Journal articles: 'Phosphorus atomic ions'

1

Harbol, M. R., J. R. Appling, and A. C. Goren. "State selective production of phosphorus ions via multiphoton ionization of atomic phosphorus." Journal of Chemical Physics 101, no. 4 (August 15, 1994): 2659–64. http://dx.doi.org/10.1063/1.467645.

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HARBOL, M. R., J. R. APPLING, and A. C. GOREN. "ChemInform Abstract: State Selective Production of Phosphorus Ions via Multiphoton Ionization of Atomic Phosphorus." ChemInform 25, no. 49 (August 18, 2010): no. http://dx.doi.org/10.1002/chin.199449029.

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Bacchus-Montabonel, M. C., and Y. S. Tergiman. "Charge transfer processes induced by collision of phosphorus P2+ ions with atomic hydrogen." Chemical Physics Letters 422, no. 1-3 (April 2006): 122–26. http://dx.doi.org/10.1016/j.cplett.2006.02.019.

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Liu, Zhao-yang, Rong-bin Huang, and Lan-sun Zheng. "Bare phosphorus and binary phosphide cluster ions generated by laser ablation." Zeitschrift f�r Physik D Atoms, Molecules and Clusters 38, no. 2 (September 3, 1996): 171–77. http://dx.doi.org/10.1007/s004600050079.

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Furuyama, Taniyuki, Ryosuke Harako, and Nagao Kobayashi. "Structural changes in non-planar octaaryl substituted phthalocyanine phosphorus complexes." Journal of Porphyrins and Phthalocyanines 19, no. 01-03 (January 2015): 500–509. http://dx.doi.org/10.1142/s1088424615500364.

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Phosphorus complexes of non-planar α-octaaryl phthalocyanine derivatives ((α- Ar )8 Pc ), 3a and 3b have been synthesized by introduction of phosphorus(V) ions into free-base Pcs 2a and 2b. 3a and 3b were characterized by MS, 1 H and 31 P NMR spectra. The solid state structure of 3a indicated a ruffled Pc structure due to the small atomic radius of phosphorus, although the corresponding free-base Pc 2a has a saddled Pc structure. The phosphorus complexes showed intense absorption bands (Q-bands) in the near-IR region, while the introduction of electron-donating groups at the peripheral phenyl groups was efficient for additional red-shifting of the Q-band. Electrochemical data revealed that the red-shift of the Q-band is attributable to a decrease in the HOMO–LUMO gap due to significant and moderate stabilization of the LUMO and HOMO, respectively. MO calculations suggested that the phosphorus(V) ion intensified the electronic interaction between the peripheral aryl moieties and the Pc macrocyclic core.

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Luo, Shi-Zhong, Yan-Mei Li, Yan-Ling Niu, Yi Chen, Yu-Yang Jiang, Jing Chen, and Yu-Fen Zhao. "Characterization of Electrospray Ionization Mass Spectrometry for N-Diisopropyloxyphosphoryl Dipeptide Methyl Esters." European Journal of Mass Spectrometry 11, no. 1 (February 2005): 107–17. http://dx.doi.org/10.1255/ejms.733.

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A systematic study of the fragmentation pattern of N-diisopropyloxyphosphoryl (DIPP) dipeptide methyl esters in an electrospray ionization (ESI) tandem mass spectrometry (MS/MS) was presented. A combination of accurate mass measurement and tandem mass spectrometry had been used to characterize the major fragment ions observed in the ESI mass spectrum. It was found that the alkali metal ions acted as a fixed charge site and expelled the DIPP group after transferring a proton to the amide nitrogen. For all the N-phosphoryl dipeptide methyl esters, under the activation of a metal ion, the rearrangement product ion at m/z 163 was observed and confirmed to be the sodium adduct of phosphoric acid mono-isopropyl esters (PAIE), via a specific five-membered penta-coordinated phosphorus intermediate. However, no rearrangement ion was observed when a β-amino acid was at the N-terminal. This could be used to develop a novel method for differentiating isomeric compounds when either α- or β-amino acid are at the N-terminus of peptides. From the [M + Na]+ ESI-MS/MS spectra of N-phosphoryl dipeptide methyl esters (DIPP – Xaa1 – Xaa2 – OMe), the peaks corresponding to the [M + Na – Xaa1 – C3H6]+ were observed and explained. The [M + Na]+ ESI-MS/MS spectra of N-phosphoryl dipeptide methyl esters with Phe located in the C-terminal, such as DIPP–Val–Phe–OMe, DIPP–Leu–Phe–OMe, DIPP–Ile–Phe–OMe, DIPP–Ala–Phe–OMe and DIPP–Phe–Phe–OMe, had characteristic fragmentation. Two unusual gas-phase intramolecular rearrangement mechanisms were first proposed for this fragmentation. These rearrangements were not observed in dipeptide methyl ester analogs which did not contain the DIPP at the N-terminal, suggesting that this moiety was critical for the rearrangement.

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Nakabayashi, N., H. Ohyama, E. Simoen, M. Ikegami, C. Claeys, K. Kobayashi, M. Yoneoka, and K. Miyahara. "Mechanical stress of the electrical performance of polycrystalline-silicon resistors." Journal of Materials Research 16, no. 9 (September 2001): 2579–82. http://dx.doi.org/10.1557/jmr.2001.0354.

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Results are presented of a study on the mechanical stress dependence of the resistance of polycrystalline silicon (Poly-Si) films doped with different atomic species. Two types of Poly-Si film implanted with boron and phosphorus ions were studied, namely, B-doped films of 400 nm and P-doped films of 250 nm thickness, which were deposited by low-pressure chemical vapor deposition at 620 °C on thermally oxidized silicon wafers. The film doping was done by ion implantation at 50 keV, with a dose of boron and phosphorus of 2 × 1014 and 5.3 × 1014 cm−2, respectively. The Poly-Si films were annealed in a N2 ambient at 1000 °C for 20 min to activate the implanted atoms. A controlled amount of external stress was applied to the silicon wafers to study the impact on the electrical performance of the implanted Poly-Si resistors. The resistance of the B-doped Poly-Si films is shown to increase by the mechanical stress, while the resistance of the P-implanted Poly-Si films remained unchanged. It is concluded that this difference is related to the structural differences between Poly-Si films implanted with boron and phosphorus, respectively.

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Djosic, Marija, Miodrag Mitric, and Vesna Miskovic-Stankovic. "The porosity and roughness of electrodeposited calcium phosphate coatings in simulated body fluid." Journal of the Serbian Chemical Society 80, no. 2 (2015): 237–51. http://dx.doi.org/10.2298/jsc140626098d.

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Calcium phosphate coatings were electrochemically deposited on titanium from the aqueous solution of Ca(NO3)2 and NH4H2PO4 with the current density of 10 mA cm-2 for deposition time of 15 min. The obtained brushite coatings, (CaHPO4?2H2O), were converted to hydroxyapatite (HA) by soaking in simulated body fluid (SBF) for 2, 7 and 14 days. The brushite and hydroxyapatite coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). It was shown that the increase in soaking time increases the porosity, roughness and crystallite domain size of HA coatings and decreases the unit cell parameters and unit cell volume, while does not affect the HA mean pore area. The calcium and phosphorus ions concentrations in SBF were determined by atomic absorption spectroscopy (AAS) and UV-Vis spectroscopy, respectively and the mechanism of HA growth based on dissolution-precipitation was proposed.

