Influence of MgO codoping on Er concentration in congruent LiNbO3 crystal: Mg threshold concentration effect

2010 ◽  
Vol 25 (2) ◽  
pp. 235-239 ◽  
Author(s):  
De-Long Zhang ◽  
Li-Zhu Zhang ◽  
Chao Xu ◽  
Liang Sun ◽  
Yu-Heng Xu ◽  
...  
Keyword(s):  
Czochralski Method ◽  
Threshold Effect ◽  
Threshold Concentration ◽  
The Other ◽  
Concentration Effect ◽  
Segregation Coefficient ◽  
Linbo3 Crystal ◽  
Mg Doping ◽  
Mg Content ◽  
Doping Case

Congruent Er:Mg:LiNbO3 crystals were grown by the Czochralski method from the melts containing fixed 0.5 mol% Er2O3 while varied MgO content ranged from 0.0 to 8.0 mol%. The Mg and Er contents in the crystals were determined by neutron activation analysis. In the presence of Er codopant, the Mg threshold concentration with respect to optical damage is determined from the measured OH absorption spectra. The results show that the Er codopant has less effect on both the Mg threshold concentration and Mg segregation coefficient, which is within 1.13–1.23 as the Mg concentration is below the threshold while within 0.88–0.98 when above the threshold, consistent with the only MgO doping case. On the other hand, the practical Er concentration in the crystal is closely related to the Mg content and shows definite Mg threshold effect. Below the threshold, the Er concentration decreases linearly with the increased Mg concentration in the crystal; above the threshold, the decrease is more remarkable and follows another linear function. The Mg concentration effect on the Er segregation coefficient is discussed from the viewpoint of the Mg doping effect on the solubility of Er ions in the crystal.

Effect of [Li]/[Nb] ratios on segregation coefficient and dopant occupancy of In:Yb:Nd:LiNbO3 crystals

2019 ◽  
Vol 33 (13) ◽  
pp. 1950160
Author(s):  
Li Dai ◽  
Yu Shao ◽  
Xianbo Han ◽  
Chunrui Liu ◽  
Luping Wang
Keyword(s):  
Transmission Spectrum ◽  
Inductively Coupled Plasma ◽  
Emission Spectroscopy ◽  
Czochralski Method ◽  
Atomic Emission ◽  
Threshold Concentration ◽  
Segregation Coefficient ◽  
Plasma Atomic Emission ◽  
Inductively Coupled ◽  
Ir Transmission

A series of [Formula: see text] crystals with various [Li]/[Nb] ratios (0.946, 1.05, 1.20 and 1.38) were grown by the Czochralski method. They were analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). As the [Li]/[Nb] ratio increases in the melt, the segregation coefficients of [Formula: see text] and [Formula: see text] ions increase, while the segregation coefficient of [Formula: see text] ions decrease. The [Li]/[Nb] ratio in the crystal of sample [Formula: see text] is 0.996, which is near stoichiometric. The dopant occupancy with different [Li]/[Nb] ratios was analyzed by IR transmission spectrum and UV-VIS-NIR spectrum. When the [Li]/[Nb] ratio reaches 1.20, the absorption peak at [Formula: see text] indicates that the threshold concentration of [Formula: see text] is 1 mol.% in the sample [Formula: see text].

Diagnostic relevance of suppressed basal concentrations of TSH compared with the negative TRH test in detection and exclusion of hyperthyroidism

1991 ◽  
Vol 124 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Michael Roden ◽  
Peter Nowotny ◽  
Heinrich Vierhapper ◽  
Werner Waldhäusl
Keyword(s):  
Outpatient Clinic ◽  
Correct Diagnosis ◽  
Threshold Concentration ◽  
The Other ◽  
Trh Test ◽  
Other Hand ◽  
Concomitant Decrease ◽  
Euthyroid Patient ◽  
Definition Of ◽  
Hyperthyroid Patients

