scholarly journals Considerations About Bi and Pb in the Crystal Structure of Cu-Bearing Tourmaline

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 706
Author(s):  
Andreas Ertl ◽  
Peter Bačík
Keyword(s):  
Crystal Structure ◽  
Correlation Analysis ◽  
Correlation Coefficient ◽  
Site Occupancy ◽  
Bond Valence ◽  
Stable Arrangement

Copper- and Mn-bearing elbaitic tourmaline (“Paraíba tourmaline”) sometimes contains significant amounts of Pb and Bi. Their position in the tourmaline crystal structure was studied with correlation analysis and bond valence calculations. Correlations between the F content and the X-site charge allow predicting the X-site occupancy. Three sets of tourmaline analyses were studied: (1) Pb-rich tourmalines from the Minh Tien pegmatite, Vietnam; (2) Cu-, Pb- and Bi-bearing tourmalines from the Mulungu mine, Brazil; (3) Cu- and Bi-bearing tourmalines from the Alto dos Quintos mine, Brazil. Two correlations were plotted: (1) the charge by considering only Na1+, Ca2+ and K1+; (2) the charge by adding Pb2+ and Bi3+ to the X-site charge. When plotting correlations for the Minh Tien tourmalines, the correlation significantly improves by adding Pb2+ to the X site. For the Alto dos Quintos tourmalines, only a slight increase of the correlation coefficient is observed, while such a correlation for tourmalines from Mulungu interestingly shows a slight decrease of the correlation coefficient. Bond valence calculations revealed that Bi3+ and Pb2+ can indeed occupy the X site via BiLi(NaAl)−1, PbLi(NaCu)−1 and possibly PbCu(NaAl)−1 substitutions as seen in the investigated tourmaline samples. At the Y site, Pb4+ can be substituted via PbLi(AlCu)−1, and PbVO(AlVOH)−1, while Bi5+ does not have any stable arrangement in Cu-bearing fluor-elbaite. The occurrence of Pb4+ at the Y site could be one explanation for the results of the correlations of the Mulungu tourmalines. Another explanation could be that during the tourmaline crystallization some additional Bi and Pb came into the pegmatitic system and hence disturbed the correlation between the average X-site charge and the F content. Further plots of such correlations in “Paraíba tourmaline” samples might also help to distinguish between the worldwide localities of these rare and sought-after tourmalines.

Structural/Property Relationships for Optical Materials

1993 ◽  
Vol 329 ◽  
Author(s):  
Vivien D.
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Electronic Structure ◽  
Chemical Composition ◽  
Field Strength ◽  
Optical Materials ◽  
Site Occupancy ◽  
Laser Materials ◽  
Crystal Field Strength ◽  
The Matrix

AbstractIn this paper the relationships between the crystal structure, chemical composition and electronic structure of laser materials, and their optical properties are discussed. A brief description is given of the different laser activators and of the influence of the matrix on laser characteristics in terms of crystal field strength, symmetry, covalency and phonon frequencies. The last part of the paper lays emphasis on the means to optimize the matrix-activator properties such as control of the oxidation state and site occupancy of the activator and influence of its concentration.

Crystallochemical analysis of the crystal structure of PbGa2S4: the bond valence model

2016 ◽  
Vol 39 (0) ◽  
pp. 7-11
Author(s):  
А. Я. Штейфан ◽  
В. І. Сідей ◽  
І. І. Небола ◽  
І. П. Студеняк
Keyword(s):  
Crystal Structure ◽  
Bond Valence ◽  
Bond Valence Model ◽  
Crystallochemical Analysis

A Crystallographic Study of Bis[S-benzyl-5-bromo-2-oxoindolin-3-ylidenemethanehydrazonthioate] Disulfide Solvated with Dimethylsulfoxide

2012 ◽  
Vol 9 (2) ◽  
pp. 87
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
M. Ibrahim M. Tahir ◽  
Karen A. Crouse ◽  
Fiona N.-F. How ◽  
David J. Watkin
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Solvent Molecule ◽  
Site Occupancy ◽  
Unit Cell Parameters ◽  
Intermolecular Hydrogen Bonds ◽  
Triclinic Space Group ◽  
Cell Parameters ◽  
Crystallographic Study ◽  
Thiol Form

