Science.gov

Sample records for multiple-depot heterogeneous vehicle

  1. Heterogeneous Participant Recruitment for Comprehensive Vehicle Sensing.

    PubMed

    Liu, Yazhi; Li, Xiong

    2015-01-01

    Widely distributed mobile vehicles wherein various sensing devices and wireless communication interfaces are installed bring vehicular participatory sensing into practice. However, the heterogeneity of vehicles in terms of sensing capability and mobility, and the participants' expectations on the incentives blackmake the collection of comprehensive sensing data a challenging task. A sensing data quality-oriented optimal heterogeneous participant recruitment strategy is proposed in this paper for vehicular participatory sensing. In the proposed strategy, the differences between the sensing data requirements and the collected sensing data are modeled. An optimization formula is established to model the optimal participant recruitment problem, and a participant utility analysis scheme is built based on the sensing and mobility features of vehicles. Besides, a greedy algorithm is then designed according to the utility of vehicles to recruit the most efficient vehicles with a limited total incentive budget. Real trace-driven simulations show that the proposed strategy can collect 85.4% of available sensing data with 34% incentive budget. PMID:26407102

  2. Heterogeneous Participant Recruitment for Comprehensive Vehicle Sensing

    PubMed Central

    Liu, Yazhi; Li, Xiong

    2015-01-01

    Widely distributed mobile vehicles wherein various sensing devices and wireless communication interfaces are installed bring vehicular participatory sensing into practice. However, the heterogeneity of vehicles in terms of sensing capability and mobility, and the participants’ expectations on the incentives blackmake the collection of comprehensive sensing data a challenging task. A sensing data quality-oriented optimal heterogeneous participant recruitment strategy is proposed in this paper for vehicular participatory sensing. In the proposed strategy, the differences between the sensing data requirements and the collected sensing data are modeled. An optimization formula is established to model the optimal participant recruitment problem, and a participant utility analysis scheme is built based on the sensing and mobility features of vehicles. Besides, a greedy algorithm is then designed according to the utility of vehicles to recruit the most efficient vehicles with a limited total incentive budget. Real trace-driven simulations show that the proposed strategy can collect 85.4% of available sensing data with 34% incentive budget. PMID:26407102

  3. Decomposing the dynamics of heterogeneous delayed networks with applications to connected vehicle systems

    NASA Astrophysics Data System (ADS)

    Szalai, Róbert; Orosz, Gábor

    2013-10-01

    Delay-coupled networks are investigated with nonidentical delay times and the effects of such heterogeneity on the emergent dynamics of complex systems are characterized. A simple decomposition method is presented that decouples the dynamics of the network into node-size modal equations in the vicinity of equilibria. The resulting independent components contain distributed delays that map the spatiotemporal complexity of the system to the time domain. We demonstrate that this approach can be used to reveal physical phenomena in heterogenous vehicular traffic when vehicles are linked via vehicle-to-vehicle communication.

  4. Analysis of vehicle-following heterogeneity using self-organizing feature maps.

    PubMed

    Yang, Jie; Cheu, Ruey Long; Guo, Xiucheng; Romo, Alicia

    2014-01-01

    A self-organizing feature map (SOM) was used to represent vehicle-following and to analyze the heterogeneities in vehicle-following behavior. The SOM was constructed in such a way that the prototype vectors represented vehicle-following stimuli (the follower's velocity, relative velocity, and gap) while the output signals represented the response (the follower's acceleration). Vehicle trajectories collected at a northbound segment of Interstate 80 Freeway at Emeryville, CA, were used to train the SOM. The trajectory information of two selected pairs of passenger cars was then fed into the trained SOM to identify similar stimuli experienced by the followers. The observed responses, when the stimuli were classified by the SOM into the same category, were compared to discover the interdriver heterogeneity. The acceleration profile of another passenger car was analyzed in the same fashion to observe the interdriver heterogeneity. The distribution of responses derived from data sets of car-following-car and car-following-truck, respectively, was compared to ascertain inter-vehicle-type heterogeneity. PMID:25538767

  5. Analysis of Vehicle-Following Heterogeneity Using Self-Organizing Feature Maps

    PubMed Central

    Cheu, Ruey Long; Guo, Xiucheng; Romo, Alicia

    2014-01-01

    A self-organizing feature map (SOM) was used to represent vehicle-following and to analyze the heterogeneities in vehicle-following behavior. The SOM was constructed in such a way that the prototype vectors represented vehicle-following stimuli (the follower's velocity, relative velocity, and gap) while the output signals represented the response (the follower's acceleration). Vehicle trajectories collected at a northbound segment of Interstate 80 Freeway at Emeryville, CA, were used to train the SOM. The trajectory information of two selected pairs of passenger cars was then fed into the trained SOM to identify similar stimuli experienced by the followers. The observed responses, when the stimuli were classified by the SOM into the same category, were compared to discover the interdriver heterogeneity. The acceleration profile of another passenger car was analyzed in the same fashion to observe the interdriver heterogeneity. The distribution of responses derived from data sets of car-following-car and car-following-truck, respectively, was compared to ascertain inter-vehicle-type heterogeneity. PMID:25538767

  6. Urban signalised intersections: Impact of vehicle heterogeneity and driver type on cross-traffic manoeuvres

    NASA Astrophysics Data System (ADS)

    Deo, Puspita; Ruskin, Heather J.

    2014-07-01

    This paper presents a model for heterogeneous traffic at simple X and T-intersections of a single lane and two lane urban roads. Traffic at the intersections is controlled by a set of lights, operated to one of several fixed-time schemes. The heterogeneous traffic consists of both short (e.g. cars) and long (buses/trucks or equivalent) vehicles and is modelled, using a one-dimensional two-component cellular automaton. For intersections, we consider the implications for both homogeneous and heterogeneous traffic flows, based on a minimum space rule. For longer vehicles, this implies occupation of multiple road cells. The distributions of traffic mix and driver type are shown to have significant effect on intersection performance and patterns of flow. Example findings are presented and simple validation of the model basis is given, using available, but limited, local Dublin field data.

  7. A heterogeneous fleet vehicle routing model for solving the LPG distribution problem: A case study

    NASA Astrophysics Data System (ADS)

    Onut, S.; Kamber, M. R.; Altay, G.

    2014-03-01

    Vehicle Routing Problem (VRP) is an important management problem in the field of distribution and logistics. In VRPs, routes from a distribution point to geographically distributed points are designed with minimum cost and considering customer demands. All points should be visited only once and by one vehicle in one route. Total demand in one route should not exceed the capacity of the vehicle that assigned to that route. VRPs are varied due to real life constraints related to vehicle types, number of depots, transportation conditions and time periods, etc. Heterogeneous fleet vehicle routing problem is a kind of VRP that vehicles have different capacity and costs. There are two types of vehicles in our problem. In this study, it is used the real world data and obtained from a company that operates in LPG sector in Turkey. An optimization model is established for planning daily routes and assigned vehicles. The model is solved by GAMS and optimal solution is found in a reasonable time.

  8. Properties analyses for the heterogeneous nonmotorized vehicle traffic based on cellular automaton model

    NASA Astrophysics Data System (ADS)

    Jiang, Hang; Ren, Gang; Zheng, Liang; Chen, Jingxu; Huang, Zhengfeng

    2014-04-01

    As traffic phenomena can be explained by physical method, this interdisciplinary domain has attracted many physicists to explore. The primary object of this research is to reveal the physical characteristics of heterogeneous nonmotorized vehicle traffic composing of conventional bicycles and electric bicycles. Cellular automaton (CA) model is an effective method to reveal the characteristics of the traffic, so a new CA model is proposed to simulate the flow characteristics, overtaking maneuvers patterns and segregation effect in the heterogeneous traffic. In order to realistically describe the traffic characteristics, the new model incorporates the honk effect, performance variance and erratic riding behavior of the nonmotorized vehicles. The simulations achieve three conclusions. First, increasing the ratio of electric bicycles can obtain higher flow and increase the number of overtaking maneuvers. Second, the honk can influence the density-flow diagram and stir up more overtaking maneuvers in the intermediate density region. Third, the existence of segregation effect which means conventional bicycles and electric bicycles could respectively gather together to form clusters is verified and elucidated in the heterogeneous traffic.

  9. Heterogeneous impacts of gender-interpreted contributing factors on driver injury severities in single-vehicle rollover crashes.

    PubMed

    Wu, Qiong; Zhang, Guohui; Chen, Cong; Tarefder, Rafiqul; Wang, Haizhong; Wei, Heng

    2016-09-01

    In this study, a mixed logit model is developed to identify the heterogeneous impacts of gender-interpreted contributing factors on driver injury severities in single-vehicle rollover crashes. The random parameter of the variables in the mixed logit model, the heterogeneous mean, is elaborated by driver gender-based linear regression models. The model is estimated using crash data in New Mexico from 2010 to 2012. The percentage changes of factors' predicted probabilities are calculated in order to better understand the model specifications. Female drivers are found more likely to experience severe or fatal injuries in rollover crashes than male drivers. However, the probability of male drivers being severely injured is higher than female drivers when the road surface is unpaved. Two other factors with fixed parameters are also found to significantly increase driver injury severities, including Wet and Alcohol Influenced. This study provides a better understanding of contributing factors influencing driver injury severities in rollover crashes as well as their heterogeneous impacts in terms of driver gender. Those results are also helpful to develop appropriate countermeasures and policies to reduce driver injury severities in single-vehicle rollover crashes. PMID:27240126

  10. Nitrous acid (HONO) in a polluted subtropical atmosphere: Seasonal variability, direct vehicle emissions and heterogeneous production at ground surface

    NASA Astrophysics Data System (ADS)

    Xu, Zheng; Wang, Tao; Wu, Jueqi; Xue, Likun; Chan, James; Zha, Qiaozhi; Zhou, Shengzhen; Louie, Peter K. K.; Luk, Connie W. Y.

    2015-04-01

    Although nitrous acid (HONO) plays an important role in the chemistry of polluted atmospheres, its atmospheric abundances and sources are still not well understood. This paper reports ambient measurements of HONO taken over four select months in different seasons at a suburban site in Hong Kong. The data were analyzed to elucidate the seasonal characteristics, emission ratios and rates of heterogeneous production. The monthly averaged HONO concentrations ranged from 0.35 ± 0.30 ppbv in late spring (May) to 0.93 ± 0.67 ppbv in late autumn (November). The similar variation patterns of HONO, NOx, and traffic flow from midnight to rush hours suggest that the HONO concentration was strongly influenced by vehicle emissions. The emission ratios (HONO/NOx) were derived from an analysis of 21 fresh plumes (NO/NOx > 0.80), with the range of 0.5-1.6%. The large variability in the emission ratios is attributed to the reaction of NO2 on black carbon (BC) emitted from vehicles, based on a strong correlation between the HONO/NOx and concurrently measured BC. The mean conversion rate of NO2 to HONO on ground surface during nighttime estimated on nine select days was 0.52 × 10-2 h-1, which is relatively low compared with other reported values. This paper highlights a large variability in vehicle emission ratios and heterogeneous conversions of NO2 at ground surface. Photochemical models must consider this variability to better simulate the primary sources of HONO and subsequent photochemistry in the lower part of the troposphere.

  11. Cooperative vehicle routing problem: an opportunity for cost saving

    NASA Astrophysics Data System (ADS)

    Zibaei, Sedighe; Hafezalkotob, Ashkan; Ghashami, Seyed Sajad

    2016-02-01

    In this paper, a novel methodology is proposed to solve a cooperative multi-depot vehicle routing problem. We establish a mathematical model for multi-owner VRP in which each owner (i.e. player) manages single or multiple depots. The basic idea consists of offering an option that owners cooperatively manage the VRP to save their costs. We present cooperative game theory techniques for cost saving allocations which are obtained from various coalitions of owners. The methodology is illustrated with a numerical example in which different coalitions of the players are evaluated along with the results of cooperation and cost saving allocation methods.

  12. Introducing heterogeneous users and vehicles into models and algorithms for the dial-a-ride problem.

    PubMed

    Parragh, Sophie N

    2011-08-01

    Dial-a-ride problems deal with the transportation of people between pickup and delivery locations. Given the fact that people are subject to transportation, constraints related to quality of service are usually present, such as time windows and maximum user ride time limits. In many real world applications, different types of users exist. In the field of patient and disabled people transportation, up to four different transportation modes can be distinguished. In this article we consider staff seats, patient seats, stretchers and wheelchair places. Furthermore, most companies involved in the transportation of the disabled or ill dispose of different types of vehicles. We introduce both aspects into state-of-the-art formulations and branch-and-cut algorithms for the standard dial-a-ride problem. Also a recent metaheuristic method is adapted to this new problem. In addition, a further service quality related issue is analyzed: vehicle waiting time with passengers aboard. Instances with up to 40 requests are solved to optimality. High quality solutions are obtained with the heuristic method. PMID:24511211

  13. Introducing heterogeneous users and vehicles into models and algorithms for the dial-a-ride problem

    PubMed Central

    Parragh, Sophie N.

    2011-01-01

    Dial-a-ride problems deal with the transportation of people between pickup and delivery locations. Given the fact that people are subject to transportation, constraints related to quality of service are usually present, such as time windows and maximum user ride time limits. In many real world applications, different types of users exist. In the field of patient and disabled people transportation, up to four different transportation modes can be distinguished. In this article we consider staff seats, patient seats, stretchers and wheelchair places. Furthermore, most companies involved in the transportation of the disabled or ill dispose of different types of vehicles. We introduce both aspects into state-of-the-art formulations and branch-and-cut algorithms for the standard dial-a-ride problem. Also a recent metaheuristic method is adapted to this new problem. In addition, a further service quality related issue is analyzed: vehicle waiting time with passengers aboard. Instances with up to 40 requests are solved to optimality. High quality solutions are obtained with the heuristic method. PMID:24511211

  14. Introducing the MCHF/OVRP/SDMP: Multicapacitated/Heterogeneous Fleet/Open Vehicle Routing Problems with Split Deliveries and Multiproducts

    PubMed Central

    Yilmaz Eroglu, Duygu; Caglar Gencosman, Burcu; Cavdur, Fatih; Ozmutlu, H. Cenk

    2014-01-01

    In this paper, we analyze a real-world OVRP problem for a production company. Considering real-world constrains, we classify our problem as multicapacitated/heterogeneous fleet/open vehicle routing problem with split deliveries and multiproduct (MCHF/OVRP/SDMP) which is a novel classification of an OVRP. We have developed a mixed integer programming (MIP) model for the problem and generated test problems in different size (10–90 customers) considering real-world parameters. Although MIP is able to find optimal solutions of small size (10 customers) problems, when the number of customers increases, the problem gets harder to solve, and thus MIP could not find optimal solutions for problems that contain more than 10 customers. Moreover, MIP fails to find any feasible solution of large-scale problems (50–90 customers) within time limits (7200 seconds). Therefore, we have developed a genetic algorithm (GA) based solution approach for large-scale problems. The experimental results show that the GA based approach reaches successful solutions with 9.66% gap in 392.8 s on average instead of 7200 s for the problems that contain 10–50 customers. For large-scale problems (50–90 customers), GA reaches feasible solutions of problems within time limits. In conclusion, for the real-world applications, GA is preferable rather than MIP to reach feasible solutions in short time periods. PMID:25045735

  15. Modeling blood flow heterogeneity.

    PubMed

    King, R B; Raymond, G M; Bassingthwaighte, J B

    1996-01-01

    analyzed. The separation between the distributions was further reduced when tissue content curves were analyzed. It is concluded that multipath models accounting for flow heterogeneity are a vehicle for assessing the effects of flow heterogeneity under the conditions applicable to specific laboratory protocols, that efforts should be made to assess the actual level of flow heterogeneity in the organ being studied, and that the errors in parameter estimates are generally smaller when the input function is known rather than estimated by deconvolution. PMID:8734057

  16. Heterogeneous Catalysis.

    ERIC Educational Resources Information Center

    Miranda, R.

    1989-01-01

    Described is a heterogeneous catalysis course which has elements of materials processing embedded in the classical format of catalytic mechanisms and surface chemistry. A course outline and list of examples of recent review papers written by students are provided. (MVL)

  17. Intelligent Vehicle Health Management

    NASA Technical Reports Server (NTRS)

    Paris, Deidre E.; Trevino, Luis; Watson, Michael D.

    2005-01-01

    objectives: Guidance and Navigation; Communications and Tracking; Vehicle Monitoring; Information Transport and Integration; Vehicle Diagnostics; Vehicle Prognostics; Vehicle mission Planning; Automated Repair and Replacement; Vehicle Control; Human Computer Interface; and Onboard Verification and Validation. Furthermore, the presented framework provides complete vehicle management which not only allows for increased crew safety and mission success through new intelligence capabilities, but also yields a mechanism for more efficient vehicle operations. The representative IVHM technologies for computer platform using heterogeneous communication, 3) coupled electromagnetic oscillators for enhanced communications, 4) Linux-based real-time systems, 5) genetic algorithms, 6) Bayesian Networks, 7) evolutionary algorithms, 8) dynamic systems control modeling, and 9) advanced sensing capabilities. This paper presents IVHM technologies developed under NASA's NFFP pilot project and the integration of these technologies forms the framework for IIVM.

  18. Electric vehicles

    SciTech Connect

    Not Available

    1990-03-01

    Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. This paper discusses these concepts.

  19. Descent vehicles

    NASA Technical Reports Server (NTRS)

    Popov, Y. I.

    1985-01-01

    The creation of descent vehicles marked a new stage in the development of cosmonautics, involving the beginning of manned space flight and substantial progress in space research on the distant bodies of the Solar System. This booklet describes these vehicles and their structures, systems, and purposes. It is intended for the general public interested in modern problems of space technology.

  20. Vehicle systems

    NASA Technical Reports Server (NTRS)

    Bales, Tom; Modlin, Tom; Suddreth, Jack; Wheeler, Tom; Tenney, Darrel R.; Bayless, Ernest O.; Lisagor, W. Barry; Bolstad, Donald A.; Croop, Harold; Dyer, J.

    1993-01-01

    Perspectives of the subpanel on expendable launch vehicle structures and cryotanks are: (1) new materials which provide the primary weight savings effect on vehicle mass/size; (2) today's investment; (3) typically 10-20 years to mature and fully characterize new materials.

  1. Space vehicle

    NASA Technical Reports Server (NTRS)

    Vonpragenau, G. L. (Inventor)

    1975-01-01

    A space vehicle having an improved ascent configuration for use in traveling in space is presented. Components of the vehicle are: (1) a winged orbiter having an elongater fuselage and rearwardly directed main engines fixed to the fuselage; (2) an elongated tank assembly of an improved configuration disposed forwardly of the fuselage and connected with the main engines of the vehicle for supplying liquid propellants; and (3) a booster stage comprising a pair of integrated solid rocket boosters connected with the orbiter immediately beneath the fuselage and extended in substantial parallelism.

  2. Robotic vehicle

    DOEpatents

    Box, W.D.

    1998-08-11

    A robotic vehicle is described for travel through a conduit. The robotic vehicle includes forward and rear housings each having a hub portion, and each being provided with surface engaging mechanisms for selectively engaging the walls of the conduit such that the housings can be selectively held in stationary positions within the conduit. The surface engaging mechanisms of each housing includes a plurality of extendible appendages, each of which is radially extendible relative to the operatively associated hub portion between a retracted position and a radially extended position. The robotic vehicle also includes at least three selectively extendible members extending between the forward and rear housings, for selectively changing the distance between the forward and rear housings to effect movement of the robotic vehicle. 20 figs.

  3. Robotic vehicle

    DOEpatents

    Box, W.D.

    1997-02-11

    A robotic vehicle is described for travel through a conduit. The robotic vehicle includes forward and rear housings each having a hub portion, and each being provided with surface engaging mechanisms for selectively engaging the walls of the conduit such that the housings can be selectively held in stationary positions within the conduit. The surface engaging mechanisms of each housing includes a plurality of extendable appendages, each of which is radially extendable relative to the operatively associated hub portion between a retracted position and a radially extended position. The robotic vehicle also includes at least three selectively extendable members extending between the forward and rear housings, for selectively changing the distance between the forward and rear housings to effect movement of the robotic vehicle. 20 figs.

  4. Robotic vehicle

    DOEpatents

    Box, W. Donald

    1998-01-01

    A robotic vehicle for travel through a conduit. The robotic vehicle includes forward and rear housings each having a hub portion, and each being provided with surface engaging mechanisms for selectively engaging the walls of the conduit such that the housings can be selectively held in stationary positions within the conduit. The surface engaging mechanisms of each housing includes a plurality of extendable appendages, each of which is radially extendable relative to the operatively associated hub portion between a retracted position and a radially extended position. The robotic vehicle also includes at least three selectively extendable members extending between the forward and rear housings, for selectively changing the distance between the forward and rear housings to effect movement of the robotic vehicle.

  5. Robotic vehicle

    DOEpatents

    Box, W. Donald

    1997-01-01

    A robotic vehicle for travel through a conduit. The robotic vehicle includes forward and rear housings each having a hub portion, and each being provided with surface engaging mechanisms for selectively engaging the walls of the conduit such that the housings can be selectively held in stationary positions within the conduit. The surface engaging mechanisms of each housing includes a plurality of extendable appendages, each of which is radially extendable relative to the operatively associated hub portion between a retracted position and a radially extended position. The robotic vehicle also includes at least three selectively extendable members extending between the forward and rear housings, for selectively changing the distance between the forward and rear housings to effect movement of the robotic vehicle.

  6. Autonomous vehicles

    SciTech Connect

    Meyrowitz, A.L.; Blidberg, D.R.; Michelson, R.C. |

    1996-08-01

    There are various kinds of autonomous vehicles (AV`s) which can operate with varying levels of autonomy. This paper is concerned with underwater, ground, and aerial vehicles operating in a fully autonomous (nonteleoperated) mode. Further, this paper deals with AV`s as a special kind of device, rather than full-scale manned vehicles operating unmanned. The distinction is one in which the AV is likely to be designed for autonomous operation rather than being adapted for it as would be the case for manned vehicles. The authors provide a survey of the technological progress that has been made in AV`s, the current research issues and approaches that are continuing that progress, and the applications which motivate this work. It should be noted that issues of control are pervasive regardless of the kind of AV being considered, but that there are special considerations in the design and operation of AV`s depending on whether the focus is on vehicles underwater, on the ground, or in the air. The authors have separated the discussion into sections treating each of these categories.

  7. Robotic vehicle

    DOEpatents

    Box, W.D.

    1994-03-15

    A robotic vehicle is described for travel through an enclosed or partially enclosed conduit or pipe including vertical and/or horizontal conduit or pipe. The robotic vehicle comprises forward and rear housings each provided with a surface engaging mechanism for selectively engaging the walls of the conduit through which the vehicle is travelling, whereby the housings are selectively held in a stationary position within the conduit. The vehicle also includes at least three selectively extendable members, each of which defines a cavity therein. The forward end portion of each extendable member is secured to the forward housing and the rear end portion of each housing is secured to the rear housing. Each of the extendable members is independently extendable from a retracted position to an extended position upon the injection of a gas under pressure into the cavity of the extendable member such that the distance between the forward housing and the rear housing can be selectively increased. Further, each of the extendable members is independently retractable from the extended position to the retracted position upon the application of a vacuum to the cavity of the extendable member such that the distance between the forward housing and the rear housing can be selectively decreased. 11 figures.

  8. Robotic vehicle

    DOEpatents

    Box, W.D.

    1996-03-12

    A robotic vehicle is described for travel through an enclosed or partially enclosed conduit or pipe including vertical and/or horizontal conduit or pipe. The robotic vehicle comprises forward and rear housings each provided with a surface engaging mechanism for selectively engaging the walls of the conduit through which the vehicle is travelling, whereby the housings are selectively held in a stationary position within the conduit. The vehicle also includes at least three selectively extendable members, each of which defines a cavity therein. The forward end portion of each extendable member is secured to the forward housing and the rear end portion of each housing is secured to the rear housing. Each of the extendable members is independently extendable from a retracted position to an extended position upon the injection of a gas under pressure into the cavity of the extendable member such that the distance between the forward housing and the rear housing can be selectively increased. Further, each of the extendable members is independently retractable from the extended position to the retracted position upon the application of a vacuum to the cavity of the extendable member such that the distance between the forward housing and the rear housing can be selectively decreased. 14 figs.

  9. Robotic vehicle

    DOEpatents

    Box, W. Donald

    1996-01-01

    A robotic vehicle (10) for travel through an enclosed or partially enclosed conduit or pipe including vertical and/or horizontal conduit or pipe. The robotic vehicle (10) comprises forward and rear housings (32 and 12) each provided with a surface engaging mechanism for selectively engaging the walls of the conduit through which the vehicle is travelling, whereby the housings (32 and 12) are selectively held in a stationary position within the conduit. The vehicle (10) also includes at least three selectively extendable members (46), each of which defines a cavity (56) therein. The forward end portion (50) of each extendable member (46) is secured to the forward housing (32) and the rear end portion (48) of each housing is secured to the rear housing (12). Each of the extendable members (46) is independently extendable from a retracted position to an extended position upon the injection of a gas under pressure into the cavity (56) of the extendable member such that the distance between the forward housing (32 ) and the rear housing (12) can be selectively increased. Further, each of the extendable members (46) is independently retractable from the extended position to the retracted position upon the application of a vacuum to the cavity (56) of the extendable member (46) such that the distance between the forward housing (32) and the rear housing (12) can be selectively decreased.

  10. Robotic vehicle

    DOEpatents

    Box, W. Donald

    1994-01-01

    A robotic vehicle (10) for travel through an enclosed or partially enclosed conduit or pipe including vertical and/or horizontal conduit or pipe. The robotic vehicle (10) comprises forward and rear housings (32 and 12) each provided with a surface engaging mechanism for selectively engaging the walls of the conduit through which the vehicle is travelling, whereby the housings (32 and 12) are selectively held in a stationary position within the conduit. The vehicle (10) also includes at least three selectively extendable members (46), each of which defines a cavity (56) therein. The forward end portion (50) of each extendable member (46) is secured to the forward housing (32) and the rear end portion (48) of each housing is secured to the rear housing (12). Each of the extendable members (46) is independently extendable from a retracted position to an extended position upon the injection of a gas under pressure into the cavity (56) of the extendable member such that the distance between the forward housing (32 ) and the rear housing (12) can be selectively increased. Further, each of the extendable members (46) is independently retractable from the extended position to the retracted position upon the application of a vacuum to the cavity (56) of the extendable member (46) such that the distance between the forward housing (32) and the rear housing (12) can be selectively decreased.

  11. Phenotypically heterogeneous populations in spatially heterogeneous environments

    NASA Astrophysics Data System (ADS)

    Patra, Pintu; Klumpp, Stefan

    2014-03-01

    The spatial expansion of a population in a nonuniform environment may benefit from phenotypic heterogeneity with interconverting subpopulations using different survival strategies. We analyze the crossing of an antibiotic-containing environment by a bacterial population consisting of rapidly growing normal cells and slow-growing, but antibiotic-tolerant persister cells. The dynamics of crossing is characterized by mean first arrival times and is found to be surprisingly complex. It displays three distinct regimes with different scaling behavior that can be understood based on an analytical approximation. Our results suggest that a phenotypically heterogeneous population has a fitness advantage in nonuniform environments and can spread more rapidly than a homogeneous population.

  12. Patterns of Emphysema Heterogeneity

    PubMed Central

    Valipour, Arschang; Shah, Pallav L.; Gesierich, Wolfgang; Eberhardt, Ralf; Snell, Greg; Strange, Charlie; Barry, Robert; Gupta, Avina; Henne, Erik; Bandyopadhyay, Sourish; Raffy, Philippe; Yin, Youbing; Tschirren, Juerg; Herth, Felix J.F.

    2016-01-01

    Background Although lobar patterns of emphysema heterogeneity are indicative of optimal target sites for lung volume reduction (LVR) strategies, the presence of segmental, or sublobar, heterogeneity is often underappreciated. Objective The aim of this study was to understand lobar and segmental patterns of emphysema heterogeneity, which may more precisely indicate optimal target sites for LVR procedures. Methods Patterns of emphysema heterogeneity were evaluated in a representative cohort of 150 severe (GOLD stage III/IV) chronic obstructive pulmonary disease (COPD) patients from the COPDGene study. High-resolution computerized tomography analysis software was used to measure tissue destruction throughout the lungs to compute heterogeneity (≥ 15% difference in tissue destruction) between (inter-) and within (intra-) lobes for each patient. Emphysema tissue destruction was characterized segmentally to define patterns of heterogeneity. Results Segmental tissue destruction revealed interlobar heterogeneity in the left lung (57%) and right lung (52%). Intralobar heterogeneity was observed in at least one lobe of all patients. No patient presented true homogeneity at a segmental level. There was true homogeneity across both lungs in 3% of the cohort when defining heterogeneity as ≥ 30% difference in tissue destruction. Conclusion Many LVR technologies for treatment of emphysema have focused on interlobar heterogeneity and target an entire lobe per procedure. Our observations suggest that a high proportion of patients with emphysema are affected by interlobar as well as intralobar heterogeneity. These findings prompt the need for a segmental approach to LVR in the majority of patients to treat only the most diseased segments and preserve healthier ones. PMID:26430783

  13. Tumour Cell Heterogeneity

    PubMed Central

    Gay, Laura; Baker, Ann-Marie; Graham, Trevor A.

    2016-01-01

    The population of cells that make up a cancer are manifestly heterogeneous at the genetic, epigenetic, and phenotypic levels. In this mini-review, we summarise the extent of intra-tumour heterogeneity (ITH) across human malignancies, review the mechanisms that are responsible for generating and maintaining ITH, and discuss the ramifications and opportunities that ITH presents for cancer prognostication and treatment. PMID:26973786

  14. Impacts of SOC on car-following behavior and travel time in the heterogeneous traffic system

    NASA Astrophysics Data System (ADS)

    Tang, Tie-Qiao; Xu, Ke-Wei; Yang, Shi-Chun; Ding, Chuan

    2016-01-01

    Since the SOC (state of charge) of the battery of each electric vehicle directly determines whether the battery should be charged/swapped, the SOC may affect the electric vehicle's driving behavior. In this paper, we introduce the SOC of battery into the electric vehicle's driving behavior model and propose a car-following model for electric vehicles, and then use the proposed model to study the effects of the SOC of battery and battery swap on each vehicle's driving behavior in the heterogeneous traffic system consisting of traditional vehicles and electric vehicles. The numerical results show that the proposed model can reproduce some complex traffic phenomena resulted by the SOC of battery and battery swap and that the influences on each vehicle's driving behavior are directly related to the initial traffic state, the electric vehicle's proportion, and the SOC of battery.

  15. Distributed Task Offloading in Heterogeneous Vehicular Crowd Sensing.

    PubMed

    Liu, Yazhi; Wang, Wendong; Ma, Yuekun; Yang, Zhigang; Yu, Fuxing

    2016-01-01

    The ability of road vehicles to efficiently execute different sensing tasks varies because of the heterogeneity in their sensing ability and trajectories. Therefore, the data collection sensing task, which requires tempo-spatial sensing data, becomes a serious problem in vehicular sensing systems, particularly those with limited sensing capabilities. A utility-based sensing task decomposition and offloading algorithm is proposed in this paper. The utility function for a task executed by a certain vehicle is built according to the mobility traces and sensing interfaces of the vehicle, as well as the sensing data type and tempo-spatial coverage requirements of the sensing task. Then, the sensing tasks are decomposed and offloaded to neighboring vehicles according to the utilities of the neighboring vehicles to the decomposed sensing tasks. Real trace-driven simulation shows that the proposed task offloading is able to collect much more comprehensive and uniformly distributed sensing data than other algorithms. PMID:27428967

  16. Distributed Task Offloading in Heterogeneous Vehicular Crowd Sensing

    PubMed Central

    Liu, Yazhi; Wang, Wendong; Ma, Yuekun; Yang, Zhigang; Yu, Fuxing

    2016-01-01

    The ability of road vehicles to efficiently execute different sensing tasks varies because of the heterogeneity in their sensing ability and trajectories. Therefore, the data collection sensing task, which requires tempo-spatial sensing data, becomes a serious problem in vehicular sensing systems, particularly those with limited sensing capabilities. A utility-based sensing task decomposition and offloading algorithm is proposed in this paper. The utility function for a task executed by a certain vehicle is built according to the mobility traces and sensing interfaces of the vehicle, as well as the sensing data type and tempo-spatial coverage requirements of the sensing task. Then, the sensing tasks are decomposed and offloaded to neighboring vehicles according to the utilities of the neighboring vehicles to the decomposed sensing tasks. Real trace-driven simulation shows that the proposed task offloading is able to collect much more comprehensive and uniformly distributed sensing data than other algorithms. PMID:27428967

  17. Heterogeneous Atmospheric Chemistry

    NASA Astrophysics Data System (ADS)

    Schryer, David R.

    In the past few years it has become increasingly clear that heterogeneous, or multiphase, processes play an important role in the atmosphere. Unfortunately the literature on the subject, although now fairly extensive, is still rather dispersed. Furthermore, much of the expertise regarding heterogeneous processes lies in fields not directly related to atmospheric science. Therefore, it seemed desirable to bring together for an exchange of ideas, information, and methodologies the various atmospheric scientists who are actively studying heterogeneous processes as well as other researchers studying similar processes in the context of other fields.

  18. Vehicle barrier

    DOEpatents

    Hirsh, Robert A.

    1991-01-01

    A vehicle security barrier which can be conveniently placed across a gate opening as well as readily removed from the gate opening to allow for easy passage. The security barrier includes a barrier gate in the form of a cable/gate member in combination with laterally attached pipe sections fixed by way of the cable to the gate member and lateral, security fixed vertical pipe posts. The security barrier of the present invention provides for the use of cable restraints across gate openings to provide necessary security while at the same time allowing for quick opening and closing of the gate areas without compromising security.

  19. Cosmeceutical vehicles.

    PubMed

    Epstein, Howard

    2009-01-01

    Consumers will pay a premium for high-performance skin and hair care products. The demand exists, and in return for the high cost, consumers expect the product to perform as claimed and to meet aesthetic standards beyond many products found in the mass market. To be successful in this highly competitive market, products must function as claimed or consumers will not repurchase. Effective contemporary high-end products must be properly formulated in nonirritating vehicles that consumers will perceive as elegant. PMID:19695476

  20. Teaching Heterogeneous Classes.

    ERIC Educational Resources Information Center

    Millrood, Radislav

    2002-01-01

    Discusses an approach to teaching heterogeneous English-as-a-Second/Foreign-Language classes. Draws on classroom research data to describe the features of a success-building lesson context. (Author/VWL)

  1. Heterogeneous atmospheric chemistry

    NASA Technical Reports Server (NTRS)

    Schryer, D. R.

    1982-01-01

    The present conference on heterogeneous atmospheric chemistry considers such topics concerning clusters, particles and microparticles as common problems in nucleation and growth, chemical kinetics, and catalysis, chemical reactions with aerosols, electron beam studies of natural and anthropogenic microparticles, and structural studies employing molecular beam techniques, as well as such gas-solid interaction topics as photoassisted reactions, catalyzed photolysis, and heterogeneous catalysis. Also discussed are sulfur dioxide absorption, oxidation, and oxidation inhibition in falling drops, sulfur dioxide/water equilibria, the evidence for heterogeneous catalysis in the atmosphere, the importance of heterogeneous processes to tropospheric chemistry, soot-catalyzed atmospheric reactions, and the concentrations and mechanisms of formation of sulfate in the atmospheric boundary layer.

  2. Towards heterogeneous distributed debugging

    SciTech Connect

    Damodaran-Kamal, S.K.

    1995-04-01

    Several years of research and development in parallel debugger design have given up several techniques, though implemented in a wide range of tools for an equally wide range of systems. This paper is an evaluation of these myriad techniques as applied to the design of a heterogeneous distributed debugger. The evaluation is based on what features users perceive as useful, as well as the ease of implementation of the features using the available technology. A preliminary architecture for such a heterogeneous tool is proposed. Our effort in this paper is significantly different from the other efforts at creating portable and heterogeneous distributed debuggers in that we concentrate on support for all the important issues in parallel debugging, instead of simply concentrating on portability and heterogeneity.

  3. Characterization of Paper Heterogeneity

    NASA Astrophysics Data System (ADS)

    Considine, John M.

    Paper and paperboard are the most widely-used green materials in the world because they are renewable, recyclable, reusable, and compostable. Continued and expanded use of these materials and their potential use in new products requires a comprehensive understanding of the variability of their mechanical properties. This work develops new methods to characterize the mechanical properties of heterogeneous materials through a combination of techniques in experimental mechanics, materials science and numerical analysis. Current methods to analyze heterogeneous materials focus on crystalline materials or polymer-crystalline composites, where material boundaries are usually distinct. This work creates a methodology to analyze small, continuously-varying stiffness gradients in 100% polymer systems and is especially relevant to paper materials where factors influencing heterogeneity include local mass, fiber orientation, individual pulp fiber properties, local density, and drying restraint. A unique approach was used to understand the effect of heterogeneity on paper tensile strength. Additional variation was intentionally introduced, in the form of different size holes, and their effect on strength was measured. By modifying two strength criteria, an estimate of strength in the absence of heterogeneity was determined. In order to characterize stiffness heterogeneity, a novel load fixture was developed to excite full-field normal and shear strains for anisotropic stiffness determination. Surface strains were measured with digital image correlation and were analyzed with the VFM (Virtual Fields Method). This approach led to VFM-identified stiffnesses that were similar to values determined by conventional tests. The load fixture and VFM analyses were used to measure local stiffness and local stiffness variation on heterogeneous anisotropic materials. The approach was validated on simulated heterogeneous materials and was applied experimentally to three different paperboards

  4. Forestry Vehicle

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Power Pack II provides an economical means of moving a power source into remote roadless forest areas. It was developed by Prof. Miles and his associates, working in cooperation with the University of California's Department of Forestry. The team combined its own design of an all-terrain vehicle with a suspension system based on the NASA load equalization technology. Result is an intermediate-sized unit which carries a power source and the powered tools to perform a variety of forest management tasks which cannot be done economically with current equipment. Power Pack II can traverse very rough terrain and climb a 60 degree slope; any one of the wheels can move easily over an obstacle larger than itself. Work is being done on a more advanced Power Pack III.

  5. Combination vehicle assembly

    SciTech Connect

    Silverman, M.J. Sr.

    1987-03-17

    A combination recreational vehicle assembly is described comprising: two vehicles of a different type, the vehicles comprising a first, leading vehicle having a steering mechanism for maneuvering the assembly and a drivable axle mechanism for propelling the assembly; an independently drivable second vehicle trailing the first vehicle comprising a standard road vehicle having a motor, and an axle mechanism for connecting the motor to the wheels of the second vehicle for providing power to the wheels of the vehicle. A gear means for selectively disconnecting the motor from the axle mechanism to place the vehicle in neutral, and a steering means for maneuvering the second vehicle when driven independently of the first vehicle are included; and a releasable mechanical drive connection between the second vehicle motor and the first vehicle axle mechanism to provide power for driving the assembly. The drive connection comprises a drive pinion projecting from the second vehicle motor to the front of the second vehicle, and a drive shaft projecting from the first vehicle axle mechanism to the rear of the first vehicle.

  6. Managing Power Heterogeneity

    NASA Astrophysics Data System (ADS)

    Pruhs, Kirk

    A particularly important emergent technology is heterogeneous processors (or cores), which many computer architects believe will be the dominant architectural design in the future. The main advantage of a heterogeneous architecture, relative to an architecture of identical processors, is that it allows for the inclusion of processors whose design is specialized for particular types of jobs, and for jobs to be assigned to a processor best suited for that job. Most notably, it is envisioned that these heterogeneous architectures will consist of a small number of high-power high-performance processors for critical jobs, and a larger number of lower-power lower-performance processors for less critical jobs. Naturally, the lower-power processors would be more energy efficient in terms of the computation performed per unit of energy expended, and would generate less heat per unit of computation. For a given area and power budget, heterogeneous designs can give significantly better performance for standard workloads. Moreover, even processors that were designed to be homogeneous, are increasingly likely to be heterogeneous at run time: the dominant underlying cause is the increasing variability in the fabrication process as the feature size is scaled down (although run time faults will also play a role). Since manufacturing yields would be unacceptably low if every processor/core was required to be perfect, and since there would be significant performance loss from derating the entire chip to the functioning of the least functional processor (which is what would be required in order to attain processor homogeneity), some processor heterogeneity seems inevitable in chips with many processors/cores.

  7. Vehicle/engine integration. [orbit transfer vehicles

    NASA Technical Reports Server (NTRS)

    Cooper, L. P.; Vinopal, T. J.; Florence, D. E.; Michel, R. W.; Brown, J. R.; Bergeron, R. P.; Weldon, V. A.

    1984-01-01

    VEHICLE/ENGINE Integration Issues are explored for orbit transfer vehicles (OTV's). The impact of space basing and aeroassist on VEHICLE/ENGINE integration is discussed. The AOTV structure and thermal protection subsystem weights were scaled as the vehicle length and surface was changed. It is concluded that for increased allowable payload lengths in a ground-based system, lower length-to-diameter (L/D) is as important as higher mixture ration (MR) in the range of mid L/D ATOV's. Scenario validity, geometry constraints, throttle levels, reliability, and servicing are discussed in the context of engine design and engine/vehicle integration.

  8. Evaluating foam heterogeneity

    NASA Technical Reports Server (NTRS)

    Liou, D. W.; Lee, W. M.

    1972-01-01

    New analytical tool is available to calculate the degree of foam heterogeneity based on the measurement of gas diffusivity values. Diffusion characteristics of plastic foam are described by a system of differential equations based on conventional diffusion theory. This approach saves research and computation time in studying mass or heat diffusion problems.

  9. Heterogeneous waste processing

    DOEpatents

    Vanderberg, Laura A.; Sauer, Nancy N.; Brainard, James R.; Foreman, Trudi M.; Hanners, John L.

    2000-01-01

    A combination of treatment methods are provided for treatment of heterogeneous waste including: (1) treatment for any organic compounds present; (2) removal of metals from the waste; and, (3) bulk volume reduction, with at least two of the three treatment methods employed and all three treatment methods emplyed where suitable.

  10. Electric and hybrid vehicles

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Report characterizes state-of-the-art electric and hybrid (combined electric and heat engine) vehicles. Performance data for representative number of these vehicles were obtained from track and dynamometer tests. User experience information was obtained from fleet operators and individual owners of electric vehicles. Data on performance and physical characteristics of large number of vehicles were obtained from manufacturers and available literature.

  11. ADOPT: A Historically Validated Light Duty Vehicle Consumer Choice Model

    SciTech Connect

    Brooker, A.; Gonder, J.; Lopp, S.; Ward, J.

    2015-05-04

    The Automotive Deployment Option Projection Tool (ADOPT) is a light-duty vehicle consumer choice and stock model supported by the U.S. Department of Energy’s Vehicle Technologies Office. It estimates technology improvement impacts on U.S. light-duty vehicles sales, petroleum use, and greenhouse gas emissions. ADOPT uses techniques from the multinomial logit method and the mixed logit method estimate sales. Specifically, it estimates sales based on the weighted value of key attributes including vehicle price, fuel cost, acceleration, range and usable volume. The average importance of several attributes changes nonlinearly across its range and changes with income. For several attributes, a distribution of importance around the average value is used to represent consumer heterogeneity. The majority of existing vehicle makes, models, and trims are included to fully represent the market. The Corporate Average Fuel Economy regulations are enforced. The sales feed into the ADOPT stock model. It captures key aspects for summing petroleum use and greenhouse gas emissions This includes capturing the change in vehicle miles traveled by vehicle age, the creation of new model options based on the success of existing vehicles, new vehicle option introduction rate limits, and survival rates by vehicle age. ADOPT has been extensively validated with historical sales data. It matches in key dimensions including sales by fuel economy, acceleration, price, vehicle size class, and powertrain across multiple years. A graphical user interface provides easy and efficient use. It manages the inputs, simulation, and results.

  12. Remote vehicle controller

    NASA Astrophysics Data System (ADS)

    Schmitz, John J.

    1992-06-01

    A remote control system is disclosed for use with vehicles having radios. A first vehicle has a controller attached to the radio for use in sending signals to a second vehicle. The second, remotely controlled, vehicle has a receiver connected to the vehicle radio which receives commands from the first radio to effect the desired motion and action of the second vehicle. The receiver and controller have circuitry which allows them to be reprogrammed to function on various military vehicles and also be attached to the different radio systems in use by the U.S. Military.

  13. Evolutionary optimization of cooperative heterogeneous teams

    NASA Astrophysics Data System (ADS)

    Soule, Terence; Heckendorn, Robert B.

    2007-04-01

    There is considerable interest in developing teams of autonomous, unmanned vehicles that can function in hostile environments without endangering human lives. However, heterogeneous teams, teams of units with specialized roles and/or specialized capabilities, have received relatively little attention. Specialized roles and capabilities can significantly increase team effectiveness and efficiency. Unfortunately, developing effective cooperation mechanisms is much more difficult in heterogeneous teams. Units with specialized roles or capabilities require specialized software that take into account the role and capabilities of both itself and its neighbors. Evolutionary algorithms, algorithms modeled on the principles of natural selection, have a proven track record in generating successful teams for a wide variety of problem domains. Using classification problems as a prototype, we have shown that typical evolutionary algorithms either generate highly effective teams members that cooperate poorly or poorly performing individuals that cooperate well. To overcome these weaknesses we have developed a novel class of evolutionary algorithms. In this paper we apply these algorithms to the problem of controlling simulated, heterogeneous teams of "scouts" and "investigators". Our test problem requires producing a map of an area and to further investigate "areas of interest". We compare several evolutionary algorithms for their ability to generate individually effective members and high levels of cooperation.

  14. Analytical studies on the instabilities of heterogeneous intelligent traffic flow

    NASA Astrophysics Data System (ADS)

    Ngoduy, D.

    2013-10-01

    It has been widely reported in literature that a small perturbation in traffic flow such as a sudden deceleration of a vehicle could lead to the formation of traffic jams without a clear bottleneck. These traffic jams are usually related to instabilities in traffic flow. The applications of intelligent traffic systems are a potential solution to reduce the amplitude or to eliminate the formation of such traffic instabilities. A lot of research has been conducted to theoretically study the effect of intelligent vehicles, for example adaptive cruise control vehicles, using either computer simulation or analytical method. However, most current analytical research has only applied to single class traffic flow. To this end, the main topic of this paper is to perform a linear stability analysis to find the stability threshold of heterogeneous traffic flow using microscopic models, particularly the effect of intelligent vehicles on heterogeneous (or multi-class) traffic flow instabilities. The analytical results will show how intelligent vehicle percentages affect the stability of multi-class traffic flow.

  15. Structural Weight Estimation for Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Cerro, Jeff; Martinovic, Zoran; Su, Philip; Eldred, Lloyd

    2002-01-01

    This paper describes some of the work in progress to develop automated structural weight estimation procedures within the Vehicle Analysis Branch (VAB) of the NASA Langley Research Center. One task of the VAB is to perform system studies at the conceptual and early preliminary design stages on launch vehicles and in-space transportation systems. Some examples of these studies for Earth to Orbit (ETO) systems are the Future Space Transportation System [1], Orbit On Demand Vehicle [2], Venture Star [3], and the Personnel Rescue Vehicle[4]. Structural weight calculation for launch vehicle studies can exist on several levels of fidelity. Typically historically based weight equations are used in a vehicle sizing program. Many of the studies in the vehicle analysis branch have been enhanced in terms of structural weight fraction prediction by utilizing some level of off-line structural analysis to incorporate material property, load intensity, and configuration effects which may not be captured by the historical weight equations. Modification of Mass Estimating Relationships (MER's) to assess design and technology impacts on vehicle performance are necessary to prioritize design and technology development decisions. Modern CAD/CAE software, ever increasing computational power and platform independent computer programming languages such as JAVA provide new means to create greater depth of analysis tools which can be included into the conceptual design phase of launch vehicle development. Commercial framework computing environments provide easy to program techniques which coordinate and implement the flow of data in a distributed heterogeneous computing environment. It is the intent of this paper to present a process in development at NASA LaRC for enhanced structural weight estimation using this state of the art computational power.

  16. Adaptable formations utilizing heterogeneous unmanned systems

    NASA Astrophysics Data System (ADS)

    Barnes, Laura E.; Garcia, Richard; Fields, MaryAnne; Valavanis, Kimon

    2009-05-01

    This paper addresses the problem of controlling and coordinating heterogeneous unmanned systems required to move as a group while maintaining formation. We propose a strategy to coordinate groups of unmanned ground vehicles (UGVs) with one or more unmanned aerial vehicles (UAVs). UAVs can be utilized in one of two ways: (1) as alpha robots to guide the UGVs; and (2) as beta robots to surround the UGVs and adapt accordingly. In the first approach, the UAV guides a swarm of UGVs controlling their overall formation. In the second approach, the UGVs guide the UAVs controlling their formation. The unmanned systems are brought into a formation utilizing artificial potential fields generated from normal and sigmoid functions. These functions control the overall swarm geometry. Nonlinear limiting functions are defined to provide tighter swarm control by modifying and adjusting a set of control variables forcing the swarm to behave according to set constraints. Formations derived are subsets of elliptical curves but can be generalized to any curvilinear shape. Both approaches are demonstrated in simulation and experimentally. To demonstrate the second approach in simulation, a swarm of forty UAVs is utilized in a convoy protection mission. As a convoy of UGVs travels, UAVs dynamically and intelligently adapt their formation in order to protect the convoy of vehicles as it moves. Experimental results are presented to demonstrate the approach using a fully autonomous group of three UGVs and a single UAV helicopter for coordination.

  17. Heterogeneities in granular dynamics.

    PubMed

    Mehta, A; Barker, G C; Luck, J M

    2008-06-17

    The absence of Brownian motion in granular media is a source of much complexity, including the prevalence of heterogeneity, whether static or dynamic, within a given system. Such strong heterogeneities can exist as a function of depth in a box of grains; this is the system we study here. First, we present results from three-dimensional, cooperative and stochastic Monte Carlo shaking simulations of spheres on heterogeneous density fluctuations. Next, we juxtapose these with results obtained from a theoretical model of a column of grains under gravity; frustration via competing local fields is included in our model, whereas the effect of gravity is to slow down the dynamics of successively deeper layers. The combined conclusions suggest that the dynamics of a real granular column can be divided into different phases-ballistic, logarithmic, activated, and glassy-as a function of depth. The nature of the ground states and their retrieval (under zero-temperature dynamics) is analyzed; the glassy phase shows clear evidence of its intrinsic ("crystalline") states, which lie below a band of approximately degenerate ground states. In the other three phases, by contrast, the system jams into a state chosen randomly from this upper band of metastable states. PMID:18541918

  18. Atmospheric Heterogeneous Stereochemistry

    NASA Astrophysics Data System (ADS)

    Stokes, G. Y.; Buchbinder, A. M.; Geiger, F. M.

    2009-12-01

    This paper addresses the timescale and mechanism of heterogeneous interactions of laboratory models of organic-coated mineral dust and ozone. We are particularly interested in investigating the role of stereochemistry in heterogeneous oxidation reactions involving chiral biogenic VOCs. Using the surface-specific nonlinear optical spectroscopy, sum frequency generation, we tracked terpene diastereomers during exposure to 10^11 to 10^13 molecules of ozone per cm^3 in 1 atm helium to model ozone-limited and ozone-rich tropospheric conditions. Our kinetic data indicate that the diastereomers which orient their reactive C=C double bonds towards the gas phase exhibit heterogeneous ozonolysis rate constants that are two times faster than diastereomers that orient their C=C double bonds away from the gas phase. Insofar as our laboratory model studies are representative of real world environments, our studies suggest that the propensity of aerosol particles coated with chiral semivolatile organic compounds to react with ozone may depend on stereochemistry. Implications of these results for chiral markers that would allow for source appointment of anthropogenic versus biogenic carbon emissions will be discussed.

  19. Heterogeneity in Melanoma.

    PubMed

    Shannan, Batool; Perego, Michela; Somasundaram, Rajasekharan; Herlyn, Meenhard

    2016-01-01

    Melanoma is among the most aggressive and therapy-resistant human cancers. While great strides in therapy have generated enthusiasm, many challenges remain. Heterogeneity is the most pressing issue for all types of therapy. This chapter summarizes the clinical classification of melanoma, of which the research community now adds additional layers of classifications for better diagnosis and prediction of therapy response. As the search for new biomarkers increases, we expect that biomarker analyses will be essential for all clinical trials to better select patient populations for optimal therapy. While individualized therapy that is based on extensive biomarker analyses is an option, we expect in the future genetic and biologic biomarkers will allow grouping of melanomas in such a way that we can predict therapy outcome. At this time, tumor heterogeneity continues to be the major challenge leading inevitably to relapse. To address heterogeneity therapeutically, we need to develop complex therapies that eliminate the bulk of the tumor and, at the same time, the critical subpopulations. PMID:26601857

  20. Advanced Technology Vehicle Testing

    SciTech Connect

    James Francfort

    2003-11-01

    The light-duty vehicle transportation sector in the United States depends heavily on imported petroleum as a transportation fuel. The Department of Energy’s Advanced Vehicle Testing Activity (AVTA) is testing advanced technology vehicles to help reduce this dependency, which would contribute to the economic stability and homeland security of the United States. These advanced technology test vehicles include internal combustion engine vehicles operating on 100% hydrogen (H2) and H2CNG (compressed natural gas) blended fuels, hybrid electric vehicles, neighborhood electric vehicles, urban electric vehicles, and electric ground support vehicles. The AVTA tests and evaluates these vehicles with closed track and dynamometer testing methods (baseline performance testing) and accelerated reliability testing methods (accumulating lifecycle vehicle miles and operational knowledge within 1 to 1.5 years), and in normal fleet environments. The Arizona Public Service Alternative Fuel Pilot Plant and H2-fueled vehicles are demonstrating the feasibility of using H2 as a transportation fuel. Hybrid, neighborhood, and urban electric test vehicles are demonstrating successful applications of electric drive vehicles in various fleet missions. The AVTA is also developing electric ground support equipment (GSE) test procedures, and GSE testing will start during the fall of 2003. All of these activities are intended to support U.S. energy independence. The Idaho National Engineering and Environmental Laboratory manages these activities for the AVTA.

