Defects in Self Assembled Colloidal Crystals
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2 a Primer on Polymer Colloids: Structure, Synthesis and Colloidal Stability
A. Al Shboul, F. Pierre, and J. P. Claverie 2 A primer on polymer colloids: structure, synthesis and colloidal stability 2.1 Introduction A colloid is a dispersion of very fine objects in a fluid [1]. These objects can be solids, liquids or gas, and the corresponding colloidal dispersion is then referred to as sus- pension, emulsion or foam. Colloids possess unique characteristics. For example, as their size is smaller than the wavelength of light, they scatter light. They also offer a large interfacial surface area, meaning that interfacial phenomena are of paramount importance in these dispersions. The weight of each dispersed particle being small, gravity and buoyancy forces are not sufficient to counteract the thermal random mo- tion of the particle, named Brownian motion (in tribute to the 19th century botanist Robert Brown who first characterized it). The particles do not remain in a dispersed state indefinitely: they will sooner or later aggregate (phase separation). Thus, thecol- loidal state is in general metastable and colloidal stability is one of the key features to take into account when working with colloids. Among all colloids, the polymer colloid family is one of the most widely inves- tigated [2]. Polymer colloids are used for a large number of applications, ranging from coatings, adhesives, inks, impact modifiers, drug-delivery vehicles, etc. The particles range in size from about 10 nm to 1 000 nm (1 μm) in diameter. They are usually spherical, but numerous other shapes have been observed. Polymer colloids are not uncommon in nature. For example, natural rubber latex, the secretion of the Hevea brasiliensis tree, is in fact a dispersion of polyisoprene nanoparticles in wa- ter. -
4. Fabrication of Polymer-Immobilized Colloidal Crystal Films (851Kb)
R&D Review of Toyota CRDL, Vol.45 No.1 (2014) 17- 22 17 Special Feature: Applied Nanoscale Morphology Research Report Fabrication of Polymer-immobilized Colloidal Crystal Films Masahiko Ishii Report received on Feb. 28, 2014 A fabrication method for polymer-immobilized colloidal crystal fi lms using conventional spray coating has been developed for application of the fi lms as practical colored materials. By controlling both the viscosity of the silica sphere-acrylic monomer dispersions and the wettability of the substrates, colloidal crystalline fi lms with brilliant iridescent colors were successfully obtained by spray coating and UV curing. The color could be controlled by adjusting both the sphere concentration and diameter. Scanning electron microscopy was applied to study the crystal structure of the coated fi lms, and revealed that the fi lms are composed of highly oriented face-centered-cubic grains with (111) planes parallel to the substrate surface. A method for utilizing the colloidal crystal fi lms as pigments was also proposed. Flakes obtained by crushing the colloidal crystal coated fi lms were added to a commercial clear paint and coated on a substrate. The coated fi lms exhibited iridescent colors that varies with viewing angle. Colloidal Crystal, Self-assembly, Silica, Polymeric Material, Spray Coating 1. Introduction arrays of monodispersed sub-micrometer sized spheres. They exhibit iridescent colors due to Bragg diffraction Jewels such as diamonds and rubies are beautiful, of visible light when they have a periodicity on the attracting the attention of people worldwide. Most of scale of the wavelength of the light. The most common these are natural minerals with crystalline structures. -
State-Of-The-Art Report on Structural Materials Modelling
Nuclear Science NEA/NSC/R(2016)5 May 2017 www.oecd-nea.org State-of-the-art Report on Structural Materials Modelling State-of-the-art Report on Structural Materials Modelling ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT The OECD is a unique forum where the governments of 35 democracies work together to address the economic, social and environmental challenges of globalisation. The OECD is also at the forefront of efforts to understand and to help governments respond to new developments and concerns, such as corporate governance, the information economy and the challenges of an ageing population. The Organisation provides a setting where governments can compare policy experiences, seek answers to common problems, identify good practice and work to co-ordinate domestic and international policies. The OECD member countries are: Australia, Austria, Belgium, Canada, Chile, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Israel, Italy, Japan, Korea, Latvia, Luxembourg, Mexico, the Netherlands, New Zealand, Norway, Poland, Portugal, the Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Turkey, the United Kingdom and the United States. The European Commission takes part in the work of the OECD. OECD Publishing disseminates widely the results of the Organisation’s statistics gathering and research on economic, social and environmental issues, as well as the conventions, guidelines and standards agreed by its members. NUCLEAR ENERGY AGENCY The OECD Nuclear Energy Agency (NEA) was established on 1 February 1958. Current NEA membership consists of 31 countries: Australia, Austria, Belgium, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Korea, Luxembourg, Mexico, the Netherlands, Norway, Poland, Portugal, Russia, the Slovak Republic, Slovenia, Spain, Sweden, Switzerland, Turkey, the United Kingdom and the United States. -
