Two Faces of Hydrogen in Yttrium Hydroxyhydride: Y2H3O(OH) – a New Inorganic Chiral System with Hydridic and Protonic Hydrogens

2018 ◽  
Author(s):  
Aleksandr Pishtshev ◽  
Evgenii Strugovshchikov ◽  
Smagul Karazhanov
Keyword(s):  
Material Properties ◽  
Inorganic Compounds ◽  
Charge Ordering ◽  
Structure Modeling ◽  
Specific Charge ◽  
Great Opportunity ◽  
Anionic Species ◽  
Derivatives Of ◽  
Chiral System

Design of inorganic compounds containing different anions attracts a lot of attention because it affords a great opportunity to develop new functionality across the whole range of material properties. Based on the results of structure-modeling studies of a mixed-anion system, we predicted novel derivatives of oxyhydrides – chiral hydroxyhydrides M<sub>2</sub>H<sub>3</sub>O(OH) (M = Y, Sc, La, and Gd) that are characterized by the coexistence of three anionic species, H<sup>–</sup>, O2<sup> –</sup>, and OH<sup>–</sup> inside the crystal lattice. The materials demonstrate a specific charge ordering, which is connected with the chiral organization of atoms where both the metal cations and the anions are standing in positions that form helical curves spreading along the tetragonal axis. Moreover, the twisting of the H<sup>–</sup> and H<sup>+</sup> sites gives rise to their linking via strong dihydrogen bonds. Unusual structural, electron and optical features caused by the P4<sub>1</sub> crystal structure have been investigated in the Y<sub>2</sub>H<sub>3</sub>O(OH) comprehensive case study.

Two Faces of Hydrogen in Yttrium Hydroxyhydride: Y2H3O(OH) – a New Inorganic Chiral System with Hydridic and Protonic Hydrogens

2018 ◽  
Author(s):  
Aleksandr Pishtshev ◽  
Evgenii Strugovshchikov ◽  
Smagul Karazhanov
Keyword(s):  
Material Properties ◽  
Inorganic Compounds ◽  
Charge Ordering ◽  
Structure Modeling ◽  
Specific Charge ◽  
Great Opportunity ◽  
Anionic Species ◽  
Derivatives Of ◽  
Chiral System

Design of inorganic compounds containing different anions attracts a lot of attention because it affords a great opportunity to develop new functionality across the whole range of material properties. Based on the results of structure-modeling studies of a mixed-anion system, we predicted novel derivatives of oxyhydrides – chiral hydroxyhydrides M<sub>2</sub>H<sub>3</sub>O(OH) (M = Y, Sc, La, and Gd) that are characterized by the coexistence of three anionic species, H<sup>–</sup>, O2<sup> –</sup>, and OH<sup>–</sup> inside the crystal lattice. The materials demonstrate a specific charge ordering, which is connected with the chiral organization of atoms where both the metal cations and the anions are standing in positions that form helical curves spreading along the tetragonal axis. Moreover, the twisting of the H<sup>–</sup> and H<sup>+</sup> sites gives rise to their linking via strong dihydrogen bonds. Unusual structural, electron and optical features caused by the P4<sub>1</sub> crystal structure have been investigated in the Y<sub>2</sub>H<sub>3</sub>O(OH) comprehensive case study.

scholarly journals Application of the direct peptide reactivity assay (DPRA) to inorganic compounds: a case study of platinum species

2019 ◽  
Vol 8 (6) ◽  
pp. 802-814
Author(s):  
Jocelyn D. C. Hemming ◽  
Mark Hosford ◽  
Martin M. Shafer
Keyword(s):  
High Throughput Screening ◽  
Inorganic Compounds ◽  
High Reactivity ◽  
Limited Attention ◽  
Adverse Outcome Pathway ◽  
Platinum Compounds ◽  
Metal Compounds ◽  
Work Supports ◽  
Platinum Species

