Relevant bibliographies by topics / CPMD

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'CPMD'

Author: Grafiati
Published: 4 June 2021
Last updated: 6 September 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'CPMD.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "CPMD"

1

Putra, Achmad Noerkhaerin, Unah Indayah, Nokiyah Nokiyah, and Mas Bayu Syamsunarno. "Improving quality of cassava peel meal as raw material for tilapia feed." Depik 11, no. 3 (October 1, 2022): 319–26. http://dx.doi.org/10.13170/depik.11.3.24620.

Full text
Abstract:
Cassava peel meal (CPM) has potential as a raw material for fish feed due to its abundant availability and good nutritional content. The high crude fiber content inhibits the use of CPM as a raw material for fish feed. Therefore, this study aims to evaluate the effect of Aspergillus niger fermentation of CPM on dietary nutrient digestibility and growth performance of tilapia (Oreochromis niloticus). It was conducted in 2 stages. The first stage was a fermentation process of CPM, which used a factorial randomized design consisting of a dose difference of A. niger, namely 10, 15, 20, 30 g.kg-1 and a fermentation time of 0, 12, 24 hours with 3 replications each. At a dose of 1.5% of A. niger during 24 hours of fermentation, the crude fiber content of fermented CPM was reduced up to 7.19%. the second stage was a 45 days feeding trial on tilapia used a completely randomized design consisting of 3 different treatments with 3 replications, namely: reference feed, unfermented cassava peal meal based diet (CPMD), and A. niger fermented CPMD. A. niger fermented CPMD showed an increase in growth, dry matter, protein, energy, and raw material digestibility, as well as daily growth rate compared to unfermented CPMD. The daily growth rate of fermented CPMD of 1.32%/day was significantly higher with P0.05 than the unfermented CPMD of 0.72%/day. Furthermore, the digestibility value of material test in the fermented CPMD (48.73%) was significantly higher (P0.05) than unfermented CPMD (11.74%). These results indicate that A. niger fermented CPM has the potential to be used as raw material for tilapia fish feed. Keywords:Aspergillus nigerFermentationTilapiaCrude fiber
APA, Harvard, Vancouver, ISO, and other styles
2

Huang, Qingxiang, and Jian Cao. "Research on Coal Pillar Malposition Distance Based on Coupling Control of Three-Field in Shallow Buried Closely Spaced Multi-Seam Mining, China." Energies 12, no. 3 (January 31, 2019): 462. http://dx.doi.org/10.3390/en12030462.

Full text
Abstract:
In order to explore the rational coal pillar malposition distance (CPMD) based on coupling control of stress field, displacement field and fracture field (three-field) in shallow buried closely spaced multi-seam (SBCSM-S) mining, and realize coupling control of underground concentrated stress and ground surface fractures, taking the No. 1–2 and No. 2–2 coal seams mining in the northward east area of Ningtiaota coal mine as background, through physical simulation and theoretical analysis, the three-field evolution in SBCSM-S mining was analysed, the effect of different CPMD on coal pillar concentrated stress, ground surface subsidence and fractures development was revealed, and the rational CPMD based on coupling control of three-field was put forward. The results show that the concentrated fractures and concentrated stress are due to the strata’s uneven subsidence by coal pillars. Rational arrangement of CPMD can avoid the superposition of vertical stress caused by upper and lower coal pillars and reduce the development of ground fractures and uneven subsidence. Two theoretical models were established: one was based on the control of a concentrated stress field, the other on the control of the displacement and fracture fields. These results will be applied in a follow-up arrangement at the Ningtiaota coal mine, and can provide a new way for safe and green mining in SBCSM-S.
APA, Harvard, Vancouver, ISO, and other styles
3

Lemke, Kono H. "Structure and solvation dynamics of the hydroxide ion in ice-like water clusters: a CCSD(T) and car–parrinello molecular dynamics study." Physical Chemistry Chemical Physics 23, no. 34 (2021): 18990–98. http://dx.doi.org/10.1039/d1cp02524d.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Mosconi, Edoardo, Claudio Quarti, Tanja Ivanovska, Giampiero Ruani, and Filippo De Angelis. "Structural and electronic properties of organo-halide lead perovskites: a combined IR-spectroscopy and ab initio molecular dynamics investigation." Phys. Chem. Chem. Phys. 16, no. 30 (2014): 16137–44. http://dx.doi.org/10.1039/c4cp00569d.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Frank, Irmgard. "Some simple facts about water: CPMD simulation." Molecular Physics 118, no. 21-22 (August 6, 2020): e1802074. http://dx.doi.org/10.1080/00268976.2020.1802074.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Nelissen, Geoffrey, Konstantinos Bletsas, and Joël Goossens. "CPMD-mindful task assignment for NPS-F." Real-Time Systems 50, no. 5-6 (July 19, 2014): 585–91. http://dx.doi.org/10.1007/s11241-014-9206-8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Tilocca, Antonio, and Alastair N. Cormack. "The initial stages of bioglass dissolution: a Car–Parrinello molecular-dynamics study of the glass–water interface." Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 467, no. 2131 (February 9, 2011): 2102–11. http://dx.doi.org/10.1098/rspa.2010.0519.

Full text
Abstract:
The initial dissolution stages following implantation of a biomaterial in a physiological environment are critical for its bioactive properties. Car–Parrinello molecular-dynamics (CPMD) simulations of the interface between the 45S5 bioglass surface and liquid water have been carried out to investigate these processes. The analysis of a 40 ps CPMD trajectory has highlighted the potential mechanism of Na + /H + exchange, leading to formation of surface silanols through water dissociation. Moreover, by comparing the properties of water layers arranged at different distances from the glass surface, we discuss the way in which the particular structure and composition of the bioglass surface affects the hydrogen-bond network and orientation of water in its close proximity.
APA, Harvard, Vancouver, ISO, and other styles
8

Bühl, Michael. "Structure and stability of aquotetrafluorouranyl(VI) in the solid state — Density functional study of [UO2F4(H2O)][NMe4]2·2H2O,." Canadian Journal of Chemistry 87, no. 7 (July 2009): 818–23. http://dx.doi.org/10.1139/v08-182.

Full text
Abstract:
Periodic density functional computations have been performed for solid [UO2F4(H2O)][NMe4]2·2H2O at the BLYP level. A model with disordered fluoro and aquo ligands in the uranyl anion is significantly lower in energy than one with a symmetrical assignment of these sites, which was favored in the original X-ray crystallography study. According to optimized energies and Car–Parrinello molecular dynamics (CPMD) simulations, the [UO2F4(H2O)]2− ion in the solid is stable with respect to loss of the coordinated water molecule. In contrast, CPMD simulations had found this ligand to be unbound in aqueous solution. The role of the counterions in stabilizing the higher coordination number in the crystal is discussed.
APA, Harvard, Vancouver, ISO, and other styles
9

Yu, Shi, Ruizhi Chu, Xiao Li, Guoguang Wu, and Xianliang Meng. "Combined ReaxFF and Ab Initio MD Simulations of Brown Coal Oxidation and Coal–Water Interactions." Entropy 24, no. 1 (December 31, 2021): 71. http://dx.doi.org/10.3390/e24010071.

