Metal Pairs Research Articles

Optical Magnetic Field Enhancement by Strong Coupling in Metamaterials

We study theoretically the interaction effects between optical waveguide modes and magnetic resonances in metamaterials, consisting of periodic arrays of paired metallic nanodisks lying on a dielectric waveguide substrate. The plasmon near-field coupling in individual metallic nanodisk pairs results into magnetic resonances. The periodic arrangement of the paired metallic nanodisks can excite optical waveguide modes propagating in the adjacent dielectric waveguide. When optical waveguide modes are close to magnetic resonances by varying the array period, they interact to form two hybridized modes. A coupling model of two oscillators is also proposed to predict well the positions of the hybridized modes. In the strong interaction regime, the hybridized modes have an obvious anticrossing, and thus exhibit an interesting phenomenon of Rabi splitting. Furthermore, the magnetic fields within metallic nanodisk pairs exhibit a huge enhancement, which could find promising potential applications in magnetic nonlinearity and sensors.

Separation of transition metals from rare earths by non-aqueous solvent extraction from ethylene glycol solutions using Aliquat 336

Abstract Solvent extraction is a widely used separation technique in extractive metallurgy. A conventional solvent extraction system consists of an aqueous phase and an immiscible organic phase. In this work, we show that replacement of water by a polar organic solvent can lead to superior metal separations. Cobalt(II) and samarium(III) chlorides dissolved in water and ethylene glycol (EG), respectively, with LiCl as chloride source, were extracted by Aliquat 336 diluted in toluene. Both cobalt and samarium were extracted from the aqueous solutions, but cobalt was extracted more efficiently from the ethylene glycol solutions than from the aqueous solutions, whereas samarium was not extracted at all from the ethylene glycol solutions. As a result, cobalt and samarium could be separated completely in a single extraction step from ethylene glycol solutions. The mechanisms of cobalt extraction by Aliquat 336 from the ethylene glycol and aqueous solutions were found to be similar, as validated by slope analysis and UV–VIS absorption spectroscopy. Samarium was extracted from the aqueous solution through the salting-out effect of LiCl. Interestingly, LiCl has a much lower salting-out effect for samarium in ethylene glycol than in water due to the lower dielectric constant of ethylene glycol and the lower solubility of LiCl in ethylene glycol. Consequently, samarium is not salted out from ethylene glycol, leading to a very efficient separation of cobalt and samarium. This separation effect can also be applied to the separation of other transition metal and rare-earth metal pairs, including iron/neodymium and zinc/europium.

Plasma metals as potential biomarkers in dementia: a case\u2013control study in patients with sporadic Alzheimer\u2019s disease

Sporadic Alzheimer’s disease (AD) is a neurodegenerative disorder that causes the most prevalent form of age-related dementia but its pathogenesis remains obscure. Altered regulation of metals, particularly pan-cerebral copper deficiency, and more regionally-localized perturbation of other metals, are prominent in AD brain although data on how these CNS perturbations are reflected in the peripheral bloodstream are inconsistent to date. To assess the potential use of metal dysregulation to generate biomarkers in AD, we performed a case–control study of seven essential metals and selenium, measured by inductively coupled plasma mass-spectrometry, in samples from AD and matched control cases. Metals were sodium, potassium, calcium, magnesium, iron, zinc, and copper. In the whole study-group and in female participants, plasma metal levels did not differ between cases and controls. In males by contrast, there was moderate evidence that zinc levels trended towards increase in AD [10.8 (10.2–11.5)] µmol/L, mean (± 95% CI; P = 0.021) compared with controls [10.2 (9.6–10.4)]. Thus alterations in plasma zinc levels differed between genders in AD. In correlational analysis, there was evidence for an increased number of ‘strong’ metal co-regulations in AD cases and differential co-modulations of metal pairs: copper-sodium (Rcontrol = − 0.03, RAD = 0.65; P = 0.009), and copper-calcium (Rcontrol = − 0.01, RAD = 0.65; P = 0.01) were significant in AD males, potentially consistent with reported evidence for dysregulation of copper in severely damaged brain regions in AD. In conclusion, our data suggest that the measurement of metals co-regulation in plasma may provide a useful representation of those metal perturbations taking place in the AD brain and therefore might be useful as plasma-based biomarkers.Graphical

