9MV/cm). Fig. 7 is a comparison of WERR between O3 cured film and UV cured film inside the narrow STI Trench Features. The films were steam annealed followed by 2x900°C-1min soak RTA in N2. Data shows 30% lower in-trench WERR for UV cure compared to O3cure. In conclusion, UV cure has been demonstrated as a means to provide improved FCVD quality over O3cure as measured by wet etch rate ratio, in blanket films and within trenches for STI applications. This work was performed by the Research Alliance Teams at various IBM Research and Development Facilities. Figure 1

Magnetoelectronic and optical properties of nonuniform graphene nanoribbons

The electronic and optical properties of nonuniform bilayer graphene nanoribbons are worth investigating as they exhibit rich magnetic quantization. Based on our numerical results, their electronic and optical properties strongly depend on the competition between magnetic quantization, lateral confinement, and stacking configuration. The results of our calculations lead to four categories of magneto-electronic energy spectra, namely monolayer-like, bilayer-like, coexistent, and irregular quasi-Landau-level like. Various types of spectra described in this paper are mainly characterized by unusual spatial distributions of wave functions in the system under study. In our paper, we demonstrate that these unusual quantized modes lead to the appearance of such diverse magneto-optical spectra. Moreover, the investigation of the density of states in our model leads to the appearance of many prominent symmetric and weakly asymmetric peaks. The almost well-behaved quasi-Landau levels exhibit high-intensity peaks with specific selection rules, and the distorted energy subbands present numerous low-intensity peaks without any selection rules.

Re‐examining the roles of surface heat flux and latent heat release in a “hurricane‐like” polar low over the Barents Sea

AbstractPolar lows are intense mesoscale cyclones that occur at high latitudes in both hemispheres during winter. Their sometimes evidently convective nature, fueled by strong surface fluxes and with cloud‐free centers, have led to some polar lows being referred to as “arctic hurricanes.” Idealized studies have shown that intensification by hurricane development mechanisms is theoretically possible in polar winter atmospheres, but the lack of observations and realistic simulations of actual polar lows have made it difficult to ascertain if this occurs in reality. Here the roles of surface heat fluxes and latent heat release in the development of a Barents Sea polar low, which in its cloud structures showed some similarities to hurricanes, are studied with an ensemble of sensitivity experiments, where latent heating and/or surface fluxes of sensible and latent heat were switched off before the polar low peaked in intensity. To ensure that the polar lows in the sensitivity runs did not track too far away from the actual environmental conditions, a technique known as spectral nudging was applied. This was shown to be crucial for enabling comparisons between the different model runs. The results presented here show that (1) no intensification occurred during the mature, postbaroclinic stage of the simulated polar low; (2) surface heat fluxes, i.e., air‐sea interaction, were crucial processes both in order to attain the polar low's peak intensity during the baroclinic stage and to maintain its strength in the mature stage; and (3) latent heat release played a less important role than surface fluxes in both stages.

Surface‐enhanced Raman scattering characterization of monohydroxylated polymethoxyflavones

Polymethoxyflavones (PMFs) belong to a unique class of flavonoids mainly found in citrus fruits. Characterization of different PMFs is important to further understand and apply these compounds as functional ingredients in food. The objective of this study is to characterize three monohydroxylated PMFs using surface‐enhanced Raman spectroscopy (SERS) and to determine the role of hydroxylation in their SERS behaviors. Serial concentrations of 3′‐hydroxylnobiletin (3HN), 4′‐hydroxylnobiletin (4HN), and 5‐hydroxylnobiletin (5HN) were incubated with silver dendrites for SERS analysis. Results demonstrated that three PMFs exhibited significantly different SERS behaviors. 5HN produced saturation peak intensity at relative low concentration (0.05 mM), while 3HN and 4HN produced saturation peak intensity at much higher concentrations (0.5 and 1 mM, respectively) according to principal component analysis. Below saturation, 5HN had the highest peak intensity, while 3HN had the lowest peak intensity. After reaching saturation, 4HN and 5HN had similar relative peak intensities that were much greater than 3HN. The HPLC analysis revealed that 36.13 ± 1.06% of 5HN, 18.40 ± 3.31% of 4HN, and 9.66 ± 0.94% of 3HN were bound to silver. Based on these results, we speculated that different positions of hydroxylation of PMFs were critical for determining spatial conformation of PMFs on binding sites, resulting in different binding affinities and saturation points, therefore their SERS behaviors. This study first reported that the position of hydroxylation in the monohydroxylated PMFs was crucial for their interactions with silver dendrites and provided valued information for further applying SERS for molecular characterization of flavonoids. Copyright © 2016 John Wiley & Sons, Ltd.