The crystal structure of the title compound has been determined. The compound crystallized in the triclinic space group P -1, Z = 2, V = 1839 .42( 18) A3 and unit cell parameters a= 11. 0460( 6) A, b = 13 .3180(7) A, c=13. 7321 (8) A, a = 80.659(3 )0, b = 69 .800(3 )0 and g = 77 .007 (2)0 with one disordered dimethylsulfoxide solvent molecule with the sulfur and oxygen atoms are distributed over two sites; S101/S102 [site occupancy factors: 0.6035/0.3965] and 0130/0131 [site occupancy factor 0.3965/0.6035]. The C22-S2 l and C 19-S20 bond distances of 1. 779(7) A and 1. 788(8) A indicate that both of the molecules are connected by the disulfide bond [S20-S21 2.055(2) A] in its thiol form. The crystal structure reveals that both of the 5-bromoisatin moieties are trans with respect to the [S21-S20 and CI 9-Nl 8] and [S20-S21 and C22-N23] bonds whereas the benzyl group from the dithiocarbazate are in the cis configuration with respect to [S21-S20 and C19-S44] and [S20-S21 and C22-S36] bonds. The crystal structure is further stabilized by intermolecular hydrogen bonds of N9-H35···O16 formed between the two molecules and N28-H281 ···O130, N28-H281 ···O131 and C4 l-H4 l l ···O 131 with the solvent molecule.

scholarly journals Correlating Capsaicinoid Levels and Physicochemical Proper-ties of Kimchi and Its Perceived Spiciness

Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 86
Author(s):  
So-Ra Yoon ◽  
Yun-Mi Dang ◽  
Su-Yeon Kim ◽  
Su-Yeon You ◽  
Mina K. Kim ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Physicochemical Properties ◽  
Correlation Coefficient ◽  
Partial Correlation ◽  
Sugar Content ◽  
Amino Acid Content ◽  
Titratable Acidity ◽  
Free Sugar ◽  
Partial Correlation Analysis ◽  
The Relationship

Capsaicinoid content, among other factors, affects the perception of spiciness of commercial kimchi. Here, we investigated whether the physicochemical properties of kimchi affect the spicy taste of capsaicinoids perceived by the tasting. High-performance liquid chromatography (HPLC) was used to evaluate the capsaicinoid content (mg/kg) of thirteen types of commercial kimchi. The physicochemical properties such as pH, titratable acidity, salinity, free sugar content, and free amino acid content were evaluated, and the spicy strength grade was determined by selected panel to analyze the correlation between these properties. Panels were trained for 48 h prior to actual evaluation by panel leaders trained for over 1000 h according to the SpectrumTM method. Partial correlation analysis was performed to examine other candidate parameters that interfere with the sensory evaluation of spiciness and capsaicinoid content. To express the specific variance after eliminating the effects of other variables, partial correlations were used to estimate the relationships between two variables. We observed a strong correlation between spiciness intensity ratings and capsaicinoid content, with a Pearson’s correlation coefficient of 0.78 at p ≤ 0.001. However, other specific variables may have influenced the relationship between spiciness intensity and total capsaicinoid content. Partial correlation analysis indicated that the free sugar content most strongly affected the relationship between spiciness intensity and capsaicinoid content, showing the largest first-order partial correlation coefficient (rxy/z: 0.091, p ≤ 0.01).

scholarly journals β-Li0.37Na0.63Fe(MoO4)2

2014 ◽  
Vol 70 (2) ◽  
pp. i9-i10 ◽  
Author(s):  
Amira Souilem ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
General Position ◽  
Site Occupancy ◽  
The Other ◽  
Main Structure ◽  
Axis Direction ◽  
A Site

The title compound, lithium/sodium iron(III) bis[orthomolybdate(VI)], was obtained by a solid-state reaction. The main structure units are an FeO6octahedron, a distorted MoO6octahedron and an MoO4tetrahedron sharing corners. The crystal structure is composed of infinite double MoFeO11chains along theb-axis direction linked by corner-sharing to MoO4tetrahedra so as to form Fe2Mo3O19ribbons. The cohesion between ribbonsviamixed Mo—O—Fe bridges leads to layers arranged parallel to thebcplane. Adjacent layers are linked by corners shared between MoO4tetrahedra of one layer and FeO6octahedra of the other layer. The Na+and Li+ions partially occupy the same general position, with a site-occupancy ratio of 0.631 (9):0.369 (1). A comparison is made withAFe(MoO4)2(A= Li, Na, K and Cs) structures.

