721 research outputs found
GeV CLIC Collider Based on its Drive Beam FEL
CLIC is a linear () collider project which uses a
drive beam to accelerate the main beam. The drive beam provides RF power for
each corresponding unit of the main linac through energy extracting RF
structures. CLIC has a wide range of center-of-mass energy options from 150 GeV
to 3 TeV. The present paper contains optimization of Free Electron Laser (FEL)
using one bunch of CLIC drive beam in order to provide polarized light
amplification using appropriate wiggler and luminosity spectrum of
collider for =0.5 TeV. Then amplified laser can be
converted to a polarized high-energy beam at the Conversion point
(CP-prior to electron positron interaction point) in the process of Compton
backscattering. At the CP a powerful laser pulse (FEL) focused to main linac
electrons (positrons). Here this scheme described and it is show that CLIC
drive beam parameters satisfy the requirement of FEL additionally essential
undulator parameters has been defined. Achievable luminosity is
above .Comment: 20 pages, 4 figure
Thresholds for global existence and blow-up in a general class of doubly dispersive nonlocal wave equations
In this article we study global existence and blow-up of solutions for a
general class of nonlocal nonlinear wave equations with power-type
nonlinearities, , where the
nonlocality enters through two pseudo-differential operators and . We
establish thresholds for global existence versus blow-up using the potential
well method which relies essentially on the ideas suggested by Payne and
Sattinger. Our results improve the global existence and blow-up results given
in the literature for the present class of nonlocal nonlinear wave equations
and cover those given for many well-known nonlinear dispersive wave equations
such as the so-called double-dispersion equation and the traditional
Boussinesq-type equations, as special cases.Comment: 17 pages. Accepted for publication in Nonlinear Analysis:Theory,
Methods & Application
DEUTSCHE AFRIKA KORPS: Peranan Field Marshal Erwin Rommel dalam Perang Dunia II di Afrika Utara 1941-1943
Latar belakang penelitian ini dikarenakan ketertarikan penulis akan suasana Perang Dunia II di Afrika Utara yang mempunyai ciri khas tersendiri dibanding pertempuran lainnya yang terjadi selama Perang Dunia II berlangsung. Masalah utama yang dibahas dalam skripsi ini adalah ‘bagaimana peranan Field Marshal Erwin Rommel dalam Perang Dunia II di Afrika Utara?’. Masalah utama ini kemudian dijabarkan kedalam beberapa pernyataan penelitian, yakni (1) bagaimana latar belakang keterlibatan Jerman dalam pertempuran di Afrika Utara 1941-1943?, (2) apa yang melatarbelakangi Jerman menunjuk Field Marshal Erwin Rommel untuk memimpin Deutsche Afrika Korps?, (3) bagaimana proses pertempuran yang dipimpin Field Marshal Erwin Rommel di Afrika Utara 1941-943?, (4) Bagaimana akhir dari pertempuran Jerman pada Perang Dunia II di Afrika Utara 1941-1943? Metode yang digunakan adalah metode historis meliputi pengumpulan sumber, kritik sumber, interpretasi dan historiografi. Untuk memperdalam analisis, peneliti menggunakan pendekatan interdisipliner melalui kajian ilmu sosiologi, militer dan politik dengan menggunakan konsep-konsep seperti peran, status, perang, serta menggunakan teori konflik Lewis A. Coser dan teori geopolitik Karl Haushoffer. Deutsche Afrika Korps dibentuk akibat keterlibatan Jerman dalam pertempuran di Afrika Utara. Keterlibatan Jerman di Afrika Utara disebabkan karena Afrika Utara memiliki arti penting bagi Jerman karena memiliki Terusan Suez dan benteng Gibraltar. Selain itu hubungan Italia-Jerman yang merupakan blok Poros akibat perjanjian Pakta Baja dan Pakta Tripartit membuat Jerman harus terlibat dalam pertempuran. Deutsche Afrika Korps ini dipimpin oleh Field Marshal Erwin Rommel yang dipercayai oleh Hitler karena kepimpinannya dan kepopulerannya dikalangan pasukan Jerman. Rommel memiliki peranan yang sangat penting ketika Jerman membantu Italia di Afrika Utara. Taktik dan strategi Rommel yang jenius membuat Sekutu kewalahan. Strategi yang digunakan diantaranya membuat tank dari kayu untuk mengelabui musuh dan juga memposisikan Flak 88mm dalam bentuk U untuk menjebak tank musuh dalam jebakannya. Proses pertempuran di Afrika Utara ini diawali ketika Rommel mendarat di Tripoli dengan langsung melakukan ofensif mendesak Sekutu menuju perbatasan Libya-Mesir. Selain itu juga Rommel mendapatkan perlawanan dari Sekutu yang melakukan beberapa operasi yang bertujuan untuk memukul mundur Jerman dari Afrika Utara. Operasi tersebut diantaranya operasi Brevity, operasi Battleaxe dan operasi Crusader. Perlawanan Rommel berakhir ketika kekalahan Jerman di El Alamein yang disebabkan faktor kurangnya logistik dan ketidakseimbangan kuantitas pasukan yang dimiliki antara Poros dan Sekutu di El Alamein. Kekalahan Jerman di El Alamein merupakan salah satu turning point bagi Sekutu dalam Perang Dunia II ini dan mengubah arah berlangsungnya perang kedepannya.