  1. Robust object matching for persistent tracking with heterogeneous features.

    PubMed

    Guo, Yanlin; Hsu, Steve; Sawhney, Harpreet S; Kumar, Rakesh; Shan, Ying

    2007-05-01

    This paper addresses the problem of matching vehicles across multiple sightings under variations in illumination and camera poses. Since multiple observations of a vehicle are separated in large temporal and/or spatial gaps, thus prohibiting the use of standard frame-to-frame data association, we employ features extracted over a sequence during one time interval as a vehicle fingerprint that is used to compute the likelihood that two or more sequence observations are from the same or different vehicles. Furthermore, since our domain is aerial video tracking, in order to deal with poor image quality and large resolution and quality variations, our approach employs robust alignment and match measures for different stages of vehicle matching. Most notably, we employ a heterogeneous collection of features such as lines, points, and regions in an integrated matching framework. Heterogeneous features are shown to be important. Line and point features provide accurate localization and are employed for robust alignment across disparate views. The challenges of change in pose, aspect, and appearances across two disparate observations are handled by combining a novel feature-based quasi-rigid alignment with flexible matching between two or more sequences. However, since lines and points are relatively sparse, they are not adequate to delineate the object and provide a comprehensive matching set that covers the complete object. Region features provide a high degree of coverage and are employed for continuous frames to provide a delineation of the vehicle region for subsequent generation of a match measure. Our approach reliably delineates objects by representing regions as robust blob features and matching multiple regions to multiple regions using Earth Mover's Distance (EMD). Extensive experimentation under a variety of real-world scenarios and over hundreds of thousands of Confirmatory Identification (CID) trails has demonstrated about 95 percent accuracy in vehicle

  2. Heterogeneity in expected longevities.

    PubMed

    Pijoan-Mas, Josep; Ríos-Rull, José-Víctor

    2014-12-01

    We develop a new methodology to compute differences in the expected longevity of individuals of a given cohort who are in different socioeconomic groups at a certain age. We address the two main problems associated with the standard use of life expectancy: (1) that people's socioeconomic characteristics change, and (2) that mortality has decreased over time. Our methodology uncovers substantial heterogeneity in expected longevities, yet much less heterogeneity than what arises from the naive application of life expectancy formulae. We decompose the longevity differences into differences in health at age 50, differences in the evolution of health with age, and differences in mortality conditional on health. Remarkably, education, wealth, and income are health-protecting but have very little impact on two-year mortality rates conditional on health. Married people and nonsmokers, however, benefit directly in their immediate mortality. Finally, we document an increasing time trend of the socioeconomic gradient of longevity in the period 1992-2008, and we predict an increase in the socioeconomic gradient of mortality rates for the coming years. PMID:25391225

  3. Biclustering with heterogeneous variance.

    PubMed

    Chen, Guanhua; Sullivan, Patrick F; Kosorok, Michael R

    2013-07-23

    In cancer research, as in all of medicine, it is important to classify patients into etiologically and therapeutically relevant subtypes to improve diagnosis and treatment. One way to do this is to use clustering methods to find subgroups of homogeneous individuals based on genetic profiles together with heuristic clinical analysis. A notable drawback of existing clustering methods is that they ignore the possibility that the variance of gene expression profile measurements can be heterogeneous across subgroups, and methods that do not consider heterogeneity of variance can lead to inaccurate subgroup prediction. Research has shown that hypervariability is a common feature among cancer subtypes. In this paper, we present a statistical approach that can capture both mean and variance structure in genetic data. We demonstrate the strength of our method in both synthetic data and in two cancer data sets. In particular, our method confirms the hypervariability of methylation level in cancer patients, and it detects clearer subgroup patterns in lung cancer data. PMID:23836637

  4. Heterogeneous broadband network

    NASA Astrophysics Data System (ADS)

    Dittmann, Lars

    1995-11-01

    Although the vision for the future Integrated Broadband Communication Network (IBCN) is an all optical network, it is certain that for a long period to come, the network will remain very heterogeneous, with a mixture of different physical media (fiber, coax and twisted pair), transmission systems (PDH, SDH, ADSL) and transport protocols (TCP/IP, AAL/ATM, frame relay). In the current work towards the IBCN, the ATM concept is considered the generic network protocol for both public and private network, with the ability to use different underlying transmission protocols and, through adaptation protocols, provide the appropriate services (old as well as new) to the customer. One of the major difficulties of heterogeneous network is the restriction that is usually given by the lowest common denominator, e.g. in terms of single channel capacity. A possible way to overcome these limitations is by extending the ATM concept with a multilink capability, that allows us to use separate resources as one common. The improved flexibility obtained by this protocol extension further allows a real time optimization of network and call configuration, without any impact on the quality of service seen from the user. This paper describes an example of an ATM based multilink protocol that has been experimentally implemented within the RACE project 'STRATOSPHERIC'. The paper outlines the complexity of introducing an extra network functionality compared with the added value, such as an improved ability to recover an error due to a malfunctioning network component.

  5. Solar space vehicle

    SciTech Connect

    Lee, R.E.

    1982-10-19

    This invention relates to space vehicle where solar energy is used to generate steam, which in turn, propels the vehicle in space. A copper boiler is provided and a novel solar radiation condensing means is used to focus the sunlight on said boiler. Steam generated in said boiler is exhausted to the environment to provide a thrust for the vehicle.

  6. Motor Vehicle Safety

    MedlinePlus

    ... from motor vehicle crashes. Trying to prevent these crashes is one part of motor vehicle safety. Here are some things you can do to be safer on the road: Make sure your vehicle is safe and in working order Use car seats for children Wear your seat belt Don' ...

  7. Automotive vehicle sensors

    SciTech Connect

    Sheen, S.H.; Raptis, A.C.; Moscynski, M.J.

    1995-09-01

    This report is an introduction to the field of automotive vehicle sensors. It contains a prototype data base for companies working in automotive vehicle sensors, as well as a prototype data base for automotive vehicle sensors. A market analysis is also included.

  8. Electric Vehicle Technician

    ERIC Educational Resources Information Center

    Moore, Pam

    2011-01-01

    With President Obama's goal to have one million electric vehicles (EV) on the road by 2015, the electric vehicle technician should have a promising and busy future. "The job force in the car industry is ramping up for a revitalized green car industry," according to Greencareersguide.com. An electric vehicle technician will safely troubleshoot and…

  9. Marine vehicle ride quality

    NASA Technical Reports Server (NTRS)

    Gornstein, R. J.; Shultz, W. M.; Stair, L. D.

    1972-01-01

    The effects of marine vehicle design on passenger exposure to vibration and discomfort are discussed. The ride quality of advanced marine vehicles is examined. as a basis for marine vehicle selection in modern water transport systems. The physiological effects of rough water on passengers are identified as requiring investigation in order to determine the acceptable limits.

  10. Energy 101: Electric Vehicles

    SciTech Connect

    2012-01-01

    This edition of Energy 101 highlights the benefits of electric vehicles, including improved fuel efficiency, reduced emissions, and lower maintenance costs. For more information on electric vehicles from the Office of Energy Efficiency and Renewable Energy, visit the Vehicle Technologies Program website: http://www1.eere.energy.gov/vehiclesandfuels/

  11. Energy 101: Electric Vehicles

    ScienceCinema

    None

    2013-05-29

    This edition of Energy 101 highlights the benefits of electric vehicles, including improved fuel efficiency, reduced emissions, and lower maintenance costs. For more information on electric vehicles from the Office of Energy Efficiency and Renewable Energy, visit the Vehicle Technologies Program website: http://www1.eere.energy.gov/vehiclesandfuels/

  12. MRV - Modular Robotic Vehicle

    NASA Technical Reports Server (NTRS)

    Ridley, Justin; Bluethmann, Bill

    2015-01-01

    The Modular Robotic Vehicle, or MRV, completed in 2013, was developed at the Johnson Space Center in order to advance technologies which have applications for future vehicles both in space and on Earth. With seating for two people, MRV is a fully electric vehicle modeled as a "city car", suited for busy urban environments.

  13. Large epidemic thresholds emerge in heterogeneous networks of heterogeneous nodes

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Tang, Ming; Gross, Thilo

    2015-08-01

    One of the famous results of network science states that networks with heterogeneous connectivity are more susceptible to epidemic spreading than their more homogeneous counterparts. In particular, in networks of identical nodes it has been shown that network heterogeneity, i.e. a broad degree distribution, can lower the epidemic threshold at which epidemics can invade the system. Network heterogeneity can thus allow diseases with lower transmission probabilities to persist and spread. However, it has been pointed out that networks in which the properties of nodes are intrinsically heterogeneous can be very resilient to disease spreading. Heterogeneity in structure can enhance or diminish the resilience of networks with heterogeneous nodes, depending on the correlations between the topological and intrinsic properties. Here, we consider a plausible scenario where people have intrinsic differences in susceptibility and adapt their social network structure to the presence of the disease. We show that the resilience of networks with heterogeneous connectivity can surpass those of networks with homogeneous connectivity. For epidemiology, this implies that network heterogeneity should not be studied in isolation, it is instead the heterogeneity of infection risk that determines the likelihood of outbreaks.

  14. Cooperative robotic sentry vehicles

    NASA Astrophysics Data System (ADS)

    Feddema, John T.; Lewis, Christopher L.; Klarer, Paul; Eisler, G. R.; Caprihan, Rahul

    1999-08-01

    As part of a project for the Defense Advanced Research Projects Agency, Sandia National Laboratories' Intelligent Systems and Robotics Center is developing and testing the feasibility of a cooperative team of robotic sentry vehicles to guard a perimeter and to perform a surround task. This paper describes on-going activities in the development of these robotic sentry vehicles. To date, we have developed a robotic perimeter detection system which consists of eight 'Roving All Terrain Lunar Explorer Rovers' (RATLER), a laptop-based base-station, and several Miniature Intrusion Detection Sensors (MIDS). A radio frequency receiver on each of the RATLER vehicles alerts the sentry vehicles of alarms from the hidden MIDS. When an alarm is received, each vehicle decides whether it should investigate the alarm based on the proximity of itself and the other vehicles to the alarm. As one vehicle attends an alarm, the other vehicles adjust their position around the perimeter to better prepare for another alarm. For the surround task, both potential field and A* search path planners have been added to the base-station and vehicles. At the base-station, the operator specifies goal and exclusion regions on a GIS map. The path planner generates vehicles paths that are previewed by the operator. Once the operator has validated the path, the appropriate information is downloaded t the vehicles. For the potential field path planner, the polygons and line segments that represent the obstacles and goals are downloaded to the vehicles, instead of the simulated paths. On board the vehicles, the same potential field path planner generates the path except that it uses the true location of itself and the nearest neighboring vehicle. For the A* path planner, the actual path is downloaded to the vehicles because of limited on-board computational power.

  15. Energy efficient passenger vehicle

    SciTech Connect

    Dessert, R.

    1983-02-22

    An energy efficient passenger carrying vehicle for road use. The vehicle basically comprises a long, narrow body carrying two passengers in a back-to-back relationship. The vehicle is basically a battery powered electric vehicle that can be charged by all free energy sources; namely, the sun, the wind, human muscles and momentum. The vehicle comprises four modules, namely body, solar, and two power modules. An electric power module is located within each end of the body module. This module includes electric motors driving the vehicle supporting wheels and rechargeable batteries to power the motors. Pedals, similar to those on a bicycle, located at each power module, drive generators to help recharge the batteries during operation of the vehicle, or directly help drive the vehicle wheels. A solar module comprising a large electricity generating solar cell panel covers most of the vehicle roof to aid in charging the batteries. Means are provided to tilt the solar cell panel toward the sun about a longitudinal axis. A unique flexible duct below the solar panel serves to cool the cells and, if desired, heat the passenger compartment. Further energy savings are obtained by canting the rear wheels while steering with the front wheels, so that the vehicle moves down the road at a crab angle which provides a sail effect when wind is from the vehicle beam or aft of the beam. Regenerative braking means can be used when slowing down, on a long down grade, when sailing speed is greater than required, or any other time when vehicle momentum is greater than necessary for vehicle operation, to use the excess forward momentum to drive generators to charge the batteries. Thus, a single battery charge will be conserved and vehicle operation will be assisted in a manner giving maximum vehicle range and speed.

  16. VEHICLE FOR SLAVE ROBOT

    DOEpatents

    Goertz, R.C.; Lindberg, J.F.

    1962-01-30

    A reeling device is designed for an electrical cable supplying power to the slave slde of a remote control manipulator mounted on a movable vehicle. As the vehicle carries the slave side about in a closed room, the device reels the cable in and out to maintain a variable length of the cable between the vehicle and a cable inlet in the wall of the room. The device also handles a fixed length of cable between the slave side and the vehicle, in spite of angular movement of the slave side with respect to the vehicle. (AEC)

  17. Disordered hyperuniform heterogeneous materials.

    PubMed

    Torquato, Salvatore

    2016-10-19

    Disordered hyperuniform many-body systems are distinguishable states of matter that lie between a crystal and liquid: they are like perfect crystals in the way they suppress large-scale density fluctuations and yet are like liquids or glasses in that they are statistically isotropic with no Bragg peaks. These systems play a vital role in a number of fundamental and applied problems: glass formation, jamming, rigidity, photonic and electronic band structure, localization of waves and excitations, self-organization, fluid dynamics, quantum systems, and pure mathematics. Much of what we know theoretically about disordered hyperuniform states of matter involves many-particle systems. In this paper, we derive new rigorous criteria that disordered hyperuniform two-phase heterogeneous materials must obey and explore their consequences. Two-phase heterogeneous media are ubiquitous; examples include composites and porous media, biological media, foams, polymer blends, granular media, cellular solids, and colloids. We begin by obtaining some results that apply to hyperuniform two-phase media in which one phase is a sphere packing in d-dimensional Euclidean space [Formula: see text]. Among other results, we rigorously establish the requirements for packings of spheres of different sizes to be 'multihyperuniform'. We then consider hyperuniformity for general two-phase media in [Formula: see text]. Here we apply realizability conditions for an autocovariance function and its associated spectral density of a two-phase medium, and then incorporate hyperuniformity as a constraint in order to derive new conditions. We show that some functional forms can immediately be eliminated from consideration and identify other forms that are allowable. Specific examples and counterexamples are described. Contact is made with well-known microstructural models (e.g. overlapping spheres and checkerboards) as well as irregular phase-separation and Turing-type patterns. We also ascertain a family

  18. Operator Informational Needs for Multiple Autonomous Small Vehicles

    NASA Technical Reports Server (NTRS)

    Trujillo, Anna C.; Fan, Henry; Cross, Charles D.; Hempley, Lucas E.; Cichella, Venanzio; Puig-Navarro, Javier; Mehdi, Syed Bilal

    2015-01-01

    With the anticipated explosion of small unmanned aerial vehicles, it is highly likely that operators will be controlling fleets of autonomous vehicles. To fulfill the promise of autonomy, vehicle operators will not be concerned with manual control of the vehicle; instead, they will deal with the overall mission. Furthermore, the one operator to many vehicles is becoming a constant meme with various industries including package delivery, search and rescue, and utility companies. In order for an operator to concurrently control several vehicles, his station must look and behave very differently than the current ground control station instantiations. Furthermore, the vehicle will have to be much more autonomous, especially during non-normal operations, in order to accommodate the knowledge deficit or the information overload of the operator in charge of several vehicles. The expected usage increase of small drones requires presenting the operational information generated by a fleet of heterogeneous autonomous agents to an operator. NASA Langley Research Center's Autonomy Incubator has brought together researchers in various disciplines including controls, trajectory planning, systems engineering, and human factors to develop an integrated system to study autonomy issues. The initial human factors effort is focusing on mission displays that would give an operator the overall status of all autonomous agents involved in the current mission. This paper will discuss the specifics of the mission displays for operators controlling several vehicles.

  19. Vehicle capture system

    NASA Astrophysics Data System (ADS)

    Tacke, Kenneth L.

    1998-12-01

    Primex Aerospace Company, under contract with the U.S. Army Armament Research Development & Engineering Center (ARDEC), has developed a portable vehicle capture system for use at vehicle checkpoints. Currently when a vehicle does not stop at a checkpoint, there are three possible reactions: let the vehicle go unchallenged, pursue the vehicle or stop the vehicle with lethal force. This system provides a non-lethal alternative that will stop and contain the vehicle. The system is completely portable with the heaviest component weighing less than 120 pounds. It can be installed with no external electrical power or permanent anchors required. In its standby mode, the system does not impede normal traffic, but on command erects a barrier in less than 1.5 seconds. System tests have been conducted using 5,100 and 8.400 pound vehicles, traveling at speeds up to 45 mph. The system is designed to minimize vehicle damage and occupant injury, typically resulting in deceleration forces of less than 2.5 gs on the vehicle. According to the drivers involved in tests at 45 mph, the stopping forces feel similar to a panic stop with the vehicle brakes locked. The system is completely reusable and be rapidly reset.

  20. [Neutrophilic functional heterogeneity].

    PubMed

    2006-02-01

    Blood neutrophilic functional heterogeneity is under discussion. The neutrophils of one subpopulation, namely killer neutrophils (Nk), potential phagocytes, constitute a marginal pool and a part of the circulating pool, intensively produce active oxygen forms (AOF) and they are adherent to the substrate. The neutrophils of another subpopulation, cager neutrophils (Nc), seem to perform a transport function of delivering foreign particles to the competent organs, to form about half of the circulating pool, to produce APC to a lesser extent, exclusively for self-defense and, probably, in usual conditions, to fail to interact with substrate. Analysis of the experimental findings suggests that the phylogenetic age of Nk is older than that of Nc and Nk has predominantly a tendency to spontaneous apoptosis under physiological conditions. PMID:16610631

  1. Multipartite entanglement in heterogeneous systems

    NASA Astrophysics Data System (ADS)

    Goyeneche, Dardo; Bielawski, Jakub; Życzkowski, Karol

    2016-07-01

    Heterogeneous bipartite quantum pure states, composed of two subsystems with a different number of levels, cannot have both reductions maximally mixed. In this work, we demonstrate the existence of a wide range of highly entangled states of heterogeneous multipartite systems consisting of N >2 parties such that every reduction to one and two parties is maximally mixed. Two constructions of generating genuinely multipartite maximally entangled states of heterogeneous systems for an arbitrary number of subsystems are presented. Such states are related to quantum error correction codes over mixed alphabets and mixed orthogonal arrays. Additionally, we show the advantages of considering heterogeneous systems in practical implementations of multipartite steering.

  2. Interconnecting heterogeneous database management systems

    NASA Technical Reports Server (NTRS)

    Gligor, V. D.; Luckenbaugh, G. L.

    1984-01-01

    It is pointed out that there is still a great need for the development of improved communication between remote, heterogeneous database management systems (DBMS). Problems regarding the effective communication between distributed DBMSs are primarily related to significant differences between local data managers, local data models and representations, and local transaction managers. A system of interconnected DBMSs which exhibit such differences is called a network of distributed, heterogeneous DBMSs. In order to achieve effective interconnection of remote, heterogeneous DBMSs, the users must have uniform, integrated access to the different DBMs. The present investigation is mainly concerned with an analysis of the existing approaches to interconnecting heterogeneous DBMSs, taking into account four experimental DBMS projects.

  3. Energy efficient passenger vehicle

    SciTech Connect

    Dessert, R.

    1980-01-01

    An energy efficient passenger carrying vehicle for road use comprised of a long, narrow body carrying two passengers in a back-to-back relationship is described. The vehicle is basically a battery powered electric vehicle that can be charged by all free energy sources; namely, the sun, the wind, human muscles and momentum. The vehicle comprises four modules: body, solar, and two power modules. An electric power module is located within each end of the body module. This module includes electric motors driving the vehicle supporting wheels and rechargeable batteries to power the motors. Pedals, similar to those on a bicycle, located at each power module, drive generators to help recharge the batteries during operation of the vehicle, or directly help drive the vehicle wheels. A solar module comprising a large electricity generating solar cell panel covers most of the vehicle roof to aid in charging the batteries. Means are provided to tilt the solar cell panel toward the sun about a longitudinal axis. A unique flexible duct below the solar panel serves to cool the cells and, if desired, heat the passenger compartment. Further energy savings are obtained by canting the rear wheels while steering with the front wheels, so that the vehicle moves down the road at a crab angle which provides a sail effect when wind is from the vehicle beam or aft of the beam. Regenerative braking means can be used when slowing down, on a long down grade, when sailing speed is greater than required, or any other time when vehicle momentum is greater than necessary for vehicle operation, to use the excess forward momentum to drive generators to charge the batteries. Thus, a single battery charge will be conserved and vehicle operation will be assisted in a manner giving maximum vehicle range and speed.

  4. The Vehicle Ecosystem

    NASA Astrophysics Data System (ADS)

    Kuschel, Jonas

    Ubiquitous computing in the vehicle industry has primarily focused on sensor data serving different ubiquitous on-board services (e.g., crash detection, antilock brake systems, or air conditioning). These services mainly address vehicle drivers while driving. However, in view of the role of vehicles in today's society, it goes without saying that vehicles relate to more than just the driver or occupants; they are part of a larger ecosystem, including traffic participants, authorities, customers and the like. To serve the ecosystem with ubiquitous services based on vehicle sensor data, there is a need for an open information infrastructure that enables service development close to the customer. This paper presents results from a research project on designing such an infrastructure at a major European vehicle manufacturer. Our empirical data shows how the vehicle manufacturer's conceptualization of services disagrees with the needs of vehicle stakeholders in a more comprehensive vehicle ecosystem. In light of this, we discuss the effect on information infrastructure design and introduce the distinction between information infrastructure as product feature and service facilitator. In a more general way, we highlight the importance of information infrastructure to contextualize the vehicle as part of a larger ecosystem and thus support open innovation.

  5. Political Jurisdictions in Heterogeneous Communities.

    ERIC Educational Resources Information Center

    Alesina, Alberto; Baqir, Reza; Hoxby, Caroline

    2004-01-01

    We investigate whether political jurisdictions form in response to the trade-off between economies of scale and the costs of a heterogeneous population. We consider heterogeneity in income, race, ethnicity, and religion, and we test the model using American school districts, school attendance areas, municipalities, and special districts. We find…

  6. Biomarker Discovery for Heterogeneous Diseases

    PubMed Central

    Wallstrom, Garrick; Anderson, Karen S.; LaBaer, Joshua

    2013-01-01

    Background Modern genomic and proteomic studies reveal that many diseases are heterogeneous, comprising multiple different subtypes. The common notion that one biomarker can be predictive for all patients may need to be replaced by an understanding that each subtype has its own set of unique biomarkers, affecting how discovery studies are designed and analyzed. Methods We used Monte Carlo simulation to measure and compare the performance of eight selection methods with homogeneous and heterogeneous diseases using both single-stage and two-stage designs. We also applied the selection methods in an actual proteomic biomarker screening study of heterogeneous breast cancer cases. Results Different selection methods were optimal and more than 2-fold larger sample sizes were needed for heterogeneous diseases compared with homogeneous diseases. We also found that for larger studies, two-stage designs can achieve nearly the same statistical power as single-stage designs at significantly reduced cost. Conclusions We found that disease heterogeneity profoundly affected biomarker performance. We report sample size requirements and provide guidance on the design and analysis of biomarker discovery studies for both homogeneous and heterogeneous diseases. Impact We have shown that studies to identify biomarkers for the early detection of heterogeneous disease require different statistical selection methods and larger sample sizes than if the disease were homogeneous. These findings provide a methodological platform for biomarker discovery of heterogeneous diseases. PMID:23462916

  7. Heterogeneity of an earth

    NASA Astrophysics Data System (ADS)

    Litvinova, T.; Petrova, A.

    2009-04-01

    The study of magnetic anomaly field structure of the Barents Sea water area along seismic and extended profiles intersecting known fields is carried out. Geomagnetic and density sections down to 40 km depth are constructed. This allowed the estimation of heterogeneities of the Barents Sea water area deep structure. The analysis of geomagnetic and density sections along extended profiles showed the confinedness of oil-and-gas bearing provinces to deep permeable zones characterized by reduced magnetic and density features. Based on the analysis of permeable zones, regional diagnostic features similar to those obtained earlier in oil-and-gas bearing provinces in other regions, for example, in Timan-Pechora, Volga-Urals and Siberian, as well as in the Northern and Norwegian seas water areas, are revealed. The analysis of magnetic and gravity fields over the region area allowed the delineation of weakened zones as intersection areas of weakly magnetic areals with reduced density. Within the Barents Sea water area, permeable areas with lenticular-laminated structure of the upper and lower Earth's crust containing weakly magnetic areals with reduced rock density within the depth range of 8-12 and 15-20 km are revealed. Such ratio of magnetic and density heterogeneities in the Earth's crust is characteristic for zones with proved oil-and-gas content in the European part of the Atlantic Ocean water area. North Kildin field on 1 AR profile is confined to a trough with thick weakly magnetic stratum discontinuously traced to a depth of 6-10 km. At a depth of approximately 15 km, a lens of weakly magnetic and porous formations is observed. Ludlov field in the North Barents trough is confined to a zone of weakly magnetic rocks with reduced density traced to a depth of 8-9 km. Deeper, at Н=15 km, a lenticular areal of weakly magnetic formations with reduced density is observed. The profile transecting the Stockman field shows that it is located in the central part of a permeable

  8. Vehicle underbody fairing

    DOEpatents

    Ortega, Jason M.; Salari, Kambiz; McCallen, Rose

    2010-11-09

    A vehicle underbody fairing apparatus for reducing aerodynamic drag caused by a vehicle wheel assembly, by reducing the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly. The fairing body has a tapered aerodynamic surface that extends from a front end to a rear end of the fairing body with a substantially U-shaped cross-section that tapers in both height and width. Fasteners or other mounting devices secure the fairing body to an underside surface of the vehicle body, so that the front end is immediately downstream of the vehicle wheel assembly and a bottom section of the tapered aerodynamic surface rises towards the underside surface as it extends in a downstream direction.

  9. Vehicle speed control system

    SciTech Connect

    Yoshida, D.; Tanno, T.; Fukunaga, T.

    1987-06-16

    This patent describes a vehicle speed control system for performing vehicle speed control by controlling the displacement of at least one of a hydraulic pump and a hydraulic motor of a hydraulic transmission through an electric servo device, comprising: vehicle speed setting means for generating a voltage signal corresponding to a vehicle speed to be set; compensating means interposed between the vehicle speed setting means and the electric servo device, the compensating means comprising a first delay element; and second delay element having a response characteristic slower than that of the first delay element. A selecting means for judging as to whether a voltage signal changed by the operation of the vehicle speed setting means represents an acceleration command or a deceleration command and for selecting the first delay element when the voltage signal represents an acceleration command and for selecting the second delay element when the voltage signal represents a deceleration command.

  10. Advanced Technology Vehicle Testing

    SciTech Connect

    James Francfort

    2004-06-01

    The goal of the U.S. Department of Energy's Advanced Vehicle Testing Activity (AVTA) is to increase the body of knowledge as well as the awareness and acceptance of electric drive and other advanced technology vehicles (ATV). The AVTA accomplishes this goal by testing ATVs on test tracks and dynamometers (Baseline Performance testing), as well as in real-world applications (Fleet and Accelerated Reliability testing and public demonstrations). This enables the AVTA to provide Federal and private fleet managers, as well as other potential ATV users, with accurate and unbiased information on vehicle performance and infrastructure needs so they can make informed decisions about acquiring and operating ATVs. The ATVs currently in testing include vehicles that burn gaseous hydrogen (H2) fuel and hydrogen/CNG (H/CNG) blended fuels in internal combustion engines (ICE), and hybrid electric (HEV), urban electric, and neighborhood electric vehicles. The AVTA is part of DOE's FreedomCAR and Vehicle Technologies Program.

  11. Angiotensin II receptor heterogeneity

    SciTech Connect

    Herblin, W.F.; Chiu, A.T.; McCall, D.E.; Ardecky, R.J.; Carini, D.J.; Duncia, J.V.; Pease, L.J.; Wong, P.C.; Wexler, R.R.; Johnson, A.L. )

    1991-04-01

    The possibility of receptor heterogeneity in the angiotensin II (AII) system has been suggested previously, based on differences in Kd values or sensitivity to thiol reagents. One of the authors earliest indications was the frequent observation of incomplete inhibition of the binding of AII to adrenal cortical membranes. Autoradiographic studies demonstrated that all of the labeling of the rat adrenal was blocked by unlabeled AII or saralasin, but not by DuP 753. The predominant receptor in the rat adrenal cortex (80%) is sensitive to dithiothreitol (DTT) and DuP 753, and is designated AII-1. The residual sites in the adrenal cortex and almost all of the sites in the rat adrenal medulla are insensitive to both DTT and DuP 753, but were blocked by EXP655. These sites have been confirmed by ligand binding studies and are designated AII-2. The rabbit adrenal cortex is unique in yielding a nonuniform distribution of AII-2 sites around the outer layer of glomerulosa cells. In the rabbit kidney, the sites on the glomeruli are AII-1, but the sites on the kidney capsule are AII-2. Angiotensin III appears to have a higher affinity for AII-2 sites since it inhibits the binding to the rabbit kidney capsule but not the glomeruli. Elucidation of the distribution and function of these diverse sites should permit the development of more selective and specific therapeutic strategies.

  12. Heterogeneous recording media

    NASA Astrophysics Data System (ADS)

    Sukhanov, Vitaly I.

    1991-02-01

    The paper summarizes the results of investigations performed to obtain deep 3-D holograms with 102 i0 mkm physical thickness allowing the postexposure amplification and the a posteriori changing of the grating parameters. This aim has been achieved by developing heterogeneous systems on the basis of porous glass with light-sensitive compositions introduced into it. 1. INTRODUCTION. LIGHT-SENSITIVE MEDIA FOR 3-D HOLOGRAMS RECORDING. The 3-D holograms have many useful properties: very high diffraction efficiency angular and spectral selectivity but low level of noise. It shoud be noted that in this case deep 3-D holograms are dealt with whose physical thickness is as high as 102 -i mkm. Such hologram recording is usually done using homogeneous light-sensitive media for example dyed acid-halide and electrooptical crystals photochrome glass photostructurized polimer compositions and so on. The nature of photophisical and photochemical processes responsible for the light sensitivity of these materials exclude the possibility of post-exposure treatment. This does not allow to enhance the recorded holograms and considerably hampers their fixing or makes it practically impossible. The object of our work is to create the media which are quite suitable for two-stage processes of the deep hologram formation with post-exposure processing. Such material must satisfy the following requirements: a)they must have high permeability for the developing substances in order to make the development duration suitable for practical applications b)they must be shrinkproof to prevent deformation of the

  13. Aerodynamics of Heavy Vehicles

    NASA Astrophysics Data System (ADS)

    Choi, Haecheon; Lee, Jungil; Park, Hyungmin

    2014-01-01

    We present an overview of the aerodynamics of heavy vehicles, such as tractor-trailers, high-speed trains, and buses. We introduce three-dimensional flow structures around simplified model vehicles and heavy vehicles and discuss the flow-control devices used for drag reduction. Finally, we suggest important unsteady flow structures to investigate for the enhancement of aerodynamic performance and future directions for experimental and numerical approaches.

  14. Semisolid ophthalmic vehicles.

    PubMed

    Giannaccini, B; Alderigi, C

    1989-09-01

    The present review is concerned with some essential formulative and therapeutic aspects of semisolid ophthalmic vehicles. The history and the most recent developments of the traditional lipophilic vehicles (ointments) are first outlined. The hydrophilic vehicles (hydrogels) based on synthetic polymers (polyacrylates, PEG, PVA, Pluronics, etc.), semisynthetic polymers (cellulose derivatives) and natural polymers (hyaluronic and polygalacturonic acid, alginates, etc.) are then examined. Some recent formulations of particular type are finally described. PMID:2699716

  15. Electric vehicle propulsion alternatives

    NASA Technical Reports Server (NTRS)

    Secunde, R. R.; Schuh, R. M.; Beach, R. F.

    1983-01-01

    Propulsion technology development for electric vehicles is summarized. Analytical studies, technology evaluation, and the development of technology for motors, controllers, transmissions, and complete propulsion systems are included.

  16. Routing Vehicles with Ants

    NASA Astrophysics Data System (ADS)

    Tan, Wen Fang; Lee, Lai Soon; Majid, Zanariah Abdul; Seow, Hsin Vonn

    Routing vehicles involve the design of an optimal set of routes for a fleet of vehicles to serve a number of customers with known demands. This research develops an Ant Colony Optimization for the vehicle routing with one central depot and identical vehicles. The procedure simulates the behavior of real ants that always find the shortest path between their nest and a food source through a form of communication, pheromone trail. Finally, preliminary results on the learning of the algorithm testing on benchmark data set will be presented in this paper.

  17. Distributed tactical reasoning framework for intelligent vehicles

    NASA Astrophysics Data System (ADS)

    Sukthankar, Rahul; Pomerleau, Dean A.; Thorpe, Chuck E.

    1998-01-01

    In independent vehicle concepts for the Automated Highway System (AHS), the ability to make competent tactical-level decisions in real-time is crucial. Traditional approaches to tactical reasoning typically involve the implementation of large monolithic systems, such as decision trees or finite state machines. However, as the complexity of the environment grows, the unforeseen interactions between components can make modifications to such systems very challenging. For example, changing an overtaking behavior may require several, non-local changes to car-following, lane changing and gap acceptance rules. This paper presents a distributed solution to the problem. PolySAPIENT consists of a collection of autonomous modules, each specializing in a particular aspect of the driving task - classified by traffic entities rather than tactical behavior. Thus, the influence of the vehicle ahead on the available actions is managed by one reasoning object, while the implications of an approaching exit are managed by another. The independent recommendations form these reasoning objects are expressed in the form of votes and vetos over a 'tactical action space', and are resolved by a voting arbiter. This local independence enables PolySAPIENT reasoning objects to be developed independently, using a heterogenous implementation. PolySAPIENT vehicles are implemented in the SHIVA tactical highway simulator, whose vehicles are based on the Carnegie Mellon Navlab robots.

  18. Lifting Body Flight Vehicles

    NASA Technical Reports Server (NTRS)

    Barret, Chris

    1998-01-01

    NASA has a technology program in place to build the X-33 test vehicle and then the full sized Reusable Launch Vehicle, VentureStar. VentureStar is a Lifting Body (LB) flight vehicle which will carry our future payloads into orbit, and will do so at a much reduced cost. There were three design contenders for the new Reusable Launch Vehicle: a Winged Vehicle, a Vertical Lander, and the Lifting Body(LB). The LB design won the competition. A LB vehicle has no wings and derives its lift solely from the shape of its body, and has the unique advantages of superior volumetric efficiency, better aerodynamic efficiency at high angles-of-attack and hypersonic speeds, and reduced thermal protection system weight. Classically, in a ballistic vehicle, drag has been employed to control the level of deceleration in reentry. In the LB, lift enables the vehicle to decelerate at higher altitudes for the same velocity and defines the reentry corridor which includes a greater cross range. This paper outlines our LB heritage which was utilized in the design of the new Reusable Launch Vehicle, VentureStar. NASA and the U.S. Air Force have a rich heritage of LB vehicle design and flight experience. Eight LB's were built and over 225 LB test flights were conducted through 1975 in the initial LB Program. Three LB series were most significant in the advancement of today's LB technology: the M2-F; HL-1O; and X-24 series. The M2-F series was designed by NASA Ames Research Center, the HL-10 series by NASA Langley Research Center, and the X-24 series by the Air Force. LB vehicles are alive again today.

  19. Node assignment in heterogeneous computing

    NASA Technical Reports Server (NTRS)

    Som, Sukhamoy

    1993-01-01

    A number of node assignment schemes, both static and dynamic, are explored for the Algorithm to Architecture Mapping Model (ATAMM). The architecture under consideration consists of heterogeneous processors and implements dataflow models of real-time applications. Terminology is developed for heterogeneous computing. New definitions are added to the ATAMM for token and assignment classifications. It is proved that a periodic execution is possible for dataflow graphs. Assignment algorithms are developed and proved. A design procedure is described for satisfying an objective function in an heterogeneous architecture. Several examples are provided for illustration.

  20. Vehicles for Outdoor Recreation.

    ERIC Educational Resources Information Center

    Exceptional Parent, 1983

    1983-01-01

    The Wheelchair Motorcycle Association tests various motorized vehicles that might help the physically disabled child get about outdoors. Vehicles found to be practical for older children and adolescents include three-wheeled motorcycles and customized go-carts. An address for obtaining more information on the association is provided. (SW)

  1. Electric vehicle technology

    SciTech Connect

    Not Available

    1990-01-01

    This book contains proceedings on electric vehicle technology. Topics covered include: flow-by lead-acid---improving the performance standard for EV battery systems; Townobile purpose-built electric commuter cars, vans and mini-buses; An electric van with extended range; and The future of electric vehicles in meeting the air quality challenges in Southern California.

  2. Launch Vehicle Description

    NASA Technical Reports Server (NTRS)

    Coffey, E. E.; Geye, R. P.

    1970-01-01

    The Thorad-Agena is a two-stage launch vehicle consisting of a Thorad first-stage and an Agena second-stage, connected by a booster adapter. The composite vehicle, including the shroud and the booster adapter, is about 33 meters (109 ft) long. The total weight at lift-off is approximately 91 625 kilograms (202 000 lbm).

  3. Nuclear air cushion vehicles

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    The state-of-the-art of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant is identified. Using mission studies and cost estimates, some of the advantages of nuclear power for large air cushion vehicles are described. The technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies are summarized.

  4. Vehicle barrier systems

    SciTech Connect

    Sena, P.A.

    1986-01-01

    The ground vehicle is one of the most effective tools available to an adversary force. Vehicles can be used to penetrate many types of perimeter barriers, transport equipment and personnel rapidly over long distances, and deliver large amounts of explosives directly to facilities in suicide missions. The function of a vehicle barrier system is to detain or disable a defined threat vehicle at a selected distance from a protected facility. Numerous facilities are installing, or planning to install, vehicle barrier systems and many of these facilities are requesting guidance to do so adequately. Therefore, vehicle barriers are being evaluated to determine their stopping capabilities so that systems can be designed that are both balanced and capable of providing a desired degree of protection. Equally important, many of the considerations that should be taken into account when establishing a vehicle barrier system have been identified. These considerations which pertain to site preparation, barrier selection, system integration and operation, and vehicle/barrier interaction, are discussed in this paper. 2 tabs.

  5. Vehicle barrier systems

    SciTech Connect

    Sena, P.A.

    1986-01-01

    The ground vehicle is one of the most effective tools available to an adversary force. Vehicles can be used to penetrate many types of perimeter barriers, transport equipment, and personnel rapidly over long distances, and deliver large amounts of explosives directly to facilities in suicide missions. The function of a vehicle barrier system is to detain or disable a defined threat vehicle at a selected distance from a protected facility. Numerous facilities are installing, or planning to install, vehicle barrier systems and many of these facilities are requesting guidance to do so adequately. Therefore, vehicle barriers are being evaluated to determine their stopping capabilities so that systems can be designed that are both balanced and capable of providing a desired degree of protection. Equally important, many of the considerations that should be taken into account when establishing a vehicle barrier system have been identified. These considerations which pertain to site preparation, barrier selection, system integration and operation, and vehicle/barrier interaction, are discussed in this paper.

  6. Vehicle barrier systems

    SciTech Connect

    Sena, P.A.

    1986-01-01

    The ground vehicle is one of the most effective tools available to an adversary force. Vehicles can be used to penetrate many types of perimeter barriers, transport equipment and personnel rapidly over long distances, and deliver large amounts of explosives directly to facilities in suicide missions. The function of a vehicle barrier system is to detain or disable a defined threat vehicle at a selected distance from a protected facility. Numerous facilities are installing, or planning to install, vehicle barrier systems and many of these facilities are requesting guidance to do so adequately. Therefore, vehicle barriers are being evaluated to determine their stopping capabilities so that systems can be designed that are both balanced and capable of providing a desired degree of protection. Equally important, many of the considerations that should be taken into account when establishing a vehicle barrier system have been identified. These considerations which pertain to site preparation, barrier selection, system integration and operation, and vehicle/barrier interaction, are discussed in this paper.

  7. Light Vehicle Preventive Maintenance.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to instruct students in the performance of preventive maintenance on motor vehicles. Instructional materials are presented in three chapters as follows: (1) Major Maintenance Areas (maintenance system, tires, batteries, cooling systems, and vehicle lubrication; (2)…

  8. Electric Vehicle Battery Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2014-01-01

    A serious drawback to electric vehicles [batteries only] is the idle time needed to recharge their batteries. In this challenge, students can develop ideas and concepts for battery change-out at automotive service stations. Such a capability would extend the range of electric vehicles.

  9. Lunar material transport vehicle

    NASA Technical Reports Server (NTRS)

    Fisher, Charles D.; Lyons, Douglas; Wilkins, W. Allen, Jr.; Whitehead, Harry C., Jr.

    1988-01-01

    The proposed vehicle, the Lunar Material Transport Vehicle (LMTV), has a mission objective of efficient lunar soil material transport. The LMTV was designed to meet a required set of performance specifications while operating under a given set of constraints. The LMTV is essentially an articulated steering, double-ended dump truck. The vehicle moves on four wheels and has two identical chassis halves. Each half consists of a chassis frame, a material bucket, two wheels with integral curvilinear synchronous motors, a fuel cell and battery arrangement, an electromechanically actuated dumping mechanism, and a powerful microprocessor. The vehicle, as designed, is capable of transporting up to 200 cu ft of material over a one mile round trip per hour. The LMTV is capable of being operated from a variety of sources. The vehicle has been designed as simply as possible with attention also given to secondary usage of components.

  10. Vehicle track loading simulation

    NASA Astrophysics Data System (ADS)

    Chalupa, Milan; Severa, Libor; Vlach, Radek

    2011-12-01

    The paper describes possible design of the vehicle track computational model and basic testing procedure of the track dynamic loading simulation. The proposed approach leads to an improvement of track vehicle course stability. The computational model is built for MSC. ADAMS, AVT computational simulating system. Model, which is intended for MSC computational system, is built from two basic parts. The first one is represented by geometrical part, while the second one by contact computational part of the model. The aim of the simulating calculation consist in determination of change influence of specific vehicle track constructive parameters on changes of examined qualities of the vehicle track link and changes of track vehicle course stability. The work quantifies the influence of changes of track preloading values on the demanded torque changes of driving sprocket. Further research possibilities and potential are also presented.

  11. Lunar material transport vehicle

    NASA Astrophysics Data System (ADS)

    Fisher, Charles D.; Lyons, Douglas; Wilkins, W. Allen, Jr.; Whitehead, Harry C., Jr.

    1988-03-01

    The proposed vehicle, the Lunar Material Transport Vehicle (LMTV), has a mission objective of efficient lunar soil material transport. The LMTV was designed to meet a required set of performance specifications while operating under a given set of constraints. The LMTV is essentially an articulated steering, double-ended dump truck. The vehicle moves on four wheels and has two identical chassis halves. Each half consists of a chassis frame, a material bucket, two wheels with integral curvilinear synchronous motors, a fuel cell and battery arrangement, an electromechanically actuated dumping mechanism, and a powerful microprocessor. The vehicle, as designed, is capable of transporting up to 200 cu ft of material over a one mile round trip per hour. The LMTV is capable of being operated from a variety of sources. The vehicle has been designed as simply as possible with attention also given to secondary usage of components.

  12. Heterogeneous Oxidation of Catechol.

    PubMed

    Pillar, Elizabeth A; Zhou, Ruixin; Guzman, Marcelo I

    2015-10-15

    Natural and anthropogenic emissions of aromatic hydrocarbons from biomass burning, agro-industrial settings, and fossil fuel combustion contribute precursors to secondary aerosol formation (SOA). How these compounds are processed under humid tropospheric conditions is the focus of current attention to understand their environmental fate. This work shows how catechol thin films, a model for oxygenated aromatic hydrocarbons present in biomass burning and combustion aerosols, undergo heterogeneous oxidation at the air-solid interface under variable relative humidity (RH = 0-90%). The maximum reactive uptake coefficient of O3(g) by catechol γO3 = (7.49 ± 0.35) × 10(-6) occurs for 90% RH. Upon exposure of ca. 104-μm thick catechol films to O3(g) mixing ratios between 230 ppbv and 25 ppmv, three main reaction pathways are observed. (1) The cleavage of the 1,2 carbon-carbon bond at the air-solid interface resulting in the formation of cis,cis-muconic acid via primary ozonide and hydroperoxide intermediates. Further direct ozonolysis of cis,cis-muconic yields glyoxylic, oxalic, crotonic, and maleic acids. (2) A second pathway is evidenced by the presence of Baeyer-Villiger oxidation products including glutaconic 4-hydroxy-2-butenoic and 5-oxo-2-pentenoic acids during electrospray ionization mass spectrometry (MS) and ion chromatography MS analyses. (3) Finally, indirect oxidation by in situ produced hydroxyl radical (HO(•)) results in the generation of semiquinone radical intermediates toward the synthesis of polyhydoxylated aromatic rings such as tri-, tetra-, and penta-hydroxybenzene. Remarkably, heavier polyhydroxylated biphenyl and terphenyl products present in the extracted oxidized films result from coupling reactions of semiquinones of catechol and its polyhydroxylated rings. The direct ozonolysis of 1,2,3- and 1,2,4-trihydroxybenezene yields 2- and 3-hydroxy-cis,cis-muconic acid, respectively. The production of 2,4- or 3,4-dihdroxyhex-2-enedioic acid is

  13. Hydrogen vehicle fueling station

    SciTech Connect

    Daney, D.E.; Edeskuty, F.J.; Daugherty, M.A.

    1995-09-01

    Hydrogen fueling stations are an essential element in the practical application of hydrogen as a vehicle fuel, and a number of issues such as safety, efficiency, design, and operating procedures can only be accurately addressed by a practical demonstration. Regardless of whether the vehicle is powered by an internal combustion engine or fuel cell, or whether the vehicle has a liquid or gaseous fuel tank, the fueling station is a critical technology which is the link between the local storage facility and the vehicle. Because most merchant hydrogen delivered in the US today (and in the near future) is in liquid form due to the overall economics of production and delivery, we believe a practical refueling station should be designed to receive liquid. Systems studies confirm this assumption for stations fueling up to about 300 vehicles. Our fueling station, aimed at refueling fleet vehicles, will receive hydrogen as a liquid and dispense it as either liquid, high pressure gas, or low pressure gas. Thus, it can refuel any of the three types of tanks proposed for hydrogen-powered vehicles -- liquid, gaseous, or hydride. The paper discusses the fueling station design. Results of a numerical model of liquid hydrogen vehicle tank filling, with emphasis on no vent filling, are presented to illustrate the usefulness of the model as a design tool. Results of our vehicle performance model illustrate our thesis that it is too early to judge what the preferred method of on-board vehicle fuel storage will be in practice -- thus our decision to accommodate all three methods.

  14. Homogeneous, Heterogeneous, and Enzymatic Catalysis.

    ERIC Educational Resources Information Center

    Oyama, S. Ted; Somorjai, Gabor A.

    1988-01-01

    Discusses three areas of catalysis: homegeneous, heterogeneous, and enzymatic. Explains fundamentals and economic impact of catalysis. Lists and discusses common industrial catalysts. Provides a list of 107 references. (MVL)

  15. EMPIRICAL MODEL OF VEHICLE EMISSIONS

    EPA Science Inventory

    An empirical model that characterizes the relationship between equilibrium vehicle emission distributions and malfunction, repair, and replacement rates by splitting vehicles into two emission categories has been developed. ross emitters and clean vehicles are defined by the magn...

  16. Heterogeneity in motor driven transport

    NASA Astrophysics Data System (ADS)

    Tabei, Ali

    2015-03-01

    I will discuss quantitative analysis of particle tracking data for motor driven vesicles inside an insulin secreting cell. We use this method to study the dynamical and structural heterogeneity inside the cell. I will discuss our effort to explain the origin of observed heterogeneity in intracellular transport. Finally, I will explain how analyzing directional correlations in transport trajectories reveals self-similarity in the diffusion media.

  17. Analysis of active renin heterogeneity.

    PubMed

    Katz, S A; Malvin, R L; Lee, J; Kim, S H; Murray, R D; Opsahl, J A; Abraham, P A

    1991-09-01

    Active renin is a heterogeneous enzyme that can be separated into multiple forms with high-resolution isoelectric focusing. The isoelectric heterogeneity may result from differences in glycosylation between the different forms. In order to determine the relationship between active renin heterogeneity and differences in composition or attachment of oligosaccharides, two separate experiments were performed: (i) Tunicamycin, which interferes with normal glycosylation processing, increased the proportion of relatively basic renin forms secreted into the incubation media by rat renal cortical slices. (ii) Endoglycosidase F, which enzymatically removes carbohydrate from some classes of glycoprotein, similarly increased the proportion of relatively basic forms when incubated with active human recombinant renin. In addition, further studies with inhibitors of human renin activity revealed that the heterogeneous renin forms were similarly inhibited by two separate renin inhibitors. These results are consistent with the hypothesis that renin isoelectric heterogeneity is due in part to differences in carbohydrate moiety attachment and that the heterogeneity of renin does not influence access of direct renin inhibitors to the active site of renin. PMID:1908097

  18. Methane emissions from vehicles.

    PubMed

    Nam, E K; Jensen, T E; Wallington, T J

    2004-04-01

    Methane (CH4) is an important greenhouse gas emitted by vehicles. We report results of a laboratory study of methane emissions using a standard driving cycle for 30 different cars and trucks (1995-1999 model years) from four different manufacturers. We recommend the use of an average emission factor for the U.S. on-road vehicle fleet of (g of CH/g of CO2) = (15 +/- 4) x 10(-5) and estimate that the global vehicle fleet emits 0.45 +/- 0.12 Tg of CH4 yr(-1) (0.34 +/- 0.09 Tg of C yr(-1)), which represents < 0.2% of anthropogenic CH4 emissions. This estimate includes the effects of vehicle aging, cold start, and hot running emissions. The contribution of CH4 emissions from vehicles to radiative forcing of climate change is 0.3-0.4% of that of CO2 emissions from vehicles. The environmental impact of CH4 emissions from vehicles is negligible and is likely to remain so for the foreseeable future. PMID:15112800

  19. Electric vehicle activities

    NASA Astrophysics Data System (ADS)

    Delmonaco, J. L.; Pandya, D. A.

    1995-02-01

    The data and information collected for the Public Service Electric and Gas Company's (PSE&G) electric vehicle demonstration program were intended to support and enhance DOE's Electric and Hybrid Vehicle Site Operator Program. The DOE Site Operator Program is focused on the life cycle and reliability of Electric Vehicles (EV's). Of particular interest are vehicles currently available with features that are likely to be put into production or demonstrate new technology. PSE&G acquired eight GMC Electric G-Vans in 1991, and three TEVans in 1993, and conducted a program plan to test and assess the overall performance of these electric vehicles. To accomplish the objectives of DOE's Site Operator's test program, a manual data collection system was implemented. The manual data collection system has provided energy use and mileage data. From September 1991 to October 1994 PSE&G logged 69,368 miles on eleven test vehicles. PSE&G also demonstrated the EVs to diverse groups and associations at fifty seven various events. Included in the report are lessons learned concerning maintenance, operation, public reactions, and driver's acceptance of the electric vehicles.

  20. Mars manned transportation vehicle

    SciTech Connect

    Perez-Davis, M.E.; Faymon, K.A.

    1987-07-01

    A viable power system technology for a surface transportation vehicle to explore the planet Mars is presented. A number of power traction systems were investigated, and it was found that a regenerative hydrogen-oxygen fuel cell appears to be attractive for a manned Mars rover application. Mission requirements were obtained from the Manned Mars Mission Working Group. Power systems weights, power, and reactants requirements were determined as a function of vehicle weights for vehicles weighing from 6,000 to 16,000 lb (2,722 to 7,257 kg), (Earth weight). The vehicle performance requirements were: velocity, 10 km/hr; range, 100 km; slope climbing capability, 30 deg uphill for 50 km; mission duration, 5 days; and crew, 5. Power requirements for the operation of scientific equipment and support system capabilities were also specified and included in this study. The concept developed here would also be applicable to a Lunar based vehicle for Lunar exploration. The reduced gravity on the Lunar surface, (over that on the Martian surface), would result in an increased range or capability over that of the Mars vehicle since many of the power and energy requirements for the vehicle are gravity dependent.

  1. Orchestrated management of heterogeneous sensors incorporating feedback from intelligence assets

    NASA Astrophysics Data System (ADS)

    Sarkale, Yugandhar; Chong, Edwin K. P.

    2015-05-01

    We develop a method for autonomous management of multiple heterogeneous sensors mounted on unmanned aerial vehicles (UAVs) for multitarget tracking. The main contribution of the paper is incorporation of feedback received from intelligence assets (humans) on priorities assigned to specific targets. We formulate the problem as a partially observable Markov decision processes (POMDP) where information received from assets is captured as a penalty on the cost function. The resulting constrained optimization problem is solved using an augmented Lagrangian method. Information obtained from sensors and assets is fused centrally for guiding the UAVs to track these targets.

