Ni-P System Research Articles

Amorphous Alloys Atomic Structure Investigation by Means of Electron Microscopy and Diffraction

In the paper, the atomic structure of amorphous and nanocrystalline alloys of the electrolytically obtained CoP, NiP, CoNiP, CoW, and CoNiW systems has been studied. The structure was investigated by electron microscopy and diffraction using a Libra 200 HR FE transmission electron microscope at an accelerating voltage of 200 kV within a temperature range of 50-35 °C. The obtained radial atom distribution function and the coordination sphere radii are in good agreement with the data for the cobalt structure in the cubic and hexagonal modifications. The high coordination numbers of the third and fourth coordination spheres allow suggesting a predominantly cubic structure of the local atom environment in CoP samples but somewhat lower, which is explained by the presence of free volume and phosphorus atoms distorting the local structure. When heating, the near atomic order also corresponds to the cubic phase of cobalt, and the ordering occurs in the second, third, and fourth coordination spheres. The data obtained for CoNiP alloys indicate that by configuration, the local atomic environment is closer to the hexagonal structure of nickel. In general, the structure of the CoP-CoNiP system alloy films obtained by electrolytic deposition is already in one of the local minima of the total system energy, which is confirmed by the near atomic order similar to the cubic phase of cobalt or hexagonal phase of nickel. This determines the good stability of the structure and properties during thermal exposure.

Enhanced crystallization resistance and thermal stability via suppressing the metastable superlattice phase in Ni-(Pd)-P metallic glasses

Virtually, glass formation is to avoid crystallization during solidification, i.e., a consequence of the competition between the undercooled liquid and primary crystalline phases. It is found that the crystallization resistance of the binary Ni-P system was drastically enhanced with alloying of Pd and correspondingly, the critical size for glass formation increased significantly from the micrometer to millimeter scale. Thermodynamically, the introduction of Pd could effectively increase the atomic size mismatch and heat of mixing, which are beneficial to stabilize the supercooled liquid. Kinetically, the introduction of Pd not only successfully suppresses the formation of metastable superlattice phase, which is prone to nucleation and growth in the supercooled liquid state, but also changes the crystallization mechanism from the primary to eutectic mode. The current finding sheds light on understanding glass formation of the most studied Pd-Ni-P system and the glass-forming ability in general.

Construction of a TiO2–Fe3O4‐decorated molecularly imprinted polymer nanocomposite for tartrazine degradation: Response surface methodology modeling and optimization

We synthesized a novel recoverable and reusable photocatalyst system for tartrazine degradation by one‐step incorporation of Fe3O4 and TiO2 nanoparticles into a molecularly imprinted polymer through a facile precipitation polymerization method. The as‐prepared samples were systematically characterized using X‐ray diffraction, infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy‐dispersive spectroscopy, and vibrating sample magnetometry. Benefiting from the positive synergistic effect, tartrazine was almost completely degraded under UV‐C within 180 min by the multicomponent photocatalyst (Fe3O4 + TiO2 + MIP) in comparison with far fewer activities by the corresponding NIP system and the nonmagnetic and bare structures. On the other hand, the central composite design in response surface methodology was applied to optimize the tartrazine photocatalytic degradation process. Twenty experiments were conducted by adjusting three parameters (nanocomposite dosage, initial pH of the reaction solution, and initial dye concentration) in the multiple variable analysis method. A satisfactory correlation between the experimental and predicted values was obtained (R2 = 0.956). Additionally, ANOVA analysis with a p value of 1.15 × 10–5 indicated that the model terms are highly significant. Under the determined optimum conditions, a verification experiment was conducted and shown the adequately approximate value between the predicted (99%) and the experimental (97%) results, which confirmed the validity of the model.

Disposable electrochemical detection of breast cancer tumour marker CA 15-3 using poly(Toluidine Blue) as imprinted polymer receptor

