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Sample records for pyramidal capacitated vehicle

  1. The pyramidal capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    2010-01-01

    This paper introduces the pyramidal capacitated vehicle routing problem (PCVRP) as a restricted version of the capacitated vehicle routing problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the pyramidal traveling salesman problem (PTSP). A pyramidal...

  2. The Pyramidal Capacitated Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Lysgaard, Jens

    This paper introduces the Pyramidal Capacitated Vehicle Routing Problem (PCVRP) as a restricted version of the Capacitated Vehicle Routing Problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the Pyramidal Traveling Salesman Problem (PTSP). A pyramidal...... found in many optimal solutions to CVRP instances. An optimal solution to the PCVRP may therefore be useful in itself as a heuristic solution to the CVRP. Further, an attempt can be made to find an even better CVRP solution by solving a TSP, possibly leading to a non-pyramidal route, for each...... of the routes in the PCVRP solution. This paper develops an exact branch-and-cut-and-price (BCP) algorithm for the PCVRP. At the pricing stage, elementary routes can be computed in pseudo-polynomial time in the PCVRP, unlike in the CVRP. We have therefore implemented pricing algorithms that generate only...

  3. Locating Depots for Capacitated Vehicle Routing

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath

    2016-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input to the k-location capacitated vehicle routing problem (k-LocVRP) consists of a set of demand locations in a metric space and a fleet of k identical vehicles, each of capacity Q. The objective is to locate k...... depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for k-LocVRP. In obtaining this result, we introduce a common generalization of the k-median and minimum...... spanning tree problems (called k median forest), which might be of independent interest. We give a local-search based (3+ε)-approximation algorithm for k median forest, which leads to a (12+ε)-approximation algorithm for k-LocVRP, for any constant ε>0....

  4. Fund allocation using capacitated vehicle routing problem

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita; Darus, Maslina

    2014-09-01

    In investment fund allocation, it is unwise for an investor to distribute his fund into several assets simultaneously due to economic reasons. One solution is to allocate the fund into a particular asset at a time in a sequence that will either maximize returns or minimize risks depending on the investor's objective. The vehicle routing problem (VRP) provides an avenue to this issue. VRP answers the question on how to efficiently use the available fleet of vehicles to meet a given service demand, subjected to a set of operational requirements. This paper proposes an idea of using capacitated vehicle routing problem (CVRP) to optimize investment fund allocation by employing data of selected stocks in the FTSE Bursa Malaysia. Results suggest that CRVP can be applied to solve the issue of investment fund allocation and increase the investor's profit.

  5. Locating Depots for Capacitated Vehicle Routing

    CERN Document Server

    Goertz, Inge Li

    2011-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input is a set of demand locations in a metric space and a fleet of k vehicles each of capacity Q. The objective is to locate k depots, one for each vehicle, and compute routes for the vehicles so that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for this problem. To achieve this result, we reduce to the k-median-forest problem, which generalizes both k-median and minimum spanning tree, and which might be of independent interest. We give a (3+c)-approximation algorithm for k-median-forest, which leads to a (12+c)-approximation algorithm for the above location-routing problem, for any constant c>0. The algorithm for k-median-forest is just t-swap local search, and we prove that it has locality gap 3+2/t; this generalizes the corresponding result known for k-median. Finally we consider the "non-uniform" k-median-forest problem which has different cost ...

  6. Locating Depots for Capacitated Vehicle Routing

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath

    2011-01-01

    We study a location-routing problem in the context of capacitated vehicle routing. The input to k-LocVRP is a set of demand locations in a metric space and a fleet of k vehicles each of capacity Q. The objective is to locate k depots, one for each vehicle, and compute routes for the vehicles so...... that all demands are satisfied and the total cost is minimized. Our main result is a constant-factor approximation algorithm for k-LocVRP. To achieve this result, we reduce k-LocVRP to the following generalization of k median, which might be of independent interest. Given a metric (V, d), bound k...... median forest, which leads to a (12+E)-approximation algorithm for k-LocVRP, for any constant E > 0. The algorithm for k median forest is t-swap local search, and we prove that it has locality gap 3 + 2 t ; this generalizes the corresponding result for k median [3]. Finally we consider the k median...

  7. Capacitated Vehicle Routing with Non-Uniform Speeds

    CERN Document Server

    Gortz, Inge Li; Nagarajan, Viswanath; Ravi, R

    2010-01-01

    The capacitated vehicle routing problem (CVRP) involves distributing (identical) items from a depot to a set of demand locations, using a single capacitated vehicle. We study a generalization of this problem to the setting of multiple vehicles having non-uniform speeds (that we call Heterogenous CVRP), and present a constant-factor approximation algorithm. The technical heart of our result lies in achieving a constant approximation to the following TSP variant (called Heterogenous TSP). Given a metric denoting distances between vertices, a depot r containing k vehicles with possibly different speeds, the goal is to find a tour for each vehicle (starting and ending at r), so that every vertex is covered in some tour and the maximum completion time is minimized. This problem is precisely Heterogenous CVRP when vehicles are uncapacitated. The presence of non-uniform speeds introduces difficulties for employing standard tour-splitting techniques. In order to get a better understanding of this technique in our con...

  8. OPTIMIZATION OF CAPACITATED VEHICLE ROUTING PROBLEM USING PSO

    Directory of Open Access Journals (Sweden)

    S.R.VENKATESAN

    2011-10-01

    Full Text Available This paper presents solution techniques for Capacitated Vehicle Routing Problem (CVRP using metaheuristics. Capacitated Vehicle Routing Problem is divided into set of customers called cluster, and find optimum travel distance of vehicle route. The CVRP is a combinatorial optimization problem; particle swarm optimization(PSO technique is adapted in this paper to solve this problem. The main problem is divided into subprograms/clusters and each subprogram is treated as travelling salesman problem and solved by usingparticle swarm optimization techniques (PSO. This paper presents a sweep, Clark and wright algorithm to form the clusters. This model is then solved by using a particle swarm optimization (PSO method to find optimum travel distance of vehicle route. Our analysis suggests that the proposed model enables users to establish route to serve all given customers with minimum distance of vehicles and maximum capacity.

  9. An Effective Hybrid Optimization Algorithm for Capacitated Vehicle Routing Problem

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Capacitated vehicle routing problem (CVRP) is an important combinatorial optimization problem. However, it is quite difficult to achieve an optimal solution with the traditional optimization methods owing to the high computational complexity. A hybrid algorithm was developed to solve the problem, in which an artificial immune clonal algorithm (AICA) makes use of the global search ability to search the optimal results and simulated annealing (SA) algorithm employs certain probability to avoid becoming trapped in a local optimum. The results obtained from the computational study show that the proposed algorithm is a feasible and effective method for capacitated vehicle routing problem.

  10. A novel heuristic algorithm for capacitated vehicle routing problem

    Science.gov (United States)

    Kır, Sena; Yazgan, Harun Reşit; Tüncel, Emre

    2017-02-01

    The vehicle routing problem with the capacity constraints was considered in this paper. It is quite difficult to achieve an optimal solution with traditional optimization methods by reason of the high computational complexity for large-scale problems. Consequently, new heuristic or metaheuristic approaches have been developed to solve this problem. In this paper, we constructed a new heuristic algorithm based on the tabu search and adaptive large neighborhood search (ALNS) with several specifically designed operators and features to solve the capacitated vehicle routing problem (CVRP). The effectiveness of the proposed algorithm was illustrated on the benchmark problems. The algorithm provides a better performance on large-scaled instances and gained advantage in terms of CPU time. In addition, we solved a real-life CVRP using the proposed algorithm and found the encouraging results by comparison with the current situation that the company is in.

  11. Vehicle routing problem and capacitated vehicle routing problem frameworks in fund allocation problem

    Science.gov (United States)

    Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah@Rozita

    2016-11-01

    Two new methods adopted from methods commonly used in the field of transportation and logistics are proposed to solve a specific issue of investment allocation problem. Vehicle routing problem and capacitated vehicle routing methods are applied to optimize the fund allocation of a portfolio of investment assets. This is done by determining the sequence of the assets. As a result, total investment risk is minimized by this sequence.

  12. Flexible Bond Wire Capacitive Strain Sensor for Vehicle Tyres

    Directory of Open Access Journals (Sweden)

    Siyang Cao

    2016-06-01

    Full Text Available The safety of the driving experience and manoeuvrability of a vehicle can be improved by detecting the strain in tyres. To measure strain accurately in rubber, the strain sensor needs to be flexible so that it does not deform the medium that it is measuring. In this work, a novel flexible bond wire capacitive strain sensor for measuring the strain in tyres is developed, fabricated and calibrated. An array of 25 micron diameter wire bonds in an approximately 8 mm × 8 mm area is built to create an interdigitated structure, which consists of 50 wire loops resulting in 49 capacitor pairs in parallel. Laser machining was used to pattern copper on a flexible printed circuit board PCB to make the bond pads for the wire attachment. The wire array was finally packaged and embedded in polydimethylsiloxane (PDMS, which acts as the structural material that is strained. The capacitance of the device is in a linear like relationship with respect to the strain, which can measure the strain up to at least ±60,000 micro-strain (±6% with a resolution of ~132 micro-strain (0.013%. In-tyre testing under static loading has shown the ability of the sensor to measure large tyre strains. The technology used for sensor fabrication lends itself to mass production and so the design is considered to be consistent with low cost commercialisable strain sensing technology.

  13. Variable neighbourhood simulated annealing algorithm for capacitated vehicle routing problems

    Science.gov (United States)

    Xiao, Yiyong; Zhao, Qiuhong; Kaku, Ikou; Mladenovic, Nenad

    2014-04-01

    This article presents the variable neighbourhood simulated annealing (VNSA) algorithm, a variant of the variable neighbourhood search (VNS) combined with simulated annealing (SA), for efficiently solving capacitated vehicle routing problems (CVRPs). In the new algorithm, the deterministic 'Move or not' criterion of the original VNS algorithm regarding the incumbent replacement is replaced by an SA probability, and the neighbourhood shifting of the original VNS (from near to far by k← k+1) is replaced by a neighbourhood shaking procedure following a specified rule. The geographical neighbourhood structure is introduced in constructing the neighbourhood structures for the CVRP of the string model. The proposed algorithm is tested against 39 well-known benchmark CVRP instances of different scales (small/middle, large, very large). The results show that the VNSA algorithm outperforms most existing algorithms in terms of computational effectiveness and efficiency, showing good performance in solving large and very large CVRPs.

  14. A branch-and-cut-and-price algorithm for the cumulative capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Wøhlk, Sanne; Lysgaard, Jens

    2014-01-01

    The paper considers the Cumulative Capacitated Vehicle Routing Problem (CCVRP), which is a variation of the well-known Capacitated Vehicle Routing Problem (CVRP). In this problem, the traditional objective of minimizing total distance or time traveled by the vehicles is replaced by minimizing the...... the sum of arrival times at the customers. A branch-and-cut-and-price algorithm for obtaining optimal solutions to the problem is proposed. Computational results based on a set of standard CVRP benchmarks are presented....

  15. Ant Colony Optimization for Capacitated Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    H. V. Seow

    2012-01-01

    Full Text Available Problem statement: The Capacitated Vehicle Routing Problem (CVRP is a well-known combinatorial optimization problem which is concerned with the distribution of goods between the depot and customers. It is of economic importance to businesses as approximately 10-20% of the final cost of the goods is contributed by the transportation process. Approach: This problem was tackled using an Ant Colony Optimization (ACO combined with heuristic approaches that act as the route improvement strategies. The proposed ACO utilized a pheromone evaporation procedure of standard ant algorithm in order to introduce an evaporation rate that depends on the solutions found by the artificial ants. Results: Computational experiments were conducted on benchmark data set and the results obtained from the proposed algorithms shown that the application of combination of two different heuristics in the ACO had the capability to improve the ants’ solutions better than ACO embedded with only one heuristic. Conclusion: ACO with swap and 3-opt heuristic has the capability to tackle the CVRP with satisfactory solution quality and run time. It is a viable alternative for solving the CVRP.

  16. A branch-and-cut algorithm for the capacitated open vehicle routing problem

    DEFF Research Database (Denmark)

    Letchford, A.N.; Lysgaard, Jens; Eglese, R.W.

    2007-01-01

    In open vehicle routing problems, the vehicles are not required to return to the depot after completing service. In this paper, we present the first exact optimization algorithm for the open version of the well-known capacitated vehicle routing problem (CVRP). The algorithm is based on branch-and...

  17. Implementasi Algoritma Clarke And Wright’s Savings Dalam Menyelesaikan Capacitated Vehicle Routing Problem (CVRP)

    OpenAIRE

    Damanik, Donna

    2016-01-01

    Model to choose vehicle route is known as Vehicle Routing Problem (VRP). VRP is related to optimal routing problem that involve more than one vehicle of each capacity to serve costumer’s demand. Capacitated Vehicle Routing Problem is one of VRP form which each of vehicle has finite capacity. Solution in this research use Clarke and Wright’s Savings Algorithm. This algorithm may get a route depand to vehicle capacity and customer’s demand. Data that use in this research is di...

  18. Capacitated vehicle routing problem with sequence-based pallet loading and axle weight constraints

    OpenAIRE

    2016-01-01

    In this paper, we introduce and study the capacitated vehicle routing problem with sequence-based pallet loading and axle weight constraints. To the best of our knowledge, it is the first time that axle weight restrictions are incorporated in a vehicle routing model. The aim of this paper is to demonstrate that incorporating axle weight restrictions in a vehicle routing model is possible and necessary for a feasible route planning. Axle weight limits impose a great challenge for transportatio...

  19. A pyramid-based approach to visual exploration of a large volume of vehicle trajectory data

    Institute of Scientific and Technical Information of China (English)

    Jing SUN; Xiang LI

    2012-01-01

    Advances in positioning and wireless communicating technologies make it possible to collect large volumes of trajectory data of moving vehicles in a fast and convenient fashion.These data can be applied to traffic studies.Behind this application,a methodological issue that still requires particular attention is the way these data should be spatially visualized.Trajectory data physically consists of a large number of positioning points.With the dramatic increase of data volume,it becomes a challenge to display and explore these data.Existing commercial software often employs vector-based indexing structures to facilitate the display of a large volume of points,but their performance downgrades quickly when the number of points is very large,for example,tens of millions.In this paper,a pyramid-based approach is proposed.A pyramid method initially is invented to facilitate the display of raster images through the tradeoff between storage space and display time.A pyramid is a set of images at different levels with different resolutions.In this paper,we convert vector-based point data into raster data,and build a gridbased indexing structure in a 2D plane.Then,an image pyramid is built.Moreover,at the same level of a pyramid,image is segmented into mosaics with respect to the requirements of data storage and management.Algorithms or procedures on grid-based indexing structure,image pyramid,image segmentation,and visualization operations are given in this paper.A case study with taxi trajectory data in Shanghai is conducted.Results demonstrate that the proposed method outperforms the existing commercial software.

  20. Capacitated Vehicle Routing with Non-Uniform Speeds

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Molinaro, Marco; Nagarajan, Viswanath

    2011-01-01

    vehicles having speeds {λ i } i = 1 k , the goal is to find a tour for each vehicle (starting and ending at r), so that every vertex is covered in some tour and the maximum completion time is minimized. This problem is precisely Heterogenous CVRP when vehicles are uncapacitated. The presence of non...

  1. Hybrid discrete particle swarm optimization algorithm for capacitated vehicle routing problem

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Capacitated vehicle routing problem (CVRP) is an NP-hard problem. For large-scale problems, it is quite difficult to achieve an optimal solution with traditional optimization methods due to the high computational complexity. A new hybrid approximation algorithm is developed in this work to solve the problem. In the hybrid algorithm, discrete particle swarm optimization (DPSO) combines global search and local search to search for the optimal results and simulated annealing (SA) uses certain probability to avoid being trapped in a local optimum. The computational study showed that the proposed algorithm is a feasible and effective approach for capacitated vehicle routing problem, especially for large scale problems.

  2. A Food Chain Algorithm for Capacitated Vehicle Routing Problem with Recycling in Reverse Logistics

    Science.gov (United States)

    Song, Qiang; Gao, Xuexia; Santos, Emmanuel T.

    2015-12-01

    This paper introduces the capacitated vehicle routing problem with recycling in reverse logistics, and designs a food chain algorithm for it. Some illustrative examples are selected to conduct simulation and comparison. Numerical results show that the performance of the food chain algorithm is better than the genetic algorithm, particle swarm optimization as well as quantum evolutionary algorithm.

  3. A branch-and-price algorithm for the capacitated vehicle routing problem with stochastic demands

    DEFF Research Database (Denmark)

    Christiansen, Christian Holk; Lysgaard, Jens

    2007-01-01

    This article introduces a new exact algorithm for the Capacitated Vehicle Routing Problem with Stochastic Demands (CVRPSD). The CVRPSD can be formulated as a Set Partitioning Problem and it is shown that the associated column generation subproblem can be solved using a dynamic programming scheme...

  4. Hybrid self organizing migrating algorithm - Scatter search for the task of capacitated vehicle routing problem

    Science.gov (United States)

    Davendra, Donald; Zelinka, Ivan; Senkerik, Roman; Jasek, Roman; Bialic-Davendra, Magdalena

    2012-11-01

    One of the new emerging application strategies for optimization is the hybridization of existing metaheuristics. The research combines the unique paradigms of solution space sampling of SOMA and memory retention capabilities of Scatter Search for the task of capacitated vehicle routing problem. The new hybrid heuristic is tested on the Taillard sets and obtains good results.

  5. A branch-and-cut algorithm for the symmetric two-echelon capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Spoorendonk, Simon; Røpke, Stefan

    2013-01-01

    This paper presents an exact method for solving the symmetric two-echelon capacitated vehicle routing problem, a transportation problem concerned with the distribution of goods from a depot to a set of customers through a set of satellite locations. The presented method is based on an edge flow...

  6. An Artificial Bee Colony Algorithm for the Capacitated Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Szeto, W.Y.; Wu, Yongzhong; Ho, Sin C.

    This paper introduces an artificial bee colony heuristic for the capacitated vehicle routing problem. The artificial bee colony heuristic is a swarm-based heuristic, which mimics the foraging behavior of a honey bee swarm. The performance of the heuristic is evaluated on two sets of benchmark ins...

  7. An artificial bee colony algorithm for the capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Szeto, W.Y.; Wu, Yongzhong; Ho, Sin C.

    2011-01-01

    This paper introduces an artificial bee colony heuristic for solving the capacitated vehicle routing problem. The artificial bee colony heuristic is a swarm-based heuristic, which mimics the foraging behavior of a honey bee swarm. An enhanced version of the artificial bee colony heuristic is also...

  8. Solving the Capacitated Vehicle Routing Problem Based on Improved Ant-clustering Algorithm

    Directory of Open Access Journals (Sweden)

    Zhang Jiashan

    2015-01-01

    Full Text Available The capacitated vehicle routing problems (CVRP are NP-hard. Most approaches can solve small-scale case studies to optimality. Furthermore, they are time-consuming. To overcome the limitation, this paper presents a novel three-phase heuristic approach for the capacitated vehicle routing problem. The first phase aims to identify sets of cost-effective feasible clusters through an improved ant-clustering algorithm, in which the adaptive strategy is adopted. The second phase assigns clusters to vehicles and sequences them on each tour. The third phase orders nodes within clusters for every tour and genetic algorithm is used to order nodes within clusters. The simulation indicates the algorithm attains high quality results in a short time.

  9. A Learning Automata Based Algorithm For Solving Capacitated Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Mir Mohammad Alipour

    2012-03-01

    Full Text Available This paper presents an approximate algorithm based on distributed learning automata for solving capacitated vehicle routing problem. The vehicle routing problem (VRP is an NP-hard problem and capacitated vehicle routing problem variant (CVRP is considered here. This problem is one of the NP-hard problems and for this reason many approximate algorithms have been designed for solving it. Distributed learning automata that is a general searching tool and is a solving tool for variety of NP-complete problems, is used to solve this problem and tested on fourteen benchmark problems. Our results were compared to the best known results. The results of comparison have shown the efficiency of the proposed algorithm.

  10. Developing a Direct Search Algorithm for Solving the Capacitated Open Vehicle Routing Problem

    Science.gov (United States)

    Simbolon, Hotman

    2011-06-01

    In open vehicle routing problems, the vehicles are not required to return to the depot after completing service. In this paper, we present the first exact optimization algorithm for the open version of the well-known capacitated vehicle routing problem (CVRP). The strategy of releasing nonbasic variables from their bounds, combined with the "active constraint" method and the notion of superbasics, has been developed for efficiently requirements; this strategy is used to force the appropriate non-integer basic variables to move to their neighborhood integer points. A study of criteria for choosing a nonbasic variable to work with in the integerizing strategy has also been made.

  11. Optimization of Capacitated Vehicle Routing Problem by Nested Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Karuppusamy Kanthavel

    2011-01-01

    Full Text Available Problem statement: Vehicle routing problem determines the optimum route for each vehicle as a sequence of visiting cities. The problem has been defined as NP-hard and exact solution is relatively difficult to achieve for real time large scale models. Though several attempts to solve the problem were made in the literature, new approaches may be tried to solve the problem to further reduce computational efforts. Approach: In this context this study focuses on maximum utilization of loading capacity and determines the optimum set of vehicle routes for Capacitated Vehicle Routing Problem (CVRP by a Nested Particle Swarm Optimization (NPSO technique. The algorithm is implemented as Master PSO and slave PSO for the identification of candidate list and route sequence in nested form to optimize the model. Results: Benchmarking data set of capacitated vehicle routing is considered for the evaluations. The total distance of set vehicle route obtained by the new approach is compared with the best known solution and other existing techniques. Conclusions/Recommendations: The NPSO produces significant results and computational performance than the existing PSO algorithms. This newly proposed NPSO algorithm develops the vehicle schedule without any local optimization technique.

  12. Using Grey Wolf Algorithm to Solve the Capacitated Vehicle Routing Problem

    Science.gov (United States)

    Korayem, L.; Khorsid, M.; Kassem, S. S.

    2015-05-01

    The capacitated vehicle routing problem (CVRP) is a class of the vehicle routing problems (VRPs). In CVRP a set of identical vehicles having fixed capacities are required to fulfill customers' demands for a single commodity. The main objective is to minimize the total cost or distance traveled by the vehicles while satisfying a number of constraints, such as: the capacity constraint of each vehicle, logical flow constraints, etc. One of the methods employed in solving the CVRP is the cluster-first route-second method. It is a technique based on grouping of customers into a number of clusters, where each cluster is served by one vehicle. Once clusters are formed, a route determining the best sequence to visit customers is established within each cluster. The recently bio-inspired grey wolf optimizer (GWO), introduced in 2014, has proven to be efficient in solving unconstrained, as well as, constrained optimization problems. In the current research, our main contributions are: combining GWO with the traditional K-means clustering algorithm to generate the ‘K-GWO’ algorithm, deriving a capacitated version of the K-GWO algorithm by incorporating a capacity constraint into the aforementioned algorithm, and finally, developing 2 new clustering heuristics. The resulting algorithm is used in the clustering phase of the cluster-first route-second method to solve the CVR problem. The algorithm is tested on a number of benchmark problems with encouraging results.

  13. A new approach on auxiliary vehicle assignment in capacitated location routing problem

    Science.gov (United States)

    Bashiri, Mahdi; Rasoulinejad, Zeinab; Fallahzade, Ehsan

    2016-03-01

    The location routing problem (LRP) considers locating depots and vehicle routing decisions simultaneously. In classic LRP the number of customers in each route depends on the capacity of the vehicle. In this paper a capacitated LRP model with auxiliary vehicle assignment is presented in which the length of each route is not restricted by main vehicle capacity. Two kinds of vehicles are considered: main vehicles with higher capacity and fixed cost and auxiliary vehicles with lower capacity and fixed cost. The auxiliary vehicles can be added to the transportation system as an alternative strategy to cover the capacity limitations and they are just used to transfer goods from depots to vehicles and cannot serve the customers by themselves. To show the applicability of the proposed model, some numerical examples derived from the well-known instances are used. Moreover the model has been solved by some meta-heuristics for large sized instances. The results show the efficiency of the proposed model and the solution approach, considering the classic model and the exact solution approach, respectively.

  14. A quasi-polynomial time approximation scheme for Euclidean capacitated vehicle routing

    CERN Document Server

    Das, Aparna

    2008-01-01

    In the capacitated vehicle routing problem, introduced by Dantzig and Ramser in 1959, we are given the locations of n customers and a depot, along with a vehicle of capacity k, and wish to find a minimum length collection of tours, each starting from the depot and visiting at most k customers, whose union covers all the customers. We give a quasi-polynomial time approximation scheme for the setting where the customers and the depot are on the plane, and distances are given by the Euclidean metric.

  15. Combination of nearest neighbor and heuristics algorithms for sequential two dimensional loading capacitated vehicle routing problem

    Science.gov (United States)

    Sarwono, A. A.; Ai, T. J.; Wigati, S. S.

    2017-01-01

    Vehicle Routing Problem (VRP) is a method for determining the optimal route of vehicles in order to serve customers starting from depot. Combination of the two most important problems in distribution logistics, which is called the two dimensional loading vehicle routing problem, is considered in this paper. This problem combines the loading of the freight into the vehicles and the successive routing of the vehicles along the route. Moreover, an additional feature of last-in-first-out loading sequencesis also considered. In the sequential two dimensional loading capacitated vehicle routing problem (sequential 2L-CVRP), the loading must be compatible with the trip sequence: when the vehicle arrives at a customer i, there must be no obstacle (items for other customers) between the item of i and the loading door (rear part) of the vehicle. In other words, it is not necessary to move non-i’s items whenever the unloading process of the items of i. According with aforementioned conditions, a program to solve sequential 2L-CVRP is required. A nearest neighbor algorithm for solving the routing problem is presented, in which the loading component of the problem is solved through a collection of 5 packing heuristics.

  16. A Particle Swarm Optimization with Adaptive Multi-Swarm Strategy for Capacitated Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Kui-Ting CHEN

    2015-12-01

    Full Text Available Capacitated vehicle routing problem with pickups and deliveries (CVRPPD is one of the most challenging combinatorial optimization problems which include goods delivery/pickup optimization, vehicle number optimization, routing path optimization and transportation cost minimization. The conventional particle swarm optimization (PSO is difficult to find an optimal solution of the CVRPPD due to its simple search strategy. A PSO with adaptive multi-swarm strategy (AMSPSO is proposed to solve the CVRPPD in this paper. The proposed AMSPSO employs multiple PSO algorithms and an adaptive algorithm with punishment mechanism to search the optimal solution, which can deal with large-scale optimization problems. The simulation results prove that the proposed AMSPSO can solve the CVRPPD with the least number of vehicles and less transportation cost, simultaneously.

  17. A Hybrid Algorithm Based on ACO and PSO for Capacitated Vehicle Routing Problems

    Directory of Open Access Journals (Sweden)

    Yucheng Kao

    2012-01-01

    Full Text Available The vehicle routing problem (VRP is a well-known combinatorial optimization problem. It has been studied for several decades because finding effective vehicle routes is an important issue of logistic management. This paper proposes a new hybrid algorithm based on two main swarm intelligence (SI approaches, ant colony optimization (ACO and particle swarm optimization (PSO, for solving capacitated vehicle routing problems (CVRPs. In the proposed algorithm, each artificial ant, like a particle in PSO, is allowed to memorize the best solution ever found. After solution construction, only elite ants can update pheromone according to their own best-so-far solutions. Moreover, a pheromone disturbance method is embedded into the ACO framework to overcome the problem of pheromone stagnation. Two sets of benchmark problems were selected to test the performance of the proposed algorithm. The computational results show that the proposed algorithm performs well in comparison with existing swarm intelligence approaches.

  18. A Column Generation Approach to the Capacitated Vehicle Routing Problem with Stochastic Demands

    DEFF Research Database (Denmark)

    Christiansen, Christian Holk; Lysgaard, Jens

    In this article we introduce a new exact solution approach to the Capacitated Vehicle Routing Problem with Stochastic Demands (CVRPSD). In particular, we consider the case where all customer demands are distributed independently and where each customer's demand follows a Poisson distribution....... The CVRPSD can be formulated as a Set Partitioning Problem. We show that, under the above assumptions on demands, the associated column generation subproblem can be solved using a dynamic programming scheme which is similar to that used in the case of deterministic demands. To evaluate the potential of our...

  19. A new formulation for the 2-echelon capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Røpke, Stefan; Spoorendonk, Simon

    The 2-echelon capacitated vehicle routing problem (2E-CVRP) is a transportation and distribution problem where goods are transported from a depot to a set of customers possible via optional satellite facilities. The 2E-CVRP is relevant in city-logistic applications where legal restrictions make...... it infeasible to use large trucks within the center of large cities. We propose a new mathematical formulation for the 2E-CVRP with much fewer variables than the previously proposed but with several constraint sets of exponential size. The strength of the model is implied by the facts that many cutting planes...

  20. Simulation of product distribution at PT Anugrah Citra Boga by using capacitated vehicle routing problem method

    Science.gov (United States)

    Lamdjaya, T.; Jobiliong, E.

    2017-01-01

    PT Anugrah Citra Boga is a food processing industry that produces meatballs as their main product. The distribution system of the products must be considered, because it needs to be more efficient in order to reduce the shipment cost. The purpose of this research is to optimize the distribution time by simulating the distribution channels with capacitated vehicle routing problem method. Firstly, the distribution route is observed in order to calculate the average speed, time capacity and shipping costs. Then build the model using AIMMS software. A few things that are required to simulate the model are customer locations, distances, and the process time. Finally, compare the total distribution cost obtained by the simulation and the historical data. It concludes that the company can reduce the shipping cost around 4.1% or Rp 529,800 per month. By using this model, the utilization rate can be more optimal. The current value for the first vehicle is 104.6% and after the simulation it becomes 88.6%. Meanwhile, the utilization rate of the second vehicle is increase from 59.8% to 74.1%. The simulation model is able to produce the optimal shipping route with time restriction, vehicle capacity, and amount of vehicle.

  1. Design of a Capacitive Flexible Weighing Sensor for Vehicle WIM System

    Directory of Open Access Journals (Sweden)

    Qing Li

    2007-08-01

    Full Text Available With the development of the Highway Transportation and Business Trade, vehicle weigh-in-motion (WIM technology has become a key technology and trend of measuring traffic loads. In this paper, a novel capacitive flexible weighing sensor which is light weight, smaller volume and easy to carry was applied in the vehicle WIM system. The dynamic behavior of the sensor is modeled using the Maxwell-Kelvin model because the materials of the sensor are rubbers which belong to viscoelasticity. A signal processing method based on the model is presented to overcome effects of rubber mechanical properties on the dynamic weight signal. The results showed that the measurement error is less than ���±10%. All the theoretic analysis and numerical results demonstrated that appliance of this system to weigh in motion is feasible and convenient for traffic inspection.

  2. Capacitated Windy Rural Postman Problem with Several Vehicles: A Hybrid Multi-Objective Simulated Annealing Algorithm

    Directory of Open Access Journals (Sweden)

    Masoud Rabbani

    2016-02-01

    Full Text Available This paper presents the capacitated Windy Rural Postman Problem with several vehicles. For this problem, two objectives are considered. One of them is the minimization of the total cost of all vehicle routes expressed by the sum of the total traversing cost and another one is reduction of the maximum cost of vehicle route in order to find a set of equitable tours for the vehicles. Mathematical formulation is provided. The multi-objective simulated annealing (MOSA algorithm has been modified for solving this bi-objective NP-hard problem. To increase algorithm performance, Taguchi technique is applied to design experiments for tuning parameters of the algorithm. Numerical experiments are proposed to show efficiency of the model. Finally, the results of the MOSA have been compared with MOCS (multi-objective Cuckoo Search algorithm to validate the performance of the proposed algorithm. The experimental results indicate that the proposed algorithm provides good solutions and performs significantly better than the MOCS.

  3. Robust Branch-and-Cut-and-Price for the Capacitated Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Fukasawa, R.; Longo, H.; Lysgaard, Jens

    2006-01-01

    The best exact algorithms for the Capacitated Vehicle Routing Problem (CVRP) have been based on either branch-and-cut or Lagrangean relaxation/column generation. This paper presents an algorithm that combines both approaches: it works over the intersection of two polytopes, one associated...... with a traditional Lagrangean relaxation over q-routes, the other defined by bound, degree and capacity constraints. This is equivalent to a linear program with exponentially many variables and constraints that can lead to lower bounds that are superior to those given by previous methods. The resulting branch......-and-cut-and-price algorithm can solve to optimality all instances from the literature with up to 135 vertices. This more than doubles the size of the instances that can be consistently solved....

  4. Approximability of the d-dimensional Euclidean capacitated vehicle routing problem

    Science.gov (United States)

    Khachay, Michael; Dubinin, Roman

    2016-10-01

    Capacitated Vehicle Routing Problem (CVRP) is the well known intractable combinatorial optimization problem, which remains NP-hard even in the Euclidean plane. Since the introduction of this problem in the middle of the 20th century, many researchers were involved into the study of its approximability. Most of the results obtained in this field are based on the well known Iterated Tour Partition heuristic proposed by M. Haimovich and A. Rinnoy Kan in their celebrated paper, where they construct the first Polynomial Time Approximation Scheme (PTAS) for the single depot CVRP in ℝ2. For decades, this result was extended by many authors to numerous useful modifications of the problem taking into account multiple depots, pick up and delivery options, time window restrictions, etc. But, to the best of our knowledge, almost none of these results go beyond the Euclidean plane. In this paper, we try to bridge this gap and propose a EPTAS for the Euclidean CVRP for any fixed dimension.

  5. A New Improved Quantum Evolution Algorithm with Local Search Procedure for Capacitated Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Ligang Cui

    2013-01-01

    Full Text Available The capacitated vehicle routing problem (CVRP is the most classical vehicle routing problem (VRP; many solution techniques are proposed to find its better answer. In this paper, a new improved quantum evolution algorithm (IQEA with a mixed local search procedure is proposed for solving CVRPs. First, an IQEA with a double chain quantum chromosome, new quantum rotation schemes, and self-adaptive quantum Not gate is constructed to initialize and generate feasible solutions. Then, to further strengthen IQEA's searching ability, three local search procedures 1-1 exchange, 1-0 exchange, and 2-OPT, are adopted. Experiments on a small case have been conducted to analyze the sensitivity of main parameters and compare the performances of the IQEA with different local search strategies. Together with results from the testing of CVRP benchmarks, the superiorities of the proposed algorithm over the PSO, SR-1, and SR-2 have been demonstrated. At last, a profound analysis of the experimental results is presented and some suggestions on future researches are given.

  6. Computational results with a branch and cut code for the capacitated vehicle routing problem

    Energy Technology Data Exchange (ETDEWEB)

    Augerat, P.; Naddef, D. [Institut National Polytechnique, 38 - Grenoble (France); Belenguer, J.M.; Benavent, E.; Corberan, A. [Valencia Univ. (Spain); Rinaldi, G. [Consiglio Nazionale delle Ricerche, Rome (Italy)

    1995-09-01

    The Capacitated Vehicle Routing Problem (CVRP) we consider in this paper consists in the optimization of the distribution of goods from a single depot to a given set of customers with known demand using a given number of vehicles of fixed capacity. There are many practical routing applications in the public sector such as school bus routing, pick up and mail delivery, and in the private sector such as the dispatching of delivery trucks. We present a Branch and Cut algorithm to solve the CVRP which is based in the partial polyhedral description of the corresponding polytope. The valid inequalities used in our method can ne found in Cornuejols and Harche (1993), Harche and Rinaldi (1991) and in Augerat and Pochet (1995). We concentrated mainly on the design of separation procedures for several classes of valid inequalities. The capacity constraints (generalized sub-tour eliminations inequalities) happen to play a crucial role in the development of a cutting plane algorithm for the CVRP. A large number of separation heuristics have been implemented and compared for these inequalities. There has been also implemented heuristic separation algorithms for other classes of valid inequalities that also lead to significant improvements: comb and extended comb inequalities, generalized capacity inequalities and hypo-tour inequalities. The resulting cutting plane algorithm has been applied to a set of instances taken from the literature and the lower bounds obtained are better than the ones previously known. Some branching strategies have been implemented to develop a Branch an Cut algorithm that has been able to solve large CVRP instances, some of them which had never been solved before. (authors). 32 refs., 3 figs., 10 tabs.

  7. A Problem-Reduction Evolutionary Algorithm for Solving the Capacitated Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Wanfeng Liu

    2015-01-01

    Full Text Available Assessment of the components of a solution helps provide useful information for an optimization problem. This paper presents a new population-based problem-reduction evolutionary algorithm (PREA based on the solution components assessment. An individual solution is regarded as being constructed by basic elements, and the concept of acceptability is introduced to evaluate them. The PREA consists of a searching phase and an evaluation phase. The acceptability of basic elements is calculated in the evaluation phase and passed to the searching phase. In the searching phase, for each individual solution, the original optimization problem is reduced to a new smaller-size problem. With the evolution of the algorithm, the number of common basic elements in the population increases until all individual solutions are exactly the same which is supposed to be the near-optimal solution of the optimization problem. The new algorithm is applied to a large variety of capacitated vehicle routing problems (CVRP with customers up to nearly 500. Experimental results show that the proposed algorithm has the advantages of fast convergence and robustness in solution quality over the comparative algorithms.

  8. Capacitated vehicle routing problem for PSS uses based on ubiquitous computing: An emerging markets approach

    Directory of Open Access Journals (Sweden)

    Alberto Ochoa-Ortíz

    2015-01-01

    Full Text Available El problema de ruteo de vehículos bajo las limitaciones de capacidad y basado en computación ubicua desde una perspectiva relacionada con PSS (Producto-Servicio de Sistemas para desarrollar configuraciones para el transporte urbano de mercancías es abordado. Éste trabajo considera las especificidades de la logística urbana bajo un contexto de mercados emergentes. En este caso, involucra: i bajas competencias logísticas de los tomadores de decisiones; ii la limitada disponibilidad de datos; y iii restringido acceso a tecnología de alto desempeño para calcular rutas de transporte óptimas. Por lo tanto, se propone el uso de un software libre que proporciona soluciones de bajo costo (en tiempo y recursos. El artículo muestra la aplicación de los resultados de una herramienta de software basado en la Teoría de Grafos utilizado para analizar y resolver un CVRP (Capacitated Vehicle Routing Problem. Se utilizó el caso de una empresa local de distribución de alimentos situada en una gran ciudad de México. Sobre la base de una flora de vehículos pequeños, todos con las mismas especificaciones técnicas y una capacidad de carga comparable.

  9. Cheapest Insertion Constructive Heuristic based on Two Combination Seed Customer Criterion for the Capacitated Vehicle Routing Problem

    Directory of Open Access Journals (Sweden)

    Mansour Alssager

    2017-02-01

    Full Text Available The heuristic method is a well-known constructive method for initialize trail quality solutions in capacitated vehicle routing problem. Cheapest insertion heuristic is a popular construction heuristic known for being fast, producing decent solutions, simple to implement and easy to extend handling complicated constraints. However, in previous work, there was less focus on diverse initial quality solutions. Therefore, this study proposed an extension to the cheapest insertion heuristic which consider various combinations of seed customer criteria (the first customer inserted on a route to preserve solutions diversification. Three seed customer criteria proposed which based on the combination of two criteria based on (farthest, nearest and random criteria. The best performing criteria selected and tested on benchmark dataset, later compared with Clarke and Wright saving heuristic. The results shown that the combination of (farthest and random criteria obtained the best initial solution which preserve balance between the quality and diversity, with less time when compared to Clarke and wright saving heuristic. This approach is for generating diverse and quality starting solutions for the capacitated vehicle routing problem.

  10. Biased random key genetic algorithm with insertion and gender selection for capacitated vehicle routing problem with time windows

    Science.gov (United States)

    Rochman, Auliya Noor; Prasetyo, Hari; Nugroho, Munajat Tri

    2017-06-01

    Vehicle Routing Problem (VRP) often occurs when the manufacturers need to distribute their product to some customers/outlets. The distribution process is typically restricted by the capacity of the vehicle and the working hours at the distributor. This type of VRP is also known as Capacitated Vehicle Routing Problem with Time Windows (CVRPTW). A Biased Random Key Genetic Algorithm (BRKGA) was designed and coded in MATLAB to solve the CVRPTW case of soft drink distribution. The standard BRKGA was then modified by applying chromosome insertion into the initial population and defining chromosome gender for parent undergoing crossover operation. The performance of the established algorithms was then compared to a heuristic procedure for solving a soft drink distribution. Some findings are revealed (1) the total distribution cost of BRKGA with insertion (BRKGA-I) results in a cost saving of 39% compared to the total cost of heuristic method, (2) BRKGA with the gender selection (BRKGA-GS) could further improve the performance of the heuristic method. However, the BRKGA-GS tends to yield worse results compared to that obtained from the standard BRKGA.

  11. An optimization algorithm for a capacitated vehicle routing problem with time windows

    Indian Academy of Sciences (India)

    PINAR KIRCI

    2016-05-01

    In this paper, vehicle routing problem (VRP) with time windows and real world constraints are considered as a real-world application on google maps. Also, tabu search is used and Hopfield neural networks is utilized. Basic constraints consist of customer demands, time windows, vehicle speed, vehicle capacity andworking hours. Recently, cost and on-time delivery are the most important actors in logistics. Thus, the logistic applications attract attention of companies. In logistic management, determining the locations of delivery points and deciding the path are the vital components that should be considered. Deciding the paths of vehicles provides companies to use their vehicles efficiently. And with utilizing optimized paths, big amounts of cost and time savings will be gained. The main aim of the work is providing the best path according to the needs of the customers, minimizing the costs with utilizing the VRP and presenting an application for companies that need logistic management. To compare the results, simulated annealing is used on special scenarios. And t-test is performed in the study for the visited path in km with p-value of 0.05.

  12. Design of a High Voltage Bidirectional DC-DC Converter for Driving Capacitive Incremental Actuators usable in Electric Vehicles (EVs)

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

    2014-01-01

    the converter for efficiently charging and discharging the capacitive actuator from 0 V to 2.5 kV and vice versa, respectively. The converter is used to drive a dielectric electro active polymer (DEAP) based capacitive incremental actuator, which has the potential to be used in automotive (e.g., EVs), space...

  13. Flat pyramid

    OpenAIRE

    Doherty, Kevin Andrew

    2017-01-01

    'Flat pyramid' is a multi-channel video installation. The project employs appropriated promotional and instructional video from a defunct pyramid scheme as the source material for fictionalized reenactment. The footage primarily consists of presentation documentation, testimonial interviews, and product photography—throughout all of which cutting rarely occurs between takes. Perpetrators and victims are seen moving in and out of their promotional personas, inadvertently making their disquieti...

  14. Technical evaluation of vehicle ignition systems: conduct differences between a high energy capacitive system and a standard inductive system

    Directory of Open Access Journals (Sweden)

    Bruno Santos Goulart

    2014-09-01

    Full Text Available An efficient combustion depends on many factors, such as injection, turbulence and ignition characteristics. With the improvement of internal combustion engines the turbulence intensity and internal pressure have risen, demanding more efficient and powerful ignition systems. In direct injection engines, the stratified charge resultant from the wall/air-guided or spray-guided system requires even more energy. The Paschen’s law shows that spark plug gap and mixture density are proportional to the dielectric rupture voltage. It is known that larger spark gaps promote higher efficiency in the internal combustion engines, since the mixture reaction rate rises proportionally. However, the ignition system must be adequate to the imposed gap, not only on energy, but also on voltage and spark duration. For the reported study in this work two test benches were built: a standard inductive ignition system and a capacitive discharge high energy ignition system, with variable voltage and capacitance. The influence of the important parameters energy and ignition voltage on the spark duration, as well as the electrode gap and shape were analyzed. It was also investigated the utilization of a coil with lower resistance and inductance values, as well as spark plugs with and without internal resistances.

  15. Pyramid Comet Sampler Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Based on the sampling requirements, we propose an Inverted Pyramid sampling system. Each face of the pyramid includes a cutting blade which is independently actuated...

  16. Thermoluminescence of pyramid stones

    Energy Technology Data Exchange (ETDEWEB)

    Gomaa, M.A.; Eid, A.M. (Atomic Energy Establishment, Cairo (Egypt))

    1982-01-01

    It is the aim of the present study to investigate some thermoluminescence properties of pyramid stones. Using a few grammes of pyramid stones from Pyramids I and II, the TL glow peaks were observed at 250 and 310/sup 0/C, respectively. The TL glow peaks of samples annealed at 600/sup 0/C, then exposed to /sup 60/Co ..gamma..-rays were observed at 120, 190 and 310/sup 0/C, respectively. The accumulated dose of natural samples is estimated to be around 310 Gray (31 krad). By assuming an annual dose is 1 mGy, the estimated age of pyramid stones is 0.31 M year.

  17. Pyramid beam splitter

    Science.gov (United States)

    McKeown, Mark H.; Beason, Steven C.; Fairer, George

    1992-01-01

    The apparatus of the present invention provides means for obtaining accurate, dependable, measurement of bearings and directions for geologic mapping in subterranean shafts, such as, for example, nuclear waste storage investigations. In operation, a laser beam is projected along a reference bearing. A pyramid is mounted such that the laser beam is parallel to the pyramid axis and can impinge on the apex of the pyramid thus splitting the beam several ways into several beams at right angles to each other and at right angles to the reference beam. The pyramid is also translatable and rotatable in a plane perpendicular to the reference beam.

  18. Food chain algorithm for capacitated vehicle routing problem in reverse logistics%有能力约束回收车辆路径问题的食物链算法

    Institute of Scientific and Technical Information of China (English)

    陈可嘉; 于先康

    2013-01-01

    The capacitated vehicle routing problem in reverse logistics is introduced. The food chain algorithm for the capacitated vehicle routing problem in reverse logistics is designed. A representative example is selected to conduct simulation and comparison. Numerical results show that the performance of the food chain algorithm is better than genetic algorithm, particle swarm optimi-zation as well as quantum evolutionary algorithm.%介绍了有能力约束逆向物流回收车辆路径问题,设计了求解有能力约束逆向物流回收车辆路径问题的食物链算法;选取文献典型算例进行了仿真求解及比较分析,结果表明设计的食物链算法性能优于遗传算法、粒子群算法和量子进化算法。

  19. Rebuilding the Food Pyramid.

    Science.gov (United States)

    Willet, Walter C.; Stampfer, Meir J.

    2003-01-01

    Discusses the old food guide pyramid released in 1992 by the U.S. Department of Agriculture. Contradicts the message that fat is bad, which was presented to the public by nutritionists, and the effects of plant oils on cholesterol. Introduces a new food pyramid. (YDS)

  20. The Healthy Eating Pyramid

    Institute of Scientific and Technical Information of China (English)

    Jimmy; Lin

    2007-01-01

    Experts from the Harvard School of Public Health created the Healthy Eating Pyramid.The pyramid is about the links between diet and health and offers useable information to help people make better choices about what to eat. Remember:its base is daily exercise and weight control.

  1. Vehicle Load Detection System Based on Differential Capacitance Sensor%基于差动式电容传感器的车辆载荷检测系统

    Institute of Scientific and Technical Information of China (English)

    陈梅

    2011-01-01

    针对传统车辆载荷检测系统存在的不足,提出了一种电容式车辆载荷检测系统,该系统的载荷检测传感器采用差动式结构,大大提高了测量的灵敏度和非线性,电容测量线路采用差动脉冲宽度调制集成测量电路,数据的采集和处理采用自带A/D转换器的STC89LE516AD单片机芯片,数据通信采用无线通信模式.这种载荷检测系统结构简单、成本低廉、安装方便、性能可靠、测量电路简单、抗干扰性好,可用于交通数据的采集和便携式测量,具有良好的使用前景.%Aiming at the shorrage of present vehicle load detection system, a capacitive vehicle load detection system is introduced. In the system, the load detection sensor used differential structure, which greatly improved the measurement sensitivity and non-linear, the capacitance measurement circuit used differential pulse width modulation integrated circuit, data acquisition and processing used STC89LE516AD single chip which has its own A / D converter, data communication used wireless communication mode. This load detection system has simple structure, low cost, easy installation, reliable performance,simpLe measurement circuit and good anti-jamming. The system can be used for traffic data collection and portable measurement, and has good application prospects.

  2. Capacitated Vehicle Routing Problem Based on Improved Immune Genetic Algorithm%基于改进免疫算法的有能力约束车辆路径问题

    Institute of Scientific and Technical Information of China (English)

    梁勤欧

    2011-01-01

    针对遗传算法、免疫遗传算法在解决车辆路径问题(VRP)中存在的问题与不足,提出了一种改进免疫遗传算法.该算法主要在检查个体的多样性程度方面进行了简化,运用多样性指数阈值控制种群个体的多样性.通过有能力约束VRP的实验验证了新算法,得到了满意的效果.%There are some problems when genetic algorithm and immune genetic algorithm are used to solve Vehicle Routing Problem ( VRP). An improved immune genetic algorithm was proposed to overcome these disadvantages. The characteristic of the improved immune genetic algorithm is that the diversity detection method was simplified and population diversity was controlled by threshold determination method. Then a simple example of capacitated vehicle routing problem was conducted, and an improved immune genetic algorithm and perfect results were obtained.

  3. Climbing the Needs Pyramids

    Directory of Open Access Journals (Sweden)

    J. C. Lomas

    2013-08-01

    Full Text Available Abraham Maslow’s theory of human adult motivation is often represented by a pyramid image showing two proposals: First, the five needs stages in emergent order of hierarchical ascension and second, a percentage of the adult population suggested to occupy each needs tier. Specifically, Maslow proposed that adults would be motivated to satisfy their unfilled needs until they reached the hierarchy’s apex and achieved self-transcendence. Yet how adults can purposefully ascend Maslow’s pyramid through satisfying unfilled needs remains elusive. This brief article challenges this on the theory’s 70th anniversary by presenting a new image of the needs hierarchy, based on ecological design principles to support adults’ purposeful endeavors to climb the needs pyramid.

  4. PYRAMID ROADLESS AREA, CALIFORNIA.

    Science.gov (United States)

    Armstrong, Augustus K.; Scott, Douglas F.

    1984-01-01

    A geologic and mineral survey was conducted in the Pyramid Roadless Area, California. The area contains mineral showings, but no mineral-resource potential was identified during our studies. Three granodiorite samples on the west side of the roadless area contained weakly anomalous concentrations of uranium. Two samples of roof-pendant rocks, one metasedimentary rock and one metavolcanic rock, contain low concentrations of copper, and of copper and molybdenum, respectively. Although none was identified, the geologic terrane is permissive for mineral occurrences and large-scale, detailed geologic mapping of the areas of metasedimentary and metavolcanic roof pendants in the Pyramid Roadless Area could define a mineral-resource potential for tungsten and precious metals.