Photoluminescence and electron-beam excitation induced cathodoluminescence properties of novel green-emitting Ba4La6O(SiO4)6:Tb3+phosphors

Tb3+ions activated Ba4La6O(SiO4)6 (BLSO:Tb3+) phosphors were synthesized by a citrate sol-gel method. The X-ray diffraction pattern confirmed their oxyapatite structure. The field-emission scanning electron microscope image established that the BLSO:Tb3+phosphor particles were closely-packed and acquired irregular shapes. The photoluminescence (PL) excitation spectra of BLSO:Tb3+phosphors showed intense f–d transitions along with low intense peaks corresponding to the f–f transitions of Tb3+ions in the lower energy region. The PL emission spectra displayed the characteristic emission bands of Tb3+ions, and the optimized concentrations were found to be at 1 and 6mol% for blue and green emission peaks, respectively. The cathodoluminescece (CL) spectra exhibited a similar behavior that was observed in the PL spectra except the intensity variations in the blue and green regions. The CL spectra of the BLSO:6mol% Tb3+phosphor unveiled accelerating voltage induced luminescent properties.

Real-time bilinear rotation decoupling in absorptive mode J-spectroscopy: Detecting low-intensity metabolite peak close to high-intensity metabolite peak with convenience

“Pure shift” NMR spectra display singlet peak per chemical site. Thus, high resolution is offered at the cost of valuable J-coupling information. In the present work, real-time BIRD (BIlinear Rotation Decoupling) is applied to the absorptive-mode 2D J-spectroscopy to provide pure shift spectrum in the direct dimension and J-coupling information in the indirect dimension. Quite often in metabolomics, proton NMR spectra from complex bio-fluids display tremendous signal overlap. Although conventional J-spectroscopy in principle overcomes this problem by separating the multiplet information from chemical shift information, however, only magnitude mode of the experiment is practical, sacrificing much of the potential high resolution that could be achieved. Few J-spectroscopy methods have been reported so far that produce high-resolution pure shift spectrum along with J-coupling information for crowded spectral regions. In the present work, high-quality J-resolved spectrum from important metabolomic mixture such as tissue extract from rat cortex is demonstrated. Many low-intensity metabolite peaks which are obscured by the broad dispersive tails from high-intensity metabolite peaks in regular magnitude mode J-spectrum can be clearly identified in real-time BIRD J-resolved spectrum. The general practice of removing such spectral overlap is tedious and time-consuming as it involves repeated sample preparation to change the pH of the tissue extract sample and subsequent spectra recording.

Studies on photo- and thermal stability of PVA-encapsulated Mn-doped ZnS nanoparticles

In this study, an aqueous-based synthesis route has been developed to prepare highly luminescent polyvinyl alcohol (PVA)-capped manganese-doped ZnS quantum dots (QDs). The QDs showed markedly blue shift in their optical absorbance, indicating strong quantum size effect and the average diameter of the QDs calculated ~3 nm. The QDs showed high-intensity Mn2+-related orange luminescence at 585 nm with a very low-intensity peak at 430 nm for the surface defect states. X-ray powder diffraction, transmission electron microscopy, UV–visible spectroscopy and spectrofluorometry have been used to characterize the doped QDs. Studies on the thermal and photochemical stability of the photoluminescence properties are carried out, which showed that after 5 h of photoexcitation and 30 min of 70 °C treatments, the nanoparticles retain almost 40 % of their initial quantum yield. Our systematic investigation shows that these PVA-capped Mn:ZnS QDs may be used as fluorescent labels in biological applications.

