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At least 19 records

Scatter in Cargo Radiography

As a complement to passive detection systems, radiographic inspection of cargo is an increasingly important tool for homeland security because it has the potential to detect highly attenuating objects associated with special nuclear material or surrounding shielding, in addition to screening for items such as drugs or contraband. Radiographic detection of such threat objects relies on high image contrast between regions of different density and atomic number (Z). Threat detection is affected by scatter of the interrogating beamin the cargo, the radiographic system itself, and the surrounding environment, which degrades image contrast. Here, we estimate the extent to which scatter plays a role in radiographic imaging of cargo containers. Stochastic transport simulations were performed to determine the details of the radiography equipment and surrounding environment, which are important in reproducing measured data and to investigate scatter magnitudes for typical cargo. We find that scatter plays a stronger role in cargo radiography than in typicalmedical imaging scenarios, even for low-density cargo, with scatter-toprimary ratios ranging from 0.14 for very low density cargo, to between 0.20 and 0.40 for typical cargo, and higher yet for dense cargo.

99 GENERAL AND MISCELLANEOUS↗

Preliminary Characterization of Unmanned Air Cargo Routes Using Current Cargo Operations Survey

The introduction of regional cargo unmanned aircraft systems into the National Airspace System is anticipated within the coming years. Because they are remotely piloted, these aircraft are expected to utilize increasing aircraft automation and autonomy, require special infrastructure accommodations for navigation, communication, command and control and potentially need special treatment from air traffic control. In order to assess the accessibility and impacts of these operations across the national airspace, this preliminary study investigates current and estimated future demand for air cargo operations in the continental United States. Air cargo demand is broken down by aircraft type and airport categories to produce a rough nation-wide classification of cargo operations. Then, the state of Texas is investigated as a focus region, where the impacts of regional cargo unmanned aircraft systems on the airspace are investigated in further detail. The potential technologies that can assist in regional cargo unmanned aircraft system accessibility are defined at airports across the focus region. A single airport, Fort Worth Alliance, is highlighted to discuss airport-level statistics. Finally, a qualitative classification of airports by the type of cargo operations is suggested.

Unmanned Aircraft↗

Preliminary Characterization of Unmanned Air Cargo Routes Using Current Cargo Operations Survey

The introduction of regional cargo unmanned aircraft systems into the National Airspace System is anticipated within the coming years. Because they are remotely piloted, these aircraft are expected to utilize increasing aircraft automation and autonomy, require special infrastructure accommodations for navigation, communication, command and control and potentially need special treatment from air traffic control. In order to assess the accessibility and impacts of these operations across the national airspace, this preliminary study investigates current and estimated future demand for air cargo operations in the continental United States. Air cargo demand is broken down by aircraft type and airport categories to produce a rough nation-wide classification of cargo operations. Then, the state of Texas is investigated as a focus region, where the impacts of regional cargo unmanned aircraft systems on the airspace are investigated in further detail. The potential technologies that can assist in regional cargo unmanned aircraft system accessibility are defined at airports across the focus region. A single airport, Fort Worth Alliance, is highlighted to discuss airport-level statistics. Finally, a qualitative classification of airports by the type of cargo operations is suggested.

Unmanned Aircraft, Unmanned Aircraft Systems, UAS,↗

Cargo Logistics Airlift Systems Study (CLASS). Volume 1: Analysis of current air cargo system

The material presented in this volume is classified into the following sections; (1) analysis of current routes; (2) air eligibility criteria; (3) current direct support infrastructure; (4) comparative mode analysis; (5) political and economic factors; and (6) future potential market areas. An effort was made to keep the observations and findings relating to the current systems as objective as possible in order not to bias the analysis of future air cargo operations reported in Volume 3 of the CLASS final report.