  5. Building the next pyramid

    CERN Document Server

    West, Joseph; Waters, Kevin; Ward, Stephen; Ward, Tia

    2015-01-01

    The results of experimental tests of a novel method for moving large (pyramid construction size) stone blocks by rolling them are presented. The method is implemented by tying 12 identical rods of appropriately chosen radius to the faces of the block forming a rough dodecagon prism. Experiments using a 1,000 kg block show that it can be moved across level open ground with a dynamic coefficient of friction of less than 0.06. This value is a factor of five lower than that obtained for dragging the block, and the best values reported for dragging by others, at 0.3. the results are more dramatic than those obtained on smaller scale experiments on a 29.6 kg block, also reported here. For full scale pyramid blocks, the wooden "rods" woudl need to be posts of order 30 cm in diameter, similar in size to those used as masts on ships in the Nile.

  6. Climbing the Needs Pyramids

    OpenAIRE

    J. C. Lomas

    2013-01-01

    Abraham Maslow’s theory of human adult motivation is often represented by a pyramid image showing two proposals: First, the five needs stages in emergent order of hierarchical ascension and second, a percentage of the adult population suggested to occupy each needs tier. Specifically, Maslow proposed that adults would be motivated to satisfy their unfilled needs until they reached the hierarchy’s apex and achieved self...

  7. Climbing the Needs Pyramids

    OpenAIRE

    J. C. Lomas

    2013-01-01

    Abraham Maslow’s theory of human adult motivation is often represented by a pyramid image showing two proposals: First, the five needs stages in emergent order of hierarchical ascension and second, a percentage of the adult population suggested to occupy each needs tier. Specifically, Maslow proposed that adults would be motivated to satisfy their unfilled needs until they reached the hierarchy’s apex and achieved self...

  8. Imaging the Cheops Pyramid

    CERN Document Server

    Bui, H D

    2012-01-01

    In this book Egyptian Archeology  and Mathematics meet. The author is an expert in theories and applications in Solid Mechanics and Inverse Problems, a former professor at Ecole Polytechnique and now works with Electricité de France on maintenance operations on nuclear power plants. In the Autumn of 1986, after the end of the operation on the King’s chamber conducted under the Technological and Scientific Sponsorship of EDF, to locate a cavity, he was called to solve a mathematical inverse problem, to find the unknown tomb of the King and the density structure of the whole pyramid based on measurements of microgravity made inside and outside of the pyramid. This book recounts the various search operations on the pyramid of Cheops made at the request of the Egyptian and French authorities in 1986-1987. After the premature end of the Cheops operation in the Autumn of 1986, following the fiasco of unsuccessful drillings in the area suspected by both architects G. Dormion and J.P. Goidin and microgravity aus...

  9. Event Detection by Velocity Pyramid

    OpenAIRE

    2014-01-01

    In this paper, we propose velocity pyramid for multimediaevent detection. Recently, spatial pyramid matching is proposed to in-troduce coarse geometric information into Bag of Features framework,and is eective for static image recognition and detection. In video, notonly spatial information but also temporal information, which repre-sents its dynamic nature, is important. In order to fully utilize it, wepropose velocity pyramid where video frames are divided into motionalsub-regions. Our meth...

  10. PYRAMID LAKE RENEWEABLE ENERGY PLAN

    Energy Technology Data Exchange (ETDEWEB)

    HIGH DESERT GEOCULTURE, LLC

    2009-06-06

    The Pyramid Lake Renewable Energy Plan covers these areas: energy potential (primarily focusing on geothermal resource potential, but also more generally addressing wind energy potential); renewable energy market potential; transmission system development; geothermal direct use potential; and business structures to accomplish the development objectives of the Pyramid Lake Paiute Tribe.

  11. Capacitive chemical sensor

    Science.gov (United States)

    Manginell, Ronald P; Moorman, Matthew W; Wheeler, David R

    2014-05-27

    A microfabricated capacitive chemical sensor can be used as an autonomous chemical sensor or as an analyte-sensitive chemical preconcentrator in a larger microanalytical system. The capacitive chemical sensor detects changes in sensing film dielectric properties, such as the dielectric constant, conductivity, or dimensionality. These changes result from the interaction of a target analyte with the sensing film. This capability provides a low-power, self-heating chemical sensor suitable for remote and unattended sensing applications. The capacitive chemical sensor also enables a smart, analyte-sensitive chemical preconcentrator. After sorption of the sample by the sensing film, the film can be rapidly heated to release the sample for further analysis. Therefore, the capacitive chemical sensor can optimize the sample collection time prior to release to enable the rapid and accurate analysis of analytes by a microanalytical system.

  12. Locating Depots for Capacitated Vehicle Routing

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath

    2011-01-01

    and parameter ρ ∈ R+, the goal in the k median forest problem is to find S ⊆ V with |S| = k minimizing: E u∈V d(u, S) + ρ · d(MST(V/S) ), where d(u, S) = minw∈S d(u,w) and MST(V/S) is a minimum spanning tree in the graph obtained by contracting S to a single vertex. We give a (3+E)-approximation algorithm for k...... median forest, which leads to a (12+E)-approximation algorithm for k-LocVRP, for any constant E > 0. The algorithm for k median forest is t-swap local search, and we prove that it has locality gap 3 + 2 t ; this generalizes the corresponding result for k median [3]. Finally we consider the k median...... forest problem when there is a different (unrelated) cost function c for the MST part, i.e. the objective is Eu∈V d(u, S) + c(MST(V/S) ). We show that the locality gap for this problem is unbounded even under multi-swaps, which contrasts with the c = d case. Nevertheless, we obtain a constant...

  13. Capacitated Vehicle Routing with Nonuniform Speeds

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Molinaro, Marco; Nagarajan, Viswanath

    2016-01-01

    is the distance traveled divided by its speed.Our algorithm relies on a new approximate minimum spanning tree construction called Level-Prim, which is related to but different from Light Approximate Shortest-path Trees. We also extend the widely used tour-splitting technique to nonuniform speeds, using ideas from...

  14. A Capacitated Facility Location Approach for the Tanker Employment Problem

    Science.gov (United States)

    2005-03-01

    Depot (MD) Vehicle Routing Problem (VRP) ......................................... 14 2.5 Capacitated Facility Location Problem (CFLP) with Sole...service receiver groups. In this sense the problem can be viewed as a multi-depot vehicle routing problem . Anchor points are two stationary points...for future research. 2.4 Multi-Depot (MD) Vehicle Routing Problem (VRP) Another approach to the Tanker Employment Problem is to model it as a VRP

  15. Quasi-Convolution Pyramidal Blurring

    OpenAIRE

    Kraus, Martin

    2008-01-01

    Efficient image blurring techniques based on the pyramid algorithm can be implemented on modern graphics hardware; thus, image blurring with arbitrary blur width is possible in real time even for large images. However, pyramidal blurring methods do not achieve the image quality provided by convolution filters; in particular, the shape of the corresponding filter kernel varies locally, which potentially results in objectionable rendering artifacts. In this work, a new analysis filter is design...

  16. Overcomplete steerable pyramid filters and rotation invariance

    OpenAIRE

    Greenspan, H.; Belongie, S; Goodman, R; Perona, P.; Rakshit, S.; C. H. Anderson

    1994-01-01

    A given (overcomplete) discrete oriented pyramid may be converted into a steerable pyramid by interpolation. We present a technique for deriving the optimal interpolation functions (otherwise called 'steering coefficients'). The proposed scheme is demonstrated on a computationally efficient oriented pyramid, which is a variation on the Burt and Adelson (1983) pyramid. We apply the generated steerable pyramid to orientation-invariant texture analysis in order to demonstrate its excellent rotat...

  17. Overcomplete steerable pyramid filters and rotation invariance

    OpenAIRE

    1994-01-01

    A given (overcomplete) discrete oriented pyramid may be converted into a steerable pyramid by interpolation. We present a technique for deriving the optimal interpolation functions (otherwise called 'steering coefficients'). The proposed scheme is demonstrated on a computationally efficient oriented pyramid, which is a variation on the Burt and Adelson (1983) pyramid. We apply the generated steerable pyramid to orientation-invariant texture analysis in order to demonstrate its excellent rotat...

  18. Steerable Capacitive Proximity Sensor

    Science.gov (United States)

    Jenstrom, Del T.; Mcconnell, Robert L.

    1994-01-01

    Steerable capacitive proximity sensor of "capaciflector" type based partly on sensing units described in GSC-13377 and GSC-13475. Position of maximum sensitivity adjusted without moving sensor. Voltage of each driven shield adjusted separately to concentrate sensing electric field more toward one side or other.

  19. Membrane capacitive deionization

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Wal, van der A.

    2010-01-01

    Membrane capacitive deionization (MCDI) is an ion-removal process based on applying an electrical potential difference across an aqueous solution which flows in between oppositely placed porous electrodes, in front of which ion-exchange membranes are positioned. Due to the applied potential, ions ar

  20. A branch-and-cut-and-price algorithm for the mixed capacitated general routing problem

    DEFF Research Database (Denmark)

    Bach, Lukas; Wøhlk, Sanne; Lysgaard, Jens

    2016-01-01

    In this paper, we consider the Mixed Capacitated General Routing Problem which is a combination of the Capacitated Vehicle Routing Problem and the Capacitated Arc Routing Problem. The problem is also known as the Node, Edge, and Arc Routing Problem. We propose a Branch-and-Cut-and-Price algorithm...... for obtaining optimal solutions to the problem and present computational results based on a set of standard benchmark instances....

  1. Pyramid Lake Task Force : Final report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Pyramid Lake Task Force was created to address Pyramid Lake’s recession and recommend possible solutions that would consider both the needs for preserving the...

  2. One Kind of Network Complexity Pyramid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Pyramid architecture can be widely found in nature and most social fields. For example, Zoltvai and Barabasi firstly proposed the life’s complexity pyramid in biology science, and it was found that the

  3. A Rebuttal of NTL Institute's Learning Pyramid

    Science.gov (United States)

    Letrud, Kare

    2012-01-01

    This article discusses the learning pyramid corroborated by National Training Laboratories Institute. It present and compliment historical and methodological critique against the learning pyramid, and call upon NTL Institute ought to retract their model.

  4. Capacitive deionization of seawater

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Fix, D.V.; Mack, G.V. [and others

    1995-10-01

    Capacitive deionization with carbon aerogel electrodes is an efficient and economical new process for removing salt and impurities from water. Carbon aerogel is a material that enables the successful purification of water because of its high surface area, optimum pore size, and low electrical resistivity. The electrodes are maintained at a potential difference of about one volt; ions are removed from the water by the imposed electrostatic field and retained on the electrode surface until the polarity is reversed. The capacitive deionization of water with a stack of carbon aerogel electrodes has been successfully demonstrated. The overall process offers advantages when compared to conventional water-purification methods, requiring neither pumps, membranes, distillation columns, nor thermal heaters. Consequently, the overall process is both robust and energy efficient. The current state of technology development, commercialization, and potential applications of this process are reviewed.

  5. Induced Charge Capacitive Deionization

    CERN Document Server

    Rubin, S; Biesheuvel, P M; Bercovici, M

    2016-01-01

    We demonstrate the phenomenon of induced-charge capacitive deionization (ICCDI) that occurs around a porous and conducting particle immersed in an electrolyte, under the action of an external electrostatic field. The external electric field induces an electric dipole in the porous particle, leading to capacitive charging of its volume by both cations and anions at opposite poles. This regime is characterized both by a large RC charging time and a small electrochemical charge relaxation time, which leads to rapid and significant deionization of ionic species from a volume which is on the scale of the particle. We show by theory and experiment that the transient response around a cylindrical particle results in spatially non-uniform charging and non-steady growth of depletion regions which emerge around the particle's poles. Potentially, ICCDI can be useful in applications where fast concentration changes of ionic species are required over large volumes.

  6. Urban Public Health: Is There a Pyramid?

    OpenAIRE

    Meirong Su; Bin Chen; Zhifeng Yang; Yanpeng Cai; Jiao Wang

    2013-01-01

    Early ecologists identified a pyramidal trophic structure in terms of number, biomass and energy transfer. In 1943, the psychologist Maslow put forward a pyramid model to describe layers of human needs. It is indicated that the pyramid principle is universally applicable in natural, humanistic and social disciplines. Here, we report that a pyramid structure also exists in urban public health (UPH). Based on 18 indicators, the UPH states of four cities (Beijing, Tokyo, New York, and London) ar...

  7. An Approximation Algorithm for the Capacitated Arc Routing Problem

    DEFF Research Database (Denmark)

    Wøhlk, Sanne

    2008-01-01

    In this paper we consider approximation of the Capacitated Arc Routing Problem, which is the problem of servicing a set of edges in a graph using a fleet of capacity constrained vehicles. We present a 7/2 - 3/W-approximation algorithm for the problem and prove that this algorithm outperforms...

  8. A magic pyramid of supergravities

    Energy Technology Data Exchange (ETDEWEB)

    Anastasiou, A.; Borsten, L.; Duff, M.J.; Hughes, L.J.; Nagy, S. [Theoretical Physics, Blackett Laboratory, Imperial College London,London SW7 2AZ (United Kingdom)

    2014-04-29

    By formulating N=1,2,4,8, D=3, Yang-Mills with a single Lagrangian and single set of transformation rules, but with fields valued respectively in ℝ,ℂ,ℍ,O, it was recently shown that tensoring left and right multiplets yields a Freudenthal-Rosenfeld-Tits magic square of D=3 supergravities. This was subsequently tied in with the more familiar ℝ,ℂ,ℍ,O description of spacetime to give a unified division-algebraic description of extended super Yang-Mills in D=3,4,6,10. Here, these constructions are brought together resulting in a magic pyramid of supergravities. The base of the pyramid in D=3 is the known 4×4 magic square, while the higher levels are comprised of a 3×3 square in D=4, a 2×2 square in D=6 and Type II supergravity at the apex in D=10. The corresponding U-duality groups are given by a new algebraic structure, the magic pyramid formula, which may be regarded as being defined over three division algebras, one for spacetime and each of the left/right Yang-Mills multiplets. We also construct a conformal magic pyramid by tensoring conformal supermultiplets in D=3,4,6. The missing entry in D=10 is suggestive of an exotic theory with G/H duality structure F{sub 4(4)}/Sp(3)×Sp(1)

  9. A magic pyramid of supergravities

    Science.gov (United States)

    Anastasiou, A.; Borsten, L.; Duff, M. J.; Hughes, L. J.; Nagy, S.

    2014-04-01

    By formulating = 1, 2, 4, 8, D = 3, Yang-Mills with a single Lagrangian and single set of transformation rules, but with fields valued respectively in , it was recently shown that tensoring left and right multiplets yields a Freudenthal-Rosenfeld-Tits magic square of D = 3 supergravities. This was subsequently tied in with the more familiar description of spacetime to give a unified division-algebraic description of extended super Yang-Mills in D = 3, 4, 6, 10. Here, these constructions are brought together resulting in a magic pyramid of supergravities. The base of the pyramid in D = 3 is the known 4 × 4 magic square, while the higher levels are comprised of a 3 × 3 square in D = 4, a 2 × 2 square in D = 6 and Type II supergravity at the apex in D = 10. The corresponding U-duality groups are given by a new algebraic structure, the magic pyramid formula, which may be regarded as being defined over three division algebras, one for spacetime and each of the left/right Yang-Mills multiplets. We also construct a conformal magic pyramid by tensoring conformal supermultiplets in D = 3, 4, 6. The missing entry in D = 10 is suggestive of anexotic theory with G/ H duality structure F 4(4)/Sp(3) × Sp(1).

  10. The Base of the Pyramid

    NARCIS (Netherlands)

    Hutte, E.; Vermeulen, P.A.M.

    2014-01-01

    This chapter provides a brief background to the Base of the Pyramid (BoP) phenomenon. It begins with a discussion on what sets the BoP markets apart from more traditional markets and why companies have not identified them as a business opportunity. The chapter then provides an overview of how

  11. Three Types of Network Complexity Pyramid

    Institute of Scientific and Technical Information of China (English)

    FANG; Jin-qing; LI; Yong; LIU; Qiang

    2012-01-01

    <正>Exploring the complexity and diversity of complex networks have been very challenging issues in network science and engineering. Among them exploring the network complexity pyramids (NCP) are one of important expressions in network complexity. So far as we have proposed the three types of the network complexity pyramid (NCP). The first type of NCP is the network model complexity pyramid with

  12. The Chinese Pyramids and the Sun

    CERN Document Server

    Sparavigna, Amelia Carolina

    2012-01-01

    The Chinese Pyramids are huge ancient burial mounds. In the satellite images we can see some complexes where the main buildings are the pyramidal mounds of an emperor and his empress. Here we discuss a possible sunrise/sunset orientation of these two pyramids on the solstices and equinoxes.

  13. Capacitance of circular patch resonator

    Energy Technology Data Exchange (ETDEWEB)

    Miano, G.; Verolino, L. [Dip. di Ingegneria Elettrica, Ist. Nazionale di Fisica Nucleare, Naples (Italy); Panariello, G. [Dip. di Ingegneria Elettronica, Naples (Italy); Vaccaro, V.G. [Ist. Nazionale di Fisica Nucleare, Naples (Italy). Dipt. di Scienze Fisiche

    1995-11-01

    In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants.

  14. Capacitive label reader

    Science.gov (United States)

    Arlowe, H. Duane

    1985-01-01

    A capacitive label reader includes an outer ring transmitting portion, an inner ring transmitting portion, and a plurality of insulated receiving portions. A label is the mirror-image of the reader except that identifying portions corresponding to the receiving portions are insulated from only one of two coupling elements. Positive and negative pulses applied, respectively, to the two transmitting rings biased a CMOS shift register positively to either a 1 or 0 condition. The output of the CMOS may be read as an indication of the label.

  15. The Vehicle Rescheduling Problem

    NARCIS (Netherlands)

    R. Spliet (Remy); A.F. Gabor (Adriana); R. Dekker (Rommert)

    2009-01-01

    textabstractThe capacitated vehicle routing problem is to find a routing schedule describing the order in which geographically dispersed customers are visited to satisfy demand by supplying goods stored at the depot, such that the traveling costs are minimized. In many practical applications, a long

  16. The Digital Von Fahrenheid Pyramid

    Science.gov (United States)

    Bura, M.; Janowski, J.; Wężyk, P.; Zięba, K.

    2017-08-01

    3D Scanners Lab from Digital Humanities Laboratory at the University of Warsaw initiated the scientific project, the purpose of which was to call attention to systematically penetrated and devastated pyramid-shaped tomb from the XVIII/XIX century, of family von Fahrenheid in Rapa in Banie Mazurskie commune (NE Poland). By conducting a series of non-invasive studies, such as 3D inventory using terrestrial laser scanning (TLS), thermal imaging, georadar measurements (around and inside the tomb) and anthropological research of mummified remains as well - the complete dataset was collected. Through the integration of terrestrial (TLS) and airborne laser scanning (ALS) authors managed to analyse the surroundings of Fahrenheid pyriamid and influence of some objects (like trees) on the condition and visibility of the Pyramids in the landscape.

  17. A magic pyramid of supergravities

    CERN Document Server

    Anastasiou, A; Duff, M J; Hughes, L J; Nagy, S

    2013-01-01

    By formulating N = 1, 2, 4, 8, D = 3, Yang-Mills with a single Lagrangian and single set of transformation rules, but with fields valued respectively in R,C,H,O, it was recently shown that tensoring left and right multiplets yields a Freudenthal-Rosenfeld-Tits magic square of D = 3 supergravities. This was subsequently tied in with the more familiar R,C,H,O description of spacetime to give a unified division-algebraic description of extended super Yang-Mills in D = 3, 4, 6, 10. Here, these constructions are brought together resulting in a magic pyramid of supergravities. The base of the pyramid in D = 3 is the known 4x4 magic square, while the higher levels are comprised of a 3x3 square in D = 4, a 2x2 square in D = 6 and Type II supergravity at the apex in D = 10. The corresponding U-duality groups are given by a new algebraic structure, the magic pyramid formula, which may be regarded as being defined over three division algebras, one for spacetime and each of the left/right Yang-Mills multiplets. We also c...

  18. A novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances

    Institute of Scientific and Technical Information of China (English)

    Dong Linxi; Chen Jindan; Yan Haixia; Huo Weihong; Li Yongjie; Sun Lingling

    2009-01-01

    The comb capacitances fabricated by deep reactive ion etching (RIE) process have high aspect ratio which is usually smaller than 30 : 1 for the complicated process factors, and the combs are usually not parallel due to the well-known micro-loading effect and other process factors, which restricts the increase of the seismic mass by increasing the thickness of comb to reduce the thermal mechanical noise and the decrease of the gap of the comb capacitances for increasing the sensitive capacitance to reduce the electrical noise. Aiming at the disadvantage of the deep RIE, a novel capacitive micro-accelerometer with grid strip capacitances and sensing gap alterable capacitances is developed. One part of sensing of inertial signal of the micro-accelerometer is by the grid strip capacitances whose overlapping area is variable and which do not have the non-parallel plate's effect caused by the deep RIE process. Another part is by the sensing gap alterable capacitances whose gap between combs can be reduced by the actuators. The designed initial gap of the alterable comb capacitances is relatively large to depress the effect of the maximum aspect ratio (30 : 1) of deep RIE process. The initial gap of the capacitance of the actuator is smaller than the one of the comb capacitances. The difference between the two gaps is the initial gap of the sensitive capacitor. The designed structure depresses greatly the requirement of deep RIE process. The effects of non-parallel combs on the accelerometer are also analyzed. The characteristics of the micro-accelerometer are discussed by field emission microscopy (FEM) tool ANSYS. The tested devices based on slide-film damping effect are fabricated, and the tested quality factor is 514, which shows that grid strip capacitance design can partly improve the resolution and also prove the feasibility of the designed silicon-glass anodically bonding process.

  19. Optimal pricing of capacitated networks

    NARCIS (Netherlands)

    Grigoriev, Alexander; Loon, van Joyce; Sitters, René; Uetz, Marc

    2009-01-01

    We address the algorithmic complexity of a profit maximization problem in capacitated, undirected networks. We are asked to price a set of $m$ capacitated network links to serve a set of $n$ potential customers. Each customer is interested in purchasing a network connection that is specified by a si

  20. Efficiency of Capacitively Loaded Converters

    DEFF Research Database (Denmark)

    Andersen, Thomas; Huang, Lina; Andersen, Michael A. E.;

    2012-01-01

    This paper explores the characteristic of capacitance versus voltage for dielectric electro active polymer (DEAP) actuator, 2kV polypropylene film capacitor as well as 3kV X7R multi layer ceramic capacitor (MLCC) at the beginning. An energy efficiency for capacitively loaded converters...... is introduced as a definition of efficiency. The calculated and measured efficiency curves for charging DEAP actuator, polypropylene film capacitor and X7R MLCC are provided and compared. The attention has to be paid for the voltage dependent capacitive load, like X7R MLCC, when evaluating the charging...... polypropylene film capacitor can be the equivalent capacitive load. Because of the voltage dependent characteristic, X7R MLCC cannot be used to replace the DEAP actuator. However, this type of capacitor can be used to substitute the capacitive actuator with voltage dependent property at the development phase....

  1. Pyramid Schemes on the Tibetan Plateau

    OpenAIRE

    Devin Gonier; Rgyal yum sgrol ma

    2012-01-01

    The unique features of pyramid schemes and certain underlying causes for their development on the Tibetan Plateau are analyzed. Research was conducted by analyzing 521 surveys, allowing estimation of pyramid scheme activity on the Plateau and an identification of related cultural and social specificities. Firsthand accounts were collected revealing details of personal involvement. Survey data and similarities in the accounts were studied to suggest how involvement in pyramid schemes might be ...

  2. Urban Public Health: Is There a Pyramid?

    Science.gov (United States)

    Su, Meirong; Chen, Bin; Yang, Zhifeng; Cai, Yanpeng; Wang, Jiao

    2013-01-01

    Early ecologists identified a pyramidal trophic structure in terms of number, biomass and energy transfer. In 1943, the psychologist Maslow put forward a pyramid model to describe layers of human needs. It is indicated that the pyramid principle is universally applicable in natural, humanistic and social disciplines. Here, we report that a pyramid structure also exists in urban public health (UPH). Based on 18 indicators, the UPH states of four cities (Beijing, Tokyo, New York, and London) are compared from the point of view of five aspects, namely physical health, living conditions, social security, environmental quality, and education and culture. A pyramid structure was found in each city when focusing on 2000–2009 data. The pyramid of Beijing is relatively similar to that of Tokyo, and the pyramids of New York and London are similar to each other. A general development trend in UPH is proposed and represented by different pyramid modes. As a basic conjecture, the UPH pyramid model can be verified and developed with data of more cities over a longer period, and be used to promote healthy urban development. PMID:23358233

  3. The pyramids of Greece: Ancient meridian observatories?

    Science.gov (United States)

    Theodossiou, Efstratios; Manimanis, Vassilios N.; Dimitrijević, Milan S.; Katsiotis, Marco

    Pyramids, "Dragon Houses" ("Drakospita") and megalithic structures in general create always a special interest. We postulate that, as happens with the Drakospita of Euboea, the pyramid-like structures of Argolis (Eastern Peloponnese) were constructed by the Dryops. It is known that, in addition to Euboea and some Cyclades islands, this prehellenic people had also settled in Argolis, where they founded the city of Asine. We also propose that the pyramids of Argolis and in particular the pyramid of Hellinikon village were very likely, besides being a burial monument or guard house, might be served also for astronomical observations.

  4. Urban Public Health: Is There a Pyramid?

    Directory of Open Access Journals (Sweden)

    Meirong Su

    2013-01-01

    Full Text Available Early ecologists identified a pyramidal trophic structure in terms of number, biomass and energy transfer. In 1943, the psychologist Maslow put forward a pyramid model to describe layers of human needs. It is indicated that the pyramid principle is universally applicable in natural, humanistic and social disciplines. Here, we report that a pyramid structure also exists in urban public health (UPH. Based on 18 indicators, the UPH states of four cities (Beijing, Tokyo, New York, and London are compared from the point of view of five aspects, namely physical health, living conditions, social security, environmental quality, and education and culture. A pyramid structure was found in each city when focusing on 2000–2009 data. The pyramid of Beijing is relatively similar to that of Tokyo, and the pyramids of New York and London are similar to each other. A general development trend in UPH is proposed and represented by different pyramid modes. As a basic conjecture, the UPH pyramid model can be verified and developed with data of more cities over a longer period, and be used to promote healthy urban development.

  5. Urban public health: is there a pyramid?

    Science.gov (United States)

    Su, Meirong; Chen, Bin; Yang, Zhifeng; Cai, Yanpeng; Wang, Jiao

    2013-01-28

    Early ecologists identified a pyramidal trophic structure in terms of number, biomass and energy transfer. In 1943, the psychologist Maslow put forward a pyramid model to describe layers of human needs. It is indicated that the pyramid principle is universally applicable in natural, humanistic and social disciplines. Here, we report that a pyramid structure also exists in urban public health (UPH). Based on 18 indicators, the UPH states of four cities (Beijing, Tokyo, New York, and London) are compared from the point of view of five aspects, namely physical health, living conditions, social security, environmental quality, and education and culture. A pyramid structure was found in each city when focusing on 2000-2009 data. The pyramid of Beijing is relatively similar to that of Tokyo, and the pyramids of New York and London are similar to each other. A general development trend in UPH is proposed and represented by different pyramid modes. As a basic conjecture, the UPH pyramid model can be verified and developed with data of more cities over a longer period, and be used to promote healthy urban development.

  6. Update on the Pyramid Scheme

    Science.gov (United States)

    Banks, Tom; Torres, T. J.

    2012-10-01

    We summarize recent work in which we attempt to make consistent models of LHC physics, from the Pyramid Scheme. The models share much with the NMSSM, in particular, enhanced tree level contributions to the Higgs mass and a preference for small tan β. There are three different singlet fields, and a new strongly coupled gauge theory, so the constraints of perturbative unification are quite different. We outline our general approach to the model, which contains a Kähler potential for three of the low energy fields, which is hard to calculate. Detailed calculations, based on approximations to the Kähler potential, will be presented in a future publication.

  7. Active browsing using similarity pyramids

    Science.gov (United States)

    Chen, Jau-Yuen; Bouman, Charles A.; Dalton, John C.

    1998-12-01

    In this paper, we describe a new approach to managing large image databases, which we call active browsing. Active browsing integrates relevance feedback into the browsing environment, so that users can modify the database's organization to suit the desired task. Our method is based on a similarity pyramid data structure, which hierarchically organizes the database, so that it can be efficiently browsed. At coarse levels, the similarity pyramid allows users to view the database as large clusters of similar images. Alternatively, users can 'zoom into' finer levels to view individual images. We discuss relevance feedback for the browsing process, and argue that it is fundamentally different from relevance feedback for more traditional search-by-query tasks. We propose two fundamental operations for active browsing: pruning and reorganization. Both of these operations depend on a user-defined relevance set, which represents the image or set of images desired by the user. We present statistical methods for accurately pruning the database, and we propose a new 'worm hole' distance metric for reorganizing the database, so that members of the relevance set are grouped together.

  8. The cradle of pyramids in satellite images

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

    We propose the use of image processing to enhance the Google Maps of some archaeological areas of Egypt. In particular we analyse that place which is considered the cradle of pyramids, where it was announced the discovery of a new pyramid by means of an infrared remote sensing.

  9. An Approximation Algorithm for the Capacitated Arc Routing Problem

    DEFF Research Database (Denmark)

    Wøhlk, Sanne

    2008-01-01

    In this paper we consider approximation of the Capacitated Arc Routing Problem, which is the problem of servicing a set of edges in a graph using a fleet of capacity constrained vehicles. We present a 7/2 - 3/W-approximation algorithm for the problem and prove that this algorithm outperforms...... the only existing approximation algorithm for the problem. Furthermore, we give computational results showing that the new algorithm performs very well  in practice....

  10. Capacitance probe for detection of anomalies in non-metallic plastic pipe

    Science.gov (United States)

    Mathur, Mahendra P.; Spenik, James L.; Condon, Christopher M.; Anderson, Rodney; Driscoll, Daniel J.; Fincham, Jr., William L.; Monazam, Esmail R.

    2010-11-23

    The disclosure relates to analysis of materials using a capacitive sensor to detect anomalies through comparison of measured capacitances. The capacitive sensor is used in conjunction with a capacitance measurement device, a location device, and a processor in order to generate a capacitance versus location output which may be inspected for the detection and localization of anomalies within the material under test. The components may be carried as payload on an inspection vehicle which may traverse through a pipe interior, allowing evaluation of nonmetallic or plastic pipes when the piping exterior is not accessible. In an embodiment, supporting components are solid-state devices powered by a low voltage on-board power supply, providing for use in environments where voltage levels may be restricted.

  11. Maskless inverted pyramid texturization of silicon.

    Science.gov (United States)

    Wang, Yan; Yang, Lixia; Liu, Yaoping; Mei, Zengxia; Chen, Wei; Li, Junqiang; Liang, Huili; Kuznetsov, Andrej; Xiaolong, Du

    2015-06-02

    We discovered a technical solution of such outstanding importance that it can trigger new approaches in silicon wet etching processing and, in particular, photovoltaic cell manufacturing. The so called inverted pyramid arrays, outperforming conventional pyramid textures and black silicon because of their superior light-trapping and structure characteristics, can currently only be achieved using more complex techniques involving lithography, laser processing, etc. Importantly, our data demonstrate a feasibility of inverted pyramidal texturization of silicon by maskless Cu-nanoparticles assisted etching in Cu(NO3)2 / HF / H2O2 / H2O solutions and as such may have significant impacts on communities of fellow researchers and industrialists.

  12. Bioenergetics of Mammalian Sperm Capacitation

    Directory of Open Access Journals (Sweden)

    Alessandra Ferramosca

    2014-01-01

    Full Text Available After ejaculation, the mammalian male gamete must undergo the capacitation process, which is a prerequisite for egg fertilization. The bioenergetics of sperm capacitation is poorly understood despite its fundamental role in sustaining the biochemical and molecular events occurring during gamete activation. Glycolysis and mitochondrial oxidative phosphorylation (OXPHOS are the two major metabolic pathways producing ATP which is the primary source of energy for spermatozoa. Since recent data suggest that spermatozoa have the ability to use different metabolic substrates, the main aim of this work is to present a broad overview of the current knowledge on the energy-producing metabolic pathways operating inside sperm mitochondria during capacitation in different mammalian species. Metabolism of glucose and of other energetic substrates, such as pyruvate, lactate, and citrate, is critically analyzed. Such knowledge, besides its obvious importance for basic science, could eventually translate into the development of novel strategies for treatment of male infertility, artificial reproduction, and sperm selection methods.

  13. Unified capacitance modelling of MOSFETs

    Science.gov (United States)

    Johannessen, O. G.; Fjeldly, T. A.; Ytterdal, T.

    1994-01-01

    A unified physics based capacitance model for MOSFETs suitable for implementation in circuit simulators is presented. This model is based on the charge conserving, so-called Meyer-like approach proposed by Turchetti et al., and utilizes a unified charge control model to assure a continuous description of the MOSFET capacitances both above and below threshold. The capacitances associated with the model are comparable to those of the well-known BSIM model in the above-threshold regime, but it is more precise in the description of near-threshold and subthreshold behaviour. Moreover, the discontinuities at the transitions between the various regimes of operation are removed. The present modelling scheme was implemented in our circuit simulator AIM-Spice, and simulations of the dynamic behaviour of various demanding benchmark circuits clearly reveal its superiority over simulations using the simple Meyer model.

  14. FABRIC DEFECT DETECTION USING STEERABLE PYRAMID

    Directory of Open Access Journals (Sweden)

    S. Mythili

    2011-05-01

    Full Text Available In this paper, a novel idea is proposed for fabric defect detection. De- fects are detected in the fabric using steerable pyramid along with a defect detection algorithm. Various steerable pyramid of four size 256*256, 128*128, 64*64, 32*32 and with four orientation bands 00,450, 900, 1350 are used. Utilizing a Steerable pyramid proved ade- quate in the representation of fabric images in multi-scale and multi- orientations; thus allowing defect detection algorithms to run more effectively. Defect detection algorithm identifies and locates the im- perfection in the defective sample using the statistics mean and stan- dard deviation. This statistics represents the relative amount of inten- sity in the texture and is sufficient to measure defects in the current model .The obtained result are compared with the existing methods wavelet based system and with Gaussian and Laplacian pyramid.

  15. Evaluation of the Green Egyptian Pyramid

    Directory of Open Access Journals (Sweden)

    Mohamed Gamal Ammar

    2012-12-01

    The research concluded to the need of developing the Egyptian pyramid system through studying more global systems, in addition to the need to benefit from the Egyptian experience stock of solutions and environmental treatments in ancient architecture.

  16. Waring’s Problem for Pyramidal Numbers

    Institute of Scientific and Technical Information of China (English)

    邓越凡; 杨振宁

    1994-01-01

    It has been proved that every positive integer is expressible as a sum of no more than eight pyramidal numbers P(m)=(m-1)m(m+1)/6.This paper reports on a computer calculation of the partition of integers from n=1 to 109 into pyramidal numbers.We find that no integer≤10°needs more than five pyramidal numbers for its partition,and only 241 of them do need five.We define J(n) as the least number of pyramidal numbers to partition n,and Nk(n) as the number of positive integers l less than or equal to n for which J(l)=k.Based on our numerical results we make conjectures about the asymptotic form of Nk(n) for n→∞

  17. Simulation of gene pyramiding in Drosophila melanogaster

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Gene pyramiding has been successfully practiced in plant breeding for developing new breeds or lines in which favorable genes from several different lines were integrated.But it has not been used in animal breeding,and some theoretical investigation and simulation analysis with respect to its strategies,feasibility and efficiency are needed before it can be implemented in animals.In this study,we used four different pure fines of Drosophila melanogaster,each of which is homozygous at a specific mutant gene with a visible effect on phenotype,to simulate the gene pyramiding process and analyze the duration and population size required in different pyramiding strategies.We finally got the ideal individuals,which are homozygous at the four target genes simultaneously.This study demonstrates that gene pyramiding is feasible in animal breeding and the interaction between genes may affect the final results.

  18. Work, gravitational energy and the Great Pyramid

    Science.gov (United States)

    Tort, A. C.

    2015-09-01

    According to the Greek historian Herodotus, it took a task force of 100 000 men and 20 years to build up the Great Pyramid of Gizeh or Khufu’s Pyramid. In this work we discuss an analytical solution obtained in the framework of basic Newtonian mechanics that allows us to check Herodotus’s statement. Numerical estimates are compared to more detailed calculations. An estimation of the dietary energy intake necessary to accomplish the task is also discussed.

  19. Capacitated arc routing problem and its extensions in waste collection

    Science.gov (United States)

    Fadzli, Mohammad; Najwa, Nurul; Luis, Martino

    2015-05-01

    Capacitated arc routing problem (CARP) is the youngest generation of graph theory that focuses on solving the edge/arc routing for optimality. Since many years, operational research devoted to CARP counterpart, known as vehicle routing problem (VRP), which does not fit to several real cases such like waste collection problem and road maintenance. In this paper, we highlighted several extensions of capacitated arc routing problem (CARP) that represents the real-life problem of vehicle operation in waste collection. By purpose, CARP is designed to find a set of routes for vehicles that satisfies all pre-setting constraints in such that all vehicles must start and end at a depot, service a set of demands on edges (or arcs) exactly once without exceeding the capacity, thus the total fleet cost is minimized. We also addressed the differentiation between CARP and VRP in waste collection. Several issues have been discussed including stochastic demands and time window problems in order to show the complexity and importance of CARP in the related industry. A mathematical model of CARP and its new version is presented by considering several factors such like delivery cost, lateness penalty and delivery time.

  20. Capacitated arc routing problem and its extensions in waste collection

    Energy Technology Data Exchange (ETDEWEB)

    Fadzli, Mohammad; Najwa, Nurul [Institut Matematik Kejuruteraan, Universiti Malaysia Perlis, Kampus Pauh Putra, 02600 Arau, Perlis (Malaysia); Luis, Martino [Othman Yeop Abdullah Graduate School of Business, Universiti Utara Malaysia, 06010 Sintok, Kedah (Malaysia)

    2015-05-15

    Capacitated arc routing problem (CARP) is the youngest generation of graph theory that focuses on solving the edge/arc routing for optimality. Since many years, operational research devoted to CARP counterpart, known as vehicle routing problem (VRP), which does not fit to several real cases such like waste collection problem and road maintenance. In this paper, we highlighted several extensions of capacitated arc routing problem (CARP) that represents the real-life problem of vehicle operation in waste collection. By purpose, CARP is designed to find a set of routes for vehicles that satisfies all pre-setting constraints in such that all vehicles must start and end at a depot, service a set of demands on edges (or arcs) exactly once without exceeding the capacity, thus the total fleet cost is minimized. We also addressed the differentiation between CARP and VRP in waste collection. Several issues have been discussed including stochastic demands and time window problems in order to show the complexity and importance of CARP in the related industry. A mathematical model of CARP and its new version is presented by considering several factors such like delivery cost, lateness penalty and delivery time.

  1. An Improved Pyramid for Spatially Scalable Video Coding

    OpenAIRE

    2005-01-01

    This paper discusses an improved pyramid for spatially scalable video coding. We introduce additional update steps in the analysis and the synthesis of the Laplacian pyramid. Our pyramid is able to control efficiently the quantization noise energy in the reconstruction. Hence, it provides improved coding performance when compared to the standard Laplacian pyramid. Moreover, our pyramid does not require biorthogonal filters as they should be used for the frame reconstruction of the Laplacian p...

  2. Water desalination via capacitive deionization

    NARCIS (Netherlands)

    Suss, M.E.; Porada, S.; Sun, X.; Biesheuvel, P.M.; Yoon, J.; Presser, V.

    2015-01-01

    Capacitive deionization (CDI) is an emerging technology for the facile removal of charged ionic species from aqueous solutions, and is currently being widely explored for water desalination applications. The technology is based on ion electrosorption at the surface of a pair of electrically charg

  3. Water desalination via capacitive deionization

    NARCIS (Netherlands)

    Suss, M.E.; Porada, S.; Sun, X.; Biesheuvel, P.M.; Yoon, J.; Presser, V.

    2015-01-01

    Capacitive deionization (CDI) is an emerging technology for the facile removal of charged ionic species from aqueous solutions, and is currently being widely explored for water desalination applications. The technology is based on ion electrosorption at the surface of a pair of electrically charg

  4. Voltage Dependence of Supercapacitor Capacitance

    Directory of Open Access Journals (Sweden)

    Szewczyk Arkadiusz

    2016-09-01

    Full Text Available Electronic Double-Layer Capacitors (EDLC, called Supercapacitors (SC, are electronic devices that are capable to store a relatively high amount of energy in a small volume comparing to other types of capacitors. They are composed of an activated carbon layer and electrolyte solution. The charge is stored on electrodes, forming the Helmholtz layer, and in electrolyte. The capacitance of supercapacitor is voltage- dependent. We propose an experimental method, based on monitoring of charging and discharging a supercapacitor, which enables to evaluate the charge in an SC structure as well as the Capacitance-Voltage (C-V dependence. The measurement setup, method and experimental results of charging/discharging commercially available supercapacitors in various voltage and current conditions are presented. The total charge stored in an SC structure is proportional to the square of voltage at SC electrodes while the charge on electrodes increases linearly with the voltage on SC electrodes. The Helmholtz capacitance increases linearly with the voltage bias while a sublinear increase of total capacitance was found. The voltage on SC increases after the discharge of electrodes due to diffusion of charges from the electrolyte to the electrodes. We have found that the recovery voltage value is linearly proportional to the initial bias voltage value.

  5. Interfacial capacitance effects in magnetic tunneling junctions

    CERN Document Server

    Landry, G; Du, J; Xiao, J Q

    2001-01-01

    We have investigated the AC transport properties of magnetic tunnel junctions (MTJ) in order to characterize interfacial properties. One such property is interfacial charge accumulation, which leads to a voltage drop in the electrodes of the MTJ and the measured capacitance differing from the geometrical capacitance. Through measurement of capacitance spectra, we have extracted an interfacial capacitance of 16 mu F/cm sup 2 per interface and a screening length of 0.55 A for FeNi electrodes.

  6. A Memetic Algorithm for the Capacitated Location-Routing Problem

    Directory of Open Access Journals (Sweden)

    Laila KECHMANE

    2016-06-01

    Full Text Available In this paper, a hybrid genetic algorithm is proposed to solve a Capacitated Location-Routing Problem. The objective is to minimize the total cost of the distribution in a network composed of depots and customers, both depots and vehicles have limited capacities, each depot has a homogenous vehicle fleet and customers’ demands are known and must be satisfied. Solving this problem involves making strategic decisions such as the location of depots, as well as tactical and operational decisions which include assigning customers to the opened depots and organization of the vehicle routing. To evaluate the performance of the proposed algorithm, its results are compared to those obtained by a greedy randomized adaptive search procedure, computational results shows that the algorithm gave good quality solutions.

  7. Sensors in Unmanned Robotic Vehicle

    Directory of Open Access Journals (Sweden)

    B. Rohini

    2008-05-01

    Full Text Available Unmanned tracked vehicles are developed for deployment in dangerous zones that are notsafe for human existence. These vehicles are to be fitted with various sensors for safe manoeuvre.Wide range of sensors for vehicle control, vision, and navigation are employed. The main purposeof the sensors is to infer the intended parameter precisely for further utilisation. Software isinseparable part of the sensors and plays major role in scaling, noise reduction, and fusion.Sensor fusion is normally adapted to enhance the decision-making. Vehicle location  andorientation can be sensed through global positioning system, accelerometer, gyroscope, andcompass. The unmanned vehicle can be navigated with the help of CCD camera, radar, lidar,ultrasonic sensor, piezoelectric sensor, microphone, etc.  Proximity sensors like capacitive andRF proximity detectors can detect obstacles in close vicinity.  This paper presents an overviewof sensors normally deployed in unmanned tracked vehicles.

  8. Quantum Capacitance in Topological Insulators

    Science.gov (United States)

    Xiu, Faxian; Meyer, Nicholas; Kou, Xufeng; He, Liang; Lang, Murong; Wang, Yong; Yu, Xinxin; Fedorov, Alexei V.; Zou, Jin; Wang, Kang L.

    2012-01-01

    Topological insulators show unique properties resulting from massless, Dirac-like surface states that are protected by time-reversal symmetry. Theory predicts that the surface states exhibit a quantum spin Hall effect with counter-propagating electrons carrying opposite spins in the absence of an external magnetic field. However, to date, the revelation of these states through conventional transport measurements remains a significant challenge owing to the predominance of bulk carriers. Here, we report on an experimental observation of Shubnikov-de Haas oscillations in quantum capacitance measurements, which originate from topological helical states. Unlike the traditional transport approach, the quantum capacitance measurements are remarkably alleviated from bulk interference at high excitation frequencies, thus enabling a distinction between the surface and bulk. We also demonstrate easy access to the surface states at relatively high temperatures up to 60 K. Our approach may eventually facilitate an exciting exploration of exotic topological properties at room temperature. PMID:22993694

  9. The Babinski sign and the pyramidal syndrome.

    Science.gov (United States)

    Van Gijn, J

    1978-10-01

    The presence or absence of a Babinski sign can be puzzling, but in the light of existing pathological studies it is more fruitful to consider which pyramidal tract fibres release it than whether they release it. This was investigated clinically, by looking for correlations with other reflex changes and with motor deficits in the leg. A survey of 50 patients with a unilateral Babinski sign and six patients who lacked it in spite of other pyramidal tract signs was supplemented with follow-up of the patients who had acute lesions. Appearance of the Bibinski sign proved to depend on the interaction of two factors: (1) activity (not necessarily hyperactivity) in the segmental pathways of the flexion synergy; (2) a motor deficit of the foot, in some cases consisting only in an impairment of rapid foot movements, and probably representing a disturbance of direct pyramidal tract projections to distal motoneurones.

  10. A 3D pyramid spline element

    Institute of Scientific and Technical Information of China (English)

    Juan Chen; Chong-Jun Li; Wan-Ji Chen

    2011-01-01

    In this paper,a 13-node pyramid spline element is derived by using the tetrahedron volume coordinates and the B-net method,which achieves the second order completeness in Cartesian coordinates.Some appropriate examples were employed to evaluate the performance of the proposed element.The numerical results show that the spline element has much better performance compared with the isoparametric serendipity element Q20 and its degenerate pyramid element P13 especially when mesh is distorted,and it is comparable to the Lagrange element Q27.It has been demonstrated that the spline finite element method is an efficient tool for developing high accuracy elements.

  11. Tiling a Pyramidal Polycube with Dominoes

    Directory of Open Access Journals (Sweden)

    Olivier Bodini

    2007-05-01

    Full Text Available The notion of pyramidal polycubes, namely the piling-up of bricks of a non-increasing size, generalizes in ℝ n the concept of trapezoidal polyominoes. In the present paper, we prove that n-dimensional dominoes can tile a pyramidal polycube if and only if the latter is balanced, that is, if the number of white cubes is equal to the number of black ones for a chessboard-like coloration, generalizing the result of [BC92] when n=2

  12. Capacitance variation measurement method with a continuously variable measuring range for a micro-capacitance sensor

    Science.gov (United States)

    Lü, Xiaozhou; Xie, Kai; Xue, Dongfeng; Zhang, Feng; Qi, Liang; Tao, Yebo; Li, Teng; Bao, Weimin; Wang, Songlin; Li, Xiaoping; Chen, Renjie

    2017-10-01

    Micro-capacitance sensors are widely applied in industrial applications for the measurement of mechanical variations. The measurement accuracy of micro-capacitance sensors is highly dependent on the capacitance measurement circuit. To overcome the inability of commonly used methods to directly measure capacitance variation and deal with the conflict between the measurement range and accuracy, this paper presents a capacitance variation measurement method which is able to measure the output capacitance variation (relative value) of the micro-capacitance sensor with a continuously variable measuring range. We present the principles and analyze the non-ideal factors affecting this method. To implement the method, we developed a capacitance variation measurement circuit and carried out experiments to test the circuit. The result shows that the circuit is able to measure a capacitance variation range of 0–700 pF linearly with a maximum relative accuracy of 0.05% and a capacitance range of 0–2 nF (with a baseline capacitance of 1 nF) with a constant resolution of 0.03%. The circuit is proposed as a new method to measure capacitance and is expected to have applications in micro-capacitance sensors for measuring capacitance variation with a continuously variable measuring range.

  13. Multiresolution maximum intensity volume rendering by morphological adjunction pyramids

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    We describe a multiresolution extension to maximum intensity projection (MIP) volume rendering, allowing progressive refinement and perfect reconstruction. The method makes use of morphological adjunction pyramids. The pyramidal analysis and synthesis operators are composed of morphological 3-D

  14. Multiresolution Maximum Intensity Volume Rendering by Morphological Adjunction Pyramids

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2001-01-01

    We describe a multiresolution extension to maximum intensity projection (MIP) volume rendering, allowing progressive refinement and perfect reconstruction. The method makes use of morphological adjunction pyramids. The pyramidal analysis and synthesis operators are composed of morphological 3-D

  15. Comparison of Morphological Pyramids for Multiresolution MIP Volume Rendering

    NARCIS (Netherlands)

    Roerdink, Jos B.T.M.

    2002-01-01

    We recently proposed a multiresolution representation for maximum intensity projection (MIP) volume rendering based on morphological adjunction pyramids which allow progressive refinement and have the property of perfect reconstruction. In this algorithm the pyramidal analysis and synthesis

  16. Redox regulation of mammalian sperm capacitation

    Directory of Open Access Journals (Sweden)

    Cristian O′Flaherty

    2015-01-01

    Full Text Available Capacitation is a series of morphological and metabolic changes necessary for the spermatozoon to achieve fertilizing ability. One of the earlier happenings during mammalian sperm capacitation is the production of reactive oxygen species (ROS that will trigger and regulate a series of events including protein phosphorylation, in a time-dependent fashion. The identity of the sperm oxidase responsible for the production of ROS involved in capacitation is still elusive, and several candidates are discussed in this review. Interestingly, ROS-induced ROS formation has been described during human sperm capacitation. Redox signaling during capacitation is associated with changes in thiol groups of proteins located on the plasma membrane and subcellular compartments of the spermatozoon. Both, oxidation of thiols forming disulfide bridges and the increase on thiol content are necessary to regulate different sperm proteins associated with capacitation. Reducing equivalents such as NADH and NADPH are necessary to support capacitation in many species including humans. Lactate dehydrogenase, glucose-6-phospohate dehydrogenase, and isocitrate dehydrogenase are responsible in supplying NAD (P H for sperm capacitation. Peroxiredoxins (PRDXs are newly described enzymes with antioxidant properties that can protect mammalian spermatozoa; however, they are also candidates for assuring the regulation of redox signaling required for sperm capacitation. The dysregulation of PRDXs and of enzymes needed for their reactivation such as thioredoxin/thioredoxin reductase system and glutathione-S-transferases impairs sperm motility, capacitation, and promotes DNA damage in spermatozoa leading to male infertility.

