Preserving the Past as Society Evolves

2019 ◽  
Author(s):  
Robert P. Antes ◽  
Eric R. Ober ◽  
Greggrey G. Cohen
Keyword(s):  
Material Properties ◽  
Urban Environments ◽  
Structural Systems ◽  
The Past ◽  
Investigation Process ◽  
Existing Structure

<p>In urban environments, historic and significant structures are often altered or adapted multiple times for new uses to meet the needs of society. These modifications may occur years apart over the life of the structure, resulting in a combination of different materials and structural systems. Modern-day designers need to fully understand not only the original archaic construction but also the changes imposed during the prior modifications. Drawings for the original building, and subsequent modifications, oftentimes are lacking or incomplete and an investigation is needed to identify the configuration of the existing structure and the various material properties. When considering restoration and strengthening, the information obtained from a well-planned investigation and evaluation can maximize retention of the historic fabric of the structure.</p><p>In this paper/presentation we discuss the importance of performing an investigation prior to modifying the existing structure, the components of an investigation for historic or significant structures, and the challenges that can arise during the investigation process.</p>

Aminocoumarins: A Privileged Precursor for the Synthesis of Fused Heterocycles

2019 ◽  
Vol 23 (9) ◽  
pp. 1045-1075 ◽  
Author(s):  
Saigal ◽  
Sumbulunnisan Shareef ◽  
Habibur Rahman ◽  
Md. Musawwer Khan
Keyword(s):  
Chemical Reactivity ◽  
Structural Systems ◽  
Natural Occurrence ◽  
Amino Group ◽  
Active Compounds ◽  
The Past ◽  
Fused Heterocycles

Aminocoumarins are one of the important core structural systems, present in several biologically and medicinally active compounds. Owing to its natural occurrence, potential pharmacological applications and remarkable versatility as a privileged precursor, several proficient synthetic protocols have been reported in the literature over the past years. The presence of an amino group and enamine carbon enhances its chemical reactivity and thus such functionality is repeatedly used for the construction of various fused and simple heterocycles. This review highlights the preparation of different aminocoumarins and their applications for the construction of a variety of five, six and eight membered fused heterocycles.

scholarly journals Multi-stable composite twisting structure for morphing applications

2012 ◽  
Vol 468 (2141) ◽  
pp. 1230-1251 ◽  
Author(s):  
X. Lachenal ◽  
P. M. Weaver ◽  
S. Daynes
Keyword(s):  
Analytical Model ◽  
Material Properties ◽  
Degrees Of Freedom ◽  
Design Parameters ◽  
Engineering Structures ◽  
The Past ◽  
Wide Range ◽  
Morphing Structure ◽  
Low Mass ◽  
Unstable States

Conventional shape-changing engineering structures use discrete parts articulated around a number of linkages. Each part carries the loads, and the articulations provide the degrees of freedom of the system, leading to heavy and complex mechanisms. Consequently, there has been increased interest in morphing structures over the past decade owing to their potential to combine the conflicting requirements of strength, flexibility and low mass. This article presents a novel type of morphing structure capable of large deformations, simply consisting of two pre-stressed flanges joined to introduce two stable configurations. The bistability is analysed through a simple analytical model, predicting the positions of the stable and unstable states for different design parameters and material properties. Good correlation is found between experimental results, finite-element modelling and predictions from the analytical model for one particular example. A wide range of design parameters and material properties is also analytically investigated, yielding a remarkable structure with zero stiffness along the twisting axis.

Potential Use of the Theory of Vulnerability in Information Systems

2012 ◽  
Vol 25 (2) ◽  
pp. 22-33
Author(s):  
Pedro Sá Silva ◽  
Jorge Pinto ◽  
João Varajão ◽  
António Trigo ◽  
Isabel Bentes ◽  
...  
Keyword(s):  
Information Systems ◽  
Structural Systems ◽  
Sensitive Information ◽  
Simulation Studies ◽  
Damage Scenarios ◽  
The Past ◽  
Interesting Approach ◽  
Systems Simulation ◽  
Type Of Failure ◽  
Potential Use

Information Systems in the past few years became a keystone of society. History shows that in some Information Systems one simple failure can lead to disproportioned economic and social damages. Initially used in structural systems, the theory of vulnerability searches for this type of failure. This theory identifies failures in which small damage can have disproportionate impact consequences in terms of the functionality of the whole system. To test and evaluate these failures injections and analyze the impacts of them in sensitive Information Systems, simulation provides an interesting approach. By mimicking systems and representing them through models, simulation studies an imitated system without disrupting the system itself. Simulation provides a safer approach to explore and test the system in damage scenarios without real consequences. This paper discusses the use of the theory of vulnerability in Information Systems simulation.

