Physics Commons^™

Simulation Model Of An Automatic Commercial Ice Machine, Haithem Murgham, David Myszka, Vijay Bahel, Rajan Rajendran, Kurt Knapke, Suresh Shivashankar, Kyaw Wynn

David Myszka

Automatic commercial ice-making machines that produce a batch of cube ice at regular intervals are known as “cubers." Such machines are commonly used in food service, food preservation, hotel, and health service industries. The machines are typically rated for the weight of ice produced over a 24-hour period at ambient air temperatures of 90°F and water inlet temperature of 70°F.

These cubers typically utilize an air-cooled, vapor-compression cycle to freeze circulating water flowing over an evaporator grid. Once a sufficient amount ice is formed, a valve switches to enable a harvest mode, where the compressor’s discharge gas is routed into …

Anisoplanatic Electromagnetic Image Propagation Through Narrow Or Extended Phase Turbulence Using Altitude-Dependent Structure Parameter, Monish Ranjan Chatterjee, Ali Mohamed

Monish R. Chatterjee

The effects of turbulence on anisoplanatic imaging are often modeled through the use of a sequence of phase screens distributed along the optical path. We implement the split-step wave algorithm to examine turbulence-corrupted images.

Creating Low-Cost ‘Balloonsats’ For Stem Education With 3d Printing, Jeremy Straub

Jeremy Straub

A new technology, known as 3D printing, allows the rapid fabrication of plastic structures of virtually any configuration. These structures are light-weight, durable and inexpensive. This paper considers the utility of utilizing 3D printing to create enclosures for ‘BalloonSats’ – small, low-cost spacecraft analog which can be utilized by students to understand space engineering, conduct near-space science (e.g., physics, biological and other experiments) and touch the edge of space.

The utility of 3D printed structures for use in the near-space low-temperature and low-pressure environment is considered. This analysis falls into four key areas. First, the ability of the structures to …

Report Of The Commission To Assess The Threat To The United States From Emp Attack: Critical National Infrastructures, William R. Graham

George H Baker

The physical and social fabric of the United States is sustained by a system of systems; a complex and dynamic network of interlocking and interdependent infrastructures (“critical national infrastructures”) whose harmonious functioning enables the myriad actions, transactions, and information flow that undergird the orderly conduct of civil society in this country. The vulnerability of these frastructures to threats — deliberate, accidental, and acts of nature — is the focus of greatly heightened concern in the current era, a process accelerated by the events of 9/11 and recent hurricanes, including Katrina and Rita. This report presents the results of the Commission’s …

A Unified Topological Approach To Electromagnetic Environmental Effects Protection, George H. Baker, J. Philip Castillo, Edward F. Vance

George H Baker

The presentation recommends an approach for unifying electronic system protection designs for a wide spectrum of electromagnetic environments. A general electromagnetic topological construct is developed as the basis for a consistent shielding and terminal protection methodology. Spectral characteristics of multiple interfering electromagnetic sources, both internal and external, are described. Effects addressed include EMI/EMC, lightning, nuclear EMP, and RF weapons. Protection practices for individual effects are discussed and means for integrating these into a single protection topology.

Sliding Mode Control Of The Systems With Uncertain Direction Of Control Vector, Sergey V. Drakunov

Sergey V. Drakunov

No abstract provided.

Sliding-Mode Observers Based On Equivalent Control Method, Sergey V. Drakunov

Sergey V. Drakunov

No abstract provided.