  17. Khufu, Khafre and Menkaure Pyramids and the Sun

    CERN Document Server

    Sparavigna, Amelia Carolina

    2016-01-01

    In this paper we discuss the orientation of the Egyptian pyramids at Giza with respect to sunrises and sunsets, using SunCalc.net software. We can see that Khufu and Khafre pyramids had been positioned in a manner that, from each pyramid, it was always possible to observe the points of the horizon where the sun was rising and setting on each day of the year. A discussion for the Menkaure pyramid is also proposed.

  18. The Dairy Group. The Food Guide Pyramid.

    Science.gov (United States)

    Frost, Helen

    This booklet for young children is part of a series that supports national science standards related to physical health and nutrition, describing and illustrating the importance of using the Food Guide Pyramid and eating from the dairy group. Colorful photographs support early readers in understanding the text. The repetition of words and phrases…

  19. Ancient Pyramids Help Students Learn Math Concepts

    Science.gov (United States)

    Smith, Courtney D.; Stump, Amanda M.; Lazaros, Edward J.

    2010-01-01

    This article presents an activity that allows students to use mathematics and critical-thinking skills to emulate processes used by the ancient Egyptians to prepare the site for the Pyramids of Giza. To accomplish this, they use three different methods. First, they create a square using only simple technological tools that were available to the…

  20. Comparing Volumes of Prisms and Pyramids

    Science.gov (United States)

    Vinogradova, Natalya

    2012-01-01

    Students' experience in using formulas for volumes is often limited to substituting numbers into given formulas. An activity presented in this article may help students make connections between the formulas for volumes of prisms and volumes of pyramids. In addition, some interesting facts from number theory arise, demonstrating strong connections…

  1. Toddler Teachers' Use of "Teaching Pyramid" Practices

    Science.gov (United States)

    Branson, Diane; Demchak, MaryAnn

    2011-01-01

    Effective strategies to promote social-emotional development and prevent occurrence of challenging behaviors in young children is critical. The "Teaching Pyramid", a framework for supporting social-emotional development and preventing and addressing challenging behaviors, was developed for preschool children. This mixed methods study investigated…

  2. Modified Mean-Pyramid Coding Scheme

    Science.gov (United States)

    Cheung, Kar-Ming; Romer, Richard

    1996-01-01

    Modified mean-pyramid coding scheme requires transmission of slightly fewer data. Data-expansion factor reduced from 1/3 to 1/12. Schemes for progressive transmission of image data transmitted in sequence of frames in such way coarse version of image reconstructed after receipt of first frame and increasingly refined version of image reconstructed after receipt of each subsequent frame.

  3. Digital pyramid wavefront sensor with tunable modulation.

    Science.gov (United States)

    Akondi, Vyas; Castillo, Sara; Vohnsen, Brian

    2013-07-29

    The pyramid wavefront sensor is known for its high sensitivity and dynamic range that can be tuned by mechanically altering its modulation amplitude. Here, a novel modulating digital scheme employing a reflecting phase only spatial light modulator is demonstrated. The use of the modulator allows an easy reconfigurable pyramid with digital control of the apex angle and modulation geometry without the need of any mechanically moving parts. Aberrations introduced by a 140-actuator deformable mirror were simultaneously sensed with the help of a commercial Hartmann-Shack wavefront sensor. The wavefronts reconstructed using the digital pyramid wavefront sensor matched very closely with those sensed by the Hartmann-Shack. It is noted that a tunable modulation is necessary to operate the wavefront sensor in the linear regime and to accurately sense aberrations. Through simulations, it is shown that the wavefront sensor can be extended to astronomical applications as well. This novel digital pyramid wavefront sensor has the potential to become an attractive option in both open and closed loop adaptive optics systems.

  4. Pyramid Servings Database (PSDB) for NHANES III

    Science.gov (United States)

    The National Cancer Institute developed a database to examine dietary data from the National Center for Health Statistics' Third National Health and Nutrition Examination Survey in terms of servings from each of United States Department of Agriculture's The Food Guide Pyramid's major and minor food groups.

  5. Toddler Teachers' Use of "Teaching Pyramid" Practices

    Science.gov (United States)

    Branson, Diane; Demchak, MaryAnn

    2011-01-01

    Effective strategies to promote social-emotional development and prevent occurrence of challenging behaviors in young children is critical. The "Teaching Pyramid", a framework for supporting social-emotional development and preventing and addressing challenging behaviors, was developed for preschool children. This mixed methods study…

  6. Modified Mean-Pyramid Coding Scheme

    Science.gov (United States)

    Cheung, Kar-Ming; Romer, Richard

    1996-01-01

    Modified mean-pyramid coding scheme requires transmission of slightly fewer data. Data-expansion factor reduced from 1/3 to 1/12. Schemes for progressive transmission of image data transmitted in sequence of frames in such way coarse version of image reconstructed after receipt of first frame and increasingly refined version of image reconstructed after receipt of each subsequent frame.

  7. Jonestown in the Shadow of Maslow's Pyramid.

    Science.gov (United States)

    Easley, Edgar M.; Wigglesworth, David C.

    1979-01-01

    Reviews Maslow's hierarchy of needs in the light of the Jonestown tragedy. Maintains that members of the People's Temple felt frustrated in attaining the lower levels in the world of reality, and so moved outside the pyramid in search of the top, self-actualization. In the process, their primary needs were met. Journal availability: see SO 507…

  8. Jonestown in the Shadow of Maslow's Pyramid.

    Science.gov (United States)

    Easley, Edgar M.; Wigglesworth, David C.

    1979-01-01

    Reviews Maslow's hierarchy of needs in the light of the Jonestown tragedy. Maintains that members of the People's Temple felt frustrated in attaining the lower levels in the world of reality, and so moved outside the pyramid in search of the top, self-actualization. In the process, their primary needs were met. Journal availability: see SO 507…

  9. Idea Bank: Assessing Your Curriculum with the Creative Rights Pyramid

    Science.gov (United States)

    Thibeault, Matthew D.

    2011-01-01

    This article presents a creative rights pyramid that was developed as part of the author's efforts to: (1) teach about copyright and intellectual property; and (2) increase students' awareness of their own intellectual property in and outside the music classroom. The pyramid is based on the U.S. Department of Agriculture's food pyramid to suggest…

  10. LANDSAT-BASED WATER QUALITY MONITORING OF PYRAMID LAKE

    Science.gov (United States)

    Pyramid Lake Paiute Tribe (PLPT) in cooperation with federal, state and local entities has been able to increase stream flow, establish water quality standards and improve fish habitat in the Truckee River, a primary source of water for pyramid Lake. In the past, pyramid Lake wat...

  11. On the astronomical orientation of the IV dynasty Egyptian pyramids and the dating of the second Giza pyramid

    OpenAIRE

    Magli, Giulio

    2003-01-01

    The data on the astronomical orientation of the IV dynasty Egyptian pyramids are re-analyzed and it is shown that such data suggest an inverse chronology between the `first` and the `second` Giza pyramid.

  12. Pyramidal fractal dimension for high resolution images

    Science.gov (United States)

    Mayrhofer-Reinhartshuber, Michael; Ahammer, Helmut

    2016-07-01

    Fractal analysis (FA) should be able to yield reliable and fast results for high-resolution digital images to be applicable in fields that require immediate outcomes. Triggered by an efficient implementation of FA for binary images, we present three new approaches for fractal dimension (D) estimation of images that utilize image pyramids, namely, the pyramid triangular prism, the pyramid gradient, and the pyramid differences method (PTPM, PGM, PDM). We evaluated the performance of the three new and five standard techniques when applied to images with sizes up to 8192 × 8192 pixels. By using artificial fractal images created by three different generator models as ground truth, we determined the scale ranges with minimum deviations between estimation and theory. All pyramidal methods (PM) resulted in reasonable D values for images of all generator models. Especially, for images with sizes ≥1024 ×1024 pixels, the PMs are superior to the investigated standard approaches in terms of accuracy and computation time. A measure for the possibility to differentiate images with different intrinsic D values did show not only that the PMs are well suited for all investigated image sizes, and preferable to standard methods especially for larger images, but also that results of standard D estimation techniques are strongly influenced by the image size. Fastest results were obtained with the PDM and PGM, followed by the PTPM. In terms of absolute D values best performing standard methods were magnitudes slower than the PMs. Concluding, the new PMs yield high quality results in short computation times and are therefore eligible methods for fast FA of high-resolution images.

  13. Capacitance enhancement via electrode patterning

    Science.gov (United States)

    Ho, Tuan A.; Striolo, Alberto

    2013-11-01

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties.

  14. Capacitance enhancement via electrode patterning

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Tuan A.; Striolo, Alberto, E-mail: a.striolo@ucl.ac.uk [School of Chemical, Biological and Materials Engineering, The University of Oklahoma, Norman, Oklahoma 73019 (United States); Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)

    2013-11-28

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties.

  15. Dual Cryogenic Capacitive Density Sensor

    Science.gov (United States)

    Youngquist, Robert; Mata, Carlos; Vokrot, Peter; Cox, Robert

    2009-01-01

    A dual cryogenic capacitive density sensor has been developed. The device contains capacitive sensors that monitor two-phase cryogenic flow density to within 1% accuracy, which, if temperature were known, could be used to determine the ratio of liquid to gas in the line. Two of these density sensors, located a known distance apart, comprise the sensor, providing some information on the velocity of the flow. This sensor was constructed as a proposed mass flowmeter with high data acquisition rates. Without moving parts, this device is capable of detecting the density change within a two-phase cryogenic flow more than 100 times a second. Detection is enabled by a series of two sets of five parallel plates with stainless steel, cryogenically rated tubing. The parallel plates form the two capacitive sensors, which are measured by electrically isolated digital electronics. These capacitors monitor the dielectric of the flow essentially the density of the flow and can be used to determine (along with temperature) the ratio of cryogenic liquid to gas. Combining this information with the velocity of the flow can, with care, be used to approximate the total two-phase mass flow. The sensor can be operated at moderately high pressures and can be lowered into a cryogenic bath. The electronics have been substantially improved over the older sensors, incorporating a better microprocessor, elaborate ground loop protection and noise limiting circuitry, and reduced temperature sensitivity. At the time of this writing, this design has been bench tested at room temperature, but actual cryogenic tests are pending

  16. Flexible PVDF ferroelectric capacitive temperature sensor

    KAUST Repository

    Khan, Naveed

    2015-08-02

    In this paper, a capacitive temperature sensor based on polyvinylidene fluoride (PVDF) capacitor is explored. The PVDF capacitor is characterized below its Curie temperature. The capacitance of the PVDF capacitor changes vs temperature with a sensitivity of 16pF/°C. The linearity measurement of the capacitance-temperature relation shows less than 0.7°C error from a best fit straight line. An LC oscillator based temperature sensor is demonstrated based on this capacitor.

  17. Compact monolithic capacitive discharge unit

    Science.gov (United States)

    Roesler, Alexander W.; Vernon, George E.; Hoke, Darren A.; De Marquis, Virginia K.; Harris, Steven M.

    2007-06-26

    A compact monolithic capacitive discharge unit (CDU) is disclosed in which a thyristor switch and a flyback charging circuit are both sandwiched about a ceramic energy storage capacitor. The result is a compact rugged assembly which provides a low-inductance current discharge path. The flyback charging circuit preferably includes a low-temperature co-fired ceramic transformer. The CDU can further include one or more ceramic substrates for enclosing the thyristor switch and for holding various passive components used in the flyback charging circuit. A load such as a detonator can also be attached directly to the CDU.

  18. How they (should have) built the pyramids

    CERN Document Server

    West, J; Waters, K

    2014-01-01

    A novel method is proposed for moving large, pyramid construction size, stone blocks. The method is inspired by a well known introductory physics homework problem, and is implemented by tying 12 identical rods of appropriately chosen radius to the faces of the block. The rods form the corners and new faces that transform the square prism into a dodecagon which can then be moved more easily by rolling than by dragging. Experimental results are presented and compared to independent work by another group which utilized wooden attachments providing a cylindrical shape. It is found that a small scale stone block converted to dodecagons can be moved across level open ground with a dynamic coefficient of friction of the order 0.2. For full scale pyramid blocks, the wooden rods would need to be posts of order 30 cm in diameter, similar in size to those used as masts on ships in the Nile.

  19. Approximate particle spectra in the pyramid scheme

    Science.gov (United States)

    Banks, Tom; Torres, T. J.

    2012-12-01

    We construct a minimal model inspired by the general class of pyramid schemes [T. Banks and J.-F. Fortin, J. High Energy Phys. 07 (2009) 046JHEPFG1029-8479], which is consistent with both supersymmetry breaking and electroweak symmetry breaking. In order to do computations, we make unjustified approximations to the low energy Kähler potential. The phenomenological viability of the resultant mass spectrum is then examined and compared with current collider limits. We show that for certain regimes of parameters, the model, and thus generically the pyramid scheme, can accommodate the current collider mass constraints on physics beyond the standard model with a tree-level light Higgs mass near 125 GeV. However, in this regime the model exhibits a little hierarchy problem, and one must permit fine-tunings that are of order 5%.

  20. Compression asphyxia from a human pyramid.

    Science.gov (United States)

    Tumram, Nilesh Keshav; Ambade, Vipul Namdeorao; Biyabani, Naushad

    2015-12-01

    In compression asphyxia, respiration is stopped by external forces on the body. It is usually due to an external force compressing the trunk such as a heavy weight on the chest or abdomen and is associated with internal injuries. In present case, the victim was trapped and crushed under the falling persons from a human pyramid formation for a "Dahi Handi" festival. There was neither any severe blunt force injury nor any significant pathological natural disease contributing to the cause of death. The victim was unable to remove himself from the situation because his cognitive responses and coordination were impaired due to alcohol intake. The victim died from asphyxia due to compression of his chest and abdomen. Compression asphyxia resulting from the collapse of a human pyramid and the dynamics of its impact force in these circumstances is very rare and is not reported previously to the best of our knowledge.

  1. Novel RF-MEMS capacitive switching structures

    NARCIS (Netherlands)

    Rottenberg, X.; Jansen, H.; Fiorini, P.; De Raedt, W.; Tilmans, H.A.C.

    2002-01-01

    This paper reports on novel RF-MEMS capacitive switching devices implementing an electrically floating metal layer covering the dielectric to ensure intimate contact with the bridge in the down state. This results in an optimal switch down capacitance and allows optimisation of the down/up capacitan

  2. Characterization of Textile-Insulated Capacitive Biosensors

    Directory of Open Access Journals (Sweden)

    Charn Loong Ng

    2017-03-01

    Full Text Available Capacitive biosensors are an emerging technology revolutionizing wearable sensing systems and personal healthcare devices. They are capable of continuously measuring bioelectrical signals from the human body while utilizing textiles as an insulator. Different textile types have their own unique properties that alter skin-electrode capacitance and the performance of capacitive biosensors. This paper aims to identify the best textile insulator to be used with capacitive biosensors by analysing the characteristics of 6 types of common textile materials (cotton, linen, rayon, nylon, polyester, and PVC-textile while evaluating their impact on the performance of a capacitive biosensor. A textile-insulated capacitive (TEX-C biosensor was developed and validated on 3 subjects. Experimental results revealed that higher skin-electrode capacitance of a TEX-C biosensor yields a lower noise floor and better signal quality. Natural fabric such as cotton and linen were the two best insulating materials to integrate with a capacitive biosensor. They yielded the lowest noise floor of 2 mV and achieved consistent electromyography (EMG signals measurements throughout the performance test.

  3. Energy-Efficient Capacitive-Sensor Interfaces

    NARCIS (Netherlands)

    Tan, Z.

    2013-01-01

    This thesis describes the theory, design and realization of energy-efficient capacitive-sensor interfaces that are dedicated to energy-constrained applications. The goal of this work is to explore energy-efficient capacitive-sensor interface design techniques both at the system and the circuit level

  4. Capacitance Measurement Methods for Integrated Sensor Applications

    Directory of Open Access Journals (Sweden)

    Alireza Hassanzadeh

    2013-09-01

    Full Text Available In this paper different measurement methods that have been used for integrated capacitance measurement are reviewed and their advantage and disadvantages are discussed. For the designers of high accuracy on chip integrated circuits for capacitive sensors, it is important to know which method will provide the best approach for high accuracy, small chip area and power consumption especially for array sensors. These methods include on chip capacitive sensor and transducer measurement techniques that have been implemented for low value capacitance evaluations using CMOS technology. After the best structure is known the designer can optimize the chip for specific application. Voltage mode and current mode, linear and switched mode techniques are reviewed and a useful comparison table comparing all figures of merit including accuracy, range of measurement, chip area, speed and complexity is provided. The provided comparison table can be used as a reference for analog designers in the design of high accuracy integrated capacitive sensor interface

  5. Periodic capacitated arc routing problem applied in a real context

    Directory of Open Access Journals (Sweden)

    Guilherme Vinicyus Batista

    2015-09-01

    Full Text Available A good inspection and maintenance planning in railways is essential to ensure the flow of trains and avoid possible accidents. This inspection should be performed periodically by vehicle traveling on rails collecting data and identifying gaps that need to be corrected. The aim of this paper is to present a mathematical model based on binary linear programming, capable of solving this problem, which is a real application of Periodic Capacitated Arc Routing Problem (PCARP. In the PCARP each arc of a network has a demand over a well-defined time horizon and routes must be created for each car so that it covers all the requests in the best way possible without exceeding the vehicles capacity at service. The proposed application has different characteristics to those already proposed in the literature because the vehicle does not need to come back to the depot at the end of the day and the service can be delayed if necessary. The result is satisfactory, covering the demands with a synchronized movement of vehicles.

  6. Capacitively-coupled chopper amplifiers

    CERN Document Server

    Fan, Qinwen; Huijsing, Johan H

    2017-01-01

    This book describes the concept and design of the capacitively-coupled chopper technique, which can be used in precision analog amplifiers. Readers will learn to design power-efficient amplifiers employing this technique, which can be powered by regular low supply voltage such as 2V and possibly having a +\\-100V input common-mode voltage input. The authors provide both basic design concepts and detailed design examples, which cover the area of both operational and instrumentation amplifiers for multiple applications, particularly in power management and biomedical circuit designs. Discusses basic working principles and details of implementation for proven designs; Includes a diverse set of applications, along with measurement results to demonstrate the effectiveness of the technique; Explains advantages and drawbacks of the technique, given particular circumstances.

  7. Centre of pressure correlates with pyramid performance in acrobatic gymnastics.

    Science.gov (United States)

    Floría, Pablo; Gómez-Landero, Luis Arturo; Harrison, Andrew J

    2015-01-01

    Acrobatic gymnasts need excellent balance control to execute pyramids where one gymnast is supported by another. The objectives of this study were: (1) to describe balance performance by assessing the centre of pressure displacement in a group of acrobatic gymnasts executing pyramids; (2) to determine the relationship between the parameters describing the centre of pressure oscillations and pyramid score; and (3) to examine the role of each foot in providing a solid base of support to maintain the balance of the pyramid. Sixteen acrobatic gymnasts grouped in pairs performed a Half pyramid and a Straddle pyramid held for 7 s on two force platforms. Path length, variance, range trajectory, and surface area of the centre of pressure of each foot were examined to analyse the balance of the pyramid. The path length was correlated with the pyramid score (Straddle: p = 0.692 [large]; Half: p = 0.407 [moderate]). There were differences in the functions of each leg to maintain balance, with the non-preferred leg supporting a higher weight of the pyramid while the preferred leg performed control movements to maintain balance. The results suggested that quantitative analysis of balance can provide important information on pyramid performance.

  8. Pyramids: a platform for designing multifunctional plasmonic particles.

    Science.gov (United States)

    Lee, Jeunghoon; Hasan, Warefta; Stender, Christopher L; Odom, Teri W

    2008-12-01

    This Account explores nanofabricated pyramids, a new class of nanoparticles with tunable optical properties at visible and near-infrared wavelengths. This system is ideally suited for designing multifunctional plasmonic materials for use in diagnostics, imaging, sensing, and therapeutics. The nanofabrication scheme that we developed (called PEEL) for these asymmetric metal particles is extremely versatile and offers several advantages over synthetic methodologies. The PEEL approach yields pyramids with variable sizes, thicknesses, and multimetal compositions, as well as blunt or ultrasharp tips or no tips. In addition, we have prepared pyramids with site-specific chemical and biological functionality on different portions of the pyramids. This is an important design feature for biological applications, as suggested by the generation of amphiphilic gold pyramids functionalized with alkanethiols on the hydrophobic portions and DNA on the hydrophilic portions. The optical characteristics of these pyramids depend on particle orientation, wavevector direction, and polarization direction and can be tuned. Using the multipolar surface plasmon resonances of large (>250 nm) pyramids, imaging and spectral identification of pyramid orientation in condensed media was possible. We were also able to direct pyramids to assemble into one- and two-dimensional arrays with interesting optical properties. Furthermore, modification of the PEEL fabrication scheme allowed the production of multimaterial pyramidal structures with complex attributes, highlighting the power of this platform for exacting nanometer-scale control over particle structure and composition.

  9. Activation of functional α7-containing nAChRs in hippocampal CA1 pyramidal neurons by physiological levels of choline in the presence of PNU-120596.

    Directory of Open Access Journals (Sweden)

    Bopanna I Kalappa

    Full Text Available BACKGROUND: The level of expression of functional α7-containing nicotinic acetylcholine receptors (nAChRs in hippocampal CA1 pyramidal neurons is believed to be very low compared to hippocampal CA1 interneurons, and for many years this expression was largely overlooked. However, high densities of expression of functional α7-containing nAChRs in CA1 pyramidal neurons may not be necessary for triggering important cellular and network functions, especially if activation of α7-containing nAChRs occurs in the presence of positive allosteric modulators such as PNU-120596. METHODOLOGY/PRINCIPAL FINDINGS: An approach previously developed for α7-containing nAChRs expressed in tuberomammillary neurons was applied to investigate functional CA1 pyramidal α7-containing nAChRs using rat coronal hippocampal slices and patch-clamp electrophysiology. The majority (∼71% of tested CA1 pyramidal neurons expressed low densities of functional α7-containing nAChRs as evidenced by small whole-cell responses to choline, a selective endogenous agonist of α7 nAChRs. These responses were potentiated by PNU-120596, a novel positive allosteric modulator of α7 nAChRs. The density of functional α7-containing nAChRs expressed in CA1 pyramidal neurons (and thus, the normalized net effect of activation, i.e., response net charge per unit of membrane capacitance per unit of time was estimated to be ∼5% of the density observed in CA1 interneurons. The results of this study demonstrate that despite low levels of expression of functional pyramidal α7-containing nAChRs, physiological levels of choline (∼10 µM are sufficient to activate these receptors and transiently depolarize and even excite CA1 pyramidal neurons in the presence of PNU-120596. The observed effects are possible because in the presence of 10 µM choline and 1-5 µM PNU-120596, a single opening of an individual pyramidal α7-containing nAChR ion channel appears to transiently depolarize (∼4 mV the

  10. THE PERIODIC CAPACITATED ARC ROUTING PROBLEM LINEAR PROGRAMMING MODEL,METAHEURISTIC AND LOWER BOUNDS

    Institute of Scientific and Technical Information of China (English)

    Feng CHU; Nacima LABADI; Christian PRINS

    2004-01-01

    The Periodic Capacitated Arc Routing Problem (PCARP) generalizes the well known NP-hard Capacitated Arc Routing Problem (CARP) by extending the single period to multi-period horizon.The Capacitated Arc Routing Problem (CARP) is defined on an undirected network in which a fleet of identical vehicles is based at a depot node. A subset of edges, called tasks, must be serviced by a vehicle. The CARP consists of determining a set of feasible vehicle trips that minimizes the total cost of traversed edges. The PCARP involves the assignment of tasks to periods and the determination of vehicles trips in each period, to minimize the total cost on the whole horizon. This new problem arises in various real life applications such as waste collection, mail delivery, etc. In this paper, a new linear programming model and preliminary lower bounds based on graph transformation are proposed. A meta-heuristic approach - Scatter Search (SS) is developed for the PCARP and evaluated on a large variety of instances.

  11. Optimizing pyramided transgenic Bt crops for sustainable pest management.

    Science.gov (United States)

    Carrière, Yves; Crickmore, Neil; Tabashnik, Bruce E

    2015-02-01

    Transgenic crop pyramids producing two or more Bacillus thuringiensis (Bt) toxins that kill the same insect pest have been widely used to delay evolution of pest resistance. To assess the potential of pyramids to achieve this goal, we analyze data from 38 studies that report effects of ten Bt toxins used in transgenic crops against 15 insect pests. We find that compared with optimal low levels of insect survival, survival on currently used pyramids is often higher for both susceptible insects and insects resistant to one of the toxins in the pyramid. Furthermore, we find that cross-resistance and antagonism between toxins used in pyramids are common, and that these problems are associated with the similarity of the amino acid sequences of domains II and III of the toxins, respectively. This analysis should assist in future pyramid design and the development of sustainable resistance management strategies.

  12. Sperm capacitation in the porcine oviduct.

    Science.gov (United States)

    Tienthai, P; Johannisson, A; Rodriguez-Martinez, H

    2004-01-01

    In vitro studies suggests that sperm capacitation occurs in the sperm reservoir (SR) of the pig, with spermatozoa progressing towards the ampullary-isthmic junction (AIJ) around ovulation as a consequence of capacitation/hyperactivation. In contrast, in vivo studies are scarce. Consequently, we determined the degree of capacitation in boar spermatozoa that were retrieved from the SR of sows at well-defined periods of spontaneous standing oestrus, namely pre-, peri- and post-ovulation, using flow cytometry of Merocyanine-540/Yo-Pro-1-loaded spermatozoa. SR-spermatozoa retrieved and incubated in non-capacitating medium (bicarbonate-free mBO [mBO-]) were largely viable (70-85%) and uncapacitated (69-73%), irrespective of the stage of oestrus considered. Those undergoing capacitation were a minor proportion (1-5%) during pre- and peri-ovulation, but they significantly increased (14%) in post-ovulation oestrus. To clarify whether these SR-spermatozoa were able to undergo capacitation under stimuli, sperm aliquots were challenged in vitro either by incubation in a bicarbonate-rich medium (capacitation medium, mBO+), then further in mBO+ with 20% (v/v) of in vivo collected homologous pre-ovulatory isthmic oviductal fluid (IOF), or incubation with hyaluronan (HA, 500 microg/ml). Exposure to mBO+ significantly increased the sub-population of capacitated spermatozoa from the pre- and peri-ovulation SR, indicating that the uncapacitated SR-spermatozoa were responsive to the effector/inducer bicarbonate at levels recorded in peri-ovulatory AIJ/ampulla in vivo. While addition of IOF or HA to SR-spermatozoa incubated in capacitating medium (mBO+) maintained sperm viability without obviously inducing capacitation in pre- or peri-ovulatory SR-spermatozoa, they significantly increased these percentages during post-ovulation, when compared to baseline values of control incubations (mBO-). The results suggest that massive sperm capacitation does not occur in vivo in the porcine SR

  13. Reducing the capacitance of piezoelectric film sensors

    Energy Technology Data Exchange (ETDEWEB)

    González, Martín G., E-mail: mggonza@fi.uba.ar [Grupo de Láser, Óptica de Materiales y Aplicaciones Electromagnéticas (GLOMAE), Departamento de Física, Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colón 850, C1063ACV Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1425FQB Buenos Aires (Argentina); Sorichetti, Patricio A.; Santiago, Guillermo D. [Grupo de Láser, Óptica de Materiales y Aplicaciones Electromagnéticas (GLOMAE), Departamento de Física, Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colón 850, C1063ACV Buenos Aires (Argentina)

    2016-04-15

    We present a novel design for large area, wideband, polymer piezoelectric sensor with low capacitance. The large area allows better spatial resolution in applications such as photoacoustic tomography and the reduced capacitance eases the design of fast transimpedance amplifiers. The metalized piezoelectric polymer thin film is segmented into N sections, electrically connected in series. In this way, the total capacitance is reduced by a factor 1/N{sup 2}, whereas the mechanical response and the active area of the sensor are not modified. We show the construction details for a two-section sensor, together with the impedance spectroscopy and impulse response experimental results that validate the design.

  14. Content-adaptive pyramid representation for 3D object classification

    DEFF Research Database (Denmark)

    Kounalakis, Tsampikos; Boulgouris, Nikolaos; Triantafyllidis, Georgios

    2016-01-01

    In this paper we introduce a novel representation for the classification of 3D images. Unlike most current approaches, our representation is not based on a fixed pyramid but adapts to image content and uses image regions instead of rectangular pyramid scales. Image characteristics, such as depth ...... and color, are used for defining regions within images. Multiple region scales are formed in order to construct the proposed pyramid image representation. The proposed method achieves excellent results in comparison to conventional representations....

  15. AHP 21: Pyramid Schemes on the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Devin Gonier

    2017-09-01

    Full Text Available The unique features of pyramid shemes and certain underlying causes for their development on the Tibetan Plateau are analyzed. Research was conducted by analyzing 521 surveys, allowing estimation of pyramid scheme activity on the Plateau and an identification of related cultural and social specificities. Firsthand accounts were collected revealing details of personal involvement. Survey data and similarities in the accounts were studied to suggest how involvement in pyramid schemes might be reduced at both institutional and individual levels.

  16. Double Pyramidal Central Configurations with a Concave Quadrilateral Base

    Institute of Scientific and Technical Information of China (English)

    LIUXuefei

    2002-01-01

    As for a doudle pyramidal central configuration in 6-body problems,the case when its bese is a concave polygon is studied.By advancing several assumptions according to the definition of double pyramidal central configuration and deducing two theorems and two corollaries on this subject,the essential and sufficient conditions to form a double pyramidal central configuration with a concave quadriateral base are demonstrated.

  17. Revisiting static modulation in pyramid wavefront sensing

    Science.gov (United States)

    Marafatto, L.; Ragazzoni, R.; Vassallo, D.; Bergomi, M.; Biondi, F.; Farinato, J.; Greggio, D.; Magrin, D.; Viotto, V.

    2016-07-01

    The Pyramid Sensor (PS) is based on the Focault knife-edge test, yielding then, in geometrical approximation, only the sign of the wavefront slope. To provide linear measurements of the wavefront slopes the PS relies on a technique known as modulation, which also plays a central role to improve the linear range of the pyramid WFS, very small in the nonmodulated case. In the main PS using modulation so far, this task is achieved by moving optical components in the WFS, increasing the complexity of the system. An attractive idea to simplify the optical and mechanical design of a pyramid WFS is to work without any dynamic modulation. This concept was only merely described and functionally tested in the framework of MAD, and subsequently, with a holographic diffuser. The latter produce a sort of random distribution of the light coming out from the pupil plane, leading to sort of inefficient modulation, as most of the rays are focused in the central region of the light diffused by such device. The bi-dimensional original grating is, in contrast, producing a well defined deterministic distribution of the light onto a specifically shaped pattern. A crude option has been already discussed as a possibility, and it is here generalized to holographic plates leading to various distribution of lights, including a circle whose diameter would match the required modulation pattern, or more cost effective approaches like the one of a square pattern. These holographic diffusers would exhibit also zero-th and high order patterns and the actual size of the equivalent modulation would be linearly wavelength dependent, leading to colour effects that requires a careful handling in order to properly choose the right amount of equivalent modulation.

  18. PyramidalExplorer: A New Interactive Tool to Explore Morpho-Functional Relations of Human Pyramidal Neurons.

    Science.gov (United States)

    Toharia, Pablo; Robles, Oscar D; Fernaud-Espinosa, Isabel; Makarova, Julia; Galindo, Sergio E; Rodriguez, Angel; Pastor, Luis; Herreras, Oscar; DeFelipe, Javier; Benavides-Piccione, Ruth

    2015-01-01

    This work presents PyramidalExplorer, a new tool to interactively explore and reveal the detailed organization of the microanatomy of pyramidal neurons with functionally related models. It consists of a set of functionalities that allow possible regional differences in the pyramidal cell architecture to be interactively discovered by combining quantitative morphological information about the structure of the cell with implemented functional models. The key contribution of this tool is the morpho-functional oriented design that allows the user to navigate within the 3D dataset, filter and perform Content-Based Retrieval operations. As a case study, we present a human pyramidal neuron with over 9000 dendritic spines in its apical and basal dendritic trees. Using PyramidalExplorer, we were able to find unexpected differential morphological attributes of dendritic spines in particular compartments of the neuron, revealing new aspects of the morpho-functional organization of the pyramidal neuron.

  19. Extracting the abstraction pyramid from complex networks

    Directory of Open Access Journals (Sweden)

    Hu Yuh-Jyh

    2010-08-01

    Full Text Available Abstract Background At present, the organization of system modules is typically limited to either a multilevel hierarchy that describes the "vertical" relationships between modules at different levels (e.g., module A at level two is included in module B at level one, or a single-level graph that represents the "horizontal" relationships among modules (e.g., genetic interactions between module A and module B. Both types of organizations fail to provide a broader and deeper view of the complex systems that arise from an integration of vertical and horizontal relationships. Results We propose a complex network analysis tool, Pyramabs, which was developed to integrate vertical and horizontal relationships and extract information at various granularities to create a pyramid from a complex system of interacting objects. The pyramid depicts the nested structure implied in a complex system, and shows the vertical relationships between abstract networks at different levels. In addition, at each level the abstract network of modules, which are connected by weighted links, represents the modules' horizontal relationships. We first tested Pyramabs on hierarchical random networks to verify its ability to find the module organization pre-embedded in the networks. We later tested it on a protein-protein interaction (PPI network and a metabolic network. According to Gene Ontology (GO and the Kyoto Encyclopedia of Genes and Genomes (KEGG, the vertical relationships identified from the PPI and metabolic pathways correctly characterized the inclusion (i.e., part-of relationship, and the horizontal relationships provided a good indication of the functional closeness between modules. Our experiments with Pyramabs demonstrated its ability to perform knowledge mining in complex systems. Conclusions Networks are a flexible and convenient method of representing interactions in a complex system, and an increasing amount of information in real-world situations is

  20. Cosmological SUSY Breaking and the Pyramid Schemes

    CERN Document Server

    Banks, T

    2014-01-01

    I review the ideas of holographic space-time (HST), Cosmological SUSY breaking (CSB), and the Pyramid Schemes, which are the only known models of Tera-scale physics consistent with CSB, current particle data, and gauge coupling unification. There is considerable uncertainty in the estimate of the masses of supersymmetric partners of the standard model particles, but the model predicts that the gluino is probably out of reach of the LHC, squarks may be in reach, and the NLSP is a right handed slepton, which should be discovered soon.

  1. Cosmological SUSY breaking and the pyramid scheme

    Science.gov (United States)

    Banks, Tom

    2015-04-01

    I review the ideas of holographic spacetime (HST), cosmological SUSY breaking (CSB), and the Pyramid Schemes, which are the only known models of Tera-scale physics consistent with CSB, current particle data, and gauge coupling unification. There is considerable uncertainty in the estimate of the masses of supersymmetric partners of the Standard Model particles, but the model predicts that the gluino is probably out of reach of the LHC, squarks may be in reach, and the NLSP is a right-handed slepton, which should be discovered soon.

  2. Base-of-the-pyramid global strategy

    Directory of Open Access Journals (Sweden)

    Boşcor, D.

    2010-12-01

    Full Text Available Global strategies for MNCs should focus on customers in emerging and developing markets instead of customers in developed economies. The “base-of-the-pyramid segment” comprises 4 billion people in the world. In order to be successful, companies will be required to form unconventional partnerships- with entities ranging from local governments to non-profit organizations - to gain the community’s trust and understand the environmental, infrastructure and political issues that may affect business. Being able to provide affordable, high-quality products and services in this market segment often means new approaches to marketing- new packaging and pricing structures, and using unfamiliar distribution structures.

  3. Plasmonic Tipless Pyramid Arrays for Cell Poration.

    Science.gov (United States)

    Courvoisier, Sébastien; Saklayen, Nabiha; Huber, Marinus; Chen, Jun; Diebold, Eric D; Bonacina, Luigi; Wolf, Jean-Pierre; Mazur, Eric

    2015-07-08

    Improving the efficiency, cell survival, and throughput of methods to modify and control the genetic expression of cells is of great benefit to biology and medicine. We investigate, both computationally and experimentally, a nanostructured substrate made of tipless pyramids for plasmonic-induced transfection. By optimizing the geometrical parameters for an excitation wavelength of 800 nm, we demonstrate a 100-fold intensity enhancement of the electric near field at the cell-substrate contact area, while the low absorption typical for gold is maintained. We demonstrate that such a substrate can induce transient poration of cells by a purely optically induced process.

  4. Effect of surface asperities on the capacitances of capacitive RF MEMS switches

    Science.gov (United States)

    Chen, Zhiqiang; Tian, Wenchao; Zhang, Xiaotong

    2017-03-01

    The effects of surface asperities on the up- and down-state capacitances of the capacitive radio frequency (RF) micro electromechanical system (MEMS) switches were studied in this paper based on the single asperity model and statics. The research results demonstrated that surface asperities effects on the up-state capacitance could be neglected, whereas surface asperities must be taken into consideration at the down-state position in the RF MEMS switches because the surface asperities significantly affected the down-state capacitance. The down-state capacitance typically decreased as the root mean square (RMS) roughness and asperity radius increased. The down-state capacitance was approximately 26% of the theoretical value when the RMS roughness was 20 nm, and 32% of the theoretical value when the asperity radius was 100 nm. The experimental results were in good agreement with the simulation results.

  5. Vehicle to Vehicle Services

    DEFF Research Database (Denmark)

    Brønsted, Jeppe Rørbæk

    2008-01-01

    , mobility, and availability of services. The dissertation consists of two parts. Part I gives an overview of service oriented architecture for pervasive computing systems and describes the contributions of the publications listed in part II. We investigate architecture for vehicular technology applications......As computing devices, sensors, and actuators pervade our surroundings, new applications emerge with accompanying research challenges. In the transportation domain vehicles are being linked by wireless communication and equipped with an array of sensors and actuators that make is possible to provide...... location aware infotainment, increase safety, and lessen environmental strain. This dissertation is about service oriented architecture for pervasive computing with an emphasis on vehicle to vehicle applications. If devices are exposed as services, applications can be created by composing a set of services...

  6. Complementary surface charge for enhanced capacitive deionization

    NARCIS (Netherlands)

    Gao, X.; Porada, S.; Omosebi, A.; Liu, K.L.; Biesheuvel, P.M.; Landon, J.

    2016-01-01

    Commercially available activated carbon cloth electrodes are treated using nitric acid and ethylenediamine solutions, resulting in chemical surface charge enhanced carbon electrodes for capacitive deionization (CDI) applications. Surface charge enhanced electrodes are then configured in a CDI cel

  7. Capacitive Cells for Dielectric Constant Measurement

    Science.gov (United States)

    Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco

    2015-01-01

    A simple capacitive cell for dielectric constant measurement in liquids is presented. As an illustrative application, the cell is used for measuring the degradation of overheated edible oil through the evaluation of their dielectric constant.

  8. Capacitive Cells for Dielectric Constant Measurement

    Science.gov (United States)

    Aguilar, Horacio Munguía; Maldonado, Rigoberto Franco

    2015-01-01

    A simple capacitive cell for dielectric constant measurement in liquids is presented. As an illustrative application, the cell is used for measuring the degradation of overheated edible oil through the evaluation of their dielectric constant.

  9. Highly sensitive micromachined capacitive pressure sensor with reduced hysteresis and low parasitic capacitance

    DEFF Research Database (Denmark)

    Pedersen, Thomas; Fragiacomo, Giulio; Hansen, Ole

    2009-01-01

    This paper describes the design and fabrication of a capacitive pressure sensor that has a large capacitance signal and a high sensitivity of 76 pF/bar in touch mode operation. Due to the large signal, problems with parasitic capacitances are avoided and hence it is possible to integrate the sens...... bonding to create vacuum cavities. The exposed part of the sensor is perfectly flat such that it can be coated with corrosion resistant thin films. Hysteresis is an inherent problem in touch mode capacitive pressure sensors and a technique to significantly reduce it is presented....

  10. Commentary on "Management Education and the Base of the Pyramid"

    Science.gov (United States)

    Rosile, Grace Ann

    2008-01-01

    This commentary asks some critical questions concerning the article "Management Education and the Base of the Pyramid" included in this special issue. Are "bottom of the pyramid" (BOP) multidisciplinary action project (MAP) students prepared to critically assess the impact of their interventions beyond a narrow definition of profit in complex and…

  11. A multi octaves directive dielectric lens: The Pyramid Antenna

    NARCIS (Netherlands)

    Marliani, L.; Bruni, S.; Neto, A.

    2005-01-01

    Leaky wave antennas have been investigated for a long time and are typically an inexpensive solution for beam scanning antennas. We have designed a novel antenna topology, named the pyramid antenna, based on the broadband leaky concept. The pyramid antenna, currently covered by a patent application,

  12. Management Education and the Base of the Pyramid

    Science.gov (United States)

    Gordon, Michael D.

    2008-01-01

    Doing business at the base of the pyramid is a topic of increasing interest to business practitioners and academics. Base of the pyramid business offers the promise of great economic gains for companies and the possibility of a powerful new approach to alleviate poverty. At the same time, it may threaten local culture and independence while…

  13. The Alphabet Pyramid of Team Development and Situation Leadership.

    Science.gov (United States)

    Jarvis, Roy

    2001-01-01

    This pyramid model of team development has four sides--awareness, behavior, communication, and direction--on a foundation of evaluation. The four equal sides of a pyramid represent the equal importance of the different roles, including leader, within a team. All team members are involved in evaluation and deciding what is important, which empowers…

  14. 38 CFR 4.14 - Avoidance of pyramiding.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Avoidance of pyramiding. 4.14 Section 4.14 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES General Policy in Rating § 4.14 Avoidance of pyramiding. The evaluation of...

  15. Tunneling and propping : A justification for pyramidal ownership

    NARCIS (Netherlands)

    Riyanto, Y.E.; Toolsema-Veldman, Linda

    2008-01-01

    This paper links existence of the pyramidal ownership structure to tunneling and propping. Tunneling refers to a transfer of resources from a lower-level firm to a higher-level firm in the pyramidal chain, whereas propping concerns a transfer in the opposite direction intended to bail out the receiv

  16. Tribonacci-like sequences and generalized Pascal's pyramids

    Science.gov (United States)

    Anatriello, Giuseppina; Vincenzi, Giovanni

    2014-11-01

    A well-known result of Feinberg and Shannon states that the tribonacci sequence can be detected by the so-called Pascal's pyramid. Here we will show that any tribonacci-like sequence can be obtained by the diagonals of the Feinberg's triangle associated to a suitable generalized Pascal's pyramid. The results also extend similar properties of Fibonacci-like sequences.

  17. The establishment of GABAergic and glutamatergic synapses on CA1 pyramidal neurons is sequential and correlates with the development of the apical dendrite.

    Science.gov (United States)

    Tyzio, R; Represa, A; Jorquera, I; Ben-Ari, Y; Gozlan, H; Aniksztejn, L

    1999-12-01

    We have performed a morphofunctional analysis of CA1 pyramidal neurons at birth to examine the sequence of formation of GABAergic and glutamatergic postsynaptic currents (PSCs) and to determine their relation to the dendritic arborization of pyramidal neurons. We report that at birth pyramidal neurons are heterogeneous. Three stages of development can be identified: (1) the majority of the neurons (80%) have small somata, an anlage of apical dendrite, and neither spontaneous nor evoked PSCs; (2) 10% of the neurons have a small apical dendrite restricted to the stratum radiatum and PSCs mediated only by GABA(A) receptors; and (3) 10% of the neurons have an apical dendrite that reaches the stratum lacunosum moleculare and PSCs mediated both by GABA(A) and glutamate receptors. These three groups of pyramidal neurons can be differentiated by their capacitance (C(m) = 17.9 +/- 0.8; 30.2 +/- 1.6; 43.2 +/- 3.0 pF, respectively). At birth, the synaptic markers synapsin-1 and synaptophysin labeling are present in dendritic layers but not in the stratum pyramidale, suggesting that GABAergic peridendritic synapses are established before perisomatic ones. The present observations demonstrate that GABAergic and glutamatergic synapses are established sequentially with GABAergic synapses being established first most likely on the apical dendrites of the principal neurons. We propose that different sets of conditions are required for the establishment of functional GABA and glutamate synapses, the latter necessitating more developed neurons that have apical dendrites that reach the lacunosum moleculare region.

  18. Conditions for Eltonian Pyramids in Lotka-Volterra Food Chains.

    Science.gov (United States)

    Jonsson, Tomas

    2017-09-07

    In ecological communities consumers (excluding parasites and parasitoids) are in general larger and less numerous than their resource. This results in a well-known observation known as 'Eltonian pyramids' or the 'pyramid of numbers', and metabolic arguments suggest that this pattern is independent of the number of trophic levels in a system. At the same time, Lotka-Volterra (LV) consumer-resource models are a frequently used tool to study many questions in community ecology, but their capacity to produce Eltonian pyramids has not been formally analysed. Here, I address this knowledge gap by investigating if and when LV food chain models give rise to Eltonian pyramids. I show that Eltonian pyramids are difficult to reproduce without density-dependent mortality in the consumers, unless biologically plausible relationships between mortality rate and interaction strength are taken into account.

  19. Carbon flow electrodes for continuous operation of capacitive deionization and capacitive mixing energy generation

    NARCIS (Netherlands)

    Porada, S.; Hamelers, H.V.M.; Bryjak, M.; Presser, V.; Biesheuvel, P.M.; Weingarth, D.

    2014-01-01

    Capacitive technologies, such as capacitive deionization and energy harvesting based on mixing energy (“capmix” and “CO2 energy”), are characterized by intermittent operation: phases of ion electrosorption from the water are followed by system regeneration. From a system application point of view, c

  20. The NGS Pyramid wavefront sensor for ERIS

    Science.gov (United States)

    Riccardi, A.; Antichi, J.; Quirós-Pacheco, F.; Esposito, S.; Carbonaro, L.; Agapito, G.; Biliotti, V.; Briguglio, R.; Di Rico, G.; Dolci, M.; Ferruzzi, D.; Pinna, E.; Puglisi, A.; Xompero, M.; Marchetti, E.; Fedrigo, E.; Le Louarn, M.; Conzelmann, R.; Delabre, B.; Amico, P.; Hubin, N.

    2014-07-01

    ERIS is the new Single Conjugate Adaptive Optics (AO) instrument for VLT in construction at ESO with the collaboration of Max-Planck Institut fuer Extraterrestrische Physik, ETH-Institute for Astronomy and INAF - Osservatorio Astrofisico di Arcetri. The ERIS AO system relies on a 40×40 sub-aperture Pyramid Wavefront Sensor (PWFS) for two operating modes: a pure Natural Guide Star high-order sensing for high Strehl and contrast correction and a low-order visible sensing in support of the Laser Guide Star AO mode. In this paper we present in detail the preliminary design of the ERIS PWFS that is developed under the responsibility of INAF-Osservatorio Astrofisico di Arcetri in collaboration with ESO.

  1. Ion channels, phosphorylation and mammalian sperm capacitation.

    Science.gov (United States)

    Visconti, Pablo E; Krapf, Dario; de la Vega-Beltrán, José Luis; Acevedo, Juan José; Darszon, Alberto

    2011-05-01

    Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.

  2. Ion channels, phosphorylation and mammalian sperm capacitation

    Institute of Scientific and Technical Information of China (English)

    Pablo E Visconti; Dario Krapf; José Luis de la Vega-Beltrán; Juan José Acevedo; Alberto Darszon

    2011-01-01

    Sexually reproducing animals require an orchestrated communication between spermatozoa and the egg to generate a new individual. Capacitation, a maturational complex phenomenon that occurs in the female reproductive tract, renders spermatozoa capable of binding and fusing with the oocyte, and it is a requirement for mammalian fertilization. Capacitation encompasses plasma membrane reorganization, ion permeability regulation, cholesterol loss and changes in the phosphorylation state of many proteins. Novel tools to study sperm ion channels, image intracellular ionic changes and proteins with better spatial and temporal resolution, are unraveling how modifications in sperm ion transport and phosphorylation states lead to capacitation. Recent evidence indicates that two parallel pathways regulate phosphorylation events leading to capacitation, one of them requiring activation of protein kinase A and the second one involving inactivation of ser/thr phosphatases. This review examines the involvement of ion transporters and phosphorylation signaling processes needed for spermatozoa to achieve capacitation. Understanding the molecular mechanisms leading to fertilization is central for societies to deal with rising male infertility rates, to develop safe male gamete-based contraceptives and to preserve biodiversity through better assisted fertilization strategies.

  3. Real-time and label-free monitoring of nanoparticle cellular uptake using capacitance-based assays

    Science.gov (United States)

    Lee, Rimi; Jo, Dong hyun; Chung, Sang J.; Na, Hee-Kyung; Kim, Jeong Hun; Lee, Tae Geol

    2016-01-01

    Nanoparticles have shown great potential as vehicles for the delivery of drugs, nucleic acids, and therapeutic proteins; an efficient, high-throughput screening method to analyze nanoparticle interaction with the cytomembrane would substantially improve the efficiency and accuracy of the delivery. Here, we developed a capacitance sensor array that monitored the capacitance values of nanoparticle-treated cells in a real-time manner, without the need for labeling. Upon cellular uptake of the nanoparticles, a capacitance peak was observed at a low frequency (e.g., 100 Hz) as a function of time based on zeta potential changes. In the high frequency region (e.g., 15–20 kHz), the rate of decreasing capacitance slowed as a function of time compared to the cell growth control group, due to increased cytoplasm resistance and decreased membrane capacitance and resistance. The information provided by our capacitance sensor array will be a powerful tool for scientists designing nanoparticles for specific purposes. PMID:27641838

  4. Imaging a Pyramid Interior by ERT-3D Methods, Preliminar Results at El Castillo Pyramid, Chichen Itza, Mexico

    Science.gov (United States)

    Chavez, R. E.; Tejero, A.; Cifuentes, G.; HernaNdez-Quintero, J. E.; Garcia-Serrano, A.