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Vilkas, Marius J., and Yasuyuki Ishikawa. "Relativistic multireference many-body perturbation theory calculations on ions of the phosphorus isoelectronic sequence." Journal of Physics B: Atomic, Molecular and Optical Physics 37, no. 24 (December 7, 2004): 4763–78. http://dx.doi.org/10.1088/0953-4075/37/24/004.

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Yin, Yu, Shi Li, Shunbin Wang, Shijie Jia, Jing Ren, Gerald Farrell, Elfed Lewis, and Pengfei Wang. "Ultra-high-resolution detection of Pb2+ ions using a black phosphorus functionalized microfiber coil resonator." Photonics Research 7, no. 6 (May 3, 2019): 622. http://dx.doi.org/10.1364/prj.7.000622.

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11

Lu, Huansheng, Bo Xu, Jing Shi, Musheng Wu, Yinquan Hu, and Chuying Ouyang. "Structural, electronic, sodium diffusion and elastic properties of Na–P alloy anode for Na-ion batteries: Insight from first-principles calculations." Modern Physics Letters B 30, no. 32n33 (November 30, 2016): 1650385. http://dx.doi.org/10.1142/s0217984916503851.

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Sodium-ion batteries (NIBs) as an alternative to lithium-ion batteries (LIBs) have recently received great attentions because of the relatively high abundance of sodium. Searching for suitable anode materials has always been a hot topic in the field of NIB study. Recent reports show that phosphorus-based materials are potential as the anode materials for NIBs. Using first-principles calculations, herein, we study the atomic and electronic structures, diffusion dynamics and intrinsic elastic properties of various Na–P alloy compounds (NaP5, Na3P[Formula: see text], NaP and Na3P) as the intermediate phases during Na extraction/insertion in phosphorus-based anode materials. It is found that all the crystalline phases of Na–P alloy phases considered in our study are semiconductors with band gaps larger than that of black phosphorus (BP). The calculations of Na diffusion dynamics indicate a relatively fast Na diffusion in these materials, which is important for good rate performance. In addition, the diffusion channels of sodium ions are one-dimensional in NaP5 phase and three-dimensional in other three phases (Na3P[Formula: see text], NaP and Na3P). Elastic constant calculations indicate that all four phases are mechanically stable. Among them, however, NaP5, Na3P[Formula: see text] and NaP alloy phases are ductile, while the fully sodiated phase Na3P is brittle. In order to improve the electrochemical performance of Na–P alloy anodes for NIBs, thus, promoting ductility of Na–P phase with high sodium concentration may be an effective way.

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Le, Thi Hoa, Hyun Jong Lee, Ji Hyeon Kim, and Sang Joon Park. "Detection of Ferric Ions and Catecholamine Neurotransmitters via Highly Fluorescent Heteroatom Co-Doped Carbon Dots." Sensors 20, no. 12 (June 19, 2020): 3470. http://dx.doi.org/10.3390/s20123470.

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Carbon dots (CDs) demonstrate very poor fluorescence quantum yield (QY). In this study, with the help of a hydrothermal method, we combined CDs with nitrogen and phosphorus elements belonging to the VA group (in the periodic table) to form heteroatom co-doped CDs, i.e., nitrogen and phosphorus co-doped carbon dots (NPCDs). These displayed a significant improvement in the QY (up to 84%), which was as much as four times than that of CDs synthesized by the same method. The as-prepared NPCDs could be used as an “off-on” fluorescence detector for the rapid and effective sensing of ferric ions (Fe3+) and catecholamine neurotransmitters (CNs) such as dopamine (DA), adrenaline (AD), and noradrenaline (NAD). The fluorescence of NPCDs was “turned off” and the emission wavelength was slightly red-shifted upon increasing the Fe3+ concentration. However, when CNs were incorporated, the fluorescence of NPCDs was recovered in a short response time; this indicated that CN concentration could be monitored, relying on enhancing the fluorescence signal of NPCDs. As a result, NPCDs are considered as a potential fluorescent bi-sensor for Fe3+ and CN detection. Particularly, in this research, we selected DA as the representative neurotransmitter of the CN group along with Fe3+ to study the sensing system based on NPCDs. The results exhibited good linear ranges with a limit of detection (LOD) of 0.2 and 0.1 µM for Fe3+ and DA, respectively.

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13

Dyachenko, P. P., V. V. Kalinin, E. A. Seregina, O. D. Shevchuk, G. V. Tichonov, O. N. Gilyarov, Yu I. Krasilov, B. N. Kulikovskiy, and T. L. Novoderyozhkina. "Inorganic liquid laser doped with neodymium and uranyl." Laser and Particle Beams 11, no. 3 (September 1993): 493–98. http://dx.doi.org/10.1017/s0263034600005140.

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Spectral-luminescent properties of the Nd3+-activated laser liquid based upon POCl3-SnCI4 upon excitation by-products of nuclear reactions have been researched. It was concluded that the main luminescence characteristics such as T, Δλ, and λmax depend slightly upon the way of the medium excitation. It was obtained that the pumping efficiency δ of the upper working level is directly proportional to the activator ions' concentration and almost independent of the uranyl presence in the liquid. The measured values t, Δλ, λmax, and δ were used for the estimates of some parameters of nuclear-pumped lasers based upon phosphorus oxychloride. The effect of the Nd3+ ions laser action from the 4F3/2 level to the 4I11/2 level (λ = 1,050 nm) in aprotic liquids POCI3-SnCl4 in the presence of uranium by flashlamp pumping has been obtained.

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14

Molkenova, Anara, and Timur Sh Atabaev. "Phosphorus-doped carbon dots (P-CDs) from dextrose for low-concentration ferric ions sensing in water." Optik 187 (June 2019): 70–73. http://dx.doi.org/10.1016/j.ijleo.2019.05.013.

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15

Reid, David G., Matthew J. Mason, Benny K. K. Chan, and Melinda J. Duer. "Characterization of the phosphatic mineral of the barnacle Ibla cumingi at atomic level by solid-state nuclear magnetic resonance: comparison with other phosphatic biominerals." Journal of The Royal Society Interface 9, no. 72 (January 2012): 1510–16. http://dx.doi.org/10.1098/rsif.2011.0895.

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Ibliform barnacles are among the few invertebrate animals harnessing calcium phosphate to construct hard tissue. The 31 P solid-state NMR (SSNMR) signal from the shell plates of Ibla cumingi (Iblidae) is broader than that of bone, and shifted by ca 1 ppm to low frequency. 1 H– 31 P heteronuclear correlation (HETCOR) experiments show a continuum of different phosphorus/phosphate atomic environments, close to hydrogen populations with resonance frequencies between ca 10 and 20 ppm. Associated 1 H and 31 P chemical shifts argue the coexistence of weakly (high 31 P frequency, low 1 H frequency) to more strongly (lower 31 P frequency, higher 1 H frequency) hydrogen-bonded hydrogen phosphate-like molecular/ionic species. There is no resolved signal from discrete OH − ions. 13 C SSNMR shows chitin, protein and other organic biomolecules but, unlike bone, there are no significant atomic scale organic matrix–mineral contacts. The poorly ordered hydrogen phosphate-like iblid mineral is strikingly different, structurally and compositionally, from both vertebrate bone mineral and the more crystalline fluoroapatite of the linguliform brachiopods. It probably represents a previously poorly characterized calcium phosphate biomineral, the evolution of which may have reflected either the chemical conditions of ancestral seas or the mechanical advantages of phosphatic biomineralization over a calcium carbonate equivalent.