The reason of research because author interested with World War II situation in Northern Africa that have characterized be compared another war in World War II. The main problem to discuss in this research is “ How Field Marshal Erwin Rommel role in the World War II in Northern Africa?”. The main problem divided into four research questions, (1) what the purpose Germany includes in battle of Northern Africa 1941-1943?, (2) what the reason Germany choose Field Marshal Erwin Rommel to led Deutsche Afrika Korps?, (3) what is the process that led Field Marshal Erwin Rommel in Northern Africa 1941-1943?, (4) how to end the Germany battle in the World War II in Northern Afrika 1941-1943?. The research uses historic methodology involved Heuristics, source criticism, interpretation, and historiography. To deepen the analysis, researcher uses interdisciplinary approach through the study sociology, military, and politics with concept and theory like role, status, war, conflict theory from Lewis A. Coser, and geopolitical theory from Karl Haushoffer. Deutsche Afrika Korps formed as result of Germany includes in Battle of Northern Africa. Germany involvement in Northern Africa due to Northern Africa has significance for Germany because have Suez Canal and Fort Gibraltar. In addtion, the relation between Germany and Italy who where Axis due to Agreement Steel Pact and Tripartit Pact makes Germany must includes in the battle. Deutsche Afrika Korps is led by Field Marshal Erwin Rommel and believed Hitler because leadership and popularity among the Germany Troops. Rommel has a very important role when Germany helped Italy in Northern Africa. Tactics and strategy genius Rommel make allied overwhelmed. The strategy used them made of wood tanks to trick enemy and Flak 88m in form U to trap enemy tanks. The process battle in Northern Africa begins when Rommel landed in Tripoli and makes offensive to push Allied towards Libya-Egypt border. It also Rommel get resistance from Allied who perform several operations aimed at repelling Germany of Northern Africa. Such operations include Brevity Operation, Battleaxe Operation, and Crusader Operation. Rommel resistance ended when Germany defeat in El Alamein due to lack of logistical factors and troops possessed imbalance quantity between Axis and Allied. The defeat of Germany in El Alamein is one of turning point for Allied in World War and changing the direction of war in the future
PENDIDIKAN MULTIKULTURAL SEBAGAI SOLUSI KONFLIK SARA
Abstrak:Bangsa Indonesia dikenal sebagai Bangsa-Negara yang fluralistik dalam berbagai aspek, baik agama, suku, bahasa, etnis, budaya dan adat istiadat. Kemajmukan ini di satu sisi menjadi hal yang sangat baik, namun disisi lain menjadi rawan konflik khorizontal, terutama konflik antar agama. Dalam kondisi yang demikian, maka dibutuhkan suatu mekanisme yang bisa dijadikan lihat djembatan solusif bagi harmni. Pendidikan multikulturalisme yang ahir-ahir ini marak diperbincangkan diharpakan bisa menjadi jembatan solusif untuk harmoni tersebut. Hal ini terrlihat dari fungsi dan tujuan dari pendidikan multikulturalisme tersebut yang mengedepankan sikap demokratis, toleran dan keadilan. Dengan sikap yang demikian, maka konflik SARA diharapkan bisa dipreventifikasi
Hardness and inapproximability results for minimum verification set and minimum path decision tree problems
Minimization of decision trees is a well studied problem. In this work, we introduce two new problems related to minimization of decision trees. The problems are called minimum verification set (MinVS) and minimum path decision tree (MinPathDT) problems. Decision tree problems ask the question "What is the unknown given object?". MinVS problem on the other hand asks the question "Is the unknown object z?", for a given object z. Hence it is not an identification, but rather a verification problem. MinPathDT problem aims to construct a decision tree where only the cost of the root-to-leaf path corresponding to a given object is minimized, whereas decision tree problems in general try to minimize the overall cost of decision trees considering all the
objects. Therefore, MinVS and MinPathDT are seemingly easier problems.