    2016-12-01

    The well known Pyramid El Castillo, located in the archaeological site of Chichen Itza, in the Yucatan Peninsula is the emblematic structure of this archaeological site and elected as one of the man-made world seven wonders. The archaeological team that restored this structure during the 1920's discovered a smaller pyramid inside this prehispanic body, which corresponded to an older Mayan period. The possibility of finding other constructive periods inside this edifice should be important to reconstruct the Mayan history. Previous geophysical studies carried out by us in 2014, employed novel Electrical Resistivity Tomography (ERT) arrays that surrounded the pyramids surface with flat electrodes to obtain a 3D image of the subsoil. At that time, a low resistivity body was found beneath the pyramid, which was associated to a sinkhole filled with sweet water. Employing the same technique, a series of flat electrodes were deployed on each body conforming the pyramid, a total of 10 bodies were covered, employing a different number of electrodes trying to keep the distance between each electrode constant ( 3 m). Each body was treated as a single observation cube, where the apparent resistivity data measured was later inverted. A precise topographic control for each electrode was realized and introduced in the inversion process. 45,000 observation points within the pyramid were obtained. Initially, each working cube corresponding to a given pyramid's body was inverted. A composition of each inversion was assembled to form the resistivity distribution within the pyramid using a smooth interpolation method. A high resistivity anomaly was found towards the northern portion of the model that could be associated to the main stairway of the inner pyramid. The cavity detected during the 2014 survey was observed as a low resistivity anomaly found at the pyramid's base. At the moment, we are assembling the full observed resistivity data as a single file to compute an integrated

  5. Microphonics in biopotential measurements with capacitive electrodes.

    Science.gov (United States)

    Luna-Lozano, Pablo S; Pallas-Areny, Ramon

    2010-01-01

    Biopotential measurements with capacitive electrodes do not need any direct contact between electrode and skin, which saves the time devoted to expose and prepare the contact area when measuring with conductive electrodes. However, mechanical vibrations resulting from physiological functions such as respiration and cardiac contraction can change the capacitance of the electrode and affect the recordings. This transformation of mechanical vibrations into undesired electric signals is termed microphonics. We have evaluated microphonics in capacitive ECG recordings obtained from a dressed subject seated on a common chair with electrodes placed on the front side of the backrest of the chair. Depending on the softness of the backrest, the recordings may be clearly affected by the displacement of the thorax back wall due to the respiration and to the heart's mechanical activity.

  6. Carbon nanofiber supercapacitors with large areal capacitances

    KAUST Repository

    McDonough, James R.

    2009-01-01

    We develop supercapacitor (SC) devices with large per-area capacitances by utilizing three-dimensional (3D) porous substrates. Carbon nanofibers (CNFs) functioning as active SC electrodes are grown on 3D nickel foam. The 3D porous substrates facilitate a mass loading of active electrodes and per-area capacitance as large as 60 mg/ cm2 and 1.2 F/ cm2, respectively. We optimize SC performance by developing an annealing-free CNF growth process that minimizes undesirable nickel carbide formation. Superior per-area capacitances described here suggest that 3D porous substrates are useful in various energy storage devices in which per-area performance is critical. © 2009 American Institute of Physics.

  7. Template-stripped asymmetric metallic pyramids for tunable plasmonic nanofocusing.

    Science.gov (United States)

    Cherukulappurath, Sudhir; Johnson, Timothy W; Lindquist, Nathan C; Oh, Sang-Hyun

    2013-01-01

    We demonstrate a novel scheme for plasmonic nanofocusing with internally illuminated asymmetric metallic pyramidal tips using linearly polarized light. A wafer-scale array of sharp metallic pyramids is fabricated via template stripping with films of different thicknesses on opposing pyramid facets. This structural asymmetry is achieved through a one-step angled metal deposition that does not require any additional lithography processing and when internally illuminated enables the generation of plasmons using a Kretschmann-like coupling method on only one side of the pyramids. Plasmons traveling toward the tip on one side will converge at the apex, forming a nanoscale "hotspot." The asymmetry is necessary for these focusing effects since symmetric pyramids display destructive plasmon interference at the tip. Computer simulations confirm that internal illumination with linearly polarized light at normal incidence on these asymmetric pyramids will focus optical energy into nanoscale volumes. Far-field optical experiments demonstrate large field enhancements as well as angle-dependent spectral tuning of the reradiated light. Because of the low background light levels, wafer-scale fabrication, and a straightforward excitation scheme, these asymmetric pyramidal tips will find applications in near-field optical microscopy and array-based optical trapping.

  8. Nonlinear multiresolution signal decomposition schemes--part I: morphological pyramids.

    Science.gov (United States)

    Goutsias, J; Heijmans, H M

    2000-01-01

    Interest in multiresolution techniques for signal processing and analysis is increasing steadily. An important instance of such a technique is the so-called pyramid decomposition scheme. This paper presents a general theory for constructing linear as well as nonlinear pyramid decomposition schemes for signal analysis and synthesis. The proposed theory is based on the following ingredients: 1) the pyramid consists of a (finite or infinite) number of levels such that the information content decreases toward higher levels and 2) each step toward a higher level is implemented by an (information-reducing) analysis operator, whereas each step toward a lower level is implemented by an (information-preserving) synthesis operator. One basic assumption is necessary: synthesis followed by analysis yields the identity operator, meaning that no information is lost by these two consecutive steps. Several examples of pyramid decomposition schemes are shown to be instances of the proposed theory: a particular class of linear pyramids, morphological skeleton decompositions, the morphological Haar pyramid, median pyramids, etc. Furthermore, the paper makes a distinction between single-scale and multiscale decomposition schemes, i.e., schemes without or with sample reduction. Finally, the proposed theory provides the foundation of a general approach to constructing nonlinear wavelet decomposition schemes and filter banks.

  9. Role of the oviduct in sperm capacitation.

    Science.gov (United States)

    Rodriguez-Martinez, H

    2007-09-01

    Following insemination of spermatozoa pre-ovulation, the mammalian oviduct ensures, by the formation of a functional sperm reservoir (SR), that suitable (low) numbers of viable and potentially fertile spermatozoa are available for fertilization at the ampullary isthmic junction (AIJ). As ovulation approaches, a proportion of the SR-stored spermatozoa is continuously distributed towards the AIJ and individually activated leading to step-wise capacitation and the attainment of hyperactivated motility. This paper reviews in vivo changes in the intra-luminal milieu of the oviduct of pigs and cows, in particular the SR and the AIJ which relate to the modulation of sperm capacitation around spontaneous ovulation. In vivo, most viable spermatozoa in the pre-ovulatory SR are uncapacitated. Capacitation rates significantly increase after ovulation, apparently not massively but concurrent with the individual, continuous sperm dislocation from the SR. Bicarbonate, whose levels differ between the SR and the AIJ, appears as the common primary effector of the membrane destabilizing changes that encompasses the first stages of capacitation. Sperm activation can be delayed or even reversed by co-incubation with membrane proteins of the tubal lining, isthmic fluid or specific tubal glycosaminoglycans, such as hyaluronan. Although the pattern of response to in vitro induction of sperm activation - capacitation in particular - is similar for all spermatozoa, the capacity and speed of the response is very individual. Such diversity in responsiveness among spermatozoa insures full sperm viability before ovulation and the presence of spermatozoa at different stages of capacitation at the AIJ, thus maximizing the chances of normal fertilization.

  10. Relevance of the pyramidal syndrome in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Álvarez, N; Díez, L; Avellaneda, C; Serra, M; Rubio, M Á

    2016-06-20

    Pyramidal signs (hyperreflexia, spasticity, Babinski sign) are essential for the diagnosis of amyotrophic lateral sclerosis (ALS). However, these signs are not always present at onset and may vary over time, besides which their role in disease evolution is controversial. Our goal was to describe which pyramidal signs were present and how they evolved in a cohort of patients with ALS, as well as their role in prognosis. Retrospective analysis of prospectively collected patients diagnosed with ALS in our centre from 1990 to 2015. Of a total of 130 patients with ALS, 34 (26.1%) patients showed no pyramidal signs at the first visit while 15 (11.5%) had a complete pyramidal syndrome. Of those patients without initial pyramidal signs, mean time of appearance of the first signs was 4.5 months. Babinski sign was positive in 64 (49.2%) patients, hyperreflexia in 90 (69.2%) and 22 (16.9%) patients had spasticity. Pyramidal signs tended to remain unchanged over time, although they seem to appear at later stages or even disappear with time in some patients. We found no association between survival and the presence of changes to pyramidal signs, although decreased spasticity was associated with greater clinical deterioration (ALSFR scale) (P<.001). A quarter of patients with ALS initially showed no pyramidal signs and in some cases they even disappear over time. These data support the need for tools that assess the pyramidal tract. Copyright © 2016 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  11. Capacitance sensor for automatic soil retreat measurements

    Institute of Scientific and Technical Information of China (English)

    GU Jun; YANG Juan; YIN Wu-liang; WANG Chao; WANG Hua-xiang; LIU Ze; CHENG Su-sen

    2008-01-01

    To continuously monitor the soil retreat due to erosion in field, provide valuable information about the erosion processes and overcome the disadvantages of inefficiency, high time-consumption and labor-intensity of existing methods, this paper describes a novel capacitance sensor for measuring the soil retreat. A capaci-tance sensor based probe is proposed, which can measure the depth of the soil around it automatically and the data can be recorded by a data logger. Experimental results in the lab verify its usefulness.

  12. Experimental study of negative capacitance in LEDs

    Institute of Scientific and Technical Information of China (English)

    FENG Lie-feng; WANG Jun; ZHU Chuan-yun; CONG Hong-xia; CHEN Yong; WANG Cun-da

    2005-01-01

    The experimental study on negative capacitance(NC) of various light-emitting diodes(LEDs) is presented.Experimental result shows that all LEDs display the NC phenomenon.The voltage modulated electroluminescence(VMEL) experiment confirms that the reason of negative capacitance is the strong recombination of the injected carriers in the active region of luminescence.The measures also verify that the dependence of NC on voltage and frequency in different LEDs is similar: NC phenomenon is more obvious with higher voltage or lower frequency.

  13. NONLINEAR BENDING THEORY OF DIAGONAL SQUARE PYRAMID RETICULATED SHALLOW SHELLS

    Institute of Scientific and Technical Information of China (English)

    肖潭; 刘人怀

    2001-01-01

    Double-deck reticulated shells are a main form of large space structures. One of the shells is the diagonal square pyramid reticulated shallow shell, whose its upper and lower faces bear most of the load but its core is comparatively flexible. According to its geometrical and mechanical characteristics, the diagonal square pyramid reticulated shallow shell is treated as a shallow sandwich shell on the basis of three basic assumptions. Its constitutive relations are analyzed from the point of view of energy and internal force equivalence. Basic equations of the geometrically nonlinear bending theory of the diagonal square pyramid reticulated shallow shell are established by means of the virtual work principle .

  14. Inclinations of Egyptian pyramids and finding of the divine essence

    OpenAIRE

    GRIGORIEV STANISLAV ARKADIEVICH

    2015-01-01

    The aim of this research is discovery of astronomical reasons in orientation of slopes of Egyptian pyramids used as tombs for pharaohs of Ancient Egypt. The article contains results of statistical analysis of change in inclination of slopes of the pyramids (3rd 2nd millennia BC) depending on time of their building. The first year of the corresponding pharaoh’s reign has been accepted, as usually it is considered that building of pyramids ones started during either the first or second year of ...

  15. Ischemic stroke of the pyramidal decussation causing quadriplegia and anarthria.

    Science.gov (United States)

    Wilkins, Emilia G; Kamel, Hooman; Johnson, Eric C B; Shalev, Sarah M; Josephson, S Andrew

    2012-10-01

    A 52-year-old man with a history of hypertension and previously irradiated head and neck cancer presented with quadriplegia and anarthria sparing the face and sensory functions. Brain magnetic resonance imaging (MRI) demonstrated acute infarction of the pyramidal decussation. We describe the clinical and radiological characteristics of infarction at the pyramidal decussation and review the arterial supply to this region in the lower brainstem. Although rare, infarction of the pyramidal decussation should be considered in the differential diagnosis when patients present with atraumatic pure motor quadriplegia.

  16. Fabrication and measurement of a flexoelectric micro-pyramid composite

    Directory of Open Access Journals (Sweden)

    Wenbin Huang

    2014-12-01

    Full Text Available A fabrication method by combining precision mechanical dicing and wet etching was developed to prepare micro-pyramid structures based on (Ba0.67Sr0.33TiO3 ceramics. The effective piezoelectric properties of flexoelectric pyramid structures in ten micrometers scale were investigated and measured through converse flexoelectric effect. The scaling effect of the flexoelectric response was demonstrated as the structure size shrinks down. The results do suggest the great potential of flexoelectric micro pyramids as an alternative to lead-free piezoelectric material.

  17. Papillary Carcinoma Arising from the Pyramidal Lobe of the Thyroid

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Gi; Lee, Sarah; Kim, Eun Kyung; Moon, Hee Jung; Kwak, Jin Young [Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2012-03-15

    The authors present a rare case of papillary carcinoma arising from the pyramidal lobe of the thyroid in a 54-year-old woman, who presented with a right submental palpable mass. An ultrasound evaluation depicted a 3 cm mixed echoic mass from the thyroid cartilage level without a focal lesion in the thyroid gland. Surgical specimens obtained during bilateral thyroidectomy confirmed papillary carcinoma of the pyramidal lobe. To the authors' knowledge, this is the first case report to describe papillary carcinoma arising from the pyramidal lobe of the thyroid gland

  18. General heuristics algorithms for solving capacitated arc routing problem

    Science.gov (United States)

    Fadzli, Mohammad; Najwa, Nurul; Masran, Hafiz

    2015-05-01

    In this paper, we try to determine the near-optimum solution for the capacitated arc routing problem (CARP). In general, NP-hard CARP is a special graph theory specifically arises from street services such as residential waste collection and road maintenance. By purpose, the design of the CARP model and its solution techniques is to find optimum (or near-optimum) routing cost for a fleet of vehicles involved in operation. In other words, finding minimum-cost routing is compulsory in order to reduce overall operation cost that related with vehicles. In this article, we provide a combination of various heuristics algorithm to solve a real case of CARP in waste collection and benchmark instances. These heuristics work as a central engine in finding initial solutions or near-optimum in search space without violating the pre-setting constraints. The results clearly show that these heuristics algorithms could provide good initial solutions in both real-life and benchmark instances.

  19. A mathematical modeling proposal for a Multiple Tasks Periodic Capacitated Arc Routing Problem

    Directory of Open Access Journals (Sweden)

    Cleverson Gonçalves dos Santos

    2015-12-01

    Full Text Available The countless accidents and incidents occurred at dams at the last years, propelled the development of politics related with dams safety. One of the strategies is related to the plan for instrumentation and monitoring of dams. The monitoring demands from the technical team the reading of the auscultation data, in order to periodically monitor the dam. The monitoring plan of the dam can be modeled as a problem of mathematical program of the periodical capacitated arcs routing program (PCARP. The PCARP is considered as a generalization of the classic problem of routing in capacitated arcs (CARP due to two characteristics: 1 Planning period larger than a time unity, as that vehicle make several travels and; 2 frequency of associated visits to the arcs to be serviced over the planning horizon. For the dam's monitoring problem studied in this work, the frequent visits, along the time horizon, it is not associated to the arc, but to the instrument with which is intended to collect the data. Shows a new problem of Multiple tasks Periodic Capacitated Arc Routing Problem and its elaboration as an exact mathematical model. The new main characteristics presented are: multiple tasks to be performed on each edge or edges; different frequencies to accomplish each of the tasks; heterogeneous fleet; and flexibility for more than one vehicle passing through the same edge at the same day. The mathematical model was implemented and examples were generated randomly for the proposed model's validation.

  20. Quantum capacitance of the armchair-edge graphene nanoribbon

    Indian Academy of Sciences (India)

    Ling-Feng Mao

    2013-08-01

    The quantum capacitance, an important parameter in the design of nanoscale devices, is derived for armchair-edge single-layer graphene nanoribbon with semiconducting property. The quantum capacitance oscillations are found and these capacitance oscillations originate from the lateral quantum confinement in graphene nanoribbon. Detailed studies of the capacitance oscillations demonstrate that the local channel electrostatic potential at the capacitance peak, the height and the number of the capacitance peak strongly depend on the width, especially a few nanometres, of the armchair-edge graphene nanoribbon. It implies that the capacitance oscillations observed in the experiments can be utilized to measure the width of graphene nanoribbon. The results also show that the capacitance oscillations are not seen when the width is larger than 30 nm.

  1. Investigation on a Novel Capacitive Electrode for Geophysical Surveys

    Directory of Open Access Journals (Sweden)

    Zhiyu Wang

    2016-01-01

    Full Text Available Nonpolarizable electrodes are applied widely in the electric field measurement for geophysical surveys. However, there are two major problems: (1 systematic errors caused by poor electrical contact in the high resistive terrains and (2 environmental damage associated with using nonpolarizable electrodes. A new alternative structure of capacitive electrode, which is capable of sensing surface potential through weak capacitive coupling, is presented to solve the above problems. A technique is introduced to neutralize distributed capacitance and input capacitance of the detection circuit. With the capacitance neutralization technique, the transmission coefficient of capacitive electrode remains stable when environmental conditions change. The simulation and field test results indicate that the new capacitive electrode has an operating bandwidth range from 0.1 Hz to 1 kHz. The capacitive electrodes have a good prospect of the applications in geophysical prospecting, especially in resistive terrains.

  2. Inside-out electrical capacitance tomography

    DEFF Research Database (Denmark)

    Kjærsgaard-Rasmussen, Jimmy; Meyer, Knud Erik

    2011-01-01

    In this work we demonstrate the construction of an ‘inside-out’ sensor geometry for electrical capacitance tomography (ECT). The inside-out geometry has the electrodes placed around a tube, as usual, but measuring ‘outwards’. The flow between the electrodes and an outer tube is reconstructed...

  3. Comparison of piezoresistive and capacitive ultrasonic transducers

    Science.gov (United States)

    Neumann, John J.; Greve, David W.; Oppenheim, Irving J.

    2004-07-01

    MEMS ultrasonic transducers for flaw detection have heretofore been built as capacitive diaphragm-type devices. A diaphragm forms a moveable electrode, placed at a short gap from a stationary electrode, and diaphragm movement has been detected by capacitance change. Although several research teams have successfully demonstrated that technology, the detection of capacitance change is adversely affected by stray and parasitic capacitances, limiting the sensitivity of such transducers and typically requiring relatively large diaphragm areas. We describe the design and fabrication of what to our knowledge is the first CMOS-MEMS ultrasonic phased array transducer using piezoresistive strain sensing. Piezoresistors have been patterned within the diaphragms, and diaphragm movement creates bending strain which is detected by a bridge circuit, for which conductor losses will be less significant. The prospective advantage of such piezoresistive transducers is that sufficient sensitivity may be achieved with very small diaphragms. We compare transducer response under fluid-coupled ultrasonic excitation and report the experimental gauge factor for the piezoresistors. We also discuss the phased array performance of the transducer in sensing the direction of an incoming wave.

  4. Negative capacitance in multidomain ferroelectric superlattices

    Science.gov (United States)

    Zubko, Pavlo; Wojdeł, Jacek C.; Hadjimichael, Marios; Fernandez-Pena, Stéphanie; Sené, Anaïs; Luk'Yanchuk, Igor; Triscone, Jean-Marc; Íñiguez, Jorge

    2016-06-01

    The stability of spontaneous electrical polarization in ferroelectrics is fundamental to many of their current applications, which range from the simple electric cigarette lighter to non-volatile random access memories. Research on nanoscale ferroelectrics reveals that their behaviour is profoundly different from that in bulk ferroelectrics, which could lead to new phenomena with potential for future devices. As ferroelectrics become thinner, maintaining a stable polarization becomes increasingly challenging. On the other hand, intentionally destabilizing this polarization can cause the effective electric permittivity of a ferroelectric to become negative, enabling it to behave as a negative capacitance when integrated in a heterostructure. Negative capacitance has been proposed as a way of overcoming fundamental limitations on the power consumption of field-effect transistors. However, experimental demonstrations of this phenomenon remain contentious. The prevalent interpretations based on homogeneous polarization models are difficult to reconcile with the expected strong tendency for domain formation, but the effect of domains on negative capacitance has received little attention. Here we report negative capacitance in a model system of multidomain ferroelectric-dielectric superlattices across a wide range of temperatures, in both the ferroelectric and paraelectric phases. Using a phenomenological model, we show that domain-wall motion not only gives rise to negative permittivity, but can also enhance, rather than limit, its temperature range. Our first-principles-based atomistic simulations provide detailed microscopic insight into the origin of this phenomenon, identifying the dominant contribution of near-interface layers and paving the way for its future exploitation.

  5. Constant capacitance in nanopores of carbon monoliths.

    Science.gov (United States)

    García-Gómez, Alejandra; Moreno-Fernández, Gelines; Lobato, Belén; Centeno, Teresa A

    2015-06-28

    The results obtained for binder-free electrodes made of carbon monoliths with narrow micropore size distributions confirm that the specific capacitance in the electrolyte (C2H5)4NBF4/acetonitrile does not depend significantly on the micropore size and support the foregoing constant result of 0.094 ± 0.011 F m(-2).

  6. Thermodynamic cycle analysis for capacitive deionization

    NARCIS (Netherlands)

    Biesheuvel, P.M.

    2009-01-01

    Capacitive deionization (CDI) is an ion removal technology based on temporarily storing ions in the polarization layers of two oppositely positioned electrodes. Here we present a thermodynamic model for the minimum work required for ion separation in the fully reversible case by describing the ionic

  7. Residential solar-heating system uses pyramidal optics

    Science.gov (United States)

    1981-01-01

    Report describes reflective panels which optimize annual solar energy collection in attic installation. Subunits include collection, storage, distribution, and 4-mode control systems. Pyramid optical system heats single-family and multi-family dwellings.

  8. The Fishery of Truckee River and Pyramid Lake, Nevada

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides an overview of the Washoe Project Act. Trout populations in Pyramid Lake began to decline in the 1930s due to poor water quality and poor...

  9. Improving Drought Tolerance of Rice by Designed QTL Pyramiding

    Institute of Scientific and Technical Information of China (English)

    Z.K. Li; Y. Sun; L.H. Zhu; D. Dwivedi; Y.M. Gao; T.Q. Zheng; R. Lafitte; J.L. Xu; D. Mackill; B.Y. Fu; J.Domingo

    2007-01-01

    @@ Drought is the most important factor limiting rice yields in the rainfed areas of Asia. To overcome the problem, we developed a new strategy 'designed QTL pyramiding' to more efficiently develop drought tolerant (DT)rice cultivars.

  10. A Remark on the Mallat Pyramidal Algorithm of Wavelet Analysis

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    The exact relationships between the lenthgs of scale sequences and wavelet sequences in the Mallat pyramidal algorithm for computing wavelet trans-form coefficients are obtained,and the maximum possible scale of arbitrary discrete signal is derived.

  11. PYRAMIDAL-HOLLOW-BEAM DIPOLE TRAP FOR ALKALI ATOMS

    Institute of Scientific and Technical Information of China (English)

    YIN JIAN-PING; GAO WEI-JIAN; WANG YU-ZHU; ZHU YI-FU; WANG YI-QIU

    2000-01-01

    We propose a dark gravito-optical dipole trap, for alkali atoms, consisting of a blue-detuned, pyramidal-hollow laser beam propagating upward and the gravity field. When cold atoms from a magneto-optical trap are loaded into the pyramidal-hollow beam and bounce inside the pyramidal-hollow beam, they experience efficient Sisyphus cooling and geometric cooling induced by the pyramidal-hollow beam and the weak repumping beam propagating downward. Our study shows that an ultracold and dense atomic sample with an equilibrium 3D momentum of ~ 3hk and an atomic density above the point of Bose-Einstein condensation may be obtained in this pure optical trap.

  12. ``Zeptofarad'' (10-21 F) resolution capacitance sensor for scanning capacitance microscopy

    Science.gov (United States)

    Tran, T.; Oliver, D. R.; Thomson, D. J.; Bridges, G. E.

    2001-06-01

    We describe a sensor for use in a scanning capacitance microscope (SCM) that is capable of "zeptofarad" (10-21 F) capacitance measurement resolution in a 1 Hz bandwidth with a peak-to-peak sense voltage on the probe tip of no more than 300 mV. This sensitivity is based on experimental data and simulation results that are in excellent agreement. The complete sensor incorporates an oscillator (phase locked to a 10 MHz crystal oscillator), a coupled transmission line resonator, an amplifier, and a peak detector. The resonator is fabricated from copper-clad, low-loss dielectric material and its size is such that it is easily incorporated with a scanning probe microscope. The sensor's use in the SCM enables capacitance resolution that has not previously been possible while retaining the instrumental advantages of imaging at low sense voltages. The performance of this sensor is discussed and compared to alternative scanning capacitance microscopy methodologies.

  13. MOS Capacitance-Voltage Characteristics:V.Methods to Enhance the Trapping Capacitance

    Institute of Scientific and Technical Information of China (English)

    揭斌斌; 薩支唐

    2012-01-01

    Low-frequency and High-frequency Capacitance-Voltage (C-V) curves of Silicon Metal-Oxide-Semiconductor Capacitors,showing electron and hole trapping at shallow-level dopant and deep-level generationrecombination-trapping impurities,are presented to illustrate the enhancement of the giant trapping capacitances by physical means via device and circuit designs,in contrast to chemical means via impurity characteristics previously reported.Enhancement is realized by masking the electron or/and hole storage capacitances to make the trapping capacitances dominant at the terminals.Device and materials properties used in the computed CV curves are selected to illustrate experimental realizations for fundamental trapping parameter characterizations and for electrical and optical signal processing applications.

  14. Dendritic potassium channels in hippocampal pyramidal neurons.

    Science.gov (United States)

    Johnston, D; Hoffman, D A; Magee, J C; Poolos, N P; Watanabe, S; Colbert, C M; Migliore, M

    2000-05-15

    Potassium channels located in the dendrites of hippocampal CA1 pyramidal neurons control the shape and amplitude of back-propagating action potentials, the amplitude of excitatory postsynaptic potentials and dendritic excitability. Non-uniform gradients in the distribution of potassium channels in the dendrites make the dendritic electrical properties markedly different from those found in the soma. For example, the influence of a fast, calcium-dependent potassium current on action potential repolarization is progressively reduced in the first 150 micrometer of the apical dendrites, so that action potentials recorded farther than 200 micrometer from the soma have no fast after-hyperpolarization and are wider than those in the soma. The peak amplitude of back-propagating action potentials is also progressively reduced in the dendrites because of the increasing density of a transient potassium channel with distance from the soma. The activation of this channel can be reduced by the activity of a number of protein kinases as well as by prior depolarization. The depolarization from excitatory postsynaptic potentials (EPSPs) can inactivate these A-type K+ channels and thus lead to an increase in the amplitude of dendritic action potentials, provided the EPSP and the action potentials occur within the appropriate time window. This time window could be in the order of 15 ms and may play a role in long-term potentiation induced by pairing EPSPs and back-propagating action potentials.

  15. [TURNING THE PYRAMID IN PRENATAL CARE].

    Science.gov (United States)

    Ohel-Shani, Iris; Daniel-Spiegel, Etty

    2015-10-01

    Most complications of pregnancy manifest towards the latter part of pregnancy. Nevertheless, present day diagnostic techniques, such as sonography, Doppler, biochemical screening tests, and the newly developed ability to study free fetal DNA in maternal blood, enables early identification of high risk groups for maternal and fetal morbidity, as well as fetal genetic and anatomical pathology. Dr. Nicolaides has coined this changing trend with the term "Turning the Pyramid". Early screening enables earlier and more directed follow-up with the application of relevant diagnostic tests. Obvious advantages include the potential to reduce maternal-fetal morbidity before it becomes apparent clinically. Additionally, the earlier diagnosis of fetal pathology, allows more time for parents and medical staff to assess the situation, and reach a decision regarding the continuation of the pregnancy. A possible drawback of such an approach, of early identification of high risk groups, is the uncertainty it arouses, sometimes for a long duration, with the accompanying apprehension and stress parents have to endure. A multidisciplinary team, consisting of specialists in fetal-maternal medicine, genetics, ultrasound, and perinatology, will be needed in order to best deal with the often complex information, which is becoming increasingly available at a very early stage of pregnancy.

  16. Landau pole in the pyramid scheme

    Science.gov (United States)

    Banks, Tom; Fortin, Jean-François; Kathrein, Scott

    2010-12-01

    We revisit the problem of the hidden sector Landau pole in the pyramid scheme. There is a fixed line in the plane of hidden sector gauge coupling and Yukawa couplings between the trianon fields. We postulate that the couplings flow to this line, at a point where the hidden sector gauge coupling is close to the strong coupling edge of its perturbative regime. Below the masses of the heavier trianons, the model quickly flows to a confining NF=NC=3 supersymmetric gauge theory, as required by phenomenological considerations. We study possible discrete R symmetries, which guarantee, among other things, that the basin of attraction of the fixed line has full codimension in the space of R-allowed couplings. The Yukawa couplings required to get the fixed line violate the pyrma-baryon symmetries we invoked in previous work to find a dark matter candidate. Omitting one of them, we have a dark matter candidate, and an acceptable renormalization group flow down from the unification scale, if the confinement scale of the hidden sector group is lowered from 5 to 2 TeV. However, we cannot find anomaly-free symmetries, which guarantee a set of pyrma-baryon violating couplings that eliminate the Landau pole, but do not allow a supersymmetry preserving vacuum of the model. We can do this with only one pyrma-baryon violating coupling, but this lowers the confinement scale to 900 GeV, which may already be ruled out due to light hidden sector baryons.

  17. Disparity map estimation using image pyramid

    Science.gov (United States)

    Roszkowski, Mikołaj

    2013-10-01

    The task of a short baseline stereo matching algorithm is to calculate the disparity map given two rectified images of one scene. Most algorithms assume that a maximal possible disparity exists and search all disparities in the range from 1 to this maximal disparity. In the case of large images and wide disparity search range this can be very computationally demanding. In this article a simple coarse to fine hierarchical matching method based on the Gaussian pyramid and local stereo matching is investigated. Such an approach allows significant reduction of the number of disparities searched compared to the full search algorithm. Moreover it is shown, that grouping pixels into simple square regions is in most cases sufficient to avoid significant errors that typically appear at disparity map discontinuities when hierarchical schemes are used. Finally, it is presented that in most cases the quality of the disparity map obtained using the investigated algorithm is of comparable quality to a disparity map obtained using full-search local stereo algorithm.

  18. ASTRONOMICAL ALGORITHMS OF EGYPTIAN PYRAMIDS SLOPES AND THEIR MODULES DIVIDER

    OpenAIRE

    Aboulfotouh, Hossam M. K.

    2015-01-01

    This paper is an attempt to show the astronomical design principles that are encoded in the geometrical forms of the largest five pyramids of the fourth Egyptian dynasty, in Giza and Dahshur plateaus, based on using the pyramids’ design-modules that are mentioned in the so-called Rhind Mathematical Papyrus. It shows the astronomical algorithms for quantifying the slopes of pyramids, with reference to specific range of earth’s axial tilt, within spherical co-ordinates system. Besid...

  19. Searching for Chambers and Caves in Teotihuacan's Sun Pyramid

    Science.gov (United States)

    Alfaro, R.; Arrieta, E.; Barba P., L.; Becerril, A. D.; Belmont, E.; Carrillo, I.; Cabrera M., J. I.; Esquivel, O.; Grabski, V.; López R., J. M.; Manzanilla N., L.; Martínez D., A.; Menchaca R., A.; Moreno, M.; Núñez C., R.; Plascencia, J. C.; Rangel, M.; Villoro, M.

    2003-06-01

    In this work a status report of a search for caves in the Sun pyramid in Teotihuacan, México is presented. From an archeological perspective the main goal is to gather evidence to determine whether the pyramid was a state or a funerary temple. The general layout of the detector that is being built is an updated version of the one originally proposed by Alvarez et al..

  20. Winding Capacitance Dividing Method for Powerformer

    Institute of Scientific and Technical Information of China (English)

    TIAN Qing; LIN Xiang-ning; LI Jian-jian; TAO Yong-hong

    2008-01-01

    It presents a method which can equivalently arrange the capacitance distribution along with the winding ofthe generator on the terminal and neutral respectively in a reasonable partition, particularly for a type of high-voltagegraded insulated cable wound generator, Powerformer. The winding of the Powerformer adopts graded insulation,which leads to the various cable thicknesses in different portion of the winding, and thus, the uneven capacitancedistribution. The large capacitive currents and large transient outrush currents resulting from the cable consisting ofthe stator winding of Powerformer may cause problems to the generator differential protection. Most of literatures a-vailable in the field of compensated differential protection focus on the charging current compensation for long trans-mission line, instead of for generator. The authors give a method which can be used to compensate the capacitivecurrent wholly to improve the reliability of the differential protection of Powerformer. It is proved that the distribu-ted capacitance can be equivalent as the lump circuit with a capacitance partition coefficient p, and p is proved as aconstant no matter whether the generator experiences the normal operation, external phase(s) fault or internal phase(s) fault. The formula of the partition coefficient is provided and the corresponding equivalent circuit of the Power-former cable to calculate capacitance currents is given. An analysis programming resolving the minimum value of thecoefficient p is written in MATLAB 7. 0/m according to this formula, using the function fmincon() which can workin any type of constraint condition. The program always gets the same global minimum points under the different in-itial values condition which proves our point by mathematical test. With this new approach to winding capacitancedividing method, the protection scheme used for Powerformer can be validated and improved accordingly.

  1. Conductive MOF electrodes for stable supercapacitors with high areal capacitance

    Science.gov (United States)

    Sheberla, Dennis; Bachman, John C.; Elias, Joseph S.; Sun, Cheng-Jun; Shao-Horn, Yang; Dincă, Mircea

    2016-10-01

    Owing to their high power density and superior cyclability relative to batteries, electrochemical double layer capacitors (EDLCs) have emerged as an important electrical energy storage technology that will play a critical role in the large-scale deployment of intermittent renewable energy sources, smart power grids, and electrical vehicles. Because the capacitance and charge-discharge rates of EDLCs scale with surface area and electrical conductivity, respectively, porous carbons such as activated carbon, carbon nanotubes and crosslinked or holey graphenes are used exclusively as the active electrode materials in EDLCs. One class of materials whose surface area far exceeds that of activated carbons, potentially allowing them to challenge the dominance of carbon electrodes in EDLCs, is metal-organic frameworks (MOFs). The high porosity of MOFs, however, is conventionally coupled to very poor electrical conductivity, which has thus far prevented the use of these materials as active electrodes in EDLCs. Here, we show that Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 (Ni3(HITP)2), a MOF with high electrical conductivity, can serve as the sole electrode material in an EDLC. This is the first example of a supercapacitor made entirely from neat MOFs as active materials, without conductive additives or other binders. The MOF-based device shows an areal capacitance that exceeds those of most carbon-based materials and capacity retention greater than 90% over 10,000 cycles, in line with commercial devices. Given the established structural and compositional tunability of MOFs, these results herald the advent of a new generation of supercapacitors whose active electrode materials can be tuned rationally, at the molecular level.

  2. Conductive MOF electrodes for stable supercapacitors with high areal capacitance

    Science.gov (United States)

    Sheberla, Dennis; Bachman, John C.; Elias, Joseph S.; Sun, Cheng-Jun; Shao-Horn, Yang; Dincă, Mircea

    2017-02-01

    Owing to their high power density and superior cyclability relative to batteries, electrochemical double layer capacitors (EDLCs) have emerged as an important electrical energy storage technology that will play a critical role in the large-scale deployment of intermittent renewable energy sources, smart power grids, and electrical vehicles. Because the capacitance and charge-discharge rates of EDLCs scale with surface area and electrical conductivity, respectively, porous carbons such as activated carbon, carbon nanotubes and crosslinked or holey graphenes are used exclusively as the active electrode materials in EDLCs. One class of materials whose surface area far exceeds that of activated carbons, potentially allowing them to challenge the dominance of carbon electrodes in EDLCs, is metal-organic frameworks (MOFs). The high porosity of MOFs, however, is conventionally coupled to very poor electrical conductivity, which has thus far prevented the use of these materials as active electrodes in EDLCs. Here, we show that Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 (Ni3(HITP)2), a MOF with high electrical conductivity, can serve as the sole electrode material in an EDLC. This is the first example of a supercapacitor made entirely from neat MOFs as active materials, without conductive additives or other binders. The MOF-based device shows an areal capacitance that exceeds those of most carbon-based materials and capacity retention greater than 90% over 10,000 cycles, in line with commercial devices. Given the established structural and compositional tunability of MOFs, these results herald the advent of a new generation of supercapacitors whose active electrode materials can be tuned rationally, at the molecular level.

  3. Influence of alignment of the pyramid on its beneficial effects.

    Science.gov (United States)

    Bhat, Surekha; Rao, Guruprasad; Murthy, K Dilip; Bhat, P Gopalakrishna

    2007-05-01

    The present study was aimed to find out whether a change in the alignment of the pyramid from the north-south axis causes any variation in the effects produced by it on plasma cortisol levels and markers of oxidative stress in erythrocytes of adult-female Wistar rats. Plasma cortisol and erythrocyte TBARS levels were significantly lower whereas erythrocyte GSH was significantly higher in rats kept in pyramid that was aligned on the four cardinal points--north, east, south and west, as compared to normal control rats. Although there was a significant difference in the plasma cortisol level between normal control group and the group of rats kept in randomly aligned pyramid, there was no significant difference between these two groups for the other parameters. Erythrocyte TBARS levels in the group of rats kept in the randomly aligned pyramid was significantly higher than that in the group kept in the magnetically aligned pyramid. The results suggest that the north-south alignment of the pyramid is crucial for its expected effects.

  4. Macro-pyramid in GaN Film

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jing; YANG Zhi-Jian; XU Shi-Fa; ZHU Xing; ZHANG Guo-Yi

    2001-01-01

    A thin film of GaN with the thickness of 1.0μm was grown on α-Al2Oa substrate by metal organic chemical vapour disposition and then a thick GaN film with thickness of 12μm was grown in the halide vapour phase epitaxy system. Some macro-pyramids appeared on the surface of the sample. The macro-pyramids made the surfaceof the GaN film rough, which was harmful to the devices made by GaN materials. These defects changed the distribution of carrier concentration and affected the optical properties of GaN. The step height of the pyramids was about 30-40 nm measured by atomic force microscopy. A simple model was proposed to explain the macro- pyramid phenomenon compared with the growth spiral The growth of the macro-pyramid was relative to the physical conditions in the reaction zone. Both increasing growth temperature and low pressure may reduce the pyramid size.

  5. Hippocampal CA3 pyramidal cells selectively innervate aspiny interneurons.

    Science.gov (United States)

    Wittner, Lucia; Henze, Darrell A; Záborszky, László; Buzsáki, György

    2006-09-01

    The specific connectivity among principal cells and interneurons determines the flow of activity in neuronal networks. To elucidate the connections between hippocampal principal cells and various classes of interneurons, CA3 pyramidal cells were intracellularly labelled with biocytin in anaesthetized rats and the three-dimensional distribution of their axon collaterals was reconstructed. The sections were double-stained for substance P receptor (SPR)- or metabotropic glutamate receptor 1alpha (mGluR-1alpha)-immunoreactivity to investigate interneuron targets of the CA3 pyramidal cells. SPR-containing interneurons represent a large portion of the GABAergic population, including spiny and aspiny classes. Axon terminals of CA3 pyramidal cells contacted SPR-positive interneuron dendrites in the hilus and in all hippocampal strata in both CA3 and CA1 regions (7.16% of all boutons). The majority of axons formed single contacts (87.5%), but multiple contacts (up to six) on single target neurons were also found. CA3 pyramidal cell axon collaterals innervated several types of morphologically different aspiny SPR-positive interneurons. In contrast, spiny SPR-interneurons or mGluR-1alpha-positive interneurons in the hilus, CA3 and CA1 regions were rarely contacted by the filled pyramidal cells. These findings indicate a strong target selection of CA3 pyramidal cells favouring the activation of aspiny classes of interneurons.

  6. Capacitive Bioanodes Enable Renewable Energy Storage in Microbial Fuel Cells

    NARCIS (Netherlands)

    Deeke, A.; Sleutels, T.H.J.A.; Hamelers, H.V.M.; Buisman, C.J.N.

    2012-01-01

    We developed an integrated system for storage of renewable electricity in a microbial fuel cell (MFC). The system contained a capacitive electrode that was inserted into the anodic compartment of an MFC to form a capacitive bioanode. This capacitive bioanode was compared with a noncapacitive

  7. Electric vehicles

    Science.gov (United States)

    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. These concepts are discussed.

  8. Characteristics of the aberrant pyramidal tract in comparison with the pyramidal tract in the human brain

    Directory of Open Access Journals (Sweden)

    Kwon Yong

    2011-11-01

    Full Text Available Abstract Background The aberrant pyramidal tract (APT refers to the collateral pathway of the pyramidal tract (PT through the medial lemniscus in the midbrain and pons. Using diffusion tensor tractography (DTT, we investigated the characteristics of the APT in comparison with the PT in the normal human brain. Results In thirty-four (18.3%, right hemisphere: 20, left hemisphere: 14 of the 186 hemispheres, the APTs separated from the PT at the upper midbrain level, descended through the medial lemniscus from the midbrain to the pons, and then rejoined with the PT at the upper medulla. Nine (26.5% of the 34 APTs were found to originate from the primary somatosensory cortex without a primary motor cortex origin. Values of fractional anisotropy (FA and tract volume of the APT were lower than those of the PT (P P >0.05. Conclusion We found that the APT has different characteristics, including less directionality, fewer neural fibers, and less origin from the primary motor cortex than the PT.

  9. Conductive two-dimensional titanium carbide `clay' with high volumetric capacitance

    Science.gov (United States)

    Ghidiu, Michael; Lukatskaya, Maria R.; Zhao, Meng-Qiang; Gogotsi, Yury; Barsoum, Michel W.

    2014-12-01

    Safe and powerful energy storage devices are becoming increasingly important. Charging times of seconds to minutes, with power densities exceeding those of batteries, can in principle be provided by electrochemical capacitors--in particular, pseudocapacitors. Recent research has focused mainly on improving the gravimetric performance of the electrodes of such systems, but for portable electronics and vehicles volume is at a premium. The best volumetric capacitances of carbon-based electrodes are around 300 farads per cubic centimetre; hydrated ruthenium oxide can reach capacitances of 1,000 to 1,500 farads per cubic centimetre with great cyclability, but only in thin films. Recently, electrodes made of two-dimensional titanium carbide (Ti3C2, a member of the `MXene' family), produced by etching aluminium from titanium aluminium carbide (Ti3AlC2, a `MAX' phase) in concentrated hydrofluoric acid, have been shown to have volumetric capacitances of over 300 farads per cubic centimetre. Here we report a method of producing this material using a solution of lithium fluoride and hydrochloric acid. The resulting hydrophilic material swells in volume when hydrated, and can be shaped like clay and dried into a highly conductive solid or rolled into films tens of micrometres thick. Additive-free films of this titanium carbide `clay' have volumetric capacitances of up to 900 farads per cubic centimetre, with excellent cyclability and rate performances. This capacitance is almost twice that of our previous report, and our synthetic method also offers a much faster route to film production as well as the avoidance of handling hazardous concentrated hydrofluoric acid.

  10. Conductive two-dimensional titanium carbide 'clay' with high volumetric capacitance.

    Science.gov (United States)

    Ghidiu, Michael; Lukatskaya, Maria R; Zhao, Meng-Qiang; Gogotsi, Yury; Barsoum, Michel W

    2014-12-04

    Safe and powerful energy storage devices are becoming increasingly important. Charging times of seconds to minutes, with power densities exceeding those of batteries, can in principle be provided by electrochemical capacitors--in particular, pseudocapacitors. Recent research has focused mainly on improving the gravimetric performance of the electrodes of such systems, but for portable electronics and vehicles volume is at a premium. The best volumetric capacitances of carbon-based electrodes are around 300 farads per cubic centimetre; hydrated ruthenium oxide can reach capacitances of 1,000 to 1,500 farads per cubic centimetre with great cyclability, but only in thin films. Recently, electrodes made of two-dimensional titanium carbide (Ti3C2, a member of the 'MXene' family), produced by etching aluminium from titanium aluminium carbide (Ti3AlC2, a 'MAX' phase) in concentrated hydrofluoric acid, have been shown to have volumetric capacitances of over 300 farads per cubic centimetre. Here we report a method of producing this material using a solution of lithium fluoride and hydrochloric acid. The resulting hydrophilic material swells in volume when hydrated, and can be shaped like clay and dried into a highly conductive solid or rolled into films tens of micrometres thick. Additive-free films of this titanium carbide 'clay' have volumetric capacitances of up to 900 farads per cubic centimetre, with excellent cyclability and rate performances. This capacitance is almost twice that of our previous report, and our synthetic method also offers a much faster route to film production as well as the avoidance of handling hazardous concentrated hydrofluoric acid.

  11. Housing under the pyramid reduces susceptibility of hippocampal CA3 pyramidal neurons to prenatal stress in the developing rat offspring.

    Science.gov (United States)

    Murthy, Krishna Dilip; George, Mitchel Constance; Ramasamy, Perumal; Mustapha, Zainal Arifin

    2013-12-01

    Mother-offspring interaction begins before birth. The foetus is particularly vulnerable to environmental insults and stress. The body responds by releasing excess of the stress hormone cortisol, which acts on glucocorticoid receptors. Hippocampus in the brain is rich in glucocorticoid receptors and therefore susceptible to stress. The stress effects are reduced when the animals are placed under a model wooden pyramid. The present study was to first explore the effects of prenatal restraint-stress on the plasma corticosterone levels and the dendritic arborisation of CA3 pyramidal neurons in the hippocampus of the offspring. Further, to test whether the pyramid environment would alter these effects, as housing under a pyramid is known to reduce the stress effects, pregnant Sprague Dawley rats were restrained for 9 h per day from gestation day 7 until parturition in a wire-mesh restrainer. Plasma corticosterone levels were found to be significantly increased. In addition, there was a significant reduction in the apical and the basal total dendritic branching points and intersections of the CA3 hippocampal pyramidal neurons. The results thus suggest that, housing in the pyramid dramatically reduces prenatal stress effects in rats.

  12. Tonic GABAA conductance decreases membrane time constant and increases EPSP-spike precision in hippocampal pyramidal neurons

    Directory of Open Access Journals (Sweden)

    Agnieszka I Wlodarczyk

    2013-12-01

    Full Text Available Because of a complex dendritic structure, pyramidal neurons have a large membrane surface relative to other cells and so a large electrical capacitance and a large membrane time constant (τm. This results in slow depolarizations in response to excitatory synaptic inputs, and consequently increased and variable action potential latencies, which may be computationally undesirable. Tonic activation of GABAA receptors increases membrane conductance and thus regulates neuronal excitability by shunting inhibition. In addition, tonic increases in membrane conductance decrease the membrane time constant (τm, and improve the temporal fidelity of neuronal firing. Here we performed whole-cell current clamp recordings from hippocampal CA1 pyramidal neurons and found that bath application of 10 µM GABA indeed decreases τm in these cells. GABA also decreased first spike latency and jitter (standard deviation of the latency produced by current injection of 2 rheobases (500 ms. However, when larger current injections (3-6 rheobases were used, GABA produced no significant effect on spike jitter, which was low. Using mathematical modelling we demonstrate that the tonic GABAA conductance decreases rise time, decay time and half-width of EPSPs in pyramidal neurons. A similar effect was observed on EPSP/IPSP pairs produced by stimulation of Schaffer collaterals: the EPSP part of the response became shorter after application of GABA. Consistent with the current injection data, a significant decrease in spike latency and jitter was obtained in cell attached recordings only at near-threshold stimulation (50% success rate, S50. When stimulation was increased to 2- or 3- times S50, GABA significantly affected neither spike latency nor spike jitter. Our results suggest that a decrease in τm associated with elevations in ambient GABA can improve EPSP-spike precision at near-threshold synaptic inputs.

  13. Tonic GABAA conductance decreases membrane time constant and increases EPSP-spike precision in hippocampal pyramidal neurons.

    Science.gov (United States)

    Wlodarczyk, Agnieszka I; Xu, Chun; Song, Inseon; Doronin, Maxim; Wu, Yu-Wei; Walker, Matthew C; Semyanov, Alexey

    2013-01-01

    Because of a complex dendritic structure, pyramidal neurons have a large membrane surface relative to other cells and so a large electrical capacitance and a large membrane time constant (τm). This results in slow depolarizations in response to excitatory synaptic inputs, and consequently increased and variable action potential latencies, which may be computationally undesirable. Tonic activation of GABAA receptors increases membrane conductance and thus regulates neuronal excitability by shunting inhibition. In addition, tonic increases in membrane conductance decrease the membrane time constant (τm), and improve the temporal fidelity of neuronal firing. Here we performed whole-cell current clamp recordings from hippocampal CA1 pyramidal neurons and found that bath application of 10μM GABA indeed decreases τm in these cells. GABA also decreased first spike latency and jitter (standard deviation of the latency) produced by current injection of 2 rheobases (500 ms). However, when larger current injections (3-6 rheobases) were used, GABA produced no significant effect on spike jitter, which was low. Using mathematical modeling we demonstrate that the tonic GABAA conductance decreases rise time, decay time and half-width of EPSPs in pyramidal neurons. A similar effect was observed on EPSP/IPSP pairs produced by stimulation of Schaffer collaterals: the EPSP part of the response became shorter after application of GABA. Consistent with the current injection data, a significant decrease in spike latency and jitter was obtained in cell attached recordings only at near-threshold stimulation (50% success rate, S50). When stimulation was increased to 2- or 3- times S50, GABA significantly affected neither spike latency nor spike jitter. Our results suggest that a decrease in τm associated with elevations in ambient GABA can improve EPSP-spike precision at near-threshold synaptic inputs.

  14. Porous Alumina Based Capacitive MEMS RH Sensor

    CERN Document Server

    Juhasz, L; Timar-Horvath, Veronika; Desmulliez, Marc; Dhariwal, Resh

    2008-01-01

    The aim of a joint research and development project at the BME and HWU is to produce a cheap, reliable, low-power and CMOS-MEMS process compatible capacitive type relative humidity (RH) sensor that can be incorporated into a state-of-the-art, wireless sensor network. In this paper we discuss the preparation of our new capacitive structure based on post-CMOS MEMS processes and the methods which were used to characterize the thin film porous alumina sensing layer. The average sensitivity is approx. 15 pF/RH% which is more than a magnitude higher than the values found in the literature. The sensor is equipped with integrated resistive heating, which can be used for maintenance to reduce drift, or for keeping the sensing layer at elevated temperature, as an alternative method for temperature-dependence cancellation.