Burby, R. J.↗

Aviation System Analysis Capability Air Carrier Investment Model-Cargo

The purpose of the Aviation System Analysis Capability (ASAC) Air Cargo Investment Model-Cargo (ACIMC), is to examine the economic effects of technology investment on the air cargo market, particularly the market for new cargo aircraft. To do so, we have built an econometrically based model designed to operate like the ACIM. Two main drivers account for virtually all of the demand: the growth rate of the Gross Domestic Product (GDP) and changes in the fare yield (which is a proxy of the price charged or fare). These differences arise from a combination of the nature of air cargo demand and the peculiarities of the air cargo market. The net effect of these two factors are that sales of new cargo aircraft are much less sensitive to either increases in GDP or changes in the costs of labor, capital, fuel, materials, and energy associated with the production of new cargo aircraft than the sales of new passenger aircraft. This in conjunction with the relatively small size of the cargo aircraft market means technology improvements to the cargo aircraft will do relatively very little to spur increased sales of new cargo aircraft.

Johnson, Jesse↗

Report on the 2011 and 2012 NASA Ames Research Center (ARC) / Alaska State Cargo Airship Workshops

This presentation will summarize the Cargo Airships for Northern Operations workshop that was held August 24-25, 2011. This workshop co-sponsored by NASA ARC and the Alaska State Department of Transportation was initiated by interest from Alaska Lt. Governor Mead Treadwell for assistance in investigating the potential benefits of proposed cargo airships for the Alaskan economy and societal needs. The workshop provided a brief background on the technology and operational aspects of conventional airships and hybrids followed by presentations on issues affecting cargo airship operations such as weather management, insurance, regulations, crew duty/rest rules, and available support infrastructures. Speakers representing potential cargo airship users from Alaskan State and commercial organizations presented the needs they felt could be met by cargo airship services. Presenters from Canadian private and military interests also detailed applications and missions that cargo airships could provide to remote regions of Canada. Cost drivers of cargo airship operations were also addressed and tools for modeling and analyzing operational factors and costs affecting cargo airship operations were discussed. Four breakout sessions were held which allowed workshop participants to contribute inputs to four topic areas: Business Approaches and Strategies (financing incentives public/private partnerships etc) for Airship Development and Operation, Design, Development, Production Challenges, and Possible Solutions, Regulatory, Certification, Legal, and Insurance Issues, and Operational Issues, Customer Requirements, and Airship Requirements. A follow on to the 2011 cargo airship workshop is being planned for July 31 August 2, 2012. A status update on this second workshop will also be presented.

Hochstettler, Ronald↗

Crystal Structures of the Tetratricopeptide Repeat Domains of Kinesin Light Chains: Insight into Cargo Recognition Mechanisms

Kinesin-1 transports various cargos along the axon by interacting with the cargos through its light chain subunit. Kinesin light chains (KLC) utilize its tetratricopeptide repeat (TPR) domain to interact with over 10 different cargos. Despite a high sequence identity between their TPR domains (87%), KLC1 and KLC2 isoforms exhibit differential binding properties towards some cargos. We determined the structures of human KLC1 and KLC2 tetratricopeptide repeat (TPR) domains using X-ray crystallography and investigated the different mechanisms by which KLCs interact with their cargos. Using isothermal titration calorimetry, we attributed the specific interaction between KLC1 and JNK-interacting protein 1 (JIP1) cargo to residue N343 in the fourth TRP repeat. Structurally, the N343 residue is adjacent to other asparagines and lysines, creating a positively charged polar patch within the groove of the TPR domain. Whereas, KLC2 with the corresponding residue S328 did not interact with JIP1. Based on these finding, we propose that N343 of KLC1 can form 'a carboxylate clamp' with its neighboring asparagine to interact with JIP1, similar to that of HSP70/HSP90 organizing protein-1's (HOP1) interaction with heat shock proteins. For the binding of cargos shared by KLC1 and KLC2, we propose a different site located within the groove but not involving N343. We further propose a third binding site on KLC1 which involves a stretch of polar residues along the inter-TPR loops that may form a network of hydrogen bonds to JIP3 and JIP4. Together, these results provide structural insights into possible mechanisms of interaction between KLC TPR domains and various cargo proteins.