  2. Blast resistant vehicle seat

    DOEpatents

    Ripley, Edward B

    2013-02-12

    Disclosed are various seats for vehicles particularly military vehicles that are susceptible to attack by road-bed explosive devices such as land mines or improvised explosive devices. The seats often have rigid seat shells and may include rigid bracing for rigidly securing the seat to the chassis of the vehicle. Typically embodiments include channels and particulate media such as sand disposed in the channels. A gas distribution system is generally employed to pump a gas through the channels and in some embodiments the gas is provided at a pressure sufficient to fluidize the particulate media when an occupant is sitting on the seat.

  3. Rapid road repair vehicle

    DOEpatents

    Mara, Leo M.

    1999-01-01

    Disclosed are improvments to a rapid road repair vehicle comprising an improved cleaning device arrangement, two dispensing arrays for filling defects more rapidly and efficiently, an array of pre-heaters to heat the road way surface in order to help the repair material better bond to the repaired surface, a means for detecting, measuring, and computing the number, location and volume of each of the detected surface imperfection, and a computer means schema for controlling the operation of the plurality of vehicle subsystems. The improved vehicle is, therefore, better able to perform its intended function of filling surface imperfections while moving over those surfaces at near normal traffic speeds.

  4. Assured crew return vehicle

    NASA Technical Reports Server (NTRS)

    Cerimele, Christopher J. (Inventor); Ried, Robert C. (Inventor); Peterson, Wayne L. (Inventor); Zupp, George A., Jr. (Inventor); Stagnaro, Michael J. (Inventor); Ross, Brian P. (Inventor)

    1991-01-01

    A return vehicle is disclosed for use in returning a crew to Earth from low earth orbit in a safe and relatively cost effective manner. The return vehicle comprises a cylindrically-shaped crew compartment attached to the large diameter of a conical heat shield having a spherically rounded nose. On-board inertial navigation and cold gas control systems are used together with a de-orbit propulsion system to effect a landing near a preferred site on the surface of the Earth. State vectors and attitude data are loaded from the attached orbiting craft just prior to separation of the return vehicle.

  5. Modeling conflicts of heterogeneous traffic at urban uncontrolled intersections

    SciTech Connect

    Trinadha Rao, V.; Rengaraju, V.R.

    1998-01-01

    The behavior of traffic in the heterogeneous environment of an urban uncontrolled intersection is complex and difficult to model. The present study describes the methodology of simulating the traffic flow and thereby estimating the number of conflicts in varying traffic flow conditions. The arrival pattern of vehicles was represented by a multivariate distribution to generate input to the simulation model. The model was validated externally, using field observed data, and was found to predict the number of conflicts well. As an illustration of usefulness of the model, variation of conflict rate (the probability of a vehicle`s getting involved in conflict) due to variation in traffic volume and the proportion of right-turning traffic has been quantified. Under the prevailing traffic composition and turning movements, the conflict rate is estimated to lie in the range of 0.66--0.70, 0.79--0.84, and 0.80-0.87 for intersection volumes of 2,000, 2,500, and 3,000 vehicles per hour, respectively. Issues related to the applicability of the proposed model are briefly discussed.

  6. Dealing with spatial heterogeneity

    NASA Astrophysics Data System (ADS)

    Marsily, Gh.; Delay, F.; Gonçalvès, J.; Renard, Ph.; Teles, V.; Violette, S.

    2005-03-01

    Heterogeneity can be dealt with by defining homogeneous equivalent properties, known as averaging, or by trying to describe the spatial variability of the rock properties from geologic observations and local measurements. The techniques available for these descriptions are mostly continuous Geostatistical models, or discontinuous facies models such as the Boolean, Indicator or Gaussian-Threshold models and the Markov chain model. These facies models are better suited to treating issues of rock strata connectivity, e.g. buried high permeability channels or low permeability barriers, which greatly affect flow and, above all, transport in aquifers. Genetic models provide new ways to incorporate more geology into the facies description, an approach that has been well developed in the oil industry, but not enough in hydrogeology. The conclusion is that future work should be focused on improving the facies models, comparing them, and designing new in situ testing procedures (including geophysics) that would help identify the facies geometry and properties. A world-wide catalog of aquifer facies geometry and properties, which could combine site genesis and description with methods used to assess the system, would be of great value for practical applications. On peut aborder le problème de l'hétérogénéité en s'efforçant de définir une perméabilité équivalente homogène, par prise de moyenne, ou au contraire en décrivant la variation dans l'espace des propriétés des roches à partir des observations géologiques et des mesures locales. Les techniques disponibles pour une telle description sont soit continues, comme l'approche Géostatistique, soit discontinues, comme les modèles de faciès, Booléens, ou bien par Indicatrices ou Gaussiennes Seuillées, ou enfin Markoviens. Ces modèles de faciès sont mieux capables de prendre en compte la connectivité des strates géologiques, telles que les chenaux enfouis à forte perméabilité, ou au contraire les faci

  7. Dealing with spatial heterogeneity

    NASA Astrophysics Data System (ADS)

    Marsily, Gh.; Delay, F.; Gonçalvès, J.; Renard, Ph.; Teles, V.; Violette, S.

    2005-03-01

    Heterogeneity can be dealt with by defining homogeneous equivalent properties, known as averaging, or by trying to describe the spatial variability of the rock properties from geologic observations and local measurements. The techniques available for these descriptions are mostly continuous Geostatistical models, or discontinuous facies models such as the Boolean, Indicator or Gaussian-Threshold models and the Markov chain model. These facies models are better suited to treating issues of rock strata connectivity, e.g. buried high permeability channels or low permeability barriers, which greatly affect flow and, above all, transport in aquifers. Genetic models provide new ways to incorporate more geology into the facies description, an approach that has been well developed in the oil industry, but not enough in hydrogeology. The conclusion is that future work should be focused on improving the facies models, comparing them, and designing new in situ testing procedures (including geophysics) that would help identify the facies geometry and properties. A world-wide catalog of aquifer facies geometry and properties, which could combine site genesis and description with methods used to assess the system, would be of great value for practical applications. On peut aborder le problème de l'hétérogénéité en s'efforçant de définir une perméabilité équivalente homogène, par prise de moyenne, ou au contraire en décrivant la variation dans l'espace des propriétés des roches à partir des observations géologiques et des mesures locales. Les techniques disponibles pour une telle description sont soit continues, comme l'approche Géostatistique, soit discontinues, comme les modèles de faciès, Booléens, ou bien par Indicatrices ou Gaussiennes Seuillées, ou enfin Markoviens. Ces modèles de faciès sont mieux capables de prendre en compte la connectivité des strates géologiques, telles que les chenaux enfouis à forte perméabilité, ou au contraire les faci

  8. Compact Robotic Vehicle

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian H.; Ohm, Timothy R.

    1993-01-01

    Radio-controlled microrover features light weight and agility. Miniature robotic vehicle, called Go-For, implements new fork-wheeled mobility concept to traverse extremely rough terrain. Weighs 4 kg and is 0.4 m long, climbs over obstacles as large as 60 percent of its length. Mobility concept applied to much larger vehicles. Demonstrates such applications as exploration of planetary surfaces, military surveillance, and assessing hazardous situations. Video camera on vehicle sends images to control station, where human supervisor chooses sequence of paths to traverse to reach locations of interest. For planetary exploration, spectrometer and seisometer on vehicle sends scientific data to control station, and onboard tools collect soil and rock samples. Terrestrial version equipped similarly to take samples in chemically and/or biologically contaminated areas.

  9. Space Vehicle Valve System

    NASA Technical Reports Server (NTRS)

    Kelley, Anthony R. (Inventor); Lindner, Jeffrey L. (Inventor)

    2014-01-01

    The present invention is a space vehicle valve system which controls the internal pressure of a space vehicle and the flow rate of purged gases at a given internal pressure and aperture site. A plurality of quasi-unique variable dimension peaked valve structures cover the purge apertures on a space vehicle. Interchangeable sheet guards configured to cover valve apertures on the peaked valve structure contain a pressure-activated surface on the inner surface. Sheet guards move outwardly from the peaked valve structure when in structural contact with a purge gas stream flowing through the apertures on the space vehicle. Changing the properties of the sheet guards changes the response of the sheet guards at a given internal pressure, providing control of the flow rate at a given aperture site.

  10. Vehicle speed control device

    SciTech Connect

    Thornton-Trump, W.E.

    1987-03-10

    An apparatus is described for automatically limiting the speed of a vehicle powered by an internal combustion engine having a spark ignition system with an ignition coil, comprising: sensor means for generating a speed signal directly representative of the speed of the vehicle comprising a series of speed signal pulses having a pulse repetition frequency proportional to the speed of the vehicle; control means for converting speed signal pulses into a DC voltage proportional to the vehicle speed; means for comparing the DC voltage to a predetermined DC voltage having substantially zero AC components representative of a predetermined maximum speed and for generating a difference signal in response thereto; and means for generating a pulse-width modulated control signal responsive to the difference signal; power means responsive to the control signal for intermittently interrupting the ignition system.

  11. Motor Vehicle Safety

    MedlinePlus

    ... these crashes is one part of motor vehicle safety. Here are some things you can do to ... speed or drive aggressively Don't drive impaired Safety also involves being aware of others. Share the ...

  12. Experimental Semiautonomous Vehicle

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian H.; Mishkin, Andrew H.; Litwin, Todd E.; Matthies, Larry H.; Cooper, Brian K.; Nguyen, Tam T.; Gat, Erann; Gennery, Donald B.; Firby, Robert J.; Miller, David P.; Loch, John L.; Slack, Marc G.

    1993-01-01

    Semiautonomous rover vehicle serves as testbed for evaluation of navigation and obstacle-avoidance techniques. Designed to traverse variety of terrains. Concepts developed applicable to robots for service in dangerous environments as well as to robots for exploration of remote planets. Called Robby, vehicle 4 m long and 2 m wide, with six 1-m-diameter wheels. Mass of 1,200 kg and surmounts obstacles as large as 1 1/2 m. Optimized for development of machine-vision-based strategies and equipped with complement of vision and direction sensors and image-processing computers. Front and rear cabs steer and roll with respect to centerline of vehicle. Vehicle also pivots about central axle, so wheels comply with almost any terrain.

  13. Vehicle Technologies Program Implementation

    SciTech Connect

    none,

    2009-06-19

    The Vehicle Technologies Program takes a systematic approach to Program implementation. Elements of this approach include the evaluation of new technologies, competitive selection of projects and partners, review of Program and project improvement, project tracking, and portfolio management and adjustment.

  14. TRACKED VEHICLE Rev 75

    SciTech Connect

    Raby, Eric Y.

    2007-05-08

    Revision 75 of the Tracked Vehicle software is a soft real-time simulation of a differentially steered, tracked mobile robot, which, because of the track flippers, resembles the iRobot PackBot (http://www.irobot.com/). Open source libraries are used for the physics engine (http://www.ode.org/), the display and user interface (http://www.mathies.com/cpw/), and the program command line and configuration file parameters (http://www.boost.org/). The simulation can be controlled by a USB joystick or the keyboard. The configuration file contains demonstration model parameters of no particular vehicle. This simulation can be used as a starting point for those doing tracked vehicle simulations. This simulation software is essentially a research tool which can be modified and adapted for certain types of tracked vehicle research. An open source license allows an individual researchers to tailor the code to their specific research needs.

  15. TRACKED VEHICLE Rev 75

    2007-05-08

    Revision 75 of the Tracked Vehicle software is a soft real-time simulation of a differentially steered, tracked mobile robot, which, because of the track flippers, resembles the iRobot PackBot (http://www.irobot.com/). Open source libraries are used for the physics engine (http://www.ode.org/), the display and user interface (http://www.mathies.com/cpw/), and the program command line and configuration file parameters (http://www.boost.org/). The simulation can be controlled by a USB joystick or the keyboard. The configuration file contains demonstration model parametersmore » of no particular vehicle. This simulation can be used as a starting point for those doing tracked vehicle simulations. This simulation software is essentially a research tool which can be modified and adapted for certain types of tracked vehicle research. An open source license allows an individual researchers to tailor the code to their specific research needs.« less

  16. Hybrid vehicle control

    SciTech Connect

    Shallvari, Iva; Velnati, Sashidhar; DeGroot, Kenneth P.

    2015-07-28

    A method and apparatus for heating a catalytic converter's catalyst to an efficient operating temperature in a hybrid electric vehicle when the vehicle is in a charge limited mode such as e.g., the charge depleting mode or when the vehicle's high voltage battery is otherwise charge limited. The method and apparatus determine whether a high voltage battery of the vehicle is incapable of accepting a first amount of charge associated with a first procedure to warm-up the catalyst. If it is determined that the high voltage battery is incapable of accepting the first amount of charge, a second procedure with an acceptable amount of charge is performed to warm-up the catalyst.

  17. Vehicle Technologies Program Planning

    SciTech Connect

    2009-06-19

    The Vehicle Technologies Program’s strategic goal is to develop sustainable, cost-competitive technologies to reduce U.S. dependence on petroleum, increase fuel efficiency, reduce greenhouse gas emissions and improve the Nation's energy security.

  18. Vehicle Technologies Program Overview

    SciTech Connect

    none,

    2006-09-05

    Overview of the Vehicle Technologies Program including external assessment and market view; internal assessment, program history and progress; program justification and federal role; program vision, mission, approach, strategic goals, outputs, and outcomes; and performance goals.

  19. Reaction Selectivity in Heterogeneous Catalysis

    SciTech Connect

    Somorjai, Gabor A.; Kliewer, Christopher J.

    2009-02-02

    The understanding of selectivity in heterogeneous catalysis is of paramount importance to our society today. In this review we outline the current state of the art in research on selectivity in heterogeneous catalysis. Current in-situ surface science techniques have revealed several important features of catalytic selectivity. Sum frequency generation vibrational spectroscopy has shown us the importance of understanding the reaction intermediates and mechanism of a heterogeneous reaction, and can readily yield information as to the effect of temperature, pressure, catalyst geometry, surface promoters, and catalyst composition on the reaction mechanism. DFT calculations are quickly approaching the ability to assist in the interpretation of observed surface spectra, thereby making surface spectroscopy an even more powerful tool. HP-STM has revealed three vitally important parameters in heterogeneous selectivity: adsorbate mobility, catalyst mobility, and selective site-blocking. The development of size controlled nanoparticles from 0.8 to 10 nm, of controlled shape, and of controlled bimetallic composition has revealed several important variables for catalytic selectivity. Lastly, DFT calculations may be paving the way to guiding the composition choice for multi-metallic heterogeneous catalysis for the intelligent design of catalysts incorporating the many factors of selectivity we have learned.

  20. Nuclear air cushion vehicles.

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    This paper serves several functions. It identifies the 'state-of-the-art' of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant. Using mission studies and cost estimates, the report describes some of the advantages of nuclear power for large air cushion vehicles. The paper also summarizes the technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies that have been performed at NASA Lewis Research Center.

  1. Launch Vehicle Operations Simulator

    NASA Technical Reports Server (NTRS)

    Blackledge, J. W.

    1974-01-01

    The Saturn Launch Vehicle Operations Simulator (LVOS) was developed for NASA at Kennedy Space Center. LVOS simulates the Saturn launch vehicle and its ground support equipment. The simulator was intended primarily to be used as a launch crew trainer but it is also being used for test procedure and software validation. A NASA/contractor team of engineers and programmers implemented the simulator after the Apollo XI lunar landing during the low activity periods between launches.

  2. Sleep related vehicle accidents.

    PubMed Central

    Horne, J. A.; Reyner, L. A.

    1995-01-01

    OBJECTIVES--To assess the incidence, time of day, and driver morbidity associated with vehicle accidents where the most likely cause was the driver falling asleep at the wheel. DESIGN--Two surveys were undertaken, in southwest England and the midlands, by using police databases or on the spot interviews. SUBJECTS--Drivers involved in 679 sleep related vehicle accidents. RESULTS--Of all vehicle accidents to which the police were summoned, sleep related vehicle accidents comprised 16% on major roads in southwest England, and over 20% on midland motorways. During the 24 hour period there were three major peaks: at around 0200, 0600, and 1600. About half these drivers were men under 30 years; few such accidents involved women. CONCLUSIONS--Sleep related vehicle accidents are largely dependent on the time of day and account for a considerable proportion of vehicle accidents, especially those on motorways and other monotonous roads. As there are no norms for the United Kingdom on road use by age and sex for time of day with which to compare these data, we cannot determine what the hourly exposure v risk factors are for these subgroups. The findings are in close agreement with those from other countries. PMID:7888930

  3. Space robot simulator vehicle

    NASA Technical Reports Server (NTRS)

    Cannon, R. H., Jr.; Alexander, H.

    1985-01-01

    A Space Robot Simulator Vehicle (SRSV) was constructed to model a free-flying robot capable of doing construction, manipulation and repair work in space. The SRSV is intended as a test bed for development of dynamic and static control methods for space robots. The vehicle is built around a two-foot-diameter air-cushion vehicle that carries batteries, power supplies, gas tanks, computer, reaction jets and radio equipment. It is fitted with one or two two-link manipulators, which may be of many possible designs, including flexible-link versions. Both the vehicle body and its first arm are nearly complete. Inverse dynamic control of the robot's manipulator has been successfully simulated using equations generated by the dynamic simulation package SDEXACT. In this mode, the position of the manipulator tip is controlled not by fixing the vehicle base through thruster operation, but by controlling the manipulator joint torques to achieve the desired tip motion, while allowing for the free motion of the vehicle base. One of the primary goals is to minimize use of the thrusters in favor of intelligent control of the manipulator. Ways to reduce the computational burden of control are described.

  4. Electric/Hybrid Vehicle Simulation

    NASA Technical Reports Server (NTRS)

    Slusser, R. A.; Chapman, C. P.; Brennand, J. P.

    1985-01-01

    ELVEC computer program provides vehicle designer with simulation tool for detailed studies of electric and hybrid vehicle performance and cost. ELVEC simulates performance of user-specified electric or hybrid vehicle under user specified driving schedule profile or operating schedule. ELVEC performs vehicle design and life cycle cost analysis.

  5. Quantifying tumour heterogeneity with CT

    PubMed Central

    Miles, Kenneth A.

    2013-01-01

    Abstract Heterogeneity is a key feature of malignancy associated with adverse tumour biology. Quantifying heterogeneity could provide a useful non-invasive imaging biomarker. Heterogeneity on computed tomography (CT) can be quantified using texture analysis which extracts spatial information from CT images (unenhanced, contrast-enhanced and derived images such as CT perfusion) that may not be perceptible to the naked eye. The main components of texture analysis can be categorized into image transformation and quantification. Image transformation filters the conventional image into its basic components (spatial, frequency, etc.) to produce derived subimages. Texture quantification techniques include structural-, model- (fractal dimensions), statistical- and frequency-based methods. The underlying tumour biology that CT texture analysis may reflect includes (but is not limited to) tumour hypoxia and angiogenesis. Emerging studies show that CT texture analysis has the potential to be a useful adjunct in clinical oncologic imaging, providing important information about tumour characterization, prognosis and treatment prediction and response. PMID:23545171

  6. Heterogeneous surfaces to repel proteins.

    PubMed

    Shen, Lei; Zhu, Jintao

    2016-02-01

    The nonspecific adsorption of proteins is usually undesirable on solid surfaces as it induces adverse responses, such as platelet adhesion on medical devices, negative signals of biosensors and contamination blockage of filtration membranes. Thus, an important scheme in material science is to design and fabricate protein-repulsive surfaces. Early approaches in this field focused on homogeneous surfaces comprised of single type functionality. Yet, recent researches have demonstrated that surfaces with heterogeneities (chemistry and topography) show promising performance against protein adsorption. In this review, we will summarize the recent achievements and discuss the new perspectives in the research of developing and characterizing heterogeneous surfaces to repel proteins. The protein repulsion mechanisms of different heterogeneous surfaces will also be discussed in details, followed by the perspective and challenge of this emerging field. PMID:26691416

  7. Resource heterogeneity can facilitate cooperation

    PubMed Central

    Kun, Ádám; Dieckmann, Ulf

    2013-01-01

    Although social structure is known to promote cooperation, by locally exposing selfish agents to their own deeds, studies to date assumed that all agents have access to the same level of resources. This is clearly unrealistic. Here we find that cooperation can be maintained when some agents have access to more resources than others. Cooperation can then emerge even in populations in which the temptation to defect is so strong that players would act fully selfishly if their resources were distributed uniformly. Resource heterogeneity can thus be crucial for the emergence and maintenance of cooperation. We also show that resource heterogeneity can hinder cooperation once the temptation to defect is significantly lowered. In all cases, the level of cooperation can be maximized by managing resource heterogeneity. PMID:24088665

  8. Simulator for heterogeneous dataflow architectures

    NASA Technical Reports Server (NTRS)

    Malekpour, Mahyar R.

    1993-01-01

    A new simulator is developed to simulate the execution of an algorithm graph in accordance with the Algorithm to Architecture Mapping Model (ATAMM) rules. ATAMM is a Petri Net model which describes the periodic execution of large-grained, data-independent dataflow graphs and which provides predictable steady state time-optimized performance. This simulator extends the ATAMM simulation capability from a heterogenous set of resources, or functional units, to a more general heterogenous architecture. Simulation test cases show that the simulator accurately executes the ATAMM rules for both a heterogenous architecture and a homogenous architecture, which is the special case for only one processor type. The simulator forms one tool in an ATAMM Integrated Environment which contains other tools for graph entry, graph modification for performance optimization, and playback of simulations for analysis.

  9. Static heterogeneities in liquid water

    NASA Astrophysics Data System (ADS)

    Stanley, H. Eugene; Buldyrev, Sergey V.; Giovambattista, Nicolas

    2004-10-01

    The thermodynamic behavior of water seems to be closely related to static heterogeneities. These static heterogeneities are related to the local structure of water molecules, and when properly characterized, may offer an economical explanation of thermodynamic data. The key feature of liquid water is not so much that the existence of hydrogen bonds, first pointed out by Linus Pauling, but rather the local geometry of the liquid molecules is not spherical or oblong but tetrahedral. In the consideration of static heterogeneities, this local geometry is critical. Recent experiments suggested more than one phase of amorphous solid water, while simulations suggest that one of these phases is metastable with respect to another, so that in fact there are only two stable phases.

  10. Advanced Vehicle Testing and Evaluation

    SciTech Connect

    Garetson, Thomas

    2013-03-31

    The objective of the United States (U.S.) Department of Energy's (DOEs) Advanced Vehicle Testing and Evaluation (AVTE) project was to provide test and evaluation services for advanced technology vehicles, to establish a performance baseline, to determine vehicle reliability, and to evaluate vehicle operating costs in fleet operations.Vehicles tested include light and medium-duty vehicles in conventional, hybrid, and all-electric configurations using conventional and alternative fuels, including hydrogen in internal combustion engines. Vehicles were tested on closed tracks and chassis dynamometers, as well as operated on public roads, in fleet operations, and over prescribed routes. All testing was controlled by procedures developed specifically to support such testing.

  11. Upgraded demonstration vehicle task report

    NASA Technical Reports Server (NTRS)

    Bryant, J.; Hardy, K.; Livingston, R.; Sandberg, J.

    1981-01-01

    Vehicle/battery performance capabilities and interface problems that occurred when upgraded developmental batteries were integrated with upgraded versions of comercially available electric vehicles were investigated. Developmental batteries used included nickel zinc batteries, a nickel iron battery, and an improved lead acid battery. Testing of the electric vehicles and upgraded batteries was performed in the complete vehicle system environment to characterize performance and identify problems unique to the vehicle/battery system. Constant speed tests and driving schedule range tests were performed on a chassis dynamometer. The results from these tests of the upgraded batteries and vehicles were compared to performance capabilities for the same vehicles equipped with standard batteries.

  12. Unmanned ground vehicles for integrated force protection

    NASA Astrophysics Data System (ADS)

    Carroll, Daniel M.; Mikell, Kenneth; Denewiler, Thomas

    2004-09-01

    The combination of Command and Control (C2) systems with Unmanned Ground Vehicles (UGVs) provides Integrated Force Protection from the Robotic Operation Command Center. Autonomous UGVs are directed as Force Projection units. UGV payloads and fixed sensors provide situational awareness while unattended munitions provide a less-than-lethal response capability. Remote resources serve as automated interfaces to legacy physical devices such as manned response vehicles, barrier gates, fence openings, garage doors, and remote power on/off capability for unmanned systems. The Robotic Operations Command Center executes the Multiple Resource Host Architecture (MRHA) to simultaneously control heterogeneous unmanned systems. The MRHA graphically displays video, map, and status for each resource using wireless digital communications for integrated data, video, and audio. Events are prioritized and the user is prompted with audio alerts and text instructions for alarms and warnings. A control hierarchy of missions and duty rosters support autonomous operations. This paper provides an overview of the key technology enablers for Integrated Force Protection with details on a force-on-force scenario to test and demonstrate concept of operations using Unmanned Ground Vehicles. Special attention is given to development and applications for the Remote Detection Challenge and Response (REDCAR) initiative for Integrated Base Defense.

  13. Vehicle performance computer

    SciTech Connect

    Pugh, R.D.

    1987-07-14

    A vehicle performance computer is described in the form of a circular slide rule for determining the relationship between the vehicle performance parameters of time, distance, braking, coasting, and acceleration as a function of vehicle weight, horsepower, speed, and roadway percent grade, the computer comprising: substantially planar base having a center and also including: a first logarithmic scale arcuately disposed about the base center and having indicia associated representing the speed of the vehicle; a second logarithmic scale arcuately disposed in a predetermined position with respect to the first logarithmic scale and having indicia associated representing the weight-to-horsepower of the vehicle; a third logarithmic scale arcuately disposed about the base center in a predetermined position with respect to the first and second logarithmic scales and having indicia representing the required time for the vehicle to alter its speed from one particular speed to another; a substantially planar intermediate slide having a center and rotatably mounted atop the base both the centers are aligned, the intermediate slide including: a fourth logarithmic scale arcuately disposed and having indicia associated representing the percent grade upon which the vehicle is traveling; a window arcuately disposed about the intermediate slide center in a predetermined position with respect to the fourth logarithmic scale for viewing the second logarithmic scale in cooperative viewable alignment with the fourth logarithmic scale; a fifth logarithmic scale arcuately disposed about the intermediate slide center in a predetermined position a sixth logarithmic scale arcuately disposed about the intermediate slide center in a predetermined position with respect to the fourth and fifth logarithmic scale.

  14. Verification of heterogeneous multi-agent system using MCMAS

    NASA Astrophysics Data System (ADS)

    Choi, Jiyoung; Kim, Seungkeun; Tsourdos, Antonios

    2015-03-01

    The focus of the paper is how to model autonomous behaviours of heterogeneous multi-agent systems such that it can be verified that they will always operate within predefined mission requirements and constraints. This is done by using formal methods with an abstraction of the behaviours modelling and model checking for their verification. Three case studies are presented to verify the decision-making behaviours of heterogeneous multi-agent system using a convoy mission scenario. The multi-agent system in a case study has been extended by increasing the number of agents and function complexity gradually. For automatic verification, model checker for multi-agent systems (MCMAS) is adopted due to its novel capability to accommodate the multi-agent system and successfully verifies the targeting behaviours of the team-level autonomous systems. The verification results help retrospectively the design of decision-making algorithms improved by considering additional agents and behaviours during three steps of scenario modification. Consequently, the last scenario deals with the system composed of a ground control system, two unmanned aerial vehicles, and four unmanned ground vehicles with fault-tolerant and communication relay capabilities.

  15. Social Capital and Community Heterogeneity

    ERIC Educational Resources Information Center

    Coffe, Hilde

    2009-01-01

    Recent findings indicate that more pronounced community heterogeneity is associated with lower levels of social capital. These studies, however, concentrate on specific aspects in which people differ (such as income inequality or ethnic diversity). In the present paper, we introduce the number of parties in the local party system as a more…

  16. Floodplain heterogeneity and meander migration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of horizontal heterogeneity of floodplain soils on rates and patterns of meander migration is analyzed with a Ikeda et al. (1981)-type model for hydrodynamics and bed morphodynamics, coupled with a physically-based bank erosion model according to the approach developed by Motta et al. (20...

  17. Teaching about Heterogeneous Response Models

    ERIC Educational Resources Information Center

    Murray, Michael P.

    2014-01-01

    Individuals vary in their responses to incentives and opportunities. For example, additional education will affect one person differently than another. In recent years, econometricians have given increased attention to such heterogeneous responses and to the consequences of such responses for interpreting regression estimates, especially…

  18. Electoral Competition in Heterogeneous Districts

    ERIC Educational Resources Information Center

    Callander, Steven

    2005-01-01

    This paper considers a model of elections in which parties compete simultaneously for multiple districts. I show that if districts are heterogeneous, then a unique two-party equilibrium exists under plurality rule in which further entry is deterred. The equilibrium requires that parties choose noncentrist policy platforms and not converge to the…

  19. 77 FR 12355 - Enabling a Secure Environment for Vehicle-to-Vehicle and Vehicle-to-Infrastructure Transactions...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ... Enabling a Secure Environment for Vehicle-to-Vehicle and Vehicle- to-Infrastructure Transactions Workshop... Environment for Vehicle- to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) Transactions on April 19-20... presented in August 2012 during the annual Connected Vehicle Safety public meeting and via other...

  20. Distributed Propulsion Vehicles

    NASA Technical Reports Server (NTRS)

    Kim, Hyun Dae

    2010-01-01

    Since the introduction of large jet-powered transport aircraft, the majority of these vehicles have been designed by placing thrust-generating engines either under the wings or on the fuselage to minimize aerodynamic interactions on the vehicle operation. However, advances in computational and experimental tools along with new technologies in materials, structures, and aircraft controls, etc. are enabling a high degree of integration of the airframe and propulsion system in aircraft design. The National Aeronautics and Space Administration (NASA) has been investigating a number of revolutionary distributed propulsion vehicle concepts to increase aircraft performance. The concept of distributed propulsion is to fully integrate a propulsion system within an airframe such that the aircraft takes full synergistic benefits of coupling of airframe aerodynamics and the propulsion thrust stream by distributing thrust using many propulsors on the airframe. Some of the concepts are based on the use of distributed jet flaps, distributed small multiple engines, gas-driven multi-fans, mechanically driven multifans, cross-flow fans, and electric fans driven by turboelectric generators. This paper describes some early concepts of the distributed propulsion vehicles and the current turboelectric distributed propulsion (TeDP) vehicle concepts being studied under the NASA s Subsonic Fixed Wing (SFW) Project to drastically reduce aircraft-related fuel burn, emissions, and noise by the year 2030 to 2035.

  1. Methylotroph cloning vehicle

    DOEpatents

    Hanson, Richard S.; Allen, Larry N.

    1989-04-25

    A cloning vehicle comprising: a replication determinant effective for replicating the vehicle in a non-C.sub.1 -utilizing host and in a C.sub.1 -utilizing host; DNA effective to allow the vehicle to be mobilized from the non-C.sub.1 -utilizing host to the C.sub.1 -utilizing host; DNA providing resistance to two antibiotics to which the wild-type C.sub.1 -utilizing host is susceptible, each of the antibiotic resistance markers having a recognition site for a restriction endonuclease; a cos site; and a means for preventing replication in the C.sub.1 -utilizing host. The vehicle is used for complementation mapping as follows. DNA comprising a gene from the C.sub.1 -utilizing organism is inserted at the restriction nuclease recognition site, inactivating the antibiotic resistance marker at that site. The vehicle can then be used to form a cosmid structure to infect the non-C.sub.1 -utilizing (e.g., E. coli) host, and then conjugated with a selected C.sub.1 -utilizing mutant. Resistance to the other antibiotic by the mutant is a marker of the conjugation. Other phenotypical changes in the mutant, e.g., loss of an auxotrophic trait, is attributed to the C.sub.1 gene. The vector is also used to inactivate genes whose protein products catalyze side reactions that divert compounds from a biosynthetic pathway to a desired product, thereby producing an organism that makes the desired product in higher yields.

  2. Flammability of Heterogeneously Combusting Metals

    NASA Technical Reports Server (NTRS)

    Jones, Peter D.

    1998-01-01

    Most engineering materials, including some metals, most notably aluminum, burn in homogeneous combustion. 'Homogeneous' refers to both the fuel and the oxidizer being in the same phase, which is usually gaseous. The fuel and oxidizer are well mixed in the combustion reaction zone, and heat is released according to some relation like q(sub c) = delta H(sub c)c[((rho/rho(sub 0))]exp a)(exp -E(sub c)/RT), Eq. (1) where the pressure exponent a is usually close to unity. As long as there is enough heat released, combustion is sustained. It is useful to conceive of a threshold pressure beyond which there is sufficient heat to keep the temperature high enough to sustain combustion, and beneath which the heat is so low that temperature drains away and the combustion is extinguished. Some materials burn in heterogeneous combustion, in which the fuel and oxidizer are in different phases. These include iron and nickel based alloys, which burn in the liquid phase with gaseous oxygen. Heterogeneous combustion takes place on the surface of the material (fuel). Products of combustion may appear as a solid slag (oxide) which progressively covers the fuel. Propagation of the combustion melts and exposes fresh fuel. Heterogeneous combustion heat release also follows the general form of Eq.(1), except that the pressure exponent a tends to be much less than 1. Therefore, the increase in heat release with increasing pressure is not as dramatic as it is in homogeneous combustion. Although the concept of a threshold pressure still holds in heterogeneous combustion, the threshold is more difficult to identify experimentally, and pressure itself becomes less important relative to the heat transfer paths extant in any specific application. However, the constants C, a, and E(sub c) may still be identified by suitable data reduction from heterogeneous combustion experiments, and may be applied in a heat transfer model to judge the flammability of a material in any particular actual

  3. Surface heterogeneity of small asteroids

    NASA Astrophysics Data System (ADS)

    Sasaki, Sho

    A rubble pile model of asteroid origin would predict averaged rather homogeneous surface of an asteroid. Previous spacecraft observations (mostly S-type asteroids) did not show large color/albedo variation on the surface. Vesta would be exceptional since HST observation suggested that its surface should be heterogeneous due to the impact excavation of the interior. As for a young asteroid (832) Karin (age being 5Ma), Sasaki et al. (2004) detected variation of infrared spectra which could be explained by the difference of the space weathering degree. They discussed the possibility of the survival of the old surface. However, the variation was not confirmed by later observation (Chapman et al., 2007; Vernazza et al., 2007). Recent observation of a small (550m) asteroid Itokawa by Hayabusa spacecraft revealed that Itokawa is heterogeneous in color and albedo although the overall rocky structure is considered as a rubble pile (Saito et al., 2006). The color difference can be explained by the difference of weathering degree (Ishiguro et al., 2008). The heterogeneity could be explained by mass movement caused by rapid rotation from YORP effect (Scheeres et al., 2007) or seismic shaking (Sasaki, 2006). Probably small silicate asteroids without significant regolith could have heterogeneous in color and albedo. On large asteroids (˜ a few 10km), regolith reaccumulation should have covered the underlying heterogeneity. References: Chapman, C. R. et al (2007) Icarus, 191, 323-329 Ishiguro, M. et al. (2008) MAPS, in press. Saito, J. et al. (2006) Science, 312, 1341-1344 Sasaki, S. (2006) in Spacecraft Reconnaissance of Asteroid and Comet Interiors Sasaki, T. et al (2004) Astrophys. J. 615, L161-L164 Scheeres, D. J. (2007) Icarus 188, 425-429 Vernazza, P. et al. (2007) Icarus 191, 330-336.

  4. Apparatus for stopping a vehicle

    DOEpatents

    Wattenburg, Willard H.; McCallen, David B.

    2007-03-20

    An apparatus for externally controlling one or more brakes on a vehicle having a pressurized fluid braking system. The apparatus can include a pressurizable vessel that is adapted for fluid-tight coupling to the braking system. Impact to the rear of the vehicle by a pursuit vehicle, shooting a target mounted on the vehicle or sending a signal from a remote control can all result in the fluid pressures in the braking system of the vehicle being modified so that the vehicle is stopped and rendered temporarily inoperable. A control device can also be provided in the driver's compartment of the vehicle for similarly rendering the vehicle inoperable. A driver or hijacker of the vehicle preferably cannot overcome the stopping action from the driver's compartment.

  5. Smart Vehicle System

    NASA Astrophysics Data System (ADS)

    Pahadiya, Pallavi; Gupta, Rajni

    2010-11-01

    An approach to overcome the accidental problem happens in the night, while the driver is drunk or feels sleepy. This system controls the speed of the vehicle at steep turns. It is designed, to provide the information to the driver, whether the next turn is right/left, is there any traffic jam or land sliding in the coming way. It also assists during heavy rains and mist conditions. It may be implemented by using computer or by using a dedicated microcontroller. If we have a group of vehicles connected with the system then we can locate them by using the cameras, at different places. Information regarding any vehicle can be transmitted anywhere using Internet provided at the monitoring system, so as to prevent accidents or provide information during any calamity.

  6. Personnel emergency carrier vehicle

    NASA Technical Reports Server (NTRS)

    Owens, Lester J. (Inventor); Fedor, Otto H. (Inventor)

    1987-01-01

    A personnel emergency carrier vehicle is disclosed which includes a vehicle frame supported on steerable front wheels and driven rear wheels. A supply of breathing air is connected to quick connect face mask coupling and umbilical cord couplings for supplying breathing air to an injured worker or attendant either with or without a self-contained atmospheric protection suit for protection against hazardous gases at an accident site. A non-sparking hydraulic motion is utilized to drive the vehicle and suitable direction and throttling controls are provided for controlling the delivery of a hydraulic driving fluid from a pressurized hydraulic fluid accumulator. A steering axis is steerable through a handle to steer the front wheels through a linkage assembly.

  7. Vehicle stabilizing means

    SciTech Connect

    Dornier, C.M.

    1986-12-16

    An air foil assembly is described for use with a racing vehicle positioned and attached to the rear of the racing vehicle by a support structure, comprising: (a) a flap pivotable from a horizontal plane by a positioning assembly, the flap extending between parallel vertical panels and a stop means protruding from at least one of the panels at a pre-determined position above the flap; and (b) a hydraulic cylinder assembly having a hydraulic cylinder fixedly attached to the support structure and operatively connected to the vehicle braking system to provide hydraulic pressure to the hydraulic cylinder. The hydraulic cylinder has its piston rod pivotally attached to a linking assembly connected to the support structure and operatively contacting the flap to cause the flap to pivot upward or downward upon movement of the piston rod.

  8. Hydrogen vehicle fueling station

    SciTech Connect

    Daney, D.E.; Edeskuty, F.J.; Daugherty, M.A.

    1996-12-31

    The authors describe a hydrogen vehicle fueling station that receives and stores hydrogen in liquid form and dispenses it either as a liquid or compressed gas. The economics of distribution that accrue from the favorable weight and volume advantages of liquid hydrogen support this concept both now and for some time to come. The authors model for liquid transfer to a 120 L vehicle tank shows that tank filling times under five minutes are feasible with pump-assisted transfer, or for pressure transfer with subcooling greater than 1 K. The authorsmodel for compressed gas transfer shows that vehicle tank underfilling of nearly 30 percent can occur during rapid refueling. Cooling the fill gas to 214 K completely eliminates the underfilling problem.

  9. Assured Crew Return Vehicle

    NASA Technical Reports Server (NTRS)

    Stone, D. A.; Craig, J. W.; Drone, B.; Gerlach, R. H.; Williams, R. J.

    1991-01-01

    The developmental status is discussed regarding the 'lifeboat' vehicle to enhance the safety of the crew on the Space Station Freedom (SSF). NASA's Assured Crew Return Vehicle (ACRV) is intended to provide a means for returning the SSF crew to earth at all times. The 'lifeboat' philosophy is the key to managing the development of the ACRV which further depends on matrixed support and total quality management for implementation. The risk of SSF mission scenarios are related to selected ACRV mission requirements, and the system and vehicle designs are related to these precepts. Four possible ACRV configurations are mentioned including the lifting-body, Apollo shape, Discoverer shape, and a new lift-to-drag concept. The SCRAM design concept is discussed in detail with attention to the 'lifeboat' philosophy and requirements for implementation.

  10. Dynamics of aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Schmidt, David K.

    1991-01-01

    The focus of this research was to address the modeling, including model reduction, of flexible aerospace vehicles, with special emphasis on models used in dynamic analysis and/or guidance and control system design. In the modeling, it is critical that the key aspects of the system being modeled be captured in the model. In this work, therefore, aspects of the vehicle dynamics critical to control design were important. In this regard, fundamental contributions were made in the areas of stability robustness analysis techniques, model reduction techniques, and literal approximations for key dynamic characteristics of flexible vehicles. All these areas are related. In the development of a model, approximations are always involved, so control systems designed using these models must be robust against uncertainties in these models.

  11. Aerobraking orbital transfer vehicle

    NASA Technical Reports Server (NTRS)

    Scott, Carl D. (Inventor); Nagy, Kornel (Inventor); Roberts, Barney B. (Inventor); Ried, Robert C. (Inventor); Kroll, Kenneth R. (Inventor); Gamble, Joe (Inventor)

    1989-01-01

    An aerobraking orbital transfer vehicle which includes an aerobraking device which also serves as a heat shield in the shape of a raked-off elliptic or circular cone with a circular or elliptical base, and with an ellipsoid or other blunt shape nose. The aerobraking device is fitted with a toroid-like skirt and is integral with the support structure of the propulsion system and other systems of the space vehicle. The vehicle is intended to be transported in components to a space station in lower earth orbit where it is assembled for use as a transportation system from low earth orbit to geosynchronous earth orbit and return. Conventional guidance means are included for autonomous flight.

  12. Aeroacoustics of Space Vehicles

    NASA Technical Reports Server (NTRS)

    Panda, Jayanta

    2014-01-01

    While for airplanes the subject of aeroacoustics is associated with community noise, for space vehicles it is associated with vibro-acoustics and structural dynamics. Surface pressure fluctuations encountered during launch and travel through lower part of the atmosphere create intense vibro-acoustics environment for the payload, electronics, navigational equipment, and a large number of subsystems. All of these components have to be designed and tested for flight-certification. This presentation will cover all three major sources encountered in manned and unmanned space vehicles: launch acoustics, ascent acoustics and abort acoustics. Launch pads employ elaborate acoustic suppression systems to mitigate the ignition pressure waves and rocket plume generated noise during the early part of the liftoff. Recently we have used large microphone arrays to identify the noise sources during liftoff and found that the standard model by Eldred and Jones (NASA SP-8072) to be grossly inadequate. As the vehicle speeds up and reaches transonic speed in relatively denser part of the atmosphere, various shock waves and flow separation events create unsteady pressure fluctuations that can lead to high vibration environment, and occasional coupling with the structural modes, which may lead to buffet. Examples of wind tunnel tests and computational simulations to optimize the outer mold line to quantify and reduce the surface pressure fluctuations will be presented. Finally, a manned space vehicle needs to be designed for crew safety during malfunctioning of the primary rocket vehicle. This brings the subject of acoustic environment during abort. For NASAs Multi-Purpose Crew Vehicle (MPCV), abort will be performed by lighting rocket motors atop the crew module. The severe aeroacoustics environments during various abort scenarios were measured for the first time by using hot helium to simulate rocket plumes in the Ames unitary plan wind tunnels. Various considerations used for the

  13. Heterogeneous Viscoelasticity: A Combined Theory of Dynamic and Elastic Heterogeneity.

    PubMed

    Schirmacher, Walter; Ruocco, Giancarlo; Mazzone, Valerio

    2015-07-01

    We present a heterogeneous version of Maxwell's theory of viscoelasticity based on the assumption of spatially fluctuating local viscoelastic coefficients. The model is solved in coherent-potential approximation. The theory predicts an Arrhenius-type temperature dependence of the viscosity in the vanishing-frequency limit, independent of the distribution of the activation energies. It is shown that this activation energy is generally different from that of a diffusing particle with the same barrier-height distribution, which explains the violation of the Stokes-Einstein relation observed frequently in glasses. At finite but low frequencies, the theory describes low-temperature asymmetric alpha relaxation. As examples, we report the good agreement obtained for selected inorganic, metallic, and organic glasses. At high frequencies, the theory reduces to heterogeneous elasticity theory, which explains the occurrence of the boson peak and related vibrational anomalies. PMID:26182108

  14. BEEST: Electric Vehicle Batteries

    SciTech Connect

    2010-07-01

    BEEST Project: The U.S. spends nearly a $1 billion per day to import petroleum, but we need dramatically better batteries for electric and plug-in hybrid vehicles (EV/PHEV) to truly compete with gasoline-powered cars. The 10 projects in ARPA-E’s BEEST Project, short for “Batteries for Electrical Energy Storage in Transportation,” could make that happen by developing a variety of rechargeable battery technologies that would enable EV/PHEVs to meet or beat the price and performance of gasoline-powered cars, and enable mass production of electric vehicles that people will be excited to drive.

  15. EPRI electric vehicle conference

    SciTech Connect

    Pfleeger, D.

    1999-10-01

    Lower operating and maintenance costs, quiet and clean operation appear the main factors in choosing electric over the typical internal combustion powered equipment. The Conference was sponsored by the Electric Power Research Institute (EPRI). EPRI is a cooperative effort by major electric companies across the USA, founded in 1973 and headquartered in Palo Alto, CA. Featured at the Conference were presentations on regulatory issues, lift truck technologies, automotive advances and other industrial applications to include automated guided vehicles, personnel carriers and electric bicycles. Approximately 25 exhibitors displayed components, subassemblies and complete vehicles.

  16. Affordable Vehicle Avionics Overview

    NASA Technical Reports Server (NTRS)

    Cockrell, James J.

    2015-01-01

    Public and private launch vehicle developers are reducing the cost of propulsion for small commercial launchers, but conventional high-performance, high-reliability avionics remain the disproportionately high cost driver for launch. AVA technology performs as well or better than conventional launch vehicle avionics, but with a fraction of the recurring costs. AVA enables small launch providers to offer affordable rides to LEO to nano-satellites as primary payloads meaning, small payloads can afford to specify their own launch and orbit parameters

  17. Affordable Vehicle Avionics Overview

    NASA Technical Reports Server (NTRS)

    Cockrell, James J.

    2015-01-01

    Public and private launch vehicle developers are reducing the cost of propulsion for small commercial launchers, but conventional high-performance, high-reliability avionics remain the disproportionately high cost driver for launch. AVA technology performs as well or better than conventional launch vehicle avionics, but with a fraction of the recurring costs. AVA enables small launch providers to offer affordable rides to LEO to nano-satellites as primary payloads meaning, small payloads can afford to specify their own launch and orbit parameters.

  18. Vehicle brake testing system

    DOEpatents

    Stevens, Samuel S [Harriman, TN; Hodgson, Jeffrey W [Lenoir City, TN

    2002-11-19

    This invention relates to a force measuring system capable of measuring forces associated with vehicle braking and of evaluating braking performance. The disclosure concerns an invention which comprises a first row of linearly aligned plates, a force bearing surface extending beneath and beside the plates, vertically oriented links and horizontally oriented links connecting each plate to a force bearing surface, a force measuring device in each link, a transducer coupled to each force measuring device, and a computing device coupled to receive an output signal from the transducer indicative of measured force in each force measuring device. The present invention may be used for testing vehicle brake systems.

  19. Hybrid electric vehicles TOPTEC

    SciTech Connect

    1994-06-21

    This one-day TOPTEC session began with an overview of hybrid electric vehicle technology. Updates were given on alternative types of energy storage, APU control for low emissions, simulation programs, and industry and government activities. The keynote speech was about battery technology, a key element to the success of hybrids. The TOPEC concluded with a panel discussion on the mission of hybrid electric vehicles, with a perspective from industry and government experts from United States and Canada on their view of the role of this technology.

  20. Environmental Evaluation of New Generation Vehicles and Vehicle Components

    SciTech Connect

    Schexnayder, S.M.

    2002-02-06

    This report documents assessments that address waste issues and life cycle impacts associated with the vehicle materials and vehicle technologies being developed under the Partnership for a New Generation of Vehicles (PNGV) program. We refer to these vehicles as 3XVs, referring to the PNGV goal that their fuel mileage be three times better than the baseline vehicle. To meet the program's fuel consumption goals, these vehicles substitute lightweight materials for heavier materials such as steel and iron that currently dominate the composition of vehicles, and use engineering and power system changes. Alternative power systems being developed through the PNGV program include batteries for hybrid electric vehicles and fuel cells. With respect to all these developments, it is imperative to learn what effects they will have on the environment before adopting these designs and technologies on a large-scale basis.

  1. NASA GSFC Perspective on Heterogeneous Processing

    NASA Technical Reports Server (NTRS)

    Powell, Wesley A.

    2016-01-01

    This presentation provides an overview of NASA GSFC, our onboard processing applications, the applicability heterogeneous processing to these applications, and necessary developments to enable heterogeneous processing to be infused into our missions.

  2. Biodiesel production using heterogeneous catalysts.

    PubMed

    Semwal, Surbhi; Arora, Ajay K; Badoni, Rajendra P; Tuli, Deepak K

    2011-02-01

    The production and use of biodiesel has seen a quantum jump in the recent past due to benefits associated with its ability to mitigate greenhouse gas (GHG). There are large number of commercial plants producing biodiesel by transesterification of vegetable oils and fats based on base catalyzed (caustic) homogeneous transesterification of oils. However, homogeneous process needs steps of glycerol separation, washings, very stringent and extremely low limits of Na, K, glycerides and moisture limits in biodiesel. Heterogeneous catalyzed production of biodiesel has emerged as a preferred route as it is environmentally benign needs no water washing and product separation is much easier. The present report is review of the progress made in development of heterogeneous catalysts suitable for biodiesel production. This review shall help in selection of suitable catalysts and the optimum conditions for biodiesel production. PMID:21106371

  3. Heterogeneous, weakly coupled map lattices

    NASA Astrophysics Data System (ADS)

    Sotelo Herrera, M.a. Dolores; San Martín, Jesús; Porter, Mason A.

    2016-07-01

    Coupled map lattices (CMLs) are often used to study emergent phenomena in nature. It is typically assumed (unrealistically) that each component is described by the same map, and it is important to relax this assumption. In this paper, we characterize periodic orbits and the laminar regime of type-I intermittency in heterogeneous weakly coupled map lattices (HWCMLs). We show that the period of a cycle in an HWCML is preserved for arbitrarily small coupling strengths even when an associated uncoupled oscillator would experience a period-doubling cascade. Our results characterize periodic orbits both near and far from saddle-node bifurcations, and we thereby provide a key step for examining the bifurcation structure of heterogeneous CMLs.

  4. Diesel Vehicle Maintenance Competencies.

    ERIC Educational Resources Information Center

    Braswell, Robert; And Others

    Designed to provide a model set of competencies, this manual presents tasks which were identified by employers, employees, and teachers as important in a postsecondary diesel vehicle maintenance curriculum. The tasks are divided into seven major component areas of instruction: chassis and suspension, diesel engines, diesel fuel, electrical,…

  5. Batteries for Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Conover, R. A.

    1985-01-01

    Report summarizes results of test on "near-term" electrochemical batteries - (batteries approaching commercial production). Nickel/iron, nickel/zinc, and advanced lead/acid batteries included in tests and compared with conventional lead/acid batteries. Batteries operated in electric vehicles at constant speed and repetitive schedule of accerlerating, coasting, and braking.

  6. Battery for vehicle

    SciTech Connect

    Uehara, M.

    1984-04-24

    In a battery of a vehicle such as motorcycle, the bottom is indented at both ends in the longitudinal direction; i.e., with respect to both end portions, in the longitudinal direction of the bottom, the middle portion protrudes downwardly, so that the battery is more advantageously accommodated in the triangular space formed by the motorcycle frame.

  7. Recreational Vehicle Trades.

    ERIC Educational Resources Information Center

    Felice, Michael

    This curriculum guide provides materials for a competency-based course in recreational vehicle trades at the secondary level. The curriculum design uses the curriculum infused model for the teaching of basic skills as part of vocational education and demonstrates the relationship of vocationally related skills to communication, mathematics, and…

  8. Vehicle Cabin Atmosphere Monitor

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara; Darrach, Muray

    2007-01-01

    Vehicle Cabin Atmosphere Monitor (VCAM) identifies gases that are present in minute quantities in the International Space Station (ISS) breathing air that could harm the crew s health. If successful, instruments like VCAM could accompany crewmembers during long-duration exploration missions to the Moon or traveling to Mars.

  9. Mars Exploratory Vehicles.

    ERIC Educational Resources Information Center

    Canizo, Thea L.; And Others

    1997-01-01

    Presents an activity in which students learn about the characteristics of the planet Mars. Challenges students to design and build a model of a robotic vehicle that can travel on the surface of Mars and accomplish an assigned task that will provide information useful for future manned trips to the planet. Outlines mission task cards and progress…

  10. AST Launch Vehicle Acoustics

    NASA Technical Reports Server (NTRS)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  11. The Electric Vehicle Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2010-01-01

    This article describes a design activity that provides students with a solid understanding of the many issues involved with alternate energy system design. In this activity, students will be able to learn about electric vehicles and have the opportunity to design a way to recharge the batteries while the cars are parked in a commuter garage. The…

  12. Hybrid Turbine Electric Vehicle

    NASA Technical Reports Server (NTRS)

    Viterna, Larry A.