  15. CMOS Integrated Capacitive DC-DC Converters

    CERN Document Server

    Van Breussegem, Tom

    2013-01-01

    This book provides a detailed analysis of all aspects of capacitive DC-DC converter design: topology selection, control loop design and noise mitigation. Readers will benefit from the authors’ systematic overview that starts from the ground up, in-depth circuit analysis and a thorough review of recently proposed techniques and design methodologies.  Not only design techniques are discussed, but also implementation in CMOS is shown, by pinpointing the technological opportunities of CMOS and demonstrating the implementation based on four state-of-the-art prototypes.  Provides a detailed analysis of all aspects of capacitive DC-DC converter design;  Analyzes the potential of this type of DC-DC converter and introduces a number of techniques to unleash their full potential; Combines system theory with practical implementation techniques; Includes unique analysis of CMOS technology for this application; Provides in-depth analysis of four fabricated prototypes.

  16. Automatic Power Factor Correction Using Capacitive Bank

    Directory of Open Access Journals (Sweden)

    Mr.Anant Kumar Tiwari,

    2014-02-01

    Full Text Available The power factor correction of electrical loads is a problem common to all industrial companies. Earlier the power factor correction was done by adjusting the capacitive bank manually [1]. The automated power factor corrector (APFC using capacitive load bank is helpful in providing the power factor correction. Proposed automated project involves measuring the power factor value from the load using microcontroller. The design of this auto-adjustable power factor correction is to ensure the entire power system always preserving unity power factor. The software and hardware required to implement the suggested automatic power factor correction scheme are explained and its operation is described. APFC thus helps us to decrease the time taken to correct the power factor which helps to increase the efficiency.

  17. A Versatile Prototyping System for Capacitive Sensing

    Directory of Open Access Journals (Sweden)

    Daniel HRACH

    2008-04-01

    Full Text Available This paper presents a multi-purpose and easy to handle rapid prototyping platform that has been designed for capacitive measurement systems. The core of the prototype platform is a Digital Signal Processor board that allows for the entire data acquisition, data (pre- processing and storage, and communication with any host computer. The platform is running on uCLinux operating system and features the possibility of a fast design and evaluation of capacitive sensor developments. To show the practical benefit of the prototyping platform, three exemplary applications are presented. For all applications, the platform is just plugged to the electrode structure of the sensor front-end without the need for analogue signal pre-conditioning.

  18. Minimum Makespan Multi-vehicle Dial-a-Ride

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath; Ravi, R.

    2009-01-01

    -a-Ride problem, there are q vehicles each having capacity k and where each vehicle j ∈ [q] has its own depot-vertex rj ∈ V. A feasible schedule consists of a capacitated route for each vehicle (where vehicle j originates and ends at its depot rj) that together move all objects from their sources to destinations....... The objective is to find a feasible schedule that minimizes the maximum completion time (i.e. makespan) of vehicles, where the completion time of vehicle j is the time when it returns to its depot rj at the end of its route. We consider the preemptive version of multi-vehicle Dial-a-Ride, where an object may...

  19. Evaluation of a Capacitance Scaling System

    Science.gov (United States)

    2007-01-01

    2009 at 11:32 from IEEE Xplore . Restrictions apply. Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the...Downloaded on January 30, 2009 at 11:32 from IEEE Xplore . Restrictions apply. 2162 IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 56, NO. 6...30, 2009 at 11:32 from IEEE Xplore . Restrictions apply. AVRAMOV-ZAMUROVIC et al.: EVALUATION OF A CAPACITANCE SCALING SYSTEM 2163 measured to vary by

  20. THERMAL DRIFT CHARACTERISTICS OF CAPACITIVE PRESSURE SENSORS

    OpenAIRE

    2016-01-01

    The capacitive pressure sensors based on silicon are characterized by their very high sensitivities and their low power consumption. Nevertheless, their thermal behavior remains more or less unpredictable because they can indicate very high thermal coefficients. The study of the thermal behavior of these sensors is essential to define the parameters that cause the output characteristics drift. In this study, we modeled the thermal behavior of this sensors, using Finite Element Analysis (FE...

  1. Evaluation of EHD films by electrical capacitance

    Science.gov (United States)

    Jablonka, Karolina; Glovnea, Romeo; Bongaerts, Jeroen

    2012-09-01

    The elastohydrodynamic (EHD) lubrication regime occurs in many machine elements where a combination of hydrodynamic effect, elastic deformation of the loaded surfaces and increase in the viscosity of the lubricant with pressure ensures the formation of a very thin, but continuous film of lubricant separating the contacting surfaces. Electrical methods to determine this film's thickness have preceded optical methods, which are widely used today. Although they generally give more qualitative thickness information, electrical methods have the main advantage that they can be applied to metallic contacts in machines, which makes them useful tools in the study of elastohydrodynamically lubricated contacts. This paper is part of a larger study on the application of electrical capacitance for the evaluation of film formation in EHD contacts. The main focus is on the quantitative measurements of film thickness using electrical capacitance. A new approach allowing the lubricant film thickness to be extracted from the measured capacitance is developed using a chromium-coated glass disc and subsequently applied to a steel-on-steel contact. The results show good agreement with optical measurements and theoretical models over a range of film thickness.

  2. Effect of Astaxanthin on Human Sperm Capacitation

    Directory of Open Access Journals (Sweden)

    Luciana Bordin

    2013-06-01

    Full Text Available In order to be able to fertilize oocytes, human sperm must undergo a series of morphological and structural alterations, known as capacitation. It has been shown that the production of endogenous sperm reactive oxygen species (ROS plays a key role in causing cells to undergo a massive acrosome reaction (AR. Astaxanthin (Asta, a photo-protective red pigment belonging to the carotenoid family, is recognized as having anti-oxidant, anti-cancer, anti-diabetic and anti-inflammatory properties and is present in many dietary supplements. This study evaluates the effect of Asta in a capacitating buffer which induces low ROS production and low percentages of acrosome-reacted cells (ARC. Sperm cells were incubated in the presence or absence of increasing concentrations of Asta or diamide (Diam and analyzed for their ROS production, Tyr-phosphorylation (Tyr-P pattern and percentages of ARC and non-viable cells (NVC. Results show that Asta ameliorated both sperm head Tyr-P and ARC values without affecting the ROS generation curve, whereas Diam succeeded in enhancing the Tyr-P level but only of the flagellum without increasing ARC values. It is suggested that Asta can be inserted in the membrane and therefore create capacitation-like membrane alteration which allow Tyr-P of the head. Once this has occurred, AR can take place and involves a higher numbers of cells.

  3. A new desalination technique using capacitive deionization

    Science.gov (United States)

    Rostamy, Mohammad Sajjad; Khashechi, Morteza; Pipelzadeh, Ehsan; desalination Team

    2016-11-01

    Capacitive deionization (CDI) is an emerging energy efficient, low pressure and low capital intensive desalination process where ions are separated by a pure electrostatic force imposed by a small bias potential as low as 1 V That funded by an external Renewable (Solar) power supply to materials with high specific surface area. The main objective of this configuration is to separate the cation and anions on oppositely charged electrodes. Various electrode materials have been developed in the past, which have suffered from instability and lack of performance. Preliminary experimental results using carbon black, graphite powder, graphene ∖graphite ∖PTFE (Active ∖Conductive ∖binder), show that the graphene reduced via urea method is a suitable method to develop CDI electrode materials with capacitance as high as 52.2 mg/g for free standing graphene electrode. The focus of these studies has been mainly on developing electrodes with high specific surface area, high capacitance, excellent electronic conductivity and fast charge discharge cycles for desalination. Although some progress has been made, production of efficient and stable carbon based electrode materials for large scale desalination has not been fully realized.

  4. Capacitive Structures for Gas and Biological Sensing

    KAUST Repository

    Sapsanis, Christos

    2015-04-01

    The semiconductor industry was benefited by the advances in technology in the last decades. This fact has an impact on the sensors field, where the simple transducer was evolved into smart miniaturized multi-functional microsystems. However, commercially available gas and biological sensors are mostly bulky, expensive, and power-hungry, which act as obstacles to mass use. The aim of this work is gas and biological sensing using capacitive structures. Capacitive sensors were selected due to its design simplicity, low fabrication cost, and no DC power consumption. In the first part, the dominant structure among interdigitated electrodes (IDEs), fractal curves (Peano and Hilbert) and Archimedean spiral was investigated from capacitance density perspective. The investigation consists of geometrical formula calculations, COMSOL Multiphysics simulations and cleanroom fabrication of the capacitors on a silicon substrate. Moreover, low-cost fabrication on flexible plastic PET substrate was conducted outside cleanroom with rapid prototyping using a maskless laser etching. The second part contains the humidity, Volatile Organic compounds (VOCs) and Ammonia sensing of polymers, Polyimide and Nafion, and metal-organic framework (MOF), Cu(bdc)2.xH2O using IDEs and tested in an automated gas setup for experiment control and data extraction. The last part includes the biological sensing of C - reactive protein (CRP) quantification, which is considered as a biomarker of being prone to cardiac diseases and Bovine serum albumin (BSA) protein quantification, which is used as a reference for quantifying unknown proteins.

  5. Polychromatic white LED using GaN nano pyramid structure

    Science.gov (United States)

    Kim, Taek; Kim, Jusung; Yang, Moonseung; Park, Yongsoo; Chung, U.-In; Ko, Yongho; Cho, Yonghoon

    2013-03-01

    We have developed monolithic white light emitting diodes (LEDs) with a hybrid structure of planar c-planes and nano size hexagonal pyramids. The white spectrum is composed of blue and yellow emissions from the InGaN multi quantum wells (MQWs) on the planar c-planes and on the nano pyramids, respectively. The yellow emission is originated from quantum wells, wires, and dots that are formed at the sides, edges, and tops of the nano-pyramids, respectively. As a result, the emission peaks are different and the entire yellow spectrum is broad enough to make a white in combination with a blue emission. The longer wavelength from the InGaN on nano-pyramids than the wavelength from the InGaN on c-planes is explained by excess In supply from the dielectric selective growth mask. The color temperature is tuned from 3600K to 6400K by controlling the relative area ratio of c-plane and nano-pyramids.

  6. Ancient Egyptian chronology and the astronomical orientation of pyramids

    Science.gov (United States)

    Spence, Kate

    2000-11-01

    The ancient Egyptian pyramids at Giza have never been accurately dated, although we know that they were built approximately around the middle of the third millennium BC. The chronologies of this period have been reconstructed from surviving lists of kings and the lengths of their reigns, but the lists are rare, seldom complete and contain known inconsistencies and errors. As a result, the existing chronologies for that period (the Old Kingdom) can be considered accurate only to about +/-100 years, a figure that radiocarbon dating cannot at present improve. Here I use trends in the orientation of Old Kingdom pyramids to demonstrate that the Egyptians aligned them to north by using the simultaneous transit of two circumpolar stars. Modelling the precession of these stars yields a date for the start of construction of the Great Pyramid that is accurate to +/-5 yr, thereby providing an anchor for the Old Kingdom chronologies.

  7. Pyramidal ice crystal scattering phase functions and concentric halos

    Directory of Open Access Journals (Sweden)

    C. Liu

    Full Text Available Phase functions have been calculated using the Monte Carlo/geometric ray tracing method for single hexagonal pyramidal ice crystals (such as solid and hollow bullets randomly oriented in space and horizontal plane, in order to study the concentric halo formations. Results from three dimensional model calculations show that 9° halo can be as bright as the common 22° halo for pyramidal angle of 28°, and the 18°, 20°, 24° and 35° halos cannot be seen due to the strong 22° halo domination in the scattering phase function between 18° and 35°. For solid pyramidal ice crystals randomly oriented horizontally, the 35° arc can be produced and its intensity depends on the incident ray solar angle and the particle aspect ratio.

  8. Pyramidal cell-interneuron interactions underlie hippocampal ripple oscillations.

    Science.gov (United States)

    Stark, Eran; Roux, Lisa; Eichler, Ronny; Senzai, Yuta; Royer, Sebastien; Buzsáki, György

    2014-07-16

    High-frequency ripple oscillations, observed most prominently in the hippocampal CA1 pyramidal layer, are associated with memory consolidation. The cellular and network mechanisms underlying the generation, frequency control, and spatial coherence of the rhythm are poorly understood. Using multisite optogenetic manipulations in freely behaving rodents, we found that depolarization of a small group of nearby pyramidal cells was sufficient to induce high-frequency oscillations, whereas closed-loop silencing of pyramidal cells or activation of parvalbumin- (PV) or somatostatin-immunoreactive interneurons aborted spontaneously occurring ripples. Focal pharmacological blockade of GABAA receptors abolished ripples. Localized PV interneuron activation paced ensemble spiking, and simultaneous induction of high-frequency oscillations at multiple locations resulted in a temporally coherent pattern mediated by phase-locked interneuron spiking. These results constrain competing models of ripple generation and indicate that temporally precise local interactions between excitatory and inhibitory neurons support ripple generation in the intact hippocampus.

  9. A study of correlation technique on pyramid processed images

    Indian Academy of Sciences (India)

    M Sankar Kishore; K Veerabhadra Rao

    2000-02-01

    The pyramid algorithm is potentially a powerful tool for advanced television image processing and for pattern recognition. An attempt is made to design and develop both hardware and software for a system which performs decomposition and reconstruction of digitized images by implementing the Burt pyramid algorithm. In this work, an attempt is also made to study correlation performance on reconstructed images. That is, the reference image is taken from the original image and correlation is performed on expanded images of the same size. Similarly, correlation performance study is carried out on different pyramid- processed levels. In this paper results are presented in terms of RMS error between original and expanded images. Only still images are considered, and the hardware is designed around an i486 processor and software is developed in PL/M 86.

  10. Chloride Is Essential for Capacitation and for the Capacitation-associated Increase in Tyrosine Phosphorylation*

    Science.gov (United States)

    Wertheimer, Eva V.; Salicioni, Ana M.; Liu, Weimin; Trevino, Claudia L.; Chavez, Julio; Hernández-González, Enrique O.; Darszon, Alberto; Visconti, Pablo E.

    2008-01-01

    After epididymal maturation, sperm capacitation, which encompasses a complex series of molecular events, endows the sperm with the ability to fertilize an egg. This process can be mimicked in vitro in defined media, the composition of which is based on the electrolyte concentration of the oviductal fluid. It is well established that capacitation requires Na+, \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}{\\mathrm{HCO}}_{3}^{-}\\end{equation*}\\end{document}, Ca2+, and a cholesterol acceptor; however, little is known about the function of Cl– during this important process. To determine whether Cl–, in addition to maintaining osmolarity, actively participates in signaling pathways that regulate capacitation, Cl– was replaced by either methanesulfonate or gluconate two nonpermeable anions. The absence of Cl– did not affect sperm viability, but capacitation-associated processes such as the increase in tyrosine phosphorylation, the increase in cAMP levels, hyperactivation, the zona pellucidae-induced acrosome reaction, and most importantly, fertilization were abolished or significantly reduced. Interestingly, the addition of cyclic AMP agonists to sperm incubated in Cl–-free medium rescued the increase in tyrosine phosphorylation and hyperactivation suggesting that Cl– acts upstream of the cAMP/protein kinase A signaling pathway. To investigate Cl– transport, sperm incubated in complete capacitation medium were exposed to a battery of anion transport inhibitors. Among them, bumetanide and furosemide, two blockers of Na+/K+/Cl– cotransporters (NKCC), inhibited all capacitation-associated events, suggesting that these transporters may mediate Cl– movements in sperm. Consistent with these results, Western blots

  11. Vehicle Routing Optimization in Logistics Distribution Using Hybrid Ant Colony Algorithm

    Directory of Open Access Journals (Sweden)

    Chengming Qi

    2013-09-01

    Full Text Available The Vehicle Routing Problem (VRP is an important management problem in the field of physical distribution and logistics. Good vehicle routing can not only increase the profit of logistics but also make logistics management more scientific. The Capacitated Vehicle Routing Problem (CVRP constrained by the capacity of a vehicle is the extension of VRP. Our research applies a two-phase algorithm to address CVRP. It takes the advantages of Simulated Annealing (SA and ant colony optimization for solving the capacitated vehicle routing problem. In the first phase of proposed algorithm, simulated annealing provides a good initial solution for ant colony optimization. In the second phase, Iterative Local Search (ILS method is employed to seeking the close-to-optimal solution in local scope based on the capacity of the vehicle. Experimental results show that the proposed algorithm is superior to original ant colony optimization and simulated annealing separately reported on partial benchmark problems.

  12. Image fusion based on expectation maximization algorithm and steerable pyramid

    Institute of Scientific and Technical Information of China (English)

    Gang Liu(刘刚); Zhongliang Jing(敬忠良); Shaoyuan Sun(孙韶媛); Jianxun Li(李建勋); Zhenhua Li(李振华); Henry Leung

    2004-01-01

    In this paper, a novel image fusion method based on the expectation maximization (EM) algorithm and steerable pyramid is proposed. The registered images are first decomposed by using steerable pyramid.The EM algorithm is used to fuse the image components in the low frequency band. The selection method involving the informative importance measure is applied to those in the high frequency band. The final fused image is then computed by taking the inverse transform on the composite coefficient representations.Experimental results show that the proposed method outperforms conventional image fusion methods.

  13. Radial microwire array solar cell with pyramidal structure

    Science.gov (United States)

    Priyadarshini, Bindu; Das, Mukul Kumar; Sen, Mrinal; Kumar, Subindu

    2016-10-01

    In this work, a theoretical model for radial p-n junction microwire array solar cell with pyramidal structures in the space between microwires has been developed. Incorporation of pyramidal structures results in reflection of light, which would otherwise be unused, and illuminates side walls of the microwires. This additional illumination enhances absorption and, hence, efficiency of the whole structure. Efficiency enhancement is analyzed by varying different device parameters e.g., radius and length of each microwire and packing fraction of the structure. Results show that the maximum fractional efficiency enhancement can be obtained as 30% by suitable choice of these parameters.

  14. Field emission properties of an array of pyramidal structures

    Energy Technology Data Exchange (ETDEWEB)

    De Assis, Thiago A [Departamento de QuImica, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Borondo, F [Departamento de QuImica, Instituto Mixto de Ciencias Matematicas CSIC-UAM-UC3M-UCM, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); De Castilho, C M C; Brito Mota, F [Grupo de Fisica de SuperfIcies e Materiais, Instituto de Fisica, Universidade Federal da Bahia, Campus Universitario da Federacao, 40210-340, Salvador, BA (Brazil); Benito, R M, E-mail: t.albuquerque@uam.e, E-mail: f.borondo@uam.e, E-mail: caio@ufba.b, E-mail: fbmota@ufba.b, E-mail: rosamaria.benito@upm.e [Grupo de Sistemas Complejos, Departamento de Fisica y Mecanica, Escuela Tecnica Superior de Ingenieros Agronomos, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain)

    2009-10-07

    The properties and efficiency of the emission current density produced by a metallic array of pyramidal structures are investigated. The theoretical results obtained by numerical integration of the corresponding Laplace equation using a finite differences scheme offer useful information for the optimization of field emission devices based on cathodes with this geometry. Our study shows that the inter-pyramidal distance strongly affects the current density, and even more important for this issue is the protrusion characteristics of these structures. Another relevant, although less important, parameter determining this density is the anode-cathode distance. The effect of the array characteristics on the maximum local electric field intensity is also discussed.

  15. Stray Capacitances of an Air-Cored Eddy Current Sensor

    Directory of Open Access Journals (Sweden)

    Yi Jia

    2009-12-01

    Full Text Available Stray capacitance of an air-cored eddy current sensor is one of the most crucial issues for successful development of an eddy current based residual stress assessment technology at frequency above 50 MHz. A two dimensional finite element model and an equivalent lumped capacitance network have been developed to accurately quantify overall stray capacitances of an air-cored eddy current sensor with specimen being tested. A baseline model was used to evaluate sensor design parameters, including the effects of pitch distance, trace width, trace thickness, number of turns, inner diameter, substrate thickness, lift-off distance, and dielectric constant of shim on the stray capacitances of the sensor. The results clearly indicate that an appropriate sensor design parameters could reduce the stray capacitance and improve the sensor performance. This research opens up a new design space to minimize stray capacitance effect and improve the sensor sensitivity and its lift-off uncertainty at elevated high frequencies.

  16. Tunable Lowpass Filter with RF MEMS Capacitance and Transmission Line

    Directory of Open Access Journals (Sweden)

    Shimul C. Saha

    2012-01-01

    Full Text Available We have presented an RF MEMS tuneable lowpass filter. Both distributed transmission lines and RF MEMS capacitances were used to replace the lumped elements. The use of RF MEMS capacitances gives the flexibility of tuning the cutoff frequency of the lowpass filter. We have designed a low-pass filter at 9–12 GHz cutoff frequency using the theory of stepped impedance transmission lines. A prototype of the filter has been fabricated using parallel plate capacitances. The variable shunt capacitances are formed by a combination of a number of parallel plate RF MEMS capacitances. The cutoff frequency is tuned from C to X band by actuating different combinations of parallel capacitive bridges. The measurement results agree well with the simulation result.

  17. Numerical analysis of capacitive pressure micro-sensors

    Institute of Scientific and Technical Information of China (English)

    WANG; Xiaomin; LI; Mingxuan; WANG; Chenghao

    2005-01-01

    Pseudo-spectral method is used to numerically model the diaphragm deflection of capacitive pressure micro-sensor under uniform load. The relationship between the capacitance of the micro-sensor and the load is then analyzed after the description of the computational principle. For normal mode micro-sensor, the tensile force on the diaphragm can be ignored and thereby the capacitance increases linearly with the load increase only when the load is so small that the resultant deflection is less than the diaphragm thickness. The linear relationship between the capacitance and the load turns to be nonlinear thereafter and the capacitance rises dramatically with the constant increase of the load. For touch mode micro-sensor, an algorithm to determine the touch radius of the diaphragm and substrate is presented and the curve of capacitance versus load is shown on the numerical results laying a theoretical foundation for micro-sensor design.

  18. CMOS MEMS capacitive absolute pressure sensor

    Science.gov (United States)

    Narducci, M.; Yu-Chia, L.; Fang, W.; Tsai, J.

    2013-05-01

    This paper presents the design, fabrication and characterization of a capacitive pressure sensor using a commercial 0.18 µm CMOS (complementary metal-oxide-semiconductor) process and postprocess. The pressure sensor is capacitive and the structure is formed by an Al top electrode enclosed in a suspended SiO2 membrane, which acts as a movable electrode against a bottom or stationary Al electrode fixed on the SiO2 substrate. Both the movable and fixed electrodes form a variable parallel plate capacitor, whose capacitance varies with the applied pressure on the surface. In order to release the membranes the CMOS layers need to be applied postprocess and this mainly consists of four steps: (1) deposition and patterning of PECVD (plasma-enhanced chemical vapor deposition) oxide to protect CMOS pads and to open the pressure sensor top surface, (2) etching of the sacrificial layer to release the suspended membrane, (3) deposition of PECVD oxide to seal the etching holes and creating vacuum inside the gap, and finally (4) etching of the passivation oxide to open the pads and allow electrical connections. This sensor design and fabrication is suitable to obey the design rules of a CMOS foundry and since it only uses low-temperature processes, it allows monolithic integration with other types of CMOS compatible sensors and IC (integrated circuit) interface on a single chip. Experimental results showed that the pressure sensor has a highly linear sensitivity of 0.14 fF kPa-1 in the pressure range of 0-300 kPa.

  19. Abandoned vehicles

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The services in charge of managing the CERN site have recently noted an increase in the number of abandoned vehicles. This poses a risk from the point of view of safety and security and, on the eve of several important events in honour of CERN's fiftieth anniversary, is detrimental to the Organization's image. Owners of vehicles that have been left immobile for some time on the CERN site, including on the external car park by the flags, are therefore invited to contact the Reception and Access Control Service (service-parking-longterm@cern.ch) before 1st October 2004 and, where appropriate, move their vehicle to a designated long-term parking area. After this date, any vehicle whose owner has failed to respond to this request and which is without a number plate, has been stationary for several weeks or is out of service, may be impounded at the owner's risk and expense. Relations with the Host States Service Tel. 72848

  20. Programmable differential capacitance-to-voltage converter for MEMS accelerometers

    Science.gov (United States)

    Royo, G.; Sánchez-Azqueta, C.; Gimeno, C.; Aldea, C.; Celma, S.

    2017-05-01

    Capacitive MEMS sensors exhibit an excellent noise performance, high sensitivity and low power consumption. They offer a huge range of applications, being the accelerometer one of its main uses. In this work, we present the design of a capacitance-to-voltage converter in CMOS technology to measure the acceleration from the capacitance variations. It is based on a low-power, fully-differential transimpedance amplifier with low input impedance and a very low input noise.

  1. Magnetic field tunable capacitive dielectric:ionic-liquid sandwich composites

    Science.gov (United States)

    Wu, Ye; Bhalla, Amar; Guo, Ruyan

    2016-03-01

    We examined the tunability of the capacitance for GaFeO3-ionic liquid-GaFeO3 composite material by external magnetic and electric field. Up to 1.6 folds of capacitance tunability could be achieved at 957 kHz with voltage 4 V and magnetic field 0.02 T applied. We show that the capacitance enhancement is due to the polarization coupling between dielectric layer and ionic liquid layer.

  2. Carrier Statistics and Quantum Capacitance Models of Graphene Nanoscroll

    Directory of Open Access Journals (Sweden)

    M. Khaledian

    2014-01-01

    schematic perfect scroll-like Archimedes spiral. The DOS model was derived at first, while it was later applied to compute the carrier concentration and quantum capacitance model. Furthermore, the carrier concentration and quantum capacitance were modeled for both degenerate and nondegenerate regimes, along with examining the effect of structural parameters and chirality number on the density of state and carrier concentration. Latterly, the temperature effect on the quantum capacitance was studied too.

  3. Capacitive tool standoff sensor for dismantlement tasks

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, D.J.; Weber, T.M. [Sandia National Labs., Albuquerque, NM (United States); Liu, J.C. [Univ. of Illinois, Urbana, IL (United States)

    1996-12-31

    A capacitive sensing technology has been applied to develop a Standoff Sensor System for control of robotically deployed tools utilized in Decontamination and Dismantlement (D and D) activities. The system combines four individual sensor elements to provide non-contact, multiple degree-of-freedom control of tools at distances up to five inches from a surface. The Standoff Sensor has been successfully integrated to a metal cutting router and a pyrometer, and utilized for real-time control of each of these tools. Experiments demonstrate that the system can locate stationary surfaces with a repeatability of 0.034 millimeters.

  4. Pyramidal anchor stone from Baga waters of Goa, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Tripati, S.

    Underwater exploration in the coastal region off Baga (Goa, India) led to the recovery of an isolated stone artefact, which resembles a pyramidal type of anchor stone. This anchor stone is unlike to other pyramidal anchor stones found elsewhere...

  5. 76 FR 15358 - Culturally Significant Objects Imported for Exhibition Determinations: “Before the Pyramids: The...

    Science.gov (United States)

    2011-03-21

    ... ``Before the Pyramids: The Origins of Egyptian Civilization'' imported from abroad for temporary exhibition... Culturally Significant Objects Imported for Exhibition Determinations: ``Before the Pyramids: The Origins of Egyptian Civilization'' SUMMARY: Notice is hereby given of the following determinations: Pursuant to...

  6. The Indoor Radon Concentration within the Tunnels of the Cholula Pyramid Through a Nuclear Tracks Methodology

    National Research Council Canada - National Science Library

    A. Lima Flores; R. Palomino-Merino; E. Espinosa; V. M. Castaño; E. Merlo Juárez; M. Cruz Sanchez; G. Espinosa

    2016-01-01

    .... Accordingly, a study and analysis of the indoors radon concentrate in the Cholula Pyramid contributes to understand the Radon dynamic inside of the Pyramid tunnels and to evaluate the radiological...

  7. Performance of resistance gene pyramids to races of rice bacterial blight in Zhejiang Province

    Institute of Scientific and Technical Information of China (English)

    ZHENGKangle; ZHUANGJieyun; WANGHanrong

    1998-01-01

    The effect of gene pyramiding on resistance to bacterial blight (BB) in rice was evahlated among the IR24-based near isogenic lines conraining single resistance gene and gene pyramids containing two, three or lour resistancegenes (see table).

  8. A variable neighborhood descent based heuristic to solve the capacitated location-routing problem

    Directory of Open Access Journals (Sweden)

    M. S. Jabal-Ameli

    2011-01-01

    Full Text Available Location-routing problem (LRP is established as a new research area in the context of location analysis. The primary concern of LRP is on locating facilities and routing of vehicles among established facilities and existing demand points. In this work, we address the capacitated LRP which arises in many practical applications within logistics and supply chain management. The objective is to minimize the overall system costs which include the fixed costs of opening depots and using vehicles at each depot site, and the variable costs associated with delivery activities. A novel heuristic is proposed which is based on variable neighborhood descent (VND algorithm to solve the resulted problem. The computational study indicates that the proposed VND based heuristic is highly competitive with the existing solution algorithms in terms of solution quality.

  9. Circuit analysis and simulation of an ultrahigh-frequency capacitance sensor for scanning capacitance microscopy

    Science.gov (United States)

    Yang, Jing; Postula, A.; Bialkowski, M.

    2004-03-01

    Quantitative two-dimensional dopant profiling tools are urgently needed for nowadays semiconductor industry. Scanning Capacitance Microscopy (SCM) holds most promise to become such a tool. The key component of SCM is an ultra high frequency (UHF) capacitance sensor. The output of the sensor has been approximately regarded as dC/dV, the derivative of the capacitance between the SCM tip and the sample versus the applied bias voltage. The SCM dopant profiling involves extracting the dopant profile from the SCM signal using analytic or numerical simulation models of Metal-Oxide-Semiconductor physics. To achieve a quantitative SCM dopant profiling, the operational principle of the whole SCM measurement has to be well understood and correctly included in those models. Recently, experimental evidences show the SCM signal is dramatically affected by many SCM experimental factors, including the behavior of the UHF capacitance sensor. However, till now, very little research has been reported on the behavior of the sensor in SCM measurement of semiconductors. In this paper, we derive an analytic expression of the sensor output, a circuit simulation model of the sensor is established using Advanced Design System 2003, and the dependences of the sensor output on the SCM operational factors are simulated.

  10. Design and Test of Capacitive Micromachined Ultrasonic Transducer

    National Research Council Canada - National Science Library

    Hongliang Wang; Xiangjun Wang; Changde He; Chenyang Xue; Jijun Xiong; Wendong Zhang; Jing Miao; Yuping Li

    2014-01-01

      Currently, most capacitive micromachined ultrasound transducers, adopting surface sacrificial technology encounter various problems such as difficult cavity etch, low controllability of membrane thickness etc...

  11. A capacitive biosensor based on an interdigitated electrode with nanoislands.

    Science.gov (United States)

    Jung, Ha-Wook; Chang, Young Wook; Lee, Ga-yeon; Cho, Sungbo; Kang, Min-Jung; Pyun, Jae-Chul

    2014-09-24

    A capacitive biosensor based on an interdigitated electrode (IDE) with nanoislands was developed for label-free detection of antigen-antibody interactions. To enable sensitive capacitive detection of protein adsorption, the nanoislands were fabricated between finger electrodes of the IDE. The effect of the nanoislands on the sensitive capacitive measurement was estimated using horseradish peroxidase (HRP) as a model protein. Additionally, a parylene-A film was coated on the IDE with nanoislands to improve the efficiency of protein immobilization. By using HRP and hepatitis B virus surface antigen (HBsAg) as model analytes, the effect of the parylene-A film on the capacitive detection of protein adsorption was demonstrated.

  12. Vehicle detection algorithm based on codebook and local binary patterns algorithms

    Institute of Scientific and Technical Information of China (English)

    许雪梅; 周立超; 墨芹; 郭巧云

    2015-01-01

    Detecting the moving vehicles in jittering traffic scenes is a very difficult problem because of the complex environment. Only by the color features of the pixel or only by the texture features of image cannot establish a suitable background model for the moving vehicles. In order to solve this problem, the Gaussian pyramid layered algorithm is proposed, combining with the advantages of the Codebook algorithm and the Local binary patterns (LBP) algorithm. Firstly, the image pyramid is established to eliminate the noises generated by the camera shake. Then, codebook model and LBP model are constructed on the low-resolution level and the high-resolution level of Gaussian pyramid, respectively. At last, the final test results are obtained through a set of operations according to the spatial relations of pixels. The experimental results show that this algorithm can not only eliminate the noises effectively, but also save the calculating time with high detection sensitivity and high detection accuracy.

  13. The FINUT healthy lifestyles guide: Beyond the food pyramid.

    Science.gov (United States)

    Gil, Angel; Ruiz-Lopez, Maria Dolores; Fernandez-Gonzalez, Miguel; Martinez de Victoria, Emilio

    2014-05-01

    The WHO has proposed that health be promoted and protected through the development of an environment that enables sustainable actions at individual, community, national, and global levels. Indeed, food-based dietary guidelines, i.e., food pyramids, have been developed in numerous countries to disseminate nutritional information to the general population. However, wider recommendations are needed, with information on an active healthy lifestyle, not just healthy eating. The objective of the present work is to propose a three-dimensional pyramid as a new strategy for promoting adequate nutrition and active healthy lifestyles in a sustainable way. Indeed, the Iberoamerican Nutrition Foundation (FINUT) pyramid of healthy lifestyles has been designed as a tetrahedron, with its 3 lateral faces corresponding to the facets of food and nutrition, physical activity and rest, and education and hygiene. Each lateral face is divided into 2 triangles. These faces show the following: 1) food-based guidelines and healthy eating habits as related to a sustainable environment; 2) recommendations for rest and physical activity and educational, social, and cultural issues; and 3) selected hygiene and educational guidelines that, in conjunction with the other 2 faces, would contribute to better health for people in a sustainable planet. The new FINUT pyramid is addressed to the general population of all ages and should serve as a guide for living a healthy lifestyle within a defined social and cultural context. It includes an environmental and sustainability dimension providing measures that should contribute to the prevention of noncommunicable chronic diseases.

  14. [The finut healthy lifestyles guide: beyond the food pyramid].

    Science.gov (United States)

    Gil, Angel; Ruiz-Lopez, Maria Dolores; Fernandez-Gonzalez, Miguel; Martinez de Victoria, Emilio

    2015-05-01

    The World Health Organization has proposed that health be promoted and protected through the development of an environment that enables sustainable actions at individual, community, national and global levels. Indeed, food-based dietary guidelines, i.e., food pyramids, have been developed in numerous countries to disseminate nutritional information to the general population. However, wider recommendations are needed, with information on an active, healthy lifestyle, not just healthy eating. The objective of the present work is to propose a three-dimensional pyramid as a new strategy for promoting adequate nutrition and active healthy lifestyles in a sustainable way. Indeed, the Iberomerican Nutrition Foundation (FINUT) pyramid of healthy lifestyles has been designed as a tetrahedron, its three lateral faces corresponding to the binomials food and nutrition, physical activity and rest, and education and hygiene. Each lateral face is divided into two triangles. These faces show the following: 1. food-based guidelines and healthy eating habits as related to a sustainable environment; 2. recommendations for rest and physical activity and educational, social and cultural issues; 3. selected hygiene and educational guidelines that, in conjunction with the other two faces, would contribute to better health and provide measures to promote environmental sustainability. The new FINUT pyramid is addressed to the general population of all ages and should serve as a guide for living a healthy lifestyle within a defined social and cultural context. It includes an environmental and sustainability dimension providing measures that should contribute to the prevention of non-communicable chronic diseases.

  15. Using the Pyramid Approach to Teaching Marketing Research.

    Science.gov (United States)

    Peltier, James W.; Westfall, John; Ainscough, Thomas L.

    2001-01-01

    Underscores the need for teaching marketing research skills at the secondary level and shows how marketing research fits into marketing education. Provides an example of how to use the pyramid approach to research, which involves review of secondary sources, key informant interviews, focus groups, and quantitative research. (Author/JOW)

  16. Building trust at the Base of the Pyramid

    NARCIS (Netherlands)

    Grootveld, P.; Vermeulen, P.A.M.

    2014-01-01

    More and more companies are serving the poorest communities of our world, the so-called Base of the Pyramid (BoP). Wal-Mart, for example, moved into the Mexican retail-banking sector, claiming not only to “sell more stuff” but also to compete against the entrenched domestic businesses that are not

  17. Using the Pyramid Approach to Teaching Marketing Research.

    Science.gov (United States)

    Peltier, James W.; Westfall, John; Ainscough, Thomas L.

    2001-01-01

    Underscores the need for teaching marketing research skills at the secondary level and shows how marketing research fits into marketing education. Provides an example of how to use the pyramid approach to research, which involves review of secondary sources, key informant interviews, focus groups, and quantitative research. (Author/JOW)

  18. Angles of Elevation of the Pyramids of Egypt.

    Science.gov (United States)

    Smith, Arthur F.

    1982-01-01

    The nature and history of the construction of pyramids in Egypt is detailed. It is noted that one can only theorize about why the Egyptians used particular angles of elevation. It is thought, perhaps, that new clues will provide a clear solution to this mystery as additional artifacts and hieroglyphics are discovered. (MP)

  19. Correlation between pyramidal signs and the severity of cervical myelopathy.

    Science.gov (United States)

    Chikuda, Hirotaka; Seichi, Atsushi; Takeshita, Katsushi; Shoda, Naoki; Ono, Takashi; Matsudaira, Ko; Kawaguchi, Hiroshi; Nakamura, Kozo

    2010-10-01

    A retrospective study was performed to determine the sensitivities of the pyramidal signs in patients with cervical myelopathy, focusing on those with increased signal intensity (ISI) in T2-weighted magnetic resonance imaging (MRI). The relationship between prevalence of the pyramidal signs and the severity of myelopathy was investigated. We reviewed the records of 275 patients with cervical myelopathy who underwent surgery. Of these, 143 patients were excluded from this study due to comorbidities that might complicate neurological findings. The MR images of the remaining 132 patients were evaluated in a blinded fashion. The neurological findings of 120 patients with ISI (90 men and 30 women; mean age 61 years) were reviewed for hyperreflexia (patellar tendon reflex), ankle clonus, Hoffmann reflex, and Babinski sign. To assess the severity of myelopathy, the motor function scores of the upper and lower extremities for cervical myelopathy set by the Japanese Orthopaedic Association (m-JOA score) were used. The most prevalent signs were hyperreflexia (94%), Hoffmann reflex (81%), Babinski sign (53%), and ankle clonus (35%). Babinski sign (P Babinski sign, and ankle clonus. The prevalence of the pyramidal signs correlated with increasing severity of myelopathy. Considering their low sensitivity in patients with mild disability, the pyramidal signs may have limited utility in early diagnosis of cervical myelopathy.

  20. [Diagnostic significance of pathologic synkinesis for detection of pyramidal pathology].

    Science.gov (United States)

    Baliasnyĭ, M M

    1991-01-01

    Five types of pathological synkinesis (++blepharo-ocular, ++blepharo-facial, ++bucco-manual, ++digito-digital on the hands, ++pedo-digital) are described. They are of definite importance for revealing pyramidal pathology including its early stages as well as for objective evaluation and observation of the time-course of changes in the illness.

  1. Modelling the Somatic Electrical Response of Hippocampal Pyramidal Neurons

    Science.gov (United States)

    1989-09-01

    non-linear, time-varying conductances in the soma, including those that underly three putative sodium currents , (IN.-tr,, INa-tail, and INa-rep), a...for excitation and propagation of the nerve impulse. Biophysics Journal. 6:, 1966. [12] C. French and P. Gage. A threshold sodium current in pyramidal

  2. Building trust at the Base of the Pyramid

    NARCIS (Netherlands)

    Grootveld, P.; Vermeulen, P.A.M.

    2014-01-01

    More and more companies are serving the poorest communities of our world, the so-called Base of the Pyramid (BoP). Wal-Mart, for example, moved into the Mexican retail-banking sector, claiming not only to “sell more stuff” but also to compete against the entrenched domestic businesses that are not f

  3. Succeeding at the Bottom-of-the-Pyramid

    DEFF Research Database (Denmark)

    Boxenbaum, Eva; Olsen, Mette

    initiative to build a social impact venture at the interface of a multi-national corporation and a hybrid organization that is operating on the Bottom-of-the-Pyramid market. Our study identifies how corporate social entrepreneurs dynamically use framing and organizational anchoring strategies to build...

  4. Budding Architects: Exploring the Designs of Pyramids and Prisms

    Science.gov (United States)

    Leavy, Aisling; Hourigan, Mairéad

    2015-01-01

    The context of students as architects is used to examine the similarities and differences between prisms and pyramids. Leavy and Hourigan use the Van Hiele Model as a tool to support teachers to develop expectations for differentiating geometry in the classroom using practical examples.

  5. KINEMATICS OF 3-DOF PYRAMID MANIPULATOR BY PRINCIPAL SCREWS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Kinematics of a 3-RPS parallel pyramid manipulator are investigated by principal screw. Firstly, the principal screws are identified by quadric degeneration. The planar conics representing the relations between the pitches and the three linear inputs are described, and the three-dimensional distribution of the axes of all the twists is illustrated. Finally, a numerical example is given successfully.

  6. Catalyzing new product adoption at the base of the pyramid

    NARCIS (Netherlands)

    Marinakis, Y.D.; Walsh, S.T.; Harms, R.

    2016-01-01

    One of the more perplexing of the entrepreneurial issues at the Base of the Pyramid (BoP) is how to catalyze new product adoption by BoP consumers. Because S-shaped adoption dynamics are the result of cultural transmission bias, the question can be rephrased as, how can an entrepreneur overcome conf

  7. Nano-pyramid arrays for nano-particle trapping

    NARCIS (Netherlands)

    Sun, Xingwu; Veltkamp, Henk-Willem; Berenschot, Johan W.; Gardeniers, Johannes G.E.; Tas, Niels Roelof

    2016-01-01

    Abstract In this paper we present the drastic miniaturization of nano-wire pyramids fabricated by corner lithography. A particle trapping device was fabricated in a well-defined and symmetrical array. The entrance and exit hole-size can be tuned by adjusting fabrication parameters. We describe here

  8. Fats, Oils, and Sweets. The Food Guide Pyramid.

    Science.gov (United States)

    Frost, Helen

    This booklet for young children is part of a series that supports national science standards related to physical health and nutrition, describing and illustrating the importance of using the Food Guide Pyramid and avoiding excesses of fats, oils, and sweets. It presents appealing alternatives to these unhealthy foods. Colorful photographs support…

  9. The pyramid model as a structured way of quality management

    Directory of Open Access Journals (Sweden)

    van der Tuuk Adriani Willem

    2008-01-01

    Full Text Available Three quality systems that can be used in blood establishments are briefly explained. The Pyramid model is described as a tool to manage the quality systems. Finally, some experiences in other countries are given to prove the validity of the system.

  10. A Modern Myth - The "Pyramids" of Güímar

    Science.gov (United States)

    Aparicio, Antonio; Esteban, César

    We discuss about the construction of a modern myth where archaeoastronomy has played an essential role: the Pyramids of Güímar, located in the island of Tenerife (Canary Islands). We summarize the results of archaeoastronomical, archaeological, historical, and ethnographic studies devoted to them as well as our hypothesis for explaining the motivation of their astronomical alignments.

  11. The Learning Pyramid: Does It Point Teachers in the Right Direction?

    Science.gov (United States)

    Lalley, James P.; Miller, Robert H.

    2007-01-01

    This paper raises serious questions about the reliability of the learning pyramid as a guide to retention among students. The pyramid suggests that certain teaching methods are connected with a corresponding hierarchy of student retention. No specific credible research was uncovered to support the pyramid, which is loosely associated with the…

  12. An algorithm for benchmarking an SIMD pyramid with the Abingdon Cross

    NARCIS (Netherlands)

    Teeuw, W.B.; Duin, R.P.W.

    1990-01-01

    Benchmarking an SIMD pyramid with the Abingdon Cross is discussed. Measured results for a simulated pyramid architecture on a CLIP4 processor array are presented, as well as estimates for a hypothetical hardware pyramid built with CLIP4 like processing elements.

  13. Nanostructured conducting polymer based reagentless capacitive immunosensor.

    Science.gov (United States)

    Bandodkar, Amay Jairaj; Dhand, Chetna; Arya, Sunil K; Pandey, M K; Malhotra, Bansi D

    2010-02-01

    Nanostructured polyaniline (PANI) film electrophoretically fabricated onto indium-tin-oxide (ITO) coated glass plate has been utilized for development of an immunosensor based on capacitance change of a parallel plate capacitor (PPC) by covalently immobilizing anti-human IgG (Anti-HIgG) using N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide chemistry. These fabricated PANI/ITO and Anti-HIgG/PANI/ITO plates have been characterized using scanning electron microscopy, cyclic voltammetry, differential pulse voltammetry and Fourier transform infra-red studies. The capacitance measurements indicate that dielectric medium of this biologically modified PPC (Anti-HIgG/PANI/ITO) is sensitive to HIgG in 5 - 5 x 10(5) ng mL(-1) range and has lower detection limit of 1.87 ng mL(-1). The observed results reveal that this Anti-HIgG modified PPC can be used as a robust, easy-to-use, reagentless, sensitive and selective immunosensor for estimation of human IgG.

  14. THERMAL DRIFT CHARACTERISTICS OF CAPACITIVE PRESSURE SENSORS

    Directory of Open Access Journals (Sweden)

    ABDELAZIZ BEDDIAF

    2016-03-01

    Full Text Available The capacitive pressure sensors based on silicon are characterized by their very high sensitivities and their low power consumption. Nevertheless, their thermal behavior remains more or less unpredictable because they can indicate very high thermal coefficients. The study of the thermal behavior of these sensors is essential to define the parameters that cause the output characteristics drift. In this study, we modeled the thermal behavior of this sensors, using Finite Element Analysis (FEA made in COMSOL. The model solved by COMSOL environment takes into account the entire sensor and thermal effects due to the temperature considering the materials’ properties, the geometric shape and also the heat transfer mechanisms. By COMSOL we determine how the temperature affects the sensor during the manufacturing process. For that end, we calculated the thermal drift of capacitance at rest, the thermal coefficients and we compared them with experimental results to validate our model. Further, we studied the thermal drift of sensor characteristics both at rest and under constant and uniform pressure. Further, our study put emphasis on the geometric influence parameters on these characteristics to optimize the sensor performance. Finally, this study allows us to predict the sensor behavior against temperature and to minimize this effect by optimizing the geometrical parameters.

  15. Nanopore formation on Au coated pyramid under electron beam irradiations (plasmonic nanopore on pyramid

    Directory of Open Access Journals (Sweden)

    Seong Soo Choi

    2016-03-01

    Full Text Available There have been tremendous interests about the single molecule analysis using a sold-state nanopore. The solid-state nanopore can be fabricated either by drilling technique, or diffusion technique by using electron beam irradiations. The solid-state SiN nanopore device with electrical detection technique recently fabricated, however, the solid-state Au nanopore with optical detection technique can be better utilized as the next generation single molecule sensor. In this report, the nanometer size openings with its size less than 10 nm on the diffused membrane on the 200 nm Au pyramid were fabricated by using field emission scanning electron microscopy (FESEM electron beam irradiations, transmission electron microscopy (TEM, etc. After the sample was being kept under a room environment for several months, several Au (111 clusters with ~6 nm diameter formed via Ostwald ripening are observed using a high resolution TEM imaging. The nanopore with Au nanoclusters on the diffused membrane can be utilized as an optical nanopore device.

  16. Development and validation of a food pyramid for Swiss athletes.

    Science.gov (United States)

    Mettler, Samuel; Mannhart, Christof; Colombani, Paolo C

    2009-10-01

    Food-guide pyramids help translate nutrient goals into a visual representation of suggested food intake on a population level. No such guidance system has ever been specifically designed for athletes. Therefore, the authors developed a Food Pyramid for Swiss Athletes that illustrates the number of servings per food group needed in relation to the training volume of an athlete. As a first step, an average energy expenditure of 0.1 kcal . kg(-1) . min(-1) for exercise was defined, which then was translated into servings of different food groups per hour of exercise per day. Variable serving sizes were defined for athletes' different body-mass categories. The pyramid was validated by designing 168 daily meal plans according to the recommendations of the pyramid for male and female athletes of different body-mass categories and training volumes of up to 4 hr/d. The energy intake of the meal plans met the calculated reference energy requirement by 97% +/- 9%. The carbohydrate and protein intakes were linearly graded from 4.6 +/- 0.6-8.5 +/- 0.8 g . kg(-1) . d(-1) and 1.6 +/- 0.2-1.9 +/- 0.2 g . kg(-1) . d(-1), respectively, for training volumes of 1-4 hr of exercise per day. The average micronutrient intake depended particularly on the dietary energy intake level but was well above the dietary reference intake values for most micronutrients. No tolerable upper intake level was exceeded for any micronutrient. Therefore, this Food Pyramid for Swiss Athletes may be used as a new tool in sports nutrition education (e.g., teaching and counseling).

  17. Hermes vehicle

    Science.gov (United States)

    Cretenet, J. C.

    1985-11-01

    The presence of Europe in the future developments of spatial programs, which are foreseen, for the 1990s and further, needs the availability of vehicles, modules and all related technologies adapted to operational use of low earth orbit station. The manned HERMES vehicle shall be part of the in-orbit infrastructure realized either in the European context or in cooperation between Europe and the United States. The main mission for this vehicle will be to run a shuttle with the station that means transport and change of the crews, its safe return in abort condition and cargo transport of consumable and experimental equipment. Secondary missions could be servicing on automatic platform, making autonomous scientific experiments. Lastly, the vehicle, by means of its on-board propulsion capability, could be used to accomplish in-orbit tow and assembly missions. Studies which are undertaken now about the vehicle are devoted to the aerodynamic shape (research of a compromise between aerothermic and overall fitting), the system (functional architecture, ground and flight configuration); further works dealing with technology are presently on hand in the field of thermal protection, aerodynamics, power generation with a high massic yield.

  18. electric vehicle

    Directory of Open Access Journals (Sweden)

    W. R. Lee

    1999-01-01

    Full Text Available A major problem facing battery-powered electric vehicles is in their batteries: weight and charge capacity. Thus, a battery-powered electric vehicle only has a short driving range. To travel for a longer distance, the batteries are required to be recharged frequently. In this paper, we construct a model for a battery-powered electric vehicle, in which driving strategy is to be obtained such that the total travelling time between two locations is minimized. The problem is formulated as an optimization problem with switching times and speed as decision variables. This is an unconventional optimization problem. However, by using the control parametrization enhancing technique (CPET, it is shown that this unconventional optimization is equivalent to a conventional optimal parameter selection problem. Numerical examples are solved using the proposed method.

  19. Distributed Capacitance of Coaxial Line With Perturbed Walls

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Perturbation method of boundary geometry(PMOBG) used in Laplacian problems is dealt with and the three-term perturbation expression of distributed capacitance of a coaxial line with perturbed walls is obtained. As an example,four-order expression of distributed capacitance of a elliptic coaxial line with small eccentricity is given.