However, in this work we prove that MinVS and MinPathDT problems are both NP-complete and cannot be approximated within a factor in o(lg n) unless P = NP
Derivation of the Camassa-Holm equations for elastic waves
In this paper we provide a formal derivation of both the Camassa-Holm
equation and the fractional Camassa-Holm equation for the propagation of
small-but-finite amplitude long waves in a nonlocally and nonlinearly elastic
medium. We first show that the equation of motion for the nonlocally and
nonlinearly elastic medium reduces to the improved Boussinesq equation for a
particular choice of the kernel function appearing in the integral-type
constitutive relation. We then derive the Camassa-Holm equation from the
improved Boussinesq equation using an asymptotic expansion valid as
nonlinearity and dispersion parameters tend to zero independently. Our approach
follows mainly the standard techniques used widely in the literature to derive
the Camassa-Holm equation for shallow water waves. The case where the Fourier
transform of the kernel function has fractional powers is also considered and
the fractional Camassa-Holm equation is derived using the asymptotic expansion
technique.Comment: 15 page
Preparation of Carboxylic Acid Functionalized Glycopolymers through RAFT and Post-Polymerization Modification for Biomedical Application
The primary theme of this dissertation involves the synthesis of well-defined primary amine functionalized polymers, subsequent modification of the polymers to produce novel carboxylic acid functionalized glycopolymers and surface polymerization of these systems utilizing controlled polymerization techniques. Additionally, the synthesis of new water-based allylic copolymer latexes is described. Carbohydrates are natural polymers which possess unlimited structural variations. They carry a huge density of information, and play major roles in recognition events and complex biological operations. For example, hyaluronic acid (HA), an anionic glycosaminoglycan, provides lubricating and cushioning properties in the extracellular matrix and has been found to be involved in the regulation of many cellular and biological processes. In industry, HA is used in a wide range of biomedical applications, including post surgical adhesion prevention, rheology modification in orthopedics, ophthalmic procedures, tissue engineering, hydrogels and implants. Limitations of current systems include cost, allergy induction and reduced performance capabilities in comparison to native HA. Therefore, it is of interest to prepare synthetic glycopolymer analogues to specifically target performance capabilities for biomedical applications.
Reversible addition-fragmentation chain transfer polymerization (RAFT) is arguably the most versatile living radical polymerization technique in terms of the reaction conditions and monomer selection. Since the introduction of RAFT in 1998, researchers have employed the RAFT process to synthesize a wide range of water soluble (co)polymers with predetermined molecular weights, low polydispersities, and advanced architectures. However the RAFT polymerization of primary amine containing monomers such as 2-(aminoethyl metharylate) (AEMA) and ./V-(3-aminopropyl methacrylamide) (APMA) directly in water has yet to be reported. Since primary amine groups are amenable to a wide range of post-polymerization chemistries, primary amine functionalized polymers enable developments in the synthesis of controlled architecture glycopolymers. In addition, click chemistry can provide us an easy route to modify solid substrates with these polymers due to its simple reaction conditions and high reaction yield properties. The overall goal of this research is to prepare well-defined synthetic anionic glycosaminoglycan polymers by combining well-defined primary amine functionalized polymers with carboxylic acid functionalized sugars through a one-step reductive amination reaction. To achieve these goals, first, primary amine functionalized polymers were prepared through aqueous RAFT polymerization of AEMA and APMA. Second, Dglucuronic acid sodium salt was attached to reactive polymer precursors via reductive amination reactions in alkaline medium. Finally, the surface modification capabilities of primary amine functionalized polymers were investigated using click chemistry to create reactive surfaces allowing post-polymerization reactions.