In this work, electrically-conducting poly(Toludine Blue) was employed for the first time as synthetic receptor film, prepared by Molecular Imprinting strategies and using electrochemical methods, for the specific screening of breast cancer biomarker Carbohydrate Antigen 15-3 (CA 15-3).The protein imprinted poly(Toluidine Blue) film was grown in a pre-formed Toluidine Blue (TB) tailed SAM at the AuSPE surface, which greatly enhanced the stability against degradation of the Molecular Imprinted Polymer (MIP) film at the electrode surface.The MIP receptor film recognition ability towards the protein was investigated by fitting data to Freundlich isotherm. The binding affinity (KF) obtained for the MIP system was significantly higher (~ 12-fold) to that obtained for the NIP system, demonstrating the success of the approach in creating imprinted materials that specifically respond to CA 15-3 protein.The incubation of the MIP modified electrode with increasing concentration of protein (from 0.10 U mL−1 to 1000 U mL−1) resulted in a decrease of the ferro/ferricyanide redox current. The device displayed linear response from 0.10 U mL−1 to 100 U mL−1 and LODs below 0.10 U mL−1 were obtained from calibration curves built in neutral buffer and diluted artificial serum, using DPV technique, enabling the detection of the protein biomarker at clinically relevant levels. The developed MIP biosensor was applied to the determination of CA 15-3 in spiked serum samples with satisfactory results.The developed device provides a new strategy for sensitive, rapid, simple and cost-effective screening of CA 15-3 biomarker. Importantly, the overall approach seems suitable for point-of-care (PoC) use in clinical context.

Kinetics of cathodic evolution of hydrogen on Ni-P systems electrodeposited alloys

Analysis of experimental data on kinetics of hydrogen evolution reaction from sulfuric acid solutions on electrodeposited Ni,P alloys of various compositions is conducted. It is shown that changeover of mechanism of the process is observed upon increase of cathodic potential: at low overvoltages it occurs mainly via the Volmer-Heyrovsky pathway with control of the charge transfer stage, and the Volmer-Tafel mechanism, the slow stage of which is mechanical recombination, is realized at high potentials. The influence of the alloy composition on the parameters of the process is manifested in the change of charge transfer coefficients of both electrochemical stages and degree of surface filling by adsorbed hydrogen.

Needle image plates compared to conventional CR in chest radiography: Is dose reduction possible?

PurposeTo compare image quality of standard-dose computed radiography and dose reduced needle-technology CR for supine CXR in a clinical setting. Materials and methodsWe prospectively evaluated 128 radiographs of 32 immunocompromised patients. For each patient four clinical CXR were performed within one week, two with powder image plates (PIP; Fuji ST-V) and two with needle image plates (NIP; Agfa DXS) at standard and half dose, respectively. One experienced radiologist and two residents blinded to dose level and kind of imaging system rated different anatomical structures, image noise, tubes/lines and abnormalities on a image quality scale from 1 to 10 (1=poor, 10=excellent). The rating scores were tested for statistical differences using analysis of variance with repeated measures. ResultsA statistical difference (p<0.05) was found for the two systems as well as for the two dose levels. Overall rating scores were 6.5 for PIP with full dose, 6.2 for PIP with half dose, 7.6 for NIP with full dose and 7.4 for NIP with half dose. There was a significant difference in favour of the NIP system at the same dose level. Also the NIP images obtained at half dose were ranked significantly better compared to the PIP images at standard dose. The differences in ranking of anatomical structures and abnormalities were more pronounced in low absorption areas (pulmonary vessels, parenchyma) than in high absorption areas (mediastinum, spine). ConclusionFor supine chest radiograms the NIP technology allows for a dose reduction of 50% while providing higher image quality.

Transient Liquid Phase Bonding of High Strength Low Alloy Steel Coiled Tubing

The oil and gas industry of Alberta, Canada use coiled tubing made from high strength low alloyed steel (HSLA) to extract oil from reservoirs deep beneath the earth’s surface. The repeated use of the coiled tubing in down-hole wells results in fatigue failure of the tube material. In order to repair the coiled tube, a section of tubing is fusion welded using tungsten inert gas welding onto the remaining tube steel. However, the fusion weld often fails within the weld region and therefore, alternative joining methods need to be explored to minimize detrimental changes at the joint region. In this study transient liquid phase (TLP) bonding is used with the aid of metal interlayers based on the Ag-Cu and Ni-P systems. These interlayers form a liquid at the melting point and the gradual diffusion of alloying elements into the joint and the diffusion of elements out of the joint region induces isothermal solidification whilst the joint is held at the bonding temperature. The TLP bonding behaviour of the HSLA steel as a function of bonding parameters was investigated and the quality of the joint region determined using metallurgical techniques (light and scanning electron microscopy, energy dispersive spectroscopy) and mechanical testing.

Kinetic surface roughening of electrodeposited amorphous PdP and NiP films – A comparative study

Kinetic surface roughening of electrodeposited PdP and NiP amorphous films were investigated by atomic force microscopy and X-rays phase-contrast radiography. Anomalous scaling of the interface width was observed for PdP system, with H = 0.75 ± 0.06, β loc = 0.49 ± 0.07 and β = 0.38 ± 0.08. In contrast, NiP system shows normal scaling behavior, with H = 0.70 ± 0.02 and β = 0.16 ± 0.03. The results suggest that surface roughening during film growth is strongly influenced by local behaviors like hydrogen evolution reaction, which shifts surface roughening from normal scaling in NiP to anomalous scaling in PdP.