A nitrogen-rich mesoporous polymer for photocatalytic hydrogen evolution from water

Nitrogen-rich hierarchical mesoporous polymers with photocatalytic activity for H2 evolution from water were prepared, which was based on aminal bonds constructed by catalyst-free Schiff-base condensation. The effects of the reaction time, concentration of terephthaldehyde and the mole ratio of aldehyde to amine groups on the structure and properties of polymers were discussed. By tuning reaction conditions, the surface area of these polymers changed from 216.83 to 569.04m2/g. Among all these materials, the polymer with moderate surface area (391.76m2/g), the smallest average pore size (4.27nm) and low intensity peak of photoluminescence showed the highest H2 evolution rate of 18.56μmol·h−1. When loaded with palladium, it exhibited enhanced H2 evolution rate of up to 43.58μmol·h−1. The results demonstrated that the nitrogen-rich porous polymer has a good potential for H2 evolution from water under UV–Vis light irradiation (λ=380–780nm). This study expanded the scope of porous polymers in photocatalysis applications. The outstanding advantages of the polymers presented here include their low price, commercially available starting compounds and the easy method of synthesis. This kind of porous polymer has promise for further applications.

Convective Self-Aggregation and Tropical Cyclogenesis under the Hypohydrostatic Rescaling

Abstract The behavior of rotating and nonrotating aggregated convection is examined at various horizontal resolutions using the hypohydrostatic, or reduced acceleration in the vertical (RAVE), rescaling. This modification of the equations of motion reduces the scale separation between convective- and larger-scale motions, enabling the simultaneous and explicit representation of both types of flow in a single model without convective parameterization. Without the RAVE rescaling, a dry bias develops when simulations of nonrotating radiative–convective equilibrium are integrated at coarse resolution in domains large enough to permit convective self-aggregation. The rescaling reduces this dry bias, and here it is suggested that the rescaling moistens the troposphere by weakening the amplitude and slowing the group velocity of gravity waves, thus reducing the subsidence drying around aggregated convection. Separate simulations of rotating radiative–convective equilibrium exhibit tropical cyclogenesis; as horizontal resolution is coarsened without the rescaling, the resulting storms intensify more slowly and achieve lower peak intensities. At a given horizontal resolution, using RAVE increases peak storm intensity and reduces the time needed for tropical cyclogenesis—effects here suggested to be caused at least in part by the environmental moistening produced by RAVE. Consequently, the RAVE rescaling has the potential to improve simulations of tropical cyclones and other aggregated convection in models with horizontal resolutions of order 10–100 km.

Mechanical Properties of Cr/CrN/CrCN/ZrN Multilayer Coatings by Physical Vapour Deposition (PVD)

Multilayer coating onto orthopedic implants has been studied extensively due to their excellence mechanical and biological properties. A multilayer coating was coated onto metal implants to prevent the leaching of metallic ions into human body. This paper aims to study the hardness of multilayer coatings of Chromium (Cr), Chromium Nitride (CrN), Chromium Carbonitride (CrCN) and Zirconium Nitride (ZrN) by Physical Vapour Deposition (PVD). The deposited multilayer coating was characterised by Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and Energy Dispersive X-ray (EDX). Cr, CrN, CrCN and ZrN have been successfully deposited onto stainless steel substrates by PVD. XRD analysis detected major peak in preferred orientation of (200) and other peaks with (111), (220), (311) for CrN cubic phase. For CrCN, XRD analysis detected only low intensity peaks of Cr7C3 and ZrN peaks with preferred orientation of (111), (200) with other peak (220), (311) and (222). Microvickers Hardness results showed an increment in hardness value from substrates with 160HV to 174HV for Cr, 236HV for CrN, 362HV for CrCN, 364HV for ZrN and 370HV for multilayer coatings.

