Active Ion Concentration Research Articles

The Influence of Albumin and pH on Total and Ionized Calcium and Magnesium

Objectives: The objectives of this study were to demonstrate the effect of albumin and pH on total and ionized calcium (TCa, iCa) and total and ionized magnesium (TMg, iMg) in a tertiary level hospital. The ionized fraction was tested on 2 different blood gas analyzers (Nova Prime Plus and Siemens RapidPoint 500), whereas iMg was only available on the Prime Plus.Methods: The study consisted of 3 parts. Part 1 was to investigate the effects of increasing albumin by using a pooled serum sample and then spiking aliquots with Albumix to provide a wide concentration range. Part 2 investigated the effects of pH in fresh whole blood and pooled serum by spiking the aliquots with sodium hydroxide (NaOH) or hydrochloric acid (HCl) to provide a wide concentration range. The final part was to determine the percentage range of the ionized fractions in normal samples.Results: Total calcium and iCa decreased by 0.01 mmol/L per 1 g/L with increasing albumin at a similar rate in response to increasing albumin concentration. Total magnesium and iMg also decreased but to a lesser degree by 0.003 and 0.005 mmol/L, respectively. As the pH increased, iCa decreased by approximately 0.04 mmol/L per 0.1 pH units in both sample types. The iMg decreased at a much smaller magnitude, by 0.002 mmol/L in whole blood and 0.001 mmol/L in serum per 0.1 pH unit. The ionized fraction percentages in the normal samples were as follows: iCa, 51% (44-57), and iMg, 69% (61-77).Conclusions: The iCa and iMg should be routinely measured, owing to their clear inverse relationship with albumin and pH. Routine measurement of the ionized fractions would avoid the need for correction factors and would highlight the physiologically active ion concentration for better patient care decisions.

Surface plasmonic bismuth ion-doped waveguide with black phosphorus cladding.

In this paper, a waveguide device with bismuth ion (Bi+)-doped glass as the core and black phosphorus acting as the cladding is theoretically proposed. Finite-difference time-domain and numerical methods are used to elucidate the waveguide dispersion characteristics, elaborate the transverse-electric mode profiles, solve the characteristic eigenvalue equations, and calculate the gain/noise figure characteristics of the guiding medium. The numerical results show that the mode confinement factor for the fundamental mode with h=5 μm can reach 99.8%. The analytical results also indicate that with pump power fixed at 100mW, the active ion concentration fixed at 2×1027 ion/m3, the gain and noise figure of a waveguide device with 0.10m length are 34dB and 3.38dB, respectively. The proposed waveguide device is a promising candidate as a building block for various integrated photonic circuits.

800 nm Bandwidth Amplified Spontaneous Emission of Divalent Cobalt Ion-doped Fiber Pumped at 550 nm

ABSTRACTIn this work, the energy levels, transition configuration and numerical model of cobalt ion-doped fiber is proposed and analyzed. A three-level system is employed to model the amplified spontaneous emission (ASE) of the doped fiber pumped at 550 nm, and the rate and power propagation equations are solved to analyze the effect of fiber length, active ion concentration, pump power and temperature on the ASE. It is shown that the fiber has an ultra-broadband ASE in 1100-1900 nm range, which will be promising for fiber communication system, fiber sensor and medical imaging.

Synthesis, structure and photoluminescent characterization of MYAl3O7:Eu3+ (M=Ca, Sr, Mg and Ba) red emitting materials for display applications

MYAl3O7:Eu3+ (M=Ca, Sr, Mg and Ba) materials were synthesized via combustion method at 600 °C temperature. These materials were further given two heat treatments at 900 and 1050 °C for 2 h each to demonstrate the consequences of higher temperature on emission intensity and crystal assembly. The optimal concentration of activator ion in CaYAl3O7 lattice was 0.03 mol. The prepared phosphors were characterized with different techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and photoluminescence (PL). XRD spectra showed CaYAl3O7 phosphor was of tetragonal symmetry with P421m space group. Particle size of the proposed materials was also calculated by this technique using Scherer’s equation. Chemical bonding, mainly metal–oxygen bonds were explained by FTIR technique. TEM analysis was used to study the three dimensional structure as well as to estimate the size of particles (55–70 nm). At 254 nm excitation wavelength, these were found to be strong red emitters due to typical 5D0 → 7F2 (forced electric dipole) transition at 610–616 nm. Their PL spectra were also having some weak emission bands viz. 5D0 → 7F1 (magnetic dipole) transition located at 587–591 nm and 5D0 → 7F3 transition at 650–655 nm. The nano size of the phosphors had made them suitable for a variety of display applications.