    1997-01-01

    Hybrid electric power trains may revolutionize today's ground passenger vehicles by significantly improving fuel economy and decreasing emissions. The NASA Lewis Research Center is working with industry, universities, and Government to develop and demonstrate a hybrid electric vehicle. Our partners include Bowling Green State University, the Cleveland Regional Transit Authority, Lincoln Electric Motor Division, the State of Ohio's Department of Development, and Teledyne Ryan Aeronautical. The vehicle will be a heavy class urban transit bus offering double the fuel economy of today's buses and emissions that are reduced to 1/10th of the Environmental Protection Agency's standards. At the heart of the vehicle's drive train is a natural-gas-fueled engine. Initially, a small automotive engine will be tested as a baseline. This will be followed by the introduction of an advanced gas turbine developed from an aircraft jet engine. The engine turns a high-speed generator, producing electricity. Power from both the generator and an onboard energy storage system is then provided to a variable-speed electric motor attached to the rear drive axle. An intelligent power-control system determines the most efficient operation of the engine and energy storage system.

  13. Engine & Vehicle Mechanics Curriculum.

    ERIC Educational Resources Information Center

    Alaska State Dept. of Education, Juneau. Div. of Adult and Vocational Education.

    This competency-based curriculum includes all competencies a student will acquire in an engine and vehicle mechanics educational program. It follows guidelines established for automobile technician training programs leading toward certification and addresses requirements of the National Institute for Automotive Service Excellence (ASE). The…

  14. Advanced electric vehicle

    SciTech Connect

    O'Connell, L.G.

    1980-07-01

    The Advanced Electric Vehicle is defined as an automobile which can fulfill the general-purpose role of today's internal-combustion-engine-powered car without utilizing petroleum fuels directly. It relies principally on the utilization of electricity. A number of candidate systems are described. The present status of each is discussed as are the problems to be overcome before implementation can proceed.

  15. Vehicle fuel system

    DOEpatents

    Risse, John T.; Taggart, James C.

    1976-01-01

    A vehicle fuel system comprising a plurality of tanks, each tank having a feed and a return conduit extending into a lower portion thereof, the several feed conduits joined to form one supply conduit feeding fuel to a supply pump and using means, unused fuel being returned via a return conduit which branches off to the several return conduits.

  16. Vehicle Technologies Program Results

    SciTech Connect

    2009-06-19

    The Vehicle Technologies Program's progress is closely monitored by both internal and external organizations. The Program's results are detailed in a wide range of documents and tools that can be accessed through the PIR website. Descriptions of these materials are provided on this program results page.

  17. Heavy Vehicle Systems

    SciTech Connect

    Sid Diamond; Richard Wares; Jules Routbort

    2000-04-11

    Heavy Vehicle (HV) systems are a necessary component of achieving OHVT goals. Elements are in place for a far-ranging program: short, intermediate, and long-term. Solicitation will bring industrial input and support. Future funding trend is positive, outlook for HV systems is good.

  18. Sizing of scramjet vehicles

    NASA Astrophysics Data System (ADS)

    Ingenito, A.; Gulli, S.; Bruno, C.

    2011-10-01

    The current European project LAPCAT II has the ambitious goal to define a conceptual vehicle capable of achieving the antipodal range Brussels-Sydney (~18,000 km) in about 2 h at Mach number Ma = 8. At this high speed, the requirement of high lift to drag (L/D) ratio is critical to high performance, because of high skin friction and wave drag: in fact, as the Mach number increases, the L/D ratio decreases. The design of the vehicle architecture (shape and propulsion system) is, as a consequence, crucial to achieve a reasonably high L/D. In this work, critical parameters for the preliminary sizing of a hypersonic airbreathing airliner have been identified. In particular, for a given Technology Readiness Level (TRL) and mission requirements, a solution space of possible vehicle architectures at cruise have been obtained. In this work, the Gross Weight at Take-Off (TOGW) was deliberately discarded as a constraint, based on previous studies by Czysz and Vanderkerkhove [1]. Typically, limiting from the beginning, the TOGW leads to a vicious spiral where weight and propulsion system requirements keep growing, eventually denying convergence. In designing passenger airliners, in fact, it is the payload that is assumed fixed from the start, not the total weight. In order to screen the solutions found, requirements for taking-off (TO) and landing as well as the trajectory have been accounted for. A consistent solution has finally been obtained by imposing typical airliner constraints: emergency take-off and landing. These constraints enable singling out a realistic design from the broad family of vehicles capable of performing the given mission. This vehicle has been obtained by integrating not only aerodynamics, trajectory, and airliner constraints, but also by integrating the propulsion system, the trimming devices and by doing some adjustments to the conceptual vehicle shape (i. e., spatular nose). Thus, the final vehicle is the result of many iterations in the design

  19. Specialization and Bet Hedging in Heterogeneous Populations

    NASA Astrophysics Data System (ADS)

    Rulands, Steffen; Jahn, David; Frey, Erwin

    2014-09-01

    Phenotypic heterogeneity is a strategy commonly used by bacteria to rapidly adapt to changing environmental conditions. Here, we study the interplay between phenotypic heterogeneity and genetic diversity in spatially extended populations. By analyzing the spatiotemporal dynamics, we show that the level of mobility and the type of competition qualitatively influence the persistence of phenotypic heterogeneity. While direct competition generally promotes persistence of phenotypic heterogeneity, specialization dominates in models with indirect competition irrespective of the degree of mobility.

  20. On comparing heterogeneity across biomarkers

    PubMed Central

    Steininger, Robert J.; Rajaram, Satwik; Girard, Luc; Minna, John D.; Wu, Lani F.; Altschuler, Steven J.

    2015-01-01

    Microscopy reveals complex patterns of cellular heterogeneity that can be biologically informative. However, a limitation of microscopy is that only a small number of biomarkers can typically be monitored simultaneously. Thus, a natural question is whether additional biomarkers provide a deeper characterization of the distribution of cellular states in a population. How much information about a cell’s phenotypic state in one biomarker is gained by knowing its state in another biomarker? Here, we describe a framework for comparing phenotypic states across biomarkers. Our approach overcomes the current limitation of microscopy by not requiring co-staining biomarkers on the same cells; instead we require staining of biomarkers (possibly separately) on a common collection of phenotypically diverse cell lines. We evaluate our approach on two image datasets: 33 oncogenically diverse lung cancer cell lines stained with 7 biomarkers, and 49 less diverse subclones of one lung cancer cell line stained with 12 biomarkers. We first validate our method by comparing it to the “gold standard” of co-staining. We then apply our approach to all pairs of biomarkers and use it to identify biomarkers that yield similar patterns of heterogeneity. The results presented in this work suggest that many biomarkers provide redundant information about heterogeneity. Thus, our approach provides a practical guide for selecting independently informative biomarkers and, more generally, will yield insights into both the connectivity of biological networks and the complexity of the state space of biological systems. PMID:25425168

  1. Translational Implications of Tumor Heterogeneity

    PubMed Central

    Jamal-Hanjani, Mariam; Quezada, Sergio A.; Larkin, James; Swanton, Charles

    2015-01-01

    Advances in next-generation sequencing and bioinformatics have led to an unprecedented view of the cancer genome and its evolution. Genomic studies have demonstrated the complex and heterogeneous clonal landscape of tumors of different origins, and the potential impact of intratumor heterogeneity on treatment response and resistance, cancer progression and the risk of disease relapse. However, the significance of subclonal mutations, in particular mutations in driver genes, and their evolution through time and their dynamics in response to cancer therapies, is yet to be determined. The necessary tools are now available to prospectively determine whether clonal heterogeneity can be used as a biomarker of clinical outcome, and to what extent subclonal somatic alterations might influence clinical outcome. Studies that employ longitudinal tissue sampling, integrating both genomic and clinical data, have the potential to reveal the subclonal composition and track the evolution of tumors in order to address these questions, and to begin to define the breadth of genetic diversity in different tumor types, and its relevance to patient outcome. Such studies may provide further evidence for novel drug resistance mechanisms informing novel combinatorial, adaptive and tumour immune-therapies placed within the context of tumor evolution. PMID:25770293

  2. Heterogeneous nucleation or homogeneous nucleation?

    NASA Astrophysics Data System (ADS)

    Liu, X. Y.

    2000-06-01

    The generic heterogeneous effect of foreign particles on three dimensional nucleation was examined both theoretically and experimentally. It shows that the nucleation observed under normal conditions includes a sequence of progressive heterogeneous processes, characterized by different interfacial correlation function f(m,x)s. At low supersaturations, nucleation will be controlled by the process with a small interfacial correlation function f(m,x), which results from a strong interaction and good structural match between the foreign bodies and the crystallizing phase. At high supersaturations, nucleation on foreign particles having a weak interaction and poor structural match with the crystallizing phase (f(m,x)→1) will govern the kinetics. This frequently leads to the false identification of homogeneous nucleation. Genuine homogeneous nucleation, which is the up-limit of heterogeneous nucleation, may not be easily achievable under gravity. In order to check these results, the prediction is confronted with nucleation experiments of some organic and inorganic crystals. The results are in excellent agreement with the theory.

  3. Analyzing and modeling heterogeneous behavior

    NASA Astrophysics Data System (ADS)

    Lin, Zhiting; Wu, Xiaoqing; He, Dongyue; Zhu, Qiang; Ni, Jixiang

    2016-05-01

    Recently, it was pointed out that the non-Poisson statistics with heavy tail existed in many scenarios of human behaviors. But most of these studies claimed that power-law characterized diverse aspects of human mobility patterns. In this paper, we suggest that human behavior may not be driven by identical mechanisms and can be modeled as a Semi-Markov Modulated Process. To verify our suggestion and model, we analyzed a total of 1,619,934 records of library visitations (including undergraduate and graduate students). It is found that the distribution of visitation intervals is well fitted with three sections of lines instead of the traditional power law distribution in log-log scale. The results confirm that some human behaviors cannot be simply expressed as power law or any other simple functions. At the same time, we divided the data into groups and extracted period bursty events. Through careful analysis in different groups, we drew a conclusion that aggregate behavior might be composed of heterogeneous behaviors, and even the behaviors of the same type tended to be different in different period. The aggregate behavior is supposed to be formed by "heterogeneous groups". We performed a series of experiments. Simulation results showed that we just needed to set up two states Semi-Markov Modulated Process to construct proper representation of heterogeneous behavior.

  4. Hybrid-Vehicle Transmission System

    NASA Technical Reports Server (NTRS)

    Lupo, G.; Dotti, G.

    1985-01-01

    Continuously-variable transmission system for hybrid vehicles couples internal-combustion engine and electric motor section, either individually or in parallel, to power vehicle wheels during steering and braking.

  5. Household vehicles energy consumption 1991

    SciTech Connect

    Not Available

    1993-12-09

    The purpose of this report is to provide information on the use of energy in residential vehicles in the 50 States and the District of Columbia. Included are data about: the number and type of vehicles in the residential sector, the characteristics of those vehicles, the total annual Vehicle Miles Traveled (VMT), the per household and per vehicle VMT, the vehicle fuel consumption and expenditures, and vehicle fuel efficiencies. The data for this report are based on the household telephone interviews from the 1991 RTECS, conducted during 1991 and early 1992. The 1991 RTECS represents 94.6 million households, of which 84.6 million own or have access to 151.2 million household motor vehicles in the 50 States and the District of Columbia.

  6. Vehicle Integrated Propulsion Research Tests

    NASA Technical Reports Server (NTRS)

    Lekki, John D.; Hunter, Gary W.; Simon, Don; Meredith, Roger; Wrbanek, John; Woike, Mark; Tokars, Roger; Guffanti, Marianne; Lyall, Eric

    2013-01-01

    Overview of the Vehicle Integrated Propulsion Research Tests in the Vehicle Systems Safety Technologies project. This overview covers highlights of the completed VIPR I and VIPR II tests and also covers plans for the VIPR III test.

  7. Methylotroph cloning vehicle

    DOEpatents

    Hanson, R.S.; Allen, L.N.

    1989-04-25

    A cloning vehicle comprising: a replication determinant effective for replicating the vehicle in a non-C[sub 1]-utilizing host and in a C[sub 1]-utilizing host; DNA effective to allow the vehicle to be mobilized from the non-C[sub 1]-utilizing host to the C[sub 1]-utilizing host; DNA providing resistance to two antibiotics to which the wild-type C[sub 1]-utilizing host is susceptible, each of the antibiotic resistance markers having a recognition site for a restriction endonuclease; a cos site; and a means for preventing replication in the C[sub 1]-utilizing host. The vehicle is used for complementation mapping as follows. DNA comprising a gene from the C[sub 1]-utilizing organism is inserted at the restriction nuclease recognition site, inactivating the antibiotic resistance marker at that site. The vehicle can then be used to form a cosmid structure to infect the non-C[sub 1]-utilizing (e.g., E. coli) host, and then conjugated with a selected C[sub 1]-utilizing mutant. Resistance to the other antibiotic by the mutant is a marker of the conjugation. Other phenotypical changes in the mutant, e.g., loss of an auxotrophic trait, is attributed to the C[sub 1] gene. The vector is also used to inactivate genes whose protein products catalyze side reactions that divert compounds from a biosynthetic pathway to a desired product, thereby producing an organism that makes the desired product in higher yields. 3 figs.

  8. Investigating Population Heterogeneity With Factor Mixture Models

    ERIC Educational Resources Information Center

    Lubke, Gitta H.; Muthen, Bengt

    2005-01-01

    Sources of population heterogeneity may or may not be observed. If the sources of heterogeneity are observed (e.g., gender), the sample can be split into groups and the data analyzed with methods for multiple groups. If the sources of population heterogeneity are unobserved, the data can be analyzed with latent class models. Factor mixture models…

  9. Introduction to LNG vehicle safety

    NASA Astrophysics Data System (ADS)

    Bratvold, Delma; Friedman, David; Chernoff, Harry; Farkhondehpay, Dariush; Comay, Claudia

    1994-03-01

    Basic information on the characteristics of liquefied natural gas (LNG) is assembled to provide an overview of safety issues and practices for the use of LNG vehicles. This document is intended for those planning or considering the use of LNG vehicles, including vehicle fleet owners and operators, public transit officials and boards, local fire and safety officials, manufacturers and distributors, and gas industry officials. Safety issues and mitigation measures that should be considered for candidate LNG vehicle projects are addressed.

  10. Knowledge Navigation for Virtual Vehicles

    NASA Technical Reports Server (NTRS)

    Gomez, Julian E.

    2004-01-01

    A virtual vehicle is a digital model of the knowledge surrounding a potentially real vehicle. Knowledge consists not only of the tangible information, such as CAD, but also what is known about the knowledge - its metadata. This paper is an overview of technologies relevant to building a virtual vehicle, and an assessment of how to bring those technologies together.

  11. Motor Vehicle Theft. Special Report.

    ERIC Educational Resources Information Center

    Harlow, Caroline Wolf

    Thirteen years of data from the National Crime Survey were analyzed to examine the characteristics of motor vehicle theft, to identify trends during the past 13 years, and to determine who are most likely to be victims of motor vehicle theft. All motor vehicle thefts reported to the National Crime Survey from 1973 through 1985 were examined.…

  12. Emergency-vehicle VHF antenna

    NASA Technical Reports Server (NTRS)

    Anderson, R. E.; Carlson, A. W.; Lewis, J.

    1977-01-01

    Helical VHF antenna mounts on roof of moving vehicle to communicate with distant stations via earth satellites. Antenna requires no pointing and can provide two-way communication while vehicle moves at high speed. Device has proved extremely successful in electrocardiogram transmission tests between medical services vehicle and hospital emergency room.

  13. Emerging Needs for Pervasive Passive Wireless Sensor Networks on Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Juarez, Peter D.

    2014-01-01

    NASA is investigating passive wireless sensor technology to reduce instrumentation mass and volume in ground testing, air flight, and space exploration applications. Vehicle health monitoring systems (VHMS) are desired on all aerospace programs to ensure the safety of the crew and the vehicles. Pervasive passive wireless sensor networks facilitate VHMS on aerospace vehicles. Future wireless sensor networks on board aerospace vehicles will be heterogeneous and will require active and passive network systems. Since much has been published on active wireless sensor networks, this work will focus on the need for passive wireless sensor networks on aerospace vehicles. Several passive wireless technologies such as microelectromechanical systems MEMS, SAW, backscatter, and chipless RFID techniques, have all shown potential to meet the pervasive sensing needs for aerospace VHMS applications. A SAW VHMS application will be presented. In addition, application areas including ground testing, hypersonic aircraft and spacecraft will be explored along with some of the harsh environments found in aerospace applications.

  14. Appendix J - GPRA06 vehicle technologies program

    SciTech Connect

    None, None

    2009-01-18

    The target market for the Office of FreedomCAR and Vehicle Technologies (FCVT) program include light vehicles (cars and light trucks) and heavy vehicles (trucks more than 10,000 pounds Gross Vehicle Weight).

  15. Factors affecting heavy-duty diesel vehicle emissions.

    PubMed

    Clark, Nigel N; Kern, Justin M; Atkinson, Christopher M; Nine, Ralph D

    2002-01-01

    Societal and governmental pressures to reduce diesel exhaust emissions are reflected in the existing and projected future heavy-duty certification standards of these emissions. Various factors affect the amount of emissions produced by a heterogeneous charge diesel engine in any given situation, but these are poorly quantified in the existing literature. The parameters that most heavily affect the emissions from compression ignition engine-powered vehicles include vehicle class and weight, driving cycle, vehicle vocation, fuel type, engine exhaust aftertreatment, vehicle age, and the terrain traveled. In addition, engine control effects (such as injection timing strategies) on measured emissions can be significant. Knowing the effect of each aspect of engine and vehicle operation on the emissions from diesel engines is useful in determining methods for reducing these emissions and in assessing the need for improvement in inventory models. The effects of each of these aspects have been quantified in this paper to provide an estimate of the impact each one has on the emissions of diesel engines. PMID:15152668

  16. Miniature Autonomous Robotic Vehicle (MARV)

    SciTech Connect

    Feddema, J.T.; Kwok, K.S.; Driessen, B.J.; Spletzer, B.L.; Weber, T.M.

    1996-12-31

    Sandia National Laboratories (SNL) has recently developed a 16 cm{sup 3} (1 in{sup 3}) autonomous robotic vehicle which is capable of tracking a single conducting wire carrying a 96 kHz signal. This vehicle was developed to assess the limiting factors in using commercial technology to build miniature autonomous vehicles. Particular attention was paid to the design of the control system to search out the wire, track it, and recover if the wire was lost. This paper describes the test vehicle and the control analysis. Presented in the paper are the vehicle model, control laws, a stability analysis, simulation studies and experimental results.

  17. Intelligent behaviors through vehicle-to-vehicle and vehicle-to-infrastructure communication

    NASA Astrophysics Data System (ADS)

    Garcia, Richard D.; Sturgeon, Purser; Brown, Mike

    2012-06-01

    The last decade has seen a significant increase in intelligent safety devices on private automobiles. These devices have both increased and augmented the situational awareness of the driver and in some cases provided automated vehicle responses. To date almost all intelligent safety devices have relied on data directly perceived by the vehicle. This constraint has a direct impact on the types of solutions available to the vehicle. In an effort to improve the safety options available to a vehicle, numerous research laboratories and government agencies are investing time and resources into connecting vehicles to each other and to infrastructure-based devices. This work details several efforts in both the commercial vehicle and the private auto industries to increase vehicle safety and driver situational awareness through vehicle-to-vehicle and vehicle-to-infrastructure communication. It will specifically discuss intelligent behaviors being designed to automatically disable non-compliant vehicles, warn tractor trailer vehicles of unsafe lane maneuvers such as lane changes, passing, and merging, and alert drivers to non-line-of-sight emergencies.

  18. Methane-Powered Vehicles

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Liquid methane is beginning to become an energy alternative to expensive oil as a power source for automotive vehicles. Methane is the principal component of natural gas, costs less than half as much as gasoline, and its emissions are a lot cleaner than from gasoline or diesel engines. Beech Aircraft Corporation's Boulder Division has designed and is producing a system for converting cars and trucks to liquid methane operation. Liquid methane (LM) is a cryogenic fuel which must be stored at a temperature of 260 degrees below zero Fahrenheit. The LM system includes an 18 gallon fuel tank in the trunk and simple "under the hood" carburetor conversion equipment. Optional twin-fuel system allows operator to use either LM or gasoline fuel. Boulder Division has started deliveries for 25 vehicle conversions and is furnishing a liquid methane refueling station. Beech is providing instruction for Northwest Natural Gas, for conversion of methane to liquid state.

  19. Three orbital transfer vehicles

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Aerospace engineering students at the Virginia Polytechnic Institute and State University undertook three design projects under the sponsorship of the NASA/USRA Advanced Space Design Program. All three projects addressed cargo and/or crew transportation between low Earth orbit and geosynchronous Earth orbit. Project SPARC presents a preliminary design of a fully reusable, chemically powered aeroassisted vehicle for a transfer of a crew of five and a 6000 to 20000 pound payload. The ASTV project outlines a chemically powered aeroassisted configuration that uses disposable tanks and a relatively small aerobrake to realize propellant savings. The third project, LOCOST, involves a reusable, hybrid laser/chemical vehicle designed for large cargo (up to 88,200 pounds) transportation.

  20. Rapid road repair vehicle

    DOEpatents

    Mara, Leo M.

    1998-01-01

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find an the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was was heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past.

  1. Rapid road repair vehicle

    DOEpatents

    Mara, L.M.

    1998-05-05

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find at the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was not heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past. 2 figs.

  2. Hydrogen vehicle fueling station

    SciTech Connect

    Daney, D.E.; Edeskuty, F.J.; Daugherty, M.A.; Prenger, F.C.; Hill, D.D.

    1995-09-01

    The authors describe a hydrogen vehicle fueling station that receives and stores hydrogen in liquid form and dispenses it either as a liquid or compressed gas. The economics that accrue from the favorable weight and volume advantages of liquid hydrogen support this concept both now and probably for some time to come. The model for liquid transfer to a 120-liter vehicle tank shows that transfer times under five minutes are feasible with pump-assisted transfer, or for pressure transfer with subcooling greater than 1 K. The model for compressed gas transfer shows that underfilling of nearly 30% can occur during rapid filling. Cooling the fill gas to 214 K completely eliminates underfilling.

  3. Simple Electric Vehicle Simulation

    1993-07-29

    SIMPLEV2.0 is an electric vehicle simulation code which can be used with any IBM compatible personal computer. This general purpose simulation program is useful for performing parametric studies of electric and series hybrid electric vehicle performance on user input driving cycles.. The program is run interactively and guides the user through all of the necessary inputs. Driveline components and the traction battery are described and defined by ASCII files which may be customized by themore » user. Scaling of these components is also possible. Detailed simulation results are plotted on the PC monitor and may also be printed on a printer attached to the PC.« less

  4. Traffic behavior of mixed traffic flow with two kinds of different self-stabilizing control vehicles

    NASA Astrophysics Data System (ADS)

    Li, Zhipeng; Li, Wenzhong; Xu, Shangzhi; Qian, Yeqing; Sun, Jian

    2015-10-01

    In this paper, we propose a heterogeneous car following model in terms of an extension to the original optimal velocity model characterizing two classes of different self-stabilizing control vehicles. Linear stability analysis method is utilized to the extended model, for purpose to explore how the varying percentages of the vehicles with short-duration self-stabilizing control influence the stability of the heterogeneous traffic flow. We obtain the neutral stability lines for different percentages of two classes of vehicles, with finding that the traffic flow trends to stable with the decrease of the percentage for short-duration self-stabilizing control vehicles. Moreover, we explore a special case that the same numbers of two different classes of vehicles with self-stabilizing control. We theoretically derive the stability condition of the special case, and conclude the effect of the average value and the standard deviation of two time gaps, on the heterogeneous traffic stability. At last, direct simulations are conducted to verify the conclusion of theoretical analysis.

  5. Expendable launch vehicle propulsion

    NASA Technical Reports Server (NTRS)

    Fuller, Paul N.

    1991-01-01

    The current status is reviewed of the U.S. Expendable Launch Vehicle (ELV) fleet, the international competition, and the propulsion technology of both domestic and foreign ELVs. The ELV propulsion technology areas where research, development, and demonstration are most needed are identified. These propulsion technology recommendations are based on the work performed by the Commercial Space Transportation Advisory Committee (COMSTAC), an industry panel established by the Dept. of Transportation.

  6. Vehicle propulsion system

    SciTech Connect

    Ridgway, S.L.

    1981-11-17

    A hybrid vehicle propulsion system is disclosed which utilizes an internal combustion engine, an afterburner, and a steam engine in combination for improved efficiency and reduced emission of pollutants. The afterburner is provided to reduce the level of pollutants emitted and to increase the temperature of the exhaust gases from the internal combustion engine. The heat from the exhaust gases, together with the heat removed from the internal combustion cylinders, is then utilized in the steam engine to provide additional propulsion.

  7. Electric vehicle drive systems

    NASA Astrophysics Data System (ADS)

    Appleyard, M.

    1992-01-01

    New legislation in the State of California requires that 2% of vehicles sold there from 1998 will be 'zero-emitting'. This provides a unique market opportunity for developers of electric vehicles but substantial improvements in the technology are probably required if it is to be successfully exploited. There are around a dozen types of battery that are potentially relevant to road vehicles but, at the present, lead/acid and sodium—sulphur come closest to combining acceptable performance, life and cost. To develop an efficient, lightweight electric motor system requires up-to-date techniques of magnetics design, and the latest power-electronic and microprocessor control methods. Brushless machines, coupled with solid-state inverters, offer the most economical solution for mass production, even though their development costs are higher than for direct-current commutator machines. Fitted to a small car, even the highest energy-density batteries will only provide around 200 km average range before recharging. Therefore, some form of supplementary on-board power generation will probably be needed to secure widespread acceptance by the driving public. Engine-driven generators of quite low power can achieve useful increases in urban range but will fail to qualify as 'zero-emitting'. On the other hand, if the same function could be economically performed by a small fuel-cell using hydrogen derived from a methanol reformer, then most of the flexibility provided by conventional vehicles would be retained. The market prospects for electric cars would then be greatly enhanced and their dependence on very advanced battery technology would be reduced.

  8. Unmanned Aerospace Vehicle Workshop

    SciTech Connect

    Vitko, J. Jr.

    1995-04-01

    The Unmanned Aerospace Vehicle (UAV) Workshop concentrated on reviewing and refining the science experiments planned for the UAV Demonstration Flights (UDF) scheduled at the Oklahoma Cloud and Radiation Testbed (CART) in April 1994. These experiments were focused around the following sets of parameters: Clear sky, daylight; Clear-sky, night-to-day transition; Clear sky - improve/validate the accuracy of radiative fluxes derived from satellite-based measurements; Daylight, clouds of opportunity; and, Daylight, broken clouds.

  9. Electric Vehicle Battery Performance

    1992-02-20

    DIANE is used to analyze battery performance in electric vehicle (EV) applications. The principal objective of DIANE is to enable the prediction of EV performance on the basis of laboratory test data for batteries. The model provides a second-by-second simulation of battery voltage and current for any specified velocity/time or power/time profile. Two releases are included with the package. Diane21 has a graphics capability; DIANENP has no graphics capability.

  10. Household vehicles energy consumption 1994

    SciTech Connect

    1997-08-01

    Household Vehicles Energy Consumption 1994 reports on the results of the 1994 Residential Transportation Energy Consumption Survey (RTECS). The RTECS is a national sample survey that has been conducted every 3 years since 1985. For the 1994 survey, more than 3,000 households that own or use some 6,000 vehicles provided information to describe vehicle stock, vehicle-miles traveled, energy end-use consumption, and energy expenditures for personal vehicles. The survey results represent the characteristics of the 84.9 million households that used or had access to vehicles in 1994 nationwide. (An additional 12 million households neither owned or had access to vehicles during the survey year.) To be included in then RTECS survey, vehicles must be either owned or used by household members on a regular basis for personal transportation, or owned by a company rather than a household, but kept at home, regularly available for the use of household members. Most vehicles included in the RTECS are classified as {open_quotes}light-duty vehicles{close_quotes} (weighing less than 8,500 pounds). However, the RTECS also includes a very small number of {open_quotes}other{close_quotes} vehicles, such as motor homes and larger trucks that are available for personal use.

  11. Vehicle storage battery system

    SciTech Connect

    Binkley, B.I.

    1986-01-14

    This patent describes a vehicle storage battery system. Included in this system is a storage battery which has three separate storage battery portions. The main battery portion has a capacity for starting the vehicle under normal circumstances. The first and second standby portions of the battery when connected in a series have a rated capacity sufficient to transfer enough charge to the main battery portion when in a discharged state to start the engine of the vehicle. Another integral component of the system is a battery control having a circuit for connecting the two standby portions in series for charging the main battery portion when it is in a discharged state. This circuit also includes a means for restricting a charging current flow from the standby portions to the main portion to a predetermined safe level. An analogous circuit connects the standby portions in parallel for recharging from the main battery portion with a means for restricting a recharge current flow to a predetermined safe level. The last component is a switch means to switch between the above circuits.

  12. Japan's launch vehicles

    NASA Astrophysics Data System (ADS)

    Kuroda, Y.; Hara, N.

    The development of Japan's Mu series scientific research launch vehicles, and N and H series practical applications vehicles, is described. The three-stage M-3C features a second-stage radio inertial guidance system. The evolution to the M-3S includes a first-stage TVC and Solid Motor Roll Control device, and eight 310-m strap-on boosters (SOB's). The M-3SII developed to launch an interplanetary satellite for the 1986 Halley's Comet apparition, employs two 735-mm SOB's and a microprocessor digitalized flight control system, and can put a 770 kg satellite into low earth orbit. The N-1 is a three-stage radio-guided vehicle using first and second stage liquid engines, a solid motor third stage, three SOB's, and having the capability to launch a 145 kg geostationary satellite. N-II improvements include a 350 kg geostationary payload capacity, nine SOB's, and an inertial guidance system. The H-1 planned for 1987 has a 550 kg geostationary payload capacity and a domestically developed cryogenic engine. The H-II planned for 1992 will be capable of launching a two-ton geostationary satellite, or LOX/LH2 plural satellites simultaneously. It will be powered by a single 95-ton thrust LE-7 main engine.

  13. Lunar construction utility vehicle

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The lunar construction utility vehicle (LCUV) is an all-purpose construction vehicle which will aid in the robotic assembly of a lunar outpost. The LCUV will have the following capabilities: (1) must be self supporting including repairs; (2) must offload itself from a lunar lander; (3) must be telerobotic and semi-autonomous; (4) must be able to transport one space station common module; (5) must allow for man-rated operation; and (6) must be able to move lunar regolith for site preparation. This study recommends the use of an elastic tracked vehicle. Detailed material analyses of most of the LCUV components were accomplished. The body frame, made of pinned truss elements, was stress analyzed using NASTRAN. A track connection system was developed; however, kinematic and stress analyses are still required. This design recommends the use of hydrogen-oxygen fuel cells for power. Thermal control has proven to be a problem which may be the most challenging technically. A tentative solution has been proposed which utilizes an onboard and towable radiator. Detailed study of the heat dissipation requirements is needed to finalize radiator sizing. Preliminary work on a man-rated cabin has begun; however, this is not required during the first mission phase of the LCUV. Finally, still in the conceptual phases, are the communication, navigation and mechanical arm systems.

  14. High mobility vehicle

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian H. (Inventor); Nasif, Annette K. (Inventor)

    2001-01-01

    A vehicle, for driving over a ground surface, has a body with a left side, a right side, a front and a back. The vehicle includes left and right drive mechanisms. Each mechanism includes first and second traction elements for engaging the ground surface and transmitting a driving force between the vehicle and ground surface. Each mechanism includes first and second arms coupled to the first and second traction elements for relative rotation about first and second axis respectively. Each mechanism includes a rotor having a third axis, the rotor coupled to the body for rotation about the third axis and coupled to the first and second arms for relative rotation about the third axis. The mechanism includes first and second drive motors for driving the first and second traction elements and first and second transmissions, driven by the first and second motors and engaging the rotor. Driving the first and second traction elements simultaneously rotates the rotor relative to the first and second arms, respectively.

  15. Modular Robotic Vehicle

    NASA Technical Reports Server (NTRS)

    Borroni-Bird, Christopher E. (Inventor); Vitale, Robert L. (Inventor); Lee, Chunhao J. (Inventor); Ambrose, Robert O. (Inventor); Bluethmann, William J. (Inventor); Junkin, Lucien Q. (Inventor); Lutz, Jonathan J. (Inventor); Guo, Raymond (Inventor); Lapp, Anthony Joseph (Inventor); Ridley, Justin S. (Inventor)

    2015-01-01

    A modular robotic vehicle includes a chassis, driver input devices, an energy storage system (ESS), a power electronics module (PEM), modular electronic assemblies (eModules) connected to the ESS via the PEM, one or more master controllers, and various embedded controllers. Each eModule includes a drive wheel containing a propulsion-braking module, and a housing containing propulsion and braking control assemblies with respective embedded propulsion and brake controllers, and a mounting bracket covering a steering control assembly with embedded steering controllers. The master controller, which is in communication with each eModule and with the driver input devices, communicates with and independently controls each eModule, by-wire, via the embedded controllers to establish a desired operating mode. Modes may include a two-wheel, four-wheel, diamond, and omni-directional steering modes as well as a park mode. A bumper may enable docking with another vehicle, with shared control over the eModules of the vehicles.

  16. A Heterogeneous Medium Analytical Benchmark

    SciTech Connect

    Ganapol, B.D.

    1999-09-27

    A benchmark, called benchmark BLUE, has been developed for one-group neutral particle (neutron or photon) transport in a one-dimensional sub-critical heterogeneous plane parallel medium with surface illumination. General anisotropic scattering is accommodated through the Green's Function Method (GFM). Numerical Fourier transform inversion is used to generate the required Green's functions which are kernels to coupled integral equations that give the exiting angular fluxes. The interior scalar flux is then obtained through quadrature. A compound iterative procedure for quadrature order and slab surface source convergence provides highly accurate benchmark qualities (4- to 5- places of accuracy) results.

  17. Root Patterns in Heterogeneous Soils

    NASA Astrophysics Data System (ADS)

    Dara, A.; Moradi, A. B.; Carminati, A.; Oswald, S. E.

    2010-12-01

    Heterogeneous water availability is a typical characteristic of soils in which plant roots grow. Despite the intrinsic heterogeneity of soil-plant water relations, we know little about the ways how plants respond to local environmental quality. Furthermore, increasing use of soil amendments as partial water reservoirs in agriculture calls for a better understanding of plant response to soil heterogeneity. Neutron radiography is a non-invasive imaging that is highly sensitive to water and root distribution and that has high capability for monitoring spatial and temporal soil-plant water relations in heterogeneous systems. Maize plants were grown in 25 x 30 x 1 cm aluminum slabs filled with sandy soil. On the right side of the compartments a commercial water absorbent (Geohumus) was mixed with the soil. Geohumus was distributed with two patterns: mixed homogeneously with the soil, and arranged as 1-cm diameter aggregates (Fig. 1). Two irrigation treatments were applied: sufficient water irrigation and moderate water stress. Neutron radiography started 10 days after planting and has been performed twice a day for one week. At the end of the experiment, the containers were opened, the root were removed and dry root weight in different soil segments were measured. Neutron radiography showed root growth tendency towards Geohumus treated parts and preferential water uptake from Geohumus aggregates. Number and length of fine lateral roots were lower in treated areas compared to the non-treated zone and to control soil. Although corn plants showed an overall high proliferation towards the soil water sources, they decreased production of branches and fine root when water was more available near the main root parts. However there was 50% higher C allocation in roots grown in Geohumus compartments, as derived by the relative dry weight of root. The preferential C allocation in treated regions was higher when plants grew under water stress. We conclude that in addition to the

  18. Socially Aware Heterogeneous Wireless Networks.

    PubMed

    Kosmides, Pavlos; Adamopoulou, Evgenia; Demestichas, Konstantinos; Theologou, Michael; Anagnostou, Miltiades; Rouskas, Angelos

    2015-01-01

    The development of smart cities has been the epicentre of many researchers' efforts during the past decade. One of the key requirements for smart city networks is mobility and this is the reason stable, reliable and high-quality wireless communications are needed in order to connect people and devices. Most research efforts so far, have used different kinds of wireless and sensor networks, making interoperability rather difficult to accomplish in smart cities. One common solution proposed in the recent literature is the use of software defined networks (SDNs), in order to enhance interoperability among the various heterogeneous wireless networks. In addition, SDNs can take advantage of the data retrieved from available sensors and use them as part of the intelligent decision making process contacted during the resource allocation procedure. In this paper, we propose an architecture combining heterogeneous wireless networks with social networks using SDNs. Specifically, we exploit the information retrieved from location based social networks regarding users' locations and we attempt to predict areas that will be crowded by using specially-designed machine learning techniques. By recognizing possible crowded areas, we can provide mobile operators with recommendations about areas requiring datacell activation or deactivation. PMID:26110402

  19. Immunophenotype Heterogeneity in Nasal Glomangiopericytoma

    PubMed Central

    Handra-Luca, Adriana; Abd Elmageed, Zakaria Y.; Magkou, Christina; Lae, Marick

    2015-01-01

    Nasal glomangiopericytoma is rare. The immunophenotype is heterogeneous, more frequently smooth-muscle-actin and CD34-positive. We report expression patterns for several vascular-related proteins such as CD99, CD146, Bcl2, and WT1 as well as for treatment-related proteins such as mTOR and EGFR in a nasal glomangiopericytoma. The patient (woman, 86 years) presented with a left nasal tumefaction. The resected specimen (1.5-cm) showed a glomangiopericytoma. Tumor cells expressed smooth-muscle-actin, CD31, CD34, and progesterone receptor. They also expressed the vascular-cell-related proteins Bcl2, CD99, CD146, and WT1, as well as mTOR and EGFR. Nasal glomangiopericytomas show immunohistochemical heterogeneity for vascular-related markers, suggesting a possible extensive pericytic differentiation. The expression of potential targets for drug treatments such as mTOR and EGFR may impact on the clinical follow-up of these tumors occurring at advanced ages, which may require complex surgery. PMID:26351605

  20. On evolutionary spatial heterogeneous games

    NASA Astrophysics Data System (ADS)

    Fort, H.

    2008-03-01

    How cooperation between self-interested individuals evolve is a crucial problem, both in biology and in social sciences, that is far from being well understood. Evolutionary game theory is a useful approach to this issue. The simplest model to take into account the spatial dimension in evolutionary games is in terms of cellular automata with just a one-parameter payoff matrix. Here, the effects of spatial heterogeneities of the environment and/or asymmetries in the interactions among the individuals are analysed through different extensions of this model. Instead of using the same universal payoff matrix, bimatrix games in which each cell at site ( i, j) has its own different ‘temptation to defect’ parameter T(i,j) are considered. First, the case in which these individual payoffs are constant in time is studied. Second, an evolving evolutionary spatial game such that T=T(i,j;t), i.e. besides depending on the position evolves (by natural selection), is used to explore the combination of spatial heterogeneity and natural selection of payoff matrices.

  1. Shock Initiation of Heterogeneous Explosives

    SciTech Connect

    Reaugh, J E

    2004-05-10

    The fundamental picture that shock initiation in heterogeneous explosives is caused by the linking of hot spots formed at inhomogeneities was put forward by several researchers in the 1950's and 1960's, and more recently. Our work uses the computer hardware and software developed in the Advanced Simulation and Computing (ASC) program of the U.S. Department of Energy to explicitly include heterogeneities at the scale of the explosive grains and to calculate the consequences of realistic although approximate models of explosive behavior. Our simulations are performed with ALE-3D, a three-dimensional, elastic-plastic-hydrodynamic Arbitrary Lagrange-Euler finite-difference program, which includes chemical kinetics and heat transfer, and which is under development at this laboratory. We developed the parameter values for a reactive-flow model to describe the non-ideal detonation behavior of an HMX-based explosive from the results of grain-scale simulations. In doing so, we reduced the number of free parameters that are inferred from comparison with experiment to a single one - the characteristic defect dimension. We also performed simulations of the run to detonation in small volumes of explosive. These simulations illustrate the development of the reaction zone and the acceleration of the shock front as the flame fronts start from hot spots, grow, and interact behind the shock front. In this way, our grain-scale simulations can also connect to continuum experiments directly.

  2. Heterogeneous Integration of Compound Semiconductors

    NASA Astrophysics Data System (ADS)

    Moutanabbir, Oussama; Gösele, Ulrich

    2010-08-01

    The ability to tailor compound semiconductors and to integrate them onto foreign substrates can lead to superior or novel functionalities with a potential impact on various areas in electronics, optoelectronics, spintronics, biosensing, and photovoltaics. This review provides a brief description of different approaches to achieve this heterogeneous integration, with an emphasis on the ion-cut process, also known commercially as the Smart-Cut™ process. This process combines semiconductor wafer bonding and undercutting using defect engineering by light ion implantation. Bulk-quality heterostructures frequently unattainable by direct epitaxial growth can be produced, provided that a list of technical criteria is fulfilled, thus offering an additional degree of freedom in the design and fabrication of heterogeneous and flexible devices. Ion cutting is a generic process that can be employed to split and transfer fine monocrystalline layers from various crystals. Materials and engineering issues as well as our current understanding of the underlying physics involved in its application to cleaving thin layers from freestanding GaN, InP, and GaAs wafers are presented.

  3. Dispersivity in heterogeneous permeable media

    SciTech Connect

    Chesnut, D.A.

    1994-01-01

    When one fluid displaces another through a one-dimensional porous medium, the composition changes from pure displacing fluid at the inlet to pure displaced fluid some distance downstream. The distance over which an arbitrary percentage of this change occurs is defined as the mixing zone length, which increases with increasing average distance traveled by the displacement front. For continuous injection, the mixing zone size can be determined from a breakthrough curve as the time required for the effluent displacing fluid concentration to change from, say, 10% to 90%. In classical dispersion theory, the mixing zone grows in proportion to the square root of the mean distance traveled, or, equivalently, to the square root of the mean breakthrough time. In a multi-dimensional heterogeneous medium, especially at field scales, the size of the mixing zone grows almost linearly with mean distance or travel time. If an observed breakthrough curve is forced to fit the, clinical theory, the resulting effective dispersivity, instead of being constant, also increases almost linearly with the spatial or temporal scale of the problem. This occurs because the heterogeneity in flow properties creates a corresponding velocity distribution along the different flow pathways from the inlet to the outlet of the system. Mixing occurs mostly at the outlet, or wherever the fluid is sampled, rather than within the medium. In this paper, we consider the effects. of this behavior on radionuclide or other contaminant migration.

  4. Heterogeneous catalytic transesterification of phosphatidylcholine.

    PubMed

    Balasubramanian, Rajesh Kumar; Obbard, Jeffrey Philip

    2011-01-01

    The transesterification of phosphatidylcholine (PC) via homogeneous and heterogeneous catalysis was investigated for the production of fatty acid methyl esters (FAME) i.e. biodiesel. Calcium methoxide and calcium oxide were used as heterogeneous catalysts, and KOH as a homogeneous catalyst for the transesterification of phosphatidylcholine (PC)--a polar phospholipid prevalent in eukaryotic organisms. The initial reaction rate was higher for KOH (24.23 g of FAME/g of catalyst.min) than for calcium methoxide (17.06 g of FAME/g of catalyst.min) and calcium oxide (1.06 g of FAME/g of catalyst.min). PC was then mixed with soybean oil at different proportions (i.e. 10%, 30% and 50%, PC10, PC30 and PC50, respectively) which was then used as the feedstock for transesterification using calcium methoxide. When the mass fraction of PC was increased in the feedstock reaction rate also increased. Phosphorus content of the FAME layer of PC100, PC50, PC30 and PC10 was 0.081, 0.041, 0.035 and 0.028% (w/w), respectively. PMID:20832299

  5. Socially Aware Heterogeneous Wireless Networks

    PubMed Central

    Kosmides, Pavlos; Adamopoulou, Evgenia; Demestichas, Konstantinos; Theologou, Michael; Anagnostou, Miltiades; Rouskas, Angelos

    2015-01-01

    The development of smart cities has been the epicentre of many researchers’ efforts during the past decade. One of the key requirements for smart city networks is mobility and this is the reason stable, reliable and high-quality wireless communications are needed in order to connect people and devices. Most research efforts so far, have used different kinds of wireless and sensor networks, making interoperability rather difficult to accomplish in smart cities. One common solution proposed in the recent literature is the use of software defined networks (SDNs), in order to enhance interoperability among the various heterogeneous wireless networks. In addition, SDNs can take advantage of the data retrieved from available sensors and use them as part of the intelligent decision making process contacted during the resource allocation procedure. In this paper, we propose an architecture combining heterogeneous wireless networks with social networks using SDNs. Specifically, we exploit the information retrieved from location based social networks regarding users’ locations and we attempt to predict areas that will be crowded by using specially-designed machine learning techniques. By recognizing possible crowded areas, we can provide mobile operators with recommendations about areas requiring datacell activation or deactivation. PMID:26110402

  6. Thermal properties of heterogeneous grains

    NASA Technical Reports Server (NTRS)

    Lien, David J.

    1988-01-01

    Cometary dust is not spherical nor homogeneous, yet these are the assumptions used to model its thermal, optical, and dynamical properties. To better understand the effects of heterogeneity on the thermal and optical properties of dust grains, the effective dielectric constant for an admixture of magnetite and a silicate were calculated using two different effective medium theories: the Maxwell-Garnett theory and the Bruggeman theory. In concept, the MG theory describes the effective dielectric constant of a matrix material into which is embedded a large number of very small inclusions of a second material. The Bruggeman theory describes the dielectric constant of a well mixed aggregate of two or more types of materials. Both theories assume that the individual particles are much smaller than the wavelength of the incident radiation. The refractivity for a heterogeneous grain using the MG theory is very similar to the refractivity of the matrix material, even for large volume fractions of the inclusion. The equilibrium grain temperature for spherical particles sized from .001 to 100 microns in radius at 1 astronomical unit from the sun was calculated. Further explanation is given.

  7. Heterogeneous Transmutation Sodium Fast Reactor

    SciTech Connect

    S. E. Bays

    2007-09-01

    The threshold-fission (fertile) nature of Am-241 is used to destroy this minor actinide by capitalizing upon neutron capture instead of fission within a sodium fast reactor. This neutron-capture and its subsequent decay chain leads to the breeding of even neutron number plutonium isotopes. A slightly moderated target design is proposed for breeding plutonium in an axial blanket located above the active “fast reactor” driver fuel region. A parametric study on the core height and fuel pin diameter-to-pitch ratio is used to explore the reactor and fuel cycle aspects of this design. This study resulted in both non-flattened and flattened core geometries. Both of these designs demonstrated a high capacity for removing americium from the fuel cycle. A reactivity coefficient analysis revealed that this heterogeneous design will have comparable safety aspects to a homogeneous reactor of comparable size. A mass balance analysis revealed that the heterogeneous design may reduce the number of fast reactors needed to close the current once-through light water reactor fuel cycle.

  8. Groundwater pumping by heterogeneous users

    NASA Astrophysics Data System (ADS)

    Saak, Alexander E.; Peterson, Jeffrey M.

    2012-08-01

    Farm size is a significant determinant of both groundwater-irrigated farm acreage and groundwater-irrigation-application rates per unit land area. This paper analyzes the patterns of groundwater exploitation when resource users in the area overlying a common aquifer are heterogeneous. In the presence of user heterogeneity, the common resource problem consists of inefficient dynamic and spatial allocation of groundwater because it impacts income distribution not only across periods but also across farmers. Under competitive allocation, smaller farmers pump groundwater faster if farmers have a constant marginal periodic utility of income. However, it is possible that larger farmers pump faster if the Arrow-Pratt coefficient of relative risk-aversion is sufficiently decreasing in income. A greater farm-size inequality may either moderate or amplify income inequality among farmers. Its effect on welfare depends on the curvature properties of the agricultural output function and the farmer utility of income. Also, it is shown that a flat-rate quota policy that limits the quantity of groundwater extraction per unit land area may have unintended consequences for the income distribution among farmers.

  9. A cellular automata traffic flow model considering the heterogeneity of acceleration and delay probability

    NASA Astrophysics Data System (ADS)

    Li, Qi-Lang; Wong, S. C.; Min, Jie; Tian, Shuo; Wang, Bing-Hong

    2016-08-01

    This study examines the cellular automata traffic flow model, which considers the heterogeneity of vehicle acceleration and the delay probability of vehicles. Computer simulations are used to identify three typical phases in the model: free-flow, synchronized flow, and wide moving traffic jam. In the synchronized flow region of the fundamental diagram, the low and high velocity vehicles compete with each other and play an important role in the evolution of the system. The analysis shows that there are two types of bistable phases. However, in the original Nagel and Schreckenberg cellular automata traffic model, there are only two kinds of traffic conditions, namely, free-flow and traffic jams. The synchronized flow phase and bistable phase have not been found.

  10. Integrated Vehicle Thermal Management for Advanced Vehicle Propulsion Technologies

    SciTech Connect

    Bennion, K.; Thornton, M.

    2010-04-01

    A critical element to the success of new propulsion technologies that enable reductions in fuel use is the integration of component thermal management technologies within a viable vehicle package. Vehicle operation requires vehicle thermal management systems capable of balancing the needs of multiple vehicle systems that may require heat for operation, require cooling to reject heat, or require operation within specified temperature ranges. As vehicle propulsion transitions away from a single form of vehicle propulsion based solely on conventional internal combustion engines (ICEs) toward a wider array of choices including more electrically dominant systems such as plug-in hybrid electric vehicles (PHEVs), new challenges arise associated with vehicle thermal management. As the number of components that require active thermal management increase, so do the costs in terms of dollars, weight, and size. Integrated vehicle thermal management is one pathway to address the cost, weight, and size challenges. The integration of the power electronics and electric machine (PEEM) thermal management with other existing vehicle systems is one path for reducing the cost of electric drive systems. This work demonstrates techniques for evaluating and quantifying the integrated transient and continuous heat loads of combined systems incorporating electric drive systems that operate primarily under transient duty cycles, but the approach can be extended to include additional steady-state duty cycles typical for designing vehicle thermal management systems of conventional vehicles. The work compares opportunities to create an integrated low temperature coolant loop combining the power electronics and electric machine with the air conditioning system in contrast to a high temperature system integrated with the ICE cooling system.

  11. Vehicle following controller design for autonomous intelligent vehicles

    NASA Technical Reports Server (NTRS)

    Chien, C. C.; Lai, M. C.; Mayr, R.

    1994-01-01

    A new vehicle following controller is proposed for autonomous intelligent vehicles. The proposed vehicle following controller not only provides smooth transient maneuvers for unavoidable nonzero initial conditions but also guarantees the asymptotic platoon stability without the availability of feedforward information. Furthermore, the achieved asymptotic platoon stability is shown to be robust to sensor delays and an upper bound for the allowable sensor delays is also provided in this paper.

  12. Motor vehicle drivers' injuries in train-motor vehicle crashes.

    PubMed

    Zhao, Shanshan; Khattak, Aemal

    2015-01-01

    The objectives of this research were to: (1) identify a more suitable model for modeling injury severity of motor vehicle drivers involved in train-motor vehicle crashes at highway-rail grade crossings from among three commonly used injury severity models and (2) to investigate factors associated with injury severity levels of motor vehicle drivers involved in train-motor vehicle crashes at such crossings. The 2009-2013 highway-rail grade crossing crash data and the national highway-rail crossing inventory data were combined to produce the analysis dataset. Four-year (2009-2012) data were used for model estimation while 2013 data were used for model validation. The three injury severity levels-fatal, injury and no injury-were based on the reported intensity of motor-vehicle drivers' injuries at highway-rail grade crossings. The three injury severity models evaluated were: ordered probit, multinomial logit and random parameter logit. A comparison of the three models based on different criteria showed that the random parameter logit model and multinomial logit model were more suitable for injury severity analysis of motor vehicle drivers involved in crashes at highway-rail grade crossings. Some of the factors that increased the likelihood of more severe crashes included higher train and vehicle speeds, freight trains, older drivers, and female drivers. Where feasible, reducing train and motor vehicle speeds and nighttime lighting may help reduce injury severities of motor vehicle drivers. PMID:25463957

  13. Sensor Technology for Integrated Vehicle Health Management of Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Prosser, W. H.; Brown, T. L.; Woodard, S. E.; Fleming, G. A.; Cooper, E. G.

    2002-01-01

    NASA is focusing considerable efforts on technology development for Integrated Vehicle Health Management systems. The research in this area is targeted toward increasing aerospace vehicle safety and reliability, while reducing vehicle operating and maintenance costs. Onboard, real-time sensing technologies that can provide detailed information on structural integrity are central to such a health management system. This paper describes a number of sensor technologies currently under development for integrated vehicle health management. The capabilities, current limitations, and future research needs of these technologies are addressed.

  14. Laser powered interorbital vehicle

    NASA Technical Reports Server (NTRS)

    Clarke, M. T.; Cooper, J. J.; Eggleston, G. P.; Farkas, M. A.; Hunt, D. C.; King, J.; Nguyen, H.; Rahal, G.; Saw, K.; Tipton, R.

    1989-01-01

    A preliminary design of a low-thrust Laser Powered Interorbital Vehicle (LPIV) intended for cargo transportation between an Earth space station and a lunar base is presented. The selected mission utilizes a spiral trajectory, characteristic of a low-thrust spacecraft, requiring eight days for a lunar rendezvous and an additional nine days for return. The ship's configuration consists primarily of an optical train, two hydrogen plasma engines, a 37.1 m box-beam truss, a payload module, and propellant tanks. The total mass of the vehicle, fully loaded, is 63,300 kg. A single plasma, regeneratively cooled engine design is incorporated into the two 500 N engines. These are connected to the spacecraft by turntables that allow the vehicle to thrust tangential to the flight path. Proper collection and transmission of the laser beam to the thrust chambers is provided through the optical train. This system consists of a 23-m-diameter primary mirror, a convex parabolic secondary mirror, a beam splitter, and two concave parabolic tertiary mirrors. The payload bay is capable of carrying 18,000 kg of cargo and is located opposite the primary mirror on the main truss. Fuel tanks carrying a maximum of 35,000 kg of liquid hydrogen are fastened to tracks that allow the tanks to be moved perpendicular to the main truss. This capability is required to prevent the center of mass from moving out of the thrust vector line. The laser beam is located and tracked by means of an acquisition, pointing, and tracking system that can be locked onto the space-based laser station. Correct orientation of the spacecraft with the laser beam is maintained by control moment gyros and reaction control rockets. In addition, an aerobrake configuration was designed to provide the option of using the atmospheric drag in place of propulsion for a return trajectory.