  20. Capacitance tuning of nanoscale split-ring resonators

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Xiao, Sanshui; Mortensen, Niels Asger;

    2010-01-01

    In this paper, we investigate the capacitance tuning of nanoscale split-ring resonators. Based on a simple LC circuit model (LC-model), we derive an expression where the inductance is proportional to the area while the capacitance reflects the aspect ratio of the slit. The resonance frequency may...

  1. Capacitance tuning of nanoscale split-ring resonators

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Mortensen, Asger; Kristensen, Anders

    2009-01-01

    We investigate the capacitance tuning of nanoscale split-ring resonators. Based on a simple inductor-capacitor circuit model, we derive an expression, where the inductance is proportional to the area while the capacitance reflects the aspect ratio of the slit. The resonance frequency may thus be ...

  2. Nonlinear dynamics of capacitive charging and desalination by porous electrodes

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Bazant, M.Z.

    2010-01-01

    The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by supercapacitors, water desalination and purification by capacitive deionization, and capacitive extraction of renewable energy from a salin

  3. Electric field theory and the fallacy of void capacitance

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    1991-01-01

    The concept of the capacitance of a gaseous void is discussed as applied to electrical insulation science. The most pertinent aspect of the capacitance definition is that of reference to a single-valued potential difference between surfaces. This implies that these surfaces must be surfaces...

  4. Nanoscale capacitance: A quantum tight-binding model

    Science.gov (United States)

    Zhai, Feng; Wu, Jian; Li, Yang; Lu, Jun-Qiang

    2017-01-01

    Landauer-Buttiker formalism with the assumption of semi-infinite electrodes as reservoirs has been the standard approach in modeling steady electron transport through nanoscale devices. However, modeling dynamic electron transport properties, especially nanoscale capacitance, is a challenging problem because of dynamic contributions from electrodes, which is neglectable in modeling macroscopic capacitance and mesoscopic conductance. We implement a self-consistent quantum tight-binding model to calculate capacitance of a nano-gap system consisting of an electrode capacitance C‧ and an effective capacitance Cd of the middle device. From the calculations on a nano-gap made of carbon nanotube with a buckyball therein, we show that when the electrode length increases, the electrode capacitance C‧ moves up while the effective capacitance Cd converges to a value which is much smaller than the electrode capacitance C‧. Our results reveal the importance of electrodes in modeling nanoscale ac circuits, and indicate that the concepts of semi-infinite electrodes and reservoirs well-accepted in the steady electron transport theory may be not applicable in modeling dynamic transport properties.

  5. Capacitive bioanodes enable renewable energy storage in microbial fuel cells.

    Science.gov (United States)

    Deeke, Alexandra; Sleutels, Tom H J A; Hamelers, Hubertus V M; Buisman, Cees J N

    2012-03-20

    We developed an integrated system for storage of renewable electricity in a microbial fuel cell (MFC). The system contained a capacitive electrode that was inserted into the anodic compartment of an MFC to form a capacitive bioanode. This capacitive bioanode was compared with a noncapacitive bioanode on the basis of performance and storage capacity. The performance and storage capacity were investigated during polarization curves and charge-discharge experiments. During polarization curves the capacitive electrode reached a maximum current density of 1.02 ± 0.04 A/m(2), whereas the noncapacitive electrode reached a current density output of only 0.79 ± 0.03 A/m(2). During the charge-discharge experiment with 5 min of charging and 20 min of discharging, the capacitive electrode was able to store a total of 22,831 C/m(2), whereas the noncapacitive electrode was only able to store 12,195 C/m(2). Regarding the charge recovery of each electrode, the capacitive electrode was able to recover 52.9% more charge during each charge-discharge experiment compared with the noncapacitive electrode. The capacitive electrode outperformed the noncapacitive electrode throughout each charge-discharge experiment. With a capacitive electrode it is possible to use the MFC simultaneously for production and storage of renewable electricity.

  6. Large Capacitance Measurement by Multiple Uses of MBL Charge Sensor

    Science.gov (United States)

    Lee, Jung Sook; Chae, Min; Kim, Jung Bog

    2010-01-01

    A recent article by Morse described interesting electrostatics experiments using an MBL charge sensor. In this application, the charge sensor has a large capacitance compared to the charged test object, so nearly all charges can be transferred to the sensor capacitor from the capacitor to be measured. However, the typical capacitance of commercial…

  7. Characterizing Inductive and Capacitive Nonlinear RLC Circuits : A Passivity Test

    NARCIS (Netherlands)

    García-Canseco, Eloísa; Jeltsema, Dimitri; Ortega, Romeo; Scherpen, Jacquelien M.A.

    2004-01-01

    Linear time-invariant RLC circuits are said to be inductive (capacitive) if the current waveform in sinusoidal steady-state has a negative (resp., positive) phase shift with respect to the voltage. Furthermore, it is known that the circuit is inductive (capacitive) if and only if the magnetic energy

  8. The Consistent Vehicle Routing Problem

    Energy Technology Data Exchange (ETDEWEB)

    Groer, Christopher S [ORNL; Golden, Bruce [University of Maryland; Edward, Wasil [American University

    2009-01-01

    In the small package shipping industry (as in other industries), companies try to differentiate themselves by providing high levels of customer service. This can be accomplished in several ways, including online tracking of packages, ensuring on-time delivery, and offering residential pickups. Some companies want their drivers to develop relationships with customers on a route and have the same drivers visit the same customers at roughly the same time on each day that the customers need service. These service requirements, together with traditional constraints on vehicle capacity and route length, define a variant of the classical capacitated vehicle routing problem, which we call the consistent VRP (ConVRP). In this paper, we formulate the problem as a mixed-integer program and develop an algorithm to solve the ConVRP that is based on the record-to-record travel algorithm. We compare the performance of our algorithm to the optimal mixed-integer program solutions for a set of small problems and then apply our algorithm to five simulated data sets with 1,000 customers and a real-world data set with more than 3,700 customers. We provide a technique for generating ConVRP benchmark problems from vehicle routing problem instances given in the literature and provide our solutions to these instances. The solutions produced by our algorithm on all problems do a very good job of meeting customer service objectives with routes that have a low total travel time.

  9. Hybrid vehicles

    Energy Technology Data Exchange (ETDEWEB)

    West, J.G.W. [Electrical Machines (United Kingdom)

    1997-07-01

    The reasons for adopting hybrid vehicles result mainly from the lack of adequate range from electric vehicles at an acceptable cost. Hybrids can offer significant improvements in emissions and fuel economy. Series and parallel hybrids are compared. A combination of series and parallel operation would be the ideal. This can be obtained using a planetary gearbox as a power split device allowing a small generator to transfer power to the propulsion motor giving the effect of a CVT. It allows the engine to run at semi-constant speed giving better fuel economy and reduced emissions. Hybrid car developments are described that show the wide range of possible hybrid systems. (author)

  10. Effect of estrogens on boar sperm capacitation in vitro

    Directory of Open Access Journals (Sweden)

    Ded Lukas

    2010-07-01

    Full Text Available Abstract Background Mammalian sperm must undergo a series of controlled molecular processes in the female reproductive tract called capacitation before they are capable of penetrating and fertilizing the egg. Capacitation, as a complex biological process, is influenced by many molecular factors, among which steroidal hormone estrogens play their role. Estrogens, present in a high concentration in the female reproductive tract are generally considered as primarily female hormones. However, there is increasing evidence of their important impact on male reproductive parameters. The purpose of this study is to investigate the effect of three natural estrogens such as estrone (E1, 17beta-estradiol (E2 and estriol (E3 as well as the synthetical one, 17alpha-ethynylestradiol (EE2 on boar sperm capacitation in vitro. Methods Boar sperm were capacitated in vitro in presence of estrogens. Capacitation progress in control and experimental samples was analyzed by flow cytometry with the anti-acrosin monoclonal antibody (ACR.2 at selected times of incubation. Sperm samples were analyzed at 120 min of capacitation by CTC (chlortetracycline assay, immunocytochemistry and flow cytometry with anti-acrosin ACR.2 antibody. Furthermore, sperm samples and capacitating media were analyzed by immunocytochemistry, ELISA with the ACR.2 antibody, and the acrosin activity assay after induced acrosomal reaction (AR. Results Estrogens stimulate sperm capacitation of boar sperm collected from different individuals. The stimulatory effect depends on capacitation time and is highly influenced by differences in the response to estrogens such as E2 by individual animals. Individual estrogens have relatively same effect on capacitation progress. In the boar samples with high estrogen responsiveness, estrogens stimulate the capacitation progress in a concentration-dependent manner. Furthermore, estrogens significantly increase the number of acrosome-reacted sperm after zona

  11. Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Septon, Kendall K [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-11

    Electric-drive 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, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  12. Study of High Capacitance Ratios CPW MEMS Shunt Switches

    Institute of Scientific and Technical Information of China (English)

    Jianhai Sun; Dafu Cui

    2006-01-01

    This paper describes a fixed-fixed beam ohmic switch in series with a fixed capacitor as a replacement for a capacitive switch. In this switch, a metal plate deposited on the dielectric ensures perfectly contact with the dielectric layer in the down state. The area size of the metal plate directly influences the capacitance ratio of the switch, as the area size of the metal cap decreases, the capacitance ratio dramatically rises up. The down/up capacitance ratio can exceed 800 times over the conventional designs using the same materials and the equal size. Measurement results show that high capacitance ratio of the switches has a large effect on the isolation, and can actually improve the performance of the switches.

  13. Study of CMOS integrated signal processing circuit in capacitive sensors

    Institute of Scientific and Technical Information of China (English)

    CAO Yi-jiang; YU Xiang; WANG Lei

    2007-01-01

    A CMOS integrated signal processing circuit based on capacitance resonance principle whose structure is simple in capacitive sensors is designed. The waveform of output voltage is improved by choosing bootstrap reference current mirror with initiate circuit, CMOS analogy switch and positive feedback of double-stage inverter in the circuit. Output voltage of this circuit is a symmetric square wave signal. The variation of sensitive capacitance, which is part of the capacitive sensors, can be denoted by the change of output voltage's frequency. The whole circuit is designed with 1.5 μm P-well CMOS process and simulated by PSpice software.Output frequency varies from 261.05 kHz to 47.93 kHz if capacitance varies in the range of 1PF~15PF. And the variation of frequency can be easily detected using counter or SCU.

  14. Nonlinear Dynamics of Capacitive Charging and Desalination by Porous Electrodes

    CERN Document Server

    Biesheuvel, P M

    2009-01-01

    The rapid and efficient exchange of ions between porous electrodes and aqueous solutions is important in many applications, such as electrical energy storage by super-capacitors, water desalination and purification by capacitive deionization (or desalination), and capacitive extraction of renewable energy from a salinity difference. Here, we present a unified mean-field theory for capacitive charging and desalination by ideally polarizable porous electrodes (without Faradaic reactions or specific adsorption of ions) in the limit of thin double layers (compared to typical pore dimensions). We illustrate the theory in the case of a dilute, symmetric, binary electrolyte using the Gouy-Chapman-Stern (GCS) model of the double layer, for which simple formulae are available for salt adsorption and capacitive charging of the diffuse part of the double layer. We solve the full GCS mean-field theory numerically for realistic parameters in capacitive deionization, and we derive reduced models for two limiting regimes wi...

  15. Implementation Weather-Type Models of Capacitated Arc Routing Problem via Heuristics

    Directory of Open Access Journals (Sweden)

    Zuhaimy Ismail

    2011-01-01

    Full Text Available Problem statement: In this study, we introduced a new and real-life condition of Capacitated Arc Routing Problem (CARP, a model that represents vehicles operation in waste collection. In general, we studied the element of rain drops that affected the collected waste weight in total by imposed a new variable namely rainy weight age. In rainy days, the household refusals did not increase in volumes, but in weights due to rain drops. Consequently, this matter thus burdened vehicles capacity and prolonged its operation time. This dynamic variable thus changes the initial CARP model where the existing model did not consider other external elements that have effected onto the model. Approach: Then we developed and enhanced CARP by integrating stochastic demand and time windows to suit the models with our specific case. Results: Objectively, CARP with stochastic demand (CARPSD and CARP with time windows (CARPTW were designed to minimize the total routing cost and number of trips for a vehicle. Our approach is to design CARP models in almost likely to road layout in residential area and graphically this model is called mesh network. We also developed a constructive heuristic that is called nearest procedure based on highest demand/cost (NPHDC and work in conjunction with switching rules to search the feasible solution. Conclusion: Our preliminary results show a higher cost and more trips are needed when the vehicle operates in rainy day compared to normal day operation.

  16. Creatinine Diffusion Modeling in Capacitive Sensors

    Science.gov (United States)

    Mohabbati-Kalejahi, Elham; Azimirad, Vahid; Bahrami, Manouchehr

    2016-12-01

    In this paper, creatinine diffusion in capacitive sensors is discussed. The factors influencing the response time of creatinine biosensors are mathematically formulated and then three novel approaches for decreasing the response time are presented. At first, a piezoelectric actuator is used to vibrate the microtube that contains the blood sample, in order to reduce the viscosity of blood, and thus to increase the coefficient of diffusion. Then, the blood sample is assumed to be pushed through a porous medium, and the relevant conditions are investigated. Finally, the effect of the dentate shape of dielectric on response time is studied. The algorithms and the mathematical models are presented and discussed, and the results of simulations are illustrated. The response times for the first, second and third method are 60, 0.036 and about 31 s, respectively. It is also found that pumping results in very fast responses.

  17. Capacitated dynamic lot sizing with capacity acquisition

    DEFF Research Database (Denmark)

    Li, Hongyan; Meissner, Joern

    2011-01-01

    batch, along with inventory carrying costs. The production per period is limited by a capacity restriction. The underlying capacity must be purchased up front for the upcoming season and remains constant over the entire season. We assume that the capacity acquisition cost is smooth and convex......One of the fundamental problems in operations management is determining the optimal investment in capacity. Capacity investment consumes resources and the decision, once made, is often irreversible. Moreover, the available capacity level affects the action space for production and inventory...... planning decisions directly. In this article, we address the joint capacitated lot-sizing and capacity-acquisition problems. The firm can produce goods in each of the finite periods into which the production season is partitioned. Fixed as well as variable production costs are incurred for each production...

  18. [Wireless ECG measurement system with capacitive coupling].

    Science.gov (United States)

    Aleksandrowicz, Adrian; Walter, Marian; Leonhardt, Steffen

    2007-04-01

    This paper describes a measurement system that captures an electrocardiogram (ECG) using capacitively coupled electrodes. The measurement system was integrated into an off-the-shelf office chair (so-called "Aachen SmartChair"). Whereas for classical ECG measurement adhesive is used to attach conductively coupled electrodes to bare skin, the system presented allows ECG measurement through clothing without direct skin contact. Furthermore, a ZigBee communication module was integrated to allow wireless transmission of ECG data to a PC or an ICU patient monitor. For system validation, classical ECG using conductive electrodes was obtained simultaneously. First measurement results, including variations of cloth thickness and material, are presented and some of the system-specific problems of this approach are discussed.

  19. MOS Capacitance-Voltage Characteristics Ⅲ.Trapping Capacitance from 2-Charge-State Impurities

    Institute of Scientific and Technical Information of China (English)

    Jie Binbin; Sah Chihtang

    2011-01-01

    Low-frequency and high-frequency capacitance-voltage curves of Metal-Oxide-Semiconductor Capacitors are presented to illustrate giant electron and hole trapping capacitances at many simultaneously present two-charge-state and one-trapped-carrier,or one-energy-level impurity species.Models described include a donor electron trap and an acceptor hole trap,both donors,both acceptors,both shallow energy levels,both deep,one shallow and one deep,and the identical donor and acceptor.Device and material parameters are selected to simulate chemically and physically realizable capacitors for fundamental trapping parameter characterizations and for electrical and optical signal processing applications.

  20. Value Chain and Innovation at the Base of the Pyramid

    DEFF Research Database (Denmark)

    Esko, Siim; Zeromskis, Mindaugas; Hsuan, Juliana

    2013-01-01

    Purpose – This paper aims to investigate the factors a multinational corporation should adapt when doing business at the bottom of the pyramid (BoP) markets. Design/methodology/approach – Based on a systematic literature review on BoP, value chain and innovation, an integrative framework is intro......Purpose – This paper aims to investigate the factors a multinational corporation should adapt when doing business at the bottom of the pyramid (BoP) markets. Design/methodology/approach – Based on a systematic literature review on BoP, value chain and innovation, an integrative framework...... and financial measurements. Working in the value chain requires diverse thinking in terms of interactivity, partners, setup, and governance. Involving customers and consumers in the innovation process is crucial. The venture also needs to make its offerings accessible, affordable, acceptable, available...

  1. Distributed GIS oriented generalized image pyramid and its practice

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Gaussian pyramid framework (GPF) and Laplacian pyramid framework (LPF) are the two main frameworks used for transmission and structure of spatial image and geometric data.LPF is the main approach for progressive transmission of spatial image data.This paper discusses the issues in structure,transmission and storage efficiency of spatial data in the current spatially distributed visualization system.Later in the paper a novel approach is introduced to structure and store spatial data based on the LPF.This new approach builds (spatial) index for transformed frequency data within different ranges based on splitting high-frequency and low-frequency data by biorthogonal transformation.This approach decreases the storage consumption and network data traffic for transmission while enables the progressive transmission of spatial image.

  2. Characterization of electrical and mechanical activities of rabbit uterus associated with the presence of capacitated and non-capacitated spermatozoa

    Directory of Open Access Journals (Sweden)

    J.F. Lazcano-Reyes

    2013-12-01

    Full Text Available To investigate the effects capacitated spermatozoa may exert upon motility of the rabbit uterus, both contractility and electrical activity (frequency and intensity were measured in 3 distinctive uterine segments of anaesthetized does: horn (UH, uterotubal junction (UTJ and tube (UT after 1 natural mating, 2 infusion of either seminal plasma or PBS, 3 infusion of either capacitated or non-capacitated spermatozoa. Basal values were: 17.1, 15.7, 16.4 g (contractility, P>0.05; 3.5, 3.5, 3.4 Hz (frequency, P>0.05; 0.49, 0.50, 0.57 μV (intensity, P>0.05 for UH, UTJ, UT, respectively. Seminal plasma caused an increase (P<0.05 in the UH contractility: 26.3 vs. 11.7 (natural mating and 17.0 g (PBS; it also caused a decrease (P<0.05 in electrical intensity at the UTJ: 0.24 vs. 0.67 (natural mating and 0.58 μV (PBS. The presence of either capacitated or non-capacitated spermatozoa caused no changes in contractility and electrical frequency in any of the uterine segments. However, there was a change in electrical intensity at UTJ (0.37 vs. 0.57 μV for non-capacitated and capacitated spermatozoa, respectively; P<0.05. There were also differences between segments by treatment: UTJ (0.37 vs. UT (0.59 μV for non-capacitated; UH (0.46 vs. UT (0.71 μV for capacitated spermatozoa (P<0.05. In conclusion, use of this experimental model showed that uterine electrical activity was slightly modified by the presence of capacitated spermatozoa.

  3. PLAN FOR PERFORMANCE ADMINISTRATION IN PYRAMIDAL STRUCTURE ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Domingo Alarcón Ortiz

    2013-11-01

    Full Text Available Performance administration has become a current strategy in evaluating management within organizations, but its implementation often lacks an action plan, resulting from the valuation of climate and leadership styles embedded in the culture of the organization. This paper proposes a model action plan for performance management, which has been implemented, executed and evaluated in pyramidal organizational structure organizations where a diagnosis of the cultural climate and leadership styles recurring in the organization have been previously made.

  4. Pyramid diffraction in parity-time-symmetric optical lattices

    CERN Document Server

    Nixon, Sean

    2013-01-01

    Nonlinear dynamics of wave packets in two-dimensional parity-time-symmetric optical lattices near the phase-transition point are analytically studied. A novel fourth-order equation is derived for the envelope of these wave packets. A pyramid diffraction pattern is demonstrated in both the linear and nonlinear regimes. Blow-up is also possible in the nonlinear regime for both focusing and defocusing nonlinearities.

  5. Puusepp's sign--clinical significance of a forgotten pyramidal sign.

    Science.gov (United States)

    Tacik, Pawel; Krasnianski, M; Zierz, S

    2009-12-01

    The pyramidal signs in the lower extremity can be divided into three groups: (1) Babinski's group characterised by dorsoflexion of the great toe, (2) pyramidal signs marked by plantar flexion of the toes (e.g. Rossolimo's sign), and (3) synkinetic movements such as Strümpell's phenomenon. Puusepp's sign described by the Estonian neurologist and neurosurgeon Ludvig Puusepp belongs to none of these three groups. Its eliciting does not differ from that of Babinski's sign. The response, however, is different and consists of a tonic slow abduction of the little toe. We showed its relevance on the basis of clinical examination of six patients: four females aged 29, 50, 43 and 57 years and two males aged 42 and 49 years. The diagnoses were as follows: a new relapse of multiple sclerosis, a secondary progressive multiple sclerosis, a left middle cerebral artery stroke, a lumbago resulting in L3-L4 fusion surgery, an amyotrophic lateral sclerosis and a left intracerebral haemorrhage respectively. Puusepp's sign was the only elicitable pyramidal sign in all the patients but two. The 50-year-old female patient revealed on neurological examination Babinski's sign on the left side and Puusepp's sign on the right side. The testing of pyramidal signs in the 57-year-old woman displayed a bilateral Strümpell's sign and a left Puusepp's sign. These six cases showed that although rarely recognized in the clinical practice Puusepp's sign contributed to establishing the diagnosis of a central motor neuron involvement in the case of an absent Babinski's sign. Thus, its testing does not differ from that of Babinski's sign which requires only a little attention from the examiner, but provides an important piece of clinical information.

  6. Staircase effect alleviation based on multiscale analysis of Laplacian Pyramid

    Science.gov (United States)

    Chen, Wenjie; Ye, Yutang; Huang, Yonglin

    2012-01-01

    Image denoising with second order partial differential equations (PDEs) often leads to undesirable staircase effect, namely, the transformation of smooth regions into piecewise constant regions. In this paper, staircase effect is analyzed in spatial frequency domain which is different from previous studies. A method of nonlinear diffusion based on Laplacian Pyramid is proposed. The experimental results show that the proposed method alleviates the staircase effect and leads to more natural restored images.

  7. BOUNDING PYRAMIDS AND BOUNDING CONES FOR TRIANGULAR BEZIER SURFACES

    Institute of Scientific and Technical Information of China (English)

    Jian-song Deng; Fa-lai Chen; Li-li Wang

    2000-01-01

    This paper describes practical approaches on how to construct bounding pyramids and bounding cones for triangular Bézier surfaces. Examples are provided to illustrate the process of construction and comparison is made between various surface bounding volumes. Furthermore, as a starting point for the construction,we provide a way to compute hodographs of triangular Bézier surfaces and improve the algorithm for computing the bounding cone of a set of vectors.

  8. Pyramid wavefront sensors for astronomy and for the human eye

    OpenAIRE

    Bergomi, Maria

    2013-01-01

    WaveFront Sensors (WFSs) may be defined as the heart of an adaptive optics system since they analyze the radiation coming from reference sources and allow to quantify the distortion of a wavefront. Among the varieties of existing WFSs, my PhD research thesis focuses especially on innovative optical systems taking advantage of the peculiarities of the Pyramid WFS. In my PhD project I have designed, implemented, characterized or studied three different applications characterized by the f...

  9. X-Y separable pyramid steerable scalable kernels

    OpenAIRE

    Shy, Douglas; Perona, Pietro

    1994-01-01

    A new method for generating X-Y separable, steerable, scalable approximations of filter kernels is proposed which is based on a generalization of the singular value decomposition (SVD) to three dimensions. This “pseudo-SVD” improves upon a previous scheme due to Perona (1992) in that it reduces convolution time and storage requirements. An adaptation of the pseudo-SVD is proposed to generate steerable and scalable kernels which are suitable for use with a Laplacian pyramid. The properties of ...

  10. Fast modulation and dithering on a pyramid wavefront sensor bench

    Science.gov (United States)

    van Kooten, Maaike; Bradley, Colin; Veran, Jean-Pierre; Herriot, Glen; Lardiere, Olivier

    2016-07-01

    A pyramid wavefront sensor (PWFS) bench has been setup at NRC-Herzberg (Victoria, Canada) to investigate, first, the feasibility of a double roof prism PWFS, and second, test the proposed pyramid wavefront sensing methodology to be used in NFIRAOS for the Thirty Meter Telescope. Traditional PWFS require shallow angles and strict apex tolerances, making them difficult to manufacture. Roof prisms, on the other hand, are common optical components and can easily be made to the desired specifications. Understanding the differences between a double roof prism PWFS and traditional PWFS will allow for the double roof prism PWFS to become more widely used as an alternative to the standard pyramid, especially in a laboratory setting. In this work, the response of the double roof prism PWFS as the amount of modulation is changed, is compared to an ideal PWFS modelled using the adaptive optics toolbox, OOMAO in MATLAB. The object oriented toolbox uses physical optics to model complete AO systems. Fast modulation and dithering using a PI mirror has been implemented using a micro-controller to drive the mirror and trigger the camera. The various trade offs of this scheme, in a controlled laboratory environment, are studied and reported.

  11. Degeneration of pyramidal tract of MRI (magnetic resonance imaging)

    Energy Technology Data Exchange (ETDEWEB)

    Yamagami, Tatsuhito; Harada, Noboru; Gotoh, Yasunobu; Imataka, Kiyoharu; Kinuta, Yuji; Okumura, Teizo; Niijima, Kyo; Taki, Waro; Kikuchi, Haruhiko.

    1988-02-01

    MRI (magnetic resonance imaging) examinaion was performed on cases of hemiplegia and hemiparesis. These included seven cases of intracerebral hemorrhage, four cases of subarachnoid hemorrhage, one case of cerebral infarct, and two cases of head trauma. The pyramidal tract in the brain stem was studied in five patients with complete hemiplegia and in nine with incomplete hemiparesis. The scanner of the MRI was a resistive type operating at a field of 0.2 Tesla. The inversion recovery (IR) and saturation recovery (SR) techniques were utilized. The pyramidal tract at the level of the midbrain and the pons was recognized as a low intensity area on the T/sub 1/ image (IR 150043) in the cases of complete hemiplegia. However, it was recognized as a high intensity area on the SR image (SR 100060) and the T/sub 2/ image (SR 2000100). No abnormal signal intensity was found in the cases of incomplete hemiparesis. A low intensity area on the T/sub 1/ image and a high intensity area on the T/sub 2/ image were recognized in the ventral portion of the midbrain and the pons on the affected side. These findings indicate a degeneration of the pyramidal tract at the level of the brain stem in patients with complete hemiplegia.

  12. Image content authentication technique based on Laplacian Pyramid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper proposes a technique of image content authentication based on the Laplacian Pyramid to verify the authenticity of image content.First,the image is decomposed into Laplacian Pyramid before the transformation.Next,the smooth and detail properties of the original image are analyzed according to the Laplacian Pyramid,and the properties are classified and encoded to get the corresponding characteristic values.Then,the signature derived from the encrypted characteristic values is embedded in the original image as a watermark.After the reception,the characteristic values of the received image are compared with the watermark drawn out from the image.The algorithm automatically identifies whether the content is tampered by means of morphologic filtration.The information of tampered location is Presented at the same time.Experimental results show that the pro posed authentication algorithm can effectively detect the event and location when the original image content is tampered.Moreover,it can tolerate some distortions produced by compression,filtration and noise degradation.

  13. Amending Miller's Pyramid to Include Professional Identity Formation.

    Science.gov (United States)

    Cruess, Richard L; Cruess, Sylvia R; Steinert, Yvonne

    2016-02-01

    In 1990, George Miller published an article entitled "The Assessment of Clinical Skills/Competence/Performance" that had an immediate and lasting impact on medical education. In his classic article, he stated that no single method of assessment could encompass the intricacies and complexities of medical practice. To provide a structured approach to the assessment of medical competence, he proposed a pyramidal structure with four levels, each of which required specific methods of assessment. As is well known, the layers are "Knows," "Knows How," "Shows How," and "Does." Miller's pyramid has guided assessment since its introduction; it has also been used to assist in the assessment of professionalism.The recent emphasis on professional identity formation has raised questions about the appropriateness of "Does" as the highest level of aspiration. It is believed that a more reliable indicator of professional behavior is the incorporation of the values and attitudes of the professional into the identity of the aspiring physician. It is therefore proposed that a fifth level be added at the apex of the pyramid. This level, reflecting the presence of a professional identity, should be "Is," and methods of assessing progress toward a professional identity and the nature of the identity in formation should be guided by currently available methods.

  14. Spatio-temporal Laplacian pyramid coding for action recognition.

    Science.gov (United States)

    Shao, Ling; Zhen, Xiantong; Tao, Dacheng; Li, Xuelong

    2014-06-01

    We present a novel descriptor, called spatio-temporal Laplacian pyramid coding (STLPC), for holistic representation of human actions. In contrast to sparse representations based on detected local interest points, STLPC regards a video sequence as a whole with spatio-temporal features directly extracted from it, which prevents the loss of information in sparse representations. Through decomposing each sequence into a set of band-pass-filtered components, the proposed pyramid model localizes features residing at different scales, and therefore is able to effectively encode the motion information of actions. To make features further invariant and resistant to distortions as well as noise, a bank of 3-D Gabor filters is applied to each level of the Laplacian pyramid, followed by max pooling within filter bands and over spatio-temporal neighborhoods. Since the convolving and pooling are performed spatio-temporally, the coding model can capture structural and motion information simultaneously and provide an informative representation of actions. The proposed method achieves superb recognition rates on the KTH, the multiview IXMAS, the challenging UCF Sports, and the newly released HMDB51 datasets. It outperforms state of the art methods showing its great potential on action recognition.

  15. Homeostatic responses by surviving cortical pyramidal cells in neurodegenerative tauopathy.

    Science.gov (United States)

    Crimins, Johanna L; Rocher, Anne B; Peters, Alan; Shultz, Penny; Lewis, Jada; Luebke, Jennifer I

    2011-11-01

    Cortical neuron death is prevalent by 9 months in rTg(tau(P301L))4510 tau mutant mice (TG) and surviving pyramidal cells exhibit dendritic regression and spine loss. We used whole-cell patch-clamp recordings to investigate the impact of these marked structural changes on spontaneous excitatory and inhibitory postsynaptic currents (sEPSCs and sIPSCs) of layer 3 pyramidal cells in frontal cortical slices from behaviorally characterized TG and non-transgenic (NT) mice at this age. Frontal lobe function of TG mice was intact following a short delay interval but impaired following a long delay interval in an object recognition test, and cortical atrophy and cell loss were pronounced. Surviving TG cells had significantly reduced dendritic diameters, total spine density, and mushroom spines, yet sEPSCs were increased and sIPSCs were unchanged in frequency. Thus, despite significant regressive structural changes, synaptic responses were not reduced in TG cells, indicating that homeostatic compensatory mechanisms occur during progressive tauopathy. Consistent with this idea, surviving TG cells were more intrinsically excitable than NT cells, and exhibited sprouting of filopodia and axonal boutons. Moreover, the neuropil in TG mice showed an increased density of asymmetric synapses, although their mean size was reduced. Taken together, these data indicate that during progressive tauopathy, cortical pyramidal cells compensate for loss of afferent input by increased excitability and establishment of new synapses. These compensatory homeostatic mechanisms may play an important role in slowing the progression of neuronal network dysfunction during neurodegenerative tauopathies.

  16. Aberrant pyramidal tract in a patient with corona radiata infarct A diffusion tensor tractography study

    Institute of Scientific and Technical Information of China (English)

    Ji Heon Hong; Sung Ho Jang

    2011-01-01

    The aberrant pyramidal tract refers to the collateral pathway of the pyramidal tract through the medial lemniscus in the brainstem. A 63-year-old male patient presented with severe paralysis of the left extremities due to a right corona radiata infarct. He was able to extend the affected fingers against resistance at 2 months after stroke onset. At 6 months after stroke onset, he was able to perform some fine motor activities, as well as to walk with a nearly normal gait. Functional MRI, which was performed at 6 months after onset, showed that the contralateral primary sensorimotor cortex was activated during affected (left) hand movements. Diffusion tensor tractography results showed that at 2 weeks after stroke onset, pyramidal tracts of the affected hemisphere originated from the primary motor cortex and descended along the known pathway of the pyramidal tract with an aberrant pyramidal tract, which was bypassed through the medial lemniscus from the midbrain to the lower pons. However, the pyramidal tract from midbrain to pons in the affected hemisphere could not be depicted by diffusion tensor tractography at 6 months after stroke onset; instead, only the aberrant pyramidal tract existed for the course of the disappeared pyramidal tract. Results from this study indicate that the main motor functions of the affected extremities appeared to be controlled via the aberrant pyramidal tract with degeneration of the pyramidal tract in the brainstem of the affected hemisphere.

  17. Bloch inductance in small-capacitance Josephson junctions.

    Science.gov (United States)

    Zorin, A B

    2006-04-28

    We show that the electrical impedance of a small-capacitance Josephson junction also includes, in addition to the capacitive term -i/(omega)CB, an inductive term i(omega)LB. Similar to the known Bloch capacitance CB(q), the Bloch inductance LB(q) also depends periodically on the quasicharge, q, and its maximum value achieved at q=e(mod 2e) always exceeds the value of the Josephson inductance of this junction LJ(phi) at fixed phi=0. The effect of the Bloch inductance on the dynamics of a single junction and a one-dimensional array is described.

  18. Human body capacitance: static or dynamic concept? [ESD

    DEFF Research Database (Denmark)

    Jonassen, Niels M

    1998-01-01

    A standing human body insulated from ground by footwear and/or floor covering is in principle an insulated conductor and has, as such, a capacitance, i.e. the ability to store a charge and possibly discharge the stored energy in a spark discharge. In the human body, the human body capacitance (HBC...... when a substantial part of the flux extends itself through badly defined stray fields. Since the concept of human body capacitance is normally used in a static (electric) context, it is suggested that the HBC be determined by a static method. No theoretical explanation of the observed differences...

  19. Clinical characteristics of papillary thyroid carcinoma arising from the pyramidal lobe

    Science.gov (United States)

    Yoon, Sang Gab; Yi, Jin Wook; Seong, Chan-Yong; Kim, Jong-Kyu; Kim, Su-Jin; Chai, Young Jun; Choi, June Young

    2017-01-01

    Purpose Papillary thyroid carcinoma (PTC) arising from the pyramidal lobe is rare; therefore, clinicopathologic evaluation is lacking. In addition, the rate of occult malignancy in the pyramidal lobe after thyroid surgery is unclear. This study is to evaluate the clinical characteristics of PTCs that involve the pyramidal lobe. Methods The study enrolled 1,107 patients who underwent thyroid surgery for PTC at Seoul National University Hospital from 2006 to 2015. Pyramidal lobe status in pathologic reports was clear in all cases. “Pyramidal lobe-dominant PTC” was defined as single pyramidal lobe cancer or multifocal cancer with larger pyramidal lobe tumor. “Incidental pyramidal lobe PTC” was defined as occult cancer identified after thyroidectomy or as multifocal cancer with smaller pyramidal lobe tumor. Results Ten patients were included in the pyramidal lobe-dominant PTC group. The mean age was 58 ± 12.5 years, and the mean tumor size was 0.7 ± 0.7 cm. Cervical lymph node metastasis was found in 5 patients (50%). Three patients had microscopic lymphatic invasion, and 7 had advanced American Joint Comitee on Cancer (AJCC) stage disease (5 with stage III and 2 with stage IV). Compared with conventional PTC (n = 1,058), pyramidal lobe-dominant PTC was significantly associated with lymphatic invasion (P = 0.031) and advanced AJCC stage (P = 0.022). The prevalence of incidental pyramidal lobe PTC was 3.56%. Conclusion Pyramidal lobe PTC is relatively small in size; however, the rate of extrathyroidal extension and lymph node metastasis is high. Preoperative evaluation of nodal status is important, and the extent of surgery should be determined in accordance with the preoperative diagnosis. PMID:28289665

  20. Joining and Assembly of Bulk Metallic Glass Composites Through Capacitive Discharge

    Science.gov (United States)

    Hofmann, Douglas C.; Roberts, Scott; Kozachkov, Henry; Demetriou, Marios D.; Schramm, Joseph P.; Johnson, William L.

    2012-01-01

    . This removes many complicated and costly fabrication steps. Moreover, the cellular structures detailed in this work are among the highest- strength and most energy-absorbent materials known. This implies that a fabricated structure made from these materials would have unequaled mechanical properties compared to other metal foams or trusses. The process works by taking advantage of the electrical properties of the matrix material in the metal-matrix composite, which in this case is a metallic glass. Due to the random nanoscale arrangement of atoms (without any grain boundaries), the matrix glass exhibits a near-constant electrical resistivity as a function of temperature. By placing the composite panels between two copper electrode plates and discharging a capacitor, the entire matrix of the panel can be heated to approximately 700 C in 10 milliseconds, which is above the alloy s solidus but below the liquidus. By designing the geometry of the panels into the shape of an egg box, the electrical discharge localizes only in the tips of each pyramidal cell. By applying a forging load during discharge, the nodes of the panels can be fused together into a single piece, which then dissipates heat through radiation back into a glassy state. This means that two panels can be metallurgically fused into one panel with no heat-affected zone, creating a seamless connection between panels. During the process, the soft metal particles (dendrites) that are uniformly distributed in the glassy matrix to increase the toughness are completely unaffected by the thermoplastic joining. The novelty is that a truss (or foam-like) structure can be formed with excellent energy- absorbing capabilities without the need for machining. The technique allows for large-scale fabrication of panels, well-suited for spacecraft shields or military vehicle door panels. Crystalline metal cellular structures cannot be fabricated using the thermoplastic joining technique described here. If metal panels were te

  1. Micromachined capacitive transducer arrays for intravascular ultrasound

    Science.gov (United States)

    Degertekin, F. Levent; Guldiken, R. Oytun; Karaman, Mustafa

    2005-01-01

    Intravascular ultrasound (IVUS) imaging has become an essential imaging modality for the effective diagnosis and treatment of cardiovascular diseases during the past decade enabled by innovative applications of piezoelectric transducer technology. The limitations in the manufacture and performance of the same piezoelectric transducers have also impeded the improvement of IVUS for emerging clinically important applications such as forward viewing arrays for guiding interventions and high resolution imaging of arterial structure such as vulnerable plaque and fibrous cap, and also implementation of techniques such as harmonic imaging of the tissue and of the contrast agents. Capacitive micromachined ultrasonic transducer (CMUT) technology shows great potential for transforming IVUS not only to satisfy these clinical needs but also to open up possibilities for low-cost imaging devices integrated to therapeutic tools. We have developed manufacturing processes with a maximum process temperature of 250°C to build CMUTs on the same silicon chip with integrated electronics. Using these processes we fabricated CMUT arrays suitable for forward viewing IVUS in the 10-20MHz range. We characterized these array elements in terms of pulse-echo response, radiation pattern measurements and demonstrated its volumetric imaging capabilities on various imaging targets.

  2. Instabilities in a capacitively coupled oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Küllig, C., E-mail: kuellig@physik.uni-greifswald.de; Wegner, Th., E-mail: physics@thwegner.com; Meichsner, J., E-mail: meichsner@physik.uni-greifswald.de [Institute of Physics, University of Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald (Germany)

    2015-04-15

    Periodic fluctuations in the frequency range from 0.3 to 3 kHz were experimentally investigated in capacitively coupled radio frequency (13.56 MHz) oxygen plasma. The Gaussian beam microwave interferometry directly provides the line integrated electron density fluctuations. A system of two Langmuir probes measured the floating potential spatially (axial, radial) and temporally resolved. Hence, the floating potential fluctuation development is mapped within the discharge volume and provides a kind of discharge breathing and no wave propagation. Finally, it was measured the optical emission pattern of atomic oxygen during the fluctuation as well as the RF phase resolved optical emission intensity at selected phase position of the fluctuation by an intensified charge-coupled device camera. The deduced excitation rate pattern reveals the RF sheath dynamics and electron heating mechanisms, which is changing between low and high electronegativity during a fluctuation cycle. A perturbation calculation was taken into account using a global model with 15 elementary collision processes in the balance equations for the charged plasma species (O{sub 2}{sup +}, e, O{sup −}, O{sub 2}{sup −}) and a harmonic perturbation. The calculated frequencies agree with the experimentally observed frequencies. Whereby, the electron attachment/detachment processes are important for the generation of this instability.

  3. An uncooled capacitive sensor for IR detection

    Science.gov (United States)

    Siebke, Georg; Gerngroß, Kathrin; Holik, Peter; Schmitz, Sam; Rohloff, Markus; Tätzner, Simon; Steltenkamp, Siegfried

    2014-06-01

    The beetle Melanophila acuminata detects forest fires from distances as far as 80 miles away. To accomplish this, the beetle uses highly specific IR receptors with a diameter of approximately 15 μm. These receptors are mechanoreceptors that detect deformations induced by the absorption of radiation. Although the detection mechanism is understood in principle, it is still unclear how the beetle reaches such high sensitivity. In this work, we present the biomimetic approach of an uncooled IR sensor based on the beetle's receptors. This sensor is based on a fluid-filled pressure cell and operates at room temperature. Upon absorbing IR radiation, the fluid heats up and expands. The expanding fluid deflects one electrode of a plate capacitor. By measuring the change in capacitance, the volume increase and the absorbed energy can be inferred. To prevent the risk of damage at high energy absorption, a compensation mechanism is presented in this work. The mechanism prevents large but slow volume changes inside the pressure cell by a microfluidic connection of the pressure cell with a compensation chamber. The channel and the compensation chamber act as a microfluidic low-pass filter and do not affect the overall sensitivity above an appropriate cut-off frequency. Using MEMS technology, we are able to incorporate the complete system into a silicon chip with an area of a few mm2. Here, we show a proof-of-concept and first measurements of the sensor.

  4. Design Considerations in Capacitively Coupled Plasmas

    Science.gov (United States)

    Song, Sang-Heon; Ventzek, Peter; Ranjan, Alok

    2015-11-01

    Microelectronics industry has driven transistor feature size scaling from 10-6 m to 10-9 m during the past 50 years, which is often referred to as Moore's law. It cannot be overstated that today's information technology would not have been so successful without plasma material processing. One of the major plasma sources for the microelectronics fabrication is capacitively coupled plasmas (CCPs). The CCP reactor has been intensively studied and developed for the deposition and etching of different films on the silicon wafer. As the feature size gets to around 10 nm, the requirement for the process uniformity is less than 1-2 nm across the wafer (300 mm). In order to achieve the desired uniformity, the hardware design should be as precise as possible before the fine tuning of process condition is applied to make it even better. In doing this procedure, the computer simulation can save a significant amount of resources such as time and money which are critical in the semiconductor business. In this presentation, we compare plasma properties using a 2-dimensional plasma hydrodynamics model for different kinds of design factors that can affect the plasma uniformity. The parameters studied in this presentation include chamber accessing port, pumping port, focus ring around wafer substrate, and the geometry of electrodes of CCP.

  5. Hydrogen atom kinetics in capacitively coupled plasmas

    Science.gov (United States)

    Nunomura, Shota; Katayama, Hirotaka; Yoshida, Isao

    2017-05-01

    Hydrogen (H) atom kinetics has been investigated in capacitively coupled very high frequency (VHF) discharges at powers of 16-780 mW cm-2 and H2 gas pressures of 0.1-2 Torr. The H atom density has been measured using vacuum ultra violet absorption spectroscopy (VUVAS) with a micro-discharge hollow cathode lamp as a VUV light source. The measurements have been performed in two different electrode configurations of discharges: conventional parallel-plate diode and triode with an intermediate mesh electrode. We find that in the triode configuration, the H atom density is strongly reduced across the mesh electrode. The H atom density varies from ˜1012 cm-3 to ˜1010 cm-3 by crossing the mesh with 0.2 mm in thickness and 36% in aperture ratio. The fluid model simulations for VHF discharge plasmas have been performed to study the H atom generation, diffusion and recombination kinetics. The simulations suggest that H atoms are generated in the bulk plasma, by the electron impact dissociation (e + H2 \\to e + 2H) and the ion-molecule reaction (H2 + + H2 \\to {{{H}}}3+ + H). The diffusion of H atoms is strongly limited by a mesh electrode, and thus the mesh geometry influences the spatial distribution of the H atoms. The loss of H atoms is dominated by the surface recombination.

  6. Fringe Capacitance of a Parallel-Plate Capacitor.

    Science.gov (United States)

    Hale, D. P.

    1978-01-01

    Describes an experiment designed to measure the forces between charged parallel plates, and determines the relationship among the effective electrode area, the measured capacitance values, and the electrode spacing of a parallel plate capacitor. (GA)

  7. Integration of Capacitive Micromachined Ultrasound Transducers to Microfluidic Devices

    KAUST Repository

    Viržonis, Darius

    2013-10-22

    The design and manufacturing flexibility of capacitive micromachined ultrasound transducers (CMUT) makes them attractive option for integration with microfluidic devices both for sensing and fluid manipulation. CMUT concept is introduced here by presentin

  8. Voidage measurement based on genetic algorithm and electrical capacitance tomography

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-wei; WANG Bao-liang; HUANG Zhi-yao; LI Hai-qing

    2005-01-01

    A new voidage measurement method based on electrical capacitance tomography (ECT) technique, Genetic Algorithm (GA) and Partial Least Square (PLS) method was proposed. The voidage measurement model, linear capacitance combination, was developed to measure on-line voidage. GA and PLS method were used to determine the coefficients of the voidage measurement model. GA was used to explore the optimal capacitance combination which gave significant contribution to the voidage measurement. PLS method was applied to determine the weight coefficient of the contribution of each capacitance to the voidage measurement. Flow pattern identification result was introduced to improve the voidage measurement accuracy. Experimental results showed that the proposed voidage measurement method is effective and that the measurement accuracy is satisfactory.

  9. Capacitance-Power-Hysteresis Trilemma in Nanoporous Supercapacitors

    Directory of Open Access Journals (Sweden)

    Alpha A. Lee

    2016-06-01

    Full Text Available Nanoporous supercapacitors are an important player in the field of energy storage that fill the gap between dielectric capacitors and batteries. The key challenge in the development of supercapacitors is the perceived trade-off between capacitance and power delivery. Current efforts to boost the capacitance of nanoporous supercapacitors focus on reducing the pore size so that they can only accommodate a single layer of ions. However, this tight packing compromises the charging dynamics and hence power density. We show via an analytical theory and Monte Carlo simulations that charging is sensitively dependent on the affinity of ions to the pores, and that high capacitances can be obtained for ionophobic pores of widths significantly larger than the ion diameter. Our theory also predicts that charging can be hysteretic with a significant energy loss per cycle for intermediate ionophilicities. We use these observations to explore the parameter regimes in which a capacitance-power-hysteresis trilemma may be avoided.

  10. High Voltage Bi-directional Flyback Converter for Capacitive Actuator

    DEFF Research Database (Denmark)

    Thummala, Prasanth; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    This paper presents a high voltage DC-DC converter topology for bi-directional energy transfer between a low voltage DC source and a high voltage capacitive load. The topology is a bi-directional flyback converter with variable switching frequency control during the charge mode, and constant...... switching frequency control during the discharge mode. The converter is capable of charging the capacitive load from 24 V DC source to 2.5 kV, and discharges it to 0 V. The flyback converter has been analyzed in detail during both charge and discharge modes, by considering all the parasitic elements...... in the converter, including the most dominating parameters of the high voltage transformer viz., self-capacitance and leakage inductance. The specific capacitive load for this converter is a dielectric electro active polymer (DEAP) actuator, which can be used as an effective replacement for conventional actuators...

  11. A Review of High Voltage Drive Amplifiers for Capacitive Actuators

    DEFF Research Database (Denmark)

    Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.

    2012-01-01

    This paper gives an overview of the high voltage amplifiers, which are used to drive capacitive actuators. The amplifiers for both piezoelectric and DEAP (dielectric electroactive polymer) actuator are discussed. The suitable topologies for driving capacitive actuators are illustrated in detail, ......, including linear as well as switched mode amplifiers. In the past much attention has been paid on the driver for piezoelectric actuator. As DEAP is a type of new material, there is not much literature reference for it.......This paper gives an overview of the high voltage amplifiers, which are used to drive capacitive actuators. The amplifiers for both piezoelectric and DEAP (dielectric electroactive polymer) actuator are discussed. The suitable topologies for driving capacitive actuators are illustrated in detail...

  12. Quantum Capacitance of a Topological Insulator-Ferromagnet Interface.

    Science.gov (United States)

    Siu, Zhuo Bin; Chowdhury, Debashree; Jalil, Mansoor B A; Basu, Banasri

    2017-03-24

    We study the quantum capacitance in a topological insulator thin film system magnetized in the in-plane direction in the presence of an out-of-plane magnetic field and hexagonal warping. To first order, the modification in quantum capacitance due to hexagonal warping compared to the clean case, where both the in-plane magnetization and hexagonal warping are absent, is always negative, and increases in magnitude monotonically with the energy difference from the charge neutrality point. In contrast, the change in the quantum capacitance due to in-plane magnetization oscillates with the energy in general, except when a certain relation between the inter-surface coupling, out of plane Zeeman energy splitting and magnetic field strength is satisfied. In this special case, the quantum capacitance remains unchanged by the in-plane magnetization for all energies.

  13. development and testing of a capacitive digital soil moisture metre

    African Journals Online (AJOL)

    user

    moisture affects crop growth, seed development, root development and agricultural ... benefits, capacitive sensor techniques are applied in precision agriculture [3]. ..... lentil moisture content using dielectric properties. Journal of Agricultural ...

  14. Prostaglandin modulation of mouse and human sperm capacitation.

    Science.gov (United States)

    Herrero, M B; Viggiano, J M; Boquet, M; Gimeno, M A

    1997-09-01

    To determine whether prostaglandins produce a capacitation and/or acrosome reaction, the effect of prostaglandins on capacitated mouse spermatozoa and the effect of prostaglandin pre-incubation on human and mouse spermatozoa were studied. Prostaglandins did not induce an acrosome reaction in capacitated mouse sperm. PGE1 pre-incubation in a protein-free medium enhanced acrosome loss of mouse sperm challenged with A-23187 or solubilized mouse zona pellucida. Human sperm were pre-incubated in media containing prostaglandins, and an acrosome reaction was induced with calcium ionophore or human follicular fluid. PGE1 pre-incubation enhanced acrosome loss by human sperm when the action was induced with calcium ionophore, but had no effect on follicular fluid induction. We conclude that PGE1 acts as a capacitating factor in vitro for mouse spermatozoa, and enhances acrosome-reaction induction with calcium ionophore in human spermatozoa.