On the NP-Completeness of the Minimum Circuit Size Problem
On the NP-Completeness of the Minimum Circuit Size Problem John M. Hitchcock∗ A. Pavany Department of Computer Science Department of Computer Science University of Wyoming Iowa State University Abstract We study the Minimum Circuit Size Problem (MCSP): given the truth-table of a Boolean function f and a number k, does there exist a Boolean circuit of size at most k computing f? This is a fundamental NP problem that is not known to be NP-complete. Previous work has studied consequences of the NP-completeness of MCSP. We extend this work and consider whether MCSP may be complete for NP under more powerful reductions. We also show that NP-completeness of MCSP allows for amplification of circuit complexity. We show the following results. • If MCSP is NP-complete via many-one reductions, the following circuit complexity amplifi- Ω(1) cation result holds: If NP\co-NP requires 2n -size circuits, then ENP requires 2Ω(n)-size circuits. • If MCSP is NP-complete under truth-table reductions, then EXP 6= NP \ SIZE(2n ) for some > 0 and EXP 6= ZPP. This result extends to polylog Turing reductions. 1 Introduction Many natural NP problems are known to be NP-complete. Ladner's theorem [14] tells us that if P is different from NP, then there are NP-intermediate problems: problems that are in NP, not in P, but also not NP-complete. The examples arising out of Ladner's theorem come from diagonalization and are not natural. A canonical candidate example of a natural NP-intermediate problem is the Graph Isomorphism (GI) problem. -
The Complexity Zoo
The Complexity Zoo Scott Aaronson www.ScottAaronson.com LATEX Translation by Chris Bourke [email protected] 417 classes and counting 1 Contents 1 About This Document 3 2 Introductory Essay 4 2.1 Recommended Further Reading ......................... 4 2.2 Other Theory Compendia ............................ 5 2.3 Errors? ....................................... 5 3 Pronunciation Guide 6 4 Complexity Classes 10 5 Special Zoo Exhibit: Classes of Quantum States and Probability Distribu- tions 110 6 Acknowledgements 116 7 Bibliography 117 2 1 About This Document What is this? Well its a PDF version of the website www.ComplexityZoo.com typeset in LATEX using the complexity package. Well, what’s that? The original Complexity Zoo is a website created by Scott Aaronson which contains a (more or less) comprehensive list of Complexity Classes studied in the area of theoretical computer science known as Computa- tional Complexity. I took on the (mostly painless, thank god for regular expressions) task of translating the Zoo’s HTML code to LATEX for two reasons. First, as a regular Zoo patron, I thought, “what better way to honor such an endeavor than to spruce up the cages a bit and typeset them all in beautiful LATEX.” Second, I thought it would be a perfect project to develop complexity, a LATEX pack- age I’ve created that defines commands to typeset (almost) all of the complexity classes you’ll find here (along with some handy options that allow you to conveniently change the fonts with a single option parameters). To get the package, visit my own home page at http://www.cse.unl.edu/~cbourke/. -
Colloidal Crystals with a 3D Photonic Bandgap
Part I General Introduction I.1 Photonic Crystals A photonic crystal (PC) is a regularly structured material, with feature sizes on the order of a wavelength (or smaller), that exhibits strong interaction with light.1-3 The main concept behind photonic crystals is the formation of a 'photonic band gap'. For a certain range of frequencies, electromagnetic waves are diffracted by the periodic modulations in the dielectric constant of the PC forming (directional) stop bands. If the stop bands are wide enough to overlap for both polarization states along all crystal directions, the material is said to possess a complete photonic band gap (CPBG). In such a crystal, propagation of electromagnetic waves with frequencies lying within the gap is forbidden irrespective of their direction of propagation and polarization.1,2 This leads to the possibility to control the spontaneous emission of light. For example, an excited atom embedded in a PC will not be able to make a transition to a lower energy state as readily if the frequency of the emitted photon lies within the band gap, hence increasing the lifetime of the excited state.1,2 Photonic crystals with a (directional) stop gap can also have a significant effect on the spontaneous-emission rate.4 If a defect or mistake in the periodicity is introduced in the otherwise perfect crystal, localized photonic states in the gap will be created. A point defect could act like a microcavity, a line defect like a wave-guide, and a planar defect like a planar wave-guide. By introducing defects, light can be localized or guided along the defects modes.1,2 1 2 a b Figure I.1–1 Scanning electron micrograph (SEM) of a face-centered-cubic (fcc) colloidal crystal of closed-packed silica spheres (R = 110 nm). -