08 HYDROGEN↗

Gamma-Ray and Cosmic Ray Muon Modalities for Cargo Inspection

Screening and inspection of cargo containers are two essential methods to nondestructively examine the contents of shipment. These methods enable the detection of illicit transportation of unauthorized materials such as nuclear and radioactive materials, explosives, drugs, and so on, typically at borders or secure facilities. Although high-energy X-ray transmission is a standard system and is widely used for cargo inspection, the inherent challenges of high false-positive rates and high attenuation factors necessitate the development of complementary techniques that can increase the detection efficiency and accuracy in large and dense materials. Gamma-rays, which possess higher penetration characteristics because of their high energy, offer an alternative nonintrusive modality for cargo scanning. They represent a promising inspection method when compared to X-rays for three reasons: (1) improved ability to detect nuclear and radioactive materials, (2) higher inspection throughput rates, and (3) lower false-positive rates. Currently, there are two main gamma-ray inspection techniques, active and passive interrogation. Active interrogation can be further grouped into (1) gamma-ray transmission imaging and (2) neutron-induced gamma-ray emission detection. Gamma-ray transmission imaging utilizes differences in material densities for mapping the shipment contents and detecting anomalies. It is analogous to the X-ray transmission method; however, the high-energy photons make it more difficult to shield against, which enables more efficient performance in large and dense material inspection. Neutron-induced gamma-ray emission inspection is designed for the detection of nuclear and radioactive material because those materials emit characteristic gamma-rays when they are activated by neutron absorption. On the other hand, passive interrogation techniques rely on high-efficiency detectors to detect radiation emitted from hidden special nuclear or other radioactive materials. Similar to passive interrogation, cosmic ray muon monitoring and imaging are relatively new techniques that do not require external radioactive sources. These techniques have received attention as a potential next-generation radiographic probe to identify illicit transportation of nuclear and radioactive materials in cargo containers. Cosmic ray muons have unique features, (1) much higher energies than X-rays or gamma-rays (on the order of 10−1—104 GeV), (2) enhanced penetration capability, and (3) natural occurrence, thereby eliminating the need for induced radiation sources. These features enable cosmic ray muons to be utilized for detection of special nuclear materials in high-background-noise environments. By analyzing incoming and outgoing muon trajectories, scattering angles, and energies, it has been shown that it would be possible to locate hidden and well-shielded materials in cargo containers via three-dimensional muon tomography images or signal analysis. Gamma-rays, cosmic ray muons, and other nonintrusive cargo inspection modalities are complementary to each other, allowing them to address various cargo inspection conditions (i.e., scanning time, cost, radiation exposure level, and types of target materials). This chapter presents a detailed review of the theoretical fundamentals and technical principles behind the current gamma-ray and cosmic ray muon modalities for cargo inspection. Additionally, critical assessments and suggestions for the future directions to advance the use of gamma and muon modalities are discussed.