Improved Lithium Iodide neutron scintillator with Eu[formula omitted] activation II: Activator zoning and concentration effects in Bridgman-grown crystals

We have previously reported on the formation of Suzuki Phase precipitate particles as a result of the addition of the divalent activator ion Eu 2+ to the monovalent alkali halide host LiI. [Boatner et al. (2017)]. These precipitates form during Bridgman or other melt-growth processes, even at low Eu2+ concentrations (e.g., 0.1% EuI2 doping), and scatter the scintillation light reducing the optical transparency of the scintillator and adversely affecting its radiation-detection performance. In our prior work, we developed a two-stage thermal-treatment method for the post-growth removal of the Suzuki Phase particles and the realization of a significant improvement in the optical transparency and associated neutron-detection of LiI:Eu2+ scintillators. These improvements resulted in neutron-detection performance that is superior to GS-20 glass and that allows for the application of pulse height gamma-ray discrimination over a wide range of gamma ray energies as opposed to pulse shape discrimination. Here, we apply the two-stage thermal-processing method for the removal of Suzuki phase precipitates and carry out an in-depth study, first, of the neutron scintillator performance versus the Eu2+ activator-ion-concentration spatial variation as a result of zoning effects during the Bridgman growth of LiI:Eu2+ and, second, of the effects of varying the initial Eu2+ activator ion concentration prior to crystal growth. The Eu2+ zoning variation results allow one to identify and select the most efficient location of the scintillation performance in a directionally solidified single-crystal boule. The present study of the initial activator concentration levels shows that there are, in fact, two distinct types of luminescence centers with varying performance properties — one that occurs only at low EuI2 addition levels (e.g., 0.01 to 0.06 %EuI2) and that is quickly replaced by a second luminescing center with increasing Eu2+ content (e.g., at ∼0.1% EuI2). The light yield for the luminescing center formed using a Eu activator in LiI is a critical function of the Eu concentration in the range of 0.01 to 0.1 % EuI2, and a high light yield of 100,000 photons/neutron is observed at the 0.06 %EuI2additive level prior to thermal processing.

How activator ion concentration affects spectroscopic properties on Ba4Y3F17: Er3+, Yb3+, a new perspective up-conversion material

Ba4Y3F17 with Er3+ and Yb3+, a promising material for up-conversion luminescence, was synthesized. Excellent isomorphic capacity was detected. Low-temperature measurements show that erbium ions are incorporated in multiple lattice positions, which is inconsistent with the current model of Ba4Y3F17 crystal lattice structure. Activator ion concentration has a different impact on 4S3/2 and 4F9/2, states (for the green and red luminescence, respectively) depopulation. Energy transfer from Er3+ 4S3/2 state to Yb3+ is observed even at low temperature (15 K) while Er-Er cross-relaxation is observed from 120 K and above. Yb3+ concentration has a great impact to red-to-green up-conversion luminescence intensity ratio. Spectroscopic measurements allow to conclude that red up-conversion luminescence origins from 2.6 energy transfer steps form Yb3+ to Er3+ and violet up-conversion –3.5. Calculation shows that for the green up-conversion luminescence band, the internal quantum yield is in range 1.6–2.8% and for the red up-conversion luminescence, in the range –2.2–3.9%.

Synthesis and Photoluminescence Properties of BaWO4:RE3+ (RE = Eu or Sm) Phosphors

BaWO4:RE3+ (RE = Eu or Sm) phosphor powders were prepared with different doping concentrations of the activator ion by using the conventional solid-state reaction method. The dependences in the crystal structure, luminescence intensity, and morphology on the Eu3+ and the Sm3+ concentrations in BaWO4 were investigated using X-ray diffraction (XRD), photoluminescence spectrophotometry, and scanning electron microscopy (SEM), respectively. XRD analysis showed tetragonal BaWO4 structures for all the phosphors synthesized, regardless of the type and the doping concentration of the activator ion. SEM images indicated that as the concentration of activator ions was increased, the crystalline particles showed an increasing tendency to agglomerate irregularly. The room temperature excitation spectra of Eu3+- or Sm3+-doped BaWO4 phosphors consisted of a broad charge transfer band in the ultraviolet region and several sharp 4f-4f transitions. When Eu3+-doped BaWO4 phosphors were excited at 274 nm, the emission spectra exhibited sharp bands due to inner shell transitions occurring from the excited energy state 5D0 to the lower energy levels 7F J (J = 1, 2, 3, and 4). For Sm3+-doped BaWO4 phosphors, three intense emission peaks at 568, 603, and 649 nm and a very weak line at 712 nm were observed. The highest asymmetry ratio-the intensity ratio of the 4G5/2 → 6H9/2 electric dipole to the 4G5/2 → 6H5/2 magnetic dipole transitions-was obtained for 1 mol% doping of Sm3+, indicating that the Sm3+ ions occupied the non-inversion symmetry sites.