  15. Mack LNG vehicle development

    SciTech Connect

    Southwest Research Institute

    2000-01-05

    The goal of this project was to install a production-ready, state-of-the-art engine control system on the Mack E7G natural gas engine to improve efficiency and lower exhaust emissions. In addition, the power rating was increased from 300 brake horsepower (bhp) to 325 bhp. The emissions targets were oxides of nitrogen plus nonmethane hydrocarbons of less than 2.5 g/bhp-hr and particulate matter of less than 0.05 g/bhp-hr on 99% methane. Vehicle durability and field testing were also conducted. Further development of this engine should include efficiency improvements and oxides of nitrogen reductions.

  16. Juno II Launch Vehicle

    NASA Technical Reports Server (NTRS)

    1958-01-01

    The modified Jupiter C (sometimes called Juno I), used to launch Explorer I, had minimum payload lifting capabilities. Explorer I weighed slightly less than 31 pounds. Juno II was part of America's effort to increase payload lifting capabilities. Among other achievements, the vehicle successfully launched a Pioneer IV satellite on March 3, 1959, and an Explorer VII satellite on October 13, 1959. Responsibility for Juno II passed from the Army to the Marshall Space Flight Center when the Center was activated on July 1, 1960. On November 3, 1960, a Juno II sent Explorer VIII into a 1,000-mile deep orbit within the ionosphere.

  17. Hybrid vehicle motor alignment

    DOEpatents

    Levin, Michael Benjamin

    2001-07-03

    A rotor of an electric motor for a motor vehicle is aligned to an axis of rotation for a crankshaft of an internal combustion engine having an internal combustion engine and an electric motor. A locator is provided on the crankshaft, a piloting tool is located radially by the first locator to the crankshaft. A stator of the electric motor is aligned to a second locator provided on the piloting tool. The stator is secured to the engine block. The rotor is aligned to the crankshaft and secured thereto.

  18. Remote control for motor vehicle

    NASA Technical Reports Server (NTRS)

    Johnson, Dale R. (Inventor); Ciciora, John A. (Inventor)

    1984-01-01

    A remote controller is disclosed for controlling the throttle, brake and steering mechanism of a conventional motor vehicle, with the remote controller being particularly advantageous for use by severely handicapped individuals. The controller includes a remote manipulator which controls a plurality of actuators through interfacing electronics. The remote manipulator is a two-axis joystick which controls a pair of linear actuators and a rotary actuator, with the actuators being powered by electric motors to effect throttle, brake and steering control of a motor vehicle adapted to include the controller. The controller enables the driver to control the adapted vehicle from anywhere in the vehicle with one hand with minimal control force and range of motion. In addition, even though a conventional vehicle is adapted for use with the remote controller, the vehicle may still be operated in the normal manner.

  19. Energy management and vehicle synthesis

    NASA Technical Reports Server (NTRS)

    Czysz, P.; Murthy, S. N. B.

    1995-01-01

    The major drivers in the development of launch vehicles for the twenty-first century are reduction in cost of vehicles and operations, continuous reusability, mission abort capability with vehicle recovery, and readiness. One approach to the design of such vehicles is to emphasize energy management and propulsion as being the principal means of improvements given the available industrial capability and the required freedom in selecting configuration concept geometries. A methodology has been developed for the rational synthesis of vehicles based on the setting up and utilization of available data and projections, and a reference vehicle. The application of the methodology is illustrated for a single stage to orbit (SSTO) with various limits for the use of airbreathing propulsion.

  20. Weakly bound states in heterogeneous waveguides

    NASA Astrophysics Data System (ADS)

    Amore, Paolo; Fernández, Francisco M.; Hofmann, Christoph P.

    2016-07-01

    We study the spectrum of the Helmholtz equation in a two-dimensional infinite waveguide, containing a weak heterogeneity localized at an internal point, and obeying Dirichlet boundary conditions at its border. We use the variational theorem to derive the condition for which the lowest eigenvalue of the spectrum falls below the continuum threshold and a bound state appears, localized at the heterogeneity. We devise a rigorous perturbation scheme and derive the exact expression for the energy to third order in the heterogeneity.

  1. Hybrid and Plug-in Electric Vehicles

    SciTech Connect

    2014-05-20

    Hybrid and plug-in electric vehicles use electricity either as their primary fuel or to improve the efficiency of conventional vehicle designs. This new generation of vehicles, often called electric drive vehicles, can be divided into three categories: hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles(PHEVs), and all-electric vehicles (EVs). Together, they have great potential to reduce U.S. petroleum use.

  2. Heterogeneous Reburning By Mixed Fuels

    SciTech Connect

    Anderson Hall

    2009-03-31

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  3. Genetic heterogeneity of hepatocellular carcinoma

    SciTech Connect

    Unsal, H.; Isselbacher, K.J. ); Yakicier, C.; Marcais, C.; Ozturk, M. ); Kew, M. ); Volkmann, M. ); Zentgraf, H. )

    1994-01-18

    The authors studied 80 hepatocellular carcinomas from three continents for p53 gene (TP53) mutations and hepatitis B virus (HBV) sequences. p53 mutations were frequent in tumors from Mozambique but not in tumors from South Africa, China, and Germany. Independent of geographic origin, most tumors were positive for HBV sequences. X gene coding sequences of HBV were detected in 78% of tumors, whereas viral sequences in the surface antigen- and core antigen-encoding regions were present in less than 35% of tumors. These observations indicate that hepatocellular carcinomas are genetically heterogeneous. Mozambican-types of hepatocellular carcinomas are characterized by a high incidence of p53 mutations related to aflatoxins. In other tumors, the rarity of p53 mutations combined with the frequent presence of viral X gene coding sequences suggests a possible interference of HBV with the wild-type p53 function.

  4. HETEROGENEOUS REBURNING BY MIXED FUELS

    SciTech Connect

    Wei-Yin Chen; Benson B. Gathitu

    2005-01-14

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  5. Mesoscale poroelasticity of heterogeneous media

    NASA Astrophysics Data System (ADS)

    Monfared, Siavash; Laubie, Hadrien; Radjai, Farhang; Pellenq, Roland; Ulm, Franz-Josef

    Poroelastic behavior of heterogeneous media is revisited. Lattice Element Method (LEM) is used to model interaction between solid constituents due to a pressurized pore space. Exploring beyond mean-field based theories in continuum microporomechanics, local textural variations and its contribution to the global anisotropic poroelastic behavior of real multiphase porous media are captured. To this end, statistical distributions of mesoscale poroelastic coefficients from numerical simulations on X-ray microscopy scans of two different organic-rich shales with different microtextures are presented. The results are compared with predictions using mean-field based tools of continuum micromechanics. The textural dependency of strain localization and stress chain formation captured in this framework promises a powerful tool for modeling poroelastic response of complex porous composites and a path to incorporate local textural and elastic variations into a continuum description. Visiting Scientist, CNRS-MIT, MIT.

  6. Heterogeneous fuel for hybrid rocket

    NASA Technical Reports Server (NTRS)

    Stickler, David B. (Inventor)

    1996-01-01

    Heterogeneous fuel compositions suitable for use in hybrid rocket engines and solid-fuel ramjet engines, The compositions include mixtures of a continuous phase, which forms a solid matrix, and a dispersed phase permanently distributed therein. The dispersed phase or the matrix vaporizes (or melts) and disperses into the gas flow much more rapidly than the other, creating depressions, voids and bumps within and on the surface of the remaining bulk material that continuously roughen its surface, This effect substantially enhances heat transfer from the combusting gas flow to the fuel surface, producing a correspondingly high burning rate, The dispersed phase may include solid particles, entrained liquid droplets, or gas-phase voids having dimensions roughly similar to the displacement scale height of the gas-flow boundary layer generated during combustion.

  7. Data Integration for Heterogenous Datasets

    PubMed Central

    2014-01-01

    Abstract More and more, the needs of data analysts are requiring the use of data outside the control of their own organizations. The increasing amount of data available on the Web, the new technologies for linking data across datasets, and the increasing need to integrate structured and unstructured data are all driving this trend. In this article, we provide a technical overview of the emerging “broad data” area, in which the variety of heterogeneous data being used, rather than the scale of the data being analyzed, is the limiting factor in data analysis efforts. The article explores some of the emerging themes in data discovery, data integration, linked data, and the combination of structured and unstructured data. PMID:25553272

  8. [Systemic mastocytosis: a heterogeneous disease].

    PubMed

    Hermans, M A W; Verburg, M; van Laar, J A M; van Hagen, P M; Pasmans, S G M A; van Daele, P L A

    2016-01-01

    Systemic mastocytosis (SM) is an acquired myeloproliferative disease, which is caused by an uncontrolled proliferation of aberrant mast cells. SM patients can have very different clinical phenotypes and may therefore initially present to different specialties. Diagnosis is often delayed because many physicians are unfamiliar with this illness. This can lead to substantial morbidity and puts patients at risk of complications such as severe anaphylaxis. Measurement of serum tryptase levels is always a sensible first step in the diagnostic work-up, but a normal serum tryptase does not rule out SM completely, and a bone marrow biopsy is essential for a conclusive diagnosis. Here, we describe two patient cases to illustrate the heterogeneous nature of this disease, and provide an overview of the symptoms, diagnostic work-up and current treatments options for SM. PMID:27229688

  9. Lunar roving vehicle deployment mechanism

    NASA Technical Reports Server (NTRS)

    Hunter, A. B.; Spacey, B. W.

    1972-01-01

    The space support equipment that supports the lunar roving vehicle during the flight to the moon and permits the vehicle to be deployed from the lunar module onto the lunar surface with a minimum amount of astronaut participation is discussed. The design and evolution of the equipment are reviewed. The success of the overall lunar roving vehicle design, including the space support equipment, was demonstrated on the Apollo 15 and 16 missions.

  10. Systems Challenges for Hypersonic Vehicles

    NASA Technical Reports Server (NTRS)

    Hunt, James L.; Laruelle, Gerard; Wagner, Alain

    1997-01-01

    This paper examines the system challenges posed by fully reusable hypersonic cruise airplanes and access to space vehicles. Hydrocarbon and hydrogen fueled airplanes are considered with cruise speeds of Mach 5 and 10, respectively. The access to space matrix is examined. Airbreathing and rocket powered, single- and two-stage vehicles are considered. Reference vehicle architectures are presented. Major systems/subsystems challenges are described. Advanced, enhancing systems concepts as well as common system technologies are discussed.

  11. Idling Reduction for Personal Vehicles

    SciTech Connect

    2015-05-07

    Fact sheet on reducing engine idling in personal vehicles. Idling your vehicle--running your engine when you're not driving it--truly gets you nowhere. Idling reduces your vehicle's fuel economy, costs you money, and creates pollution. Idling for more than 10 seconds uses more fuel and produces more emissions that contribute to smog and climate change than stopping and restarting your engine does.

  12. Space vehicle gyroscope sensor applications

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Considerations which form the basis for the specification, design and evaluation of gyroscopes for spaceborne sensor applications are presented. The applications are distinguished by basic vehicle category: launch vehicles, spacecraft, entry vehicles and sounding rockets. Specifically excluded from discussion are gyroscope effector applications. Exotic or unconventional gyroscopes for which operational experience is nonexistent are mentioned only briefly to alert the reader of future trends. General requirements for testing and evaluation are discussed.

  13. Toward understanding and exploiting tumor heterogeneity

    PubMed Central

    Alizadeh, Ash A; Aranda, Victoria; Bardelli, Alberto; Blanpain, Cedric; Bock, Christoph; Borowski, Christine; Caldas, Carlos; Califano, Andrea; Doherty, Michael; Elsner, Markus; Esteller, Manel; Fitzgerald, Rebecca; Korbel, Jan O; Lichter, Peter; Mason, Christopher E; Navin, Nicholas; Pe’er, Dana; Polyak, Kornelia; Roberts, Charles W M; Siu, Lillian; Snyder, Alexandra; Stower, Hannah; Swanton, Charles; Verhaak, Roel G W; Zenklusen, Jean C; Zuber, Johannes; Zucman-Rossi, Jessica

    2016-01-01

    The extent of tumor heterogeneity is an emerging theme that researchers are only beginning to understand. How genetic and epigenetic heterogeneity affects tumor evolution and clinical progression is unknown. The precise nature of the environmental factors that influence this heterogeneity is also yet to be characterized. Nature Medicine, Nature Biotechnology and the Volkswagen Foundation organized a meeting focused on identifying the obstacles that need to be overcome to advance translational research in and tumor heterogeneity. Once these key questions were established, the attendees devised potential solutions. Their ideas are presented here. PMID:26248267

  14. Toward understanding and exploiting tumor heterogeneity.

    PubMed

    Alizadeh, Ash A; Aranda, Victoria; Bardelli, Alberto; Blanpain, Cedric; Bock, Christoph; Borowski, Christine; Caldas, Carlos; Califano, Andrea; Doherty, Michael; Elsner, Markus; Esteller, Manel; Fitzgerald, Rebecca; Korbel, Jan O; Lichter, Peter; Mason, Christopher E; Navin, Nicholas; Pe'er, Dana; Polyak, Kornelia; Roberts, Charles W M; Siu, Lillian; Snyder, Alexandra; Stower, Hannah; Swanton, Charles; Verhaak, Roel G W; Zenklusen, Jean C; Zuber, Johannes; Zucman-Rossi, Jessica

    2015-08-01

    The extent of tumor heterogeneity is an emerging theme that researchers are only beginning to understand. How genetic and epigenetic heterogeneity affects tumor evolution and clinical progression is unknown. The precise nature of the environmental factors that influence this heterogeneity is also yet to be characterized. Nature Medicine, Nature Biotechnology and the Volkswagen Foundation organized a meeting focused on identifying the obstacles that need to be overcome to advance translational research in and tumor heterogeneity. Once these key questions were established, the attendees devised potential solutions. Their ideas are presented here. PMID:26248267

  15. Heterogeneous sensor networks: a bio-inspired overlay architecture

    NASA Astrophysics Data System (ADS)

    Burman, Jerry; Hespanha, Joao; Madhow, Upamanyu; Klein, Daniel; Isaacs, Jason; Venkateswaran, Sriram; Pham, Tien

    2010-04-01

    Teledyne Scientific Company, the University of California at Santa Barbara (UCSB) and the Army Research Lab are developing technologies for automated data exfiltration from heterogeneous sensor networks through the Institute for Collaborative Biotechnologies (ICB). Unmanned air vehicles (UAV) provide an effective means to autonomously collect data from unattended ground sensors (UGSs) that cannot communicate with each other. UAVs are used to reduce the system reaction time by generating autonomous data-driven collection routes. Bio-inspired techniques for search provide a novel strategy to detect, capture and fuse data across heterogeneous sensors. A fast and accurate method has been developed for routing UAVs and localizing an event by fusing data from a sparse number of UGSs; it leverages a bio-inspired technique based on chemotaxis or the motion of bacteria seeking nutrients in their environment. The system was implemented and successfully tested using a high level simulation environment using a flight simulator to emulate a UAV. A field test was also conducted in November 2009 at Camp Roberts, CA using a UAV provided by AeroMech Engineering. The field test results showed that the system can detect and locate the source of an acoustic event with an accuracy of about 3 meters average circular error.

  16. Battery requirements for electric vehicles

    NASA Astrophysics Data System (ADS)

    Gosden, D. F.

    1993-05-01

    As interest grows in the possibility of electric vehicles (EVs) replacing conventional internal-combustion-engined-powered vehicles in many major cities, attention is being given to the development of improved batteries. Heavy-duty, lead/acid batteries have served the needs of low-performance vehicles, such as milk floats and fork-lifts, for many years. The demands of high performance in a lightweight vehicle, however, have increased the battery loading substantially. The performance requirements of a modern, traffic-compatible EV are reviewed and corresponding requirements on the battery discussed.

  17. Hybrid Vehicle Program. Final report

    SciTech Connect

    1984-06-01

    This report summarizes the activities on the Hybrid Vehicle Program. The program objectives and the vehicle specifications are reviewed. The Hybrid Vehicle has been designed so that maximum use can be made of existing production components with a minimum compromise to program goals. The program status as of the February 9-10 Hardware Test Review is presented, and discussions of the vehicle subsystem, the hybrid propulsion subsystem, the battery subsystem, and the test mule programs are included. Other program aspects included are quality assurance and support equipment. 16 references, 132 figures, 47 tables.

  18. Manrating orbital transfer vehicle propulsion

    NASA Technical Reports Server (NTRS)

    Cooper, L. P.

    1985-01-01

    The expended capabilities for Orbital Transfer Vehicles (OTV) which will be needed to meet increased payload requirements for transporting materials and men to geosynchronous orbit are discussed. The requirement to provide manrating offers challenges and opportunities to the propulsion system designers. The propulsion approaches utilized in previous manned space vehicles of the United States are reviewed. The principals of reliability analysis are applied to the Orbit Transfer Vehicle. Propulsion system options are characterized in terms of the test requirements to demonstrate reliability goals and are compared to earlier vehicle approaches.

  19. Vehicle systems design optimization study

    NASA Technical Reports Server (NTRS)

    Gilmour, J. L.

    1980-01-01

    The optimum vehicle configuration and component locations are determined for an electric drive vehicle based on using the basic structure of a current production subcompact vehicle. The optimization of an electric vehicle layout requires a weight distribution in the range of 53/47 to 62/38 in order to assure dynamic handling characteristics comparable to current internal combustion engine vehicles. Necessary modification of the base vehicle can be accomplished without major modification of the structure or running gear. As long as batteries are as heavy and require as much space as they currently do, they must be divided into two packages, one at front under the hood and a second at the rear under the cargo area, in order to achieve the desired weight distribution. The weight distribution criteria requires the placement of batteries at the front of the vehicle even when the central tunnel is used for the location of some batteries. The optimum layout has a front motor and front wheel drive. This configuration provides the optimum vehicle dynamic handling characteristics and the maximum passenger and cargo space for a given size vehicle.

  20. Visiting Vehicle Ground Trajectory Tool

    NASA Technical Reports Server (NTRS)

    Hamm, Dustin

    2013-01-01

    The International Space Station (ISS) Visiting Vehicle Group needed a targeting tool for vehicles that rendezvous with the ISS. The Visiting Vehicle Ground Trajectory targeting tool provides the ability to perform both realtime and planning operations for the Visiting Vehicle Group. This tool provides a highly reconfigurable base, which allows the Visiting Vehicle Group to perform their work. The application is composed of a telemetry processing function, a relative motion function, a targeting function, a vector view, and 2D/3D world map type graphics. The software tool provides the ability to plan a rendezvous trajectory for vehicles that visit the ISS. It models these relative trajectories using planned and realtime data from the vehicle. The tool monitors ongoing rendezvous trajectory relative motion, and ensures visiting vehicles stay within agreed corridors. The software provides the ability to update or re-plan a rendezvous to support contingency operations. Adding new parameters and incorporating them into the system was previously not available on-the-fly. If an unanticipated capability wasn't discovered until the vehicle was flying, there was no way to update things.

  1. Gearbox assembly for vehicles

    SciTech Connect

    Imaizumi, M.; Masumura, M.; Ishikawa, T.; Hosoya, E.

    1987-01-13

    A gearbox assembly is described for a vehicle for transmitting an output of an engine to driving wheels of the vehicle, comprising: a main gearbox receiving the output and having plural forward gear-shift steps; a shift lever; a sub gearbox coupled to an output of the main gearbox having at least two relatively high and low speed gearshift steps (GH,GL) and a reverse transmission system (GR), the two steps and the reverse transmission system being selectively established through switching operation of the shift lever; wherein the sub gearbox further comprises: a rotary member connected to the shift lever for selecting one of the steps and the reverse transmission system according to its rotation; a stopper mechanism engaging the rotary member for preventing the rotary member from rotating to a position where the reverse transmission system is established; and interlinking means between the stopper mechanism and the main gearbox for releasing the stopper mechanism only when the main gearbox is in neutral or in a low speed gear-shift step; wherein the stopper mechanism comprises: a cam rotatable in response to the gear-shift operation of the main gearbox; a stopper lever one end of which faces the periphery of the cam and the other end facing the rotary member, the stopper lever being pivotally supported at its middle portion; and a spring urging the stopper level to abut against the periphery of the cam.

  2. Transatmospheric vehicle research

    NASA Technical Reports Server (NTRS)

    Adelman, Henry G.; Cambier, Jean-Luc

    1990-01-01

    Research was conducted into the alternatives to the supersonic combustion ramjet (scramjet) engine for hypersonic flight. A new engine concept, the Oblique Detonation Wave Engine (ODWE) was proposed and explored analytically and experimentally. Codes were developed which can couple the fluid dynamics of supersonic flow with strong shock waves, with the finite rate chemistry necessary to model the detonation process. An additional study was conducted which compared the performance of a hypersonic vehicle powered by a scramjet or an ODWE. Engineering models of the overall performances of the two engines are included. This information was fed into a trajectory program which optimized the flight path to orbit. A third code calculated the vehicle size, weight, and aerodynamic characteristics. The experimental work was carried out in the Ames 20MW arc-jet wind tunnel, focusing on mixing and combustion of fuel injected into a supersonic airstream. Several injector designs were evaluated by sampling the stream behind the injectors and analyzing the mixture with an on-line mass spectrometer. In addition, an attempt was made to create a standing oblique detonation wave in the wind tunnel using hydrogen fuel. It appeared that the conditions in the test chamber were marginal for the generation of oblique detonation waves.

  3. Electric-vehicle batteries

    NASA Astrophysics Data System (ADS)

    Oman, Henry; Gross, Sid

    1995-02-01

    Electric vehicles that can't reach trolley wires need batteries. In the early 1900's electric cars disappeared when owners found that replacing the car's worn-out lead-acid battery costs more than a new gasoline-powered car. Most of today's electric cars are still propelled by lead-acid batteries. General Motors in their prototype Impact, for example, used starting-lighting-ignition batteries, which deliver lots of power for demonstrations, but have a life of less than 100 deep discharges. Now promising alternative technology has challenged the world-wide lead miners, refiners, and battery makers into forming a consortium that sponsors research into making better lead-acid batteries. Horizon's new bipolar battery delivered 50 watt-hours per kg (Wh/kg), compared with 20 for ordinary transport-vehicle batteries. The alternatives are delivering from 80 Wh/kg (nickel-metal hydride) up to 200 Wh/kg (zinc-bromine). A Fiat Panda traveled 260 km on a single charge of its zinc-bromine battery. A German 3.5-ton postal truck traveled 300 km with a single charge in its 650-kg (146 Wh/kg) zinc-air battery. Its top speed was 110 km per hour.

  4. Vehicle with magnetic engine

    SciTech Connect

    Wortham, C.

    1993-06-15

    A vehicle is described comprising a vehicle frame fitted with axles and wheels rotatably carried by the axles; an engine block mounted on the frame; a plurality of magnetic cylinders provided in the engine block and a plurality of magnetic pistons disposed in the magnetic cylinders, respectively, in reciprocating relationship, the magnetic cylinders having a first magnetic polarity in one end and a second magnetic polarity in the opposite end for alternately attracting and repelling the magnetic pistons, respectively; a crankshaft journalled for rotation in the engine block; power transmission means connecting the crankshaft to at least one of the axles in driving relationship; and connecting rods connecting the crankshaft to the magnetic pistons, respectively, whereby reciprocation of the magnetic pistons in the magnetic cylinders effects rotation of the crankshaft; a cylinder head provided on the engine block and piston electromagnetic means provided in the cylinder head above the magnetic cylinders and the magnetic pistons, respectively for alternately attracting and repelling the magnetic pistons; at least one battery carried by the frame; and polarity timing means electrically connected to the battery and the piston electromagnetic means, for alternating the polarity of the piston electromagnet means, whereby electric current is supplied to the piston electromagnetic means in current-reversing relationship to alternately attract and repel the magnetic pistons in reciprocating relationship responsive to operation of the polarity timing means.

  5. Superpressure stratospheric vehicle

    SciTech Connect

    Chocol, C.; Robinson, W.; Epley, L.

    1990-09-15

    Our need for wide-band global communications, earth imaging and sensing, atmospheric measurements and military reconnaissance is extensive, but growing dependence on space-based systems raises concerns about vulnerability. Military commanders require space assets that are more accessible and under local control. As a result, a robust and low cost access to space-like capability has become a national priority. Free floating buoyant vehicles in the middle stratosphere can provide the kind of cost effective access to space-like capability needed for a variety of missions. These vehicles are inexpensive, invisible, and easily launched. Developments in payload electronics, atmospheric modeling, and materials combined with improving communications and navigation infrastructure are making balloon-borne concepts more attractive. The important milestone accomplished by this project was the planned test flight over the continental United States. This document is specifically intended to review the technology development and preparations leading up to the test flight. Although the test flight experienced a payload failure just before entering its assent altitude, significant data were gathered. The results of the test flight are presented here. Important factors included in this report include quality assurance testing of the balloon, payload definition and characteristics, systems integration, preflight testing procedures, range operations, data collection, and post-flight analysis. 41 figs., 5 tabs.

  6. Vehicle to grid: electric vehicles as an energy storage solution

    NASA Astrophysics Data System (ADS)

    McGee, Rodney; Waite, Nicholas; Wells, Nicole; Kiamilev, Fouad E.; Kempton, Willett M.

    2013-05-01

    With increased focus on intermittent renewable energy sources such as wind turbines and photovoltaics, there comes a rising need for large-scale energy storage. The vehicle to grid (V2G) project seeks to meet this need using electric vehicles, whose high power capacity and existing power electronics make them a promising energy storage solution. This paper will describe a charging system designed by the V2G team that facilitates selective charging and backfeeding by electric vehicles. The system consists of a custom circuit board attached to an embedded linux computer that is installed both in the EVSE (electric vehicle supply equipment) and in the power electronics unit of the vehicle. The boards establish an in-band communication link between the EVSE and the vehicle, giving the vehicle internet connectivity and the ability to make intelligent decisions about when to charge and discharge. This is done while maintaining compliance with existing charging protocols (SAEJ1772, IEC62196) and compatibility with standard "nonintelligent" cars and chargers. Through this system, the vehicles in a test fleet have been able to successfully serve as portable temporary grid storage, which has implications for regulating the electrical grid, providing emergency power, or supplying power to forward military bases.

  7. Hybrid vehicle potential assessment. Volume 7: Hybrid vehicle review

    NASA Technical Reports Server (NTRS)

    Leschly, K. O.

    1979-01-01

    Review of hybrid vehicles built during the past ten years or planned to be built in the near future is presented. An attempt is made to classify and analyze these vehicles to get an overall picture of their key characteristics. The review includes onroad hybrid passenger cars, trucks, vans, and buses.

  8. Habitat heterogeneity, disturbance, and productivity work in concert to regulate biodiversity in deep submarine canyons.

    PubMed

    McClain, Craig R; Barry, James P

    2010-04-01

    Habitat heterogeneity is a major structuring agent of ecological assemblages promoting beta diversity and ultimately contributing to overall higher global diversity. The exact processes by which heterogeneity increases diversity are scale dependent and encompass variation in other well-known processes, e.g., productivity, disturbance, and temperature. Thus, habitat heterogeneity likely triggers multiple and cascading diversity effects through ecological assemblages. Submarine canyons, a pervasive feature of the world's oceans, likely increase habitat heterogeneity at multiple spatial scales similar to their terrestrial analogues. However, our understanding of how processes regulating diversity, and the potential for cascading effects within these important topographic features, remains incomplete. Utilizing remote-operated vehicles (ROVs) for coring and video transects, we quantified faunal turnover in the deep-sea benthos at a rarely examined scale (1 m-1 km). Macrofaunal community structure, megafaunal density, carbon flux, and sediment characteristics were analyzed for the soft-bottom benthos at the base of cliff faces in Monterey Canyon (northeast Pacific Ocean) at three depths. We documented a remarkable degree of faunal turnover and changes in overall community structure at scales < 100 m, and often < 10 m, related to geographic features of a canyon complex. Ultimately, our findings indicated that multiple linked processes related to habitat heterogeneity, ecosystem engineering, and bottom-up dynamics are important to deep-sea biodiversity. PMID:20462112

  9. Expendable launch vehicle studies

    NASA Technical Reports Server (NTRS)

    Bainum, Peter M.; Reiss, Robert

    1995-01-01

    Analytical support studies of expendable launch vehicles concentrate on the stability of the dynamics during launch especially during or near the region of maximum dynamic pressure. The in-plane dynamic equations of a generic launch vehicle with multiple flexible bending and fuel sloshing modes are developed and linearized. The information from LeRC about the grids, masses, and modes is incorporated into the model. The eigenvalues of the plant are analyzed for several modeling factors: utilizing diagonal mass matrix, uniform beam assumption, inclusion of aerodynamics, and the interaction between the aerodynamics and the flexible bending motion. Preliminary PID, LQR, and LQG control designs with sensor and actuator dynamics for this system and simulations are also conducted. The initial analysis for comparison of PD (proportional-derivative) and full state feedback LQR Linear quadratic regulator) shows that the split weighted LQR controller has better performance than that of the PD. In order to meet both the performance and robustness requirements, the H(sub infinity) robust controller for the expendable launch vehicle is developed. The simulation indicates that both the performance and robustness of the H(sub infinity) controller are better than that for the PID and LQG controllers. The modelling and analysis support studies team has continued development of methodology, using eigensensitivity analysis, to solve three classes of discrete eigenvalue equations. In the first class, the matrix elements are non-linear functions of the eigenvector. All non-linear periodic motion can be cast in this form. Here the eigenvector is comprised of the coefficients of complete basis functions spanning the response space and the eigenvalue is the frequency. The second class of eigenvalue problems studied is the quadratic eigenvalue problem. Solutions for linear viscously damped structures or viscoelastic structures can be reduced to this form. Particular attention is paid to

  10. Chemical and seismological constraints on mantle heterogeneity.

    PubMed

    Helffrich, George

    2002-11-15

    Recent seismological studies that use scattered waves to detect heterogeneities in the mantle reveal the presence of a small, distributed elastic heterogeneity in the lower mantle which does not appear to be thermal in nature. The characteristic size of these heterogeneities appears to be ca. 8 km, suggesting that they represent subducted recycled oceanic crust. With this stimulus, old ideas that the mantle is heterogeneous in structure, rather than stratified, are reinterpreted and a simple, end-member model for the heterogeneity structure is proposed. The volumetrically largest components in the model are recycled oceanic crust, which contains the heat-producing elements, and mantle depleted of these and other incompatible trace elements. About 10% of the mantle's mass is made up of recycled oceanic crust, which is associated with the observed small-scale seismic heterogeneity. The way this heterogeneity is distributed is in convectively stretched and thinned bodies ranging downwards in size from 8 km. With the present techniques to detect small bodies through scattering, only ca. 55% of the mantle's small-scale heterogeneities are detectable seismically. PMID:12460477

  11. Heterogeneous Factor Analysis Models: A Bayesian Approach.

    ERIC Educational Resources Information Center

    Ansari, Asim; Jedidi, Kamel; Dube, Laurette

    2002-01-01

    Developed Markov Chain Monte Carlo procedures to perform Bayesian inference, model checking, and model comparison in heterogeneous factor analysis. Tested the approach with synthetic data and data from a consumption emotion study involving 54 consumers. Results show that traditional psychometric methods cannot fully capture the heterogeneity in…

  12. Understanding the Executive Functioning Heterogeneity in Schizophrenia

    ERIC Educational Resources Information Center

    Raffard, Stephane; Bayard, Sophie

    2012-01-01

    Schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions implied in the executive functioning. The dysexecutive syndrome is one of the most prominent and functionally cognitive features of schizophrenia. Nevertheless, it is not clear to what extend executive deficits are heterogeneous in schizophrenia…

  13. Heterogeneity in Health Care Computing Environments

    PubMed Central

    Sengupta, Soumitra

    1989-01-01

    This paper discusses issues of heterogeneity in computer systems, networks, databases, and presentation techniques, and the problems it creates in developing integrated medical information systems. The need for institutional, comprehensive goals are emphasized. Using the Columbia-Presbyterian Medical Center's computing environment as the case study, various steps to solve the heterogeneity problem are presented.

  14. Solar powered model vehicle races

    NASA Astrophysics Data System (ADS)

    Yılmaz, Nazmi; Serpengüzel, Ali

    2014-09-01

    Koç University SPIE student chapter has been organizing the solar powered model vehicle race and outreaching K-12 students. The solar powered model vehicle race for car, boat, blimp, all solar panel boat, submarine, underwater rower, amphibian, and glider have been successfully organized.

  15. 1997 hybrid electric vehicle specifications

    SciTech Connect

    Sluder, S.; Larsen, R.; Duoba, M.

    1996-10-01

    The US DOE sponsors Advanced Vehicle Technology competitions to help educate the public and advance new vehicle technologies. For several years, DOE has provided financial and technical support for the American Tour de Sol. This event showcases electric and hybrid electric vehicles in a road rally across portions of the northeastern United States. The specifications contained in this technical memorandum apply to vehicles that will be entered in the 1997 American Tour de Sol. However, the specifications were prepared to be general enough for use by other teams and individuals interested in developing hybrid electric vehicles. The purpose of the specifications is to ensure that the vehicles developed do not present a safety hazard to the teams that build and drive them or to the judges, sponsors, or public who attend the competitions. The specifications are by no means the definitive sources of information on constructing hybrid electric vehicles - as electric and hybrid vehicles technologies advance, so will the standards and practices for their construction. In some cases, the new standards and practices will make portions of these specifications obsolete.

  16. Vehicle Safety. Managing Liability Series.

    ERIC Educational Resources Information Center

    Newby, Deborah, Ed.

    This monograph discusses the safety of vehicles owned, leased, maintained, and operated by colleges and universities. First, the risks by colleges and universities is discussed. First, the risks associated with college vehicles are outlined, including the liability that comes with staff/faculty and student drivers and such special concerns as…

  17. Going Green with Electric Vehicles

    ERIC Educational Resources Information Center

    Deal, Walter F., III

    2010-01-01

    There is considerable interest in electric and hybrid cars because of environmental and climate change concerns, tougher fuel efficiency standards, and increasing dependence on imported oil. In this article, the author describes the history of electric vehicles in the automotive world and discusses the components of a hybrid electric vehicle.…

  18. Personal watercraft vehicle engine

    SciTech Connect

    Webb, E.H.

    1991-12-17

    This paper describes a personal watercraft vehicle engine. It comprises: a crankcase having an upper portion and a lower portion a crankshaft operatively mounted in the crankcase, the crankshaft residing in a substantially horizontal orientation, the crankshaft having a longitudinal axis; a sealed flywheel housing, the sealed flywheel housing being axially aligned with the crankshaft; a flywheel cooperatively connected to the crankshaft, the flywheel residing in the flywheel housing, the flywheel housing being rigidly affixed to the crankcase; the flywheel having a plurality of gear teeth around its periphery; and a starter mounted in an opening defined in a plane parallel to the crankshaft and perpendicular to the starter axis, the starter being perpendicular to the crankshaft, in an upper-most portion of the sealed flywheel housing, the starter having a pinion gear, the pinion gear being engagable with the plurality of gear teeth on the periphery of the flywheel, whereby the starter is not as adversely affected by water.

  19. All wheel drive vehicle

    SciTech Connect

    Watanabe, M.; Yagasaki, A.; Kawashima, Y.

    1986-07-15

    An all-wheel-drive vehicle is described which consists of: (a) a body; (b) an engine mounted on the body and having an output shaft; (c) front and rear pairs of wheels drivable by power from the engine, the front and rear wheels being vertically movably suspended from the body; (d) axles coupled to the front and rear wheels; (e) first power transmitting means for transmitting power from the output shaft of the engine to one of the axles of the front and rear wheels; (f) a power output unit mounted on the one axle; and (g) second power transmitting means for transmitting power from the power output unit to the other of the axles of the front and rear wheels.

  20. Launch Vehicle Systems Analysis

    NASA Technical Reports Server (NTRS)

    Olds, John R.

    1999-01-01

    This report summaries the key accomplishments of Georgia Tech's Space Systems Design Laboratory (SSDL) under NASA Grant NAG8-1302 from NASA - Marshall Space Flight Center. The report consists of this summary white paper, copies of technical papers written under this grant, and several viewgraph-style presentations. During the course of this grant four main tasks were completed: (1)Simulated Combined-Cycle Rocket Engine Analysis Module (SCCREAM), a computer analysis tool for predicting the performance of various RBCC engine configurations; (2) Hyperion, a single stage to orbit vehicle capable of delivering 25,000 pound payloads to the International Space Station Orbit; (3) Bantam-X Support - a small payload mission; (4) International Trajectory Support for interplanetary human Mars missions.

  1. Propane Vehicle Demonstration Grant Program

    SciTech Connect

    Jack Mallinger

    2004-08-27

    Project Description: Propane Vehicle Demonstration Grants The Propane Vehicle Demonstration Grants was established to demonstrate the benefits of new propane equipment. The US Department of Energy, the Propane Education & Research Council (PERC) and the Propane Vehicle Council (PVC) partnered in this program. The project impacted ten different states, 179 vehicles, and 15 new propane fueling facilities. Based on estimates provided, this project generated a minimum of 1,441,000 new gallons of propane sold for the vehicle market annually. Additionally, two new off-road engines were brought to the market. Projects originally funded under this project were the City of Portland, Colorado, Kansas City, Impco Technologies, Jasper Engines, Maricopa County, New Jersey State, Port of Houston, Salt Lake City Newspaper, Suburban Propane, Mutual Liquid Propane and Ted Johnson.

  2. 2012 Vehicle Technologies Market Report

    SciTech Connect

    Davis, Stacy Cagle; Diegel, Susan W; Boundy, Robert Gary

    2013-03-01

    The Oak Ridge National Laboratory s Center for Transportation Analysis developed and published the first Vehicle Technologies Market Report in 2008. Three editions of the report have been published since that time. This 2012 report details the major trends in U.S. light vehicle and medium/heavy truck markets as well as the underlying trends that caused them. The opening section on Energy and Economics discusses the role of transportation energy and vehicle markets on a national scale. The following section examines light-duty vehicle use, markets, manufacture, and supply chains. The discussion of medium and heavy trucks offers information on truck sales and fuel use. The technology section offers information on alternative fuel vehicles and infrastructure, and the policy section concludes with information on recent, current, and near-future Federal policies like the Corporate Average Fuel Economy standards.

  3. Large engines and vehicles, 1958

    NASA Technical Reports Server (NTRS)

    1978-01-01

    During the mid-1950s, the Air Force sponsored work on the feasibility of building large, single-chamber engines, presumably for boost-glide aircraft or spacecraft. In 1956, the Army missile development group began studies of large launch vehicles. The possibilities opened up by Sputnik accelerated this work and gave the Army an opportunity to bid for the leading role in launch vehicles. The Air Force had the responsibility for the largest ballistic missiles and hence a ready-made base for extending their capability for spaceflight. During 1958, actions taken to establish a civilian space agency, and the launch vehicle needs seen by its planners, added a third contender to the space vehicle competition. These activities during 1958 are examined as to how they resulted in the initiation of a large rocket engine and the first large launch vehicle.

  4. Aggregate vehicle travel forecasting model

    SciTech Connect

    Greene, D.L.; Chin, Shih-Miao; Gibson, R.

    1995-05-01

    This report describes a model for forecasting total US highway travel by all vehicle types, and its implementation in the form of a personal computer program. The model comprises a short-run, econometrically-based module for forecasting through the year 2000, as well as a structural, scenario-based longer term module for forecasting through 2030. The short-term module is driven primarily by economic variables. It includes a detailed vehicle stock model and permits the estimation of fuel use as well as vehicle travel. The longer-tenn module depends on demographic factors to a greater extent, but also on trends in key parameters such as vehicle load factors, and the dematerialization of GNP. Both passenger and freight vehicle movements are accounted for in both modules. The model has been implemented as a compiled program in the Fox-Pro database management system operating in the Windows environment.

  5. The aerobraking space transfer vehicle

    NASA Technical Reports Server (NTRS)

    Andrews, Glen; Carpenter, Brian; Corns, Steve; Harris, Robert; Jun, Brian; Munro, Bruce; Pulling, Eric; Sekhon, Amrit; Welton, Walt; Jakubowski, A.

    1990-01-01

    With the advent of the Space Station and the proposed Geosynchronous Operation Support Center (GeoShack) in the early 21st century, the need for a cost effective, reusable orbital transport vehicle has arisen. This transport vehicle will be used in conjunction with the Space Shuttle, the Space Station, and GeoShack. The vehicle will transfer mission crew and payloads between low earth and geosynchronous orbits with minimal cost. Recent technological advances in thermal protection systems such as those employed in the Space Shuttle have made it possible to incorporate and aerobrake on the transfer vehicle to further reduce transport costs. The research and final design configuration of the aerospace senior design team from VPISU, working in conjunction with NASA, are presented. The topic of aerobraking and focuses on the evolution of an Aerobraking Space Transfer Vehicle (ASTV), is addressed.

  6. Hydrogen ICE Vehicle Testing Activities

    SciTech Connect

    J. Francfort; D. Karner

    2006-04-01

    The Advanced Vehicle Testing Activity teamed with Electric Transportation Applications and Arizona Public Service to develop and monitor the operations of the APS Alternative Fuel (Hydrogen) Pilot Plant. The Pilot Plant provides 100% hydrogen, and hydrogen and compressed natural gas (H/CNG)-blended fuels for the evaluation of hydrogen and H/CNG internal combustion engine (ICE) vehicles in controlled and fleet testing environments. Since June 2002, twenty hydrogen and H/CNG vehicles have accumulated 300,000 test miles and 5,700 fueling events. The AVTA is part of the Department of Energy’s FreedomCAR and Vehicle Technologies Program. These testing activities are managed by the Idaho National Laboratory. This paper discusses the Pilot Plant design and monitoring, and hydrogen ICE vehicle testing methods and results.

  7. Quantification of heterogeneity observed in medical images

    PubMed Central

    2013-01-01

    Background There has been much recent interest in the quantification of visually evident heterogeneity within functional grayscale medical images, such as those obtained via magnetic resonance or positron emission tomography. In the case of images of cancerous tumors, variations in grayscale intensity imply variations in crucial tumor biology. Despite these considerable clinical implications, there is as yet no standardized method for measuring the heterogeneity observed via these imaging modalities. Methods In this work, we motivate and derive a statistical measure of image heterogeneity. This statistic measures the distance-dependent average deviation from the smoothest intensity gradation feasible. We show how this statistic may be used to automatically rank images of in vivo human tumors in order of increasing heterogeneity. We test this method against the current practice of ranking images via expert visual inspection. Results We find that this statistic provides a means of heterogeneity quantification beyond that given by other statistics traditionally used for the same purpose. We demonstrate the effect of tumor shape upon our ranking method and find the method applicable to a wide variety of clinically relevant tumor images. We find that the automated heterogeneity rankings agree very closely with those performed visually by experts. Conclusions These results indicate that our automated method may be used reliably to rank, in order of increasing heterogeneity, tumor images whether or not object shape is considered to contribute to that heterogeneity. Automated heterogeneity ranking yields objective results which are more consistent than visual rankings. Reducing variability in image interpretation will enable more researchers to better study potential clinical implications of observed tumor heterogeneity. PMID:23453000

  8. Heterogeneous Chemistry in Global Chemistry Transport Models

    NASA Astrophysics Data System (ADS)

    Stadtler, Scarlet; Simpson, David; Schultz, Martin; Bott, Andreas

    2016-04-01

    The impact of six tropospheric heterogeneous reactions on ozone and nitrogen species was studied using two chemical transport models EMEP MSC-W and ECHAM6-HAMMOZ. Since heterogeneous reactions depend on reactant concentrations (in this study these are N_2O_5, NO_3, NO_2, O_3, HNO_3, HO_2) and aerosol surface area S_a, the modeled surface area of both models was compared to a satellite product retrieving the surface area. This comparison shows a good agreement in global pattern and especially the capability of both models to capture the extreme aerosol loadings in East Asia. Further, the impact of the heterogeneous reactions was evaluated by the simulation of a reference run containing all heterogeneous reactions and several sensitivity runs. One reaction was turned off in each sensitivity run to compare it with the reference run. As previously shown, the analysis of the sensitivity runs shows that the globally most important heterogeneous reaction is the one of N_2O_5. Nevertheless, NO_2, NO_3, HNO3 and HO2 heterogeneous reactions gain relevance particular in East China due to presence of high NOx concentrations and high Sa in the same region. The heterogeneous reaction of O3 itself on dust is compared to the other heterogeneous reactions of minor relevance. Evaluation of the models with northern hemispheric ozone surface observations yields a better agreement of the models with observations when the heterogeneous reactions are incorporated. Impacts of emission changes on the importance of the heterogeneous chemistry will be discussed.

  9. Genetic heterogeneity in juvenile NCL

    SciTech Connect

    Hart, Y.M.; Andermann, E.; Mitchison, H.M.

    1994-09-01

    The neuronal ceroid lipofuscinoses (NCL) are a group of related lysosomal storage diseases classified according to the age of onset, clinical syndrome, and pathology. The clinical syndromes include myoclonus, visual failure, progressive dementia, ataxia and generalized tonic clonic seizures in varying combinations depending on the age of onset and pathology. The mode of inheritance is autosomal recessive in most cases, except for several families with the adult form (Kufs` disease) which have autosomal dominant inheritance. Linkage for the infantile (Halatia-Santavuori) form (CLN1), characterized ultrastructurally by lysosomal granular osmiophilic deposits (GROD), has been demonstrated with markers on chromosome lp, while the gene for the typical juvenile (Spielmeyer-Vogt) form (CLN3), characterized by fingerprint-profile inclusions, has been linked to chromosome 16p. The gene locations of the late infantile (Jansky-Bielschowsky) and adult (Kufs` disease) forms are unknown, although it has recently been shown that the late infantile form does not link to chromosome 16p. We describe three siblings, including a pair of monozygotic twins, with juvenile onset NCL with GROD in whom linkage to the CLN3 region of chromsome 16p has been excluded. This would suggest that there is genetic heterogeneity not only among the different clinical syndromes, but also among identical clinical syndromes with different ultrastructural characteristics. Preliminary studies of linkage to chromosome 1p employing the microsatellite marker HY-TM1 have been uninformative. Further studies with other chromosome 1 markers are underway.

  10. Operating a heterogeneous telescope network

    NASA Astrophysics Data System (ADS)

    Allan, Alasdair; Bischoff, Karsten; Burgdorf, Martin; Cavanagh, Brad; Christian, Damien; Clay, Neil; Dickens, Rob; Economou, Frossie; Fadavi, Mehri; Frazer, Stephen; Granzer, Thomas; Grosvenor, Sandy; Hessman, Frederic V.; Jenness, Tim; Koratkar, Anuradha; Lehner, Matthew; Mottram, Chris; Naylor, Tim; Saunders, Eric S.; Solomos, Nikolaos; Steele, Iain A.; Tuparev, Georg; Vestrand, W. Thomas; White, Robert R.; Yost, Sarah

    2006-06-01

    In the last few years the ubiquitous availability of high bandwidth networks has changed the way both robotic and non-robotic telescopes operate, with single isolated telescopes being integrated into expanding "smart" telescope networks that can span continents and respond to transient events in seconds. The Heterogeneous Telescope Networks (HTN)* Consortium represents a number of major research groups in the field of robotic telescopes, and together we are proposing a standards based approach to providing interoperability between the existing proprietary telescope networks. We further propose standards for interoperability, and integration with, the emerging Virtual Observatory. We present the results of the first interoperability meeting held last year and discuss the protocol and transport standards agreed at the meeting, which deals with the complex issue of how to optimally schedule observations on geographically distributed resources. We discuss a free market approach to this scheduling problem, which must initially be based on ad-hoc agreements between the participants in the network, but which may eventually expand into a electronic market for the exchange of telescope time.

  11. Heterogeneity of the Tumor Vasculature

    PubMed Central

    Nagy, Janice A.; Chang, Sung-Hee; Shih, Shou-Ching; Dvorak, Ann M.; Dvorak, Harold F.

    2012-01-01

    The blood vessels supplying tumors are strikingly heterogeneous and differ from their normal counterparts with respect to organization, structure, and function. Six distinctly different tumor vessel types have been identified, and much has been learned about the steps and mechanisms by which they form. Four of the six vessel types (mother vessels, capillaries, glomeruloid microvascular proliferations, and vascular malformations) develop from preexisting normal venules and capillaries by angiogenesis. The two remaining vessel types (feeder arteries and draining veins) develop from arterio-venogenesis, a parallel, poorly understood process that involves the remodeling of preexisting arteries and veins. All six of these tumor vessel types can be induced to form sequentially in normal mouse tissues by an adenoviral vector expressing vascular endothelial growth factor (VEGF)-A164. Current antiangiogenic cancer therapies directed at VEGF-A or its receptors have been of only limited benefit to cancer patients, perhaps because they target only the endothelial cells of the tumor blood vessel subset that requires exogenous VEGF-A for maintenance. A goal of future work is to identify therapeutic targets on tumor blood vessel endothelial cells that have lost this requirement. PMID:20490982

  12. Distributional Scaling in Heterogeneous Aquifers

    NASA Astrophysics Data System (ADS)

    Polsinelli, J. F.

    2015-12-01

    An investigation is undertaken into the fractal scaling properties of the piezometric head in a heterogeneous unconfined aquifer. The governing equations for the unconfined flow are derived from conservation of mass and the Darcy law. The Dupuit approximation will be used to model the dynamics. The spatially varying nature of the tendency to conduct flow (e.g. the hydraulic conductivity) is represented as a stochastic process. Experimental studies in the literature have indicated that the conductivity belongs to a class of non-stationary stochastic fields, called H-ss fields. The uncertainty in the soil parameters is imparted onto the flow variables; in groundwater investigations the potentiometric head will be a random function. The structure of the head field will be analyzed with an emphasis on the scaling properties. The scaling scheme for the modeling equations and the simulation procedure for the saturated hydraulic conductivity process will be explained, then the method will be validated through numerical experimentation using the USGS Modflow-2005 software. The results of the numerical simulations demonstrate that the head will exhibit multi-fractal scaling if the hydraulic conductivity exhibits multi-fractal scaling and the differential equations for the groundwater equation satisfy a particular set of scale invariance conditions.

  13. Adaptation Driven by Spatial Heterogeneities

    NASA Astrophysics Data System (ADS)

    Hermsen, Rutger

    2011-03-01

    Biological evolution and ecology are intimately linked, because the reproductive success or ``fitness'' of an organism depends crucially on its ecosystem. Yet, most models of evolution (or population genetics) consider homogeneous, fixed-size populations subjected to a constant selection pressure. To move one step beyond such ``mean field'' descriptions, we discuss stochastic models of evolution driven by spatial heterogeneity. We imagine a population whose range is limited by a spatially varying environmental parameter, such as a temperature or the concentration of an antibiotic drug. Individuals in the population replicate, die and migrate stochastically. Also, by mutation, they can adapt to the environmental stress and expand their range. This way, adaptation and niche expansion go hand in hand. This mode of evolution is qualitatively different from the usual notion of a population climbing a fitness gradient. We analytically calculate the rate of adaptation by solving a first passage time problem. Interestingly, the joint effects of reproduction, death, mutation and migration result in two distinct parameter regimes depending on the relative time scales of mutation and migration. We argue that the proposed scenario may be relevant for the rapid evolution of antibiotic resistance. This work was supported by the Center for Theoretical Biological Physics sponsored by the National Science Foundation (NSF) (Grant PHY-0822283).

  14. Bedload sheets in heterogeneous sediment

    SciTech Connect

    Whiting, P.J.; Dietrich, W.E.; Leopold, L.B.; Drake, T.G.; Shreve, R.L.

    1988-02-01

    Field observations in streams with beds of coarse sand and fine gravel have revealed that bedload moves primarily as thin, migrating accumulations of sediment, and coarse grains cluster at their leading edge. These accumulations are one or two coarse grains high and are much longer (0.2-0.6 m long in sand; 0.5-2.0 m in fine gravel) than their height. The authors propose the term bedload sheet for these features, and the authors argue that they result from an instability inherent to bedload movement of moderately and poorly sorted sediment. In essence, coarse particles in the bedload slow or stop each other, trap finer particles in their interstices, and thus cause the coarse particles to become mobile again. Bedload sheets develop on the stoss side of dunes, causing the dune to advance incrementally with the arrival of each sheet. Successive deposition of coarse sediment from the leading edge followed by fine sediment may generate the grain-size sorting that distinguishes cross-bedding. Available flume experiments and field observations indicate that bedload sheets are a common, but generally unrecognized, feature of heterogeneous sediment transport.

  15. Surface area controlled heterogeneous nucleation

    NASA Astrophysics Data System (ADS)

    Steer, Brian; Gorbunov, Boris; Rowles, Jonathan; Green, David

    2012-02-01

    Heterogeneous nucleation of liquid from a gas phase on nanoparticles has been studied under various saturation ratios and nuclei size. The probability of liquid droplet nucleation, especially at a low degree of deviation from equilibrium, was measured for both atmospheric aerosol particles and engineered nanoparticles Cr2O3. The concept of a critical saturation ratio and the validity of the one-to-one relationship between the nuclei number and the number of droplets were examined. A transient zone between no nucleation and established nucleation termed the surface area controlled nucleation was observed. In this zone, the probability of stable phase formation is determined by the surface area of nuclei. There are two distinctive features of the surface area controlled nucleation: the nucleation probability is much less than 1 and is proportional to the surface area of nuclei. For condensation particle counters (CPCs) counting nanoparticles, these features mean that counts measured are proportional to the surface area of nanoparticles and, therefore, the CPCs counts can be calibrated to measure the surface area.

