Downloads & Free Reading Options - Results

A more unified approach to communication theory can evolve through systems modeling of information theory, communication modes, and mass media operations. Such systematic analysis proposes, as is the case care here, that information models be based upon combinations of energy changes and exchanges and changes in receiver systems. The mass media is particularly exemplary as a model for such methodological procedure. (CH)

The general relativistic notion of gravitational and inertial mass is discussed from the general viewpoint of the tidal forces implicit in the curvature and the Einstein field equations within ponderable matter. A simple yet rigorously general derivation is given for the Tolman gravitational mass viewpoint wherein the computation of gravitational mass requires both a rest energy contribution (the inertial mass) and a pressure contribution. The pressure contribution is extremely small under normal conditions which implies the equality of gravitational and inertial mass to a high degree of accuracy. However, the pressure contribution is substantial for conformal symmetric systems such as Maxwell radiation, whose constituent photons are massless. Implications of the Tolman mass for standard cosmology and standard high energy particle physics models are briefly explored.

We present a method for the production of segmented optics. It is a novel processing developed at INAF-Osservatorio Astronomico di Brera (INAF-OAB) employing commercial of-the-shelf materials. It is based on the shaping of thin glass foils by means of forced bending, this occurring at room temperature (cold-shaping). The glass is then assembled into a sandwich structure for retaining the imposed shape. The principal mechanical features of the mirrors are the very low weight, rigidity and environmental robustness. The cost and production time also turns to be very competitive. In this paper we sum up the results achieved during the r&d performed in the past years. We have investigated the theoretical limits of the structural components by means of parametric finite elements analyses; we also discuss the effects caused by the most common structural loads. Finally, the process implementation, the more significant validation tests and the mass production at the industry is described.

Since 2012, the Defense Threat Reduction Agency (DTRA) has sponsored the Project onAdvanced Systems and Concepts for Countering WMD (PASCC) at the Naval PostgraduateSchool (NPS) in Monterey, California. PASCCs mission is to support DTRA by selecting a portfolio of strategic dialogues and studies to provide over-the-horizon analysis aimed at reducing the threats posed by weapons of mass destruction (WMD) and emerging weapons of mass effect (WME). PASCC is also interested in new means of supporting strategic stability and regional security in regard to WMD/WME, as well as mechanisms for increasing the effectiveness of both deterrence and nonproliferation/arms control efforts. The dialogues and studies PASCC supports are of direct value to the U.S. government and the broader public. PASCC reports are widely available through its website as well as the NPS sponsored Homeland Security Digital Library (www.hsdl.org). PASCC also facilitates briefings by project performers at events it organizes twice a year in Washington, DC, as well as assisting in setting up direct meetings with interested government stakeholders responsible for WMD/WME policies. The positive feedback PASCC receives from a variety of stakeholders stems from the thoroughness of its products, their objectivity, and their relevance to current and futureWMD/WME threats and challenges.PASCC sponsors innovative studies by working with a diverse set of research partners. The annual merit-based, peer-review process for selecting projects ensures that DTRA and other stakeholders benefit from the most rigorous research by the best subject matter experts (SMEs) in the field. In FY15, in accordance with the PASCC Broad Agency Announcement (BAA) released the previous spring, PASCC made 27 project awards to a variety of research performers.

This Occasional Paper combines three separate threads of analysis on culture and violent nonstate actors as a launching pad to spur further research into this critical arena of culture and security. In the first contribution, Strategic Culture and Violent NonState Actors: Concepts and Templates for Analysis, James M. Smith lays out a conceptual basis and a series of templates for guiding the analysis of culture and violent nonstate actors. These templates focus on the analysis of WMD acquisition and use, and on culturally driven operational campaigns. In the second contribution, Strategic Culture, Al Qaida, and Weapons of Mass Destruction, Jerry M. Long applies a cultural analysis of radical Islam and al Qaida in discussing the many factors and influences involved in the core al Qaida group's WMD decisions. His work graphically demonstrates the complexity of such decisions for that core group, and suggests that what many may find as counter-intuitive caution plays a major role here. In the final contribution, The Taliban Insurgency and Its Tribal Dynamics: An Analysis of 'Shabnamah' (Night Letters), Thomas H. Johnson, in examining a tribal insurgent psychological campaign in Afghanistan, demonstrates that traditional beliefs, myths and stories, and behavioral influences can be manipulated for significant effect in countering U.S. efforts to gain stability and legitimacy for the Afghan government. Together these papers underscore the central role of culture in analyzing and understanding nonstate adversaries.