Full text
Abstract:
In this manuscript, we use a combination of Car–Parrinello molecular dynamics (CPMD) and ReaxFF reactive molecular dynamics (ReaxFF-MD) simulations to study the brown coal–water interactions and coal oxidation. Our Car–Parrinello molecular dynamics simulation results reveal that hydrogen bonds dominate the water adsorption process, and oxygen-containing functional groups such as carboxyl play an important role in the interaction between brown coal and water. The discrepancy in hydrogen bonds formation between our simulation results by ab initio molecular dynamics (CPMD) and that by ReaxFF-MD indicates that the ReaxFF force field is not capable of accurately describing the diffusive behaviors of water on lignite at low temperatures. The oxidations of brown coal for both fuel rich and fuel lean conditions at various temperatures were investigated using ReaxFF-MD simulations through which the generation rates of major products were obtained. In addition, it was observed that the density decrease significantly enhances the generation of gaseous products due to the entropy gain by reducing system density. Although the ReaxFF-MD simulation of complete coal combustion process is limited to high temperatures, the combined CPMD and ReaxFF-MD simulations allow us to examine the correlation between water adsorption on brown coal and the initial stage of coal oxidation.
APA, Harvard, Vancouver, ISO, and other styles
10

Jezierska, Aneta, Kacper Błaziak, Sebastian Klahm, Arne Lüchow, and Jarosław J. Panek. "Non-Covalent Forces in Naphthazarin—Cooperativity or Competition in the Light of Theoretical Approaches." International Journal of Molecular Sciences 22, no. 15 (July 27, 2021): 8033. http://dx.doi.org/10.3390/ijms22158033.

Full text
Abstract:
Non-covalent interactions responsible for molecular features and self-assembly in Naphthazarin C polymorph were investigated on the basis of diverse theoretical approaches: Density Functional Theory (DFT), Diffusion Quantum Monte Carlo (DQMC), Symmetry-Adapted Perturbation Theory (SAPT) and Car-Parrinello Molecular Dynamics (CPMD). The proton reaction paths in the intramolecular hydrogen bridges were studied. Two potential energy minima were found indicating that the proton transfer phenomena occur in the electronic ground state. Diffusion Quantum Monte Carlo (DQMC) and other levels of theory including Coupled Cluster (CC) employment enabled an accurate inspection of Potential Energy Surface (PES) and revealed the energy barrier for the proton transfer. The structure and reactivity evolution associated with the proton transfer were investigated using Harmonic Oscillator Model of Aromaticity - HOMA index, Fukui functions and Atoms In Molecules (AIM) theory. The energy partitioning in the studied dimers was carried out based on Symmetry-Adapted Perturbation Theory (SAPT) indicating that dispersive forces are dominant in the structure stabilization. The CPMD simulations were performed at 60 K and 300 K in vacuo and in the crystalline phase. The temperature influence on the bridged protons dynamics was studied and showed that the proton transfer phenomena were not observed at 60 K, but the frequent events were noticed at 300 K in both studied phases. The spectroscopic signatures derived from the CPMD were computed using Fourier transformation of autocorrelation function of atomic velocity for the whole molecule and bridged protons. The computed gas-phase IR spectra showed two regions with OH absorption that covers frequencies from 2500 cm−1 to 2800 cm−1 at 60 K and from 2350 cm−1 to 3250 cm−1 at 300 K for both bridged protons. In comparison, the solid state computed IR spectra revealed the environmental influence on the vibrational features. For each of them absorption regions were found between 2700–3100 cm−1 and 2400–2850 cm−1 at 60 K and 2300–3300 cm−1 and 2300–3200 cm−1 at 300 K respectively. Therefore, the CPMD study results indicated that there is a cooperation of intramolecular hydrogen bonds in Naphthazarin molecule.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "CPMD"

1

Heßke, Holger. "Car-Parrinello Moleküldynamik-Simulationen zur Hydratisierung und Protonierung von Aminen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1200758724333-78070.

Full text
Abstract:
Ziel dieser Arbeit war die Untersuchung des Hydratationsverhaltens von alkylsubstituierten Aminen und deren korrespondierenden Ammoniumionen mit Hilfe von Car-Parrinello-Moleküldynamik Simulationen (CPMD). Dabei konnten Fragestellungen hinsichtlich der Koordinationszahlen, des Lösungsmittelaustausches und der molekülspezifischen pKB-Werte beantwortet werden. Des Weiteren lässt die Arbeit Aussagen über einen Zusammenhang von Hydratation und anormaler Basiszitätsreihenfolge der Amine zu und ermöglicht zusätzlich die Beschreibung von Systemen mit mehreren Aminfunktionen durch die Anwendung der gewählten Bedingungen. Zur Simulation des Hydratationsverhaltens wurden Wasser enthaltende Lösungsmittelboxen erstellt, bei denen das zu untersuchende Molekül zentral angeordnet war. Nach dem Ausschluss dimensionsabhängiger Effekte durch die Equilibrierung auf Grundlage einer kraftfeldbasierten Moleküldynamik, konnte eine geeignete Boxgröße bestimmt werden, die neben der Berechnung der ersten Hydratationssphäre auch die Beschreibung einer möglichen zweiten Hydratationssphäre erlaubt. Anhand der erhaltenen CPMD-Trajektorien aus den erfolgreichen Simulation wurden Verteilungsfunktionen berechnet. Der Vergleich dieser Ergebnisse mit experimentell bekannten Werten und Berechnungen an reinem Wasser zeigte, dass das System real vorliegende Bedingungen wiedergibt. Die ermittelten gNO(r) -Verteilungsfunktionen der Amine bzw. deren korrespondierender Ammoniumionen weisen signifikante Unterschiede auf und spiegeln einen grundsätzlich verschiedenen Aufbau der Hydratationssphären wieder. Dabei besitzen alle freien Amine eine starke Wasserstoffbrückenbindung unter Einbeziehung des freien Elektronenpaares am Stickstoffatom, während sich an den Aminwasserstoffatomen nur sehr schwache Wechselwirkungen beobachten ließen. Abgesehen vom Trimethylamin sind die Hydratationssphären der Amine wenig strukturiert und der Wasseraustausch zwischen erster und zweiter Hydratationssphäre verläuft sehr schnell. Im Gegensatz dazu ist die Umgebung der Ammoniumionen stark strukturiert. Alle Ammoniumwasserstoffatome sind in Wasserstoffbrückenbindungen einbezogen und es existiert ein vergleichsweise langlebiger Käfig aus Wassermolekülen um das Ammoniumion. Zusätzlich befindet sich zeitweise ein weiteres, wesentlich mobileres Wassermolekül in der ersten Hydratationssphäre, das in der Lage ist einen Wasseraustausch einzuleiten. Dabei konnten für das Ammoniumion und das Methylammoniumion konkrete Mechanismen des Wasseraustausches bestimmt werden. Die Berechnung der pKB- bzw. pKA -Werte für die untersuchten Systeme war ein weiterer Bestandteil der Arbeit. Dazu wurde ein statistischer Ansatz zur Ermittlung der freien Energie herangezogen, bei dem die Mittelwerte der Verteilungsfunktionen verwendet werden, so dass die zu erwartende Genauigkeit eng mit der Simulationszeit verknüpft ist. Auf Grundlage von Strukturoptimierungen an Ammoniumionen, die mit wenigen Wassermolekülen umgeben waren, konnten unter Variation der NH-Bindungslängen Energiegradienten ermittelt werden, die eine Aussage über die möglichen Übergangszustände bei der Deprotonierung lieferten. Als gute Näherung des Übergangszustandes kann demnach für alle Methylammoniumionen eine NH-Bindungslänge von 1,22 Ǻ in Betracht gezogen werden. Mit Hilfe dieser Bindungslänge wurde die Wahrscheinlichkeit der Deprotonierung für alle Ammoniumionen berechnet, wobei Simulationen bei denen ein spontaner Protonenübergang auftrat keine Berücksichtigung fanden. Die Ergebnisse der methylsubstituierten Amine zeigen eine gute Übereinstimmung mit den experimentellen Werten mit einer Abweichung von maximal +0,3 pK-Einheiten. Diese Abweichung entspricht in etwa 1,5 kJ/mol, was für theoretische Arbeiten einen sehr kleinen Fehler darstellt. Auf Grund der gewählten Bedingungen ist beim Ammoniumion die Wahrscheinlichkeit für die Deprotonierung unterschätzt wurden. Dadurch ist der entsprechende pKB -Wert kleiner als der experimentell ermittelte Wert. Im Verlauf der Arbeit konnte weiterhin gezeigt werden, dass das Verfahren und die gewählten Bedingungen auch für ethylsubstituierte Alkylamine und deren korrespondierende Ammoniumionen angewendet werden können. Die Genauigkeit der Ergebnisse hängt dabei hauptsächlich von der Simulationszeit ab. Ein entscheidender Punkt der Arbeit ist der Nachweis, das mit Hilfe dieser Moleküldynamik-Simulationen auch Moleküle mit mehreren Aminfunktionen berechnet werden können. Es ist somit möglich Differenzierungen in der Protonierung und Hydratation der einzelnen Aminfunktionen vorherzusagen.
APA, Harvard, Vancouver, ISO, and other styles
2