Near-infrared and blue cooperative Yb3+ luminescence in Lu3Sc2Ga3O12 nano-garnets

Nanocrystalline Lu3Sc2Ga3O12 garnet powders doped with different concentrations of trivalent ytterbium (Yb3+) ions have been prepared by sol-gel method. These garnet nano-powders have been characterized for their structural and luminescence properties using X-ray diffraction, diffuse reflectance and luminescence spectra. Near-infrared and blue cooperative upconversion luminescence spectra and decay curves of Yb3+ ions in these nano-garnets have been measured as a function of the optically active ion concentration. Quenching of near-infrared and cooperative luminescence intensity beyond 5.0 mol% of Yb3+ ion concentration have been observed. Variation of blue cooperative luminescence intensity with pump power has also been discussed.

On the crystal structure and luminescence characteristics of a novel deep red emitting SrLaScO4:Mn4+

A novel Mn4+ activated SrLaScO4 was synthesized and investigated for its crystal structure and optical characteristics. SrLaScO4 exhibits a well-known K2NiF4 structure, it crystalizes in Abma space group and provides an octahedral site of ScO6 which was exploited for Mn4+ incorporation. The synthesized phosphor showed broad excitation bands and an uncommon narrow emission band centered at 690 nm with an full width at half maximum (FWHM) of ∼35 nm. The optimal activator ion concentration for SrLaScO4:Mn4+ was found to be ∼0.8 mol%. The photoluminescence and photoluminescence excitation characteristics indicate that it can be opted as red emitting material for the white LEDs for indoor agriculture where the deep red emissions are favored. However the tendency of luminescence quenching in the phosphor is very high and ∼85% of original intensity is damped with a temperature rise of 150°C.

New Insights into the Compositional Dependence of Li-Ion Transport in Polymer-Ceramic Composite Electrolytes.

Composite electrolytes are widely studied for their potential in realizing improved ionic conductivity and electrochemical stability. Understanding the complex mechanisms of ion transport within composites is critical for effectively designing high-performance solid electrolytes. This study examines the compositional dependence of the three determining factors for ionic conductivity, including ion mobility, ion transport pathways, and active ion concentration. The results show that with increase in the fraction of ceramic Li7La3Zr2O12 (LLZO) phase in the LLZO-poly(ethylene oxide) composites, ion mobility decreases, ion transport pathways transit from polymer to ceramic routes, and the active ion concentration increases. These changes in ion mobility, transport pathways, and concentration collectively explain the observed trend of ionic conductivity in composite electrolytes. Liquid additives alter ion transport pathways and increase ion mobility, thus enhancing ionic conductivity significantly. It is also found that a higher content of LLZO leads to improved electrochemical stability of composite electrolytes. This study provides insight into the recurring observations of compositional dependence of ionic conductivity in current composite electrolytes and pinpoints the intrinsic limitations of composite electrolytes in achieving fast ion conduction.

Effect of borate and bismuth glass compositions on luminescence properties of rare earth ions

Rare earth (RE) doped luminescent materials (glasses, glass-ceramics and nanophosphors) are widely studied due to their numerous applications in the field of solid state lasers, optical telecommunication, near infrared (NIR)-to-visible up-converting (UC) luminescence for biolabels, solar cells, white light emitting diodes, optical sensors, etc. The spectroscopic techniques are used to identify the best optimum glass composition and active ion concentration to get efficient luminescence. The importance of bismuth borate glasses, optimization of optical properties and active ion concentration have been carried out through spectroscopic techniques. The present paper reports the effect of bismuth borate glasses on luminescence properties of Ce3+, Nd3+ and Sm3+ ions. Judd-Ofelt theory has been used to quantify the fluorescence properties of luminescent levels.