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INFORMATION TO USERS This material was produced from a microfilm copy of the original document. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependant upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns which may appear on this reproduction. 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting thru an image and duplicating adjacent pages to insure you complete continuity. 2. When an image on the film is obliterated with a large round black mark, it is an indication that the photographer suspected that the copy may have moved during exposure and thus cause a blurred image. You w ill find a good image of the page in the adjacent frame. 3. When a map, drawing or chart, etc., was part of the material being photographed the photographer followed a definite method in "sectioning" the material. It is customary to begin photoing at the upper left hand corner of a large sheet and to continue photoing from left to right in equal sections with a small overlap. If necessary, sectioning is continued again — beginning below the first row and continuing on until complete. 4. The majority of users indicate that the textual content is of greatest value, however, a somewhat higher quality reproduction could be made from "photographs" if essential to the understanding of the dissertation. -
The Correlation Among Software Complexity Metrics with Case Study
International Journal of Advanced Computer Research (ISSN (print): 2249-7277 ISSN (online): 2277-7970) Volume-4 Number-2 Issue-15 June-2014 The Correlation among Software Complexity Metrics with Case Study Yahya Tashtoush1, Mohammed Al-Maolegi2, Bassam Arkok3 Abstract software product attributes such as functionality, quality, complexity, efficiency, reliability or People demand for software quality is growing maintainability. For example, a higher number of increasingly, thus different scales for the software code lines will lead to greater software complexity are growing fast to handle the quality of software. and so on. The software complexity metric is one of the measurements that use some of the internal The complexity of software effects on maintenance attributes or characteristics of software to know how activities like software testability, reusability, they effect on the software quality. In this paper, we understandability and modifiability. Software cover some of more efficient software complexity complexity is defined as ―the degree to which a metrics such as Cyclomatic complexity, line of code system or component has a design or implementation and Hallstead complexity metric. This paper that is difficult to understand and verify‖ [1]. All the presents their impacts on the software quality. It factors that make program difficult to understand are also discusses and analyzes the correlation between responsible for complexity. So it is necessary to find them. It finally reveals their relation with the measurements for software to reduce the impacts of number of errors using a real dataset as a case the complexity and guarantee the quality at the same study. time as much as possible. -
On the Computational Complexity of Maintaining GPS Clock in Packet Scheduling
On the Computational Complexity of Maintaining GPS Clock in Packet Scheduling Qi (George) Zhao Jun (Jim) Xu College of Computing Georgia Institute of Technology qzhao, jx ¡ @cc.gatech.edu Abstract— Packet scheduling is an important mechanism to selects the one with the lowest GPS virtual finish time provide QoS guarantees in data networks. A scheduling algorithm among the packets currently in queue to serve next. generally consists of two functions: one estimates how the GPS We study an open problem concerning the complexity lower (General Processor Sharing) clock progresses with respect to the real time; the other decides the order of serving packets based bound for computing the GPS virtual finish times of the ' on an estimation of their GPS start/finish times. In this work, we packets. This complexity has long been believed to be 01%2 answer important open questions concerning the computational per packe [11], [12], [3], [9], where 2 is the number of complexity of performing the first function. We systematically sessions. For this reason, many scheduling algorithms such study the complexity of computing the GPS virtual start/finish 89,/. ,4,/. 8!:1,/. as +-,435.76 [2], [7], [11], and [6] times of the packets, which has long been believed to be ¢¤£¦¥¨§ per packet but has never been either proved or refuted. We only approximate the GPS clock (with certain error), trading also answer several other related questions such as “whether accuracy for lower complexity. However, it has never been the complexity can be lower if the only thing that needs to be carefully studied whether the complexity lower bound of computed is the relative order of the GPS finish times of the ' tracking GPS clock perfectly is indeed 01;2 per packet. -