Heßke, Holger. "Car-Parrinello Moleküldynamik-Simulationen zur Hydratisierung und Protonierung von Aminen." Doctoral thesis, Technische Universität Dresden, 2007. https://tud.qucosa.de/id/qucosa%3A24040.

Full text
Abstract:
Ziel dieser Arbeit war die Untersuchung des Hydratationsverhaltens von alkylsubstituierten Aminen und deren korrespondierenden Ammoniumionen mit Hilfe von Car-Parrinello-Moleküldynamik Simulationen (CPMD). Dabei konnten Fragestellungen hinsichtlich der Koordinationszahlen, des Lösungsmittelaustausches und der molekülspezifischen pKB-Werte beantwortet werden. Des Weiteren lässt die Arbeit Aussagen über einen Zusammenhang von Hydratation und anormaler Basiszitätsreihenfolge der Amine zu und ermöglicht zusätzlich die Beschreibung von Systemen mit mehreren Aminfunktionen durch die Anwendung der gewählten Bedingungen. Zur Simulation des Hydratationsverhaltens wurden Wasser enthaltende Lösungsmittelboxen erstellt, bei denen das zu untersuchende Molekül zentral angeordnet war. Nach dem Ausschluss dimensionsabhängiger Effekte durch die Equilibrierung auf Grundlage einer kraftfeldbasierten Moleküldynamik, konnte eine geeignete Boxgröße bestimmt werden, die neben der Berechnung der ersten Hydratationssphäre auch die Beschreibung einer möglichen zweiten Hydratationssphäre erlaubt. Anhand der erhaltenen CPMD-Trajektorien aus den erfolgreichen Simulation wurden Verteilungsfunktionen berechnet. Der Vergleich dieser Ergebnisse mit experimentell bekannten Werten und Berechnungen an reinem Wasser zeigte, dass das System real vorliegende Bedingungen wiedergibt. Die ermittelten gNO(r) -Verteilungsfunktionen der Amine bzw. deren korrespondierender Ammoniumionen weisen signifikante Unterschiede auf und spiegeln einen grundsätzlich verschiedenen Aufbau der Hydratationssphären wieder. Dabei besitzen alle freien Amine eine starke Wasserstoffbrückenbindung unter Einbeziehung des freien Elektronenpaares am Stickstoffatom, während sich an den Aminwasserstoffatomen nur sehr schwache Wechselwirkungen beobachten ließen. Abgesehen vom Trimethylamin sind die Hydratationssphären der Amine wenig strukturiert und der Wasseraustausch zwischen erster und zweiter Hydratationssphäre verläuft sehr schnell. Im Gegensatz dazu ist die Umgebung der Ammoniumionen stark strukturiert. Alle Ammoniumwasserstoffatome sind in Wasserstoffbrückenbindungen einbezogen und es existiert ein vergleichsweise langlebiger Käfig aus Wassermolekülen um das Ammoniumion. Zusätzlich befindet sich zeitweise ein weiteres, wesentlich mobileres Wassermolekül in der ersten Hydratationssphäre, das in der Lage ist einen Wasseraustausch einzuleiten. Dabei konnten für das Ammoniumion und das Methylammoniumion konkrete Mechanismen des Wasseraustausches bestimmt werden. Die Berechnung der pKB- bzw. pKA -Werte für die untersuchten Systeme war ein weiterer Bestandteil der Arbeit. Dazu wurde ein statistischer Ansatz zur Ermittlung der freien Energie herangezogen, bei dem die Mittelwerte der Verteilungsfunktionen verwendet werden, so dass die zu erwartende Genauigkeit eng mit der Simulationszeit verknüpft ist. Auf Grundlage von Strukturoptimierungen an Ammoniumionen, die mit wenigen Wassermolekülen umgeben waren, konnten unter Variation der NH-Bindungslängen Energiegradienten ermittelt werden, die eine Aussage über die möglichen Übergangszustände bei der Deprotonierung lieferten. Als gute Näherung des Übergangszustandes kann demnach für alle Methylammoniumionen eine NH-Bindungslänge von 1,22 Ǻ in Betracht gezogen werden. Mit Hilfe dieser Bindungslänge wurde die Wahrscheinlichkeit der Deprotonierung für alle Ammoniumionen berechnet, wobei Simulationen bei denen ein spontaner Protonenübergang auftrat keine Berücksichtigung fanden. Die Ergebnisse der methylsubstituierten Amine zeigen eine gute Übereinstimmung mit den experimentellen Werten mit einer Abweichung von maximal +0,3 pK-Einheiten. Diese Abweichung entspricht in etwa 1,5 kJ/mol, was für theoretische Arbeiten einen sehr kleinen Fehler darstellt. Auf Grund der gewählten Bedingungen ist beim Ammoniumion die Wahrscheinlichkeit für die Deprotonierung unterschätzt wurden. Dadurch ist der entsprechende pKB -Wert kleiner als der experimentell ermittelte Wert. Im Verlauf der Arbeit konnte weiterhin gezeigt werden, dass das Verfahren und die gewählten Bedingungen auch für ethylsubstituierte Alkylamine und deren korrespondierende Ammoniumionen angewendet werden können. Die Genauigkeit der Ergebnisse hängt dabei hauptsächlich von der Simulationszeit ab. Ein entscheidender Punkt der Arbeit ist der Nachweis, das mit Hilfe dieser Moleküldynamik-Simulationen auch Moleküle mit mehreren Aminfunktionen berechnet werden können. Es ist somit möglich Differenzierungen in der Protonierung und Hydratation der einzelnen Aminfunktionen vorherzusagen.
APA, Harvard, Vancouver, ISO, and other styles
3

Wang, S. Q. "Car-Parrinello Molecular Dynamics of Nanosized Graphene Sheets." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35242.