Abstract. To evaluate the sensitivity of basal TSH concentrations as determined by an "ultrasensitive" IRMA-assay (RIA-gnost h-TSH-monoclonal, Behring) versus a "negative" TRH test (defined as an increment of TSH ≥0.2 mU/l 20 min after administration of 400 μg TRH iv) in the diagnosis of hyperthyroidism we examined 193 consecutive patients from our thyroid outpatient clinic: 34 patients displayed hyperthyroidism (total T4: 184.4±26.0 μmol/l, effective thyroxine index: 1.25±0.08), whereas 12 had isolated T3-hyperthyroidism (total T3: 3.47±0.48 nmol/l). Employing the producer's definition of subnormal ("suppressed") bTSH concentrations (≤0.1 mU/l), only 19 (41.3%) hyperthyroid patients would have been detected; on the other hand, one euthyroid patient would have been recognized false positively as hyperthyroid. Using the TRH test as criterion led to the correct diagnosis in 42 (sensitivity: 91.3%) hyperthyroid patients, whereas two had low bTSH concentrations (≤0.5 mU/l), but a normal TSH response to TRH (>2.0 mU/l). Raising the threshold concentration to 0.2 and, subsequently, to 0.4 mU TSH/l increased the number of correct results to 38 (sensitivity: 82.6%) and 43 (93.5%), respectively. This was associated with a concomitant decrease in specificity in the diagnosis of hyperthyroidism from 93.7 (0.1 mU/l) to 27.9% (0.4 mU/l). In conclusion, despite ultrasensitive methods for estimation of low TSH concentrations, the TRH test remains an irreplaceable tool for the correct diagnosis of hyperthyroidism.

scholarly journals Gustatory responses of eel palatine receptors to amino acids and carboxylic acids.

1979 ◽  
Vol 74 (3) ◽  
pp. 301-317 ◽  
Author(s):  
K Yoshii ◽  
N Kamo ◽  
K Kurihara ◽  
Y Kobatake
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Carboxylic Acids ◽  
Carbon Chain ◽  
Threshold Concentration ◽  
The Other ◽  
Carbon Chain Length ◽  
High Concentration ◽  
Gustatory Receptors ◽  
Cross Adaptation

The gustatory receptors of the eel palate were found to be extremely sensitive to amino acids and carboxylic acids. The results obtained are as follows: (a) 11 amino acids which are among naturally occurring amino acids elicited responses in the palatine nerve, but 9 amino acids did not elicit a response even at a high concentration. The effect of D-amino acids was always much less than that of their corresponding L-isomers. There was no appreciable difference in the effectiveness of an alpha-amino acid (alpha-alanine) and beta-amino acid (beta-alanine). (b) The threshold concentrations of the most potent amino acids (arginine, glycine) were between 10(-8) and 10(-9) M. A linear relation between the magnitude of the response and log stimulus concentration held for a wide concentration range for all the amino acids examined. (c) The palatine receptors responded sensitively to various carboxylic acid solutions whose pH was adjusted to neutral. The threshold concentrations varied between 10(-4) and 10(-7) M. The magnitude of the response at 10(-2) M increased with an increase of carbon chain length. (d) The extent of cross-adaptation was examined with various combinations of amino acids. A variety of the response patterns showing complete cross-adaptation, no cross-adaptation, or synergetic interaction was observed. The synergetic interaction was also observed when one amino acid below its threshold concentration was added to the other amino acid below its threshold concentration was added to the other amino acid. No cross-adaptation was observed between amino acids and fatty acids. (e) The treatment of the palate with papain led to loss of the responses to arginine, glycine, and histidine without affecting those to proline and acetic acid. The treatment with pronase E eliminated selectively the response to proline. The possibility that the eel gustatory receptors are responsible for sensing food at a distance was discussed.

Near-stoichiometric LiNbO3 crystal grown using the Czochralski method from Li-rich melt

2004 ◽  
Vol 58 (25) ◽  
pp. 3119-3121 ◽  
Author(s):  
Hai-Li Wang ◽  
Yin Hang ◽  
Jun Xu ◽  
Lian-Han Zhang ◽  
Shi-Ning Zhu ◽  
...  
Keyword(s):  
Czochralski Method ◽  
Linbo3 Crystal ◽  
Stoichiometric Linbo3 Crystal

scholarly journals Effect of black peat, pH and Mg on growth of heather on sandy soil.

1986 ◽  
Vol 34 (1) ◽  
pp. 103-106
Author(s):  
H. Niers ◽  
J. van der Boon
Keyword(s):  
Soil Ph ◽  
Sandy Soil ◽  
Calluna Vulgaris ◽  
Field Trials ◽  
The Other ◽  
High Ph ◽  
Visual Rating ◽  
Top Soil ◽  
Negative Effect ◽  
Mg Content

Eight field trials were carried out with various heather cultivars (Calluna vulgaris Carmen, Cuprea, Robert Chapman; Erica tetralix Con Underwood; E. carnea [herbacea] King George and E. cinerea C.D. Eason). Peat at 0-8 msuperscript 3/100 msuperscript 2 was incorporated into the top soil or applied as a layer and soil pH-KCl was maintained at levels between 3 and 6.8. Increasing peat application up to 4 msuperscript 3/100 msuperscript 2 improved the growth and quality (visual rating) of the stand; higher amounts had little additional effect. Peat applied as a layer gave some slightly better results than peat incorporated into the topsoil. A soil pH-KCl value of 4.2 was the optimum for growth of most cultivars and reasonable growth could be expected in the range 3.8-4.7. Cv. King George was more tolerant to high pH than cultivars of the other species tested. In 3 trials with Calluna cultivars MgO application at 150 or 200 kg/ha increased the Mg content of the soil and shoots but had a slight negative effect on growth. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Do City Size and Population Density Influence Regional Innovation Output Evidence from China?

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Cai Shukai ◽  
Wang Haochen ◽  
Zhou Xiaohong
Keyword(s):  
Population Density ◽  
Large Scale ◽  
Positive Impact ◽  
Threshold Value ◽  
Threshold Effect ◽  
The Other ◽  
City Size ◽  
Regional Innovation ◽  
Innovation Output ◽  
The Impact

This paper proposed a substantial gap to a large-scale population density and city size on regional innovation output. To measure the impact of population density and city size on regional innovation output, this study employs the threshold effect model with panel data of 230 prefectures and cities from 2007 to 2016. Based on the econometric analysis, the results exhibit a positive and significant relationship between population density, city size, and innovation output. This correlation suggests that when one factor increases, the other increases in the parallel direction and vice versa. Moreover, when the city size expands the threshold value of 2.934 percent, the innovation promotes and increases the effects of urban-scale expansion. On the other hand, for medium- and low-density cities, the increase of urban population density has a significant and positive impact on urban innovation output. However, for high-density cities, the increase of population density has no significant impact on innovation output.

Analaysis of volatile odour compounds in digested sewage sludge and aged sewage sludge cake

2000 ◽  
Vol 41 (6) ◽  
pp. 73-80 ◽  
Author(s):  
P. Winter ◽  
S. C. Duckham
Keyword(s):  
Sewage Sludge ◽  
Sewage Treatment ◽  
Threshold Concentration ◽  
The Other ◽  
Gas Chromatography Mass Spectrometry ◽  
Treated Sewage ◽  
Odour Threshold ◽  
Sludge Cake ◽  
Digested Sewage Sludge ◽  
Purge And Trap Sampling

A number of malodorous compounds were identified in digested sludge and the corresponding sludge cakes. The major components included a number of sulfides. The levels of these compounds were monitored in order to investigate the influence of the sludge treatment process and length of cake storage on the malodour of treated sewage sludge. Two sewage treatment works (STWs) were surveyed. One of the works (Site B) produced very malodorous sludge cake, whilst the other produced a much less odorous cake (Site A). The analysis consisted of purge and trap sampling of liquefied samples followed by gas chromatography-mass spectrometry (GC-MS). Afteran initial screening of samples, by full mass scan GC-MS analysis, targetcompounds were identified for quantification. Sulfide levels inthe majority of the liquid digested sludges were significantly lower than that in sludge cakes. Large differences in the level of sulfides were found in stockpiled sludge cakes. The majority of malodorous sludge cakes had higher sulfide levels than less odorous sludge cakes. The most abundant compounds were dimethylsulfide, dimethyldisulfide and dimethyltrisulfide. Thehighest sulfide levels were found during the first month of stockpiling. Whenthe odour threshold concentration of these compounds was taken into account and odour unit values were calculated, dimethyltrisulfide was found to have a proportionally greater impact on odour than any of the other compounds studied. The use of sulfide levels as indicators of malodour formation and possible strategies for reducing odour in stockpiled sludge cake are discussed.