Customer Investigation Process at Credit Suisse

2009 ◽  
pp. 1787-1807
Author(s):  
Daniel Maier ◽  
Thomas Muegeli ◽  
Andrea Krejza
Keyword(s):  
Data Warehouse ◽  
Banking Industry ◽  
Regulatory Requirements ◽  
Complex Time ◽  
The Past ◽  
Considerable Cost ◽  
Two Measures ◽  
Time Savings ◽  
Investigation Process

Customer investigations in the banking industry are carried out in connection with prosecutions, the administration of estates or other legal actions. The Investigation & Inquiries Department of Credit Suisse has to handle approximately 5,000 client investigations per year. To date, the investigation process has been very complex, time consuming and expensive. Several redundant query processes are needed to achieve satisfactory results. In the past few years, new regulatory requirements have led to a massive increase in the number of investigations to be performed. This case study describes how these requirements can be met by redesigning the process and building a data-warehouse-based application that automates most of the process. These two measures have significantly improved the customer investigation process, resulting in considerable cost and time savings for Credit Suisse.

scholarly journals Broadening Understanding on Managing the Communication Infrastructure in Vehicular Networks: Customizing the Coverage Using the Delta Network

2018 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
Cristiano Silva ◽  
Lucas Silva ◽  
Leonardo Santos ◽  
João Sarubbi ◽  
Andreas Pitsillides
Keyword(s):  
Urban Areas ◽  
Road Network ◽  
Vehicular Networks ◽  
Urban Environments ◽  
Urban Mobility ◽  
Circle Pattern ◽  
The Road ◽  
The Past ◽  
Communication Devices ◽  
Definition Of

Over the past few decades, the growth of the urban population has been remarkable. Nowadays, 50% of the population lives in urban areas, and forecasts point that by 2050 this number will reach 70%. Today, 64% of all travel made is within urban environments and the total amount of urban kilometers traveled is expected to triple by 2050. Thus, seeking novel solutions for urban mobility becomes paramount for 21st century society. In this work, we discuss the performance of vehicular networks. We consider the metric Delta Network. The Delta Network characterizes the connectivity of the vehicular network through the percentage of travel time in which vehicles are connected to roadside units. This article reviews the concept of the Delta Network and extends its study through the presentation of a general heuristic based on the definition of scores to identify the areas of the road network that should receive coverage. After defining the general heuristic, we show how small changes in the score computation can generate very distinct (and interesting) patterns of coverage, each one suited to a given scenario. In order to exemplify such behavior, we propose three deployment strategies based on simply changing the computation of scores. We compare the proposed strategies to the intuitive strategy of allocating communication units at the most popular zones of the road network. Experiments show that the strategies derived from the general heuristic provide higher coverage than the intuitive strategy when using the same number of communication devices. Moreover, the resulting pattern of coverage is very interesting, with roadside units deployed a circle pattern around the traffic epicenter.

Spreadsheet solutions of elastic plate–beam problems

1990 ◽  
Vol 17 (6) ◽  
pp. 931-939
Author(s):  
Gregory E. Small ◽  
Sidney H. Simmonds
Keyword(s):  
Finite Difference ◽  
Material Properties ◽  
Iterative Solution ◽  
Difference Operators ◽  
Structural Systems ◽  
Convergence Criteria ◽  
Spreadsheet Program ◽  
Structural Problem ◽  
Special Computer Program ◽  
Slab Bending

Spreadsheets are among the most common microcomputer programs used by engineers because they provide an easy means of formulating equations in algebraic format. By introducing appropriate stiffness equations with numerical values representative of material properties, boundary conditions, and loading, spreadsheet templates can be developed to model specific structural systems. These equations are mutually dependent and may be solved using the iteration techniques that are part of the spreadsheet program. A common structural problem that is difficult to solve without a special computer program is the analysis of a slab arbitrarily supported on elastic beams and columns. The use of readily available spreadsheet programs to solve this problem is demonstrated. Equations for slab bending and for beams with finite flexural and torsional stiffnesses are derived using finite difference operators. These equations are then recast into a form more convenient for an iterative solution. The use of these equations is demonstrated with numerical examples. Key words: analysis, convergence criteria, deflections, finite difference, plates, spreadsheets.