In this thesis, the first chapter concerns the first successful RAFT polymerization of unprotected AEMA directly in water and its successful block copolymerization with iV-2-hydroxypropylmethacrylamide (HPMA). The controlled living polymerization of AEMA was carried out directly in aqueous buffer using 4-cyanopentanoic acid dithiobenzoate (CTP) as the chain transfer agent (CTA), and 2,2\u27-Azobis(2- imidazolinylpropane) dihydrochloride (VA-044) as the initiator at 50 °C. The living character of the polymerization was verified with pseudo first order kinetic plots, a linear increase of the molecular weight with conversion, and low polydispersities (PDIs) (\u3c1.2). In addition, well-defined copolymers of poly(2aminoethyl methacrylate-6-./V-2- hydroxypropylmethacrylamide) (PAEMA-6-PHPMA) have been prepared through chain extension of poly(2-aminoethyl methacrylate) (PAEMA) macroCTA with HPMA in water. It is shown that the macroCTA can be extended in a controlled fashion resulting in near monodisperse block copolymers. The second chapter demonstrates the synthesis of novel carboxylic acid functionalized glycopolymers prepared via one step post-polymerization modification of poly(JV-[3-aminopropyl] methacrylamide) (PAPMA), a water soluble primary amine methacrylamide, in aqueous medium. PAPMA was first polymerized via aqueous RAFT polymerization using CTP as CTA, and 4,4\u27-Azobis(4-cyanovaleric acid) (V-501) as the initiator at 70 °C. The resulting well-defined PAPMA was then conjugated with Dglucuronic acid sodium salt through reductive amination in alkaline medium (pH 8.5) at 45 °C. The successful bioconjugation was proven through proton (^H) and carbon (13C) Nuclear Magnetic Resonance (NMR) spectroscopy and Matrix Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) mass spectroscopy analysis, which indicated near quantitative conversion. A similar bioconjugation reaction was conducted with PAEMA and PAEMA-6-PHPMA. For the PAEMA homo and block copolymers, however, poor conversion was obtained, most likely due to degradation reactions of PAEMA in alkaline medium. The third chapter details the direct preparation of a-alkynyl-functionalized PAEMA via RAFT polymerization. The controlled living polymerization of AEMA was carried out directly in dimethylsulfoxide (DMSO) using a-alkynyl functionalized CTP as CTA, and 2,2\u27-azobis(2,4-dimethyl-4-methoxyvaleronitrile) (V-70) as the initiator at 45 °C. The resulting polymers display low PDIs (\u3c1.2). In addition, the a-alkynylfuntionalized PAEMA was attached to an azide functionalized silicon wafer via click chemistry. Various characterization techniques including ellipsometry, contact angle measurements, attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-IR), and atomic force microscopy (AFM) were used to characterize the polymer modified silicon wafers. It was shown that a non-uniform surface with a thickness of 11.1 nm was obtained. The last chapter (an additional chapter) details the copolymerization behavior of styrene with sec-butenyl acetate, whose copolymerization properties have not been reported. Copolymers were produced via semicontinuous emulsion polymerization and characterized via NMR, gel permeation chromatography, differential scanning calorimetry, dynamic light scattering, and atomic force microscopy. A high degree of chain termination due to allylic hydrogen abstraction was observed, as expected, with resultant decreases in molecular weight and in monomer conversion. How percentages of the ever, high conversions were achieved, and it was possible to incorporate high allylic acetate comonomer into the polymer chain. Copolymer thermal properties are reported
A higher-order Boussinesq equation in locally non-linear theory of one-dimensional non-local elasticity
In one space dimension, a non-local elastic model is based on a single integral law, giving the stress when the strain is known at all spatial points. In this study, we first derive a higher-order Boussinesq equation using locally non-linear theory of 1D non-local elasticity and then we are able to show that under certain conditions the Cauchy problem is globally well-posed
Global existence and blow-up for a class of nonlocal nonlinear Cauchy problems arising in elasticity
We study the initial-value problem for a general class of nonlinear nonlocal wave equations arising in one-dimensional nonlocal elasticity. The model involves a convolution integral operator with a general kernel function whose Fourier transform is nonnegative. We show that some well-known examples of nonlinear wave equations, such as Boussinesq-type equations, follow from the present model for suitable choices of the kernel function. We establish global existence of solutions of the model assuming enough smoothness on the initial data together with some positivity conditions on the nonlinear term. Furthermore, conditions for finite time blow-up are provided
- …