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& et al., Al-Sabbagh. "STRUCTURE CHARACTERIZATION OF CALCIUM DEFICIENT ELEMENT-SUBSTITUTED HYDROXYAPATITE WITH CONSTANT DOPANT RATIO OF DIFFERENT ELEMENTS." IRAQI JOURNAL OF AGRICULTURAL SCIENCES 51, no. 5 (October 31, 2020): 1420–27. http://dx.doi.org/10.36103/ijas.v51i5.1152.

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The element-substituted calcium Deficient hydroxyapatite samples were synthesized using liquid-phase precipitation method. Different element ions (Mg+2, Zn+2, and Cu+2) were added at constant ratio (5% wt.). The phase composition of the element-substituted calcium hydroxyapatite samples was investigated by using X-ray diffraction. A comparison with known characteristics of the synthetic ion-substituted forms of hydroxyapatite was conducted. It was determined, that the investigated materials are single-phase solid solutions of the element-substituted hydroxyapatite. By the methods of IR spectroscopy and Raman scattering (RS) it was discovered the dependence of incorporation of the carbonate anion that occupies a positions of phosphorus-oxygen groups in the hydroxyapatite structure as a result of embedding element ions (Zn+2, Cu+2, Mg+2) in the crystal lattice. Besides, It was determined, that the ratio of the intensities for the C03 group mode to the P04 groups mode depended on the nature of the element atom, which replace the calcium in the lattice of HAP, and reduced by substituting the calcium atoms by the atoms of Zn, Cu, and Mg from 0.15 to 0.06. Modeling of the vibration modes of Raman spectroscopy showed that incorporation of carbon atoms to the hydroxyapatite structure correlate with the Zn, Cu and Mg atomic radius, charge, and activity

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17

Fritzsche, S., C. Froese Fischer, and B. Fricke. "CALCULATED LEVEL ENERGIES, TRANSITION PROBABILITIES, AND LIFETIMES FOR PHOSPHORUS-LIKE IONS OF THE IRON GROUP IN THE 3s3p4AND 3s23p23dCONFIGURATIONS." Atomic Data and Nuclear Data Tables 68, no. 1 (January 1998): 149–79. http://dx.doi.org/10.1006/adnd.1997.0759.

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Piętak, Karolina, Sebastian Złotnik, Ewelina Rozbiegała, Paweł P. Michałowski, Marek Wójcik, Jarosław Gaca, and Mariusz Rudziński. "Phosphorus implantation of Mg-doped (Al)GaN heterostructures: structural examination and depth profiling." Journal of Materials Science: Materials in Electronics 31, no. 20 (September 17, 2020): 17892–902. http://dx.doi.org/10.1007/s10854-020-04342-2.

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AbstractPhosphorus introduction into Mg-doped aluminium gallium nitride ((Al)GaN) epilayers to enhance the acceptor activation is a possible strategy for a p-type conductivity improvement in III-nitride wide-bandgap semiconductors. To date, P-implanted Mg-doped (Al)GaN structures have not been systematically evaluated, regarding structural verification and elemental distribution. Here, comprehensive studies of P ions impact on structural degradation are presented. Furthermore, a post-implantation annealing conducted at different temperatures is examined as well. The results demonstrated that the structural changes in the examined compounds, namely GaN and Al0.1Ga0.9N, due to P implantation and a subsequent recovery by thermal annealing follow similar trends. Interestingly, it was revealed that P diffusion length is higher in AlGaN than in GaN, possibly due to higher oxygen content in Al-containing compounds, analogous to Mg dopant. Additionally, the initial Mg concentration in (Al)GaN is crucial because too high Mg doping could be the main cause of electrical properties degradation of (Al)GaN heterostructures after P ion implantation.

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Sølling, Theis I., and Leo Radom. "Exchange of Cl+ between Lone-Pair Donors and π-Donors: A Computational Study." European Journal of Mass Spectrometry 6, no. 2 (April 2000): 153–60. http://dx.doi.org/10.1255/ejms.335.

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The chemistry of mono-adducts ([Cl–X]+) between Cl+ and a Lewis base (X = NH3, H2O, HF, PH3, H2S or HCl) has been investigated using ab initio molecular orbital calculations at the G2 level. The reactions of such mono-adducts with additional Lewis bases (Y) are found to give [Y–Cl]+ plus X, generally without an intermediate barrier, via a bis-adduct [Y–Cl–X]+. The binding energies of the bis-adduct and the reaction energies are related to the donor properties of the Lewis bases. The reactions between the mono-adducts [Cl–X]+ and the π-donors ethylene and acetylene yield chloriranium and chlorirenium ions, respectively. These reactions proceed via complexes that resemble either the reactants or products depending on the sign of the reaction energy, the latter in turn being determined by the donor ability of the Lewis base. Results for the chlorine systems are compared with those for the corresponding phosphorus systems investigated previously.

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20

Lüdde, Hans Jürgen, Alba Jorge, Marko Horbatsch, and Tom Kirchner. "Net Electron Capture in Collisions of Multiply Charged Projectiles with Biologically Relevant Molecules." Atoms 8, no. 3 (September 17, 2020): 59. http://dx.doi.org/10.3390/atoms8030059.

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A model for the description of proton collisions from molecules composed of atoms such as hydrogen, carbon, nitrogen, oxygen and phosphorus (H, C, N, O, P) was recently extended to treat collisions with multiply charged ions with a focus on net ionization. Here we complement the work by focusing on net capture. The ion–atom collisions are computed using the two-center basis generator method. The atomic net capture cross sections are then used to assemble two models for ion–molecule collisions: An independent atom model (IAM) based on the Bragg additivity rule (labeled IAM-AR), and also the so-called pixel-counting method (IAM-PCM) which introduces dependence on the orientation of the molecule during impact. The IAM-PCM leads to significantly reduced capture cross sections relative to IAM-AR at low energies, since it takes into account the overlap of effective atomic cross sectional areas. We compare our results with available experimental and other theoretical data focusing on water vapor (H2O), methane (CH4) and uracil (C4H4N2O2). For the water molecule target we also provide results from a classical-trajectory Monte Carlo approach that includes dynamical screening effects on projectile and target. For small molecules dominated by a many-electron atom, such as carbon in methane or oxygen in water, we find a saturation phenomenon for higher projectile charges (q=3) and low energies, where the net capture cross section for the molecule is dominated by the net cross section for the many-electron atom, and the net capture cross section is not proportional to the total number of valence electrons.

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Loginov, V. N., S. L. Bogomolov, A. E. Bondarchenko, V. E. Mironov, I. A. Ivanov, M. V. Zdorovets, V. V. Alexandrenko, et al. "Production of Intense Beams of Lithium, Magnesium, Phosphorus, and Calcium Ions by the ECR Ion Source at the DC-60 Cyclotron." Physics of Particles and Nuclei Letters 16, no. 1 (January 2019): 30–33. http://dx.doi.org/10.1134/s1547477119010096.

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22

Kanoun, Olfa, Tamara Lazarević-Pašti, Igor Pašti, Salem Nasraoui, Malak Talbi, Amina Brahem, Anurag Adiraju, et al. "A Review of Nanocomposite-Modified Electrochemical Sensors for Water Quality Monitoring." Sensors 21, no. 12 (June 16, 2021): 4131. http://dx.doi.org/10.3390/s21124131.