Spectroscopic investigation of Ce3+/Eu3+ co-doped Li2BaZrO4 nanocrystalline phosphors

This work reports on a one-pot synthesis of Li2BaZrO4 co-doped with Eu3+ and Ce3+ ions using solution combustion method at low temperature. The influence of fixing either the concentration of activator ion or sensitizer ion constant while varying the concentration of the other was investigated. Three concentrations where considered 0.005, 0.02 and 0.04 in mole % ratio. The concentration of the fixed ion was at 0.02. X-ray diffraction results show that Li2BaZrO4 sample prepared with concentration of Ba/Zr ratio of 1 and Ce3+-singly doped sample both display cubic perovskite structure of BaZrO3. Li2BaZrO4 sample with excess Ba3+, Eu3+ singly-doped sample and all co-doped samples have mixed phases of Ba(NO3)2 and BaZrO3. The band gap energy decreased with increasing concentration of dopant or co-dopant ions indicating the introduction of more defects in the band gap. Photoluminescence emissions for all the doped samples at room temperature are entirely from intraconfigurational Eu3+ emission lines when excited at 254 nm, but contain a broad band associated to the Ce3+ ions under indirect excitation at 373 nm. The dominance of the magnetic dipole transition in the entire spectra for all Eu3+ doped samples is a confirmation of the centrosymmetry around the ion. The emission intensity from the co-doped samples with fixed concentration of Ce3+ ion (sensitizer) is 4-folds of magnitude stronger than for corresponding samples with fixed Eu3+ (activator) concentration. Thus, in co-doping, the concentration of the sensitizer should be fixed while that of the activator varied if enhanced emission intensity is desired.

Surface-plasmonic right-angle waveguide amplifiers

We propose a surface-plasmonic right-angle bend waveguide with bismuth ion-doped glass film as core layer and Ag films as cladding layers for first time, to the best of our knowledge. Theoretical analysis shows that the right-angle has bend and absorption losses of 3.17 dB. The rate equations and power evolution equations of high concentration bismuth-doped glass film are setup and solved to analyze the effect of the waveguide length and active ion concentration on the signal gain and Noise Figure (NF). The theoretical results predict that with the pump power 100 mW, the active ion concentration 2.0×1026 ions/m3 and the right-angle waveguide size 1.0 cm×1.0 cm, small-signal unit-length net gain can reach 15.32 dB with NF less than 5.0 dB.

Synthesis of Ca2SiO4:Dy3+ phosphors from agricultural waste for solid state lighting applications

Trivalent dysprosium (Dy3+) ions -doped calcium silicate (Ca2SiO4) phosphors have been synthesized by utilizing agricultural waste of egg shell and rice husk through solid-state reaction method. The synthesized Ca2SiO4 powders thus obtained are crystallized in monoclinic structure with unit cell parameters of a = 5.53Å; b = 6.67Å; c = 9.13Å; β = 87.43° and irregular shape morphology. Luminescent properties of Dy3+:Ca2SiO4 phosphors were studied by varying active ion concentration. The phosphors emit characteristic blue and yellow emissions of Dy3+ ions corresponding to the 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 transitions, respectively. Color coordinates evaluated from emission spectra are found to fall in the white light region. Decay curves for the 4F9/2 level of Dy3+ ions exhibit single exponential nature and turn into non-exponential with shortening of lifetime from 739 µs to 510 µs when Dy3+ ion concentration is increased from 0.001 to 0.5mol%. All these results confirm that Ca2SiO4:Dy3+ phosphors are suitable for the use as low cost white light emitting phosphors.

Gain and noise figure analysis of Er3+-doped YAG transparent ceramic microchip amplifier

The rate equations and the power evolution equations based on excited state absorption (ESA) and cooperative upconversion (CUC) of high concentration erbium-doped yttrium aluminum garnet (YAG) transparent ceramic waveguide amplifier are set up to analyze the effects of the pump power, active ion concentration and waveguide length on the amplifier gain and noise figure (NF). The numerical analysis predicts that with a pump power of 100mW, an active ion concentration of 1.0×1026 ion/m3 and a waveguide length of 3 cm, a small-signal gain of 30 dB and an NF of 5 dB can be achieved in the micro-chip amplifier.

Gain and emission spectrum characteristics of 465nm laser diode pumped Tm3+-doped telluride glass fibers

Gain and emission spectrum characteristics of Tm3+-doped telluride glass fibers pumped with 465 nm lasers are analyzed. The rate and power propagation equation groups of the fibers are solved numerically and the effects of the fiber parameters including active ion concentration, length and pump power on the gain spectra and amplified spontaneous emission (ASE) spectra are analyzed. The results show that with a pump parameter of 465 nm/200mW, a doping concentration of 2.5×1025 ion/m3 and a fiber length of 16m, the gain and ASE spectra can cover from 1.100 to 1.900 μm, and the gain and ASE power peaks can reach 52 dB and 8mW, respectively.