Strength of ceramic–metal joints measured in planar impact experiments

SPS-processed alumina and reaction-bonded boron carbide ceramic composite (RBBC) were joined with Al10SiMg alloy by spark plasma sintering and tested in a series of planar impact experiments designed to measure dynamic tensile (spall) strength of the joints. The results of the impact testing, together with postmortem inspection of the fractured samples, confirmed the applicability of this approach for testing joint strength. The measurements show that in the case of an RBBC/metal joint, the dynamic tensile strength of the joint exceeds that of the ceramic part, and that fracture of the shock-loaded ceramic–metal pair occurred in the ceramic portion. The dynamic tensile strength of the interface between alumina and Al10SiMg alloy virtually coincides with that of the metal part, with the fracture occurring exactly at the interface. The coincidence may be explained based on the recently published results of atomistic calculations of the structure of an alumina–aluminum interface.

О необычном поведении расплава Al – Si в тонких капиллярах

The numerical simulation is devoted to the division of binary metal melt Al – Si filling the thin alundum or quartz capillary. The results of calculations have been gotten for cylindrical channel heated from above. Earlier the behaviour of the similar eutectic melts Pb – Sn, Pb – Bi, Zn – Al, Cd – Bi, Bi – Sb, Cu – Sn, Cu – Pb was considered experimentally and theoretically. The adequate theory of the observed physical phenomena was constructed for these pairs of metals. In experiments the binary melt was prepared to be homogeneous at the initial moment of time. The relatively quick and significant division of a mixture on components was observed for each binary melt. The specific feature of the process was found, namely, the heavy component moved to the lower part of the capillary. The character concentrations difference on the edges of the channel reached to the sufficiently big value 20 %. The explanation of the similar phenomenon has been done by the authors of this article and is based on the assumption of the key role of the interfacial tension on the boundary between melt and alundum wall. It is supposed that the condition of non-wetting is fulfilled on the alundum or quartz walls of the capillary for the metal pairs listed above. Thus, the surface active component appears on the interphase over the phenomenon of adsorption. In experiments under discussion the small temperature gradient oriented vertically upward takes place always in the working space of the smelting furnace. So the thermocapillary force arises on the interphase and generates the large-scale movement in the volume. The equations and laws of interfacial hydrodynamics are valid in this case and can be applied to describe the heat and mass transfer in the liquid binary metals. The transfer of heavy surface-active agent takes place along the direction where the surface tension increases i.e. to the down edge of the capillary. Heavy component continues to accumulate in lower part of the channel so long as all fluxes, caused by external forces, will be equilibrated in the volume and on the surface by the concentration-capillary force and diffusion. On the other hand it has been discovered experimentally that the alloy Al – Si behaves as anomalous melt in relation to all tested pairs of metals. On the contrary to the previous data the heavy component (silicon) accumulates in the top part of the capillary. The explanation of such anomaly is given in this article. It is necessary only to take into account in theoretical model the fact that the light aluminum is surface-active agent in our pair of metals. This component is pressed out of the volume on the surface and under the action of thermocapillary force is transferred downwards along boundary of a channel. Then it returns inside the volume near the bottom by means of the desorption. This process generates the unstable stratification since the light component is located in lower part and at the same time the heavy one is lifted to the top of the capillary. In spite of convective instability there is no large-scale transfer of the light admixture upwards because of heating from above and big hydrodynamic resistance of a thin capillary. The estimations and direct numerical modeling show that the thermocapillary mechanism dominates above the resulting Archimedean force for given geometry, therefore inflow of a light component to the bottom part of a capillary prevails of a loss that causes accumulation of the aluminum in the bottom of channel.

The content of selected heavy metals and their bioavailable fraction in sediments of Solina Reservoir (Poland)

Research on sediments of Solina Reservoir, Poland, were characterized by a content of copper higher than other heavy metals (Cr, Ni, Cd and Zn). The strongest correlations between pairs of heavy metals were Zn–Cu and Ni–Cr, were revealed while there was also a correlation between total contents of chromium and nickel, and between pH value and sediment percentage of organic matter. The content of copper at levels exceeding the geochemical background (more than 20–fold), sediments could only by classified as of the 3rd purity class (according to the PIG criterion) or the 5th purity class (according to Müller’s classification). Ecotoxicological criteria indicate that levels of chromium, copper, nickel and cadmium are all high enough to affect aquatic life. However, the heavy metals analyzed differ in their mobility and bioavailability. The highest percentage value for the ion–exchangeable fraction was noted for cadmium, the lowest for chromium. This means that sediments have a greater capacity to release cadmium into the water column, with the consequence being secondary pollution source for the aquatic ecosystem.

