Interaction entre les réactifs lanthanidiques et les bases de Lewis: Application à l'analyse conformationnelle d'alcools cyclohexaniques

1979 ◽  
Vol 57 (9) ◽  
pp. 1080-1088 ◽  
Author(s):  
James Bouquant ◽  
Alain Maujean ◽  
Josselin Chuche
Keyword(s):  
Conformational Equilibrium ◽  
Equilibrium Constants ◽  
Intrinsic Parameters ◽  
Tertiary Alcohols ◽  
Butyl Group ◽  
Tert Butyl Group ◽  
Physicochemical Methods ◽  
First Time ◽  
Good Agreement

A method for the determination of the intrinsic parameters K and Δ for lanthanide–substrate complexes has been extended to conformationally mobile molecules. These parameters, determined for a series of secondary cyclohexane alcohols (cyclohexanol and 2-methylcyclohexanol) and for tertiary alcohols (1-methylcyclohexanol and 1-ethylcyclohexanol) complexed with Eu(DPM)3 and Yb(DPM)3 lead to the determination of the conformational equilibrium constants between) the free species on one part and the complexed species on the other.The results obtained for the free species are in good agreement with those obtained by other physicochemical methods. For the complexed species an appreciable shift of conformational equilibrium is noted for low values of the association constants.For the first time, the tert-butyl group of Yb(DPM)3 has been used as a conformational probe. [Journal translation]

PRECISE DETERMINATION OF BACKBONE STRUCTURE AND CONDUCTIVITY OF 3D PERCOLATION NETWORKS BY THE DIRECT ELECTRIFYING ALGORITHM

2009 ◽  
Vol 20 (03) ◽  
pp. 423-433 ◽  
Author(s):  
CHUNYU LI ◽  
TSU-WEI CHOU
Keyword(s):  
Efficient Algorithm ◽  
Precise Determination ◽  
Scaling Exponents ◽  
Resistor Network ◽  
Backbone Structure ◽  
Definition Of ◽  
First Time ◽  
Good Agreement

This paper confirms the applicability of a newly developed efficient algorithm, the direct electrifying method, for identifying backbone for 3D site and bond percolating networks. This algorithm is based on the current-carrying definition of backbone and carried out on the predetermined spanning cluster, which is assumed to be a resistor network. The scaling exponents so obtained for backbone mass, red bonds, and conductivity are in very good agreement with some existing results. The perfectly balanced bonds in 3D backbone structures are predicted first time to be 0.00179 ± 0.00009 and 0.00604 ± 0.00008 of the backbone mass for bond and site percolations, respectively.

scholarly journals TO A QUESTION OF DETERMINATION OF HYDRAULIC RADIUS OF A BACKFILL FLOW FOR THE EXCENTRATIVE PLACEMENT OF PIPES IN DRILLING BORE

2018 ◽  
pp. 197-209
Author(s):  
V. M. Moishyshyn ◽  
Y. S. Biletskii ◽  
V. V. Vryukalo ◽  
M. V. Seniushkovych
Keyword(s):  
Cross Section ◽  
Dimensionless Parameter ◽  
Internal Surface ◽  
Outer Radius ◽  
Hydraulic Radius ◽  
Cross Sectional ◽  
Internal Radius ◽  
First Time ◽  
Good Agreement

The processes of displacement of drilling clay backfill flow from the intertubular space formed by internal surface of external and external surfaces of inner tubes are considered. In case of eccentric placement of pipes it is proposed in the form of a cross-section of the flow of a backfill to take the area limited from the outside by the Pascal's snail, and from the inside - the outer surface of the inner pipe at the first time. The formulas for determining areas of the cross section of the flow and the stagnant zone, the perimeter and the hydraulic radius of the section ofthe flow for the eccentric placement of the pipes in the bore are proposed. The dimensionless parameter α is introduced as the ratio of the centripetal distance to difference between internal radius of outer pipe and outer radius of inner tube. It was found that with increasing of α cross-sectional area and their hydraulic radii are increasing, and the area of stagnant zones decreases according to parabolic laws.It is established that with the growth of α velocity of the backfill flow decreases according to parabolic laws and their values are in good agreement with the experimental data.

scholarly journals Flexible, Fully Printable, and Inexpensive Paper-Based Chipless Arabic Alphabet-Based RFID Tags

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 564
Author(s):  
Jawad Yousaf ◽  
Eqab Almajali ◽  
Mahmoud El Najjar ◽  
Ahmed Amir ◽  
Amir Altaf ◽  
...  
Keyword(s):  
Radio Frequency Identification ◽  
Ground Plane ◽  
Metallic Copper ◽  
Rfid Tags ◽  
Robust Detection ◽  
Frequency Identification ◽  
Electromagnetic Signature ◽  
First Time ◽  
Good Agreement

This work presents the design and analysis of newly developed reconfigurable, flexible, inexpensive, optically-controlled, and fully printable chipless Arabic alphabet-based radio frequency identification (RFID) tags. The etching of the metallic copper tag strip is performed on a flexible simple thin paper substrate (ϵr = 2.31) backed by a metallic ground plane. The analysis of investigated tags is performed in CST MWS in the frequency range of 1–12 GHz for the determination of the unique signature resonance characteristics of each tag in terms of its back-scattered horizontal and vertical mono-static radar cross section (RCS). The analysis reflects that each tag has its own unique electromagnetic signature (EMS) due to the changing current distribution of metallic resonator. This EMS of each tag could be used for the robust detection and recognition of all realized 28 Arabic alphabet tags. The study also discusses, for the first time, the effect of the change in font type and size of realized tags on their EMS. The robustness and reliability of the obtained EMS of letter tags is confirmed by comparing the RCS results for selective letter tags using FDTD and MoM numerical methods, which shows very good agreement. The proposed tags could be used for smart internet of things (IoT) and product marketing applications.