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Electrochemical sensors play a significant role in detecting chemical ions, molecules, and pathogens in water and other applications. These sensors are sensitive, portable, fast, inexpensive, and suitable for online and in-situ measurements compared to other methods. They can provide the detection for any compound that can undergo certain transformations within a potential window. It enables applications in multiple ion detection, mainly since these sensors are primarily non-specific. In this paper, we provide a survey of electrochemical sensors for the detection of water contaminants, i.e., pesticides, nitrate, nitrite, phosphorus, water hardeners, disinfectant, and other emergent contaminants (phenol, estrogen, gallic acid etc.). We focus on the influence of surface modification of the working electrodes by carbon nanomaterials, metallic nanostructures, imprinted polymers and evaluate the corresponding sensing performance. Especially for pesticides, which are challenging and need special care, we highlight biosensors, such as enzymatic sensors, immunobiosensor, aptasensors, and biomimetic sensors. We discuss the sensors’ overall performance, especially concerning real-sample performance and the capability for actual field application.

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Li, Baoqiang, Jinglin Kong, Lin Zhang, Wenxiang Fu, Zhongyao Zhang, and Cuiping Li. "The ionization process of chemical warfare agent simulants in low temperature plasma ionization." European Journal of Mass Spectrometry 26, no. 5 (August 20, 2020): 341–50. http://dx.doi.org/10.1177/1469066720951943.

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The application of low-temperature plasma ionization technology in the chemical warfare agent detection was mostly focused on the research of rapid detection methods. Limited studies are available on the ionization process of chemical warfare agents in low temperature plasma. Through the intensity of protonated molecules of dimethyl methylphosphonate (DMMP) in different solvents including methanol, deuterated methanol (methanol-D4), pure water, and deuterium oxide (water-D2), it was concluded that the water molecule in the air provides the hydrogen ion (H+) needed for ionization. The product ion spectra and the collision-induced dissociation processes of protonated molecules of nerve agent simulants, including DMMP, diethyl methanephosphonate (DEMP), trimethyl phosphate (TMP), triethyl phosphate (TEP), tripropyl phosphate (TPP), and tributyl phosphate (TBP) were analyzed. Results revealed that H+ mostly combined with phosphorus oxygen double bond (P = O) in the low-temperature plasma ionization. By analyzing the peak intensity distribution of product ions of protonated molecules, the presence of proton and charge migration in the low temperature plasma ionization and collision-induced dissociation were researched. This study could provide technical guidance for the rapid and accurate detection of chemical warfare agents through low temperature plasma ionization-mass spectrometry.

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Saito, Koshi, Yoshiyuki Takahashi, and Mizu Wada. "Preparation of an Enzyme Associated with Carthamin Formation in Carthamus tinctorius L." Zeitschrift für Naturforschung C 40, no. 11-12 (October 1, 1985): 819–26. http://dx.doi.org/10.1515/znc-1985-11-1211.

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Abstract An enzyme associated with carthamin formation in Carthamus tinctorius L. (carthamin-synthe-sizing enzyme) was isolated from the soluble protein extract of the hypocotyl tips of the etiolated seedlings and purified up to 157-fold by the procedures applying (NH4)2SO4 fractionation, Ca(CH3CO2)2 precipitation, protamine sulfate treatment, Celite adsorption chromatography, and Sephadex G-100 gel filtration. Results from atomic absorption spectral analysis of the enzyme protein showed to contain K as a major component, and Ca and Mg as minor ones. Fe, Cu, and Mn could not be detected in the preparation. At pH 4.8 in 50.0 mᴍ acetate buffer, the partially purified enzyme reacted positively with a flame-coloured precarthamin to produce a reddish product in open cuvettes with incubation medium. The reaction product was identified as carthamin by examining its colour, chromatographic mobilities in different developing solvents and spectroscopic properties inclusive shifts, often by comparing with those of an authentic specimen. Anaerobic incubation reduced the enzyme activity, while exogenously applied O2 slightly enhanced the catalytic rate of carthamin formation. The enzyme was sensitive to phosphorus sub stances. Among those compounds tested at 1.2 mᴍ level, orthophosphate showed the most striking inhibitory action on the enzyme. Metal ions affected on the enzyme activity by different extents. Mn2+ stimulated the enzyme reaction, while Cu2+ and Mo6+ exhibited reverse effects. Fe2+, Fe3+, Zn2+, Mg2+, and Co2+ were also unfavourable to the enzyme catalyzed carthamin formation. The preparation of the carthamin-synthesizing enzyme showed no activity of polyphenol oxidase or peroxidase under the conditions specifically designed for detecting both enzyme activities.

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Nohrin, D., and N. Davydova. "Hydrochemical characteristics and irrigation quality of groundwater in the Sosnovskiy district of the Chelyabinsk region." Agrarian Bulletin of the, no. 14 (February 3, 2021): 56–69. http://dx.doi.org/10.32417/1997-4868-2021-14-56-69.

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Abstract. The purpose of the study was to assess the quality of groundwater used for irrigation of individual plots of land, belonging to the residents of the Sosnovskiy district of the Chelyabinsk region. Material: 73 samples taken in wells and boreholes on the territory of private land plots, villages, villa communities and garden non-profit partnerships. Methods: 30 indicators of water composition were determined (common indicators – 6, major ions and carbonate ion – 8, compounds of nitrogen, phosphorus and organic matter – 5, heavy metals and silicon – 11) using capillary electrophoresis, atomic absorption, potentiometry, spectrophotometry and conductometry. Statistical analysis included: estimation of means with 95 % confidence intervals (95 % CI) calculated by bootstrap (Kaplan – Meier method was used for censored observations), relative frequencies (in percent) with 95 % CI (Jeffreys method and simultaneous CI by Wilson). Data was visualized using Piper’s and Gibbs’ diagrams. Software: PAST, Scout 2008, R, DescTool, GW_Chart, KyPlot, QGIS. Results. On the territory of the Sosnovsky district of the Chelyabinsk region, (Ca2+–Mg2+ and HCO3––CO32–) type groundwater prevails with a pH 7.39 (95 % CI: from 7.30 to 7.48) and a TDS 651 mg/dm3 (95 % CI: from 598 to 720). Using Piper and Gibbs diagrams, it was established that the leading processes of the water chemical composition formation are: 1) the dissolution of the calcite-dolomite series’ minerals of sedimentary rocks, 2) the dissolution and the ion exchange of feldspars in the composition of granites with calcite. For mineralization and risks of chloride salinization, sodium salinization, magnesium salinization and soda formation, the proportion of samples with quality for irrigation purposes I and II category is 65.7 %. There are excesses of standards in the concentration of NO3- (24.7 % of samples), Ba (68.3 %), Cd (30.4 %), Fe (15.3 %), Mn (12.9 %), Pb (6.3 %).

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Kuzin, E. N. "TITANIUM-BASED COAGULANTS IN DOMESTIC WASTEWATER TREATMENT." Water and Ecology 25, no. 4 (2020): 16–23. http://dx.doi.org/10.23968/2305-3488.2020.25.4.16-23.