Seasonal Variations of Atmospheric Particulate Matter and its Content of Heavy Metals in Klang Valley, Malaysia

The composition of atmospheric particulate matter (PM10) can help to identify its potential sources and possible impact on human health. This study investigates the seasonal variations and sources of heavy metals in PM10 in the Cheras area. PM10 samples were collected on a 24-h basis using a high-volume air sampler in June during the southwest monsoon and in December during the northeast monsoon of 2014. Selected hazardous trace metals, viz., As, Pb, Cu, Ni, Cd, Co, Mn, Zn, Fe, Cr, V and Ba, were measured by inductively coupled plasma mass spectrometry (ICP-MS). The result showed that the mean concentrations of PM10 were 207.63 ± 7.82 and 138.32 ± 4.67 during the southwest and northeast monsoons, respectively. The heavy metal concentrations during the southwest monsoon followed the order Ba > Fe > Cu > V > Zn > Pb > Mn > Cr > As > Ni > Cd > Co, while those during the northeast monsoon followed the order Zn > Fe > Ba > Cu > Pb > V > Cr > As > Mn > Ni > Cd > Co. The results of the enrichment factors (EFs) showed that the major trace metals mainly originated from anthropogenic sources. A correlation analysis indicated that pairs of trace metals from similar sources were suspended in PM10 in the ambient air. The source apportionment by principal component analysis (PCA) and cluster analysis (CA) suggested that vehicle exhaust and brake and tire wear, industrial emissions and the re-suspension of dust, as well as oil combustion, were the most dominant sources of PM10 in this study.

A pair of polymorphous metal-organic frameworks based on an angular diisophthalate linker: synthesis, characterization and gas adsorption properties.

The combination of an angular diisophthalate ligand, 5,5'-(naphthyl-2,7-yl)diisophthalate (H4L), and copper ions under different solvothermal conditions afforded two polymorphous metal-organic frameworks (ZJNU-77 and ZJNU-78) with the same framework composition of [Cu2(L)(H2O)2], providing a platform to investigate the relationship between MOF polymorphism and gas adsorption properties. As determined by single-crystal X-ray diffraction, ZJNU-77 and ZJNU-78 exhibited three-dimensional networks crystallizing in different space groups. Their structural differences were mainly manifested by the ligand's conformation, the level of framework interpenetration and the network's topology. Interestingly, gas adsorption studies showed that the two compounds after desolvation displayed comparable gas adsorption properties with respect to C2H2, CO2 and CH4, despite their different surface areas and pore volumes. The C2H2, CO2, and CH4 uptake capacities at 298 K and 1 atm are 120.2, 78.1, and 18.4 cm3 (STP) g-1 for ZJNU-77, and 122.0, 82.0, and 18.9 cm3 (STP) g-1 for ZJNU-78, respectively. The IAST adsorption selectivities for the equimolar C2H2/CH4 and CO2/CH4 mixtures are 28.6 and 5.7 for ZJNU-77, and 28.4 and 5.9 for ZJNU-78 at 298 K and 1 atm. These results indicate that besides the surface area, the pore size also plays a crucial role in gas adsorption. This work not only represents an intriguing example of MOF polymorphism achieved by controlling solvothermal conditions, but also provides an insight into the correlation between MOF polymorphism and gas adsorption properties.

Resolving Challenges of Mass Transport in Non Pt-Group Metal Catalysts for Oxygen Reduction in Proton Exchange Membrane Fuel Cells

Mass transport properties of a pair of non-Platinum Group Metal (non-PGM) catalysts in proton exchange membrane fuel cells (PEMFCs) were evaluated through methods developed by Reshetenko et al., demonstrating that the use of different carrier gases can allow for the determination of the mass transport coefficient for oxygen in the gas phase and the electrolyte phase. The gas-phase and non-gas-phase resistances can be elucidated from the slope and intercept, respectively, of the total mass transport coefficient plotted as a function of molecular weight. It was determined through these experiments that the primary sources of mass transfer limitations of the non-PGMs when compared to the PGMs were the catalyst layer (non-gas-phase), rather than the flow fields (gas-phase, primarily Knudsen Diffusion effects), and the gas diffusion layer. This work was combined with a pseudo-2D, isothermal, steady state numerical model to estimate the gas-phase mass transfer coefficient and the fraction of hydrophobic, gas-phase pores in the catalyst layer. Sensitivity studies were also carried out, allowing for more information regarding the influence of several inherent factors on the mass transport limitations, and allow for additional validation of the model beyond simply the quality of the fit.

