scholarly journals Size consistency in smoothed dissipative particle dynamics

2016 ◽  
Vol 94 (4) ◽  
Author(s):  
Gérôme Faure ◽  
Jean-Bernard Maillet ◽  
Julien Roussel ◽  
Gabriel Stoltz
Keyword(s):  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
Size Consistency

Dispersion Size-Consistency

2022 ◽  
Author(s):  
Brian Nguyen ◽  
Devin J. Hernandez ◽  
Emmanuel Victor V. Flores ◽  
Filipp Furche
Keyword(s):  
Random Phase ◽  
System Size ◽  
State Density ◽  
Structure Theory ◽  
Dispersion Interactions ◽  
Dispersion Energy ◽  
Supramolecular Materials ◽  
Size Consistency ◽  
Additive Separability ◽  
Screening Factor

Abstract A multivariate adiabatic connection (MAC) framework for describing dispersion interactions in a system consisting of non-overlapping monomers is presented. By constraining the density to the physical ground-state density of the supersystem, the MAC enables a rigorous separation of induction and dispersion effects. The exact dispersion energy is obtained from the zero-temperature fluctuation-dissipation theorem and partitioned into increments corresponding to the interaction energy gained when an additional monomer is added to a -monomer system. The total dispersion energy of an -monomer system is independent of any partitioning into subsystems. This statement of dispersion size consistency is shown to be an exact constraint. The resulting additive separability of the dispersion energy results from multiplicative separability of the generalized screening factor defined as the inverse generalized dielectric function. Many-body perturbation theory (MBPT) is found to violate dispersion size-consistency because perturbative approximations to the generalized screening factor are nonseparable; on the other hand, random phase approximation-type methods produce separable generalized screening factors and therefore preserve dispersion size-consistency. This result further explains the previously observed increase in relative errors of MBPT for dispersion interactions as the system size increases. Implications for electronic structure theory and applications to supramolecular materials and condensed matter are discussed.

Neck lumps

2018 ◽  
Author(s):  
Max Robinson ◽  
Keith Hunter ◽  
Michael Pemberton ◽  
Philip Sloan
Keyword(s):  
Lymph Nodes ◽  
Clinical Examination ◽  
Immune Surveillance ◽  
Systemic Infection ◽  
Neck Region ◽  
Anatomical Location ◽  
Regional Lymph Nodes ◽  
Size Consistency ◽  
Routine Clinical Examination ◽  
Anatomy Of The Neck

Whilst dental healthcare professionals naturally focus on assessment of the teeth and the supporting tissues, they also have an important role in assessing the whole oro-facial complex and the neck. Assessment of the neck is particularly important, not least, because it contains the regional lymph nodes that are involved in immune surveillance of the head and neck region. The neck also contains the major salivary glands: the sub­mandibular gland and the tail of the parotid gland. Mid-line structures include the hyoid bone, larynx, and trachea, along with the thyroid gland and parathyroid glands. The assessment of these anatomical structures should form part of the routine clinical examination. The dis­covery of an abnormality in the neck, which may not have been noticed by the patient, may expedite the diagnosis of significant disease and facilitate a timely intervention. A through understanding of the anatomy of the neck is essential and informs the clinical examination. It is also important to understand the concept of the anatomical levels that map out the lymph node groups of the neck (Chapter 1; Fig. 1.2). Accurate assessment of the neck is usually best achieved by a combination of visual inspection and palpation, with the patient in a slightly reclined position, the clinician standing behind the patient. Any lumps, e.g. enlarged lymph nodes, are described by anatomical site, size, consistency (cystic, soft, rubbery, hard), whether the lump is mobile or fixed to the underlying tissue, and if palpation elic­its pain or discomfort. The combination of these parameters will help to formulate the differential diagnosis; for example, an isolated hard lump that is fixed to underlying structures is likely to represent meta­static cancer, whereas, bilateral soft lumps that are mobile and painful to palpation are likely to represent lymphadenitis as a consequence of systemic infection. Ultrasound examination can be used to ascertain important informa­tion about a neck lump such as the site (precise anatomical location, superficial or deep), size, consistency (solid or cystic), and multi-focality. Doppler settings can help to establish the vascularity of a lesion and its proximity to major vessels.

scholarly journals Boosting the accuracy and speed of quantum Monte Carlo: Size consistency and time step

2016 ◽  
Vol 93 (24) ◽  
Author(s):  
Andrea Zen ◽  
Sandro Sorella ◽  
Michael J. Gillan ◽  
Angelos Michaelides ◽  
Dario Alfè
Keyword(s):  
Monte Carlo ◽  
Quantum Monte Carlo ◽  
Time Step ◽  
Size Consistency
Sign in / Sign up

Export Citation Format

Share Document