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Introduction. Post-treatment of wastewater that has passed the stage of deep purification from biogenic elements is a pressing issue that has not been fully solved yet. Traditional reagents based on aluminum salts used to remove phosphorus compounds have a few significant drawbacks and do not always make it possible to achieve the standards established for the discharge of treated water into fishery reservoirs. Titanium-based coagulants are promising and highly effective reagents that have shown high efficiency in treating wastewater of various origins. Complex titanium-based coagulants are binary coagulants obtained by introducing hydrolysis products of titanium compounds in an amount of up to 10 % wt into the composition of traditional aluminum-based coagulants. Methods. Trial coagulation was carried out using a VELP laboratory flocculator; spectrophotometry, turbidimetry, and atomic emission spectral analysis were used to assess the purification efficiency. Results. It has been found that the use of titanium compounds and complex titanium-based coagulants can improve the efficiency of purification, as well as reduce the residual content of phosphate ion to the MPC standards. We have determined the main regularities in the use of complex titanium-based reagents and established the effect of the dose and pH of the medium on the efficiency of phosphate ion removal. It has also been found that the residual concentration of phosphate ion in treated water using titanium-based coagulants is significantly lower than when using traditional reagents. Titanium-based coagulants operate in a wider pH range, while the requirements for the residual concentration of titanium ions in treated water are much softer than for that of aluminum. It has been proved that the use of complex titanium-based reagents makes it possible to significantly intensify the processes of sedimentation and filtration of sludge formed during coagulation water treatment. Conclusion. In the course of the study, we have confirmed the prospects of using titaniumbased coagulants in domestic wastewater treatment.

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Hal Weiser, Alan Olness,, Bruce Kunze, Michael Lieser, and Jana Rinke. "Differentiation of four northern Great Plains soils using resin extraction." Canadian Journal of Soil Science 84, no. 1 (February 1, 2004): 31–42. http://dx.doi.org/10.4141/s03-046.

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Resin extraction of soils has revealed sensitivities of crops to the extractable V:(V + P) and Mg:(Mg + Ca) molar ratios. Consequently, we examined the Barnes and Buse soils in the northern Great Plains of North Dakota, South Dakota, and Minnesota. Svea and Langhei soils were included in the survey because of their close association. Samples of A or Ap horizons suspended in 20% ethanol were extracted with cation-(Na+) and anion-(NO) exchange resin-extractors for a period of 5 d. After equilibration, extractors were eluted with 1 N HCl and eluates were analyzed using inductively coupled plasma-atomic emission spectroscopy. Analytical concentrations were log transformed and analyzed using SAS PROC GLM. Each soil produced a distinct suite of extractable ions. Mean pH values ranged from about 6.8 for the Svea soil to about 8.0 for the Langhei soils. Total resin extractable Ca ranged from about 150 to 28 000 nmol g-1 soil and total resin extractable Mg ranged from 110 to 5500 nmol g-1 soil; the least amounts were found in the Svea soil and the greatest amounts were found in the Langhei soil. The pH of the Barnes and Buse soils and the amounts of extractable Ca and Mg in the Barnes and Buse soils were intermediate to those of the Svea and Langhei soils. Trivial amounts of V were detected in extracts from a few samples of Buse soils. Large fractions of S, B, and As in the Langhei soil were extracted on cation exchange resins presumably due to complex formation with the much larger amounts of Ca and Mg. Amounts of Ba, Sr, Fe, Co, Cu, and Si, detected in the extracts differed between soils with more being extracted from the Langhei than from the other soils. Only resin extractable Li and K differed from the general trend in that the amounts associated with Langhei soils were among the least. Detectable amounts of Al, Ni, and Zn usually were obtained but without differences between soils. Resin extractable P was correlated with bicarbonate extractable P but slopes of the regression lines differed between soils and two groups of Barnes soils were clearly distinguished in these relationships. Key words: extractable, nutrients, toxic elements, varadium, sulfur, phosphorus

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Vasilescu, Cora, Silviu Iulian Drob, Petre Osiceanu, Mihai Anastasescu, Jose M. Calderon-Moreno, Paula Drob, and Ecaterina Vasilescu. "The Morphostructural, Compositional, and Electrochemical Characterization of Electrodeposited Nanolayers on a New Ti-15Ta-5Zr Alloy." Journal of Nanomaterials 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/369034.

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A porous, homogeneous, phosphorous-enriched oxide nanolayer was realized on the new Ti-15Ta-5Zr alloy surface by the anodic galvanostatic electrodeposition in phosphoric acid solution. This nanolayer contains TiO2, ZrO2oxides, tantalum suboxides, andPO43-ions incorporated in the time of the electrodeposition process and has a thickness of 15.5 nm (X-ray photoelectron spectroscopy data). Atomic force microscopy determined a homogeneous roughness. Scanning electron microscopy evinced a porous microstructure that can stimulate the growth of the bone tissue into pores. The presence of thePO43-anions promotes the electrostatic bonds between the nanolayer and different species from the biofluid, namely, osteoinduction. The anodic oxidation nanolayer improved all electrochemical and corrosion parameters conferring superior protection to the substrate by its higher resistance to the ion migration. Impedance spectra showed that the electrodeposited nanolayer is formed by an inner, dense, barrier layer and an outer porous layer. The nanolayer thickened in time, namely, is bioactive. The oxidized nanolayer is able to protect the alloy from ion release, to assure long-term corrosion resistance, to minimize adverse reactions, to increase alloy bioactivity, to stimulate cell growth, and to favor osseointegration.

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Chu, Jun Fu, Yi Hua Hu, Hai Wang Yin, and Yi Wu Hao. "Controllable Luminescent Properties of Phosphors Sr_2.97-XCa_xMgSi₂O₈: Eu_0.01²⁺, Dy_0.02³⁺ by Adjusting Sr/Ca Ratio." Materials Science Forum 663-665 (November 2010): 118–24. http://dx.doi.org/10.4028/www.scientific.net/msf.663-665.118.

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Divalent europium and trivalent dysprosium co-doping in the compounds Sr2.97-xCaxMgSi2O8 (x=0, 0.5, 1.5, 2, 2.5, 2.97) produces phosphors of high luminescence yield. These phosphors were prepared at high temperature and weak reductive atmosphere. The ratio of Eu/Dy is 1/2. The phosphors were characterized for their crystal phases by x-ray powder diffraction. Slight shifts of the peaks in the structure, which indicate a small change of the interplanar crystal spacing, were observed for each different x’s. The interplanar spacing becomes narrow as increasing the value of x. These phosphors respond well to the ultraviolet excitation. The peak of the emission band occurs at progressively longer wavelength and widens as the ratio of alkaline earth Sr/Ca ions is decreased. The emission peaks of the phosphors indicated on the emission spectra range from 463nm to 490nm. It is probably due to the influence of 5d electron states of Eu2+ in the crystal field because of atomic size variation causing crystal defects. Dy3+ ion doping in the phosphor generates deep traps, which results in long afterglow phosphorescence. As the proportion of Ca in the composition increases, the attenuation time of the phosphors becomes short.

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García, C. R., J. Oliva, M. T. Romero, R. Ochoa-Valiente, and L. A. Garcia Trujillo. "Effect of Eu3+Concentration on the Luminescent Properties of SrTiO3Phosphors Prepared by Pressure-Assisted Combustion Synthesis." Advances in Materials Science and Engineering 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/291230.

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This work presents the structural, morphological, and luminescent characterization of pure SrTiO3and SrTiO3:Eu3+powders doped with different europium atomic concentrations from 3.0 to 7.0 a.t.%. Those phosphors were prepared by pressure-assisted combustion synthesis using titanium oxide as precursor and were subjected to postannealing at 1200°C. XRD measurements indicated that undoped and Eu3+doped samples presented a single cubic crystalline phase and SEM images demonstrated that we have particles with sizes in the range of 0.2 µm–1.0 µm. Moreover, the size of the grains increases as the content of Eu3+dopant increases. A strong red emission from Eu3+ions was obtained by photoluminescence under excitation at 396 nm and confirmed by cathodoluminescence. All those results indicate that our red phosphors could be useful for potential applications in solid state lighting and field emission displays.