Full text
Abstract:
Car-Parronello molecular dynamics simulations of twelve nanosized graphene sheets with a dozen to a hundred carbon atoms are performed using a mixed Gaussian and planewave approach within the frame-work of the density-functional theory. Two different origins for the rippled structure of graphene are found: the thermodynamic vibration of atoms and the local lattice defect. We suggest that the lattice defect, which changes the local atomic bonding state, should be responsible for the intrinsic ripples in graphene sheet. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35242
APA, Harvard, Vancouver, ISO, and other styles
4

Patel, Chandan. "Hybrid molecular simulations of oxidative complex lesions." Thesis, Lyon, École normale supérieure, 2013. http://www.theses.fr/2013ENSL0835.

Full text
Abstract:
L'ADN est en permanence exposé à un grand nombre d'événements dommageables déclenchées par des agents endogènes et exogènes. De nombreux travaux expérimentaux ont fourni des informations cruciales sur les propriétés structurelles et la réparation de certains des lésions de l'ADN. Cependant, il manque une vision mécanistique ou énergétique sur leur formation. La biochimie computationnelle a émergé comme un outil puissant pour comprendre les réactions biochimiques et les propriétés électroniques de systèmes complexes.Dans cette thèse, nous étudions la formation de lésions complexes intra-brin et inter-brin. Ces lésions tandem constituent une puissant menace à l'intégrité du génome, en raison de leur haute fréquence mutagenique. Tout d'abord, nous discutons l'attaque d'une liaison covalente entre un radical pyrimidinique. En comparant avec les bases isolees, nos simulations hybrides Car-Parrinello demontrent que la reactivité de la thymine et de la cytosine radicalaires sont inversees dans l'environnement B-helical. De plus, nos resultats montrent egalement une deformation plus importante pour la lesion G[8-5]C.Nous rationalisons également la plus grande réactivité des cytosines par rapport aux purines vers la formation multi-etapes de lésions complexes inter-brins par condensation avec un site C4' abasique. Ces résultats bases sur des simulations avec solvatation explicite et combines a la théorie de la fonctionnelle de la densité sont en accord avec les données expérimentales
DNA is continuously exposed to a vast number of damaging events triggered by endogenous and exogenous agents. Numerous experimental studies have provided key information regarding structural properties of some of the DNA lesions and their repair. However, they lack in mechanistic or energetic information pertaining to their formation. Computational Biochemistry has emerged as a powerful tool to understand biochemical reactions and electronic properties of large systems.In this thesis we study the formation of inter- and intra-strand cross-links. These tandem lesions pose a potent threat to genome integrity, because of their high mutagenic frequency. First, we discuss the formation of complex defects which arise from the attack of a pyrimidine radical onto guanine. In comparison with the reactivity of isolated nucleobases, our hybrid Car-Parrinello Molecular Dynamics simulations reveal that the reactivity of hydrogen-abstracted thymine and cytosine is reversed within a B-helix environment. Further, our data also suggest a more severe distortion of the B-helix for G[8-5]C.Second, we rationalize the higher reactivity of cytosine vs. purines toward the multistep formation of inter-strand crosslinks with a C4' oxidized a basic site, which is in qualitative agreement with experiments on isolated nucleobases, using explicit solvent simulations combined to density functional theory
APA, Harvard, Vancouver, ISO, and other styles
5

Coiffier, Claire. "Approche Top-down pour la synthèse de substrats biologiquement actifs : analyse des conformations préférentielles de C-furanosides à l'aide de la chimie théorique." Thesis, Reims, 2011. http://www.theses.fr/2011REIMS021/document.

Full text
Abstract:
Dans notre laboratoire rémois, le travail sur les sucres est à la base de toutes les recherches, que ce soit pour la synthèse de molécules d'intérêt biologique telles que des analogues du KRN 7000 (un glycolipide présentant une activité antitumorale), ou encore la mise en place de stratégies de synthèse (avec par exemple la stratégie NOE : addition nucléophile stéréosélective suivie d'une ouverture intramoléculaire régiosélective d'un époxyde). Mon trravail a consisté à étudier la flexibilité, et donc les conformations stables ou moins stables, de petites molécules que sont les C-furanosides, le but étant d'établir un certain nombre de règles permettant d'anticiper les questions concernant à la fois l'entrée et la pose de la structure dans un site actif. J'ai donc débuté avec une étude théorique dans le vide, puis j'ai considéré le milieu solvaté, l'objectif à long terme étant la prise en compte d'un site actif. Durant ces études, jai aussi eu la possibilité de réaliser un certain nombre de travaux en synthèse organique, allant jusqu'à l'établissement d'une voie de synthèse vers différents C-furanosides possédant un bras alcyne pouvant être personnalisé par notre partenaire lyonnais via une réaction de chimie click, pour la synthèse de molécules actives contre le diabète
In our laboratory (in Reims), working on sugars is the base of all researches, whether for biologically interesting molecules synthesis as analogues of KRN 7000 (a glycolipid showing antitumor effects), or for the development of strategies for synthesis (for example the NEO stragegy : stereoselective nucleophilic addition followed by a regioselective intramolecular epoxide opening). My work was about studying the flexibility, and consequently stable and less stable conformations of small molecules : C-furanosides, the aim being the establishment of several rules anticipating the questions concerning the entry and the pose of the structure in an active site. So I have started with a theoretical study in vacuum, then I have considered solvation. The long term goal being the consideration of an active site. During these stdies, I have also realized several works in the field of organic chemistry, going to the establishment of a synthetic pathway to different C-furanosides with an alkyne arm, which could be functionalized by our partner (in Lyon) with a click reaction, for the synthesis of bioactive molecules against diabetes
APA, Harvard, Vancouver, ISO, and other styles
6

Dupuis, Romain. "Calculs réalistes du fractionnement isotopique du silicium et du lithium pour des équilibres impliquant des phases liquides." Toulouse 3, 2014. http://thesesups.ups-tlse.fr/2732/.