A Compact and Low-Loss Bandpass Filter Using Self-Coupled Folded-Line Resonator With Capacitive Feeding Technique

This letter proposes a compact and low-loss on-chip bandpass filter (BPF) design in (Bi)-CMOS technology. The proposed BPF consists of a self-coupled folded-line resonator and a pair of metal–insulator–metal capacitors. The proposed resonator has a property of flexible self-resonant frequency to form a transmission zero, which is analyzed in detail by a simplified LC equivalent circuit. Moreover, the parametric studies of the feeding capacitance for the proposed BPF design have been performed to demonstrate the tenability of the resonant frequency. For verification, the proposed BPF is fabricated in a standard 0.13- $\mu \text{m}$ (Bi)-CMOS technology. The measured results show that the proposed BPF has a notch with 25.4-dB suppression at 65 GHz and an insertion loss of 1.66 dB in the passband. The chip size of the device, excluding the test pads, is only 0.009 mm2 ( $0.11\times 0.086$ mm2).

Diffuse electron of alkali metals (Li, Na, K) or diffuse electron pair of alkaline earth metals (Be, Mg, Ca) which predict larger second hyperpolarizability? A comprehensive study of M⋯NH3 model compounds

In the present work, model M⋯NH3 complexes of alkali and alkaline earth metals are considered to calculate second hyperpolarizability using HF, MP2, CCSD and DFT methods. The diffuse electrons of alkali metals are more efficient than diffuse electron pair of alkaline earth metals in enhancing the magnitude of second hyperpolarizability. The radiation frequency has a dramatic effect on γav. Although MP2 γzzzz is overestimated by a smaller margin the corresponding γav fairly agrees with the CCSD result. The large second hyperpolarizability of alkali metal (versus alkaline earth metal) complexes arises from the lower energy intense transition.

Metallurgists’ Insights on Diffusion-Assisted Dissimilar-Joints of Light- and Heavy-Alloys

In metallurgy and materials engineering, a number of phase transformation in solids like precipitation, oxidation, creep, annealing, homogenization, etc. are brought about by the process of diffusion. Many industrial manufacturing processes utilize solid-state diffusion principle, to name a few: 1. Rotating or sliding parts of steel have a hard outside case for wear resistance and a tough inner core for fracture resistance by gas carburizing procedure; 2. Integrated circuits were produced by diffusing impurity into silicon wafers; and 3. Joints between similar and dissimilar metals, alloys, and non-metals, were made using diffusion bonding (DB) technique. Day by day, the science of solid-state diffusion phenomenon is spreading inevitably into new areas of engineering and technology. Diffusion-Assisted-Joints (DAJs) meet the requirements for most critical structures in terms of strength, toughness, tightness, and resistance to heat and corrosion. DAJs can be made out of 730 pairs of dissimilar metals. Hence, DB is considered as an engineering marvel among all the physical welding metallurgists. Herein, experiments were performed to exactly map the quantum influence of the bonding temperature variation on the dissimilar joints of a popular light alloy, Ti-6Al-4V (TiA), and a heavily used heavy alloy, stainless steel (SS), using diffusion mechanism in high-vacuum environment. Cu foil (~200μm) was used as an interlayer. Necessary characterization tools for metallurgical investigations were used to understand the extent of diffusion along the TiA/Cu and Cu/SS interfaces, room-temperature mechanical properties, fracture morphologies, and fracture path of the TiA/Cu/SS DAJs. This paper discussed rational reasons backing the results of the characterizations.

Multi-wavelength lenses for terahertz surface wave.