Untersuchungen zur Qualität von Thoraxaufnahmen bei Katzen mit einem auf einer Nadelstruktur basierenden Speicherfoliensystem – Modelluntersuchungen zur Bewertung der Bildqualität bei Neugeborenen

Is the image quality of thoracic radiographs of cats obtained with a needle-based storage phosphor (NIP) system superior to conventional (PIP) storage phosphor radiography? Is it possible to decrease the mAs by 50 % with the NIP system without significant loss of information? From each of the 20 animals, three lateral radiographs were acquired. The assessment of the exposure level was based on the generated lgM-values. Images were acquired 1. with the NIP system and exposure settings equivalent to an lgM of 1.9, 2. with the PIP system and identical settings, and 3. with the NIP system and 50 % of the mAs. Six blinded readers used a 5-step scale to assess the reproducibility of five anatomical structures and image noise sensation. Data were analysed using Visual Grading Characteristics Analysis (VGC). While applying identical exposure values the NIP system for all features revealed superior ratings to those of the PIP system (AUC (VGC) values ranged from 0.81 for "cardiac silhouette" to 0.92 for "trachea"). Even when reducing mAs by 50 % in the NIP images all features were rated better compared with the PIP images and original settings (AUC (VGC) values ranged from 0.60 for "cardiac silhouette" to 0.74 for "trachea" and "caudal thoracic field"). The NIP system demonstrates clearly better image quality compared to the reference PIP system. A dose reduction of 50 % seems to be possible without relevant detraction from image quality. The results obtained in the animal model are valid for simulating conditions in neonatal radiological practise.

Visual Comparison of Screening Quality in Digital Printing Systems

Best characteristics in resolution fields showed the offset systems. This became clear at the investigations of the motive &#x201C;Circles&#x201D; and &#x201C;Text&#x201D;, whereby in the text fields the NexPress machine was in the leading group too. In the vignettes the conventional printing machines were best, but as in the resolution fields it is only a small gap to the NIP systems. In the images &#x201C;Patches&#x201D;, &#x201C;Silver&#x201D;, &#x201C;Pigeons&#x201D; and &#x201C;Textile&#x201D; got the offset systems with comparable screenings lower ranking then some of the NIP systems. Thus the statement is, that the digital systems do at least print in the images as good as offset systems with same screening, some do better. They partially obtain amazing, nearly halftone like illustrations, which show a detail reproduction, which was not reached by some conventional systems. To the results of the NIP systems should be said, that the NexPress machine convinced in all tests. If the evaluations in survey a got compared with the publication date of the engines, a clear connection can be recognized. As oldest machines Indigo UltraStream and Xeikon stand usually at the end of the rank order, followed by the newer Xerox, and the recently released NexPress. If this trend continues further, it will be interesting how good the new Xerox IGen 3 will be, which is still in the development phase. At this criterion it is disappointing that the new Indigo Platinum in survey b could not convince. Remarkably is the good evaluation of the HP system in survey b. That's a proof of the potential of the Inkjet systems, which however still has strong restrictions in speed and substrate choice. Further interesting will be which multi color development will show up, because the screening solution of a more than 4 color system is excitingly. For the master thesis samples from the new Oc&#xE9; 7-Colormachine (CPS 700) were available, but these were not used for the evaluation, because at this time the quality of the print samples where not satisfying and not comparable to the other systems that got evaluated.