  16. Anatomical heterogeneity of Alzheimer disease

    PubMed Central

    Noh, Young; Jeon, Seun; Seo, Sang Won; Kim, Geon Ha; Cho, Hanna; Ye, Byoung Seok; Yoon, Cindy W.; Kim, Hee Jin; Chin, Juhee; Park, Kee Hyung; Heilman, Kenneth M.

    2014-01-01

    Objective: Because the signs associated with dementia due to Alzheimer disease (AD) can be heterogeneous, the goal of this study was to use 3-dimensional MRI to examine the various patterns of cortical atrophy that can be associated with dementia of AD type, and to investigate whether AD dementia can be categorized into anatomical subtypes. Methods: High-resolution T1-weighted volumetric MRIs were taken of 152 patients in their earlier stages of AD dementia. The images were processed to measure cortical thickness, and hierarchical agglomerative cluster analysis was performed using Ward's clustering linkage. The identified clusters of patients were compared with an age- and sex-matched control group using a general linear model. Results: There were several distinct patterns of cortical atrophy and the number of patterns varied according to the level of cluster analyses. At the 3-cluster level, patients were divided into (1) bilateral medial temporal–dominant atrophy subtype (n = 52, ∼34.2%), (2) parietal-dominant subtype (n = 28, ∼18.4%) in which the bilateral parietal lobes, the precuneus, along with bilateral dorsolateral frontal lobes, were atrophic, and (3) diffuse atrophy subtype (n = 72, ∼47.4%) in which nearly all association cortices revealed atrophy. These 3 subtypes also differed in their demographic and clinical features. Conclusions: This cluster analysis of cortical thickness of the entire brain showed that AD dementia in the earlier stages can be categorized into various anatomical subtypes, with distinct clinical features. PMID:25344382

  17. Aggregation of Heterogeneously Charged Colloids.

    PubMed

    Dempster, Joshua M; Olvera de la Cruz, Monica

    2016-06-28

    Patchy colloids are attractive as programmable building blocks for metamaterials. Inverse patchy colloids, in which a charged surface is decorated with patches of the opposite charge, are additionally noteworthy as models for heterogeneously charged biological materials such as proteins. We study the phases and aggregation behavior of a single charged patch in an oppositely charged colloid with a single-site model. This single-patch inverse patchy colloid model shows a large number of phases when varying patch size. For large patch sizes we find ferroelectric crystals, while small patch sizes produce cross-linked gels. Intermediate values produce monodisperse clusters and unusual worm structures that preserve finite ratios of area to volume. The polarization observed at large patch sizes is robust under extreme disorder in patch size and shape. We examine phase-temperature dependence and coexistence curves and find that large patch sizes produce polarized liquids, in contrast to mean-field predictions. Finally, we introduce small numbers of unpatched charged colloids. These can either suppress or encourage aggregation depending on their concentration and the size of the patches on the patched colloids. These effects can be exploited to control aggregation and to measure effective patch size. PMID:27253725

  18. Transmission imaging in heterogeneous media

    NASA Astrophysics Data System (ADS)

    Bongajum, E. L.; Meng, Y.; Milkereit, B.

    2010-12-01

    Wave propagation in heterogeneous media is characterized by amplitude, traveltime, and spectral fluctuations that reflect the variations in elastic properties (e.g. Vp, Vs, density). Variations in physical rock properties exist at different scales and occasionally result in effective anisotropy in medium parameters. If the variations in rock properties can be characterized from existing information such as logs, then it becomes possible to incorporate this information in wave modeling algorithms to understand its impact on acquisition design, processing of seismic waves for velocity information, AVO analysis as well as reverse time migration (RTM) routines. This study evaluates some of these aspects by using transmitted (direct) waves. When the variations exist over large scale lengths, RTM can be successfully implemented on Vertical Seismic Profiling (VSP) data in order to image the interface between two inhomogeneities as well as characterize the velocity distribution beyond the borehole location. However, when the existing geology causes anisotropy in the variability of the physical rock properties, the use of transmitted waves becomes strongly dependent on the acquisition geometry. In this circumstance, travel time fluctuations are influenced by the strength of the perturbations of the elastic parameters and the direction with the least variability (large scale lengths) in these parameters. This has according implications for seismic imaging in hardrock environment as well microseismic imaging applications.

  19. Clinical significance of monocyte heterogeneity.

    PubMed

    Stansfield, Brian K; Ingram, David A

    2015-01-01

    Monocytes are primitive hematopoietic cells that primarily arise from the bone marrow, circulate in the peripheral blood and give rise to differentiated macrophages. Over the past two decades, considerable attention to monocyte diversity and macrophage polarization has provided contextual clues into the role of myelomonocytic derivatives in human disease. Until recently, human monocytes were subdivided based on expression of the surface marker CD16. "Classical" monocytes express surface markers denoted as CD14(++)CD16(-) and account for greater than 70% of total monocyte count, while "non-classical" monocytes express the CD16 antigen with low CD14 expression (CD14(+)CD16(++)). However, recognition of an intermediate population identified as CD14(++)CD16(+) supports the new paradigm that monocytes are a true heterogeneous population and careful identification of specific subpopulations is necessary for understanding monocyte function in human disease. Comparative studies of monocytes in mice have yielded more dichotomous results based on expression of the Ly6C antigen. In this review, we will discuss the use of monocyte subpopulations as biomarkers of human disease and summarize correlative studies in mice that may yield significant insight into the contribution of each subset to disease pathogenesis. PMID:25852821

  20. An optimized international vehicle monitor

    SciTech Connect

    York, R.L.; Close, D.A.; Fehlau, P.E.

    1997-03-01

    The security plans for many DOE facilities require the monitoring of pedestrians and vehicles to control the movement of special nuclear material (SNM). Vehicle monitors often provide the outer-most barrier against the theft of SNM. Automatic monitors determine the presence of SNM by comparing the gamma-ray and neutron intensity while occupied, to the continuously updated background radiation level which is measured while the unit is unoccupied. The most important factors in choosing automatic vehicle monitors are sensitivity, cost and in high traffic applications total monitoring time. The two types of automatic vehicle monitors presently in use are the vehicle monitoring station and the drive-through vehicle monitor. These two types have dramatically different cost and sensitivities. The vehicle monitoring station has a worst-case detection sensitivity of 40 g of highly enriched uranium, HEU, and a cost approximately $180k. This type of monitor is very difficult to install and can only be used in low traffic flow locations. The drive-through vehicle portal has a worst-case detection sensitivity of 1 kg of HEU and a cost approximately $20k. The world`s political situation has created a pressing need to prevent the diversion of SNM from FSU nuclear facilities and across international borders. Drive-through vehicle monitors would be an effective and practical nuclear material proliferation deterrent if their sensitivity can be improved to a sufficient level. The goal of this project is to evaluate different detector configurations as a means of improving the sensitivity of these instruments to achieve a vehicle monitor that is economical, practical to install, and has adequate sensitivity to be an effective barrier to illegal transportation of SNM.

  1. 77 FR 40921 - Communication With Transport Vehicles

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-11

    ... COMMISSION Communication With Transport Vehicles AGENCY: Nuclear Regulatory Commission. ACTION: Regulatory... withdrawing Regulatory Guide 5.32, Revision 1, ``Communication with Transport Vehicles,'' published in May..., ``Communication with Transport Vehicles,'' published in May 1975. This RG describes radiotelephone...

  2. 40 CFR 1066.415 - Vehicle operation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... VEHICLE-TESTING PROCEDURES Preparing Vehicles and Running an Exhaust Emission Test § 1066.415 Vehicle... causes the engine to start running. (2) Place the transmission in gear as described by the test cycle...

  3. 77 FR 72337 - Apps for Vehicles Challenge

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ... of Energy Efficiency and Renewable Energy Apps for Vehicles Challenge AGENCY: Office of Energy... Vehicles: improving safety and fuel efficiency through technology innovation''. DATES: See, 1. Key Challenge Dates & Deadlines in SUPPLEMENTARY INFORMATION. ADDRESSES: The Apps for Vehicles Challenge...

  4. Breast cancer intra-tumor heterogeneity

    PubMed Central

    2014-01-01

    In recent years it has become clear that cancer cells within a single tumor can display striking morphological, genetic and behavioral variability. Burgeoning genetic, epigenetic and phenomenological data support the existence of intra-tumor genetic heterogeneity in breast cancers; however, its basis is yet to be fully defined. Two of the most widely evoked concepts to explain the origin of heterogeneity within tumors are the cancer stem cell hypothesis and the clonal evolution model. Although the cancer stem cell model appeared to provide an explanation for the variability among the neoplastic cells within a given cancer, advances in massively parallel sequencing have provided several lines of evidence to suggest that intra-tumor genetic heterogeneity likely plays a fundamental role in the phenotypic heterogeneity observed in cancers. Many challenges remain, however, in the interpretation of the next generation sequencing results obtained so far. Here we review the models that explain tumor heterogeneity, the causes of intra-tumor genetic diversity and their impact on our understanding and management of breast cancer, methods to study intra-tumor heterogeneity and the assessment of intra-tumor genetic heterogeneity in the clinic. PMID:25928070

  5. Interoperability of heterogeneous distributed systems

    NASA Astrophysics Data System (ADS)

    Zaschke, C.; Essendorfer, B.; Kerth, C.

    2016-05-01

    To achieve knowledge superiority in today's operations interoperability is the key. Budget restrictions as well as the complexity and multiplicity of threats combined with the fact that not single nations but whole areas are subject to attacks force nations to collaborate and share information as appropriate. Multiple data and information sources produce different kinds of data, real time and non-real time, in different formats that are disseminated to the respective command and control level for further distribution. The data is most of the time highly sensitive and restricted in terms of sharing. The question is how to make this data available to the right people at the right time with the right granularity. The Coalition Shared Data concept aims to provide a solution to these questions. It has been developed within several multinational projects and evolved over time. A continuous improvement process was established and resulted in the adaptation of the architecture as well as the technical solution and the processes it supports. Coming from the idea of making use of existing standards and basing the concept on sharing of data through standardized interfaces and formats and enabling metadata based query the concept merged with a more sophisticated service based approach. The paper addresses concepts for information sharing to facilitate interoperability between heterogeneous distributed systems. It introduces the methods that were used and the challenges that had to be overcome. Furthermore, the paper gives a perspective how the concept could be used in the future and what measures have to be taken to successfully bring it into operations.

  6. Heterogeneity of packing: structural approach.

    PubMed Central

    Kurochkina, N.; Privalov, G.

    1998-01-01

    Analysis of the heterogeneity of packing in proteins showed that different groups of the protein preferentially contribute to low- or high-density regions. Statistical distribution reveals the two preferable values for packing density in the form of two peaks. One peak occurs in the range of densities 0.55-0.65, the other occurs in the range 0.75-0.8. The high-density peak is originated primarily by high packing inside the hydrogen bonded backbone and to some extent by side chains. Polar/charged and apolar side chains both contribute to the low-density peak. The average packing density values of individual atomic groups significantly vary for backbone atoms as well as for side chain atoms. The carbonyl oxygen atoms of protein backbone and the end groups of side chains show lower packing density than the rest of the protein. The side-chain atomic groups of a secondary structure element when packed against the neighboring secondary structure element form stronger contacts with the side chains of this element than with its backbone. Analysis of the low-density regions around each buried peptide group was done for the set of proteins with different types of packing, including alpha-alpha, alpha-beta, and beta-beta packing. It was shown that cavities are regularly situated in the groove of secondary structure element packed against neighboring elements for all types of packing. Low density in the regions surrounding the peptide groups and the end groups of side chains can be explained by their positioning next to a cavity formed upon the association of secondary structure elements. The model proposed can be applied to the analysis of protein internal motions, mechanisms of cellular signal transduction, diffusion through protein matrix, and other events. PMID:9568896

  7. Mechanical heterogeneities and lithospheric extension

    NASA Astrophysics Data System (ADS)

    Duretz, Thibault; Petri, Benoit; Mohn, Geoffroy; Schenker, Filippo L.; Schmalholz, Stefan

    2016-04-01

    Detailed geological and geophysical studies of passive margins have highlighted the multi-stage and depth-dependent aspect of lithospheric thinning. Lithospheric thinning involves a variety of structures (normal faults, low angle detachments, extensional shear zones, extraction faults) and leads to a complex architecture of passive margins (with e.g. necking zone, mantle exhumation, continental allochthons). The processes controlling the generation and evolution of these structures as well as the impact of pre-rift inheritance are so far incompletely understood. In this study, we investigate the impact of pre-rift inheritance on the development of rifted margins using two-dimensional thermo-mechanical models of lithospheric thinning. To first order, we represent the pre-rift mechanical heterogeneities with lithological layering. The rheologies are kept simple (visco-plastic) and do not involve any strain softening mechanism. Our models show that mechanical layering causes multi-stage and depth-dependent extension. In the initial rifting phase, lithospheric extension is decoupled: as the crust undergoes thinning by brittle (frictional-plastic) faults, the lithospheric mantle accommodates extension by symmetric ductile necking. In a second rifting phase, deformation in the crust and lithospheric mantle is coupled and marks the beginning of an asymmetric extension stage. Low angle extensional shear zones develop across the lithosphere and exhume subcontinental mantle. Furthemore, crustal allochthons and adjacent basins develop coevally. We describe as well the thermal evolution predicted by the numerical models and discuss the first-order implications of our results in the context of the Alpine geological history.

  8. Graphene-Si heterogeneous nanotechnology

    NASA Astrophysics Data System (ADS)

    Akinwande, Deji; Tao, Li

    2013-05-01

    It is widely envisioned that graphene, an atomic sheet of carbon that has generated very broad interest has the largest prospects for flexible smart systems and for integrated graphene-silicon (G-Si) heterogeneous very large-scale integrated (VLSI) nanoelectronics. In this work, we focus on the latter and elucidate the research progress that has been achieved for integration of graphene with Si-CMOS including: wafer-scale graphene growth by chemical vapor deposition on Cu/SiO2/Si substrates, wafer-scale graphene transfer that afforded the fabrication of over 10,000 devices, wafer-scalable mitigation strategies to restore graphene's device characteristics via fluoropolymer interaction, and demonstrations of graphene integrated with commercial Si- CMOS chips for hybrid nanoelectronics and sensors. Metrology at the wafer-scale has led to the development of custom Raman processing software (GRISP) now available on the nanohub portal. The metrology reveals that graphene grown on 4-in substrates have monolayer quality comparable to exfoliated flakes. At room temperature, the high-performance passivated graphene devices on SiO2/Si can afford average mobilities 3000cm2/V-s and gate modulation that exceeds an order of magnitude. The latest growth research has yielded graphene with high mobilities greater than 10,000cm2/V-s on oxidized silicon. Further progress requires track compatible graphene-Si integration via wafer bonding in order to translate graphene research from basic to applied research in commercial R and D laboratories to ultimately yield a viable nanotechnology.

  9. Vehicle systems design optimization study

    SciTech Connect

    Gilmour, J. L.

    1980-04-01

    The optimization of an electric vehicle layout requires a weight distribution in the range of 53/47 to 62/38 in order to assure dynamic handling characteristics comparable to current production internal combustion engine vehicles. It is possible to achieve this goal and also provide passenger and cargo space comparable to a selected current production sub-compact car either in a unique new design or by utilizing the production vehicle as a base. Necessary modification of the base vehicle can be accomplished without major modification of the structure or running gear. As long as batteries are as heavy and require as much space as they currently do, they must be divided into two packages - one at front under the hood and a second at the rear under the cargo area - in order to achieve the desired weight distribution. The weight distribution criteria requires the placement of batteries at the front of the vehicle even when the central tunnel is used for the location of some batteries. The optimum layout has a front motor and front wheel drive. This configuration provides the optimum vehicle dynamic handling characteristics and the maximum passsenger and cargo space for a given size vehicle.

  10. Mobile remote manipulator vehicle system

    NASA Technical Reports Server (NTRS)

    Bush, Harold G. (Inventor); Mikulas, Martin M., Jr. (Inventor); Wallsom, Richard E. (Inventor); Jensen, J. Kermit (Inventor)

    1987-01-01

    A mobile remote manipulator system is disclosed for assembly, repair and logistics transport on, around and about a space station square bay truss structure. The vehicle is supported by a square track arrangement supported by guide pins integral with the space station truss structure and located at each truss node. Propulsion is provided by a central push-pull drive mechanism that extends out from the vehicle one full structural bay over the truss and locks drive rods into the guide pins. The draw bar is now retracted and the mobile remote manipulator system is pulled onto the next adjacent structural bay. Thus, translation of the vehicle is inchworm style. The drive bar can be locked onto two guide pins while the extendable draw bar is within the vehicle and then push the vehicle away one bay providing bidirectional push-pull drive. The track switches allow the vehicle to travel in two orthogonal directions over the truss structure which coupled with the bidirectional drive, allow movement in four directions on one plane. The top layer of this trilayered vehicle is a logistics platform. This platform is capable of 369 degees of rotation and will have two astronaut foot restraint platforms and a space crane integral.

  11. A Framework for Integration of IVHM Technologies for Intelligent Integration for Vehicle Management

    NASA Technical Reports Server (NTRS)

    Paris, Deidre E.; Trevino, Luis; Watson, Mike

    2005-01-01

    objectives: Guidance and Navigation; Communications and Tracking; Vehicle Monitoring; Information Transport and Integration; Vehicle Diagnostics; Vehicle Prognostics; Vehicle mission Planning; Automated Repair and Replacement; Vehicle Control; Human Computer Interface; and Onboard Verification and Validation. Furthermore, the presented framework provides complete vehicle management which not only allows for increased crew safety and mission success through new intelligence capabilities, but also yields a mechanism for more efficient vehicle operations. The representative IVHM technologies for IIVH includes: 1) robust controllers for use in re-usable launch vehicles, 2) scaleable/flexible computer platform using heterogeneous communication, 3) coupled electromagnetic oscillators for enhanced communications, 4) Linux-based real-time systems, 5) genetic algorithms, 6) Bayesian Networks, 7) evolutionary algorithms, 8) dynamic systems control modeling, and 9) advanced sensing capabilities. This paper presents IVHM technologies developed under NASA's NFFP pilot project. The integration of these IVHM technologies forms the framework for IIVM.

  12. A heterogeneous graph-based recommendation simulator

    SciTech Connect

    Yeonchan, Ahn; Sungchan, Park; Lee, Matt Sangkeun; Sang-goo, Lee

    2013-01-01

    Heterogeneous graph-based recommendation frameworks have flexibility in that they can incorporate various recommendation algorithms and various kinds of information to produce better results. In this demonstration, we present a heterogeneous graph-based recommendation simulator which enables participants to experience the flexibility of a heterogeneous graph-based recommendation method. With our system, participants can simulate various recommendation semantics by expressing the semantics via meaningful paths like User Movie User Movie. The simulator then returns the recommendation results on the fly based on the user-customized semantics using a fast Monte Carlo algorithm.

  13. Heterogeneous Chemistry Involving Methanol in Tropospheric Clouds

    NASA Technical Reports Server (NTRS)

    Tabazadeh, A.; Yokelson, R. J.; Singh, H. B.; Hobbs, P. V.; Crawford, J. H.; Iraci, L. T.

    2004-01-01

    In this report we analyze airborne measurements to suggest that methanol in biomass burning smoke is lost heterogeneously in clouds. When a smoke plume intersected a cumulus cloud during the SAFARI 2000 field project, the observed methanol gas phase concentration rapidly declined. Current understanding of gas and aqueous phase chemistry cannot explain the loss of methanol documented by these measurements. Two plausible heterogeneous reactions are proposed to explain the observed simultaneous loss and production of methanol and formaldehyde, respectively. If the rapid heterogeneous processing of methanol, seen in a cloud impacted by smoke, occurs in more pristine clouds, it could affect the oxidizing capacity of the troposphere on a global scale.

  14. Neural Field Dynamics with Heterogeneous Connection Topology

    NASA Astrophysics Data System (ADS)

    Qubbaj, Murad R.; Jirsa, Viktor K.

    2007-06-01

    Neural fields receive inputs from local and nonlocal sources. Notably in a biologically realistic architecture the latter vary under spatial translations (heterogeneous), the former do not (homogeneous). To understand the mutual effects of homogeneous and heterogeneous connectivity, we study the stability of the steady state activity of a neural field as a function of its connectivity and transmission speed. We show that myelination, a developmentally relevant change of the heterogeneous connectivity, always results in the stabilization of the steady state via oscillatory instabilities, independent of the local connectivity. Nonoscillatory instabilities are shown to be independent of any influences of time delay.

  15. The automation of remote vehicle control. [in Mars roving vehicles

    NASA Technical Reports Server (NTRS)

    Paine, G.

    1977-01-01

    The automation of remote vehicles is becoming necessary to overcome the requirement of having man present as a controller. By removing man, remote vehicles can be operated in areas where the environment is too hostile for man, his reaction times are too slow, time delays are too long, and where his presence is too costly, or where system performance can be improved. This paper addresses the development of automated remote vehicle control for nonspace and space tasks from warehouse vehicles to proposed Mars rovers. The state-of-the-art and the availability of new technology for implementing automated control are reviewed and the major problem areas are outlined. The control strategies are divided into those where the path is planned in advance or constrained, or where the system is a teleoperator, or where automation or robotics have been introduced.

  16. X-24C research vehicle

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A group of experiments that might be accomplished on the X-24C research vehicle are discussed indicating in each case the technology development needed to ready the experiments for flight, and also indicating interface problems between the vehicle and the experiment. Experiments that could be cheaply done using test platforms other than the X-24C have been eliminated. Experiments that are clearly applicable only to the X-24C research vehicle are, of course, included. Experiments that might be accomplished on either the X-24C or some other platform requiring further investigation concerning proper applicability are included for consideration.

  17. Research on Hybrid Vehicle Drivetrain

    NASA Astrophysics Data System (ADS)

    Xie, Zhongzhi

    Hybrid cars as a solution to energy saving, emission reduction measures, have received widespread attention. Motor drive system as an important part of the hybrid vehicles as an important object of study. Based on the hybrid electric vehicle powertrain control system for permanent magnet synchronous motor as the object of study. Can be applied to hybrid car compares the characteristics of traction motors, chose permanent magnet synchronous Motors as drive motors for hybrid vehicles. Building applications in hybrid cars in MATLAB/Simulink simulation model of permanent-magnet synchronous motor speed control system and analysis of simulation results.

  18. The Scout Launch Vehicle program

    NASA Technical Reports Server (NTRS)

    Foster, L. R., Jr.; Urash, R. G.

    1981-01-01

    The Scout Launch Vehicle Program to utilize solid propellant rockets by the DOD and to provide a reliable, low cost vehicle for scientific and applications aircraft is discussed. The program's history is reviewed and a vehicle description is given. The Vandenberg Air Force Base and the San Marco launch sites are described, and capabilities such as payload weight, orbital inclinations, payload volume and mission integration time spans are discussed. Current and future plans for improvement, including larger heat shields and individual rocket motors are also reviewed.

  19. Vehicle health management technology needs

    NASA Technical Reports Server (NTRS)

    Hammond, Walter E.; Jones, W. G.

    1992-01-01

    Background material on vehicle health management (VHM) and health monitoring/control is presented. VHM benefits are described and a list of VHM technology needs that should be pursued is presented. The NASA funding process as it impacts VHM technology funding is touched upon, and the VHM architecture guidelines for generic launch vehicles are described. An example of a good VHM architecture, design, and operational philosophy as it was conceptualized for the National Launch System program is presented. Consideration is given to the Strategic Avionics Technology Working Group's role in VHM, earth-to-orbit, and space vehicle avionics technology development considerations, and some actual examples of VHM benefits for checkout are given.

  20. Mars transfer vehicle studies

    NASA Technical Reports Server (NTRS)

    Woodcock, Gordon

    1993-01-01

    Earth-to-Mars distances vary from 60 to 400 million kilometers over a 14-year cycle. This complicates Mars mission design as a function of calendar time. Stay times at Mars are also strongly driven by opportunities for a return flight path which are within the limits of delta-V associated with practical space vehicles. The biggest difference between Mars and lunar transfer missions is mission time, which grows from a few days for the moon, to as much as a few hundred days for Mars missions. As a result, modules for similarly sized crews must be much larger for Mars missions that for transfer to lunar orbit. Technology challenges for one Mars mission scenario analyzed by Boeing include aerobrakes, propulsion, and life support systems. Mission performance is very sensitive to aerobrake weight fraction and, as a result, there is an incentive to use high performance materials such as advanced composites and thermal protection systems. Lander aerobrake would be used twice (for both planetary capture and descent to the Mars surface), and it would need to survive temperatures up to 3500 degrees.

  1. All-terrain vehicle

    SciTech Connect

    Somerton-Rayner, M.

    1986-12-16

    This patent describes an all-terrain vehicle comprising: a chassis; four road wheel axles equally spaced along the chassis; suspension means mounting the axles on the chassis; wheels mounted adjacent both ends of each of the axles, the wheels on the foremost and the rearmost axles being steerably mounted; propulsion and driving means including a single internal combustion engine and gearbox, and first and second transfer boxes both coupled to be driven by the engine through the gearbox; the first transfer box driving the first and third axles and the second transfer box driving the second and fourth axles; means for driving in the alternative all four wheels and only the center two wheels; power-assisted steering gear means operatively connected to the steerably-mounted wheels of the foremost axle; and steering coupling means extending between the steerably-mounted wheels on the foremost and rearmost axles so dimensioned that upon steering of the front wheels, the rear wheels perform castoring constrained to a smaller turning angle and a lower rate of angular movement than the front wheels.

  2. Mars transfer vehicle studies

    NASA Astrophysics Data System (ADS)

    Woodcock, Gordon

    1993-02-01

    Earth-to-Mars distances vary from 60 to 400 million kilometers over a 14-year cycle. This complicates Mars mission design as a function of calendar time. Stay times at Mars are also strongly driven by opportunities for a return flight path which are within the limits of delta-V associated with practical space vehicles. The biggest difference between Mars and lunar transfer missions is mission time, which grows from a few days for the moon, to as much as a few hundred days for Mars missions. As a result, modules for similarly sized crews must be much larger for Mars missions that for transfer to lunar orbit. Technology challenges for one Mars mission scenario analyzed by Boeing include aerobrakes, propulsion, and life support systems. Mission performance is very sensitive to aerobrake weight fraction and, as a result, there is an incentive to use high performance materials such as advanced composites and thermal protection systems. Lander aerobrake would be used twice (for both planetary capture and descent to the Mars surface), and it would need to survive temperatures up to 3500 degrees.

  3. GPS Moving Vehicle Experiment

    NASA Technical Reports Server (NTRS)

    Oaks, O. J.; Reid, Wilson; Wright, James; Duffey, Christopher; Williams, Charles; Warren, Hugh; Zeh, Tom; Buisson, James

    1996-01-01

    The Naval Research Laboratory (NRL) in the development of timing systems for remote locations, had a technical requirement for a Y code (SA/AS) Global Positioning System (GPS) precise time transfer receiver (TTR) which could be used both in a stationary mode or mobile mode. A contract was awarded to the Stanford Telecommunication Corporation (STEL) to build such a device. The Eastern Range (ER) als had a requirement for such a receiver and entered into the contract with NRL for the procurement of additional receivers. The Moving Vehicle Experiment (MVE) described in this paper is the first in situ test of the STEL Model 5401C Time Transfer System in both stationary and mobile operations. The primary objective of the MVE was to test the timing accuracy of the newly developed GPS TTR aboard a moving vessel. To accomplish this objective, a joint experiment was performed with personnel from NRL and the er at the Atlantic Undersea Test and Evaluation Center (AUTEC) test range at Andros Island. Results and discussion of the test are presented in this paper.

  4. Thermodynamic equilibrium at heterogeneous pressure

    NASA Astrophysics Data System (ADS)

    Vrijmoed, Johannes C.; Podladchikov, Yuri Y.

    2014-05-01

    Recent advances in metamorphic petrology point out the importance of grain-scale pressure variations in high-temperature metamorphic rocks. Pressures derived from chemical zonation using unconventional geobarometry based on equal chemical potentials fit mechanically feasible pressure variations. Here a thermodynamic equilibrium method is presented that predicts chemical zoning as a result of pressure variations by Gibbs energy minimization. Equilibrium thermodynamic prediction of the chemical zoning in the case of pressure heterogeneity is done by constraint Gibbs minimization using linear programming techniques. Compositions of phases considered in the calculation are discretized into 'pseudo-compounds' spanning the entire compositional space. Gibbs energies of these discrete compounds are generated for a given range and resolution of pressures for example derived by barometry or from mechanical model predictions. Gibbs energy minimization is subsequently performed considering all compounds of different composition and pressure. In addition to constraining the system composition a certain proportion of the system is constraint at a specified pressure. Input pressure variations need to be discretized and each discrete pressure defines an additional constraint for the minimization. The proportion of the system at each different pressure is equally distributed over the number of input pressures. For example if two input pressures P1 and P2 are specified, two constraints are added: 50 percent of the system is constraint at P1 while the remaining 50 percent is constraint at P2. The method has been tested for a set of 10 input pressures obtained by Tajčmanová et al. (2014) using their unconventional geobarometry method in a plagioclase rim around kyanite. Each input pressure is added as constraint to the minimization (1/10 percent of the system for each discrete pressure). Constraining the system composition to the average composition of the plagioclase rim

  5. Eradication of infectious diseases in heterogeneous populations

    SciTech Connect

    Travis, C.C.; Lenhart, S.M.

    1987-04-01

    A model is presented of infectious disease in heterogeneous populations, which allows for variable intra- to intergroup contact ratios. The authors give necessary and sufficient conditions for disease eradication by means of vaccination. Smallpox is used as an illustrative example.

  6. Heterogeneity and Risk Sharing in Village Economies*

    PubMed Central

    Chiappori, Pierre-André; Samphantharak, Krislert; Schulhofer-Wohl, Sam; Townsend, Robert M.

    2013-01-01

    We show how to use panel data on household consumption to directly estimate households’ risk preferences. Specifically, we measure heterogeneity in risk aversion among households in Thai villages using a full risk-sharing model, which we then test allowing for this heterogeneity. There is substantial, statistically significant heterogeneity in estimated risk preferences. Full insurance cannot be rejected. As the risk sharing, as-if-complete-markets theory might predict, estimated risk preferences are unrelated to wealth or other characteristics. The heterogeneity matters for policy: Although the average household would benefit from eliminating village-level risk, less-risk-averse households who are paid to absorb that risk would be worse off by several percent of household consumption. PMID:24932226

  7. Heterogeneous photocatalytic oxidation of atmospheric trace contaminants

    NASA Technical Reports Server (NTRS)

    Ollis, David F.

    1993-01-01

    Work performed during the period 1 May - 31 Oct. 1992 on heterogeneous photocatalytic oxidation of atmospheric trace contaminants is presented. Topics discussed include photoreactor monolith fundamental studies and monolith reactor operation: batch recirculation system.

  8. Heterogeneous treatment in the variational nodal method

    SciTech Connect

    Fanning, T.H.; Palmiotti, G.

    1995-06-01

    The variational nodal transport method is reduced to its diffusion form and generalized for the treatment of heterogeneous nodes while maintaining nodal balances. Adapting variational methods to heterogeneous nodes requires the ability to integrate over a node with discontinuous cross sections. In this work, integrals are evaluated using composite gaussian quadrature rules, which permit accurate integration while minimizing computing time. Allowing structure within a nodal solution scheme avoids some of the necessity of cross section homogenization, and more accurately defines the intra-nodal flux shape. Ideally, any desired heterogeneity can be constructed within the node; but in reality, the finite set of basis functions limits the practical resolution to which fine detail can be defined within the node. Preliminary comparison tests show that the heterogeneous variational nodal method provides satisfactory results even if some improvements are needed for very difficult, configurations.

  9. Changing Emulsion Dynamics with Heterogeneous Surface Wettability

    NASA Astrophysics Data System (ADS)

    Tsai, Peichun Amy; Meng, Qiang; Zhang, Yali; Li, Jiang; Lammertink, Rob; Chen, Haosheng

    2015-11-01

    We elucidate the effect of heterogeneous surface wettability on the morphology and dynamics of microfluidic emulsions, generated by a co-flowing device. We first design a useful methodology of modifying a micro-capillary with desired heterogeneous wettability, such as alternating hydrophilic and hydrophobic regions. Subsequently, the effects of flow rates and heterogeneous wettability on the emulsion morphology and motion in the micro-capillary are investigated. Our experimental data reveal a universal critical time scale of advective emulsions, above which the microfluidic emulsions remain intact, whereas below this time-scale emulsions become adhesive or inverse. A simple model based on a force balance can be used to explain this critical transition. These results show a control of emulsion dynamics by tuning the droplet size and the Capillary number, the ratio of viscous to surface effects, with heterogeneous surface wettability.

  10. Heterogeneous Clustering: Operational and User Impacts

    NASA Technical Reports Server (NTRS)

    Salm, Saita Wood

    1999-01-01

    Heterogeneous clustering can improve overall utilization of multiple hosts and can provide better turnaround to users by balancing workloads across hosts. Building a cluster requires both operational changes and revisions in user scripts.

  11. Lipid rafts: heterogeneity on the high seas.

    PubMed Central

    Pike, Linda J

    2004-01-01

    Lipid rafts are membrane microdomains that are enriched in cholesterol and glycosphingolipids. They have been implicated in processes as diverse as signal transduction, endocytosis and cholesterol trafficking. Recent evidence suggests that this diversity of function is accompanied by a diversity in the composition of lipid rafts. The rafts in cells appear to be heterogeneous both in terms of their protein and their lipid content, and can be localized to different regions of the cell. This review summarizes the data supporting the concept of heterogeneity among lipid rafts and outlines the evidence for cross-talk between raft components. Based on differences in the ways in which proteins interact with rafts, the Induced-Fit Model of Raft Heterogeneity is proposed to explain the establishment and maintenance of heterogeneity within raft populations. PMID:14662007

  12. Wetting of a chemically heterogeneous surface

    SciTech Connect

    Frink, L.J.; Salinger, A.G.

    1999-03-01

    Theories for inhomogeneous fluids have focused in recent years on wetting, capillary condensation, and solvation forces for model systems where the surface(s) is(are) smooth homogeneous parallel plates, cylinders, or spherical drops. Unfortunately natural systems are more likely to be heterogeneous both in surface shape and surface chemistry. In this paper we discuss the consequences of chemical heterogeneity on wetting. Specifically, a two-dimensional (2D) implementation of a nonlocal density-functional theory is solved for a striped surface model. Both the strength and range of the heterogeneity are varied. Contact angles are calculated, and phase transitions (both the wetting transition and a local layering transition) are located. The wetting properties of the surface are shown to be strongly dependent on the nature of the surface heterogeneity. In addition highly ordered nanoscopic phases are found, and the operational limits for formation of ordered or crystalline phases of nanoscopic extent are discussed. {copyright} {ital 1999 American Institute of Physics.}

  13. Exploring heterogeneous market hypothesis using realized volatility

    NASA Astrophysics Data System (ADS)

    Chin, Wen Cheong; Isa, Zaidi; Mohd Nor, Abu Hassan Shaari

    2013-04-01

    This study investigates the heterogeneous market hypothesis using high frequency data. The cascaded heterogeneous trading activities with different time durations are modelled by the heterogeneous autoregressive framework. The empirical study indicated the presence of long memory behaviour and predictability elements in the financial time series which supported heterogeneous market hypothesis. Besides the common sum-of-square intraday realized volatility, we also advocated two power variation realized volatilities in forecast evaluation and risk measurement in order to overcome the possible abrupt jumps during the credit crisis. Finally, the empirical results are used in determining the market risk using the value-at-risk approach. The findings of this study have implications for informationally market efficiency analysis, portfolio strategies and risk managements.

  14. Dehydrogenation of Formic Acid by Heterogeneous Catalysts.

    PubMed

    Li, Jun; Zhu, Qi-Long; Xu, Qiang

    2015-01-01

    Formic acid has recently been considered as one of the most promising hydrogen storage materials. The basic concept is briefly discussed and the research progress is detailledly reviewed on the dehydrogenation of aqueous formic acid by heterogeneous catalysts. PMID:26507481

  15. HETEROGENOUS PHOTOREACTION OF FORMALDEHYDE WITH HYDROXYL RADICALS

    EPA Science Inventory

    Atmospheric heterogeneous photoreactions occur between formaldehyde and hydroxyl radicals to produce formic acid. hese photoreactions not only occur in clouds, but also in other tropospheric hydrometeors such as precipitation and dew droplets. xperiments were performed by irradia...

  16. Heterogeneity and Risk Sharing in Village Economies.

    PubMed

    Chiappori, Pierre-André; Samphantharak, Krislert; Schulhofer-Wohl, Sam; Townsend, Robert M

    2014-03-01

    We show how to use panel data on household consumption to directly estimate households' risk preferences. Specifically, we measure heterogeneity in risk aversion among households in Thai villages using a full risk-sharing model, which we then test allowing for this heterogeneity. There is substantial, statistically significant heterogeneity in estimated risk preferences. Full insurance cannot be rejected. As the risk sharing, as-if-complete-markets theory might predict, estimated risk preferences are unrelated to wealth or other characteristics. The heterogeneity matters for policy: Although the average household would benefit from eliminating village-level risk, less-risk-averse households who are paid to absorb that risk would be worse off by several percent of household consumption. PMID:24932226

  17. Sparse representation for vehicle recognition

    NASA Astrophysics Data System (ADS)

    Monnig, Nathan D.; Sakla, Wesam

    2014-06-01

    The Sparse Representation for Classification (SRC) algorithm has been demonstrated to be a state-of-the-art algorithm for facial recognition applications. Wright et al. demonstrate that under certain conditions, the SRC algorithm classification performance is agnostic to choice of linear feature space and highly resilient to image corruption. In this work, we examined the SRC algorithm performance on the vehicle recognition application, using images from the semi-synthetic vehicle database generated by the Air Force Research Laboratory. To represent modern operating conditions, vehicle images were corrupted with noise, blurring, and occlusion, with representation of varying pose and lighting conditions. Experiments suggest that linear feature space selection is important, particularly in the cases involving corrupted images. Overall, the SRC algorithm consistently outperforms a standard k nearest neighbor classifier on the vehicle recognition task.

  18. Heavy Lift Launch Vehicle Concept

    NASA Technical Reports Server (NTRS)

    2004-01-01

    During the Space Shuttle development phase, Marshall plarners concluded a Heavy Lift Launch Vehicle (HLLV) would be needed for successful Space Industrialization. Shown here in this 1976's artist's conception is an early version of the HLLV during launch.

  19. Advanced batteries for electric vehicles

    SciTech Connect

    Henriksen, G.L.; DeLuca, W.H.; Vissers, D.R. )

    1994-11-01

    The idea of battery-powered vehicles is an old one that took on new importance during the oil crisis of 1973 and after California passed laws requiring vehicles that would produce no emissions (so-called zero-emission vehicles). In this overview of battery technologies, the authors review the major existing or near-term systems as well as advanced systems being developed for electric vehicle (EV) applications. However, this overview does not cover all the advanced batteries being developed currently throughout the world. Comparative characteristics for the following batteries are given: lead-acid; nickel/cadmium; nickel/iron; nickel/metal hydride; zinc/bromine; sodium/sulfur; sodium/nickel chloride; zinc/air; lithium/iron sulfide; and lithium-polymer.

  20. Dynamics of railway freight vehicles

    NASA Astrophysics Data System (ADS)

    Iwnicki, S. D.; Stichel, S.; Orlova, A.; Hecht, M.

    2015-07-01

    This paper summarises the historical development of railway freight vehicles and how vehicle designers have tackled the difficult challenges of producing running gear which can accommodate the very high tare to laden mass of typical freight wagons whilst maintaining stable running at the maximum required speed and good curving performance. The most common current freight bogies are described in detail and recent improvements in techniques used to simulate the dynamic behaviour of railway vehicles are summarised and examples of how these have been used to improve freight vehicle dynamic behaviour are included. A number of recent developments and innovative components and sub systems are outlined and finally two new developments are presented in more detail: the LEILA bogie and the SUSTRAIL bogie.

  1. EADS Roadmap for Launch Vehicles

    NASA Astrophysics Data System (ADS)

    Eymar, Patrick; Grimard, Max

    2002-01-01

    still think about the future, especially at industry level in order to make the most judicious choices in technologies, vehicle types as well as human resources and facilities specialization (especially after recent merger moves). and production as prime contractor, industrial architect or stage provider have taken benefit of this expertise and especially of all the studies ran under national funding and own financing on reusable vehicles and ground/flight demonstrators have analyzed several scenarios. VEHICLES/ASTRIUM SI strategy w.r.t. launch vehicles for the two next decades. Among the main inputs taken into account of course visions of the market evolutions have been considered, but also enlargement of international cooperations and governments requests and supports (e.g. with the influence of large international ventures). 1 patrick.eymar@lanceurs.aeromatra.com 2

  2. Air cushion vehicles: A briefing

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.; Finnegan, P. M.

    1971-01-01

    Experience and characteristics; the powering, uses, and implications of large air cushion vehicles (ACV); and the conceptual design and operation of a nuclear powered ACV freighter and supporting facilities are described.

  3. 2013 Vehicle Technologies Market Report

    SciTech Connect

    Davis, Stacy Cagle; Williams, Susan E; Boundy, Robert Gary; Moore, Sheila A

    2014-03-01

    This is the fifth edition of this report, which details the major trends in U.S. light-duty vehicle and medium/heavy truck markets as well as the underlying trends that caused them. This report is supported by the U.S. Department of Energy s (DOE) Vehicle Technologies Office (VTO), and, in accord with its mission, pays special attention to the progress of high-efficiency and alternative-fuel technologies. After opening with a discussion of energy and economics, this report features a section each on the light-duty vehicle and heavy/medium truck markets, and concluding with a section each on technology and policy. The first section on Energy and Economics discusses the role of transportation energy and vehicle markets on a national (and even international) scale. For example, Figures 12 through 14 discuss the connections between global oil prices and U.S. GDP, and Figures 21 and 22 show U.S. employment in the automotive sector. The following section examines Light-Duty Vehicle use, markets, manufacture, and supply chains. Figures 24 through 51 offer snapshots of major light-duty vehicle brands in the U.S. and Figures 56 through 64 examine the performance and efficiency characteristics of vehicles sold. The discussion of Medium and Heavy Trucks offers information on truck sales (Figures 73 through 75) and fuel use (Figures 78 through 81). The Technology section offers information on alternative fuel vehicles and infrastructure (Figures 84 through 95), and the Policy section concludes with information on recent, current, and near-future Federal policies like the Corporate Average Fuel Economy standard (Figures 106 through 110). In total, the information contained in this report is intended to communicate a fairly complete understanding of U.S. highway transportation energy through a series of easily digestible nuggets.

  4. World representations for unmanned vehicles

    NASA Astrophysics Data System (ADS)

    Broten, Gregory S.; Monckton, Simon P.; Mackay, David; Collier, Jack

    2007-04-01

    Unmanned vehicles (UxV) operate in numerous environments, with air, ground and marine representing the majority of the implementations. All unmanned vehicles, when traversing unknown space, have similar requirements. They must sense their environment, create a world representation, and, then plan a path that safely avoids obstacles and hazards. Traditionally, each unmanned vehicle class used environment specific assumptions to create a unique world representation that was tailored to it operating environment. Thus, an unmanned aerial vehicle (UAV) used the simplest possible world representation, where all space above the ground plane was free of obstacles. Conversely, an unmanned ground vehicle (UGV) required a world representation that was suitable to its complex and unstructured environment. Such a clear cut differentiation between UAV and UGV environments is no longer valid as UAVs have migrated down to elevations where terrestrial structures are located. Thus, the operating environment for a low flying UAV contains similarities to the environments experienced by UGVs. As a result, the world representation techniques and algorithms developed for UGVs are now applicable to UAVs, since low flying UAVs must sense and represent its world in order to avoid obstacles. Defence R&D Canada (DRDC) conducts research and development in both the UGV and UAV fields. Researchers have developed a platform neutral world representation, based upon a uniform 21/ II-D elevation grid, that is applicable to many UxV classes, including aerial and ground vehicles. This paper describes DRDC's generic world representation, known as the Global Terrain map, and provides an example of unmanned ground vehicle implementation, along with details of it applicability to aerial vehicles.

  5. Tumor heterogeneity and circulating tumor cells.

    PubMed

    Zhang, Chufeng; Guan, Yan; Sun, Yulan; Ai, Dan; Guo, Qisen

    2016-05-01

    In patients with cancer, individualized treatment strategies are generally guided by an analysis of molecular biomarkers. However, genetic instability allows tumor cells to lose monoclonality and acquire genetic heterogeneity, an important characteristic of tumors, during disease progression. Researchers have found that there is tumor heterogeneity between the primary tumor and metastatic lesions, between different metastatic lesions, and even within a single tumor (either primary or metastatic). Tumor heterogeneity is associated with heterogeneous protein functions, which lowers diagnostic precision and consequently becomes an obstacle to determining the appropriate therapeutic strategies for individual cancer patients. With the development of novel testing technologies, an increasing number of studies have attempted to explore tumor heterogeneity by examining circulating tumor cells (CTCs), with the expectation that CTCs may comprehensively represent the full spectrum of mutations and/or protein expression alterations present in the cancer. In addition, this strategy represents a minimally invasive approach compared to traditional tissue biopsies that can be used to dynamically monitor tumor evolution. The present article reviews the potential efficacy of using CTCs to identify both spatial and temporal tumor heterogeneity. This review also highlights current issues in this field and provides an outlook toward future applications of CTCs. PMID:26902424

  6. Heterogeneous reactions in aircraft gas turbine engines

    NASA Astrophysics Data System (ADS)

    Brown, R. C.; Miake-Lye, R. C.; Lukachko, S. P.; Waitz, I. A.

    2002-05-01

    One-dimensional flow models and unity probability heterogeneous rate parameters are used to estimate the maximum effect of heterogeneous reactions on trace species evolution in aircraft gas turbines. The analysis includes reactions on soot particulates and turbine/nozzle material surfaces. Results for a representative advanced subsonic engine indicate the net change in reactant mixing ratios due to heterogeneous reactions is <10-6 for O2, CO2, and H2O, and <10-10 for minor combustion products such as SO2 and NO2. The change in the mixing ratios relative to the initial values is <0.01%. Since these estimates are based on heterogeneous reaction probabilities of unity, the actual changes will be even lower. Thus, heterogeneous chemistry within the engine cannot explain the high conversion of SO2 to SO3 which some wake models require to explain the observed levels of volatile aerosols. Furthermore, turbine heterogeneous processes will not effect exhaust NOx or NOy levels.

  7. Materials properties: heterogeneity and appropriate sampling modes.

    PubMed

    Esbensen, Kim H

    2015-01-01

    The target audience for this Special Section comprises parties related to the food and feed sectors, e.g., field samplers, academic and industrial scientists, laboratory personnel, companies, organizations, regulatory bodies, and agencies who are responsible for sampling, as well as project leaders, project managers, quality managers, supervisors, and directors. All these entities face heterogeneous materials, and the characteristics of heterogeneous materials needs to be competently understood by all of them. Before delivering analytical results for decision-making, one form or other of primary sampling is always necessary, which must counteract the effects of the sampling target heterogeneity. Up to five types of sampling error may arise as a specific sampling process interacts with a heterogeneous material; two sampling errors arise because of the heterogeneity of the sampling target, and three additional sampling errors are produced by the sampling process itself-if not properly understood, reduced, and/or eliminated, which is the role of Theory of Sampling. This paper discusses the phenomenon and concepts involved in understanding, describing, and managing the adverse effects of heterogeneity in sampling. PMID:25807041

  8. 2014 Vehicle Technologies Market Report

    SciTech Connect

    Davis, Stacy Cagle; Diegel, Susan W; Boundy, Robert Gary; Moore, Sheila A

    2015-03-01

    This is the sixth edition of this report, which details the major trends in U.S. light-duty vehicle and medium/heavy truck markets as well as the underlying trends that caused them. This report is supported by the U.S. Department of Energy s (DOE) Vehicle Technologies Office (VTO), and, in accord with its mission, pays special attention to the progress of high-efficiency and alternative-fuel technologies. After opening with a discussion of energy and economics, this report features a section each on the light-duty vehicle and heavy/medium truck markets, and concluding with a section each on technology and policy. The first section on Energy and Economics discusses the role of transportation energy and vehicle markets on a national (and even international) scale. The following section examines Light-Duty Vehicle use, markets, manufacture, and supply chains. The discussion of Medium and Heavy Trucks offers information on truck sales and technologies specific to heavy trucks. The Technology section offers information on alternative fuel vehicles and infrastructure, and the Policy section concludes with information on recent, current, and near-future Federal policies like the Corporate Average Fuel Economy standards. In total, the information contained in this report is intended to communicate a fairly complete understanding of U.S. highway transportation energy through a series of easily digestible tables and figures.

  9. Reusable Launch Vehicle Technology Program

    NASA Technical Reports Server (NTRS)

    Freeman, Delma C., Jr.; Talay, Theodore A.; Austin, R. Eugene

    1996-01-01

    Industry/NASA Reusable Launch Vehicle (RLV) Technology Program efforts are underway to design, test, and develop technologies and concepts for viable commercial launch systems that also satisfy national needs at acceptable recurring costs. Significant progress has been made in understanding the technical challenges of fully reusable launch systems and the accompanying management and operational approaches for achieving a low-cost program. This paper reviews the current status of the Reusable Launch Vehicle Technology Program including the DC-XA, X-33 and X-34 flight systems and associated technology programs. It addresses the specific technologies being tested that address the technical and operability challenges of reusable launch systems including reusable cryogenic propellant tanks, composite structures, thermal protection systems, improved propulsion, and subsystem operability enhancements. The recently concluded DC-XA test program demonstrated some of these technologies in ground and flight tests. Contracts were awarded recently for both the X-33 and X-34 flight demonstrator systems. The Orbital Sciences Corporation X-34 flight test vehicle will demonstrate an air-launched reusable vehicle capable of flight to speeds of Mach 8. The Lockheed-Martin X-33 flight test vehicle will expand the test envelope for critical technologies to flight speeds of Mach 15. A propulsion program to test the X-33 linear aerospike rocket engine using a NASA SR-71 high speed aircraft as a test bed is also discussed. The paper also describes the management and operational approaches that address the challenge of new cost-effective, reusable launch vehicle systems.

  10. Self-propelled vehicle

    SciTech Connect

    Morrison, R.D.

    1986-03-04

    A self-propelled vehicle is described which includes a body and a set of four internal-force generating devices, each device having a central axis about which internal portions thereof rotate, the four devices being configured as two opposed pairs, the two devices of one pair having parallel axes, but turning in opposite directions, the two devices of the other pair also having parallel axes but turning in opposite directions the axes of the one pair being at right angles to the axes of the other pair. Each device consists of: stationary frame means, a stationary sun gear on the frame means, the sun gear being coaxial with the central axis of its respective device, a rotor pivoted about the axis of the sun gear, three crankshafts carried by the rotor at substantially 120/sup 0/ intervals, each having an eccentric portion, for each crankshaft a cylinder in the rotor, a piston mounted for riciprocation in each cylinder, and a connecting rod from the piston to the eccentric portion of the crankshaft, each crankshaft being fixed to rotate with a respective planetary gear, all planetary gears meshing with the sun gear and having the same pitch diameter as the sun gear, whereby any point on the pitch circle of a planetary gear describes a cardioid as the planetary gear rotates around the sun gear once, the crankshaft eccentricity being substantially 1/3 of the pitch radius of a planetary gear, fuel metering means for providing a combustible mixture for the cylinder, ignition means to ignite the combustible mixture in each cylinder, and valve means for admitting the combustible mixture to, and exhausting combustion gases from, each cylinder.

  11. 76 FR 19829 - Clean Alternative Fuel Vehicle and Engine Conversions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-08

    ... include conversions of conventional gasoline or diesel vehicles to hybrid-electric vehicles, and conversions from hybrid-electric vehicles to plug-in hybrid electric vehicles. Since alternative fuel... Parts Manufacturing. 336322 Other Motor Vehicle Electrical and Electronic Equipment...

  12. Optical guidance system for industrial vehicles

    DOEpatents

    Dyer, Robert D.; Eschbach, Eugene A.; Griffin, Jeffrey W.; Lind, Michael A.; Buck, Erville C.; Buck, Roger L.

    1990-01-01

    An automatically guided vehicle system for steering a vehicle. Optical sensing detects an image of a segment of track mounted above the path of the vehicle. Electrical signals corresponding to the position of the track are generated. A control circuit then converts these signals into movements for the steering of the vehicle.

  13. 15 CFR 265.19 - Unattended vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Unattended vehicles. 265.19 Section... Unattended vehicles. No person shall leave a motor vehicle unattended on the site with the engine running or a key in the ignition switch or the vehicle not effectively braked....

  14. 49 CFR 176.134 - Vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Vehicles. 176.134 Section 176.134 Transportation... Class 1 (Explosive) Materials Stowage § 176.134 Vehicles. Closed vehicles may be used to transport Class... requirements relating to the transport of Class 1 (explosive) materials in vehicles....

  15. 43 CFR 423.40 - Vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... addition to the regulations in this part, the regulations governing off-road-vehicle use in 43 CFR part 420... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Vehicles. 423.40 Section 423.40 Public... Vehicles. (a) When operating a vehicle on Reclamation lands and Reclamation projects, you must comply...