Full text
Abstract:
Le fractionnement des isotopes est utilisé comme marqueur d'évènements géochimiques pour de multiples applications. Les calculs permettent d'expliquer et de quantifier les mécanismes de fractionnement pour des conditions parfois difficiles à atteindre expérimentalement ; ils permettent de décomposer les mécanismes sous-jacents responsables du fractionnement mesuré. Au cours de cette étude, nous nous sommes intéressés aux isotopes du silicium - dans le quartz, la kaolinite, H4SiO4,aq et H3SiO4,aq - et du lithium - dans Li2O, la polylithionite et Li+ en solution. Nous avons mis en place des approches pour réaliser des calculs réalistes et, si possible, prédictifs afin de comprendre des fractionnements isotopique à l'équilibre impliquant au moins une phase liquide. D'une part, nous avons montré l'importance de la prise en compte du désordre configurationnel dans les liquides. D'autre part, nous avons montré qu'il est crucial de prendre en compte de l'anharmonicité, particulièrement pour l'étude d'un équilibre entre un minéral et une solution. Les résultats présentés dans ce manuscrit sont en bon accord avec les facteurs de fractionnement isotopique mesurés sur des échantillons naturels ou expérimentaux, ce qui met en avant l'intérêt d'utiliser ces nouvelles méthodes
Plentiful applications of isotopes recently emerged in geology since the isotopic fractionation properties are markers of geochemical events. With calculations, one can explain and quantify a fractionation mechanism in conditions that can be challenging to achieve experimentally. Therefore, it is possible to decompose underlying mechanisms that lead to a measured fractionation factor. In the course of this study, we were interested in isotopes of silicon - in quartz, kaolinite, H4SiO4,aq and H3SiO4,aq - and of lithium - in Li2O, polylithionite and Li+ in solution. We took up methods that are well suited to perform realists and, if possible, predictive calculations for equilibriums implying at least one liquid phase. This study highlights the importance of the configurational disorder in liquids. We pointed at the necessity to take into account the effects of anharmonicity, in particular for the study of equilibria between a mineral and a solution. Moreover, results showed in this manuscript are in good agreement with the experimental and natural data that have been measured, which features the interest of these new methods
APA, Harvard, Vancouver, ISO, and other styles
7

Merchant, Alexander Raymond. "An investigation of carbon nitride." Thesis, The University of Sydney, 2001. http://hdl.handle.net/2123/832.

Full text
Abstract:
This thesis employs experimental and theoretical methods to characterise carbon nitride solids and proposes a generalstructural model for amorphous carbon nitride (a-C:N). It finds that a-C:N deposited by several methods is essentially identical, with similar bonding environments for carbon and nitrogen atoms. Using evidence from several techniques, the saturation of nitrogen in an sp2 carbon matrix is discussed. The experimental studies on a range of carbon nitride solids show no evidence for a crystalline form of carbon nitride. In addition to the experimental characterisation of a-C:N, ab initio molecular dynamics were used to investigate bonding and structure in carbon nitride. These simulations show that the most common form of nitrogen bonding was three-fold sites with a lone pair of electrons. Two-fold nitrogen sites were also found in agreement with experimental findings. An increase of nitrogen in a-C:N decreases the sp3-carbon fraction, but this is not localised on the nitrogen and the effect is most severe at high densities. A simulation of a low density/high nitrogen content network shows that the nitrogen saturation seen experimentally may be due to the formation of N2 dimers and C-N molecules which are easily driven out of the structure. The ab initio simulations also explore the nature of charged nitrogen and carbon sites in a-C:N. An analysis based on Wannier Function centres provided further information about the bonding and allowed for a detailed classification of these sites. The removal of electrons from the networks caused structural changes that could explain the two-state conductivity in ta-C:N memory devices. Finally, a theoretical study of the electron energy-loss near-edge structure (ELNES) calculated using multiple scattering theory is presented. The calculated ELNES of diamond, graphite and boron, silicon and carbon nitride structures compare well to experiment and supports the experimental finding that no crystalline carbon nitride had (or has) been produced. These ELNES calculations will however, provide a means of identifying crystalline beta-C3N4 should it be synthesised.
APA, Harvard, Vancouver, ISO, and other styles
8

Merchant, Alexander Raymond. "An investigation of carbon nitride." University of Sydney. Physics, 2001. http://hdl.handle.net/2123/832.

Full text
Abstract:
This thesis employs experimental and theoretical methods to characterise carbon nitride solids and proposes a generalstructural model for amorphous carbon nitride (a-C:N). It finds that a-C:N deposited by several methods is essentially identical, with similar bonding environments for carbon and nitrogen atoms. Using evidence from several techniques, the saturation of nitrogen in an sp2 carbon matrix is discussed. The experimental studies on a range of carbon nitride solids show no evidence for a crystalline form of carbon nitride. In addition to the experimental characterisation of a-C:N, ab initio molecular dynamics were used to investigate bonding and structure in carbon nitride. These simulations show that the most common form of nitrogen bonding was three-fold sites with a lone pair of electrons. Two-fold nitrogen sites were also found in agreement with experimental findings. An increase of nitrogen in a-C:N decreases the sp3-carbon fraction, but this is not localised on the nitrogen and the effect is most severe at high densities. A simulation of a low density/high nitrogen content network shows that the nitrogen saturation seen experimentally may be due to the formation of N2 dimers and C-N molecules which are easily driven out of the structure. The ab initio simulations also explore the nature of charged nitrogen and carbon sites in a-C:N. An analysis based on Wannier Function centres provided further information about the bonding and allowed for a detailed classification of these sites. The removal of electrons from the networks caused structural changes that could explain the two-state conductivity in ta-C:N memory devices. Finally, a theoretical study of the electron energy-loss near-edge structure (ELNES) calculated using multiple scattering theory is presented. The calculated ELNES of diamond, graphite and boron, silicon and carbon nitride structures compare well to experiment and supports the experimental finding that no crystalline carbon nitride had (or has) been produced. These ELNES calculations will however, provide a means of identifying crystalline beta-C3N4 should it be synthesised.
APA, Harvard, Vancouver, ISO, and other styles
9

Bouzid, Assil. "First-principles investigation of binary and ternary amorphous chalcogenide systems." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAE029/document.

Full text
Abstract:
Ce travail de thèse s’inscrit dans le cadre d'études théoriques ayant pour but l’établissement de la structure des chalcogénures binaires et ternaires sous différentes conditions thermodynamiques. Des techniques de modélisation numérique ab-initio ont été employées. En particulier, nous avons utilisé la dynamique moléculaire par premiers principes selon l’approche de Car et Parrinello ainsi que sa version dite "deuxième génération". La première partie est consacrée à l’étude des chalcogénures binaires, notamment les verres GeSe2 et GeSe4 sous pression ainsi qu'à l’étude des effets des forces de van der Waals et des fonctionnelles d’échange et corrélation DFT sur la structure de l’amorphe GeTe4. Dans la deuxième partie, l’intérêt a été porté à l’étude d'un matériau à changement de phase récemment proposé par les expérimentateurs comme un bon candidat pour le stockage de données, le ternaire Ga4Sb6Te3
This thesis reflects efforts toward an accurate understanding of the atomic scale structure of chalcogenide glasses. These compounds have an impact on electronics, optoelectronics and memory devices. I resorted to the most advanced first-principles molecular dynamics simulations such as the standard Car-Parrinello method as well as its second generation version. In the first part of this thesis we provide a detailed study of the topological changes undergone under pressure by glassy GeSe2 and by glassy GeSe4. Structural transition and bonding features are described and compared to the results of neutron and X-ray diffraction experiments. Furthermore, in the case of glassy GeTe4 we demonstrated that the inclusion of van der Waals forces leads to substantial improvements in the description of the structure. In the second part of this thesis, we established the atomic-scale organization of a promising candidate for phase change memory applications, glassy Ge4Sb6Te3
APA, Harvard, Vancouver, ISO, and other styles
10

Holroyd, Leo. "Mutagenicity of 5-bromouracil : quantum chemical study." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7063.