Bae, Junghyun↗

LMI Automated Air Cargo Operations Market Research and Forecast

Air cargo companies and aircraft manufacturers are making significant investments to enable the movement of cargo via various levels of automated aircraft, such as aircraft with simplified operations requiring a pilot, remotely monitored or piloted aircraft, and fully autonomous aircraft. These investments will enable greater utilization of aircraft while unlocking new air markets traditionally served by ground transportation only. Many cargo companies and aerospace experts envision an operating environment where a single pilot can remotely pilot numerous aircraft for significant increases in aircraft utilization. The future operating environment is also expected to include air cargo companies flying smaller aircraft from airports and distribution centers outside of major U.S. cities directly to city centers, avoiding congested roads and increasing the velocity of cargo shipments, particularly those that are high-value, time-sensitive, and security sensitive (e.g., pharmaceuticals). These are just a few benefits and use cases cargo companies and aerospace experts see with the advancement of automated aircraft. To better understand industry’s direction, NASA asked the LMI team to research the forecasted market, timeline, risks, and opportunities for integrating unmanned air cargo vehicles into the National Airspace System (NAS) for the development and prioritization of the NASA Air Traffic Management Exploration’s research portfolio. To begin the market assessment, we gathered data via numerous interviews with key stakeholders and subject matter experts and literature reviews. We then incorporated the data into a custom-developed systems dynamics model and visualization dashboard. The systems dynamics model classifies the size of the market (e.g., overall fleet size of automated aircraft) for four distinct use cases over the next 20 years. The model projects the year in which various types of automated aircraft will enter the commercial cargo market based on our team’s collective research on when the aircraft will become viable due to manufacturing and certification timelines and the lifespan of current, traditional aircraft in service, to name a few factors. While this report defines our team’s estimated timeline of entry and growth, the model is dynamic—it enables NASA users to change variables based on future-year events. If the necessary technology does not mature in accordance with our assumptions, then NASA can change the entry of service point to a future year to evaluate the changes in market size in the out years. This flexibility will be key to deciding when and how NASA should invest in various areas.

air traffic management↗

Indirect Estimation of Radioactivity in Containerized Cargo

Detecting illicit nuclear and radiological material in containerized cargo challenges the state of the art in detection systems. Current systems are being evaluated and new systems envisioned to address the need for the high probability of detection and extremely low false alarm rates necessary to thwart potential threats and extremely low nuisance and false alarm rates while maintaining necessary to maintain the flow of commerce impacted by the enormous volume of commodities imported in shipping containers. Maintaining flow of commerce also means that primary inspection must be rapid, requiring relatively indirect measurements of cargo from outside the containers. With increasing information content in such indirect measurements, it is natural to ask how the information might be combined to improved detection. Toward this end, we present an approach to estimating isotopic activity of naturally occurring radioactive material in cargo grouped by commodity type, combining container manifest data with radiography and gamma spectroscopy aligned to location along the container. The heart of this approach is our statistical model of gamma counts within peak regions of interest, which captures the effects of background suppression, counting noise, convolution of neighboring cargo contributions, and down-scattered photons to provide physically constrained estimates of counts due to decay of specific radioisotopes in cargo alone. Coupled to that model, we use a mechanistic model of self-attenuated radiation flux to estimate the isotopic activity within cargo, segmented by location within each container, that produces those counts. We demonstrate our approach by applying it to a set of measurements taken at the Port of Seattle in 2006. This approach to synthesizing disparate available data streams and extraction of cargo characteristics holds the potential to improve primary inspection using current detection capabilities and to enable simulation-based evaluation of new candidate detection systems.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

A whole-system approach to x-ray spectroscopy in cargo inspection systems

The bremsstrahlung x-ray spectrum used in high-energy, high-intensity x-ray cargo inspection systems is attenuated and modified by the materials in the cargo in a Z-dependent way. Therefore, spectroscopy of the detected x rays yields information about the Z of the x-rayed cargo material. It has previously been shown that such ZSpectroscopy (Z-SPEC) is possible under certain circumstances. A statistical approach, Z-SCAN (Z-determination by Statistical Count-rate ANalysis), has also been shown to be effective, and it can be used either by itself or in conjunction with Z-SPEC when the x-ray count rate is too high for individual x-ray spectroscopy. Both techniques require fast x-ray detectors and fast digitization electronics. It is desirable (and possible) to combine all techniques, including x-ray imaging of the cargo, in a single detector array, to reduce costs, weight, and overall complexity. In this paper, we take a whole-system approach to x-ray spectroscopy in x-ray cargo inspection systems, and show how the various parts interact with one another. Faster detectors and read-out electronics are beneficial for both techniques. A higher duty-factor x-ray source allows lower instantaneous count rates at the same overall x-ray intensity, improving the range of applicability of Z-SPEC in particular. Using an intensity-modulated advanced x-ray source (IMAXS) allows reducing the x-ray count rate for cargoes with higher transmission, and a stacked-detector approach may help material discrimination for the lowest attenuations. Image processing and segmentation allow derivation of results for entire objects, and subtraction of backgrounds. We discuss R and D performed under a number of different programs, showing progress made in each of the interacting subsystems. We discuss results of studies into faster scintillation detectors, including ZnO, BaF{sub 2} and PbWO{sub 4}, as well as suitable photo-detectors, read-out and digitization electronics. We discuss high-duty-factor linear-accelerator x-ray sources and their associated requirements, and how such sources improve spectroscopic techniques. We further discuss how image processing techniques help in correcting for backgrounds and overlapping materials. In sum, we present an integrated picture of how to optimize a cargo inspection system for x-ray spectroscopy.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Operational efficiency in STS cargo processing