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MORI, KENTAROU, YOSHIYUKI KOJIMA, and NOBUYUKI NISHIMIYA. "EFFECT OF REDUCING ATMOSPHERE ON THE AFTERGLOW PROPERTIES OF RED-EMITTING CaS:Eu2+,Pr3+ PHOSPHORS." Functional Materials Letters 05, no. 02 (June 2012): 1260012. http://dx.doi.org/10.1142/s1793604712600120.

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The afterglow time of typical red-emitting phosphors is much shorter than those of green- or blue-emitting phosphors which afterglow time were longer than 1000 min. CaS has been used as an effective host material for afterglow phosphors because trapping centers can be easily created in the host by doping with an activator. This study reports on the effect of a reducing atmosphere on the afterglow properties of a red-emitting CaS:Eu2+,Pr3+ phosphor. The phosphor was prepared by reduction under an Ar-H2 (5%) or H2S atmosphere from a CaSO4:Eu3+,Pr3+ phosphor prepared using a liquid phase method. Heating the CaSO4:Eu3+,Pr3+ phosphor for 2 h under an Ar-H2 (5%) atmosphere at 1050°C gave CaO as by-product in addition to CaS . The resulting phosphor exhibited red-emission at 646 nm originating from Eu2+ ions upon visible light irradiation, and gave some afterglow after cessation of visible light irradiation. Addition of Li+ ions extended the afterglow time of the phosphor as a result of a slight change in the CaS host structure. For preparation of a CaSO4:Eu3+,Pr3+ phosphor under a H2S atmosphere, a CaS monophase was obtained. The emission and afterglow of the phosphor were similar to that prepared under the Ar-H2 (5%) atmosphere, but the afterglow time resulting from the CaS monophase was longer. The longest afterglow time obtained was about 60 min for a phosphor prepared under a H2S atmosphere with an initial Li/Ca atomic ratio of 0.04.

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Guo, Wen Lei, Yan Ting Jiao, Ping Shun Wang, Qi Liu, Shan Liu, and Feng Hou. "Energy Transfer and Spectroscopic Characterization of New Green Emitting Li₃Ba₂Gd₃(WO₄)₈:Tb³⁺ Phosphor." Solid State Phenomena 281 (August 2018): 686–91. http://dx.doi.org/10.4028/www.scientific.net/ssp.281.686.

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A new tungstate family, Li3Ba2Gd3(WO4)8doped with Tb3+is synthesized by using a conventional high-temperature solid-state method to explore new pure green phosphors for white light-emitting diodes (WLEDs). The results from the X-Ray patterns show that the crystal structures of the hosts are composed of tungstate zigzags and the Gd3+-Gd3+units, which are isolated by the [WO4]2-groups. The critical concentration of Tb3+is up to x=2.0 in the singly doped phosphors, which is ascribed to the interaction of the isolated Gd3+ions being mitigated by [WO4]2-groups. The characteristic green emission peaks at around 547 nm are also observed, which result from the5D4→7F5transition of Tb3+ions, and the optimal doping concentration is x=2.0.

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Singh, Vijay, N. Singh, M. S. Pathak, S. Watanabe, T. K. Gundu Rao, Pramod K. Singh, and Vikas Dubey. "UV emission from Gd3+ ions in LaAl11O18 phosphors." Optik 157 (March 2018): 1391–96. http://dx.doi.org/10.1016/j.ijleo.2017.12.034.

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Xiao, Wei, Hongbo Zhao, Wenqing Qin, Guanzhou Qiu, and Jun Wang. "Adsorption Mechanism of Pb2+ Activator for the Flotation of Rutile." Minerals 8, no. 7 (June 25, 2018): 266. http://dx.doi.org/10.3390/min8070266.

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In general, the flotation of minerals containing titanium needs to be activated by metal ions due to a lack of activating sites on their surface. However, the activating process is indirectly inferred due to the lack of direct experimental observation. In this study, atomic force microscopy (AFM) was used to observe the activation process. The results revealed that the hydroxyl compounds of Pb2+ ions were adsorbed on the rutile surface in the form of multiple molecular associates, rather than through single molecule adsorption. Styryl phosphoric acid (SPA) could largely be adsorbed on the activated rutile surface with a single and double layer rather than on the un-activated rutile surface. The results of contact angle measurements also revealed that the hydrophobicity of the activated rutile surface was significantly greater than that of the un-activated rutile surface after SPA was adsorbed. This study will be helpful to understanding the activating process from the microscale.

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35

Godlewski, M., S. Yatsunenko, A. Opalińska, and Witold Łojkowski. "How Can the Intra-Shell Emissions of Rare Earth and Transition Metal Ions in Thin Films and Nanoparticles Be Stimulated?" Solid State Phenomena 140 (October 2008): 3–8. http://dx.doi.org/10.4028/www.scientific.net/ssp.140.3.

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Nanoparticles of the wide band gap oxides doped with rare earth (RE) ions are prospective materials for application in optoelectronics as phosphors in a new generation of light sources. In this paper the mechanisms of the excitation of efficient 4f-4f intra-shell transitions in RE doped nanoparticles are discussed. These mechanisms either enhance the rate of host to impurity energy transfer or stimulate the intra-shell transitions of RE ions.

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Ma, S., Y. Yang, D. L. Carnes, K. Kim, S. Park, S. H. Oh, and J. L. Ong. "Effects of Dissolved Calcium and Phosphorous on Osteoblast Responses." Journal of Oral Implantology 31, no. 2 (April 1, 2005): 61–67. http://dx.doi.org/10.1563/0-742.1.

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Abstract The dissolution behavior of hydroxyapatite (HA) and its effect on the initial cellular response is of both fundamental and clinical importance. In this study, plasma-sprayed HA coatings were characterized by X-ray diffraction and Fourier transform infrared spectroscopy (FTIR). Calcium (Ca) and inorganic phosphorous (Pi) ions released from plasma-sprayed HA coatings within 3 weeks were measured by flame atomic absorption and colorimetrically molybdenum blue complex, respectively. To investigate the effect of dissolution of HA coatings on osteoblast response, additional Ca and Pi were added into the cell culture media to simulate the dissolution concentrations. Human embryonic palatal mesenchyme cells, an osteoblast precursor cell line, were used to evaluate the biological responses to enhanced Ca and Pi media over 2 weeks. Osteoblast differentiation and mineralization were measured by alkaline phosphatase–specific assay and 1,25 (OH)2 vitamin D3 stimulated osteocalcin production. The coatings exhibited an HA-type structure. FTIR indicated the possible presence of carbonates on the coatings. A dissolution study indicated a continual increase in Ca and Pi over time. In the cell culture study, enhanced osteoblast differentiation occurred in the presence of additional Ca concentration in the cell culture media. However, additional Pi concentration in the cell culture media was suggested to slow down osteoblast differentiation and mineralization.

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Widjonarko, Dian Maruto, Jumina Jumina, Indriana Kartini, and Nuryono Nuryono. "Phosphonate Modified Silica for Adsorption of Co(II), Ni(II), Cu(II), and Zn(II)." Indonesian Journal of Chemistry 14, no. 2 (July 25, 2014): 143–51. http://dx.doi.org/10.22146/ijc.21251.