Full text
Abstract:
This thesis describes a computational investigation of the mutagenicity of 5-bromouracil (BrU). In Chapter 1, three models of spontaneous and BrU-induced base mispairing (rare tautomer, wobble pair, and ion) are reviewed. Chapter 2 presents the computational techniques used: electronic structure methods (Hartree–Fock-based and density functional theory) and molecular dynamics. Chapter 3 presents optimisations of the keto and enol tautomers of BrU and uracil (U) in water clusters. The enol tautomer of BrU is found to be more stable than that of U. Chapter 4 is a molecular dynamics study of the keto-enol tautomerism of BrU and U in a periodic water box. The pKₐ of BrU at N3 is found to be lower than that of U. Chapter 5 is a study of stacked base dimers containing BrU, U, or thymine (T) stacking with natural bases. Some structures were taken from the Protein Data Bank, while others were generated using an in-house methodology. BrU is found to stack more strongly than T in vacuo, but solvation and thermal effects nullify this difference. Chapter 6 discusses the significance of the results in Chapters 3–5 in terms of BrU-induced mutagenesis. Appendices A and B–D provide supplementary material to Chapters 2 and 5, respectively. Appendix E is an investigation of the “base flipping” pathway of 2-aminopurine (2AP). Both 2AP/N and A/N dinucleosides (N = thymine or guanine) are found to adopt a wide range of energy-minimum conformations – not only stacked and “flipped”, but also intermediate – and the stacked are not the most favourable by free energy. Appendix F is a list of publications and papers in preparation. One publication concerns BrU stacking. The other is a conformational study of the dipeptide tyrosine-glycine: the theoretical results are shown to be consistent with experiment (R2PI spectra) if thermal effects are taken into account.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "CPMD"

1

Teracine, Edson Baptista, Renata Cristina Bigaram Della Volpe, and Fernando Luis de Castro Miquelino. CPqD 30 anos. Campinas, SP: CPqD, 2006.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

plc, Barbour Index, ed. CPD briefing. Windsor: Barbour Index plc, 1995.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

plc, Barbour Index, ed. CPD briefing. Windsor: Barbour Index plc, 1999.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

plc, Barbour Index, ed. CPD briefing. Windsor: Barbour Index plc, 1996.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

British Library. Dept. of Printed Books. CPM plus. [London]: Bowker-Saur, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

plc, Barbour Index, ed. CPD briefing. Windsor: Barbour Index plc, 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Azambuja, Jocelin. CPMs & APMs: Uma revolução comunitária. Porto Alegre: EdiPUCRS, 2008.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

United States. Administrative Office of the United States Courts. Human Resources Division., ed. Court personnel management systems: CPMS. Washington, DC: The Division, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

United States. Administrative Office of the United States Courts. Human Resources Division, ed. CPMS: Court Personnel Management System. Washington, DC (1 Columbus Circle, NE, Room 5-500B, Washington 20544): Administrative Office of the U.S. Courts, Human Resources Division, 1993.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Physiotherapy, Chartered Society of, ed. The CPD process. London: Chartered Society of Physiotherapy, 2000.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "CPMD"

1

Mohammad, Yasser, Yoshimasa Ohmoto, and Toyoaki Nishida. "CPMD: A Matlab Toolbox for Change Point and Constrained Motif Discovery." In Advanced Research in Applied Artificial Intelligence, 114–23. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31087-4_13.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Ma, Teng, Aurelien Bouteiller, George Bosilca, and Jack J. Dongarra. "Impact of Kernel-Assisted MPI Communication over Scientific Applications: CPMD and FFTW." In Recent Advances in the Message Passing Interface, 247–54. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-24449-0_28.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Weber, Valéry, A. Cristiano I. Malossi, Ivano Tavernelli, Teodoro Laino, Costas Bekas, Manish Modani, Nina Wilner, Tom Heller, and Alessandro Curioni. "First Experiences with ab initio Molecular Dynamics on OpenPOWER: The Case of CPMD." In Lecture Notes in Computer Science, 228–34. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-46079-6_16.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

McIntosh, Lawrence. "CPMG." In Encyclopedia of Biophysics, 386. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-16712-6_320.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Bass, R. "EEC/CPMP." In The Contribution of Acute Toxicity Testing to the Evaluation of Pharmaceuticals, 55–59. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-70390-4_8.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Hewett, Victoria. "CPD." In Making it as a Teacher, 182–90. Abingdon, Oxon ; New York, NY : Routledge, 2019.: Routledge, 2019. http://dx.doi.org/10.4324/9780429489341-16.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Peters, Nils, Martin Dichgans, Sankar Surendran, Josep M. Argilés, Francisco J. López-Soriano, Sílvia Busquets, Klaus Dittmann, et al. "CPM." In Encyclopedia of Molecular Mechanisms of Disease, 458. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-540-29676-8_8218.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Al-Tubaikh, Jarrah Ali. "CPPD and HADD." In Internal Medicine, 265–68. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-03709-2_47.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Ishima, Rieko. "CPMG Relaxation Dispersion." In Protein Dynamics, 29–49. Totowa, NJ: Humana Press, 2013. http://dx.doi.org/10.1007/978-1-62703-658-0_2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Höher, Peter Adam. "CPM-Modulationsverfahren." In Grundlagen der digitalen Informationsübertragung, 353–60. Wiesbaden: Vieweg+Teubner, 2011. http://dx.doi.org/10.1007/978-3-8348-9927-9_16.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "CPMD"

1

Rodrigues, Allane C. C., Priscila Gomes, Ademir João Camargo, and Heibbe C. B. Oliveira. "Estudo da Energia Livre de Formação das Ligações de Hidrogênio da Dopamina em Solução Aquosa Usando CPMD." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol2020105.

Full text
Abstract:
Dopamine is an important neurotransmitter belonging to the catecholamine family, which acts on the central nervous system. This catecholamine plays a key role in regulating a variety of functions, such as motor and cognitive functions. This class of neurotransmitters is important for normal neurophysiology and is also the target of a broad spectrum of therapeutic and illicit agents. Evaluating the interaction of these neurotransmitters, in particular, dopamine with water molecules, is crucial for a better understanding of the conformational preferences of dopamine in solution, which consequently assists in the design of new drugs for the treatment of diseases associated with a malfunction of the system, and direct measurement, which is particularly essential for early warning of certain diseases. In this sense, the objective of this work is to examine the effects of aqueous solvation on the geometric and electronic parameters of dopamine using Car-Parrinelo Molecular Dynamics. The Car-Parrinello Molecular Dynamics simulation was performed using the CPMD program package (Version 4.1). The results indicate that dopamine interact swith several water molecules, with the formation of hydrogen bonds. In particular, there are two hydrogen bonds (H5···Owf and N3···Hwd) with an infinite residence time that strongly suggests the protonation of these groups.
APA, Harvard, Vancouver, ISO, and other styles
2

Hao, Guangbo, and Xianwen Kong. "A 3-DOF Translational Compliant Parallel Manipulator Based on Flexure Motion." In ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/detc2009-86075.