Metasurface-based surface wave (SW) devices working at multi-wavelength has been continuously arousing enormous curiosity recently, especially in the terahertz community. In this work, we propose a multi-layer metasurface structure composed of metallic slit pairs to build terahertz SW devices. The slit pair has a narrow bandwidth and its response frequency can be altered by its geometric parameter, thereby suppressing the frequency crosstalk and reducing the difficulty of design. By elaborately tailoring the distribution of the slit pairs, a series of achromatic SW lenses (SWLs) working at 0.6, 0.75 and 1 THz are experimentally demonstrated by the near field scanning terahertz microscope (NSTM) system. In addition, a wavelength-division-multiplexer (WDM) is further designed and implemented, which is promising in building multiplexed devices for plasmonic circuits. The structure proposed here cannot only couple the terahertz wave from free space to SWs, but also control its propagation. Moreover, our findings demonstrate the great potential to design multi-wavelength plasmonic metasurface devices, which can be extended to microwave and visible frequencies as well.

Evaluation of the mobility and pollution index of selected essential/toxic metals in paddy soil by sequential extraction method

Comparative distribution and mobility of selected essential and toxic metals in the paddy soil from district Sargodha, Pakistan was evaluated by the modified Community Bureau of Reference (mBCR) sequential extraction procedure. Most of the soil samples showed slightly alkaline nature while the soil texture was predominantly silty loam in nature. The metal contents were quantified in the exchangeable, reducible, oxidisable and residual fractions of the soil by flame atomic absorption spectrophotometry and the metal data were subjected to the statistical analyses in order to evaluate the mutual relationships among the metals in each fraction. Among the metals, Ca, Sr and Mn were found to be more mobile in the soil. A number of significant correlations between different metal pairs were noted in various fractions. Contamination factor, geoaccumulation index and enrichment factor revealed extremely severe enrichment/contamination for Cd; moderate to significant enrichment/contamination for Ni, Zn, Co and Pb while Cr, Sr, Cu and Mn revealed minimal to moderate contamination and accumulation in the soil. Multivariate cluster analysis showed significant anthropogenic intrusions of the metals in various fractions.

CD3+ lymphocytosis in the peri-implant membrane of 222 loosened joint endoprostheses depends on the tribological pairing

Background and purpose — The most frequent cause of arthroplasty failure is aseptic loosening—often induced by particles. Abrasion material triggers inflammatory reactions with lymphocytic infiltration and the formation of synovial-like interface membranes (SLIM) in the bone–implant interface. We analyzed CD3 quantities in SLIM depending on articulating materials and possible influences of proven material allergies on CD3 quantities.Patients and methods — 222 SLIM probes were obtained from revision surgeries of loosened hip and knee arthroplasties. SLIM cases were categorized according to the SLIM-consensus classification and to the particle algorithm. The CD3 quantities were analyzed immunohistochemically, quantified, and correlated to the particle types.Results — Metal–metal pairings showed the highest CD3 quantities (mean 1,367 counted cells). CD3 quantities of metal–polyethylene (mean 243), ceramic–polyethylene (mean 182), and ceramic–ceramic pairings (mean 124) were significantly smaller. Patients with contact allergy to implant materials had high but not statistically significantly higher CD3 quantities than patients without allergies. For objective assessment of the CD3 response as result of a pronounced inflammatory reaction with high lymphocytosis (adverse reaction), a defined CD3 quantity per high power field was established, the “CD3 focus score” (447 cells/0.3 mm2, sensitivity 0.92; specificity 0.90; positive predictive value 0.71; negative predictive value 0.98).Interpretation — The high CD3 quantities for metal–metal pairings may be interpreted as substrate for previously described adverse reactions that cause severe peri-implant tissue destruction and SLIM formation. It remains unclear whether the low CD3 quantities with only slight differences in the various non-metal–metal pairings and documented contact allergies to implant materials have a direct pathogenetic relevance.

Metal Pollution Indices of Bottom Sediment and Surface Water Affected by Acid Mine Drainage

Sediments are normally the final pathway of both natural and anthropogenic components produced or derived from the environment. Sediment quality is a good indicator of pollution in the water column, where heavy metals and other organic pollutants tend to concentrate. Metals are introduced in aquatic systems as a result of the weathering of soils and rocks, from volcanic eruptions, and from a variety of human activities involving the mining, processing, or use of metals and/or substances that contain metal pollutants. Heavy metal concentration in the water column can be relatively low in some cases, but the concentrations in the sediment may be elevated. The presented work aimed to investigate the pollutant levels of some heavy metals (Fe, Mn, Al, Cu, Zn, As, Cd, Pb) in the water and sediments related to acid mine drainage (AMD) produced from an abandoned sulphide mine in Smolnik in Eastern Slovakia. A metal pollution index was used to compare the total content of metals at five sampling stations. The level of partitioning of the metals between the surface water and sediments in the area was calculated using Partition coefficients and the correlation coefficients between the metal pairs in both media were calculated by a Pearson coefficient.