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A new phosphonate modified silica (PMS) has been investigated for adsorption of Co(II), Ni(II), Cu(II), and Zn(II) in aqueous solution. The adsorbent was modified of silica by immobilizing aminoethyl dihydrogen phosphate (AEPH2) on 1,4-dibromobutane grafted silica. The physicochemical of the adsorbent was investigated using Fourier Transform Infra-red (FTIR) spectroscopy, X-ray Fluorescence (XRF), and N2 gas adsorption/desorption. The adsorption study was carried out in a batch system by mixing solution of metal ions at various pHs, contact times, and initial metal ion concentrations. The unadsorbed metals were determined by Flame Atomic Absorption Spectrophotometry (FAAS). Result of characterization showed that PMS has been successfully prepared. The product contained 45.99% (w/w) silica and 1.33% (w/w) phosphorous with surface area, pore volume, and pore size of 115.3 m2g-1; 0.7578 mLg-1; and 131.44 Å, respectively. Adsorption of metal ions on PMS occurred quite fast, less than 30 min. Modification of phosphonate on silica increased the adsorption capability, up to 8 times higher than that of unmodified silica, depending on metal ion type and pH solution. The capacity order of the metals adsorption was Cu(II)>Co(II)>Ni(II)>Zn(II). Based on the adsorption characteristic, the adsorbent is promising to be applied as a material for solid phase extraction of transition metal ions.

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38

Li, Jianguo, Hongying Dong, Fan Yang, Liangcheng Sun, Zhigang Zhao, Ruixi Bai, and Hao Zhang. "Simple Preparation of LaPO4:Ce, Tb Phosphors by an Ionic-Liquid-Driven Supported Liquid Membrane System." International Journal of Molecular Sciences 20, no. 14 (July 12, 2019): 3424. http://dx.doi.org/10.3390/ijms20143424.

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In this work, LaPO4:Ce, Tb phosphors were prepared by firing a LaPO4:Ce, Tb precipitate using an ionic-liquid-driven supported liquid membrane system. The entire system consisted of three parts: a mixed rare earth ion supply phase, a phosphate supply phase, and an ionic-liquid-driven supporting liquid membrane phase. This method showed the advantages of a high flux, high efficiency, and more controllable reaction process. The release rate of PO43− from the liquid film under different types of ionic liquid, the ratio of the rare earth ions in the precursor mixture, and the structure, morphology, and photoluminescence properties of LaPO4:Ce, Tb were investigated by inductively coupled plasma-atomic emission spectroscopy, X-ray diffraction, Raman spectra, scanning electron microscopy, and photoluminescence emission spectra methods. The results showed that a pure phase of lanthanum orthophosphate with a monoclinic structure can be formed. Due to differences in the anions in the rare earth supply phase, the prepared phosphors showed micro-spherical (when using rare earth sulfate as the raw material) and nanoscale stone-shape (when using rare earth nitrate as the raw material) morphologies. Moreover, the phosphors prepared by this method had good luminescent properties, reaching a maximum emission intensity under 277 nm excitation with a predominant green emission at 543 nm which corresponded to the 5D4-7F5 transition of Tb3+.

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Yanti, Gema Nazri, and Christina Kosasih. "Efektifitas Mengunyah Keju Cheddar Terhadap Peningkatan Konsentrasi Ion Kalisum Saliva Sebagai Alternatif Pencegahan Karies Gigi." Talenta Conference Series: Tropical Medicine (TM) 1, no. 1 (October 2, 2018): 176–80. http://dx.doi.org/10.32734/tm.v1i1.60.

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Keju merupakan salah satu produk susu yang kaya akan mineral, vitamin, fosfor, kalsium dan protein (kasein) yang berperan dalam mengurangi insidens karies. Keju cheddar dapat mengurangi risiko karies karena ion kalsium pada keju dapat melindungi gigi dari asam dengan cara meningkatkan pH saliva (buffer). Tujuan penelitian ini untuk mengetahui konsentrasi ion kalsium pada saliva sebelum, sesudah 3 dan 5 menit mengunyah keju. Jenis penelitian ini adalah eksperimental klinis dengan rancangan pre dan post test control group design. Subjek penelitian adalah 30 orang mahasiswa Fakultas Kedokteran Gigi USU yang secara random dibagi menjadi 2 kelompok yaitu kelompok perlakuan mengunyah keju cheddar dan kelompok kontrol mengunyah paraffin wax. Sampel saliva awal (baseline) diambil lalu kelompok perlakuan diberikan 5 gr keju cheddar dan 5 gr paraffin wax untuk kelompok kontrol. Kedua kelompok diinstruksikan mengunyah selama 3 menit lalu sampel saliva diambil. Subjek diinstruksikan untuk tidak mengonsumsi apapun selama 5 menit dan pengambilan sampel saliva kembali dilakukan. Konsentrasi ion kalsium saliva diukur dengan metode Spektofotometri Serapan Atom (SSA). Untuk mengetahui perbedaan rata-rata konsentrasi ion kalsium pada saliva sebelum, sesudah mengunyah 3 dan 5 menit antara kelompok mengunyah keju cheddar dengan kelompok kontrol dilakukan dengan uji t. Hasil penelitian menunjukkan adanya peningkatan konsentrasi ion kalsium dalam saliva yang signifikan antara sebelum mengunyah 1,67 ± 0,44 µg/ml, sesudah mengunyah 3 menit yaitu 4,63 ± 2,21 µg/ml dan setelah 5 menit perlakuan menjadi 2,34 ± 0,89 µg/ml (p<0,05) sedangkan tidak terdapat peningkatan yang signifikan pada kelompok kontrol, yaitu sebelum mengunyah 1,61 ± 0,54 µg/ml sesudah mengunyah 3 menit 2,16 ± 1,22 µg/ml dan setelah 5 menit perlakuan 2,15 ± 0,77 µg/ml (p>0,05). Dapat disimpulkan bahwa mengunyah keju cheddar efektif dalam meningkatkan konsentrasi ion kalsium dalam saliva sehingga dapat mencegah terjadinya karies. Cheese is a dairy product that is rich in minerals, vitamins, phosphorus, calcium and protein (casein) which plays a role in reducing caries. Cheddar cheese can reduce caries risk because calcium ions in cheese can protect teeth from acid by increasing the pH of saliva (buffer). The objective of this study was to determine the calcium ion concentration in saliva before and after 3 and 5 minutes chewing cheese. This study employed clinical experimental research with a pre and post test control group design. The research subjects were 30 students of Faculty of Dentistry University of North Sumatera who were randomly divided into 2 groups, namely the treatment group chewing cheddar cheese and the control group chewing paraffin wax. The baseline saliva sample was taken and the treatment group was given 5 grams of cheddar cheese and 5 grams of paraffin wax for the control group. The two groups were instructed to chew for 3 minutes then the saliva sample was taken. Subjects were instructed not to consume anything for 5 minutes and saliva sample was taken once again. Calcium ion concentration in saliva was measured by Atomic Absorption Spectofotometry (AAS). Then t-test was conducted to find out the difference in calcium ion concentration in saliva before and after chewing 3 and 5 minutes between groups chewing cheddar cheese with the control group. The results showed that there was a significant increase in the concentration of calcium ion in saliva; before chewing, it was 1.67 ± 0.44 µg/ml, after chewing for 3 minutes it was 4.63 ± 2.21 µg/ml and after chewing for 5 minutes it became 2.34 ± 0.89 µg/ml (p<0.05). However, there was no significant increase in the control group; before chewing it was 1.61 ± 0.54 µg/ml, after chewing 3 minutes it was 2.16 ± 1.22 µg/ml, and after chewing 5 minutes it was 2.15 ± 0.77 µg/ml (p> 0.05). It could be concluded that chewing cheddar cheese was effective in increasing the concentration of calcium ions in saliva so that it could prevent the occurrence of caries.