Full text
Abstract:
This paper presents a novel class of 3-DOF translational compliant parallel manipulators (CPMs) based on flexure motion. The analytic mathematic modeling of CPMs is first developed. The analysis of CPMs is then implemented. It is shown that the proposed CPMs have many characteristics such as large range of motion, negligible cross-axis coupling, actuator complete isolation, and no loss motion and no rotational yaw. The inverse relationships of force-displacement of the 3-DOF CPM are further derived to calculate the input forces required for generating a specified path. In addition, the 3-DOF CPM can also be turned into a 2-DOF CPM. This work lays the foundation for the development of new spatial CPMs based on flexure motions for applications such as ultra precision manipulation.
APA, Harvard, Vancouver, ISO, and other styles
3

Martins, Bruna Nery, Allane C. C. Rodrigues, Arsênio P. V. Neto, Ademir J. Camargo, and Heibbe C. B. de Oliveira. "Estudo dos efeitos da solvatação aquosa na norepinefrina usando Dinâmica Molecular de Car-Parrinello." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol2020104.

Full text
Abstract:
Norepinephrine, synthesized from tyrosine, is a neurotransmitter of sympathetic post-ganglion neurons. Norepinephrine regulates many critical functions which include attention, memory, learning and cardiovascular functions. This neurotransmitter has several pharmacological uses, such as adrenergic stimulants, widely used in the treatment of hypertension, cardiac surgery and in myocardial infarction. It is extremely important to study the interaction between drugs and water molecules, for a better understanding of absorption, transport and biological action. Within this context, the Car-Parrinello Molecular Dynamics, by treating the solvent explicitly, becomes ideal for the study of solvated media. In this sense, the objective of this work is to analyze the effects of aqueous solvation on the geometric and electronic parameters of norepinephrine using the Molecular Dynamics of Car-Parrinelo. The solvation dynamics was performed using the CPMD program package (version 4.1). The Radial Distribution Function of the hydrogen and oxygen atoms of the water molecules in the first solvation shell were performed for the O1, O2, O3, N7, H4, H5, H6, H8 and H9 atoms of the norepinephrine. The Radial Distribution Function analyzes indicate that most sites have a well-defined peak (N7, O1, O3, H4, H5 and H6). For the O2, H8 e H9 atoms, there are no well-defined peaks, suggesting that these sites do not interact with the atoms of the water molecules, or even the possibility of intra-molecular interactions. These criteria were considered for the next stages of this work, which are already being carried out, and they are analyzes of possible interactions of hydrogen with these sites.
APA, Harvard, Vancouver, ISO, and other styles
4

Hao, Guangbo, and Xianwen Kong. "Novel XY Compliant Parallel Manipulators for Large Displacement Translation With Enhanced Stiffness." In ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-28141.

Full text
Abstract:
A novel XY compliant parallel manipulator (CPM) and a spatial double three-beam module both with distributed compliance are first proposed for large range of translation. Then, an improved XY CPM is proposed by combining the above XY CPM and a spatial double three-beam module in parallel. The normalized analytical models are further presented for the novel XY CPM, double three-beam module and improved XY CPM. It is shown that the improved XY CPM has the following merits: (1) large range of motion, constrained parasitic error motion, output-decoupling, maximal actuation isolation and minimal lost motion; and (2) large out-of-plane stiffness and no friction with base. The improved XY CPM may also be used as a building block to construct new spatial CPMs.
APA, Harvard, Vancouver, ISO, and other styles
5

Yu, Jingjun, Zhenguo Li, Dengfeng Lu, Guanghua Zong, and Guangbo Hao. "Design and Analysis of New Large-Range XY Compliant Parallel Micromanipulators." In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-34982.

Full text
Abstract:
The need for a compliant parallel micromanipulator (CPM) providing large motion range and high precision is increasing. Existing CPMs vary in constraint configurations and therefore it is necessary to verify/compare their characteristics. This paper compares three kinds of typical over-constrained CPMs, and derives their theoretical compliance matrix models pointing out constraint characteristics of the three kinematic configurations. Then the three CPMs are analyzed with FEA (finite element analysis), and results illustrate that the theoretical compliance matrix models are close to their FEA models. Moreover, cross-axis coupling along two motion axes (X&Y), parasitic motion and compliance fluctuation of motion stages are described in details. Through analyzing the FEA results, we present an improved CPM with a mirror-symmetry structure and redundant-constraint characteristic which can effectively constrain in-plane yaw and cross-axis coupling. It is shown that the improved CPM presented in this paper has a series of merits: large motion range up to 10mm×10mm in the dimension of 311mm×311mm×24mm, small compliance fluctuation (only 37.32% of that of the initial model), a smaller cross-axis coupling (only 24.39% of that of the initial model generated by a single-axis 5mm driving), a smaller in-plane parasitic yaw (only 53.57% of that of the initial model generated by double-axis 5mm driving).
APA, Harvard, Vancouver, ISO, and other styles
6

Zhu, Jiaxiang, Guangbo Hao, Shiyao Li, Shuwen Yu, and Xianwen Kong. "A Mirror-Symmetrical XY Compliant Parallel Manipulator With Improved Performances Without Increasing the Footprint." In ASME 2021 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/detc2021-69032.

Full text
Abstract:
Abstract The design of XY compliant parallel manipulators (CPMs) remains challenging considering the tradeoff between the mirror-symmetry for better constrained undesired rotations and the small footprint, although a significant number of XY CPMs have been reported in extensive applications. This paper presents a new XY CPM using mirror-symmetry without increasing its footprint, mainly aiming to reduce the undesired parasitic rotations of input and output motion stages. The concept of higher degree of stiffness centre symmetry is deployed to tackle the parasitic rotations, leading to a multi-layer compact XY CPM design with each layer being a rotation-symmetrical design. A nonlinear and analytical model of the proposed XY CPM is derived using free body diagrams and the Beam Constrained Model (BCM) to accurately analyse its performance characteristics over a large range of motion. The designed XY CPM is then verified by the nonlinear finite element analysis (FEA) method. Finally, the proposed multi-layer design is comprehensively compared with the well-received single-layer rotation-symmetrical design. It is shown in the new design that the parasitic rotations of input and output stages along with the actuator isolation are significantly reduced and that the out-of-plane-stiffness is also significantly increased.
APA, Harvard, Vancouver, ISO, and other styles
7

Li, Haiyang, Guangbo Hao, and Richard Kavanagh. "Synthesis of Decoupled Spatial Translational Compliant Parallel Mechanisms via Freedom and Actuation Method (FAM)." In ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/esda2014-20196.