  16. 43 CFR 423.40 - Vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... addition to the regulations in this part, the regulations governing off-road-vehicle use in 43 CFR part 420... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Vehicles. 423.40 Section 423.40 Public... Vehicles. (a) When operating a vehicle on Reclamation lands and Reclamation projects, you must comply...

  17. 43 CFR 423.40 - Vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... addition to the regulations in this part, the regulations governing off-road-vehicle use in 43 CFR part 420... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Vehicles. 423.40 Section 423.40 Public... Vehicles. (a) When operating a vehicle on Reclamation lands and Reclamation projects, you must comply...

  18. Explosion proof vehicle for tank inspection

    DOEpatents

    Zollinger, William T.; Klingler, Kerry M.; Bauer, Scott G.

    2012-02-28

    An Explosion Proof Vehicle (EPV) having an interior substantially filled with an inert fluid creating an interior pressure greater than the exterior pressure. One or more flexible tubes provide the inert fluid and one or more electrical conductors from a control system to the vehicle. The vehicle is preferably used in subsurface tank inspection, whereby the vehicle is submerged in a volatile fluid.

  19. 32 CFR 263.7 - Emergency vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Emergency vehicles. 263.7 Section 263.7 National... TRAFFIC AND VEHICLE CONTROL ON CERTAIN DEFENSE MAPPING AGENCY SITES § 263.7 Emergency vehicles. No person shall fail or refuse to yield the right-of-way to an emergency vehicle when operating with siren...

  20. 49 CFR 575.7 - Special vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Special vehicles. 575.7 Section 575.7... 112(d) of the National Traffic and Motor Vehicle Safety Act; General § 575.7 Special vehicles. A manufacturer who produces vehicles having a configuration not available for purchase by the general public...

  1. 36 CFR 327.2 - Vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Vehicles. 327.2 Section 327.2... Vehicles. (a) This section pertains to all vehicles, including, but not limited to, automobiles, trucks, motorcycles, mini-bikes, snowmobiles, dune buggies, all-terrain vehicles, and trailers, campers, bicycles,...

  2. 49 CFR 575.7 - Special vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Special vehicles. 575.7 Section 575.7... 112(d) of the National Traffic and Motor Vehicle Safety Act; General § 575.7 Special vehicles. A manufacturer who produces vehicles having a configuration not available for purchase by the general public...

  3. 32 CFR 263.7 - Emergency vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Emergency vehicles. 263.7 Section 263.7 National... TRAFFIC AND VEHICLE CONTROL ON CERTAIN DEFENSE MAPPING AGENCY SITES § 263.7 Emergency vehicles. No person shall fail or refuse to yield the right-of-way to an emergency vehicle when operating with siren...

  4. 49 CFR 575.7 - Special vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Special vehicles. 575.7 Section 575.7... 112(d) of the National Traffic and Motor Vehicle Safety Act; General § 575.7 Special vehicles. A manufacturer who produces vehicles having a configuration not available for purchase by the general public...

  5. 49 CFR 176.134 - Vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Vehicles. 176.134 Section 176.134 Transportation... Class 1 (Explosive) Materials Stowage § 176.134 Vehicles. Closed vehicles may be used to transport Class... requirements relating to the transport of Class 1 (explosive) materials in vehicles....

  6. 43 CFR 8365.1-3 - Vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... operating a vehicle on the public lands, no person shall exceed posted speed limits, willfully endanger... vehicle is prohibited from operating a motor vehicle in motion, unless the operator and each front seat... by the vehicle operator and any front seat passenger. It also applies on public lands, or...

  7. 32 CFR 263.7 - Emergency vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Emergency vehicles. 263.7 Section 263.7 National... TRAFFIC AND VEHICLE CONTROL ON CERTAIN DEFENSE MAPPING AGENCY SITES § 263.7 Emergency vehicles. No person shall fail or refuse to yield the right-of-way to an emergency vehicle when operating with siren...

  8. Method and system for vehicle refueling

    DOEpatents

    Surnilla, Gopichandra; Leone, Thomas G; Prasad, Krishnaswamy Venkatesh; Argarwal, Apoorv; Hinds, Brett Stanley

    2012-11-20

    Methods and systems are provided for facilitating refueling operations in vehicles operating with multiple fuels. A vehicle operator may be assisted in refueling the multiple fuel tanks of the vehicle by being provided one or more refueling profiles that take into account the vehicle's future trip plans, the predicted environmental conditions along a planned route, and the operator's preferences.

  9. Method and system for vehicle refueling

    DOEpatents

    Surnilla, Gopichandra; Leone, Thomas G; Prasad, Krishnaswamy Venkatesh; Agarwal, Apoorv; Hinds, Brett Stanley

    2014-06-10

    Methods and systems are provided for facilitating refueling operations in vehicles operating with multiple fuels. A vehicle operator may be assisted in refueling the multiple fuel tanks of the vehicle by being provided one or more refueling profiles that take into account the vehicle's future trip plans, the predicted environmental conditions along a planned route, and the operator's preferences.

  10. Orbital-Transfer Vehicle With Aerodynamic Braking

    NASA Technical Reports Server (NTRS)

    Scott, C. D.; Nagy, K.; Roberts, B. B.; Ried, R. C.; Kroll, K.; Gamble, J.

    1986-01-01

    Vehicle includes airbrake for deceleration into lower orbit. Report describes vehicle for carrying payloads between low and high orbits around Earth. Vehicle uses thin, upper atmosphere for braking when returning to low orbit. Since less propellant needed than required for full retrorocket braking, vehicle carries larger payload and therefore reduces cost of space transportation.

  11. Regional Heterogenity In Ceres' Subsurface

    NASA Astrophysics Data System (ADS)

    Raymond, Carol A.; Marchi, Simone; Bland, Michael T.; Castillo-Rogez, Julie C.; Park, Ryan S.; Russell, Christopher T.; Hughson, Kynan G.; Scully, Jennifer E. C.

    2016-04-01

    subdued or degraded rims. Regional-scale variations in roughness and cratering could be caused by varia-bility in the viscosity of the volatile-rich shell, or could reflect a resurfacing process. However, these two processes would yield differences that would help to distinguish them. In the case of relaxation, the degree of crater obilitera-tion would be a function of crater size and age, and possibly would vary with latitude (temperature). If caused by resurfacing, the crater size frequency distribution would be similar to but offset with respect to that of the surround-ing terrains. Some correlation is seen between variations in the visible spectrum and the areas of smooth terrain. In either case, relaxation or resurfacing would indicate an internal process that resulted in primordial heterogeneity in the volatile-rich shell, or subsequent convective processes that drove regional resurfacing.

  12. Using Natural Language to Enable Mission Managers to Control Multiple Heterogeneous UAVs

    NASA Technical Reports Server (NTRS)

    Trujillo, Anna C.; Puig-Navarro, Javier; Mehdi, S. Bilal; Mcquarry, A. Kyle

    2016-01-01

    The availability of highly capable, yet relatively cheap, unmanned aerial vehicles (UAVs) is opening up new areas of use for hobbyists and for commercial activities. This research is developing methods beyond classical control-stick pilot inputs, to allow operators to manage complex missions without in-depth vehicle expertise. These missions may entail several heterogeneous UAVs flying coordinated patterns or flying multiple trajectories deconflicted in time or space to predefined locations. This paper describes the functionality and preliminary usability measures of an interface that allows an operator to define a mission using speech inputs. With a defined and simple vocabulary, operators can input the vast majority of mission parameters using simple, intuitive voice commands. Although the operator interface is simple, it is based upon autonomous algorithms that allow the mission to proceed with minimal input from the operator. This paper also describes these underlying algorithms that allow an operator to manage several UAVs.

  13. Electric vehicle performance in 1994 DOE competitions

    SciTech Connect

    Quong, S.; Duoba, M.; Larsen, R.; LeBlanc, N.; Gonzales, R.; Buitrago, C.

    1995-06-01

    The US Department of Energy (DOE) through Argonne National Laboratory sponsored and recorded energy data of electric vehicles (EVs) at five competitions in 1994. Each competition provided different test conditions (closed-track, on-road, and dynamometer). The data gathered at these competitions includes energy efficiency, range, acceleration, and vehicle characteristics. The results of the analysis show that the vehicles performed as expected. Some of the EVs were also tested on dynamometers and compared to gasoline vehicles, including production vehicles with advanced battery systems. Although the EVs performed well at these competitions, the results show that only the vehicles with advanced technologies perform as well or better than conventional gasoline vehicles.

  14. Electric vehicle performance in 1994 DOE competitions

    NASA Astrophysics Data System (ADS)

    Quong, Spencer; Duoba, Michael; Larsen, Robert; Leblanc, Nicole; Gonzales, Richard; Buitrago, Carlos

    The US Department of Energy (DOE) through Argonne National Laboratory sponsored and recorded energy data of electric vehicles (EV's) at five competitions in 1994. Each competition provided different test conditions (closed-track, on-road, and dynamometer). The data gathered at these competitions includes energy efficiency, range, acceleration, and vehicle characteristics. The results of the analysis show that the vehicles performed as expected. Some of the EV's were also tested on dynamometers and compared to gasoline vehicles, including production vehicles with advanced battery systems. Although the EV's performed well at these competitions, the results show that only the vehicles with advanced technologies perform as well or better than conventional gasoline vehicles.

  15. Protection against malevolent use of vehicles at Nuclear Power Plants. Vehicle barrier system selection guidance

    SciTech Connect

    Nebuda, D.T.

    1994-08-01

    This manual provides a simplified procedure for selecting land vehicle barriers that will stop the design basis vehicle threat adopted by the U.S. Nuclear Regulatory Commission. Proper selection and construction of vehicle barriers should prevent intrusion of the design basis vehicle. In addition, vital safety related equipment should survive a design basis vehicle bomb attack when vehicle barriers are properly selected, sited, and constructed. This manual addresses passive vehicle barriers, active vehicle barriers, and site design features that can be used to reduce vehicle impact velocity.

  16. A green vehicle routing problem with customer satisfaction criteria

    NASA Astrophysics Data System (ADS)

    Afshar-Bakeshloo, M.; Mehrabi, A.; Safari, H.; Maleki, M.; Jolai, F.

    2016-08-01

    This paper develops an MILP model, named Satisfactory-Green Vehicle Routing Problem. It consists of routing a heterogeneous fleet of vehicles in order to serve a set of customers within predefined time windows. In this model in addition to the traditional objective of the VRP, both the pollution and customers' satisfaction have been taken into account. Meanwhile, the introduced model prepares an effective dashboard for decision-makers that determines appropriate routes, the best mixed fleet, speed and idle time of vehicles. Additionally, some new factors evaluate the greening of each decision based on three criteria. This model applies piecewise linear functions (PLFs) to linearize a nonlinear fuzzy interval for incorporating customers' satisfaction into other linear objectives. We have presented a mixed integer linear programming formulation for the S-GVRP. This model enriches managerial insights by providing trade-offs between customers' satisfaction, total costs and emission levels. Finally, we have provided a numerical study for showing the applicability of the model.

  17. Robust analysis of an underwater navigational strategy in electrically heterogeneous corridors.

    PubMed

    Dimble, Kedar D; Ranganathan, Badri N; Keshavan, Jishnu; Humbert, J Sean

    2016-01-01

    Obstacles and other global stimuli provide relevant navigational cues to a weakly electric fish. In this work, robust analysis of a control strategy based on electrolocation for performing obstacle avoidance in electrically heterogeneous corridors is presented and validated. Static output feedback control is shown to achieve the desired goal of reflexive obstacle avoidance in such environments in simulation and experimentation. The proposed approach is computationally inexpensive and readily implementable on a small scale underwater vehicle, making underwater autonomous navigation feasible in real-time. PMID:27478091

  18. 41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 41 Public Contracts and Property Management 3 2014-01-01 2014-01-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle...

  19. 41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 41 Public Contracts and Property Management 3 2012-01-01 2012-01-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle...

  20. Prevention of motor‐vehicle deaths by changing vehicle factors

    PubMed Central

    Robertson, Leon S

    2007-01-01

    Objective To estimate the effect of changing vehicle factors to reduce mortality in a comprehensive study. Design/methods Odds of death in the United States during 2000–2005 were analyzed, involving specific makes and models of 1999–2005 model year cars, minivans, and sport utility vehicles using logistic regression after selection of factors to be included by examination of least‐squares correlations of vehicle factors to maximize independence of predictors. Based on the regression coefficients, percentages of deaths preventable by changes in selected factors were calculated. Correlations of vehicle characteristics to environmental and behavioral risk factors were also examined to assess any potential confounding. Results Deaths in the studied vehicles would have been 42% lower had all had electronic stability control (ESC) systems. Improved crashworthiness as measured by offset frontal and side crash tests would have produced an additional 28% reduction, and static stability improvement would have reduced the deaths 11%. Although weight–power that reduces fuel economy is associated with lower risk to drivers, it increases risk of deaths to pedestrians and bicyclists but has an overall minor effect compared to the other factors. Conclusion A large majority of motor‐vehicle‐related fatalities could be avoided by universal adoption of the most effective technologies. PMID:17916886

  1. Vehicle Disturbance Test

    NASA Astrophysics Data System (ADS)

    Clapp, Brian

    2001-07-01

    The Vehicle Disturbance Test {VDT} is used to characterize uncompensated environmental disturbances acting upon the HST during normal operation. The VDT is a passive test {not a forced-response test} used to obtain signatures for both externally induced {e.g. SA-3} and internally induced {e.g. NCC and ACS mechanisms} disturbances for comparison with past VDT results. The disturbances observed will be used as the nominal on-orbit disturbances in pointing control simulations until the next VDT is run. The test occurs after release, and most of the VDT can be run during the BEA period. The -V1 sunpoint portion of the VDT occurs after the BEA period is complete. The VDT shall consist of five separate tests that need not occur consecutively. The overall duration of the VDT tests is at least 17 orbits of spacecraft time including {1} at least 1 full orbit at +V3 sunpoint prior to NCS CPL turn-on while performing ACS mechanism motions simulating routine flight operations, {2} at least 5 full orbits at +V3 sunpoint prior to NCS CPL turn-on, {3} at least 1 full orbit at +V3 sunpoint during NCC startup, {4} at least 5 full orbits at +V3 sunpoint while NCC is operating at steady-state, and {5} at least 5 full orbits at -V1 sunpoint with the NCC operating at steady-state. Each test is initiated via SMS execution of stored program macros in the HST flight computer to switch the attitude control law gains to low-bandwidth maneuver gains, command the gyros into low mode, terminate Velocity aberration and parallax {VAP} processing, and modify flight computer diagnostic mnemonics to display the roll component of DVTHEP. The nominal attitude control law configuration will be restored at the end of each test via SMS execution of stored program macros. The stored program command macros are developed specifically for the VDT by the Flight Software and Pointing Control System groups.

  2. Overview of medium heterogeneity and transport processes

    SciTech Connect

    Tsang, Y.; Tsang, C.F.

    1993-11-01

    Medium heterogeneity can have significant impact on the behavior of solute transport. Tracer breakthrough curves from transport in a heterogeneous medium are distinctly different from that in a homogeneous porous medium. Usually the shape of the breakthrough curves are highly non-symmetrical with a fast rise at early times and very long tail at late times, and often, they consist of multiple peaks. Moreover, unlike transport in a homogeneous medium where the same transport parameters describe the entire medium, transport through heterogeneous media gives rise to breakthrough curves which have strong spatial dependence. These inherent characteristics of transport in heterogeneous medium present special challenge to the performance assessment of a potential high level nuclear waste repository with respect to the possible release of radio nuclides to the accessible environment. Since an inherently desirable site characteristic for a waste repository is that flow and transport should be slow, then transport measurements in site characterization efforts will necessarily be spatially small and temporally short compare to the scales which are of relevance to performance assessment predictions. In this paper we discuss the role of medium heterogeneity in site characterization and performance assessment. Our discussion will be based on a specific example of a 3D heterogeneous stochastic model of a site generally similar to, the Aespoe Island, the site of the Hard Rock Laboratory in Southern Sweden. For our study, alternative 3D stochastic fields of hydraulic conductivities conditioned on ``point`` measurements shall be generated. Results of stochastic flow and transport simulations would be used to address the issues of (1) the relationship of tracer breakthrough with the structure of heterogeneity, and (2) the inference from small scale testing results to large scale and long term predictions.

  3. Molecular-Level Design of Heterogeneous Chiral Catalysis

    SciTech Connect

    Francisco Zaera

    2012-03-21

    The following is a proposal to continue our multi-institutional research on heterogeneous chiral catalysis. Our team combines the use of surface-sensitive analytical techniques for the characterization of model systems with quantum and statistical mechanical calculations to interpret experimental data and guide the design of future research. Our investigation focuses on the interrelation among the three main mechanisms by which enantioselectivity can be bestowed to heterogeneous catalysts, namely: (1) by templating chirality via the adsorption of chiral supramolecular assemblies, (2) by using chiral modifiers capable of forming chiral complexes with the reactant and force enantioselective surface reactions, and (3) by forming naturally chiral surfaces using imprinting chiral agents. Individually, the members of our team are leaders in these various aspects of chiral catalysis, but the present program provides the vehicle to generate and exploit the synergies necessary to address the problem in a comprehensive manner. Our initial work has advanced the methodology needed for these studies, including an enantioselective titration procedure to identify surface chiral sites, infrared spectroscopy in situ at the interface between gases or liquids and solids to mimic realistic catalytic conditions, and DFT and Monte Carlo algorithms to simulate and understand chirality on surfaces. The next step, to be funded by the monies requested in this proposal, is to apply those methods to specific problems in chiral catalysis, including the identification of the requirements for the formation of supramolecular surface structures with enantioselective behavior, the search for better molecules to probe the chiral nature of the modified surfaces, the exploration of the transition from supramolecular to one-to-one chiral modification, the correlation of the adsorption characteristics of one-to-one chiral modifiers with their physical properties, in particular with their configuration

  4. 2011 Vehicle Technologies Market Report

    SciTech Connect

    Davis, Stacy Cagle; Boundy, Robert Gary; Diegel, Susan W

    2012-02-01

    This report details the major trends in U.S. light-duty vehicle and medium/heavy truck markets as well as the underlying trends that caused them. This report is supported by the U.S. Department of Energy s (DOE) Vehicle Technologies Program (VTP), and, in accord with its mission, pays special attention to the progress of high-efficiency and alternative-fuel technologies. This third edition since this report was started in 2008 offers several marked improvements relative to its predecessors. Most significantly, where earlier editions of this report focused on supplying information through an examination of market drivers, new vehicle trends, and supplier data, this edition uses a different structure. After opening with a discussion of energy and economics, this report features a section each on the light-duty vehicle and heavy/medium truck markets, and concluding with a section each on technology and policy. In addition to making this sectional re-alignment, this year s edition of the report also takes a different approach to communicating information. While previous editions relied heavily on text accompanied by auxiliary figures, this third edition relies primarily on charts and graphs to communicate trends. Any accompanying text serves to introduce the trends communication by the graphic and highlight any particularly salient observations. The opening section on Energy and Economics discusses the role of transportation energy and vehicle markets on a national (and even international) scale. For example, Figures 11 through 13 discuss the connections between global oil prices and U.S. GDP, and Figures 20 and 21 show U.S. employment in the automotive sector. The following section examines Light-Duty Vehicle use, markets, manufacture, and supply chains. Figures 26 through 33 offer snapshots of major light-duty vehicle brands in the U.S. and Figures 38 through 43 examine the performance and efficiency characteristics of vehicles sold. The discussion of Medium and

  5. Heterogeneous physicochemistry of the winter polar stratosphere

    NASA Technical Reports Server (NTRS)

    Turco, R. P.; Toon, O. B.

    1988-01-01

    Present chemical theories of the Antarctic ozone hole assume that heterogeneous reactions involving polar stratospheric clouds (PSCs) are the precursor of springtime ozone depletions. However, none of the theories quantify the rates of proposed heterogeneous processed, and none utilize the extensive data base on PSC's. Thus, all of the theories must be considered incomplete until the heterogeneous mechanisms are properly defined. A unified treatment developed of the cloud related processes, both physical and chemical, and the importance of these processes using observation data is calibrated. The rates are compared competitive heterogeneous processes to place reasonable limits on critical mechanisms such as the denitrification and dechlorination of the polar winter stratosphere. Among the subjects addressed here are the physical/chemical properties of PSC's including their relevant microphysical, optical and compositional characteristics, mass transfer rates of gaseous constituents to cloud particles, adsorption, accommodation and sticking coefficients on cloud particles, time constants for condensation, absorption and other microphysical processes, effects of solubility and vapor pressure on cloud composition, the statistics of cloud processing of chemically active condensible species, rate limiting steps in heterogeneous chemical reactions, and the nonlinear dependence of ozone loss on physical and chemical parameters.

  6. Computational model of heterogeneous heating in melanin

    NASA Astrophysics Data System (ADS)

    Kellicker, Jason; DiMarzio, Charles A.; Kowalski, Gregory J.

    2015-03-01

    Melanin particles often present as an aggregate of smaller melanin pigment granules and have a heterogeneous surface morphology. When irradiated with light within the absorption spectrum of melanin, these heterogeneities produce measurable concentrations of the electric field that result in temperature gradients from thermal effects that are not seen with spherical or ellipsoidal modeling of melanin. Modeling melanin without taking into consideration the heterogeneous surface morphology yields results that underestimate the strongest signals or over{estimate their spatial extent. We present a new technique to image phase changes induced by heating using a computational model of melanin that exhibits these surface heterogeneities. From this analysis, we demonstrate the heterogeneous energy absorption and resulting heating that occurs at the surface of the melanin granule that is consistent with three{photon absorption. Using the three{photon dluorescence as a beacon, we propose a method for detecting the extents of the melanin granule using photothermal microscopy to measure the phase changes resulting from the heating of the melanin.

  7. Heterogeneity of liver cancer and personalized therapy.

    PubMed

    Li, Liang; Wang, Hongyang

    2016-09-01

    Liver cancer is an extraordinarily heterogeneous malignant disease among the tumors that have so far been identified. Hepatocellular carcinoma (HCC) arises most frequently in the setting of chronic liver inflammation and fibrosis, and takes a variety of course in individual patients to process to tumor. The risk factors such as HBV and/or HCV infections, aflatoxin infection, abuse alcohol intake, metabolic syndrome, obesity and diabetes are closely related to the environmental and genetic susceptibilities to HCC. The consequent resulting genomic instability, molecular and signal transduction network disorders and microenvironmental discrepancies are characterized by the extraordinary heterogeneity of liver cancer. The histology-based definition of the morphological heterogeneity of liver cancer has been modified and refined to treat patients with targeted therapies, but this still cannot solve all the problems. Lack of consistent outcome for anticancer agents and conventional therapies in liver cancer treatment calls for assessing the benefits of new molecularly targeted drugs and combined therapy, under the heterogeneity condition of tumor. The present review article will provide the complex mechanism and phenotype of liver cancer heterogeneity, and help us to execute precision medicine in a really personalized manner. PMID:26213370

  8. On the origin of sperm epigenetic heterogeneity.

    PubMed

    Laurentino, Sandra; Borgmann, Jennifer; Gromoll, Jörg

    2016-05-01

    The influence of epigenetic modifications on reproduction and on the function of male germ cells has been thoroughly demonstrated. In particular, aberrant DNA methylation levels in sperm have been associated with abnormal sperm parameters, lower fertilization rates and impaired embryo development. Recent reports have indicated that human sperm might be epigenetically heterogeneous and that abnormal DNA methylation levels found in the sperm of infertile men could be due to the presence of sperm populations with different epigenetic quality. However, the origin and the contribution of different germ cell types to this suspected heterogeneity remain unclear. In this review, we focus on sperm epigenetics at the DNA methylation level and its importance in reproduction. We take into account the latest developments and hypotheses concerning the functional significance of epigenetic heterogeneity coming from the field of stem cell and cancer biology and discuss the potential importance and consequences of sperm epigenetic heterogeneity for reproduction, male (in)fertility and assisted reproductive technologies (ART). Based on the current information, we propose a model in which spermatogonial stem cell variability, either intrinsic or due to external factors (such as endocrine action and environmental stimuli), can lead to epigenetic sperm heterogeneity, sperm epimutations and male infertility. The elucidation of the precise causes for epimutations, the conception of adequate therapeutic options and the development of sperm selection technologies based on epigenetic quality should be regarded as crucial to the improvement of ART outcome in the near future. PMID:26884419

  9. Implications of Heterogeneity in Multiple Myeloma

    PubMed Central

    de Mel, Sanjay; Lim, Su Hong; Tung, Moon Ley; Chng, Wee-Joo

    2014-01-01

    Multiple myeloma is the second most common hematologic malignancy in the world. Despite improvement in outcome, the disease is still incurable for most patients. However, not all myeloma are the same. With the same treatment, some patients can have very long survival whereas others can have very short survival. This suggests that there is underlying heterogeneity in myeloma. Studies over the years have revealed multiple layers of heterogeneity. First, clinical parameters such as age and tumor burden could significantly affect outcome. At the genetic level, there are also significant heterogeneity ranging for chromosome numbers, genetic translocations, and genetic mutations. At the clonal level, there appears to be significant clonal heterogeneity with multiple clones coexisting in the same patient. At the cell differentiation level, there appears to be a hierarchy of clonally related cells that have different clonogenic potential and sensitivity to therapies. These levels of complexities present challenges in terms of treatment and prognostication as well as monitoring of treatment. However, if we can clearly delineate and dissect this heterogeneity, we may also be presented with unique opportunities for precision and personalized treatment of myeloma. Some proof of concepts of such approaches has been demonstrated. PMID:25101266

  10. Multiscale hyporheic exchange through strongly heterogeneous sediments

    NASA Astrophysics Data System (ADS)

    Pryshlak, Timothy T.; Sawyer, Audrey H.; Stonedahl, Susa H.; Soltanian, Mohamad Reza

    2015-11-01

    Heterogeneity in hydraulic conductivity (K) and channel morphology both control surface water-groundwater exchange (hyporheic exchange), which influences stream ecosystem processes and biogeochemical cycles. Here we show that heterogeneity in K is the dominant control on exchange rates, residence times, and patterns in hyporheic zones with abrupt lithologic contrasts. We simulated hyporheic exchange in a representative low-gradient stream with 300 different bimodal K fields composed of sand and silt. Simulations span five sets of sand-silt ratios and two sets of low and high K contrasts (1 and 3 orders of magnitude). Heterogeneity increases interfacial flux by an order of magnitude relative to homogeneous cases, drastically changes the shape of residence time distributions, and decreases median residence times. The positioning of highly permeable sand bodies controls patterns of interfacial flux and flow paths. These results are remarkably different from previous studies of smooth, continuous K fields that indicate only moderate effects on hyporheic exchange. Our results also show that hyporheic residence times are least predictable when sand body connectivity is low. As sand body connectivity increases, the expected residence time distribution (ensemble average for a given sand-silt ratio) remains approximately constant, but the uncertainty around the expectation decreases. Including strong heterogeneity in hyporheic models is imperative for understanding hyporheic fluxes and solute transport. In streams with strongly heterogeneous sediments, characterizing lithologic structure is more critical for predicting hyporheic exchange metrics than characterizing channel morphology.

  11. Consumer Vehicle Choice Model Documentation

    SciTech Connect

    Liu, Changzheng; Greene, David L

    2012-08-01

    In response to the Fuel Economy and Greenhouse Gas (GHG) emissions standards, automobile manufacturers will need to adopt new technologies to improve the fuel economy of their vehicles and to reduce the overall GHG emissions of their fleets. The U.S. Environmental Protection Agency (EPA) has developed the Optimization Model for reducing GHGs from Automobiles (OMEGA) to estimate the costs and benefits of meeting GHG emission standards through different technology packages. However, the model does not simulate the impact that increased technology costs will have on vehicle sales or on consumer surplus. As the model documentation states, “While OMEGA incorporates functions which generally minimize the cost of meeting a specified carbon dioxide (CO2) target, it is not an economic simulation model which adjusts vehicle sales in response to the cost of the technology added to each vehicle.” Changes in the mix of vehicles sold, caused by the costs and benefits of added fuel economy technologies, could make it easier or more difficult for manufacturers to meet fuel economy and emissions standards, and impacts on consumer surplus could raise the costs or augment the benefits of the standards. Because the OMEGA model does not presently estimate such impacts, the EPA is investigating the feasibility of developing an adjunct to the OMEGA model to make such estimates. This project is an effort to develop and test a candidate model. The project statement of work spells out the key functional requirements for the new model.

  12. An Integrated Vehicle Modeling Environment

    NASA Technical Reports Server (NTRS)

    Totah, Joseph J.; Kinney, David J.; Kaneshige, John T.; Agabon, Shane

    1999-01-01

    This paper describes an Integrated Vehicle Modeling Environment for estimating aircraft geometric, inertial, and aerodynamic characteristics, and for interfacing with a high fidelity, workstation based flight simulation architecture. The goals in developing this environment are to aid in the design of next generation intelligent fight control technologies, conduct research in advanced vehicle interface concepts for autonomous and semi-autonomous applications, and provide a value-added capability to the conceptual design and aircraft synthesis process. Results are presented for three aircraft by comparing estimates generated by the Integrated Vehicle Modeling Environment with known characteristics of each vehicle under consideration. The three aircraft are a modified F-15 with moveable canards attached to the airframe, a mid-sized, twin-engine commercial transport concept, and a small, single-engine, uninhabited aerial vehicle. Estimated physical properties and dynamic characteristics are correlated with those known for each aircraft over a large portion of the flight envelope of interest. These results represent the completion of a critical step toward meeting the stated goals for developing this modeling environment.

  13. X-34 Vehicle Aerodynamic Characteristics

    NASA Technical Reports Server (NTRS)

    Brauckmann, Gregory J.

    1998-01-01

    The X-34, being designed and built by the Orbital Sciences Corporation, is an unmanned sub-orbital vehicle designed to be used as a flying test bed to demonstrate key vehicle and operational technologies applicable to future reusable launch vehicles. The X-34 will be air-launched from an L-1011 carrier aircraft at approximately Mach 0.7 and 38,000 feet altitude, where an onboard engine will accelerate the vehicle to speeds above Mach 7 and altitudes to 250,000 feet. An unpowered entry will follow, including an autonomous landing. The X-34 will demonstrate the ability to fly through inclement weather, land horizontally at a designated site, and have a rapid turn-around capability. A series of wind tunnel tests on scaled models was conducted in four facilities at the NASA Langley Research Center to determine the aerodynamic characteristics of the X-34. Analysis of these test results revealed that longitudinal trim could be achieved throughout the design trajectory. The maximum elevon deflection required to trim was only half of that available, leaving a margin for gust alleviation and aerodynamic coefficient uncertainty. Directional control can be achieved aerodynamically except at combined high Mach numbers and high angles of attack, where reaction control jets must be used. The X-34 landing speed, between 184 and 206 knots, is within the capabilities of the gear and tires, and the vehicle has sufficient rudder authority to control the required 30-knot crosswind.

  14. Reusable Launch Vehicle Technology Program

    NASA Technical Reports Server (NTRS)

    Freeman, Delma C., Jr.; Talay, Theodore A.; Austin, R. Eugene

    1997-01-01

    Industry/NASA reusable launch vehicle (RLV) technology program efforts are underway to design, test, and develop technologies and concepts for viable commercial launch systems that also satisfy national needs at acceptable recurring costs. Significant progress has been made in understanding the technical challenges of fully reusable launch systems and the accompanying management and operational approaches for achieving a low cost program. This paper reviews the current status of the RLV technology program including the DC-XA, X-33 and X-34 flight systems and associated technology programs. It addresses the specific technologies being tested that address the technical and operability challenges of reusable launch systems including reusable cryogenic propellant tanks, composite structures, thermal protection systems, improved propulsion and subsystem operability enhancements. The recently concluded DC-XA test program demonstrated some of these technologies in ground and flight test. Contracts were awarded recently for both the X-33 and X-34 flight demonstrator systems. The Orbital Sciences Corporation X-34 flight test vehicle will demonstrate an air-launched reusable vehicle capable of flight to speeds of Mach 8. The Lockheed-Martin X-33 flight test vehicle will expand the test envelope for critical technologies to flight speeds of Mach 15. A propulsion program to test the X-33 linear aerospike rocket engine using a NASA SR-71 high speed aircraft as a test bed is also discussed. The paper also describes the management and operational approaches that address the challenge of new cost effective, reusable launch vehicle systems.

  15. Passive detection of vehicle loading

    NASA Astrophysics Data System (ADS)

    McKay, Troy R.; Salvaggio, Carl; Faulring, Jason W.; Salvaggio, Philip S.; McKeown, Donald M.; Garrett, Alfred J.; Coleman, David H.; Koffman, Larry D.

    2012-01-01

    The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

  16. PASSIVE DETECTION OF VEHICLE LOADING

    SciTech Connect

    Garrett, A.

    2012-01-03

    The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

  17. Motor vehicle safety during pregnancy

    PubMed Central

    Vladutiu, Catherine J.; Weiss, Harold B.

    2013-01-01

    Motor vehicle crashes during pregnancy are the leading cause of traumatic fetal mortality and serious maternal injury morbidity and mortality in the United States, injuring approximately 92,500 pregnant women each year. Little is known about the circumstances surrounding these crash events and the maternal characteristics that may increase women’s vulnerability to crash-related injuries during pregnancy. Even less is known about the effects of crashes on fetal outcomes. Crash simulation studies using female anthropomorphic test devices and computational models have been conducted to better understand the mechanisms of maternal and fetal injuries and death resulting from motor vehicle crashes. In addition, several case reports describing maternal and fetal outcomes following crashes have been published in the literature. Only a few population-based studies have explored the association between motor vehicle crashes and adverse maternal and/or fetal outcomes and even fewer have examined the effectiveness of seat belts and/or airbags in reducing the risk of these outcomes. This paper reviews what is presently known about motor vehicle crashes during pregnancy, their effects on maternal and fetal outcomes, and the role of vehicle safety devices and other safety approaches in mitigating the occurrence and severity of maternal crashes and subsequent injuries. In addition, this paper suggests interventions targeted towards the prevention of crashes during pregnancy. PMID:23710161

  18. Electric and hybrid vehicles program

    NASA Astrophysics Data System (ADS)

    1990-04-01

    This thirteenth annual report on the implementation of the Electric and Hybrid Vehicle Research, Development and Demonstration Act of 1976 (Public Law 94-413), referred to as the Act, complies with the reporting requirements established in section 14 of the Act. In addition to informing Congress of the progress and plans of the Department of Energy's Electric and Hybrid Vehicles Program, this report is intended to serve as a communication link between the Department and all of the public and private interests involved in making the program a success. During FY 1989, significant progress was made in this program. There has been continuing interest shown by both the automobile manufacturers and supply sectors of our economy in electric and hybrid vehicles. The three major domestic automobile manufacturers all are devoting some effort towards electric vehicles. Their participation includes cost-shared contracts with Department of Energy and the Electric Power Research Institute as well as independently funded activities. Research and development efforts in batteries and propulsion components continue to achieve significant progress in providing industry with technology that will result in vehicles that will be more economically competitive.

  19. Reusable launch vehicle technology program

    NASA Astrophysics Data System (ADS)

    Freeman, Delma C.; Talay, Theodore A.; Austin, R. Eugene

    Industry/NASA reusable launch vehicle (RLV) technology program efforts are underway to design, test, and develop technologies and concepts for viable commercial launch systems that also satisfy national needs at acceptable recurring costs. Significant progress has been made in understanding the technical challenges of fully reusable launch systems and the accompanying management and operational approaches for achieving a low-cost program. This paper reviews the current status of the RLV technology program including the DC-XA, X-33 and X-34 flight systems and associated technology programs. It addresses the specific technologies being tested that address the technical and operability challenges of reusable launch systems including reusable cryogenic propellant tanks, composite structures, thermal protection systems, improved propulsion, and subsystem operability enhancements. The recently concluded DC-XA test program demonstrated some of these technologies in ground and flight tests. Contracts were awarded recently for both the X-33 and X-34 flight demonstrator systems. The Orbital Sciences Corporation X-34 flight test vehicle will demonstrate an air-launched reusable vehicle capable of flight to speeds of Mach 8. The Lockheed-Martin X-33 flight test vehicle will expand the test envelope for critical technologies to flight speeds of Mach 15. A propulsion program to test the X-33 linear aerospike rocket engine using a NASA SR-71 high speed aircraft as a test bed is also discussed. The paper also describes the management and operational approaches that address the challenge of new cost-effective, reusable launch vehicle systems.

  20. Vehicle security apparatus and method

    DOEpatents

    Veligdan, James T.

    1996-02-13

    A vehicle security apparatus for use in a motor vehicle, the apparatus comprising an optical key, a receptacle, a receiver and at least one optical fiber. The optical key has a transmitter having at least one first preprogrammed coded signal stored in a first electric circuit. The receptacle receives the optical key and at least one transmittable coded optical signal from the transmitter corresponding to the at least one preprogrammed coded signal stored in the first electric circuit. The receiver compares the at least one transmittable coded optical signal to at least one second preprogrammed coded signal stored in a second electric circuit and the receiver is adapted to trigger switching effects for at least one of enabling starting the motor vehicle and starting the motor vehicle upon determination that the at least one transmittable coded optical signal corresponds to the at least one second preprogrammed signal in the second electric circuit. The at least one optical fiber is operatively connected between the receptacle and the receiver for carrying the optical signal from the receptacle to the receiver. Also disclosed is a method for permitting only authorized use of a motor vehicle.

  1. Vehicle security apparatus and method

    DOEpatents

    Veligdan, J.T.

    1996-02-13

    A vehicle security apparatus for use in a motor vehicle is disclosed, the apparatus comprising an optical key, a receptacle, a receiver and at least one optical fiber. The optical key has a transmitter having at least one first preprogrammed coded signal stored in a first electric circuit. The receptacle receives the optical key and at least one transmittable coded optical signal from the transmitter corresponding to the at least one preprogrammed coded signal stored in the first electric circuit. The receiver compares the at least one transmittable coded optical signal to at least one second preprogrammed coded signal stored in a second electric circuit and the receiver is adapted to trigger switching effects for at least one of enabling starting the motor vehicle and starting the motor vehicle upon determination that the at least one transmittable coded optical signal corresponds to the at least one second preprogrammed signal in the second electric circuit. The at least one optical fiber is operatively connected between the receptacle and the receiver for carrying the optical signal from the receptacle to the receiver. Also disclosed is a method for permitting only authorized use of a motor vehicle. 7 figs.

  2. Device for coupling a first vehicle to a second vehicle

    NASA Technical Reports Server (NTRS)

    Rudmann, A. A. (Inventor)

    1980-01-01

    A device is disclosed, carried by a first vehicle such as an orbiting space shuttle, having a plurality of contact members for engaging and holding an annular ring on a second vehicle such as an orbiting payload. The contact members are connected to manipulator arms which are mounted at a fulcrum point and which are moved by an iris type mechanism. Movement of the manipulator arms causes the contact members to grasp or release the annular ring. Bumper devices are provided to axially align the annular ring and draw the contact members into engagement therewith.

  3. 75 FR 22317 - Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... National Highway Traffic Safety Administration 23 CFR Parts 1200 and 1300 Federal Motor Vehicle Safety Standards; Small Business Impacts of Motor Vehicle Safety AGENCY: National Highway Traffic Safety... that specifically relate to passenger cars, multipurpose passenger vehicles, trucks, buses,...

  4. Damages and Expected Deaths Due to Excess NOx Emissions from 2009 to 2015 Volkswagen Diesel Vehicles.

    PubMed

    Holland, Stephen P; Mansur, Erin T; Muller, Nicholas Z; Yates, Andrew J

    2016-02-01

    We estimate the damages and expected deaths in the United States due to excess emissions of NOx from 2009 to 2015 Volkswagen diesel vehicles. Using data on vehicle registrations and a model of pollution transport and valuation, we estimate excess damages of $430 million and 46 excess expected deaths. Accounting for uncertainty about emissions gives a range for damages from $350 million to $500 million, and a range for excess expected deaths from 40 to 52. Our estimates incorporate significant local heterogeneity: for example, Minneapolis has the highest damages despite having fewer noncompliant vehicles than 13 other cities. Our estimated damages greatly exceed possible benefits from reduced CO2 emissions due to increased fuel economy. PMID:26720281

  5. Mobile robot vehicles for physical security

    SciTech Connect

    McGovern, D.E.

    1987-07-01

    A fleet of vehicles is being developed and maintained by Sandia National Labs for studies in remote control and autonomous operation. These vehicles range from modified commercial vehicles to specially constructed mobile platforms and are utilized as test beds for developing concepts in the application of robotics to interior and exterior physical security. Actuators control the vehicle speed, brakes, and steering through manual input from a remote driving station or through some level of digital computer control. On-board processing may include simple vehicle control functions or may allow for unmanned, autonomous operation. communication links are provided for digital communication between control computers, television transmission for vehicle vision, and voice for local control. With these vehicles, SNL can develop, test, and evaluate sensors, processing requirements, various methods of actuator implementation, operator controlled feedback requirements, and vehicle operations. A description of the major features and uses for each of the vehicles in the fleet is provided.

  6. Estrogen deficiency heterogeneously affects tissue specific stem cells in mice

    PubMed Central

    Kitajima, Yuriko; Doi, Hanako; Ono, Yusuke; Urata, Yoshishige; Goto, Shinji; Kitajima, Michio; Miura, Kiyonori; Li, Tao-Sheng; Masuzaki, Hideaki

    2015-01-01

    Postmenopausal disorders are frequently observed in various organs, but their relationship with estrogen deficiency and mechanisms remain unclear. As tissue-specific stem cells have been found to express estrogen receptors, we examined the hypothesis that estrogen deficiency impairs stem cells, which consequently contributes to postmenopausal disorders. Six-week-old C57BL/6 female mice were ovariectomized, following which they received 17β-estradiol replacement or vehicle (control). Sham-operated mice were used as healthy controls. All mice were killed for evaluation 2 months after treatments. Compared with the healthy control, ovariectomy significantly decreased uterine weight, which was partially recovered by 17β-estradiol replacement. Ovariectomy significantly increased the numbers of c-kit-positive hematopoietic stem/progenitor cells in bone marrow, but impaired their capacity to grow mixed cell-type colonies in vitro. Estrogen replacement further increased the numbers of c-kit-positive hematopoietic stem/progenitor cells in bone marrow, without significantly affecting colony growth in vitro. The number of CD105-positive mesenchymal stem cells in bone marrow also significantly decreased after ovariectomy, but completely recovered following estrogen replacement. Otherwise, neither ovariectomy nor estrogen replacement changed the number of Pax7-positive satellite cells, which are a skeletal muscle-type stem cell. Estrogen deficiency heterogeneously affected tissue-specific stem cells, suggesting a likely and direct relationship with postmenopausal disorders. PMID:26245252

  7. Design and implementation of a mechanically heterogeneous robot group

    NASA Astrophysics Data System (ADS)

    Sukhatme, Gaurav S.; Montgomery, James F.; Mataric, Maja J.

    1999-08-01

    This paper describes the design and construction of a cooperative, heterogeneous robot group comprised of one semi-autonomous aerial robot and two autonomous ground robots. The robots are designed to perform automated surveillance and reconnaissance of an urban outdoor area using onboard sensing. The ground vehicles have GPS, sonar for obstacle detection and avoidance, and a simple color- based vision system. Navigation is performed using an optimal mixture of odometry and GPS. The helicopter is equipped with a GPS/INS system, a camera, and a framegrabber. Each robot has an embedded 486 PC/104 processor running the QNX real-time operating system. Individual robot controllers are behavior-based and decentralized. We describe a control strategy and architecture that coordinates the robots with minimal top- down planning. The overall system is controlled at high level by a single human operator using a specially designed control unit. The operator is able to task the group with a mission using a minimal amount of training. The group can re-task itself based on sensor inputs and can also be re- tasked by the operator. We describe a particular reconnaissance mission that the robots have been tested with, and lessons learned during the design and implementation. Our initial results with these experiments are encouraging given the challenging mechanics of the aerial robot. We conclude the paper with a discussion of ongoing and future work.

  8. Booster propulsion/vehicle impact study, 2

    NASA Technical Reports Server (NTRS)

    Johnson, P.; Satterthwaite, S.; Carson, C.; Schnackel, J.

    1988-01-01

    This is the final report in a study examining the impact of launch vehicles for various boost propulsion design options. These options included: differing boost phase engines using different combinations of fuels and coolants to include RP-1, methane, propane (subcooled and normal boiling point), and hydrogen; variable and high mixture ratio hydrogen engines; translating nozzles on boost phase engines; and cross feeding propellants from the booster to second stage. Vehicles examined included a fully reusable two stage cargo vehicle and a single stage to orbit vehicle. The use of subcooled propane as a fuel generated vehicles with the lowest total vehicle dry mass. Engines with hydrogen cooling generated only slight mass reductions from the reference, all-hydrogen vehicle. Cross feeding propellants generated the most significant mass reductions from the reference two stage vehicle. The use of high mixture ratio or variable mixture ratio hydrogen engines in the boost phase of flight resulted in vehicles with total dry mass 20 percent greater than the reference hydrogen vehicle. Translating nozzles for boost phase engines generated a heavier vehicle. Also examined were the design impacts on the vehicle and ground support subsystems when subcooled propane is used as a fuel. The most significant cost difference between facilities to handle normal boiling point versus subcooled propane is 5 million dollars. Vehicle cost differences were negligible. A significant technical challenge exists for properly conditioning the vehicle propellant on the ground and in flight when subcooled propane is used as fuel.

  9. Integrated Design and Analysis for Heterogeneous Objects

    NASA Astrophysics Data System (ADS)

    Qian, Xiaoping; Yang, Pinghai

    2008-02-01

    The recent advancement of solid freeform fabrication, design techniques and fundamental understanding of material properties in functionally graded material objects has made it possible to design and fabricate multifunctional heterogeneous objects. In this paper, we present an integrated design and analysis approach for heterogeneous object realization, which employs a unified design and analysis model based on B-splines and allows for direct interaction between the design and analysis model without a laborious meshing operation. In the design module, a new approach for intuitively modeling multi-material objects, termed heterogeneous lofting, is presented. In the analysis module, a novel graded B-spline finite element solution procedure is described, which gives orders of magnitude better convergence rate in comparison with current methods, as demonstrated in several case studies. Further advantages of this approach include simplified mesh construction, exact geometry/material composition representation and easy extraction of iso-material surface for manufacturing process planning.

  10. Self-attracting walk on heterogeneous networks

    NASA Astrophysics Data System (ADS)

    Kim, Kanghun; Kyoung, Jaegu; Lee, D.-S.

    2016-05-01

    Understanding human mobility in cyberspace becomes increasingly important in this information era. While human mobility, memory-dependent and subdiffusive, is well understood in Euclidean space, it remains elusive in random heterogeneous networks like the World Wide Web. Here we study the diffusion characteristics of self-attracting walks, in which a walker is more likely to move to the locations visited previously than to unvisited ones, on scale-free networks. Under strong attraction, the number of distinct visited nodes grows linearly in time with larger coefficients in more heterogeneous networks. More interestingly, crossovers to sublinear growths occur in strongly heterogeneous networks. To understand these phenomena, we investigate the characteristic volumes and topology of the cluster of visited nodes and find that the reinforced attraction to hubs results in expediting exploration first but delaying later, as characterized by the scaling exponents that we derive. Our findings and analysis method can be useful for understanding various diffusion processes mediated by human.

  11. Seismoelectric effects due to mesoscopic heterogeneities

    NASA Astrophysics Data System (ADS)

    Jougnot, Damien; Rubino, J. GermáN.; Carbajal, Marina Rosas; Linde, Niklas; Holliger, Klaus

    2013-05-01

    While the seismic effects of wave-induced fluid flow due to mesoscopic heterogeneities have been studied for several decades, the role played by these types of heterogeneities on seismoelectric phenomena is largely unexplored. To address this issue, we have developed a novel methodological framework which allows for the coupling of wave-induced fluid flow, as inferred through numerical oscillatory compressibility tests, with the pertinent seismoelectric conversion mechanisms. Simulating the corresponding response of a water-saturated sandstone sample containing mesoscopic fractures, we demonstrate for the first time that these kinds of heterogeneities can produce measurable seismoelectric signals under typical laboratory conditions. Given that this phenomenon is sensitive to key hydraulic and mechanical properties, we expect that the results of this pilot study will stimulate further exploration on this topic in several domains of the Earth, environmental, and engineering sciences.

  12. Characterizing hydrogeologic heterogeneity using lithologic data

    SciTech Connect

    Flach, G.; Hamm, LL.L.; Harris, M.K.; Thayer, P.A.; Haselow, J.S.; Smits, A.D.

    1997-06-13

    Large-scale (>1 m) variability in hydraulic conductivity is usually the main influence on field-scale groundwater flow patterns and dispersive transport. Incorporating realistic hydraulic conductivity heterogeneity into flow and transport models is paramount to accurate simulations, particularly for contaminant migration. Sediment lithologic descriptions and geophysical logs typically offer finer spatial resolution, and therefore more potential information about site-scale heterogeneity, than other site characterization data. In this study, a technique for generating a heterogeneous, three- dimensional hydraulic conductivity field from sediment lithologic descriptions is presented. The approach involves creating a three-dimensional, fine-scale representation of mud (silt and clay) percentage using a stratified interpolation algorithm. Mud percentage is then translated into horizontal and vertical conductivity using direct correlations derived from measured data and inverse groundwater flow modeling. Lastly, the fine-scale conductivity fields are averaged to create a coarser grid for use in groundwater flow and transport modeling.

  13. A physical mechanism of cancer heterogeneity

    PubMed Central

    Chen, Cong; Wang, Jin

    2016-01-01

    We studied a core cancer gene regulatory network motif to uncover possible source of cancer heterogeneity from epigenetic sources. When the time scale of the protein regulation to the gene is faster compared to the protein synthesis and degradation (adiabatic regime), normal state, cancer state and an intermediate premalignant state emerge. Due to the epigenetics such as DNA methylation and histone remodification, the time scale of the protein regulation to the gene can be slower or comparable to the protein synthesis and degradation (non-adiabatic regime). In this case, many more states emerge as possible phenotype alternations. This gives the origin of the heterogeneity. The cancer heterogeneity is reflected from the emergence of more phenotypic states, larger protein concentration fluctuations, wider kinetic distributions and multiplicity of kinetic paths from normal to cancer state, higher energy cost per gene switching, and weaker stability. PMID:26854017

  14. Correlation between spatial heterogeneity and local dynamics

    NASA Astrophysics Data System (ADS)

    Bhatia, Ritwik; Medvedev, Grigori; Corti, David; Caruthers, James

    2003-03-01

    Spatially correlated dynamic heterogeneity has been observed in binary Lennard-Jones mixtures [1]; however, the properites that cause the dynamic heterogeneity are not completely understood. In order to investigate the origin of the dynamic heterogeneity, we have examined the correlation of various thermodynamic properties in the region surrounding the mobile particles. Specifically, the simulation box is divided into a number of sub-volumes and the autocorrelation functions of the density, potential energy and thermal energy are determioned for each sub-volume. A comparison of autocorrelation functions of the sub-volumes containing a large number of mobile particles to sub-volumes containing no mobile particles is reported. [1] Donati et. al., Phys Rev E. v60, n3, p3107, 1999.

  15. Heterogeneous Chemistry Related to Stratospheric Aircraft

    NASA Technical Reports Server (NTRS)

    Tolbert, Margaret A.

    1995-01-01

    Emissions from stratospheric aircraft that may directly or indirectly affect ozone include NO(y), H2O, soot and sulfuric acid. To fully assess the impact of such emissions, it is necessary to have a full understanding of both the homogeneous and heterogeneous transformations that may occur in the stratosphere. Heterogeneous reactions on stratospheric particles play a key role in partitioning ozone-destroying species between their active and reservoir forms. In particular, heterogeneous reactions tend to activate odd chlorine while deactivating odd nitrogen. Accurate modeling of the net atmospheric effects of stratospheric aircraft requires a thorough understanding of the competing effects of this activation/deactivation. In addition, a full understanding of the potential aircraft impacts requires that the abundance, composition and formation mechanisms of the particles themselves be established. Over the last three years with support from the High Speed Research Program, we have performed laboratory experiments to determine the chemical composition, formation mechanism, and reactivity of stratospheric aerosols.