Glossary of Complexity Classes
App endix A Glossary of Complexity Classes Summary This glossary includes selfcontained denitions of most complexity classes mentioned in the b o ok Needless to say the glossary oers a very minimal discussion of these classes and the reader is re ferred to the main text for further discussion The items are organized by topics rather than by alphab etic order Sp ecically the glossary is partitioned into two parts dealing separately with complexity classes that are dened in terms of algorithms and their resources ie time and space complexity of Turing machines and complexity classes de ned in terms of nonuniform circuits and referring to their size and depth The algorithmic classes include timecomplexity based classes such as P NP coNP BPP RP coRP PH E EXP and NEXP and the space complexity classes L NL RL and P S P AC E The non k uniform classes include the circuit classes P p oly as well as NC and k AC Denitions and basic results regarding many other complexity classes are available at the constantly evolving Complexity Zoo A Preliminaries Complexity classes are sets of computational problems where each class contains problems that can b e solved with sp ecic computational resources To dene a complexity class one sp ecies a mo del of computation a complexity measure like time or space which is always measured as a function of the input length and a b ound on the complexity of problems in the class We follow the tradition of fo cusing on decision problems but refer to these problems using the terminology of promise problems -
CS 6505: Computability & Algorithms Lecture Notes for Week 5, Feb 8-12 P, NP, PSPACE, and PH a Deterministic TM Is Said to B
CS 6505: Computability & Algorithms Lecture Notes for Week 5, Feb 8-12 P, NP, PSPACE, and PH A deterministic TM is said to be in SP ACE (s (n)) if it uses space O (s (n)) on inputs of length n. Additionally, the TM is in TIME(t (n)) if it uses time O(t (n)) on such inputs. A language L is polynomial-time decidable if ∃k and a TM M to decide L such that M ∈ TIME(nk). (Note that k is independent of n.) For example, consider the langage P AT H, which consists of all graphsdoes there exist a path between A and B in a given graph G. The language P AT H has a polynomial-time decider. We can think of other problems with polynomial-time decider: finding a median, calculating a min/max weight spanning tree, etc. P is the class of languages with polynomial time TMs. In other words, k P = ∪kTIME(n ) Now, do all decidable languages belong to P? Let’s consider a couple of lan- guages: HAM PATH: Does there exist a path from s to t that visits every vertex in G exactly once? SAT: Given a Boolean formula, does there exist a setting of its variables that makes the formula true? For example, we could have the following formula F : F = (x1 ∨ x2 ∨ x3) ∧ (x1 ∨ x2 ∨ x3) ∧ (x1 ∨ x2 ∨ x3) The assignment x1 = 1, x2 = 0, x3 = 0 is a satisfying assignment. No polynomial time algorithms are known for these problems – such algorithms may or may not exist. -
Colloidal Crystal: Emergence of Long Range Order from Colloidal Fluid
Colloidal Crystal: emergence of long range order from colloidal fluid Lanfang Li December 19, 2008 Abstract Although emergence, or spontaneous symmetry breaking, has been a topic of discussion in physics for decades, they have not entered the set of terminologies for materials scientists, although many phenomena in materials science are of the nature of emergence, especially soft materials. In a typical soft material, colloidal suspension system, a long range order can emerge due to the interaction of a large number of particles. This essay will first introduce interparticle interactions in colloidal systems, and then proceed to discuss the emergence of order, colloidal crystals, and finally provide an example of applications of colloidal crystals in light of conventional molecular crystals. 1 1 Background and Introduction Although emergence, or spontaneous symmetry breaking, and the resultant collective behav- ior of the systems constituents, have manifested in many systems, such as superconductivity, superfluidity, ferromagnetism, etc, and are well accepted, maybe even trivial crystallinity. All of these phenonema, though they may look very different, share the same fundamental signature: that the property of the system can not be predicted from the microscopic rules but are, \in a real sense, independent of them. [1] Besides these emergent phenonema in hard condensed matter physics, in which the interaction is at atomic level, interactions at mesoscale, soft will also lead to emergent phenemena. Colloidal systems is such a mesoscale and soft system. This size scale is especially interesting: it is close to biogical system so it is extremely informative for understanding life related phenomena, where emergence is origin of life itself; it is within visible light wavelength, so that it provides a model system for atomic system with similar physics but probable by optical microscope.