CLINICAL, ECHOGRAPHIC, MORPHOLOGICAL AND IMMUNOLOGICAL CRITERIA FOR EVALUATING A WELL-FOUNDED SCAR ON THE UTERUS AFTER CESAREAN SECTION

2021 ◽  
Vol Special issue (1) ◽  
pp. 57-61
Author(s):  
Venera Kurbaniyazova ◽  
Keyword(s):  
Correlation Analysis ◽  
Cesarean Section ◽  
Correlation Coefficient ◽  
Significant Relationship ◽  
Strong Correlation ◽  
Type I Collagen ◽  
Morphological Features ◽  
Average Degree ◽  
Type I ◽  
Uterine Scar

The results of the conducted studies 102 of the manufacturer testify to the presence of essential clinical and echographic, immunological and morphological features of the "wealthy" or "insolvent" scar on the uterus after the cesarean section. The correlation analysis with the calculation of the Correlation coefficient of Gamma (G) indicates a statistically significant relationship between the average degree between the way of the delivery and the scar thickness (G = 0.55, p = 0.001), strong correlation between the ultrasound data (G = 0.74 , p = 0.002) and antibodies to type I collagen (G = 0.93, p = 0.003). Determining the level of antibodies to the type I collagen is the mostimportant criterion confirming the usefulness of the scar on the uterus.Keywords: cesarean section, uterine scar, pregnancy

scholarly journals HUBUNGAN PERSEPSI TENTANG PROFESI FISIOTERAPI DENGAN MOTIVASI BELAJAR MAHASISWA AKADEMI FISIOTERAPI UKI

2018 ◽  
Vol 10 (3) ◽  
pp. 226
Author(s):  
Maksimus Bisa
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Correlation Analysis ◽  
Correlation Coefficient ◽  
Linear Regression Analysis ◽  
Motivation To Learn ◽  
Simple Linear Regression ◽  
Level 1 ◽  
Relationship Of ◽  
The Relationship

ABSTRACTThis study is descriptive analitik, aims to describe the relationship of perceptions about the physiotherapy profession with the motivation to learn students of the Academy of Physiotherapy UKI. Data collection through questionnaires to students of Physiotherapy Academy UKI level 1, 2, and 3 with a sample of 53 students, then give a score of each statement of questionnaire.The result of correlation analysis shows that p = 0,584> α (0,05) ho is accepted, so there is no significant relationship between the two variables. To measure the closeness and intensity of the relationship between the two variables, test of correlation coefficient and simple linear regression. The result of correlation coefficient test (r) obtained by -0,077, lies below the value of -0.30 (very weak) thus can be said there is no relation between perception about physiotherapy profession with motivation learn student Akfis UKI. Result of linear regression analysis obtained equation: Y = 73,52 + (-0,088) X. This means that every 1 point decrease of perception value will influence motivation value equal to 0,088 times.Keywords: Perception, motivation, physiotherapy profession, and learning achievement. ABSTRAKPenelitian ini bersifat deskriptif analitik, bertujuan untuk mendeskripsikan hubungan persepsi tentang profesi fisioterapi dengan motivasi belajar siswa Akademi Fisioterapi UKI. Pengumpulan data melalui kuesioner kepada siswa Fisioterapi Academy UKI tingkat 1, 2, dan 3 dengan sampel sebanyak 53 siswa, kemudian memberikan skor masing-masing kuesioner pernyataan. Hasil analisis korelasi menunjukkan bahwa p = 0,584> α (0,05) ho diterima, sehingga tidak ada hubungan yang signifikan antara kedua variabel tersebut. Untuk mengukur kedekatan dan intensitas hubungan antara kedua variabel tersebut, uji koefisien korelasi dan regresi linier sederhana. Hasil uji koefisien korelasi (r) diperoleh sebesar -0,077, berada di bawah nilai -0,30 (sangat lemah) sehingga dapat dikatakan tidak ada hubungan antara persepsi tentang profesi fisioterapi dengan motivasi belajar siswa Akfis UKI. Hasil analisis regresi linier diperoleh persamaan: Y = 73,52 + (-0,088) X. Artinya setiap 1 titik penurunan nilai persepsi akan mempengaruhi nilai motivasi sebesar 0,088 kali.Kata kunci: Persepsi, motivasi, profesi fisioterapi, dan prestasi belajar.