Full text
Abstract:
This paper introduces a screw theory based approach termed the freedom and actuation method (FAM) to the synthesis of decoupled spatial translational compliant parallel mechanisms (XYZ CPMs) with consideration of actuator isolation (input decoupling). This approach is unique in that (a) actuator arrangement is taken into account; and (b) it is based on a set of rules and mathematical expressions, rather than rigid-body mechanism design experience mainly used at present. According to the rules, XYZ CPMs are firstly decomposed into simple function modules, and the degrees of freedom (DOF) of each function module are identified based on the mathematical expressions. Each function module is then synthesized based only on the DOF without consideration of the actuator arrangement, so existing flexure mechanism design approaches such as the constraint-based design, the screw-theory-based method, and the freedom and constraint topology can be employed for the synthesis of the function module. The synthesis process is finally summarized and demonstrated step by step via a monolithic XYZ CPM design example. It can be envisaged that a variety of configurations of each function module can be derived under a specific DOF. Therefore, one can obtain a great number of XYZ CPM designs with consideration of actuator isolation through changing the structure of each function module, even though there is no any rigid-body mechanism design experience. The proposed FAM will enable designers to (a) decompose XYZ CPMs into the function modules; (b) yield multiple solutions to meet the DOF requirement of each compliant function module; and (c) obtain a variety of XYZ CPMs with consideration of actuator isolation.
APA, Harvard, Vancouver, ISO, and other styles
8

Hao, Guangbo, Xianwen Kong, and Qiaoling Meng. "Design and Modelling of Spatial Compliant Parallel Mechanisms for Large Range of Translation." In ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/detc2010-28046.

Full text
Abstract:
A new distributed-compliance module, which can be used as a building block, is proposed at first. A novel 3-DOF compliant parallel mechanism (CPM) and its improved configuration for large range of translation are then proposed using the new building blocks. The analytical models of the spatial modules and 3-DOF translational CPMs are then presented and analyzed. The proposed improved 3-DOF translational CPM has the following merits: (1) It is approximately decoupled and has a workspace of 0.1Lmm×0.1Lmm×0.1Lmm (L: the beam length in the module) with constrained parasitic error, maximal actuation isolation and minimal lost motion. (2) Its configuration is simple and compact, and it is actuated by three linear actuators directly. (3) The normalization strategy not only simplifies the representation and derivation of the equations, but also makes the compliance matrix reflect the displacement associated with each degree of freedom in a straightforward manner. The proposed analytical model for the improved 3-DOF CPM has been verified using FEA.
APA, Harvard, Vancouver, ISO, and other styles
9

Xia, Jun, Yanqiao Zhu, Yuanqi Du, and Stan Z. Li. "A Systematic Survey of Chemical Pre-trained Models." In Thirty-Second International Joint Conference on Artificial Intelligence {IJCAI-23}. California: International Joint Conferences on Artificial Intelligence Organization, 2023. http://dx.doi.org/10.24963/ijcai.2023/760.

Full text
Abstract:
Deep learning has achieved remarkable success in learning representations for molecules, which is crucial for various biochemical applications, ranging from property prediction to drug design. However, training Deep Neural Networks (DNNs) from scratch often requires abundant labeled molecules, which are expensive to acquire in the real world. To alleviate this issue, tremendous efforts have been devoted to Chemical Pre-trained Models (CPMs), where DNNs are pre-trained using large-scale unlabeled molecular databases and then fine-tuned over specific downstream tasks. Despite the prosperity, there lacks a systematic review of this fast-growing field. In this paper, we present the first survey that summarizes the current progress of CPMs. We first highlight the limitations of training molecular representation models from scratch to motivate CPM studies. Next, we systematically review recent advances on this topic from several key perspectives, including molecular descriptors, encoder architectures, pre-training strategies, and applications. We also highlight the challenges and promising avenues for future research, providing a useful resource for both machine learning and scientific communities.
APA, Harvard, Vancouver, ISO, and other styles
10

Yalcin, Selin, and Ihsan Kaya. "Design and Analysis of Cpm and Cpmk Indices for Uncertainty Environment by Using Pythagorean Fuzzy Sets." In 2022 International Conference on Innovation and Intelligence for Informatics, Computing, and Technologies (3ICT). IEEE, 2022. http://dx.doi.org/10.1109/3ict56508.2022.9990663.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "CPMD"

1

Fenves, Steven J., Sebti Foufou, Conrad Bock, Rachuri Sudarsan, Nicolas Bouillon, and Ram D. Sriram. CPM 2:. Gaithersburg, MD: National Institute of Standards and Technology, 2004. http://dx.doi.org/10.6028/nist.ir.7185.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Maugham, Charlotte. Land governance and transparency livelihoods. CPD event: overview. Evidence on Demand, January 2013. http://dx.doi.org/10.12774/eod_cr.nov2013b.maugham.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Berges, B. P. J., S. C. V. Geelhoed, M. Scheidat, and J. Tougaard. Quantifying harbour porpoise foraging behaviour in CPOD data: identification, automatic detection and potential application. IJmuiden: Wageningen Marine Research, 2019. http://dx.doi.org/10.18174/475270.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Greer, T. Richard. Final Report Roberts Wesleyan College Geothermal Energy Project CPD No. 84.09. Office of Scientific and Technical Information (OSTI), March 2016. http://dx.doi.org/10.2172/1240147.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Elmaghraby, Salah E., and David J. Michael. Documentation of BIDNET: Project Bidding for CPM and PERT Activity Networks. Fort Belvoir, VA: Defense Technical Information Center, June 1988. http://dx.doi.org/10.21236/ada198761.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Wylie, Marilynn, and Glenn Green. On the Performance of Serially Concatenated CPM-OFDMA Schemes for Aeronautical Telemetry. Fort Belvoir, VA: Defense Technical Information Center, April 2011. http://dx.doi.org/10.21236/ada543383.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Allen, J. C., and B. E. Wahlen. Multi-h CPM Synchronization in Military Channels Phase 2: A Simulation Framework. Fort Belvoir, VA: Defense Technical Information Center, September 2003. http://dx.doi.org/10.21236/ada419930.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Prather, Craig S. CPM Scheduling: The Contracting Officers' Guide for Risk Minimization and Claims Analysis. Fort Belvoir, VA: Defense Technical Information Center, January 1998. http://dx.doi.org/10.21236/ada350969.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Chelluri, Bhanumathi, and Edward Knoth. High Performance PrFeB Permanent Magnets through Novel Pulse Alignment and Compaction Method for Cryogenic Permanent Magnet Undulators (CPMU). Office of Scientific and Technical Information (OSTI), December 2012. http://dx.doi.org/10.2172/1428153.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Dutta-Roy, Kunal, Vernon Mallu, and David Shaw. PR-426-123723-R01 Pipeline Variable Uncertainties and Their Effects on Leak Detection Sensitivity. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), July 2018. http://dx.doi.org/10.55274/r0011502.

Full text
Abstract:
This document is a revision of industry standard procedures for the assessment of uncertainties in software-based leak detection systems. This document describes procedures for predicting uncertainties in the detection of leaks in pipelines using computational methods based upon physical hydraulic state measurements. This class of pipeline leak detection methods is commonly called Computational Pipeline Monitoring (CPM). The API1149 process and software-based leak detection systems (LDS), often loosely referred to as Computational Pipeline Monitoring (CPM) rely upon field measurement and instrumentation and simulation of operation. This creates a need for systematic procedures to allow rational design of CPM systems by providing an estimate of the sensitivity that can be expected given a CPM type and instrumentation, and given the engineering factors and operational environment of the pipeline. This document has a Click here to view related webinar. (member login required)
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'CPMD' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography