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Baker E.L.,U.S. Army | Cornell R.E.,U.S. Army | Stiel L.I.,Six Metrotech Center
Proceedings - 29th International Symposium on Ballistics, BALLISTICS 2016 | Year: 2016

It is now common to experimentally reduce Gurney energies associated with detonation products expansions using experimental cylinder expansion tests and the traditional Gurney formula for cylinders. However, this methodology results in Gurney energy values that are inherently geometrically dependent and do not provide quantitative measurements of explosive work output per mass. It is well known that the outside surface of an explosively expanding metal cylinder has a somewhat lower radial velocity than the cylinder inside due to wall thinning. It is also well known that the cylinder wall bends during acceleration resulting in a material motion Lagrangian velocity that is neither perpendicular to the original wall surface nor to the instantaneous wall surface. In addition, the high explosive detonation products have axial flow that is not accounted for using the cylinder Gurney formula. A number of researchers have identified these issues and have used various different methods to address them. One increasingly common methodology is to calculate Gurney energies using an analytic cylinder model along with thermochemical equation of state calculations. This methodology has proven to provide excellent agreement with experimental Gurney energies for a wide variety of high explosives.

Jazebi S.,Six Metrotech Center | Hadji M.M.,University of Alberta | Naghizadeh R.A.,Hamedan University of Technology
IEEE Transactions on Smart Grid | Year: 2014

This paper deals with reconfiguration of distribution system to minimize power losses, deviation of nodes voltages and branches current constraint violations. This means alternation of feeders' topological structure by changing the status of tie and sectionalizing switches. The work presented here is a step forward to define the reconfiguration problem closer to reality by considering the effect of harmonic loads. To solve this complicated combinatorial, non-differentiable constrained optimization problem, novel heuristic optimization techniques such as Shuffled Frog Leaping Algorithm (SFLA) and Imperialist Competitive Algorithm (ICA) are employed. The methods are compared with Discrete Particle Swarm Optimization (DPSO) algorithm to examine their performance including computational time, convergence rate, and accuracy of results. In this context, experiments are conducted on 69-bus and 84-bus distribution test systems for the short- and long-term reconfiguration scenarios. The obtained results establish that harmonic losses are a major deciding factor in reconfiguration and harmonic loads cannot be represented with only fundamental components. © 2014 IEEE.

Maiorana A.,Rensselaer Polytechnic Institute | Spinella S.,Rensselaer Polytechnic Institute | Spinella S.,Six Metrotech Center | Gross R.A.,Rensselaer Polytechnic Institute
Biomacromolecules | Year: 2015

A series of biobased epoxy monomers were prepared from diphenolic acid (DPA) by transforming the free acid into n-alkyl esters and the phenolic hydroxyl groups into diglycidyl ethers. NMR experiments confirmed that the diglycidyl ethers of diphenolates (DGEDP) with methyl and ethyl esters have 6 and 3 mol % of glycidyl ester. Increasing the chain length of DGEDP n-alkyl esters from methyl to n-pentyl resulted in large decreases in epoxy resin viscosity (700-to-11 Pa·s). Storage modulus of DPA epoxy resins, cured with isophorone diamine, also varied with n-alkyl ester chain length (e.g., 3300 and 2100 MPa for the methyl and n-pentyl esters). The alpha transition temperature of the cured materials showed a linear decrease from 158 to 86°C as the ester length increases. The Young's modulus and tensile strengths were about 1150 and 40 MPa, respectively, for all the cured resins tested (including DGEBA) and varied little as a function of ester length. Degree of cure for the different epoxy resins, determined by FTIR and DSC, closely approached the theoretical maximum. The result of this work demonstrates that diglycidyl ethers of n-alkyl diphenolates represent a new family of biobased liquid epoxy resins that, when cured, have similar properties to those from DGEBA. (Graph Presented). © 2015 American Chemical Society.

Grieco L.A.,Polytechnic of Bari | Rizzo A.,Polytechnic of Bari | Rizzo A.,Six MetroTech Center | Colucci S.,Polytechnic of Bari | And 4 more authors.
Computer Communications | Year: 2014

The ongoing revolution of Internet of Things (IoT), together with the growing diffusion of robots in many activities of every day life, makes IoT-aided robotics applications a tangible reality of our upcoming future. Accordingly, new advanced services, based on the interplay between robots and "things", are being conceived in assisting humans. Nevertheless, the path to a mature development of IoT-aided robotics applications requires several pivotal issues to be solved, design methodologies to be consolidated, and strong architectural choices to be discussed. This paper discusses technological implications, open issues, and target applications in the IoT-aided robotics domain. In particular, the present contribution is four-folded. First, it provides a solid state of the art on the main topics related to IoT-aided robotics services: communication networks, robotics applications in distributed and pervasive environments, semantic-oriented approaches to consensus, and network security. Second, it highlights the most important research challenges to be faced. Third, it describes the technological tools available nowadays. Fourth, it summarizes lessons learned to foster a joint scientific investigation among research teams with complementary skills. © 2014 Elsevier B.V.

Azimi E.,Six MetroTech Center | Gholitabar S.,Six MetroTech Center | Griffis F.H.,Six MetroTech Center
Construction Research Congress 2016: Old and New Construction Technologies Converge in Historic San Juan - Proceedings of the 2016 Construction Research Congress, CRC 2016 | Year: 2016

The primary aim of this study is to determine the relative effectiveness, strengths, and weaknesses of hazard mitigation plans (HMPs) in New York State. In addition to evaluating HMPs based on certain principles, they were also evaluated using real life scenarios. Further, this study determined their impact on reducing flood damage from storms, and concluded with recommendations to the state for improving the procedures and planning process of HMPs. The counties that were evaluated were considered federal disaster areas under the community development block grant action plan. Eight evaluation principles were selected based on content analysis and coding drawn from federal emergency management agency guidance documents and other hazard mitigation literature: (1) plan basics; (2) participation; (3) inter-organizational coordination; (4) hazard identification; (5) capability assessment; (6) goals; (7) proposed actions; and (8) monitoring. A combination of binary or ordinal scale were used to measure the eight plan quality principles. Results show that the principles that received the lowest scores were proposed action, monitoring and implementation and capability assessment. Additionally, results show that there is no coordination between the damages that occurred during hurricane sandy, tropical storm Lee and hurricane Irene in each county and their HMP overall resiliency score. © ASCE.

Dias P.,Six MetroTech Center | Ergan S.,Six MetroTech Center
Construction Research Congress 2016: Old and New Construction Technologies Converge in Historic San Juan - Proceedings of the 2016 Construction Research Congress, CRC 2016 | Year: 2016

The usage of building information models (BIMs) is well established within the architectural, construction and engineering industry to improve design, engineering and construction processes and exchange project information. BIMs proved to be beneficial by enabling off-site fabrication, reduction (even elimination) of change orders and facilitating access and exchange of digital information beyond the construction phase. This resulted in exploring the potential of utilizing BIMs for assisting facilities management (FM) tasks on a daily basis. Although there are mechanisms (e.g., COBie) to enable delivery of design information to the FM phase, the challenge is the need for customized facility information for operators when they perform FM tasks such as space management, and maintenance. Previous studies showed that BIMs should be customized for the requirements of an FM task at hand. Towards that vision to automatically customize BIMs for an FM task, the objective of the study is to identify the facilities operators' requirements on as-built BIM, with a focus on the maintenance of HVAC systems. The study builds on the level of development (LOD) and industry foundation classes (IFC) efforts to depict the level of detail of the geometric, spatial and semantic facility information during requirements elicitation phase with facility operators. The paper reports the initial findings of the requirements and LOD of the information for HVAC system maintenance. © ASCE.