scholarly journals CORRELATION OF KI67 LEVEL TO METASTATIC EVENTS IN NASOPHARYNGEAL CARCINOMA

2020 ◽  
Vol 2 (02) ◽  
pp. 31-34
Author(s):  
Eriza ◽  
Ermalinda Kurnia ◽  
Denny Satria Utama
Keyword(s):  
Cell Proliferation ◽  
Nasopharyngeal Carcinoma ◽  
Correlation Analysis ◽  
Correlation Coefficient ◽  
Distant Metastases ◽  
Abdominal Ultrasound ◽  
Neck Surgery ◽  
Cross Sectional ◽  
Ki67 Expression ◽  
Positive Correlation

Introduction Nasopharyngeal carcinoma (KNF) is a malignant squamous cell tumor occurring in the nasopharyngeal epithelial region where the cuboid epithelium is transformed into squamous cells. One of the typical signs of malignancy is uncontrolled cell proliferation. K67 is an immunohistochemical (IHC) test to assess cell proliferation activity. Increased Ki67 expression is associated with increased mitotic activity in cell proliferation. Objective To determine the correlation of ki67 expression to regional and distant metastases events of nasopharyngeal carcinoma at KNF in Dr. Mohammad Hoesin Palembang. Methods This cross-sectional study was conducted on 31 subjects of KNF patients who had been diagnosed in Oncology Division of Department of Ear Nose and Throat Head Neck Surgery, then performed immunohistochemistry inspection of KI67 in Department of Anatomical Pathology of Dr. Mohammad Hoesin Palembang. The subjects were collected consecutive sampling from October to December 2017 and performed other tests for staging such as computer tomography, chest x ray and abdominal ultrasound. Results In the Ki67 level correlation analysis of the incidence of metastasis in nasopharyngeal carcinoma, the correlation coefficient was 0.98 with very strong correlation strength and the positive correlation was not statistically significant (p=0.599). However, in Ki67 level correlation analysis of histopathology result of nasopharyngeal carcinoma was found correlation coefficient of 0.385 and positive correlation which was statistically significant (p=0.032). Conclusion Ki67 levels of metastatic occurrence in nasopharyngeal carcinoma have no statistically significant correlation. However, Ki67 level on histopathological results of nasopharyngeal carcinoma and Ki67 immunoreactivity with primary tumor has a statistically significant correlation.

The role of OH and H2O in oxide and oxysalt minerals

1992 ◽  
Vol 201 (3-4) ◽  
Author(s):  
Frank C. Hawthorne
Keyword(s):  
Crystal Structure ◽  
Structural Unit ◽  
Bond Valence ◽  
Valence Theory

AbstractHydrogen plays an extremely important role in the structure and chemistry of the oxide and oxysalt minerals. The characteristics of this role can be profitably analyzed in a simple and intuitive fashion using bond-valence theory. For any crystal structure, theAs components of the structural unit, (OH)

scholarly journals Crystal structure of (2-{3-[4-(4′-cyanobiphenyl-4-yloxy)butoxy]pyridin-2-yl-κN}-5-(dodecyloxy)phenyl-κC1)(9-oxotetracos-7-en-7-olato-κ2O,O′)platinum(II)

2014 ◽  
Vol 70 (12) ◽  
pp. m392-m393
Author(s):  
Kaijun Luo ◽  
Hanlin Liu ◽  
Qing Guo ◽  
Daibing Luo
Keyword(s):  
Crystal Structure ◽  
Dihedral Angle ◽  
Title Compound ◽  
Site Occupancy ◽  
Coordination Environment ◽  
Square Planar ◽  
C And N ◽  
Alkane Chain

The central PtIIatom in the title compound, [Pt(C40H47N2O3)(C24H45O2)], has a slightly distorted square-planar coordination environment. The dihedral angle between the plane formed by Pt and the chelating C and N atoms and that formed by Pt and the chelating O atoms is 2.1 (3)°. The angle between the planes of the two rings in the biphenyl-4-carbonitrile unit is 35.1 (5)°. One lateral alkane chain is disordered over two sets of sites with site occupancy factors in a 0.595 (7):0.405 (7) ratio.

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