Magneto-Optical Study of Martensitic Transition in Ni45Mn36.7In13.3Co5 (at. %) Single Crystals

2015 ◽  
Vol 233-234 ◽  
pp. 225-228 ◽  
Author(s):  
Elena Gan’shina ◽  
Andrey Novikov ◽  
Volodymyr Chernenko ◽  
J. Barandiaran ◽  
Eduard Cesari ◽  
...  
Keyword(s):  
Single Crystals ◽  
Kerr Effect ◽  
Cold Water ◽  
Czochralski Method ◽  
The Other ◽  
Martensitic Transition ◽  
Optical Study ◽  
Scanning Calorimetry ◽  
Characteristic Temperatures ◽  
Annealing Conditions

Transverse Kerr effect (TKE) was used to study magneto-optical (MO) properties of Ni45Mn36.7In13.3Co5 (at.%) single crystals. A single crystalline ingot of such composition was grown by the Czochralski method. One series of samples was quenched into cold water (WQ) and the other series after quenching was heated at 770 K for 20 min and slowly cooled to assure a complete atomic order (SC). Accordingly to differential scanning calorimetry (DSC), magnetic and magneto-optical (MO) measurements, WQ samples exhibit well-defined martensitic transition (MT), but the SC samples do not show MT. It is found that TKE for WQ samples shows the following features (i) MO signal is well pronounced far below the martensitic transition in spite of a weak magnetization of martensitic phase; (ii) the characteristic temperatures of martensitic transition differ from those for the bulk and depend on annealing conditions; (iii) MO spectra profile do not change significantly during the martensitic transition and is similar but not identical with that for Ni50Mn35In15 thin films and Ni43.7Mn43.6In12.7 ribbons measured before; (iv) MO signal is anisotropic.

Effects of Mg-Doping on Structure and Electric Properties of MgxZn1-xO:Al Ceramics

2010 ◽  
Vol 97-101 ◽  
pp. 475-478
Author(s):  
Hua Wang ◽  
Zhu Huang ◽  
Ji Wen Xu ◽  
Ling Yang ◽  
Ming Fang Ren
Keyword(s):  
Phase Separation ◽  
Carrier Concentration ◽  
Electrical Conduction ◽  
Doping Level ◽  
Single Phase ◽  
Raw Materials ◽  
Electric Properties ◽  
Al Doping ◽  
Mg Doping ◽  
Mg Content

MgxZn1-xO:Al ceramics with low resistivity using ZnO, MgO and Al2O3 nano-powders as raw materials were obtained by unpressurized sintering. The influence of Mg content on structure and electric properties of MgxZn1-xO:Al ceramics were studied. The results indicate that there is a single phase of wurtzite structure of ZnO in MgxZn1-xO:Al ceramics at x ≤ 0.3, and when the value of x was 0.3, phase separation was observed. The grains become smaller and more homogeneous with increasing Mg content to above 0.3. The resistivity of MgxZn1-xO:Al ceramics obviously increases with increasing Mg concentration due to the decrease of the carrier concentration and the mobility deriving from the decrease of Al-doping efficiency. The electrical conduction of MgxZn1-xO:Al ceramics can be markedly improved by increasing the Al-doping level and the lowest resistivity of 8.3×10-4Ω•cm can be obtained when Mg/(Mg+Zn)=0.2 and Al/(Mg+Zn+Al)=0.03.

Sign in / Sign up

Export Citation Format

Share Document