Phosphate glass core/silica clad fibres with a high concentration of active rare-earth ions

We report a study of silica-clad composite optical fibres having a phosphate glass core doped with active rare-earth elements. The phosphate glass core allows a high concentration of active rare-earth ions to be obtained, and the silica cladding ensures high mechanical strength and facilitates fusion splicing of such fibres to silica fibres. Owing to the high concentration of active rare-earth ions, this type of fibre is potentially attractive for applications where a small cavity length and high lasing efficiency are needed.

Atomic Layer Engineering of Er-Ion Distribution in Highly Doped Er:Al2O3 for Photoluminescence Enhancement

For the past decade, erbium-doped integrated waveguide amplifiers and lasers have shown excellent potential for on-chip amplification and generation of light at the important telecommunication wavelength regime. However, Er-based integrated devices can only provide small gain per unit length due to the severe energy-transfer between the Er-ions at high concentration levels. Therefore, active ion concentrations have been limited to <1% levels in these devices for optimal performance. Here, we show an efficient and practical way of fabricating Er-doped Al2O3 with Er-concentration as high as ∼3.5% before concentration quenching starts to limit the C-band emission in our material. The Er-doped Al2O3 was fabricated by engineering the distribution of the Er-ions in Al2O3 with the atomic layer deposition (ALD) technique. By choosing a proper precursor for the fabrication of Er2O3, the steric hindrance effect was utilized to increase the distance between the Er-ions in the lateral direction. In the vertical direc...

Synthesis and Photoluminescence Properties of Sr2Be2B2O7 Doped with Dy3+, Sm3+, Tb3+, and Pb2+

Pure and Dy3+-, Sm3+-, Tb3+-, and Pb2+-doped Sr2Be2B2O7 materials were prepared by a solution combustion synthesis method. The phase analysis of all synthesized materials was carried out using powder XRD. The photoluminescent properties of Dy3+-, Sm3+-, Tb3+-, and Pb2+-doped Sr2Be2B2O7 materials were investigated using a spectrofl uorometer at room temperature. The fi rst luminescent material, Sr2Be2B2O7:Dy3+, emits 478–493, 573, and 661 nm upon excitation with 344 nm; Sr2Be2B2O7:Sm3+ emits 563–574, 599–613, 647–666, and 705–713 nm upon excitation with 395 nm; Sr2Be2B2O7:Tb3+ emits 489, 545, 584–591, and 622 nm upon excitation with 248 nm; Sr2Be2B2O7:Pb2+ emits 371 nm upon excitation with 281 nm. Also, the dependence of the emission intensity on the activator ion (Dy3+, Sm3+, Tb3+, and Pb2+) concentration for the Sr2Be2B2O7 was studied. It was observed that the concentration quenching of Dy3+, Sm3+, Tb3+, and Pb2+ in Sr2Be2B2O7 is 0.05, 0.02, 0.07, and 0.02 mol.%, respectively.

Physical and Chemical Properties Study on the Groundwater in Tuz District

The present study is carried out to detect some quality properties of groundwater at Tuz,. The results showed that air temperature noted minimum at ranged between (8-35)C° , and The recorded temperatures of ground water values range between (18-25)C°, Turbidity values for all wells water at the study area ranged (0.00-29.88)NTU, It is obtained that wells near-off the mountain chain Nafed dag increase of electric conductivity comparative ranged between (734-6890)µs/cm. Groundwater in the study area was Brackish dependence to the total dissolved salts ranged (20-5860)mg/l . The pH values ranging between (4.15-8.91) . It was noted that the values of the dissolved oxygen are few and almost non-existent in some cases it ranged between (0.8 -0.30)mg/l. Analysis of biological oxygen demand refers to wells water (very clean) levels involving (0.00 -0.15)mg/l. Reason of groundwater very hardness ranging values of total hardness , calcium and magnesium hardness between (300-2440) mg/l , (160-1400)mg/l and (44-1580)mg/l respectively. The total alkalinity ranged between (74-600)mg/l , The chloride ions in ground water of the studied within the permissible limits for watering of animals and irrigation of plants, with values range (0.00-349.89)mg/l . Sulphates range between (134.5-3326)mg/l .Sodium values for all wells water at the study area ranged (112.35 -495.59)mg/l. Potassium values for all wells water at the study area ranged (1.158-51.036)mg/l. As for plant nutrients , ranged between the values of silica (9.688-25.981)mg/l.The concentration of active nitrite ions ranged between (0.000 –1.212) µg NO-NO2/L .As the values of phosphate , ranged between (0.26-0.399) µg P-PO4/L during the study period.