  16. Multiple roles of graphene in heterogeneous catalysis.

    PubMed

    Fan, Xiaobin; Zhang, Guoliang; Zhang, Fengbao

    2015-05-21

    Scientific interest in graphene as a catalyst and as a catalyst support in heterogeneous catalytic reactions has grown dramatically over the past several years. The present critical review summarizes the multiple roles of graphene in heterogeneous catalysis and highlights the influence of defects, heteroatom-containing functionalities, and graphene's two-dimensional structure on catalytic performance. We first discuss the role and advantages of graphene as a catalyst support, with emphasis on its interactions with the catalytic phases and the influence of mass transfer processes. We then clarify the origin of the intrinsic catalytic activity of graphene in heterogeneous catalytic reactions. Finally we suggest challenges and potential practical applications for graphene in industrial processes. PMID:25777748

  17. Stretchable heterogeneous composites with extreme mechanical gradients.

    PubMed

    Libanori, Rafael; Erb, Randall M; Reiser, Alain; Le Ferrand, Hortense; Süess, Martin J; Spolenak, Ralph; Studart, André R

    2012-01-01

    Heterogeneous composite materials with variable local stiffness are widespread in nature, but are far less explored in engineering structural applications. The development of heterogeneous synthetic composites with locally tuned elastic properties would allow us to extend the lifetime of functional devices with mechanically incompatible interfaces, and to create new enabling materials for applications ranging from flexible electronics to regenerative medicine. Here we show that heterogeneous composites with local elastic moduli tunable over five orders of magnitude can be prepared through the site-specific reinforcement of an entangled elastomeric matrix at progressively larger length scales. Using such a hierarchical reinforcement approach, we designed and produced composites exhibiting regions with extreme soft-to-hard transitions, while still being reversibly stretchable up to 350%. The implementation of the proposed methodology in a mechanically challenging application is illustrated here with the development of locally stiff and globally stretchable substrates for flexible electronics. PMID:23232395

  18. Dynamical robustness of coupled heterogeneous oscillators

    NASA Astrophysics Data System (ADS)

    Tanaka, Gouhei; Morino, Kai; Daido, Hiroaki; Aihara, Kazuyuki

    2014-05-01

    We study tolerance of dynamic behavior in networks of coupled heterogeneous oscillators to deterioration of the individual oscillator components. As the deterioration proceeds with reduction in dynamic behavior of the oscillators, an order parameter evaluating the level of global oscillation decreases and then vanishes at a certain critical point. We present a method to analytically derive a general formula for this critical point and an approximate formula for the order parameter in the vicinity of the critical point in networks of coupled Stuart-Landau oscillators. Using the critical point as a measure for dynamical robustness of oscillator networks, we show that the more heterogeneous the oscillator components are, the more robust the oscillatory behavior of the network is to the component deterioration. This property is confirmed also in networks of Morris-Lecar neuron models coupled through electrical synapses. Our approach could provide a useful framework for theoretically understanding the role of population heterogeneity in robustness of biological networks.

  19. Impact of Aquifer Heterogeneities on Autotrophic Denitrification.

    NASA Astrophysics Data System (ADS)

    McCarthy, A.; Roques, C.; Selker, J. S.; Istok, J. D.; Pett-Ridge, J. C.

    2015-12-01

    Nitrate contamination in groundwater is a big challenge that will need to be addressed by hydrogeologists throughout the world. With a drinking water standard of 10mg/L of NO3-, innovative techniques will need to be pursued to ensure a decrease in drinking water nitrate concentration. At the pumping site scale, the influence and relationship between heterogeneous flow, mixing, and reactivity is not well understood. The purpose of this project is to incorporate both physical and chemical modeling techniques to better understand the effect of aquifer heterogeneities on autotrophic denitrification. We will investigate the link between heterogeneous hydraulic properties, transport, and the rate of autotrophic denitrification. Data collected in previous studies in laboratory experiments and pumping site scale experiments will be used to validate the models. The ultimate objective of this project is to develop a model in which such coupled processes are better understood resulting in best management practices of groundwater.

  20. Self-attracting walk on heterogeneous networks.

    PubMed

    Kim, Kanghun; Kyoung, Jaegu; Lee, D-S

    2016-05-01

    Understanding human mobility in cyberspace becomes increasingly important in this information era. While human mobility, memory-dependent and subdiffusive, is well understood in Euclidean space, it remains elusive in random heterogeneous networks like the World Wide Web. Here we study the diffusion characteristics of self-attracting walks, in which a walker is more likely to move to the locations visited previously than to unvisited ones, on scale-free networks. Under strong attraction, the number of distinct visited nodes grows linearly in time with larger coefficients in more heterogeneous networks. More interestingly, crossovers to sublinear growths occur in strongly heterogeneous networks. To understand these phenomena, we investigate the characteristic volumes and topology of the cluster of visited nodes and find that the reinforced attraction to hubs results in expediting exploration first but delaying later, as characterized by the scaling exponents that we derive. Our findings and analysis method can be useful for understanding various diffusion processes mediated by human. PMID:27300913

  1. Stretchable heterogeneous composites with extreme mechanical gradients

    NASA Astrophysics Data System (ADS)

    Libanori, Rafael; Erb, Randall M.; Reiser, Alain; Le Ferrand, Hortense; Süess, Martin J.; Spolenak, Ralph; Studart, André R.

    2012-12-01

    Heterogeneous composite materials with variable local stiffness are widespread in nature, but are far less explored in engineering structural applications. The development of heterogeneous synthetic composites with locally tuned elastic properties would allow us to extend the lifetime of functional devices with mechanically incompatible interfaces, and to create new enabling materials for applications ranging from flexible electronics to regenerative medicine. Here we show that heterogeneous composites with local elastic moduli tunable over five orders of magnitude can be prepared through the site-specific reinforcement of an entangled elastomeric matrix at progressively larger length scales. Using such a hierarchical reinforcement approach, we designed and produced composites exhibiting regions with extreme soft-to-hard transitions, while still being reversibly stretchable up to 350%. The implementation of the proposed methodology in a mechanically challenging application is illustrated here with the development of locally stiff and globally stretchable substrates for flexible electronics.

  2. A physical mechanism of cancer heterogeneity

    NASA Astrophysics Data System (ADS)

    Chen, Cong; Wang, Jin

    2016-02-01

    We studied a core cancer gene regulatory network motif to uncover possible source of cancer heterogeneity from epigenetic sources. When the time scale of the protein regulation to the gene is faster compared to the protein synthesis and degradation (adiabatic regime), normal state, cancer state and an intermediate premalignant state emerge. Due to the epigenetics such as DNA methylation and histone remodification, the time scale of the protein regulation to the gene can be slower or comparable to the protein synthesis and degradation (non-adiabatic regime). In this case, many more states emerge as possible phenotype alternations. This gives the origin of the heterogeneity. The cancer heterogeneity is reflected from the emergence of more phenotypic states, larger protein concentration fluctuations, wider kinetic distributions and multiplicity of kinetic paths from normal to cancer state, higher energy cost per gene switching, and weaker stability.

  3. Heterogeneous Distributed Computing for Computational Aerosciences

    NASA Technical Reports Server (NTRS)

    Sunderam, Vaidy S.

    1998-01-01

    The research supported under this award focuses on heterogeneous distributed computing for high-performance applications, with particular emphasis on computational aerosciences. The overall goal of this project was to and investigate issues in, and develop solutions to, efficient execution of computational aeroscience codes in heterogeneous concurrent computing environments. In particular, we worked in the context of the PVM[1] system and, subsequent to detailed conversion efforts and performance benchmarking, devising novel techniques to increase the efficacy of heterogeneous networked environments for computational aerosciences. Our work has been based upon the NAS Parallel Benchmark suite, but has also recently expanded in scope to include the NAS I/O benchmarks as specified in the NHT-1 document. In this report we summarize our research accomplishments under the auspices of the grant.

  4. Information flow in heterogeneously interacting systems.

    PubMed

    Yamaguti, Yutaka; Tsuda, Ichiro; Takahashi, Yoichiro

    2014-02-01

    Motivated by studies on the dynamics of heterogeneously interacting systems in neocortical neural networks, we studied heterogeneously-coupled chaotic systems. We used information-theoretic measures to investigate directions of information flow in heterogeneously coupled Rössler systems, which we selected as a typical chaotic system. In bi-directionally coupled systems, spontaneous and irregular switchings of the phase difference between two chaotic oscillators were observed. The direction of information transmission spontaneously switched in an intermittent manner, depending on the phase difference between the two systems. When two further oscillatory inputs are added to the coupled systems, this system dynamically selects one of the two inputs by synchronizing, selection depending on the internal phase differences between the two systems. These results indicate that the effective direction of information transmission dynamically changes, induced by a switching of phase differences between the two systems. PMID:24465282

  5. Spatial Heterogeneity in the Tumor Microenvironment.

    PubMed

    Yuan, Yinyin

    2016-01-01

    Recent developments in studies of tumor heterogeneity have provoked new thoughts on cancer management. There is a desperate need to understand influence of the tumor microenvironment on cancer development and evolution. Applying principles and quantitative methods from ecology can suggest novel solutions to fulfil this need. We discuss spatial heterogeneity as a fundamental biological feature of the microenvironment, which has been largely ignored. Histological samples can provide spatial context of diverse cell types coexisting within the microenvironment. Advanced computer-vision techniques have been developed for spatial mapping of cells in histological samples. This has enabled the applications of experimental and analytical tools from ecology to cancer research, generating system-level knowledge of microenvironmental spatial heterogeneity. We focus on studies of immune infiltrate and tumor resource distribution, and highlight statistical approaches for addressing the emerging challenges based on these new approaches. PMID:27481837

  6. Heavy Duty Vehicle Futures Analysis.

    SciTech Connect

    Askin, Amanda Christine; Barter, Garrett.; West, Todd H.; Manley, Dawn Kataoka

    2014-05-01

    This report describes work performed for an Early Career Research and Development project. This project developed a heavy-duty vehicle (HDV) sector model to assess the factors influencing alternative fuel and efficiency technology adoption. This model builds on a Sandia light duty vehicle sector model and provides a platform for assessing potential impacts of technological advancements developed at the Combustion Research Facility. Alternative fuel and technology adoption modeling is typically developed around a small set of scenarios. This HDV sector model segments the HDV sector and parameterizes input values, such as fuel prices, efficiencies, and vehicle costs. This parameterization enables sensitivity and trade space analyses to identify the inputs that are most associated with outputs of interest, such as diesel consumption and greenhouse gas emissions. Thus this analysis tool enables identification of the most significant HDV sector drivers that can be used to support energy security and climate change goals.

  7. 2010 Vehicle Technologies Market Report

    SciTech Connect

    Ward, Jacob; Davis, Stacy Cagle; Diegel, Susan W

    2011-06-01

    In the past five years, vehicle technologies have advanced on a number of fronts: power-train systems have become more energy efficient, materials have become more lightweight, fuels are burned more cleanly, and new hybrid electric systems reduce the need for traditional petroleum-fueled propulsion. This report documents the trends in market drivers, new vehicles, and component suppliers. This report is supported by the U.S. Department of Energy s (DOE s) Vehicle Technologies Program, which develops energy-efficient and environmentally friendly transportation technologies that will reduce use of petroleum in the United States. The long-term aim is to develop "leap frog" technologies that will provide Americans with greater freedom of mobility and energy security, while lowering costs and reducing impacts on the environment.

  8. 2008 Vehicle Technologies Market Report

    SciTech Connect

    Ward, J.; Davis, S.

    2009-07-01

    In the past five years, vehicle technologies have advanced on a number of fronts: power-train systems have become more energy efficient, materials have become more lightweight, fuels are burned more cleanly, and new hybrid electric systems reduce the need for traditional petroleum-fueled propulsion. This report documents the trends in market drivers, new vehicles, and component suppliers. This report is supported by the Department of Energy's (DOE's) Vehicle Technologies Program, which develops energy-efficient and environmentally friendly highway transportation technologies that will reduce use of petroleum in the United States. The long-term aim is to develop 'leap frog' technologies that will provide Americans with greater freedom of mobility and energy security, while lowering costs and reducing impacts on the environment.

  9. Vehicle to Grid Demonstration Project

    SciTech Connect

    Willett Kempton; Meryl Gardner; Michael Hidrue; Fouad Kamilev; Sachin Kamboj; Jon Lilley; Rodney McGee; George Parsons; Nat Pearre; Keith Trnka

    2010-12-31

    This report summarizes the activities and accomplishments of a two-year DOE-funded project on Grid-Integrated Vehicles (GIV) with vehicle to grid power (V2G). The project included several research and development components: an analysis of US driving patterns; an analysis of the market for EVs and V2G-capable EVs; development and testing of GIV components (in-car and in-EVSE); interconnect law and policy; and development and filing of patents. In addition, development activities included GIV manufacturing and licensing of technologies developed under this grant. Also, five vehicles were built and deployed, four for the fleet of the State of Delaware, plus one for the University of Delaware fleet.

  10. Vehicle and cargo inspection system

    NASA Astrophysics Data System (ADS)

    Verbinski, Victor V.; Orphan, Victor J.

    1997-02-01

    Vehicle and Cargo Inspection System (VACIS) is comprised of a 1 Curie 137Cs gamma-ray source in a shield and collimator which produces a fan-shaped beam designed to intercept a vertical array of gama-ray detectors contained in a tower structure. The source and detector modules straddle the vehicle or container being inspected and are mounted on self-propelled trolleys which travel in synchronization along two parallel tracks covering the length of the scanned object. The signals from the gamma-ray detector array are processed and displayed so as to produce a 2D gamma-radiographic image of the object. Testing of the system on a variety of empty and lightly-loaded vehicles and containers has demonstrated the effectiveness of VACIS in detecting hidden contraband. For example, a small sample of cocaine only 1.5 inches thick was readily detected in a container.

  11. Advancements in Topical Antifungal Vehicles.

    PubMed

    Kircik, Leon H

    2016-02-01

    The primary treatment for superficial fungal infections is antifungal topical formulations, and allylamines and azoles represent the two major classes of topical formulations that are used to treat these infections. The stratum corneum (SC) is composed of keratinocytes that are surrounded by a matrix of lipids. The efficacy of topically applied formulations depends on their ability to penetrate this lipid matrix, and the vehicle plays an integral role in the penetration of active molecule into skin. There are several challenges to formulating topical drugs, which include the biotransformation of the active molecules as they pass through the SC and the physical changes that occur to the vehicle itself when it is applied to the skin. This article will review current and emerging topical antifungal vehicles. PMID:26885798

  12. Vehicle Battery Safety Roadmap Guidance

    SciTech Connect

    Doughty, D. H.

    2012-10-01

    The safety of electrified vehicles with high capacity energy storage devices creates challenges that must be met to assure commercial acceptance of EVs and HEVs. High performance vehicular traction energy storage systems must be intrinsically tolerant of abusive conditions: overcharge, short circuit, crush, fire exposure, overdischarge, and mechanical shock and vibration. Fail-safe responses to these conditions must be designed into the system, at the materials and the system level, through selection of materials and safety devices that will further reduce the probability of single cell failure and preclude propagation of failure to adjacent cells. One of the most important objectives of DOE's Office of Vehicle Technologies is to support the development of lithium ion batteries that are safe and abuse tolerant in electric drive vehicles. This Roadmap analyzes battery safety and failure modes of state-of-the-art cells and batteries and makes recommendations on future investments that would further DOE's mission.

  13. Hybrid and Plug-In Electric Vehicles (Brochure)

    SciTech Connect

    Not Available

    2014-05-01

    Hybrid and plug-in electric vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), all-electric vehicles (EVs). Together, they have great potential to cut U.S. petroleum use and vehicle emissions.

  14. Emergency vehicle alert system (EVAS)

    NASA Technical Reports Server (NTRS)

    Reed, Bill; Crump, Roger; Harper, Warren; Myneni, Krishna

    1995-01-01

    The Emergency Vehicle Alert System (EVAS) program is sponsored by the NASA/MSFC Technology Utilization (TU) office. The program was conceived to support the needs of hearing impaired drivers. The objective of the program is to develop a low-cost, small device which can be located in a personal vehicle and warn the driver, via a visual means, of the approach of an emergency vehicle. Many different technologies might be developed for this purpose and each has its own advantages and drawbacks. The requirements for an acoustic detection system, appear to be pretty stringent and may not allow the development of a reliable, low-cost device in the near future. The problems include variations in the sirens between various types of emergency vehicles, distortions due to wind and surrounding objects, competing background noise, sophisticated signal processing requirements, and omni-directional coverage requirements. Another approach is to use a Radio Frequency (RF) signal between the Emergency Vehicle (EV) and the Personal Vehicle (PV). This approach requires a transmitter on each EV and a receiver in each PV, however it is virtually assured that a system can be developed which works. With this approach, the real technology issue is how to make a system work as inexpensively as possible. This report gives a brief summary of the EVAS program from its inception and concentrates on describing the activities that occurred during Phase 4. References 1-3 describe activities under Phases 1-3. In the fourth phase of the program, the major effort to be expended was in development of the microcontroller system for the PV, refinement of some system elements and packaging for demonstration purposes. An EVAS system was developed and demonstrated which used standard spread spectrum modems with minor modifications.

  15. Vehicle positioning using image processing

    NASA Astrophysics Data System (ADS)

    Kaur, Amardeep; Watkins, Steve E.; Swift, Theresa M.

    2009-03-01

    An image-processing approach is described that detects the position of a vehicle on a bridge. A load-bearing vehicle must be carefully positioned on a bridge for quantitative bridge monitoring. The personnel required for setup and testing and the time required for bridge closure or traffic control are important management and cost considerations. Consequently, bridge monitoring and inspections are good candidates for smart embedded systems. The objectives of this work are to reduce the need for personnel time and to minimize the time for bridge closure. An approach is proposed that uses a passive target on the bridge and camera instrumentation on the load vehicle. The orientation of the vehicle-mounted camera and the target determine the position. The experiment used pre-defined concentric circles as the target, a FireWire camera for image capture, and MATLAB for computer processing. Various image-processing techniques are compared for determining the orientation of the target circles with respect to speed and accuracy in the positioning application. The techniques for determining the target orientation use algorithms based on using the centroid feature, template matching, color feature, and Hough transforms. Timing parameters are determined for each algorithm to determine the feasibility for real-time use in a position triggering system. Also, the effect of variations in the size and color of the circles are examined. The development can be combined with embedded sensors and sensor nodes for a complete automated procedure. As the load vehicle moves to the proper position, the image-based system can trigger an embedded measurement, which is then transmitted back to the vehicle control computer through a wireless link.

  16. Hypersonic Airbreathing Vehicles/Technologies

    NASA Technical Reports Server (NTRS)

    Hunt, James L.

    1996-01-01

    Hypersonic airbreathing horizontal takeoff and landing (HTOL) vehicles are highly integrated systems involving many advanced technologies. The design environment is variable rich, intricately networked, and sensitivity intensive; as such, it represents a tremendous challenge. Creating a viable design requires addressing three main elements: (1) an understanding of the 'figures of merit' and their relationship, (2) the development of sophisticated configuration discipline prediction methods and a synthesis procedure, and (3) the synergistic integration of advanced technologies across the discipline spectrum. This paper will focus on the vision for hypersonic airbreathing vehicles and the advanced technologies that forge the designs. Airbreathing hypersonics encompass endoatmospheric (airplanes...missiles are a part of the matrix but will not be included in this paper since they are an air force focus) and space access vehicles with speed from Mach 4 up to Mach 25 (orbital). These vehicles can be divided into two classes...cruisers and accelerators. The cruiser designs reflect high lift-to-drag whereas the accelerators reflect low drag per unit inlet capture; thus, the cross section of the accelerator attributes a much larger percentage to propulsion. One of the more design influencing items is fuel. The hydrogen fueled vehicles must be very volumetric efficient to contain the low density fuel and thus tend to be a bit bulgy (more conducive to lifting bodies or wing bodies) whereas with hydrocarbon fueled vehicles, the concern is loading because of the high density fuel; thus, they may tend to be more towards waveriders which are not usually very volumetric efficient. Hydrocarbon fuels (endothermic) are limited in their engine cooling capacity to below Mach 8.

  17. Turbo-flywheel-powered vehicle

    SciTech Connect

    Gamell, J.A.

    1982-06-29

    A turbo-flywheel-powered vehicle has as the flywheel the rotor of a gas driven drag turbine, which rotor has a mass distribution such that the radius of gyration is at least 0.7 times the radius of the rotor, a combustion can for producing propellant fluid and delivering it to the drag turbine, a rotary air compressor mounted to rotate as a unit with the rotor and having conduit means for conducting compressed air to the combustion can and drive means for coupling the motor to the rolling stock of the vehicle.

  18. Vehicle barrier with access delay

    DOEpatents

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  19. Thermoelectric generator for motor vehicle

    DOEpatents

    Bass, John C.

    1997-04-29

    A thermoelectric generator for producing electric power for a motor vehicle from the heat of the exhaust gasses produced by the engine of the motor vehicle. The exhaust gasses pass through a finned heat transfer support structure which has seat positions on its outside surface for the positioning of thermoelectric modules. A good contact cylinder provides a framework from which a spring force can be applied to the thermoelectric modules to hold them in good contact on their seats on the surface of the heat transfer support structure.

  20. An Optimized International Vehicle Monitor

    SciTech Connect

    York, R.L.; Close, D.A.; Fehlau, P.E.

    1999-07-16

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of this project was to evaluate detector configurations to achieve a vehicle monitor that is economical, practical to install, and has adequate sensitivity to be an effective barrier to illegal transportation of special nuclear materials. We designed a new detector configuration that improves the sensitivity of available drive-through vehicle monitors by more than a factor of 5 while not changing the nuisance alarm rate.

  1. Electric Vehicle Site Operator Program

    NASA Astrophysics Data System (ADS)

    1992-05-01

    Kansas State University, with funding support from federal, state, public, and private companies, is participating in the Department of Energy's Electric Vehicle Site Operator Program. Through participation is this program, Kansas State is demonstrating, testing, and evaluating electric or hybrid vehicle technology. This participation will provide organizations the opportunity to examine the latest EHV prototypes under actual operating conditions. KSU proposes to purchase one electric or hybrid van and four electric cars during the first two years of this five year program. KSU has purchased one G-Van built by Conceptor Industries, Toronto, Canada and has initiated a procurement order to purchase two Soleq 1992 Ford EVcort stationwagons.

  2. Electric Vehicle Site Operator Program

    SciTech Connect

    Not Available

    1992-01-01

    Kansas State University, with funding support from federal, state, public, and private companies, is participating in the Department of Energy's Electric Vehicle Site Operator Program. Through participation is this program, Kansas State is demonstrating, testing, and evaluating electric or hybrid vehicle technology. This participation will provide organizations the opportunity to examine the latest EHV prototypes under actual operating conditions. KSU proposes to purchase one (1) electric or hybrid van and four (4) electric cars during the first two years of this five year program. KSU has purchased one G-Van built by Conceptor Industries, Toronto, Canada and has initiated a procurement order to purchase two (2) Soleq 1992 Ford EVcort stationwagons.

  3. Vehicle Technologies Program Funding Opportunities

    SciTech Connect

    2011-12-13

    The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) provides funding opportunities for advanced vehicle technology projects that are aimed at removing technical and cost barriers. Much of the funding available to the Vehicle Technologies Program is distributed to private firms, educational institutions, nonprofit organizations, state and local governments, Native American organizations, and individuals, through competitive solicitations. DOE is strongly committed to partnerships to help ensure the eventual market acceptance of the technologies being developed. New solicitations are announced regularly.

  4. Road Weather and Connected Vehicles

    NASA Astrophysics Data System (ADS)

    Pisano, P.; Boyce, B. C.

    2015-12-01

    On average, there are over 5.8 M vehicle crashes each year of which 23% are weather-related. Weather-related crashes are defined as those crashes that occur in adverse weather or on slick pavement. The vast majority of weather-related crashes happen on wet pavement (74%) and during rainfall (46%). Connected vehicle technologies hold the promise to transform road-weather management by providing improved road weather data in real time with greater temporal and geographic accuracy. This will dramatically expand the amount of data that can be used to assess, forecast, and address the impacts that weather has on roads, vehicles, and travelers. The use of vehicle-based measurements of the road and surrounding atmosphere with other, more traditional weather data sources, and create road and atmospheric hazard products for a variety of users. The broad availability of road weather data from mobile sources will vastly improve the ability to detect and forecast weather and road conditions, and will provide the capability to manage road-weather response on specific roadway links. The RWMP is currently demonstrating how weather, road conditions, and related vehicle data can be used for decision making through an innovative Integrated Mobile Observations project. FHWA is partnering with 3 DOTs (MN, MI, & NV) to pilot these applications. One is a mobile alerts application called the Motorists Advisories and Warnings (MAW) and a maintenance decision support application. These applications blend traditional weather information (e.g., radar, surface stations) with mobile vehicle data (e.g., temperature, brake status, wiper status) to determine current weather conditions. These weather conditions, and other road-travel-relevant information, are provided to users via web and phone applications. The MAW provides nowcasts and short-term forecasts out to 24 hours while the EMDSS application can provide forecasts up to 72 hours in advance. The three DOTs have placed readers and external

  5. Aerodynamics for Revolutionary Air Vehicles

    NASA Technical Reports Server (NTRS)

    Sellers, William L., III; Singer, Bart A.; Leavitt, Laurence D.

    2003-01-01

    Aeronautics research has seriously declined partly because of the perception that it is a mature science and only incremental improvements are possible. Recent aeronautics roadmapping activities at NASA Langley paint a different picture of the future. Breakthroughs are still felt to be possible if we expand the current design space of today's vehicles and optimize the airspace and vehicles as a system. The paper describes some of the challenges that the aircraft and airline industry face. These challenges include political, technical and environmental issues. Examples of the opportunities and technologies that could provide a different vision for the future are discussed.

  6. Micro-unmanned aerodynamic vehicle

    DOEpatents

    Reuel, Nigel; Lionberger, Troy A.; Galambos, Paul C.; Okandan, Murat; Baker, Michael S.

    2008-03-11

    A MEMS-based micro-unmanned vehicle includes at least a pair of wings having leading wing beams and trailing wing beams, at least two actuators, a leading actuator beam coupled to the leading wing beams, a trailing actuator beam coupled to the trailing wing beams, a vehicle body having a plurality of fulcrums pivotally securing the leading wing beams, the trailing wing beams, the leading actuator beam and the trailing actuator beam and having at least one anisotropically etched recess to accommodate a lever-fulcrum motion of the coupled beams, and a power source.

  7. Low floor mass transit vehicle

    DOEpatents

    Emmons, J. Bruce; Blessing, Leonard J.

    2004-02-03

    A mass transit vehicle includes a frame structure that provides an efficient and economical approach to providing a low floor bus. The inventive frame includes a stiff roof panel and a stiff floor panel. A plurality of generally vertical pillars extend between the roof and floor panels. A unique bracket arrangement is disclosed for connecting the pillars to the panels. Side panels are secured to the pillars and carry the shear stresses on the frame. A unique seating assembly that can be advantageously incorporated into the vehicle taking advantage of the load distributing features of the inventive frame is also disclosed.

  8. Heterogeneity and Scaling in Geologic Media

    SciTech Connect

    Gregory N. Boitnott; Gilles Y. Bussod; Paul N. Hagin; Stephen R. Brown

    2005-04-18

    The accurate characterization and remediation of contaminated subsurface environments requires the detailed knowledge of subsurface structures and flow paths. Enormous resources are invested in scoping and characterizing sites using core sampling, 3-D geophysical surveys, well tests, etc.... Unfortunately, much of the information acquired is lost to compromises and simplifications made in constructing numerical grids for the simulators used to predict flow and transport from the contaminated area to the accessible environment. In rocks and soils, the bulk geophysical and transport properties of the matrix and of fracture systems are determined by the juxtaposition of geometric features at many length scales. In the interest of computational efficiency, recognized heterogeneities are simplified, averaged out, or entirely ignored in spite of recent studies that recognize that: (1) Structural and lithologic heterogeneities exist on all scales in rocks. (2) Small heterogeneities influence, and can control the physical and chemical properties of rocks. In this work we propose a physically based approach for the description and treatment of heterogeneities, that highlights the use of laboratory equipment designed to measure the effect on physical properties of fine scale heterogeneities observed in rocks and soils. We then discuss the development of an integration methodology that uses these measurements to develop and upscale flow and transport models. Predictive simulations are 'calibrated' to the measured heterogeneity data, and subsequently upscaled in a way that is consistent with the transport physics and the efficient use of environmental geophysics. This methodology provides a more accurate interpretation and representation of the subsurface for both environmental engineering and remediation. We show through examples, (i) the important influence of even subtle heterogeneity in the interpreting of geophysical data, and (ii) how physically based upscaling can lead

  9. PDA based control of multiple heterogeneous robots

    NASA Astrophysics Data System (ADS)

    Kim, Tae Geun; Suk, Sung Youn; Park, Jae Suk; Kim, Sung Rock; Jeon, You Ju; Lee, Suk Gyu

    2005-12-01

    This paper proposed PDA based control of multiple heterogeneous robots by sharing information to perform surveillance and reconnaissance. Since heterogeneous groups were equipped with different sensor systems, they in particular allow a potentially greater degree of fault-tolerance compared to homogeneous groups. In this paper, unknown environment around robots was recognized efficiently by multiple robots using internet based PDA, where communication between PDA(user interface) and host PC(a controller for robots) is based on TCP/IP protocol. Each of the robots collects sensor data regarding its own motion and environment to share this information with the rest of he team during he update cycles.

  10. A framework for querying heterogeneous images repositories

    NASA Astrophysics Data System (ADS)

    Albanesi, Maria G.; Falchero, Emanuele; Guerrini, Federico; Ferretti, Marco

    2003-12-01

    In this paper we describe a new system for storing annotated images in a large database and querying by means of a dynamical retrieval of images through use of metadata. It is based on a three-tier architecture suitable for building a common gateway for accessing heterogeneous data. Based on XML schema of documents, the extraction of metadata is used for successive querying. We give an example on a database of astronomical and geographical images, but the method is quite general and can be applied to more general case of large heterogeneous databases.

  11. Heterogeneity in the muscle satellite cell population

    PubMed Central

    Biressi, Stefano; Rando, Thomas A.

    2010-01-01

    Satellite cells, the adult stem cells responsible for skeletal muscle regeneration, are defined by their location between the basal lamina and the fiber sarcolemma. Increasing evidence suggests that satellite cells represent a heterogeneous population of cells with distinct embryological origin and multiple levels of biochemical and functional diversity. This review focuses on the rich diversity of the satellite cell population based on studies across species. Ultimately, a more complete characterization of the heterogeneity of satellite cells will be essential to understand the functional significance in terms of muscle growth, homeostasis, tissue repair, and aging. PMID:20849971

  12. Effective permeabilities for model heterogeneous porous media

    SciTech Connect

    Otevo, C.; Rusinek, I. ); Saez, A.E. )

    1990-01-01

    This paper presents a technique to evaluate effective absolute permeabilities for heterogeneous porous media. The technique is based on a perturbation analysis of the equations of motion of a slightly compressible fluid in a homogeneous porous medium at low Reynolds numbers. The effective permeabilities can be calculated once the local geometry of the heterogeneous medium is specified. The technique is used to evaluate two- and three-dimensional effective vertical permeabilities in porous media with shale intercalations, including the case in which the porous matrix is anisotropic.

  13. Method for Accessing Distributed Heterogeneous Databases

    NASA Technical Reports Server (NTRS)

    Jacobs, B. E.

    1984-01-01

    A scenario of relational, hierarchial, and network data bases is presented and a distributed access view integrated data base system (DAVID) is described for uniformly accessing data bases which are heterogeneous and physically distributed. The DAVID system is based on data base logic so that the relational approach is generalized to the heterogeneous approach. The global data manager is explained as are global data manipulation languages which can operate on all the data bases and can query the data dictionary and the data directory.

  14. Random sphere packing model of heterogeneous propellants

    NASA Astrophysics Data System (ADS)

    Kochevets, Sergei Victorovich

    It is well recognized that combustion of heterogeneous propellants is strongly dependent on the propellant morphology. Recent developments in computing systems make it possible to start three-dimensional modeling of heterogeneous propellant combustion. A key component of such large scale computations is a realistic model of industrial propellants which retains the true morphology---a goal never achieved before. The research presented develops the Random Sphere Packing Model of heterogeneous propellants and generates numerical samples of actual industrial propellants. This is done by developing a sphere packing algorithm which randomly packs a large number of spheres with a polydisperse size distribution within a rectangular domain. First, the packing code is developed, optimized for performance, and parallelized using the OpenMP shared memory architecture. Second, the morphology and packing fraction of two simple cases of unimodal and bimodal packs are investigated computationally and analytically. It is shown that both the Loose Random Packing and Dense Random Packing limits are not well defined and the growth rate of the spheres is identified as the key parameter controlling the efficiency of the packing. For a properly chosen growth rate, computational results are found to be in excellent agreement with experimental data. Third, two strategies are developed to define numerical samples of polydisperse heterogeneous propellants: the Deterministic Strategy and the Random Selection Strategy. Using these strategies, numerical samples of industrial propellants are generated. The packing fraction is investigated and it is shown that the experimental values of the packing fraction can be achieved computationally. It is strongly believed that this Random Sphere Packing Model of propellants is a major step forward in the realistic computational modeling of heterogeneous propellant of combustion. In addition, a method of analysis of the morphology of heterogeneous

  15. Atmospheric pressure microwave assisted heterogeneous catalytic reactions.

    PubMed

    Chemat-Djenni, Zoubida; Hamada, Boudjema; Chemat, Farid

    2007-01-01

    The purpose of the study was to investigate microwave selective heating phenomena and their impact on heterogeneous chemical reactions. We also present a tool which will help microwave chemists to answer to such questions as "My reaction yields 90% after 7 days at reflux; is it possible to obtain the same yield after a few minutes under microwaves?" and to have an approximation of their reactions when conducted under microwaves with different heterogeneous procedures. This model predicting reaction kinetics and yields under microwave heating is based on the Arrhenius equation, in agreement with experimental data and procedures. PMID:17909495

  16. Retinal regionalization and heterogeneity of butterfly eyes

    NASA Astrophysics Data System (ADS)

    Stavenga, D.; Kinoshita, M.; Yang, E.-C.; Arikawa, K.

    2001-11-01

    The regional characteristics of the eyes of butterflies from different families have been surveyed using epi-illumination microscopy, utilizing the eyeshine visible due to the tapetum situated proximally to the rhabdom. All butterflies studied have a high spatial acuity in the frontal region. The facet diameter varies slightly across the eye, and the interommatidial angle and the eye parameter p are especially large dorsally. Whereas the ommatidial lattice is generally highly regular, the eyeshine colours distinctly depend on the species. Sometimes the eyeshine is locally uniform, but often it is heterogeneous. It is hypothesized that the regional characteristics as well as the local heterogeneity are adaptations that optimize spectral discrimination.

  17. Launch Vehicle Debris Models and Crew Vehicle Ascent Abort Risk

    NASA Technical Reports Server (NTRS)

    Gee, Ken; Lawrence, Scott

    2013-01-01

    For manned space launch systems, a reliable abort system is required to reduce the risks associated with a launch vehicle failure during ascent. Understanding the risks associated with failure environments can be achieved through the use of physics-based models of these environments. Debris fields due to destruction of the launch vehicle is one such environment. To better analyze the risk posed by debris, a physics-based model for generating launch vehicle debris catalogs has been developed. The model predicts the mass distribution of the debris field based on formulae developed from analysis of explosions. Imparted velocity distributions are computed using a shock-physics code to model the explosions within the launch vehicle. A comparison of the debris catalog with an existing catalog for the Shuttle external tank show good comparison in the debris characteristics and the predicted debris strike probability. The model is used to analyze the effects of number of debris pieces and velocity distributions on the strike probability and risk.

  18. Hydrogen Storage Development for Utility Vehicles

    SciTech Connect

    Heung, L.K.

    2001-07-18

    Hydrogen storage for mobile applications is still a challenge. Savannah River Technology Center (SRTC) and its partners have identified industrial utility vehicles and mining vehicles as potential early niche markets for the use of metal hydride to store hydrogen. The weight of metal hydride is not a problem for these vehicles. The low pressure of metal hydride gives a safety advantage. SRTC has developed onboard hydrogen storage containers using metal hydrides for the demonstration of two generations of fuel cell powered utility vehicles. Another storage container is being developed for a mining vehicle. This paper provides a brief overview of the utility vehicle project and a detail discussion of the hydrogen storage system.

  19. Generalised multi-axle vehicle handling

    NASA Astrophysics Data System (ADS)

    Williams, Daniel Eugene

    2012-01-01

    The familiar two-axle bicycle model and associated basic concepts of vehicle handling are reviewed and used to introduce minor changes in convention from the literature. The two-axle model is extended to a three-axle vehicle to illustrate the effectiveness of the notation combined with a simplifying mathematical identity found in the two-axle vehicle literature. A generalised model is then developed that produces dynamic equations of motion by inspection for a vehicle with an arbitrary number of steerable and non-steerable axles. Furthermore, the vehicle dynamic concepts of understeer and wheelbase are generalised and can be directly computed for various arbitrary vehicle configurations.

  20. Vehicle propulsion system with external propellant supply

    SciTech Connect

    Criswell, D.R.

    1993-07-06

    A vehicle propulsion system is described, comprising: a vehicle designed for travel along an arranged travel path in a single extended surrounding medium; propellant depositing means for distributing propellant into a propellant trail having no structural constraint in the extended medium and extending along at least part of the travel path in advance of the vehicle; and the vehicle having combustion means for immediate combustion and expansion of at least some of the propellant distributed along the path to produce thrust on the vehicle, and exhaust means for expelling burnt propellant from the vehicle.

  1. Challenges for the vehicle tester in characterizing hybrid electric vehicles

    SciTech Connect

    Duoba, M.

    1997-08-01

    Many problems are associated with applying test methods, like the Federal Test Procedure (FTP), for HEVs. Although there has been considerable progress recently in the area of HEV test procedure development, many challenges are still unsolved. A major hurdle to overcoming the challenges of developing HEV test procedures is the lack of HEV designs available for vehicle testing. Argonne National Laboratory has tested hybrid electric vehicles (HEVs) built by about 50 colleges and universities from 1994 to 1997 in annual vehicle engineering competitions sponsored in part by the U.S. Department of Energy (DOE). From this experience, the Laboratory has gathered information about the basics of HEV testing and issues important to successful characterization of HEVs. A collaboration between ANL and the Society of Automotive Engineer`s (SAE) HEV Test Procedure Task Force has helped guide the development of test protocols for their proposed procedures (draft SAE J1711) and test methods suited for DOE vehicle competitions. HEVs use an electrical energy storage device, which requires that HEV testing include more time and effort to deal with the effects of transient energy storage as the vehicle is operating in HEV mode. HEV operation with electric-only capability can be characterized by correcting the HEV mode data using results from electric-only operation. HEVs without electric-only capability require multiple tests conducted to form data correlations that enable the tester to find the result that corresponds to a zero net change in SOC. HEVs that operate with a net depletion of charge cannot be corrected for battery SOC and are characterized with emissions and fuel consumption results coupled with the electrical energy usage rate. 9 refs., 8 figs.

  2. A 'green' chitosan silver nanoparticle composite as a heterogeneous as well as micro-heterogeneous catalyst

    NASA Astrophysics Data System (ADS)

    Murugadoss, A.; Chattopadhyay, Arun

    2008-01-01

    In this paper, we report on the catalytic activity of a new metal nanoparticle-polymer composite consisting of Ag nanoparticles (NPs) and environmentally friendly ('green') chitosan. The polymer (chitosan) not only acted as the reducing agent for the metal ions, but also stabilized the product NPs by anchoring them. The majority of the particles produced in this way had sizes less than 5 nm. The catalytic activity of the composite was investigated photometrically by monitoring the reduction of 4-nitrophenol (4NP) in the presence of excess NaBH4 in water, under both heterogeneous and micro-heterogeneous conditions. The reaction was first order with respect to the concentration of 4NP. We also observed that the apparent rate constant, kapp, for the reaction was linearly dependent on the amount of Ag NPs present in the composite. Moreover, the turn-over frequency (TOF) of the catalyst was found to be (1.5 ± 0.3) × 10-3 s-1, when the reaction was carried out under heterogeneous conditions. The Ag NPs in the composite retained their catalytic activities even after using them for ten cycles. Our observations also suggest that the catalytic efficiency under micro-heterogeneous conditions is much higher than under heterogeneous conditions. Thus the composite we have represents an ideal case of an environmentally friendly and stable catalyst, which works under heterogeneous as well as micro-heterogeneous conditions with the advantage of nanoscopic particles as the catalyst.

  3. Test-vehicle cycle programmer

    NASA Technical Reports Server (NTRS)

    Lesco, D. J.; Soltis, R. F.

    1978-01-01

    Instrument reduces manpower needed for testing electric powered vehicles. Device has dual scale that allows operator to compare actual speed with preprogrammed test speed. Features include large meter, buzzer, packaging to allow ready interchange of memories with different profiles, small size, minimal current drain, and reverse supply voltage protection.

  4. The ground vehicle manager's associate

    NASA Technical Reports Server (NTRS)

    Edwards, Gary R.; Burnard, Robert H.; Bewley, William L.; Bullock, Bruce L.

    1994-01-01

    An overview of MAX, a software framework for manager's associate systems, is presented. MAX is used to develop and execute a problem-solving strategy for the task planning of semi-autonomous agents with the assistance of human performance. This paper describes the use of MAX in the supervisory management of robotic vehicles as they explore a planetary surface.

  5. 2015 Vehicle Buyer's Guide (Brochure)

    SciTech Connect

    Not Available

    2015-02-01

    Drivers and fleets are increasingly turning to the hundreds of light-duty, alternative fuel, and advanced technology vehicle models that reduce petroleum use, save on fuel costs, and cut emissions. This guide provides a comprehensive list of the 2015 light-duty models that use alternative fuels or advanced fuel-saving technologies.

  6. Orbital transfer vehicle - An overview

    NASA Astrophysics Data System (ADS)

    Caluori, V. A.; Saxton, D. R.

    1981-05-01

    A summary is given of the concept definition phase of NASA's Orbital Transfer Vehicle (OTV) program. The mission requirements are threefold: (1) the ability to deliver payloads well beyond the capability of any current system at low acceleration levels, (2) the extension of the cost effectiveness from reusability and operational flexibility provided by the Shuttle at LEO to the geosynchronous altitude, and (3) the provision of the round trip capability needed to service and maintain this expanded and more valuable resource at GEO. The initial Shuttle-matched, reusable OTV is shown to be cost effective with low development cost, relatively short development period and high projected reliability. The performance enhancement provided by aero-assist is discussed, which will enable the difficult round trip to be flown in a single Shuttle launch. Two methods of reducing vehicle velocity are available: (1) aeromaneuvering, which uses vehicle lift to climb or descend and thereby correct for density variations, and (2) aerobraking which varies vehicle drag directly to correct for density.

  7. Delta launch vehicle accident investigation

    NASA Astrophysics Data System (ADS)

    1986-03-01

    The text of the testimony given by several witnesses during the House hearings on the Delta launch vehicle accident of May 3, 1986 is given. Pre-launch procedures, failure analysis, the possibility of sabotage, and design and testing are among the topics discussed.

  8. Electric and hybrid vehicles program

    NASA Astrophysics Data System (ADS)

    1992-05-01

    The Department of Energy's (DOE) Electric and Hybrid Vehicles (EHV) Program is conducting research, development, testing, and evaluation activities to encourage the use of electricity and alternative fuels for transportation. This program supports the expanded DOE involvement as recommended in the National Energy Strategy. The transportation sector is the single largest user of petroleum; it consumed 63 percent of all petroleum used in the United States last year. Only a small fraction (5 percent) of electricity is generated from petroleum. Electric vehicles, which are themselves virtually pollution-free, could play a key role in helping to reduce both urban pollution and our dependence on petroleum imports. The program's goals are to develop, in cooperation with industry, the technology that will lead to the production and introduction of pollution-free electric vehicles into the Nation's transportation fleet and substitute domestic sources of energy for petroleum-based fuels. This report describes progress achieved in developing electric and hybrid vehicle technologies, beginning with highlights of recent accomplishments in FY-91. Detailed descriptions are provided of program activities during FY-91 in the areas of battery, fuel-cell, and propulsion system development, and testing and evaluation of new technology in fleet site operations and in laboratories. In accordance with the reporting requirements of the Act, this annual report contains a status report on incentives and use of foreign components and concludes with a list of publications resulting from the DOE program.

  9. Electric-hybrid-vehicle simulation

    NASA Astrophysics Data System (ADS)

    Pasma, D. C.

    The simulation of electric hybrid vehicles is to be performed using experimental data to model propulsion system components. The performance of an existing ac propulsion system will be used as the baseline for comparative purposes. Hybrid components to be evaluated include electrically and mechanically driven flywheels, and an elastomeric regenerative braking system.

  10. Vehicle assisted harpoon breaching tool

    DOEpatents

    Pacheco, James E.; Highland, Steven E.

    2011-02-15

    A harpoon breaching tool that allows security officers, SWAT teams, police, firemen, soldiers, or others to forcibly breach metal doors or walls very quickly (in a few seconds), without explosives. The harpoon breaching tool can be mounted to a vehicle's standard receiver hitch.

  11. Launch Vehicle Control Center Architectures

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Epps, Amy; Woodruff, Van; Vachon, Michael Jacob; Monreal, Julio; Levesque, Marl; Williams, Randall; Mclaughlin, Tom

    2014-01-01

    Launch vehicles within the international community vary greatly in their configuration and processing. Each launch site has a unique processing flow based on the specific launch vehicle configuration. Launch and flight operations are managed through a set of control centers associated with each launch site. Each launch site has a control center for launch operations; however flight operations support varies from being co-located with the launch site to being shared with the space vehicle control center. There is also a nuance of some having an engineering support center which may be co-located with either the launch or flight control center, or in a separate geographical location altogether. A survey of control center architectures is presented for various launch vehicles including the NASA Space Launch System (SLS), United Launch Alliance (ULA) Atlas V and Delta IV, and the European Space Agency (ESA) Ariane 5. Each of these control center architectures shares some similarities in basic structure while differences in functional distribution also exist. The driving functions which lead to these factors are considered and a model of control center architectures is proposed which supports these commonalities and variations.

  12. Intelligence Applied to Air Vehicles

    NASA Technical Reports Server (NTRS)

    Rosen, Robert; Gross, Anthony R.; Fletcher, L. Skip; Zornetzer, Steven (Technical Monitor)

    2000-01-01

    The exponential growth in information technology has provided the potential for air vehicle capabilities that were previously unavailable to mission and vehicle designers. The increasing capabilities of computer hardware and software, including new developments such as neural networks, provide a new balance of work between humans and machines. This paper will describe several NASA projects, and review results and conclusions from ground and flight investigations where vehicle intelligence was developed and applied to aeronautical and space systems. In the first example, flight results from a neural network flight control demonstration will be reviewed. Using, a highly-modified F-15 aircraft, a NASA/Dryden experimental flight test program has demonstrated how the neural network software can correctly identify and respond to changes in aircraft stability and control characteristics. Using its on-line learning capability, the neural net software would identify that something in the vehicle has changed, then reconfigure the flight control computer system to adapt to those changes. The results of the Remote Agent software project will be presented. This capability will reduce the cost of future spacecraft operations as computers become "thinking" partners along with humans. In addition, the paper will describe the objectives and plans for the autonomous airplane program and the autonomous rotorcraft project. Technologies will also be developed.

  13. Towards inverse modeling of intratumor heterogeneity

    NASA Astrophysics Data System (ADS)

    Brutovsky, Branislav; Horvath, Denis

    2015-08-01

    Development of resistance limits efficiency of present anticancer therapies and preventing it remains a big challenge in cancer research. It is accepted, at the intuitive level, that resistance emerges as a consequence of the heterogeneity of cancer cells at the molecular, genetic and cellular levels. Produced by many sources, tumor heterogeneity is extremely complex time dependent statistical characteristics which may be quantified by measures defined in many different ways, most of them coming from statistical mechanics. In this paper, we apply the Markovian framework to relate population heterogeneity to the statistics of the environment. As, from an evolutionary viewpoint, therapy corresponds to a purposeful modi- fication of the cells' fitness landscape, we assume that understanding general relationship between the spatiotemporal statistics of a tumor microenvironment and intratumor heterogeneity will allow to conceive the therapy as an inverse problem and to solve it by optimization techniques. To account for the inherent stochasticity of biological processes at cellular scale, the generalized distancebased concept was applied to express distances between probabilistically described cell states and environmental conditions, respectively.

  14. Heterogeneous nucleation in hypermonotectic aluminum alloys

    NASA Astrophysics Data System (ADS)

    Köhler, M.; Ratke, L.; Kaban, I.; Hoyer, W.

    2012-01-01

    Simple casting experiments were set up to solve the question, if heterogeneous nucleation of the liquid-liquid decomposition in monotectic systems is possible. Al-Pb alloys with different inoculants were solidified, and the resulting microstructure was analysed by SEM and X-ray microtomography. Pronounced changes in the distribution of the lead precipitations indicate that it is possible to trigger the nucleation.

  15. Heterogeneity: The key to failure forecasting

    NASA Astrophysics Data System (ADS)

    Vasseur, Jérémie; Wadsworth, Fabian B.; Lavallée, Yan; Bell, Andrew F.; Main, Ian G.; Dingwell, Donald B.

    2015-08-01

    Elastic waves are generated when brittle materials are subjected to increasing strain. Their number and energy increase non-linearly, ending in a system-sized catastrophic failure event. Accelerating rates of geophysical signals (e.g., seismicity and deformation) preceding large-scale dynamic failure can serve as proxies for damage accumulation in the Failure Forecast Method (FFM). Here we test the hypothesis that the style and mechanisms of deformation, and the accuracy of the FFM, are both tightly controlled by the degree of microstructural heterogeneity of the material under stress. We generate a suite of synthetic samples with variable heterogeneity, controlled by the gas volume fraction. We experimentally demonstrate that the accuracy of failure prediction increases drastically with the degree of material heterogeneity. These results have significant implications in a broad range of material-based disciplines for which failure forecasting is of central importance. In particular, the FFM has been used with only variable success to forecast failure scenarios both in the field (volcanic eruptions and landslides) and in the laboratory (rock and magma failure). Our results show that this variability may be explained, and the reliability and accuracy of forecast quantified significantly improved, by accounting for material heterogeneity as a first-order control on forecasting power.

  16. Fragmentation of metal particles during heterogeneous explosion

    NASA Astrophysics Data System (ADS)

    Ripley, R. C.; Donahue, L.; Zhang, F.

    2015-03-01

    Heterogeneous explosives contain a mixture of standard explosive material and reactive metal particles. The inclusion of metal particles alters the energy density and energy release timescales involved in the blast event. Available experimental evidence indicates that metal particles may be damaged or fragmented during heterogeneous blast, altering the distribution of particle sizes from their initial state. This paper discusses adaptation and application of fragmentation theory and physical models for particle damage during condensed matter detonation, aerodynamic breakup of molten particles, and particle impact fragmentation with nearby structures. The shock compression and impact fragmentation models are based on the energy methods for dynamic fragmentation by Grady and Kipp, while aerodynamic breakup is treated according to Weber number stability criteria for droplets. These particle fragmentation models are validated against fundamental test cases from the literature. The models are then applied to heterogeneous blast scenarios including free field and wall reflection in a semi-confined urban street. Comparison with experimental records of pressure shows good agreement despite challenges inherent in the complexity of heterogeneous blast measurement and multiphase simulation.

  17. Heterogeneity: The key to failure forecasting.

    PubMed

    Vasseur, Jérémie; Wadsworth, Fabian B; Lavallée, Yan; Bell, Andrew F; Main, Ian G; Dingwell, Donald B

    2015-01-01

    Elastic waves are generated when brittle materials are subjected to increasing strain. Their number and energy increase non-linearly, ending in a system-sized catastrophic failure event. Accelerating rates of geophysical signals (e.g., seismicity and deformation) preceding large-scale dynamic failure can serve as proxies for damage accumulation in the Failure Forecast Method (FFM). Here we test the hypothesis that the style and mechanisms of deformation, and the accuracy of the FFM, are both tightly controlled by the degree of microstructural heterogeneity of the material under stress. We generate a suite of synthetic samples with variable heterogeneity, controlled by the gas volume fraction. We experimentally demonstrate that the accuracy of failure prediction increases drastically with the degree of material heterogeneity. These results have significant implications in a broad range of material-based disciplines for which failure forecasting is of central importance. In particular, the FFM has been used with only variable success to forecast failure scenarios both in the field (volcanic eruptions and landslides) and in the laboratory (rock and magma failure). Our results show that this variability may be explained, and the reliability and accuracy of forecast quantified significantly improved, by accounting for material heterogeneity as a first-order control on forecasting power. PMID:26307196

  18. Heterogeneity: The key to failure forecasting

    PubMed Central

    Vasseur, Jérémie; Wadsworth, Fabian B.; Lavallée, Yan; Bell, Andrew F.; Main, Ian G.; Dingwell, Donald B.

    2015-01-01

    Elastic waves are generated when brittle materials are subjected to increasing strain. Their number and energy increase non-linearly, ending in a system-sized catastrophic failure event. Accelerating rates of geophysical signals (e.g., seismicity and deformation) preceding large-scale dynamic failure can serve as proxies for damage accumulation in the Failure Forecast Method (FFM). Here we test the hypothesis that the style and mechanisms of deformation, and the accuracy of the FFM, are both tightly controlled by the degree of microstructural heterogeneity of the material under stress. We generate a suite of synthetic samples with variable heterogeneity, controlled by the gas volume fraction. We experimentally demonstrate that the accuracy of failure prediction increases drastically with the degree of material heterogeneity. These results have significant implications in a broad range of material-based disciplines for which failure forecasting is of central importance. In particular, the FFM has been used with only variable success to forecast failure scenarios both in the field (volcanic eruptions and landslides) and in the laboratory (rock and magma failure). Our results show that this variability may be explained, and the reliability and accuracy of forecast quantified significantly improved, by accounting for material heterogeneity as a first-order control on forecasting power. PMID:26307196

  19. Diffusion and Surface Reaction in Heterogeneous Catalysis

    ERIC Educational Resources Information Center

    Baiker, A.; Richarz, W.

    1978-01-01

    Ethylene hydrogenation on a platinum catalyst, electrolytically applied to a tube wall, is a good system for the study of the interactions between diffusion and surface reaction in heterogeneous catalysis. Theoretical background, apparatus, procedure, and student performance of this experiment are discussed. (BB)

  20. Scale Reliability Evaluation with Heterogeneous Populations

    ERIC Educational Resources Information Center

    Raykov, Tenko; Marcoulides, George A.

    2015-01-01

    A latent variable modeling approach for scale reliability evaluation in heterogeneous populations is discussed. The method can be used for point and interval estimation of reliability of multicomponent measuring instruments in populations representing mixtures of an unknown number of latent classes or subpopulations. The procedure is helpful also…