Baamer M.,New York University | Suescun-Florez E.,New York University | Machairas N.,New York University | Iskander M.,Six MetroTech Center
Geotechnical Special Publication | Year: 2015

An experimental program was conducted to quantify the strain rate dependency of silica sand under different low to intermediate strain rates. Measurements of axial stress, axial strain and stiffness were explored to assess the sensitivity of mechanical properties to strain rate. Strain rates were applied on samples subjected to uniaxial compression stresses within a range of 0.01 to 100 %/s. The tests help facilitate the incorporation of strain rate dependency of soil response in geotechnical modeling of soil-structure interaction problems. Available observations of the response of sand under monotonic loading suggest that sand may exhibit significant strain rate dependency. © ASCE 2015.

Frank J.A.,Six MetroTech Center | Kapila V.,Six MetroTech Center
IEEE Control Systems | Year: 2014

Mobile devices have been widely adopted in recent years. Market researchers and futurists forecast that personal computers (PCs) will become a relic of the past, being gradually overshadowed by low-cost portable devices like tablet computers and mobile phones [1]. Today's mobile devices have wireless network connectivity, granting users increased accessibility and mobility. In industry, engineers have already begun to leverage these benefits of mobile devices to perform their jobs more conveniently and collaboratively [2]. Companies that design applications (a.k.a. apps) for engineering say "people need tools equivalent with what they have on their desktop but that they can take with them wherever they go" [2]. In a similar vein, mobile applications that free users from being tethered to a PC to monitor, command, or control laboratory equipment can allow hands-on experiential learning to be accessible from virtually anywhere and at any time, including at unexpected moments. For instance, if an engineering student is reminded of a laboratory experiment while going about her daily life, a mobile app can enable her to connect with the experiment to examine her hypotheses immediately instead of waiting to access the laboratory on campus and possibly forgetting valuable ideas. That is, since new ideas often arise spontaneously, mobile devices may support the creative learning process [3]. © 2014 IEEE.

Jazebi S.,Six Metrotech Center | De Leon F.,Six Metrotech Center
IEEE Transactions on Power Delivery | Year: 2015

This paper presents a general method for building equivalent electric circuits of power transformers, including eddy current effects in windings and core. A high-frequency equivalent dual model for single- and three-phase transformers with two multilayer windings is derived from the application of the principle of duality. The model is built from elements available in circuit simulation programs, such as Electromagnetic Transients Program (EMTP)-Alternative Transients Program, EMTP-RV, PSCAD, and PSpice. The parameters of the frequency-dependent leakage inductance and winding resistance are computed with analytical formulae obtained from the solution of Maxwell's equations that are based on the geometrical dimensions and material information. Ideal transformers are utilized to isolate the electric components (winding resistors and capacitors) from the magnetic components (inductors). The physically correct connection points for electric and magnetic components are clearly identified. The proposed methodology is successfully validated versus finite- element simulations and laboratory measurements. © 1986-2012 IEEE.

Guzman I.L.,New Jersey Institute of Technology | Iskander M.,Six Metrotech Center | Bless S.,New York University
Mechanics Research Communications | Year: 2015

In this study, a transparent sand surrogate was employed along with high-speed imagery to un-intrusively visualize the penetration of a spherical projectile into the center of a saturated granular target, representing angular sand, at speeds ranging between 60 and 150 m/s. The transparent sand was made by saturating an angular granular fused quartz waste product with a matched refractive index pore fluid made of sucrose. A distinct zone of opacity was observed traveling ahead of the projectile. The opacity zone appears circular during initial penetration and transitions into the shape of an elongated cone in shots with higher initial velocities. Some healing was also observed with time and some increase in transparency was observed. Some of the opacity is attributed to dilatancy of the granular fused quartz during penetration, and healing is attributed to flow of pore fluid into the dilated zone. © 2015 Elsevier Ltd.

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