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Tu, Dong, Yujun Liang, Rong Liu, and Daoyi Li. "Eu/Tb ions co-doped white light luminescence Y2O3 phosphors." Journal of Luminescence 131, no. 12 (December 2011): 2569–73. http://dx.doi.org/10.1016/j.jlumin.2011.05.036.

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Araujo, Romel M., Emanuel Felipe dos Santos Mattos, Bento Francisco dos Santos Júnior, Marcos V. dos S. Rezende, Mário E. G. Valerio, and Robert A. Jackson. "Optical spectroscopy study of Eu-doped ions in BaAl2O4 phosphors." Journal of Luminescence 236 (August 2021): 118011. http://dx.doi.org/10.1016/j.jlumin.2021.118011.

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Deng, Taoli, and Qiuyun Zhang. "Optimization of LaPO4:Bi3+ Single-Phased White-Emitting Phosphor Luminescence Properties by Li+/Na+ Doping." International Journal of Optics 2019 (March 3, 2019): 1–6. http://dx.doi.org/10.1155/2019/4530978.

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LaPO4:Bi3+ single-phased white-emitting phosphors doped with both Li+/Na+ ions were successfully prepared by a conventional solid-state reaction technique. Microstructures were analyzed by both X-ray diffraction and high-resolution scanning electron microscopy experiments. Under the excitation of 335 nm, the La0.97PO4:Bi3+0.03 phosphor showed four emission bands with maxima at 460 nm, 487 nm (blue), 530 nm (yellow), and 637 nm (red); these can be successfully combined to form pure white light in a single host lattice only by simple activator Bi3+ ion. It was found that changing the concentration of dopant (Li+, Na+ ions) did not produce a change in shape or location of the emission peaks, but the value of the emission intensity increased; this was particularly evident in the red emission, which could optimize the white light emitting performance of the phosphors. When the Na+ doping concentration was 0.02, the CIE chromaticity coordinate of phosphor La0.95PO4:Bi3+0.03, Na+0.02 was (0.3008, 0.3203), close to that of the standard white light.

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Deng, Taoli, Shirun Yan, Xiangbang Jiang, and Qiuyun Zhang. "Improving Upconversion Photoluminescence of GdAlO3:Er3+, Yb3+ Phosphors via Ga3+, Lu3+ Doping." International Journal of Optics 2019 (July 1, 2019): 1–6. http://dx.doi.org/10.1155/2019/4814793.

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GdAlO3:Er3+, Yb3+ phosphors doped with Lu3+, Ga3+ ions were prepared via coprecipitation. The influences of substituting Ga3+ for Al3+ and substituting Lu3+ for Gd3+ on the structure and upconversion photoluminescence (UCPL) of the phosphors were studied. The experimental results show that the crystal textures did not change but the lattice parameters changed slightly via Lu3+, Ga3+ doping. This results in a decrease in the host phonon energy and a marked improvement in the green emission spectrum at 546nm. Moreover, the amounts of surface CO2, CO32-, and OH- species gradually decreased with Lu3+, Ga3+ doping. The combined effects led to an improvement in the UCPL efficiency with Ga3+, Lu3+ doping.

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Ma, Nan, Wei Li, Balaji Devakumar, Shaoying Wang, Liangling Sun, Zongjie Zhang, and Xiaoyong Huang. "Bright red luminescence from Mn4+ ions doped Sr2LuTaO6 double-perovskite phosphors." Journal of Luminescence 233 (May 2021): 117901. http://dx.doi.org/10.1016/j.jlumin.2021.117901.

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Dai, Pin-Lun, Bin-Siang Tsai, Yeou-Yih Tsai, Hao-Long Chen, Te-Hua Fang, Kun-Hou Liao, and Yee-Shin Chang. "Synthesis and luminescence properties of YInGe2O7 phosphors activated by dysprosium ions." Optical Materials 32, no. 2 (December 2009): 392–97. http://dx.doi.org/10.1016/j.optmat.2009.09.011.

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Wang, Fang, Hongwei Song, Guohui Pan, Libo Fan, Biao Dong, Lina Liu, Xue Bai, et al. "Luminescence properties of Ce3+and Tb3+ ions codoped strontium borate phosphate phosphors." Journal of Luminescence 128, no. 12 (December 2008): 2013–18. http://dx.doi.org/10.1016/j.jlumin.2008.06.012.

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Yoshida, Hisashi, Ryo Yoshimatsu, and Kazuyoshi Ogasawara. "Luminescence properties of YAl3(BO3)4:Gd3+ phosphors substituted with Sc3+ ions." Journal of Luminescence 122-123 (January 2007): 488–91. http://dx.doi.org/10.1016/j.jlumin.2006.01.215.

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Silveira, Wellisson S., Ariosvaldo Junior Sousa Silva, Patresio Alexandro Miranda do Nascimento, Iure da Silva Carvalho, and Marcos V. dos S. Rezende. "Improving the luminescence properties of YAG:Ce3+ phosphors by co-doping Sr2+ ions." Optik 231 (April 2021): 166363. http://dx.doi.org/10.1016/j.ijleo.2021.166363.

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Brojanowska, Agnieszka, Konrad Kowalczyk, Dominika Sadłowska, and Jerzy Robert Sobiecki. "Corrosion Properties of Anodically Oxidised and Alkaline Treated Titanium Nitride." Solid State Phenomena 227 (January 2015): 467–70. http://dx.doi.org/10.4028/www.scientific.net/ssp.227.467.

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The article compares the corrosion properties of oxide layers formed on titanium nitride (obtained by means of glow-discharge nitriding) using anodic and plasma oxidation. The corrosion properties are analysed in relation to the surface morphology and microstructure of the layers. The oxidation processes were carried out in phosphoric acid (V) (25wt%) containing Ca2+calcium ions. In this environment, oxide layers were produced using two anode oxidation potentials: 5 V and 9.5 V and two plasma oxidation potentials of 200 V and 600 V. The layers were then subjected to alkaline treatment in concentrated NaOH. The concentration of acid and calcium ions contained in the oxidation solution affected the surface morphology and corrosion properties of the oxide layers obtained after alkaline treatment.

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Kaps, Harald, Mohammad Lutful Arefin, Ulrich Herr, and Heiko Paul. "Concentration Dependent Fluorescence Lifetime in Nanocrystalline Y₂O₃:Eu Phosphors." Solid State Phenomena 128 (October 2007): 165–71. http://dx.doi.org/10.4028/www.scientific.net/ssp.128.165.

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Nanocrystalline (Y1-xEux)2O3 powder was synthesized via a chemical vapour reaction. Xray diffraction revealed the structure of cubic yttria with crystallite sizes of about 5 nm. The Eudopand concentrations x for the samples in the range from 0.003 up to 0.165 were determined by EDX-spectra. The luminescence of the nanopowders was investigated by continuous and timeresolved UV-fluorescence spectroscopy and compared to a microcrystalline Y2O3:Eu phosphor as a reference. The emission spectra show an increasing intensity for higher doping concentrations. However, compared to the microcrystalline material the yield was significantly lower. The lifetime of the 5D0 – 7FJ transition in the nanocrystalline Y2O3:Eu was found to be significantly longer than for the microcrystalline reference sample. For increasing Eu-content the lifetime in the nanocrystalline samples decreased continuously from 3.71 ms to a value of 1.20 ms for the highest doping concentration. The concentration dependent lifetime behaviour was interpreted by energy transfer between Eu ions and from Eu ions to impurities as a competing process to the radiative 5D0 – 7F2 transition.

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Journal articles on the topic 'Phosphorus atomic ions'

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