球状黒鉛鋳鉄の固相接合 ８ Ｎｉ系ろう材を用いた球状黒鉛鋳鉄接合材の引張特性

The authors have studied the tensile strength, the fatigue strength and the impact characteristics of the joints of the ferritic spheroidal graphite cast iron produced by the solid state bonding method and found that the mechanical characteristics of the joints were comparable to those of the base metal. With respect to practical uses, it is considered that the brazing method with a brazing sheet is easier than the solid state bonding for bonding of the cast iron. In this study, the ferritic spheroidal graphite cast irons were bonded with Ni-base brazing sheets using the high frequency induction heating apparatus. Those sheets were MBF 15 (Ni-Cr-Si-B system), MBF 30 (Ni-Si-B system) and MBF 60 (Ni-P system) in the thickness of 40μm. Furthermore, effects of bonding time, surface roughness of the surfaces to be bonded, and bonding atmosphere on the tensile strength of the joints were investigated. Main results obtained are as follows: (1) When the cast irons were bonded for 2 and 10 minutes with MBF 15 and MBF 60, the joints were fractured at the bonded zone on the tensile test. When the cast irons were bonded for 30 minutes, however, the tensile strength of the joints was nearly equal to that of the base metal. On the other hand, when the cast irons were bonded for 2, 10 and 30 minutes with MBF 30, all of the joints were fractured in the base metal on the tensile test. (2) When the surface roughness was 2.3μm, the tensile strength of the joints bonded with MBF 15 was nearly equal to that of the base metal. When the surface roughness was 13.9μm, however, all of the joints were tensile-fractured at the bonded zone because small shrinkages were formed at the center of the bonded zone. (3) The tensile strength of the joints bonded in argon was a little lower than that of the joints bonded in vacuum with MBF 15 and MBF 60. However, the strength of the joints bonded in air was decreased considerably because the oxides of Cr were produced in the center of the melting zone. On the other hand, when the joints were bonded with MBF 30 in air, in argon, and in vacuum, all of the joints were tensile-fractured in the base metal. (4) In the case of MBF 15 containing Cr, the high density zone of Cr was formed at the center of the melted brazing metal and Cr2O3 particles were produced by oxygen in air. By the final stage of the bonding, Si was accumulated near the Cr2O3 particles, and they were reduced by the Si, and the SiO2 particles were formed instead of the Cr2O3 particles. (5) When the brazing sheets having 5 levels of the Cr content were used for the bonding, the tensile strength of the joints was decreased with an increase of the Cr content.

Tone Reproduction Characteristics of Offset Press Printing

In order to obtain color matching between DDCP and offset press printing, it is important to know the printing characteristic of the press system. In this paper, we report its tone reproduction and ink transfer characteristics. Its dot percent signal has good tone reproduction characteristic corresponds to human lightness scale, especially for film and positive working plate system. But this characteristic is slightly changed by printing plate type such as negative working plate and CTP. Ink transfer ratio from blanket to paper is near 20% level and quite different from that of NIP system.

Biochemical fingerprinting of coliform bacterial populations — comparisons between polluted river water and factory effluents

Bacteria from different pollution sources may consist of essentially the same species but with different strains predominating. Therefore, sub-typing of bacterial strains recovered in the polluted water and comparison with those present in possible pollution sources is a valuable tool for idenlification of the source. Since such studies require investigations of large numbers of isolates, simple laboratory methods combined with automated data evaluation and presentation are necessary. The Phene Plate (PhP) system for biochemical fingerprinting of bacteria is based on measurements of the kinetics of biochemical tests, performed in micro-plates. The system also includes mathematical models to calculate the diversity (Di) of the bacterial flora within samples, as well as the similarities between bacterial populations in different samples as the population similarity coefficient (Sp). We have used the NIP system to type coliform bacteria isolated from a polluted river in Sweden and from the outlets from three paper mills that were suspected contamination sources. From each of 27 river water samples and 8 samples from factory outlets, collected on eight Sampling occasions, between 10 and 50 coliforms were typed, yielding altogether 1,027 isolates. The diversity among the bacteria in river water samples was generally high (mean Di = 0.95) compared with factory Outlets (mean Di = 0.63) which usually were dominated by isolates belonging to a few NIP types. These PhP types were very rarely recovered from the river water samples which is also reflected in low similarities between bacterial populations in river water and factory outlets (mean Sp = 0.03). Thus the bacteria from factory outlets did not seem to have spread downstream. In contrast, bacterial populations from sampling sites close to each other in the river were more similar to each other (mean Sp 0.13), indicating the presence of several, diffuse contamination sources, possibly from animal or human faecal material.

Tunneling in real structural glasses: A universal theory.

We present a universal theory that describes the low-temperature properties of real structural glasses. The key ingredient is a mapping of real and possibly complex glasses on Lennard-Jones glasses. A dimensional analysis allows us to find a general explicit expression that relates the tunneling parameters [density of tunneling systems (TS's), coupling constant between TS's and heat bath] to material constants. Experimental evidence is presented, and the relation to recent numerical calculations on the NiP system is discussed.

The short-range order in amorphous NiP system changed by deep-freezing and subsequent relaxation

A model system of amorphous NiP is calculated by molecular dynamics. A rapid quench from liquid to solid and a subsequent deep-freezing to 5 K is investigated, simulating by computer the rapid cooling from 2000 K to 300 K, yielding a glass-state. Subsequently the system was further cooled, and then reheated to 300 K. A detailed Voronoi analysis is given to follow the change in short-range order. Characteristic differences have been observed between the two states at 300 K. A possible relaxation effect is discussed.