Book chapter

A study of kinematics of a 2-body system is used to show that the Mach principle, previously rejected by general relativity, can still serve as an alternative to the concept of absolute space, if one takes into account that the background of distant stars (galaxies) determines {\it both} the inertial and the gravitational masses of a body.

http://uf.catalog.fcla.edu/uf.jsp?st=UF001479628&ix=nu&I=0&V=D

The specific mass (mass per unit of electric power output) of an NEP power conversion system is an important metric for the performance and feasibility of a crewed NEP vehicle. This work explores a component level buildup of the specific mass for a crewed NEP vehicle. The buildup is highly parametric and avoids being tied to specific technologies where practical. This allows the specific mass to be calculated for a variety of assumptions and operating conditions and be used to optimize particular design variables or compare different system configurations. The values of specific mass are dependent on assumptions with significant uncertainty; comparison between cases and trends observed in the models are the main goal of the work presented here. To demonstrate the level of insight this type of modeling can provide, the impacts of compressor inlet temperature, turbine inlet temperature, and radiator pressure drop on specific mass are explored. In addition, the specific mass can be used to assess the benefit of separating the radiator and reactor loop from the power conversion cycle.

Parametric solid and surface models of the crew exploration vehicle (CEV) command module (CM) structure concepts are developed for rapid finite element analyses, structural sizing and estimation of optimal structural mass. The effects of the structural configuration and critical design parameters on the stress distribution are visualized, examined to arrive at an efficient design. The CM structural components consisted of the outer heat shield, inner pressurized crew cabin, ring bulkhead and spars. For this study only the internal cabin pressure load case is considered. Component stress, deflection, margins of safety and mass are used as design goodness criteria. The design scenario is explored by changing the component thickness parameters and materials until an acceptable design is achieved. Aluminum alloy, titanium alloy and an advanced composite material properties are considered for the stress analysis and the results are compared as a part of lessons learned and to build up a structural component sizing knowledge base for the future CEV technology support. This independent structural analysis and the design scenario based optimization process may also facilitate better CM structural definition and rapid prototyping.

Parametric solid and surface models of the crew exploration vehicle (CEV) command module (CM) structure concepts are developed for rapid finite element analyses, structural sizing and estimation of optimal structural mass. The effects of the structural configuration and critical design parameters on the stress distribution are visualized, examined to arrive at an efficient design. The CM structural components consisted of the outer heat shield, inner pressurized crew cabin, ring bulkhead and spars. For this study only the internal cabin pressure load case is considered. Component stress, deflection, margins of safety and mass are used as design goodness criteria. The design scenario is explored by changing the component thickness parameters and materials until an acceptable design is achieved. Aluminum alloy, titanium alloy and an advanced composite material properties are considered for the stress analysis and the results are compared as a part of lessons learned and to build up a structural component sizing knowledge base for the future CEV technology support. This independent structural analysis and the design scenario based optimization process may also facilitate better CM structural definition and rapid prototyping.

Some recollections on the recent history of the concepts of vacuum and mass and the search for higgs. According to the widely spread terminology the Higgs field permeates vacuum and serves as the origin of masses of all fundamental particles including the Higgs Boson -- the higgs.

Some recollections on the recent history of the concepts of vacuum and mass and the search for higgs. According to the widely spread terminology the Higgs field permeates vacuum and serves as the origin of masses of all fundamental particles including the Higgs Boson -- the higgs.

Certain linear objects, termed physical lines, are considered, and initial assumptions concerning their properties are introduced. A closed physical line in the form of a circle, termed J-string, is singled out for investigation. It is shown that this curve consists of indivisible line segments of length $\ell_\Delta$. It is assumed that a J-string has an angular momentum whose value is $\hbar$.It is then established that a J-string of radius $R$ possesses a mass $m_J$, equal to $h/2\pi c R$, a corresponding energy, as well as a charge $q_J$, where $q_J = (hc/2\pi)^{1/2}$. It is also established that $\ell_\Delta = 2\pi(hG/c^3)^{1/2}$, where $c$ is the speed of light and $G$ is the gravitational constant. % Based upon investigation of the properties and characteristics of J-strings, a method is developed for the computation of the Planck length and mass $(\ell^*_P, m^*_P)$. The values of $\ell^*_P$ and $m^*_P$ are computed according to the resulting formulae (and given in the paper); these values differ from the currently accepted ones.