Metal Release of Multilayer Coatings by Physical Vapour Deposition (PVD)

Orthopaedic implants are mostly fabricated by Stainless Steel, Titanium, and Ni-Cr Alloys that consist of Chromium (Cr), Cobalt (Co), Nickel (Ni) and Molybdenum (Mo). 10-15% of population are affected by metals (Ni, Co, Cr, Mo) hypersensitivity reaction. Multilayer coating by Physical Vapour Deposition (PVD) has been applied onto orthopedic implants to prevent metallic ions leaching into human body. This paper aims to study the metal ions leaching of Cr, Ni, Mo, and Co from multilayer coatings of Chromium (Cr), Chromium Nitride (CrN), Chromium Carbonitride (CrCN) and Zirconium Nitride (ZrN) by Physical Vapour Deposition (PVD). Cr, CrN, CrCN and ZrN have been successfully deposited onto stainless steel substrates by CAPVD. XRD analysis detected major peak in preferred orientation of (200) and other peaks with (111), (220), (311) for CrN cubic phase. For CrCN, XRD analysis detected only low intensity peaks of Cr7C3 and ZrN peaks with preferred orientation of (111), (200) with other peak (220), (311) and (222). A seven days metal released test by ICP-MS showed that generally all ions concentration for Ni, Co, Mo decreased from uncoated substrate to multilayer coatings except for Cr. Metal released showed higher concentration for coatings deposition with longer deposition time at 10minutes.

Interpolational and smoothing cubic spline for mass spectrometry data analysis

A special cubic spline for histograms was examined as a possible tool for the processing of mass spectrometry data. Algorithms of interpolating and smoothing cubic splines are described shortly. It was shown that peak apex localizations using splines yield similar results as peak apex determinations using parabolas and centroids for high intensity peaks, while for low intensity peaks, the peak apex localizations using splines are superior. It also was shown that peak localization accuracies for real experimental time-of-flight mass spectral data are higher in case of peak localizations that use apex determinations as compared to peaks determined by centroid or Gaussian approximation of peaks. Some examples of peak detection algorithms using splines are given. A new method of peak intensity calculations is proposed taking into account the baseline. All approaches are directly applicable for the processing of TOF MS data, though specific changes may be desirable for other MS data.

Determination of nitrogen and water stress with hyper spectral reflectance on maize using classification tree (CT) analysis

Field experiments were conducted at the Tamil Nadu Agricultural University, Coimbatore, Tamilnadu, India during rabi (winter) season of 2013-14 with maize crop (TNAU maize hybrid Co 6). To ensure the stressed environment, the crop was subjected to two irrigation levels (IW/CPE: 0.80 and 0.50) and five staggered nitrogen levels (0, 50, 75, 100 and 125 % of recommended dose of nitrogen (RDN).The experiment was laid out in factorial randomized blocks design RBD (Factorial) with three replications. Hyper spectral observations were made with spectroradiometer GER 1500 at 60 and 90 days after sowing (DAS). Measured spectral reflectance curve of maize exhibited a broad low intensity peak centered in the green region at 550 nm and a sharp rise starting at about 675 nm to a plateau in the vicinity of 762 nm under unstressed environment created with irrigation at 0.80 IW/CPE ratio and fertilizer application at 100 % RDN. Significant differences in reflectance were established for nitrogen and water stress at green and NIR region. The results of Classification tree analysis revealed that nitrogen and water stress can be assessed and differentiated using reflectance data when transformed into spectral vegetation indices viz., NDVI, GNDVI, RVI, LCI, IR-RED and SR. Further the Classification tree algorithm coulddetermine that NDVI was the most effective index to assess the combined effect of nitrogen and water stress in maize crop.