Source identification of PCBs in sediments from the Milwaukee Harbor Estuary, USA

1998 ◽  
Vol 37 (6-7) ◽  
pp. 199-206 ◽  
Author(s):  
P. Rachdawong ◽  
E. R. Christensen ◽  
S. Chi
Keyword(s):  
Principal Component Analysis ◽  
Mass Balance ◽  
Source Identification ◽  
Principal Component ◽  
Chemical Mass Balance ◽  
Pollutant Sources ◽  
First Time ◽  
Nonnegative Constraints ◽  
Good Agreement

This work focuses on the determination of PCB source profiles and their contributions to sediments in the Milwaukee Harbor Estuary by a principal component analysis (PCA) model. The model was recently developed and, for the first time, applied to apportion pollutant sources in sediments. Factor loadings and scores were computed, rotated via nonnegative constraints, and matched with candidate Aroclor profiles. Contamination by Aroclors 1016, 1242, 1254, and 1260 were identified for cores VC 6, 9, and 12 based on a log Q2 criterion. The majority of PCB contribution was from a combination of Aroclors 1016 and 1242. Similarity between Aroclors 1016 and 1242 obscured resolution between the two profiles. Results from a chemical mass balance (CMB) model with known Aroclor profiles were in good agreement with the prediction from the PCA model.

Electrometric studies on molecular complexes. Part 1. Biamperometric study of some molecular complexes of iodine

1986 ◽  
Vol 64 (12) ◽  
pp. 2371-2375
Author(s):  
Ram Adhar Singh
Keyword(s):  
Recent Literature ◽  
Equilibrium Constants ◽  
Molecular Complexes ◽  
The Other ◽  
Separate Determination ◽  
Simple Method ◽  
Dissociation Equilibrium ◽  
Present Technique ◽  
Good Agreement

A simple method for separate determination of thermodynamic parameters of molecular complexes in solution is reported. It is based on a polyiodide dissociation equilibrium in conjunction with the biamperometry. The equilibrium constants and the enthalpies determined by this method are in good agreement with the recent literature data, lending support for the applicability of the method. The advantages of the present technique over the other have been outlined.

COMPARATIVE ACTION OF VARIOUS OESTROGENIC COMPOUNDS ON MOUSE VAGINAL SIALIC ACIDS (II)

1969 ◽  
Vol 62 (4) ◽  
pp. 663-670 ◽  
Author(s):  
Lars Carlborg
Keyword(s):  
Sialic Acid ◽  
Response Curve ◽  
Sialic Acids ◽  
Clear Cut ◽  
Suitable Parameter ◽  
Sufficient Degree ◽  
Comparative Action ◽  
Relative Potencies ◽  
Good Agreement

ABSTRACT Oestrogens administered in lower doses than necessary to induce full cornification of the mouse vagina induce mucification. It was shown previously that the degree of mucification could be estimated by quantitative determination of sialic acids. A suitable parameter for oestrogen assay was the measurement of vaginal sialic acid concentration which exhibited a clear cut dose response curve. Eleven assays of various oestrogens were performed with this method. Their estimated relative potencies were in good agreement with other routine oestrogen assays. A statistically sufficient degree of precision was found. The sensitivity was of the same order, or slightly higher, than the Allen-Doisy test.

Disability as a social phenomenon

2020 ◽  
pp. 22-38
Author(s):  
Natalia Guseva ◽  
Vitaliy Berdutin
Keyword(s):  
Social Protection ◽  
Russian Society ◽  
Stage Model ◽  
High Quality ◽  
Rehabilitation Programs ◽  
Current State ◽  
The Social ◽  
Consistent Solution ◽  
First Time

At present, the problem of establishing disability is a point at issue in Russia. Despite the fact that medical criteria for disability are being developed very actively, high-quality methods for assessing social hallmarks are still lacking. Since disability is a phenomenon inherent in any society, each state forms a social and economic policy for people with disabilities in accordance with its level of development, priorities and opportunities. We have proposed a three-stage model, which includes a system for the consistent solution of the main tasks aimed at studying the causes and consequences of the problems encountered today in the social protection of citizens with health problems. The article shows why the existing approaches to the determination of disability and rehabilitation programs do not correspond to the current state of Russian society and why a decrease in the rate of persons recognized as disabled for the first time does not indicate an improvement in the health of the population. The authors proposed a number of measures with a view to correcting the situation according to the results of the study.

Phytochemical Constituents of Annona reticulata and their Cytotoxic Activity

2020 ◽  
Vol 17 (3) ◽  
pp. 206-210
Author(s):  
Ty Viet Pham ◽  
Thang Quoc Le ◽  
Anh Tuan Le ◽  
Hung Quoc Vo ◽  
Duc Viet Ho
Keyword(s):  
Cytotoxic Activity ◽  
Cell Lines ◽  
Structural Determination ◽  
Phytochemical Investigation ◽  
Ic50 Values ◽  
Phytochemical Constituents ◽  
First Time ◽  
Annona Reticulata

A phytochemical investigation of the leaves of Annona reticulata led to the isolation and structural determination of β-sitosterol (1), ent-pimara-8(14),15-dien-19-oic acid (2), ent-pimara- 8(14),15-dien-19-ol (3), quercetin (4), quercetin 3-O-α-L-arabinopyranoside (5), and a mixture of quercetin 3-O-β-D-galactopyranoside (6a) and quercetin 3-O-β-D-glucopyranoside (6b). Of these, compounds 2 and 3 were isolated from the genus Annona for the first time. Compound 3 showed strong cytotoxicity against SK-LU-1 and SW626 cell lines with IC50 values of 17.64 ± 1.07 and 19.79 ± 1.41 μg mL-1, respectively.

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