  15. Structure and Capacitance of Electrical Double Layers inside Micropores

    Science.gov (United States)

    Feng, Guang; Qiao, Rui; Huang, Jingsong; Sumpter, Bobby G.; Meunier, Vincent

    2010-03-01

    Recent experiments indicate that the specific capacitance of micropores (diameter less than 2nm) increases anomalously as the pore size decreases^[1]. To understand the physical origin of this discovery, we performed a series of molecular dynamics simulations to study the electrical double layers (EDLs) in micropores with different shapes (tube vs slit) and pore sizes (0.668nm - 3.342nm). Several different aqueous electrolytes (K^+, Na^+, Cl^-, and F^- in water) were used in these micropores. We quantified the structure of EDLs inside the pores, and computed the capacitance of EDLs. The scaling of capacitance shows a qualitative agreement with the experimental observations. We attribute the anomalous enhancement of capacitance in micropores to the short-range ionelectrode and ionsolvent interactions.[1] J. Chmiola, G. Yushin, Y. Gogotsi, C. Portet, P. Simon, and P.L. Taberna, Science 2006, 313, 1760.

  16. Search and Pursuit with Unmanned Aerial Vehicles in Road Networks

    Science.gov (United States)

    2013-11-01

    added without loss of generality assuming edge costs adhere to the triangle inequality. A similar problem is the Vehicle Routing Problem ( VRP ), a multi...sequence of and path between this set of orbits. To accomplish this, it is treated as an instance of a discrete 106 routing problem (a TSP or VRP ). A...This problem is substantially less well studied, and though more elaborate solutions may be applied, repeated invocations of a capacitated VRP were

  17. Technique Based on Image Pyramid and Bayes Rule for Noise Reduction in Unsupervised Change Detection

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-qiang; HUO hong; FANG Tao; ZHU Ju-lian; GE Wei-li

    2009-01-01

    In this paper, a technique based on image pyramid and Bayes rule for reducing noise effects in unsupervised change detection is proposed. By using Gaussian pyramid to process two multitemporal images respectively, two image pyramids are constructed. The difference pyramid images are obtained by point-by-point subtraction between the same level images of the two image pyramids. By resizing all difference pyramid images to the size of the original multitemporal image and then making product operator among them, a map being similar to the difference image is obtained. The difference image is generated by point-by-point subtraction between the two multitemporal images directly. At last, the Bayes rule is used to distinguish the changed pixels. Both synthetic and real data sets are used to evaluate the performance of the proposed technique. Experimental results show that the map from the proposed technique is more robust to noise than the difference image.

  18. Negative capacitance for various electrode materials in organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Roesch, Roland; Hoppe, Harald [Institute of Physics, TU Ilmenau (Germany); Pivrikas, Almantas; Sariciftci, Niyazi Serdar [LIOS, Johannes Kepler University Linz (Austria)

    2009-07-01

    Electrical behaviour of bulk heterojunction polymer solar cells is strongly influenced by their contacts. Charge carrier injection/extraction at contact-active layer interface depends on type of contact. In the literature different models - Schottky-contact, thermionic injection and injection via hopping processes - for the cathode contact are discussed. We use different contact materials and investigate the resulting capacitance via impedance spectroscopy, a non-invasive technique for electrical analysis. We observe a dependence of Negative Capacitance on contact type.

  19. Modeling high-frequency capacitance in SOI MOS capacitors

    Science.gov (United States)

    Łukasiak, Lidia; Jasiński, Jakub; Beck, Romuald B.; Ikraiam, Fawzi A.

    2016-12-01

    This paper presents a model of high frequency capacitance of a SOI MOSCAP. The capacitance in strong inversion is described with minority carrier redistribution in the inversion layer taken into account. The efficiency of the computational process is significantly improved. Moreover, it is suitable for the simulation of thin-film SOI structures. It may also be applied to the characterization of non-standard SOI MOSCAPS e.g. with nanocrystalline body.

  20. Capacitance Variation of Electrolyte-Gated Bilayer Graphene Based Transistors

    OpenAIRE

    Hediyeh Karimi; Rubiyah Yusof; Mohammad Taghi Ahmadi; Mehdi Saeidmanesh; Meisam Rahmani; Elnaz Akbari; Wong King Kiat

    2013-01-01

    Quantum capacitance of electrolyte-gated bilayer graphene field-effect transistors is investigated in this paper. Bilayer graphene has received huge attention due to the fact that an energy gap could be opened by chemical doping or by applying external perpendicular electric field. So, this extraordinary property can be exploited to use bilayer graphene as a channel in electrolyte-gated field-effect transistors. The quantum capacitance of bi-layer graphene with an equivalent circuit is presen...

  1. Capacitive Coupling in Double-Circuit Transmission Lines

    Directory of Open Access Journals (Sweden)

    Zdenka Benesova

    2004-01-01

    Full Text Available The paper describes an algorithm for calculation of capacitances and charges on conductors in systems with earth wires and in double-circuit overhead lines with respect to phase arrangement. A balanced voltage system is considered. A suitable transposition of individual conductors enables to reduce the electric and magnetic fields in vicinity of overhead lines and to limit the inductive and capacitive linkage. The procedure is illustrated on examples the results of which lead to particular recommendations for designers.

  2. Current Progress of Capacitive Deionization for Removal of Pollutant Ions

    Science.gov (United States)

    Gaikwad, Mahendra S.; Balomajumder, Chandrajit

    2016-08-01

    A mini review of a recently developing water purification technology capacitive deionization (CDI) applied for removal of pollutant ions is provided. The current progress of CDI for removal of different pollutant ions such as arsenic, fluoride, boron, phosphate, lithium, copper, cadmium, ferric, and nitrate ions is presented. This paper aims at motivating new research opportunities in capacitive deionization technology for removal of pollutant ions from polluted water.

  3. Introduction of a pyramid guiding process for general musculoskeletal physical rehabilitation

    OpenAIRE

    Stark Timothy W

    2006-01-01

    Abstract Successful instruction of a complicated subject as Physical Rehabilitation demands organization. To understand principles and processes of such a field demands a hierarchy of steps to achieve the intended outcome. This paper is intended to be an introduction to a proposed pyramid scheme of general physical rehabilitation principles. The purpose of the pyramid scheme is to allow for a greater understanding for the student and patient. As the respected Food Guide Pyramid accomplishes, ...

  4. On the Modeling of a MEMS Based Capacitive Accelerometer for Measurement of Tractor Seat Vibration

    Directory of Open Access Journals (Sweden)

    M. Alidoost

    2010-04-01

    Full Text Available Drivers of heavy vehicles often face with higher amplitudes of frequencies range between 1-80 Hz. Hence, this range of frequency results in temporary or even sometimes permanent damages to the health of drivers. Examples for these problems are damages to the vertebral column and early tiredness, which both reduce the driver’s performance significantly. One solution to this problem is to decrease the imposed vibration to the driver’s seat by developing an active seat system. These systems require an online measuring unit to sense vibrations transferred to the seat. The measuring unit can include a capacitive micro-accelerometer on the basis of MEMS which measure online vibrations on the seat. In this study, the mechanical behavior of a capacitive micro-accelerometer for the vibration range applied to a tractor seat has been simulated. The accelerometer is capable to measure step, impact and harmonic external excitations applied to the system. The results of the study indicate that, with increasing the applied voltage, the system sensitivity also increases, but the measuring range of vibrations decreases and vice versa. The modeled accelerometer, at damping ratio of 0.67 is capable to measure accelerations within the frequency range of lower than 130 Hz.

  5. Simulation Study on Quantum Capacitances of Graphene Nanoribbon VLSI Interconnects

    Science.gov (United States)

    Dutta, Arin; Rahman, Silvia; Nandy, Turja; Mahmood, Zahid Hasan

    2016-03-01

    In this paper, study on the capacitive effects of Graphene nanoribbon (GNR) in VLSI interconnect has been studied as a function of GNR width, Fermi function and gate voltage. The quantum capacitance of GNR has been simulated in terms of Fermi function for three different values of insulator thickness — 1.5nm, 2nm and 2.5nm. After that, quantum capacitance is studied in both degenerate and nondegenerate region with respect to Fermi function and gate voltage of range 1-5V. Then, the total capacitance of GNR is studied as a function of gate voltage of -2-5V range at degenerate and nondegenerate regions, where width of GNR is considered 4nm. Finally, the total capacitance of GNR is studied in both regions with varying GNR width, considering fixed gate voltage of 3V. After analyzing these simulations, it has been found that GNR in degenerate region shows nearly steady capacitance under a certain applied gate voltage.

  6. Optimizing the Materials Response in Humidity Capacitive Sensors

    Directory of Open Access Journals (Sweden)

    Elham Noroozi Afshar

    2015-10-01

    Full Text Available The number of humidity outputs on the cap of a cylindrical capacitance sensor is optimized by designing three different probes with direct and indirect windows. The time interval is measured within which 30-70 % humidity can influence the dielectric constant and conductivity of the capacitance when exposed to a range of relative humidity. It is then compared with a simple set-up including a simplified equivalent circuit. The direct probes had four and double outputs on the window of the cylindrical capacitive sensor while the indirect probe had a thin plastic layer only. We observed that the dielectric constant and its conductivity depend closely to the humidity outgoing pathway and also to the increasing rate of humidity between the capacitance plates. The final variation in the materials properties alters the capacitance of the sensor which is measured simply by a LCR. This technique presents a simple method for tracking the recovery and reliability of the humidity sensors over time and assists in optimizing and controlling the materials response to the relative environment humidity. As a result, by controlling the environment humidity rate (0.02 %/s., we could measure the increment rate of capacitance with accuracy of 0.01 pf/%.

  7. A algorithm for the Vehicle Problem

    Directory of Open Access Journals (Sweden)

    Aziz Ezzatneshan

    2010-09-01

    Full Text Available In this paper, we propose a hybrid ACO algorithm for solving vehicle routing problem (VRP heuristically in combination with an exact In the basic VRP, geographically scattered customers of known demand are supplied from a single depot by a fleet of identically capacitated vehicles. The intuition of the proposed algorithm is that nodes which are near to each other will probably belong to the same branch of the minimum spanning tree of the problem graph and thus will probably belong to the same route in VRP. Given a clustering of client nodes, the solution is to find a route in these clusters by using ACO with a modified version of transition rule of the ants. At the end of each iteration, ACO tries to improve the quality of solutions by using a local search algorithm, and update the associated weights of the graph arcs.

  8. A Algorithm for the Vehicle Problem

    Directory of Open Access Journals (Sweden)

    Aziz Ezzatneshan

    2010-06-01

    Full Text Available In this paper, we propose a hybrid ACO algorithm for solving vehicle routing problem (VRP heuristically in combination with an exact In the basic VRP, geographically scattered customers of known demand are supplied from a single depot by a fleet of identically capacitated vehicles. The intuition of the proposed algorithm is that nodes which are near to each other will probably belong to the same branch of the minimum spanning tree of the problem graph and thus will probably belong to the same route in VRP. Given a clustering of client nodes, the solution is to find a route in these clusters by using ACO with a modified version of transition rule of the ants. At the end of each iteration, ACO tries to improve the quality of solutions by using a local search algorithm, and update the associated weights of the graph arcs.

  9. Partial Path Column Generation for the Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Jepsen, Mads Kehlet; Petersen, Bjørn

    This paper presents a column generation algorithm for the Capacitated Vehicle Routing Problem (CVRP) and the Vehicle Routing Problem with Time Windows (VRPTW). Traditionally, column generation models of the CVRP and VRPTW have consisted of a Set Partitioning master problem with each column repres...... of the giant tour’; a so-called partial path, i.e., not necessarily starting and ending in the depot. This way, the length of the partial path can be bounded and a better control of the size of the solution space for the pricing problem can be obtained....

  10. Rezension zu: Emily Teeter (Hg.), Before the pyramids. The origins of Egyptian civilization

    OpenAIRE

    Köpp-Junk, Heidi

    2013-01-01

    Rezension zu: Emily Teeter (Hg.), Before the Pyramids. The Origins of Egyptian Civilization. The Oriental Institute of the University of Chicago, Oriental Institute Museum Publications 33 (Chicago 2011)

  11. Enumeration of pyramids of one-dimensional pieces of arbitrary fixed integer length

    DEFF Research Database (Denmark)

    Durhuus, Bergfinnur; Eilers, Søren

    We consider pyramids made of one-dimensional pieces of fixed integer length a and which may have pairwise overlaps of integer length from 1 to a. We prove that the number of pyramids of size m, i.e. consisting of m pieces, equals (am-1,m-1) for each a >= 2. This generalises a well known result...... for a = 2. A bijective correspondence between so-called right (or left) pyramids and a-ary trees is pointed out, and it is shown that asymptotically the average width of pyramids is proportional to the square root of the size....

  12. Astronomical Orientation of Pyramid Tombs in North China

    Science.gov (United States)

    Rusell Tiede, Vance

    2010-01-01

    Two ancient Chinese texts, the Chou Bei Suan Ching and Chou Li (Western Han Dynasty, ca. 100 BC), record that the Imperial Astronomer (Feng Hsian Shin) made solar observations to determine the solstices and equinoxes, and for determining the cardinal directions with a circle and gnomon. By combining the techniques of astro-archaeology (G. S. Hawkins, 1968) with both overhead imagery and ground survey, the present study seeks to link historical Chinese descriptions of astronomical phenomena with contemporary architectural orientation. In the process, several unexpected astronomical orientation patterns emerged which apparently do not appear in the surviving historical record. For example, at the imperial Western Han capital of Ch'ang-an (N 34° latitude), the diagonals of cardinally oriented square pyramid mounds (ling) align to zenith (+34° declination) and nadir (-34° declination) star rise and set points on the skyline. This is in accord with the Chou (Zhou) Dynasty's name of Chung-Kuo, meaning Central Country or Middle Kingdom. That is, the imperial capital is centered both politico-geographically with respect to its vassal states of the Eastern Yi, Southern Man, Western Rong, and Northern Di, as well as astro-geomantically regarding the color-coded Five Sacred Directions East-South-West-North-Zenith/Nadir in the Cosmos. Our ground survey also confirmed pyramid orientation to the lunar standstills (+28°, +18° and +5° declination) that we reported from overhead imagery in 1980 (155th AAS Meeting, HAD 18.CE.12, Lunar and Solar Alignments of Ancient Chinese Pyramids). Grateful acknowledgment is given to the Chinese Academy of Sciences for the invitation to conduct an astro-archaeological survey of the Wei-ho valley, Shensi (Shaanxi) Province.

  13. Tracking visual objects using pyramidal rotation invariant features

    Science.gov (United States)

    Paheding, Sidike; Essa, Almabrok; Krieger, Evan; Asari, Vijayan

    2016-02-01

    Challenges in object tracking such as object deformation, occlusion, and background variations require a robust tracker to ensure accurate object location estimation. To address these issues, we present a Pyramidal Rotation Invariant Features (PRIF) that integrates Gaussian Ringlet Intensity Distribution (GRID) and Fourier Magnitude of Histogram of Oriented Gradients (FMHOG) methods for tracking objects from videos in challenging environments. In this model, we initially partition a reference object region into increasingly fine rectangular grid regions to construct a pyramid. Histograms of local features are then extracted for each level of pyramid. This allows the appearance of a local patch to be captured at multiple levels of detail to make the algorithm insensitive to partial occlusion. Then GRID and magnitude of discrete Fourier transform of the oriented gradient are utilized to achieve a robust rotation invariant feature. The GRID feature creates a weighting scheme to emphasize the object center. In the tracking stage, a Kalman filter is employed to estimate the center of the object search regions in successive frames. Within the search regions, we use a sliding window technique to extract the PRIF of candidate objects, and then Earth Mover's Distance (EMD) is used to classify the best matched candidate features with respect to the reference. Our PRIF object tracking algorithm is tested on two challenging Wide Area Motion Imagery (WAMI) datasets, namely Columbus Large Image Format (CLIF) and Large Area Image Recorder (LAIR), to evaluate its robustness. Experimental results show that the proposed PRIF approach yields superior results compared to state-of-the-art feature based object trackers.

  14. Integrated Scheduling of Production and Distribution with Release Dates and Capacitated Deliveries

    Directory of Open Access Journals (Sweden)

    Xueling Zhong

    2016-01-01

    Full Text Available This paper investigates an integrated scheduling of production and distribution model in a supply chain consisting of a single machine, a customer, and a sufficient number of homogeneous capacitated vehicles. In this model, the customer places a set of orders, each of which has a given release date. All orders are first processed nonpreemptively on the machine and then batch delivered to the customer. Two variations of the model with different objective functions are studied: one is to minimize the arrival time of the last order plus total distribution cost and the other is to minimize total arrival time of the orders plus total distribution cost. For the former one, we provide a polynomial-time exact algorithm. For the latter one, due to its NP-hard property, we provide a heuristic with a worst-case ratio bound of 2.

  15. Lower and upper bounds for the two-echelon capacitated location-routing problem

    Science.gov (United States)

    Contardo, Claudio; Hemmelmayr, Vera; Crainic, Teodor Gabriel

    2012-01-01

    In this paper, we introduce two algorithms to address the two-echelon capacitated location-routing problem (2E-CLRP). We introduce a branch-and-cut algorithm based on the solution of a new two-index vehicle-flow formulation, which is strengthened with several families of valid inequalities. We also propose an adaptive large-neighbourhood search (ALNS) meta-heuristic with the objective of finding good-quality solutions quickly. The computational results on a large set of instances from the literature show that the ALNS outperforms existing heuristics. Furthermore, the branch-and-cut method provides tight lower bounds and is able to solve small- and medium-size instances to optimality within reasonable computing times. PMID:24511176

  16. Lower and upper bounds for the two-echelon capacitated location-routing problem.

    Science.gov (United States)

    Contardo, Claudio; Hemmelmayr, Vera; Crainic, Teodor Gabriel

    2012-12-01

    In this paper, we introduce two algorithms to address the two-echelon capacitated location-routing problem (2E-CLRP). We introduce a branch-and-cut algorithm based on the solution of a new two-index vehicle-flow formulation, which is strengthened with several families of valid inequalities. We also propose an adaptive large-neighbourhood search (ALNS) meta-heuristic with the objective of finding good-quality solutions quickly. The computational results on a large set of instances from the literature show that the ALNS outperforms existing heuristics. Furthermore, the branch-and-cut method provides tight lower bounds and is able to solve small- and medium-size instances to optimality within reasonable computing times.

  17. The Maslowian Portfolio Theory Versus the Pyramid Portfolio

    Directory of Open Access Journals (Sweden)

    Majewski Sebastian

    2014-06-01

    Full Text Available This article refers to De Brouwer’s modification of portfolio selection from 2009. He modified the existing portfolio’s theories so that they could take into account the Maslov’s hierarchy of needs. This proposal could be also an alternative concept to the behavioural portfolio theory. Another theoretical concept which includes not only the hierarchy of needs but the pyramid portfolio is presented in this paper as well. The base point in this case is Markowitz’s model and the safety-first criterion by Roy. Such a construction should be a starting point for building an application in this field.

  18. A New Fuzzy System Based on Rectangular Pyramid

    Science.gov (United States)

    Jiang, Mingzuo; Yuan, Xuehai; Li, Hongxing; Wang, Jiaxia

    2015-01-01

    A new fuzzy system is proposed in this paper. The novelty of the proposed system is mainly in the compound of the antecedents, which is based on the proposed rectangular pyramid membership function instead of t-norm. It is proved that the system is capable of approximating any continuous function of two variables to arbitrary degree on a compact domain. Moreover, this paper provides one sufficient condition of approximating function so that the new fuzzy system can approximate any continuous function of two variables with bounded partial derivatives. Finally, simulation examples are given to show how the proposed fuzzy system can be effectively used for function approximation. PMID:25874253

  19. A threshold sodium current in pyramidal cells in rat hippocampus.

    Science.gov (United States)

    French, C R; Gage, P W

    1985-05-23

    Maintained, inward currents were activated by small depolarizations from the resting membrane potential (-50 to -60 mV) in voltage-clamped, pyramidal neurons in rat hippocampal slices. The currents were apparently Na currents as they were blocked by tetrodotoxin or removal of extracellular Na and were not affected by Cd. They showed little decrease in amplitude during prolonged depolarizations. The increase in Na conductance with depolarization was sigmoidal, with half-maximum conductance at about -50 mV, and saturated at -20 to -30 mV. This 'threshold' Na current may be involved in setting patterns of repetitive firing of action potentials.

  20. A cold atom pyramidal gravimeter with a single laser beam

    Science.gov (United States)

    Bodart, Q.; Merlet, S.; Malossi, N.; Dos Santos, F. Pereira; Bouyer, P.; Landragin, A.

    2010-03-01

    We demonstrate a scheme for realizing a compact cold atom gravimeter. The use of a hollow pyramidal configuration allows to achieve all functions: trapping, interferometer and detection with a unique laser beam leading to a drastic reduction in complexity and volume. In particular, we demonstrate a relative sensitivity to acceleration of gravity (g) of 1.7×10-7 at one second, with a moderate laser power of 50 mW. This simple geometry combined to such a high sensitivity opens wide perspectives for practical applications.

  1. A cold atom pyramidal gravimeter with a single laser beam

    CERN Document Server

    Bodart, Quentin; Malossi, Nicola; Santos, Franck Pereira Dos; Bouyer, Philippe; Landragin, Arnaud

    2010-01-01

    We demonstrate a scheme for realizing a compact cold atom gravimeter. The use of a hollow pyramidal configuration allows to achieve all functions: trapping, interferometer and detection with a unique laser beam leading to a drastic reduction in complexity and volume. In particular, we demonstrate a relative sensitivity to acceleration of gravity (g) of 1.7 x 10-7 at one second, with a moderate laser power of 50 mW. This simple geometry combined to such a high sensitivity opens wide perspectives for practical applications (P. Bouyer and A. Landragin, patent number FR2009/000252, 2009).

  2. Papillary thyroid microcarcinoma in a thyroid pyramidal lobe

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Tae Kwan; Kim, Dong Wook; Park, Ha Kyoung; Jung, Soo Jin [Busan Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2014-12-15

    We report an extremely rare case of papillary thyroid microcarcinoma (PTMC) in the thyroid pyramidal lobe (TPL). A 48-year-old woman underwent ultrasound-guided fine-needle aspiration for a small thyroid nodule in the right lobe in local clinic, and it revealed a malignant cytology. On preoperative ultrasonography for tumor staging in our hospital, another small suspiciously malignant hypoechoic nodule was detected in the left TPL. Total thyroidectomy and central nodal dissection were performed. Histopathology confirmed PTMCs in the left TPL and both thyroid lobes. Ultrasonography for TPL should be required for complete evaluation of possible multifocality of thyroid malignancy.

  3. Catalyzing new product adoption at the base of the pyramid

    OpenAIRE

    Marinakis, Y.D.; Walsh, S. T.; Harms, R.

    2016-01-01

    One of the more perplexing of the entrepreneurial issues at the Base of the Pyramid (BoP) is how to catalyze new product adoption by BoP consumers. Because S-shaped adoption dynamics are the result of cultural transmission bias, the question can be rephrased as, how can an entrepreneur overcome conformity bias. We modified the Technology Acceptance Model (TAM) to include conformity bias. We then qualitatively applied the model to three examples from the literature, namely fuel stoves in Darfu...

  4. FPGA implementation of a pyramidal Weightless Neural Networks learning system.

    Science.gov (United States)

    Al-Alawi, Raida

    2003-08-01

    A hardware architecture of a Probabilistic Logic Neuron (PLN) is presented. The suggested model facilitates the on-chip learning of pyramidal Weightless Neural Networks using a modified probabilistic search reward/penalty training algorithm. The penalization strategy of the training algorithm depends on a predefined parameter called the probabilistic search interval. A complete Weightless Neural Network (WNN) learning system is modeled and implemented on Xilinx XC4005E Field Programmable Gate Array (FPGA), allowing its architecture to be configurable. Various experiments have been conducted to examine the feasibility and performance of the WNN learning system. Results show that the system has a fast convergence rate and good generalization ability.

  5. Flexible solar cells based on curved surface nano-pyramids

    Science.gov (United States)

    Shrestha, Anil; Mizuno, Genki; Oduor, Patrick; Dutta, Achyut K.; Dhar, Nibir K.; Lewis, Jay

    2016-05-01

    The advent of ultrathin crystalline silicon (c-Si) solar cells has significantly reduced the cost of silicon solar cells by consuming less material. However, the very small thickness of ultrathin solar cells poses a challenge to the absorption of sufficient light to provide efficiency that is competitive to commercial solar cells. Light trapping mechanisms utilizing nanostructure technologies have been utilized to alleviate this problem. Unfortunately, a significant portion of light is still being lost even before entering the solar cells because of reflection. Different kinds of nanostructures have been employed to reduce reflection from solar cells, but reflection losses still prevail. In an effort to reduce reflection loss, we have used an array of modified nanostructures based cones or pyramids with curved sides, which matches the refractive index of air to that of silicon. Moreover, use of these modified nano-pyramids provides a quintic (fifth power) gradient index layer between air and silicon, which significantly reduces reflection. The solar cells made of such nanostructures not only significantly increase conversion efficiency at reduced usage of crystalline silicon material (e.g. thinner), but it also helps to make the c-Si based solar cell flexible. Design and optimization of flexible c-Si solar cell is presented in the paper.

  6. Renal Pelviceal Keratinizing Squamous Metaplasia with Sparing of Pyramidal Zones

    Directory of Open Access Journals (Sweden)

    Richard H. Siderits

    2012-01-01

    Full Text Available Metaplastic changes in the urothelium of the upper urinary tract are relatively infrequent. Metaplasia may present as either squamous or less often glandular differentiation. The process may be associated with chronic inflammation or associated chronic infections. There may be malignant transformation to either squamous cell carcinoma or adenocarcinoma. The demarcation of the metaplastic process in the minor calyces has not been well documented to date. We report the case of a 74-year-old female patient who presented with a history of chronic renal disease and acute pyohydronephrosis. The patient underwent a nephroureterectomy which revealed keratinizing desquamative squamous metaplasia throughout the renal pelvis and upper urinary tract with abrupt termination of metaplasia at the junction of the renal pelvis and the minor calyx (pyramidal zone. Immunohistochemical evaluation documents metaplastic urothelium stained positive for CK5, before converting sharply to simple cuboidal epithelium in the minor calyx (pyramidal zones which stained positive CK7. At the junction of the metaplastic components and low cuboidal lined minor calyceal surfaces, the underlying stroma showed loss of ureteral muscularis mucosa with transition to renal parenchymal type stroma. We believe that this observation is unique and potentially relevant to the etiology and pathophysiology of pelviceal metaplasia.

  7. The orientations of the Giza pyramids and associated structures

    CERN Document Server

    Nell, Erin

    2013-01-01

    Ever since Flinders Petrie undertook a theodolite survey on the Giza plateau in 1881 and drew attention to the extraordinary degree of precision with which the three colossal pyramids are oriented upon the four cardinal directions, there have been a great many suggestions as to how this was achieved and why it was of importance. Surprisingly, given the many astronomical hypotheses and speculations that have been offered in the intervening 130 years, there have been remarkably few attempts to reaffirm or improve on the basic survey data concerning the primary orientations. This paper presents the results of a week-long Total Station survey undertaken by the authors during December 2006 whose principal aim was to clarify the basic data concerning the orientation of each side of the three large pyramids and to determine, as accurately as possible, the orientations of as many as possible of the associated structures. The principal difference between this and all previous surveys is that it focuses upon measuremen...

  8. Sensory deprivation differentially impacts the dendritic development of pyramidal versus non-pyramidal neurons in layer 6 of mouse barrel cortex.

    Science.gov (United States)

    Chen, Chia-Chien; Tam, Danny; Brumberg, Joshua C

    2012-04-01

    Early postnatal sensory experience can have profound impacts on the structure and function of cortical circuits affecting behavior. Using the mouse whisker-to-barrel system we chronically deprived animals of normal sensory experience by bilaterally trimming their whiskers every other day from birth for the first postnatal month. Brain tissue was then processed for Golgi staining and neurons in layer 6 of barrel cortex were reconstructed in three dimensions. Dendritic and somatic parameters were compared between sensory-deprived and normal sensory experience groups. Results demonstrated that layer 6 non-pyramidal neurons in the chronically deprived group showed an expansion of their dendritic arbors. The pyramidal cells responded to sensory deprivation with increased somatic size and basilar dendritic arborization but overall decreased apical dendritic parameters. In sum, sensory deprivation impacted on the neuronal architecture of pyramidal and non-pyramidal neurons in layer 6, which may provide a substrate for observed physiological and behavioral changes resulting from whisker trimming.

  9. Negative capacitance for ultra-low power computing

    Science.gov (United States)

    Khan, Asif Islam

    Owing to the fundamental physics of the Boltzmann distribution, the ever-increasing power dissipation in nanoscale transistors threatens an end to the almost-four-decade-old cadence of continued performance improvement in complementary metal-oxide-semiconductor (CMOS) technology. It is now agreed that the introduction of new physics into the operation of field-effect transistors---in other words, "reinventing the transistor'"--- is required to avert such a bottleneck. In this dissertation, we present the experimental demonstration of a novel physical phenomenon, called the negative capacitance effect in ferroelectric oxides, which could dramatically reduce power dissipation in nanoscale transistors. It was theoretically proposed in 2008 that by introducing a ferroelectric negative capacitance material into the gate oxide of a metal-oxide-semiconductor field-effect transistor (MOSFET), the subthreshold slope could be reduced below the fundamental Boltzmann limit of 60 mV/dec, which, in turn, could arbitrarily lower the power supply voltage and the power dissipation. The research presented in this dissertation establishes the theoretical concept of ferroelectric negative capacitance as an experimentally verified fact. The main results presented in this dissertation are threefold. To start, we present the first direct measurement of negative capacitance in isolated, single crystalline, epitaxially grown thin film capacitors of ferroelectric Pb(Zr0.2Ti0.8)O3. By constructing a simple resistor-ferroelectric capacitor series circuit, we show that, during ferroelectric switching, the ferroelectric voltage decreases, while the stored charge in it increases, which directly shows a negative slope in the charge-voltage characteristics of a ferroelectric capacitor. Such a situation is completely opposite to what would be observed in a regular resistor-positive capacitor series circuit. This measurement could serve as a canonical test for negative capacitance in any novel

  10. Capacitance and compressibility of heterostructures with strong electronic correlations

    Science.gov (United States)

    Steffen, Kevin; Frésard, Raymond; Kopp, Thilo

    2017-01-01

    Strong electronic correlations related to a repulsive local interaction suppress the electronic compressibility in a single-band model, and the capacitance of a corresponding metallic film is directly related to its electronic compressibility. Both statements may be altered significantly when two extensions to the system are implemented which we investigate here: (i) we introduce an attractive nearest-neighbor interaction V as antagonist to the repulsive onsite repulsion U , and (ii) we consider nanostructured multilayers (heterostructures) assembled from two-dimensional layers of these systems. We determine the respective total compressibility κ and capacitance C of the heterostructures within a strong coupling evaluation, which builds on a Kotliar-Ruckenstein slave-boson technique. Whereas the capacitance C (n ) for electronic densities n close to half-filling is suppressed, illustrated by a correlation induced dip in C (n ) , it may be appreciably enhanced close to a van Hove singularity. Moreover, we show that the capacitance may be a nonmonotonic function of U close to half-filling for both attractive and repulsive V . The compressibility κ can differ from C substantially, as κ is very sensitive to internal electrostatic energies which in turn depend on the specific setup of the heterostructure. In particular, we show that a capacitor with a polar dielectric has a smaller electronic compressibility and is more stable against phase separation than a standard nonpolar capacitor with the same capacitance.

  11. Capacitance-Based Frequency Adjustment of Micro Piezoelectric Vibration Generator

    Directory of Open Access Journals (Sweden)

    Xinhua Mao

    2014-01-01

    Full Text Available Micro piezoelectric vibration generator has a wide application in the field of microelectronics. Its natural frequency is unchanged after being manufactured. However, resonance cannot occur when the natural frequencies of a piezoelectric generator and the source of vibration frequency are not consistent. Output voltage of the piezoelectric generator will sharply decline. It cannot normally supply power for electronic devices. In order to make the natural frequency of the generator approach the frequency of vibration source, the capacitance FM technology is adopted in this paper. Different capacitance FM schemes are designed by different locations of the adjustment layer. The corresponding capacitance FM models have been established. Characteristic and effect of the capacitance FM have been simulated by the FM model. Experimental results show that the natural frequency of the generator could vary from 46.5 Hz to 42.4 Hz when the bypass capacitance value increases from 0 nF to 30 nF. The natural frequency of a piezoelectric vibration generator could be continuously adjusted by this method.

  12. Recent advances in understanding the capacitive storage in microporous carbons

    Energy Technology Data Exchange (ETDEWEB)

    Daffos, B.; Taberna, P.L. [Universite de Toulouse, CIRIMAT, UMR-CNRS 5085, Toulouse (France); Gogotsi, Y. [Department of Materials Science and Engineering, A.J. Drexel Nanotechnology Institute, Drexel University, Philadelphia, PA (United States); Simon, P.

    2010-10-15

    This paper presents a review of our recent work on capacitance of carbide-derived carbons (CDCs). Specific capacitance as high as 14 {mu}F cm{sup -2} or 160 F g{sup -1} was achieved using CDCs with tailored subnanometer pore size, which is significantly higher than 6 {mu}F cm{sup -2} or 100 F g{sup -1} for conventional activated carbons. Such high capacitance was obtained in several types of organic electrolytes with or without solvent. A maximum is obtained for the carbons with the mean pore size close to the bare ion size, ruling out the traditional point of view that mesoporosity is highly required for maximum capacitance. Surprisingly, carbons with subnanometer porosity exhibit high capacitance retention, since only a 10% loss is measured when 6 A g{sup -1} discharge is drawn. These findings show the importance of fitting the ion size with the mean pore size. The double layer theory falls short to explain such charge storage mechanisms at the nanometer scale; thus atomistic modelling is required to find out an alternative charge storage model. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  13. Provisions for the pyramid builders: new evidence from the ancient site of Giza

    Directory of Open Access Journals (Sweden)

    Mary Anne Murray

    2004-08-01

    Full Text Available The great pyramids of Giza are famous emblems of ancient Egyptian civilization, but until recently little was known about where and how the pyramid builders lived. The site of their large settlement has now been found, and excavation is revealing its complex layout and providing evidence of the plants and animals on which the builders depended for their food supply.

  14. The Multiple Insertion Pyramid: A Fast Parameter-Less Population Scheme.

    NARCIS (Netherlands)

    den Besten, Willem; Thierens, D.; Bosman, P.A.N.

    2016-01-01

    The Parameter-less Population Pyramid (P3) uses a novel population scheme, called the population pyramid. This population scheme does not require a fixed population size, instead it keeps adding new solutions to an ever growing set of layered populations. P3 is very efficient in terms of number of

  15. The multiple insertion pyramid: a fast parameter-less population scheme

    NARCIS (Netherlands)

    den Besten, W. (Willem); D. Thierens (Dirk); P.A.N. Bosman (Peter)

    2016-01-01

    textabstractThe Parameter-less Population Pyramid (P3) uses a novel population scheme, called the population pyramid. This population scheme does not require a fixed population size, instead it keeps adding new solutions to an ever growing set of layered populations. P3 is very efficient in terms of

  16. Pyramid of Interventions: Results of a School Counselor's Action Research Study at One Suburban Middle School

    Science.gov (United States)

    Miller, Nicholas J.

    2008-01-01

    This paper examines the implementation of the Pyramid of Interventions (POI) at a suburban Georgia Middle School through an examination of teacher understanding, assessment of overall effectiveness, and the need for further professional development. The Pyramid of Interventions is the response to intervention (RTI) component of the Individuals…

  17. Left common basal pyramid torsion following left upper lobectomy/segmentectomy.

    Science.gov (United States)

    Wang, Wei-Li; Cheng, Yen-Po; Cheng, Ching-Yuan; Wang, Bing-Yen

    2015-05-01

    Lobar or segmental lung torsion is a severe complication of lung resection. To the best of our knowledge, common basal pyramid torsion has never been reported. We describe a case of left basal pyramid torsion after left upper lobectomy and superior segmentectomy, which was successfully treated by thoracoscopic surgery.

  18. Effect of varying durations of pyramid exposure - an indication towards a possibility of overexposure.

    Science.gov (United States)

    Bhat, Surekha; Rao, Guruprasad; Murthy, K Dilip; Bhat, P Gopalakrishna

    2009-10-01

    Miniature replicas modeled after the Great Pyramid of Giza are believed to concentrate geoelectromagnetic energy within their cavities and hence act as antistressors in humans and animals. Although there are not many reports of adverse effects of 'overexposure' in the pyramid, subjects have claimed to feel uneasy after certain duration of staying in the pyramid. The present study was aimed to analyze the effects of prolonged pyramid exposure on plasma cortisol level, markers of oxidative damage and antioxidant defense in erythrocytes of adult female Wistar rats. Rats were divided into three groups, normal controls (NC, n=6) that were maintained under standard laboratory conditions in their home cages, pyramid exposed group-2 (PE-2, n=6) & pyramid exposed group-4 (PE-4, n=6) where the rats were housed under the pyramid for 6 hours/day for 2 weeks and 4 weeks respectively. Plasma cortisol and erythrocyte TBARS levels were significantly lower in both PE-2 and PE-4 rats and erythrocyte GSH levels and GSH-Px activity were significantly higher in them as compared to the NC rats. There was no significant difference in the results for these parameters between the PE-2 and PE-4 rats except for erythrocyte GSH-Px activity which was significantly more in the PE-2 rats than in the PE-4 rats. Although these results don't confirm any adverse effects of prolonged exposure in pyramids, they indicate a possibility of such adverse effects.

  19. Integrating Early Childhood Mental Health Consultation with the Pyramid Model. Issue Brief

    Science.gov (United States)

    Perry, Deborah F.; Kaufmann, Roxane K.

    2009-01-01

    A growing number of states and communities are implementing the Pyramid Model in early care and education settings, and in many of these places there are also early childhood mental health consultation (ECMHC) programs operating. This policy brief provides an overview of ECMHC, how it can support the implementation of the Pyramid Model and the…

  20. The Conflict Pyramid: A Holistic Approach to Structuring Conflict Resolution in Schools

    Science.gov (United States)

    Hakvoort, Ilse

    2010-01-01

    This paper examines how the conflict pyramid, originally defined and used by Richard Cohen, can be used as a model to describe the relations between different conflict resolution education programs and activities included in the programs. The central questions posed in the paper are: How can Richard Cohen's conflict pyramid be used as a model for…

  1. A Comparison of Pyramidal Staff Training and Direct Staff Training in Community-Based Day Programs

    Science.gov (United States)

    Haberlin, Alayna T.; Beauchamp, Ken; Agnew, Judy; O'Brien, Floyd

    2012-01-01

    This study evaluated two methods of training staff who were working with individuals with developmental disabilities: pyramidal training and consultant-led training. In the pyramidal training, supervisors were trained in the principles of applied behavior analysis (ABA) and in delivering feedback. The supervisors then trained their direct-care…

  2. Simulating Capacitances to Silicon Quantum Dots: Breakdown of the Parallel Plate Capacitor Model

    Science.gov (United States)

    Thorbeck, Ted; Fujiwara, Akira; Zimmerman, Neil M.

    2012-09-01

    Many electrical applications of quantum dots rely on capacitively coupled gates; therefore, to make reliable devices we need those gate capacitances to be predictable and reproducible. We demonstrate in silicon nanowire quantum dots that gate capacitances are reproducible to within 10% for nominally identical devices. We demonstrate the experimentally that gate capacitances scale with device dimensions. We also demonstrate that a capacitance simulator can be used to predict measured gate capacitances to within 20%. A simple parallel plate capacitor model can be used to predict how the capacitances change with device dimensions; however, the parallel plate capacitor model fails for the smallest devices because the capacitances are dominated by fringing fields. We show how the capacitances due to fringing fields can be quickly estimated.

  3. Estimation of Transformer Winding Capacitances through Frequency Response Analysis - An Experimental Investigation

    Science.gov (United States)

    Shah, Krupa; Ragavan, K.

    2013-10-01

    This article focuses on developing a non-invasive method for determining capacitances using frequency response data. The proposed methodology involves acquiring driving-point impedance of the winding under consideration over wide frequency range. With certain terminal conditions and using the terminal impedance measured at specific frequencies, input and shunt capacitances are determined. For the purpose of estimating series capacitance of the winding, an algorithm is proposed. To demonstrate the capability of the method, initially model coils that have provisions for connecting external capacitances are considered. Then, it is found that the estimated values of capacitances are nearly same as those of connected capacitances. The method is, then, extended to transformer winding, and a capacitive ladder network is constructed. To assess the accuracy of estimation, capacitive voltage distribution is utilized. That is, the voltage distribution in the winding is compared with that of synthesized circuit. A good agreement between those data reveals that the estimated capacitance values are accurate.

  4. Renal pyramid echogenicity in ureteropelvic junction obstruction: correlation between altered echogenicity and differential renal function

    Energy Technology Data Exchange (ETDEWEB)

    Chavhan, Govind; Daneman, Alan; Lim, Ruth; Traubici, Jeffrey [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Moineddin, Rahim [University of Toronto, Department of Family and Community Medicine, Toronto (Canada); Langlois, Valerie [University of Toronto, Division of Nephrology, Department of Pediatrics, Hospital for Sick Children, Toronto (Canada)

    2008-10-15

    Improvement in resolution and use of high-frequency transducers in US has enabled visualization of previously unreported changes in medullary pyramid echogenicity in children with obstructive hydronephrosis. To determine whether these unreported changes in echogenicity and morphology of the renal pyramids in ureteropelvic junction (UPJ) obstruction correlate with differential renal function (DRF) of the kidney as determined by technetium-99m mercaptoacetyltriglycine ({sup 99m}Tc-MAG3) scan. Renal sonograms in 60 children with UPJ obstruction were retrospectively reviewed. Children were divided into three groups based on the echogenicity of the pyramids: (1) normal echogenicity of the pyramids, (2) increased echogenicity of the pyramids with maintained corticomedullary differentiation (CMD), and (3) loss of CMD. DRF, as determined by {sup 99m}Tc-MAG3 scan, of the obstructed kidney of {>=}45% was considered normal and of {<=}44% was considered abnormal based on a published study correlating histological changes with DRF. Fisher's exact test was performed for assessing the association between DRF and altered echogenicity of the pyramids. In group 1, which consisted of 13 patients with normal pyramids on US, DRF was normal in 11 and abnormal in two. In group 2, which consisted of 33 patients with echogenic pyramids and preserved CMD, DRF was normal in 15 and abnormal in 18. In group 3, which consisted of 14 patients with complete loss of CMD, DRF was normal in 2 and abnormal in 12. There was a strong correlation between abnormal pyramids and DRF (P=0.0009). The risk ratio (RR) of DRF becoming abnormal for those kidneys with abnormal echogenicity of the pyramids with preserved CMD (group 2) compared to normal pyramid echogenicity (group 1) was 1.56 (95% CI 1.088-2.236). The RR of DRF becoming abnormal for those kidneys with loss of CMD (group 3) compared to normal pyramid echogenicity (group 1) was 5.571 (95% CI 1.530-20.294). We observed that in obstructed kidneys

  5. Vehicle Development Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the development of prototype deployment platform vehicles for offboard countermeasure systems.DESCRIPTION: The Vehicle Development Laboratory is...

  6. Vehicle Development Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the development of prototype deployment platform vehicles for offboard countermeasure systems. DESCRIPTION: The Vehicle Development Laboratory is...

  7. The roles of exploration and exploitation in the export market integration of Beninese producers at the base of the pyramid

    NARCIS (Netherlands)

    Adékambi, S.A.

    2015-01-01

    Keywords: Base of the pyramid, Bottom of the pyramid, Supply chains, Export market integration, Market learning, Developing and Emerging countries, Exploitation and Exploration, Institutional arrangements, Transaction cost economics, Livelihood performance, BoP producers Abs

  8. The architectonic encoding of the minor lunar standstills in the horizon of the Giza pyramids.

    Science.gov (United States)

    Hossam, M. K. Aboulfotouh

    The paper is an attempt to show the architectonic method of the ancient Egyptian designers for encoding the horizontal-projections of the moon's declinations during two events of the minor lunar standstills, in the design of the site-plan of the horizon of the Giza pyramids, using the methods of descriptive geometry. It shows that the distance of the eastern side of the second Giza pyramid from the north-south axis of the great pyramid encodes a projection of a lunar declination, when earth's obliquity-angle was ~24.10°. Besides, it shows that the angle of inclination of the causeway of the second Giza pyramid, of ~13.54° south of the cardinal east, encodes the projection of another lunar declination when earth's obliquity-angle reaches ~22.986°. In addition, it shows the encoded coordinate system in the site-plan of the horizon of the Giza pyramids.

  9. Variation around a Pyramid theme: optical recombination and optimal use of photons

    CERN Document Server

    Fauvarque, O; Fusco, T; Sauvage, J F

    2015-01-01

    We propose a new type of Wave Front Sensor (WFS) derived from the Pyramid WFS (PWFS). This new WFS, called the Flattened Pyramid-WFS (FPWFS), has a reduced Pyramid angle in order to optically overlap the four pupil images into an unique intensity. This map is then used to derive the phase information. In this letter this new WFS is compared to three existing WFSs, namely the PWFS, the Modulated PWFS (MPWFS) and the Zernike WFS (ZWFS) following tests about sensitivity, linearity range and low photon flux behavior. The FPWFS turns out to be more linear than a modulated pyramid for the high-spatial order aberrations but it provides an improved sensitivity compared to the non-modulated pyramid. The noise propagation may even be as low as the ZWFS for some given radial orders. Furthermore, the pixel arrangement being more efficient than for the PWFS, the FPWFS seems particularly well suited for high-contrast applications.

  10. Variation around a pyramid theme: optical recombination and optimal use of photons.

    Science.gov (United States)

    Fauvarque, Olivier; Neichel, Benoit; Fusco, Thierry; Sauvage, Jean-Francois

    2015-08-01

    We propose a new type of wave-front sensor (WFS) derived from the pyramid WFS (PWFS). This new WFS, called the flattened pyramid-WFS (FPWFS), has a reduced pyramid angle in order to optically overlap the four pupil images into an unique intensity. This map is then used to derive the phase information. In this Letter, this new WFS is compared to three existing WFSs, namely the PWFS, the modulated PWFS (MPWFS), and the Zernike WFS (ZWFS) following tests about sensitivity, linearity range, and low-photon-flux behavior. The FPWFS turns out to be more linear than a modulated pyramid for the high-spatial order aberrations, but it provides an improved sensitivity compared to the non-modulated pyramid. The noise propagation may even be as low as the ZWFS for some given radial orders. Furthermore, the pixel arrangement being more efficient than for the PWFS, the FPWFS seems particularly well suited for high-contrast applications.

  11. The time-dependent two-echelon capacitated vehicle routing problem with environmental considerations

    NARCIS (Netherlands)

    Soysal, M.; Bloemhof, J.M.; Bektas, T.

    2015-01-01

    Multi-echelon distribution strategies in which freight is delivered to customers via intermediate depots rather than direct shipments is an increasingly popular strategy in urban logistics. This is primarily to alleviate the environmental (e.g., energy usage and congestion) and social (e.g., traffic

  12. Disjunctive cuts in a branch-and-price algorithm for the capacitated vehicle routing problem

    DEFF Research Database (Denmark)

    Røpke, Stefan

    This talk presents computational results that show the usefulness of the general-purpose valid inequalities disjunctive cuts when applied to the CVRP. Results indicate that the disjunctive cuts are able to reduce the gap between lower bound and upper bound more than state-of-the-art problem speci...

  13. A Branch-and-Cut Algorithm for the Capacitated Open Vehicle Routing Problem

    DEFF Research Database (Denmark)

    Letchford, Adam N.; Lysgaard, Jens; Eglese, Richard W.

    -and-cut. We show that, even though the open CVRP initially looks like a minor variation of the standard CVRP, the integer programming formulation and cutting planes need to be modified in subtle ways. Computational results are given for several standard test instances, which enables us for the first time...... to assess the quality of existing heuristic methods, and to compare the relative difficulty of open and closed versions of the same problem....

  14. The time-dependent two-echelon capacitated vehicle routing problem with environmental considerations

    NARCIS (Netherlands)

    Soysal, M.; Bloemhof, J.M.; Bektas, T.

    2015-01-01

    Multi-echelon distribution strategies in which freight is delivered to customers via intermediate depots rather than direct shipments is an increasingly popular strategy in urban logistics. This is primarily to alleviate the environmental (e.g., energy usage and congestion) and social (e.g.,

  15. Last-passage Monte Carlo algorithm for mutual capacitance.

    Science.gov (United States)

    Hwang, Chi-Ok; Given, James A

    2006-08-01

    We develop and test the last-passage diffusion algorithm, a charge-based Monte Carlo algorithm, for the mutual capacitance of a system of conductors. The first-passage algorithm is highly efficient because it is charge based and incorporates importance sampling; it averages over the properties of Brownian paths that initiate outside the conductor and terminate on its surface. However, this algorithm does not seem to generalize to mutual capacitance problems. The last-passage algorithm, in a sense, is the time reversal of the first-passage algorithm; it involves averages over particles that initiate on an absorbing surface, leave that surface, and diffuse away to infinity. To validate this algorithm, we calculate the mutual capacitance matrix of the circular-disk parallel-plate capacitor and compare with the known numerical results. Good agreement is obtained.

  16. Noise and mismatch optimization for capacitive MEMS readout

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Chong; Wu Qisong; Yin Tao; Yang Haigang, E-mail: yanghg@mail.ie.ac.c [Institute of Electronics, Chinese Academy of Sciences, Beijing 100190 (China)

    2009-11-15

    This paper presents a high precision CMOS readout circuit for a capacitive MEMS gyroscope. A continuous time topology is employed as well as the chopper noise cancelling technique. A detailed analysis of the noise and mismatch of the capacitive readout circuit is given. The analysis and measurement results have shown that thermal noise dominates in the proposed circuit, and several approaches should be used for both noise and mismatch optimization. The circuit chip operates under a single 5 V supply, and has a measured capacitance resolution of 0.2 aF/sq rootHz. With such a readout circuit, the gyroscope can accurately measure the angular rate with a sensitivity of 15.3 mV/{sup 0}/s. (semiconductor integrated circuits)

  17. Noise and mismatch optimization for capacitive MEMS readout

    Institute of Scientific and Technical Information of China (English)

    Zhang Chong; Wu Qisong; Yin Tao; Yang Haigang

    2009-01-01

    This paper presents a high precision CMOS readout circuit for a capacitive MEMS gyroscope. A continuous time topology is employed as well as the chopper noise cancelling technique. A detailed analysis of the noise and mismatch of the capacitive readout circuit is given. The analysis and measurement results have shown that thermal noise dominates in the proposed circuit, and several approaches should be used for both noise and mismatch optimization. The circuit chip operates under a single 5 V supply, and has a measured capacitance resolution of 0.2 aF/√Hz. With such a readout circuit, the gyroscope can accurately measure the angular rate with a sensitivity of 15.3 mV/°/s.

