The Physical World

January 2009
Essential Science Glossary II;2009, p29
Reference Entry
Definitions of several terms including "density," "element," and "gravity," are presented. Density depicts how heavy something is compared to how much space it occupies. Element refers to the simplest things that all other things are created from. Gravity is the force that pulls two things toward each other.


Related Articles

  • Piezoresistance Effect of n-type Silicon; Temperature and Concentration Dependencies, Stress Dependent Effective Masses. Kanda, Yozo; Matsuda, Kazunori // AIP Conference Proceedings;2007, Vol. 893 Issue 1, p173 

    N-type piezoresistance (PR) tensor component π44 is essentially independent of temperature and carrier concentration, but depends on them in higher impurity concentration (> 1020) since the Fermi level lowers due to the tail of the density-of-state (DOS). Although conduction effective masses...

  • density.  // Taber's Cyclopedic Medical Dictionary (2009);2009, Issue 21, p602 

    A definition of the term "density," which refers to the relative weight of a substance compared with a reference standard, is presented.

  • Density and microhardness of glasses in the SrO-B2O3-SiO2 system. N. Tyurnina; Z. Tyurnina; S. Sviridov // Glass Physics & Chemistry;Apr2009, Vol. 35 Issue 2, p153 

    Abstract  The density d at a temperature of 25°C is measured by the hydrostatic weighing method, the Vickers microhardness H V is determined, and the fluctuation free volume fraction f g is calculated for glasses in the SrO-B2O3-SiO2 system with a constant strontium...

  • RESEARCH OF PILES DRIVING PROCESS IN VARIOUS TYPES OF SOILS BY IMPACT METHOD. Polukoshko, Svetlana; Kononova, Olga; Sokolova, Svetlana // Transport & Engineering;2008, Vol. 28, p151 

    he process of pile driving into the different types of soils by means of impact hammer is considered in this work. Three types of soils are examined -- coarse sand of middle density, fine sand of middle density and clayey soils with the index of liquidity IL=0.5. Resistance of soils to...

  • DENSITY.  // Encyclopedia of Operations Research & Management Science;2001, p209 

    A definition of the term "density" is presented. It refers to the proportion of the coefficients of a constraint matrix that are nonzero. Some large-scale linear-programming problems have a low density of the order of 0.01. A mathematical problem on density is provided.

  • soft.  // Taber's Cyclopedic Medical Dictionary;2005, p2022 

    A definition of the term "soft" is presented, which means not hard, firm,or solid.

  • A simplified relativistic time-dependent density-functional theory formalism for the calculations of excitation energies including spin-orbit coupling effect. Fan Wang; Ziegler, Tom // Journal of Chemical Physics;10/15/2005, Vol. 123 Issue 15, p154102 

    In the present work we have proposed an approximate time-dependent density-functional theory (TDDFT) formalism to deal with the influence of spin-orbit coupling effect on the excitation energies for closed-shell systems. In this formalism scalar relativistic TDDFT calculations are first...

  • Systematic Methodology for Velocity-dependent Gravity Modelling of Density Crustal Cross-Sections, using an Optimization Procedure. KRYSIŃSKI, LECH // Pure & Applied Geophysics;Mar2009, Vol. 166 Issue 3, p375 

    The paper describes a new method of gravity modelling of the density cross section along a DSS profile. We propose a systematic procedure of gravity interpretation using structural information contained both in the velocity distribution of the seismic model and the geometry of its layers. The...

  • Influence of Density on the Hydraulic and Mechanical Properties of Sands. de Freitas Neto, Osvaldo; Santos, Olavo; Severo, Ricardo // Applied Mechanics & Materials;2014, Issue 580-583, p659 

    This article aims at assessing the influence of relative density on the hydraulic conductivity and shear strength of two sands, denominated SOI and S02, derived from different regions and formation processes. SOI is wind-blown and S2 alluvial. The results of characterization and hydraulic...


Read the Article

Other Topics