Abstract The in chemico Direct Peptide Reactivity Assay (DPRA) was developed as a non-animal, relatively high throughput, screening tool for skin sensitization potential. Although the Adverse Outcome Pathway (AOP) for respiratory sensitization remains to be fully elucidated, it is recognized that the molecular initiation event for both skin and respiratory sensitization to low molecular weight chemicals involves haptenation with proteins. The DPRA examines the reactivity of a test compound to two model peptides (containing either cysteine or lysine) and consequently is able to screen for both skin and respiratory sensitization potential. The DPRA was primarily developed for and validated with organic compounds and assessment of the applicability of the assay to metal compounds has received only limited attention. This paper reports the successful application of the DPRA to a series of platinum compounds, including hexachloroplatinate and tetrachloroplatinate salts, which are some of the most potent chemical respiratory sensitizers known. Eleven platinum compounds were evaluated using the DPRA protocol as detailed by Lalko et al., with only minor modification. Two palladium compounds with structures similar to that of the platinum species studied and cobalt chloride were additionally tested for comparison. The hexachloroplatinate and tetrachloroplatinate salts showed exceptionally high reactivity with the cysteine peptide (EC15 values of 1.4 and 14 μM, respectively). However, for platinum compounds (e.g. hydrogen hexahydroxyplatinate and tetraammineplatinum) where clinical and epidemiological evidence indicates limited sensitization potential, the cysteine DPRA showed only minor or no reactivity (EC15 values of 24 600 and &gt;30 000 μM, respectively). The outcomes of the lysine peptide assays were less robust and where EC15 was measurable, values were substantially higher than the corresponding results from the cysteine assay. This work supports the value of in chemico peptide reactivity as a metric for assessment of platinum sensitization potential and therefore in screening of new platinum compounds for low or absent sensitization potential. Additional studies are required to determine whether the DPRA may be successfully applied to other metals. We provide details on method modifications and precautions important to the success of the DPRA in the assessment of metal reactivity.

Parking at Sporting Event Stadiums in Denver, Colorado

2013 ◽  
Vol 2359 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Alejandro Henao ◽  
Wesley E. Marshall
Keyword(s):  
Travel Behavior ◽  
Professional Sports ◽  
The United States ◽  
Opportunity Costs ◽  
Sporting Events ◽  
Great Opportunity ◽  
Sporting Event ◽  
Sports Venues ◽  
Parking Demand

Millions of people in the United States travel by personal automobile to attend professional sports matches played at various stadiums. Engineering and planning publications lack information on parking provisions for major sporting events. The results from this paper on parking outcomes suggest that the current parking provisions are not efficient. This case study examines parking supply, parking utilization, event auto occupancy, and event auto modal share at four major professional sports venues in the Denver, Colorado, region. The percentage of parking supply per parking demand was calculated for several surveyed games in terms of the average attendance, and parking utilization was evaluated during nonevent periods. In general, the surveys of the games indicated that more parking was provided than was necessary, even when attendance was higher than typical. For an event with average attendance, parking utilization was as low as 65%, with 2.2 persons per vehicle. In contrast, when parking occupancy was high, auto occupancy increased to 3.0 persons per vehicle. With such different carpool rates, as well as evidence suggesting that spectators who travel to some facilities are willing to park and walk farther than a half-mile, the results suggest that parking supply and travel behavior are endogenous and should not be treated independently. This study also considered parking occupancy at nonevent times and found whole-scale underutilization, even in downtown locations with great opportunity costs.

Iterative Reverse Monte Carlo and Molecular Statics for Improved Atomic Structure Modeling: A Case Study of Zinc Oxide Grown by Atomic Layer Deposition

2021 ◽  
Author(s):  
Ryan C Gettler ◽  
Henry D Koenig ◽  
Matthias J Young
Keyword(s):  
Monte Carlo ◽  
Zinc Oxide ◽  
Diffraction Data ◽  
Atomic Structure ◽  
Atomic Layer ◽  
Structure Modeling ◽  
Reverse Monte Carlo ◽  
Layer Deposition ◽  
Energetic Constraints

Reverse Monte Carlo (RMC) modeling is a common method to derive atomic structure models of materials from experimental diffraction data. However, RMC modeling does not impose energetic constraints and can...

scholarly journals Anatomical, morphological and phytochemical properties of Aegopodium alpestre Ledeb.: a case study of Kazakhstan

2020 ◽  
Vol 48 (3) ◽  
pp. 1473-1482
Author(s):  
Elzira A. KYRBASSOVA ◽  
Akmaral A. SARTAYEVA ◽  
Elmira M. IMANOVA ◽  
Nurdana N. SALYBEKOVA ◽  
Gulraikhan E. ZHANTEYEVA ◽  
...  
Keyword(s):  
Large Scale ◽  
Inorganic Compounds ◽  
Biologically Active Substances ◽  
Biologically Active ◽  
High Concentration ◽  
Vegetative Organs ◽  
Study Results ◽  
Cultivation Practice ◽  
Active Substances