  18. Intrinsic Low Hysteresis Touch Mode Capacitive Pressure Sensor

    DEFF Research Database (Denmark)

    Fragiacomo, Giulio; Pedersen, Thomas; Hansen, Ole

    2011-01-01

    Hysteresis has always been one of the main concerns when fabricating touch mode capacitive pressure sensors (TMCPS). This phenomenon can be fought at two different levels: during fabrication or after fabrication with the aid of a dedicated signal conditioning circuit. We will describe a microfabr......Hysteresis has always been one of the main concerns when fabricating touch mode capacitive pressure sensors (TMCPS). This phenomenon can be fought at two different levels: during fabrication or after fabrication with the aid of a dedicated signal conditioning circuit. We will describe...... a microfabrication step that can be introduced in order to reduce drastically the hysteresis of this type of sensors without compromising their sensitivity. Medium-high range (0 to 10 bar absolute pressure) TMCPS with a capacitive signal span of over 100pF and less than 1 % hysteresis in the entire pressure range...

  19. Extracting Impurity Locations using Scanning Capacitance Microscopy Measurements

    Directory of Open Access Journals (Sweden)

    AGHAEI, S.

    2016-08-01

    Full Text Available In this article we investigate the possibility to use scanning capacitance microscopy (SCM for the 2-D and 3-D "atomistic" dopant profiling of semiconductor materials. For this purpose, we first analyze the effects of random dopant fluctuations (RDF on SCM measurements with nanoscale probes and show that the discrete and random locations of dopant impurities significantly affect the differential capacitance measured in SCM experiments if the dimension of the probe is below 50 nm. Then, we present an algorithm to compute the x, y, and z coordinates of the ionized impurities in the semiconductor material using a set of SCM measurements. The algorithm is based on evaluating the doping sensitivity functions of the differential capacitance and uses a gradient-based iterative method to compute the locations of dopants. Finally, we discuss a standard simulation case and show that we are able to successfully retrieve the locations of the ionized impurities using the proposed algorithm.

  20. Preamplifiers for non-contact capacitive biopotential measurements*

    Science.gov (United States)

    Peng, GuoChen; Ignjatovic, Zeljko; Bocko, Mark F.

    2014-01-01

    Non-contact biopotential sensing is an attractive measurement strategy for a number of health monitoring applications, primarily the ECG and the EEG. In all such applications a key technical challenge is the design of a low-noise trans-impedance preamplifier for the typically low-capacitance, high source impedance sensing electrodes. In this paper, we compare voltage and charge amplifier designs in terms of their common mode rejection ratio, noise performance, and frequency response. Both amplifier types employ the same operational-transconductance amplifier (OTA), which was fabricated in a 0.35um CMOS process. The results show that a charge amplifier configuration has advantages for small electrode-to-subject coupling capacitance values (less than 10 pF - typical of noncontact electrodes) and that the voltage amplifier configuration has advantages for electrode capacitances above 10 pF. PMID:24109979

  1. Preamplifiers for non-contact capacitive biopotential measurements.

    Science.gov (United States)

    Peng, GuoChen; Ignjatovic, Zeljko; Bocko, Mark F

    2013-01-01

    Non-contact biopotential sensing is an attractive measurement strategy for a number of health monitoring applications, primarily the ECG and the EEG. In all such applications a key technical challenge is the design of a low-noise trans-impedance preamplifier for the typically low-capacitance, high source impedance sensing electrodes. In this paper, we compare voltage and charge amplifier designs in terms of their common mode rejection ratio, noise performance, and frequency response. Both amplifier types employ the same operational-transconductance amplifier (OTA), which was fabricated in a 0.35 um CMOS process. The results show that a charge amplifier configuration has advantages for small electrode-to-subject coupling capacitance values (less than 10 pF--typical of noncontact electrodes) and that the voltage amplifier configuration has advantages for electrode capacitances above 10 pF.

  2. A Wearable Capacitive Sensor for Monitoring Human Respiratory Rate

    Science.gov (United States)

    Kundu, Subrata Kumar; Kumagai, Shinya; Sasaki, Minoru

    2013-04-01

    Realizing an untethered, low-cost, and comfortably wearable respiratory rate sensor for long-term breathing monitoring application still remains a challenge. In this paper, a conductive-textile-based wearable respiratory rate sensing technique based on the capacitive sensing approach is proposed. The sensing unit consists of two conductive textile electrodes that can be easily fabricated, laminated, and integrated in garments. Respiration cycle is detected by measuring the capacitance of two electrodes placed on the inner anterior and posterior sides of a T-shirt at either the abdomen or chest position. A convenient wearable respiratory sensor setup with a capacitance-to-voltage converter has been devised. Respiratory rate as well as breathing mode can be accurately identified using the designed sensor. The sensor output provides significant information on respiratory flow. The effectiveness of the proposed system for different breathing patterns has been evaluated by experiments.

  3. Quantum Capacitance Modifies Interionic Interactions in Semiconducting Nanopores

    CERN Document Server

    Lee, Alpha A; Goriely, Alain

    2016-01-01

    Nanopores made with low dimensional semiconducting materials, such as carbon nanotubes and graphene slit pores, are used in supercapacitors. In theories and simulations of their operation, it is often assumed that such pores screen ion-ion interactions like metallic pores, i.e. that screening leads to an exponential decay of the interaction potential with ion separation. By introducing a quantum capacitance that accounts for the density of states in the material, we show that ion-ion interactions in carbon nanotubes and graphene slit pores actually decay algebraically with ion separation. This result suggests a new avenue of capacitance optimization based on tuning the electronic structure of a pore: a marked enhancement in capacitance might be achieved by developing nanopores made with metallic materials or bulk semimetallic materials.

  4. CMOS capacitive biosensors for highly sensitive biosensing applications.

    Science.gov (United States)

    Chang, An-Yu; Lu, Michael S-C

    2013-01-01

    Magnetic microbeads are widely used in biotechnology and biomedical research for manipulation and detection of cells and biomolecules. Most lab-on-chip systems capable of performing manipulation and detection require external instruments to perform one of the functions, leading to increased size and cost. This work aims at developing an integrated platform to perform these two functions by implementing electromagnetic microcoils and capacitive biosensors on a CMOS (complementary metal oxide semiconductor) chip. Compared to most magnetic-type sensors, our detection method requires no externally applied magnetic fields and the associated fabrication is less complicated. In our experiment, microbeads coated with streptavidin were driven to the sensors located in the center of microcoils with functionalized anti-streptavidin antibody. Detection of a single microbead was successfully demonstrated using a capacitance-to-frequency readout. The average capacitance changes for the experimental and control groups were -5.3 fF and -0.2 fF, respectively.

  5. Extraction method for parasitic capacitances and inductances of HEMT models

    Science.gov (United States)

    Zhang, HengShuang; Ma, PeiJun; Lu, Yang; Zhao, BoChao; Zheng, JiaXin; Ma, XiaoHua; Hao, Yue

    2017-03-01

    A new method to extract parasitic capacitances and inductances for high electron-mobility transistors (HEMTs) is proposed in this paper. Compared with the conventional extraction method, the depletion layer is modeled as a physically significant capacitance model and the extrinsic values obtained are much closer to the actual results. In order to simulate the high frequency behaviour with higher precision, series parasitic inductances are introduced into the cold pinch-off model which is used to extract capacitances at low frequency and the reactive elements can be determined simultaneously over the measured frequency range. The values obtained by this method can be used to establish a 16-elements small-signal equivalent circuit model under different bias conditions. The results show good agreements between the simulated and measured scattering parameters up to 30 GHz.

  6. On Machine Capacitance Dimensional and Surface Profile Measurement System

    Science.gov (United States)

    Resnick, Ralph

    1993-01-01

    A program was awarded under the Air Force Machine Tool Sensor Improvements Program Research and Development Announcement to develop and demonstrate the use of a Capacitance Sensor System including Capacitive Non-Contact Analog Probe and a Capacitive Array Dimensional Measurement System to check the dimensions of complex shapes and contours on a machine tool or in an automated inspection cell. The manufacturing of complex shapes and contours and the subsequent verification of those manufactured shapes is fundamental and widespread throughout industry. The critical profile of a gear tooth; the overall shape of a graphite EDM electrode; the contour of a turbine blade in a jet engine; and countless other components in varied applications possess complex shapes that require detailed and complex inspection procedures. Current inspection methods for complex shapes and contours are expensive, time-consuming, and labor intensive.

  7. Low Power/Low Voltage Interface Circuitry for Capacitive Sensors

    DEFF Research Database (Denmark)

    Furst, Claus Efdmann

    This thesis focuses mainly on low power/low voltage interface circuits, implemented in CMOS, for capacitive sensors. A brief discussion of demands and possibilities for analog signal processing in the future is presented. Techniques for low power design is presented. This is done by analyzing power...... consumption of different amplifier topologies. Next, low power features of different amplifier types are analyzed on transistor level. A brief comparison of SI circuits for low power applications vs. SC circuits is presented. Methodologies for low voltage design is presented. This is followed by a collection...... power consumption. It is shown that the Sigma-Delta modulator is advantageous when embedded in a feedback loop with a mechanical sensor. Here a micro mechanical capacitive microphone. Feedback and detection circuitry for a capacitive microphone is presented. Practical implementations of low power...

  8. SEMICONDUCTOR DEVICES Multi-bias capacitance voltage characteristic of AlGaN/GaN HEMT

    Science.gov (United States)

    Yan, Pu; Liang, Wang; Tingting, Yuan; Sihua, Ouyang; Lei, Pang; Guoguo, Liu; Weijun, Luo; Xinyu, Liu

    2010-10-01

    The method of multi-bias capacitance voltage measurement is presented. The physical meaning of gate—source and gate—drain capacitances in AlGaN/GaN HEMT and the variations in them with different bias conditions are discussed. A capacitance model is proposed to reflect the behaviors of the gate—source and gate—drain capacitances, which shows a good agreement with the measured capacitances, and the power performance obtains good results compared with the measured data from the capacitance model.

  9. Penicillamine prevents ram sperm agglutination in media that support capacitation.

    Science.gov (United States)

    Leahy, T; Rickard, J P; Aitken, R J; de Graaf, S P

    2016-02-01

    Ram spermatozoa are difficult to capacitate in vitro. Here we describe a further complication, the unreported phenomenon of head-to-head agglutination of ram spermatozoa following dilution in the capacitation medium Tyrodes plus albumin, lactate and pyruvate (TALP). Sperm agglutination is immediate, specific and persistent and is not associated with a loss of motility. Agglutination impedes in vitro sperm handling and analysis. So the objectives of this study were to investigate the cause of sperm agglutination and potential agents which may reduce agglutination. The percentage of non-agglutinated, motile spermatozoa increased when bicarbonate was omitted from complete TALP suggesting that bicarbonate ions stimulate the agglutination process. d-penicillamine (PEN), a nucleophilic thiol, was highly effective at reducing agglutination. The inclusion of 250 μM PEN in TALP reduced the incidence of motile, agglutinated spermatozoa from 76.7 ± 2.7% to 2.8 ± 1.4%. It was then assessed if PEN (1 mM) could be included in existing ram sperm capacitation protocols (TALP +1 mM dibutyryl cAMP, caffeine and theophylline) to produce spermatozoa that were simultaneously capacitated and non-agglutinated. This protocol resulted in a sperm population which displayed high levels of tyrosine phosphorylated proteins and lipid disordered membranes (merocyanine-540) while remaining motile, viable, acrosome-intact and non-agglutinated. In summary, PEN (1 mM) can be included in ram sperm capacitation protocols to reduce sperm agglutination and allow for the in vitro assessment of ram sperm capacitation.

  10. Comprehensive measurements of GaAs pixel detectors capacitance

    CERN Document Server

    Caria, M; D'Auria, S; Lai, A; Randaccio, P; Cadeddu, S

    2002-01-01

    We have studied GaAs pixel detectors on semi-insulating wafers with Schottky contacts. We performed comprehensive measurements on the inter-pixel and capacitance to back plane. Being semi-insulating, the behaviour is totally different with respect to other common semiconductors, such as high resistivity silicon. Non-homogeneities are also an issue, due to both the contacts and the crystal bulk. In order to detect them and their influence on capacitance, we undertook systematic measurements with different configurations of the measuring electrodes.

  11. Capacitive Touch User Interface and Implementation with Virtual Refrigerator

    Directory of Open Access Journals (Sweden)

    MIT Academy of Engineering Global Technology and Engineering centre, Whirlpool of India

    2014-05-01

    Full Text Available The proposed User Interface incorporates 14 Touch keys, including slider and wheeler functionality using self capacitance technology, 24 side throw LED with intensity controlled Fade-IN, Fade-OUT effects, Buzzer chime, Voltage regulator circuit, and communication circuitry for the control board. The major advantage that this User Interface is that the entire assembly is less than 10mm thick including PCB, components, light guide and graphics sticker. In this project the mentioned capacitive touch user Interface is interfaced with a Lab view system simulating a virtual refrigerator capable of responding to the commands from the User Interface.

  12. Quantum capacitance in monolayers of silicene and related buckled materials

    Science.gov (United States)

    Nawaz, S.; Tahir, M.

    2016-02-01

    Silicene and related buckled materials are distinct from both the conventional two dimensional electron gas and the famous graphene due to strong spin orbit coupling and the buckled structure. These materials have potential to overcome limitations encountered for graphene, in particular the zero band gap and weak spin orbit coupling. We present a theoretical realization of quantum capacitance which has advantages over the scattering problems of traditional transport measurements. We derive and discuss quantum capacitance as a function of the Fermi energy and temperature taking into account electron-hole puddles through a Gaussian broadening distribution. Our predicted results are very exciting and pave the way for future spintronic and valleytronic devices.

  13. [Impact of sperm capacitation on various populations of human spermatozoa].

    Science.gov (United States)

    Villanueva Díaz, C; Suárez Juárez, M; Díaz, M A; Ayala Ruiz, A

    1989-02-01

    With the purpose of evaluating the impact of spermatic capacitation on different spermatozooa populations, 49 samples of semen, before and after in vitro spermatic capacitation with Ham F-10 medium, were studied; motility of cells was evaluated according to WHO criteria. There was diminution of percentage of immobile cells, 27.8 to 20.0, as well as increase in population of cells with more mobility, 28.6% to 39.1%. Both difference were statistically significant (p = less than 0.05 and p = less than 0.005, respectively). These data suggest that spermatic capacitacion activates "in cascade" all groups of gametes.

  14. Nickel Oxide/Carbon Nanotubes Nanocomposite for Electrochemical Capacitance

    Institute of Scientific and Technical Information of China (English)

    Kui LIANG; Kayhyeok AN; Younghee LEE

    2005-01-01

    A nanocomposite of nickel oxide/carbon nanotubes was prepared through a simple chemical precipitation followed by thermal annealing. The electrochemical capacitance of this electrode material was studied. When the mass fraction of CNTs (carbon nanotubes) in NiO/CNT composites increases, the electrical resistivity of nanocomposites decreases and becomes similar to that of pure CNTs when it reaches 30%. The specific surface area of composites increases with increasing CNT mass fraction and the specific capacitance reaches 160 F/g under 10 mA/g discharge current density at CNT mass fraction of 10%.

  15. Micromachined capacitive pressure sensor with signal conditioning electronics

    DEFF Research Database (Denmark)

    Fragiacomo, Giulio

    Micromachined capacitive pressure sensors for harsh environment together with interfacing electronic circuits have been studied in this project. Micro-electromechanical systems (MEMS) have been proposed as substitutes for macro scale sensor’s systems in many different fields and are the only...... a great deal of sensors are used. Pressure sensors are among the most successful MEMS and are used in a huge variety of applications. In this project an absolute capacitive pressure sensor has been developed with the aim to integrate it in pump control systems to improve the efficiency of the pump...

  16. Skin Capacitance Mapping of Eccrine Sweat Gland Activity during Pregnancy

    Directory of Open Access Journals (Sweden)

    Claudine Piérard-Franchimont

    2016-02-01

    Full Text Available Skin capacitance mapping is a real-time non-invasive method useful in the assessment of eccrine gland activity. We presently revisit and explore the sweat gland production in pregnant women. Sprouts of sweat vapour are progressively increased during pregnancy by recruiting increasing numbers of active sweat pores. An overall moisturization of the stratum corneum ensues in absence of increased liquid sweat production. These aspects are conveniently assessed using skin capacitance mapping. The sweat duct opening could represent an increased way for percutaneous penetration of some xenobiotics during pregnancy.

  17. Analysis of Capacitive Parasitism in PWM Inverter-Fed Motor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effects of parasitic capacitance in induction motor system are unnoticed when it is fed from the AC line. but they are obvious when supplied directly from a PWM inverter. Consequently. many parasitic problems occur, such as motor-to-earth leakage current, bearing current, incoming line current distortion and uneven distribution of electrical stresses along the winding. On the ba sis of the uniform transmission line principle, a complete equivalent circuit of the PWM inverter-fed motor system is presented, based on which all the capacitive parasitic problems mentioned above are analyzed and simulated by means of PSPICE. All the results are consistent with the existing ones.

  18. Flexible Capacitive Electrodes for Minimizing Motion Artifacts in Ambulatory Electrocardiograms

    Directory of Open Access Journals (Sweden)

    Jeong Su Lee

    2014-08-01

    Full Text Available This study proposes the use of flexible capacitive electrodes for reducing motion artifacts in a wearable electrocardiogram (ECG device. The capacitive electrodes have conductive foam on their surface, a shield, an optimal input bias resistor, and guarding feedback. The electrodes are integrated in a chest belt, and the acquired signals are transmitted wirelessly for ambulatory heart rate monitoring. We experimentally validated the electrode performance with subjects standing and walking on a treadmill at speeds of up to 7 km/h. The results confirmed the highly accurate heart rate detection capacity of the developed system and its feasibility for daily-life ECG monitoring.

  19. The modelling of a capacitive microsensor for biosensing applications

    Science.gov (United States)

    Bezuidenhout, P. H.; Schoeman, J.; Joubert, T. H.

    2014-06-01

    Microsensing is a leading field in technology due to its wide application potential, not only in bio-engineering, but in other fields as well. Microsensors have potentially low-cost manufacturing processes, while a single device type can have various uses, and this consequently helps with the ever-growing need to provide better health conditions in rural parts of the world. Capacitive biosensors detect a change in permittivity (or dielectric constant) of a biological material, usually within a parallel plate capacitor structure which is often implemented with integrated electrodes of an inert metal such as gold or platinum on a microfluidic substrate typically with high dielectric constant. There exist parasitic capacitance components in these capacitive sensors, which have large influence on the capacitive measurement. Therefore, they should be considered for the development of sensitive and accurate sensing devices. An analytical model of a capacitive sensor device is discussed, which accounts for these parasitic factors. The model is validated with a laboratory device of fixed geometry, consisting of two parallel gold electrodes on an alumina (Al2O3) substrate mounted on a glass microscope slide, and with a windowed cover layer of poly-dimethyl-siloxane (PDMS). The thickness of the gold layer is 1μm and the electrode spacing is 300μm. The alumina substrate has a thickness of 200μm, and the high relative permittivity of 11.5 is expected to be a significantly contributing factor to the total device capacitance. The 155μm thick PDMS layer is also expected to contribute substantially to the total device capacitance since the relative permittivity for PDMS is 2.7. The wideband impedance analyser evaluation of the laboratory device gives a measurement result of 2pF, which coincides with the model results; while the handheld RLC meter readout of 4pF at a frequency of 10kHz is acceptable within the measurement accuracy of the instrument. This validated model will

  20. A Walkthrough of Nonlinear Capacitance Measurement of Outer Hair Cells.

    Science.gov (United States)

    Song, Lei; Santos-Sacchi, Joseph

    2016-01-01

    Nonlinear capacitance (NLC) measures are often used as surrogate measures of outer hair cell (OHC) electromotility (eM), since the two are commonly thought to share many biophysical features. The measurement of NLC is simpler than direct measurements of eM and, therefore, many investigators have adopted it. A standard patch-clamp hardware configuration is sufficient for recording NLC, given the proper software interface. Thus, the approach is cost effective. We use the software jClamp since it is tailored to capacitance measurement. Here we detail steps that we use to measure NLC. The walk through includes isolation of guinea pig OHCs, building voltage commands, recording, and analysis.

  1. Touch mode micromachined capacitive pressure sensor with signal conditioning electronics

    DEFF Research Database (Denmark)

    Fragiacomo, Giulio; Eriksen, Gert F.; Christensen, Carsten

    2010-01-01

    is one of the key challenges nowadays. In this context, house heating is a priority for environmental issues. For this reason, the possibilities of using a low power consumption technique, such as capacitive pressure sensing, in harsh environments is a concrete market opportunity. Our aim is therefore....... A measurement setup was arranged and tested for accuracy and reliability with respect to hysteresis. Finally, designs with different radii of the top plate were characterized by a capacitance versus pressure curve at different frequencies and temperatures (Fig. 3). Industrial possibilities Energy saving systems...

  2. Current Kink and Capacitance Frequency Dispersion in Silicon PIN Photodiodes

    Science.gov (United States)

    Guo, Xia; Feng, Yajie; Liu, Qiaoli; Wang, Huaqiang; Li, Chong; Hu, Zonghai; He, Xiaoying

    2017-09-01

    Silicon PIN photodiodes in the visible wavelength range have been widely applied in aerospace, defense, security, medical, and scientific instruments because of their high sensitivity and low cost. In this paper, the phenomena of the current kink and the capacitance frequency dispersion are observed. Contamination at the p-type Ohmic contact interface is proposed to explain the current kink effect and capacitance frequency dispersion, according to the temperature-dependent I-V measurement results in which trap-assisted tunneling process demonstrated.

  3. Segmented telescopes co-phasing using Pyramid Sensor

    Science.gov (United States)

    Esposito, Simone; Devaney, Nicholas

    The high resolution performance of present segmented mirror telescopes like 10m Keck and GTC or the future generation of ELT's like 100m OWL, 50m MAXAT, and 30 CELT will depend critically an the accurate co-phasing of the mirror segments. This paper describes the use of a Pyramid wavefron sensor to detect and correct the segments misalignement. The sensing operation is performed using light from a natural reference star. Our simulations take into account various effects like the atmospheric wavefront disturbances that take place during the sensing process, the bandwith of the detected light and wavefront perturbation static aberration of the telescope optics due to decentering, tilting and so on. The achieved results in terms of the segmented mirror residual phase rms are shown and discussed.

  4. Video coding scheme using DCT-pyramid vector quantization.

    Science.gov (United States)

    Dalessandro, P; Lancini, R

    1995-01-01

    A new and effective video coding scheme for contribution quality is proposed. The CMTT/2, a joint committee of CCIR and CCITT, has proposed a video coding scheme (already approved at European level by ETS) working at 34-45 Mbit/s. Basically this proposal includes a DCT transform for spatial correlation removal and motion compensation for temporal correlation removal. The individual transform coefficients are then scalar quantized with a non uniform bit assignment. Starting from the CMTT/2 proposal, the study presents a new video coding scheme designed using a vector quantizer solution instead of the scalar one. Specifically, the pyramid vector quantization (PVQ) has been chosen as the vector quantization method as it is able to reduce the DCT coefficients Laplacian distribution. Simulation results show that the proposed video coding scheme gives the same contribution quality at 22 Mbit/s as the one obtained with the CMTT/2 proposal at 45 Mbit/s.

  5. Mediterranean Diet Pyramid: A Proposal for Italian People

    Directory of Open Access Journals (Sweden)

    Annunziata D'Alessandro

    2014-10-01

    Full Text Available Bread was a staple in the traditional Mediterranean diet of the early 1960s, as well as nowadays; however, it was a stone ground sourdough bread in Nicotera and probably in the Greek cohorts of the Seven Countries Study. In the present review, the nutritional characteristics of this food are analyzed in relation to its protective effects on coronary heart disease, metabolic diseases and cancer. According to our traditions, cultural heritage and scientific evidence, we propose that only cereal foods with low glycemic index (GI and rich in fiber have to be placed at the base of the Mediterranean diet pyramid, whereas refined grains and high GI starchy foods have to be sited at the top.

  6. Mediterranean Diet Pyramid: A Proposal for Italian People

    Science.gov (United States)

    D’Alessandro, Annunziata; De Pergola, Giovanni

    2014-01-01

    Bread was a staple in the traditional Mediterranean diet of the early 1960s, as well as nowadays; however, it was a stone ground sourdough bread in Nicotera and probably in the Greek cohorts of the Seven Countries Study. In the present review, the nutritional characteristics of this food are analyzed in relation to its protective effects on coronary heart disease, metabolic diseases and cancer. According to our traditions, cultural heritage and scientific evidence, we propose that only cereal foods with low glycemic index (GI) and rich in fiber have to be placed at the base of the Mediterranean diet pyramid, whereas refined grains and high GI starchy foods have to be sited at the top. PMID:25325250

  7. Mediterranean diet pyramid: a proposal for Italian people.

    Science.gov (United States)

    D'Alessandro, Annunziata; De Pergola, Giovanni

    2014-10-16

    Bread was a staple in the traditional Mediterranean diet of the early 1960s, as well as nowadays; however, it was a stone ground sourdough bread in Nicotera and probably in the Greek cohorts of the Seven Countries Study. In the present review, the nutritional characteristics of this food are analyzed in relation to its protective effects on coronary heart disease, metabolic diseases and cancer. According to our traditions, cultural heritage and scientific evidence, we propose that only cereal foods with low glycemic index (GI) and rich in fiber have to be placed at the base of the Mediterranean diet pyramid, whereas refined grains and high GI starchy foods have to be sited at the top.

  8. Tilt correction method of text image based on wavelet pyramid

    Science.gov (United States)

    Yu, Mingyang; Zhu, Qiguo

    2017-04-01

    Text images captured by camera may be tilted and distorted, which is unfavorable for document character recognition. Therefore,a method of text image tilt correction based on wavelet pyramid is proposed in this paper. The first step is to convert the text image captured by cameras to binary images. After binarization, the images are layered by wavelet transform to achieve noise reduction, enhancement and compression of image. Afterwards,the image would bedetected for edge by Canny operator, and extracted for straight lines by Radon transform. In the final step, this method calculates the intersection of straight lines and gets the corrected text images according to the intersection points and perspective transformation. The experimental result shows this method can correct text images accurately.

  9. Intrinsic oscillations of neocortex generated by layer 5 pyramidal neurons.

    Science.gov (United States)

    Silva, L R; Amitai, Y; Connors, B W

    1991-01-25

    Rhythmic activity in the neocortex varies with different behavioral and pathological states and in some cases may encode sensory information. However, the neural mechanisms of these oscillations are largely unknown. Many pyramidal neurons in layer 5 of the neocortex showed prolonged, 5- to 12-hertz rhythmic firing patterns at threshold. Rhythmic firing was due to intrinsic membrane properties, sodium conductances were essential for rhythmicity, and calcium-dependent conductances strongly modified rhythmicity. Isolated slices of neocortex generated epochs of 4- to 10-hertz synchronized activity when N-methyl-D-aspartate receptor-mediated channels were facilitated. Layer 5 was both necessary and sufficient to produce these synchronized oscillations. Thus, synaptic networks of intrinsically rhythmic neurons in layer 5 may generate or promote certain synchronized oscillations of the neocortex.

  10. Intrinsic Oscillations of Neocortex Generated by Layer 5 Pyramidal Neurons

    Science.gov (United States)

    Silva, Laurie R.; Amitai, Yael; Connors, Barry W.

    1991-01-01

    Rhythmic activity in the neocortex varies with different behavioral and pathological states and in some cases may encode sensory information. However, the neural mechanisms of these oscillations are largely unknown. Many pyramidal neurons in layer 5 of the neocortex showed prolonged, 5- to 12-hertz rhythmic firing patterns at threshold. Rhythmic firing was due to intrinsic membrane properties, sodium conductances were essential for rhythmicity, and calcium-dependent conductances strongly modified rhythmicity. Isolated slices of neocortex generated epochs of 4- to 10-hertz synchronized activity when N-methyl-D-aspartate receptor-mediated channels were facilitated. Layer 5 was both necessary and sufficient to produce these synchronized oscillations. Thus, synaptic networks of intrinsically rhythmic neurons in layer 5 may generate or promote certain synchronized oscillations of the neocortex.

  11. 78 FR 21703 - Extension of Public Review and Comment Period for the Pyramid Way and McCarran Boulevard...

    Science.gov (United States)

    2013-04-11

    ... Federal Highway Administration Extension of Public Review and Comment Period for the Pyramid Way and Mc... Department of Transportation (NDOT), is extending the review and comment period of the DEIS for the Pyramid... available for review at the Spanish Springs Library, 7100A Pyramid Lake Highway, Sparks, NV; the...

  12. Spatial Pyramid Pooling in Deep Convolutional Networks for Visual Recognition.

    Science.gov (United States)

    He, Kaiming; Zhang, Xiangyu; Ren, Shaoqing; Sun, Jian

    2015-09-01

    Existing deep convolutional neural networks (CNNs) require a fixed-size (e.g., 224 × 224) input image. This requirement is "artificial" and may reduce the recognition accuracy for the images or sub-images of an arbitrary size/scale. In this work, we equip the networks with another pooling strategy, "spatial pyramid pooling", to eliminate the above requirement. The new network structure, called SPP-net, can generate a fixed-length representation regardless of image size/scale. Pyramid pooling is also robust to object deformations. With these advantages, SPP-net should in general improve all CNN-based image classification methods. On the ImageNet 2012 dataset, we demonstrate that SPP-net boosts the accuracy of a variety of CNN architectures despite their different designs. On the Pascal VOC 2007 and Caltech101 datasets, SPP-net achieves state-of-the-art classification results using a single full-image representation and no fine-tuning. The power of SPP-net is also significant in object detection. Using SPP-net, we compute the feature maps from the entire image only once, and then pool features in arbitrary regions (sub-images) to generate fixed-length representations for training the detectors. This method avoids repeatedly computing the convolutional features. In processing test images, our method is 24-102 × faster than the R-CNN method, while achieving better or comparable accuracy on Pascal VOC 2007. In ImageNet Large Scale Visual Recognition Challenge (ILSVRC) 2014, our methods rank #2 in object detection and #3 in image classification among all 38 teams. This manuscript also introduces the improvement made for this competition.

  13. Development of the stapedius muscle and pyramidal eminence in humans.

    Science.gov (United States)

    Rodríguez-Vázquez, J F

    2009-09-01

    The aim of the study was to systematize the key developmental phases of the stapedius muscle and the pyramidal eminence to clarify their formation, as well as to understand the variations and anomalies that can affect these structures. Sixty human embryos and fetuses between 38 days and 17 weeks of development were studied. The stapedius muscle is formed by two anlagen, one for the tendon, which derives from the internal segment of the interhyale, and another for the belly, located in the second pharyngeal arch medial to the facial nerve and near the interhyale but forming a completely independent anlage. In the interhyale, two segments were differentiated, these forming an angle; at the vertex, the belly of the stapedius muscle is attached. The internal segment is located from the attachment of the belly of the stapedius muscle to the anlage of the stapes, forming the anlage of the tendon of the stapedius muscle. The external segment completely disappears at the beginning of the fetal period. The pyramidal eminence is formed by an anlage independent of Reichert's cartilage, from the mesenchymal tissue of the tympanic cavity, which condenses around the belly of the stapedius muscle from 12 weeks of post-conception development. The length of the tendon of the stapedius muscle in adults varies, depending on the attachment site of the belly of the stapedius muscle in the interhyale, which would determine the length of the internal segment (anlage of the tendon) and consequently the tendon length. This variation depends on the greater or lesser persistence of the angulation observed during development, between the tendon and the belly of the stapedius muscle.

  14. A ROBUST GA/KNN BASED HYPOTHESIS VERIFICATION SYSTEM FOR VEHICLE DETECTION

    Directory of Open Access Journals (Sweden)

    Nima Khairdoost

    2015-03-01

    Full Text Available Vehicle detection is an important issue in driver assistance systems and self-guided vehicles that includes two stages of hypothesis generation and verification. In the first stage, potential vehicles are hypothesized and in the second stage, all hypothesis are verified. The focus of this work is on the second stage. We extract Pyramid Histograms of Oriented Gradients (PHOG features from a traffic image as candidates of feature vectors to detect vehicles. Principle Component Analysis (PCA and Linear Discriminant Analysis (LDA are applied to these PHOG feature vectors as dimension reduction and feature selection tools parallelly. After feature fusion, we use Genetic Algorithm (GA and cosine similarity-based K Nearest Neighbor (KNN classification to improve the performance and generalization of the features. Our tests show good classification accuracy of more than 97% correct classification on realistic on-road vehicle images.

  15. Minimum Makespan Multi-Vehicle Dial-a-Ride

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath; Ravi, R.

    2015-01-01

    Dial-a-Ride problem, there are q vehicles, each having capacity k and where each vehicle j epsilon [q] has its own depot-vertex r(j) epsilon V. A feasible schedule consists of a capacitated route for each vehicle (where vehicle j originates and ends at its depot r(j)) that together move all objects...... from their sources to destinations. The objective is to find a feasible schedule that minimizes the maximum completion time (i.e., makespan) of vehicles, where the completion time of vehicle j is the time when it returns to its depot r(j) at the end of its route. We study the preemptive version......Dial-a-Ride problems consist of a set V of n vertices in a metric space (denoting travel time between vertices) and a set of m objects represented as source-destination pairs {(s(i), t(i))}(i-1)(m), where each object requires to be moved from its source to destination vertex. In the multi-vehicle...

  16. Pyramidal tract abnormalities in the human fetus and infant with trisomy 18 syndrome.

    Science.gov (United States)

    Miyata, Hajime; Miyata, Mio; Ohama, Eisaku

    2014-06-01

    Trisomy 18 or Edwards syndrome is known to exhibit various developmental abnormalities in the central nervous system. We report dominant uncrossed pyramidal tract in trisomy 18 syndrome, based on the postmortem neuropathologic study of eight consecutive autopsied fetuses and infants with trisomy 18 ranging in age from 16 to 39 weeks of gestation, including six males and two females, along with autopsy cases of a stillborn triploid infant with 69XXX and two stillborn infants without chromosomal or neurodevelopmental abnormalities. Five out of eight cases with trisomy 18 showed a larger proportion of uncrossed than crossed pyramidal tract. All of these cases were male, and the anterior corticospinal tract on one side was constantly larger than the contralateral lateral corticospinal tract in the spinal cord on both sides, while the pyramidal tract was hypoplastic in female cases with trisomy 18 and a case with 69XXX. Abnormal pyramidal decussation has been found in cases with posterior fossa malformations such as occipital encephaloceles, Dandy-Walker malformation, Joubert syndrome and Möbius syndrome, but has not been described in cases with trisomy 18. Our data, together with the previous reports describing uncrossed aberrant ipsilateral pyramidal tract in patients with congenital mirror movements caused by DCC gene mutation in chromosome 18, and hypolasia and hyperplasia of the pyramidal tract in X-linked recessive disorders caused by L1CAM and Kal1 gene mutations, respectively, suggest a role of trisomy 18 in association with X-chromosome in the abnormal development of the pyramidal tract.

  17. Dendritic development of hippocampal CA1 pyramidal cells in a neonatal hypoxia-ischemia injury model.

    Science.gov (United States)

    Zhao, Yan Dong; Ou, Shan; Cheng, Sai Yu; Xiao, Zhi; He, Wen Juan; Zhang, Jin Hai; Ruan, Huai Zhen

    2013-09-01

    It is believed that neonatal hypoxia-ischemia (HI) brain injury causes neuron loss and brain functional defects. However, the effect of HI brain injury on dendritic development of the remaining pyramidal cells of the hippocampus and the reaction of contralateral hippocampal neurons require further studies. The Morris water maze and Golgi-Cox staining were used to evaluate the learning and memory and dendritic morphology of pyramidal cells. The results of Golgi-Cox staining showed CA1 pyramidal neurons of HI injury models with fewer bifurcations and shorter dendrite length than the naive control group. The density of dendritic spines of hippocampal CA1 pyramidal neurons was significantly lower in the HI brain injury group than in controls. With respect to hippocampal function, the HI brain injury group presented cognitive deficits in the reference memory task and probe trail. In the HI group, the pyramidal cells of left hippocampus that did not experienced ischemia but did experience hypoxia had more complex dendrites and higher density of spine than the HI injury side and control. The functional implementation of injured hippocampus might depend mainly on the hypertrophy of contralateral hippocampus after HI brain injury. Corticosterone can partially prevent the hippocampal pyramidal cells from HI injury and reduce the difference of the bilateral hippocampus pyramidal cells, but there was no improvement in learning and memory.

  18. Finite-element simulations of coupling capacitances in capacitively coupled pixel detectors

    CERN Document Server

    AUTHOR|(SzGeCERN)755510

    2017-01-01

    Capacitively coupled hybrid silicon pixel-detector assemblies are under study for the vertex detector at the proposed future CLIC linear electron-positron collider. The assemblies consist of active CCPDv3 sensors, with 25 μm pixel pitch implemented in a 180 nm High- Voltage CMOS process, which are glued to the CLICpix readout ASIC, with the same pixel pitch and processed in a commercial 65 nm CMOS technology. The signal created in the silicon bulk of the active sensors passes a two-stage amplifier, in each pixel, and gets transferred as a voltage pulse to metal pads facing the readout chip (ROC). The coupling of the signal to the metal pads on the ROC side proceeds through the capacitors formed between the two chips by a thin layer of epoxy glue. The coupling strength and the amount of unwanted cross coupling to neighbouring pixels depends critically on the uniformity of the glue layer, its thickness and on the alignment precision during the flip-chip assembly process. Finite-element calculations of the coup...

  19. Performance analysis of a digital capacitance measuring circuit.

    Science.gov (United States)

    Xu, Lijun; Sun, Shijie; Cao, Zhang; Yang, Wuqiang

    2015-05-01

    This paper presents the design and study of a digital capacitance measuring circuit with theoretical analysis, numerical simulation, and experimental evaluation. The static and dynamic performances of the capacitance measuring circuit are first defined, including signal-to-noise ratio (SNR), standard deviation, accuracy, linearity, sensitivity, and response time, within a given measurement range. Then numerical simulation is carried out to analyze the SNR and standard deviation of the circuit, followed by experiments to validate the overall performance of the circuit. The simulation results show that when the standard deviation of noise is 0.08 mV and the measured capacitance decreases from 6 pF to 3 fF, the SNR decreases from 90 dB to 22 dB and the standard deviation is between 0.17 fF and 0.24 fF. The experimental results show that when the measured capacitance decreases from 6 pF to 40 fF and the data sampled in a single period are used for demodulation, the SNR decreases from 88 dB to 40 dB and the standard deviation is between 0.18 fF and 0.25 fF. The maximum absolute error and relative error are 5.12 fF and 1.26%, respectively. The SNR and standard deviation can be further improved if the data sampled in more than one period are used for demodulation by the circuit.

  20. Capacitive technology for energy extraction from chemical potential differences

    NARCIS (Netherlands)

    Bastos Sales, B.

    2013-01-01

    This thesis introduces the principle of Capacitive energy extraction based on Donnan Potential (CDP) to exploit salinity gradients. It also shows the fundamental characterization and improvements of CDP. An alternative application of this technology aimed at thermal gradients was tested.  

  1. Production of pulsed electric fields using capacitively coupled electrodes

    Science.gov (United States)

    Kendall, B. R. F.; Schwab, F. A. S.

    1980-01-01

    It is shown that pulsed electric fields can be produced over extended volumes by taking advantage of the internal capacitances in a stacked array of electrodes. The design, construction, and performance of practical arrays are discussed. The prototype arrays involved fields of 100-1000 V/cm extending over several centimeters. Scaling to larger physical dimensions is straightforward.

  2. High bandwidth on-chip capacitive tuning of microtoroid resonators

    CERN Document Server

    Baker, Christopher G; McAuslan, David L; Sheridan, Eoin; Bowen, Warwick P

    2016-01-01

    We report on the design, fabrication and characterization of silica microtoroid based cavity opto-electromechanical systems (COEMS). Electrodes patterned onto the microtoroid resonators allow for rapid capacitive tuning of the optical whispering gallery mode resonances while maintaining their ultrahigh quality factor, enabling applications such as efficient radio to optical frequency conversion, optical routing and switching applications.

  3. Simple and economical capacitive displacement system for UHV operation.

    Science.gov (United States)

    Chow, R; Tiller, W A

    1979-12-01

    A parallel plate capacitor was assembled as a displacement transducer for operation in an UHV environment. The capacitive displacement system was linear over a 2.5 mum range with a resolution of 0.051 mum. Components in the electric circuit were common laboratory instruments.

  4. An integrated energy-efficient capacitive sensor digital interface circuit

    KAUST Repository

    Omran, Hesham

    2014-06-19

    In this paper, we propose an energy-efficient 13-bit capacitive sensor interface circuit. The proposed design fully relies on successive approximation algorithm, which eliminates the need for oversampling and digital decimation filtering, and thus low-power consumption is achieved. The proposed architecture employs a charge amplifier stage to acheive parasitic insensitive operation and fine absolute resolution. Moreover, the output code is not affected by offset voltages or charge injection. The successive approximation algorithm is implemented in the capacitance-domain using a coarse-fine programmable capacitor array, which allows digitizing wide capacitance range in compact area. Analysis for the maximum achievable resolution due to mismatch is provided. The proposed design is insensitive to any reference voltage or current which translates to low temperature sensitivity. The operation of a prototype fabricated in a standard CMOS technology is experimentally verified using both on-chip and off-chip capacitive sensors. Compared to similar prior work, the fabricated prototype achieves and excellent energy efficiency of 34 pJ/step.

  5. Water Desalination Using Capacitive Deionization with Microporous Carbon Electrodes

    NARCIS (Netherlands)

    Porada, S.; Weinstein, L.; Dash, R.; Wal, van der A.F.; Bryjak, M.; Gogotsi, Y.; Biesheuvel, P.M.

    2012-01-01

    Capacitive deionization (CDI) is a water desalination technology in which salt ions are removed from brackish water by flowing through a spacer channel with porous electrodes on each side. Upon applying a voltage difference between the two electrodes, cations move to and are accumulated in electrost

  6. Optimization of salt adsorption rate in membrane capacitive deionization

    NARCIS (Netherlands)

    Zhao, R.; Satpradit, O.A.; Rijnaarts, H.; Biesheuvel, P.M.; Wal, van der A.

    2013-01-01

    Membrane capacitive deionization (MCDI) is a water desalination technique based on applying a cell voltage between two oppositely placed porous electrodes sandwiching a spacer channel that transports the water to be desalinated. In MCDI, ion-exchange membranes are positioned in front of each porous

  7. Topology Optimization of Stressed Capacitive RF MEMS Switches

    DEFF Research Database (Denmark)

    Philippine, Mandy A.; Sigmund, Ole; Rebeiz, Gabriel M.

    2013-01-01

    Geometry design can improve a capacitive radio-frequency microelectromechanical system switch's reliability by reducing the impacts of intrinsic biaxial stresses and stress gradients on the switch's membrane. Intrinsic biaxial stresses cause stress stiffening, whereas stress gradients cause out-o...

  8. Characterization of dielectric charging in RF MEMS capacitive switches

    NARCIS (Netherlands)

    Herfst, R.W.; Huizing, H.G.A.; Steeneken, P.G.; Schmitz, Jurriaan

    2006-01-01

    RF MEMS capacitive switches show great promise for use in wireless communication devices such as mobile phones, but the successful application of these switches is hindered by reliability concerns: charge injection in the dielectric layer (SiN) can cause irreversible stiction of the moving part of

  9. Microfluidic desalination. Capacitive deionization on chip for microfluidic sample preparation

    NARCIS (Netherlands)

    Roelofs, Susan Helena

    2015-01-01

    The main aim of the work described in this thesis is to implement the desalination technique capacitive deionization (CDI) on a microfluidic chip to improve the reproducibility in the analysis of biological samples for drug development. Secondly, microfluidic CDI allows for the in situ study of ion

  10. A Low-Cost Universal Integrated Interface for Capacitive Sensors

    NARCIS (Netherlands)

    Heidary, A.

    2010-01-01

    This thesis reports the results of research on features, options and limitations of low-cost, high-performance, universal integrated interface for capacitive sensors. It concerns development-driven research, where the objectives of the research focus upon possible realization and application of the

  11. Resistance identification and rational process design in Capacitive Deionization

    NARCIS (Netherlands)

    Dijkstra, J.E.; Zhao, R.; Biesheuvel, P.M.; Wal, van der A.

    2016-01-01

    Capacitive Deionization (CDI) is an electrochemical method for water desalination employing porous carbon electrodes. To enhance the performance of CDI, identification of electronic and ionic resistances in the CDI cell is important. In this work, we outline a method to identify these resistances. W

  12. Capacitive pressure sensor in post-processing on LTCC substrates

    NARCIS (Netherlands)

    Meijerink, M.G.H.; Nieuwkoop, E.; Veninga, E.P.; Meuwissen, M.H.H.; Tijdink, M.W.W.J.

    2005-01-01

    A capacitive pressure sensor was realized by means of a post-processing step on a low temperature co-fired ceramics (LTCC) substrate. The new sensor fabrication technology allows for integration of the sensor with interface circuitry and possibly also wireless transmission circuits on LTCC substrate

  13. Carbon nanotube yarns as strong flexible conductive capacitive electrodes

    NARCIS (Netherlands)

    Liu, F.; Wagterveld, R.M.; Gebben, B.; Otto, M.J.; Biesheuvel, P.M.; Hamelers, H.V.M.

    2015-01-01

    Carbon nanotube (CNT) yarn, consisting of 23 µm diameter CNT filaments, can be used as capacitive electrodes that are long, flexible, conductive and strong, for applications in energy and electrochemical water treatment. We measure the charge storage capacity as function of salt concentration, and u

  14. A Micro Dynamically Tuned Gyroscope with Adjustable Static Capacitance

    Directory of Open Access Journals (Sweden)

    Lun Kong

    2013-02-01

    Full Text Available This paper presents a novel micro dynamically tuned gyroscope (MDTG with adjustable static capacitance. First, the principle of MDTG is theoretically analyzed. Next, some simulations under the optimized structure parameters are given as a reference for the mask design of the rotor wafer and electrode plates. As two key components, the process flows of the rotor wafer and electrode plates are described in detail. All the scanning electron microscopy (SEM photos show that the fabrication process is effective and optimized. Then, an assembly model is designed for the static capacitance adjustable MDTG, whose static capacitance can be changed by rotating the lower electrode plate support and substituting gasket rings of different thicknesses. Thus, the scale factor is easily changeable. Afterwards, the digitalized closed-loop measurement circuit is simulated. The discrete correction and decoupling modules are designed to make the closed-loop stable and cross-coupling effect small. The dual axis closed-loop system bandwidths can reach more than 60 Hz and the dual axis scale factors are completely symmetrical. All the simulation results demonstrate the proposed fabrication of the MDTG can meet the application requirements. Finally, the paper presents the test results of static and dynamic capacitance values which are consistent with the simulation values.

  15. A micro dynamically tuned gyroscope with adjustable static capacitance.

    Science.gov (United States)

    Xia, Dunzhu; Yu, Cheng; Kong, Lun

    2013-02-06

    This paper presents a novel micro dynamically tuned gyroscope (MDTG) with adjustable static capacitance. First, the principle of MDTG is theoretically analyzed. Next, some simulations under the optimized structure parameters are given as a reference for the mask design of the rotor wafer and electrode plates. As two key components, the process flows of the rotor wafer and electrode plates are described in detail. All the scanning electron microscopy (SEM) photos show that the fabrication process is effective and optimized. Then, an assembly model is designed for the static capacitance adjustable MDTG, whose static capacitance can be changed by rotating the lower electrode plate support and substituting gasket rings of different thicknesses. Thus, the scale factor is easily changeable. Afterwards, the digitalized closed-loop measurement circuit is simulated. The discrete correction and decoupling modules are designed to make the closed-loop stable and cross-coupling effect small. The dual axis closed-loop system bandwidths can reach more than 60 Hz and the dual axis scale factors are completely symmetrical. All the simulation results demonstrate the proposed fabrication of the MDTG can meet the application requirements. Finally, the paper presents the test results of static and dynamic capacitance values which are consistent with the simulation values.

  16. An organic integrated capacitive DC-DC up-converter

    NARCIS (Netherlands)

    Marien, H.; Steyaert, M.; Steudel, S.; Vicca, P.; Smout, S.; Gelinck, G.H.; Heremans, P.L.

    2010-01-01

    In this paper a fully integrated organic DC-DC upconverter is presented in a pentacene p-type only technology. This 3-stage Dickson converter reaches a voltage conversion factor of 3 for a purely capacitive load and 2.5 for a 10 μA load current. The maximal output voltage goes up to 75 V and the Dic

  17. RF-MEMS capacitive switches with high reliability

    Science.gov (United States)

    Goldsmith, Charles L.; Auciello, Orlando H.; Carlisle, John A.; Sampath, Suresh; Sumant, Anirudha V.; Carpick, Robert W.; Hwang, James; Mancini, Derrick C.; Gudeman, Chris

    2013-09-03

    A reliable long life RF-MEMS capacitive switch is provided with a dielectric layer comprising a "fast discharge diamond dielectric layer" and enabling rapid switch recovery, dielectric layer charging and discharging that is efficient and effective to enable RF-MEMS switch operation to greater than or equal to 100 billion cycles.

  18. Energy consumption and constant current operation in membrane capacitive deionization

    NARCIS (Netherlands)

    Zhao, R.; Biesheuvel, P.M.; Wal, van der A.F.

    2012-01-01

    Membrane capacitive deionization (MCDI) is a water desalination technology based on applying a cell voltage between two oppositely placed porous electrodes sandwiching a spacer channel that transports the water to be desalinated. In the salt removal step, ions are adsorbed at the carbon–water interf

  19. Micro coriolis mass flow sensor with integrated capacitive readout

    NARCIS (Netherlands)

    Haneveld, J.; Lammerink, T.S.J.; Boer, de M.J.; Wiegerink, R.J.

    2009-01-01

    We have realized a micromachined micro Coriolis mass flow sensor with integrated capacitive readout to detect the extremely small Coriolis vibration of the sensor tube. A special comb-like detection electrode design eliminates the need for multiple metal layers and sacrificial layer etching methods.

  20. A Multifunction Low-Power Preamplifier for MEMS Capacitive Microphones

    DEFF Research Database (Denmark)

    Jawed, Syed Arsalan; Nielsen, Jannik Hammel; Gottardi, Massimo;

    2009-01-01

    A multi-function two-stage chopper-stabilized preamplifier (PAMP) for MEMS capacitive microphones (MCM) is presented. The PAMP integrates digitally controllable gain, high-pass filtering and offset control, adding flexibility to the front-end readout of MCMs. The first stage of the PAMP consists...