Optical properties of polycrystalline and amorphous Ni1?xPx layers by ellipsometry

The optical properties of polycrystalline and amorphous d.c.-electrodeposited Ni1−xPx alloys in the visible spectral range are reported. Spectroscopic ellipsometry measurements of the pseudo-optical constants were performed from 1.65 to 3.1 eV for specimens with atomic fraction of phosphorus of 0.06<x<0.28. It was found that the dielectric functions of asdeposited Ni1−xPx could be expressed in the modified Drude-like form, including separate contributions from the interband transitions. Estimated values of the plasmon energy in the range of 5.3–3.1 eV and scattering time of the order of 10−15 s seem to show quantitative validity. A decrease in plasma frequency by a factor of about 1.4 across the glass-forming range agrees well with the predicted decrease in the s-p density of states at the Fermi level. Transformation of the amorphous Ni0.725P0.275 to the crystalline Ni3P+Ni phase caused by heating results in changed optical functions which exhibit large deviation from the single nearly-free-carrier approach. This would suggest a two-carrier and/or frequency-dependent Drude parameters model as offering a more reasonable description of the optical conductivity of crystalline two-phase Ni-P systems.

Magnetic properties of amorphous and liquid Ni-P-B alloys

In order to study the change of the magnetic properties upon the transition from the Ni-B to the Ni-P system, the amorphous alloy series Ni 81.5P x B 18.5− x with x = 0, 1.8, 3.7, 7.4, 13, 16.7 and 18.5 at% were prepared by the melt-spinning technique. First, the magnetization isotherms were measured for the amorphous state from 5 to 300 K in magnetic fields up to 9 kOe. For the alloys with 3.7 ⩽ x ⩽ 18.5, a Pauli susceptibility could easily be deduced for the amorphous matrix. For x = 0 and 1.8, nonlinear magnetization curves were obtained which could not be saturated up to 9 kOe; however, based on previous 11B NMR and magnetization studies on another amorphous Ni 81.5B 18.5 alloy, these two alloys are also considered to be Pauli paramagnetic. Second, the magnetic susceptibility in 17 kOe magnetic field was measured as a function of temperature from 300 to 1600 K yielding crystallization temperatures of the amorphous alloys and the susceptibilities of the liquid state. These latter values were in good agreement with the Pauli susceptibilities of the amorphous state. Based on these data and on the results of previous low-temperature specific heat studies on the same alloys, the electronic structure of these metallic glasses is discussed.

ChemInform Abstract: Solid Solution Phases with MnP Type Structure: T1‐tNitP (T: Ti‐Co)

AbstractMnP type solid solution phases are identified in the CrP‐ NiP, MnP‐ NiP, FeP‐ NiP, and CoP‐ NiP systems.

Theoretical estimates of phosphorus concentration profiles across grain boundaries in Fe-P and Fe Ni-P systems

The equilibrium “intergranular segregation extent (ISE)” of P in the above two alloy systems has been calculated on the basis of a model presented here. The ISE of P is defined as the monolayer thickness of a P-enriched bulk region adjacent to the grain boundary, where a normalized concentration of P is greater than one-tenth of that of the grain boundary. The model is in principle analogous to Ono's discrete lattice approach based on a simple regular solution model under the assumption of the nearest neighbor interaction of atoms. The ISE of P thus calculated is. irrespective of the Ni-concentration of the alloys, ~ one monolayer thick at most whatever magnitudes are chosen for the various parameters adopted within their limited ranges in the present model. This suggests that the equilibrium intergranular segregation of P occurs exclusively at grain boundaries per se in ferrous alloys.

Activated sintering of chromium-carbide-nickel alloys

1. Small phosphorus additions (0.1–0.2%) activate the initial state of sintering of chromium-carbide-nickel alloys, as a result of which a volume shrinkage of specimens amounting to 80–90% of the maximum attainable shrinkage is observed at a sintering temperature as low as 1100°C. 2. When the amount of phosphorus in the nickel binder corresponds to the eutectic composition in the Ni-P system, full sintering of KKhNF alloys is observed at 1100°C, i.e., a temperature 100–150°C lower than that for phosphorus-free alloys. 3. The low temperature of liquid phase formation in chromium-carbide-nickel-phosphorus alloys enables them to be hot-pressed at 950–1070°C, i.e., at temperatures 150–200°C lower than the hot-pressing temperatures of alloys without a phosphorus addition.