scholarly journals Application of Photocatalytic Concrete Paving Blocks in Poland—Verification of Effectiveness of Nitric Oxides Reduction and Novel Test Method

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5183
Author(s):  
Hubert Witkowski ◽  
Janusz Jarosławski ◽  
Anna Tryfon-Bojarska
Keyword(s):  
Test Method ◽  
Light Irradiation ◽  
Nitric Oxides ◽  
Field Campaign ◽  
Airborne Pollutants ◽  
The Past ◽  
Nitric Oxide Reduction ◽  
Photocatalytic Concrete ◽  
Solar Position ◽  
Investigation Process

Photocatalytic concrete is one of the most promising concrete technologies of the past decades. Application of nanometric TiO2 to cement matrices enables the reduction of harmful airborne pollutants. Although a number of implementations of this technology are described in this paper, problems related to test conditions are also reported. One major issue is the sufficient light irradiation that for higher latitudes can be significantly reduced. In this paper, a field campaign on the implementation of photocatalytic concrete pavement in Warsaw (52.23° N) is briefly described. Based on experience from the field campaign, a novel test method is developed. In the research, the effectiveness of nitric oxide reduction is verified at natural light irradiation for various dates of solar position at noon in central Poland (51.83° N). The results confirm the benefits of using photocatalytic materials at higher latitudinal locations. The experimental setup presented in the study combines the advantages of controlled measurement conditions typical in laboratory tests with the possibility of including natural sunlight conditions in the investigation process.

STUDY ON A SORT OF CONTROLLABLE NONLINEAR LEFT-HANDED MATERIALS

2009 ◽  
Vol 18 (03) ◽  
pp. 441-456 ◽  
Author(s):  
HONG XIN ZHANG ◽  
LAN ZHAO ◽  
YING HUA LU
Keyword(s):  
Resonance Frequency ◽  
Time Domain ◽  
Material Properties ◽  
Finite Difference Time Domain ◽  
Transmission Properties ◽  
The Past ◽  
Left Handed ◽  
High Harmonics ◽  
Fdtd Simulations ◽  
Difference Time

In this paper, three kinds of controllable nonlinear left-handed materials (DNLHMs) are proposed and analyzed, which are designed by introducing inductors and capacitors into the traditional nonlinear left-handed materials (NLHMs) as inhomogeneous doped elements. Due to such changes, several new transmission properties have been presented through finite-difference time-domain (FDTD) simulations. These have brought new features to our DNLHMs. On one hand, the original passband in the traditional nonlinear left-handed material is narrowed after introducing inductors. In addition, a new passband, which does not exist in doped linear LHMs, is generated. On the other hand, through introducing capacitors, the original passband of the nonlinear left-handed material can be shifted, resonance frequency can be changed, and a new passband can be generated. When capacitors and inductors are introduced simultaneously, the material properties, such as the number of passbands, the characteristic resonance frequency, and the bandwidth, can also be changed. Noting these characteristics, the values of the introduced inductors and capacitors are varied to investigate the spectrum changes of DNLHMs. Then, a series of controllable properties of the DNLHMs can be retrieved. And more importantly, the designed DNLHMs give the adjustability of suppressing high harmonics, which is not possible in the past materials.

Predicted Ductility Demands for Steel Moment Resisting Frames

1989 ◽  
Vol 5 (2) ◽  
pp. 409-427 ◽  
Author(s):  
Charles W. Roeder ◽  
James E. Carpenter ◽  
Hidetake Taniguchi
Keyword(s):  
United States ◽  
Seismic Design ◽  
The United States ◽  
Structural Systems ◽  
Ductility Demand ◽  
Steel Moment Resisting Frames ◽  
The Past ◽  
Moment Resisting Frames ◽  
Column System ◽  
Moment Resisting

Recent changes to the United States seismic design provisions permit the use of weak column-strong beam steel moment resisting frames. This design concept has not been used in the past, because it results in plastic hinges in the columns during moderate or extreme earthquakes. This paper shows the results of inelastic dynamic response calculations on a weak column frame and a comparable strong column system. The results show that the ductility demand is much greater for the weak column strong beam framing system with some acceleration records. The required ductility is then compared for the different structural systems and both are compared to the results of experiments. The comparison suggests that the weak column system may not be able to develop the required ductility. The results of this paper should help define the viability and limits in applicability of the weak column system.

Sign in / Sign up

Export Citation Format

Share Document