This article deals with the phytochemical, morphological and anatomical investigation of ethanol-based extracts derived from the leaves and stems of the Aegopodium alpestre. The vegetative organs of A. alpestre were conserved according to Strasburger-Fleµming method using a 1:1:1 mixture of alcohol-glycerin-water. A total of 1200 ethanol-based extracts (2 from leaves and 2 from stem tissues per plant) were prepared using the Soxhlet extractor. All extracts were used to identify organic and inorganic compounds in the leaves and stems of the studied plant. Contents of biologically active substances, microelements, vitamins and amino acids were determined. This article is the first paper to display very high concentration and diversity of vitamins (6 types), micronutrients (5 types), and aminoacids (13 types) in the leaves and steams of A. alpestre. Findings conclude that identification of biologically active substances in the above the ground vegetative organs of A. alpestre may be a common practice in the future. Considering the study results, A. alpestre may be used as a medicinal plant on a large scale. For this, the cultivation practice needs to be scaled up.

Some Issues in Relations between Microstructure and Indentation Measurements

2016 ◽  
Vol 258 ◽  
pp. 131-136 ◽  
Author(s):  
Petr Haušild ◽  
Aleš Materna ◽  
Lenka Kocmanová ◽  
Jiří Matějíček
Keyword(s):  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Material Properties ◽  
Metal Matrix ◽  
Depth Of Penetration ◽  
Progressive Change ◽  
Tungsten Metal ◽  
Materials Behavior ◽  
Measured Hardness

Case study on copper-tungsten metal-matrix composite was performed. The influence of presence of an interface on the distribution of measured hardness and/or modulus was incorporated by a statistical distribution taking into account a progressive change of materials behavior as a function of depth of penetration. Unbiased (intrinsic) material properties (hardness and Young’s modulus) were then successfully extracted from the experimental grid indentation data.

Probabilistic Fatigue Reliability of Large Diameter Steel Catenary Risers (SCR) for Ultra-Deepwater Operations

2007 ◽  
Author(s):  
U. O. Akpan ◽  
T. S. Koko ◽  
P. A. Rushton ◽  
A. Tavassoli ◽  
M. Else
Keyword(s):  
Fatigue Strength ◽  
Case Studies ◽  
Material Properties ◽  
Large Diameter ◽  
Random Variables ◽  
Fatigue Reliability ◽  
Strength Parameters ◽  
Stress Levels ◽  
Steel Catenary Risers

For deepwater development in the Gulf of Mexico, steel catenary risers (SCRs) supported from both SPAR and semi-submersible platforms have proven to be successful solutions for in-field flowlines, tie-backs, and export systems. It is envisaged that this will continue to be a promising solution in ultra deep-water applications, up to and beyond 10,000 ft. The study, commissioned by the Mineral Management Service (MMS), investigated the reliability of large-diameter SCRs in ultra-deepwater operations. The primary damage mode considered is fatigue failure. A probabilistic methodology for fatigue reliability is developed, which utilizes deterministic cumulative fatigue damage indicators, namely the stress levels and cycles associated with the various sea states and the fatigue strength of the members. Uncertainties in structural load and material properties are accounted for by assigning probability distributions and standard deviations to the deterministic stress levels. Furthermore, fatigue strength parameters, Miner’s indices, and capacities are modeled as random variables. First order reliability method (FORM) is employed for estimating fatigue reliability. The methodology is applied to three deterministic case studies presented by Intec Engineering (2006a, 2006b). The case studies involved either a SPAR or a semi-submersible platform. For the sake of brevity, a case study involving only a SPAR platform is presented in this paper. The effect of uncertainties in parameters on fatigue reliabilities is investigated. It is observed that the fatigue reliability estimates followed similar trends as the deterministic cumulative damage results, and hence can be used to complement deterministic estimates. Additional benefit and insight gained from the probabilistic study, which can be used for design decisions, include information regarding probabilistic importance and probabilistic sensitivity analysis. For case study presented here, it is seen that in general, uncertainty in the fatigue strength exponent (m) has the highest impact on fatigue reliability of SCRs. The second most important random variable is the stress range (S), which captures uncertainties in parameters such as loads and material properties. Parametric sensitivity studies on the fatigue strength parameters indicate that SCR reliability is sensitive to both the standard deviation and probability distribution of the parameters, thus highlighting the need for accurate probabilistic calibration of the random variables.

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