A multifaceted program is presented that addresses both the operational aspects of Shuttle-cargo integration and the needs of the STS Cargo Community. The program consists of the following key elements: (1) processing team awareness of cargo needs and requirements; (2) standardization of Orbiter preparation and cargo integration procedures and methods; (3) maximum application of state-of-the-art ADP techniques in all relevant areas; (4) continual review of cargo integration facility and ground system capabilities versus requirements and enhancement; (5) continual assessment of proposed cargo processing changes for safety and other needs; and (6) review of cargo processing philosophies, policies, and concepts for potential improvements.

Wilson, R. E.↗

Launch packaging options for the photovoltaic power module cargo element

The National Aeronautics and Space Administration recently embarked on the Space Station Freedom program, which will utilize the Shuttle Orbiter for transportation to orbit. This task will be accomplished with a number of flights over several years. Each flight is unique in terms of the hardware that is manifested and the method by which it is integrated to form viable cargo elements. Work Package 4 is responsible for the electric power system for Space Station Freedom, and was delegated the authority to develop a photovoltaic (PV) power module cargo element. The PV power module consists of several unique assemblies. The first of these is the combined solar array/beta gimbal assembly. The remaining assemblies form the single combined integrated equipment assembly for each PV power module. These three combined assemblies are packaged into a launch cradle to form the PV power module cargo element, which is placed in the cargo bay of the Shuttle Orbiter for transportation to orbit. Various constraints determine the packaging options for the three PV power module combined assemblies. The size and shape of the combined assemblies in relation to the Shuttle Orbiter cargo bay dimensions and other manifested hardware are ultimately a factor in determining the acceptable packaging schemes for the PV power module cargo element. Several packaging options for the PV power module cargo element are presented. These options are discussed in terms of their impact on the overall flight hardware manifest as determined by the various constraints.

Hoberecht, Mark A.↗

Systems Analysis and Structural Design of an Unpressurized Cargo Delivery Vehicle

The International Space Station will require a continuous supply of replacement parts for ongoing maintenance and repair after the planned retirement of the Space Shuttle in 2010. These parts are existing line-replaceable items collectively called Orbital Replacement Units, and include heavy and oversized items such as Control Moment Gyroscopes and stowed radiator arrays originally intended for delivery aboard the Space Shuttle. Current resupply spacecraft have limited to no capability to deliver these external logistics. In support of NASA's Exploration Systems Architecture Study, a team at Langley Research Center designed an Unpressurized Cargo Delivery Vehicle to deliver bulk cargo to the Space Station. The Unpressurized Cargo Delivery Vehicle was required to deliver at least 13,200 lbs of cargo mounted on at least 18 Flight Releasable Attachment Mechanisms. The Crew Launch Vehicle design recommended in the Exploration Systems Architecture Study would be used to launch one annual resupply flight to the International Space Station. The baseline vehicle design developed here has a cargo capacity of 16,000 lbs mounted on up to 20 Flight Releasable Attachment Mechanisms. Major vehicle components are a 5.5m-diameter cargo module containing two detachable cargo pallets with the payload, a Service Module to provide propulsion and power, and an aerodynamic nose cone. To reduce cost and risk, the Service Module is identical to the one used for the Crew Exploration Vehicle design.