Controlling the optical properties of a Cd_1−xZn_xS phosphor that contains pairs of dopant metals based on copper, silver, and manganese

This paper discusses the structure parameters and the optical and luminescence properties of Cd1−xZnxS phosphor—a solid solution based on zinc and cadmium sulfides—that contains one of the following pairs of dopant ions: copper and silver, manganese and silver, or manganese and copper. The synthesis and simultaneous doping of the phosphor are carried out by colloid chemistry. It is shown that doping with two ions in combination decreases the crystallographic symmetry of the cubic lattice of the matrix solid solution. Broadening of the photoluminescence spectrum of the doped solid solutions is observed in the long-wavelength region. Doping the phosphor with copper paired with silver makes it possible to obtain white luminescence and to increase its emission intensity by a factor of 2 at wavelength 500 nm by comparison with the undoped solid solution.

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Room temperature spin Kondo effect and intermixing in Co/Cu non-local spin valves

The anomalous low temperature suppression of the spin accumulation signal ΔRNL in non-local spin valves (NLSVs) based on common ferromagnet (FM)/normal metal (N) pairings has recently been shown to result from a manifestation of the Kondo effect. Local magnetic moments in the N due to even minor levels of FM/N interdiffusion depolarize the injected spin current, suppressing the effective spin polarization around and below the Kondo temperature TK. Previous studies have focused on FM/N combinations that happen to have low TK so that Kondo effects occur only well below 300 K. Here, we study NLSVs based on Co/Cu, a materials combination that is not only technologically relevant but also has a high TK, up to 500 K. Despite the negligible equilibrium solubility of Co in Cu, we find clear Kondo effects in both ΔRNL and Cu resistivity, due to Co/Cu intermixing that we probe via quantitative transmission electron microscopy. Most significantly, under certain conditions the spin Kondo effect suppresses the injected spin polarization even at room temperature, with important technological implications. Studies as a function of the Cu thickness and annealing temperature reveal complex trends in interdiffusion lengths and Kondo effects, which we interpret in terms of the interplay between diffusion kinetics and thermodynamics, as well as the thickness dependence of the Kondo effect.

Tetranitrocalix[4]Arene Tetraradical Tetraanion As an Electrochemically Generated Ligand

A tetraradical tetraanion is a stable product of 4-electron reduction of cone-5,11,17,23-tetranitro-25,26,27,28-tetrapropoxycalix[4]arene in nonaqueous dimethyl-formamide (DMF) [1]. It represents an electrochemically generated ligand which is able to coordinate all alkali metal ions. The existence of these complexes was recently proved by DC-polarography, cyclic voltammetry and UV-VIS spectroelectrochemistry. Observed stoichiometries are 2:1 (for Li+, Na+, Cs+), 3:1 (Rb+, Cs+) and 4:1 (K+). The complexes are kinetic labile and they have character of ion pairs between negatively charged nitroradical group and metal cations. The „normalized“ values of the stability constants were compared with stability constants of ionic pairs of alkali metals with nitrite anions. About three orders higher values for calix[4]arene radicals can be explained by a „structural vector“. Four charged and oriented nitroradicals on calix-scaffold as donor groups form considerably higher „field for electrostatic interaction“ than randomly oriented simple anions. The same type of interaction was revealed also for cone-5,11,17,23-tetranitro-25,26,27,28-tetrakis(ethoxycarbonylmethoxy)calix[4]arene. This compound was originally suspicious of binding alkali metal ions by ester groups on the lower rim, however, the experimental data exclude this possibility. Reference [1] A. Liška, P. Vojtíšek, A.J. Fry, J. Ludvík, Electrochemical and Quantum Chemical Investigation of Tetranitrocalix[4]arenes: Molecules with Multiple Redox Centers, J. Org. Chem. 78 (2013) 10651-10656.