Wu, K. Chauncey↗

Characterizing Complexity of Containerized Cargo X-ray Images

X-ray imaging can be used to inspect cargos imported into the United States. In order to better understand the performance of X-ray inspection systems, the X-ray characteristics (density, complexity) of cargo need to be quantified. In this project, an image complexity measure called integrated power spectral density (IPSD) was studied using both DNDO engineered cargos and stream-of-commerce (SOC) cargos. A joint distribution of cargo density and complexity was obtained. A support vector machine was used to classify the SOC cargos into four categories to estimate the relative fractions.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

The encapsulin from Thermotoga maritima is a flavoprotein with a symmetry matched ferritin-like cargo protein

Abstract Bacterial nanocompartments, also known as encapsulins, are an emerging class of protein-based ‘organelles’ found in bacteria and archaea. Encapsulins are virus-like icosahedral particles comprising a ~ 25–50 nm shell surrounding a specific cargo enzyme. Compartmentalization is thought to create a unique chemical environment to facilitate catalysis and isolate toxic intermediates. Many questions regarding nanocompartment structure–function remain unanswered, including how shell symmetry dictates cargo loading and to what extent the shell facilitates enzymatic activity. Here, we explore these questions using the model Thermotoga maritima nanocompartment known to encapsulate a redox-active ferritin-like protein. Biochemical analysis revealed the encapsulin shell to possess a flavin binding site located at the interface between capsomere subunits, suggesting the shell may play a direct and active role in the function of the encapsulated cargo. Furthermore, we used cryo-EM to show that cargo proteins use a form of symmetry-matching to facilitate encapsulation and define stoichiometry. In the case of the Thermotoga maritima encapsulin, the decameric cargo protein with fivefold symmetry preferentially binds to the pentameric-axis of the icosahedral shell. Taken together, these observations suggest the shell is not simply a passive barrier—it also plays a significant role in the structure and function of the cargo enzyme.

59 BASIC BIOLOGICAL SCIENCES↗

Fuel Economy and Emissions Effects of Low Tire Pressure, Open Windows, Roof Top and Hitch-Mounted Cargo, and Trailer

To quantify the fuel economy (FE) effect of some common vehicle accessories or alterations, a compact passenger sedan and a sport utility vehicle (SUV) were subjected to SAE J2263 coastdown procedures. Coastdowns were conducted with low tire pressure, all windows open, with a roof top or hitch-mounted cargo carrier, and with the SUV pulling an enclosed cargo trailer. From these coastdowns, vehicle dynamometer coefficients were developed which enabled the execution of vehicle dynamometer experiments to determine the effect of these changes on vehicle FE and emissions over standard drive cycles and at steady highway speeds. The FE penalty associated with the rooftop cargo box mounted on the compact sedan was as high as 25-27% at higher speeds, where the aerodynamic drag is most pronounced. For both vehicles, use of a hitch mounted cargo tray carrying a similar load resulted in very small FE penalties, unlike the rooftop cargo box. The results for the SUV pulling a 3500 pound enclosed cargo trailer were rather dramatic, resulting in FE penalties ranging from 30%, for the city cycle, to 50% at 80 mph, at which point significant CO generation indicated protective enrichment due to high load. Low tire pressure cases resulted in negligible to 10% FE penalty depending on the specific case and test point. Driving with all four windows open decreased FE by 4-8.5% for the compact sedan, and 1-4% for the SUV.

fuel economy↗

The promise of air cargo: System aspects and vehicle design

The current operation of the air cargo system is reviewed. An assessment of the future of air cargo is provided by: (1) analyzing statistics and trends, (2) by noting system problems and inefficiencies, (3) by analyzing characteristics of 'air eligible' commodities, and (4) by showing the promise of new technology for future cargo aircraft with significant improvements in costs and efficiency. The following topics are discussed: (1) air cargo demand forecasts; (2) economics of air cargo transport; (3) the integrated air cargo system; (4) evolution of airfreighter design; and (5) the span distributed load concept.

Whitehead, A. H., Jr.↗